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Sample records for higher molecular mass

  1. Molecular Imaging Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kovac, S.

    2009-05-01

    Full Text Available Molecular imaging mass spectrometry (IMS is a recently developed method for direct determination of spatial distribution of biopolymers, preferably proteins on cell surface and tissues. Imaging mass spectrometry data are mainly based on Matrix-Assisted Laser Desorption/Ionization- Time of Flight (MALDI TOF. The MALDI TOF based imaging mass spectrometry was applied for determination of changes in kidney tissue of sensitive mice after poisoning with aristolochic acid I. The second application presented here were changes in the gastric tissue in mice after infection with Helicobacter pylori, as a model of gastric cancer in humans caused by this pathogen microorganism. Molecular imaging mass spectrometry can be applied in medicine, mostly for identification of candidate biomarkers for malignant and non-malignant diseases. Furthermore, imaging MS has almost unlimited capacity in agriculture, food technology and biotechnology, e. g. for monitoring, process development and quality control of manufactured tissue of animal, plant and microbial origin.

  2. Higher plant transformation: principles and molecular tools.

    Science.gov (United States)

    Anami, Sylvester; Njuguna, Elizabeth; Coussens, Griet; Aesaert, Stijn; Van Lijsebettens, Mieke

    2013-01-01

    In higher plants, genetic transformation, which is part of the toolbox for the study of living organisms, had been reported only 30 years ago, boosting basic plant biology research, generating superior crops, and leading to the new discipline of plant biotechnology. Here, we review its principles and the corresponding molecular tools. In vitro regeneration, through somatic embryogenesis or organogenesis, is discussed because they are prerequisites for the subsequent Agrobacterium tumefaciens-mediated transferred (T)-DNA or direct DNA transfer methods to produce transgenic plants. Important molecular components of the T-DNA are examined, such as selectable marker genes that allow the selection of transformed cells in tissue cultures and are used to follow the gene of interest in the next generations, and reporter genes that have been developed to visualize promoter activities, protein localizations, and protein-protein interactions. Genes of interest are assembled with promoters and termination signals in Escherichia coli by means of GATEWAY-derived binary vectors that represent the current versatile cloning tools. Finally, future promising developments in transgene technology are considered.

  3. Reaching towards higher masses of supersymmetric particles

    CERN Document Server

    Olsen, Agnethe Seim

    This thesis presents an optimisation of the search for SUSY in final states with one tau lepton, jets and large missing transverse energy. The search is performed in proton-proton collisions at sqrt(s) = 8TeV corresponding to an integrated luminosity of 20.3 fb^(−1). The SUSY model considered is mSUGRA with parameter values: m0 and m1/2 are treated as grid parameters, A0 = −2m0, tan beta = 30 and mu>0. The event selection is optimised for maximal sensitivity to mSUGRA in the low m0, high m1/2 region of the mass plane. The result of the optimised analysis is interpreted in the mSUGRA model and a limit in the (m0, m1/2) plane is obtained. Values of m1/2 up to 640 GeV are excluded for low m0 and 300 GeV for high m0 ( 2000 GeV < m0 < 5400 GeV).

  4. The molecular gas mass of M 33

    NARCIS (Netherlands)

    Gratier, P.; Braine, J.; Schuster, K.; Rosolowsky, E.; Boquien, M.; Calzetti, D.; Combes, F.; Kramer, C.; Henkel, C.; Herpin, F.; Israel, F.; Koribalski, B. S.; Mookerjea, B.; Tabatabaei, F. S.; Röllig, M.; van der Tak, F. F. S.; van der Werf, P.; Wiedner, M.

    2017-01-01

    Do some environments favor efficient conversion of molecular gas into stars? To answer this, we need to be able to estimate the H2 mass. Traditionally, this is done using CO observations and a few assumptions but the Herschel observations which cover the far-IR dust spectrum make it possible to

  5. Enhanced functionality of cantilever based mass sensors using higher modes

    DEFF Research Database (Denmark)

    Dohn, Søren; Sandberg, Rasmus Kousholt; Svendsen, Winnie Edith

    2005-01-01

    By positioning a single gold particle at different locations along the length axis on a cantilever based mass sensor, we have investigated the effect of mass position on the mass responsivity and compared the results to simulations. A significant improvement in quality factor and responsivity...... was achieved by operating the cantilever in the fourth bending mode thereby increasing the intrinsic sensitivity. It is shown that the use of higher bending modes grants a spatial resolution and thereby enhances the functionality of the cantilever based mass sensor. (c) 2005 American Institute of Physics....

  6. Chemoselectivity in the Dehydrocoupling Synthesis of Higher Molecular Weight Polysilanes

    OpenAIRE

    Christoph Marschner; Florian Lunzer

    2010-01-01

    The Cp2ZrCl2/2 BuLi catalyzed co-polymerization of H2MeSiSiMeH2 and PhSiH3 was compared to the homo-polymerization of H2MeSiSiPhH2. In contrast to the co-polymerization, which gave molecular weights comparable to homo-polymerization of phenylsilane, the reaction of 1-methyl-2-phenyldisilane yielded a partially cross-linked high molecular weight polymer with very broad molecular weight distribution. A higher reactivity of phenyl-substituted silicon atoms compared to methyl-substituted ones was...

  7. Higher Order Parametric Excitation Modes for Spaceborne Quadrupole Mass Spectrometers

    Science.gov (United States)

    Gershman, D. J.; Block, B. P.; Rubin, M.; Benna, M.; Mahaffy, P. R.; Zurbuchen, T. H.

    2011-01-01

    This paper describes a technique to significantly improve upon the mass peak shape and mass resolution of spaceborne quadrupole mass spectrometers (QMSs) through higher order auxiliary excitation of the quadrupole field. Using a novel multiresonant tank circuit, additional frequency components can be used to drive modulating voltages on the quadrupole rods in a practical manner, suitable for both improved commercial applications and spaceflight instruments. Auxiliary excitation at frequencies near twice that of the fundamental quadrupole RF frequency provides the advantages of previously studied parametric excitation techniques, but with the added benefit of increased sensed excitation amplitude dynamic range and the ability to operate voltage scan lines through the center of upper stability islands. Using a field programmable gate array, the amplitudes and frequencies of all QMS signals are digitally generated and managed, providing a robust and stable voltage control system. These techniques are experimentally verified through an interface with a commercial Pfeiffer QMG422 quadrupole rod system.When operating through the center of a stability island formed from higher order auxiliary excitation, approximately 50% and 400% improvements in 1% mass resolution and peak stability were measured, respectively, when compared with traditional QMS operation. Although tested with a circular rod system, the presented techniques have the potential to improve the performance of both circular and hyperbolic rod geometry QMS sensors.

  8. The effect of the molecular mass on the sputtering by electrosprayed nanodroplets

    Energy Technology Data Exchange (ETDEWEB)

    Borrajo-Pelaez, Rafael; Gamero-Castaño, Manuel, E-mail: mgameroc@uci.edu

    2015-07-30

    Highlights: • We study the effect of the molecular mass on nanodroplet sputtering of silicon. • The impact phenomenology is a strong function of the projectile’s molecular mass. • Nanodroplet sputtering intrinsically is a molecular scale phenomenon. - Abstract: Energetic bombardment of covalently bonded materials by electrosprayed nanodroplets causes sputtering and topographic changes on the surface of the target. This work investigates the influence of the projectile's molecular mass on these phenomena by sputtering single-crystal silicon wafers with a variety of liquids (molecular masses between 45.0 and 773.3 amu), and acceleration voltages. The electrosprays are characterized via time of flight to determine the charge to mass ratio of the nanodroplets which, together with the acceleration voltage, yield the impact velocity, the stagnation pressure, and the molecular kinetic energy of the projectile. The estimated range of droplet diameters is 20–79 nm, while the impact velocity, the stagnation pressure and the molecular kinetic energy range between 2.9–10 km/s, 4.7–63 GPa, and 2.1–98 eV. We find that the damage on the surface of the targets strongly depends on the molecular mass of the projectile: liquids with low molecular mass sputter significantly less and produce nanometric indentations and low surface roughness, the latter increasing moderately with stagnation pressure; in contrast, the roughness and sputtering caused by the impacts of droplets with larger molecular mass reach significantly higher values, and exhibit non-monotonic behaviors. The maximum sputtering yields for formamide, EAN, EMI-BF{sub 4}, EMI-Im, TES, and TPP are 0.20, 0.75, 1.20, 2.80, 4.00 and 2.90 silicon atoms per molecule in the projectile. These trends indicate that despite their rather large diameters, the sputtering by electrosprayed nanodroplets is intrinsically a molecular scale phenomenon.

  9. Molecular line tracers of high-mass star forming regions

    NARCIS (Netherlands)

    Nagy, Zsofia; Van der Tak, Floris; Ossenkopf, Volker; Bergin, Edwin; Black, John; Faure, Alexandre; Fuller, Gary; Gerin, Maryvonne; Goicoechea, Javier; Joblin, Christine; Le Bourlot, Jacques; Le Petit, Franck; Makai, Zoltan; Plume, Rene; Roellig, Markus; Spaans, Marco; Tolls, Volker

    2013-01-01

    High-mass stars influence their environment in different ways including feedback via their FUV radiation. The penetration of FUV photons into molecular clouds creates Photon Dominated Regions (PDRs) with different chemical layers where the mainly ionized medium changes into mainly molecular.

  10. Molecular line tracers of high-mass star forming regions

    NARCIS (Netherlands)

    Nagy, Zsofia; Van der Tak, Floris; Ossenkopf, Volker; Bergin, Edwin; Black, John; Faure, Alexandre; Fuller, Gary; Gerin, Maryvonne; Goicoechea, Javier; Joblin, Christine; Le Bourlot, Jacques; Le Petit, Franck; Makai, Zoltan; Plume, Rene; Roellig, Markus; Spaans, Marco; Tolls, Volker

    High-mass stars influence their environment in different ways including feedback via their FUV radiation. The penetration of FUV photons into molecular clouds creates Photon Dominated Regions (PDRs) with different chemical layers where the mainly ionized medium changes into mainly molecular.

  11. Higher body mass index associated with severe early childhood caries.

    Science.gov (United States)

    Davidson, Katherine; Schroth, Robert J; Levi, Jeremy A; Yaffe, Aaron B; Mittermuller, Betty-Anne; Sellers, Elizabeth A C

    2016-08-20

    Severe Early Childhood Caries (S-ECC) is an aggressive form of tooth decay in preschool children affecting quality of life and nutritional status. The purpose was to determine whether there is an association between Body Mass Index (BMI) and S-ECC. Children with S-ECC were recruited on the day of their slated dental surgery under general anesthesia. Age-matched, caries-free controls were recruited from the community. All children were participating in a larger study on nutrition and S-ECC. Analysis was restricted to children ≥ 24 months of age. Parents completed a questionnaire and heights and weights were recorded. BMI scores and age and gender adjusted BMI z-scores and percentiles were calculated. A p-value ≤ 0.05 was significant. Two hundred thirty-five children were included (141 with S-ECC and 94 caries-free). The mean age was 43.3 ± 12.8 months and 50.2 % were male. Overall, 34.4 % of participants were overweight or obese. Significantly more children with S-ECC were classified as overweight or obese when compared to caries-free children (p = 0.038) and had significantly higher mean BMI z-scores than caries-free children (0.78 ± 1.26 vs. 0.22 ± 1.36, p = 0.002). Those with S-ECC also had significantly higher BMI percentiles (69.0 % ± 29.2 vs. 56.8 % ± 31.7, p = 0.003). Multiple linear regression analyses revealed that BMI z-scores were significantly and independently associated with S-ECC and annual household income as were BMI percentiles. Children with S-ECC in our sample had significantly higher BMI z-scores than caries-free peers.

  12. Higher body mass index may increase prehypertension risk

    Directory of Open Access Journals (Sweden)

    Rika Rachmawati

    2012-07-01

    Indonesia (Riskesdas 2007. Analysis was carried out among 18-60 years old subjects. Criteria for prehypertension refers to Joint National Committee on Prevention, Detection, Evaluation, And Treatment of High Blood Pressure, USA (JNC 7, whereas the overweight and obesity criteria refer to the Western Pacific Region of WHO (WPRO 2000. Results: Of the total 2884 subjects, consisted of 57.6% prehypertension and 42.4% normal blood pressure. Overweight than normal BMI subjects had 15% higher risk of prehypertension [adjusted relative risk (RRa=1.15; 95% confidence interval (CI=1.06-1.24], while obese than normal subjects had 25% increase risk of prehypertension (RRa=1.25; 95% CI=1; 16-1.34. Furthermore, those who had high than normal level of LDL had 11% more prehypertension risk (RRa=1.11; 95% CI=0.99-1.24. Conclusion: Higher body mass index, and higher LDL may increase prehypertension risk. Monitoring of body weight and LDL level control routinely recommended. (Health Science Indones 2011;2:21-7

  13. Electron impact mass spectrometry of alkanes in supersonic molecular beams.

    Science.gov (United States)

    Dagan, S; Amirav, A

    1995-02-01

    The electron impact mass spectrometry of straight chain alkanes C8H18-C40H82, squalane, methylstearate, 1-chlorohexadecane, 1-bromohexadecane, and dioctylphthalate was studied by sampling them with supersonic molecular beams. A fly-through Brink-type electron impact ion source was used, utilizing a vacuum background ion filtration technique based on differences between the kinetic energy of the supersonic beam species and that of thermal molecules. The 70-eV electron impact mass spectra of all the alkanes were characterized by a pronounced or dominant molecular weight peak together with all the fragment ions normally exhibited by the standard thermal 70-eV EI mass spectra. In contrast, the NIST library of most of these molecules did not show any molecular weight peak. By eliminating tile intramolecular thermal vibrational energy we gained control over the degree of molecular ion fragmentation by the electron energy. At an electron energy of 18 eV the molecular ion dissociation was further reduced considerably, with only a small absolute reduction in the peak height by less than a factor of 2. The effect of vibrational cooling increased with the molecular size and number of atoms. Pronounced differences were observed between the mass spectra of the straight chain triacontane and its branched isomer squalane. Similar mass spectra of octacosane (C28H58) achieved with 70-eV EI in a supersonic molecular beam were obtained with a magnetic sector mass spectrometer by using an electron energy of 14 eV and an ion source temperature of 150 °C. However, this ion source temperature precluded the gas chromatography-mass spectrometry (GC-MS) of octacosane. The GC-MS of alkanes was studied with an ion trap gas chromatograph-mass spectrometer at an ion source temperature of 230 °C. Thermal peak tailing was observed for C20H42 and heavier alkanes, whereas for C28H58 and heavier alkanes the severe peak tailing made quantitative GC-MS impractical. In contrast, no peak tailing

  14. Higher bone mass in prepubertal and peripubertal female footballers.

    Science.gov (United States)

    Plaza-Carmona, M; Vicente-Rodríguez, G; Gómez-Cabello, A; Martín-García, M; Sánchez-Sánchez, J; Gallardo, L; Ara, I

    2016-10-01

    The main aim of this study was to compare the bone mass of female football players with controls of different pubertal stages. Sixty five girls aged 8-14 years (10.14 ± 0.1, Tanner stages I-IV) participated in the study. Twenty participants were prepubertal (10 prepubertal control) and 45 peripubertal (15 peripubertal control). All footballers trained two days per week while the control group did not perform regular physical activity outside of school. Body composition was assessed by Dual-energy X-ray absorptiometry. Analysis of covariance was performed to evaluate differences in lean and bone masses. Significant differences in lower-body extremities lean mass (LLM) between peripubertal groups were found (P pubertal spurt.

  15. Molecular characterization and expression analysis of fat mass and ...

    Indian Academy of Sciences (India)

    2013-12-03

    Dec 3, 2013 ... Abstract. Fat mass and obesity-associated (FTO) gene codes for a nuclear protein of the AlkB related nonhaem iron and 2-oxoglutarate- dependent oxygenase superfamily, and is involved in animal fat deposition and human obesity. In this work, the molecular characterization and expression features of ...

  16. Reforming Iraqi Journalism and Mass Communication Higher Education: Adapting the UNESCO Model Curricula for Journalism Education to Iraqi Higher Education

    Science.gov (United States)

    Pavlik, John V.; Laufer, Peter D.; Burns, David P.; Ataya, Ramzi T.

    2012-01-01

    Journalism and mass communication higher education in Iraq is well established but largely isolated from global developments since the 1970s. In the post-Iraq war period, the United Nations Educational, Scientific and Cultural Organization (UNESCO) implemented a multiyear project to work with the leadership of Iraqi higher education to help update…

  17. Higher Body Mass Index Is Associated with Subjective Olfactory Dysfunction

    Directory of Open Access Journals (Sweden)

    Z. M. Patel

    2015-01-01

    Full Text Available Background. Morbidly obese patients demonstrate altered olfactory acuity. There has been no study directly assessing Body Mass Index (BMI in patients with olfactory dysfunction. Our purpose was to compare BMI in a group of patients with subjective olfactory dysfunction to those without subjective olfactory complaints. Methods. Retrospective matched case-control study. Sixty patients who presented to a tertiary care otolaryngology center with subjective smell dysfunction over one year were identified. Neoplastic and obstructive etiologies were excluded. Demographics, BMI, and smoking status were reviewed. Sixty age, gender, and race matched control patients were selected for comparison. Chi-square testing was used. Results. 48 out of 60 patients (80% in the olfactory dysfunction group fell into the overweight or obese categories, compared to 36 out of 60 patients (60% in the control group. There was a statistically significant difference between the olfactory dysfunction and control groups for this stratified BMI (p= 0.0168.  Conclusion. This study suggests high BMI is associated with olfactory dysfunction. Prospective clinical research should examine this further to determine if increasing BMI may be a risk factor in olfactory loss and to elucidate what role olfactory loss may play in diet and feeding habits of obese patients.

  18. Thermogravimetry for measuring the molecular mass distribution of perfluorinated oligomers

    Science.gov (United States)

    Kim, I. P.; Kolesnikova, A. M.

    2011-09-01

    A method for determinoffing the molecular mass distribution (MMD) in mixtures of perfluorinated oligomers based on analysis of the differential thermogravimetric (DTG) curves (temperature dependences of the rate of mass loss) is proposed. It is indicated that this method allows us to measure the MMD of oligomers whose boiling temperature is less than the temperature of their thermal decomposition, and the total portion of longer oligomers. This method was applied to the determination of MMD of products of the radiation-chemical telomerization of tetrafluoroethylene in solution.

  19. Reinterpreting Higher Education Quality in Response to Policies of Mass Education: The Australian Experience

    Science.gov (United States)

    Pitman, Tim

    2014-01-01

    This article explores the relationship between mass education, higher education quality and policy development in Australia in the period 2008-2014, during which access to higher education was significantly increased. Over this time, which included a change of national government, the discursive relationship between mass higher education and…

  20. Utilizing Ion-Mobility Data to Estimate Molecular Masses

    Science.gov (United States)

    Duong, Tuan; Kanik, Isik

    2008-01-01

    A method is being developed for utilizing readings of an ion-mobility spectrometer (IMS) to estimate molecular masses of ions that have passed through the spectrometer. The method involves the use of (1) some feature-based descriptors of structures of molecules of interest and (2) reduced ion mobilities calculated from IMS readings as inputs to (3) a neural network. This development is part of a larger effort to enable the use of IMSs as relatively inexpensive, robust, lightweight instruments to identify, via molecular masses, individual compounds or groups of compounds (especially organic compounds) that may be present in specific environments or samples. Potential applications include detection of organic molecules as signs of life on remote planets, modeling and detection of biochemicals of interest in the pharmaceutical and agricultural industries, and detection of chemical and biological hazards in industrial, homeland-security, and industrial settings.

  1. Gene Concepts in Higher Education Cell and Molecular Biology Textbooks

    Science.gov (United States)

    Albuquerque, Pitombo Maiana; de Almeida, Ana Maria Rocha; El-Hani, Nino Charbel

    2008-01-01

    Despite being a landmark of 20th century biology, the "classical molecular gene concept," according to which a gene is a stretch of DNA encoding a functional product, which may be a single polypeptide or RNA molecule, has been recently challenged by a series of findings (e.g., split genes, alternative splicing, overlapping and nested…

  2. Molecular farming: production of drugs and vaccines in higher plants.

    Science.gov (United States)

    Shinmyo, Atsuhiko; Kato, Ko

    2010-08-01

    On the basis of developments in plant biotechnology, drug and vaccine production by higher plants can be added to microbial and animal cell culture processes. When genes encoding drug or vaccine formation under a suitable promoter are introduced into plants, these useful compounds can be economically produced from CO(2) and inorganic chemicals using sunlight. The merits and demerits of the plant process are discussed in this paper.

  3. Molecular systematics of higher primates: genealogical relations and classification.

    Science.gov (United States)

    Miyamoto, M M; Koop, B F; Slightom, J L; Goodman, M; Tennant, M R

    1988-01-01

    We obtained 5' and 3' flanking sequences (5.4 kilobase pairs) from the psi eta-globin gene region of the rhesus macaque (Macaca mulatta) and combined them with available nucleotide data. The completed sequence, representing 10.8 kilobase pairs of contiguous noncoding DNA, was compared to the same orthologous regions available for human (Homo sapiens, as represented by five different alleles), common chimpanzee (Pan troglodytes), gorilla (Gorilla gorilla), and orangutan (Pongo pygmaeus). The nucleotide sequence for Macaca mulatta provided the outgroup perspective needed to evaluate better the relationships of humans and great apes. Pairwise comparisons and parsimony analysis of these orthologues clearly demonstrated (i) that humans and great apes share a high degree of genetic similarity and (ii) that humans, chimpanzees, and gorillas form a natural monophyletic group. These conclusions strongly favor a genealogical classification for higher primates consisting of a single family (Hominidae) with two subfamilies (Homininae for Homo, Pan, and Gorilla and Ponginae for Pongo). PMID:3174657

  4. [Mass disasters with higher quantity of dead bodies and DVIT concept in the Czech Republic].

    Science.gov (United States)

    Sokol, M; Pilin, A; Bendl, P; Zikmund, P

    2010-07-01

    Authors deal with problems related to identification of higher number of dead bodies in cases of mass disaster, organization and DVI (disaster victim identification) teams assignment in the Czech Republic, interoperation with so-called Integrated Rescue System and cooperation between experts by mass disaster solution. The paper comes out from investigation of the research project and the main principles for organization of operations in victims identification of mass disaster are mentioned.

  5. Study of molecular iodine-epoxy paint mass transfer

    Energy Technology Data Exchange (ETDEWEB)

    Belval-Haltier, E. [Inst. de Protection et Surete Nucleaire, IPSN, CEN Cadarache, St. Paul-lez-Durance (France)

    1996-12-01

    The mass transfer phenomena may have a significant influence on the quantity of I{sub 2} which could be released following a severe accident of a nuclear power plant and specially the mass transfer of iodine onto containment surfaces. So, the objective of the present work was to evaluate which phase limited the adsorption process of iodine onto gaseous epoxy paint under a range of conditions which may be relevant to a severe reactor accident. In this aim, a series of experiments was conducted in which the sorption kinetics of molecular iodine, labelled with {sup 131}I, was measured by monitoring continuously the accumulation of this species on the epoxy surface. For each test condition, the initial deposition velocity was determined and the corresponding gas phase mass transfer, kg, was estimated by using the heat transfer analogy for a laminar flow passing over a flat plate. Then, the surface reaction rate, Kr, was deduced from these two values. Experiments performed indicated that iodine adsorption onto epoxy paint is highly dependent on temperature, relative humidity of the carrier gas and moisture content of the painted coupon. In dry air flow conditions, the adsorption of iodine onto paint was found to increase with temperature and to be limited by the surface reaction rate, Kr. The I{sub 2} adsorption rate was found to increase with the humidity of carrier gas and in some studied conditions, the initial deposition velocity appeared to be controlled by gas phase mass transfer rather than surface interaction. The same phenomenon has been observed with an increase of the initial water content of the painted coupon. (author) 6 figs., 1 tab., 8 refs.

  6. Molecular shells in IRC+10216: tracing the mass loss history,.

    Science.gov (United States)

    Cernicharo, J; Marcelino, N; Agúndez, M; Guélin, M

    2015-03-01

    Thermally-pulsating AGB stars provide three-fourths of the matter returned to the interstellar medium. The mass and chemical composition of their ejecta largely control the chemical evolution of galaxies. Yet, both the mass loss process and the gas chemical composition remain poorly understood. We present maps of the extended 12CO and 13CO emissions in IRC+10216, the envelope of CW Leo, the high mass loss star the closest to the Sun. IRC+10216 is nearly spherical and expands radially with a velocity of 14.5 km s-1. The observations were made On-the-Fly with the IRAM 30 m telescope; their sensibility, calibration, and angular resolution are far higher than all previous studies. The telescope resolution at λ = 1.3 mm (11″ HPBW) corresponds to an expansion time of 500 yr. The CO emission consists of a centrally peaked pedestal and a series of bright, nearly spherical shells. It peaks on CW Leo and remains relatively strong up to rphot = 180″. Further out the emission becomes very weak and vanishes as CO gets photodissociated. As CO is the best tracer of the gas up to rphot, the maps show the mass loss history in the last 8000 yr. The bright CO shells denote over-dense regions. They show that the mass loss process is highly variable on timescales of hundreds of years. The new data, however, do not support previous claims of a strong decrease of the average mass loss in the last few thousand years. The over-dense shells are not perfectly concentric and extend farther to the N-NW. The typical shell separation is 800-1000 yr in the middle of the envelope, but seems to increase outwards. The shell-intershell brightness contrast is ≥3. All those key features can be accounted for if CW Leo has a companion star with a period ≃800 yr that increases the mass loss rate when it comes close to periastron. Higher angular resolution observations are needed to fully resolve the dense shells and measure the density contrast. The latter plays an essential role in our

  7. Enhanced functionality of cantilever based mass sensors using higher modes and functionalized particles

    DEFF Research Database (Denmark)

    Dohn, Søren; Sandberg, Rasmus Kousholt; Svendsen, Winnie Edith

    2005-01-01

    By positioning a single gold-particle at different locations along the length axis on a cantilever based mass sensor, we have investigated the effect of mass position on the mass responsivity and compared the results to simulations. A significant improvement in quality factor and responsivity...... was achieved by operating the cantilever in the 4th bending mode, thereby increasing the intrinsic sensitivity. It is shown that the use of higher bending modes grants a spatial resolution and thereby enhances the functionality of the cantilever based mass sensor....

  8. Mass Spectral Molecular Networking of Living Microbial Colonies

    Energy Technology Data Exchange (ETDEWEB)

    Watrous, Jeramie D.; Roach, Patrick J.; Alexandrov, Theodore; Heath, Brandi S.; Yang, Jane Y.; Kersten, Roland; vander Voort, Menno; Pogliano, Kit; Gross, Harald; Raaijmakers, Jos M.; Moore, Bradley S.; Laskin, Julia; Bandeira, Nuno; Dorrestein, Pieter C.

    2012-06-26

    Integrating the governing chemistry with the genomics and phenotypes of microbial colonies has been a "holy grail" in microbiology. This work describes a highly sensitive, broadly applicable, and costeffective approach that allows metabolic profiling of live microbial colonies directly from a Petri dish without any sample preparation. Nanospray desorption electrospray ionization mass spectrometry (MS), combined with alignment of MS data and molecular networking, enabled monitoring of metabolite production from live microbial colonies from diverse bacterial genera, including Bacillus subtilis, Streptomyces coelicolor, Mycobacterium smegmatis, and Pseudomonas aeruginosa. This work demonstrates that, by using these tools to visualize small molecular changes within bacterial interactions, insights can be gained into bacterial developmental processes as a result of the improved organization of MS/MS data. To validate this experimental platform, metabolic profiling was performed on Pseudomonas sp. SH-C52, which protects sugar beet plants from infections by specific soil-borne fungi [R. Mendes et al. (2011) Science 332:1097–1100]. The antifungal effect of strain SHC52 was attributed to thanamycin, a predicted lipopeptide encoded by a nonribosomal peptide synthetase gene cluster. Our technology, in combination with our recently developed peptidogenomics strategy, enabled the detection and partial characterization of thanamycin and showed that it is amonochlorinated lipopeptide that belongs to the syringomycin family of antifungal agents. In conclusion, the platform presented here provides a significant advancement in our ability to understand the spatiotemporal dynamics of metabolite production in live microbial colonies and communities.

  9. Higher Protein Intake Is Associated with Higher Lean Mass and Quadriceps Muscle Strength in Adult Men and Women.

    Science.gov (United States)

    Sahni, Shivani; Mangano, Kelsey M; Hannan, Marian T; Kiel, Douglas P; McLean, Robert R

    2015-07-01

    The impact of dietary protein intake on lower extremity lean mass and strength in community-dwelling adult Americans is not fully understood. The objective was to determine the associations between total protein (TP), animal protein (AP), and plant protein (PP) intakes and lean mass of the legs and quadriceps muscle strength. We further examined whether the associations with quadriceps strength may be explained by lean mass of the legs. This cross-sectional study included men (n = 1166) and women (n = 1509) from the Framingham Offspring Cohort in Massachusetts. Protein intake in grams per day was measured in either 1995-1998 or 1998-2001. Leg lean mass and isometric quadriceps strength, both in kilograms, were measured in 1996-2001. Multilinear regression models estimated adjusted least squares means of each of the muscle measures by quartile categories of protein intake, adjusting for relevant confounders and covariates. Mean age was 59 ± 9 y (range: 29-86 y) and TP intake was 80 ± 27 g/d in men and 76 ± 26 g/d in women. In men and women, leg lean mass was higher in participants in the highest quartiles of TP and AP intake compared with those in the lowest quartiles of intake [least squares means (kg): TP-17.6 vs. 17.1 in men, P-trend: 0.005, and 11.7 vs. 11.4 in women, P-trend: 0.006; AP-17.6 vs. 17.1 in men, P-trend: 0.002, and 11.7 vs. 11.4 in women, P-trend: 0.003]. PP intake was not associated with lean mass in either sex. In men and women, quadriceps strength was higher in participants in the highest quartile of PP intake compared with those in the lowest quartile [least squares means (kg): 22.9 vs. 21.7 in men, P-trend: 0.01, and 19.0 vs. 18.2 in women, P-trend: 0.01]; this association was no longer significant after adjustment for fruit and vegetable intake (P-trend: 0.06 in men and 0.10 in women). Although no significant association was observed for AP intake in either sex, nonsignificant protective trends were observed for TP intake (P-trend: 0.08 in

  10. Higher Protein Intake Is Associated with Higher Lean Mass and Quadriceps Muscle Strength in Adult Men and Women12

    Science.gov (United States)

    Sahni, Shivani; Mangano, Kelsey M; Hannan, Marian T; Kiel, Douglas P; McLean, Robert R

    2015-01-01

    Background: The impact of dietary protein intake on lower extremity lean mass and strength in community-dwelling adult Americans is not fully understood. Objectives: The objective was to determine the associations between total protein (TP), animal protein (AP), and plant protein (PP) intakes and lean mass of the legs and quadriceps muscle strength. We further examined whether the associations with quadriceps strength may be explained by lean mass of the legs. Methods: This cross-sectional study included men (n = 1166) and women (n = 1509) from the Framingham Offspring Cohort in Massachusetts. Protein intake in grams per day was measured in either 1995–1998 or 1998–2001. Leg lean mass and isometric quadriceps strength, both in kilograms, were measured in 1996–2001. Multilinear regression models estimated adjusted least squares means of each of the muscle measures by quartile categories of protein intake, adjusting for relevant confounders and covariates. Results: Mean age was 59 ± 9 y (range: 29–86 y) and TP intake was 80 ± 27 g/d in men and 76 ± 26 g/d in women. In men and women, leg lean mass was higher in participants in the highest quartiles of TP and AP intake compared with those in the lowest quartiles of intake [least squares means (kg): TP—17.6 vs. 17.1 in men, P-trend: 0.005, and 11.7 vs. 11.4 in women, P-trend: 0.006; AP—17.6 vs. 17.1 in men, P-trend: 0.002, and 11.7 vs. 11.4 in women, P-trend: 0.003]. PP intake was not associated with lean mass in either sex. In men and women, quadriceps strength was higher in participants in the highest quartile of PP intake compared with those in the lowest quartile [least squares means (kg): 22.9 vs. 21.7 in men, P-trend: 0.01, and 19.0 vs. 18.2 in women, P-trend: 0.01]; this association was no longer significant after adjustment for fruit and vegetable intake (P-trend: 0.06 in men and 0.10 in women). Although no significant association was observed for AP intake in either sex, nonsignificant protective

  11. Higher-order triangular and tetrahedal finite elements with mass lumping for solving the wave equation.

    NARCIS (Netherlands)

    Chin-Joe-Kong, M.J.S.; Mulder, W.A.; van Veldhuizen, M.

    1999-01-01

    The higher-order finite-element scheme with mass lumping for triangles and tetrahedra is an efficient method for solving the wave equation. A number of lower-order elements have already been found. Here the search for elements of higher order is continued. Elements are constructed in a systematic

  12. Higher surface mass balance of the Greenland ice sheet revealed by high-resolution climate modeling

    NARCIS (Netherlands)

    Ettema, J.|info:eu-repo/dai/nl/304831913; van den Broeke, M.R.|info:eu-repo/dai/nl/073765643; van Meijgaard, E.; van de Berg, W.J.|info:eu-repo/dai/nl/304831611; Bamber, Jonathan L.; Box, J.E.; Bales, R.C.

    2009-01-01

    High-resolution (∼11 km) regional climate modeling shows total annual precipitation on the Greenland ice sheet for 1958–2007 to be up to 24% and surface mass balance up to 63% higher than previously thought. The largest differences occur in coastal southeast Greenland, where the much higher

  13. Disk Masses for Embedded Class I Protostars in the Taurus Molecular Cloud

    Science.gov (United States)

    Sheehan, Patrick D.; Eisner, Josh A.

    2017-12-01

    Class I protostars are thought to represent an early stage in the lifetime of protoplanetary disks, when they are still embedded in their natal envelope. Here we measure the disk masses of 10 Class I protostars in the Taurus Molecular Cloud to constrain the initial mass budget for forming planets in disks. We use radiative transfer modeling to produce synthetic protostar observations and fit the models to a multi-wavelength data set using a Markov Chain Monte Carlo fitting procedure. We fit these models simultaneously to our new Combined Array for Research in Millimeter-wave Astronomy 1.3 mm observations that are sensitive to the wide range of spatial scales that are expected from protostellar disks and envelopes so as to be able to distinguish each component, as well as broadband spectral energy distributions compiled from the literature. We find a median disk mass of 0.018 {M}ȯ on average, more massive than the Taurus Class II disks, which have median disk mass of ∼ 0.0025 {M}ȯ . This decrease in disk mass can be explained if dust grains have grown by a factor of 75 in grain size, indicating that by the Class II stage, at a few Myr, a significant amount of dust grain processing has occurred. However, there is evidence that significant dust processing has occurred even during the Class I stage, so it is likely that the initial mass budget is higher than the value quoted here.

  14. Molecular Communication over Gas Stream Channels using Portable Mass Spectrometry

    Science.gov (United States)

    Giannoukos, Stamatios; Marshall, Alan; Taylor, Stephen; Smith, Jeremy

    2017-07-01

    The synthetic generation/coding and transmission of olfactory information over a gas stream or an odor network is a new and unexplored field. Application areas vary from the entertainment or advertisement industry to security and telemedicine. However, current technological limitations frustrate the accurate reproduction of decoded and transmitted olfactory data. This study describes the development, testing, and characterization of a novel odor emitter (OE) that is used to investigate the generation-encoding of gaseous standards with odorous characteristics with a regulatable way, for scent transmission purposes. The calibration and the responses of a developed OE were examined using a portable quadrupole mass spectrometer (MS). Experiments were undertaken for a range of volatile organic compounds (VOCs) at different temperatures and flow rates. Individual compounds and mixtures were tested to investigate periodic and dynamic transmission characteristics within two different size tubular containers for distances up to 3 m. Olfactory information transmission is demonstrated using MS as the main molecular sensor for odor detection and monitoring and for the first time spatial encryption of olfactory information is shown.

  15. Higher body mass, older age and higher monounsaturated fatty acids intake reflect better quantitative ultrasound parameters in Inuit preschoolers

    Directory of Open Access Journals (Sweden)

    Jessy El Hayek

    2012-07-01

    Full Text Available Objectives. Investigate the effects of selected factors associated with quantitative ultrasound parameters among Inuit preschoolers living in Arctic communities (56° 32′–72° 40′N. Materials and methods. Children were selected randomly in summer and early fall (n=296. Dietary intake was assessed through the administration of a 24-h dietary recall (24-h recall and a food frequency questionnaire (FFQ. Anthropometry was measured using standardized procedures. Plasma 25-hydroxy vitamin D (25(OHD and parathyroid hormone (PTH were measured using a chemiluminescent assay (Liaison, Diasorin. Quantitative ultrasound parameters were measured using Sahara Sonometer, (Hologic Inc.. Results. Children divided by speed of sound (SoS and broadband ultrasound attenuation (BUA quartiles were not different for age (years, sex (M/F, calcium (mg/d and vitamin D intake (µg/d and plasma 25(OHD concentration (nmol/L. However, children in the highest BUA and SoS quartile had higher body mass index (BMI compared to those in quartile 1. Using multivariate linear regression, higher BMI, older age and monounsaturated fatty acids (MUFA intake were predictors of BUA while only BMI was a predictor of SoS. Conclusions. Further investigation assessing intakes of traditional foods (TF and nutrients affecting bone parameters along with assessment of vitamin D status of Inuit children across seasons is required.

  16. Packaging and Unpackaging Knowledge in Mass Higher Education--A Knowledge Management Perspective

    Science.gov (United States)

    Guzman, Gustavo; Trivelato, Luiz F.

    2011-01-01

    The progressive deployment of market-oriented regulatory frameworks in mass Higher Education Institutions (MHEI hereafter) triggered, in a wide variety of forms and degrees, the application of Knowledge Management principles in MHEI. This means the application of the knowledge "codification strategy", where the focus is on the economies of the…

  17. Circumnuclear Molecular Disks in Early-type Galaxies: Physical Properties and Precision Black Hole Mass Measurements

    Science.gov (United States)

    Boizelle, Benjamin

    2018-01-01

    ALMA is now capable of providing the most precise determinations of the masses of supermassive black holes in early-type galaxies (ETGs). In ALMA Cycle 2 we began a program to map the molecular gas kinematics in nearby ETGs that host central dust disks as seen in Hubble Space Telescope imaging. These initial observations targeted CO(2-1) emission at ~0.3" resolution, corresponding roughly to the projected radii of influence of the central black holes. In all cases we detect significant (~108 M⊙) molecular gas reservoirs that are in dynamically cold rotation, providing the most sensitive probes of the inner gravitational potentials of luminous ETGs. Using these gas kinematics, we verify that these molecular disks are formally stable against gravitational fragmentation and collapse. In several galaxies we detect central high-velocity gas rotation that provides direct kinematic evidence for a black hole. For two of these targets, NGC 1332 and NGC 3258, we have obtained higher-resolution observations (0.044" and 0.09") in Cycles 3 and 4 that more fully map out the gas rotation within the gravitational sphere of influence. We present dynamical modeling results for these targets, demonstrating that ALMA observations can enable black hole mass measurements at a precision of 10% or better, with minimal susceptibility to the systematic uncertainties that affect other methods of black hole mass measurement in ETGs. We discuss the impact of future high-resolution ALMA observations on black hole demographics and their potential to refine the high-mass end of the black hole-host galaxy scaling relationships.

  18. Features of organization of sport mass work at the technical higher institution.

    Directory of Open Access Journals (Sweden)

    Barybina L.M.

    2011-02-01

    Full Text Available It is considered questions and developed the system of organization of educational process of physical education in the Kharkov national university of radio electronics. During organization of educational process it is needed to take into account necessities, most answering those aims which students put, engaged in the different types of sporting activity. Sport mass measures in the higher institute unite large amount of participants, influenced on development of new types of sport that are not include educational programm. In sport mass measures took part representatives of different types of sport of different level of preparation, that promotes popularity of object "Physical education".

  19. Higher order concentration moments collapse in the expected mass fraction (EMF) based risk assessment

    Science.gov (United States)

    Srzic, Veljko; Gotovac, Hrvoje; Cvetkovic, Vladimir; Andricevic, Roko

    2014-05-01

    In this work Langrangian framework is used for conservative tracer transport simulations through 2-D extremely heterogeneous porous media. Conducted numerical simulations enable large sets of concentration values in both spatial and temporal domains. In addition to the advection, which acts on all scales, an additional mechanism considered is local scale dispersion (LSD), accounting for both mechanical dispersion and molecular diffusion. The ratio between these two mechanisms is quantified by the Peclet (Pe) number. In its base, the work gives answers to concentration scalar features when influenced by: i) different log-conductivity variance; ii) log-conductivity structures defined by the same global variogram but with different log conductivity patterns correlated; and iii) for a wide range of Peclet values. Results conducted by Monte Carlo analysis show a complex interplay between the aforementioned parameters, indicating the influence of aquifer properties to temporal LSD evolution. A remarkable collapse of higher order to second-order concentration moments [Yee, 2009] leads to the conclusion that only two concentration moments are required for an accurate description of concentration fluctuations. This explicitly holds for the pure advection case, while in the case of LSD presence the moment deriving function(MDF) is involved to ensure the moment collapse validity. An inspection of the Beta distribution leads to the conclusion that the two-parametric distribution can be used for concentration fluctuation characterization even in cases of high aquifer heterogeneity and/or for different log-conductivity structures, independent of the sampling volume used. Furthermore, the expected mass fraction (EMF) [Heagy & Sullivan, 1996] concept is applied in groundwater transport. In its origin, EMF is function of the concentration but with lower number of realizations needed for its determination, compared to the one point PDF. From practical point of view, EMF excludes

  20. Asymptotic giant branch stars at low metallicity: the challenging interplay between the mass-loss and molecular opacities

    Science.gov (United States)

    Ventura, P.; Marigo, P.

    2010-11-01

    We investigate the main physical properties of low-metallicity asymptotic giant branch (AGB) stars with the aim of quantifying the uncertainties that presently affect the predicted chemical yields of these stars, associated with the mass-loss and description of molecular opacities. We find that above a threshold mass, M ~= 3.5Msolar for Z = 0.001, the results are little dependent on the opacity treatment, as long as the hot-bottom burning (HBB) prevents the surface C/O ratio from exceeding unity; the yields of these massive AGB stars are expected to be mostly determined by the efficiency of convection, with a relatively mild dependence on the mass-loss description. A much higher degree of uncertainty is associated with the yields of less-massive models, which critically depend on the adopted molecular opacities. An interval of masses exists, say, 2.0-3.0Msolar (the exact range depends on the mass-loss), in which the HBB may be even extinguished following the cooling produced by the opacity of C-bearing molecules. The yields of these stars are the most uncertain, the variation range being the largest (up to ~2dex) for the nitrogen and sodium yields. For very low mass models, not experiencing the HBB (M <= 1.5Msolar), the description of mass-loss and the treatment of the convective boundaries are crucial for the occurrence of the third dredge-up, with a sizeable impact on the CNO yields.

  1. Higher Fat Mass Is Associated With a History of Knee Injury in Youth Sport.

    Science.gov (United States)

    Toomey, Clodagh M; Whittaker, Jackie L; Nettel-Aguirre, Alberto; Reimer, Raylene A; Woodhouse, Linda J; Ghali, Brianna; Doyle-Baker, Patricia K; Emery, Carolyn A

    2017-02-01

    Study Design Historical cohort study. Background History of a knee joint injury and increased fat mass are risk factors for joint disease. Objective The objective of this study was to examine differences in adiposity, physical activity, and cardiorespiratory fitness between youths with a 3- to 10-year history of sport-related intra-articular knee injury and uninjured controls. Methods One hundred young adults (aged 15-26 years; 55% female) with a sport-related intra-articular knee injury sustained 3 to 10 years previously and 100 controls matched for age, sex, and sport, who had no history of intra-articular knee injury, were recruited. Fat mass index (FMI) and abdominal fat (fat mass at the L1 to L4 vertebral levels) were derived using dual-energy X-ray absorptiometry. Physical activity and cardiorespiratory fitness were measured using the Godin Leisure-Time Exercise Questionnaire and the multistage 20-meter shuttle run test for aerobic fitness, respectively. Results Previously injured participants demonstrated higher FMI (within-pair difference, 1.05 kg/m2; 95% confidence interval [CI]: 0.53, 1.57) and abdominal fat (461 g; 95% CI: 228, 694) than uninjured controls. In multivariable linear regression analysis, previous injury was significantly associated with increased FMI. This increase was attenuated in those who participated in higher levels of physical activity or had higher estimated maximum volume of oxygen. Conclusion As a risk factor for osteoarthritis in an already susceptible group, excess adiposity is an undesirable trait in the potential pathway to joint disease. Increasing physical activity in this population may be a potential intervention to reduce adiposity thus impede disease initiation and/or progression. Level of Evidence Level 2b. J Orthop Sports Phys Ther 2017;47(2):80-87. doi:10.2519/jospt.2017.7101.

  2. Molecular imaging of proteins in tissues by mass spectrometry

    OpenAIRE

    Seeley, Erin H.; Caprioli, Richard M.

    2008-01-01

    Imaging MS (IMS) is an emerging technology that permits the direct analysis and determination of the distribution of molecules in tissue sections. Biological molecules such as proteins, peptides, lipids, xenobiotics, and metabolites can be analyzed in a high-throughput manner with molecular specificity not readily achievable through other means. Tissues are analyzed intact and thus spatial localization of molecules within a tissue is preserved. Several studies are presented that focus on the ...

  3. Laser desorption ionization and MALDI time-of-flight mass spectrometry for low molecular mass polyethylene analysis.

    Science.gov (United States)

    Chen, R; Yalcin, T; Wallace, W E; Guttman, C M; Li, L

    2001-11-01

    Polyethylene's inert nature and difficulty to dissolve in conventional solvents at room temperature present special problems for sample preparation and ionization in mass spectrometric analysis. We present a study of ionization behavior of several polyethylene samples with molecular masses up to 4000 Da in laser desorption ionization (LDI) time-of-flight mass spectrometers equipped with a 337 nm laser beam. We demonstrate unequivocally that silver or copper ion attachment to saturated polyethylene can occur in the gas phase during the UV LDI process. In LDI spectra of polyethylene with molecular masses above approximately 1000 Da, low mass ions corresponding to metal-alkene structures are observed in addition to the principal distribution. By interrogating a well-characterized polyethylene sample and a long chain alkane, C94H190, these low mass ions are determined to be the fragmentation products of the intact metal-polyethylene adduct ions. It is further illustrated that fragmentation can be reduced by adding matrix molecules to the sample preparation.

  4. Mass spectrometric identification of molecular species of phosphatidylcholine and lysophosphatidycholine extracted from shark liver

    NARCIS (Netherlands)

    Chen, S.; Li, K.W.

    2007-01-01

    The profile and structural characterization of molecular species of phosphatidylcholine (PC) and lysophosphatidylcholine (LysoPC) from shark liver using liquid chromatographic/electrospray ionization mass spectrometry (LC-ESI/MS) and tandem mass spectrometry (MS/MS) are described for the first time

  5. TWO MASS DISTRIBUTIONS IN THE L 1641 MOLECULAR CLOUDS: THE HERSCHEL CONNECTION OF DENSE CORES AND FILAMENTS IN ORION A

    Energy Technology Data Exchange (ETDEWEB)

    Polychroni, D. [Department of Astrophysics, University of Athens, Astronomy and Mechanics, Faculty of Physics, Panepistimiopolis, 15784 Zografos, Athens (Greece); Schisano, E.; Elia, D.; Molinari, S.; Turrini, D.; Rygl, K. L. J.; Benedettini, M.; Busquet, G.; Di Giorgio, A. M.; Pestalozzi, M.; Pezzuto, S. [Istituto di Astrofisica e Planetologia Spaziali (INAF-IAPS), via del Fosso del Cavaliere 100, I-00133 Roma (Italy); Roy, A.; André, Ph.; Hennemann, M.; Hill, T.; Könyves, V. [Laboratoire AIM, CEA/IRFU CNRS/INSU Université Paris Diderot, Paris-Saclay, F-91191 Gif-sur-Yvette (France); Martin, P. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, ON M5S 3H8 (Canada); Di Francesco, J. [National Research Council Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Arzoumanian, D. [IAS, CNRS (UMR 8617), Université Paris-Sud, Bâtiment 121, F-91400 Orsay (France); Bontemps, S., E-mail: dpolychroni@phys.uoa.gr [Université de Bordeaux, Laboratoire d' Astrophysique de Bordeaux, CNRS/INSU, UMR 5804, BP 89, F-33271, Floirac Cedex (France); and others

    2013-11-10

    We present Herschel survey maps of the L 1641 molecular clouds in Orion A. We extracted both the filaments and dense cores in the region. We identified which of the dense sources are proto- or pre-stellar, and studied their association with the identified filaments. We find that although most (71%) of the pre-stellar sources are located on filaments there, is still a significant fraction of sources not associated with such structures. We find that these two populations (on and off the identified filaments) have distinctly different mass distributions. The mass distribution of the sources on the filaments is found to peak at 4 M {sub ☉} and drives the shape of the core mass function (CMF) at higher masses, which we fit with a power law of the form dN/dlogM∝M {sup –1.4±0.4}. The mass distribution of the sources off the filaments, on the other hand, peaks at 0.8 M {sub ☉} and leads to a flattening of the CMF at masses lower than ∼4 M {sub ☉}. We postulate that this difference between the mass distributions is due to the higher proportion of gas that is available in the filaments, rather than in the diffuse cloud.

  6. Accurate calibration of a molecular beam time-of-flight mass spectrometer for on-line analysis of high molecular weight species.

    Science.gov (United States)

    Apicella, B; Wang, X; Passaro, M; Ciajolo, A; Russo, C

    2016-10-15

    Time-of-Flight (TOF) Mass Spectrometry is a powerful analytical technique, provided that an accurate calibration by standard molecules in the same m/z range of the analytes is performed. Calibration in a very large m/z range is a difficult task, particularly in studies focusing on the detection of high molecular weight clusters of different molecules or high molecular weight species. External calibration is the most common procedure used for TOF mass spectrometric analysis in the gas phase and, generally, the only available standards are made up of mixtures of noble gases, covering a small mass range for calibration, up to m/z 136 (higher mass isotope of xenon). In this work, an accurate calibration of a Molecular Beam Time-of Flight Mass Spectrometer (MB-TOFMS) is presented, based on the use of water clusters up to m/z 3000. The advantages of calibrating a MB-TOFMS with water clusters for the detection of analytes with masses above those of the traditional calibrants such as noble gases were quantitatively shown by statistical calculations. A comparison of the water cluster and noble gases calibration procedures in attributing the masses to a test mixture extending up to m/z 800 is also reported. In the case of the analysis of combustion products, another important feature of water cluster calibration was shown, that is the possibility of using them as "internal standard" directly formed from the combustion water, under suitable experimental conditions. The water clusters calibration of a MB-TOFMS gives rise to a ten-fold reduction in error compared to the traditional calibration with noble gases. The consequent improvement in mass accuracy in the calibration of a MB-TOFMS has important implications in various fields where detection of high molecular mass species is required. In combustion products analysis, it is also possible to obtain a new calibration spectrum before the acquisition of each spectrum, only modifying some operative conditions. Copyright © 2016

  7. The association between higher body mass index and poor school performance in high school students.

    Science.gov (United States)

    Tonetti, L; Fabbri, M; Filardi, M; Martoni, M; Natale, V

    2016-12-01

    This study aimed to examine the association between body mass index (BMI) and school performance in high school students by controlling for relevant mediators such as sleep quality, sleep duration and socioeconomic status. Thirty-seven high school students (mean age: 18.16 ± 0.44 years) attending the same school type, i.e. 'liceo scientifico' (science-based high school), were enrolled. Students' self-reported weight and height were used to calculate BMI. Participants wore an actigraph to objectively assess the quality and duration of sleep. School performance was assessed through the actual grade obtained at the final school-leaving exam, in which higher grades indicate higher performance. BMI, get-up time, mean motor activity, wake after sleep onset and number of awakenings were negatively correlated with the grade, while sleep efficiency was positively correlated. When performing a multiple regression analysis, BMI proved the only significant (negative) predictor of grade. When controlling for sleep quality, sleep duration and socioeconomic status, a higher BMI is associated with a poorer school performance in high school students. © 2015 World Obesity Federation.

  8. Using hydrophilic polysaccharide to modify supramolecular hydrogel from a low-molecular-mass gelator

    Energy Technology Data Exchange (ETDEWEB)

    Song Fei [Key Laboratory for Designed Synthesis and Application of Polymer Materials, School of Chemistry and Chemical Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275 (China); Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275 (China); Zhang Liming, E-mail: ceszhlm@mail.sysu.edu.cn [Key Laboratory for Designed Synthesis and Application of Polymer Materials, School of Chemistry and Chemical Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275 (China); Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275 (China); Shi Junfeng; Li, Nan-Nan [Key Laboratory for Designed Synthesis and Application of Polymer Materials, School of Chemistry and Chemical Engineering, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275 (China); Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, Sun Yat-Sen (Zhongshan) University, Guangzhou 510275 (China); Yang Chuan; Yan Li [Second Affiliated Hospital, Sun Yat-Sen (Zhongshan) University, Guangzhou 510102 (China)

    2010-07-20

    Small molecular hydrogels hold important potential applications in bioengineering and biomedicine. However, they suffer usually from weak mechanical and water-retention properties. In this work, hydrophilic dextran polysaccharide was used for the first time to modify the properties of the supramolecular hydrogel derived from a low-molecular-mass gelator, 2, 6-di[N-(carboxyethyl carbonyl)amino]pyridine (DAP). When the DAP hydrogel was formed in aqueous dextran solution with a rather low viscosity, we found that it could be significantly reinforced with respect to its viscoelastic moduli, complex viscosity and hydrogel strength. Moreover, the modified DAP hydrogel has a higher bound water content. These property changes could be attributed to the formation of intermolecular hydrogen bonds between DAP and dextran. By relating the dynamic rheological data with a scaling model, it was found that native and modified DAP hydrogels had both a fractal aggregate structure and the incorporation of dextran resulted in an increase of the fractal dimension. Scanning electron microscopy revealed that a more complex network structure was formed in the DAP hydrogel with dextran.

  9. Higher order and heavy quark mass effects in the determination of parton distribution functions

    Energy Technology Data Exchange (ETDEWEB)

    Bertone, Valerio

    2013-07-01

    The present thesis was devoted to the study of the inclusion of higher-order corrections and heavy quark mass effects in a PDF determination. This has been carried out in the NNPDF framework resulting originally in the NNPDF2.1 sets, which were at a later stage supplemented by the first LHC data leading to the most recent NNPDF2.3 sets. In Chapter 1 the concept of Parton Distribution Function (PDF) was introduced. We have shown how the analytical computation of the Deep-Inelastic-Scattering (DIS) process at order α{sub s} in QCD leads to initial-stale collinear divergences which, using the factorization theorem, can be reabsorbed into the PDFs. The energy dependence of PDFs is fully determined and the task is then reduced to the determination of the x (Bjorken variable) dependence. In Chapter 2 a detailed discussion of the factorization schemes presently available to include heavy quark mass effects into DIS structure functions has been given. It emerged that there are two possible basic approaches to the calculation of the DIS structure functions. In the first approach, the so-called Fixed-Flavour-Number Scheme (FFNS), the calculation is performed retaining the quark mass of the heavy flavours which provide a ''natural'' regulator for the infrared divergences. In the second approach, called Zero-Mass Variable-Flavour-Number Scheme (ZM-VFNS), the heavy quark masses are instead set to zero and this gives rise to the usual final-state collinear divergences that are absorbed into the PDFs. In addition, in the ZM-VFNS, the number of active flavours is assumed to increase by one unity as the energy of the process crosses the energy threshold of a given heavy quark. In order to obtain a factorization scheme that is accurate both at large and low energies, several prescriptions that interpolate between FFNS at low energy and ZM-VFNS at large energy have been proposed and implemented in as many PDF fits. In Chapter 2 they have been described showing

  10. Molecular imaging of proteins in tissues by mass spectrometry.

    Science.gov (United States)

    Seeley, Erin H; Caprioli, Richard M

    2008-11-25

    Imaging MS (IMS) is an emerging technology that permits the direct analysis and determination of the distribution of molecules in tissue sections. Biological molecules such as proteins, peptides, lipids, xenobiotics, and metabolites can be analyzed in a high-throughput manner with molecular specificity not readily achievable through other means. Tissues are analyzed intact and thus spatial localization of molecules within a tissue is preserved. Several studies are presented that focus on the unique types of information obtainable by IMS, such as Abeta isoform distributions in Alzheimer's plaques, protein maps in mouse brain, and spatial protein distributions in human breast carcinoma. The analysis of a biopsy taken 100 years ago from a patient with amyloidosis illustrates the use of IMS with formalin-fixed tissues. Finally, the registration and correlation of IMS with MRI is presented.

  11. Molecular beam mass spectrometry with tunable vacuum ultraviolet (VUV) synchrotron radiation

    Energy Technology Data Exchange (ETDEWEB)

    Golan, Amir; Ahmed, Musahid

    2012-01-01

    Tunable soft ionization coupled to mass spectroscopy is a powerful method to investigate isolated molecules, complexes and clusters and their spectroscopy and dynamics.[1-4] Fundamental studies of photoionization processes of biomolecules provide information about electronic structure of these systems. Furthermore determinations of ionization energies and other properties of biomolecules in the gas phase are not trivial, and these experiments provide a platform to generate these data. We have developed a thermal vaporization technique coupled with supersonic molecular beams that provides a gentle way to transport these species into the gas phase. Judicious combination of source gas and temperature allows for formation of dimers and higher clusters of the DNA bases. The focus of this particular work is on the effects of non-covalent interactions, i.e., hydrogen bonding, stacking, and electrostatic interactions, on the ionization energies and proton transfer of individual biomolecules, their complexes and upon micro-hydration by water.[1, 5-9] We have performed experimental and theoretical characterization of the photoionization dynamics of gas-phase uracil and 1,3-methyluracil dimers using molecular beams coupled with synchrotron radiation at the Chemical Dynamics Beamline[10] located at the Advanced Light Source and the experimental details are visualized here. This allowed us to observe the proton transfer in 1,3-dimethyluracil dimers, a system with pi stacking geometry and with no hydrogen bonds[1]. Molecular beams provide a very convenient and efficient way to isolate the sample of interest from environmental perturbations which in return allows accurate comparison with electronic structure calculations[11, 12]. By tuning the photon energy from the synchrotron, a photoionization efficiency (PIE) curve can be plotted which informs us about the cationic electronic states. These values can then be compared to theoretical models and calculations and in turn, explain

  12. The effect of molecular mass on the polymorphism and crystalline structure of isotactic polypropylene

    Directory of Open Access Journals (Sweden)

    2010-02-01

    Full Text Available This study is devoted to the investigation of the effect of molecular mass on the α-, β- and γ-crystallization tendency of isotactic polypropylene (iPP. The crystalline structure was studied by wide angle X-ray scattering (WAXS and by polarised light microscopy (PLM. The melting and crystallization characteristics were determined by differential scanning calorimetry (DSC. The results indicate clearly that iPP with low molecular mass crystallizes essentially in α-modification. However, it crystallizes in β-form in the presence of a highly efficient and selective β-nucleating agent. The α- and β-modifications form in wide molecular mass range. The decreasing molecular mass results in increased structural instability in both α- and β-modifications and consequently enhanced inclination to recrystallization during heating. The formation of γ-modification could not be observed, although some literature sources report that γ-form develops in iPP with low molecular mass.

  13. Higher body mass index is associated with episodic memory deficits in young adults.

    Science.gov (United States)

    Cheke, Lucy G; Simons, Jon S; Clayton, Nicola S

    2016-11-01

    Obesity has become an international health crisis. There is accumulating evidence that excess bodyweight is associated with changes to the structure and function of the brain and with a number of cognitive deficits. In particular, research suggests that obesity is associated with hippocampal and frontal lobe dysfunction, which would be predicted to impact memory. However, evidence for such memory impairment is currently limited. We hypothesised that higher body mass index (BMI) would be associated with reduced performance on a test of episodic memory that assesses not only content, but also context and feature integration. A total of 50 participants aged 18-35 years, with BMIs ranging from 18 to 51, were tested on a novel what-where-when style episodic memory test: the "Treasure-Hunt Task". This test requires recollection of object, location, and temporal order information within the same paradigm, as well as testing the ability to integrate these features into a single event recollection. Higher BMI was associated with significantly lower performance on the what-where-when (WWW) memory task and all individual elements: object identification, location memory, and temporal order memory. After controlling for age, sex, and years in education, the effect of BMI on the individual what, where, and when tasks remained, while the WWW dropped below significance. This finding of episodic memory deficits in obesity is of concern given the emerging evidence for a role for episodic cognition in appetite regulation.

  14. Exposure to violence in childhood is associated with higher body mass index in adolescence.

    Science.gov (United States)

    Gooding, Holly C; Milliren, Carly; Austin, S Bryn; Sheridan, Margaret A; McLaughlin, Katie A

    2015-12-01

    To determine whether different types of childhood adversity are associated with body mass index (BMI) in adolescence, we studied 147 adolescents aged 13-17 years, 41% of whom reported exposure to at least one adversity (maltreatment, abuse, peer victimization, or witness to community or domestic violence). We examined associations between adversity type and age- and sex-specific BMI z-scores using linear regression and overweight and obese status using logistic regression. We adjusted for potential socio-demographic, behavioral, and psychological confounders and tested for effect modification by gender. Adolescents with a history of sexual abuse, emotional abuse, or peer victimization did not have significantly different BMI z-scores than those without exposure (p>0.05 for all comparisons). BMI z-scores were higher in adolescents who had experienced physical abuse (β=0.50, 95% CI 0.12-0.91) or witnessed domestic violence (β=0.85, 95% CI 0.30-1.40). Participants who witnessed domestic violence had almost 6 times the odds of being overweight or obese (95% CI: 1.09-30.7), even after adjustment for potential confounders. No gender-by-adversity interactions were found. Exposure to violence in childhood is associated with higher adolescent BMI. This finding highlights the importance of screening for violence in pediatric practice and providing obesity prevention counseling for youth. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. Non-conjugated small molecule FRET for differentiating monomers from higher molecular weight amyloid beta species.

    Directory of Open Access Journals (Sweden)

    Chongzhao Ran

    2011-04-01

    Full Text Available Systematic differentiation of amyloid (Aβ species could be important for diagnosis of Alzheimer's disease (AD. In spite of significant progress, controversies remain regarding which species are the primary contributors to the AD pathology, and which species could be used as the best biomarkers for its diagnosis. These controversies are partially caused by the lack of reliable methods to differentiate the complicated subtypes of Aβ species. Particularly, differentiation of Aβ monomers from toxic higher molecular weight species (HrMW would be beneficial for drug screening, diagnosis, and molecular mechanism studies. However, fast and cheap methods for these specific aims are still lacking.We demonstrated the feasibility of a non-conjugated FRET (Förster resonance energy transfer technique that utilized amyloid beta (Aβ species as intrinsic platforms for the FRET pair assembly. Mixing two structurally similar curcumin derivatives that served as the small molecule FRET pair with Aβ40 aggregates resulted in a FRET signal, while no signal was detected when using Aβ40 monomer solution. Lastly, this FRET technique enabled us to quantify the concentrations of Aβ monomers and high molecular weight species in solution.We believe that this FRET technique could potentially be used as a tool for screening for inhibitors of Aβ aggregation. We also suggest that this concept could be generalized to other misfolded proteins/peptides implicated in various pathologies including amyloid in diabetes, prion in bovine spongiform encephalopathy, tau protein in AD, and α-synuclein in Parkinson disease.

  16. Synchrotron based mass spectrometry to investigate the molecular properties of mineral-organic associations

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Suet Yi; Kleber, Markus; Takahashi, Lynelle K.; Nico, Peter; Keiluweit, Marco; Ahmed, Musahid

    2013-04-01

    Soil organic matter (OM) is important because its decay drives life processes in the biosphere. Analysis of organic compounds in geological systems is difficult because of their intimate association with mineral surfaces. To date there is no procedure capable of quantitatively separating organic from mineral phases without creating artifacts or mass loss. Therefore, analytical techniques that can (a) generate information about both organic and mineral phases simultaneously and (b) allow the examination of predetermined high-interest regions of the sample as opposed to conventional bulk analytical techniques are valuable. Laser Desorption Synchrotron Postionization (synchrotron-LDPI) mass spectrometry is introduced as a novel analytical tool to characterize the molecular properties of organic compounds in mineral-organic samples from terrestrial systems, and it is demonstrated that when combined with Secondary Ion Mass Spectrometry (SIMS), can provide complementary information on mineral composition. Mass spectrometry along a decomposition gradient in density fractions, verifies the consistency of our results with bulk analytical techniques. We further demonstrate that by changing laser and photoionization energies, variations in molecular stability of organic compounds associated with mineral surfaces can be determined. The combination of synchrotron-LDPI and SIMS shows that the energetic conditions involved in desorption and ionization of organic matter may be a greater determinant of mass spectral signatures than the inherent molecular structure of the organic compounds investigated. The latter has implications for molecular models of natural organic matter that are based on mass spectrometric information.

  17. WISDOM Project - II. Molecular gas measurement of the supermassive black hole mass in NGC 4697

    Science.gov (United States)

    Davis, Timothy A.; Bureau, Martin; Onishi, Kyoko; Cappellari, Michele; Iguchi, Satoru; Sarzi, Marc

    2017-07-01

    As part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project, we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotating early-type galaxy NGC 4697. This estimate is based on Atacama Large Millimeter/submillimeter Array (ALMA) cycle-3 observations of the 12CO(2-1) emission line with a linear resolution of 29 pc (0.53 arcsec). We find that NGC 4697 hosts a small relaxed central molecular gas disc with a mass of 1.6 × 107 M⊙, co-spatial with the obscuring dust disc visible in optical Hubble Space Telescope imaging. We also resolve thermal 1 mm continuum emission from the dust in this disc. NGC 4697 is found to have a very low molecular gas velocity dispersion, σgas = 1.65^{+0.68}_{-0.65} km s-1. This seems to be partially because the giant molecular cloud mass function is not fully sampled, but other mechanisms such as chemical differentiation in a hard radiation field or morphological quenching also seem to be required. We detect a Keplerian increase of the rotation of the molecular gas in the very centre of NGC 4697, and use forward modelling of the ALMA data cube in a Bayesian framework with the KINematic Molecular Simulation (kinms) code to estimate an SMBH mass of (1.3_{-0.17}^{+0.18}) × 108 M⊙ and an I-band mass-to-light ratio of 2.14_{-0.05}^{+0.04} M⊙/L⊙ (at the 99 per cent confidence level). Our estimate of the SMBH mass is entirely consistent with previous measurements from stellar kinematics. This increases confidence in the growing number of SMBH mass estimates being obtained in the ALMA era.

  18. Investigation into the effect of molds in grasses on their content of low molecular mass thiols.

    Science.gov (United States)

    Skladanka, Jiri; Adam, Vojtech; Zitka, Ondrej; Krystofova, Olga; Beklova, Miroslava; Kizek, Rene; Havlicek, Zdenek; Slama, Petr; Nawrath, Adam

    2012-10-24

    The aim of this study was to investigate the effect of molds on levels of low molecular mass thiols in grasses. For this purpose, the three grass species Lolium perenne, Festulolium pabulare and Festulolium braunii were cultivated and sampled during four months, from June to September. The same species were also grown under controlled conditions. High-performance liquid chromatography with electrochemical detection was used for quantification of cysteine, reduced (GSH) and oxidized (GSSG) glutathione, and phytochelatins (PC2, PC3, PC4 and PC5). Data were statistically processed and analyzed. Thiols were present in all examined grass species. The effect of fungicide treatments applied under field conditions on the content of the evaluated thiols was shown to be insignificant. Species influenced (p < 0.05) PC3 and GSSG content. F. pabulare, an intergeneric hybrid of drought- and fungi-resistant Festuca arundinacea, was comparable in PC3 content with L. perenne and F. braunii under field conditions. Under controlled conditions, however, F. pabulare had higher (p < 0.05) PC3 content than did L. perenne and F. braunii. Under field conditions, differences between the evaluated species were recorded only in GSSG content, but only sampling in June was significant. F. pabulare had higher (p < 0.05) GSSG content in June than did L. perenne and F. braunii.

  19. An adaptive mass algorithm for Car-Parrinello and Ehrenfest ab initio molecular dynamics

    OpenAIRE

    Kadir, Ashraful; Sandberg, Mattias; Szepessy, Anders

    2014-01-01

    Ehrenfest and Car-Parrinello molecular dynamics are computational alternatives to approximate Born-Oppenheimer molecular dynamics without solving the electron eigenvalue problem at each time-step. A non-trivial issue is to choose the artificial electron mass parameter appearing in the Car-Parrinello method to achieve both good accuracy and high computational efficiency. In this paper, we propose an algorithm, motivated by the Landau-Zener probability, to systematically choose an artificial ma...

  20. A Machian definition of particle mass in higher-dimensional gravity

    CERN Document Server

    Wesson, Paul S

    2016-01-01

    A new method involving the effective wave function is used to define the mass of a particle in a standard five-dimensional extension of general relativity. The mass is inversely proportional to the magnitude of the scalar field of the extra dimension. Since the scalar field is global and depends on the coordinates, this definition for the particle mass agrees with Machs Principle.

  1. Mass Derivatives of Molecular Parameters and Distortions in r((2))(m) Structures.

    Science.gov (United States)

    Watson, James K. G.

    2001-05-01

    Expressions are derived for the derivatives of various molecular vibration-rotation parameters with respect to atomic masses. These are applied to determine an expression for the mass derivatives of the zero-point moments of inertia, and hence the theoretical substitution coordinates. It is then possible to calculate the distortions in structures determined by means of the r((2))(m) method. The latter agree well with the distortions found in r((2))(m) fits of synthetic data. Copyright 2001 Academic Press.

  2. Complex-mass shell renormalization of the higher-derivative electrodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Turcati, Rodrigo [SISSA, Trieste (Italy); INFN, Sezione di Trieste, Trieste (Italy); Universidade Federal do Espirito Santo, Departamento de Fisica e Quimica, Vitoria, ES (Brazil); Laboratorio de Fisica Experimental (LAFEX), Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro (Brazil); Neves, Mario Junior [Universidade Federal Rural do Rio de Janeiro, Departamento de Fisica, Rio de Janeiro (Brazil)

    2016-08-15

    We consider a higher-derivative extension of QED modified by the addition of a gauge-invariant dimension-6 kinetic operator in the U(1) gauge sector. The Feynman diagrams at one-loop level are then computed. The modification in the spin-1 sector leads the electron self-energy and vertex corrections diagrams finite in the ultraviolet regime. Indeed, no regularization prescription is used to calculate these diagrams because the modified propagator always occurs coupled to conserved currents. Moreover, besides the usual massless pole in the spin-1 sector, there is the emergence of a massive one, which becomes complex when computing the radiative corrections at one-loop order. This imaginary part defines the finite decay width of the massive mode. To check consistency, we also derive the decay length using the electron-positron elastic scattering and show that both results are equivalent. Because the presence of this unstable mode, the standard renormalization procedures cannot be used and is necessary adopt an appropriate framework to perform the perturbative renormalization. For this purpose, we apply the complex-mass shell scheme (CMS) to renormalize the aforementioned model. As an application of the formalism developed, we estimate a quantum bound on the massive parameter using the measurement of the electron anomalous magnetic moment and compute the Uehling potential. At the end, the renormalization group is analyzed. (orig.)

  3. TRACING EMBEDDED STELLAR POPULATIONS IN CLUSTERS AND GALAXIES USING MOLECULAR EMISSION: METHANOL AS A SIGNATURE OF THE LOW-MASS END OF THE IMF

    Energy Technology Data Exchange (ETDEWEB)

    Kristensen, Lars E. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bergin, Edwin A., E-mail: lkristensen@cfa.harvard.edu [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States)

    2015-07-10

    Most low-mass protostars form in clusters, in particular high-mass clusters; however, how low-mass stars form in high-mass clusters and what the mass distribution is are still open questions both in our own Galaxy and elsewhere. To access the population of forming embedded low-mass protostars observationally, we propose using molecular outflows as tracers. Because the outflow emission scales with mass, the effective contrast between low-mass protostars and their high-mass cousins is greatly lowered. In particular, maps of methanol emission at 338.4 GHz (J = 7{sub 0}–6{sub 0} A{sup +}) in low-mass clusters illustrate that this transition is an excellent probe of the low-mass population. We present here a model of a forming cluster where methanol emission is assigned to every embedded low-mass protostar. The resulting model image of methanol emission is compared to recent ALMA observations toward a high-mass cluster and the similarity is striking: the toy model reproduces observations to better than a factor of two and suggests that approximately 50% of the total flux originates in low-mass outflows. Future fine-tuning of the model will eventually make it a tool for interpreting the embedded low-mass population of distant regions within our own Galaxy and ultimately higher-redshift starburst galaxies, not just for methanol emission but also water and high-J CO.

  4. Tracing Embedded Stellar Populations in Clusters and Galaxies Using Molecular Emission: Methanol as a Signature of the Low-mass End of the IMF

    Science.gov (United States)

    Kristensen, Lars E.; Bergin, Edwin A.

    2015-07-01

    Most low-mass protostars form in clusters, in particular high-mass clusters; however, how low-mass stars form in high-mass clusters and what the mass distribution is are still open questions both in our own Galaxy and elsewhere. To access the population of forming embedded low-mass protostars observationally, we propose using molecular outflows as tracers. Because the outflow emission scales with mass, the effective contrast between low-mass protostars and their high-mass cousins is greatly lowered. In particular, maps of methanol emission at 338.4 GHz (J = 70-60 A+) in low-mass clusters illustrate that this transition is an excellent probe of the low-mass population. We present here a model of a forming cluster where methanol emission is assigned to every embedded low-mass protostar. The resulting model image of methanol emission is compared to recent ALMA observations toward a high-mass cluster and the similarity is striking: the toy model reproduces observations to better than a factor of two and suggests that approximately 50% of the total flux originates in low-mass outflows. Future fine-tuning of the model will eventually make it a tool for interpreting the embedded low-mass population of distant regions within our own Galaxy and ultimately higher-redshift starburst galaxies, not just for methanol emission but also water and high-J CO.

  5. Higher Desolvation Energy Reduces Molecular Recognition in Multi-Drug Resistant HIV-1 Protease

    Directory of Open Access Journals (Sweden)

    Ladislau C. Kovari

    2012-05-01

    Full Text Available Designing HIV-1 protease inhibitors that overcome drug-resistance is still a challenging task. In this study, four clinical isolates of multi-drug resistant HIV-1 proteases that exhibit resistance to all the US FDA-approved HIV-1 protease inhibitors and also reduce the substrate recognition ability were examined. A multi-drug resistant HIV-1 protease isolate, MDR 769, was co-crystallized with the p2/NC substrate and the mutated CA/p2 substrate, CA/p2 P1’F. Both substrates display different levels of molecular recognition by the wild-type and multi-drug resistant HIV-1 protease. From the crystal structures, only limited differences can be identified between the wild-type and multi-drug resistant protease. Therefore, a wild-type HIV-1 protease and four multi-drug resistant HIV-1 proteases in complex with the two peptides were modeled based on the crystal structures and examined during a 10 ns-molecular dynamics simulation. The simulation results reveal that the multi-drug resistant HIV-1 proteases require higher desolvation energy to form complexes with the peptides. This result suggests that the desolvation of the HIV-1 protease active site is an important step of protease-ligand complex formation as well as drug resistance. Therefore, desolvation energy could be considered as a parameter in the evaluation of future HIV-1 protease inhibitor candidates.

  6. Molecular characterization of shiitake medicinal mushroom, Lentinus edodes strains (higher Basidiomycetes) using RAPD and ITS sequencing.

    Science.gov (United States)

    Sharma, Shivani; Khanna, Pardeep Kumar; Kapoor, Shammi

    2014-01-01

    The molecular phylogeny in seven strains of Lentinus edodes was studied based on RAPD and their internal transcribed spacers (ITS) regions. The strains were analyzed by RAPD with 20 arbitrary primers. Fifteen primers were found efficient for the amplification of the genomic DNA. The size of the polymorphic bands were in the range of 100-1000 bp. However, the size of ITS1-2 and ITS1-4 regions varied among the strains from 278 to 575 bp and from 410 to 616 bp, respectively. The higher alignment score of the ITS 1-2 region indicated more variability in the ITS 1-4 region. Thus, on the basis of RAPD-PCR and ITS sequencing it was found that strains LeC and LeI showed a high degree of divergence from all other strains.

  7. A High-Mass Cold Core in the Auriga-California Giant Molecular Cloud

    Science.gov (United States)

    Magnus McGehee, Peregrine; Paladini, Roberta; Pelkonen, Veli-Matti; Toth, Viktor; Sayers, Jack

    2015-08-01

    The Auriga-California Giant Molecular Cloud is noted for its relatively low star formation rate, especially at the high-mass end of the Initial Mass Function. We combine maps acquired by the Caltech Submillimeter Observatory's Multiwavelength Submillimeter Inductance Camera [MUSIC] in the wavelength range 0.86 to 2.00 millimeters with Planck and publicly-available Herschel PACS and SPIRE data in order to characterize the mass, dust properties, and environment of the bright core PGCC G163.32-8.41.

  8. Note: A versatile mass spectrometer chamber for molecular beam and temperature programmed desorption experiments

    Energy Technology Data Exchange (ETDEWEB)

    Tonks, James P., E-mail: james.tonks@awe.co.uk [Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom); AWE Plc, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Galloway, Ewan C., E-mail: ewan.galloway@awe.co.uk; King, Martin O. [AWE Plc, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); Kerherve, Gwilherm [VACGEN Ltd, St. Leonards-On-Sea, East Sussex TN38 9NN (United Kingdom); Watts, John F. [Department of Mechanical Engineering Sciences, University of Surrey, Guildford, Surrey GU2 7XH (United Kingdom)

    2016-08-15

    A dual purpose mass spectrometer chamber capable of performing molecular beam scattering (MBS) and temperature programmed desorption (TPD) is detailed. Two simple features of this design allow it to perform these techniques. First, the diameter of entrance aperture to the mass spectrometer can be varied to maximize signal for TPD or to maximize angular resolution for MBS. Second, the mass spectrometer chamber can be radially translated so that it can be positioned close to the sample to maximize signal or far from the sample to maximize angular resolution. The performance of this system is described and compares well with systems designed for only one of these techniques.

  9. Molecular outflows driven by low-mass protostars. I. Correcting for underestimates when measuring outflow masses and dynamical properties

    Energy Technology Data Exchange (ETDEWEB)

    Dunham, Michael M. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, MS 78, Cambridge, MA 02138 (United States); Arce, Héctor G. [Department of Astronomy, Yale University, P.O. Box 208101, New Haven, CT 06520 (United States); Mardones, Diego [Departamento de Astronomía, Universidad de Chile, Casilla 36-D, Santiago (Chile); Lee, Jeong-Eun [Department of Astronomy and Space Science, Kyung Hee University, Yongin, Gyeonggi 446-701 (Korea, Republic of); Matthews, Brenda C. [National Research Council of Canada, Herzberg Astronomy and Astrophysics, 5071 W. Saanich Road, Victoria, BC V9E 2E7 (Canada); Stutz, Amelia M. [Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117, Heidelberg (Germany); Williams, Jonathan P., E-mail: mdunham@cfa.harvard.edu [Institute for Astronomy, University of Hawaii, Honolulu, HI 96822 (United States)

    2014-03-01

    We present a survey of 28 molecular outflows driven by low-mass protostars, all of which are sufficiently isolated spatially and/or kinematically to fully separate into individual outflows. Using a combination of new and archival data from several single-dish telescopes, 17 outflows are mapped in {sup 12}CO (2-1) and 17 are mapped in {sup 12}CO (3-2), with 6 mapped in both transitions. For each outflow, we calculate and tabulate the mass (M {sub flow}), momentum (P {sub flow}), kinetic energy (E {sub flow}), mechanical luminosity (L {sub flow}), and force (F {sub flow}) assuming optically thin emission in LTE at an excitation temperature, T {sub ex}, of 50 K. We show that all of the calculated properties are underestimated when calculated under these assumptions. Taken together, the effects of opacity, outflow emission at low velocities confused with ambient cloud emission, and emission below the sensitivities of the observations increase outflow masses and dynamical properties by an order of magnitude, on average, and factors of 50-90 in the most extreme cases. Different (and non-uniform) excitation temperatures, inclination effects, and dissociation of molecular gas will all work to further increase outflow properties. Molecular outflows are thus almost certainly more massive and energetic than commonly reported. Additionally, outflow properties are lower, on average, by almost an order of magnitude when calculated from the {sup 12}CO (3-2) maps compared to the {sup 12}CO (2-1) maps, even after accounting for different opacities, map sensitivities, and possible excitation temperature variations. It has recently been argued in the literature that the {sup 12}CO (3-2) line is subthermally excited in outflows, and our results support this finding.

  10. Greater lean tissue and skeletal muscle mass are associated with higher bone mineral content in children

    Directory of Open Access Journals (Sweden)

    Thornton John C

    2010-05-01

    Full Text Available Abstract Background To compare the relationship of skeletal muscle mass with bone mineral content in an ethnically diverse group of 6 to 18 year old boys and girls. Methods 175 healthy children (103 boys; 72 girls had assessments of body mass, height, and Tanner stage. Whole body bone mineral content, non-bone lean body mass (nbLBM, skeletal muscle mass, and fat mass were assessed using dual-energy X-ray absorptiometry (DXA. Muscle mass was estimated from an equation using appendicular lean soft tissue measured by DXA, weight and height. Estimates of skeletal muscle mass and adipose tissue were also assessed by whole body multi-slice magnetic resonance imaging (MRI. Linear regression was used to determine whether skeletal muscle mass assessed by DXA or by MRI were better predictors of bone mineral content compared with nbLBM after adjusting for sex, age, race or ethnicity, and Tanner stage. Results Greater skeletal muscle mass was associated with greater bone mineral content (p 2 statistic compared with assessment by DXA for predicting bone mineral content. The proportion of skeletal muscle mass in nbLBM was significantly associated with greater bone mineral content adjusted for total nbLBM. Conclusions This study is among the first to describe and compare the relationship of skeletal muscle to bone using both MRI and DXA estimates. The results demonstrate that the use of MRI provides a modestly better fitting model for the relationship of skeletal muscle to bone compared with DXA. Skeletal muscle had an impact on bone mineral content independent of total non-bone lean body mass. In addition, Hispanics had greater bone mineral content compared to other race and ethnic groups after adjusting for sex, age, adipose tissue, skeletal muscle mass, and height.

  11. Formation of truncated proteins and high-molecular-mass aggregates upon soft illumination of photosynthetic proteins

    DEFF Research Database (Denmark)

    Rinalducci, Sara; Campostrini, Natascia; Antonioli, Paolo

    2005-01-01

    Different spot profiles were observed in 2D gel electrophoresis of thylakoid membranes performed either under complete darkness or by leaving the sample for a short time to low visible light. In the latter case, a large number of new spots with lower molecular masses, ranging between 15,000 and 2...

  12. Cocoa content influences chocolate molecular profile investigated by MALDI-TOF mass spectrometry.

    Science.gov (United States)

    Bonatto, Cínthia C; Silva, Luciano P

    2015-06-01

    Chocolate authentication is a key aspect of quality control and safety. Matrix-assisted laser desorption ionization time-of flight (MALDI-TOF) mass spectrometry (MS) has been demonstrated to be useful for molecular profiling of cells, tissues, and even food. The present study evaluated if MALDI-TOF MS analysis on low molecular mass profile may classify chocolate samples according to the cocoa content. The molecular profiles of seven processed commercial chocolate samples were compared by using MALDI-TOF MS. Some ions detected exclusively in chocolate samples corresponded to the metabolites of cocoa or other constituents. This method showed the presence of three distinct clusters according to confectionery and sensorial features of the chocolates and was used to establish a mass spectra database. Also, novel chocolate samples were evaluated in order to check the validity of the method and to challenge the database created with the mass spectra of the primary samples. Thus, the method was shown to be reliable for clustering unknown samples into the main chocolate categories. Simple sample preparation of the MALDI-TOF MS approach described will allow the surveillance and monitoring of constituents during the molecular profiling of chocolates. © 2014 Society of Chemical Industry.

  13. Determination of the Subunit Molecular Mass and Composition of Alcohol Dehydrogenase by SDS-PAGE

    Science.gov (United States)

    Nash, Barbara T.

    2007-01-01

    SDS-PAGE is a simple, rapid technique that has many uses in biochemistry and is readily adaptable to the undergraduate laboratory. It is, however, a technique prone to several types of procedural pitfalls. This article describes the use of SDS-PAGE to determine the subunit molecular mass and composition of yeast alcohol dehydrogenase employing…

  14. ACYLTRANSFERASE ACTIVITIES OF THE HIGH-MOLECULAR-MASS ESSENTIAL PENICILLIN-BINDING PROTEINS

    NARCIS (Netherlands)

    ADAM, M; DAMBLON, C; JAMIN, M; ZORZI, W; DUSART, [No Value; GALLENI, M; ELKHARROUBI, A; PIRAS, G; SPRATT, BG; KECK, W; COYETTE, J; GHUYSEN, JM; NGUYENDISTECHE, M; FRERE, JM

    1991-01-01

    The high-molecular-mass penicillin-binding proteins (HMM-PBPs), present in the cytoplasmic membranes of all eubacteria, are involved in important physiological events such as cell elongation, septation or shape determination. Up to now it has, however, been very difficult or impossible to study the

  15. Biomolecular Imaging Mass Spectrometry : mapping molecular distributions in cells and tissue sections

    NARCIS (Netherlands)

    Altelaar, A.F.M.

    2007-01-01

    Imaging mass spectrometry (IMS) allows the investigation of both identity and localization of the molecular content directly from tissue sections, single cells and many other surfaces. To further develop the application of IMS, different approaches to IMS will be described in this thesis and the

  16. Characterization of macromolecular complexes in red wine: Composition, molecular mass distribution and particle size.

    Science.gov (United States)

    Bindon, Keren A; Carew, Anna L; Mierczynska-Vasilev, Agnieszka; Kassara, Stella; Kerslake, Fiona; Smith, Paul A

    2016-05-15

    Precipitates were prepared from two compositionally different Pinot noir wines with addition of excess ethanol, and contained primarily polysaccharide, tannin and protein. The ethanol-soluble material was further fractionated into polymeric (tannin) and monomeric phenolics. Tannin associated with precipitates was of a higher molecular mass than that remaining in ethanolic solution. Wine fractions were reconstituted at the ratios of the original wine and analyzed using nanoparticle tracking analysis. The average particle size of the tannin fraction was 75-89 nm, and increased when combined with the precipitate (≅ 200 nm). Addition of the monomeric fraction to the tannin-precipitate complex increased both the incidence and concentration of smaller particles, reducing the average particle size. The formation of aggregates occurred in all fractions and only minor differences in particle size distribution were found between wines. Differences in particle concentration between wines appear to be due to differences in the total concentration of macromolecules rather than compositional differences. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Designing and Developing Open Education Resources in Higher Education: A Molecular Biology Project.

    Science.gov (United States)

    Parisky, Alex; Boulay, Rachel

    2013-01-01

    Recent advances in internet technology have transformed how we gather and share information in today's world and have provided us with a platform to access educational resources and related information on the Internet. Every day, new technologies are developed that are changing the when and where we access that information. The capabilities of new technologies have allowed society to access information and learn virtually anywhere. As technical ingenuity continues to generate new technologies and paths of communication, we must look for opportunities to collaborate, share and extend our educational resources in higher education. Distributing Open Educational Resources (OER) in the form of freely licensed materials is necessary in order to laterally influence current advances in learning technologies. Online resources are being used in a variety of contexts to supplement instruction and training at higher education institutions. The aim of this Open Educational Resource project was to design and develop a blended learning instructional program to assist online users in developing familiarity with laboratory techniques prior to conducting molecular biology research in an authentic laboratory setting. This paper will look at the background of OER, describe the online materials that the Center for Cardiovascular Research (CCR) developed for open use, and discuss the outcomes and implications for use.

  18. Molecular Behavior of DNA Origami in Higher-Order Self-Assembly

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhe [Arizona State Univ., Tempe, AZ (United States); Liu, Minghui [Arizona State Univ., Tempe, AZ (United States); Lei, Wang [Arizona State Univ., Tempe, AZ (United States); Shandong Univ., Jinan (China); Nangreave, Jeanette [Arizona State Univ., Tempe, AZ (United States); Yan, Hao [Arizona State Univ., Tempe, AZ (United States); Liu, Yan [Arizona State Univ., Tempe, AZ (United States)

    2010-09-08

    DNA-based self-assembly is a unique method for achieving higher-order molecular architectures made possible by the fact that DNA is a programmable information-coding polymer. In the past decade, two main types of DNA nanostructures have been developed: branch-shaped DNA tiles with small dimensions (commonly up to ~20 nm) and DNA origami tiles with larger dimensions (up to ~100 nm). Here we aimed to determine the important factors involved in the assembly of DNA origami superstructures. We constructed a new series of rectangular-shaped DNA origami tiles in which parallel DNA helices are arranged in a zigzag pattern when viewed along the DNA helical axis, a design conceived in order to relax an intrinsic global twist found in the original planar, rectangular origami tiles. Self-associating zigzag tiles were found to form linear arrays in both diagonal directions, while planar tiles showed significant growth in only one direction. Although the series of zigzag tiles were designed to promote two-dimensional array formation, one-dimensional linear arrays and tubular structures were observed instead. We discovered that the dimensional aspect ratio of the origami unit tiles and intertile connection design play important roles in determining the final products, as revealed by atomic force microscopy imaging. This study provides insight into the formation of higher-order structures from self-assembling DNA origami tiles, revealing their unique behavior in comparison with conventional DNA tiles having smaller dimensions.

  19. The diverse and expanding role of mass spectrometry in structural and molecular biology.

    Science.gov (United States)

    Lössl, Philip; van de Waterbeemd, Michiel; Heck, Albert Jr

    2016-12-15

    The emergence of proteomics has led to major technological advances in mass spectrometry (MS). These advancements not only benefitted MS-based high-throughput proteomics but also increased the impact of mass spectrometry on the field of structural and molecular biology. Here, we review how state-of-the-art MS methods, including native MS, top-down protein sequencing, cross-linking-MS, and hydrogen-deuterium exchange-MS, nowadays enable the characterization of biomolecular structures, functions, and interactions. In particular, we focus on the role of mass spectrometry in integrated structural and molecular biology investigations of biological macromolecular complexes and cellular machineries, highlighting work on CRISPR-Cas systems and eukaryotic transcription complexes. © 2016 The Authors. Published under the terms of the CC BY NC ND 4.0 license.

  20. High-molecular-mass multi-c-heme cytochromes from Methylococcus capsulatus bath.

    Science.gov (United States)

    Bergmann, D J; Zahn, J A; DiSpirito, A A

    1999-02-01

    The polypeptide and structural gene for a high-molecular-mass c-type cytochrome, cytochrome c553O, was isolated from the methanotroph Methylococcus capsulatus Bath. Cytochrome c553O is a homodimer with a subunit molecular mass of 124,350 Da and an isoelectric point of 6. 0. The heme c concentration was estimated to be 8.2 +/- 0.4 mol of heme c per subunit. The electron paramagnetic resonance spectrum showed the presence of multiple low spin, S = 1/2, hemes. A degenerate oligonucleotide probe synthesized based on the N-terminal amino acid sequence of cytochrome c553O was used to identify a DNA fragment from M. capsulatus Bath that contains occ, the gene encoding cytochrome c553O. occ is part of a gene cluster which contains three other open reading frames (ORFs). ORF1 encodes a putative periplasmic c-type cytochrome with a molecular mass of 118, 620 Da that shows approximately 40% amino acid sequence identity with occ and contains nine c-heme-binding motifs. ORF3 encodes a putative periplasmic c-type cytochrome with a molecular mass of 94, 000 Da and contains seven c-heme-binding motifs but shows no sequence homology to occ or ORF1. ORF4 encodes a putative 11,100-Da protein. The four ORFs have no apparent similarity to any proteins in the GenBank database. The subunit molecular masses, arrangement and number of hemes, and amino acid sequences demonstrate that cytochrome c553O and the gene products of ORF1 and ORF3 constitute a new class of c-type cytochrome.

  1. High-Molecular-Mass Multi-c-Heme Cytochromes from Methylococcus capsulatus Bath†

    Science.gov (United States)

    Bergmann, David J.; Zahn, James A.; DiSpirito, Alan A.

    1999-01-01

    The polypeptide and structural gene for a high-molecular-mass c-type cytochrome, cytochrome c553O, was isolated from the methanotroph Methylococcus capsulatus Bath. Cytochrome c553O is a homodimer with a subunit molecular mass of 124,350 Da and an isoelectric point of 6.0. The heme c concentration was estimated to be 8.2 ± 0.4 mol of heme c per subunit. The electron paramagnetic resonance spectrum showed the presence of multiple low spin, S = 1/2, hemes. A degenerate oligonucleotide probe synthesized based on the N-terminal amino acid sequence of cytochrome c553O was used to identify a DNA fragment from M. capsulatus Bath that contains occ, the gene encoding cytochrome c553O. occ is part of a gene cluster which contains three other open reading frames (ORFs). ORF1 encodes a putative periplasmic c-type cytochrome with a molecular mass of 118,620 Da that shows approximately 40% amino acid sequence identity with occ and contains nine c-heme-binding motifs. ORF3 encodes a putative periplasmic c-type cytochrome with a molecular mass of 94,000 Da and contains seven c-heme-binding motifs but shows no sequence homology to occ or ORF1. ORF4 encodes a putative 11,100-Da protein. The four ORFs have no apparent similarity to any proteins in the GenBank database. The subunit molecular masses, arrangement and number of hemes, and amino acid sequences demonstrate that cytochrome c553O and the gene products of ORF1 and ORF3 constitute a new class of c-type cytochrome. PMID:9922265

  2. Thermally modulated nano-trampoline material as smart skin for gas molecular mass detection

    Science.gov (United States)

    Xia, Hua

    2012-06-01

    Conventional multi-component gas analysis is based either on laser spectroscopy, laser and photoacoustic absorption at specific wavelengths, or on gas chromatography by separating the components of a gas mixture primarily due to boiling point (or vapor pressure) differences. This paper will present a new gas molecular mass detection method based on thermally modulated nano-trampoline material as smart skin for gas molecular mass detection by fiber Bragg grating-based gas sensors. Such a nanomaterial and fiber Bragg grating integrated sensing device has been designed to be operated either at high-energy level (highly thermal strained status) or at low-energy level (low thermal strained status). Thermal energy absorption of gas molecular trigs the sensing device transition from high-thermal-energy status to low-thermal- energy status. Experiment has shown that thermal energy variation due to gas molecular thermal energy absorption is dependent upon the gas molecular mass, and can be detected by fiber Bragg resonant wavelength shift with a linear function from 17 kg/kmol to 32 kg/kmol and a sensitivity of 0.025 kg/kmol for a 5 micron-thick nano-trampoline structure and fiber Bragg grating integrated gas sensing device. The laboratory and field validation data have further demonstrated its fast response characteristics and reliability to be online gas analysis instrument for measuring effective gas molecular mass from single-component gas, binary-component gas mixture, and multi-gas mixture. The potential industrial applications include fouling and surge control for gas charge centrifugal compressor ethylene production, gas purity for hydrogen-cooled generator, gasification for syngas production, gasoline/diesel and natural gas fuel quality monitoring for consumer market.

  3. Improving the convergence of closed and open path integral molecular dynamics via higher order Trotter factorization schemes.

    Science.gov (United States)

    Pérez, Alejandro; Tuckerman, Mark E

    2011-08-14

    Higher order factorization schemes are developed for path integral molecular dynamics in order to improve the convergence of estimators for physical observables as a function of the Trotter number. The methods are based on the Takahashi-Imada and Susuki decompositions of the Boltzmann operator. The methods introduced improve the averages of the estimators by using the classical forces needed to carry out the dynamics to construct a posteriori weighting factors for standard path integral molecular dynamics. The new approaches are straightforward to implement in existing path integral codes and carry no significant overhead. The Suzuki higher order factorization was also used to improve the end-to-end distance estimator in open path integral molecular dynamics. The new schemes are tested in various model systems, including an ab initio path integral molecular dynamics calculation on the hydrogen molecule and a quantum water model. The proposed algorithms have potential utility for reducing the cost of path integral molecular dynamics calculations of bulk systems.

  4. A black-hole mass measurement from molecular gas kinematics in NGC4526.

    Science.gov (United States)

    Davis, Timothy A; Bureau, Martin; Cappellari, Michele; Sarzi, Marc; Blitz, Leo

    2013-02-21

    The masses of the supermassive black holes found in galaxy bulges are correlated with a multitude of galaxy properties, leading to suggestions that galaxies and black holes may evolve together. The number of reliably measured black-hole masses is small, and the number of methods for measuring them is limited, holding back attempts to understand this co-evolution. Directly measuring black-hole masses is currently possible with stellar kinematics (in early-type galaxies), ionized-gas kinematics (in some spiral and early-type galaxies) and in rare objects that have central maser emission. Here we report that by modelling the effect of a black hole on the kinematics of molecular gas it is possible to fit interferometric observations of CO emission and thereby accurately estimate black-hole masses. We study the dynamics of the gas in the early-type galaxy NGC 4526, and obtain a best fit that requires the presence of a central dark object of 4.5(+4.2)(-3.1) × 10(8) solar masses (3σ confidence limit). With the next-generation millimetre-wavelength interferometers these observations could be reproduced in galaxies out to 75 megaparsecs in less than 5 hours of observing time. The use of molecular gas as a kinematic tracer should thus allow one to estimate black-hole masses in hundreds of galaxies in the local Universe, many more than are accessible with current techniques.

  5. WISDOM project - I. Black hole mass measurement using molecular gas kinematics in NGC 3665

    Science.gov (United States)

    Onishi, Kyoko; Iguchi, Satoru; Davis, Timothy A.; Bureau, Martin; Cappellari, Michele; Sarzi, Marc; Blitz, Leo

    2017-07-01

    As a part of the mm-Wave Interferometric Survey of Dark Object Masses (WISDOM) project, we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotator early-type galaxy NGC 3665. We obtained the Combined Array for Research in Millimeter Astronomy (CARMA) B and C array observations of the 12CO(J = 2 - 1) emission line with a combined angular resolution of 0.59 arcsec. We analysed and modelled the three-dimensional molecular gas kinematics, obtaining a best-fitting SMBH mass M_BH=5.75^{+1.49}_{-1.18} × 108 M⊙, a mass-to-light ratio at H-band (M/L)H = 1.45 ± 0.04 (M/L)⊙,H and other parameters describing the geometry of the molecular gas disc (statistical errors, all at 3σ confidence). We estimate the systematic uncertainties on the stellar M/L to be ≈0.2 (M/L)⊙,H, and on the SMBH mass to be ≈0.4 × 108 M⊙. The measured SMBH mass is consistent with that estimated from the latest correlations with galaxy properties. Following our older works, we also analysed and modelled the kinematics using only the major-axis position-velocity diagram, and conclude that the two methods are consistent.

  6. Characterization and Physiological Function of Class I Low-Molecular-Mass, Heat-Shock Protein Complex in Soybean.

    Science.gov (United States)

    Jinn, T. L.; Chen, Y. M.; Lin, C. Y.

    1995-06-01

    Examination of an ammonium sulfate-enriched fraction (70-100% saturation) of heat-shock proteins (HSPs) by nondenaturing polyacrylamide gel electrophoresis revealed the presence of a high molecular mass complex (280 kD) in soybean (Glycine max) seedlings. This complex cross-reacted with antibodies raised against soybean class I low-molecular-mass (LMW) HSPs. Dissociation of the complex by denaturing polyacrylamide gel electrophoresis showed the complex to contain at least 15 polypeptides of the 15-to 18-kD class I LMW HSPs that could be detected by staining, radiolabeling, and western blotting. A similar LMW-HSP complex was observed in mung bean (Vigna radiata L.; 295 kD), in pea (Pisum sativum L.; 270 kD), and in rice (Oryza sativa L.; 310 kD). The complex was stable under high salt conditions (250 mM KCI), and the integrity was not affected by 1% Nonidet P-40 and 3 [mu]g/ML RNase treatment. The size of the isolated HSP complex in vitro was conserved to 55[deg]C; however, starting at 37.5[deg]C, it changed to higher molecular forms in the presence of soluble proteins. The isolated HSP complex was able to protect up to 75% of the soluble proteins from heat denaturation in vitro.

  7. A Lower Olfactory Capacity Is Related to Higher Circulating Concentrations of Endocannabinoid 2-Arachidonoylglycerol and Higher Body Mass Index in Women.

    Science.gov (United States)

    Pastor, Antoni; Fernández-Aranda, Fernando; Fitó, Montserrat; Jiménez-Murcia, Susana; Botella, Cristina; Fernández-Real, Jose M; Frühbeck, Gema; Tinahones, Francisco J; Fagundo, Ana B; Rodriguez, Joan; Agüera, Zaida; Langohr, Klaus; Casanueva, Felipe F; de la Torre, Rafael

    2016-01-01

    The endocannabinoid (eCB) system can promote food intake by increasing odor detection in mice. The eCB system is over-active in human obesity. Our aim is to measure circulating eCB concentrations and olfactory capacity in a human sample that includes people with obesity and explore the possible interaction between olfaction, obesity and the eCB system. The study sample was made up of 161 females with five groups of body mass index sub-categories ranging from under-weight to morbidly obese. We assessed olfactory capacity with the "Sniffin´Sticks" test, which measures olfactory threshold-discrimination-identification (TDI) capacity. We measured plasma concentrations of the eCBs 2-arachidonoylglycerol (2-AG) and N-arachidonoylethanolamine or anandamide (AEA), and several eCB-related compounds, 2-acylglycerols and N-acylethanolamines. 2-AG and other 2-acylglycerols fasting plasma circulating plasma concentrations were higher in obese and morbidly obese subjects. AEA and other N-acylethanolamine circulating concentrations were lower in under-weight subjects. Olfactory TDI scores were lower in obese and morbidly obese subjects. Lower TDI scores were independently associated with higher 2-AG fasting plasma circulating concentrations, higher %body fat, and higher body mass index, after controlling for age, smoking, menstruation, and use of contraceptives. Our results show that obese subjects have a lower olfactory capacity than non-obese ones and that elevated fasting plasma circulating 2-AG concentrations in obesity are linked to a lower olfactory capacity. In agreement with previous studies we show that eCBs AEA and 2-AG, and their respective congeners have a distinct profile in relation to body mass index. The present report is the first study in humans in which olfactory capacity and circulating eCB concentrations have been measured in the same subjects.

  8. A Lower Olfactory Capacity Is Related to Higher Circulating Concentrations of Endocannabinoid 2-Arachidonoylglycerol and Higher Body Mass Index in Women.

    Directory of Open Access Journals (Sweden)

    Antoni Pastor

    Full Text Available The endocannabinoid (eCB system can promote food intake by increasing odor detection in mice. The eCB system is over-active in human obesity. Our aim is to measure circulating eCB concentrations and olfactory capacity in a human sample that includes people with obesity and explore the possible interaction between olfaction, obesity and the eCB system. The study sample was made up of 161 females with five groups of body mass index sub-categories ranging from under-weight to morbidly obese. We assessed olfactory capacity with the "Sniffin´Sticks" test, which measures olfactory threshold-discrimination-identification (TDI capacity. We measured plasma concentrations of the eCBs 2-arachidonoylglycerol (2-AG and N-arachidonoylethanolamine or anandamide (AEA, and several eCB-related compounds, 2-acylglycerols and N-acylethanolamines. 2-AG and other 2-acylglycerols fasting plasma circulating plasma concentrations were higher in obese and morbidly obese subjects. AEA and other N-acylethanolamine circulating concentrations were lower in under-weight subjects. Olfactory TDI scores were lower in obese and morbidly obese subjects. Lower TDI scores were independently associated with higher 2-AG fasting plasma circulating concentrations, higher %body fat, and higher body mass index, after controlling for age, smoking, menstruation, and use of contraceptives. Our results show that obese subjects have a lower olfactory capacity than non-obese ones and that elevated fasting plasma circulating 2-AG concentrations in obesity are linked to a lower olfactory capacity. In agreement with previous studies we show that eCBs AEA and 2-AG, and their respective congeners have a distinct profile in relation to body mass index. The present report is the first study in humans in which olfactory capacity and circulating eCB concentrations have been measured in the same subjects.

  9. Imaging mass spectrometry: Molecular microscopy for the new age of biology and medicine.

    Science.gov (United States)

    Caprioli, Richard M

    2016-06-01

    Imaging mass spectrometry provides a powerful tool for monitoring and discovery of molecular processes in the spatial domain in tissues for research and practical applications in both biology and medicine. This technology directly measures molecular compounds in tissues without the use of target-specific reagents such as antibodies, is applicable to a wide variety of analytes, and can provide spatial resolutions below the single cell level. Importantly, it has paradigm shifting capabilities in clinical applications, especially for anatomic pathology. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. ARE MOLECULAR OUTFLOWS AROUND HIGH-MASS STARS DRIVEN BY IONIZATION FEEDBACK?

    Energy Technology Data Exchange (ETDEWEB)

    Peters, Thomas; Klessen, Ralf S. [Institut fuer Theoretische Astrophysik, Universitaet Heidelberg, Zentrum fuer Astronomie, Albert-Ueberle-Str. 2, D-69120 Heidelberg (Germany); Klaassen, Pamela D. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany); Mac Low, Mordecai-Mark [Department of Astrophysics, American Museum of Natural History, 79th Street at Central Park West, New York, NY 10024-5192 (United States); Banerjee, Robi, E-mail: tpeters@physik.uzh.ch [Hamburger Sternwarte, Gojenbergsweg 112, D-21029 Hamburg (Germany)

    2012-11-20

    The formation of massive stars exceeding 10 M {sub Sun} usually results in large-scale molecular outflows. Numerical simulations, including ionization, of the formation of such stars show evidence for ionization-driven molecular outflows. Here we examine whether the outflows seen in these models reproduce the observations. We compute synthetic ALMA and CARMA maps of CO emission lines of the outflows, and compare their signatures to existing single-dish and interferometric data. We find that the ionization-driven models can only reproduce weak outflows around high-mass star-forming regions. We argue that expanding H II regions probably do not represent the dominant mechanism for driving observed outflows. We suggest instead that observed outflows are driven by the collective action of the outflows from the many lower-mass stars that inevitably form around young massive stars in a cluster.

  11. A Guide to the Use of Mass Instruction Techniques. Teaching and Learning in Higher Education, 3.

    Science.gov (United States)

    Ellington, Henry

    This booklet is the first of three sequels to "A Guide to the Selection of Instructional Methods." Following a brief introduction, a discussion of the most common methods used in mass instructional techniques deals with the strenghts and weaknesses of lectures and similar expository techniques, film and video presentations, educational broadcasts,…

  12. The Importance of Minority Role Models in Higher Education Mass Communication Curriculum.

    Science.gov (United States)

    Reppert, James E.

    The broadcast journalism sequence at Southern Arkansas University allows African-American students as many opportunities as possible to review role models from different perspectives. The school has an enrollment of 18% Black students. Each area studied in the introduction to mass media course involves sections dealing with multicultural and…

  13. [Mass spectrometry of triterpene glycosides molecular complexation with purine bases of nucleic acids].

    Science.gov (United States)

    Lekar', A V; Vetrova, E V; Borisenko, N I; Iakovishin, L A; Grishkovets, V I

    2011-01-01

    The molecular complexation of adenine and guanine with hederagenin 3-O-alpha-L-rhamnopyranosyl-(1-->2)-O-alpha-L-arabinopyranoside (alpha-hederin) and its 28-O-alpha-L-rhamnopyranosyl-(1-->4)-O-beta-D-glucopyranosyl-(1-->6)-O-beta-D-glucopyranosyl ester (hederasaponin C) was investigated for the first time using the method of electrospray ionization mass spectrometry. Guanine forms complexes more diverse in composition than adenine.

  14. The Impact of Mass and Universal Higher Education on Curriculum and Instruction: Case Studies of China and Japan

    Science.gov (United States)

    Huang, Futao

    2017-01-01

    Based on case studies of China and Japan, this study undertakes comparative research on major aspects of university curriculum and instruction-teaching activities of academics, their role in curriculum development, and their perceptions of these activities--between a mass and a universal higher education system. Major findings from the APA…

  15. Bureaucracy, Standardization, and Liberal Arts. Evidences of Mass Production in Higher Education.

    Science.gov (United States)

    Simpson, George

    1979-01-01

    The liberal arts college is felt to have made higher education impersonal, its organizational structure defeating the educational aims it purportedly serves. Higher education is seen as bureaucratization of the individual, with standardizing effects and narrowing of intellectual vision and social insight. (Article originally published in 1949.)…

  16. Enrichment of low molecular weight serum proteins using acetonitrile precipitation for mass spectrometry based proteomic analysis.

    Science.gov (United States)

    Kay, Richard; Barton, Chris; Ratcliffe, Lucy; Matharoo-Ball, Balwir; Brown, Pamela; Roberts, Jane; Teale, Phil; Creaser, Colin

    2008-10-01

    A rapid acetonitrile (ACN)-based extraction method has been developed that reproducibly depletes high abundance and high molecular weight proteins from serum prior to mass spectrometric analysis. A nanoflow liquid chromatography/tandem mass spectrometry (nano-LC/MS/MS) multiple reaction monitoring (MRM) method for 57 high to medium abundance serum proteins was used to characterise the ACN-depleted fraction after tryptic digestion. Of the 57 targeted proteins 29 were detected and albumin, the most abundant protein in serum and plasma, was identified as the 20th most abundant protein in the extract. The combination of ACN depletion and one-dimensional nano-LC/MS/MS enabled the detection of the low abundance serum protein, insulin-like growth factor-I (IGF-I), which has a serum concentration in the region of 100 ng/mL. One-dimensional sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE) analysis of the depleted serum showed no bands corresponding to proteins of molecular mass over 75 kDa after extraction, demonstrating the efficiency of the method for the depletion of high molecular weight proteins. Total protein analysis of the ACN extracts showed that approximately 99.6% of all protein is removed from the serum. The ACN-depletion strategy offers a viable alternative to the immunochemistry-based protein-depletion techniques commonly used for removing high abundance proteins from serum prior to MS-based proteomic analyses.

  17. Mass Spectrometry Based Molecular 3D-Cartography of Plant Metabolites.

    Science.gov (United States)

    Floros, Dimitrios J; Petras, Daniel; Kapono, Clifford A; Melnik, Alexey V; Ling, Tie-Jun; Knight, Rob; Dorrestein, Pieter C

    2017-01-01

    Plants play an essential part in global carbon fixing through photosynthesis and are the primary food and energy source for humans. Understanding them thoroughly is therefore of highest interest for humanity. Advances in DNA and RNA sequencing and in protein and metabolite analysis allow the systematic description of plant composition at the molecular level. With imaging mass spectrometry, we can now add a spatial level, typically in the micrometer-to-centimeter range, to their compositions, essential for a detailed molecular understanding. Here we present an LC-MS based approach for 3D plant imaging, which is scalable and allows the analysis of entire plants. We applied this approach in a case study to pepper and tomato plants. Together with MS/MS spectra library matching and spectral networking, this non-targeted workflow provides the highest sensitivity and selectivity for the molecular annotations and imaging of plants, laying the foundation for studies of plant metabolism and plant-environment interactions.

  18. Advanced solvent based methods for molecular characterization of soil organic matter by high-resolution mass spectrometry.

    Science.gov (United States)

    Tfaily, Malak M; Chu, Rosalie K; Tolić, Nikola; Roscioli, Kristyn M; Anderton, Christopher R; Paša-Tolić, Ljiljana; Robinson, Errol W; Hess, Nancy J

    2015-01-01

    Soil organic matter (SOM), a complex, heterogeneous mixture of above and belowground plant litter and animal and microbial residues at various degrees of decomposition, is a key reservoir for carbon (C) and nutrient biogeochemical cycling in soil based ecosystems. A limited understanding of the molecular composition of SOM limits the ability to routinely decipher chemical processes within soil and accurately predict how terrestrial carbon fluxes will respond to changing climatic conditions and land use. To elucidate the molecular-level structure of SOM, we selectively extracted a broad range of intact SOM compounds by a combination of different organic solvents from soils with a wide range of C content. Our use of electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and a suite of solvents with varying polarity significantly expands the inventory of the types of organic molecules present in soils. Specifically, we found that hexane is selective for lipid-like compounds with very low O/C ratios ( 0.5; methanol (MeOH) has higher selectivity toward compounds characterized with low O/C < 0.5; and hexane, MeOH, ACN, and H2O solvents increase the number and types of organic molecules extracted from soil for a broader range of chemically diverse soil types. Our study of SOM molecules by ESI FTICR MS revealed new insight into the molecular-level complexity of organics contained in soils. We present the first comparative study of the molecular composition of SOM from different ecosystems using ultra high-resolution mass spectrometry.

  19. Selenosugar determination in porcine liver using multidimensional HPLC with atomic and molecular mass spectrometry.

    Science.gov (United States)

    Lu, Ying; Pergantis, Spiros A

    2009-01-01

    A methodology based on liquid chromatography coupled online with atomic and molecular mass spectrometry was developed for identifying trace amounts of the selenosugar methyl 2-acetamido-2-deoxy-1-seleno-β-D-galactopyranoside (SeGalNAc) in porcine liver, obtained from an animal that had not received selenium supplementation. Sample preparation was especially critical for the identification of SeGalNAc by molecular mass spectrometry. This involved liver extraction using a Tris buffer, followed by sequential centrifugations. The resulting cytosolic fraction was pre-concentrated and the low molecular weight selenium (LMWSe) fraction obtained from a size exclusion column was collected, concentrated, and subsequently analyzed using a tandem dual-column HPLC-ICP-MS system which consisted of strong cation exchange (SCX) and reversed phase (RP) columns coupled in tandem. Hepatocytosolic SeGalNAc was tentatively identified by retention time matching and spiking. Its identity was further confirmed by using the same type of chromatography on-line with atmospheric pressure chemical ionization tandem mass spectrometry operated in the selected reaction monitoring (SRM) mode. Four SRM transitions, characteristic of SeGalNAc, were monitored and their intensity ratios determined in order to confirm SeGalNAc identification. Instrument limits of detection for SeGalNAc by SCX-RP HPLC-ICP-MS and SCX-RP HPLC-APCI-MS/MS were 3.4 and 2.9 μg Se L(-1), respectively. Selenium mass balance analysis revealed that trace amounts of SeGalNAc, 2.16±0.94 μg Se kg(-1) liver (wet weight) were present in the liver cytosol, corresponding to 0.4% of the total Se content in the porcine liver.

  20. The initial mass function of star clusters that form in turbulent molecular clouds

    Science.gov (United States)

    Fujii, M. S.; Portegies Zwart, S.

    2015-05-01

    We simulate the formation and evolution of young star clusters using the combination of smoothed particle hydrodynamics (SPH) simulations and direct N-body simulations. We start by performing SPH simulations of the giant molecular cloud (GMC) with a turbulent velocity field, a mass of 4 × 104 to 5 × 106 M⊙, and a density between ρ ˜ 1.7 × 103 and 170 cm-3. We continue the hydrodynamical simulations for a free-fall time-scale (tff ≃ 0.83 and 2.5 Myr), and analyse the resulting structure of the collapsed cloud. We subsequently replace a density-selected subset of SPH particles with stars by adopting a local star formation efficiency proportional to ρ1/2. As a consequence, the local star formation efficiency exceeds 30 per cent, whereas globally only a few per cent of the gas is converted to stars. The stellar distribution by the time gas is converted to stars is very clumpy, with typically a dozen bound conglomerates that consist of 100-104 stars. We continue to evolve the stars dynamically using the collisional N-body method, which accurately treats all pairwise interactions, stellar collisions and stellar evolution. We analyse the results of the N-body simulations when the stars have an age of 2 and 10 Myr. During the dynamical simulations, massive clusters grow via hierarchical merging of smaller clusters. The shape of the cluster mass function that originates from an individual molecular cloud is consistent with a Schechter function with a power-law slope of β = -1.73 at 2 Myr and β = -1.67 at 10 Myr, which fits to observed cluster mass function of the Carina region. The superposition of mass functions have a power-law slope of ≲ -2, which fits the observed mass function of star clusters in the Milky Way, M31 and M83. We further find that the mass of the most massive cluster formed in a single molecular cloud with a mass of Mg scales with 6.1 M_g^{0.51} which also agrees with recent observation of the GMC and young clusters in M51.

  1. Critical Masses for Academic Research Groups and Consequences for Higher Education Research Policy and Management

    Science.gov (United States)

    Kenna, Ralph; Berche, Bertrand

    2012-01-01

    Smaller universities may produce research which is on a par with larger, elite establishments. This is confirmed by a recently developed mathematical model, supported by data from British and French higher education research-evaluation exercises. The detailed nature of the UK system, in particular, allows quantification of the notion of critical…

  2. Martin Trow: Twentieth-Century Higher Education. Elite to Mass to Universal

    Science.gov (United States)

    Burrage, Michael, Ed.

    2010-01-01

    Distinguished by their sharp insights, eloquence, even humor, the writings of Martin Trow on the development of higher education have helped define the field. Collected here are his most influential essays, tracing the arc and evolution of his prolific scholarly career over more than four decades. Trow is well known for his pioneering work on the…

  3. Time-Resolved Mass Sensing of a Molecular Adsorbate Nonuniformly Distributed Along a Nanomechnical String

    Science.gov (United States)

    Biswas, T. S.; Xu, Jin; Miriyala, N.; Doolin, C.; Thundat, T.; Davis, J. P.; Beach, K. S. D.

    2015-06-01

    We show that the particular distribution of mass deposited on the surface of a nanomechanical resonator can be estimated by tracking the evolution of the device's resonance frequencies during the process of desorption. The technique, which relies on analytical models we have developed for the multimodal response of the system, enables mass sensing at much higher levels of accuracy than is typically achieved with a single frequency-shift measurement and no rigorous knowledge of the mass profile. We report on a series of demonstration experiments, in which the explosive molecule 1,3,5-trinitroperhydro-1,3,5-triazine (RDX) is vapor deposited along the length of a silicon nitride nanostring to create a dense, random covering of RDX crystallites on the surface. In some cases, the deposition is biased to produce distributions with a slight excess or deficit of mass at the string midpoint. The added mass is then allowed to sublimate away under vacuum conditions, with the device returning to its original state over about 4 h (and the resonance frequencies, measured via optical interferometry, relaxing back to their pre-mass-deposition values). Our claim is that the detailed time trace of observed frequency shifts is rich in information—not only about the quantity of RDX initially deposited but also about its spatial arrangement along the nanostring. The data also reveal that sublimation in this case follows a nontrivial rate law, consistent with mass loss occurring at the exposed surface area of the RDX crystallites.

  4. High-molecular-mass substances in resinites as possible precursors of specific hydrocarbons in fossil fuels

    Energy Technology Data Exchange (ETDEWEB)

    Aarssen, B.G.K. van.; de Leeuw, J.W. (Delft University of Technology, Delft (Netherlands). Organic Geochemistry Unit)

    1992-12-01

    A critical review of the literature concerning the composition of high-molecular-mass (HMM) substances in fossil resins, or resinites, indicated that rigorous assignments of chemical structures of resins of gymnosperm origin have not been performed. Detailed knowledge of the structures of such macromolecules is needed to fully understand their diagenetic and catagenetic behaviour. Therefore a representative set of fossil gymnosperm resins (Victoria, Australia) was investigated. HMM substances were separated from the low-molecular-mass (LMM) substances and studied for their structures and thermal breakdown products. The LMM compounds consist mainly of tricyclic carboxylic acids. The presence of C[sub 40]-compounds which were tentatively identified as dimeric communic acids is shown. Specific compounds that are formed upon flash pyrolysis of the HMM substances were tentatively identified by gas chromatography-mass spectrometry. Their proposed structures indicate that the basic structural unit of the macromolecule consists of a diterpenoid carboxylic acid with a labdatriene carbon skeleton. This is in agreement with literature in which the gymnosperm resinous macromolecules are described as polycommunic acids. Prolonged heating of the resinite and the separated HMM substances yields predominantly bi- and tricyclic aromatic hydrocarbons which are often encountered in fossil fuels. 47 refs., 11 figs.

  5. Comparing the Performance of Hyperbolic and Circular Rod Quadrupole Mass Spectrometers with Applied Higher Order Auxiliary Excitation

    Science.gov (United States)

    Gershman, D.J.; Block, B.P.; Rubin, M.; Benna, M.; Mahaffy, P. R.; Zurbuchen, T. H.

    2012-01-01

    This work applies higher order auxiliary excitation techniques to two types of quadrupole mass spectrometers (QMSs): commercial systems and spaceborne instruments. The operational settings of a circular rod geometry commercial system and an engineering test-bed for a hyperbolic rod geometry spaceborne instrument were matched, with the relative performance of each sensor characterized with and without applied excitation using isotopic measurements of Kr+. Each instrument was operated at the limit of the test electronics to determine the effect of auxiliary excitation on extending instrument capabilities. For the circular rod sensor, with applied excitation, a doubling of the mass resolution at 1% of peak transmission resulted from the elimination of the low-mass side peak tail typical of such rod geometries. The mass peak stability and ion rejection efficiency were also increased by factors of 2 and 10, respectively, with voltage scan lines passing through the center of stability islands formed from auxiliary excitation. Auxiliary excitation also resulted in factors of 6 and 2 in peak stability and ion rejection efficiency, respectively, for the hyperbolic rod sensor. These results not only have significant implications for the use of circular rod quadrupoles with applied excitation as a suitable replacement for traditional hyperbolic rod sensors, but also for extending the capabilities of existing hyperbolic rod QMSs for the next generation of spaceborne instruments and low-mass commercial systems.

  6. Higher sea fish intake is associated with greater bone mass and lower osteoporosis risk in postmenopausal Chinese women.

    Science.gov (United States)

    Chen, Y-m; Ho, S C; Lam, S S

    2010-06-01

    We examined the cross-sectional association of the intakes of different types of fishes with bone mass and osteoporosis risk in postmenopausal Chinese women. We found that higher intake of sea fish is independently associated with greater bone mass and lower osteoporosis risk among postmenopausal Chinese women. Fish contains many important nutrients that are beneficial on bone health, but limited data on the relationship between fish intake and bone health are available. We examined the association of the intakes of different types of fishes with bone mineral density (BMD) and bone mineral content (BMC) and osteoporosis risk. This population-based cross-sectional study was conducted among 685 postmenopausal Chinese women. Habitual dietary intakes were assessed using food frequency questionnaire. BMD and BMC at the whole body, lumbar spine, and left hip were measured with dual-energy x-ray absorptiometry. After adjusting for the potential confounders, we observed dose-dependent relations between sea fish intake and BMDs, BMCs, and osteoporosis risk; the mean BMDs were 3.2-6.8% higher, and BMCs 5.1-9.4% higher in the top quintile groups (Q5) of sea fish intake than in the bottom quintile (Q1) at the whole body and hip sites (p intake of sea fish is independently associated with greater bone mass and lower osteoporosis risk among postmenopausal Chinese women.

  7. Evidence for higher heritability of somatotype compared to body mass index in female twins.

    Science.gov (United States)

    Reis, Victor Machado; Machado, João V; Fortes, Marcos S; Fernandes, Paula Roquetti; Silva, António José; Dantas, Paulo Silva; Filho, José Fernandes

    2007-01-01

    The influence of genetics on human physique and obesity has been addressed by the literature. Evidence for heritability of anthropometric characteristics has been previously described, mainly for the body mass index (BMI). However, few studies have investigated the influence of genetics on the Heath-Carter somatotype. The aim of the present study was to assess the heritability of BMI and somatotype (endomorphy, mesomorphy, and ectomorphy) in a group of female monozygotic and dizygotic twins from childhood to early adulthood. A total of 28 females aged from 7 to 19 years old were studied. The group included 5 monozygotic and 9 dizygotic pairs of twins. The heritability was assessed by the twin method (h(2)). The anthropometric measures and somatotype were assessed using standard validated procedures. Significant differences between monozygotic and dizygotic pairs of twins were found for height, endomorphy, ectomorphy, and mesomorphy, and the heritability for these measures was high (h(2) between 0.88 and 0.97). No significant differences were found between monozygotic and dizygotic twins for weight, and the BMI and the heritability indexes were lower for these measures (respectively 0.42 and 0.52). The results of the present study have indicated that the somatotype may be more sensible to genetic influences than the BMI in females.

  8. Elucidation of Drug Metabolite Structural Isomers Using Molecular Modeling Coupled with Ion Mobility Mass Spectrometry.

    Science.gov (United States)

    Reading, Eamonn; Munoz-Muriedas, Jordi; Roberts, Andrew D; Dear, Gordon J; Robinson, Carol V; Beaumont, Claire

    2016-02-16

    Ion mobility-mass spectrometry (IM-MS) in combination with molecular modeling offers the potential for small molecule structural isomer identification by measurement of their gas phase collision cross sections (CCSs). Successful application of this approach to drug metabolite identification would facilitate resource reduction, including animal usage, and may benefit other areas of pharmaceutical structural characterization including impurity profiling and degradation chemistry. However, the conformational behavior of drug molecules and their metabolites in the gas phase is poorly understood. Here the gas phase conformational space of drug and drug-like molecules has been investigated as well as the influence of protonation and adduct formation on the conformations of drug metabolite structural isomers. The use of CCSs, measured from IM-MS and molecular modeling information, for the structural identification of drug metabolites has also been critically assessed. Detection of structural isomers of drug metabolites using IM-MS is demonstrated and, in addition, a molecular modeling approach has been developed offering rapid conformational searching and energy assessment of candidate structures which agree with experimental CCSs. Here it is illustrated that isomers must possess markedly dissimilar CCS values for structural differentiation, the existence and extent of CCS differences being ionization state and molecule dependent. The results present that IM-MS and molecular modeling can inform on the identity of drug metabolites and highlight the limitations of this approach in differentiating structural isomers.

  9. Optimized experimental workflow for tandem mass spectrometry molecular networking in metabolomics.

    Science.gov (United States)

    Olivon, Florent; Roussi, Fanny; Litaudon, Marc; Touboul, David

    2017-09-01

    New omics sciences generate massive amounts of data, requiring to be sorted, curated, and statistically analyzed by dedicated software. Data-dependent acquisition mode including inclusion and exclusion rules for tandem mass spectrometry is routinely used to perform such analyses. While acquisition parameters are well described for proteomics, no general rule is currently available to generate reliable metabolomic data for molecular networking analysis on the Global Natural Product Social Molecular Networking platform (GNPS). Following on from an exploration of key parameters influencing the quality of molecular networks, universal optimal acquisition conditions for metabolomic studies are suggested in the present paper. The benefit of data pre-clustering before initiating large datasets for GNPS analyses is also demonstrated. Moreover, an efficient workflow dedicated to Agilent Technologies instruments is described, making the dereplication process easier by unambiguously distinguishing isobaric isomers eluted at different retention times, annotating the molecular networks with chemical formulas, and giving access to semi-quantitative data. This specific workflow foreshadows future developments of the GNPS platform.

  10. Streptococcus mutans strain N produces a novel low molecular mass non-lantibiotic bacteriocin.

    Science.gov (United States)

    Balakrishnan, M; Simmonds, R S; Carne, A; Tagg, J R

    2000-02-01

    Streptococcus mutans strain N was shown to have bacteriocin production and immunity characteristics consistent with those of Group I mutacin-producing strains of S. mutans. The bacteriocin mutacin N was purified from agar cultures of S. mutans strain N using XAD andp6 reversed phase chromatography. The molecular mass of mutacin N was 4806 Da and the entire 49 amino acid sequence was determined by N-terminal sequencing. Database searches indicate that mutacin N is a novel bacteriocin, but with some homology to the protein IIC domain of a hypothetical sugar-phosphotransferase enzyme from Acholeplasma florum.

  11. Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking

    DEFF Research Database (Denmark)

    Wang, Mingxun; Carver, Jeremy J.; Pevzner, Pavel

    2016-01-01

    are well-suited to high-throughput characterization of NP, there is a pressing need for an infrastructure to enable sharing and curation of data. We present Global Natural Products Social Molecular Networking (GNPS; http://gnps.ucsd.edu), an open-access knowledge base for community-wide organization...... and sharing of raw, processed or identified tandem mass (MS/MS) spectrometry data. In GNPS, crowdsourced curation of freely available community-wide reference MS libraries will underpin improved annotations. Data-driven social-networking should facilitate identification of spectra and foster collaborations...

  12. Sharing and community curation of mass spectrometry data with Global Natural Products Social Molecular Networking

    DEFF Research Database (Denmark)

    Wang, Mingxun; Carver, Jeremy J.; Pevzner, Pavel

    2016-01-01

    The potential of the diverse chemistries present in natural products (NP) for biotechnology and medicine remains untapped because NP databases are not searchable with raw data and the NP community has no way to share data other than in published papers. Although mass spectrometry (MS) techniques...... are well-suited to high-throughput characterization of NP, there is a pressing need for an infrastructure to enable sharing and curation of data. We present Global Natural Products Social Molecular Networking (GNPS; http://gnps.ucsd.edu), an open-access knowledge base for community-wide organization...... and sharing of raw, processed or identified tandem mass (MS/MS) spectrometry data. In GNPS, crowdsourced curation of freely available community-wide reference MS libraries will underpin improved annotations. Data-driven social-networking should facilitate identification of spectra and foster collaborations...

  13. Media optimization for elevated molecular weight and mass production of pigment-free pullulan.

    Science.gov (United States)

    Yu, Xiaoliu; Wang, Yulei; Wei, Gongyuan; Dong, Yingying

    2012-07-01

    In this study, an Aureobasidium pullulans SZU 1001 mutant, deficient in pigment production, was screened by complex UV and γ-ray mutagenesis. Medium composition optimization for increased pullulan molecular weight and production was conducted using this mutant. Six nutrients: yeast extract, (NH4)2SO4, K2HPO4, NaCl, MgSO4·7H2O and CaCl2 were detected within pullulan production in flasks. It is shown that NaCl and K2HPO4 have significant influences on molecular weight of pullulan, while yeast extract and (NH4)2SO4 significantly affect pullulan yield. To achieve a higher molecular weight and more efficient pullulan production, a response surface methodology approach was introduced to predict an optimal nutrient combination. A molecular weight of 5.74 × 10(6) and pullulan yield on glucose of 51.30% were obtained under batch pullulan fermentation with the optimized media, which increased molecular weight and pullulan production by 97.25% and 11.04%, respectively compared with the control media. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Mass transfer ranking of polylysine, poly-ornithine and poly-methylene-co-guanidine microcapsule membranes using a single low molecular mass marker

    Directory of Open Access Journals (Sweden)

    Rosinski Stefan

    2003-01-01

    Full Text Available On the long way to clinical transplantable hybrid systems, comprising of cells, acting as immuno-protected bioreactors microencapsulated in a polymeric matrix and delivering desired factors (proteins, hormones, enzymes etc to the patient's body, an important step is the optimization of the microcapsule. This topic includes the selection of a proper coating membrane which could fulfil, first of all, the mass transfer as well as biocompatibility, stability and durability requirements. Three different membranes from polymerised aminoacids, formed around exactly identical alginate gel cores, were considered, concerning their mass transport properties, as potential candidates in this task. The results of the evaluation of the mass ingress and mass transfer coefficient h for the selected low molecular mass marker, vitamin B12, in poly-L-lysine (HPLL poly-L-ornithine (HPLO and poly-methylene-co-guanidine hydrochloride (HPMCG membrane alginate microcapsules demonstrate the advantage of using the mass transfer approach to a preliminary screening of various microcapsule formulations. Applying a single marker and evaluating mass transfer coefficients can help to quickly rank the investigated membranes and microcapsules according to their permeability. It has been demonstrated that HPLL, HPLO and HPMCG microcapsules differ from each other by a factor of two concerning the rate of low molecular mass marker transport. Interesting differences in mass transfer through the membrane in both directions in-out was also found, which could possibly be related to the membrane asymmetry.

  15. Higher molecular weight dissolved organic nitrogen turnover as affected by soil management history

    DEFF Research Database (Denmark)

    Lønne Enggrob, Kirsten

    High molecular weight dissolved organic nitrogen turnover as affected by soil management history *Kirsten Lønne Enggrob,1 Lars Elsgaard,1 and Jim Rasmussen1 1Aarhus University, Dept. of Agroecology, Foulum, Denmark 1. Introduction Dissolved organic nitrogen (DON) play an important role in soil N...... cycling. DON, as a collective term, refers to a diversity of organic N compounds which can operationally be grouped into high molecular weight (Mw) DON (Mw > 1 kDa) and low Mw DON (... are presented for 14CO2 evolution during 14 days of incubation. 4. Results and conclusion Results showed that the turnover rate of high Mw DON was dependent on both the Mw size of DON and on the soil liming history. Evidence showing where in the DON Mw sizes the bottleneck lies will be presented....

  16. Molecular Properties and Functional Divergence of the Dehydroascorbate Reductase Gene Family in Lower and Higher Plants.

    Directory of Open Access Journals (Sweden)

    Yuan-Jie Zhang

    Full Text Available Dehydroascorbate reductase (DHAR, which reduces oxidized ascorbate, is important for maintaining an appropriate ascorbate redox state in plant cells. To date, genome-wide molecular characterization of DHARs has only been conducted in bryophytes (Physcomitrella patens and eudicots (e.g. Arabidopsis thaliana. In this study, to gain a general understanding of the molecular properties and functional divergence of the DHARs in land plants, we further conducted a comprehensive analysis of DHARs from the lycophyte Selaginella moellendorffii, gymnosperm Picea abies and monocot Zea mays. DHARs were present as a small gene family in all of the land plants we examined, with gene numbers ranging from two to four. All the plants contained cytosolic and chloroplastic DHARs, indicating dehydroascorbate (DHA can be directly reduced in the cytoplasm and chloroplast by DHARs in all the plants. A novel vacuolar DHAR was found in Z. mays, indicating DHA may also be reduced in the vacuole by DHARs in Z. mays. The DHARs within each species showed extensive functional divergence in their gene structures, subcellular localizations, and enzymatic characteristics. This study provides new insights into the molecular characteristics and functional divergence of DHARs in land plants.

  17. Preparation of Higher Molecular Weight Poly (L-lactic Acid by Chain Extension

    Directory of Open Access Journals (Sweden)

    Chenguang Liu

    2013-01-01

    Full Text Available High molecular weight poly (lactic acid (PLA was obtained by chain extending with hexamethylene diisocyanate (HDI. The influences of the amount of chain extender, reaction time, and molecular weight changes of prepolymers on the poly(lactic acid were investigated. PLA prepolymer with a viscosity, average molecular weight (Mη of 2 × 104 g/mol was synthesized from l-lactide using stannous octoate as the catalyst. After 20 min of chain extension at 175°C, the resulting polymer had Mw of 20.3 × 104 g/mol and Mn of 10.5 × 104 g/mol. Both FT-IR and 1H-NMR verified that the structure of PLA did not change either before chain extending or after. The optically active characterized that the chain extending-product was left handed. DSC and XRD results showed that both the Tg and the crystallinity of PLA were lowered by chain-extension reaction. The crystalline transformation happened in PLA after chain extending, crystalline α′ form to α form.

  18. Racial Discrimination and Low Household Education Predict Higher Body Mass Index in African American Youth.

    Science.gov (United States)

    Nelson, Devin S; Gerras, Julia M; McGlumphy, Kellye C; Shaver, Erika R; Gill, Amaanat K; Kanneganti, Kamala; Ajibewa, Tiwaloluwa A; Hasson, Rebecca E

    2017-12-06

    The purpose of this study was to examine the relationships between environmental factors, including household education, community violence exposure, racial discrimination, and cultural identity, and BMI in African American adolescents. A community-based sample of 198 African American youth (120 girls, 78 boys; ages 11-19 years) from Washtenaw County, Michigan, were included in this analysis. Violence exposure was assessed by using the Survey of Children's Exposure to Community Violence; racial discrimination by using the Adolescent Discrimination Distress Index; cultural identity by using the Acculturation, Habits, and Interests Multicultural Scale for Adolescents; and household education by using a seven-category variable. Measured height and body weight were used to calculate BMI. Racial discrimination was positively associated with BMI, whereas household education was inversely associated with BMI in African American adolescents (discrimination: β = 0.11 ± 0.04, p = 0.01; education: β = -1.13 ± 0.47, p = 0.02). These relationships were significant when accounting for the confounding effects of stress, activity, diet, and pubertal development. Significant gender interactions were observed with racial discrimination and low household education associated with BMI in girls only (discrimination: β = 0.16 ± 0.05, p = 0.003; education: β = -1.12 ± 0.55, p = 0.045). There were no significant relationships between culture, community violence exposure, and BMI (all p's > 0.05). Environmental factors, including racial discrimination and low household education, predicted higher BMI in African American adolescents, particularly among girls. Longitudinal studies are needed to better understand the mechanisms by which these environmental factors increase obesity risk in African American youth.

  19. Mass Spectrometry-based Approaches to Understand the Molecular Basis of Memory

    Directory of Open Access Journals (Sweden)

    Arthur Henriques Pontes

    2016-10-01

    Full Text Available The central nervous system is responsible for an array of cognitive functions such as memory, learning, language and attention. These processes tend to take place in distinct brain regions; yet, they need to be integrated to give rise to adaptive or meaningful behavior. Since cognitive processes result from underlying cellular and molecular changes, genomics and transcriptomics assays have been applied to human and animal models to understand such events. Nevertheless, genes and RNAs are not the end products of most biological functions. In order to gain further insights toward the understanding of brain processes, the field of proteomics has been of increasing importance in the past years. Advancements in liquid chromatography-tandem mass spectrometry (LC-MS/MS have enable the identification and quantification of thousand of proteins with high accuracy and sensitivity, fostering a revolution in the neurosciences. Herein, we review the molecular bases of explicit memory in the hippocampus. We outline the principles of mass spectrometry (MS-based proteomics, highlighting the use of this analytical tool to study memory formation. In addition, we discuss MS-based targeted approaches as the future of protein analysis.

  20. The molecular mass of dextran used to modify magnetite nanoparticles affects insulin amyloid aggregation

    Science.gov (United States)

    Siposova, Katarina; Pospiskova, Kristyna; Bednarikova, Zuzana; Safarik, Ivo; Safarikova, Mirka; Kubovcikova, Martina; Kopcansky, Peter; Gazova, Zuzana

    2017-04-01

    Protein transformation from its soluble state into amyloid aggregates is associated with amyloid-related diseases. Amyloid deposits of insulin fibrils have been found in the sites of subcutaneous insulin application in patients with prolonged diabetes. Using atomic force microscopy and ThT fluorescence assay we have investigated the interference of insulin amyloid aggregation with superparamagnetic Fe3O4-based nanoparticles (SPIONs) coated with dextran (DEX); molecular mass of dextran was equal to 15-20, 40 or 70 kDa. The obtained data indicate that all three types of dextran coated nanoparticles (NP-FeDEXs) are able to inhibit insulin fibrillization and to destroy amyloid fibrils. The extent of anti-amyloid activities depends on the properties of NP-FeDEXs, mainly on the size of nanoparticles which is determined by molecular mass of dextran molecules. The most effective inhibiting activity was observed for the smallest nanoparticles coated with 15-20 kDa dextran. Contrary, the highest destroying activity was observed for the largest NP-FeDEX (70 kDa dextran).

  1. The molecular mass of dextran used to modify magnetite nanoparticles affects insulin amyloid aggregation

    Energy Technology Data Exchange (ETDEWEB)

    Siposova, Katarina [Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice (Slovakia); Pospiskova, Kristyna [Regional Centre of Advanced Technologies and Materials, Palacky University, Olomouc (Czech Republic); Bednarikova, Zuzana [Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice (Slovakia); Department of Biochemistry, Faculty of Science, Safarik University, Kosice (Slovakia); Safarik, Ivo [Regional Centre of Advanced Technologies and Materials, Palacky University, Olomouc (Czech Republic); Department of Nanobiotechnology, Biology Centre, ISB, CAS, Ceske Budejovice (Czech Republic); Safarikova, Mirka [Department of Nanobiotechnology, Biology Centre, ISB, CAS, Ceske Budejovice (Czech Republic); Kubovcikova, Martina; Kopcansky, Peter [Department of Magnetism, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice (Slovakia); Gazova, Zuzana, E-mail: gazova@saske.sk [Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Kosice (Slovakia)

    2017-04-01

    Protein transformation from its soluble state into amyloid aggregates is associated with amyloid-related diseases. Amyloid deposits of insulin fibrils have been found in the sites of subcutaneous insulin application in patients with prolonged diabetes. Using atomic force microscopy and ThT fluorescence assay we have investigated the interference of insulin amyloid aggregation with superparamagnetic Fe{sub 3}O{sub 4}-based nanoparticles (SPIONs) coated with dextran (DEX); molecular mass of dextran was equal to 15–20, 40 or 70 kDa. The obtained data indicate that all three types of dextran coated nanoparticles (NP-FeDEXs) are able to inhibit insulin fibrillization and to destroy amyloid fibrils. The extent of anti-amyloid activities depends on the properties of NP-FeDEXs, mainly on the size of nanoparticles which is determined by molecular mass of dextran molecules. The most effective inhibiting activity was observed for the smallest nanoparticles coated with 15–20 kDa dextran. Contrary, the highest destroying activity was observed for the largest NP-FeDEX (70 kDa dextran). - Highlights: • Interference of dextran- magnetite nanoparticles with insulin amyloid aggregation. • Nanoparticles inhibited insulin fibrillization and depolymerized insulin amyloid fibrils. • Size of nanoparticles significantly influences their anti-amyloid activities. • The most effective inhibition of insulin amyloid fibrillization was detected for the smallest nanoparticles. • Contrary, DC{sub 50} values decreased with increasing size of nanoparticles.

  2. Mass Spectrometry-based Approaches to Understand the Molecular Basis of Memory

    Science.gov (United States)

    Pontes, Arthur; de Sousa, Marcelo

    2016-10-01

    The central nervous system is responsible for an array of cognitive functions such as memory, learning, language and attention. These processes tend to take place in distinct brain regions; yet, they need to be integrated to give rise to adaptive or meaningful behavior. Since cognitive processes result from underlying cellular and molecular changes, genomics and transcriptomics assays have been applied to human and animal models to understand such events. Nevertheless, genes and RNAs are not the end products of most biological functions. In order to gain further insights toward the understanding of brain processes, the field of proteomics has been of increasing importance in the past years. Advancements in liquid chromatography-tandem mass spectrometry (LC-MS/MS) have enable the identification and quantification of thousand of proteins with high accuracy and sensitivity, fostering a revolution in the neurosciences. Herein, we review the molecular bases of explicit memory in the hippocampus. We outline the principles of mass spectrometry (MS)-based proteomics, highlighting the use of this analytical tool to study memory formation. In addition, we discuss MS-based targeted approaches as the future of protein analysis.

  3. Higher order terms of the nucleon current in the neutrino mass mechanism of neutrinoless double beta decay

    CERN Document Server

    Pantis, G

    2000-01-01

    The nuclear matrix elements for light and heavy Majorana neutrino in neutrinoless double beta decay have been reconsidered by including additional higher order terms in the nucleon current. The form of the nucleon current now includes except the usual vector and axial-vector terms additional contributions arising from weak magnetism and induced pseudoscalar coupling. The later is derived by the partially conserved axial-vector current hypothesis. We have considered all nuclei that undergo double beta decay in the mass region A=76 up to A=150 using the renormalized quasiparticle random phase approximation. Our results show that these contributions are very important. They bring significant reductions to the nuclear matrix element for both the light and the heavy neutrino. Thus new limits for the neutrino mass are extracted using the best presently available experimental limits on the half-life of neutrinoless double beta-decay.

  4. Higher compared with lower dietary protein during an energy deficit combined with intense exercise promotes greater lean mass gain and fat mass loss: a randomized trial.

    Science.gov (United States)

    Longland, Thomas M; Oikawa, Sara Y; Mitchell, Cameron J; Devries, Michaela C; Phillips, Stuart M

    2016-03-01

    A dietary protein intake higher than the Recommended Dietary Allowance during an energy deficit helps to preserve lean body mass (LBM), particularly when combined with exercise. The purpose of this study was to conduct a proof-of-principle trial to test whether manipulation of dietary protein intake during a marked energy deficit in addition to intense exercise training would affect changes in body composition. We used a single-blind, randomized, parallel-group prospective trial. During a 4-wk period, we provided hypoenergetic (~40% reduction compared with requirements) diets providing 33 ± 1 kcal/kg LBM to young men who were randomly assigned (n = 20/group) to consume either a lower-protein (1.2 g · kg(-1) · d(-1)) control diet (CON) or a higher-protein (2.4 g · kg(-1) · d(-1)) diet (PRO). All subjects performed resistance exercise training combined with high-intensity interval training for 6 d/wk. A 4-compartment model assessment of body composition was made pre- and postintervention. As a result of the intervention, LBM increased (P mass than did the CON group (PRO: -4.8 ± 1.6 kg; CON: -3.5 ± 1.4kg; P mass when combined with a high volume of resistance and anaerobic exercise. Changes in serum cortisol were associated with changes in body fat and LBM, but did not explain much variance in either measure. This trial was registered at clinicaltrials.gov as NCT01776359. © 2016 American Society for Nutrition.

  5. Molecular and system parameters governing mass and charge transport in polar liquids and electrolytes.

    Science.gov (United States)

    Petrowsky, Matt; Fleshman, Allison; Ismail, Mohd; Glatzhofer, Daniel T; Bopege, Dharshani N; Frech, Roger

    2012-08-23

    Onsager's model of the dielectric constant is used to provide a molecular-level picture of how the dielectric constant affects mass and charge transport in organic liquids and organic liquid electrolytes. Specifically, the molecular and system parameters governing transport are the molecular dipole moment μ and the solvent dipole density N. The compensated Arrhenius formalism (CAF) writes the temperature-dependent ionic conductivity or diffusion coefficient as an Arrhenius-like expression that also includes a static dielectric constant (ε(s)) dependence in the exponential prefactor. The temperature dependence of ε(s) and therefore the temperature dependence of the exponential prefactor is due to the quantity N/T, where T is the temperature. Using the procedure described in the CAF, values of the activation energy can be obtained by scaling out the N/T dependence instead of the ε(s) dependence. It has been previously shown that a plot of the prefactors versus ε(s) results in a master curve, and here it is shown that a master curve also results by plotting the prefactors against N/T. Therefore, the CAF can be applied by using temperature-dependent density data instead of temperature-dependent dielectric constant data. This application is demonstrated for diffusion data of n-nitriles, n-thiols, n-acetates, and 2-ketones, as well as conductivity data for dilute tetrabutylammonium triflate-nitrile electrolytes.

  6. Mass-spectrometry-based molecular characterization of extracellular vesicles: lipidomics and proteomics.

    Science.gov (United States)

    Kreimer, Simion; Belov, Arseniy M; Ghiran, Ionita; Murthy, Shashi K; Frank, David A; Ivanov, Alexander R

    2015-06-05

    This review discusses extracellular vesicles (EVs), which are submicron-scale, anuclear, phospholipid bilayer membrane enclosed vesicles that contain lipids, metabolites, proteins, and RNA (micro and messenger). They are shed from many, if not all, cell types and are present in biological fluids and conditioned cell culture media. The term EV, as coined by the International Society of Extracellular Vesicles (ISEV), encompasses exosomes (30-100 nm in diameter), microparticles (100-1000 nm), apoptotic blebs, and other EV subsets. EVs have been implicated in cell-cell communication, coagulation, inflammation, immune response modulation, and disease progression. Multiple studies report that EV secretion from disease-affected cells contributes to disease progression, e.g., tumor niche formation and cancer metastasis. EVs are attractive sources of biomarkers due to their biological relevance and relatively noninvasive accessibility from a range of physiological fluids. This review is focused on the molecular profiling of the protein and lipid constituents of EVs, with emphasis on mass-spectrometry-based "omic" analytical techniques. The challenges in the purification and molecular characterization of EVs, including contamination of isolates and limitations in sample quantities, are discussed along with possible solutions. Finally, the review discusses the limited but growing investigation of post-translational modifications of EV proteins and potential strategies for future in-depth molecular characterization of EVs.

  7. Mass spectrometry-based serum proteome pattern analysis in molecular diagnostics of early stage breast cancer

    Directory of Open Access Journals (Sweden)

    Stobiecki Maciej

    2009-07-01

    Full Text Available Abstract Background Mass spectrometric analysis of the blood proteome is an emerging method of clinical proteomics. The approach exploiting multi-protein/peptide sets (fingerprints detected by mass spectrometry that reflect overall features of a specimen's proteome, termed proteome pattern analysis, have been already shown in several studies to have applicability in cancer diagnostics. We aimed to identify serum proteome patterns specific for early stage breast cancer patients using MALDI-ToF mass spectrometry. Methods Blood samples were collected before the start of therapy in a group of 92 patients diagnosed at stages I and II of the disease, and in a group of age-matched healthy controls (104 women. Serum specimens were purified and the low-molecular-weight proteome fraction was examined using MALDI-ToF mass spectrometry after removal of albumin and other high-molecular-weight serum proteins. Protein ions registered in a mass range between 2,000 and 10,000 Da were analyzed using a new bioinformatic tool created in our group, which included modeling spectra as a sum of Gaussian bell-shaped curves. Results We have identified features of serum proteome patterns that were significantly different between blood samples of healthy individuals and early stage breast cancer patients. The classifier built of three spectral components that differentiated controls and cancer patients had 83% sensitivity and 85% specificity. Spectral components (i.e., protein ions that were the most frequent in such classifiers had approximate m/z values of 2303, 2866 and 3579 Da (a biomarker built from these three components showed 88% sensitivity and 78% specificity. Of note, we did not find a significant correlation between features of serum proteome patterns and established prognostic or predictive factors like tumor size, nodal involvement, histopathological grade, estrogen and progesterone receptor expression. In addition, we observed a significantly (p = 0

  8. Molecular responses during cadmium-induced stress in Daphnia magna: Integration of differential gene expression with higher-level effects

    Energy Technology Data Exchange (ETDEWEB)

    Soetaert, Anneleen [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)]. E-mail: anneleen.soetaert@ua.ac.be; Vandenbrouck, Tine [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Ven, Karlijn van der [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Maras, Marleen [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Remortel, Piet van [Department of Mathematics and Informatics, Intelligent Systems Laboratory, University of Antwerp, Middelheimlaan 1, B-2020 Antwerp (Belgium); Blust, Ronny [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium); Coen, Wim M. de [Department of Biology, Laboratory for Ecophysiology, Biochemistry and Toxicology, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp (Belgium)

    2007-07-20

    DNA microarrays offer great potential in revealing insight into mechanistic toxicity of contaminants. The aim of the present study was (i) to gain insight in concentration- and time-dependent cadmium-induced molecular responses by using a customized Daphnia magna microarray, and (ii) to compare the gene expression profiles with effects at higher levels of biological organization (e.g. total energy budget and growth). Daphnids were exposed to three cadmium concentrations (nominal value of 10, 50, 100 {mu}g/l) for two time intervals (48 and 96 h). In general, dynamic expression patterns were obtained with a clear increase of gene expression changes at higher concentrations and longer exposure duration. Microarray analysis revealed cadmium affected molecular pathways associated with processes such as digestion, oxygen transport, cuticula metabolism and embryo development. These effects were compared with higher-level effects (energy budgets and growth). For instance, next to reduced energy budgets due to a decline in lipid, carbohydrate and protein content, we found an up-regulated expression of genes related to digestive processes (e.g. {alpha}-esterase, cellulase, {alpha}-amylase). Furthermore, cadmium affected the expression of genes coding for proteins involved in molecular pathways associated with immune response, stress response, cell adhesion, visual perception and signal transduction in the present study.

  9. Hydrogen/Deuterium Exchange Mass Spectrometry for Probing Higher Order Structure of Protein Therapeutics: Methodology and Applications

    Science.gov (United States)

    Wei, Hui; Mo, Jingjie; Tao, Li; Russell, Reb J.; Tymiak, Adrienne A.; Chen, Guodong; Iacob, Roxana E.; Engen, John R.

    2014-01-01

    The higher order structure of protein therapeutics can be interrogated with hydrogen/deuterium exchange mass spectrometry (HDX-MS). HDX-MS is now a widely used tool in the structural characterization of protein therapeutics. In this article, HDX-MS based workflows designed for both protein therapeutic discovery and development processes are presented, focusing on the specific applications of epitope mapping for protein/drug interactions and biopharmaceutical comparability studies. Future trends in the application of HDX-MS to protein therapeutics characterization are also described. PMID:23928097

  10. Higher body mass index in older adults is associated with lower gray matter volume: implications for memory performance.

    Science.gov (United States)

    Masouleh, Shahrzad Kharabian; Arélin, Katrin; Horstmann, Annette; Lampe, Leonie; Kipping, Judy A; Luck, Tobias; Riedel-Heller, Steffi G; Schroeter, Matthias L; Stumvoll, Michael; Villringer, Arno; Witte, Anja Veronica

    2016-04-01

    Midlife obesity has been associated with increased dementia risk, yet reports on brain structure and function are mixed. We therefore assessed the effects of body mass index (BMI) on gray matter volume (GMV) and cognition in a well-characterized sample of community-dwelled older adults. GMV was measured using 3T-neuroimaging in 617 participants (258 women, 60-80 years, BMI 17-41 kg/m(2)). In addition, cognitive performance and various confounders including hypertension, diabetes, and apolipoprotein E genotype were assessed. A higher BMI correlated significantly with lower GMV in multiple brain regions, including (pre)frontal, temporal, insular and occipital cortex, thalamus, putamen, amygdala, and cerebellum, even after adjusting for confounders. In addition, lower GMV in prefrontal and thalamic areas partially mediated negative effects of (1) higher BMI and (2) higher age on memory performance. We here showed that a higher BMI in older adults is associated with widespread gray matter alterations, irrespective of obesity-related comorbidities and other confounders. Our results further indicate that a higher BMI induces structural alterations that translate into subtle impairments in memory performance in aging. Copyright © 2016 Elsevier Inc. All rights reserved.

  11. Dynamical Collapse of Nonrotating Magnetic Molecular Cloud Cores: Evolution through Point-Mass Formation

    Science.gov (United States)

    Ciolek, Glenn E.; Königl, Arieh

    1998-09-01

    We present a numerical simulation of the dynamical collapse of a nonrotating, magnetic molecular cloud core and follow the core's evolution through the formation of a central point mass and its subsequent growth into a 1 M⊙ protostar. The epoch of point-mass formation (PMF) is investigated by a self-consistent extension of previously presented models of core formation and contraction in axisymmetric, self-gravitating, isothermal, magnetically supported interstellar molecular clouds. Prior to PMF, the core is dynamically contracting and is not well approximated by a quasi-static equilibrium model. Ambipolar diffusion, which plays a key role in the early evolution of the core, is unimportant during the dynamical pre-PMF collapse phase. However, the appearance of a central mass, through its effect on the gravitational field in the inner core regions, leads to a ``revitalization'' of ambipolar diffusion in the weakly ionized gas surrounding the central protostar. This process is so efficient that it leads to a decoupling of the field from the matter and results in an outward-propagating hydromagnetic C-type shock. The existence of an ambipolar diffusion-mediated shock of this type was predicted by Li & McKee, and we find that the basic shock structure given by their analytic model is well reproduced by our more accurate numerical results. Our calculation also demonstrates that ambipolar diffusion, rather than Ohmic diffusivity operating in the innermost core region, is the main field-decoupling mechanism responsible for driving the shock after PMF. The passage of the shock leads to a substantial redistribution, by ambipolar diffusion but possibly also by magnetic interchange, of the mass contained within the magnetic flux tubes in the inner core. In particular, ambipolar diffusion reduces the flux initially threading a collapsing ~1 M⊙ core by a factor >~103 by the time this mass accumulates within the inner radius (~=7.3 AU) of our computational grid. This

  12. Gas-phase fluorescence excitation and emission spectroscopy of mass-selected trapped molecular ions.

    Science.gov (United States)

    Bian, Qunzhou; Forbes, Matthew W; Talbot, Francis O; Jockusch, Rebecca A

    2010-03-20

    A flexible interface to perform optical spectroscopic measurements on gaseous ions stored in a modified commercial quadrupole ion trap (QIT) mass spectrometer is described. The modifications made to the mass spectrometer did not adversely affect its operating characteristics. Gas-phase ions are produced using electrospray ionization, mass isolated and stored in the trapping mass spectrometer. The ions are subsequently irradiated with visible light from a tunable laser and dispersed fluorescence spectra are recorded simultaneously. Mass spectra are recorded after the irradiation period. This set-up allows us to track a range of possible outcomes upon photoexcitation of selected ions including fluorescence, photofragmentation and photodetachment of electrons. The experimental set-up is characterized using rhodamine 590, which is a methyl ester variant of rhodamine 6G. Fluorescence excitation and emission spectra of gaseous rhodamine 590 are measured and compared with solution-phase spectra. Excitation and emission maxima for the gaseous ions are found to lie at higher energy than for the solvated rhodamine 590. In addition, the gas-phase Stokes shift is significantly smaller than the solution-phase Stokes shift. The effects of several experimental parameters on the observed fluorescence signal are investigated, including laser power, relative number of ions, q(z) trapping parameter and buffer gas pressure. In addition to its use for the photophysical characterization of the intrinsic properties of ionic chromophores, this set-up may be used to investigate the properties of mass-selected, dye-labeled biomolecules, both alone and in well-defined complexes and clusters.

  13. Accessible surfaces of beta proteins increase with increasing protein molecular mass more rapidly than those of other proteins.

    Directory of Open Access Journals (Sweden)

    Anna V Glyakina

    Full Text Available Here we present a systematic analysis of accessible surface areas and hydrogen bonds of 2554 globular proteins from four structural classes (all-α, all-β, α/β and α+β proteins that is aimed to learn in which structural class the accessible surface area increases with increasing protein molecular mass more rapidly than in other classes, and what structural peculiarities are responsible for this effect. The beta structural class of proteins was found to be the leader, with the following possible explanations of this fact. First, in beta structural proteins, the fraction of residues not included in the regular secondary structure is the largest, and second, the accessible surface area of packaged elements of the beta-structure increases more rapidly with increasing molecular mass in comparison with the alpha-structure. Moreover, in the beta structure, the probability of formation of backbone hydrogen bonds is higher than that in the alpha helix for all residues of α+β proteins (the average probability is 0.73±0.01 for the beta-structure and 0.60±0.01 for the alpha-structure without proline and α/β proteins, except for asparagine, aspartic acid, glycine, threonine, and serine (0.70±0.01 for the beta-structure and 0.60±0.01 for the alpha-structure without the proline residue. There is a linear relationship between the number of hydrogen bonds and the number of amino acid residues in the protein (Number of hydrogen bonds=0.678·number of residues-3.350.

  14. Investigation of naproxen drug using mass spectrometry, thermal analyses and semi-empirical molecular orbital calculation

    Directory of Open Access Journals (Sweden)

    M.A. Zayed

    2017-03-01

    Full Text Available Naproxen (C14H14O3 is a non-steroidal anti-inflammatory drug (NSAID. It is important to investigate its structure to know the active groups and weak bonds responsible for medical activity. In the present study, naproxen was investigated by mass spectrometry (MS, thermal analysis (TA measurements (TG/DTG and DTA and confirmed by semi empirical molecular orbital (MO calculation, using PM3 procedure. These calculations included, bond length, bond order, bond strain, partial charge distribution, ionization energy and heat of formation (ΔHf. The mass spectra and thermal analysis fragmentation pathways were proposed and compared to select the most suitable scheme representing the correct fragmentation pathway of the drug in both techniques. The PM3 procedure reveals that the primary cleavage site of the charged molecule is the rupture of the COOH group (lowest bond order and high strain which followed by CH3 loss of the methoxy group. Thermal analysis of the neutral drug reveals a high response to the temperature variation with very fast rate. It decomposed in several sequential steps in the temperature range 80–400 °C. These mass losses appear as two endothermic and one exothermic peaks which required energy values of 255.42, 10.67 and 371.49 J g−1 respectively. The initial thermal ruptures are similar to that obtained by mass spectral fragmentation (COOH rupture. It was followed by the loss of the methyl group and finally by ethylene loss. Therefore, comparison between MS and TA helps in selection of the proper pathway representing its fragmentation. This comparison is successfully confirmed by MO-calculation.

  15. Under-reporting of energy intake in elderly Australian women is associated with a higher body mass index.

    Science.gov (United States)

    Meng, X; Kerr, D A; Zhu, K; Devine, A; Solah, V A; Wright, J; Binns, C W; Prince, R L

    2013-02-01

    Identify the extent of under-reporting of energy intake and the characteristics associated with implausible intakes in elderly women. Dietary intake was assessed using a 3-day weighed food record. Protein intake was validated by 24-hour urinary nitrogen. To examine under-reporting, participants were grouped according to their energy intake and compared to the Goldberg cut-off equation. Logistic regression was performed to assess the influence of body mass index (BMI) and social-demographic factors on under-reporting. Community dwelling elderly women from Perth, Western Australia. 217 elderly women aged 70-80 years. Under-reporters had a higher physical activity level (pmass index (BMI) (p=0.001), waist (p=0.011), hip circumference (pmass (penergy intake (BMI=25-29.9: odds ratio=2.98[95% CI=1.46-6.09]; BMI≥30: 5.84[2.41-14.14]). Under-reporting energy intake in elderly women was associated with a higher BMI, body fat and higher self-reported physical activity levels. A higher BMI (≥25) appears to be most significant factor in determining if elderly women will underreport their food intake and may be related to body image. These results have implications for undertaking surveys of food intake in elderly women.

  16. Advanced solvent based methods for molecular characterization of soil organic matter by high-resolution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Tfaily, Malak M.; Chu, Rosalie K.; Tolic, Nikola; Roscioli, Kristyn M.; Anderton, Christopher R.; Pasa-Tolic, Ljiljana; Robinson, Errol W.; Hess, Nancy J.

    2015-05-19

    Soil organic matter (SOM) a complex, heterogeneous mixture of above and belowground plant litter and animal and microbial residues at various degrees of decomposition, is a key reservoir for carbon (C) and nutrient biogeochemical cycling in soil based ecosystems. A limited understanding of the molecular composition of SOM limits the ability to routinely decipher chemical processes within soil and predict accurately how terrestrial carbon fluxes will response to changing climatic conditions and land use. To elucidate the molecular-level structure of SOM, we selectively extracted a broad range of intact SOM compounds by a combination of different organic solvents from soils with a wide range of C content. Our use of Electrospray ionization (ESI) coupled with Fourier transform ion cyclotron resonance mass spectrometry (FTICR MS) and a suite of solvents with varying polarity significantly expands the inventory of the types of organic molecules present in soils. Specifically, we found that hexane is selective for lipid-like compounds with very low O:C ratios; water was selective for carbohydrates with high O:C ratios; acetonitrile preferentially extracts lignin, condensed structures, and tannin poly phenolic compounds with O:C > 0.5; methanol has higher selectivity towards compounds characterized with low O:C < 0.5; and hexane, MeOH, ACN and water solvents increase the number and types of organic molecules extracted from soil for a broader range of chemically diverse soil types. Our study of SOM molecules by ESI-FTICR MS revealed new insight into the molecular-level complexity of organics contained in soils.

  17. Anharmonicity of internal atomic oscillation and effective antineutrino mass evaluation from gaseous molecular tritium \\beta -decay

    CERN Document Server

    Lokhov, Alexey V

    2016-01-01

    Data analysis of the next generation effective antineutrino mass measurement experiment KATRIN requires reliable knowledge of systematic corrections. In particular, the width of the daughter molecular ion excitation spectrum rovibrational band should be known with a better then 1% precision. Very precise ab initio quantum calculations exist, and we compare them with the well known tritium molecule parameters within the framework of a phenomenological model. The rovibrational band width with accuracy of a few percent is interpreted as a result of the zero-point atomic oscillation in the harmonic potential. The Morse interatomic potential is used to investigate the impact of anharmonic atomic oscillations. The calculated corrections cannot account for the difference between the ab initio quantum calculations and the phenomenological model.

  18. Method development for mass spectrometry based molecular characterization of fossil fuels and biological samples

    Science.gov (United States)

    Mahat, Rajendra K.

    In an analytical (chemical) method development process, the sample preparation step usually determines the throughput and overall success of the analysis. Both targeted and non-targeted methods were developed for the mass spectrometry (MS) based analyses of fossil fuels (coal) and lipidomic analyses of a unique micro-organism, Gemmata obscuriglobus. In the non-targeted coal analysis using GC-MS, a microwave-assisted pressurized sample extraction method was compared with the traditional extraction method, such as Soxhlet. On the other hand, methods were developed to establish a comprehensive lipidomic profile and to confirm the presence of endotoxins (a.k.a. lipopolysaccharides, LPS) in Gemmata.. The performance of pressurized heating techniques employing hot-air oven and microwave irradiation were compared with that of Soxhlet method in terms of percentage extraction efficiency and extracted analyte profiles (via GC-MS). Sub-bituminous (Powder River Range, Wyoming, USA) and bituminous (Fruitland formation, Colorado, USA) coal samples were tested. Overall 30-40% higher extraction efficiencies (by weight) were obtained with a 4 hour hot-air oven and a 20 min microwave-heating extraction in a pressurized container when compared to a 72 hour Soxhlet extraction. The pressurized methods are 25 times more economic in terms of solvent/sample amount used and are 216 times faster in term of time invested for the extraction process. Additionally, same sets of compounds were identified by GC-MS for all the extraction methods used: n-alkanes and diterpanes in the sub-bituminous sample, and n-alkanes and alkyl aromatic compounds in the bituminous coal sample. G. obscuriglobus, a nucleated bacterium, is a micro-organism of high significances from evolutionary, cell and environmental biology standpoints. Although lipidomics is an essential tool in microbiological systematics and chemotaxonomy, complete lipid profile of this bacterium is still lacking. In addition, the presence of

  19. Mass spectrometric study of molecular and ionic sublimation of lanthanum triiodide

    Energy Technology Data Exchange (ETDEWEB)

    Dunaev, A.M., E-mail: amdunaev@ro.ru [Research Institute of Thermodynamics and Kinetics, Ivanovo State University of Chemistry and Technology, Ivanovo 153000 (Russian Federation); Kudin, L.S.; Motalov, V.B.; Ivanov, D.A.; Butman, M.F. [Research Institute of Thermodynamics and Kinetics, Ivanovo State University of Chemistry and Technology, Ivanovo 153000 (Russian Federation); Krämer, K.W. [Department of Chemistry and Biochemistry, University of Bern, CH-3012 Bern (Switzerland)

    2015-12-20

    Graphical abstract: - Highlights: • Lanthanum triiodide was investigated by the Knudsen effusion mass spectrometry. • (LaI{sub 3}){sub n} molecules (n = 1–3) and [I(LaI{sub 3}){sub n}]{sup −} ions (n = 0–4) were registered in the saturated vapor. • The sublimation enthalpy was found by the second and third law of thermodynamics. • The enthalpies of ion-molecular reactions with cluster ions were calculated. • The electron work function of the crystalline LaI{sub 3} was obtained. - Abstract: The molecular and ionic composition of saturated vapor over lanthanum triiodide was studied by Knudsen effusion mass spectrometry. The (LaI{sub 3}){sub n} molecules (n = 1–3) and the [I(LaI{sub 3}){sub n}]{sup −} ions (n = 0–4) were observed. The partial pressures of the molecules were determined and the enthalpies of sublimation, Δ{sub s}H° (298.15 K) in kJ mol{sup −1}, in the form of monomers (304 ± 7), dimers (428 ± 25), and trimers (455 ± 50) were obtained by the second and third laws of thermodynamics. The enthalpy of formation, Δ{sub f}H° (298.15 K) in kJ mol{sup −1}, of the LaI{sub 3} (−376 ± 10), La{sub 2}I{sub 6} (−932 ± 25), La{sub 3}I{sub 9} (−1585 ± 50) molecules and the LaI{sub 4}{sup −} (−841 ± 24), La{sub 2}I{sub 7}{sup −} (−1486 ± 32) ions were determined. The electron work function, φ{sub e} = 3.5 ± 0.3 eV, for the LaI{sub 3} crystal was calculated from the thermochemical cycle.

  20. Transcriptional Regulation of Aluminum-Tolerance Genes in Higher Plants: Clarifying the Underlying Molecular Mechanisms

    Directory of Open Access Journals (Sweden)

    Abhijit A. Daspute

    2017-08-01

    Full Text Available Aluminum (Al rhizotoxicity is one of the major environmental stresses that decrease global food production. Clarifying the molecular mechanisms underlying Al tolerance may contribute to the breeding of Al-tolerant crops. Recent studies identified various Al-tolerance genes. The expression of these genes is inducible by Al. Studies of the major Arabidopsis thaliana Al-tolerance gene, ARABIDOPSIS THALIANA ALUMINUM-ACTIVATED MALATE TRANSPORTER 1 (AtALMT1, which encodes an Al-activated malate transporter, revealed that the Al-inducible expression is regulated by a SENSITIVE TO PROTON RHIXOTOXICITY 1 (STOP1 zinc-finger transcription factor. This system, which involves STOP1 and organic acid transporters, is conserved in diverse plant species. The expression of AtALMT1 is also upregulated by several phytohormones and hydrogen peroxide, suggesting there is crosstalk among the signals involved in the transcriptional regulation of AtALMT1. Additionally, phytohormones and reactive oxygen species (ROS activate various transcriptional responses, including the expression of genes related to increased Al tolerance or the suppression of root growth under Al stress conditions. For example, Al suppressed root growth due to abnormal accumulation of auxin and cytokinin. It activates transcription of TRYPTOPHAN AMINOTRANSFERASE OF ARABIDOPSIS 1 and other phytohormone responsive genes in distal transition zone, which causes suppression of root elongation. On the other hand, overexpression of Al inducible genes for ROS-detoxifying enzymes such as GLUTATHIONE–S-TRANSFERASE, PEROXIDASE, SUPEROXIDE DISMUTASE enhances Al resistance in several plant species. We herein summarize the complex transcriptional regulation of an Al-inducible genes affected by STOP1, phytohormones, and ROS.

  1. Vitellogenesis in Bufo arenarum: Identification, characterization and immunolocalization of high molecular mass lipovitellin during oogenesis

    Science.gov (United States)

    O’Brien, Emma D.; Salicioni, Ana M.; Cabada, Marcelo O.; Arranz, Silvia E.

    2009-01-01

    Vitellogenin (Vtg), a large lipoglycophosphoprotein, is the most important precursor of the yolk proteins, and the major source of nutrients for the developing embryo in oviparous species. After its uptake by the oocytes, Vtg is converted into lipovitellins (high and light) and phosvitin, which are deposited into crystalline yolk platelets. We describe here the presence of two high molecular mass lipovitellins isoforms in Bufo arenarum mature oocytes with masses of 113 and 100 kDa, respectively. The amino acid sequence analysis of p113 and p100 peptides showed a high sequence homology between both polypeptides and the complete reported sequences of Xenopus laevis vitellogenin. Using specific antibodies, we determined that the Vtg uptake begins early during oogenesis, at the previtellogenic stage, and continues until oocytes have reached their mature status. In addition, we found that large endocytic vesicles mediate Vtg uptake in stage I oocytes, and that the size of the endocytic vesicles declines with oogenesis progression. In terms of the Vtg protein trafficking, we detected the Vtg precursor (190 kDa) in the liver of estradiol-injected females. Finally, we propose a subclassification of B. arenarum stage-II oocytes into three physiologically and morphologically distinct periods (early, mid and late). PMID:19932187

  2. The FADE mass-stat: A technique for inserting or deleting particles in molecular dynamics simulations

    Energy Technology Data Exchange (ETDEWEB)

    Borg, Matthew K., E-mail: matthew.borg@strath.ac.uk [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Lockerby, Duncan A., E-mail: duncan.lockerby@warwick.ac.uk [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Reese, Jason M., E-mail: jason.reese@ed.ac.uk [School of Engineering, University of Edinburgh, Edinburgh EH9 3JL (United Kingdom)

    2014-02-21

    The emergence of new applications of molecular dynamics (MD) simulation calls for the development of mass-statting procedures that insert or delete particles on-the-fly. In this paper we present a new mass-stat which we term FADE, because it gradually “fades-in” (inserts) or “fades-out” (deletes) molecules over a short relaxation period within a MD simulation. FADE applies a time-weighted relaxation to the intermolecular pair forces between the inserting/deleting molecule and any neighbouring molecules. The weighting function we propose in this paper is a piece-wise polynomial that can be described entirely by two parameters: the relaxation time scale and the order of the polynomial. FADE inherently conserves overall system momentum independent of the form of the weighting function. We demonstrate various simulations of insertions of atomic argon, polyatomic TIP4P water, polymer strands, and C{sub 60} Buckminsterfullerene molecules. We propose FADE parameters and a maximum density variation per insertion-instance that restricts spurious potential energy changes entering the system within desired tolerances. We also demonstrate in this paper that FADE compares very well to an existing insertion algorithm called USHER, in terms of accuracy, insertion rate (in dense fluids), and computational efficiency. The USHER algorithm is applicable to monatomic and water molecules only, but we demonstrate that FADE can be generally applied to various forms and sizes of molecules, such as polymeric molecules of long aspect ratio, and spherical carbon fullerenes with hollow interiors.

  3. Energy eigenfunctions for position-dependent mass particles in a new class of molecular Hamiltonians

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, H. R. [Grupo de Física Teórica, State University of Ceara (UECE), Av. Paranjana 1700, 60740-903 Fortaleza - CE (Brazil); State University Vale do Acaraú, Av. da Universidade 850, 62040-370 Sobral - CE (Brazil); Cunha, M. S. [Grupo de Física Teórica, State University of Ceara (UECE), Av. Paranjana 1700, 60740-903 Fortaleza - CE (Brazil)

    2014-09-15

    Based on recent results on quasi-exactly solvable Schrodinger equations, we review a new phenomenological potential class lately reported. In the present paper, we consider the quantum differential equations resulting from position-dependent mass (PDM) particles. We first focus on the PDM version of the hyperbolic potential V(x) = asech{sup 2}x + bsech{sup 4}x, which we address analytically with no restrictioon the parameters and the energies. This is the celebrated Manning potential, a double-well widely used in molecular physics, until now not investigated for PDM. We also evaluate the PDM version of the sixth power hyperbolic potential V(x) = asech{sup 6}x + bsech{sup 4}x for which we could find exact expressions under some special settings. Finally, we address a triple-well case V(x) = asech{sup 6}x + bsech{sup 4}x + csech{sup 2}x of particular interest for its connection to the new trends in atomtronics. The PDM Schrodinger equations studied in the present paper yield analytical eigenfunctions in terms of local Heun functions in its confluents forms. In all the cases PDM particles are more likely tunneling than ordinary ones. In addition, it is observed a merging of eigenstates when the mass becomes nonuniform.

  4. Probing the Composition, Assembly and Activity of Protein Molecular Machines using Native Mass Spectrometry

    NARCIS (Netherlands)

    Waterbeemd, M.J. van de

    2017-01-01

    Native mass spectrometry and mass spectrometry in general, are powerful analytical tools for studying proteins and protein complexes. Native mass spectrometry may provide accurate mass measurements of large macromolecular assemblies enabling the investigation of their composition and stoichiometry.

  5. Blunted cortisol response to stress is associated with higher body mass index in low-income preschool-aged children.

    Science.gov (United States)

    Miller, Alison L; Clifford, Caitlin; Sturza, Julie; Rosenblum, Katherine; Vazquez, Delia M; Kaciroti, Niko; Lumeng, Julie C

    2013-11-01

    No known studies have tested the hypothesis that a blunted pattern of cortisol reactivity to stress, which is often found following exposure to chronic life stressors, is associated with a higher body mass index (BMI) in very young children. Low-income children (n=218, mean age 56.6 (range: 38.1-78.5; SD 7.0) months, 49.1% male, 56.4% white, 16.1% black, 11.5% Hispanic/Latino) participated in a series of behavioral tasks designed to elicit stress. Cortisol was sampled in saliva 5 times during the protocol, and area under the curve (AUC), representing total cortisol output during stress elicitation, was calculated. Children were weighed and height measured and body mass index (BMI) z-score was calculated. Linear regression was used to evaluate the association between cortisol AUC and BMI z-score, controlling for child age, sex, and race/ethnicity (non-Hispanic white vs. not); primary caregiver weight status (overweight, defined as BMI ≥ 25 vs. not); and family income-to-needs ratio. Mean child BMI z-score was 0.88 (SD=1.03). Mean cortisol AUC was 6.11 μg/dL/min (SD=10.44). In the fully adjusted model, for each 1-standard deviation unit decrease in cortisol AUC, the child's BMI z-score increased by 0.17 (SE 0.07) standard deviation units (pchildren. Further work is needed to understand how associations between stress, cortisol, and elevated body mass index may develop very early in the lifespan. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Biodegradation testing of chemicals with high Henry’s constants – separating mass and effective concentration reveals higher rate constants

    DEFF Research Database (Denmark)

    Birch, Heidi; Andersen, Henrik Rasmus; Comber, Mike

    During simulation-type biodegradation tests, volatile chemicals will continuously partition between water phase and headspace. This study addressed how (1) this partitioning affects biodegradation test results and (2) it can be accounted for by combining mass balance and dynamic biodegradation...... Microextraction (HS-SPME) was applied directly on the test systems to measure substrate depletion by biodegradation relative to abiotic controls. HS-SPME was also applied to determine air to water partitioning ratios. Water phase biodegradation rate constants, kwater, were up to 72 times higher than test system...... biodegradation rate constants, ksystem. True water phase degradation rate constants facilitate extrapolation to other air-water systems and are more suitable input parameters for aquatic exposure and fate models. As such, they should be considered more appropriate for risk assessments than test system rate...

  7. Reduction in energy expenditure during weight loss is higher than predicted based on fat free mass and fat mass in older adults.

    Science.gov (United States)

    Ten Haaf, Twan; Verreijen, Amely M; Memelink, Robert G; Tieland, Michael; Weijs, Peter J M

    2016-12-23

    The aim of this study was to describe a decrease in resting energy expenditure during weight loss that is larger than expected based on changes in body composition, called adaptive thermogenesis (AT), in overweight and obese older adults. Multiple studies were combined to assess AT in younger and older subjects. Body composition and resting energy expenditure (REE) were measured before and after weight loss. Baseline values were used to predict fat free mass and fat mass adjusted REE after weight loss. AT was defined as the difference between predicted and measured REE after weight loss. The median age of 55 y was used as a cutoff to compare older with younger subjects. The relation between AT and age was investigated using linear regression analysis. In this study 254 (M = 88, F = 166) overweight and obese subjects were included (BMI: 31.7 ± 4.4 kg/m2, age: 51 ± 14 y). The AT was only significant for older subjects (64 ± 185 kcal/d, 95% CI [32, 96]), but not for younger subjects (19 ± 152 kcal/d, 95% CI [-9, 46]). The size of the AT was significantly higher for older compared to younger adults (β = 47, p = 0.048), independent of gender and type and duration of the weight loss program. We conclude that adaptive thermogenesis is present only in older subjects, which might have implications for weight management in older adults. A reduced energy intake is advised to counteract the adaptive thermogenesis. Copyright © 2016. Published by Elsevier Ltd.

  8. Hybrid Imaging Labels: Providing the Link Between Mass Spectrometry-Based Molecular Pathology and Theranostics.

    Science.gov (United States)

    Buckle, Tessa; van der Wal, Steffen; van Malderen, Stijn J M; Müller, Larissa; Kuil, Joeri; van Unen, Vincent; Peters, Ruud J B; van Bemmel, Margaretha E M; McDonnell, Liam A; Velders, Aldrik H; Koning, Frits; Vanhaeke, Frank; van Leeuwen, Fijs W B

    2017-01-01

    Development of theranostic concepts that include inductively coupled plasma mass spectrometry (ICP-MS) and laser ablation ICP-MS (LA-ICP-MS) imaging can be hindered by the lack of a direct comparison to more standardly used methods for in vitro and in vivo evaluation; e.g. fluorescence or nuclear medicine. In this study a bimodal (or rather, hybrid) tracer that contains both a fluorescent dye and a chelate was used to evaluate the existence of a direct link between mass spectrometry (MS) and in vitro and in vivo molecular imaging findings using fluorescence and radioisotopes. At the same time, the hybrid label was used to determine whether the use of a single isotope label would allow for MS-based diagnostics. A hybrid label that contained both a DTPA chelate (that was coordinated with either 165Ho or 111In) and a Cy5 fluorescent dye was coupled to the chemokine receptor 4 (CXCR4) targeting peptide Ac-TZ14011 (hybrid-Cy5-Ac-TZ4011). This receptor targeting tracer was used to 1) validate the efficacy of (165Ho-based) mass-cytometry in determining the receptor affinity via comparison with fluorescence-based flow cytometry (Cy5), 2) evaluate the microscopic binding pattern of the tracer in tumor cells using both fluorescence confocal imaging (Cy5) and LA-ICP-MS-imaging (165Ho), 3) compare in vivo biodistribution patterns obtained with ICP-MS (165Ho) and radiodetection (111In) after intravenous administration of hybrid-Cy5-Ac-TZ4011 in tumor-bearing mice. Finally, LA-ICP-MS-imaging (165Ho) was linked to fluorescence-based analysis of excised tissue samples (Cy5). Analysis with both mass-cytometry and flow cytometry revealed a similar receptor affinity, respectively 352 ± 141 nM and 245 ± 65 nM (p = 0.08), but with a much lower detection sensitivity for the first modality. In vitro LA-ICP-MS imaging (165Ho) enabled clear discrimination between CXCR4 positive and negative cells, but fluorescence microscopy was required to determine the intracellular distribution. In

  9. Distributed Physical and Molecular Separations for Selective Harvest of Higher Value Wheat Straw Components Project

    Energy Technology Data Exchange (ETDEWEB)

    Hess, J.R

    2005-01-31

    Wheat straw (Triticum aestivum L.) is an abundant source of plant fiber. It is regenerated, in large quantities, every year. At present, this potentially valuable resource is greatly under-exploited. Most of the excess straw biomass (i.e., tonnage above that required for agronomic cropping system sustainability) is managed through expensive chopping/tillage operations and/or burnt in the field following harvest, resulting in air pollution and associated health problems. Potential applications for wheat straw investigated within this project include energy and composites manufacture. Other methods of straw utilization that will potentially benefit from the findings of this research project include housing and building, pulp and paper, thermal insulation, fuels, and chemicals. This project focused on components of the feedstock assembly system for supplying a higher value small grains straw residue for (1) gasification/combustion and (2) straw-thermoplastic composites. This project was an integrated effort to solve the technological, infrastructural, and economic challenges associated with using straw residue for these bioenergy and bioproducts applications. The objective of the research is to contribute to the development of a low-capital distributed harvesting and engineered storage system for upgrading wheat straw to more desirable feedstocks for combustion and for straw-plastic composites. We investigated two processes for upgrading wheat straw to a more desirable feedstock: (1) An efficient combine-based threshing system for separating the internodal stems from the leaves, sheaths, nodes, and chaff. (2) An inexpensive biological process using white-rot fungi to improve the composition of the mechanically processed straw stems.

  10. Distributed Physical and Molecular Separations for Selective Harvest of Higher Value Wheat Straw Components Project

    Energy Technology Data Exchange (ETDEWEB)

    N/A

    2004-09-30

    Wheat straw (Triticum aestivum L.) is an abundant source of plant fiber. It is regenerated, in large quantities, every year. At present, this potentially valuable resource is greatly under-exploited. Most of the excess straw biomass (i.e., tonnage above that required for agronomic cropping system sustainability) is managed through expensive chopping/tillage operations and/or burnt in the field following harvest, resulting in air pollution and associated health problems. Potential applications for wheat straw investigated within this project include energy and composites manufacture. Other methods of straw utilization that will potentially benefit from the findings of this research project include housing and building, pulp and paper, thermal insulation, fuels, and chemicals. This project focused on components of the feedstock assembly system for supplying a higher value small grains straw residue for (1) gasification/combustion and (2) straw-thermoplastic composites. This project was an integrated effort to solve the technological, infrastructural, and economic challenges associated with using straw residue for these bioenergy and bioproducts applications. The objective of the research is to contribute to the development of a low-capital distributed harvesting and engineered storage system for upgrading wheat straw to more desirable feedstocks for combustion and for straw-plastic composites. They investigated two processes for upgrading wheat straw to a more desirable feedstock: (1) an efficient combine-based threshing system for separating the intermodal stems from the leaves, sheaths, nodes, and chaff. (2) An inexpensive biological process using white-rot fungi to improve the composition of the mechanically processed straw stems.

  11. The influence of fermentation condition on production and molecular mass of EPS produced by Streptococcus thermophilus 05-34 in milk-based medium.

    Science.gov (United States)

    Li, Dan; Li, Jiaxi; Zhao, Feng; Wang, Guohong; Qin, Qianqian; Hao, Yanling

    2016-04-15

    The yield of exopolysaccharide (EPS) produced by Streptococcus thermophilus 05-34 reached up to 250 mg/L under the optimal fermentation condition, which was 4.2-fold higher than that produced under the non-optimal fermentation condition. Structure analysis showed that EPS produced under the optimal fermentation condition was composed of galactose and glucose in a molar ratio of 1.0:0.8. This EPS was with a molecular mass of 4.7×10(5) Da, which was increased by 9 times compared with that in the non-optimal fermentation condition, while monosaccharide composition did not change. Furthermore, real-time quantitative PCR showed that the transcription level of epsC, which is responsible for chain-length determination, was up-regulated by 2.7-fold, suggesting that the increased molecular mass of EPS was resulted from improving polymerization degree of monosaccharide. These findings demonstrated that the optimized fermentation condition can improve EPS molecular mass, and may consequently modify the rheological properties of EPS. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. A tendem mass spectrometric approach for determining the structure of molecular species of ceramide in the marine sponge, Haliclona cribricutis

    Digital Repository Service at National Institute of Oceanography (India)

    Tilvi, S.; Majik, M.; Naik, C.G.

    result from plasticizer contamination, most probably from the cap of a bottle of solvent or plastic washing bottles etc. 18 A comparison of signal intensities indicates that the mixture contains a substantial amount of ceramides with molecular..., “Identification and fragmentation study of plasticizers with post-source decay matrix-assisted laser desorption/ ionization mass spectrometry”, Rapid Commun. Mass Spectrom. 17, 783 (2003). 19. K. Mills, A. Johnson and B. Winchester, “Synthesis of novel internal...

  13. Higher weight, lower education: a longitudinal association between adolescents' body mass index and their subsequent educational achievement level?

    Science.gov (United States)

    Larsen, Junilla K; Kleinjan, Marloes; Engels, Rutger C M E; Fisher, Jennifer O; Hermans, Roel C J

    2014-12-01

    The purpose of this study was to examine the association between adolescents' body mass index (BMI) z-scores and their subsequent level of schooling, extending previous longitudinal research by using objectively measured weight and height data. A longitudinal study with 3 study waves (1-year intervals) involving 1248 Dutch adolescents (49% girls; mean age = 13.7 years) at schools providing different educational levels was used to determine adolescents who moved and did not move to a lower educational level in the first year, or in the second year, and to examine whether this movement could be predicted by BMI z-scores (zBMI), after controlling for a large range of potential confounding factors. A total of 1164 Dutch adolescents continued in the same level of education, whereas 84 adolescents moved to a lower educational level (43 moved in the first and 41 in the second year). A higher zBMI significantly increased the risk of a general transition to a lower educational level, and of a transition in the first year, but not in the second year, after controlling for potential demographic, behavioral, and psychological confounds. Findings suggest that a higher zBMI during adolescence immediately lowers educational achievement level during general secondary education. © 2014, American School Health Association.

  14. Proximity to Supermarkets Associated with Higher Body Mass Index among Overweight and Obese Preschool-Age Children

    Science.gov (United States)

    Fiechtner, Lauren; Block, Jason; Duncan, Dustin T.; Gillman, Matthew W.; Gortmaker, Steven L.; Melly, Steven J.; Rifas-Shiman, Sheryl L.; Taveras, Elsie M.

    2013-01-01

    Objective The objective of this study is to examine associations of proximity to food establishments with body mass index (BMI) among preschool-age children. Methods We used baseline data from 438 children ages 2–6.9 years with a BMI ≥ 85th percentile participating in a RCT in Massachusetts from 2006 to 2009. We used a geographic information system to determine proximity to six types of food establishments: 1) convenience stores, 2) bakeries, coffee shops, candy stores, 3) full service restaurants, 4) large supermarkets, 5) small supermarkets, and 6) fast-food restaurants. The main outcome was child’s BMI. Results Children’s mean (SD) BMI was 19.2 (2.4) kg/m2; 35% lived ≤ 1 mile from a large supermarket, 42% lived >1 to 2 miles, and 22% lived >2 miles. Compared to children living >2 miles from a large supermarket, those who lived within 1 mile had a BMI 1.06 kg/m2 higher. Adjustment for socioeconomic characteristics and distance to fast-food restaurants attenuated this estimate to 0.77 kg/m2. Living in any other distance category from a large supermarket and proximity to other food establishments were not associated with child BMI. Conclusions Living closer to a large supermarket was associated with higher BMI among preschool-age children who were overweight or obese. PMID:23219681

  15. Nitric oxide assisted C60 secondary ion mass spectrometry for molecular depth profiling of polyelectrolyte multilayers.

    Science.gov (United States)

    Zappalà, G; Motta, V; Tuccitto, N; Vitale, S; Torrisi, A; Licciardello, A

    2015-12-15

    Secondary ion mass spectrometry (SIMS) with polyatomic primary ions provides a successful tool for molecular depth profiling of polymer systems, relevant in many technological applications. Widespread C60 sources, however, cause in some polymers extensive damage with loss of molecular information along depth. We study a method, based on the use of a radical scavenger, for inhibiting ion-beam-induced reactions causing sample damage. Layered polystyrene sulfonate and polyacrylic acid based polyelectrolyte films, behaving differently towards C60 beam-induced damage, were selected and prepared as model systems. They were depth profiled by means of time-of-flight (TOF)-SIMS in dual beam mode, using fullerene ions for sputtering. Nitric oxide was introduced into the analysis chamber as a radical scavenger. The effect of sample cooling combined with NO-dosing on the quality of depth profiles was explored. NO-dosing during C60-SIMS depth profiling of >1 micrometer-thick multilayered polyelectrolytes allows detection, along depth, of characteristic fragments from systems otherwise damaged by C60 bombardment, and increases sputtering yield by more than one order of magnitude. By contrast, NO has little influence on those layers that are well profiled with C60 alone. Such leveling effect, more pronounced at low temperature, leads to a dramatic improvement of profile quality, with a clear definition of interfaces. NO-dosing provides a tool for extending the applicability, in SIMS depth profiling, of the widely spread fullerene ion sources. In view of the acceptable erosion rates on inorganics, obtainable with C60, the method could be of relevance also in connection with the 3D-imaging of hybrid polymer/inorganic systems. Copyright © 2015 John Wiley & Sons, Ltd.

  16. A new instrument of VUV laser desorption/ionization mass spectrometry imaging with micrometer spatial resolution and low level of molecular fragmentation

    Science.gov (United States)

    Wang, Jia; Liu, Feng; Mo, Yuxiang; Wang, Zhaoying; Zhang, Sichun; Zhang, Xinrong

    2017-11-01

    Mass spectrometry imaging (MSI) has important applications in material research, biology, and medicine. The MSI method based on UV laser desorption/ionization (UVLDI) can obtain images of intact samples, but has a high level of molecular fragmentation. In this work, we report a new MSI instrument that uses a VUV laser (125.3 nm) as a desorption/ionization source to exploit its advantages of high single photon energy and small focus size. The new instrument was tested by the mass spectra of Nile red and FGB (Fibrinogen beta chain) samples and mass spectrometric images of a fly brain section. For the tested samples, the VUVDI method offers lower levels of molecular fragmentations and higher sensitivities than those of the UVLDI method and second ion mass spectrometry imaging method using a Bi3+ beam. The ablation crater produced by the focused VUV laser on a quartz plate has an area of 10 μm2. The VUV laser is prepared based on the four-wave mixing method using three collimated laser beams and a heated Hg cell.

  17. Substrate specificity of low-molecular mass bacterial DD-peptidases.

    Science.gov (United States)

    Nemmara, Venkatesh V; Dzhekieva, Liudmila; Sarkar, Kumar Subarno; Adediran, S A; Duez, Colette; Nicholas, Robert A; Pratt, R F

    2011-11-22

    The bacterial DD-peptidases or penicillin-binding proteins (PBPs) catalyze the formation and regulation of cross-links in peptidoglycan biosynthesis. They are classified into two groups, the high-molecular mass (HMM) and low-molecular mass (LMM) enzymes. The latter group, which is subdivided into classes A-C (LMMA, -B, and -C, respectively), is believed to catalyze DD-carboxypeptidase and endopeptidase reactions in vivo. To date, the specificity of their reactions with particular elements of peptidoglycan structure has not, in general, been defined. This paper describes the steady-state kinetics of hydrolysis of a series of specific peptidoglycan-mimetic peptides, representing various elements of stem peptide structure, catalyzed by a range of LMM PBPs (the LMMA enzymes, Escherichia coli PBP5, Neisseria gonorrhoeae PBP4, and Streptococcus pneumoniae PBP3, and the LMMC enzymes, the Actinomadura R39 dd-peptidase, Bacillus subtilis PBP4a, and N. gonorrhoeae PBP3). The R39 enzyme (LMMC), like the previously studied Streptomyces R61 DD-peptidase (LMMB), specifically and rapidly hydrolyzes stem peptide fragments with a free N-terminus. In accord with this result, the crystal structures of the R61 and R39 enzymes display a binding site specific to the stem peptide N-terminus. These are water-soluble enzymes, however, with no known specific function in vivo. On the other hand, soluble versions of the remaining enzymes of those noted above, all of which are likely to be membrane-bound and/or associated in vivo and have been assigned particular roles in cell wall biosynthesis and maintenance, show little or no specificity for peptides containing elements of peptidoglycan structure. Peptidoglycan-mimetic boronate transition-state analogues do inhibit these enzymes but display notable specificity only for the LMMC enzymes, where, unlike peptide substrates, they may be able to effectively induce a specific active site structure. The manner in which LMMA (and HMM) DD

  18. Genetic predisposition to higher body mass index or type 2 diabetes and leukocyte telomere length in the Nurses' Health Study.

    Science.gov (United States)

    Du, Mengmeng; Prescott, Jennifer; Cornelis, Marilyn C; Hankinson, Susan E; Giovannucci, Edward; Kraft, Peter; De Vivo, Immaculata

    2013-01-01

    Although cross-sectional studies have linked higher body mass index (BMI) and type 2 diabetes (T2D) to shortened telomeres, whether these metabolic conditions play a causal role in telomere biology is unknown. We therefore examined whether genetic predisposition to higher BMI or T2D was associated with shortened leukocyte telomere length (LTL). We conducted an analysis of 3,968 women of European ancestry aged 43-70 years from the Nurses' Health Study, who were selected as cases or controls in genome-wide association studies and studies of telomeres and disease. Pre-diagnostic relative telomere length in peripheral blood leukocytes, collected in 1989-1990, was measured by quantitative PCR. We combined information from multiple risk variants by calculating genetic risk scores based on 32 polymorphisms near 32 loci for BMI, and 36 polymorphisms near 35 loci for T2D. After adjustment for age and case-control status, there was no association between the BMI genetic risk score and LTL (β per standard deviation increase: -0.01; SE: 0.02; P = 0.52). Similarly, the T2D genetic score was not associated with LTL (β per standard deviation increase: -0.006; SE: 0.02; P = 0.69). In this population of middle-aged and older women of European ancestry, those genetically predisposed to higher BMI or T2D did not possess shortened telomeres. Although we cannot exclude weak or modest effects, our findings do not support a causal relation of strong magnitude between these metabolic conditions and telomere dynamics.

  19. Genetic predisposition to higher body mass index or type 2 diabetes and leukocyte telomere length in the Nurses' Health Study.

    Directory of Open Access Journals (Sweden)

    Mengmeng Du

    Full Text Available Although cross-sectional studies have linked higher body mass index (BMI and type 2 diabetes (T2D to shortened telomeres, whether these metabolic conditions play a causal role in telomere biology is unknown. We therefore examined whether genetic predisposition to higher BMI or T2D was associated with shortened leukocyte telomere length (LTL.We conducted an analysis of 3,968 women of European ancestry aged 43-70 years from the Nurses' Health Study, who were selected as cases or controls in genome-wide association studies and studies of telomeres and disease. Pre-diagnostic relative telomere length in peripheral blood leukocytes, collected in 1989-1990, was measured by quantitative PCR. We combined information from multiple risk variants by calculating genetic risk scores based on 32 polymorphisms near 32 loci for BMI, and 36 polymorphisms near 35 loci for T2D.After adjustment for age and case-control status, there was no association between the BMI genetic risk score and LTL (β per standard deviation increase: -0.01; SE: 0.02; P = 0.52. Similarly, the T2D genetic score was not associated with LTL (β per standard deviation increase: -0.006; SE: 0.02; P = 0.69.In this population of middle-aged and older women of European ancestry, those genetically predisposed to higher BMI or T2D did not possess shortened telomeres. Although we cannot exclude weak or modest effects, our findings do not support a causal relation of strong magnitude between these metabolic conditions and telomere dynamics.

  20. Molecular masses and sedimentation coefficients of extracellular hemoglobin of Glossoscolex paulistus: alkaline oligomeric dissociation.

    Science.gov (United States)

    Carvalho, Francisco Adriano O; Santiago, Patrícia S; Borges, Júlio C; Tabak, Marcel

    2011-01-01

    The giant extracellular hemoglobin of Glossoscolex paulistus (HbGp) has a molecular mass (M) of 3600±100 kDa and a standard sedimentation coefficient (s20,w0) of 58 S, estimated by analytical ultracentrifugation (AUC). In the present work, further AUC studies were developed for HbGp, at pH 10.0, which favors oligomeric dissociation into lower M species. The HbGp oligomer is formed by globin chains a, b, c and d plus the linker chains. The pure monomeric fraction, subunit d, and HbGp at pH 10.0, in the presence of β-mercaptoethanol, were also studied. Our results indicate that for samples of pure subunit d, besides the monomeric species with s20,w0 of 2.0 S, formation of dimer of subunit d is observed with s20,w0 of around 2.9 S. For the whole HbGp at pH 10.0 contributions from monomers, trimers and linkers are observed. No contribution from 58 S species was observed for the sample of oxy-HbGp at pH 10.0, showing its complete dissociation. For cyanomet-HbGp form a contribution of 17% is observed for the un-dissociated oligomer, consistent with data from other techniques that show the cyanomet-form is more stable as compared to oxy-HbGp. Masses of HbGp subunits, especially trimer abc and monomeric chains a, b, c and d, were also estimated from sedimentation equilibrium data, and are in agreement with the results from MALDI-TOF-MS. Copyright © 2010 Elsevier B.V. All rights reserved.

  1. Higher mass-independent isotope fractionation of methylmercury in the pelagic food web of Lake Baikal (Russia).

    Science.gov (United States)

    Perrot, Vincent; Pastukhov, Mikhail V; Epov, Vladimir N; Husted, Søren; Donard, Olivier F X; Amouroux, David

    2012-06-05

    Mercury undergoes several transformations that influence its stable isotope composition during a number of environmental and biological processes. Measurements of Hg isotopic mass-dependent (MDF) and mass-independent fractionation (MIF) in food webs may therefore help to identify major sources and processes leading to significant bioaccumulation of methylmercury (MeHg). In this work, δ(13)C, δ(15)N, concentration of Hg species (MeHg, inorganic Hg), and stable isotopic composition of Hg were determined at different trophic levels of the remote and pristine Lake Baikal ecosystem. Muscle of seals and different fish as well as amphipods, zooplankton, and phytoplankton were specifically investigated. MDF during trophic transfer of MeHg leading to enrichment of heavier isotopes in the predators was clearly established by δ(202)Hg measurements in the pelagic prey-predator system (carnivorous sculpins and top-predator seals). Despite the low concentrations of Hg in the ecosystem, the pelagic food web reveals very high MIF Δ(199)Hg (3.15-6.65‰) in comparison to coastal fish (0.26-1.65‰) and most previous studies in aquatic organisms. Trophic transfer does not influence MIF signature since similar Δ(199)Hg was observed in sculpins (4.59 ± 0.55‰) and seal muscles (4.62 ± 0.60‰). The MIF is suggested to be mainly controlled by specific physical and biogeochemical characteristics of the water column. The higher level of MIF in pelagic fish of Lake Baikal is mainly due to the bioaccumulation of residual MeHg that is efficiently turned over and photodemethylated in deep oligotrophic and stationary (i.e., long residence time) freshwater columns.

  2. Use of multiple picosecond high-mass molecular dynamics simulations to predict crystallographic B-factors of folded globular proteins.

    Science.gov (United States)

    Pang, Yuan-Ping

    2016-09-01

    Predicting crystallographic B-factors of a protein from a conventional molecular dynamics simulation is challenging, in part because the B-factors calculated through sampling the atomic positional fluctuations in a picosecond molecular dynamics simulation are unreliable, and the sampling of a longer simulation yields overly large root mean square deviations between calculated and experimental B-factors. This article reports improved B-factor prediction achieved by sampling the atomic positional fluctuations in multiple picosecond molecular dynamics simulations that use uniformly increased atomic masses by 100-fold to increase time resolution. Using the third immunoglobulin-binding domain of protein G, bovine pancreatic trypsin inhibitor, ubiquitin, and lysozyme as model systems, the B-factor root mean square deviations (mean ± standard error) of these proteins were 3.1 ± 0.2-9 ± 1 Å2 for Cα and 7.3 ± 0.9-9.6 ± 0.2 Å2 for Cγ, when the sampling was done for each of these proteins over 20 distinct, independent, and 50-picosecond high-mass molecular dynamics simulations with AMBER forcefield FF12MC or FF14SB. These results suggest that sampling the atomic positional fluctuations in multiple picosecond high-mass molecular dynamics simulations may be conducive to a priori prediction of crystallographic B-factors of a folded globular protein.

  3. Extremely stable soluble high molecular mass multi-protein complex with DNase activity in human placental tissue.

    Directory of Open Access Journals (Sweden)

    Evgeniya E Burkova

    Full Text Available Human placenta is an organ which protects, feeds, and regulates the grooving of the embryo. Therefore, identification and characterization of placental components including proteins and their multi-protein complexes is an important step to understanding the placenta function. We have obtained and analyzed for the first time an extremely stable multi-protein complex (SPC, ∼ 1000 kDa from the soluble fraction of three human placentas. By gel filtration on Sepharose-4B, the SPC was well separated from other proteins of the placenta extract. Light scattering measurements and gel filtration showed that the SPC is stable in the presence of NaCl, MgCl2, acetonitrile, guanidinium chloride, and Triton in high concentrations, but dissociates efficiently in the presence of 8 M urea, 50 mM EDTA, and 0.5 M NaCl. Such a stable complex is unlikely to be a casual associate of different proteins. According to SDS-PAGE and MALDI mass spectrometry data, this complex contains many major glycosylated proteins with low and moderate molecular masses (MMs 4-14 kDa and several moderately abundant (79.3, 68.5, 52.8, and 27.2 kDa as well as minor proteins with higher MMs. The SPC treatment with dithiothreitol led to a disappearance of some protein bands and revealed proteins with lower MMs. The SPCs from three placentas efficiently hydrolyzed plasmid supercoiled DNA with comparable rates and possess at least two DNA-binding sites with different affinities for a 12-mer oligonucleotide. Progress in study of placental protein complexes can promote understanding of their biological functions.

  4. Mass spectrometry imaging: Towards mapping the elemental and molecular composition of the rhizosphere

    Energy Technology Data Exchange (ETDEWEB)

    Veličković, Dušan; Anderton, Christopher R.

    2017-06-01

    This short review will discuss and provide perspective into the utilization of mass spectrometry imaging (MSI) in studying the rhizosphere. It also serves to compliment the multi-omic focused review by White et al. in this journal issue, as MSI is capable of elucidating chemical distributions within samples of interest in an in situ fashions, and thus can provide spatial context to MS omics data in complementary experimental endeavors. The majority of reported MSI-based studies of plant-microbe interactions have focused on the phyllosphere and ‘associated rhizosphere’ (e.g., material that is not removed during harvesting), as sample preparation for these in situ analyses tends to be a limiting factor. These studies have provided valuable insight into the spatial arrangement of proteins, peptides, lipids, and other metabolites within these systems. We intend for this short review to be a primer about the history of MSI and its role in plant-microbe analysis. Along the way we reference many comprehensive reviews for the interested reader. Lastly, we offer a perspective on the future of MSI and its use in understanding the molecular transformations beyond what we coined as the ‘associated rhizosphere’ to the rest of rhizosphere zone and into the bulk soil.

  5. Carbohydrate-rich high-molecular-mass antigens are strongly recognized during experimental Histoplasma capsulatum infection

    Directory of Open Access Journals (Sweden)

    Fabrine Sales Massafera Tristão

    2012-04-01

    Full Text Available INTRODUCTION: During histoplasmosis, Histoplasma capsulatum soluble antigens (CFAg can be naturally released by yeast cells. Because CFAg can be specifically targeted during infection, in the present study we investigated CFAg release in experimental murine histoplasmosis, and evaluated the host humoral immune response against high-molecular-mass antigens (hMMAg. >150 kDa, the more immunogenic CFAg fraction. METHODS: Mice were infected with 2.2x10(4 H. capsulatum IMT/HC128 yeast cells. The soluble CFAg, IgG anti-CFAg, IgG anti-hMMAg, and IgG-hMMAg circulating immune complexes (CIC levels were determined by enzymelinked immunosorbent assay, at days 0, 7, 14, and 28 post-infection. RESULTS: We observed a progressive increase in circulating levels of CFAg, IgG anti-CFAg, IgG anti-hMMAg, and IgG-hMMAg CIC after H. capsulatum infection. The hMMAg showed a high percentage of carbohydrates and at least two main immunogenic components. CONCLUSIONS: We verified for the first time that hMMAg from H. capsulatum IMT/HC128 strain induce humoral immune response and lead to CIC formation during experimental histoplasmosis.

  6. Snake Venom Peptides and Low Mass Proteins: Molecular Tools and Therapeutic Agents.

    Science.gov (United States)

    Almeida, J R; Resende, L M; Watanabe, R K; Carregari, V C; Huancahuire-Vega, S; da S Caldeira, C A; Coutinho-Neto, A; Soares, A M; Vale, N; de C Gomes, P A; Marangoni, S; de A Calderon, L; Da Silva, S L

    2017-01-01

    Snake venoms are natural sources of biologically active molecules that are able to act selectively and specifically on different cellular targets, modulating physiological functions. Thus, these mixtures, composed mainly of proteins and peptides, provide ample and challenging opportunities and a diversified molecular architecture to design and develop tools and agents of scientific and therapeutic interest. Among these components, peptides and small proteins play diverse roles in numerous physiological processes, exerting a wide range of pharmacological activities, such as antimicrobial, antihypertensive, analgesic, antitumor, analgesic, among others. The pharmaceutical and cosmetic industries have recognized the huge potential of these privileged frameworks and believe them to be a promising alternative to contemporary drugs. A number of natural or synthetic peptides from snake venoms have already found preclinical or clinical applications for the treatment of pain, hypertension, cardiovascular diseases and aging skin. A well-known example is captopril, whose natural peptide precursor was isolated from Bothrops jararaca snake venom, which is a peptide-based drug that inhibits the angiotensin-converting enzyme, producing an anti-hypertensive effect. The present review looks at the main peptides (natriuretic peptides, bradykinin-potentiating peptides and sarafotoxins) and low mass proteins (crotamine, disintegrins and three-Finger toxins) from snake venoms, as well as synthetic peptides inspired by them, describing their biochemical, structural and physiological features, as well as their applications as research tools and therapeutic agents. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Higher body mass index increases the risk for biopsy-mediated detection of prostate cancer in Chinese men.

    Directory of Open Access Journals (Sweden)

    Meng-Bo Hu

    Full Text Available To investigate the relationship between body mass index (BMI and prostate cancer (PCa risk at biopsy in Chinese men.We retrospectively reviewed the records of 1,807 consecutive men who underwent initial multicore (≥10 prostate biopsy under transrectal ultrasound guidance between Dec 2004 and Feb 2014. BMI was categorised based on the Asian classification of obesity as follows: <18.5 (underweight, 18.5-22.9 (normal weight, 23-24.9 (overweight, 25-29.9 (moderately obese, and ≥30 kg/m2 (severely obese. The odds ratios (OR of each BMI category for risk of PCa and high-grade prostate cancer (HGPCa, Gleason score ≥4+3 detection were estimated in crude, age-adjusted and multivariate-adjusted models. Prevalence ratios and accuracies of PSA predicted PCa were also estimated across BMI groups.In total, PCa was detected by biopsy in 750 (45.4% men, and HGPCa was detected in 419 (25.4% men. Compared with men of normal weight, underweight men and obese men were older and had higher prostate specific antigen levels. The risk of overall PCa detection via biopsy presented an obvious U-shaped relationship with BMI in crude analysis. Overall, 50.0%, 37.4%, 45.6% 54.4% and 74.1% of the men in the underweight, normal weight, overweight, moderately obese and severely obese groups, respectively, were diagnosed with PCa via biopsy. In multivariate analysis, obesity was significantly correlated with a higher risk of PCa detection (OR = 1.17, 95%CI 1.10-1.25, P<0.001. However, higher BMI was not correlated with HGPCa detection (OR = 1.03, 95%CI 0.97-1.09, P = 0.29. There were no significant differences in the accuracy of using PSA to predict PCa or HGPCa detection across different BMI categories.Obesity was associated with higher risk of PCa detection in the present Chinese biopsy population. No significant association was detected between obesity and HGPCa.

  8. Higher prepregnancy body mass index is a risk factor for developing preeclampsia in Maya-Mestizo women: a cohort study.

    Science.gov (United States)

    Canto-Cetina, Thelma; Coral-Vázquez, Ramón Mauricio; Rojano-Mejía, David; Godoy, Sergio Pérez; Coronel, Agustín; Canto, Patricia

    2017-04-06

    Preeclampsia and obesity are two closely related syndromes. The high maternal prepregnancy body mass index (BMI) is a risk factor for present preeclampsia, independently of the ethnic background of the studied population. The aim of this study was to analyse in a prospective cohort study the relation between prepregnancy BMI and development of preeclampsia in Maya-Mestizo women. This is a prospective cohort study of 642 pregnant women that were included in the first trimester of the pregnancy (gestational age ≤12 weeks at the first antenatal visit) and all of them were of Maya-Mestizo ethnic origin from the state of Yucatán, México. We assessed the potential risk factors for preeclampsia and documented the prepregnancy BMI (kg/m2) that was based on measured height and maternal self-report of prepregnancy weight at the initial visit. Besides, in the antenatal visit we documented if the pregnant women developed preeclampsia. Of the 642 pregnant Maya-Mestizo women, 49 developed preeclampsia, with an incidence of 7.6% (44.9% had severe and 55% mild). The prepregnancy BMI was higher in women with developed preeclampsia than in those with normal pregnancies. Women with overweight or obesity in comparison with normal weight presented a RR = 2.82 (95% CI: 1.32-6.03; P = 0.008) and RR= 4.22 (95% CI: 2.07-8.61; P = 0.001), respectively. Our findings expand the previous studies to show that the higher prepregnancy BMI is a strong, independent risk factor for preeclampsia.

  9. Higher taxonomic relationships among extant mammals based on morphology, with selected comparisons of results from molecular data.

    Science.gov (United States)

    Shoshani, J; McKenna, M C

    1998-06-01

    Until a few decades ago, phylogenetic relationships among placental orders were ambiguous and usually depicted to radiate as an unresolved "bush." Resolution of this bush by various workers has been progressing slowly, but with promising results corroborated by nondental, dental, and molecular characters. In this study we continue to seek resolution. A total of 258 nondental and 2 dental characters was analyzed by PAUP and MacClade on 39 vertebrate taxa (3 reptiles, 1 nonmammalian therapsid, and 35 mammals; 20 of the mammals are extant and 15 are extinct) to study higher taxonomic relationships with emphasis on Placentalia (Eutheria). About two-thirds of the characters are osteological, the rest concern soft tissues, including myological but excluding molecular characters (most are our data, the rest are from the literature). Cladistic analysis included all 39 taxa (fossil taxa help to evaluate polarities of characters) and all characters were given equal weight. Extant Mammalia are divided into Prototheria and Theria, the latter into Marsupialia and Placentalia. Placentalia comprises Xenarthra and Epitheria. Within Epitheria, Lipotyphla and Preptotheria (emended) are sister-taxa. Preptotherian taxa group into: ungulate-related taxa and various nonungulates. The former include Carnivora, Pholidota, Tubulidentata, Artiodactyla, Cetacea, Perissodactyla, Hyracoidea, Proboscidea, and Sirenia. A possible association to embrace Lagomorpha, Rodentia, Macroscelidea, Scandentia, Primates, Chiroptera, and Dermoptera is suggested. Significant differences between our findings and those of recent investigators include the dissociation of Pholidota from Xenarthra and the plesiomorphous position of Lipotyphla within Epitheria. Congruence between morphological and molecular results is closer than previously reported. Copyright 1998 Academic Press.

  10. The evolution of the protoplanetary disk with mass influx from a molecular cloud core and the photoevaporation winds

    Science.gov (United States)

    Liu, Chunjian; Yao, Zhen; Li, Hongna; Wang, Haosen

    2018-01-01

    We investigate the formation, evolution, and dispersal processes of protoplanetary disks with mass influx from the gravitational collapse of a molecular cloud core and the photoevaporation winds. Due to the initial angular momentum of the molecular cloud core, the gravitational collapse of the molecular cloud core forms a protostar+protoplanetary disk system. We calculate the evolution of the protoplanetary disk from the gravitational collapse of the molecular cloud core to the dispersal stage. In our calculation, we include the mass influx from a molecular cloud core, the irradiation from the central star, the viscosity due to the magnetohydrodynamic (MHD) turbulence driven by the magnetorotational instability (MRI) and the gravitational instability, and the effect of photoevaporation. We find that the protoplanetary disk has some interesting properties, which are different from the previous studies. Firstly, with particular values of parameters of the molecular cloud core, the gravitational instability does not occur during the whole evolution of the resultant protoplanetary disk. With some other parameters of the molecular cloud core, the gravitational instability occurs all the time of the lifetime of the resultant protoplanetary disk. Secondly, the radial distribution of the α parameter exhibits a nearly ladder-like shape, which is different from the three regions' shape in previous studies. Thirdly, the value of the surface density is increased significantly (about a factor of 8.0) compared with that in the Minimum Mass Solar Nebula (MMSN) model. We suggest that this increased surface density can provide enough material for the formation of giant planets within the lifetime of the protoplanetary disk, and may provide a routine for reducing the timescale of the formation of giant planets. We also discuss the influence of the photoevaporation winds on the evolution of the protoplanetary disk.

  11. Higher Molecular Weight Polyethylene Glycol Increases Cell Proliferation While Improving Barrier Function in an In Vitro Colon Cancer Model

    Directory of Open Access Journals (Sweden)

    Shruthi Bharadwaj

    2011-01-01

    Full Text Available Polyethylene glycol (PEG has been previously shown to protect against enteric pathogens and prevent colon cancer invasion. To determine if PEG could indeed protect against previously observed pro-invasive effects of commensal E. coli and EPEC, Caco-2 cells grown in an in vitro model of colon cancer were infected with strains of human commensal E. coli or EPEC and treated with 10% PEG 3350, PEG 8000, and PEG 20,000, respectively. At 24 hours after infection, MMP-1 and MMP-13 activities, cell cluster thickness, depth of invasion, and proliferation were determined using standard molecular biology techniques and advanced imaging. We found that higher molecular weight PEG, especially PEG 8000 and 20,000, regardless of bacterial infection, increased proliferation and depth of invasion although a decrease in cellular density and MMP-1 activity was also noted. Maximum proliferation and depth of invasion of Caco-2 cells was observed in scaffolds treated with a combination of commensal E. coli strain, HS4 and PEG 8000. In conclusion, we found that PEG 8000 increased cell proliferation and led to the preservation of cell density in cells treated with commensal bacteria. This is important, because the preservation of a proliferative response in colon cancer results in a more chemo-responsive tumor.

  12. Atmospheric-pressure solution-cathode glow discharge: A versatile ion source for atomic and molecular mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Schwartz, Andrew J. [Department of Chemistry, Indiana University, Bloomington, IN, 47405 (United States); Williams, Kelsey L. [Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242 (United States); Hieftje, Gary M. [Department of Chemistry, Indiana University, Bloomington, IN, 47405 (United States); Shelley, Jacob T., E-mail: shellj@rpi.edu [Department of Chemistry and Biochemistry, Kent State University, Kent, OH, 44242 (United States); Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, NY, 12180 (United States)

    2017-01-15

    An atmospheric-pressure solution-cathode glow discharge (SCGD) has been evaluated as an ion source for atomic, molecular, and ambient desorption/ionization mass spectrometry. The SCGD consists of a direct-current plasma, supported in the ambient air in the absence of gas flows, and sustained upon the surface of a flowing liquid cathode. Analytes introduced in the flowing liquid, as an ambient gas, or as a solid held near the plasma are vaporized and ionized by interactions within or near the discharge. Introduction of acidic solutions containing metal salts produced bare elemental ions as well as H{sub 2}O, OH{sup −} and NO{sub 3}{sup −} adducts. Detection limits for these elemental species ranged from 0.1 to 4 ppb, working curves spanned more than 4 orders of linear dynamic range, and precision varied between 5 and 16% relative standard deviation. Small organic molecules were also efficiently ionized from solution, and both the intact molecular ion and fragments were observed in the resulting SCGD mass spectra. Fragmentation of molecular species was found to be tunable; high discharge currents led to harder ionization, while low discharge currents produced stronger molecular-ion signals. Ambient gases and solids, desorbed by the plasma from a glass probe, were also readily ionized by the SCGD. Indeed, strong analyte signals were obtained from solid samples placed at least 2 cm from the plasma. These findings indicate that the SCGD might be useful also for ambient desorption/ionization mass spectrometry. Combined with earlier results that showed the SCGD is useful for ionization of labile biomolecules, the results here indicate that the SCGD is a highly versatile ion source capable of providing both elemental and molecular mass-spectral information. - Highlights: • Solution-cathode glow discharge used as an ionization source for mass spectrometry. • SCGD-MS can provide atomic as well as intact molecular mass spectra. • Atomic limits of detection range

  13. Comparison of LAMP and PCR for molecular mass screening of sand flies for Leishmania martiniquensis infection.

    Science.gov (United States)

    Tiwananthagorn, Saruda; Kato, Hirotomo; Yeewa, Ranchana; Muengpan, Amontip; Polseela, Raxsina; Leelayoova, Saovanee

    2017-02-01

    Leishmaniasis caused by Leishmania martiniquensis infection has been reported in human and domestic animals of Martinique Island, Germany, Switzerland, USA, Myanmar and Thailand. The peculiar clinical features of disseminated cutaneous and visceral forms co-existence render the urgent need of specific diagnostic tool to identify the natural sand fly vectors for effective prevention and control strategies. Loop-mediated isothermal amplification (LAMP) of 18S rRNA gene as well as polymerase chain reaction (PCR) of minicircle kinetoplast DNA gene (PCR-mkDNA) have never been applied to detect L. martiniquensis and L. siamensis in sand fly vectors. The present study was aimed to validate malachite green-LAMP (MG-LAMP) and PCR-mkDNA techniques to detect L. martiniquensis in sand fly vectors, compared with the conventional PCR of internal transcribed spacer 1 (PCR-ITS1). We compared the validity of LAMP of 18S rRNA gene and PCR-mkDNA, to PCR-ITS1 in simulation model of L. martiniquensis infection in Sergentomyia gemmea sand flies. Attributable to the sensitivity and specificity, PCR-mkDNA was consecutively applied to detect L. martiniquensis in 380 female sand fly individuals captured in the newly identified affected region of Lamphun Province, Thailand. Results showed that PCR-mkDNA could detect at least one promastigote per sand fly, which was 10-time superior to LAMP and PCR-ITS1. In addition, PCR-mkDNA was more specific, able to differentiate L. martiniquensis from other viscerotropic Leishmania species, such as L. siamensis, L. (L.) donovani, and L. (L.) infantum. Consecutively, mass screening of L. martiniquensis in 380 female sand fly individuals by PCR-mkDNA was implemented in a new affected area of Thailand where a patient with leishmaniasis/HIV co-infection resides; however Leishmania DNA was undetected. In conclusion, PCR-mkDNA is a promising tool for molecular mass screening of L. martiniquensis infection in outbreak areas where several species of Leishmania

  14. Very stable high molecular mass multiprotein complex with DNase and amylase activities in human milk.

    Science.gov (United States)

    Soboleva, Svetlana E; Dmitrenok, Pavel S; Verkhovod, Timofey D; Buneva, Valentina N; Sedykh, Sergey E; Nevinsky, Georgy A

    2015-01-01

    For breastfed infants, human milk is more than a source of nutrients; it furnishes a wide array of proteins, peptides, antibodies, and other components promoting neonatal growth and protecting infants from viral and bacterial infection. It has been proposed that most biological processes are performed by protein complexes. Therefore, identification and characterization of human milk components including protein complexes is important for understanding the function of milk. Using gel filtration, we have purified a stable high molecular mass (~1000 kDa) multiprotein complex (SPC) from 15 preparations of human milk. Light scattering and gel filtration showed that the SPC was stable in the presence of high concentrations of NaCl and MgCl2 but dissociated efficiently under the conditions that destroy immunocomplexes (2 M MgCl2 , 0.5 M NaCl, and 10 mM DTT). Such a stable complex is unlikely to be a casual associate of different proteins. The relative content of the individual SPCs varied from 6% to 25% of the total milk protein. According to electrophoretic and mass spectrometry analysis, all 15 SPCs contained lactoferrin (LF) and α-lactalbumin as major proteins, whereas human milk albumin and β-casein were present in moderate or minor amounts; a different content of IgGs and sIgAs was observed. All SPCs efficiently hydrolyzed Plasmid supercoiled DNA and maltoheptaose. Some freshly prepared SPC preparations contained not only intact LF but also small amounts of its fragments, which appeared in all SPCs during their prolonged storage; the fragments, similar to intact LF, possessed DNase and amylase activities. LF is found in human epithelial secretions, barrier body fluids, and in the secondary granules of leukocytes. LF is a protein of the acute phase response and nonspecific defense against different types of microbial and viral infections. Therefore, LF complexes with other proteins may be important for its functions not only in human milk. Copyright © 2014

  15. Molecular regulation of high muscle mass in developing Blonde d'Aquitaine cattle foetuses

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    Isabelle Cassar-Malek

    2017-10-01

    Full Text Available The Blonde d'Aquitaine (BA is a French cattle breed with enhanced muscularity, partly attributable to a MSTN mutation. The BA m. Semitendinosus has a faster muscle fibre isoform phenotype comprising a higher proportion of fast type IIX fibres compared to age-matched Charolais (CH. To better understand the molecular network of modifications in BA compared to CH muscle, we assayed the transcriptomes of the m. Semitendinosus at 110, 180, 210 and 260 days postconception (dpc. We used a combination of differential expression (DE and regulatory impact factors (RIF to compare and contrast muscle gene expression between the breeds. Prominently developmentally regulated genes in both breeds reflected the replacement of embryonic myosin isoforms (MYL4, MYH3 with adult isoforms (MYH1 and the upregulation of mitochondrial metabolism (CKMT2, AGXT2L1 in preparation for birth. However, the transition to a fast, glycolytic muscle phenotype in the MSTN mutant BA is detectable through downregulation of various slow twitch subunits (TNNC1, MYH7, TPM3, CSRP3 beyond 210 dpc, and a small but consistent genome-wide reduction in mRNA encoding the mitoproteome. Across the breeds, NRIP2 is the regulatory gene possessing a network change most similar to that of MSTN.

  16. Higher body mass index may induce asthma among adolescents with pre-asthmatic symptoms: a prospective cohort study

    Directory of Open Access Journals (Sweden)

    Myers Leann

    2011-07-01

    Full Text Available Abstract Background Limited studies have prospectively examined the role of body mass index (BMI as a major risk factor for asthma during adolescence. This study investigates whether BMI is associated with increased risk of developing physician-diagnosed asthma during 12-month follow-up among adolescents with undiagnosed asthma-like symptoms at baseline. Methods A total of 4,052 adolescents with undiagnosed asthma-like symptoms at baseline were re-examined after a 12-month follow-up. Asthma cases were considered confirmed only after diagnosis by a physician based on the New England core and International Study of Asthma and Allergies in Childhood (ISAAC criteria video questionnaires, and accompanying pulmonary function tests. Logistic regression analyses were used to evaluate the relationship of BMI and the risk of acquiring asthma. Results The results indicated that girls with higher BMI were at an increased risk of developing asthma during the 12-month follow-up. The odds ratios for girls developing physician-diagnosed asthma were 1.75 (95% CI = 1.18-2.61 and 1.12 (95% CI = 0.76-1.67, respectively, for overweight and obesity as compared to the normal weight reference group after adjustment for other covariates. A similar relationship was not observed for overweight and obese boys who were also significantly more active than their female counterparts. Conclusions Increased BMI exaggerates the risk of acquiring asthma in symptomatic adolescent females but not in adolescent males. Thus, gender is an important modifier of BMI-related asthma risk. Additional research will be required to determine whether the increased asthma risk results from genetic, physiological or behavioural differences.

  17. Red-winged blackbirds (Agelaius phoeniceus) with higher baseline glucocorticoids also invest less in incubation and clutch mass.

    Science.gov (United States)

    Schoenle, Laura A; Dudek, Alana M; Moore, Ignacio T; Bonier, Frances

    2017-04-01

    Glucocorticoid hormones facilitate responses to environmental challenges by mediating diverse physiological and behavioral changes, including resource mobilization and altered reproductive effort. Elevated glucocorticoids might indicate that an individual is facing high levels of environmental challenges and thus, elevated concentrations might be associated with reduced fitness (CORT-fitness hypothesis). Alternatively, the energetic demands of reproduction might be a challenge that requires elevated glucocorticoids to mobilize resources to support reproductive effort, ultimately increasing reproductive investment and fitness (CORT-adaptation hypothesis). Investigations of glucocorticoid-fitness relationships have yielded mixed results. Variation in the direction of this relationship could be caused in part by differences in the contexts in which the relationship was assessed. Incorporating context, such as life history stage, could be key to understanding the role of glucocorticoids in influencing fitness outcomes. We investigated the relationship between corticosterone and reproductive effort and success within a single life history stage: incubation of eggs. In an observational study, we measured baseline corticosterone in incubating female red-winged blackbirds (Agelaius phoeniceus), monitored incubation behavior, and determined hatching success for each nest. Incubating birds with higher baseline corticosterone concentrations had more frequent, shorter incubation bouts and spent less time overall incubating their clutches of eggs than birds with lower corticosterone concentrations. Elevated corticosterone was also associated with lower clutch mass, but neither corticosterone nor incubation effort were correlated with hatching success. Although experimental tests are needed to establish causation, these results suggest that during the incubation period, corticosterone might shift resource investment towards self-maintenance, and away from current reproductive

  18. Neonatal Morbidity and Maternal Complication Rates in Women With a Delivery Body Mass Index of 60 or Higher.

    Science.gov (United States)

    Kim, Tana; Burn, Sabrina C; Bangdiwala, Ananta; Pace, Samantha; Rauk, Phillip

    2017-11-01

    To investigate neonatal morbidity and maternal complication rates with delivery body mass index (BMI) 60 or greater. This retrospective, multicenter cohort study included singleton pregnancies between 23 and 42 weeks of gestation from January 2005 to April 2016. Women with BMI 60 or greater were compared with a random sample of women with BMI 30-59. The primary outcome, composite neonatal morbidity, was defined as 5-minute Apgar score less than 7, hypoglycemia, respiratory distress syndrome, sepsis, hospital stay greater than 5 days, neonatal intensive care unit admission, or neonatal death. Secondary outcomes included maternal labor and delivery characteristics and complication rates. Kruskal-Wallis tests and χ or Fisher exact tests were used to compare BMI categories. Multivariable logistic regression was used for adjusted analysis. The study included 338 women, with 39 in the BMI 60 or greater group. An association between obesity and neonatal morbidity was found. Increasing BMI correlated with increasing neonatal morbidity, with the highest rates among those with BMI 60 or greater (BMI 30-39 [17%], 40-49 [19%], 50-59 [22%], 60 or greater [56%]; Pmorbidity compared with women with BMI 60 or greater (BMI 30-39 adjusted odds ratio [OR] 0.22 [0.1-0.5], 40-49 adjusted OR 0.23 [0.1-0.6], 50-59 adjusted OR 0.25 [0.1-0.6]). Maternal complication rates including labor induction, cesarean delivery, wound complication, postpartum hemorrhage, and hospital stay greater than 5 days were also significantly increased with BMI 60 or greater. A BMI 60 or greater at the time of delivery is significantly associated with increased neonatal morbidity and increased maternal complication rates. In addition, neonatal morbidity and maternal complication rates with BMI 60 or greater were significantly higher when compared with women in any lesser obese BMI cohort between 30 and 59.

  19. Effect of the Molecular Mass of Tremella Polysaccharides on Accelerated Recovery from Cyclophosphamide-Induced Leucopenia in Rats

    Directory of Open Access Journals (Sweden)

    Qi-Pin Gao

    2012-03-01

    Full Text Available The body of tremella were decocted with water, and hydrolyzed with 0.1 mol/L hydrochloric acid for different times, giving tremella polysaccharides with six molecular mass values. The structures of all the tremella polysaccharides had non-reducing terminals of β-D-pyranglucuronide, the backbone was composed of (1→3-linked β-D-manno-pyranoside, and the side chain composed of (1→6-linked β-D-xylopyranoside was attached to the C2 of the backbone mannopyranoside. Immunomodulatory effect studies indicated that tremella polysaccharides increased the counts of leukocytes in the peripheral blood which were significantly lowered by cyclophosphamide, and the lower the molecular mass of the tremella polysaccharide, the better this effect was.

  20. Dereplication of Flavonoid Glycoconjugates from Adenocalymma imperatoris-maximilianii by Untargeted Tandem Mass Spectrometry-Based Molecular Networking.

    Science.gov (United States)

    de Oliveira, Gibson Gomes; Carnevale Neto, Fausto; Demarque, Daniel Pecoraro; de Sousa Pereira-Junior, José Antônio; Sampaio Peixoto Filho, Rômulo César; de Melo, Sebastião José; da Silva Almeida, Jackson Roberto Guedes; Lopes, João Luiz Callegari; Lopes, Norberto Peporine

    2017-05-01

    The interpretation of large datasets acquired using high performance liquid chromatography coupled with tandem mass spectrometry represents one of the major challenges in natural products research. Here we propose the use of molecular networking to rapid identify the known secondary metabolites from untargeted MS/MS analysis of Adenocalymma imperatoris-maximilianii plant extracts. The leaves, stems and roots of A. imperatoris-maximilianii were extracted using different solvents according to Snyder selectivity triangle. The samples were analyzed by HPLC coupled with ion trap mass spectrometer in a collision-induced dissociation MS/MS configuration in both positive and negative electrospray ionization modes. Molecular networking simultaneously organized the spectra by cosine similarity. The chemical identification was performed based on the systematic study of the main fragmentation pathways observed for the resulting network. The untargeted tandem mass spectrometry-based molecular networking allowed for the identification of 63 metabolites, mainly mono-, di- and tri-, C - and/or O -glycosyl flavones. Molecular networking was capable not only to dereplicate known flavonoids, but also to point out related prenyl derivatives, described for the first time in Adenocalymma species. The gas-phase reaction route to form the characteristic [M-H 2 O-(30/60/90)] + fragments in C -glycosyl flavones was suggested as sequential sugar ring opening followed by retro-aldol elimination involving aldose-ketose isomerization. The use of molecular networking with LC-CID-MS/MS assisted the identification of various isomeric and isobaric flavonoid glycoconjugates by establishing clusters according to the fragmentation similarities. Additionally, the proposed cross-ring sugar cleavages can contribute to the identification of C -glycosides by MS/MS analysis. Georg Thieme Verlag KG Stuttgart · New York.

  1. Comparison of molecular species of various transphosphatidylated phosphatidylserine (PS) with bovine cortex PS by mass spectrometry

    NARCIS (Netherlands)

    Chen, S.; Li, K.W.

    2008-01-01

    The exogenous introduction of a molecular species mixture of bovine cortex phosphatidylserine (BC-PS) has been claimed to improve memory function in subjects suffering from age-associated memory impairment and dementia. However, it has been also reported that oral administration of another molecular

  2. Filtrates and Residues: Measuring the Atomic or Molecular Mass of a Gas with a Tire Gauge and a Butane Lighter Fluid Can.

    Science.gov (United States)

    Bodner, George M.; Magginnis, Lenard J.

    1985-01-01

    Describes the use of an inexpensive apparatus (based on a butane lighter fluid can and a standard tire pressure gauge) in measuring the atomic/molecular mass of an unknown gas and in demonstrating the mass of air or the dependence of pressure on the mass of a gas. (JN)

  3. Evaporation of liquid droplets of nano- and micro-meter size as a function of molecular mass and intermolecular interactions: experiments and molecular dynamics simulations.

    Science.gov (United States)

    Hołyst, Robert; Litniewski, Marek; Jakubczyk, Daniel

    2017-09-13

    Transport of heat to the surface of a liquid is a limiting step in the evaporation of liquids into an inert gas. Molecular dynamics (MD) simulations of a two component Lennard-Jones (LJ) fluid revealed two modes of energy transport from a vapour to an interface of an evaporating droplet of liquid. Heat is transported according to the equation of temperature diffusion, far from the droplet of radius R. The heat flux, in this region, is proportional to temperature gradient and heat conductivity in the vapour. However at some distance from the interface, Aλ, (where λ is the mean free path in the gas), the temperature has a discontinuity and heat is transported ballistically i.e. by direct individual collisions of gas molecules with the interface. This ballistic transport reduces the heat flux (and consequently the mass flux) by the factor R/(R + Aλ) in comparison to the flux obtained from temperature diffusion. Thus it slows down the evaporation of droplets of sizes R ∼ Aλ and smaller (practically for sizes from 103 nm down to 1 nm). We analyzed parameter A as a function of interactions between molecules and their masses. The rescaled parameter, A(kBTb/ε11)1/2, is a linear function of the ratio of the molecular mass of the liquid molecules to the molecular mass of the gas molecules, m1/m2 (for a series of chemically similar compounds). Here ε11 is the interaction parameter between molecules in the liquid (proportional to the enthalpy of evaporation) and Tb is the temperature of the gas in the bulk. We tested the predictions of MD simulations in experiments performed on droplets of ethylene glycol, diethylene glycol, triethylene glycol and tetraethylene glycol. They were suspended in an electrodynamic trap and evaporated into dry nitrogen gas. A changes from ∼1 (for ethylene glycol) to approximately 10 (for tetraethylene glycol) and has the same dependence on molecular parameters as obtained for the LJ fluid in MD simulations. The value of x = A(kBTb/ε11

  4. High-Resolution Liquid Chromatography Tandem Mass Spectrometry Enables Large Scale Molecular Characterization of Dissolved Organic Matter

    Directory of Open Access Journals (Sweden)

    Daniel Petras

    2017-12-01

    Full Text Available Dissolved organic matter (DOM is arguably one of the most complex exometabolomes on earth, and is comprised of thousands of compounds, that together contribute more than 600 × 1015 g carbon. This reservoir is primarily the product of interactions between the upper ocean's microbial food web, yet abiotic processes that occur over millennia have also modified many of its molecules. The compounds within this reservoir play important roles in determining the rate and extent of element exchange between inorganic reservoirs and the marine biosphere, while also mediating microbe-microbe interactions. As such, there has been a widespread effort to characterize DOM using high-resolution analytical methods including nuclear magnetic resonance spectroscopy (NMR and mass spectrometry (MS. To date, molecular information in DOM has been primarily obtained through calculated molecular formulas from exact mass. This approach has the advantage of being non-targeted, accessing the inherent complexity of DOM. Molecular structures are however still elusive and the most commonly used instruments are costly. More recently, tandem mass spectrometry has been employed to more precisely identify DOM components through comparison to library mass spectra. Here we describe a data acquisition and analysis workflow that expands the repertoire of high-resolution analytical approaches available to access the complexity of DOM molecules that are amenable to electrospray ionization (ESI MS. We couple liquid chromatographic separation with tandem MS (LC-MS/MS and a data analysis pipeline, that integrates peak extraction from extracted ion chromatograms (XIC, molecular formula calculation and molecular networking. This provides more precise structural characterization. Although only around 1% of detectable DOM compounds can be annotated through publicly available spectral libraries, community-wide participation in populating and annotating DOM datasets could rapidly increase the

  5. WISDOM Project - III. Molecular gas measurement of the supermassive black hole mass in the barred lenticular galaxy NGC4429

    Science.gov (United States)

    Davis, Timothy A.; Bureau, Martin; Onishi, Kyoko; van de Voort, Freeke; Cappellari, Michele; Iguchi, Satoru; Liu, Lijie; North, Eve V.; Sarzi, Marc; Smith, Mark D.

    2018-01-01

    As part of the mm-Wave Interferometric Survey of Dark Object Masses project we present an estimate of the mass of the supermassive black hole (SMBH) in the nearby fast-rotating early-type galaxy NGC4429, that is barred and has a boxy/peanut-shaped bulge. This estimate is based on Atacama Large Millimeter/submillimeter Array (ALMA) cycle-2 observations of the 12CO(3-2) emission line with a linear resolution of ≈13 pc (0.18 arcsec × 0.14 arcsec). NGC4429 has a relaxed, flocculent nuclear disc of molecular gas that is truncated at small radii, likely due to the combined effects of gas stability and tidal shear. The warm/dense 12CO(3-2) emitting gas is confined to the inner parts of this disc, likely again because the gas becomes more stable at larger radii, preventing star formation. The gas disc has a low velocity dispersion of 2.2^{+0.68}_{-0.65} km s-1. Despite the inner truncation of the gas disc, we are able to model the kinematics of the gas and estimate a mass of (1.5 ± 0.1^{+0.15}_{-0.35}) × 108 M⊙ for the SMBH in NGC4429 (where the quoted uncertainties reflect the random and systematic uncertainties, respectively), consistent with a previous upper limit set using ionized gas kinematics. We confirm that the V-band mass-to-light ratio changes by ≈30 per cent within the inner 400 pc of NGC4429, as suggested by other authors. This SMBH mass measurement based on molecular gas kinematics, the sixth presented in the literature, once again demonstrates the power of ALMA to constrain SMBH masses.

  6. Protein Intake, Especially Vegetable Protein Intake, Is Associated with Higher Skeletal Muscle Mass in Elderly Patients with Type 2 Diabetes

    Directory of Open Access Journals (Sweden)

    Akane Miki

    2017-01-01

    Full Text Available Background/Aims. Protein intake is important for maintaining muscle mass in general population. However, it remains to be elucidated the association between dietary protein intake and skeletal muscle mass in elderly patients with type 2 diabetes. Methods. In this cross-sectional study of 168 elderly patients with type 2 diabetes, we investigated the relationship between skeletal muscle index (SMI and protein intake. Bioimpedance analysis was used for measurement for skeletal muscle mass (kg and SMI (%, which was defined as skeletal muscle mass (kg/total body weight (kg × 100. Habitual food and nutrient intake were estimated by a questionnaire. Results. Protein intake was independently correlated with SMI after adjusting for age, hemoglobin A1c, C-peptide index, exercise, smoking, insulin treatment, total energy intake, and C-reactive protein (standardized regression coefficient = 0.664, P<0.001 in men and standardized regression coefficient = 0.516, P=0.005 in women. Additionally, the animal protein to vegetable protein ratio was negatively correlated with SMI after adjusting for covariates in men (standardized regression coefficient = −0.339, P=0.005. Conclusions. We found that total protein intake, especially vegetable protein intake, was positively associated with skeletal muscle mass in elderly patients with type 2 diabetes.

  7. Determination of the Relative Atomic Masses of Metals by Liberation of Molecular Hydrogen

    Science.gov (United States)

    Waghorne, W. Earle; Rous, Andrew J.

    2009-01-01

    Students determine the relative atomic masses of calcium, magnesium, and aluminum by reaction with hydrochloric acid and measurement of the volume of hydrogen gas liberated. The experiment demonstrates stoichiometry and illustrates clearly that mass of the reagent is not the determinant of the amounts in chemical reactions. The experiment is…

  8. Direct or indirect composite veneers in anterior teeth: which method causes higher tooth mass loss? An in vitro study.

    Science.gov (United States)

    Machado, Alessandra Nunes; Coelho-de-Souza, Fabio Herrmann; Rolla, Juliana Nunes; Erhardt, Maria Carolina Guilherme; Demarco, Flavio Fernando

    2014-01-01

    There is little information in the literature regarding the relationship between preparations made for direct and indirect veneers and the loss of tooth structure required for each technique. This in vitro study sought to quantify the different mass losses from preparation techniques used for direct and indirect veneers. Thirty artificial teeth were weighted using a digital balance and placed in a dental manikin in the position corresponding to the right maxillary central incisor. Five clinicians-all experts in esthetic dentistry-were asked to perform conventional preparations for both a direct composite resin veneer and an indirect ceramic veneer. After preparations, specimens were weighted again in the same digital balance. Teeth undergoing veneer preparations demonstrated a statistically significant mass loss compared to unprepared teeth. Indirect ceramic veneer preparations produced more mass loss than direct composite veneer preparations (P < 0.01).

  9. Slow molecular evolution in 18S rDNA, rbcL and nad5 genes of mosses compared with higher plants.

    Science.gov (United States)

    Stenøien, H K

    2008-03-01

    The evolutionary potential of bryophytes (mosses, liverworts and hornworts) has been debated for decades. Fossil record and biogeographical distribution patterns suggest very slow morphological evolution and the retainment of several ancient traits since the split with vascular plants some 450 million years ago. Many have argued that bryophytes may evolve as rapidly as higher plants on the molecular level, but this hypothesis has not been tested so far. Here, it is shown that mosses have experienced significantly lower rates of molecular evolution than higher plants within 18S rDNA (nuclear), rbcL (chloroplast) and nad5 (mitochondrial) genes. Mosses are on an average evolving 2-3 times slower than ferns, gymnosperms and angiosperms; and also green algae seem to be evolving faster than nonvascular plants. These results support the observation of a general correlation between morphological and molecular evolutionary rates in plants and also show that mosses are 'evolutionary sphinxes' regarding both morphological and molecular evolutionary potential.

  10. Higher body mass index in adults at diagnosis of the slowly progressive form of type 1 diabetes mellitus is associated with lower risk HLA genes.

    Science.gov (United States)

    Fourlanos, S; Elkassaby, S; Varney, M D; Colman, P G; Harrison, L C

    2014-06-01

    We hypothesised that higher body weight, a proposed risk factor for type 1 diabetes mellitus, would be associated with increased penetrance of lower risk genes. In adults at diagnosis of the slowly progressive form of type 1 diabetes mellitus we found that higher body mass index was associated with the absence of the highest risk HLA genes. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  11. In vitro fermentation of arabinoxylan oligosaccharides and low molecular mass arabinoxylans with different structural properties from wheat (Triticum aestivum L.) bran and psyllium (Plantago ovata Forsk) seed husk.

    Science.gov (United States)

    Pollet, Annick; Van Craeyveld, Valerie; Van de Wiele, Tom; Verstraete, Willy; Delcour, Jan A; Courtin, Christophe M

    2012-02-01

    Ball milling was used for producing complex arabinoxylan oligosaccharides (AXOS) and low molecular mass arabinoxylans (AX) from wheat bran, pericarp-enriched wheat bran, and psyllium seed husk. The arabinose to xylose ratio of the samples produced varied between 0.14 and 0.92, and their average degree of polymerization (avDP) ranged between 42 and 300. Their fermentation for 48 h in an in vitro system using human colon suspensions was compared to enzymatically produced wheat bran AXOS with an arabinose to xylose ratio of 0.22 and 0.34 and an avDP of 4 and 40, respectively. Degrees of AXOS fermentation ranged from 28% to 50% and were lower for the higher arabinose to xylose ratio and/or higher avDP materials. Arabinose to xylose ratios of the unfermented fractions exceeded those of their fermented counterparts, indicating that molecules less substituted with arabinose were preferably fermented. Xylanase, arabinofuranosidase, and xylosidase activities increased with incubation time. Enzyme activities in the samples containing psyllium seed husk AX or psyllium seed husk AXOS were generally higher than those in the wheat bran AXOS preparations. Fermentation gave rise to unbranched short-chain fatty acids. Concentrations of acetic, propionic, and butyric acids increased to 1.9-2.6, 1.9-2.8, and 1.3-2.0 times their initial values, respectively, after 24 h incubation. Results show that the human intestinal microbiota can at least partially use complex AXOS and low molecular mass AX. The tested materials are thus interesting physiologically active carbohydrates.

  12. Higher Weight, Lower Education: A Longitudinal Association between Adolescents' Body Mass Index and Their Subsequent Educational Achievement Level?

    Science.gov (United States)

    Larsen, Junilla K.; Kleinjan, Marloes; Engels, Rutger C. M. E.; Fisher, Jennifer O.; Hermans, Roel

    2014-01-01

    Background: The purpose of this study was to examine the association between adolescents' body mass index (BMI) z-scores and their subsequent level of schooling, extending previous longitudinal research by using objectively measured weight and height data. Methods: A longitudinal study with 3 study waves (1-year intervals) involving 1248 Dutch…

  13. Absorption Mode FTICR Mass Spectrometry Imaging

    NARCIS (Netherlands)

    Smith, D.F.; Kilgour, D.P.A.; Konijnenburg, M.; O'Connor, P.B.; Heeren, R.M.A.|info:eu-repo/dai/nl/105188476

    2013-01-01

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields

  14. Molecular evidence of heavy-oil weathering following the M/V Cosco Busan spill: insights from Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Lemkau, Karin L; McKenna, Amy M; Podgorski, David C; Rodgers, Ryan P; Reddy, Christopher M

    2014-04-01

    Recent studies have highlighted a critical need to investigate oil weathering beyond the analytical window afforded by conventional gas chromatography (GC). In particular, techniques capable of detecting polar and higher molecular weight (HMW; > 400 Da) components abundant in crude and heavy fuel oils (HFOs) as well as transformation products. Here, we used atmospheric pressure photoionization Fourier transform ion cyclotron resonance mass spectrometry (APPI FT-ICR MS) to identify molecular transformations in oil-residue samples from the 2007 M/V Cosco Busan HFO spill (San Francisco, CA). Over 617 days, the abundance and diversity of oxygen-containing compounds increased relative to the parent HFO, likely from bio- and photodegradation. HMW, highly aromatic, alkylated compounds decreased in relative abundance concurrent with increased relative abundance of less alkylated stable aromatic structures. Combining these results with GC-based data yielded a more comprehensive understanding of oil spill weathering. For example, dealkylation trends and the overall loss of HMW species observed by FT-ICR MS has not previously been documented and is counterintuitive given losses of lower molecular weight species observed by GC. These results suggest a region of relative stability at the interface of these techniques, which provides new indicators for studying long-term weathering and identifying sources.

  15. Molecular dynamic approach to the study of the intense heat and mass transfer processes on the vapor-liquid interface

    Science.gov (United States)

    Levashov, V. Yu; Kamenov, P. K.

    2017-10-01

    The paper is devoted to research of the heat and mass transfer processes on the vapor-liquid interface. These processes can be realized for example at metal tempering, accidents at nuclear power stations, followed by the release of the corium into the heat carrier, getting hot magma into the water during volcanic eruptions and other. In all these examples the vapor film can arise on the heated body surface. In this paper the vapor film formation process will be considered with help of molecular dynamics simulation methods. The main attention during this process modeling will be focused on the subject of the fluid and vapor interactions with the heater surface. Another direction of this work is to study of the processes inside the droplet that may take place as result of impact of the high-power laser radiation. Such impact can lead to intensive evaporation and explosive destruction of the droplet. At that the duration of heat and mass transfer processes in droplet substance is tens of femtoseconds. Thus, the methods of molecular dynamics simulation can give the possibilities describe the heat and mass transfer processes in the droplet and the vapor phase formation.

  16. A unified model for the maximum mass scales of molecular clouds, stellar clusters and high-redshift clumps

    Science.gov (United States)

    Reina-Campos, Marta; Kruijssen, J. M. Diederik

    2017-08-01

    We present a simple, self-consistent model to predict the maximum masses of giant molecular clouds (GMCs), stellar clusters and high-redshift clumps as a function of the galactic environment. Recent works have proposed that these maximum masses are set by shearing motions and centrifugal forces, but we show that this idea is inconsistent with the low masses observed across an important range of local-Universe environments, such as low-surface density galaxies and galaxy outskirts. Instead, we propose that feedback from young stars can disrupt clouds before the global collapse of the shear-limited area is completed. We develop a shear-feedback hybrid model that depends on three observable quantities: the gas surface density, the epicylic frequency and the Toomre parameter. The model is tested in four galactic environments: the Milky Way, the Local Group galaxy M31, the spiral galaxy M83 and the high-redshift galaxy zC406690. We demonstrate that our model simultaneously reproduces the observed maximum masses of GMCs, clumps and clusters in each of these environments. We find that clouds and clusters in M31 and in the Milky Way are feedback-limited beyond radii of 8.4 and 4 kpc, respectively, whereas the masses in M83 and zC406690 are shear-limited at all radii. In zC406690, the maximum cluster masses decrease further due to their inspiral by dynamical friction. These results illustrate that the maximum masses change from being shear-limited to being feedback-limited as galaxies become less gas rich and evolve towards low shear. This explains why high-redshift clumps are more massive than GMCs in the local Universe.

  17. Searching molecular structure databases with tandem mass spectra using CSI:FingerID.

    Science.gov (United States)

    Dührkop, Kai; Shen, Huibin; Meusel, Marvin; Rousu, Juho; Böcker, Sebastian

    2015-10-13

    Metabolites provide a direct functional signature of cellular state. Untargeted metabolomics experiments usually rely on tandem MS to identify the thousands of compounds in a biological sample. Today, the vast majority of metabolites remain unknown. We present a method for searching molecular structure databases using tandem MS data of small molecules. Our method computes a fragmentation tree that best explains the fragmentation spectrum of an unknown molecule. We use the fragmentation tree to predict the molecular structure fingerprint of the unknown compound using machine learning. This fingerprint is then used to search a molecular structure database such as PubChem. Our method is shown to improve on the competing methods for computational metabolite identification by a considerable margin.

  18. The applicability of molecular descriptors for designing an electrospray ionization mass spectrometry compatible library for drug discovery.

    Science.gov (United States)

    Copeland, Jennifer C; Zehr, Levi J; Cerny, Ronald L; Powers, Robert

    2012-12-01

    Detecting a small molecular-weight compound by electrospray ionization mass spectrometry (ESI-MS) requires the compound to obtain a charge. Factors such as gas-phase proton affinities and analyte surface activity are correlated with a positive ESI-MS response, but unfortunately it is extremely challenging to predict from a chemical structure alone if a compound is likely to yield an observable molecular-ion peak in an ESI-MS spectrum. Thus, the design of a chemical library for an ESI-MS ligand-affinity screen is particularly daunting. Only 56.9% of the compounds from our FAST-NMR functional library [1] were detectable by ESI-MS. An analysis of ~1,600 molecular descriptors did not identify any correlation with a positive ESI-MS response that cannot be attributed to a skewed population distribution. Unfortunately, our results suggest that molecular descriptors are not a valuable approach for designing a chemical library for an MS-based ligand affinity screen.

  19. Molecular Weight and Association of Asphaltenes: a Critical Review Masse moléculaire et association des asphaltènes : une revue critique

    Directory of Open Access Journals (Sweden)

    Speight J. G.

    2006-11-01

    Full Text Available The determination of asphaltene molecular weights is complicated by the tendency of asphaltene molecules to associate with each other and with other petroleum constituents, and reported molecular weights vary from 900 to 300 000. This paper reviews the methods (vapor pressure osmometry, size exclusion chromatography, ultrafiltration, ultracentrifugation, viscosity, small angle X-ray scattering, infrared spectroscopy, solubilization, and interfacial tension that have been used to estimate asphaltene molecular weights and to probe association phenomena. It is concluded that asphaltene fractions from typical crudes have a number average molecular weight of 1 200-2 700 and a molecular weight range of 1,000-10,000 or higher. Intermolecular association phenomena are primarily responsible for observed molecular weights up to and in excess of 100,000 but detailed mechanisms of the intermolecular associations are not well understood. Certain observations suggest that asphaltene molecules are associated in reversedmicelles and that asphaltenes interact selectively with resins although the evidence on these points is subject to alternate interpretations. H-bond interactions between asphaltenes and resins have been demonstrated. La détermination de la masse moléculaire des asphaltènes est difficile à cause de la tendance qu'ont les molécules d'asphaltènes à s'associer les unes aux autres et avec d'autres constituants des pétroles. Ces masses moléculaires varient de 900 à 300 000. Cet article passe en revue les méthodes (osmométrie par tension de vapeur, chromatographie d'exclusion stérique, ultrafiltration, ultracentrifugation, viscosité, diffusion centrale des rayons X, spectroscopie infra-rouge, solubilisation et tension interfaciale qui ont été utilisées pour estimer les masses moléculaires des asphaltènes et pour étudier les phénomènes d'association. On conclut que les asphaltènes extraits de bruts types ont des masses mol

  20. Testing a low molecular mass fraction of a mushroom (Lentinus edodes) extract formulated as an oral rinse in a cohort of volunteers

    NARCIS (Netherlands)

    Signoretto, C.; Burlacchini, G.; Marchi, A.; Grillenzoni, M.; Cavalleri, G.; Ciric, L.; Lingström, P.; Pezzati, E.; Daglia, M.; Zaura, E.; Pratten, J.; Spratt, D.A.; Wilson, M.; Canepari, P.

    2011-01-01

    Although foods are considered enhancing factors for dental caries and periodontitis, laboratory researches indicate that several foods and beverages contain components endowed with antimicrobial and antiplaque activities. A low molecular mass (LMM) fraction of an aqueous mushroom extract has been

  1. Combining phylogenomics and fossils in higher-level squamate reptile phylogeny: molecular data change the placement of fossil taxa.

    Science.gov (United States)

    Wiens, John J; Kuczynski, Caitlin A; Townsend, Ted; Reeder, Tod W; Mulcahy, Daniel G; Sites, Jack W

    2010-12-01

    Molecular data offer great potential to resolve the phylogeny of living taxa but can molecular data improve our understanding of relationships of fossil taxa? Simulations suggest that this is possible, but few empirical examples have demonstrated the ability of molecular data to change the placement of fossil taxa. We offer such an example here. We analyze the placement of snakes among squamate reptiles, combining published morphological data (363 characters) and new DNA sequence data (15,794 characters, 22 nuclear loci) for 45 living and 19 fossil taxa. We find several intriguing results. First, some fossil taxa undergo major changes in their phylogenetic position when molecular data are added. Second, most fossil taxa are placed with strong support in the expected clades by the combined data Bayesian analyses, despite each having >98% missing cells and despite recent suggestions that extensive missing data are problematic for Bayesian phylogenetics. Third, morphological data can change the placement of living taxa in combined analyses, even when there is an overwhelming majority of molecular characters. Finally, we find strong but apparently misleading signal in the morphological data, seemingly associated with a burrowing lifestyle in snakes, amphisbaenians, and dibamids. Overall, our results suggest promise for an integrated and comprehensive Tree of Life by combining molecular and morphological data for living and fossil taxa.

  2. The molecular mass of dextran used to modify magnetite nanoparticles affects insulin amyloid aggregation

    Czech Academy of Sciences Publication Activity Database

    Sipošová, K.; Pospíšková, K.; Bednáriková, Z.; Šafařík, Ivo; Šafaříková, Miroslava; Kubovčíková, M.; Kopčanský, P.; Gázová, Z.

    2017-01-01

    Roč. 427, April (2017), s. 48-53 ISSN 0304-8853 Institutional support: RVO:60077344 Keywords : amyloid aggregation * nanoparticles * magnetic fluid * dextran * insulin Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 2.630, year: 2016

  3. Ultrastructural and molecular distinctions between the porcine inner cell mass and epiblast reveal unique pluripotent cell states

    DEFF Research Database (Denmark)

    Hall, V. J.; Jacobsen, Janus Valentin; Rasmussen, M. A.

    2010-01-01

    pluripotent cell population as it develops from the ICM to the late epiblast. The ultrastructural observations revealed that the outer cells of the ICM have a high nuclear:cytoplasmic ratio but are transcriptionally inactive and contain mitochondria with few cristae. In contrast, the epiblast cells have......Characterization of the pluripotent cell populations within the porcine embryo is essential for understanding pluripotency and self-renewal regulation in the inner cell mass (ICM) and epiblast. In this study, we perform detailed ultrastructural and molecular characterization of the developing...

  4. Molecularly imprinted polymer applied to the determination of the residual mass of atrazine and metabolites within an agricultural catchment (Brévilles, France).

    Science.gov (United States)

    Amalric, L; Mouvet, C; Pichon, V; Bristeau, S

    2008-10-10

    Atrazine, desethyl-atrazine and desisopropyl-atrazine have been measured in the soils of Brévilles watershed. Pressurised liquid extraction (PLE) technique was used for extraction followed by purification with terbutylazine molecularly imprinted polymers. This clean-up procedure allowed to remove interfering compounds from the sample extracts. Thus making easier the analyses by reversed phase liquid chromatography coupled with ion trap tandem mass spectrometry. This selective sample treatment for soil extracts allowed limit of quantification (LOQ) of 0.03 ng/g for atrazine and 0.05 ng/g for metabolites. The concentrations in soil samples ranged from 7.1 ng/g to water infiltrating with concentrations higher than the drinking water limit, 7 years after the last application of atrazine.

  5. Molecular mass screening to incriminate sand fly vectors of Andean-type cutaneous leishmaniasis in Ecuador and Peru.

    Science.gov (United States)

    Kato, Hirotomo; Cáceres, Abraham G; Gomez, Eduardo A; Mimori, Tatsuyuki; Uezato, Hiroshi; Marco, Jorge D; Barroso, Paola A; Iwata, Hiroyuki; Hashiguchi, Yoshihisa

    2008-11-01

    Sand flies from the Andean areas of Ecuador and Peru were examined for Leishmania infections by using our recently established molecular mass screening method. Leishmanial minicircle DNA-positive sand flies were detected in 3 of 192 and 1 of 462 samples from Ecuador and Peru, respectively. Sand fly species were identified by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the 18S ribosomal RNA (rRNA) gene, and the positive flies were Lutzomyia (Lu.) ayacuchensis and Lu. peruensis, respectively. Furthermore, cytochrome b and mannose-phosphate isomerase gene sequence analyses identified the parasites from Ecuador and Peru as Leishmania (Leishmania) mexicana and L. (Viannia) peruviana, respectively. Thus, the mass screening method was confirmed to be a powerful tool for sand fly research.

  6. Molecular dynamics simulations of certain RGD-based peptides from Kistrin provide insight into the higher activity of REI-RGD34 protein at higher temperature.

    Science.gov (United States)

    Upadhyay, Sanjay K

    2014-05-01

    To determine the bioactive conformation required to bind with receptor aIIbb3, the peptide sequence RIPRGDMP from Kistrin was inserted into CDR 1 loop region of REI protein, resulting in REI-RGD34. The activity of REI-RGD34 was observed to increase at higher temperature towards the receptor aIIbb3. It could be justified in either way: the modified complex forces the restricted peptide to adapt bioactive conformation or it unfolds the peptide in a way that opens its binding surface with high affinity for receptor. Here, we model the conformational preference of RGD sequence in RIPRGDMP at 25 and 42 °C using multiple MD simulations. Further, we model the peptide sequence RGD, PRGD and PRGDMP from kistrin to observe the effect of flanking residues on conformational sampling of RGD. The presence of flanking residues around RGD peptide greatly influenced the conformational sampling. A transition from bend to turn conformation was observed for RGD sequence at 42 °C. The turn conformation shows pharmacophoric parameters required to recognize the receptor aIIbb3. Thus, the temperaturedependent activity of RIPRGDMP when inserted into the loop region of REI can be explained by the presence of the turn conformation. This study will help in designing potential antagonist for the receptor aIIbb3.

  7. Molecular characterization and tandem mass spectrometry of the lectin extracted from the seeds of Dioclea sclerocarpa Ducke.

    Science.gov (United States)

    Correia, Jorge Luis Almeida; do Nascimento, Antônia Sâmia Fernandes; Cajazeiras, João Batista; Gondim, Ana Cláudia Silva; Pereira, Ronniery Ilario; de Sousa, Bruno Lopes; da Silva, André Luiz Coelho; Garcia, Wanius; Teixeira, Edson Holanda; do Nascimento, Kyria Santiago; da Rocha, Bruno Anderson Matias; Nagano, Celso Shiniti; Sampaio, Alexandre Holanda; Cavada, Benildo Sousa

    2011-10-28

    Lectin from the seeds of Dioclea sclerocarpa (DSL) was purified in a single step by affinity chromatography on a Sephadex G-50 column. The primary sequence, as determined by tandem mass spectrometry, revealed a protein with 237 amino acids and 81% of identity with ConA. DSL has a molecular mass of 25,606 Da. The β and γ chains weigh 12,873 Da and 12,752 Da, respectively. DSL hemagglutinated rabbit erythrocytes (both native and treated with proteolytic enzymes), showing stability even after one hour of exposure to a specific pH range. The hemagglutinating activity of DSL was optimal between pH 6.0 and 8.0, but was inhibited after incubation with D-galactose and D-glucose. The pure protein possesses a molecular mass of 25 kDa by SDS-PAGE and 25,606 Da by mass spectrometry. The secondary structure content was estimated using the software SELCON3. The results indicate that b-sheet secondary structures are predominant in DSL (approximately 42.3% antiparallel b-sheet and 6.7% parallel b-sheet). In addition to the b-sheet, the predicted secondary structure of DSL features 4.1% a-helices, 15.8% turns and 31.3% other contributions. Upon thermal denaturation, evaluated by measuring changes in ellipticity at 218 nm induced by a temperature increase from 20 °C to 98 °C, DSL displayed cooperative sigmoidal behavior with transition midpoint at 84 °C and permitted the observation of two-state model (native and denatured).

  8. Bioavailability of sediment-associated and low-molecular-mass species of radionuclides/trace metals to the mussel Mytilus edulis

    Energy Technology Data Exchange (ETDEWEB)

    Borretzen, Peer [Department of Plant and Environmental Sciences, P.O. Box 50003, Norwegian University of Life Sciences, N-1432 As (Norway)], E-mail: peer.borretzen@gmail.com; Salbu, Brit [Department of Plant and Environmental Sciences, P.O. Box 50003, Norwegian University of Life Sciences, N-1432 As (Norway)

    2009-04-15

    Sediments can act as a sink for contaminants in effluents from industrial and nuclear installations or when released from dumped waste. However, contaminated sediments may also act as a potential source of radionuclides and trace metals to the water phase due to remobilisation of metals as dissolved species and resuspension of particles. The marine mussel Mytilus edulis is a filter-feeding organism that via the gills is subjected to contaminants in dissolved form and from contaminants associated to suspended particles via the digestive system. In this paper the bioavailability of sediment-associated and seawater diluted Cs, Co, Cd and Zn radioactive tracers to the filtering bivalve M. edulis has been examined. The mussels were exposed to tracers diluted in ultrafiltered (<10 kDa) seawater (Low Molecular Mass form) or to tracers associated with sediment particles from the Stepovogo Fjord at Novaya Zemlya in short-term uptake experiments, followed by 1-month depuration experiments in flow-through tanks. A toxicokinetic model was fitted to the uptake and depuration data, and the obtained parameters were used to simulate the significance of the two uptake pathways at different suspended sediment loads and sediment-seawater distribution coefficients. The results of the model simulations, assuming steady state conditions, suggest that resuspended particles from contaminated sediments can be a highly significant pathway for mussels in the order {sup 109}Cd {approx_equal} {sup 65}Zn < {sup 134}Cs < {sup 60}Co. The significance increases with higher suspended sediment load and with higher K{sub d}. Furthermore, the experimental depuration data suggest that Cs is retained longer and Co, Cd and Zn shorter by the mussels when associated with ingested sediments, than if the metals are taken up from the low molecular mass (LMM) phase.

  9. Mass spectrometric characterization of low-molecular-mass color pI markers and their use for direct determination of pI value of proteins.

    Science.gov (United States)

    Mazanec, Karel; Slais, Karel; Chmelík, Josef

    2006-12-01

    The use of low-molecular-mass color pI markers for the determination of pI values of proteins in gel isoelectric focusing (IEF) in combination with mass spectrometry is described. Different types of substituted phenols of known pI values within the mass range 250-400 were used here as pI markers. The pure, synthesized pI markers were studied by MALDI-TOF/TOF MS. Fragmentation studies of the pI markers were also performed. Only stable and well-characterized pI markers were used in this work. The selected pI markers were mixed with proteins, deposited on a gel and separated in a pH gradient. Color pI markers enable supervision of progress of the focusing process and also estimation of the position of the invisible focused bands. The separated bands of the pI markers (containing separated proteins) were excised, and the pI markers were eluted from each gel piece by water/ethanol and identified by MALDI-TOF/TOF MS. From the washed gel pieces the remaining carrier ampholytes were then washed out and proteins were in-gel digested with trypsin. The obtained peptides were measured by MALDI-TOF/TOF MS and the proteins identified via a protein database search. This procedure allows avoiding time-consuming protein staining and destaining procedures, which shortens the analysis time roughly by half. For comparison, IEF gels were stained with Coomassie Brilliant Blue R 250 and proteins in the gel bands were identified according to the standard proteomic protocol. This work has confirmed that our approach can give information about the correct pI values of particular proteins and shorten significantly the time of analysis.

  10. Organizing the Cellular and Molecular Heterogeneity in High-Grade Serous Ovarian Cancer by Mass Cytometry

    Science.gov (United States)

    2013-10-01

    analyze mass cytometry data, employing a “ Facebook ”-like strategy. First, “k-neighborhoods” are assigned for each single-cell measurement (in 31...intracellular signaling responses to ex vivo treatment with hydrogen peroxide, a reactive oxygen species which acts as an intracellular second messenger

  11. Ionisation in turbulent magnetic molecular clouds. I. Effect on density and mass-to-flux ratio structures

    Science.gov (United States)

    Bailey, Nicole D.; Basu, Shantanu; Caselli, Paola

    2017-05-01

    Context. Previous studies show that the physical structures and kinematics of a region depend significantly on the ionisation fraction. These studies have only considered these effects in non-ideal magnetohydrodynamic simulations with microturbulence. The next logical step is to explore the effects of turbulence on ionised magnetic molecular clouds and then compare model predictions with observations to assess the importance of turbulence in the dynamical evolution of molecular clouds. Aims: In this paper, we extend our previous studies of the effect of ionisation fractions on star formation to clouds that include both non-ideal magnetohydrodynamics and turbulence. We aim to quantify the importance of a treatment of the ionisation fraction in turbulent magnetised media and investigate the effect of the turbulence on shaping the clouds and filaments before star formation sets in. In particular, here we investigate how the structure, mass and width of filamentary structures depend on the amount of turbulence in ionised media and the initial mass-to-flux ratio. Methods: To determine the effects of turbulence and mass-to-flux ratio on the evolution of non-ideal magnetised clouds with varying ionisation profiles, we have run two sets of simulations. The first set assumes different initial turbulent Mach values for a fixed initial mass-to-flux ratio. The second set assumes different initial mass-to-flux ratio values for a fixed initial turbulent Mach number. Both sets explore the effect of using one of two ionisation profiles: step-like (SL) or cosmic ray only (CR-only). We compare the resulting density and mass-to-flux ratio structures both qualitatively and quantitatively via filament and core masses and filament fitting techniques (Gaussian and Plummer profiles). Results: We find that even with almost no turbulence, filamentary structure still exists although at lower density contours. Comparison of simulations shows that for turbulent Mach numbers above 2, there is

  12. Should We Start Worrying? Mass Higher Education, Skill Demand and the Increasingly Complex Landscape of Young Graduates' Employment

    Science.gov (United States)

    Figueiredo, Hugo; Biscaia, Ricardo; Rocha, Vera; Teixeira, Pedro

    2017-01-01

    Recent decades have seen a massive expansion in higher education (HE), fuelled by high expectations about its private benefits. This has raised concerns about the impact on the employability of recent graduates and the potential mismatches between their skills and the competences required by the job structure. Equally, it could set the ground for…

  13. Significance of the mass media in mid-higher education and university indigenous students inmigrated to Monterrey

    Directory of Open Access Journals (Sweden)

    Juan Antonio Doncel de la Colina

    2016-07-01

    Full Text Available The recent but intense flow of indigenous migrants to the Mexican border state of Nuevo León has made this region the primary recipient of Mexico's indigenous migrant population. Based on the hypothesis that the entry of indigenous youth into high-school and university education has a marked effect on the transformation of their ethnic identity, we examine the uses that these indigenous students have for certain mass media and the meanings that they award to such media. Using a qualitative method and in-depth interviews, we analyze how the different uses and meanings of film, television, and radio symbolize the process of identity transition for these youth who have migrated to Monterrey. Similarly, we identify how the "level of education" and "ethnic group" variables have a significant explanatory weight in interpreting these identity-construction processes.

  14. Void Measurements in the Regions of Sub-Cooled and Low-Quality Boiling. Part 2. Higher Mass Velocities

    Energy Technology Data Exchange (ETDEWEB)

    Rouhani, S.Z.

    1966-07-15

    This report consists mostly of tables of experimental data obtained in void measurements. It is a continuation and the completing part of a previous report with the same title. The data are from the measurements in a vertical annular channel with 25 mm O.D. and 12 mm I.D. at a heated length of 1090 mm. These experiments covered pressures from 10 to 50 bars, mass velocities from 650 to 1450 kg/m -sec., heat fluxes from 60 to 120 W/cm{sup 2}, sub-coolings from 30 to 0 C, and steam qualities from 0 to 12 %. The tables include the inlet temperatures and measured wall super-heat.

  15. Modelling exposure of oceanic higher trophic-level consumers to polychlorinated biphenyls: pollution 'hotspots' in relation to mass mortality events of marine mammals.

    Science.gov (United States)

    Handoh, Itsuki C; Kawai, Toru

    2014-08-30

    Marine mammals in the past mass mortality events may have been susceptible to infection because their immune systems were suppressed through the bioaccumulation of environmental pollutants such as polychlorinated biphenyls (PCBs). We compiled mortality event data sets of 33 marine mammal species, and employed a Finely-Advanced Transboundary Environmental model (FATE) to model the exposure of the global fish community to PCB congeners, in order to define critical exposure levels (CELs) of PCBs above which mass mortality events are likely to occur. Our modelling approach enabled us to describe the mass mortality events in the context of exposure of higher-trophic consumers to PCBs and to identify marine pollution 'hotspots' such as the Mediterranean Sea and north-western European coasts. We demonstrated that the CELs can be applied to quantify a chemical pollution Planetary Boundary, under which a safe operating space for marine mammals and humanity can exist. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Molecular mass distribution and epitopes of the beta lactoglobulin submitted to hydrolysis pre-transglutaminase treatment

    Energy Technology Data Exchange (ETDEWEB)

    Villas-Boas, M.B.; Zollner, R.L.; Netto, F.M. [Universidade Estadual de Campinas (UNICAMP), SP (Brazil); Paes Leme, A.F. [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Benede, S.; Molina, E. [Universidad Autonoma de Madrid (Spain)

    2012-07-01

    Full text: The {beta}-Lactoglobulin ({beta}-Lg) is a whey protein with important nutritional proper ties but very resistant to pepsin digestion and consequently highly antigenic. This protein can be modified by transglutaminase (TG) although it is required a pretreatment to increase their susceptibility to the TG action. In the present study the hydrolysis pre-TG treatment was used to improve the TG accessibility on {beta}-Lg and the MM distribution and antigenic fragments were evaluated. For pre-TG treatment, the {beta}-Lg (Davisco Inc.) was hydrolyzed with bromelain (3% of {beta}-Lg w/w in distilled water; 25 U enzyme g{sup 1} of substrate, pH 7.5, 240 min) and then polymerized by TG (7% hydrolysate, 10U TG g{sup 1} protein, 50 C/180 min). The samples were evaluated by SDS-PAGE/tricine and by RP-nanoUPLC (nanoAcquity UPLC, Waters) coupled with nano-electrospray tandem mass spectrometry on a Q-Tof Ultima API mass spectrometer (MicroMass/Waters) at LNBio. The products were also submitted to pepsin digestion and the peptide identification was performed by RP-HPLC-tandem mass spectrometry (RP-HPLC-MS/MS, Brucker) with support from CIAL. The {beta}-Lg hydrolysed by bromelain and polymerized by TG had a broad MM distribution. The intact mass analysis indicated that the non modified {beta}Lg -A showed 18.362 Da and the non modified {beta}Lg -B 18.274 Da, which is in agreement with the theoretical corresponding masses. The use of bromelain pre-TG treatment resulted in polymers with MM from 61.052 to 67.654 Da, although some non modified protein was still present. In addition, the non modified {beta}-Lg showed fragments that present high antigenicity (such as Leu{sub 95} - Leu{sub 104}, Asp{sub 95} - Phe{sub 105}, Tyr{sub 42} - Leu{sub 54}, lle{sub 29} - Val{sub 41}), previously identified as IgE-binding epitopes. After hydrolysis following by TG treatment the fragment Tyr{sub 42} - Leu{sub 54} was still present, however the other fragments that were observed in the non

  17. Metabolomic approach for identifying and visualizing molecular tissue markers in tadpoles of Xenopus tropicalis by mass spectrometry imaging

    Directory of Open Access Journals (Sweden)

    Naoko Goto-Inoue

    2016-09-01

    Full Text Available In developmental and cell biology it is crucial to evaluate the dynamic profiles of metabolites. An emerging frog model system using Xenopus tropicalis, whose genome sequence and inbred strains are available, is now ready for metabolomics investigation in amphibians. In this study we applied matrix-assisted laser desorption/ionization (MALDI-mass spectrometry imaging (MSI analysis to identify and visualize metabolomic molecular markers in tadpoles of Xenopus tropicalis. We detected tissue-specific peaks and visualized their distribution in tissues, and distinguished 19 tissues and their specific peaks. We identified, for the first time, some of their molecular localizations via tandem mass spectrometric analysis: hydrocortisone in artery, L-DOPA in rhombencephalon, taurine in eye, corticosterone in gill, heme in heart, inosine monophosphate and carnosine in muscle, dopamine in nerves, and phosphatidylethanolamine (16:0/20:4 in pharynx. This is the first MALDI-MSI study of X. tropicalis tadpoles, as in small tadpoles it is hard to distinguish and dissect the various organs. Furthermore, until now there has been no data about the metabolomic profile of each organ. Our results suggest that MALDI-MSI is potentially a powerful tool for examining the dynamics of metabolomics in metamorphosis as well as conformational changes due to metabolic changes.

  18. Low molecular mass thiols, disulfides and protein mixed disulfides in rat tissues: influence of sample manipulation, oxidative stress and ageing.

    Science.gov (United States)

    Giustarini, Daniela; Dalle-Donne, Isabella; Milzani, Aldo; Rossi, Ranieri

    2011-04-01

    Most of the data in studies investigating the contribution of oxidative stress to some human diseases and to ageing derive from measurements carried out in blood, on the basis of the assumption that any alteration of the hematic thiol/disulfide balance should reflect a corresponding alteration in other less accessible tissues. But it is evident that the information that can be gleaned from a direct analysis in specific tissues is largely greater. Nevertheless, the accurate measurement of disulfides is frequently hampered by the artifactual oxidation occurring during sample manipulation as a consequence of the presence of heme-proteins. Therefore, the levels of disulfide forms of low molecular mass thiols in tissues are still poorly investigated, even if their measurements could represent a powerful index of the oxidative status. Here we have used an artifact-free procedure to measure low molecular mass thiols and their disulfides in different rat tissues. Our findings suggest that disulfides are a reliable biomarker of even slight oxidative damage. In tissues of aged rats we observed that either oxidative stress or glutathione depletion alone can occur in different tissues during ageing. Interestingly, among the investigated thiols, only homocysteine showed a tendency to increase in some organs with ageing. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  19. Matter-wave interference of particles selected from a molecular library with masses exceeding 10,000 amu.

    Science.gov (United States)

    Eibenberger, Sandra; Gerlich, Stefan; Arndt, Markus; Mayor, Marcel; Tüxen, Jens

    2013-09-21

    The quantum superposition principle, a key distinction between quantum physics and classical mechanics, is often perceived as a philosophical challenge to our concepts of reality, locality or space-time since it contrasts with our intuitive expectations with experimental observations on isolated quantum systems. While we are used to associating the notion of localization with massive bodies, quantum physics teaches us that every individual object is associated with a wave function that may eventually delocalize by far more than the body's own extension. Numerous experiments have verified this concept at the microscopic scale but intuition wavers when it comes to delocalization experiments with complex objects. While quantum science is the uncontested ideal of a physical theory, one may ask if the superposition principle can persist on all complexity scales. This motivates matter-wave diffraction and interference studies with large compounds in a three-grating interferometer configuration which also necessitates the preparation of high-mass nanoparticle beams at low velocities. Here we demonstrate how synthetic chemistry allows us to prepare libraries of fluorous porphyrins which can be tailored to exhibit high mass, good thermal stability and relatively low polarizability, which allows us to form slow thermal beams of these high-mass compounds, which can be detected using electron ionization mass spectrometry. We present successful superposition experiments with selected species from these molecular libraries in a quantum interferometer, which utilizes the diffraction of matter-waves at an optical phase grating. We observe high-contrast quantum fringe patterns of molecules exceeding a mass of 10,000 amu and having 810 atoms in a single particle.

  20. Molecular Biology Masterclasses--Developing Practical Skills and Building Links with Higher Education in Years 12/13

    Science.gov (United States)

    Hooley, Paul; Cooper, Phillippa; Skidmore, Nick

    2008-01-01

    A one day practical course in molecular biology skills suitable for year 12/13 students is described. Colleagues from partner schools and colleges were trained by university staff in basic techniques and then collaborated in the design of a course suitable for their own students. Participants carried out a transformation of "E.coli"…

  1. High molecular weight SOA formation during limonene ozonolysis: insights from ultrahigh-resolution FT-ICR mass spectrometry characterization

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    S. Kundu

    2012-06-01

    Full Text Available The detailed molecular composition of laboratory generated limonene ozonolysis secondary organic aerosol (SOA was studied using ultrahigh-resolution Fourier transform ion cyclotron resonance (FT-ICR mass spectrometry. Approximately 1200 molecular formulas were identified in the SOA over the mass range of 140 to 850 Da. Four characteristic groups of high relative abundance species were observed; they indicate an array of accretion products that retain a large fraction of the limonene skeleton. The identified molecular formulas of each of the groups are related to one another by CH2, O and CH2O homologous series. The CH2 and O homologous series of the low molecular weight (MW SOA (m/z < 300 are explained with a combination of functionalization and fragmentation of radical intermediates and reactive uptake of gas-phase carbonyls. They include isomerization and elimination reactions of Criegee radicals, reactions between alkyl peroxy radicals, and scission of alkoxy radicals resulting from the Criegee radicals. The presence of compounds with 10–15 carbon atoms in the first group (e.g. C11H18O6 provides evidence for SOA formation by the reactive uptake of gas-phase carbonyls during limonene ozonolysis. The high MW compounds (m/z > 300 were found to constitute a significant number fraction of the identified SOA components. The formation of high MW compounds was evaluated by molecular formula trends, fragmentation analysis of select high MW compounds and a comprehensive reaction matrix including the identified low MW SOA, hydroperoxides and Criegee radicals as building blocks. Although the formation of high MW SOA may occur via a variety of radical and non-radical reaction channels, the combined approach indicates a greater importance of the non-condensation reactions over aldol and ester condensation reaction channels. Among these hemi-acetal reactions appear to be most

  2. Mass Spectrometry Imaging of low Molecular Weight Compounds in Garlic (Allium sativum L.) with Gold Nanoparticle Enhanced Target.

    Science.gov (United States)

    Misiorek, Maria; Sekuła, Justyna; Ruman, Tomasz

    2017-11-01

    Garlic (Allium sativum) is the subject of many studies due to its numerous beneficial properties. Although compounds of garlic have been studied by various analytical methods, their tissue distributions are still unclear. Mass spectrometry imaging (MSI) appears to be a very powerful tool for the identification of the localisation of compounds within a garlic clove. Visualisation of the spatial distribution of garlic low-molecular weight compounds with nanoparticle-based MSI. Compounds occurring on the cross-section of sprouted garlic has been transferred to gold-nanoparticle enhanced target (AuNPET) by imprinting. The imprint was then subjected to MSI analysis. The results suggest that low molecular weight compounds, such as amino acids, dipeptides, fatty acids, organosulphur and organoselenium compounds are distributed within the garlic clove in a characteristic manner. It can be connected with their biological functions and metabolic properties in the plant. New methodology for the visualisation of low molecular weight compounds allowed a correlation to be made between their spatial distribution within a sprouted garlic clove and their biological function. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  3. Anatomical-Molecular Distribution of EphrinA1 in Infarcted Mouse Heart Using MALDI Mass Spectrometry Imaging

    Science.gov (United States)

    Lefcoski, Stephan; Kew, Kimberly; Reece, Shaun; Torres, Maria J.; Parks, Justin; Reece, Sky; de Castro Brás, Lisandra E.; Virag, Jitka A. I.

    2018-01-01

    EphrinA1 is a tyrosine kinase receptor localized in the cellular membrane of healthy cardiomyocytes, the expression of which is lost upon myocardial infarction (MI). Intra-cardiac injection of the recombinant form of ephrinA1 (ephrinA1-Fc) at the time of ligation in mice has shown beneficial effects by reducing infarct size and myocardial necrosis post-MI. To date, immunohistochemistry and Western blotting comprise the only experimental approaches utilized to localize and quantify relative changes of ephrinA1 in sections and homogenates of whole left ventricle, respectively. Herein, we used matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) coupled with a time-of-flight mass spectrometer (MALDI/TOF MS) to identify intact as well as tryptic fragments of ephrinA1 in healthy controls and acutely infarcted murine hearts. The purpose of the present study was 3-fold: (1) to spatially resolve the molecular distribution of endogenous ephrinA1, (2) to determine the anatomical expression profile of endogenous ephrinA1 after acute MI, and (3) to identify molecular targets of ephrinA1-Fc action post-MI. The tryptic fragments detected were identified as the ephrinA1-isoform with 38% and 34% sequence coverage and Mascot scores of 25 for the control and MI hearts, respectively. By using MALDI-MSI, we have been able to simultaneously measure the distribution and spatial localization of ephrinA1, as well as additional cardiac proteins, thus offering valuable information for the elucidation of molecular partners, mediators, and targets of ephrinA1 action in cardiac muscle.

  4. Albumin is synthesized in epididymis and aggregates in a high molecular mass glycoprotein complex involved in sperm-egg fertilization.

    Directory of Open Access Journals (Sweden)

    Kélen Fabíola Arroteia

    Full Text Available The epididymis has an important role in the maturation of sperm for fertilization, but little is known about the epididymal molecules involved in sperm modifications during this process. We have previously described the expression pattern for an antigen in epididymal epithelial cells that reacts with the monoclonal antibody (mAb TRA 54. Immunohistochemical and immunoblotting analyses suggest that the epitope of the epididymal antigen probably involves a sugar moiety that is released into the epididymal lumen in an androgen-dependent manner and subsequently binds to luminal sperm. Using column chromatography, SDS-PAGE with in situ digestion and mass spectrometry, we have identified the protein recognized by mAb TRA 54 in mouse epididymal epithelial cells. The ∼65 kDa protein is part of a high molecular mass complex (∼260 kDa that is also present in the sperm acrosomal vesicle and is completely released after the acrosomal reaction. The amino acid sequence of the protein corresponded to that of albumin. Immunoprecipitates with anti-albumin antibody contained the antigen recognized by mAb TRA 54, indicating that the epididymal molecule recognized by mAb TRA 54 is albumin. RT-PCR detected albumin mRNA in the epididymis and fertilization assays in vitro showed that the glycoprotein complex containing albumin was involved in the ability of sperm to recognize and penetrate the egg zona pellucida. Together, these results indicate that epididymal-derived albumin participates in the formation of a high molecular mass glycoprotein complex that has an important role in egg fertilization.

  5. Time-resolved molecular characterization of limonene/ozone aerosol using high-resolution electrospray ionization mass spectrometry.

    Science.gov (United States)

    Bateman, Adam P; Nizkorodov, Sergey A; Laskin, Julia; Laskin, Alexander

    2009-09-28

    Molecular composition of limonene/O3 secondary organic aerosol (SOA) was investigated using high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) as a function of reaction time. SOA was generated by ozonation of D-limonene in a reaction chamber and sampled at different time intervals using a cascade impactor. The SOA samples were extracted into acetonitrile and analyzed using a HR-ESI-MS instrument with a resolving power of 100,000 (m/Deltam). The resulting mass spectra provided detailed information about the extent of oxidation inferred from the O:C ratios, double bond equivalency (DBE) factors, and aromaticity index (AI) values in hundreds of identified individual SOA species. The chemical composition of SOA was approximately the same for all size-fractionated samples studied in this experiment (0.05 to 0.5 microm range). The SOA constituents quickly reached an average O:C ratio of 0.43, which grew to 0.46 after one hour of additional oxidation of particles by the excess ozone. The dominant mechanism of oligomerization, inferred from high resolution ESI-MS data, was reaction between Criegee intermediates and stable first-generation products of limonene ozonolysis. Although the SOA composition was dominated by various oxidized aliphatic compounds, a small fraction of products appeared to contain aromatic rings. SOA generation was also studied in the presence of UV radiation and at elevated relative humidity (RH). The presence of UV radiation had a negligible effect on the SOA composition. The presence of water vapor resulted in a slight redistribution of peak intensities in the mass spectrum likely arising from hydration of certain SOA constituents. The data are consistent with fast production of the first-generation SOA constituents, including oligomers, followed by very slow aging processes that have a relatively small effect on the average molecular composition on the timescale of our experiments.

  6. Albumin is synthesized in epididymis and aggregates in a high molecular mass glycoprotein complex involved in sperm-egg fertilization.

    Science.gov (United States)

    Arroteia, Kélen Fabíola; Barbieri, Mainara Ferreira; Souza, Gustavo Henrique Martins Ferreira; Tanaka, Hiromitsu; Eberlin, Marcos Nogueira; Hyslop, Stephen; Alvares, Lúcia Elvira; Pereira, Luís Antonio Violin Dias

    2014-01-01

    The epididymis has an important role in the maturation of sperm for fertilization, but little is known about the epididymal molecules involved in sperm modifications during this process. We have previously described the expression pattern for an antigen in epididymal epithelial cells that reacts with the monoclonal antibody (mAb) TRA 54. Immunohistochemical and immunoblotting analyses suggest that the epitope of the epididymal antigen probably involves a sugar moiety that is released into the epididymal lumen in an androgen-dependent manner and subsequently binds to luminal sperm. Using column chromatography, SDS-PAGE with in situ digestion and mass spectrometry, we have identified the protein recognized by mAb TRA 54 in mouse epididymal epithelial cells. The ∼65 kDa protein is part of a high molecular mass complex (∼260 kDa) that is also present in the sperm acrosomal vesicle and is completely released after the acrosomal reaction. The amino acid sequence of the protein corresponded to that of albumin. Immunoprecipitates with anti-albumin antibody contained the antigen recognized by mAb TRA 54, indicating that the epididymal molecule recognized by mAb TRA 54 is albumin. RT-PCR detected albumin mRNA in the epididymis and fertilization assays in vitro showed that the glycoprotein complex containing albumin was involved in the ability of sperm to recognize and penetrate the egg zona pellucida. Together, these results indicate that epididymal-derived albumin participates in the formation of a high molecular mass glycoprotein complex that has an important role in egg fertilization.

  7. Combination of statistical methods and Fourier transform ion cyclotron resonance mass spectrometry for more comprehensive, molecular-level interpretations of petroleum samples.

    Science.gov (United States)

    Hur, Manhoi; Yeo, Injoon; Park, Eunsuk; Kim, Young Hwan; Yoo, Jongshin; Kim, Eunkyoung; No, Myoung-han; Koh, Jaesuk; Kim, Sunghwan

    2010-01-01

    Complex petroleum mass spectra obtained by Fourier-transform ion cyclotron resonance mass spectrometry (FTICR MS) were successfully interpreted at the molecular level by applying principle component analysis (PCA) and hierarchical clustering analysis (HCA). A total of 40 mass spectra were obtained from 20 crude oil samples using both positive and negative atmospheric pressure photoionization (APPI). Approximately 400,000 peaks were identified at the molecular level. Conventional data analyses would have been impractical with so much data. However, PCA grouped samples into score plots based on their molecular composition. In this way, the overall compositional difference between samples could be easily displayed and identified by comparing score and loading plots. HCA was also performed to group and compare samples based on selected peaks that had been grouped by PCA. Subsequent heat map analyses revealed detailed compositional differences among grouped samples. This study demonstrates a promising new approach for studying multiple, complex petroleum samples at the molecular level.

  8. An evolutionary model for collapsing molecular clouds and their star formation activity. II. Mass dependence of the star formation rate

    Energy Technology Data Exchange (ETDEWEB)

    Zamora-Avilés, Manuel; Vázquez-Semadeni, Enrique [Centro de Radioastronomía y Astrofísica, Universidad Nacional Autónoma de México, Apdo. Postal 3-72, Morelia, Michoacán 58089 (Mexico)

    2014-10-01

    We discuss the evolution and dependence on cloud mass of the star formation rate (SFR) and efficiency (SFE) of star-forming molecular clouds (MCs) within the scenario that clouds are undergoing global collapse and that the SFR is controlled by ionization feedback. We find that low-mass clouds (M {sub max} ≲ 10{sup 4} M {sub ☉}) spend most of their evolution at low SFRs, but end their lives with a mini-burst, reaching a peak SFR ∼10{sup 4} M {sub ☉} Myr{sup –1}, although their time-averaged SFR is only (SFR) ∼ 10{sup 2} M {sub ☉} Myr{sup –1}. The corresponding efficiencies are SFE{sub final} ≲ 60% and (SFE) ≲ 1%. For more massive clouds (M {sub max} ≳ 10{sup 5} M {sub ☉}), the SFR first increases and then reaches a plateau because the clouds are influenced by stellar feedback since earlier in their evolution. As a function of cloud mass, (SFR) and (SFE) are well represented by the fits (SFR) ≈ 100(1 + M {sub max}/1.4 × 10{sup 5} M {sub ☉}){sup 1.68} M {sub ☉} Myr{sup –1} and (SFE) ≈ 0.03(M {sub max}/2.5 × 10{sup 5} M {sub ☉}){sup 0.33}, respectively. Moreover, the SFR of our model clouds follows closely the SFR-dense gas mass relation recently found by Lada et al. during the epoch when their instantaneous SFEs are comparable to those of the clouds considered by those authors. Collectively, a Monte Carlo integration of the model-predicted SFR(M) over a Galactic giant molecular cloud mass spectrum yields values for the total Galactic SFR that are within half an order of magnitude of the relation obtained by Gao and Solomon. Our results support the scenario that star-forming MCs may be in global gravitational collapse and that the low observed values of the SFR and SFE are a result of the interruption of each SF episode, caused primarily by the ionizing feedback from massive stars.

  9. Bipolar Molecular Outflows within 1pc of Sgr A*:Evidence for Low-mass Star Formation Activity

    Science.gov (United States)

    Yusef-Zadeh, Farhad; Wardle, Mark; Kunneriath, Devaky; Royster, Marc; Wootten, Al; Roberts, Douglas

    2018-01-01

    The 4 million solar mass black hole, Sgr A*, is expected to suppress star formation because the measured density of the cloud is insufficient for self-gravity to overcome tidal disruption by the black hole's gravitational field. Nevertheless, objects resembling dust-enshrouded young stars and photo-evaporative flows from their disks have been identified within 2pc of Sgr A*. Clear identification of the nature of these objects has been hampered by the Galactic center's distance, 30 magnitudes of foreground extinction, and stellar crowding. Here, we report the discovery of 11 bipolar molecular outflows using ALMA within a projected distance of one pc from Sgr A*. These unambiguous signatures of young protostars manifest as approaching and receding lobes of dense gas swept up by the jets created during the formation and early evolution of low-mass stars. The mean dynamical age of the outflow sources and the rate of star formation are estimated to be ~6500 years and ~5x10^{-4} solar mass per year, respectively. These measurements suggest that star formation could take place in the immediate vicinity of supermassive black holes in the nuclei of external galaxies.

  10. Lower Late-Life Body-Mass Index is Associated with Higher Cortical Amyloid Burden in Clinically Normal Elderly.

    Science.gov (United States)

    Hsu, David C; Mormino, Elizabeth C; Schultz, Aaron P; Amariglio, Rebecca E; Donovan, Nancy J; Rentz, Dorene M; Johnson, Keith A; Sperling, Reisa A; Marshall, Gad A

    2016-06-18

    Lower body-mass index (BMI) in late life has been associated with an increased risk of dementia, and weight loss has been associated with more rapid decline in Alzheimer's disease (AD) dementia. To explore the association between BMI and cortical amyloid burden in clinically normal (CN) elderly at risk for AD dementia. Cross-sectional analyses were completed using baseline data from the Harvard Aging Brain Study, consisting of 280 community-dwelling CN older adults aged 62-90. Assessments included medical histories and physical exam, Pittsburgh compound B (PiB) positron emission tomography (PET) amyloid imaging, and apolipoprotein E ɛ4 (APOE4) genotyping. For the primary analysis, a general linear regression model was used to evaluate the association of BMI with PiB retention. Covariates included age, sex, years of education, and APOE4 carrier status. Secondary analyses were performed for BMI subdivisions (normal, overweight, obese), APOE4 carriers, and BMI×APOE4 interaction. In the primary analysis, greater PiB retention was associated with lower BMI (β  =  -0.14, p = 0.02). In the secondary analyses, APOE4 carrier status (β= -0.27, p = 0.02) and normal BMI (β= -0.25, p = 0.01), as opposed to overweight or obese BMI, were associated with greater PiB retention. The BMI×APOE4 interaction was also significant (β= -0.14, p = 0.04). This finding offers new insight into the role of BMI at the preclinical stage of AD, wherein lower BMI late in life is associated with greater cortical amyloid burden. Future studies are needed to elucidate the mechanism behind this association, especially in those with lower BMI who are APOE4 carriers.

  11. A critique of massification of higher education in Poland and the United States: Mass-media discourse analysis

    Directory of Open Access Journals (Sweden)

    Łukasz Stankiewicz

    2017-01-01

    Full Text Available The nearly universal access to higher education (HE in developed countries was once praised as a great democratic achievement, and a basis for both economic development and social mobility. After the onset of the 2008 recession, the narratives changed considerably. The most radical critics of HE propose a partial “deschooling” of society by reversing the process of massification. This paper aims to present a critical discourse analysis (CAD of the “don’t go to college” discourse that became popular in Poland and the United States. I trace the differences in the way the decision to go to college is conceptualized in Poland and the U.S to the differences in dominant political ideologies – democratic and egalitarian in the U.S., paternalistic and conservative in Poland. I also show how recent changes in the actual HE systems put those ideologies at odds with the educational realities of both countries.

  12. Mass Spectrometry-Based Proteomics in Molecular Diagnostics: Discovery of Cancer Biomarkers Using Tissue Culture

    Directory of Open Access Journals (Sweden)

    Debasish Paul

    2013-01-01

    Full Text Available Accurate diagnosis and proper monitoring of cancer patients remain a key obstacle for successful cancer treatment and prevention. Therein comes the need for biomarker discovery, which is crucial to the current oncological and other clinical practices having the potential to impact the diagnosis and prognosis. In fact, most of the biomarkers have been discovered utilizing the proteomics-based approaches. Although high-throughput mass spectrometry-based proteomic approaches like SILAC, 2D-DIGE, and iTRAQ are filling up the pitfalls of the conventional techniques, still serum proteomics importunately poses hurdle in overcoming a wide range of protein concentrations, and also the availability of patient tissue samples is a limitation for the biomarker discovery. Thus, researchers have looked for alternatives, and profiling of candidate biomarkers through tissue culture of tumor cell lines comes up as a promising option. It is a rich source of tumor cell-derived proteins, thereby, representing a wide array of potential biomarkers. Interestingly, most of the clinical biomarkers in use today (CA 125, CA 15.3, CA 19.9, and PSA were discovered through tissue culture-based system and tissue extracts. This paper tries to emphasize the tissue culture-based discovery of candidate biomarkers through various mass spectrometry-based proteomic approaches.

  13. Surface properties of heat-induced soluble soy protein aggregates of different molecular masses.

    Science.gov (United States)

    Guo, Fengxian; Xiong, Youling L; Qin, Fang; Jian, Huajun; Huang, Xiaolin; Chen, Jie

    2015-02-01

    Suspensions (2% and 5%, w/v) of soy protein isolate (SPI) were heated at 80, 90, or 100 °C for different time periods to produce soluble aggregates of different molecular sizes to investigate the relationship between particle size and surface properties (emulsions and foams). Soluble aggregates generated in these model systems were characterized by gel permeation chromatography and sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Heat treatment increased surface hydrophobicity, induced SPI aggregation via hydrophobic interaction and disulfide bonds, and formed soluble aggregates of different sizes. Heating of 5% SPI always promoted large-size aggregate (LA; >1000 kDa) formation irrespective of temperature, whereas the aggregate size distribution in 2% SPI was temperature dependent: the LA fraction progressively rose with temperature (80→90→100 °C), corresponding to the attenuation of medium-size aggregates (MA; 670 to 1000 kDa) initially abundant at 80 °C. Heated SPI with abundant LA (>50%) promoted foam stability. LA also exhibited excellent emulsifying activity and stabilized emulsions by promoting the formation of small oil droplets covered with a thick interfacial protein layer. However, despite a similar influence on emulsion stability, MA enhanced foaming capacity but were less capable of stabilizing emulsions than LA. The functionality variation between heated SPI samples is clearly related to the distribution of aggregates that differ in molecular size and surface activity. The findings may encourage further research to develop functional SPI aggregates for various commercial applications. © 2015 Institute of Food Technologists®

  14. Ribonucleic acid from the higher plant Matthiola incana. Molecular weight measurements and DNA-RNA hybridisation studies.

    Science.gov (United States)

    Grierson, D; Hemleben, V

    1977-04-04

    The percentage of DNA from the crucifer Matthiola incana coding for different types of RNA was measured by filter saturation hybridisation experiments using RNA labelled in vivo. In addition, the melting curves of the various DNA - RNA hybrids formed and the buoyant densities of the DNA sequences complementary to different types of RNA were measured. 1. The RNA preparations used were 25, 18, and 5 S rRNA and 4 S RNA, purified by gel electrophoresis, and poly(A)-containing RNA purified by oligo-(dT)-cellulose chromatography. The molecular weights of the 25 S and 18 S rRNAs, calculated from the mobility in formamide-acrylamide gels relative to Escherichia coli RNA, are 1.25 - 10(6) and 0.64 - 10(6). The rRNA precursor has a molecular weight of approx. 2.1 - 10(6) and the average molecular weight of the poly(A)-containing RNA from both cotyledons and roots is 4 - 10(5). 2. The percentage of the genome, calculated on the basis of double-stranded DNA, coding for these RNAs and the estimated number of genes per haploid DNA amount are approximately 0.46% and 1100 for 25 S plus 18 S rRNA, 0.032% and 3600 for 5 S rRNA and 0.072% and 13 000 for 4 S RNA. In filter hybridisation experiments very little hybridisation of poly(A)-containing RNA was found. A rapidly-hybridising component is attributed to small amounts of contaminating rRNA. 3. M. incana DNA has a main band at 1.697 g - ml-1 in CsCl and a satellite constituting approximately 3% of the DNA, at 1.708 g - ml-1 - 25 and 18 S rRNA hybridise to DNA with a buoyant density of 1.701--2 g - ml-1. The buoyant density of 5 S DNA is slightly less at 1.700--1 g - ml-1. 4. S RNA hybridises to at least two separate regions, one within the main-band DNA and a second lighter component. None of the RNAs tested hybridised to the satellite DNA. The Tm of the DNA - RNA hybrids in 1 X SSC is 89 degrees C for 25 S rRNA, 85 degrees C for 5 S rRNA and 82 degrees C for 4 S RNA. 4. 5 and 4 S RNA preparations contain fragments which hybridise

  15. Comparative evaluation of low-molecular-mass proteins from Mycobacterium tuberculosis identifies members of the ESAT-6 family as immunodominant T-cell antigens

    DEFF Research Database (Denmark)

    Skjøt, R L; Oettinger, T; Rosenkrands, I

    2000-01-01

    ), and the well-described ESAT-6 antigen. Genetic analyses demonstrated that TB10.4 as well as CFP10 belongs to the ESAT-6 family of low-mass proteins, whereas TB7.3 is a low-molecular-mass protein outside this family. The proteins were expressed in Escherichia coli, and their immunogenicity was tested...... in cultures of peripheral blood mononuclear cells from human tuberculosis (TB) patients, Mycobacterium bovis BCG-vaccinated donors, and nonvaccinated donors. The two ESAT-6 family members, TB10.4 and CFP10, were very strongly recognized and induced gamma interferon release at the same level (CFP10......) as or at an even higher level (TB10.4) than ESAT-6. The non-ESAT-6 family member, TB7.3, for comparison, was recognized at a much lower level. CFP10 was found to distinguish TB patients from BCG-vaccinated donors and is, together with ESAT-6, an interesting candidate for the diagnosis of TB. The striking...

  16. Comparative evaluation of low-molecular-mass proteins from Mycobacterium tuberculosis identifies members of the ESAT-6 family as immunodominant T-cell antigens

    DEFF Research Database (Denmark)

    Skjøt, Rikke L. V.; Oettinger, Thomas; Rosenkrands, Ida

    2000-01-01

    ), and the well-described ESAT-6 antigen. Genetic analyses demonstrated that TB10.4 as well as CFP10 belongs to the ESAT-6 family of low-mass proteins, whereas TB7.3 is a low-molecular-mass protein outside this family. The proteins were expressed in Escherichia coli, and their immunogenicity was tested...... in cultures of peripheral blood mononuclear cells from human tuberculosis (TB) patients, Mycobacterium bovis BCG-vaccinated donors, and nonvaccinated donors. The two ESAT-6 family members, TB10.4 and CFP10, were very strongly recognized and induced gamma interferon release at the same level (CFP10......) as or at an even higher level (TB10.4) than ESAT-6, The non-ESAT-6 family member, TB7.3, for comparison, was recognized at a much lower level, CFP10 tvas found to distinguish TB patients from BCG-vaccinated donors and is, together with ESAT-6 an interesting candidate for the diagnosis of TB. The striking...

  17. Novel algorithm for simultaneous component detection and pseudo-molecular ion characterization in liquid chromatography–mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yufeng; Wang, Xiaoan; Wo, Siukwan [School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China); Ho, Hingman; Han, Quanbin [School of Chinese Medicine, Hong Kong Baptist University, 7 Baptist University Road, Kowloon Tong, Hong Kong (China); Fan, Xiaohui [College of Pharmaceutical Sciences, Zhejiang University, Hangzhou 310058 (China); Zuo, Zhong, E-mail: joanzuo@cuhk.edu.hk [School of Pharmacy, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong (China)

    2015-01-01

    Highlights: • Novel stepwise component detection algorithm (SCDA) for LC–MS datasets. • New isotopic distribution and adduct-ion models for mass spectra. • Automatic component classification based on adduct-ion and isotopic distributions. - Abstract: Resolving components and determining their pseudo-molecular ions (PMIs) are crucial steps in identifying complex herbal mixtures by liquid chromatography–mass spectrometry. To tackle such labor-intensive steps, we present here a novel algorithm for simultaneous detection of components and their PMIs. Our method consists of three steps: (1) obtaining a simplified dataset containing only mono-isotopic masses by removal of background noise and isotopic cluster ions based on the isotopic distribution model derived from all the reported natural compounds in dictionary of natural products; (2) stepwise resolving and removing all features of the highest abundant component from current simplified dataset and calculating PMI of each component according to an adduct-ion model, in which all non-fragment ions in a mass spectrum are considered as PMI plus one or several neutral species; (3) visual classification of detected components by principal component analysis (PCA) to exclude possible non-natural compounds (such as pharmaceutical excipients). This algorithm has been successfully applied to a standard mixture and three herbal extract/preparations. It indicated that our algorithm could detect components’ features as a whole and report their PMI with an accuracy of more than 98%. Furthermore, components originated from excipients/contaminants could be easily separated from those natural components in the bi-plots of PCA.

  18. A 10{sup 10} solar mass flow of molecular gas in the A1835 brightest cluster galaxy

    Energy Technology Data Exchange (ETDEWEB)

    McNamara, B. R.; Russell, H. R.; Main, R. A.; Vantyghem, A. N.; Kirkpatrick, C. C. [Department of Physics and Astronomy, University of Waterloo, Waterloo (Canada); Nulsen, P. E. J. [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States); Edge, A. C. [Department of Physics, Durham University, Durham DH1 3LE (United Kingdom); Murray, N. W.; Hamer, S. [Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George Street, Toronto, M5S 3H8 ON (Canada); Combes, F.; Salome, P. [L' Observatoire de Paris, 61 Av. de L' Observatoire, F-75014 Paris (France); Fabian, A. C. [Institute of Astronomy, Madingley Road, Cambridge CB3 0HA (United Kingdom); Baum, S. A.; O' Dea, C. P. [School of Physics and Astronomy, Rochester Institute of Technology, Rochester, NY 14623 (United States); Bregman, J. N. [Department of Astronomy, University of Michigan, 500 Church Street, Ann Arbor, MI 48109 (United States); Donahue, M.; Voit, G. M. [Department of Physics and Astronomy, Michigan State University, 567 Wilson Road, East Lansing, MI 48824 (United States); Egami, E. [Steward Observatory, University of Arizona, 933 N. Cherry Avenue, Tucson, AZ 85721 (United States); Oonk, J. B. R. [Netherlands Institute for Radio Astronomy, Postbus 2, 7990 AA Dwingeloo (Netherlands); Tremblay, G. [European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching (Germany)

    2014-04-10

    We report ALMA Early Science observations of the A1835 brightest cluster galaxy (BCG) in the CO (3-2) and CO (1-0) emission lines. We detect 5 × 10{sup 10} M {sub ☉} of molecular gas within 10 kpc of the BCG. Its ensemble velocity profile width of ∼130 km s{sup –1} FWHM is too narrow for the molecular clouds to be supported in the galaxy by dynamic pressure. The gas may instead be supported in a rotating, turbulent disk oriented nearly face-on. Roughly 10{sup 10} M {sub ☉} of molecular gas is projected 3-10 kpc to the northwest and to the east of the nucleus with line-of-sight velocities lying between –250 km s{sup –1} and +480 km s{sup –1} with respect to the systemic velocity. The high-velocity gas may be either inflowing or outflowing. However, the absence of high-velocity gas toward the nucleus that would be expected in a steady inflow, and its bipolar distribution on either side of the nucleus, are more naturally explained as outflow. Star formation and radiation from the active galactic nucleus (AGN) are both incapable of driving an outflow of this magnitude. The location of the high-velocity gas projected behind buoyantly rising X-ray cavities and favorable energetics suggest an outflow driven by the radio AGN. If so, the molecular outflow may be associated with a hot outflow on larger scales reported by Kirkpatrick and colleagues. The molecular gas flow rate of approximately 200 M {sub ☉} yr{sup –1} is comparable to the star formation rate of 100-180 M {sub ☉} yr{sup –1} in the central disk. How radio bubbles would lift dense molecular gas in their updrafts, how much gas will be lost to the BCG, and how much will return to fuel future star formation and AGN activity are poorly understood. Our results imply that radio-mechanical (radio-mode) feedback not only heats hot atmospheres surrounding elliptical galaxies and BCGs, but it is able to sweep higher density molecular gas away from their centers.

  19. Three-dimensional molecular imaging using mass spectrometry and atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wucher, Andreas [Department of Physics, University of Duisburg-Essen, D-47048 Duisburg (Germany)], E-mail: andreas.wucher@uni-due.de; Cheng Juan; Zheng Leiliang; Willingham, David; Winograd, Nicholas [Department of Chemistry, Pennsylvania State University, University Park, PA 16802 (United States)

    2008-12-15

    We combine imaging ToF-SIMS depth profiling and wide area atomic force microscopy to analyze a test structure consisting of a 300 nm trehalose film deposited on a Si substrate and pre-structured by means of a focused 15-keV Ga{sup +} ion beam. Depth profiling is performed using a 40-keV C{sub 60}{sup +} cluster ion beam for erosion and mass spectral data acquisition. A generic protocol for depth axis calibration is described which takes into account both lateral and in-depth variations of the erosion rate. By extrapolation towards zero analyzed lateral area, an 'intrinsic' depth resolution of about 8 nm is found which appears to be characteristic of the cluster-surface interaction process.

  20. Comparison of several sorbents for continuous in situ derivatization and preconcentration of low-molecular mass aldehydes prior to liquid chromatography-tandem mass spectrometric determination in water samples.

    Science.gov (United States)

    Baños, Clara Eugenia; Silva, Manuel

    2009-09-18

    A comparative study of six SPE conventional and non-conventional sorbent materials (silica RP-C18, LiChrolut EN, Amberlite XAD-2, C60 fullerene, multiwall carbon nanotubes and graphitized carbon black) was carried out for the in situ derivatization/preconcentration of eight aldehydes with 2,4-dinitrophenylhydrazine. Although two of the sorbents, LiChrolut EN and RP-C18, turned out to be the most suitable for ultratrace analysis of the aldehydes, LiChrolut EN showed higher capacity for 2,4-dinitrophenylhydrazine trapping (higher efficiency for the in situ derivatization reaction) and superior performance in terms of sensitivity (likely a result of its increased sample breakthrough volume). The LiChrolut EN-based method combined with LC-MS/MS allowed the determination of aldehydes over the linear range of 0.02-15 microg l(-1), with limits of detection at 6-24 ng l(-1) and precision of 3.2-7.2%. The method was applied to determine low-molecular mass aldehydes in water samples. These results indicate that the method proposed is a straightforward and sensitive tool for the determination of these aldehydes in water samples providing better results than those LC-MS/MS reported alternatives in terms of the limit of detection, sample requirements for analysis and cost.

  1. High-Resolution Mass Spectrometry and Molecular Characterization of Aqueous Photochemistry Products of Common Types of Secondary Organic Aerosols

    Energy Technology Data Exchange (ETDEWEB)

    Romonosky, Dian E.; Laskin, Alexander; Laskin, Julia; Nizkorodov, Sergey

    2015-03-19

    A significant fraction of atmospheric organic compounds is predominantly found in condensed phases, such as aerosol particles and cloud droplets. Many of these compounds are photolabile and can degrade through direct photolysis or indirect photooxidation processes on time scales that are comparable to the typical lifetimes of aqueous droplets (hours) and particles (days). This paper presents a systematic investigation of the molecular level composition and the extent of aqueous photochemical processing in different types of secondary organic aerosol (SOA) from biogenic and anthropogenic precursors including α-pinene, β-pinene, β-myrcene, d- limonene, α-humulene, 1,3,5-trimethylbenzene, and guaiacol, oxidized by ozone (to simulate a remote atmosphere) or by OH in the presence of NOx (to simulate an urban atmosphere). Chamber- and flow tube-generated SOA samples were collected, extracted in a methanol/water solution, and photolyzed for 1 h under identical irradiation conditions. In these experiments, the irradiation was equivalent to about 3-8 h of exposure to the sun in its zenith. The molecular level composition of the dissolved SOA was probed before and after photolysis with direct-infusion electrospray ionization high-resolution mass spectrometry (ESI-HR-MS). The mass spectra of unphotolyzed SOA generated by ozone oxidation of monoterpenes showed qualitatively similar features, and contained largely overlapping subsets of identified compounds. The mass spectra of OH/NOx generated SOA had more unique visual appearance, and indicated a lower extent of products overlap. Furthermore, the fraction of nitrogen containing species (organonitrates and nitroaromatics) was highly sensitive to the SOA precursor. These observations suggest that attribution of high-resolution mass spectra in field SOA samples to specific SOA precursors should be more straightforward under OH/NOx oxidation conditions compared to the ozone driven oxidation. Comparison of the SOA constituents

  2. The formation of high-mass stars and stellar clusters in the extreme environment of the Central Molecular Zone

    Science.gov (United States)

    Walker, Daniel Lewis

    2017-08-01

    The process of converting gas into stars underpins much of astrophysics, yet many fundamental questions surrounding this process remain unanswered. For example - how sensitive is star formation to the local environmental conditions? How do massive and dense stellar clusters form, and how does this crowded environment influence the stars that form within it? How do the most massive stars form and is there an upper limit to the stellar initial mass function (IMF)? Answering questions such as these is crucial if we are to construct an end-to-end model of how stars form across the full range of conditions found throughout the Universe. The research described in this thesis presents a study that utilises a multi-scale approach to identifying and characterising the early precursors to young massive clusters and high-mass proto-stars, with a specific focus on the extreme environment in the inner few hundred parsecs of the Milky Way - the Central Molecular Zone (CMZ). The primary sources of interest that are studied in detail belong to the Galactic centre dust ridge - a group of six high-mass (M 10^(4-5) Msun), dense (R 1-3 pc, n > 10^(4) cm^(-3)), and quiescent molecular clouds. These properties make these clouds ideal candidates for representing the earliest stages of high-mass star and cluster formation. The research presented makes use of single-dish and interferometric far-infrared and (sub-)millimetre observations to study their global and small-scale properties. A comparison of the known young massive clusters (YMCs) and their likely progenitors (the dust ridge clouds) in the CMZ shows that the stellar content of YMCs is much more dense and centrally concentrated than the gas in the clouds. If these clouds are truly precursors to massive clusters, the resultant stellar population would have to undergo significant dynamical evolution to reach central densities that are typical of YMCs. This suggests that YMCs in the CMZ are unlikely to form monolithically. Extending

  3. Paper Spray Tandem Mass Spectrometry Based on Molecularly Imprinted Polymer Substrate for Cocaine Analysis in Oral Fluid

    Science.gov (United States)

    Tavares, Ludmyla S.; Carvalho, Thays C.; Romão, Wanderson; Vaz, Boniek G.; Chaves, Andréa R.

    2017-12-01

    This study proposes a new direct and fast method of analysis employing paper spray mass spectrometry (PS-MS). The paper used in the proposed method was modified with molecularly imprinted polymers (MIP) to create a specific site for cocaine analysis in oral fluid. MIP membrane was successfully synthetized and employed. The developed method showed to be linear in a concentration range from LOQ to 100 ng mL-1. The experimental value of LOQ obtained was 1 ng mL-1. The inter-day and intra-day precision and accuracy of the PS-MS method presented values lower than 15%. The total recoveries were also evaluated. The PS-MS method for the analysis of cocaine in oral fluid showed to be very promising and the validation parameters showed a good correlation with the literature. [Figure not available: see fulltext.

  4. A High Molecular-Mass Anoxybacillus sp. SK3-4 Amylopullulanase: Characterization and Its Relationship in Carbohydrate Utilization

    Directory of Open Access Journals (Sweden)

    Kian Mau Goh

    2013-05-01

    Full Text Available An amylopullulanase of the thermophilic Anoxybacillus sp. SK3-4 (ApuASK was purified to homogeneity and characterized. Though amylopullulanases larger than 200 kDa are rare, the molecular mass of purified ApuASK appears to be approximately 225 kDa, on both SDS-PAGE analyses and native-PAGE analyses. ApuASK was stable between pH 6.0 and pH 8.0 and exhibited optimal activity at pH 7.5. The optimal temperature for ApuASK enzyme activity was 60 °C, and it retained 54% of its total activity for 240 min at 65 °C. ApuASK reacts with pullulan, starch, glycogen, and dextrin, yielding glucose, maltose, and maltotriose. Interestingly, most of the previously described amylopullulanases are unable to produce glucose and maltose from these substrates. Thus, ApuASK is a novel, high molecular-mass amylopullulanase able to produce glucose, maltose, and maltotriose from pullulan and starch. Based on whole genome sequencing data, ApuASK appeared to be the largest protein present in Anoxybacillus sp. SK3-4. The α-amylase catalytic domain present in all of the amylase superfamily members is present in ApuASK, located between the cyclodextrin (CD-pullulan-degrading N-terminus and the α-amylase catalytic C-terminus (amyC domains. In addition, the existence of a S-layer homology (SLH domain indicates that ApuASK might function as a cell-anchoring enzyme and be important for carbohydrate utilization in a streaming hot spring.

  5. Prediction of body mass index in mice using dense molecular markers and a regularized neural network.

    Science.gov (United States)

    Okut, Hayrettin; Gianola, Daniel; Rosa, Guilherme J M; Weigel, Kent A

    2011-06-01

    Bayesian regularization of artificial neural networks (BRANNs) were used to predict body mass index (BMI) in mice using single nucleotide polymorphism (SNP) markers. Data from 1896 animals with both phenotypic and genotypic (12 320 loci) information were used for the analysis. Missing genotypes were imputed based on estimated allelic frequencies, with no attempt to reconstruct haplotypes based on family information or linkage disequilibrium between markers. A feed-forward multilayer perceptron network consisting of a single output layer and one hidden layer was used. Training of the neural network was done using the Bayesian regularized backpropagation algorithm. When the number of neurons in the hidden layer was increased, the number of effective parameters, γ, increased up to a point and stabilized thereafter. A model with five neurons in the hidden layer produced a value of γ that saturated the data. In terms of predictive ability, a network with five neurons in the hidden layer attained the smallest error and highest correlation in the test data although differences among networks were negligible. Using inherent weight information of BRANN with different number of neurons in the hidden layer, it was observed that 17 SNPs had a larger impact on the network, indicating their possible relevance in prediction of BMI. It is concluded that BRANN may be at least as useful as other methods for high-dimensional genome-enabled prediction, with the advantage of its potential ability of capturing non-linear relationships, which may be useful in the study of quantitative traits under complex gene action.

  6. Insights into the Self-assembly of Two Diamine Derivatives Low Molecular Mass Organogelators in Quasi-solid-state Electrolytes

    Science.gov (United States)

    Mo, Shu-Fan; Zhang, Bing; Zhou, Kai-Xuan; Yao, Jian-Xi; Dai, Song-Yuan

    2016-05-01

    Electrolyte materials are the key components in dye-sensitized solar cells and are very crucial to the performance and long-term stability of the cells. The diamide derivatives have been proved in our lab to be effective to improve the stability of the traditional liquid electrolyte as low molecular mass organogelator (LMOGs). Our previous experiments and simulations indicated that the relationship between the morphology of the electrolyte and the self-assembly of the LMOGs. In the current study, the self-assembly of two diamine derivatives (N,N'-1,8-octanediylbis-dodecanamide and N,N'-1,9-nonanediylbis-dodecanamide) has been investigated and characterized using molecular dynamics. Although the structure of the two these molecules is only different in one methylene, the simulations revealed that the self-assembly patterns of the two diamine derivatives are quite different. The differences seems to be suitable to explain the diverse morphologies formed by the assembly of the LMOGs.

  7. Microextraction by packed sorbent liquid chromatography with time-of-flight mass spectrometry of triazines employing a molecularly imprinted polymer.

    Science.gov (United States)

    Andrade, Felipe Nascimento; Santos-Neto, Álvaro José; Lanças, Fernando Mauro

    2014-11-01

    Molecularly imprinted polymers for the determination of triazines were synthesized by precipitation using atrazine as template, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as crosslinker, and 2,2'-azobisisobutrynitrile as initiator. The polymers were characterized by infrared spectroscopy and scanning electron microscopy and packed in a device for microextraction by packed sorbent aiming for the preconcentration/cleanup of herbicides, such as atrazine, simazine, simetryn, ametryn, and terbutryn in corn samples. Liquid chromatography coupled with time-of-flight mass spectrometry was used for the separation and determination of the herbicides. The selectivity coefficient of molecularly imprinted polymers was compared with that of nonimprinted polymer for the binary mixtures of atrazine/propanil and atrazine/picloram, and the values obtained were 15.6 and 2.96, respectively. The analytical curve ranged from 10 to 80 μg/kg (r = 0.989) and the limits of detection and quantification in the corn matrices were 3.3 and 10 μg/kg, respectively. Intra- and interday precisions were Polymer synthesis was successfully applied to the cleanup and preconcentration of triazines from fortified corn samples with 91.1-109.1% of recovery. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. In Situ Mass Spectrometric Determination of Molecular Structural Evolution at the Solid Electrolyte Interphase in Lithium-Ion Batteries.

    Science.gov (United States)

    Zhu, Zihua; Zhou, Yufan; Yan, Pengfei; Vemuri, Rama Sesha; Xu, Wu; Zhao, Rui; Wang, Xuelin; Thevuthasan, Suntharampillai; Baer, Donald R; Wang, Chong-Min

    2015-09-09

    Dynamic structural and chemical evolution at solid-liquid electrolyte interface is always a mystery for a rechargeable battery due to the challenge to directly probe a solid-liquid interface under reaction conditions. We describe the creation and usage of in situ liquid secondary ion mass spectroscopy (SIMS) for the first time to directly observe the molecular structural evolution at the solid-liquid electrolyte interface for a lithium (Li)-ion battery under dynamic operating conditions. We have discovered that the deposition of Li metal on copper electrode leads to the condensation of solvent molecules around the electrode. Chemically, this layer of solvent condensate tends to be depleted of the salt anions and with reduced concentration of Li(+) ions, essentially leading to the formation of a lean electrolyte layer adjacent to the electrode and therefore contributing to the overpotential of the cell. This observation provides unprecedented molecular level dynamic information on the initial formation of the solid electrolyte interphase (SEI) layer. The present work also ultimately opens new avenues for implanting the in situ liquid SIMS concept to probe the chemical reaction process that intimately involves solid-liquid interface, such as electrocatalysis, electrodeposition, biofuel conversion, biofilm, and biomineralization.

  9. Identification of clinically relevant Corynebacterium strains by Api Coryne, MALDI-TOF-mass spectrometry and molecular approaches.

    Science.gov (United States)

    Alibi, S; Ferjani, A; Gaillot, O; Marzouk, M; Courcol, R; Boukadida, J

    2015-09-01

    We evaluated the Bruker Biotyper matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry (MS) for the identification of 97 Corynebacterium clinical in comparison to identification strains by Api Coryne and MALDI-TOF-MS using 16S rRNA gene and hypervariable region of rpoB genes sequencing as a reference method. C. striatum was the predominant species isolated followed by C. amycolatum. There was an agreement between Api Coryne strips and MALDI-TOF-MS identification in 88.65% of cases. MALDI-TOF-MS was unable to differentiate C. aurimucosum from C. minutissimum and C. minutissimum from C. singulare but reliably identify 92 of 97 (94.84%) strains. Two strains remained incompletely identified to the species level by MALDI-TOF-MS and molecular approaches. They belonged to Cellulomonas and Pseudoclavibacter genus. In conclusion, MALDI-TOF-MS is a rapid and reliable method for the identification of Corynebacterium species. However, some limits have been noted and have to be resolved by the application of molecular methods. Copyright © 2015. Published by Elsevier SAS.

  10. Molecular differentiation of five Cinnamomum camphora chemotypes using desorption atmospheric pressure chemical ionization mass spectrometry of raw leaves

    Science.gov (United States)

    Guo, Xiali; Cui, Meng; Deng, Min; Liu, Xingxing; Huang, Xueyong; Zhang, Xinglei; Luo, Liping

    2017-04-01

    Five chemotypes, the isoborneol-type, camphora-type, cineole-type, linalool-type and borneol-type of Cinnamomum camphora (L.) Presl have been identified at the molecular level based on the multivariate analysis of mass spectral fingerprints recorded from a total of 750 raw leaf samples (i.e., 150 leaves equally collected for each chemotype) using desorption atmospheric pressure chemical ionization mass spectrometry (DAPCI-MS). Both volatile and semi-volatile metabolites of the fresh leaves of C. camphora were simultaneously detected by DAPCI-MS without any sample pretreatment, reducing the analysis time from half a day using conventional methods (e.g., GC-MS) down to 30 s. The pattern recognition results obtained using principal component analysis (PCA) was cross-checked by cluster analysis (CA), showing that the difference visualized by the DAPCI-MS spectral fingerprints was validated with 100% accuracy. The study demonstrates that DAPCI-MS meets the challenging requirements for accurate differentiation of all the five chemotypes of C. camphora leaves, motivating more advanced application of DAPCI-MS in plant science and forestry studies.

  11. Investigation of gamma-ray irradiation on molecular structure, optical properties and mass attenuation coefficients of colloidal gold nanoparticles

    Science.gov (United States)

    Dehghani, Z.; Vejdani Noghreiyan, A.; Nadafan, M.; Majles Ara, M. H.

    2017-08-01

    In this research, colloidal gold NPs were synthesized by turkevich method. XRD spectrum after irradiation showed the different peaks but the most important distinctive was related to (111) peaks at (2θ = 38.41°) which give an indication that the structure is cubic. The Raman spectroscopy results indicated that the intensity of peaks with the wave number of 3450 cm-1was increased in the colloidal gold NPs irradiated due to improvement of the crystalline properties of colloidal gold NPs. SEM images showed significant changes in the morphology and size of gamma irradiated colloidal gold NPs. For 10 kGy dose, gamma-ray irradiated crystals, the optical absorption increases compared to that of before irradiation which may be the consequence of the formation of point defects due to gamma-rays. Comparing nonlinear studies, the magnitude of nonlinear refraction index, n2 and nonlinear absorption coefficient, β increase after gamma-ray irradiation. The measurement of mass attenuation coefficients result shows that the gamma-ray irradiation has an influence on radiation absorption coefficients of colloidal gold NPs. It is an evidence which shows that in addition to the atomic mass number of elements, the molecular structure may affect on the attenuation coefficients and nonlinear optical properties.

  12. Zooming into Molecular Biomarker Distribution through Spatially Resolved Mass Spectrometry on Intact Sediment Sections

    Science.gov (United States)

    Wörmer, L.; Fuchser, J.; Alfken, S.; Elvert, M.; Schimmelmann, A.; Hinrichs, K. U.

    2016-02-01

    Marine microorganisms adapt to their habitat by structural modification of their membrane lipids. After sedimentation, and due to their persistence in the sedimentary record, the information archived in them remains available on geological time-scales. Thereby sedimentary lipid biomarkers become important informants of past environments. Conventional biomarker analysis is labor-intensive and requires cm-sized samples, temporal resolution is consequently low. We here present an approach, based on laser desorption ionization (LDI) coupled to ultra high resolution mass spectrometry, that avoids wet-chemical sample preparation and enables analysis directly on sediment sections at sub-mm spatial resolution. Our initial study targeted archaeal glycerol dialkyl glycerol tetraethers (GDGTs). GDGTS are ubiquitous and persistent components in marine sediments, and used in several, widely recognized paleoenvironmental proxies. Applied to an Eastern Mediterranean Sapropel layer, GDGT-profiles with previously unachieved temporal resolution were obtained, and pointed to a strong influence of high frequency cycles on sea-surface temperature and planktonic archaeal ecology. Spatial information furthermore revealed a new view on the fine-scale patchiness of lipid distribution. Following these pioneering studies, major developments are under way. A dedicated facility has been set up at MARUM/University of Bremen, which combines lipid biomarker and elemental analysis at sub-mm resolution (down to 50 µm). We present methods for other comprehensive lipid biomarkers (e.g. alkenones or sterols) that are currently being targeted; and the application of spatially resolved biomarker analysis to recent laminated sediments (Santa Barbara Basin), yielding informative profiles with subannual resolution. We also discuss criteria for analyte and sample selection, as well as the main potentialities and constraints of this new approach.

  13. Development of a didactic electrophoresis kit for the practical teaching of Molecular Biology in basic and higher education

    Directory of Open Access Journals (Sweden)

    César Silva Xavier

    2017-10-01

    Full Text Available The advances in the biotechnology area imposes a new reality, creating products that are present in our daily lives, affecting directly or indirectly the population. Applications related to DNA technologies in the industry, agriculture and medicine have social, ethical and ecological implications, in addition to the human health consequences. So, it is necessary that the public is informed of progress in this area of knowledge. In order to create an alternative method to stimulate students in scientific careers and improve the learning of biotechnology and molecular biology, we developed a junior research project with high school students of the Federal Institute of Education, Science and Technology of the Espírito Santo (Brazil, which aimed the construction of a teaching kit of electrophoresis. Electrophoresis is a technique widely used in molecular biology laboratories, which is applied to separate molecules such as proteins and nucleic acids. In this technique, electrically charged molecules are exposed to an electric field and then they move towards the oppositely charged pole, being deposited in specific points of the matrix used. The kit built in this work consists of a source of 70 V, and accessories and reagents that are readily available and present low cost and low risk to the health of users. The use of the kit allowed for electrophoretic assays with nucleic acids and food dyes. The kit also contains a printed material that addresses issues about DNA technology and the device user’s guide with suggestions of experiences to simulate paternity test, virus identification and others. The application of the teaching kit in practical classes with students and teachers of basic education showed that the activity was effective in reducing the number of errors in answers contained in a questionnaire related to the electrophoresis. Moreover, biology teachers evaluated the printed material of the didactic kit and 75% of them classified the

  14. A large-scale, higher-level, molecular phylogenetic study of the insect order Lepidoptera (moths and butterflies)

    Science.gov (United States)

    Higher-level relationships within the Lepidoptera, and particularly within the species-rich subclade Ditrysia, are generally not well understood, although recent studies have yielded progress. 483 taxa spanning 115 of 124 families were sampled for 19 protein-coding nuclear genes. Their aligned nucle...

  15. Supplementing an energy adequate, higher protein diet with protein does not enhance fat-free mass restoration after short-term severe negative energy balance.

    Science.gov (United States)

    Berryman, C E; Sepowitz, J J; McClung, H L; Lieberman, H R; Farina, E K; McClung, J P; Ferrando, A A; Pasiakos, S M

    2017-06-01

    Negative energy balance during military operations can be severe and result in significant reductions in fat-free mass (FFM). Consuming supplemental high-quality protein following such military operations may accelerate restoration of FFM. Body composition (dual-energy X-ray absorptiometry) and whole body protein turnover (single-pool [(15)N]alanine method) were determined before (PRE) and after 7 days (POST) of severe negative energy balance during military training in 63 male US Marines (means ± SD, 25 ± 3 yr, 84 ± 9 kg). After POST measures were collected, volunteers were randomized to receive higher protein (HIGH: 1,103 kcal/day, 133 g protein/day), moderate protein (MOD: 974 kcal/day, 84 g protein/day), or carbohydrate-based low protein control (CON: 1,042 kcal/day, 7 g protein/day) supplements, in addition to a self-selected, ad libitum diet, for the 27-day intervention (REFED). Measurements were repeated POST-REFED. POST total body mass (TBM; -5.8 ± 1.0 kg, -7.0%), FFM (-3.1 ± 1.6 kg, -4.7%), and net protein balance (-1.7 ± 1.1 g protein·kg(-1)·day(-1)) were lower and proteolysis (1.1 ± 1.9 g protein·kg(-1)·day(-1)) was higher compared with PRE (P energy (4,498 ± 725 kcal/day). All volunteers, independent of group assignment, achieved positive net protein balance (0.4 ± 1.0 g protein·kg(-1)·day(-1)) and gained TBM (5.9 ± 1.7 kg, 7.8%) and FFM (3.6 ± 1.8 kg, 5.7%) POST-REFED compared with POST (P energy-adequate, higher protein diets with additional protein may not be necessary to restore FFM after short-term severe negative energy balance.NEW & NOTEWORTHY This article demonstrates 1) the majority of physiological decrements incurred during military training (e.g., total and fat-free mass loss), with the exception of net protein balance, resolve and return to pretraining values after 27 days and 2) protein supplementation, in addition to an ad libitum, higher protein (~2.0 g·kg(-1)·day(-1)), energy adequate diet, is not necessary to restore

  16. Comparative study of the binding of 3 flavonoids to the fat mass and obesity-associated protein by spectroscopy and molecular modeling.

    Science.gov (United States)

    Zhang, Lijiao; Ren, Ting; Wang, Zechun; Wang, Ruiyong; Chang, Junbiao

    2017-06-01

    This study aims to investigate the interaction between 3 flavonoids (quercetin, apigenin, and naringenin) and fat mass and obesity-associated protein by fluorescence, ultraviolet-visible absorption spectroscopy, and molecular modeling. Results indicate that the intrinsic fluorescence of fat mass and obesity-associated protein can be quenched by the 3 flavonoids through a static quenching procedure. Thermodynamic analysis and molecular modeling results suggest that hydrophobic interaction and hydrogen bond forces play the major roles in the binding process. Moreover, results also show that the rank order of quenching constant and binding constant is quercetin > apigenin > naringenin. Copyright © 2017 John Wiley & Sons, Ltd.

  17. Mass spectrometry based lipid(ome) analyzer and molecular platform: a new software to interpret and analyze electrospray and/or matrix-assisted laser desorption/ionization mass spectrometric data of lipids: a case study from Mycobacterium tuberculosis.

    Science.gov (United States)

    Sabareesh, Varatharajan; Singh, Gurpreet

    2013-04-01

    Mass Spectrometry based Lipid(ome) Analyzer and Molecular Platform (MS-LAMP) is a new software capable of aiding in interpreting electrospray ionization (ESI) and/or matrix-assisted laser desorption/ionization (MALDI) mass spectrometric data of lipids. The graphical user interface (GUI) of this standalone programme is built using Perl::Tk. Two databases have been developed and constituted within MS-LAMP, on the basis of Mycobacterium tuberculosis (M. tb) lipid database (www.mrl.colostate.edu) and that of Lipid Metabolites and Pathways Strategy Consortium (LIPID MAPS; www.lipidmaps.org). Different types of queries entered through GUI would interrogate with a chosen database. The queries can be molecular mass(es) or mass-to-charge (m/z) value(s) and molecular formula. LIPID MAPS identifier also can be used to search but not for M. tb lipids. Multiple choices have been provided to select diverse ion types and lipids. Satisfying to input parameters, a glimpse of various lipid categories and their population distribution can be viewed in the output. Additionally, molecular structures of lipids in the output can be seen using ChemSketch (www.acdlabs.com), which has been linked to the programme. Furthermore, a version of MS-LAMP for use in Linux operating system is separately available, wherein PyMOL can be used to view molecular structures that result as output from General Lipidome MS-LAMP. The utility of this software is demonstrated using ESI mass spectrometric data of lipid extracts of M. tb grown under two different pH (5.5 and 7.0) conditions. Copyright © 2013 John Wiley & Sons, Ltd.

  18. Higher body mass index is associated with greater severity of alopecia in men with male-pattern androgenetic alopecia in Taiwan: a cross-sectional study.

    Science.gov (United States)

    Yang, Chao-Chun; Hsieh, Fu-Nien; Lin, Li-Yu; Hsu, Chao-Kai; Sheu, Hamm-Ming; Chen, WenChieh

    2014-02-01

    Obesity is a risk factor for multiple health problems, but its association with androgenetic alopecia (AGA) remains controversial. We sought to determine the association between body mass index (BMI) and alopecia severity in men with AGA and early-onset AGA. A cross-sectional study was conducted. The medical charts and photographs of men with a clinical diagnosis of AGA were reviewed. In all, 189 men were enrolled with a mean age of 30.8 years. In male-pattern AGA (n = 142), men with severe alopecia (grade V-VII) had higher BMI than those with mild to moderate alopecia (grade I-IV) (25.1 vs 22.8 kg/m(2), P = .01). After multivariate adjustments, the risk for severe alopecia was higher in the overweight or obese (BMI ≥24 kg/m(2)) subjects with male-pattern AGA (odds ratio 3.52, P < .01). In early-onset male-pattern AGA (n = 46), the risk for having severe alopecia was also higher in the overweight or obese subjects (odds ratio 4.97, P = .03). Parameters used to evaluate obesity were limited because of the retrospective nature of the study. Higher BMI was significantly associated with greater severity of hair loss in men with male-pattern AGA, especially in those with early-onset AGA. Copyright © 2013 American Academy of Dermatology, Inc. Published by Mosby, Inc. All rights reserved.

  19. Characterization of low-molecular weight iodine-terminated polyethylenes by gas chromatography/mass spectrometry and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry with the use of derivatization.

    Science.gov (United States)

    Zaikin, Vladimir G; Borisov, Roman S; Polovkov, Nikolai Yu; Zhilyaev, Dmitry I; Vinogradov, Aleksei A; Ivanyuk, Aleksei V

    2013-01-01

    Gas chromatography/mass spectrometry (GC/MS) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-ToF) mass spectrometry, in conjunction with various derivatization approaches, have been applied to structure determination of individual oligomers and molecular-mass distributions (MMD) in low-molecular mass polyethylene having an iodine terminus. Direct GC/MS analysis has shown that the samples under investigation composed of polyethyelene-iodides (major components) and n-alkanes. Exchange reaction with methanol in the presence of NaOH gave rise to methoxy-derivatives and n-alkenes. Electron ionization mass spectra have shown that the former contained terminal methoxy groups indicating the terminal position of the iodine atom in the initial oligomers. MMD parameters have been determined with the aid of MALDI mass spectrometry followed by preliminary derivatization-formation of covalently bonded charge through the reaction of iodides with triphenylphosphine, trialkylamines, pyridine or quinoline. The mass spectra revealed well-resolved peaks for cationic parts of derivatized oligomers allowing the determination of MMD. The latter values have been compared with those calculated from GC/MS data.

  20. Uptake of Bt endotoxins by nontarget herbivores and higher order arthropod predators: molecular evidence from a transgenic corn agroecosystem.

    Science.gov (United States)

    Harwood, James D; Wallin, William G; Obrycki, John J

    2005-08-01

    The planting of transgenic crops expressing Bacillus thuringiensis endotoxins is widespread throughout the world; the prolific increase in their application exposes nontarget organisms to toxins designed to control pests. To date, studies have focused upon the effects of Bt endotoxins on specific herbivores and detritivores, without consideration of their persistence within arthropod food webs. Here, we report the first quantitative field evaluation of levels of Bt endotoxin within nontarget herbivores and the uptake by higher order arthropods. Antibody-based assays indicated significant quantities of detectable Cry1Ab endotoxin within nontarget herbivores which feed on transgenic corn (including the corn flea beetle, Chaetocnema pulicaria, Japanese beetle, Popillia japonica and southern corn rootworm, Diabrotica undecimpunctata howardi). Furthermore, arthropod predators (Coccinellidae, Araneae, and Nabidae) collected from these agroecosystems also contained significant quantities of Cry1Ab endotoxin indicating its movement into higher trophic levels. This uptake by predators is likely to have occurred by direct feeding on plant material (in predators which are facultatively phytophagous) or the consumption of arthropod prey which contained these proteins. These data indicate that long-term exposure to insecticidal toxins occurs in the field. These levels of exposure should therefore be considered during future risk assessments of transgenic crops to nontarget herbivores and arthropod predators.

  1. Simultaneous molecular formula determinations of natural compounds in a plant extract using 15 T Fourier transform ion cyclotron resonance mass spectrometry.

    Science.gov (United States)

    Park, Kyu Hwan; Kim, Min Sun; Baek, Sun Jong; Bae, Ik Hyun; Seo, Sang-Wan; Kim, Jongjin; Shin, Yong Kook; Lee, Yong-Moon; Kim, Hyun Sik

    2013-01-01

    Plant extracts are a reservoir of pharmacologically active substances; however, conventional analytical methods can analyze only a small portion of an extract. Here, we report a high-throughput analytical method capable of determining most phytochemicals in a plant extract and of providing their molecular formulae from a single experiment using ultra-high-resolution electrospray ionization mass spectrometry (UHR ESI MS). UHR mass profiling was used to analyze natural compounds in a 70% ethanol ginseng extract, which was directly infused into a 15 T Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometer for less than 10 min without a separation process. The UHR FT-ICR MS yielded a mass accuracy of 0.5 ppm and a mass resolving power (m/Δm) of 1,000,000-270,000 for the range m/z 290-1,100. The mass resolution was sufficient to resolve the isotopic fine structure (IFS) of many compounds in the extract. After noise removal from 1,552 peaks, 405 compounds were detected. The molecular formulae of 123 compounds, including 33 ginsenosides, were determined using the observed IFS, exact monoisotopic mass, and exact mass difference. Liquid chromatography (LC)/FT-ICR MS of the extract was performed to compare the high-throughput performance of UHR ESI FT-ICR MS. The LC/FT-ICR MS detected only 129 compounds, including 19 ginsenosides. The result showed that UHR ESI FT-ICR MS identified three times more compounds than LC/FT-ICR MS and in a relatively shorter time. The molecular formula determination by UHR FT-ICR MS was validated by LC and tandem MS analyses of three known ginsenosides. UHR mass profiling of a plant extract by 15 T FT-ICR MS showed that multiple compounds were simultaneously detected and their molecular formulae were decisively determined by a single experiment with ultra-high mass resolution and mass accuracy. Simultaneous molecular determination of multiple natural products by UHR ESI FT-ICR MS would be a powerful method to profile a wide

  2. Electron-Induced (EI Mass Fragmentation is Directed by Intra- molecular H-Bonding in Two Isomeric Benzodipyran Systems

    Directory of Open Access Journals (Sweden)

    Stéphane Mabic

    2004-09-01

    Full Text Available The striking differences observed in the electron-induced (EI mass fragmentationpathways of two isomeric benzodipyrans are attributable to hydrogen bonding in thesemolecules. In the "angular" isomer, 6-butyryl-5-hydroxy-2,2,8,8-tetramethyl-3,4,9,10-tetra-hydro-2H,8H-benzo[1,2-b:3,4-b1]dipyran (2, H-bonding occurs between the aromatic OHgroup and the alpha carbonyl moiety contained in the ortho-phenone group, whereas in the"linear" isomer, 10-butyryl-5-hydroxy-2,2,8,8-tetramethyl-3,4,6,7-tetrahydro-2H,8H-benzo-[1,2-b:5,4-b1]dipyran (3, the aromatic OH group is para to the phenone moiety, effectivelyprecluding any H-bonding. Semi-empirical molecular orbital calculations (AM1 were used tocompare predicted sites of ionization with associated fragmentation patterns. In bothmolecules, the highest occupied molecular orbital (HOMO was located predominantly on thearomatic moiety. Similarly, in the radical cation species of both compounds, maximum spindensity was located over the aromatic rings. Neither the HOMO nor the spin density mapsprovided a rational explanation for the differences in fragmentation patterns of the twobenzodipyran isomers. The H-bonding favors EI alpha aromatic ring C-O bond cleavage in the"angular" benzodipyran and in 5,7-dihydroxy-2,2-dimethyl-8-butyryl chroman (1, a relatedmonochroman also containing a hydrogen proximal to the aromatic ring C-O bond. In contrast,fragmentation of the "linear" benzodipyran followed a different route, which was exhibited byits base peak resulting from the loss of a propyl group from the butyryl side-chain.

  3. Envelope structure on 700 AU scales and the molecular outflows of low-mass young stellar objects

    Science.gov (United States)

    Hogerheijde, M. R.; van Dishoeck, E. F.; Blake, G. A.; van Langevelde, H. J.

    1998-01-01

    Aperture synthesis observations of HCO+ J = 1-0, 13CO 1-0, and C18O 1-0 obtained with the Owens Valley Millimeter Array are used to probe the small-scale (5" approximately 700 AU) structure of the molecular envelopes of a well-defined sample of nine embedded low-mass young stellar objects in Taurus. The interferometer results can be understood in terms of: (1) a core of radius approximately or less than 1000 AU surrounding the central star, possibly flattened and rotating; (2) condensations scattered throughout the envelope that may be left over from the inhomogeneous structure of the original cloud core or that may have grown during collapse; and (3) material within the outflow or along the walls of the outflow cavity. Masses of the central cores are 0.001-0.1 M (solar), and agree well with dust continuum measurements. Averaged over the central 20" (3000 AU) region, an HCO+ abundance of 4 x 10(-8) is inferred, with a spread of a factor of 3 between the different sources. Reanalysis of previously presented single-dish data yields an HCO+ abundance of (5.0 +/- 1.7) x 10(-9), which may indicate an average increase by a factor of a few on the smaller scales sampled by the interferometer. Part of this apparent abundance variation could be explained by contributions from extended cloud emission to the single-dish C18O lines, and uncertainties in the assumed excitation temperatures and opacities. The properties of the molecular envelopes and outflows are further investigated through single-dish observations of 12CO J = 6-5, 4-3, and 3-2, 13CO 6-5 and 3-2, and C18O 3-2 and 2-1, obtained with the James Clerk Maxwell and IRAM 30 m telescopes, along with the Caltech Submillimeter Observatory. Ratios of the mid-J CO lines are used to estimate the excitation temperature, with values of 25-80 K derived for the gas near line centre. The outflow wings show a similar range, although Tex is enhanced by a factor of 2-3 in at least two sources. In contrast to the well-studied L1551

  4. Molecular genetic identification of skeletal remains from the Second World War Konfin I mass grave in Slovenia.

    Science.gov (United States)

    Zupanic Pajnic, Irena; Gornjak Pogorelc, Barbara; Balazic, Joze

    2010-07-01

    This paper describes molecular genetic identification of one third of the skeletal remains of 88 victims of postwar (June 1945) killings found in the Konfin I mass grave in Slovenia. Living relatives were traced for 36 victims. We analyzed 84 right femurs and compared their genetic profiles to the genetic material of living relatives. We cleaned the bones, removed surface contamination, and ground the bones into powder. Prior to DNA isolation using Biorobot EZ1 (Qiagen), the powder was decalcified. The nuclear DNA of the samples was quantified using the real-time polymerase chain reaction method. We extracted 0.8 to 100 ng DNA/g of bone powder from 82 bones. Autosomal genetic profiles and Y-chromosome haplotypes were obtained from 98% of the bones, and mitochondrial DNA (mtDNA) haplotypes from 95% of the bones for the HVI region and from 98% of the bones for the HVII region. Genetic profiles of the nuclear and mtDNA were determined for reference persons. For traceability in the event of contamination, we created an elimination database including genetic profiles of the nuclear and mtDNA of all persons that had been in contact with the skeletal remains. When comparing genetic profiles, we matched 28 of the 84 bones analyzed with living relatives (brothers, sisters, sons, daughters, nephews, or cousins). The statistical analyses showed a high confidence of correct identification for all 28 victims in the Konfin I mass grave (posterior probability ranged from 99.9% to more than 99.999999%).

  5. Molecular analysis of sulphur-rich brown coals by flash pyrolysis-gas chromatography-mass spectrometry: The type III-S kerogen

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Las Heras, F.X.C. de; Leeuw, J.W. de

    1992-01-01

    The molecular composition of five brown coals from three different basins (Maestrazgo, Mequinenza and Rubielos) in Spain was investigated by flash pyrolysis-gas chromatography and flash pyrolysis-gas chromatography-mass spectrometry. In these techniques, the macromolecular material is thermally

  6. Effects of fruit and vegetable low molecular mass fractions on gene expression in gingival cells challenged with Prevotella intermedia and Actinomyces naeslundii

    NARCIS (Netherlands)

    Canesi, L.; Borghi, C.; Stauder, M.; Lingström, P.; Papetti, A.; Pratten, J.; Signoretto, C.; Spratt, D.A.; Wilson, M.; Zaura, E.; Pruzzo, C.

    2011-01-01

    Low molecular mass (LMM) fractions obtained from extracts of raspberry, red chicory, and Shiitake mushrooms have been shown to be an useful source of specific antibacterial, antiadhesion/coaggregation, and antibiofilm agent(s) that might be used for protection towards caries and gingivitis. In this

  7. Investigation of 3111T/C polymorphism of the CLOCK gene in obese individuals with or without binge eating disorder: association with higher body mass index.

    Science.gov (United States)

    Monteleone, Palmiero; Tortorella, Alfonso; Docimo, Ludovico; Maldonato, Mauro N; Canestrelli, Benedetta; De Luca, Luca; Maj, Mario

    2008-04-11

    Loss of circadian patterning of metabolism-related functions seems to play a role in the pathogenesis of obesity; therefore, it is reasonable to hypothesize that the functional 3111T/C single nucleotide polymorphism (SNP) of the (Circadian locomotor output cycles kaput) CLOCK gene may have a part in the genetic susceptibility to obesity. The aim of this study was to assess the frequencies of 3111T/C CLOCK gene SNP in overweight/obese subjects with or without binge eating disorder (BED) as compared to normal weight healthy controls. A total of 284 Caucasian subjects, including 92 normal weight healthy subjects and 192 overweight/obese patients (107 with BED) participated into the study. Genotype and allele frequencies did not significantly differ between normal weight controls and overweight/obese patients with and/or without BED. However, overweight/obese patients carrying the CC genotype had significantly higher values of body mass index (BMI) as compared to those carrying the CT and/or TT genotypes. Moreover, obese class III individuals had a significantly higher frequency of both the CC genotype and the C allele as compared to individuals with BMISNP of the CLOCK gene is not associated to human obesity and/or BED, but it seems to predispose obese individuals to a higher BMI.

  8. Fast determination of catecholamines in human plasma using carboxyl-functionalized magnetic-carbon nanotube molecularly imprinted polymer followed by liquid chromatography-tandem quadrupole mass spectrometry.

    Science.gov (United States)

    Ma, Jian-Bo; Qiu, Hai-Wen; Rui, Qiu-Hong; Liao, Yu-Feng; Chen, Yan-Min; Xu, Jin; Zhan, Ping-Ping; Zhao, Yong-Gang

    2016-01-15

    A novel, simple and sensitive method based on the use of dispersive micro-solid-phase extraction (d-μ-SPE) procedure combined with ultra-fast liquid chromatography-tandem quadrupole mass spectrometry (UFLC-MS/MS) for the determination of catecholamines, i.e., dopamine (DA), norepinephrine(NE) and epinephrine (E), was developed and validated. The novel catecholamines molecularly imprinted polymer (MIP) on the surface of carboxyl-functionalized magnetic-carbon nanotube (CF@m-CNTs-MIP) was synthesized and characterized by vibrating sample magnetometer (VSM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The CF@m-CNTs-MIP was used as the d-μ-SPE sorbent to extract catecholamines from human plasma samples. The obtained results demonstrated the higher extraction capacity of CF@m-CNTs-MIP with recoveries between 87.5-110%. The limits of quantification (LOQs) for NE, E and DA were 76 ng/L, 18 ng/L and 10 ng/L, respectively. Validation results on linearity, specificity, accuracy, precision and stability, as well as on application to the analysis of catecholamines in 120 healthy volunteers demonstrated the applicability to clinical studies. Copyright © 2015 Elsevier B.V. All rights reserved.

  9. CAPILLARY ELECTROPHORETIC ANALYSIS OF LOW-MOLECULAR-MASS OF CA SPECIES IN PHLOEM SAP OF Ricinus communis L.

    Directory of Open Access Journals (Sweden)

    Noor Fitri

    2010-06-01

    Full Text Available A capillary electrophoretic (CE analysis with ultra-violet (UV detection was performed for further separation of low-molecular-mass (LMM calcium species in phloem sap of Ricinus communis L. Two different background electrolytes (BGE were used for the separation; these are (1 hydrogen phosphate/dihydrogen phosphate buffer containing cetyltrimethylammonium bromide (CTAB as an electro-osmotic flow (EOF modifier, and (2 boric acid buffer containing CTAB. Various parameters affecting the analysis, including the composition and pH of the BGE were systematically studied. The sensitivity, resolution, baseline noise, migration time of the species peaks, and reproducibility of the method were evaluated under optimised condition. At least 13 UV-active species were optimally separated within about ten minutes. The optimised measurement condition was also achieved using 10 mM hydrogen phosphate/10 mM dihydrogen phosphate containing 0.5 mM CTAB at pH 8.0 as BGE, and by applying voltage of ‑20 kV and temperature of 14°C. Evidently, the analytical method was successfully used for the separation of LMM calcium species in phloem sap of R. communis L.   Keywords: capillary electrophoresis, calcium species, phloem sap, Ricinus communis

  10. Stable quasi-solid-state dye-sensitized solar cell using a diamide derivative as low molecular mass organogelator

    Science.gov (United States)

    Tao, Li; Huo, Zhipeng; Dai, Songyuan; Zhu, Jun; Zhang, Changneng; Huang, Yang; Zhang, Bing; Yao, Jianxi

    2014-09-01

    High stability is a significant target for practical applications of dye-sensitized solar cells. 2-(1-oxododecyl)hydrazide, a diamide derivative, is synthesized and applied in quasi-solid-state dye-sensitized solar cells (QS-DSSCs) as a low molecular mass organogelator (LMOG). It is noteworthy that the transition temperature from gel state to liquid state (Tgel) of this gel electrolyte is 125.2 °C, which ensures the gel state of the electrolyte at the DSSC operating temperature. The influences of the gel electrolyte on the kinetic processes of electron transport and recombination are investigated. The diffusion of redox species in the gel electrolyte is hindered by the crosslinked network, and the decreased electron recombination lifetime indicates an increased electron recombination in QS-DSSC. Significantly, the QS-DSSC exhibits excellent thermal and light-soaking stabilities during accelerated aging tests for 1000 h. Especially, there is almost no change in the short-circuit current density (Jsc) in the QS-DSSC, while the Jsc of the liquid electrolyte based DSSC decreases to 79-90% of their initial values. These results are very important for the application and commercialization of DSSCs.

  11. Study of Molecular and Ionic Vapor Composition over CeI3 by Knudsen Effusion Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    A. M. Dunaev

    2016-01-01

    Full Text Available The molecular and ionic composition of vapor over cerium triiodide was studied by Knudsen effusion mass spectrometry. In the saturated vapor over CeI3 the monomer, dimer, and trimer molecules and the negative ions I−, CeI4-, and Ce2I7- were identified in the temperature range of 753–994 K. The partial pressures of CeI3, Ce2I6, and Ce3I9 were determined and the enthalpies of sublimation, ΔsH°(298.15 K in kJ·mol−1, in the form of monomers (298±9, dimers (415±30, and trimers (423±50 were obtained by the second and third laws of thermodynamics. The enthalpy of formation, ΔfH°(298.15 K in kJ·mol−1, of the CeI3 (-371±9, Ce2I6 (-924±30, and Ce3I9 (-1585±50 molecules and the CeI4- (-857±19 and Ce2I7- (-1451±50 ions were calculated. The electron work function, φe = 3.3±0.3 eV, for the CeI3 crystal was evaluated.

  12. Time-of-flight secondary ion mass spectrometry-based molecular distribution distinguishing healthy and osteoarthritic human cartilage

    CERN Document Server

    Cillero-Pastor, Berta; Kiss, Andras; Blanco, Francisco J; Heeren, Ron M A

    2013-01-01

    Osteoarthritis (OA) is a pathology that ultimately causes joint destruction. The cartilage is one of the principal affected tissues. Alterations in the lipid mediators and an imbalance in the metabolism of cells that form the cartilage (chondrocytes) have been described as contributors to the OA development. In this study, we have studied the distribution of lipids and chemical elements in healthy and OA human cartilage. Time of flight-secondary ion mass spectrometry (TOF-SIMS) allows us to study the spatial distribution of molecules at a high resolution on a tissue section. TOF-SIMS revealed a specific peak profile that distinguishes healthy from OA cartilages. The spatial distribution of cholesterol-related peaks exhibited a remarkable difference between healthy and OA cartilages. A distinctive colocalization of cholesterol and other lipids in the superficial area of the cartilage was found. A higher intensity of oleic acid and other fatty acids in the OA cartilages exhibited a similar localization. On the ...

  13. Theoretical model explaining the relationship between the molecular mass and the activation energy of the enzyme revealed by a large-scale analysis of bioinformatics data.

    Science.gov (United States)

    Pawlowski, Piotr H; Zielenkiewicz, Piotr

    2013-01-01

    A general dependence of the enzyme catalytic rate on its mass was revealed when a statistical analysis of 17065 records from the EMP database was performed. The estimated activation energy of the catalytic process decreases asymptotically with the enzyme molecular mass increase. The proposed theoretical model postulates the existence of an intermediate complex of the enzyme and the departing product. It allows for the explanation of the discovered mass-energy relationship, as an effect of the global enzyme-product interactions during complex dissociation. Fitted parameters of the model seem to be in agreement with those widely accepted for the van der Waals energy of molecular interactions. Their values also agree with the picture of the hydrogen bonding in the catalytic process and suggest that surface walk can be the favorable way of the product departure.

  14. The C242T polymorphism of the p22-phox gene (CYBA is associated with higher left ventricular mass in Brazilian hypertensive patients

    Directory of Open Access Journals (Sweden)

    Krieger José E

    2011-08-01

    Full Text Available Abstract Background Reactive oxygen species have been implicated in the physiopathogenesis of hypertensive end-organ damage. This study investigated the impact of the C242T polymorphism of the p22-phox gene (CYBA on left ventricular structure in Brazilian hypertensive subjects. Methods We cross-sectionally evaluated 561 patients from 2 independent centers [Campinas (n = 441 and Vitória (n = 120] by clinical history, physical examination, anthropometry, analysis of metabolic and echocardiography parameters as well as p22-phox C242T polymorphism genotyping. In addition, NADPH-oxidase activity was quantified in peripheral mononuclear cells from a subgroup of Campinas sample. Results Genotype frequencies in both samples were consistent with the Hardy- Weinberg equilibrium. Subjects with the T allele presented higher left ventricular mass/height2.7 than those carrying the CC genotype in Campinas (76.8 ± 1.6 vs 70.9 ± 1.4 g/m2.7; p = 0.009, and in Vitória (45.6 ± 1.9 vs 39.9 ± 1.4 g/m2.7; p = 0.023 samples. These results were confirmed by stepwise regression analyses adjusted for age, gender, blood pressure, metabolic variables and use of anti-hypertensive medications. In addition, increased NADPH-oxidase activity was detected in peripheral mononuclear cells from T allele carriers compared with CC genotype carriers (p = 0.03. Conclusions The T allele of the p22-phox C242T polymorphism is associated with higher left ventricular mass/height2.7 and increased NADPH-oxidase activity in Brazilian hypertensive patients. These data suggest that genetic variation within NADPH-oxidase components may modulate left ventricular remodeling in subjects with systemic hypertension.

  15. A novel aerosol mass spectrometric approach - Analysis of the organic molecular signature of PM by coupling of thermal EC/OC-carbon analysis to photo-ionization mass spectrometry

    Science.gov (United States)

    Zimmermann, R.; Grabowski, J.; Streibel, T.; Sklorz, M.; Chow, J.

    2012-12-01

    Carbonaceous material in airborne particulate matter (PM) is of increasing interest e.g. due to its adverse health effects and its potential influence on the climate. Its analytical assessment on a molecular level is still very challenging. Hence, analysis of carbonaceous fractions for many studies is often solely carried out by determining sum parameters such as the overall content of organic carbon (OC) and elemental carbon (EC) as well as the total carbon content, TC (sum of OC and EC). The used thermal procedure, however, allows getting additional interesting information: By defining different thermal OC fractions (i.e. temperature steps) also information on the refractory properties of the carbonaceous material is obtained. In this context it is particularly interesting to investigate the release and formation behaviors of the molecular species responsible for the different OC and EC fractions. Thus after initial promising results of pre-studies [1,2] in the current work an EC/OC carbon analyzer (Model DRI 2000) and a homebuilt photo-ionization time-of-flight mass spectrometer (PI-TOFMS) were hyphenated and applied to investigate individual organic compounds especially from the different OC fractions. The carbon analyzer enables the stepwise heating of PM loaded filter samples and provides the sum values of the "carbon" release ("Improve protocol" [2]: OC1 - 120 °C, OC2 - 250°C, OC3 - 450°C OC4 - 550°C). With the on-line coupled PI-TOFMS evolved organic compounds, as released during the thermal program, are detectable in real time. This is possible by MS with soft photo ionization methods (SPI - single photon ionization and REMPI - resonance-enhanced multi photon ionization). Soft ionization suppresses fragmentation upon the ionization step and generates molecular signatures in the MS. The EC/OC-analyzer-PI-TOFMS instrument was applied to several types of PM samples, such as ambient aerosol, emission samples (gasoline/diesel car, wood combustion) or

  16. Association of Exposure to Communities With Higher Ratios of Obesity with Increased Body Mass Index and Risk of Overweight and Obesity Among Parents and Children.

    Science.gov (United States)

    Datar, Ashlesha; Nicosia, Nancy

    2018-01-22

    Little is known about whether the substantial clustering of obesity and overweight within social and geographic networks results from causal pathways, such as social contagion and shared environments, or from self-selection. This study aimed to determine whether exposure to communities with higher rates of obesity increases the body mass index (BMI) of individuals, calculated as weight in kilograms divided by height in meters squared, and their risk of being overweight or obese, and whether social contagion, shared environments, or self-selection can account for identified differences. This natural experiment study used the routine assignment of military service members to installations as a source of exogenous variation in exposure to communities with higher vs lower rates of obesity. The study, which used data collected by the Military Teenagers' Environments, Exercise, and Nutrition Study, examined families from 38 military installations around the United States to determine if individuals had higher BMI and greater odds of overweight and obesity when assigned to installations in counties with higher rates of obesity. The study also examined if the relationship persisted after controlling for shared built environments. The participants included 1 parent and 1 child aged 12 or 13 years from 1519 families of Army-enlisted personnel. Data analysis was completed from November 2016 to October 2017. Adult obesity rate in the county where the assigned installation of the service member was located. Time at installation and location of residence (on-installation vs off-installation) were used to measure the degree of exposure. For parents, outcomes were BMI, overweight/obesity (BMI, ≥25) and obesity (BMI, ≥30). For children, outcomes were BMI z score, overweight/obesity (BMI percentile for age and sex, ≥85), and obesity (BMI percentile for age and sex, ≥95). These outcomes were based on self-reports for parents, self-reports and parent reports for all children

  17. The prevalence of the mitochondrial DNA 16189 variant in non-diabetic Korean adults and its association with higher fasting glucose and body mass index.

    Science.gov (United States)

    Kim, J H; Park, K S; Cho, Y M; Kang, B S; Kim, S K; Jeon, H J; Kim, S Y; Lee, H K

    2002-08-01

    To evaluate the prevalence of the 16189 variant of mitochondrial DNA in Korean adults and its association with insulin resistance. We investigated 160 non-diabetic subjects from a community-based diabetes survey conducted in Yonchon County, Korea in 1993. We extracted the DNA from peripheral blood and examined the 16189 variant by polymerase chain reaction and restrictive enzyme digestion. We compared body mass index (BMI), blood pressure, fasting plasma glucose, 2-h plasma glucose after 75 g glucose load, fasting insulin, cholesterol, and homeostasis model assessment of insulin resistance and beta-cell function between the subjects with 16189 variant and wild type. The prevalence of the 16189 variant in Korean adults was 28.8% (46 of 160). Subjects with the 16189 variant had higher fasting glucose and BMI than those with wild type, but fasting insulin, homeostasis model assessment of insulin resistance and beta-cell function, cholesterol, and blood pressure were not different between two groups. Our results provide evidence for an association of a frequent mitochondrial polymorphism with higher fasting glucose and the risk factors of diabetes mellitus.

  18. Higher Daily Physical Activities Continue to Preserve Muscle Strength After Mid-Life, But Not Muscle Mass After Age of 75.

    Science.gov (United States)

    Hwang, An-Chun; Zhan, Yu-Rui; Lee, Wei-Ju; Peng, Li-Ning; Chen, Liang-Yu; Lin, Ming-Hsien; Liu, Li-Kuo; Chen, Liang-Kung

    2016-05-01

    The objective of this study is to explore the impact of aging and daily physical activities (PA) on muscle mass and muscle strength among community-dwelling people in Taiwan.The design is a cross-sectional study. Setting is a population-based community study.One thousand eight hundred thirty-nine community-dwelling people aged 50 years and older in Taiwan participated in the study.Measurements include demographic characteristics, Charlson Comorbidity Index (CCI) for multimorbidity, mini-nutritional assessment (MNA) for nutritional evaluation, functional autonomy measurement system (SMAF) for functional capacity, Chinese version mini mental state examination (MMSE), 5-item Taiwan Geriatric Depression Scale (TGDS-5), Chinese version of International Physical Activity Questionnaire (IPAQ), height-adjusted skeletal muscle index (SMI) by dual-energy X-ray absorptiometry, handgrip strength, timed 6-m walking test for usual gait speed. Laboratory measurements include testosterone, sex-hormone binding globulin (SHBG), dehydroepiandrosterone sulfate (DHEA-S), insulin-like growth factor-1 (IGF-1), high-sensitivity C-reactive protein (hsCRP), 25-OH vitamin D, and insulin resistance.After adjusted for age, the lowest PA tertile was associated with multimorbidity, poorer functional capacity and nutritional status, more depressive symptoms, lower SMI and lower handgrip strength, and lower free androgen index (FAI) in men. The negative association between PA and low SMI was more significant among subjects aged younger than 65 and the association decreased with older age. For subjects aged younger than 65, moderate daily PA (Q2) group had lower risk of low SMI compared with Q1 participants (OR: 0.62, 95% CI = 0.39-0.98, P = 0.040). For muscle strength, higher daily PA was associated with lower risk of low handgrip strength after age of 65 and the effect was dose-dependent. The effect was attenuated by potential confounders during age 65 to 74, while after age 75, the

  19. Women Are Diagnosed with Type 2 Diabetes at Higher Body Mass Indices and Older Ages than Men: Korea National Health and Nutrition Examination Survey 2007-2010

    Directory of Open Access Journals (Sweden)

    Su Kyoung Kwon

    2014-02-01

    Full Text Available BackgroundMany epidemiologic studies have shown that women with type 2 diabetes have an increased risk of developing cardiovascular disease compared with men with diabetes. The aim of this study is to elucidate whether disparities of adiposity, age and insulin resistance (IR at the time of diabetes diagnosis exist between women and men in the adult Korean population.MethodsData from The Korea National Health and Nutrition Examination Survey, performed in Korea from 2007 to 2010, were used. In the survey, anthropometric data and blood samples were obtained during a fasting state. IR and β-cell function were calculated using the homeostasis model assessment (HOMA-IR and HOMA-β, respectvely.ResultsThe mean age of diabetes diagnosis was 58.5 years in women and was 55.1 years in men (P=0.015. The mean body mass index (BMI of newly diagnosed diabetes subjects was 26.1 kg/m2 in women and 25.0 kg/m2 in men (P=0.001. The BMI was inversely related to age in both genders, and the higher BMI in women than men was consistent throughout all age groups divided by decade. The HOMA-IR in women with diabetes is higher than in men with diabetes (7.25±0.77 vs. 5.20±0.32; P=0.012.ConclusionKorean adult women are diagnosed with type 2 diabetes at higher BMI and older age than men and are more insulin-resistant at the time of diabetes diagnosis. This may help explain why women with diabetes have an increased risk of developing cardiovascular disease after the diagnosis of diabetes, compared to men.

  20. Stable quasi-solid-state dye-sensitized solar cell using ionic gel electrolyte with low molecular mass organogelator

    Energy Technology Data Exchange (ETDEWEB)

    Tao, Li [Key Laboratory of Novel Thin Film Solar Cells, Division of Solar Energy Materials and Engineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Huo, Zhipeng, E-mail: zhipenghuo@163.com [Key Laboratory of Novel Thin Film Solar Cells, Division of Solar Energy Materials and Engineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Dai, Songyuan, E-mail: sydai@ncepu.edu.cn [Key Laboratory of Novel Thin Film Solar Cells, Division of Solar Energy Materials and Engineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Beijing Key Lab of Novel Thin Film Solar Cells, North China Electric Power University, Beijing 102206 (China); Zhu, Jun; Zhang, Changneng; Pan, Xu; Huang, Yang [Key Laboratory of Novel Thin Film Solar Cells, Division of Solar Energy Materials and Engineering, Institute of Plasma Physics, Chinese Academy of Sciences, Hefei, Anhui 230031 (China); Yang, Shangfeng [Hefei National Laboratory for Physical Sciences at Microscale, Department of Materials Science and Engineering, University of Science and Technology of China (USTC), Hefei 230026 (China); Zhang, Bing; Yao, Jianxi [Beijing Key Lab of Novel Thin Film Solar Cells, North China Electric Power University, Beijing 102206 (China)

    2015-02-15

    Long-term stability is essential for the application and commercialization of dye-sensitized solar cells (DSCs). A quasi-solid-state DSC (QS-DSC) with excellent long-term stability is fabricated using ionic gel electrolyte (IGE) with N,N′-methylenebisdodecanamide as low molecular mass organogelator (LMOG). The gel to solution transition temperature (T{sub gel}) of this IGE is 127 °C, well above the working temperature of the device, which contributes to the thermal properties of the IGE and the device. The electrochemical properties of the IGE and the kinetic processes of electron transport and recombination of the QS-DSC are investigated by means of electrochemical impedance spectroscopy (EIS) and controlled intensity modulated photocurrent/photovoltage spectroscopy (IMPS/IMVS). Due to the obstructed diffusion of redox species caused by the network of IGE, the electron recombination at the TiO{sub 2} photoelectrode/electrolyte interface in the QS-DSC is accelerated. More importantly, compared with the ionic liquid electrolyte (ILE) based DSC, the QS-DSC based on the IGE exhibits excellent thermal and light-soaking stabilities during the accelerated aging tests for 1000 h. Especially, there is almost no degradation in the short-circuit current density (J{sub sc}) in the IGE based QS-DSC, while the J{sub sc} of the ILE based DSC decreased to 85–94% of their initial values. - Highlights: • A novel IGE with high T{sub gel} is obtained by using a diamide derivative as LMOG. • The IGE based QS-DSC is very stable during the accelerated aging tests. • The influences of gelation on the electron kinetic processes are investigated.

  1. Associations between body mass index and molecular subtypes as well as other clinical characteristics of breast cancer in Chinese women.

    Science.gov (United States)

    Chen, Fei-Yu; Ou, Hui-Ying; Wang, Shou-Man; Wu, Yu-Hui; Yan, Guo-Jiao; Tang, Li-Li

    2013-01-01

    Several studies have shown a positive association between body mass index (BMI) and the development of hormone receptor-positive breast cancer in postmenopausal women; however, the associations between BMI groups and molecular subtypes have yet to be well defined in premenopausal breast cancer patients. A total of 2465 female breast cancer patients diagnosed at our institution were recruited for this study. Clinicopathologic information (including age, body height and weight, as well as tumor subtypes and stages) was collected; analyses of these characteristics and the associations between them were performed. A total of 1951 cases were included in the study. The mean age was 47.3 years, the majority of patients were of normal weight, premenopausal, had stage 2 cancer, and did not present with positive nodes. The prevalence of the luminal A, luminal B, human epidermal growth factor receptor 2+, and triple-negative subtypes were 57.8%, 11.6%, 6.1%, and 24.5%, respectively. There were significant differences in the clinicopathologic features among BMI groups in premenopausal patients. The case-only odds ratio (OR) analysis revealed that normal weight patients tended to have luminal B cancer (OR = 1.4, P = 0.206), and overweight and obese patients tended to have triple-negative cancer in premenopausal patients (OR = 2.8, OR = 3.7, respectively; P < 0.001). IN CHINESE WOMEN, BREAST CANCER CAME WITH THESE CHARACTERISTICS: young mean age (premenopause), luminal A subtype, and the majority of them were within a normal weight range. In premenopausal patients, underweight patients tended to have luminal A, lower human epidermal growth factor receptor 2+ expression, stage 1 and no positive node cancer. However, overweight and obese patients tended to have a triple-negative, stage 3, and lymph node metastatic cancer.

  2. Analysis of wax ester molecular species by high performance liquid chromatography/atmospheric pressure chemical ionisation mass spectrometry.

    Science.gov (United States)

    Vrkoslav, Vladimír; Urbanová, Klára; Cvacka, Josef

    2010-06-18

    High chromatographic resolution of wax esters (WEs) was achieved by non-aqueous reversed-phase liquid chromatography on a Nova-Pak C18 column by optimising the acetonitrile/ethyl acetate mobile phase gradient. The retention behaviour of WEs was studied in this chromatographic system. The WEs eluted according to their equivalent carbon number (ECN) values; within the group of WEs with the identical ECN, the most unsaturated species tended to elute first. The isobaric WEs with different positions of the ester moiety were separated from each other whenever the lengths of the chains were sufficiently different. The methyl-branched esters eluted at shorter retention times than the straight-chained analogues, and the resolution among methyl-branched WEs depended on the position of the branching. The analytes were detected by atmospheric pressure chemical ionisation mass spectrometry (APCI-MS) using data-dependent scanning. WEs provided simple full-scan spectra with abundant protonated molecules and low-intensity fragments. Collision-induced dissociation (CID) promoted identification of the WE molecular species. The responses of WEs were found to be dependent on the number of double bonds and on the alkyl-chain length; the limits of the detection ranged from 20micromol/L to 200nmol/L. The HPLC/APCI-MS was applied for the analysis of the WEs isolated from honeycomb beeswax, jojoba oil and human hair. Good agreement between reported results and the literature data was achieved, with several novel polyunsaturated WEs also being found. Copyright (c) 2010 Elsevier B.V. All rights reserved.

  3. Comparative evaluation of low-molecular-mass proteins from Mycobacterium tuberculosis identifies members of the ESAT-6 family as immunodominant T-cell antigens

    DEFF Research Database (Denmark)

    Skjøt, R L; Oettinger, T; Rosenkrands, I

    2000-01-01

    . The molecules were characterized, mapped in a two-dimensional electrophoresis reference map of short-term culture filtrate, and compared with another recently identified low-mass protein, CFP10 (F. X. Berthet, P. B. Rasmussen, I. Rosenkrands, P. Andersen, and B. Gicquel. Microbiology 144:3195-3203, 1998......), and the well-described ESAT-6 antigen. Genetic analyses demonstrated that TB10.4 as well as CFP10 belongs to the ESAT-6 family of low-mass proteins, whereas TB7.3 is a low-molecular-mass protein outside this family. The proteins were expressed in Escherichia coli, and their immunogenicity was tested......Culture filtrate from Mycobacterium tuberculosis contains protective antigens of relevance for the generation of a new antituberculosis vaccine. We have identified two previously uncharacterized M. tuberculosis proteins (TB7.3 and TB10.4) from the highly active low-mass fraction of culture filtrate...

  4. Can increased leaf photosynthesis be converted into higher crop mass production? A simulation study for rice using the crop model GECROS.

    Science.gov (United States)

    Yin, Xinyou; Struik, Paul C

    2017-04-01

    Various genetic engineering routes to enhance C3 leaf photosynthesis have been proposed to improve crop productivity. However, their potential contribution to crop productivity needs to be assessed under realistic field conditions. Using 31 year weather data, we ran the crop model GECROS for rice in tropical, subtropical, and temperate environments, to evaluate the following routes: (1) improving mesophyll conductance (gm); (2) improving Rubisco specificity (Sc/o); (3) improving both gm and Sc/o; (4) introducing C4 biochemistry; (5) introducing C4 Kranz anatomy that effectively minimizes CO2 leakage; (6) engineering the complete C4 mechanism; (7) engineering cyanobacterial bicarbonate transporters; (8) engineering a more elaborate cyanobacterial CO2-concentrating mechanism (CCM) with the carboxysome in the chloroplast; and (9) a mechanism that combines the low ATP cost of the cyanobacterial CCM and the high photosynthetic capacity per unit leaf nitrogen. All routes improved crop mass production, but benefits from Routes 1, 2, and 7 were ≤10%. Benefits were higher in the presence than in the absence of drought, and under the present climate than for the climate predicted for 2050. Simulated crop mass differences resulted not only from the increased canopy photosynthesis competence but also from changes in traits such as light interception and crop senescence. The route combinations gave larger effects than the sum of the effects of the single routes, but only Route 9 could bring an advantage of ≥50% under any environmental conditions. To supercharge crop productivity, exploring a combination of routes in improving the CCM, photosynthetic capacity, and quantum efficiency is required. © The Author 2017. Published by Oxford University Press on behalf of the Society for Experimental Biology.

  5. Higher Adolescent Body Mass Index is Associated with Lower Regional Gray and White Matter Volumes and Lower Levels of Positive Emotionality

    Directory of Open Access Journals (Sweden)

    James T Kennedy

    2016-09-01

    Full Text Available Adolescent obesity is associated with an increased chance of developing serious health risks later in life. Identifying the neurobiological and personality factors related to increases in adiposity is important to understanding what drives maladaptive consummatory and exercise behaviors that result in obesity. Previous research has largely focused on adults with few findings published on interactions among adiposity, brain structure, and personality. In this study, Voxel Based Morphometry (VBM was used to identify associations between gray and white matter volumes and increasing adiposity, as measured by Body Mass Index percentile (BMI%, in 137 adolescents (age range: 9-20 years, Body Mass Index percentile range: 5.16-99.56. Variations in gray and white matter volume and BMI% were then linked to individual differences in personality measures from the Multidimensional Personality Questionnaire (MPQ. After controlling for age and other covariates, BMI% correlated negatively with gray matter volume in the bilateral caudate (right: partial r = -0.338, left: r -0.404, medial prefrontal cortex (partial r = -0.339, anterior cingulate (partial r = -0.312, bilateral frontal pole (right: partial r = -0.368, left: r= -0.316, and uncus (partial r = -0.475 as well as white matter volume bilaterally in the anterior limb of the internal capsule (right: partial r = -0.34, left: r = -0.386, extending to the left middle frontal subgyral white matter. Agentic Positive Emotionality (PEM-AG was correlated negatively with BMI% (partial r = -0.384. PEM-AG was correlated positively with gray matter volume in the right uncus (partial r = 0.329. These results suggest that higher levels of adiposity in adolescents are associated with lower trait levels in reward-related personality domains, as well as structural variations in brain regions associated with reward processing, control, and sensory integration.

  6. Can increased leaf photosynthesis be converted into higher crop mass production? A simulation study for rice using the crop model GECROS

    Science.gov (United States)

    Struik, Paul C.

    2017-01-01

    Abstract Various genetic engineering routes to enhance C3 leaf photosynthesis have been proposed to improve crop productivity. However, their potential contribution to crop productivity needs to be assessed under realistic field conditions. Using 31 year weather data, we ran the crop model GECROS for rice in tropical, subtropical, and temperate environments, to evaluate the following routes: (1) improving mesophyll conductance (gm); (2) improving Rubisco specificity (Sc/o); (3) improving both gm and Sc/o; (4) introducing C4 biochemistry; (5) introducing C4 Kranz anatomy that effectively minimizes CO2 leakage; (6) engineering the complete C4 mechanism; (7) engineering cyanobacterial bicarbonate transporters; (8) engineering a more elaborate cyanobacterial CO2-concentrating mechanism (CCM) with the carboxysome in the chloroplast; and (9) a mechanism that combines the low ATP cost of the cyanobacterial CCM and the high photosynthetic capacity per unit leaf nitrogen. All routes improved crop mass production, but benefits from Routes 1, 2, and 7 were ≤10%. Benefits were higher in the presence than in the absence of drought, and under the present climate than for the climate predicted for 2050. Simulated crop mass differences resulted not only from the increased canopy photosynthesis competence but also from changes in traits such as light interception and crop senescence. The route combinations gave larger effects than the sum of the effects of the single routes, but only Route 9 could bring an advantage of ≥50% under any environmental conditions. To supercharge crop productivity, exploring a combination of routes in improving the CCM, photosynthetic capacity, and quantum efficiency is required. PMID:28379522

  7. Prediction of outcome of bright light treatment in patients with seasonal affective disorder: Discarding the early response, confirming a higher atypical balance, and uncovering a higher body mass index at baseline as predictors of endpoint outcome.

    Science.gov (United States)

    Dimitrova, Tzvetelina D; Reeves, Gloria M; Snitker, Soren; Lapidus, Manana; Sleemi, Aamar R; Balis, Theodora G; Manalai, Partam; Tariq, Muhammad M; Cabassa, Johanna A; Karim, Naila N; Johnson, Mary A; Langenberg, Patricia; Rohan, Kelly J; Miller, Michael; Stiller, John W; Postolache, Teodor T

    2017-11-01

    We tested the hypothesis that the early improvement in mood after the first hour of bright light treatment compared to control dim-red light would predict the outcome at six weeks of bright light treatment for depressed mood in patients with Seasonal Affective Disorder (SAD). We also analyzed the value of Body Mass Index (BMI) and atypical symptoms of depression at baseline in predicting treatment outcome. Seventy-eight adult participants were enrolled. The first treatment was controlled crossover, with randomized order, and included one hour of active bright light treatment and one hour of control dim-red light, with one-hour washout. Depression was measured on the Structured Interview Guide for the Hamilton Rating Scale for Depression-SAD version (SIGH-SAD). The predictive association of depression scores changes after the first session. BMI and atypical score balance with treatment outcomes at endpoint were assessed using multivariable linear and logistic regressions. No significant prediction by changes in depression scores after the first session was found. However, higher atypical balance scores and BMI positively predicted treatment outcome. Absence of a control intervention for the six-weeks of treatment (only the first session in the laboratory was controlled). Exclusion of patients with comorbid substance abuse, suicidality and bipolar I disorder, and patients on antidepressant medications, reducing the generalizability of the study. Prediction of outcome by early response to light treatment was not replicated, and the previously reported prediction of baseline atypical balance was confirmed. BMI, a parameter routinely calculated in primary care, was identified as a novel predictor, and calls for replication and then exploration of possible mediating mechanisms. Published by Elsevier B.V.

  8. Higher Protein Intake Does Not Improve Lean Mass Gain When Compared with RDA Recommendation in Postmenopausal Women Following Resistance Exercise Protocol: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Luana T. Rossato

    2017-09-01

    Full Text Available The aim of this study was to evaluate the effect of a higher protein intake on lean body mass (LBM gain in postmenopausal women practicing resistance exercise and compare it to the Recommended Dietary Allowance (RDA recommendation. Twenty-three postmenopausal women (63.2 ± 7.8 years were randomized into two groups. The group with higher protein intake (n = 11 (HP received a dietary plan with ~1.2 g·kg−1·day−1 of protein, while the normal protein (NP group (n = 12 was instructed to ingest ~0.8 g·kg−1·day−1 of protein (RDA recommendation. Both groups performed the same resistance training protocol, 3 times a week, with progression of the number of sets (from 1 to 6 sets and 8–12 repetitions. The intervention occurred over 10 weeks. Body composition evaluation was performed by dual-energy X-ray absorptiometry. The diet was evaluated by nine 24-h food recall summaries over the course of the study. During the intervention period, the HP group presented a higher protein (1.18 ± 0.3 vs. 0.87 ± 0.2 g·kg−1·day−1, p = 0.008 and leucine (6.0 ± 1.4 vs. 4.3 ± 0.9 g/day, p < 0.001 intake than the NP group, respectively. At the end of the intervention, there were increases in LBM both in HP (37.1 ± 6.2 to 38.4 ± 6.5 kg, p = 0.004 and in NP (37.6 ± 6.2 to 38.8 ± 6.4 kg, p < 0.001, with no differences between the groups (p = 0.572. In conclusion, increased protein intake did not promote higher LBM gain when compared to RDA recommendation in postmenopausal women performing resistance exercise during 10 weeks. This trial was registered at ClinicalTrials.gov as NCT03024125.

  9. Radioimmunoassay in Ascidiella aspersa of a gonadoliberin (GnRH)-like factor with an apparent molecular weight higher than that of mammalian decapeptide

    Energy Technology Data Exchange (ETDEWEB)

    Dufour, S.; Monniot, F.; Monniot, C. and others

    1988-02-21

    A radioimmunoassay (RIA) for mammalian gonadoliberin (mGnRH) showed the presence of a GnRH-like factor in the neural complex of a Protochordate, Ascidiella aspersa (about 0.6 pg eq mGnRH/complex). The slope of the displacement curves was slightly lower than with mGnRH indicating antigene differences. No cross reactive material was found in mantle and siphonal area. The KD on Sephadex G25 was 0.45 versus 0.90 with mGnRH. That suggests that the molecular weight of the Ascidian GnRH-like factor is higher than that of known Vertebrate GnRH's, possibly due to a different processing of the precursor.

  10. Coordination of sodium cation to an oxygen function and olefinic double bond to form molecular adduct ion in fast atom bombardment mass spectrometry.

    Science.gov (United States)

    Morisaki, Naoko; Kobayashi, Hisayoshi; Yamamura, Yumiko; Morisaki, Masuo; Nagasawa, Kazuo; Hashimoto, Yuichi

    2002-07-01

    Steroidal allylic alcohols formed Na+ adduct ion peaks [M+Na]+ by the addition of NaCl in FAB mass spectrometry. A comparison of the intensities of the adduct ion peaks of allylic alcohols with those of the corresponding saturated alcohols and olefin suggested that the olefinic double bond and the proximal hydroxyl group had coordinated to Na+. The adduct ion was stable and did not undergo dehydroxylation. We suggest that the Na+ adduction will be useful for the molecular weight determination of allylic alcohols which are susceptible to dehydroxylation under FAB mass spectrometric conditions. Na+ adduct ions of alpha,beta-unsaturated carbonyl compounds were also investigated.

  11. Higher body mass index is associated with plantar fasciopathy/'plantar fasciitis': systematic review and meta-analysis of various clinical and imaging risk factors.

    Science.gov (United States)

    van Leeuwen, K D B; Rogers, J; Winzenberg, T; van Middelkoop, M

    2016-08-01

    What (risk) factors are associated with plantar fasciopathy (PF)? Systematic review with meta-analyses. Patients with PF. All factors described in prospective, case-control or cross-sectional observational studies. 51 included studies (1 prospective, 46 case-control and 4 cross-sectional studies) evaluated a total of 104 variables. Pooling was possible for 12 variables. Higher body mass index (BMI) (BMI>27, OR 3.7 (95% CI 2.93 to 5.62)) in patients with PF was the only significant clinical association, and its effect was the strongest in the non-athletic subgroup. In people with PF compared to controls, pooled imaging data demonstrated a significantly thicker, hypoechogenic plantar fascia with increased vascular signal and perifascial fluid collection. In addition, people with PF were more likely to have a thicker loaded and unloaded heel fat pat, and bone findings, including a subcalcaneal spur and increased Tc-99 uptake. No significant difference was found in the extension of the first metatarsophalangeal joint. We found a consistent clinical association between higher BMI and plantar fasciopathy. This association may differ between athletic and non-athletic subgroups. While consistent evidence supports a range of bone and soft tissue abnormalities, there is lack of evidence for the dogma of clinical and mechanical measures of foot and ankle function. Clinicians can use this information in shared decision-making. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  12. An energy-filtering device coupled to a quadrupole mass spectrometer for soft-landing molecular ions on surfaces with controlled energy

    Energy Technology Data Exchange (ETDEWEB)

    Bodin, A.; Laloo, R.; Abeilhou, P.; Guiraud, L.; Gauthier, S.; Martrou, D. [Nanosciences Group, CEMES, CNRS UPR 8011 and University Toulouse III - Paul Sabatier, 29 rue Jeanne Marvig, BP94347, F-31055 Toulouse Cedex 4 (France)

    2013-09-15

    We have developed an energy-filtering device coupled to a quadrupole mass spectrometer to deposit ionized molecules on surfaces with controlled energy in ultra high vacuum environment. Extensive numerical simulations as well as direct measurements show that the ion beam flying out of a quadrupole exhibits a high-energy tail decreasing slowly up to several hundred eV. This energy distribution renders impossible any direct soft-landing deposition of molecular ions. To remove this high-energy tail by energy filtering, a 127° electrostatic sector and a specific triplet lenses were designed and added after the last quadrupole of a triple quadrupole mass spectrometer. The results obtained with this energy-filtering device show clearly the elimination of the high-energy tail. The ion beam that impinges on the sample surface satisfies now the soft-landing criterion for molecular ions, opening new research opportunities in the numerous scientific domains involving charges adsorbed on insulating surfaces.

  13. Higher body mass index and lower intake of dairy products predict poor glycaemic control among Type 2 Diabetes patients in Malaysia.

    Directory of Open Access Journals (Sweden)

    Ping Soon Shu

    Full Text Available This cross-sectional study was designed to determine factors contributing to glyceamic control in order to provide better understanding of diabetes management among Type 2 Diabetes patients. A pre-tested structured questionnaire was used to obtain information on socio-demographic and medical history. As a proxy measure for glycaemic control, glycosylated haemoglobin (HbA1c was obtained as secondary data from the medical reports. Perceived self-care barrier on diabetes management, diet knowledge and skills, and diet quality were assessed using pretested instruments. With a response rate of 80.3%, 155 subjects were recruited for the study. Mean HbA1c level of the subjects was 9.02 ± 2.25% with more than 70% not able to achieve acceptable level in accordance to WHO recommendation. Diet quality of the subjects was unsatisfactory especially for vegetables, fruits, fish and legumes as well as from the milk and dairy products group. Higher body mass index (BMI, poorer medication compliance, lower diet knowledge and skill scores and lower intake of milk and dairy products contributed significantly on poor glycaemic control. In conclusion, while perceived self-care barriers and diet quality failed to predict HbA1c, good knowledge and skill ability, together with appropriate BMI and adequate intake of dairy products should be emphasized to optimize glycaemic control among type 2 diabetes patients.

  14. Technical Note: Molecular characterization of aerosol-derived water soluble organic carbon using ultrahigh resolution electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

    Directory of Open Access Journals (Sweden)

    R. M. Dickhut

    2008-09-01

    Full Text Available Despite the acknowledged relevance of aerosol-derived water-soluble organic carbon (WSOC to climate and biogeochemical cycling, characterization of aerosol WSOC has been limited. Electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS was utilized in this study to provide detailed molecular level characterization of the high molecular weight (HMW; m/z>223 component of aerosol-derived WSOC collected from rural sites in Virginia and New York, USA. More than 3000 peaks were detected by ESI FT-ICR MS within a m/z range of 223–600 for each sample. Approximately 86% (Virginia and 78% (New York of these peaks were assigned molecular formulas using only carbon (C, hydrogen (H, oxygen (O, nitrogen (N, and sulfur (S as elemental constituents. H/C and O/C molar ratios were plotted on van Krevelen diagrams and indicated a strong contribution of lignin-like and lipid-like compounds to the aerosol-derived WSOC samples. Approximately 1–4% of the peaks in the aerosol-derived WSOC mass spectra were classified as black carbon (BC on the basis of double bond equivalents calculated from the assigned molecular formulas. In addition, several high-magnitude peaks in the mass spectra of samples from both sites corresponded to molecular formulas proposed in previous secondary organic aerosol (SOA laboratory investigations indicating that SOAs are important constituents of the WSOC. Overall, ESI FT-ICR MS provides a level of resolution adequate for detailed compositional and source information of the HMW constituents of aerosol-derived WSOC.

  15. Imaging mass spectrometry technology and application on ganglioside study; visualization of age-dependent accumulation of C20-ganglioside molecular species in the mouse hippocampus.

    Directory of Open Access Journals (Sweden)

    Yuki Sugiura

    Full Text Available Gangliosides are particularly abundant in the central nervous system (CNS and thought to play important roles in memory formation, neuritogenesis, synaptic transmission, and other neural functions. Although several molecular species of gangliosides have been characterized and their individual functions elucidated, their differential distribution in the CNS are not well understood. In particular, whether the different molecular species show different distribution patterns in the brain remains unclear. We report the distinct and characteristic distributions of ganglioside molecular species, as revealed by imaging mass spectrometry (IMS. This technique can discriminate the molecular species, raised from both oligosaccharide and ceramide structure by determining the difference of the mass-to-charge ratio, and structural analysis by tandem mass spectrometry. Gangliosides in the CNS are characterized by the structure of the long-chain base (LCB in the ceramide moiety. The LCB of the main ganglioside species has either 18 or 20 carbons (i.e., C18- or C20-sphingosine; we found that these 2 types of gangliosides are differentially distributed in the mouse brain. While the C18-species was widely distributed throughout the frontal brain, the C20-species selectively localized along the entorhinal-hippocampus projections, especially in the molecular layer (ML of the dentate gyrus (DG. We revealed development- and aging-related accumulation of the C-20 species in the ML-DG. Thus it is possible to consider that this brain-region specific regulation of LCB chain length is particularly important for the distinct function in cells of CNS.

  16. [Determination of the distribution of relative molecular mass of organic matter by high pressure size exclusion chromatography with UV and TOC detectors].

    Science.gov (United States)

    Zhang, Han; Dong, Bing-Zhi

    2012-09-01

    An on-line high pressure size exclusion chromatography (HPSEC) with UV and TOC detectors was adapted to examine the distribution of relative molecular mass of natural organic matter (NOM). Through synchronous determination of UV254 and TOC responses in a wide range of relative molecular mass, it was possible to accurately characterize the structure of NOM, especially for some non-aromatic and non-conjugated double bond organics which have low response to UV. It was found that, TOC detector was capable of detecting all kinds of organic matters, including sucrose, sodium alginate and other hydrophilic organic compounds. The sample volume had a positively linear correlation with the TOC response, indicating that the larger volume would produce stronger responses. The effect of ion strength was relatively low, shown by the small decrease of peak area (1.2% ) from none to 0.2 mol x L(-1) NaCl. The pH value of tested samples should be adjusted to neutral or acidic because when the samples were alkaline, the results might be inaccurate. Compared to the sample solvents adopted as ultrapure water, the samples prepared by mobile phase solvents had less interference to salt boundary peak. The on-line HPSEC-UV-TOC can be used accurately to characterize the distribution of relative molecular mass and its four fractions in River Xiang.

  17. Molecular composition of rainwater and aerosol during rain events in León, Spain, using high resolution mass spectrometry.

    Science.gov (United States)

    Fee, Anna

    2017-04-01

    Anna Fee (1), Markus Kalberer (1), Roberto Fraile (2), Amaya Castro (2), Ana. I. Calvo (2), Carlos Blanco-Alegre (2), Fernanda Oduber (2) and Mário Cerqueira (3). 1 Department of Chemistry, University of Cambridge, UK. 2 Department of Applied Chemistry and Physics, IMARENAB, University of León, Spain. 3 Department of Environmental Planning, University of Aveiro, Portugal. A wide range of atmospheric compounds which are present in rainwater are often also present in aerosol. They can be taken up during cloud droplet formation (in-cloud scavenging) or washed out during precipitation (below-cloud scavenging). Such compounds including aromatic hydrocarbons and organic nitrogen containing compounds are hazardous to health. In this study, the organic chemical composition of rainwater and aerosol from rain events in León, Spain, is being analysed using high resolution mass spectrometry. Collected rainwater along with high volume and low volume filters from rain events which occurred during spring, summer and winter of 2016 have been selected for analysis. Rainwater samples were prepared using Polymeric Reversed Phase Solid Phase Extraction (SPE) and filters have been extracted in water with and without SPE. Three different SPE polymer based sorbents were tested; one for extracting neutral compounds and two which are more suitable for extracting organic compounds containing sulphate and other polar functional groups. The sorbent for extracting neutral compounds was found to yield a higher number of compounds from the sample extraction than the other two varieties. Kendrick masses, Van Krevelen plots and carbon oxidation states have been investigated to identify compounds and patterns. Preliminary results show a predominance in peaks with O/C ratios between 0.2 and 0.7 and H/C ratios between 1 and 2 in both rain and aerosol samples which indicates substituted aromatic compounds. Cellulose material and fatty acids may also be present. The rain samples also have a

  18. Direct charge number and molecular weight determination of large individual ions by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen, R.; Wu, Q.; Mitchell, D.W.; Hofstadler, S.A.; Rockwood, A.L.; Smith, R.D. (Pacific Northwest Lab., Richland, WA (United States))

    1994-11-15

    The coupling of electrospray ionization (ESI) techniques with Fourier transform ion cyclotron resonance (FTICR) mass spectrometry allows the analysis of individual (i.e., single) multiply charged ions. In this paper, we demonstrate that individual large ions can be directly characterized through their excitation and ejection behavior in the FTICR cell. We also report the direct measurement of the charge carried by an individual poly(ethylene glycol) ion (5 [times] 10[sup 6] nominal molecular weight) and thus obtain the molecular weight of an individual ion ([approximately] 4.1 [times] 10[sup 6]) directly from the m/z measurement. These results confirm that the observed ions are indeed large individual molecular ions produced by ESI, as opposed to small fragments, and that an approximate molecular weight can be directly measured on the basis of charge determination and measured m/z. This capability augments the ability for more precise mass determination based upon the observation of a known reaction process (e.g., proton transfer) for individual ions. 39 refs., 5 figs., 1 tab.

  19. High molecular weight non-polar hydrocarbons as pure model substances and in motor oil samples can be ionized without fragmentation by atmospheric pressure chemical ionization mass spectrometry.

    Science.gov (United States)

    Hourani, Nadim; Kuhnert, Nikolai

    2012-10-15

    High molecular weight non-polar hydrocarbons are still difficult to detect by mass spectrometry. Although several studies have targeted this problem, lack of good self-ionization has limited the ability of mass spectrometry to examine these hydrocarbons. Failure to control ion generation in the atmospheric pressure chemical ionization (APCI) source hampers the detection of intact stable gas-phase ions of non-polar hydrocarbon in mass spectrometry. Seventeen non-volatile non-polar hydrocarbons, reported to be difficult to ionize, were examined by an optimized APCI methodology using nitrogen as the reagent gas. All these analytes were successfully ionized as abundant and intact stable [M-H](+) ions without the use of any derivatization or adduct chemistry and without significant fragmentation. Application of the method to real-life hydrocarbon mixtures like light shredder waste and car motor oil was demonstrated. Despite numerous reports to the contrary, it is possible to ionize high molecular weight non-polar hydrocarbons by APCI, omitting the use of additives. This finding represents a significant step towards extending the applicability of mass spectrometry to non-polar hydrocarbon analyses in crude oil, petrochemical products, waste or food. Copyright © 2012 John Wiley & Sons, Ltd.

  20. Approach to characterization of the higher order structure of disulfide-containing proteins using hydrogen/deuterium exchange and top-down mass spectrometry.

    Science.gov (United States)

    Wang, Guanbo; Kaltashov, Igor A

    2014-08-05

    Top-down hydrogen/deuterium exchange (HDX) with mass spectrometric (MS) detection has recently matured to become a potent biophysical tool capable of providing valuable information on higher order structure and conformational dynamics of proteins at an unprecedented level of structural detail. However, the scope of the proteins amenable to the analysis by top-down HDX MS still remains limited, with the protein size and the presence of disulfide bonds being the two most important limiting factors. While the limitations imposed by the physical size of the proteins gradually become more relaxed as the sensitivity, resolution and dynamic range of modern MS instrumentation continue to improve at an ever accelerating pace, the presence of the disulfide linkages remains a much less forgiving limitation even for the proteins of relatively modest size. To circumvent this problem, we introduce an online chemical reduction step following completion and quenching of the HDX reactions and prior to the top-down MS measurements of deuterium occupancy of individual backbone amides. Application of the new methodology to the top-down HDX MS characterization of a small (99 residue long) disulfide-containing protein β2-microglobulin allowed the backbone amide protection to be probed with nearly a single-residue resolution across the entire sequence. The high-resolution backbone protection pattern deduced from the top-down HDX MS measurements carried out under native conditions is in excellent agreement with the crystal structure of the protein and high-resolution NMR data, suggesting that introduction of the chemical reduction step to the top-down routine does not trigger hydrogen scrambling either during the electrospray ionization process or in the gas phase prior to the protein ion dissociation.

  1. Molecular, Cellular and Pharmaceutical Aspects of Biomaterials in Dentistry and Oral and Maxillofacial Surgery. An Internationalization of Higher Education and Research Perspective.

    Science.gov (United States)

    Wisniewska, Lidia M; Dohan Ehrenfest, David M; Galindo-Moreno, Pablo; Segovia, Jesus D; Inchingolo, Francesco; Wang, Hom-Lay; Fernandes-Cruz, Manuel

    2017-01-01

    In dentistry and oral and maxillofacial surgery, the development of implantable biomaterials and the understanding of their molecular, cellular and pharmaceutical aspects are currently major fields of research and education, with a considerable impact on the daily clinical practice and the evolution of therapeutic strategies. In the era of globalized economy of knowledge and science, this scientific domain needs the development of global cooperation and a paradigm evolution in the organizational culture of the dental sciences and related dental industry. Despite political pressure and theoretical efforts, the internationalization of higher education and research today in dentistry and biomaterials remains in general quite superficial and mostly dependent on the efforts of a few leaders of internationalization working through their personal networks, as it was assessed through the FAST scores (Fast Assessment Screening Test) calculated in various dental schools and groups worldwide through the ISAIAS program (Intercultural Sensitivity Academic Index &Advanced Standards). Cooperation in a multipolar multicultural community requires the development of strong intercultural competences, and this process remains limited in most institutions. These limits of international scientific cooperation can be observed through different markers, particularly the difficult and limited production of ISO standards (International Organization for Standardization) and the relatively low SCIENTI scores (Scientific Cooperation Internationalization Effort &Network Test &Index) of the specialized dental literature, particularly in comparison to the most significant medical literature. However, as an analytical tool to assess the scientific international cooperation effort between fields and periods, the SCIENTI screening system also highlighted a significant increase of the internationalization effort in the last years in the best dental biomaterials publications. Finally, an

  2. Identification of intact high molecular weight glutenin subunits from the wheat proteome using combined liquid chromatography-electrospray ionization mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Bert Lagrain

    Full Text Available The present paper describes a method for the identification of intact high molecular weight glutenin subunits (HMW-GS, the quality determining proteins from the wheat storage proteome. The method includes isolation of HMW-GS from wheat flour, further separation of HMW-GS by reversed-phase high-performance liquid chromatography (RP-HPLC, and their subsequent molecular identification with electrospray ionization mass spectrometry using a quadrupole-time-of-flight mass analyzer. For HMW-GS isolation, wheat proteins were reduced and extracted from flour with 50% 1-propanol containing 1% dithiothreitol. HMW-GS were then selectively precipitated from the protein mixture by adjusting the 1-propanol concentration to 60%. The composition of the precipitated proteins was first evaluated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis with Coomassie staining and RP-HPLC with ultraviolet detection. Besides HMW-GS (≥65%, the isolated proteins mainly contained ω5-gliadins. Secondly, the isolated protein fraction was analyzed by liquid chromatography-mass spectrometry. Optimal chromatographic separation of HMW-GS from the other proteins in the isolated fraction was obtained when the mobile phase contained 0.1% trifluoroacetic acid as ion-pairing agent. Individual HMW-GS were then identified by determining their molecular masses from the high-resolution mass spectra and comparing these with theoretical masses calculated from amino acid sequences. Using formic acid instead of trifluoroacetic acid in the mobile phase increased protein peak intensities in the base peak mass chromatogram. This allowed the detection of even traces of other wheat proteins than HMW-GS in the isolated fraction, but the chromatographic separation was inferior with a major overlap between the elution ranges of HMW-GS and ω-gliadins. Overall, the described method allows a rapid assessment of wheat quality through the direct determination of the HMW-GS composition and

  3. [[Molecular composition of saturated hydrocarbons in diesels by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry

    Science.gov (United States)

    Niu, Luna; Liu, Zelong; Zhou, Jian; Cai, Xinheng; Tian, Songbai

    2014-11-01

    An analytical method for separation and identification of the saturated hydrocarbons in diesels at molecular level by comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC x GC-TOF MS)was established. The saturated hydrocarbons were pre-separated from diesel samples by solid phase extraction before GC x GC-TOF MS analysis. More than 1,000 individual compounds (including paraffins, naphthenes and ole- fins) in coker diesel were tentatively identified based on NIST library search, mass spectrum resolution, boiling point distribution law and separation characteristics. Normal paraffins showed great regularity and could be identified easily through the relative position with pristane and phytane. The cyclic alkanes arranged above paraffins with the increasing number of rings. The normal alkyl cyclohexanes and cyclopentanes were well distinguished due to the difference of their polarity. Normal α-olefins which were often neglected in the past were also identified. With the support of the above-introduced identification, the distribution by structural type and carbon number were presented using peak area normalization. This analytical method was suc- cessfully used to investigate the molecular composition of saturated fractions in different diesel samples. All the results indicated that the molecular compositions of saturates in catalytic cracking diesel and coker diesel were significantly different because of the processing mechanism. This method provided technical support for the characterization of saturated hydrocar- bons in diesels and the investigation of processing mechanism.

  4. 3M™ Molecular detection system versus MALDI-TOF mass spectrometry and molecular techniques for the identification of Escherichia coli 0157:H7, Salmonella spp. &Listeria spp.

    Science.gov (United States)

    Loff, Marché; Mare, Louise; de Kwaadsteniet, Michele; Khan, Wesaal

    2014-06-01

    The aim of this study was to compare standard selective plating, conventional PCR (16S rRNA and species specific primers), MALDI-TOF MS and the 3M™ Molecular Detection System for the routine detection of the pathogens Listeria, Salmonella and Escherichia coli 0157:H7 in wastewater and river water samples. MALDI-TOF MS was able to positively identify 20/21 (95%) of the E. coli isolates obtained at genus and species level, while 16S rRNA sequencing only correctly identified 6/21 (28%) as E. coli strains. None of the presumptive positive Listeria spp. and Salmonella spp. isolates obtained by culturing on selective media were positively identified by MALDI-TOF and 16S rRNA analysis. The species-specific E. coli 0157:H7 PCR described in this present study, was not able to detect any E. coli 0157:H7 strains in the wastewater and river water samples analysed. However, E. coli strains, Listeria spp., L. monocytogenes and Salmonella spp. were detected using species specific PCR. Escherichia coli 0157:H7, Listeria spp. and Salmonella spp. were also sporadically detected throughout the sampling period in the wastewater and river water samples analysed by the 3M™ Molecular Detection System. MALDI-TOF MS, which is a simple, accurate and cost-effective detection method, efficiently identified the culturable organisms, while in the current study both species specific PCR (Listeria spp. and Salmonella spp.) and 3M™ Molecular Detection System could be utilised for the direct routine analysis of pathogens in water sources. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Comparison of the applicability of mass spectrometer ion sources using a polarity- molecular weight scattergram with a 600 sample in-house chemical library.

    Science.gov (United States)

    Sugimura, Natsuhiko; Furuya, Asami; Yatsu, Takahiro; Shibue, Toshimichi

    2015-01-01

    To provide a practical guideline for the selection of a mass spectrometer ion source, we compared the applicability of three types of ion source: direct analysis in real time (DART), electrospray ionization (ESI) and fast atom bombardment (FAB), using an in-house high-resolution mass spectrometry sample library consisting of approximately 600 compounds. The great majority of the compounds (92%), whose molecular weights (MWs) were broadly distributed between 150 and 1000, were detected using all the ion sources. Nevertheless, some compounds were not detected using specific ion sources. The use of FAB resulted in the highest sample detection rate (>98%), whereas the detection rates obtained using DART and ESI were slightly lower (>96%). A scattergram constructed using MW and topological polar surface area (tPSA) as a substitute for molecular polarity showed that the performance of ESI was weak in the low-MW (800) area. These results might provide guidelines for the selection of ion sources for inexperienced mass spectrometry users.

  6. Dietary calcium intake and higher body mass index in Mexican adults aged 20 to 59 years old: cross-sectional study

    Directory of Open Access Journals (Sweden)

    Mario Efraín Flores-Aldana

    2013-02-01

    Full Text Available Background. Although energy balance is the main factor that regulates body weight, recent studies suggest that calcium metabolism can modify the energy balance and help regulate body weight. Objective. To evaluate the association between the calcium intake in the diet and high body mass index in Mexican adults in the 20-59 age group. Material and methods. A cross-sectional secondary analytical study was conducted based on the 2006 Mexican National Health and Nutritional Survey (ENSANUT 2006. Food intake questionnaires applied to 16,494 adults were analyzed. After removing biologically implausible values or incomplete information, we arrived at a final sample of 15,662 adults grouped according to their body mass index. Linear regression was used to assess association between daily dietary calcium intake and body mass index. Results. There was an inverse association between dietary calcium consumption and a high body mass index. The mean calcium intake in subjects with normal body mass index was 903.9 mg/day versus 832.0 mg/day in obese subjects (p < 0.0001. Conclusion. The study corroborates existing evidence of an inverse association between the dietary calcium intake and a high body mass index.

  7. Determination of high molecular mass compounds from Amazonian plant's leaves; Determinacao de compostos de massa molecular alta em folhas de plantas da Amazonia

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, Denilson Soares de; Pereira, Alberto dos Santos; Aquino Neto, Francisco Radler de [Universidade Federal, Rio de Janeiro, RJ (Brazil). Inst. de Quimica]. E-mail: ladetec@iq.gov.br; Cabral, Jose Augusto; Ferreira, Carlos Alberto Cid [Instituto Nacional de Pesquisas da Amazonia (INPA), Manaus, AM (Brazil); Simoneit, Bernd R.T. [Oregon State Univ., Corvallis, OR (United States). College of Oceanic and Atmospheric Sciences. Petroleum and Environmental Geochemistry Group; Elias, Vladimir O. [Analytical Solution, Rio de Janeiro, RJ (Brazil)

    2003-10-01

    The fractions of dichloromethane extracts of leaves from andiroba (Carapa guianensis - Meliaceae), caapi (Banisteriopsis caapi - Malpighiaceae), cocoa (Theobroma cacao - Sterculiaceae), Brazil nut (Bertholletia excelsa - Lecytidaceae), cupuacu (Theobroma grandiflorum - Sterculiaceae), marupa (Simaruba amara - Simaroubaceae) and rubber tree (Hevea brasiliensis - Euphorbiaceae), were analyzed by HT-HRGC and HT-HRGC-MS. Esters of homologous series of fatty acids and long chain alcohols, phytol, amyrines and tocopherols were characterized. The characterization of the compounds was based mainly in mass spectra data and in addition by usual spectrometric data ({sup 1}H and {sup 13}C NMR, IR). (author)

  8. Investigation of colloidal graphite as a matrix for matrix-assisted laser desorption/ionisation mass spectrometry of low molecular weight analytes.

    Science.gov (United States)

    Warren, Alexander D; Conway, Ulric; Arthur, Christopher J; Gates, Paul J

    2016-07-01

    The analysis of low molecular weight compounds by matrix-assisted laser desorption/ionisation mass spectrometry is problematic due to the interference and suppression of analyte ionisation by the matrices typically employed - which are themselves low molecular weight compounds. The application of colloidal graphite is demonstrated here as an easy to use matrix that can promote the ionisation of a wide range of analytes including low molecular weight organic compounds, complex natural products and inorganic complexes. Analyte ionisation with colloidal graphite is compared with traditional organic matrices along with various other sources of graphite (e.g. graphite rods and charcoal pencils). Factors such as ease of application, spectra reproducibility, spot longevity, spot-to-spot reproducibility and spot homogeneity (through single spot imaging) are explored. For some analytes, considerable matrix suppression effects are observed resulting in spectra completely devoid of matrix ions. We also report the observation of radical molecular ions [M(-●) ] in the negative ion mode, particularly with some aromatic analytes. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  9. A molecular-level approach for characterizing water-insoluble components of ambient organic aerosol particulates using ultrahigh-resolution mass spectrometry

    Science.gov (United States)

    Willoughby, A. S.; Wozniak, A. S.; Hatcher, P. G.

    2014-09-01

    The chemical composition of organic aerosols in the atmosphere is strongly influenced by human emissions. The effect these have on the environment, human health, and climate change is determined by the molecular nature of these chemical species. The complexity of organic aerosol samples limits the ability to study the chemical composition, and therefore the associated properties and the impacts they have. Many studies have addressed the water-soluble fraction of organic aerosols and have had much success in identifying specific molecular formulas for thousands of compounds present. However, little attention is given to the water-insoluble portion, which can contain most of the fossil material that is emitted through human activity. Here we compare the organic aerosols present in water extracts and organic solvent extracts (pyridine and acetonitrile) of an ambient aerosol sample collected in a rural location that is impacted by natural and anthropogenic emission sources. A semiquantitative method was developed using proton nuclear magnetic resonance spectroscopy to determine that the amount of organic matter extracted by pyridine is comparable to that of water. Electrospray ionization Fourier transform ion cyclotron resonance mass spectra show that pyridine extracts a molecularly unique fraction of organic matter compared to water or acetonitrile, which extract chemically similar organic matter components. The molecular formulas unique to pyridine were less polar, more aliphatic, and reveal formulas containing sulfur to be an important component of insoluble aerosol organic matter.

  10. A molecular-level approach for characterizing water-insoluble components of ambient organic aerosol particulates using ultra-high resolution mass spectrometry

    Science.gov (United States)

    Willoughby, A. S.; Wozniak, A. S.; Hatcher, P. G.

    2014-04-01

    The chemical composition of organic aerosols in the atmosphere is strongly influenced by human emissions, and the effect these have on the environment, human health, and climate change is determined by the molecular nature of these chemical species. The complexity of organic aerosol samples limits the ability to study the chemical composition, and, therefore, the associated properties and the impacts they have. Many studies address the water-soluble fraction of organic aerosols, and have had much success in identifying specific molecular formulas for thousands of compounds present. However, little attention is given to the water-insoluble portion, which can contain most of the fossil material that is emitted through human activity. Here we compare the organic aerosols present in water extracts and organic solvent extracts (pyridine and acetonitrile) of an ambient aerosol sample collected in a rural location that is impacted by natural and anthropogenic emission sources. A semi-quantitative method was developed using proton nuclear magnetic resonance spectroscopy to determine that the amount of organic matter extracted by pyridine is comparable to that of water. Electrospray ionization Fourier transform ion cyclotron resonance mass spectra show that pyridine extracts a molecularly unique fraction of organic matter compared to water or acetonitrile, which extract chemically similar organic matter components. The molecular formulas unique to pyridine were less polar, more aliphatic, and reveal formulas containing sulfur to be an important component of insoluble aerosol organic matter.

  11. Collision-induced dissociation pathways of yeast sphingolipids and their molecular profiling in total lipid extracts: a study by quadrupole TOF and linear ion trap-orbitrap mass spectrometry

    DEFF Research Database (Denmark)

    Ejsing, Christer S.; Moehring, Thomas; Bahr, Ute

    2006-01-01

    The yeast Saccharomyces cerevisiae synthesizes three classes of sphingolipids: inositolphosphoceramides (IPCs), mannosyl-inositolphosphoceramides (MIPCs), and mannosyl-diinositolphosphoceramides (M(IP)2C). Tandem mass spectrometry of their molecular anions on a hybrid quadrupole time-of-flight (Q...

  12. The JCMT Spectral Legacy Survey : physical structure of the molecular envelope of the high-mass protostar AFGL2591

    NARCIS (Netherlands)

    van der Wiel, M. H. D.; van der Tak, F. F. S.; Spaans, M.; Fuller, G. A.; Plume, R.; Roberts, H.; Williams, J. L.

    Context. The understanding of the formation process of massive stars (greater than or similar to 8 M-circle dot) is limited by a combination of theoretical complications and observational challenges. The high UV luminosities of massive stars give rise to chemical complexity in their natal molecular

  13. Mass measurement with the electron microscope. [Application of scanning transmission electron microscopy in molecular weight determinations of fd phage

    Energy Technology Data Exchange (ETDEWEB)

    Wall, J.S.

    1979-01-01

    The use of electron scattering measurements performed in the electron microscope as a means of measurement of particle molecular weight is described. Various potential sources of errors are identified and estimated where possible. Specimen preparation and observation conditions to minimize errors are described. The fd phage is presented as an example of analysis and an illustration of the accuracy obtainable at low dose.

  14. An electrospray/inductively coupled plasma dual-source time-of-flight mass spectrometer for rapid metallomic and speciation analysis. Part 1. Molecular channel characterization.

    Science.gov (United States)

    Rogers, Duane A; Ray, Steven J; Hieftje, Gary M

    2010-04-01

    A new time-of-flight mass spectrometer has been developed that uses an electrospray source and an inductively coupled plasma to extract molecular, atomic, and isotopic information simultaneously from a single sample. This paper will focus on characterization of the ESI channel. Sensitivities are reported for hexadecyltrimethylammonium, tetrahexylammonium, tetraoctylammonium, myoglobin, insulin, cyanocobalamin, leucine enkephalin, and alcohol dehydrogenase. Skimmer-nozzle collisionally induced dissociation is explored for adduct removal and analyte fragmentation on the ESI channel for tetraoctylammonium ion and leucine enkephalin. Long-term and short-term spray stability is also examined.

  15. A microtiter plate-based beta-lactam binding assay for inhibitors of high-molecular-mass penicillin-binding proteins.

    Science.gov (United States)

    Stefanova, Miglena; Bobba, Sudheer; Gutheil, William G

    2010-01-01

    High-molecular-mass penicillin-binding proteins (HMM PBPs) are essential for bacterial cell wall biosynthesis and are the lethal targets of beta-lactam antibiotics. When purified, HMM PBPs give undetectable or weak enzyme activity. This has impeded efforts to develop assays for HMM PBPs and to develop new inhibitors for HMM PBPs as HMM PBP targeted antibacterial agents. However, even when purified, HMM PBPs retain their ability to bind beta-lactams. Here we describe a fluorescently detected microtiter plate-based assay for inhibitor binding to HMM PBPs based on competition with biotin-ampicillin conjugate (BIO-AMP) binding.

  16. A Microtiter Plate-Based β-Lactam Binding Assay for Inhibitors of the High Molecular Mass Penicillin-Binding Proteins†

    Science.gov (United States)

    Stefanova, Miglena; Bobba, Sudheer; Gutheil, William G.

    2009-01-01

    The high molecular mass (HMM) PBPs are essential for bacterial cell wall biosynthesis, and are the lethal targets of the β–lactam antibiotics. When purified, the HMM PBPs give undetectable or weak enzyme activity. This has impeded efforts to develop assays for the HMM PBPs, and to develop new inhibitors for the HMM PBPs as HMM PBP targeted antibacterial agents. However, even when purified the HMM PBPs retain their ability to bind β-lactams. We describe here a fluorescently detected microtiter plate-based assay for inhibitor binding to the HMM PBPs based on competition with biotin-ampicillin (BIO-AMP) conjugate binding. PMID:19748471

  17. Electrospray Ionization Mass Spectrometry: A Technique to Access the Information beyond the Molecular Weight of the Analyte

    Directory of Open Access Journals (Sweden)

    Shibdas Banerjee

    2012-01-01

    Full Text Available The Electrospray Ionization (ESI is a soft ionization technique extensively used for production of gas phase ions (without fragmentation of thermally labile large supramolecules. In the present review we have described the development of Electrospray Ionization mass spectrometry (ESI-MS during the last 25 years in the study of various properties of different types of biological molecules. There have been extensive studies on the mechanism of formation of charged gaseous species by the ESI. Several groups have investigated the origin and implications of the multiple charge states of proteins observed in the ESI-mass spectra of the proteins. The charged analytes produced by ESI can be fragmented by activating them in the gas-phase, and thus tandem mass spectrometry has been developed, which provides very important insights on the structural properties of the molecule. The review will highlight recent developments and emerging directions in this fascinating area of research.

  18. Subtle differences in molecular recognition between modified glycopeptide antibiotics and bacterial receptor peptides identified by electrospray ionization mass spectrometry

    DEFF Research Database (Denmark)

    Jørgensen, Thomas J. D.; Staroske, T; Roepstorff, P

    1999-01-01

    showing that electrospray ionization mass spectrometry (ESI-MS) can be used in the rapid quantitative analysis of mixtures of vancomycin-group antibiotics and their bacterial cell-wall receptors allowing the identification of even subtle differences in binding constants. Differences in affinities...

  19. Structure investigation of codeine drug using mass spectrometry, thermal analyses and semi-emperical molecular orbital (MO) calculations

    Science.gov (United States)

    Zayed, M. A.; Hawash, M. F.; Fahmey, M. A.

    2006-05-01

    Codeine is an analgesic with uses similar to morphine, but it has a mild sedative effect. It is preferable used as phosphate form and it is often administrated by mouth with aspirin or paracetamol. Therefore, it is important to investigate its structure to know the active groups and weak bonds responsible for its medical activity. Consequently in the present work, codeine was investigated by mass spectrometry and thermal analyses (TG, DTG and DTA) and confirming by semi-empirical MO-calculation (PM3 method) in the neutral and positively charged forms of the drug. Some results of studying the d-block element complexes of codeine were used to declare the relationship between drug structure and its chemical reactivity in vitro system. The mass spectra and thermal analyses fragmentation pathways were proposed and compared to each other to select the most suitable scheme representing the correct fragmentation of this drug. From EI mass spectra, the main primary cleavage site of the charged drug molecule is that due to β-cleavage to nitrogen atom in its skeleton. It occurs in two parallel mechanisms with the same possibility, i.e. no difference in appearance activation energy between them. In the neutral drug form the primary site cleavage is that occurs in the ether ring. Thermal analyses of the neutral form of the drug revealed the high response of the drug to the temperature variation with very fast rate. It decomposed in several sequential steps in the temperature range 200-600 °C. The initial thermal fragments are very similar to that obtained by mass spectrometric fragmentation. Therefore, comparison between mass and thermal helps in selection of the proper pathway representing the fragmentation of this drug. This comparison successfully confirmed by MOC. These calculations give the bond order, charge distribution, heat of formation and possible hybridization of some atoms in different position of the drug skeleton. This helps the successful choice of the weakest

  20. Buried Volume Analysis for Propene Polymerization Catalysis Promoted by Group 4 Metals: a Tool for Molecular Mass Prediction

    KAUST Repository

    Falivene, Laura

    2015-10-02

    A comparison of the steric properties of homogeneous single site catalysts for propene polymerization using the percentage of buried volume (%VBur) as molecular descriptor is reported. The %VBur calculated on the neutral precursors of the active species seems to be a reliable tool to explain several experimental data related to the propene insertion and to the monomer chain transfer. Interestingly, a linear correlation between the buried volume calculated for a large set of neutral precursors and the energetic difference between propagation and termination steps calculated by DFT methods is found for Group 4 metal catalysts. The “master curves” derived for Ti, Zr and Hf confirm not only that the %VBur is an appropriate molecular descriptor for the systems considered but also that it could be used as tool for a large computational screening of new ligands.

  1. Higher Education: How Freshmen and First-Year Journalism and Mass Communication Students at HBCUs and PWUs Used the Internet in Their Decision

    Science.gov (United States)

    Crawford, Jerry, II

    2013-01-01

    This study set out to explore how the Internet was used by Journalism and Mass Communications Program students at Historically Black Colleges and Universities and Predominately White Universities in their college choice and if these institutions were able to provide the information the respondents were looking for in their search. The study found…

  2. Food Stamp Participation is Associated with Fewer Meals Away From Home, yet Higher Body Mass Index and Waist Circumference in a Nationally Representative Sample

    Science.gov (United States)

    Jilcott, Stephanie B.; Liu, Haiyong; DuBose, Katrina D.; Chen, Susan; Kranz, Sibylle

    2011-01-01

    Objective: To examine associations between Food Stamp (FS) participation, meals away from home (MAFH), body mass index (BMI), and waist circumference (WC). Design: Cross-sectional study. Setting: Nationally representative. Participants: Data from low-income, FS-eligible individuals (N = 945) ages 20-65 years, responding to the 2005-2006 National…

  3. COMBINED CO AND DUST SCALING RELATIONS OF DEPLETION TIME AND MOLECULAR GAS FRACTIONS WITH COSMIC TIME, SPECIFIC STAR-FORMATION RATE, AND STELLAR MASS

    Energy Technology Data Exchange (ETDEWEB)

    Genzel, R.; Tacconi, L. J.; Lutz, D.; Berta, S.; Burkert, A. [Max-Planck-Institut für Extraterrestrische Physik (MPE), Giessenbachstr., D-85748 Garching (Germany); Saintonge, A. [Department of Physics and Astronomy, University College London, Gower Place, London WC1E 6BT (United Kingdom); Magnelli, B. [Argelander-Institut für Astronomie, Universität Bonn, Auf dem Hügel 71, D-53121 Bonn (Germany); Combes, F. [Observatoire de Paris, LERMA, CNRS, 61 Av. de l' Observatoire, F-75014 Paris (France); García-Burillo, S. [Observatorio Astronómico Nacional-OAN, Observatorio de Madrid, Alfonso XII, 3, 28014 Madrid (Spain); Neri, R.; Boissier, J. [IRAM, 300 Rue de la Piscine, F-38406 St. Martin d' Heres, Grenoble (France); Bolatto, A. [Department of Astronomy, University of Maryland, College Park, MD 20742-2421 (United States); Contini, T.; Boone, F.; Bouché, N. [Institut d' Astrophysique et de Planétologie, Universite de Toulouse, 9 Avenue du Colonel Roche BP 44346, F-31028 Toulouse Cedex 4 (France); Lilly, S.; Carollo, M. [Institute of Astronomy, Department of Physics, Eidgenössische Technische Hochschule, CH-8093 ETH Zürich (Switzerland); Bournaud, F. [Service d' Astrophysique, DAPNIA, CEA/Saclay, F-91191 Gif-sur-Yvette Cedex (France); Colina, L. [CSIC Instituto Estructura Materia, C/Serrano 121, E-28006 Madrid (Spain); Cooper, M. C., E-mail: linda@mpe.mpg.de, E-mail: genzel@mpe.mpg.de [Department of Physics and Astronomy, Frederick Reines Hall, University of California, Irvine, CA 92697 (United States); and others

    2015-02-10

    We combine molecular gas masses inferred from CO emission in 500 star-forming galaxies (SFGs) between z = 0 and 3, from the IRAM-COLDGASS, PHIBSS1/2, and other surveys, with gas masses derived from Herschel far-IR dust measurements in 512 galaxy stacks over the same stellar mass/redshift range. We constrain the scaling relations of molecular gas depletion timescale (t {sub depl}) and gas to stellar mass ratio (M {sub mol} {sub gas}/M{sub *} ) of SFGs near the star formation ''main-sequence'' with redshift, specific star-formation rate (sSFR), and stellar mass (M{sub *} ). The CO- and dust-based scaling relations agree remarkably well. This suggests that the CO → H{sub 2} mass conversion factor varies little within ±0.6 dex of the main sequence (sSFR(ms, z, M {sub *})), and less than 0.3 dex throughout this redshift range. This study builds on and strengthens the results of earlier work. We find that t {sub depl} scales as (1 + z){sup –0.3} × (sSFR/sSFR(ms, z, M {sub *})){sup –0.5}, with little dependence on M {sub *}. The resulting steep redshift dependence of M {sub mol} {sub gas}/M {sub *} ≈ (1 + z){sup 3} mirrors that of the sSFR and probably reflects the gas supply rate. The decreasing gas fractions at high M{sub *} are driven by the flattening of the SFR-M {sub *} relation. Throughout the probed redshift range a combination of an increasing gas fraction and a decreasing depletion timescale causes a larger sSFR at constant M {sub *}. As a result, galaxy integrated samples of the M {sub mol} {sub gas}-SFR rate relation exhibit a super-linear slope, which increases with the range of sSFR. With these new relations it is now possible to determine M {sub mol} {sub gas} with an accuracy of ±0.1 dex in relative terms, and ±0.2 dex including systematic uncertainties.

  4. The use of agrobiodiversity for plant improvement and the intellectual property paradigm: institutional fit and legal tools for mass selection, conventional and molecular plant breeding.

    Science.gov (United States)

    Batur, Fulya; Dedeurwaerdere, Tom

    2014-12-01

    Focused on the impact of stringent intellectual property mechanisms over the uses of plant agricultural biodiversity in crop improvement, the article delves into a systematic analysis of the relationship between institutional paradigms and their technological contexts of application, identified as mass selection, controlled hybridisation, molecular breeding tools and transgenics. While the strong property paradigm has proven effective in the context of major leaps forward in genetic engineering, it faces a systematic breakdown when extended to mass selection, where innovation often displays a collective nature. However, it also creates partial blockages in those innovation schemes rested between on-farm observation and genetic modification, i.e. conventional plant breeding and upstream molecular biology research tools. Neither overly strong intellectual property rights, nor the absence of well delineated protection have proven an optimal fit for these two intermediary socio-technological systems of cumulative incremental innovation. To address these challenges, the authors look at appropriate institutional alternatives which can create effective incentives for in situ agrobiodiversity conservation and the equitable distribution of technologies in plant improvement, using the flexibilities of the TRIPS Agreement, the liability rules set forth in patents or plant variety rights themselves (in the form of farmers', breeders' and research exceptions), and other ad hoc reward regimes.

  5. Analysis of iminosugars and other low molecular weight carbohydrates in Aglaonema sp. extracts by hydrophilic interaction liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Rodríguez-Sánchez, S; García-Sarrió, M J; Quintanilla-López, J E; Soria, A C; Sanz, M L

    2015-12-04

    A method by hydrophilic interaction liquid chromatography coupled to tandem mass spectrometry (HILIC-MS(2)) has been successfully developed for the simultaneous analysis of bioactive iminosugars and other low molecular weight carbohydrates in Aglaonema leaf extracts. Among other experimental chromatographic conditions, mobile phase eluents, additives and column temperature were evaluated in terms of retention time, resolution, peak width and symmetry provided for target carbohydrates. In general, narrow peaks (wh: 0.2-0.6min) with good symmetry (As: 0.9-1.3) and excellent resolution (Rs>1.8) were obtained for iminosugars using an acetonitrile:water gradient with 5mM ammonium acetate in both eluents at 55°C. Tandem mass spectra were used to confirm the presence of previously detected iminosugars in Aglaonema extracts and to tentatively identify for the first time others such as miglitol isomer, glycosyl-miglitol isomers and glycosyl-DMDP isomers. Concentration of total iminosugars varied from 1.35 to 2.84mgg(-1) in the extracts of the different Aglaonema samples analyzed. To the best of our knowledge, this is the first time that a HILIC-MS(2) method has been proposed for the simultaneous analysis of iminosugars and other low molecular weight carbohydrates of Aglaonema sp. extracts. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Imaging mass spectrometry and MS/MS molecular networking reveals chemical interactions among cuticular bacteria and pathogenic fungi associated with fungus-growing ants.

    Science.gov (United States)

    Boya P, Cristopher A; Fernández-Marín, Hermógenes; Mejía, Luis C; Spadafora, Carmenza; Dorrestein, Pieter C; Gutiérrez, Marcelino

    2017-07-17

    The fungus-growing ant-microbe symbiosis is an ideal system to study chemistry-based microbial interactions due to the wealth of microbial interactions described, and the lack of information on the molecules involved therein. In this study, we employed a combination of MALDI imaging mass spectrometry (MALDI-IMS) and MS/MS molecular networking to study chemistry-based microbial interactions in this system. MALDI IMS was used to visualize the distribution of antimicrobials at the inhibition zone between bacteria associated to the ant Acromyrmex echinatior and the fungal pathogen Escovopsis sp. MS/MS molecular networking was used for the dereplication of compounds found at the inhibition zones. We identified the antibiotics actinomycins D, X2 and X0β, produced by the bacterium Streptomyces CBR38; and the macrolides elaiophylin, efomycin A and efomycin G, produced by the bacterium Streptomyces CBR53.These metabolites were found at the inhibition zones using MALDI IMS and were identified using MS/MS molecular networking. Additionally, three shearinines D, F, and J produced by the fungal pathogen Escovopsis TZ49 were detected. This is the first report of elaiophylins, actinomycin X0β and shearinines in the fungus-growing ant symbiotic system. These results suggest a secondary prophylactic use of these antibiotics by A. echinatior because of their permanent production by the bacteria.

  7. Molecularly imprinted solid-phase extraction for the selective determination of methamphetamine, amphetamine, and methylenedioxyphenylalkylamine designer drugs in human whole blood by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Kumazawa, Takeshi; Hasegawa, Chika; Hara, Kenji; Uchigasaki, Seisaku; Lee, Xiao-Pen; Seno, Hiroshi; Suzuki, Osamu; Sato, Keizo

    2012-03-01

    A novel method is described for the extraction of methamphetamine, amphetamine, and methylenedioxyphenylalkylamine designer drugs, such as 3,4-methylenedioxy-methamphetamine, 3,4-methylenedioxyamphetamine, 3,4-methylenedioxyethylamphetamine, N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine, and 3,4-(methylenedioxyphenyl)-2-butanamine, from human whole blood using molecularly imprinted solid-phase extraction as highly selective sample clean-up technique. Whole blood samples were diluted with 10 mmol/L ammonium acetate (pH 8.6) and applied to a SupelMIP-Amphetamine molecularly imprinted solid-phase extraction cartridge. The cartridge was then washed to eliminate interferences, and the amphetamines of interest were eluted with formic acid/methanol (1:100, v/v). After derivatization with trifluoroacetic anhydride, the analytes were quantified using gas chromatography-mass spectrometry. Recoveries of the seven amphetamines spiked into whole blood were 89.1-102%. The limits of quantification for each compound in 200 μL of whole blood were between 0.25 and 1.0 ng. The maximum intra- and inter-day coefficients of variation were 9.96 and 13.8%, respectively. The results show that methamphetamine, amphetamine, and methylenedioxyphenylalkyl-amine designer drugs can be efficiently extracted from crude biological samples such as whole blood by molecularly imprinted solid-phase extraction with good reproducibility. This extraction method will be useful for the pretreatment of human samples before gas chromatography-mass spectrometry. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Analyzing the vibrational response of an AFM cantilever in liquid with the consideration of tip mass by comparing the hydrodynamic and contact repulsive force models in higher modes

    Science.gov (United States)

    Korayem, Moharam Habibnejad; Nahavandi, Amir

    2017-04-01

    This paper investigates the vibration of a tapping-mode Atomic Force Microscope (AFM) cantilever covered with two whole piezoelectric layers in a liquid medium. The authors of this article have already modeled the vibration of a cantilever immersed in liquid over rough surfaces. Five new ideas have been considered for improving the results of the previous work. Mass and damping of a cantilever probe tip have been considered. Since the probe tip of an AFM cantilever has a mass, which can itself affect the natural frequency of vibration, the significance of this mass has been explored. Also, two hydrodynamic force models for analyzing the mass and damping added to a cantilever in liquid medium have been evaluated. In modeling the vibration of a cantilever in liquid, simplifications are made to the theoretical equations used in the modeling, which may make the obtained results different from those in the real case. So, two hydrodynamic force models are introduced and compared with each other. In addition to the already introduced DMT model, the JKR model has been proposed. The forces acting on a probe tip have attractive and repulsive effects. The attractive Van der Waals force can vary depending on the surface smoothness or roughness, and the repulsive contact force, which is independent of the type of surface roughness and usually varies with the hardness or softness of a surface. When the first mode is used in the vibration of an AFM cantilever, the changes of the existing physical parameters in the simulation do not usually produce a significant difference in the response. Thus, three cantilever vibration modes have been investigated. Finally, an analytical approach for obtaining the response of equations is presented which solves the resulting motion equation by the Laplace method and, thus, a time function is obtained for cantilever deflection is determined. Also, using the COMSOL software to model a cantilever in a liquid medium, the computed natural

  9. CYP63A2, a Catalytically Versatile Fungal P450 Monooxygenase Capable of Oxidizing Higher-Molecular-Weight Polycyclic Aromatic Hydrocarbons, Alkylphenols, and Alkanes

    Science.gov (United States)

    Syed, Khajamohiddin; Porollo, Aleksey; Lam, Ying Wai; Grimmett, Paul E.

    2013-01-01

    Cytochrome P450 monooxygenases (P450s) are known to oxidize hydrocarbons, albeit with limited substrate specificity across classes of these compounds. Here we report a P450 monooxygenase (CYP63A2) from the model ligninolytic white rot fungus Phanerochaete chrysosporium that was found to possess a broad oxidizing capability toward structurally diverse hydrocarbons belonging to mutagenic/carcinogenic fused-ring higher-molecular-weight polycyclic aromatic hydrocarbons (HMW-PAHs), endocrine-disrupting long-chain alkylphenols (APs), and crude oil aliphatic hydrocarbon n-alkanes. A homology-based three-dimensional (3D) model revealed the presence of an extraordinarily large active-site cavity in CYP63A2 compared to the mammalian PAH-oxidizing (CYP3A4, CYP1A2, and CYP1B1) and bacterial aliphatic-hydrocarbon-oxidizing (CYP101D and CYP102A1) P450s. This structural feature in conjunction with ligand docking simulations suggested potential versatility of the enzyme. Experimental characterization using recombinantly expressed CYP63A2 revealed its ability to oxidize HMW-PAHs of various ring sizes, including 4 rings (pyrene and fluoranthene), 5 rings [benzo(a)pyrene], and 6 rings [benzo(ghi)perylene], with the highest enzymatic activity being toward the 5-ring PAH followed by the 4-ring and 6-ring PAHs, in that order. Recombinant CYP63A2 activity yielded monohydroxylated PAH metabolites. The enzyme was found to also act as an alkane ω-hydroxylase that oxidized n-alkanes with various chain lengths (C9 to C12 and C15 to C19), as well as alkyl side chains (C3 to C9) in alkylphenols (APs). CYP63A2 showed preferential oxidation of long-chain APs and alkanes. To our knowledge, this is the first P450 identified from any of the biological kingdoms that possesses such broad substrate specificity toward structurally diverse xenobiotics (PAHs, APs, and alkanes), making it a potent enzyme biocatalyst candidate to handle mixed pollution (e.g., crude oil spills). PMID:23416995

  10. Reversible uptake of molecular oxygen by heteroligand Co(II)-L-α-amino acid-imidazole systems: equilibrium models at full mass balance.

    Science.gov (United States)

    Pająk, Marek; Woźniczka, Magdalena; Vogt, Andrzej; Kufelnicki, Aleksander

    2017-09-19

    The paper examines Co(II)-amino acid-imidazole systems (where amino acid = L-α-amino acid: alanine, asparagine, histidine) which, when in aqueous solutions, activate and reversibly take up dioxygen, while maintaining the structural scheme of the heme group (imidazole as axial ligand and O2 uptake at the sixth, trans position) thus imitating natural respiratory pigments such as myoglobin and hemoglobin. The oxygenated reaction shows higher reversibility than for Co(II)-amac systems with analogous amino acids without imidazole. Unlike previous investigations of the heteroligand Co(II)-amino acid-imidazole systems, the present study accurately calculates all equilibrium forms present in solution and determines the [Formula: see text]equilibrium constants without using any simplified approximations. The equilibrium concentrations of Co(II), amino acid, imidazole and the formed complex species were calculated using constant data obtained for analogous systems under oxygen-free conditions. Pehametric and volumetric (oxygenation) studies allowed the stoichiometry of O2 uptake reaction and coordination mode of the central ion in the forming oxygen adduct to be determined. The values of dioxygen uptake equilibrium constants [Formula: see text] were evaluated by applying the full mass balance equations. Investigations of oxygenation of the Co(II)-amino acid-imidazole systems indicated that dioxygen uptake proceeds along with a rise in pH to 9-10. The percentage of reversibility noted after acidification of the solution to the initial pH ranged within ca 30-60% for alanine, 40-70% for asparagine and 50-90% for histidine, with a rising tendency along with the increasing share of amino acid in the Co(II): amino acid: imidazole ratio. Calculations of the share of the free Co(II) ion as well as of the particular complex species existing in solution beside the oxygen adduct (regarding dioxygen bound both reversibly and irreversibly) indicated quite significant values for the

  11. Hydrophilic interaction chromatography coupled matrix assisted laser desorption/ionization mass spectrometry for molecular analysis of organic compounds in medicines, tea, and coffee

    KAUST Repository

    Wang, Renqi

    2013-01-01

    Natural occurring organic compounds from food, natural organic matter, as well as metabolic products have received intense attention in current chemical and biological studies. Examination of unknown compounds in complex sample matrices is hampered by the limited choices for data readout and molecular elucidation. Herein, we report a generic method of hydrophilic interaction chromatography (HILIC) coupled with matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the rapid characterization of ingredients in pharmaceutical compounds, tea, and coffee. The analytes were first fractionated using a cationic HILIC column prior to MALDI-MS analyses. It was found that the retention times of a compound arising from different samples were consistent under the same conditions. Accordingly, molecules can be readily characterized by both the mass and chromatographic retention time. The retention behaviors of acidic and basic compounds on the cationic HILIC column were found to be significantly influenced by the pH of mobile phases, whereas neutral compounds depicted a constant retention time at different pH. The general HILIC-MALDI-MS method is feasible for fast screening of naturally occurring organic compounds. A series of homologs can be determined if they have the same retention behavior. Their structural features can be elucidated by considering their mass differences and hydrophilic properties as determined by HILIC chromatogram. © 2013 The Royal Society of Chemistry.

  12. Hydrophilic interaction chromatography coupled matrix assisted laser desorption/ionization mass spectrometry for molecular analysis of organic compounds in medicines, tea, and coffee.

    Science.gov (United States)

    Wang, Ren-Qi; Bao, Kai; Croué, Jean-Philippe; Ng, Siu Choon

    2013-11-21

    Natural occurring organic compounds from food, natural organic matter, as well as metabolic products have received intense attention in current chemical and biological studies. Examination of unknown compounds in complex sample matrices is hampered by the limited choices for data readout and molecular elucidation. Herein, we report a generic method of hydrophilic interaction chromatography (HILIC) coupled with matrix assisted laser desorption/ionization mass spectrometry (MALDI-MS) for the rapid characterization of ingredients in pharmaceutical compounds, tea, and coffee. The analytes were first fractionated using a cationic HILIC column prior to MALDI-MS analyses. It was found that the retention times of a compound arising from different samples were consistent under the same conditions. Accordingly, molecules can be readily characterized by both the mass and chromatographic retention time. The retention behaviors of acidic and basic compounds on the cationic HILIC column were found to be significantly influenced by the pH of mobile phases, whereas neutral compounds depicted a constant retention time at different pH. The general HILIC-MALDI-MS method is feasible for fast screening of naturally occurring organic compounds. A series of homologs can be determined if they have the same retention behavior. Their structural features can be elucidated by considering their mass differences and hydrophilic properties as determined by HILIC chromatogram.

  13. Molecular characterization of phytoplankton dissolved organic matter (DOM) and sulfur components using high resolution Orbitrap mass spectrometry.

    Science.gov (United States)

    Mangal, Vaughn; Stock, Naomi L; Guéguen, Celine

    2016-03-01

    Orbitrap high resolution mass spectrometry (HRMS) with electrospray ionization in both positive and negative polarity was conducted on Suwannee River fulvic acid (SRFA), Pony Lake fulvic acid (PLFA) standards, and dissolved organic matter (DOM) released by freshwater phytoplankton (Scenedesmus obliquus, Euglena mutabilis, and Euglena gracilis). Three-dimensional van Krevelen diagrams expressing various oxygenation states of sulfur molecules and abundance plots of sulfur-containing species were constructed. Orbitrap HRMS analysis of SRFA found a high density of peaks in the lignin region (77 %) and low density of protein material (6.53 %), whereas for PLFA, 25 % of the total peaks were lignin related compared to 56 % of peaks in protein regions, comparable with other HRMS studies. Phytoplankton-derived DOM of S. obliquus, E. mutabilis, and E. gracilis was dominated by protein molecules at respective percentages of 36, 46, and 49 %, and is consistent with previous experiments examining phytoplankton-derived DOM composition. The normalized percentage of SO-containing compounds was determined among the three phytoplankton to be 56 % for Scenedesmus, 54 % for E. mutabilis, and 47 % for E. gracilis, suggesting variation between sulfur content in phytoplankton-derived DOM and differences in metal binding capacities. These results suggest the level of resolution by Orbitrap mass spectrometry is sufficient for preliminary characterization of phytoplankton DOM at an affordable cost relative to other HRMS techniques.

  14. Dicyclohexylammonium bromoacetate: a low molecular mass organogelator with a one-dimensional secondary ammonium monocarboxylate (SAM) synthon.

    Science.gov (United States)

    Rojek, Tomasz; Lis, Tadeusz; Matczak-Jon, Ewa

    2015-07-01

    The asymmetric unit of the title salt, C12H24N(+)·C2H2BrO2(-), contains a dicyclohexylammonium cation connected to a bromoacetate anion by means of an N-H...O hydrogen bond. In the crystal, the ion pairs assemble via N-H...O interactions, forming zigzag infinite chains parallel to the c axis with the (...H-N-H...O-C-O...)n motif that is considered to be a prerequisite for ensuring gelation properties of secondary ammonium monocarboxylate salts. The title salt was characterized by FT-IR, X-ray powder diffraction (XRPD), TG-DTA and (1)H NMR spectroscopy in solution. Gelation experiments revealed that dicyclohexylammonium bromoacetate forms molecular gels with dimethylformamide and dimethyl sulfoxide. Scanning electron microscopy (SEM) was used to reveal morphological features of dried gels.

  15. Use of Yb-based catalyst for AGET ATRP of acrylonitrile to simultaneously control molecular mass distribution and tacticity.

    Science.gov (United States)

    Ma, Jing; Chen, Hou; Zhang, Min; Wang, Chunhua; Zhang, Ying; Qu, Rongjun

    2012-08-01

    Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2'-bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH)2) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr2, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr3 content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. Copyright © 2012 Elsevier B.V. All rights reserved.

  16. Use of Yb-based catalyst for AGET ATRP of acrylonitrile to simultaneously control molecular mass distribution and tacticity

    Energy Technology Data Exchange (ETDEWEB)

    Ma Jing; Chen Hou, E-mail: lduchenhou@hotmail.com; Zhang Min; Wang Chunhua; Zhang Ying; Qu Rongjun

    2012-08-01

    Yb-based catalyst was used for the first time for atom transfer radical polymerization using activators generated by electron transfer (AGET ATRP) of acrylonitrile (AN) with 2-bromopropionitrile (BPN) as initiator, 2, 2 Prime -bipyridine (bipy) as ligand, and tisn(II) bis(2-ethylhexanoate) (Sn(EH){sub 2}) as reducing agent in the presence of air. With respect to AGET ATRP of AN catalyzed by CuBr{sub 2}, an evident increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr{sub 3} content. The block copolymer PAN-b-PMMA with molecular weight at 60,000 and polydispersity at 1.36 was successfully prepared. - Graphical abstract: Yb-based catalyst was used for the first time for AGET ATRP of AN with BPN as the initiator, bipy as the ligand, and Sn(EH){sub 2} as the reducing agent in the presence of air. With respect to AGET ATRP with CuBr{sub 2} as catalyst, an obvious increase of polymer tacticity was observed for AGET ATRP of AN. The increase of syndiotacticity became more and more pronounced than the increase of isotacticity of polyacrylonitrile (PAN) along with YbBr{sub 3} content. The block copolymer PAN-b-PMMA with molecular weight at 60000 and polydispersity at 1.36 was successfully prepared. Highlights: Black-Right-Pointing-Pointer Yb-based catalyst was used for the first time for AGET ATRP of AN. Black-Right-Pointing-Pointer The reaction simultaneously controls polydispersity and tacticity of PAN. Black-Right-Pointing-Pointer Well-defined block copolymer PAN-b-PMMA was successfully prepared.

  17. Complement activation by PEG-functionalized multi-walled carbon nanotubes is independent of PEG molecular mass and surface density

    DEFF Research Database (Denmark)

    Andersen, Alina Joukainen; Windschiegl, Barbara; Ilbasmis-Tamer, Sibel

    2013-01-01

    Carboxylated (4%) multi-walled carbon nanotubes were covalently functionalized with poly(ethylene glycol)1000 (PEG1000), PEG1500 and PEG4000 with a PEG loading of approximately 11% in all cases. PEG loading generated non-uniform and heterogeneous higher surface structures and increased nanotube w...

  18. Molecular characterization and comparison of shale oils generated by different pyrolysis methods using FT-ICR mass spectrometry

    Science.gov (United States)

    Jin, J.M.; Kim, S.; Birdwell, J.E.

    2011-01-01

    Fourier transform ion cyclotron resonance mass spectrometry (FT ICR-MS) was applied in the analysis of shale oils generated using two different pyrolysis systems under laboratory conditions meant to simulate surface and in situ oil shale retorting. Significant variations were observed in the shale oils, particularly the degree of conjugation of the constituent molecules. Comparison of FT ICR-MS results to standard oil characterization methods (API gravity, SARA fractionation, gas chromatography-flame ionization detection) indicated correspondence between the average Double Bond Equivalence (DBE) and asphaltene content. The results show that, based on the average DBE values and DBE distributions of the shale oils examined, highly conjugated species are enriched in samples produced under low pressure, high temperature conditions and in the presence of water.

  19. Rapid identification of molecular changes in tulsi (Ocimum sanctum Linn) upon ageing using leaf spray ionization mass spectrometry.

    Science.gov (United States)

    Sarkar, Depanjan; Srimany, Amitava; Pradeep, T

    2012-10-07

    Tulsi or Holy Basil (Ocimum sanctum Linn) is a medicinally important plant. Ursolic acid (UA) and oleanolic acid (OA) are among its major constituents which account for many medicinal activities of the plant. In the present work, we deployed a new ambient ionization method, leaf spray ionization, for rapid detection of UA, OA and their oxidation products from tulsi leaves. Tandem electrospray ionization mass spectrometry (ESI-MS) has been performed on tulsi leaf extracts in methanol to establish the identity of the compounds. We probed changes occurring in the relative amounts of the parent compounds (UA and OA) with their oxidized products and the latter show an increasing trend upon ageing. The findings are verified by ESI-MS analysis of tulsi leaf extracts, which shows the same trend proving the reliability of the leaf spray method.

  20. High-field NMR spectroscopy and FTICR mass spectrometry: powerful discovery tools for the molecular level characterization of marine dissolved organic matter

    Directory of Open Access Journals (Sweden)

    N. Hertkorn

    2013-03-01

    exceptional resolution and depicted resolved molecular signatures in excess of a certain minimum abundance. Classical methyl groups terminating aliphatic chains represented ~15% of total methyl in all samples investigated. A noticeable fraction of methyl (~2% was bound to olefinic carbon. Methyl ethers were abundant in surface marine SPE-DOM, and the chemical diversity of carbohydrates was larger than that of freshwater and soil DOM. In all samples, we identified sp2-hybridized carbon chemical environments with discrimination of isolated and conjugated olefins and α,β-unsaturated double bonds. Olefinic proton and carbon atoms were more abundant than aromatic ones; olefinic unsaturation in marine SPE-DOM will be more directly traceable to ultimate biogenic precursors than aromatic unsaturation. The abundance of furan, pyrrol and thiophene derivatives was marginal, whereas benzene derivatives, phenols and six-membered nitrogen heterocycles were prominent; a yet unassigned set of six-membered N-heterocycles with likely more than one single nitrogen occurred in all samples. Various key polycyclic aromatic hydrocarbon substructures suggested the presence of thermogenic organic matter at all water depths. Progressive NMR cross-peak attenuation from surface to deep marine SPE-DOM was particularly strong in COSY NMR spectra and indicated a continual disappearance of biosignatures as well as entropy gain from an ever increased molecular diversity. Nevertheless, a specific near-seafloor SPE-DOM signature of unsaturated molecules recognized in both NMR and Fourier transform ion cyclotron mass spectrometry (FTICR/MS possibly originated from sediment leaching. The conformity of key NMR and FTICR/MS signatures suggested the presence of a large set of identical molecules throughout the entire ocean column even though the investigated water masses belonged to different oceanic regimes and currents. FTICR/MS showed abundant CHO, CHNO, CHOS and CHNOS molecular series with slightly increasing

  1. Factors Associated with Higher Body Mass Index, Weight Concern, and Weight Gain in a Multinational Cohort Study of Smokers Intending to Quit

    Directory of Open Access Journals (Sweden)

    Robert West

    2009-03-01

    Full Text Available The ATTEMPT cohort study is multi-national, longitudinal study of smokers intending to quit recruited in the U.S.A., Canada, U.K. and France. Data on demographics, medical history, body mass index (BMI, weight concerns and smoking status were collected at baseline and after six months. A total of 2,009 subjects provided data at baseline and 1,303 at six months. High baseline BMI was associated with recent quit attempts, high weight concerns and high cigarette consumption. Weight gain was associated with low income, being single and number of cigarette-free days, but not with baseline weight concerns and confidence in preventing weight gain. Quit attempts were more frequent in subjects with a high baseline BMI and low weight concerns.

  2. Revisiting shape selectivity in liquid chromatography for polycyclic aromatic hydrocarbons (PAHs) - six-ring and seven-ring Cata-condensed PAH isomers of molecular mass 328 Da and 378 Da.

    Science.gov (United States)

    Oña-Ruales, Jorge O; Sander, Lane C; Wilson, Walter B; Wise, Stephen A

    2018-01-01

    The relationship of reversed-phase liquid chromatography (RPLC) retention on a polymeric C 18 stationary phase and the shape of polycyclic aromatic hydrocarbons (PAHs) was investigated for three-ring to seven-ring cata-condensed isomers. We report the first RPLC separation for six-ring and seven-ring cata-condensed PAH isomers. Correlations of LC retention and shape parameters (length-to-breath ratio, L/B and thickness, T) were investigated for 2 three-ring isomers (molecular mass 178 Da), 5 four-ring isomers (molecular mass 228 Da), 11 five-ring isomers (molecular mass 278 Da), 17 six-ring isomers (molecular mass 328 Da), and 20 seven-ring isomers (molecular mass 378 Da). Significant linear correlations were found for all isomer groups (r = 0.71 to 0.94). Nonplanarity of the PAH isomers was found to influence retention (i.e., nonplanar isomers eluting earlier than expected based on L/B) and linear correlations of retention vs. T for isomer groups containing nonplanar isomers were significant (r = 0.71 to 0.86). Graphical abstract.

  3. Low molecular mass organogelator based gel electrolyte with effective charge transport property for long-term stable quasi-solid-state dye-sensitized solar cells.

    Science.gov (United States)

    Huo, Zhipeng; Dai, Songyuan; Zhang, Changneng; Kong, Fantai; Fang, Xiaqin; Guo, Lei; Liu, Weiqing; Hu, Linhua; Pan, Xu; Wang, Kongjia

    2008-10-16

    Stable quasi-solid-state dye-sensitized solar cells (DSC) were fabricated using 12-hydroxystearic acid as a low molecular mass organogelator (LMOG) to form gel electrolyte. TEM image of the gel exhibited the self-assembled network constructed by the LMOG, which hindered flow and volatilization of the liquid. The formation of less-mobile polyiodide ions such as I 3 (-) and I 5 (-) confirmed by Raman spectroscopy increased the conductivity of the gel electrolytes by electronic conduction process, which should be rationalized by the Grotthuss-type electron exchange mechanism caused by rather packed polyiodide species in the electrolytes. The results of the accelerated aging tests showed that the gel electrolyte based dye-sensitized solar cell could retain over 97% of its initial photoelectric conversion efficiency value after successive heating at 60 degrees C for 1000 h and device degradation was also negligible after one sun light soaking with UV cutoff filter for 1000 h.

  4. Studying the oxidation of water to molecular oxygen in photosynthetic and artificial systems by time-resolved membrane-inlet mass spectrometry

    Directory of Open Access Journals (Sweden)

    Dmitriy eShevela

    2013-11-01

    Full Text Available Monitoring isotopic compositions of gaseous products (e.g., H2, O2 and CO2 by time-resolved isotope-ratio membrane-inlet mass spectrometry (TR-IR-MIMS is widely used for kinetic and functional analyses in photosynthesis research. In particular, in combination with isotopic labelling, TR-MIMS became an essential and powerful research tool for the study of the mechanism of photosynthetic water-oxidation to molecular oxygen catalyzed by the water-oxidizing complex of photosystem II. Moreover, recently, the TR-MIMS and 18O-labeling approach was successfully applied for testing newly developed catalysts for artificial water-splitting and provided important insight about the mechanism and pathways of O2 formation. In this mini-review we summarize these results and provide a brief introduction into key aspects of the TR-MIMS technique and its perspectives for future studies of the enigmatic water-splitting chemistry.

  5. Analysis of low molecular weight acids by negative mode matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.

    Science.gov (United States)

    Shroff, Rohit; Muck, Alexander; Svatos, Ales

    2007-01-01

    Free 9-aminoacridine base is demonstrated to be a suitable matrix for negative mode matrix-assisted laser desorption/ionization time-of-flight mass spectrometric (MALDI-TOFMS) analysis of a wide range of low molecular weight organic acids including aliphatic (from acetic to palmitic acid), aromatic acids, phytohormones (e.g. jasmonic and salicylic acids), and amino acids. Low limits of quantitation in the femtomolar range (jasmonic - 250 fmol; caffeic - 160 fmol and salicylic - 12.5 fmol) and linear detector response over two concentration orders in the pico- and femtomolar range are extremely encouraging for the direct study of such acids in complex biological matrices. Copyright (c) 2007 John Wiley & Sons, Ltd.

  6. Effect of repeat unit structure and molecular mass of lactic acid bacteria hetero-exopolysaccharides on binding to milk proteins.

    Science.gov (United States)

    Birch, Johnny; Harðarson, Hörður Kári; Khan, Sanaullah; Van Calsteren, Marie-Rose; Ipsen, Richard; Garrigues, Christel; Almdal, Kristoffer; Hachem, Maher Abou; Svensson, Birte

    2017-12-01

    Interactions of exopolysaccharides and proteins are of great importance in food science, but complicated to analyze and quantify at the molecular level. A surface plasmon resonance procedure was established to characterize binding of seven structure-determined, branched hetero-exopolysaccharides (HePSs) of 0.14-4.9MDa from lactic acid bacteria to different milk proteins (β-casein, κ-casein, native and heat-treated β-lactoglobulin) at pH 4.0-5.0. Maximum binding capacity (RUmax) and apparent affinity (KA,app) were HePS- and protein-dependent and varied for example 10- and 600-fold, respectively, in the complexation with native β-lactoglobulin at pH 4.0. Highest RUmax and KA,app were obtained with heat-treated β-lactoglobulin and β-casein, respectively. Overall, RUmax and KA,app decreased 6- and 20-fold, respectively, with increasing pH from 4.0 to 5.0. KA,app was influenced by ionic strength and temperature, indicating that polar interactions stabilize HePS-protein complexes. HePS size as well as oligosaccharide repeat structure, conferring chain flexibility and hydrogen bonding potential, influence the KA,app. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Use of Molecular Methods for the Rapid Mass Detection of Schistosoma mansoni (Platyhelminthes: Trematoda) in Biomphalaria spp. (Gastropoda: Planorbidae).

    Science.gov (United States)

    Caldeira, Roberta Lima; Jannotti-Passos, Liana Konovaloffi; Dos Santos Carvalho, Omar

    2017-01-01

    The low stringency-polymerase chain reaction (LS-PCR) and loop-mediated isothermal amplification (LAMP) assays were used to detect the presence of S. mansoni DNA in (1) Brazilian intermediate hosts (Biomphalaria glabrata, B. straminea, and B. tenagophila) with patent S. mansoni infections, (2) B. glabrata snails with prepatent S. mansoni infections, (3) various mixtures of infected and noninfected snails; and (4) snails infected with other trematode species. The assays showed high sensitivity and specificity and could detect S. mansoni DNA when one positive snail was included in a pool of 1,000 negative specimens of Biomphalaria. These molecular approaches can provide a low-cost, effective, and rapid method for detecting the presence of S. mansoni in pooled samples of field-collected Biomphalaria. These assays should aid mapping of transmission sites in endemic areas, especially in low prevalence regions and improve schistosomiasis surveillance. It will be a useful tool to monitor low infection rates of snails in areas where control interventions are leading towards the elimination of schistosomiasis.

  8. Molecular cloning, mass spectrometric identification, and nutritional evaluation of 10 coixins in adlay ( Coix lachryma-jobi L.).

    Science.gov (United States)

    Lin, Li-Jen; Hsiao, Eric S L; Tseng, Hsen-Shong; Chung, Mei-Chu; Chua, Anna C N; Kuo, Ming-En; Tzen, Jason T C

    2009-11-25

    Adlay (Coix lachryma-jobi L. var. ma-yuen Stapf) is regarded as a nutritive food source as well as herbal medicine. The food nutrition is a consequence of its high protein content and superior amino acid composition. From ca. 200 expressed sequence tag (EST) sequences in maturing adlay grains, clones encoding precursor polypeptides of 10 seed storage proteins in the prolamin family, including 8 alpha-coixin isoforms, 1 delta-coixin, and 1 gamma-coixin, were identified. Full-length cDNA fragments encoding these 10 coixins were obtained by PCR cloning. Mass spectrometric analyses confirmed the presence of these 10 coixins in the extract of adlay grain. Calculated amino acid compositions indicate that all 10 coixins are rich in glutamine (>20% in alpha-coixin isoforms, 13.3% in delta-coixin, and 31.2% in gamma-coixin). The 8 alpha-coixin isoforms are low in methionine, cysteine, and lysine (on average, 0.8, 0.6, and 0.1%, respectively). However, the delta-coixin is a sulfur-rich protein (18.2% methionine and 9.1% cysteine), and the gamma-coixin is a nutritive protein composed of 2.0% methionine, 6.6% cysteine, 2.6% lysine, and 8.9% histidine. The company of delta-coixin and gamma-coixin with alpha-coixin isoforms enhances the nutritional value of alday grain for human consumption.

  9. Monolithic molecularly imprinted solid-phase extraction for the selective determination of trace cytokinins in plant samples with liquid chromatography-electrospray tandem mass spectrometry.

    Science.gov (United States)

    Du, Fuyou; Ruan, Guihua; Liang, Shenghua; Xie, Fuwei; Liu, Huwei

    2012-08-01

    Cytokinins (CTKs) are a class of growth-regulating hormones involved in various physiological and developmental processes. More novel analytical methods for the accurate identification and quantitative determination of trace CTKs in plants have been desired to better elucidate the roles of CTKs. In this work, a novel method based on monolithic molecularly imprinted solid-phase extraction followed by liquid chromatography-electrospray tandem mass spectrometry (mMI-SPE-LC-MS/MS) was developed for accurate determination of four CTKs in plant samples. The molecularly imprinted polymer monolith was prepared by using kinetin as the template in syringes and exhibited specific recognition ability for the four CTKs in comparison with that of non-imprinted polymer monolith. Several factors affecting the extraction performance of mMI-SPE, including the pH of loading sample solution, the nature and volume of elution solvent, the flow rate of sample loading, and sample volume, were investigated, respectively. Under the optimized conditions, the proposed mMI-SPE-LC-MS/MS method was successfully applied in the selective extraction and determination of four CTKs in plant tissues, and it offers detection limits (S/N = 3) of 104, 113, 130, and 89 pg/mL and mean recoveries of 85.9%, 79.3%, 73.5%, and 70.1% for kinetin, kinetin glucoside, trans-zeatin, and meta-topolin (mT), respectively, with the corresponding RSDs less than 15%.

  10. Analysis of permethrin isomers in composite diet samples by molecularly imprinted solid-phase extraction and isotope dilution gas chromatography-ion trap mass spectrometry.

    Science.gov (United States)

    Vonderheide, Anne P; Boyd, Brian; Ryberg, Anna; Yilmaz, Ecevit; Hieber, Thomas E; Kauffman, Peter E; Garris, Sherry T; Morgan, Jeffrey N

    2009-05-29

    Determination of an individual's aggregate dietary ingestion of pesticides entails analysis of a difficult sample matrix. Permethrin-specific molecularly imprinted polymer (MIP) solid-phase extraction cartridges were developed for use as a sample preparation technique for a composite food matrix. Vortexing with acetonitrile and centrifugation were found to provide optimal extraction of the permethrin isomers from the composite foods. The acetonitrile (with 1% acetic acid) was mostly evaporated and the analytes reconstituted in 90:10 water/acetonitrile in preparation for molecularly imprinted solid-phase extraction. Permethrin elution was accomplished with acetonitrile and sample extracts were analyzed by isotope dilution gas chromatography-ion trap mass spectrometry. Quantitation of product ions provided definitive identification of the pesticide isomers. The final method parameters were tested with fortified composite food samples of varying fat content (1%, 5%, and 10%) and recoveries ranged from 99.3% to 126%. Vegetable samples with incurred pesticide levels were also analyzed with the given method and recoveries were acceptable (81.0-95.7%). Method detection limits were demonstrated in the low ppb range. Finally, the applicability of the MIP stationary phase to extract other pyrethroids, specifically cyfluthrin and cypermethrin, was also investigated.

  11. Determination of Tributyltin in Seafood Based on Magnetic Molecularly Imprinted Polymers Coupled with High-Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Hua Yang

    2017-01-01

    Full Text Available In this study, Fe3O4 was adopted as a carrier for surface molecular imprinting with two-stage polymerization. First, the functional monomer (methacrylic acid, MAA was modified on the surface of Fe3O4, which was then polymerized with the template molecule (tributyltin, TBT, cross linking agent (ethylene glycol dimethacrylate, EGDMA, and porogen (acetonitrile, hereby successfully preparing Fe3O4@MIPs prone to specifically identify TBT. The physical properties of Fe3O4@MIPs were then characterized, and adsorption and selection capacities were also assessed. Compared with conventional imprinting polymers, this magnetic molecular imprinting polymer (MIP displayed significantly increased and more specific adsorption. Meanwhile, its pretreatment was simpler and faster due to magnetic separation characteristics. Using magnetic MIPs as adsorbents for enrichment and separation, detection limit, recovery rate, and linear range were 1.0 ng g−1, 79.74–95.72%, and 5 ng g−1~1000 ng g−1, respectively, for a number of seafood samples. High-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP-MS was used to analyze Tegillarca granosa, mussels, large yellow croaker, and other specimens, with recovery rates of 79.74–95.72% and RSD of 1.3%–4.7%. Overall, this method has a shorter total analysis time, lower detection limit, and wider linear range and can be more effectively applied to determine MAA in seawater and seafood.

  12. Application of nonpolar matrices for the analysis of low molecular weight nonpolar synthetic polymers by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

    Science.gov (United States)

    Macha; Limbach; Savickas

    2000-08-01

    The application of nonpolar matrices for the analysis of low molecular weight nonpolar synthetic polymers using matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is demonstrated. Anthracene, pyrene, and acenaphthene were utilized as nonpolar matrices for the analysis of polybutadiene, polyisoprene, and polystyrene samples of various average molecular weights ranging from about 700 to 5,000. The standard MALDI-MS approach for the analysis of these types of polymers involves the use of conventional acidic matrices, such as all-trans-retinoic acid, with an additional cationization reagent. The nonpolar matrices used in this study are shown to be as equally effective as the conventional matrices. The uniform mixing of the nonpolar matrices and the nonpolar analytes enhances the MALDI-MS spectral reproducibility. Silver salts were found to be the best cationization reagents for all of the cases studied. Copper salts worked well for polystyrene, poorly for polyisoprene, and not at all for polybutadiene samples. These matrices should be useful for the characterization of hydrocarbon polymers and other analytes, such as modified polymers, which may potentially be sensitive to acidic matrices.

  13. Comparing Laser Desorption Ionization and Atmospheric Pressure Photoionization Coupled to Fourier Transform Ion Cyclotron Resonance Mass Spectrometry To Characterize Shale Oils at the Molecular Level

    Science.gov (United States)

    Cho, Yunjo; Jin, Jang Mi; Witt, Matthias; Birdwell, Justin E.; Na, Jeong-Geol; Roh, Nam-Sun; Kim, Sunghwan

    2013-01-01

    Laser desorption ionization (LDI) coupled to Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) was used to analyze shale oils. Previous work showed that LDI is a sensitive ionization technique for assessing aromatic nitrogen compounds, and oils generated from Green River Formation oil shales are well-documented as being rich in nitrogen. The data presented here demonstrate that LDI is effective in ionizing high-double-bond-equivalent (DBE) compounds and, therefore, is a suitable method for characterizing compounds with condensed structures. Additionally, LDI generates radical cations and protonated ions concurrently, the distribution of which depends upon the molecular structures and elemental compositions, and the basicity of compounds is closely related to the generation of protonated ions. This study demonstrates that LDI FT-ICR MS is an effective ionization technique for use in the study of shale oils at the molecular level. To the best of our knowledge, this is the first time that LDI FT-ICR MS has been applied to shale oils.

  14. Selective solid-phase extraction using molecularly imprinted polymers for analysis of venlafaxine, O-desmethylvenlafaxine, and N-desmethylvenlafaxine in plasma samples by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Miranda, Luis Felippe C; Domingues, Diego S; Queiroz, Maria Eugênia C

    2016-08-05

    This paper focuses on the development of a novel miniaturized molecularly imprinted solid-phase extraction (MISPE) and ultra high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method to determine venlafaxine (VEN), O-desmethylvenlafaxine (ODV), and N-desmethylvenlafaxine (NDV) in plasma samples. The molecularly imprinted polymer (MIP) was prepared by the precipitation polymerization approach; VEN, metacrylic acid, ethylene glycol dimethacrylate, 2,2-azobisisobutyronitrile, and toluene were used as template, monomer, crosslinker, initiator, and porogen solvent, respectively. MIP and of the non-imprinted control polymer (NIP) sorbents were characterized by Fourier transform infrared spectroscopy and scanning electron microscopy. MIP phase presented higher extraction efficiency (MISPE, using plasma samples spiked with VEN) than the NIP phase (84 and 49% recovery rates, respectively). Analysis of other antidepressants with different chemical structures by MISPE-UHPLC-MS/MS attested to the selectivity of the developed MIP. The developed method presented precision assays with coefficients of variation (CV) smaller than 15%; accuracy assays with relative standard error (RSE%) values ranging from -12 to 16%, and linear ranges from 3 to 700ngmL(-1) for VEN, from 5 to 700ngmL(-1) for ODV, and from 3 to 500ngmL(-1) for NDV. The coefficients of determination (r(2)) were higher than 0.995. The lack-of-fit test also attested to the linearity of this method. This method was successfully applied to determine VEN, NDV, and ODV in plasma samples from depressed patients undergoing therapy with VEN. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. GAS KINEMATICS AND THE DRAGGED MAGNETIC FIELD IN THE HIGH-MASS MOLECULAR OUTFLOW SOURCE G192.16-3.84: AN SMA VIEW

    Energy Technology Data Exchange (ETDEWEB)

    Liu Hauyu Baobab; Ho, Paul T. P. [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 106, Taiwan (China); Qiu Keping [School of Astronomy and Space Science, Nanjing University, Nanjing 210093 (China); Zhang Qizhou [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Girart, Josep M. [Institut de Ciencies de l' Espai, (CSIC-IEEC), Campus UAB, Facultat de Ciencies, C5p 2, E-08193 Bellaterra, Catalonia (Spain)

    2013-07-01

    We report Submillimeter Array (SMA) observations of polarized 0.88 mm thermal dust emission and various molecular line transitions toward the early B-type (L{sub *} {approx} 2 Multiplication-Sign 10{sup 3} L{sub Sun }) star-forming region G192.16-3.84 (IRAS 05553+1631). The peak of the continuum Stokes-I emission coincides with a hot rotating disk/envelope (SO{sub 2} rotational temperature T{sub rot}{sup SO{sub 2}}{approx}84{sup +18}{sub -13} K), with a north-south velocity gradient. Joint analysis of the rotation curve traced by HCO{sup +} 4-3 and SO{sub 2} 19{sub 1,19}-18{sub 0,18} suggests that the dense molecular gas is undergoing a spinning-up rotation, marginally bound by the gravitational force of an enclosed mass M{sub *+gas+dust} {approx} 11.2-25.2 M{sub Sun }. Perpendicular to the rotational plane, a {approx}>100/cos (i) km s{sup -1} (i {approx} 63 Degree-Sign ) high velocity molecular jet and a {approx}15-20 km s{sup -1} expanding biconical cavity were revealed in the CO 3-2 emission. The polarization percentage of the 0.88 mm continuum emission decreases toward the central rotating disk/envelope. The polarization angle in the inner {approx}2'' (0.015 pc) disk/envelope is perpendicular to the plane of the rotation. The magnetic field lines, which are predominantly in the toroidal direction along the disk plane, are likely to be dragged by the gravitationally accelerated rotation.

  16. Amphetamines analysis in wastewaters - method performance of solid phase extraction - higher performance liquid chromatography mass spectrometry techniques (SPE-HPLC MS/MS)

    Science.gov (United States)

    Mustapha, Aliru Olajide; Ajao, Usman L

    2011-01-01

    Recently, many articles have reported different levels and distribution of amphetamine hitherto detected in biological fluids now appreciably found in aquatic environment at ng/L levels. Identification and measurement of amphetamine and its metabolites in surface and sewage waters using higher performance liquid chromatographic methodologies in the literatures now on current trend have provided information that are of scientific interest and effectively replaced immunological methods which only suggest the presence of these substances. Active research on both distribution and impacts of this important drug of abuse and related metabolites in the wastewaters are on-going. PMID:27857670

  17. Positive Effect of Higher Adult Body Mass Index on Overall Survival of Digestive System Cancers Except Pancreatic Cancer: A Systematic Review and Meta-Analysis

    Directory of Open Access Journals (Sweden)

    Jie Han

    2017-01-01

    Full Text Available High body mass index (BMI has been inconsistently associated with overall survival (OS of digestive system cancers (DSCs. This meta-analysis was conducted to investigate whether high BMI was associated with DSCs prognosis. 34 studies were accepted, with a total of 23,946 DSC cases. Hazard ratios (HRs with 95% confidence intervals (95% CIs for OS in BMI categories from individual studies were extracted and pooled by random-effect model. The overall HR of DSCs except pancreatic cancer for OS of adult overweight cases was 0.76 (95% CI = 0.67–0.85. DSC individuals except pancreatic cancer with adult obesity were at decreased risk for OS (HR = 0.85, 95% CI = 0.72–0.98. Among DSC patients except pancreatic cancer, the overall HR for the highest versus the lowest BMI category was 0.82 (95% CI = 0.71–0.92. Additionally, comparing the highest and lowest BMI categories, the combined HR of pancreatic cancer was 1.22 (95% CI = 1.01–1.43. Our meta-analysis suggested an increased OS among adult overweight and obese DSC survivors except pancreatic cancer. Overweight and obesity in adulthood may be important prognostic factors that indicate an increased survival from DSC patients except pancreatic cancer.

  18. Pyrolysis of methyl tert-butyl ether (MTBE). 1. Experimental study with molecular-beam mass spectrometry and tunable synchrotron VUV photoionization.

    Science.gov (United States)

    Zhang, Taichang; Wang, Jing; Yuan, Tao; Hong, Xin; Zhang, Lidong; Qi, Fei

    2008-10-23

    An experimental study of methyl tert-butyl ether (MTBE) pyrolysis (3.72% MTBE in argon) has been performed at low pressure (267 Pa) within the temperature range from 700 to 1420 K. The pyrolysis process was detected with the tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry (MBMS). About thirty intermediates are identified from near-threshold measurements of photoionization mass spectrum and photoionization efficiency spectrum. Among them, H2, CO, CH4, CH3OH and C4H8 are the major pyrolysis products. The radicals such as methyl, methoxy, propargyl, allyl, C4H5 and C4H7 are detected. The isomers of pyrolysis products are identified as well, i.e., propyne and allene, 1,2,3-butatriene and vinylacetylene, isobutene and 1-butene, propanal and acetone. Furthermore, the mole fractions of the pyrolysis products have been evaluated under various temperatures. Meanwhile, the initial formation temperatures of different pyrolysis products can be obtained. This work is anticipated to present a new experimental method for pyrolysis study and help understand the pyrolysis and combustion chemistry of MTBE and other oxygenated fuels.

  19. Matrix-free and material-enhanced laser desorption/ionization mass spectrometry for the analysis of low molecular weight compounds.

    Science.gov (United States)

    Rainer, Matthias; Qureshi, Muhammad Nasimullah; Bonn, Günther Karl

    2011-06-01

    The application of matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS) for the analysis of low molecular weight (LMW) compounds, such as pharmacologically active constituents or metabolites, is usually hampered by employing conventional MALDI matrices owing to interferences caused by matrix molecules below 700 Da. As a consequence, interpretation of mass spectra remains challenging, although matrix suppression can be achieved under certain conditions. Unlike the conventional MALDI methods which usually suffer from background signals, matrix-free techniques have become more and more popular for the analysis of LMW compounds. In this review we describe recently introduced materials for laser desorption/ionization (LDI) as alternatives to conventionally applied MALDI matrices. In particular, we want to highlight a new method for LDI which is referred to as matrix-free material-enhanced LDI (MELDI). In matrix-free MELDI it could be clearly shown, that besides chemical functionalities, the material's morphology plays a crucial role regarding energy-transfer capabilities. Therefore, it is of great interest to also investigate parameters such as particle size and porosity to study their impact on the LDI process. Especially nanomaterials such as diamond-like carbon, C(60) fullerenes and nanoparticulate silica beads were found to be excellent energy-absorbing materials in matrix-free MELDI.

  20. Chromatographic enrichment and subsequent separation of nickel and vanadyl porphyrins from natural seeps and molecular characterization by positive electrospray ionization FT-ICR mass spectrometry.

    Science.gov (United States)

    Putman, Jonathan C; Rowland, Steven M; Corilo, Yuri E; McKenna, Amy M

    2014-11-04

    We report a novel chromatographic method to enrich and separate nickel and vanadyl porphyrins from a natural seep sample and combine molecular level characterization by positive-ion electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). Vanadyl and nickel porphyrin model compound elution from primary secondary amine (PSA) stationary phase combined with UV-vis spectroscopy confirms enrichment and subsequent fractionation of nickel and vanadyl porphyrins into polarity-based subfractions. A more than 100-fold increase in signal-to-noise ratio for nickel porphyrins enables unequivocal elemental composition assignment confirmed by isotopic fine structure for all isotopes >1% relative abundance, and the first mass spectral identification of (61)Ni porphyrin isotopologues derived from natural seeps. Oxygen-containing vanadyl porphyrins and sulfur-containing vanadyl porphyrins are isolated in the same fraction simultaneously from the same sample. We provide the first chromatographic evidence of carboxylic acid functionalities peripheral to the porphyrin core, in agreement with previous studies.

  1. Molecular pathways leading to loss of skeletal muscle mass in cancer cachexia--can findings from animal models be translated to humans?

    Science.gov (United States)

    Mueller, Tara C; Bachmann, Jeannine; Prokopchuk, Olga; Friess, Helmut; Martignoni, Marc E

    2016-02-08

    Cachexia is a multi-factorial, systemic syndrome that especially affects patients with cancer of the gastrointestinal tract, and leads to reduced treatment response, survival and quality of life. The most important clinical feature of cachexia is the excessive wasting of skeletal muscle mass. Currently, an effective treatment is still lacking and the search for therapeutic targets continues. Even though a substantial number of animal studies have contributed to a better understanding of the underlying mechanisms of the loss of skeletal muscle mass, subsequent clinical trials of potential new drugs have not yet yielded any effective treatment for cancer cachexia. Therefore, we questioned to which degree findings from animal studies can be translated to humans in clinical practice and research. A substantial amount of animal studies on the molecular mechanisms of muscle wasting in cancer cachexia has been conducted in recent years. This extensive review of the literature showed that most of their observations could not be consistently reproduced in studies on human skeletal muscle samples. However, studies on human material are scarce and limited in patient numbers and homogeneity. Therefore, their results have to be interpreted critically. More research is needed on human tissue samples to clarify the signaling pathways that lead to skeletal muscle loss, and to confirm pre-selected drug targets from animal models in clinical trials. In addition, improved diagnostic tools and standardized clinical criteria for cancer cachexia are needed to conduct standardized, randomized controlled trials of potential drug candidates in the future.

  2. Isolation, purification, and immunological activities of a low-molecular-weight polysaccharide from the Lingzhi or Reishi medicinal mushroom Ganoderma lucidum (higher Basidiomycetes).

    Science.gov (United States)

    Zhu, Lina; Luo, Xi; Tang, Qingjiu; Liu, Yanfang; Zhou, Shuai; Yang, Yan; Zhang, Jingsong

    2013-01-01

    To obtain a low-molecular-weight polysaccharide with immuno-enhancing activity, hot water extract of Ganoderma lucidum fruit bodies was separated by membrane ultrafiltration, anion exchange, and gel filtration chromatography, and the immunological activities of fractions were assessed on the basis of nitric oxide production by RAW 264.7 macrophages. A novel polysaccharide (TB3-2-2) was successfully isolated and purified. TB3-2-2 is a homogeneous polysaccharide, with a relative molecular weight of 5.11 × 103 Da, identified by high-performance liquid chromatography and was composed of galactose and glucose in a molar ratio of 2:3 determined by high-performance anion exchange chromatography. TB3-2-2 had a carbohydrate content of 99%, as measured using the phenol-sulfuric acid method. Proliferation of mouse spleen lymphocytes and the expression level of interleukin-6 was significantly increased by TB3-2-2. Results indicate that the low-molecular-weight polysaccharide with immunological activity in G. lucidum is worthy of further research and development.

  3. Novel molecular-level evidence of iodine binding to natural organic matter from Fourier transform ion cyclotron resonance mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Chen, E-mail: xuchen66@tamu.edu [Laboratory for Environmental and Oceanographic Research, Department of Marine Sciences, Texas A and M University, Building 3029, Galveston, TX 77551 (United States); Chen, Hongmei [Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529 (United States); Sugiyama, Yuko [Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529 (United States); University of Hyogo, 1-1-12, Shinzaike-honcho, Himeji, Hyogo 670-0092 (Japan); Zhang, Saijin; Li, Hsiu-Ping; Ho, Yi-Fang; Chuang, Chia-ying; Schwehr, Kathleen A. [Laboratory for Environmental and Oceanographic Research, Department of Marine Sciences, Texas A and M University, Building 3029, Galveston, TX 77551 (United States); Kaplan, Daniel I. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Yeager, Chris [Los Alamos National Laboratory, Los Alamos, NM 87545 (United States); Roberts, Kimberly A. [Savannah River National Laboratory, Aiken, SC 29808 (United States); Hatcher, Patrick G. [Department of Chemistry and Biochemistry, Old Dominion University, Norfolk, VA 23529 (United States); Santschi, Peter H. [Laboratory for Environmental and Oceanographic Research, Department of Marine Sciences, Texas A and M University, Building 3029, Galveston, TX 77551 (United States)

    2013-04-01

    Major fractions of radioiodine ({sup 129}I) are associated with natural organic matter (NOM) in the groundwater and surface soils of the Savannah River Site (SRS). Electrospray ionization coupled to Fourier transform ion cyclotron resonance mass spectrometry (ESI-FTICR-MS) was applied to elucidate the interactions between inorganic iodine species (iodide and iodate) and a fulvic acid (FA) extracted from a SRS surface soil. Iodate is likely reduced to reactive iodine species by the lignin- and tannin-like compounds or the carboxylic-rich alicyclic molecules (CRAM), during which condensed aromatics and lignin-like compounds were generated. Iodide is catalytically oxidized into reactive iodine species by peroxides, while FA is oxidized by peroxides into more aliphatic and less aromatic compounds. Only 9% of the total identified organo-iodine compounds derived from molecules originally present in the FA, whereas most were iodine binding to newly-produced compounds. The resulting iodinated molecules were distributed in three regions in the van Krevelen diagrams, denoting unsaturated hydrocarbons, lignin and protein. Moreover, characteristics of these organo-iodine compounds, such as their relatively low O/C ratios (< 0.2 or < 0.4) and yet some degree of un-saturation close to that of lignin, have multiple important environmental implications concerning possibly less sterically-hindered aromatic ring system for iodine to get access to and a lower hydrophilicity of the molecules thus to retard their migration in the natural aquatic systems. Lastly, ∼ 69% of the identified organo-iodine species contains nitrogen, which is presumably present as -NH{sub 2} or -HNCOR groups and a ring-activating functionality to favor the electrophilic substitution. The ESI-FTICR-MS technique provides novel evidence to better understand the reactivity and scavenging properties of NOM towards radioiodine and possible influence of NOM on {sup 129}I migration. Highlights: ► IO{sub 3}{sup

  4. Progressing towards more quantitative analytical pyrolysis of soil organic matter using molecular beam mass spectroscopy of whole soils and added standards

    Energy Technology Data Exchange (ETDEWEB)

    Haddix, Michelle L.; Magrini-Bair, Kim; Evans, Robert J.; Conant, Richard T.; Wallenstein, Matthew D.; Morris, Sherri J.; Calderón, Francisco; Paul, Eldor A.

    2016-12-01

    Soil organic matter (SOM) is extremely complex. It is composed of hundreds of different organic substances and it has been difficult to quantify these diverse substances in a dynamic-ecosystem functioning standpoint. Analytical pyrolysis has been used to compare chemical differences between soils, but its ability to measure the absolute amount of a specific compound in the soil is still in question. Our objective was to assess whether utilizing pyrolysis-molecular beam mass spectroscopy (py-MBMS) to define the signature of known reference compounds (adenine, indole, palmitic acid, etc.) and biological samples (chitin, fungi, cellulose, etc.) separately and when added to whole soils it was possible to make py-MBMS more quantitative. Reference compounds, spanning a wide variety of compound categories, and biological samples, expected to be present in SOM, were added to three soils from Colorado, Ohio, and Massachusetts that have varying total C, % clay, and clay type. Py-MBMS, a rapid analysis technique originally developed to analyze complex biomolecules, flash pyrolyzes soil organic matter to form products that are often considered characteristic of the original molecular structure. Samples were pyrolyzed at 550 degrees C by py-MBMS. All samples were weighed and %C and %N determined both before and after pyrolysis to evaluate mass loss, C loss, and N loss for the samples.An average relationship of r2 = 0.76 (P = 0.005) was found for the amount of cellulose added to soil at 25, 50, and 100% of soil C relative to the ion intensity of select mass/charge of the compound.There was a relationship of r2 = 0.93 (P < 0.001) for the amount of indole added to soil at 25, 50, and 100% of soil C and the ion intensity of the associated mass variables (mass/charge). Comparing spectra of pure compounds with the spectra of the compounds added to soil and isolated clay showed that interference could occur based on soil type and compound with the Massachusetts soil with high C (55

  5. Combined morphological and molecular data unveils relationships of Pseudobranchiomma (Sabellidae, Annelida) and reveals higher diversity of this intriguing group of fan worms in Australia, including potentially introduced species.

    Science.gov (United States)

    Capa, María; Murray, Anna

    2016-01-01

    Pseudobranchiomma (Sabellidae, Annelida) is a small and heterogeneous group of fan worms found in shallow marine environments and is generally associated with hard substrates. The delineation and composition of this genus is problematic since it has been defined only by plesiomorphic characters that are widely distributed among other sabellids. In this study we have combined morphological and molecular (mitochondrial and nuclear DNA sequences) data to evaluate species diversity in Australia and assess the phylogenetic relationships of these and other related sabellids. Unlike morphological data alone, molecular data and combined datasets suggest monophyly of Pseudobranchiomma. In this study, a new species of Pseudobranchiomma is described and three others are considered as potential unintentional introductions to Australian waters, one of them reported for the first time for the continent. Pseudobranchiomma pallidasp. n. bears 4-6 serrations along the radiolar flanges, lacks radiolar eyes and has uncini with three transverse rows of teeth over the main fang. In the new species the colour pattern as well is characteristic and species specific.

  6. Detecting scattered light from low-mass molecular cores at 3.6 μm. Impact of global effects on the observation of coreshine

    Science.gov (United States)

    Steinacker, J.; Andersen, M.; Thi, W.-F.; Bacmann, A.

    2014-03-01

    Context. Recently discovered scattered light at 3-5 μm from low-mass cores (so-called "coreshine") reveals the presence of grains around 1 μm, which is larger than the grains found in the low-density interstellar medium. But only about half of the 100+ cores investigated so far show the effect. This prompts further studies on the origin of this detection rate. Aims: We aim to supply criteria for detecting scattered light at 3.6 μm from molecular cloud cores. Methods: From the 3D continuum radiative transfer equation, we derive the expected scattered light intensity from a core placed in an arbitrary direction seen from Earth. We use the approximation of single scattering, consider extinction up to 2nd-order Taylor approximation, and neglect spatial gradients in the dust size distribution. We analyze how scattered light can outshine the absorbing effect of extinction in front of background radiation by the core for given grain properties, anisotropic interstellar radiation field and background field. The impact of the directional characteristics of the scattering on the detection of scattered light from cores is calculated for a given grain size distribution, and local effects like additional radiation field components are discussed. The surface brightness profiles of a core with a 1D density profile are calculated for various Galactic locations, and the results are compared to the approximate detection limits. Results: We find that for optically thin radiation and a constant size distribution, a simple limit for detecting scattered light from a low-mass core can be derived that holds for grains with sizes smaller than 0.5 μm. The extinction by the core prohibits detection in bright parts of the Galactic plane, especially near the Galactic center. For scattered light received from low-mass cores with grain sizes beyond 0.5 μm, the directional characteristics of the scattering favors the detection of scattered light above and below the Galactic center, and to

  7. The association between higher maternal pre-pregnancy body mass index and increased birth weight, adiposity and inflammation in the newborn.

    Science.gov (United States)

    McCloskey, K; Ponsonby, A-L; Collier, F; Allen, K; Tang, M L K; Carlin, J B; Saffery, R; Skilton, M R; Cheung, M; Ranganathan, S; Dwyer, T; Burgner, D; Vuillermin, P

    2018-01-01

    Excess adiposity and adiposity-related inflammation are known risk factors for cardiovascular disease in adults; however, little is known regarding the determinants of adiposity-related inflammation at birth. The aim of this study was to investigate the association between maternal pre-pregnancy BMI and newborn adiposity and inflammation. Paired maternal (28-week gestation) and infant (umbilical cord) blood samples were collected from a population-derived birth cohort (Barwon Infant Study, n = 1074). Data on maternal comorbidities and infant birth anthropomorphic measures were compiled, and infant aortic intima-media thickness was measured by trans-abdominal ultrasound. In a selected subgroup of term infants (n = 161), matched maternal and cord lipids, high-sensitivity C-reactive protein (hsCRP) and maternal soluble CD14 were measured. Analysis was completed by using pairwise correlation and linear regression. Because of their non-normal distribution, pathology blood measures were log transformed prior to analysis. Maternal pre-pregnancy BMI was positively associated with increased birth weight (mean difference 17.8 g per kg m -2 , 95% CI 6.6 to 28.9; p = 0.002), newborn mean skin-fold thickness (mean difference 0.1 mm per kg m -2 , 95% CI 0.0 to 0.1; p pregnancy BMI, 95% CI 0.6 to 7.7%, p = 0.02), but not cord blood soluble CD14. Inclusion of maternal hsCRP as a covariate attenuated the associations between pre-pregnancy BMI and both newborn skin-fold thickness and cord blood hsCRP. Higher maternal pre-pregnancy BMI is associated with increased newborn adiposity and inflammation. These associations may be partially mediated by maternal inflammation during pregnancy. © 2016 World Obesity Federation.

  8. Low-molecular-weight model study of peroxide cross-linking of ethylene-propylene-diene rubber using gas chromatography and mass spectrometry II. Addition and combination reactions.

    Science.gov (United States)

    Peters, R; van Duin, M; Tonoli, D; Kwakkenbos, G; Mengerink, Y; van Benthem, R A T M; de Koster, C G; Schoenmakers, P J; van der Wal, Sj

    2008-08-08

    The dicumyl-peroxide-initiated addition and combination reactions of mixtures of alkanes (n-octane, n-decane) and alkenes [5,6-dihydrodicyclopentadiene (DCPDH), 5-ethylidene-2-norbornane (ENBH) and 5-vinylidene-2-norbornane (VNBH)] were studied to mimic the peroxide cross-linking reactions of terpolymerised ethylene, propylene and a diene monomer (EPDM). The reaction products of the mixtures were separated by both gas chromatography (GC) and comprehensive two-dimensional gas chromatography (GCxGC). The separated compounds were identified from their mass spectra and their GC and GCxGC elution pattern. Quantification of the various alkyl/alkyl, alkyl/allyl and allyl/allyl combination products shows that allylic-radicals comprise approximately 60% of the substrate radicals formed. The total concentration of the products formed by combination is found to be independent of the concentration and the type of alkene. The total concentration of the products formed by addition to the alkene increases with increasing concentration of alkene. In addition, the total concentration of the formed addition products depends strongly on the type of the alkene used, viz. VNBH>ENBH approximately DCPDH, which is a consequence of differences in steric hindrance of the unsaturation. The peroxide curing efficiency, defined as the number of moles of cross-linked products formed per mol of peroxide, is 173% using 9% (w/w) 5-vinylidene-2-norbornane (VNBH). This indicates that the addition reaction is recurrent. All these findings are consistent with experimental studies on peroxide curing of EPDM rubber. In addition, the present results provide more-detailed structural information, increasing the understanding of the mechanism of peroxide curing of EPDM. The described approach to use low-molecular-weight model compounds followed by GC-mass spectrometry (MS) and GCxGC-MS analysis is proven to be a very powerful tool to study the cross-linking of EPDM.

  9. Production of a Brassica napus low-molecular mass acyl-coenzyme A-binding protein in Arabidopsis alters the acyl-coenzyme A pool and acyl composition of oil in seeds

    Science.gov (United States)

    Low-molecular mass (10 kD) cytosolic acyl-coenzyme A-binding protein (ACBP) has a substantial influence over fatty acid (FA) composition in oilseeds, possibly via an effect on the partitioning of acyl groups between elongation and desaturation pathways. Previously, we demonstrated that the expressio...

  10. Isolation and characterization of the viscous, high-molecular-mass microbial carbohydrate fraction from faeces of healthy subjects and patients with Crohn's disease and the consequences for a therapeutic approach

    NARCIS (Netherlands)

    Ruseler- Embden, J.G.H. van; Lieshout, L.M.C. van; Binnema, D.J.; Hazenberg, M.P.

    1998-01-01

    1. An earlier study by our group revealed that the viscosity of faeces from patients with Crohn's disease is significantly lower than that of healthy subjects. This is due to low concentrations of a high-molecular-mass carbohydrate, probably of bacterial origin. The cause of this phenomenon might be

  11. Higher education

    OpenAIRE

    Wolter, Andrä

    2009-01-01

    During the last five years higher education research in Germany seems to be in a significant upturn. This is a side effect partly of the obvious boom of empirical educational research in general and partly of the reform movement that has affected the German higher education system since middle of the 1990s. The demand for data in the field of higher education will increase considerably in future. The available data infrastructure for higher education research in Germany consists of two comple...

  12. Methods and Tools to allow molecular flow simulations to be coupled to higher level continuum descriptions of flows in porous/fractured media and aerosol/dust dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Loyalka, Sudarshan [Univ. of Missouri, Columbia, MO (United States)

    2015-04-09

    The purpose of this project was to develop methods and tools that will aid in safety evaluation of nuclear fuels and licensing of nuclear reactors relating to accidents.The objectives were to develop more detailed and faster computations of fission product transport and aerosol evolution as they generally relate to nuclear fuel and/or nuclear reactor accidents. The two tasks in the project related to molecular transport in nuclear fuel and aerosol transport in reactor vessel and containment. For both the tasks, explorations of coupling of Direct Simulation Monte Carlo with Navier-Stokes solvers or the Sectional method were not successful. However, Mesh free methods for the Direct Simulation Monte Carlo method were successfully explored.These explorations permit applications to porous and fractured media, and arbitrary geometries.The computations were carried out in Mathematica and are fully parallelized. The project has resulted in new computational tools (algorithms and programs) that will improve the fidelity of computations to actual physics, chemistry and transport of fission products in the nuclear fuel and aerosol in reactor primary and secondary containments.

  13. Quantitative analysis of flavanones from citrus fruits by using mesoporous molecular sieve-based miniaturized solid phase extraction coupled to ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry.

    Science.gov (United States)

    Cao, Wan; Ye, Li-Hong; Cao, Jun; Xu, Jing-Jing; Peng, Li-Qing; Zhu, Qiong-Yao; Zhang, Qian-Yun; Hu, Shuai-Shuai

    2015-08-07

    An analytical procedure based on miniaturized solid phase extraction (SPE) and ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was developed and validated for determination of six flavanones in Citrus fruits. The mesoporous molecular sieve SBA-15 as a solid sorbent was characterised by Fourier transform-infrared spectroscopy and scanning electron microscopy. Additionally, compared with reported extraction techniques, the mesoporous SBA-15 based SPE method possessed the advantages of shorter analysis time and higher sensitivity. Furthermore, considering the different nature of the tested compounds, all of the parameters, including the SBA-15 amount, solution pH, elution solvent, and the sorbent type, were investigated in detail. Under the optimum condition, the instrumental detection and quantitation limits calculated were less than 4.26 and 14.29ngmL(-1), respectively. The recoveries obtained for all the analytes were ranging from 89.22% to 103.46%. The experimental results suggested that SBA-15 was a promising material for the purification and enrichment of target flavanones from complex citrus fruit samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  14. Method for simultaneous imaging of endogenous low molecular weight metabolites in mouse brain using TiO2 nanoparticles in nanoparticle-assisted laser desorption/ionization-imaging mass spectrometry.

    Science.gov (United States)

    Shrivas, Kamlesh; Hayasaka, Takahiro; Sugiura, Yuki; Setou, Mitsutoshi

    2011-10-01

    We report the detection of a group of endogenous low molecular weight metabolites (LMWM) in mouse brain (80-500 Da) using TiO(2) nanoparticles (NPs) in nanoparticle-assisted laser desorption/ionization-imaging mass spectrometry (Nano-PALDI-IMS) without any washing and separation step prior to MS analysis. The identification of metabolites using TiO(2) NPs was compared with a conventional organic matrix 2,5-dihydroxybenzoic acid (DHB) where signals of 179 molecules were specific to TiO(2) NPs, 4 were specific to DHB, and 21 were common to both TiO(2) NPs and DHB. The use of TiO(2) NPs enabled the detection of a higher number of LMWM as compared to DHB and gold NPs as a matrix. This approach is a simple, inexpensive, washing, and separation free for imaging and identification of LMWM in mouse brain. We believe that the biochemical information from distinct regions of the brain using a Nano-PALDI-IMS will be helpful in elucidating the imbalances linked with diseases in biomedical samples.

  15. Trace analysis of antidepressants in environmental waters by molecularly imprinted polymer-based solid-phase extraction followed by ultra-performance liquid chromatography coupled to triple quadrupole mass spectrometry.

    Science.gov (United States)

    Demeestere, Kristof; Petrović, Mira; Gros, Meritxell; Dewulf, Jo; Van Langenhove, Herman; Barceló, Damià

    2010-01-01

    This paper presents the development, optimization, and validation of an innovative method to analyze trace concentrations of seven selected psychoactive pharmaceuticals in environmental waters. Hereby, the solid-phase extraction (SPE) potential of molecularly imprinted polymers (MIPs) in terms of extraction recovery, breakthrough, precision, and selectivity is studied for the first time. Instrumental analysis by ultra-performance liquid chromatography coupled to triple quadrupole mass spectrometry allowed a rapid (run time = 7.5 min) and sensitive (instrumental detection limit Experiments performed in spiked river water, sewage treatment plant (STP) effluent and influent showed for these compounds extraction recoveries higher than 70%, breakthrough volumes up to 200 mL, method detection limits (MDL) as low as 0.5 ng/L, and good precision (exemplified by relative standard deviations better than 15%, n > or = 3). Compared to the widely used hydrophilic-lipophilic balanced (HLB) polymers, the newly developed MIPs indicated to be more resistant toward matrix effects induced ion signal suppression particularly when dealing with relative dirty samples like STP influents. As a result of the better selectivity, the MDL obtained with the MIP-based SPE method was up to a factor of 7 lower compared to those obtained with a recently reported multi-residue HLB method. However, optimizing a HLB method in terms of selectivity, e.g., by introducing a stronger washing protocol, can significantly reduce its MDL up to values approximating those obtained with MIPs.

  16. Simultaneous determination of selected chemotherapeutics in human whole blood by molecularly imprinted polymers coated solid phase microextraction fibers and liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Szultka, Malgorzata; Krzeminski, Rafal; Jackowski, Marek; Buszewski, Boguslaw

    2013-12-01

    Development and validation of novel, general liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of amoxicillin (AMOX), cefatoxime (CEF), ciprofloxacin (CIP), daptomycin (DAPTO), fluconazole (FLU), gentamicin (GEN), clindamycin (KLI), linezolid (LIN), metronidazole (MET), moxifloxacin (MOXI) in human whole blood are described. Samples were prepared on solid phase microextraction way with the use of polymeric sorption coatings with molecular imprints and analyzed using a gradient separation over an ACE C18-column (4.6mm×150mm, 3μm) with isocratic elution. Positive electrospray ionization was employed as the ionization source. The mobile phase consisted of acetonitrile-water (0.1% formic acid or 5mM ammonium acetate) at a flow 0.4ml/min. The chromatographic run time was kept less than 9min. The intra- and inter-day relative standard deviation across three validation runs over the entire concentration range was less than 7.3%, while the accuracy was within ±8.4%. The mean recovery of all the analytes ranged from 65.0 to 83.0%. This method was successfully applied to clinical samples from patients with clinically diagnosed bacterial infections process. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. A low-molecular-mass protein from Methylococcus capsulatus (Bath) is responsible for the regulation of formaldehyde dehydrogenase activity in vitro.

    Science.gov (United States)

    Tate, S; Dalton, H

    1999-01-01

    An 8.6 kDa protein, which the authors call a modifin, has been purified from Methylococcus capsulatus (Bath) and has been shown to alter the substrate specificity and kinetics of NAD+-linked formaldehyde dehydrogenase (FDH) isolated from the same organism. Purification methods for both the modifin and FDH are presented which reliably produced pure protein for further analysis. Analysis of the molecular mass and N-terminal sequence of both FDH and the modifin indicate that they are unique proteins and show no similarity to alcohol or aldehyde dehydrogenase enzymes isolated from methylotrophic bacteria. Substrate specificity studies demonstrated that FDH oxidized formaldehyde exclusively in the presence of the modifin; a diverse range of aldehydes and alcohols were oxidized by FDH in the absence of the modifin. No formaldehyde oxidation was detected in the absence of the modifin. Attempts to replace the modifin with glutathione or high concentrations of methanol to stimulate formaldehyde oxidation failed. With acetaldehyde as substrate, FDH showed standard Michaelis-Menten kinetics; interaction of FDH with the modifin using formaldehyde as substrate altered the kinetics of the reaction to sigmoidal. Kinetic analysis during turnover experiments indicated that the FDH may be associated with bound formaldehyde following enzyme isolation and that NAD may also be associated with the enzyme but in a form that is less tightly bound than found with the methanol dehydrogenase from Bacillus methanolicus. Data are presented which indicate that the modifin may play an important role in regulating formaldehyde concentration in vivo.

  18. Low molecular mass organogelator based gel electrolyte gelated by a quaternary ammonium halide salt for quasi-solid-state dye-sensitized solar cells

    Science.gov (United States)

    Huo, Zhipeng; Zhang, Changneng; Fang, Xiaqin; Cai, Molang; Dai, Songyuan; Wang, Kongjia

    Quasi-solid-state dye-sensitized solar cells (DSC) are fabricated using tetradodecylammonium bromide as a low molecular mass organogelator (LMOG) to form gel electrolyte with a high solution-to-gel transition temperature (T SG) of 75 °C to hinder flow and volatilization of the liquid. The steady-state voltammograms reveal that the diffusion of the I 3 - and I - in the gel electrolyte is hindered by the self-assembled network of the gel. An increased interfacial exchange current density (j 0) of 4.95 × 10 -8 A cm -2 and a decreased electron recombination lifetime (τ) of 117 ms reveal an increased electron recombination at the dyed TiO 2 photoelectrode/electrolyte interface in the DSC after gelation. The results of the accelerated aging tests show that the gel electrolyte based dye-sensitized solar cell can retain over 93% of its initial photoelectric conversion efficiency value after successive heating at 60 °C for 1000 h, and device degradation is negligible after one sun light soaking with UV cutoff filter for 1000 h.

  19. Low molecular mass organogelator based gel electrolyte gelated by a quaternary ammonium halide salt for quasi-solid-state dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Huo, Zhipeng; Zhang, Changneng; Fang, Xiaqin; Cai, Molang; Dai, Songyuan; Wang, Kongjia [Key Lab of Novel Thin Film Solar Cells, Chinese Academy of Sciences (China); Institute of Plasma Physics, Chinese Academy of Sciences (China)

    2010-07-01

    Quasi-solid-state dye-sensitized solar cells (DSC) are fabricated using tetradodecylammonium bromide as a low molecular mass organogelator (LMOG) to form gel electrolyte with a high solution-to-gel transition temperature (T{sub SG}) of 75 C to hinder flow and volatilization of the liquid. The steady-state voltammograms reveal that the diffusion of the I{sub 3}{sup -} and I{sup -} in the gel electrolyte is hindered by the self-assembled network of the gel. An increased interfacial exchange current density (j{sub 0}) of 4.95 x 10{sup -8} A cm{sup -2} and a decreased electron recombination lifetime ({tau}) of 117 ms reveal an increased electron recombination at the dyed TiO{sub 2} photoelectrode/electrolyte interface in the DSC after gelation. The results of the accelerated aging tests show that the gel electrolyte based dye-sensitized solar cell can retain over 93% of its initial photoelectric conversion efficiency value after successive heating at 60 C for 1000 h, and device degradation is negligible after one sun light soaking with UV cutoff filter for 1000 h. (author)

  20. A novel polysulfide hydrogel electrolyte based on low molecular mass organogelator for quasi-solid-state quantum dot-sensitized solar cells

    Science.gov (United States)

    Huo, Zhipeng; Tao, Li; Wang, Shimao; Wei, Junfeng; Zhu, Jun; Dong, Weiwei; Liu, Feng; Chen, Shuanghong; Zhang, Bing; Dai, Songyuan

    2015-06-01

    A quasi-solid-state quantum dot-sensitized solar cell (QDSSC) is fabricated by using 12-hydroxystearic acid as a low molecular mass organogelator to gelate the polysulfide electrolyte. Noticeably, the gel to liquid transition temperature of this polysulfide hydrogel electrolyte is 96 °C, which contributes to the long-term stability of the quasi-solid-state QDSSC (QS-QDSSC). The influences of gelation on the charge transport, electron recombination and photovoltaic performance of the QS-QDSSC are investigated by electrochemical impedance spectroscopy. Moreover, the network of the hydrogel is investigated by the Field emission scanning electron microscopy and polarized optical light microscopy. It is found that the charge transport is influenced by the network in the hydrogel electrolyte, and the accelerated electron recombination at the photoanode/electrolyte interface leads to the decreased open-circuit voltage. The QS-QDSSC exhibits an energy conversion efficiency of 2.40% at AM 1.5 (100 mW cm-2) which is slightly lower than that of liquid electrolyte based cell (2.88%). However, the QS-QDSSC exhibits significantly improved stability during the accelerated thermal test. Especially, during the accelerated aging test, the short-circuit current density (Jsc) of the liquid electrolyte based QDSSC sharply decreased to nearly 35% of its initial value, while there is relatively less change in the Jsc for the QS-QDSSC.

  1. Molecular Characterization of Thiols in Fossil Fuels by Michael Addition Reaction Derivatization and Electrospray Ionization Fourier Transform Ion Cyclotron Resonance Mass Spectrometry.

    Science.gov (United States)

    Wang, Meng; Zhao, Suoqi; Liu, Xuxia; Shi, Quan

    2016-10-04

    Thiols widely occur in sediments and fossil fuels. However, the molecular composition of these compounds is unclear due to the lack of appropriate analytical methods. In this work, a characterization method for thiols in fossil fuels was developed on the basis of Michael addition reaction derivatization followed by electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT-ICR MS). Model thiol compound studies showed that thiols were selectively reacted with phenylvinylsulfone and transformed to sulfones with greater than 98% conversions. This method was applied to a coker naphtha, light and heavy gas oils, and crude oils from various geological sources. The results showed that long alkyl chain thiols are readily present in petroleum, which have up to 30 carbon atoms. Large DBE dispersity of thiols indicates that naphthenic and aromatic thiols are also present in the petroleum. This method is capable of detecting thiol compounds in the part per million range by weight. This method allows characterization of thiols in a complex hydrocarbon matrix, which is complementary to the comprehensive analysis of sulfur compounds in fossil fuels.

  2. O-Linked glycome and proteome of high-molecular-mass proteins in human ovarian cancer ascites: Identification of sulfation, disialic acid and O-linked fucose.

    Science.gov (United States)

    Karlsson, Niclas G; McGuckin, Michael A

    2012-07-01

    The O-linked glycosylation of the main acidic high-molecular-weight glycoprotein from ascites fluid from patients with ovarian cancer were analyzed. The O-linked oligosaccharides were shown to consist of mainly highly sialylated core 1 and 2 structures with a smaller amount of sulfated core 2 structures. These structures were shown to be able to be further extended into small keratan sulfate (KS)-type oligosaccharides with up to four N-acetyllactosamine units. Proteomic studies of the acidic fraction of ascites fluid from patients with ovarian cancer showed that this fraction was enriched in proteoglycans. Among them, lumican, agrin, versican and dystroglycans were potential candidates, with threonine- and serine-rich domains that could carry a significant amount of O-linked glycosylation, including also the O-linked KS. Glycomic analysis using liquid chromatography (LC)-tandem mass spectrometry (MS/MS) also showed that the disialic acid NeuAc-NeuAc- was frequently found as the terminating structure on the O-linked core 1 and 2 oligosaccharides from one ascites sample. Also, a small amount of the epidermal growth factor (EGF)-associated O-linked fucose structure Gal-GlcNAc-Fucitol was detected with and without sialic acid in the LC-MS/MS analysis. Candidate proteins containing O-linked fucose were suggested to be proteoglycan-type molecules containing the O-linked fucose EGF consensus domain.

  3. Mass Spectrometry Uncovers Molecular Reactivities of Coordination and Organometallic Gold(III) Drug Candidates in Competitive Experiments That Correlate with Their Biological Effects.

    Science.gov (United States)

    Meier, Samuel M; Gerner, Christopher; Keppler, Bernhard K; Cinellu, Maria Agostina; Casini, Angela

    2016-05-02

    The reactivity of three cytotoxic organometallic gold(III) complexes with cyclometalated C,N,N and C,N ligands (either six- or five-membered metallacycles), as well as that of two representative gold(III) complexes with N-donor ligands, with biological nucleophiles has been studied by ESI-MS on ion trap and time-of-flight instruments. Specifically, the gold compounds were reacted with mixtures of nucleophiles containing l-histidine (imine), l-methionine (thioether), l-cysteine (thiol), l-glutamic acid (carboxylic acid), methylseleno-l-cysteine (selenoether), and in situ generated seleno-l-cysteine (selenol) to judge the preference of the gold compounds for binding to selenium-containing amino acid residues. Moreover, the gold compounds' reactivity was studied with proteins and nucleic acid building blocks. These experiments revealed profound differences between the coordination and organometallic families and even within the family of organometallics, which allowed insights to be gained into the compounds mechanisms of action. In particular, interactions with seleno-l-cysteine appear to reflect well the compounds' inhibition properties of the seleno-enzyme thioredoxin reductase and to a certain extent their antiproliferative effects in vitro. Therefore, mass spectrometry is successfully applied for linking the molecular reactivity and target preferences of metal-based drug candidates to their biological effects. Finally, this experimental setup is applicable to any other metallodrug that undergoes ligand substitution reactions and/or redox changes as part of its mechanism of action.

  4. Velocity selection and mass spectrometric detection of an H2S molecular beam and a collisional study of its interactions with rare gases

    Science.gov (United States)

    Aquilanti, Vincenzo; Cappelletti, David; Pirani, Fernando; Roncaratti, Luiz F.

    2009-02-01

    Total integral cross section experiments, for collisions of rotationally hot H2S projectile molecules by He and Xe targets, have been performed in the thermal energy range by using a molecular beam apparatus, which operates under high resolution conditions and exploits a quadrupole mass spectrometer as a detector. Information on the radial dependence of the intermolecular interaction, averaged over all relative orientations of colliding partners, is obtained. This study completes the investigation of H2S-rare gas family [see D. Cappelletti, A.F.A. Vilela, P.R.P. Barreto, R. Gargano, F. Pirani, V. Aquilanti, J. Chem. Phys. 125 (2006) 133111, for Ne, Ar and Kr] and permits us to discover similarities and differences with the analogous H2O-Rg series of systems. In particular, the analysis of the scattering data suggests that while the complexes of H2S-rare gases from He to Kr are essentially bound by nearly isotropic noncovalent interactions of van der Waals type, the H2S-Xe system exhibits a weak, but measurable, additional component which emerges at intermediate intermolecular distance (in proximity of the potential well), and provides a bond stabilization. This observation is of possible interest for the investigation of the phenomenology of the hydrogen bond formation.

  5. Testing a Low Molecular Mass Fraction of a Mushroom (Lentinus edodes Extract Formulated as an Oral Rinse in a Cohort of Volunteers

    Directory of Open Access Journals (Sweden)

    Caterina Signoretto

    2011-01-01

    Full Text Available Although foods are considered enhancing factors for dental caries and periodontitis, laboratory researches indicate that several foods and beverages contain components endowed with antimicrobial and antiplaque activities. A low molecular mass (LMM fraction of an aqueous mushroom extract has been found to exert these activities in in vitro experiments against potential oral pathogens. We therefore conducted a clinical trial in which we tested an LMM fraction of shiitake mushroom extract formulated in a mouthrinse in 30 young volunteers, comparing the results with those obtained in two identical cohorts, one of which received water (placebo and the other Listerine. Plaque index, gingival index and bacterial counts in plaque samples were determined in all volunteers over the 11 days of the clinical trial. Statistically significant differences (P<0.05 were obtained for the plaque index on day 12 in subjects treated with mushroom versus placebo, while for the gingival index significant differences were found for both mushroom versus placebo and mushroom versus Listerine. Decreases in total bacterial counts and in counts of specific oral pathogens were observed for both mushroom extract and Listerine in comparison with placebo. The data suggest that a mushroom extract may prove beneficial in controlling dental caries and/or gingivitis/periodontitis.

  6. Comparison of the molecular mass and optical properties of colored dissolved organic material in two rivers and coastal waters by flow field-flow fractionation.

    Science.gov (United States)

    Zanardi-Lamardo, Eliete; Clark, Catherine D; Moore, Cynthia A; Zika, Rod G

    2002-07-01

    Colored dissolved organic material (CDOM) is an important sunlight absorbing substance affecting the optical properties of natural waters. However, little is known about its structural and optical properties mainly due to its complex matrix and the limitation of the techniques available. A comparison of two southwestern Florida rivers [the Caloosahatchee River (CR) and the Shark River (SR)] was done in terms of molecular mass (MM) and diffusion coefficients (D). The novel technique Frit inlet/frit outlet-flow field-flow fractionation (FIFO-FIFFF) with absorbance and fluorescence detectors was used to determine these properties. The SR receives organic material from the Everglades. By contrast, the CR arises from Lake Okeechobee in central Florida, receiving anthropogenic inputs, farming runoff, and natural organics. Both rivers discharge to the Gulf of Mexico. Fluorescence identified, for both rivers, two different MM distributions in low salinity water samples: the first was centered at approximately 1.7 kDa (CR) and approximately 2 kDa (SR); the second centered at approximately 13 kDa for both rivers, which disappeared gradually in the river plumes to below detection limit in coastal waters. Absorbance detected only one MM distribution centered at approximately 2 kDa (CR) and 2.2-2.4 kDa (SR). Fluorescence in general peaked at a lower MM than absorbance, suggesting a different size distribution for fluorophores vs chromophores. A photochemical study showed that, after sunlight, irradiated freshwater samples have similar characteristics to more marine waters, including a shift in MM distribution of chromophores. The differences observed between the rivers in the optical characteristics, MM distributions, and D values suggest that the CDOM sources, physical, and photochemical degradation processes are different for these two rivers.

  7. High-molecular-weight adiponectin is selectively reduced in women with polycystic ovary syndrome independent of body mass index and severity of insulin resistance.

    LENUS (Irish Health Repository)

    O'Connor, A

    2010-03-01

    Context: High-molecular-weight (HMW) adiponectin contributes to insulin resistance (IR), which is closely associated with the pathophysiology of polycystic ovary syndrome (PCOS). Abnormalities in adipocyte function have been identified in PCOS and potentially contribute to lower adiponectin concentrations. Objective: Our objective was to determine which variables in plasma and adipose tissue influence HMW adiponectin in a well characterized cohort of women with PCOS. Design: This was a cross-sectional study. Settings and Participants: A teaching hospital. Women with PCOS (n = 98) and body mass index (BMI)-matched controls (n = 103) (including 68 age-, BMI-, and IR-matched pairs). Interventions: A standard 75-g oral glucose tolerance test was performed for each participant. Subcutaneous adipose tissue samples were taken by needle biopsy for a subset of PCOS women (n = 9) and controls (n = 8). Main Outcome Measures: Serum levels of HMW adiponectin and their relation to indices of insulin sensitivity, body composition, and circulating androgens as well as adipose tissue expression levels of ADIPOQ, TNFalpha, PPARgamma, and AR were assessed. Results: HMW adiponectin was significantly lower in women with PCOS compared with both BMI- and BMI- and IR-matched controls (P = 0.009 and P = 0.027, respectively). Although BMI and IR were the main predictors of HMW adiponectin, an interaction between waist to hip ratio and plasma testosterone contributed to its variance (P = 0.026). Adipose tissue gene expression analysis demonstrated that AR and TNFalpha (P = 0.008 and P = 0.035, respectively) but not ADIPOQ mRNA levels were increased in PCOS compared with controls. Conclusions: HMW adiponectin is selectively reduced in women with PCOS, independent of BMI and IR. Gene expression analysis suggests that posttranscriptional\\/translational modification contributes to reduced HMW adiponectin in PCOS.

  8. Simultaneous Determination of 11 Aminoglycoside Residues in Honey, Milk, and Pork by Liquid Chromatography with Tandem Mass Spectrometry and Molecularly Imprinted Polymer Solid Phase Extraction.

    Science.gov (United States)

    Yang, Bixia; Wang, Lian; Luo, Chunying; Wang, Xixi; Sun, Chengjun

    2017-08-08

    An analytical method was developed for the simultaneous determination of 11 aminoglycoside (AG) antibiotics, including amikacin, paromomycin, dihydrostreptomycin, gentamicin C1a, hygromycin, kanamycin, netilmicin, spectinomycin, sisomicin, streptomycin, and tobramycin in honey, milk, and pork samples by LC with tandem MS and molecularly imprinted polymer (MIP) SPE. The AG antibiotics in milk and homogenated meat samples were extracted with a solution composed of 10 mmol/L potassium dihydrogen phosphate, 0.4 mmol/L EDTA-Na₂, and 2% trichloroacetic acid. For honey samples, the extractant was 50 mmol/L potassium dihydrogen phosphate. The extracts were cleaned up with MIP SPE cartridges. The separation was performed on a zwitter ionic-HILIC column (50 × 2.1 mm, 3.5 μm), with the mobile phase consisting of methanol, 0.3% formic acid, and 175 mmol/L ammonium formate at 0.50 mL/min in gradient elution. A triple-quadrupole mass spectrometer equipped with an electrospray ionization source, which was operated in positive mode, was used for detection. The quantification was based on matrix-matched calibration curves. The method was applied to real samples with three different matrixes. The LODs of the method were 2-30 μg/kg and the LOQs were 7-100 μg/kg; the average recovery ranged from 78.2 to 94.8%; intraday RSDs and interday RSDs were ≤15 and ≤18%, respectively; and the absolute values of matrix effect for all AGs were RSDs ≤23%.

  9. Role of Low-Molecular-Mass Penicillin-Binding Proteins, NagZ and AmpR in AmpC β-lactamase Regulation of Yersinia enterocolitica.

    Science.gov (United States)

    Liu, Chang; Li, Chuchu; Chen, Yuhuang; Hao, Huijing; Liang, Junrong; Duan, Ran; Guo, Zhaoke; Zhang, Jing; Zhao, Zhongzhi; Jing, Huaiqi; Wang, Xin; Shao, Shihe

    2017-01-01

    Yersinia enterocolitica encodes a chromosomal AmpC β-lactamase under the regulation of the classical ampR-ampC system. To obtain a further understanding to the role of low-molecular-mass penicillin-binding proteins (LMM PBPs) including PBP4, PBP5, PBP6, and PBP7, as well as NagZ and AmpR in ampC regulation of Y. enterocolitica, series of single/multiple mutant strains were systematically constructed and the ampC expression levels were determined by luxCDABE reporter system, reverse transcription-PCR (RT-PCR) and β-lactamase activity test. Sequential deletion of PBP5 and other LMM PBPs result in a continuously growing of ampC expression level, the β-lactamse activity of quadruple deletion strain YEΔ4Δ5Δ6Δ7 (pbp4, pbp5, pbp6, and pbp7 inactivated) is approached to the YEΔD123 (ampD1, ampD2, and ampD3 inactivated). Deletion of nagZ gene caused two completely different results in YEΔD123 and YEΔ4Δ5Δ6Δ7, NagZ is indispensable for YEΔ4Δ5Δ6Δ7 ampC derepression phenotype but dispensable for YEΔD123. AmpR is essential for ampC hyperproduction in these two types of strains, inactivation of AmpR notable reduced the ampC expression level in both YEΔD123 and YEΔ4Δ5Δ6Δ7.

  10. Electrochemical Determination of Low Molecular Mass Thiols Content in Potatoes (Solanum tuberosum Cultivated in the Presence of Various Sulphur Forms and Infected by Late Blight (Phytophora infestans

    Directory of Open Access Journals (Sweden)

    Rene Kizek

    2008-05-01

    Full Text Available In the present paper potato plants were cultivated in the presence of ammonium sulphate or elemental sulphur supplementation into the soil to reveal the effects of different sulphur forms on content of nitrogen, phosphorus, potassium, calcium, magnesium and sulphur, and yield of tubers. During the investigation of the influence of different sulphur forms on yield of potato tubers we did not observe significant changes. Average weight of tubers of control plants per one experimental pot was 355 g. Application of sulphur in both forms resulted in moderate potato tubers weight reduction per one experimental pot compared to control group; average value ranged from 320 to 350 g per one experimental pot. Further we treated the plants with two different supplementation of sulphur with cadmium(II ions (4 mg of cadmium(II acetate per kilogram of the soil. The significantly lowest cadmium content (p < 0.05 was determined in tissues of plants treated with the highest dosage of elemental sulphur (0.64 mg Cd/kg compared to control plants (0.82 mg Cd/kg. We also aimed our attention on the cadmium content in proteins, lipids or soluble carbohydrates and ash. Application of sulphate as well as elemental sulphur resulted in significant cadmium content reduction in lipid fraction compared to control plants. In addition to this we quantified content of low molecular mass thiols in potatoes tissues. To determine the thiols content we employed differential pulse voltammetry Brdicka reaction. After twelve days of the treatment enhancing of thiols level was observed in all experimental groups regardless to applied sulphur form and its concentration. Finally we evaluated the effect of sulphur supplementation on Phytophora infestans infection of potato plants.

  11. The solvent-gelator interaction as the origin of different diffusivity behavior of diols in gels formed with sugar-based low-molecular-mass gelator.

    Science.gov (United States)

    Kowalczuk, Joanna; Bielejewski, Michał; Lapiński, Andrzej; Luboradzki, Roman; Tritt-Goc, Jadwiga

    2014-04-10

    Organogels are soft materials consisting of low-molecular-mass gelators (LMOGs) self-assembled through noncovalent interactions into 3D structures, in which free spaces are filled by organic solvents. 4,6,4',6'-O-terephthylidene-bis(methyl-α-d-glucopyranoside) (1) is found to be a new LMOG. It gelatinizes only a limited number of solvents. Here, the gels of 1 with ethylene glycol (EG) and 1,3-propanediol (PG) are investigated with FT-IR, Raman, and UV-vis spectroscopies, the NMR relaxometry and diffusometry methods, and microscopic observation. The chemical structures of both solvents are closely related, but the variety of physical characteristics of the gels is large. The 1/PG gels are thermally more stable compared to 1/EG gels. The types of aggregates are most likely the H- and J-type in 1/EG gels and the J-type in 1/PG gels. Different microstructures are observed: bundles of crossing fibers for 1/EG and a honeycomb-like matrix for 1/PG gels. The diffusivity of the EG solvent in gels with 1 behaves as expected, decreasing with increasing gelator concentration, whereas the opposite behavior is observed for the PG solvent. This is a most fascinating result. To explain the diffusion enhancement, we suggest that a dynamic hydrogen bonding network of PG solvent in gel matrixes is disrupted due to solvent-gelator interaction. The direct proof of this interaction is given by the observed low frequency dispersion of the spin-lattice relaxation time of solvents in the gel matrixes.

  12. High-molecular-weight adiponectin is selectively reduced in women with polycystic ovary syndrome independent of body mass index and severity of insulin resistance.

    Science.gov (United States)

    O'Connor, A; Phelan, N; Tun, T Kyaw; Boran, G; Gibney, J; Roche, H M

    2010-03-01

    High-molecular-weight (HMW) adiponectin contributes to insulin resistance (IR), which is closely associated with the pathophysiology of polycystic ovary syndrome (PCOS). Abnormalities in adipocyte function have been identified in PCOS and potentially contribute to lower adiponectin concentrations. Our objective was to determine which variables in plasma and adipose tissue influence HMW adiponectin in a well characterized cohort of women with PCOS. This was a cross-sectional study. A teaching hospital. Women with PCOS (n = 98) and body mass index (BMI)-matched controls (n = 103) (including 68 age-, BMI-, and IR-matched pairs). A standard 75-g oral glucose tolerance test was performed for each participant. Subcutaneous adipose tissue samples were taken by needle biopsy for a subset of PCOS women (n = 9) and controls (n = 8). Serum levels of HMW adiponectin and their relation to indices of insulin sensitivity, body composition, and circulating androgens as well as adipose tissue expression levels of ADIPOQ, TNFalpha, PPARgamma, and AR were assessed. HMW adiponectin was significantly lower in women with PCOS compared with both BMI- and BMI- and IR-matched controls (P = 0.009 and P = 0.027, respectively). Although BMI and IR were the main predictors of HMW adiponectin, an interaction between waist to hip ratio and plasma testosterone contributed to its variance (P = 0.026). Adipose tissue gene expression analysis demonstrated that AR and TNFalpha (P = 0.008 and P = 0.035, respectively) but not ADIPOQ mRNA levels were increased in PCOS compared with controls. HMW adiponectin is selectively reduced in women with PCOS, independent of BMI and IR. Gene expression analysis suggests that posttranscriptional/translational modification contributes to reduced HMW adiponectin in PCOS.

  13. Determination of fluoroquinolone antibiotics in environmental water samples based on magnetic molecularly imprinted polymer extraction followed by liquid chromatography-tandem mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Chen Ligang; Zhang Xiaopan; Xu Yang [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China); Du Xiaobo; Sun Xin [College of Physics, Jilin University, 2699 Qianjin Street, Changchun 130012 (China); Sun Lei; Wang Hui; Zhao Qi; Yu Aimin; Zhang Hanqi [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China); Ding Lan, E-mail: dinglan@jlu.edu.cn [College of Chemistry, Jilin University, 2699 Qianjin Street, Changchun 130012, Jilin (China)

    2010-03-03

    A simple method based on magnetic separation for selective extraction of fluoroquinolones (FQs) from environmental water samples has been developed using magnetic molecularly imprinted polymer (MMIP) as sorbent. The MMIP has been prepared using ciprofloxacin as template molecule, methacrylic acid as functional monomer, ethylene glycol dimethacrylate as cross-linking agent and Fe{sub 3}O{sub 4} magnetite as magnetic component. The polymer has been characterized by scanning electron microscopy, Fourier-transform infrared spectrometry and vibrating sample magnetometry. Various parameters affecting the extraction efficiency were evaluated in order to achieve optimal concentration and reduce non-specific interactions. The analytes desorbed from the polymers were determined by liquid chromatography-tandem mass spectrometry. The matrix effect was evaluated by using different washing solvents for removing interfering compounds from the MMIPs after sample loading. Under the optimal conditions, the linearity of the method obtained is in the range of 20-2000 ng L{sup -1}. The detection limits of FQs are in the range of 3.2-6.2 ng L{sup -1}. The relative standard deviations of intra- and inter-day tests ranging from 2.5 to 7.2% and from 3.6 to 9.1% are obtained. In all three spiked levels (20, 100 and 200 ng L{sup -1}), the recoveries of FQs are in the range of 76.3-94.2%. The proposed method was successfully applied to determine FQs including ciprofloxacin, enrofloxacin, lomefloxacin, levofloxacin, fleroxacin and sparfloxacin in different water samples, such as lake water, river water, primary and final sewage effluent. Ciprofloxacin and fleroxacin were found in primary and final sewage effluent samples with the contents in the range of 26-87 ng L{sup -1}.

  14. A putative low-molecular-mass penicillin-binding protein (PBP) of Mycobacterium smegmatis exhibits prominent physiological characteristics of DD-carboxypeptidase and beta-lactamase.

    Science.gov (United States)

    Bansal, Ankita; Kar, Debasish; Murugan, Rajagopal A; Mallick, Sathi; Dutta, Mouparna; Pandey, Satya Deo; Chowdhury, Chiranjit; Ghosh, Anindya S

    2015-05-01

    DD-carboxypeptidases (DD-CPases) are low-molecular-mass (LMM) penicillin-binding proteins (PBPs) that are mainly involved in peptidoglycan remodelling, but little is known about the dd-CPases of mycobacteria. In this study, a putative DD-CPase of Mycobacterium smegmatis, MSMEG_2433 is characterized. The gene for the membrane-bound form of MSMEG_2433 was cloned and expressed in Escherichia coli in its active form, as revealed by its ability to bind to the Bocillin-FL (fluorescent penicillin). Interestingly, in vivo expression of MSMEG_2433 could restore the cell shape oddities of the septuple PBP mutant of E. coli, which was a prominent physiological characteristic of DD-CPases. Moreover, expression of MSMEG_2433 in trans elevated beta-lactam resistance in PBP deletion mutants (ΔdacAdacC) of E. coli, strengthening its physiology as a dd-CPase. To confirm the biochemical reason behind such physiological behaviours, a soluble form of MSMEG_2433 (sMSMEG_2433) was created, expressed and purified. In agreement with the observed physiological phenomena, sMSMEG_2433 exhibited DD-CPase activity against artificial and peptidoglycan-mimetic DD-CPase substrates. To our surprise, enzymic analyses of MSMEG_2433 revealed efficient deacylation for beta-lactam substrates at physiological pH, which is a unique characteristic of beta-lactamases. In addition to the MSMEG_2433 active site that favours dd-CPase activity, in silico analyses also predicted the presence of an omega-loop-like region in MSMEG_2433, which is an important determinant of its beta-lactamase activity. Based on the in vitro, in vivo and in silico studies, we conclude that MSMEG_2433 is a dual enzyme, possessing both DD-CPase and beta-lactamase activities. © 2015 The Authors.

  15. Low-molecular-weight model study of peroxide cross-linking of ethylene-propylene (-diene) rubber using gas chromatography and mass spectrometry I. Combination reactions of alkanes.

    Science.gov (United States)

    Peters, R; Tonoli, D; van Duin, M; Mommers, J; Mengerink, Y; Wilbers, A T M; van Benthem, R; de Koster, Ch; Schoenmakers, P J; van der Wal, Sj

    2008-08-08

    The combination reaction of linear and branched alkanes, initiated by dicumylperoxide, has been studied as a model for the combination cross-linking reaction of peroxide-cured terpolymerised ethylene, propylene and diene monomer. Both gas chromatography-mass spectrometry (GC-MS) and comprehensive two-dimensional GC-MS (GCxGC-MS) analyses have been employed to analyse the isomeric reaction products. The identification of these products based on their MS fragmentation patterns is quite complex, due to the high tendency of random rearrangements. Careful elucidation of the high-mass ions at optimised ionisation energy (55eV) has resulted in proposed structures for the different isomeric reaction products. The structure assignment by MS is in agreement with the GCxGC elution pattern and with the result of a theoretical model to predict the boiling points and, thus, the GC retention times. In addition, a model that provided a direct correlation between chemical structure and retention times was developed and this was found to provide a useful fit. Quantification of the identified reaction products by GC separation and flame ionization detection allows classification according to the hydrogen abstraction sites for the alkanes by dicumylperoxide. The selectivity for hydrogen abstraction generally follows the expected order, but a higher reactivity was observed for the methylene group next to a primary methyl group, while a reduced reactivity of the methylene group next to ethyl and to methyl groups was observed. The used approach proved to be a very powerful tool to enhance our understanding of the mechanism of peroxide cross-linking of (branched) alkanes.

  16. Effects of low-load, higher-repetition versus high-load, lower-repetition resistance training not performed to failure on muscle strength, mass, and echo intensity in healthy young men: a time-course study.

    Science.gov (United States)

    Ikezoe, T; Kobayashi, T; Nakamura, M; Ichihashi, N

    2017-10-07

    The aim of the present study was to compare the effects of low-load, higher-repetition training (LLHR) with those of high-load, lower-repetition training (HLLR) on muscle strength, mass, and echo intensity in healthy young men. Fifteen healthy men (age, 23.1 ± 2.6 years) were randomly assigned to one of the two groups: LLHR or HLLR group. Resistance training on knee extensor muscles was performed 3 days per week for 8 weeks. One-repetition maximum (1RM) strength, maximum isometric strength, muscle thickness and muscle echo intensity on ultrasonography of the rectus femoris muscle were assessed every 2 weeks. Analysis of variance showed no significant group × time interaction, and only a significant main effect of time was observed for all variables. The 8-week resistance training increased 1RM, maximum isometric muscle strength, and muscle thickness by 36.2%-40.9%, 24.0%-25.5%, and 11.3%-20.4%, respectively, whereas it decreased echo intensity by 8.05%-16.3%. Significant improvements in muscle strength, thickness, and echo intensity were observed at weeks 2, 4, and 8, respectively. The lack of difference in time-course changes between LLHR and HLLR programs suggests that low-load training can exert similar effects on muscle mass and characteristics as high-load training by increasing the number of repetitions, even when not performed to failure.

  17. The Tate Anomally in the Mass of Cooper Pairs of Rotating Superconductors from the point of view of the Higher Dimensional Spacetime defined in function of the Dutch Equation for the Macroscopic Spacetime Shortcuts in the Manyfold Universe

    CERN Document Server

    Loup, F

    2004-01-01

    We use the Higher Dimensional Spacetime of the Manyfold Universe(as is our previous works) and Dark Matter to explain the Tate Anomally observed when measuring the mass of Cooper Pairs of Rotating Superconductors as a proof that Quantum Materials are not tied to $3+1$ Spacetime according to Matos-Tajmar studies. We demonstrate that the Dutch Equation can enlarge a Extra Dimension of the Manyfold Universe from Planck size and this enlargement can affect the Cooper Pair mass explaining the Tate Anomally. We adopt a slight deviation from the Fractal Spacetime of Matos-Tajmar with fractionary Dimensions because in the formalism of General Relativity it is difficult to conceive a Einstein Tensor with fractionary Dimensions(fractionary scripts).But the idea of Matos-Tajmar is excellent because if a Superconductor in Rotation can enlarge the Planck Size Dimension of the Manyfold Universe we can perhaps probe the Extra Dimensions in a way more acessible than TeV collisions and perhaps probe the Geometry of the Spacet...

  18. Normal/high-fat milk consumption is associated with higher lean body and muscle mass in Japanese women aged between 40 and 60 years: a cross-sectional study.

    Science.gov (United States)

    Sukenobe, Yuri; Terauchi, Masakazu; Hirose, Asuka; Hirano, Miho; Akiyoshi, Mihoko; Kato, Kiyoko; Miyasaka, Naoyuki

    2018-02-02

    Milk is known to contain various nutrients that may have health benefits for postmenopausal women who are at an increased risk of cardiovascular and musculoskeletal diseases. We investigated the association between normal/high- and low-fat milk consumption and body composition in Japanese women aged 40 to 60 years. This cross-sectional study used the baseline data collected in a previous study that examined the effects of a dietary supplement on a variety of health parameters in 85 Japanese women aged 40 to 60 years. Participants had been assessed for age, menopausal status, lifestyle factors, and body composition. We estimated the consumption of normal/high- and low-fat milk using a brief-type self-administered diet history questionnaire (BDHQ). Normal/high- and low-fat milk intake were classified as consumer (drank milk at least twice a week) or non-consumer (drank milk at most once a week), in order to identify the parameters that were independently associated with the consumption of normal/high- and low-fat milk. Of the 85 participants who completed the BDHQ, 27 were categorized as non-consumers, 18 as exclusive low-fat milk consumers, and 29 as exclusive normal/high-fat milk consumers. 11 women who consumed both low-fat and normal/high-fat milk were excluded from the analysis. Compared with non-consumers and exclusive low-fat milk consumers, exclusive high-fat milk consumers had significantly higher lean body mass (mean ± standard deviation [SD], 39.4 ± 2.7 kg vs. 37.9 ± 2.2 kg and 37.6 ± 2.9 kg, P fat milk consumption was associated with higher lean body and muscle mass in middle-aged Japanese women presumably through high vitamin D intake.

  19. Higher Education.

    Science.gov (United States)

    Hendrickson, Robert M.

    This chapter reviews litigation in higher education for 1986. The first section discusses the relationship between postsecondary institutions and various governmental agencies, in which litigation covers questions on the authority of boards, access to information through sunshine laws, questions of tax exempt status, and issues of accreditation.…

  20. Probing the dynamics of polyatomic multichannel elementary reactions by crossed molecular beam experiments with soft electron-ionization mass spectrometric detection.

    Science.gov (United States)

    Casavecchia, Piergiorgio; Leonori, Francesca; Balucani, Nadia; Petrucci, Raffaele; Capozza, Giovanni; Segoloni, Enrico

    2009-01-07

    In this Perspective we highlight developments in the field of chemical reaction dynamics. Focus is on the advances recently made in the investigation of the dynamics of elementary multichannel radical-molecule and radical-radical reactions, as they have become possible using an improved crossed molecular beam scattering apparatus with universal electron-ionization mass spectrometric detection and time-of-flight analysis. These improvements consist in the implementation of (a) soft ionization detection by tunable low-energy electrons which has permitted us to reduce interfering signals originating from dissociative ionization processes, usually representing a major complication, (b) different beam crossing-angle set-ups which have permitted us to extend the range of collision energies over which a reaction can be studied, from very low (a few kJ mol(-1), as of interest in astrochemistry or planetary atmospheric chemistry) to quite high energies (several tens of kJ mol(-1), as of interest in high temperature combustion systems), and (c) continuous supersonic sources for producing a wide variety of atomic and molecular radical reactant beams. Exploiting these new features it has become possible to tackle the dynamics of a variety of polyatomic multichannel reactions, such as those occurring in many environments ranging from combustion and plasmas to terrestrial/planetary atmospheres and interstellar clouds. By measuring product angular and velocity distributions, after having suppressed or mitigated, when needed, the problem of dissociative ionization of interfering species (reactants, products, background gases) by soft ionization detection, essentially all primary reaction products can be identified, the dynamics of each reaction channel characterized, and the branching ratios determined as a function of collision energy. In general this information, besides being of fundamental relevance, is required for a predictive description of the chemistry of these

  1. Purification and characterization of two high molecular mass snake venom metalloproteinases (P-III SVMPs), named SV-PAD-2 and HR-Ele-1, from the venom of Protobothrops elegans (Sakishima-habu).

    Science.gov (United States)

    Oyama, Etsuko; Takahashi, Hidenobu

    2015-09-01

    We herein identified two high molecular mass metalloproteinases, named SV-PAD-2 and HR-Ele-1, in the venom of Protobothrops elegans. HR-Ele-1 appeared as a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) regard under reducing and non-reducing conditions, and the molecular mass of this protease was approximately 60 kDa under reducing conditions. On the other hand, the molecular masses of SV-PAD-2 on SDS-PAGE were 110 kDa under the non-reducing condition and 52 kDa under the reducing condition. These SVMPs exhibited fibrinogenolytic and enzymatic activities against synthetic substrates for matrix metalloproteinases (MMPs) and the insulin B-chain, and were both inhibited by EDTA. SV-PAD-2 inhibited ADP- and collagen-induced platelet aggregation, with IC50 values of 240 nM and 185 nM, respectively. HR-Ele-1 exhibited hemorrhagic activity, and its minimum hemorrhagic dose (MHD) was 0.05 μg in the guinea pig. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. ACE-Inhibitory and Antioxidant Activities of Peptide Fragments Obtained from Tomato Processing By-Products Fermented Using Bacillus subtilis: Effect of Amino Acid Composition and Peptides Molecular Mass Distribution.

    Science.gov (United States)

    Moayedi, Ali; Mora, Leticia; Aristoy, M-Concepción; Hashemi, Maryam; Safari, Mohammad; Toldrá, Fidel

    2017-01-01

    The effects of amino acid composition and peptide molecular mass on ACE-inhibitory and antioxidant activities of protein fragments obtained from tomato waste fermented using Bacillus subtilis were evaluated. The addition of B. subtilis increased the relative amounts of aromatic and positively-charged amino acids which have been described to influence the biological activities of peptide fragments. IC50 values of hydrolysates for ACE-inhibitory and 2, 2'-diphenyl-1-picrylhydrazyl (DPPH) scavenging activities were found to be 1.5 and 8.2 mg/mL, respectively. Size-exclusion chromatography (SEC) pattern of the hydrolysate indicated the breakdown of parent proteins to smaller peptides with molecular weights mainly below 1400 Da. MALDI-TOF mass spectrometry analysis revealed that the highest ACE-inhibitory activity was due to peptides showing molecular mass range 500-800 Da, while the most active antioxidant peptides were found to be mainly at the two different peptide weight ranges 500-800 Da and 1200-1500 Da.

  3. Homologous series of low molecular weight (C1-C10) monocarboxylic acids, benzoic acid and hydroxyacids in fine-mode (PM2.5) aerosols over the Bay of Bengal: Influence of heterogeneity in air masses and formation pathways

    Science.gov (United States)

    Boreddy, Suresh K. R.; Mochizuki, Tomoki; Kawamura, Kimitaka; Bikkina, Srinivas; Sarin, M. M.

    2017-10-01

    Low molecular weight monocarboxylic acids (LMW monoacids) are most abundant volatile organic compounds (VOCs) in the atmosphere and often act as important contributors to the acidity of precipitation in addition to inorganic acids. However, there is a large uncertainty in the sources and secondary formations of these acids in the atmosphere. This study reports homologous series of LMW monoacids, including normal (C1-C10), branched chain (iC4-iC6), aromatic (benzoic acid) and hydroxyacids (lactic and glycolic acids) in the fine-mode (PM2.5) aerosols collected over the Bay of Bengal (BoB) during a winter cruise (December 2008 to January 2009). The samples were associated with two distinct continental air masses arriving from the Indo-Gangetic Plain (IGP-outflow) and Southeast Asia (SEA-outflow). The molecular distributions of organic acids are characterized by the dominance of formic acid (C1) followed by acetic acid (C2) and nonanoic acid (C9) in the IGP-outflow, whereas dominance of C1 or C9 was observed in the SEA-outflow followed by C2. Formic-to-acetic acid (C1/C2) ratios were higher than unity (mean: 1.3 ± 0.3) in the IGP-outflow, whereas they were less than unity (0.9 ± 0.5) in the SEA-outflow. These results suggest that secondary formation of organic acids is largely important in the IGP-outflow whereas primary emission is a major source of organic acids in the SEA-outflow. Based on the correlation coefficient matrix analysis and C1/C2 and C4/C3 ratios, we consider that the sources of C1 are probably associated with the secondary formation via the oxidation of biogenic VOCs, while C2 has both primary and secondary formations associated with anthropogenic sources in the IGP-outflow. On the other hand, C1 and C2 have similar sources (both primary and secondary) originated from biomass burning and bacterial activities via long-range atmospheric transport in the SEA-outflow, as inferred from the MODIS fire spot data, significant concentrations of isovaleric

  4. Catalytic Steam Reforming of Gasifier Tars: On-Line Monitoring of Tars with a Transportable Molecular-Beam Mass Spectrometer; Milestone Completion Report

    Energy Technology Data Exchange (ETDEWEB)

    Carpenter, D.; Ratcliff, M.; Dayton, D.

    2002-05-01

    A method for evaluating catalytic tar decomposition in real time is presented. The effectiveness of two catalysts are compared. A key technical and economic barrier to commercialization of biomass gasification technologies is the removal of tars that are unavoidably formed in this thermochemical process. Tars contain fuel value; however, they are problematic in gas engines (both reciprocating and turbine) because they condense in the fuel delivery system, forming deposits that negatively affect operation and efficiency. These tars also combust with high luminosity, potentially forming soot particles. The conventional technology for tar removal is wet scrubbing. Although this approach has shown some success, there are significant equipment and operating costs associated with it. In order to prevent the generation of toxic wastewater, the tars must be separated and either disposed as hazardous waste or, preferably, combusted in the gasification plant. A conceptually better approach is catalytic steam reforming of the tars to hydrogen and carbon monoxide (CO), effectively increasing the gasification efficiency and eliminating the problems mentioned above. In FY2000, Battelle Columbus Laboratories attempted to demonstrate integrated gasification-gas turbine operation using catalytic steam reforming of tars. NREL participated in those tests using the transportable molecular-beam mass spectrometer (TMBMS) to monitor the catalytic reactor's performance on-line [10]. Unfortunately, the pilot plant tests encountered operational problems that prevented conclusive determination of the efficacy of the selected catalyst (Battelle's DN34). In FY2001, NREL performed on-site tar steam reforming tests using a slip-stream of hot pyrolysis gas from the Thermochemical Process Development Unit (TCPDU), which was directed to a bench-scale fluidized bed reactor system designed expressly for this purpose. Supporting this effort, the TMBMS was employed to provide on-line analysis

  5. Development of magnetic molecularly imprinted polymers for solid phase extraction of cocaine and metabolites in urine before high performance liquid chromatography - tandem mass spectrometry.

    Science.gov (United States)

    Sánchez-González, Juan; Jesús Tabernero, María; Bermejo, Ana María; Bermejo-Barrera, Pilar; Moreda-Piñeiro, Antonio

    2016-01-15

    A magnetic molecularly imprinted polymer (MMIP) has been synthesized and applied for cocaine (COC) and metabolites (benzoylecgonine, BZE; cocaethylene, CE; and ecgonine methyl ester, EME) recognition/pre-concentration in urine samples. The MMIP has been prepared using COC as a template molecule, ethylene dimethacrylate (EDMA) as a functional monomer, divinylbenzene (DVB) as a cross-linker, Fe3O4 magnetite as a magnetic component, and 2,2'-azobisisobutyronitrile (AIBN) as an initiator. The best results (MIP layer on the surface of the magnetic nanoparticles) and physical properties of the prepared MMIP were obtained when assisting the synthesis procedure with ultrasounds (325W, 37kHz, 30°C, 4h). After solid phase extraction (SPE) with the prepared adsorbent material, analytes were determined by high performance liquid chromatography - tandem mass spectrometry (HPLC-MS/MS). Variables affecting the SPE process (batch mode) were fully evaluated. Optimum retention of analytes (1.8mL of urine and 50mg of MMIP) was achieved by fixing the urine pH at 5.5 (use of a KH2PO4/NaOH, pH 5.5 buffer solution), and magnetic stirring (25°C, 700rpm) for 10min. Elution was performed by using 2mL of a dichloromethane/2-propanol/ammonium hydroxide (75:20:5) mixture under ultrasounds (325W, 35kHz, room temperature) for 5min. The method was validated according to the guidance for bioanalytical method validation of the US Department of Health and Human Services, Food and Drug Administration. The detection limits were in the range of 0.39-1.4ngL(-1). The relative standard deviations of intra- and inter-day tests ranged from 5 to 11% and from 3 to 11%, respectively. Analytical recoveries were in the range of 79-106% when spiking drug-free urine samples at three concentration levels. Good results were also obtained after analyzing an FDT +25% control material. The applicability of the method was proved for screening/quantifying COC, BZE, CE and EME in several samples from poly-drug abusers

  6. Higher body mass index in 16-19 year-old Jewish Adolescents of North African, Middle Eastern and European Origins is a Predictor of Acute Myeloid Leukemia: a cohort of 2.3 million Israelis.

    Science.gov (United States)

    Shamriz, Oded; Leiba, Merav; Levine, Hagai; Derazne, Estela; Keinan-Boker, Lital; Kark, Jeremy D

    2017-04-01

    Studies evaluating adolescent risk factors for developing acute myeloid leukemia (AML) are virtually nonexistent. We assessed adolescent predictors of AML in adults, with a main focus on adolescent BMI. The study included 2,310,922 16-19-year-old Jewish Israeli adolescents (mean age 17.3 ± 0.4, 59.5% male), called up for an obligatory health examination. Sociodemographic and health data, including measured weight and height, were gathered. Body mass index (BMI) was examined both as a continuous variable and grouped according to the World Health Organization (WHO) classification and US-CDC percentiles. Bone-marrow-biopsy-verified AML cases diagnosed up to 31 December 2012 were identified by linkage to the Israel national cancer registry. Multivariable-adjusted Cox proportional-hazards models were used to model time to diagnosis. During 47 million person years of follow-up, 568 AML cases were identified (crude incidence rate 1.21/100,000 person years). There was a multivariable-adjusted hazard ratio (HR) of 1.041 (95% CI 1.015-1.068, p = 0.002) per unit BMI. The association was evident in those of Middle Eastern, North African, and European origin. A graded association was evident across the overweight and obese WHO grouping. With the US-CDC grouping, excess risk was evident in overweight but not in obese adolescents, although a test for trend in percentiles was significant (p = 0.004). Borderline associations were noted for origin (p = 0.065) (higher in the predominantly Ashkenazi European origin), sex (higher in women: HR = 1.24 (95% CI 0.99-1.55), and stature (HR = 1.013, 95% CI 1.000-1.026, per cm). Higher BMI in adolescence was associated with increased AML incidence in adulthood in this multiethnic population.

  7. Infrared spectroscopy of weakly bound molecular ions

    Energy Technology Data Exchange (ETDEWEB)

    Yeh, Lisa I-Ching

    1988-11-01

    The infrared spectra of a series of hydrated hydronium cluster ions and of protonated ethane ion are presented. A tandem mass spectrometer is ideally suited to obtaining the spectra of such weakly bound molecular ions. Traditional absorption spectroscopy is not feasible in these situations, so the techniques described in this thesis make use of some consequence of photon absorption with higher sensitivity than simply attenuation of laser power. That consequence is dissociation. By first mass selecting the parent ion under study and then mass selecting the fragment ion formed from dissociation, the near unit detection efficiency of ion counting methods has been used to full advantage.

  8. Higher Education in Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Andreasen, Lars Birch

    2015-01-01

    Higher education systems around the world have been undergoing fundamental changes through the last 50 years from more narrow self-sustaining universities for the elite and into mass universities, where new groups of students have been recruited and the number of students enrolled has increased...... dramatically. In adjusting to the role of being a mass educational institution, universities have been challenged on how to cope with external pressures, such as forces of globalization and international markets, increased national and international competition for students and research grants, increased...... an impact on the educational systems in Scandinavia, and what possible futures can be envisioned?...

  9. L-Phenylalanine catabolism and 2-phenylethanol synthesis in Yarrowia lipolytica—mapping molecular identities through whole-proteome quantitative mass spectrometry analysis

    National Research Council Canada - National Science Library

    Celińska, Ewelina; Olkowicz, Mariola; Grajek, Włodzimierz; Pretorius, Isak

    2015-01-01

    .... Although the general overview of the 2-PE synthesis pathway is commonly known, involvement of particular molecular identities in this pathway has not been elucidated in Yarrowia lipolytica to date...

  10. Higher levels of s-RANKL and osteoprotegerin in children and adolescents with type 1 diabetes mellitus may indicate increased osteoclast signaling and predisposition to lower bone mass: a multivariate cross-sectional analysis.

    Science.gov (United States)

    Tsentidis, C; Gourgiotis, D; Kossiva, L; Doulgeraki, A; Marmarinos, A; Galli-Tsinopoulou, A; Karavanaki, K

    2016-04-01

    Simultaneous lower bone mineral density, metabolic bone markers, parathyroid hormone (PTH), magnesium, insulin-like growth factor 1 (IGF1), and higher levels of total soluble receptor activator of nuclear factor-kappa B ligand (s-RANKL), osteoprotegerin (OPG), and alkaline phosphatase (ALP) are indicative of lower osteoblast and increased osteoclast signaling in children and adolescents with type 1 diabetes mellitus, predisposing to adult osteopenia and osteoporosis. Type 1 diabetes mellitus (T1DM) is a risk factor for reduced bone mass, disrupting several bone metabolic pathways. We aimed at identifying association patterns between bone metabolic markers, particularly OPG, s-RANKL, and bone mineral density (BMD) in T1DM children and adolescents, in order to study possible underlying pathophysiologic mechanisms of bone loss. We evaluated 40 children and adolescents with T1DM (mean ± SD age 13.04 ± 3.53 years, T1DM duration 5.15 ± 3.33 years) and 40 healthy age- and gender-matched controls (aged12.99 ± 3.3 years). OPG, s-RANKL, osteocalcin, C-telopeptide cross-links (CTX), IGF1, electrolytes, PTH, and total 25(OH)D were measured, and total body along with lumbar spine BMD were evaluated with dual energy X-ray absorptiometry (DXA). Multivariate regression and factor analysis were performed after classic inference. Patients had significantly lower BMD, with lower bone turnover markers, PTH, magnesium, and IGF1 than controls, indicating lower osteoblast signaling. Higher levels of total s-RANKL, OPG, and total ALP were observed in patients, with log(s-RANKL) and OPG correlation found only in controls, possibly indicating increased osteoclast signaling in patients. Coupling of bone resorption and formation was observed in both groups. Multivariate regression confirmed simultaneous lower bone turnover, IGF1, magnesium, and higher total s-RANKL, OPG, and ALP in patients, while factor analysis indicated possible activation of RANK/RANKL/OPG system in

  11. Higher Education in Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Jørgen Lerche; Birch Andreasen, Lars

    2015-01-01

    Higher education systems around the world have been undergoing fundamental changes through the last 50 years from more narrow self-sustaining universities for the elite and into mass universities, where new groups of students have been recruited and the number of students enrolled has increased....... In this chapter we will examine how higher education systems in Scandinavia are developing in relation to these challenges. To what extent has the democratic tradition had an impact on the educational systems, and what possible futures can be envisioned? In the development of higher education in Scandinavia......, there are different perspectives on education at play. One perspective sees education as a “public good” that benefits society and therefore should be free and accessible for all students who qualify to be admitted. According to this perspective, one of the main purposes of higher education is to add value to all...

  12. Molecular Electronics

    DEFF Research Database (Denmark)

    Jennum, Karsten Stein

    This thesis includes the synthesis and characterisation of organic compounds designed for molecular electronics. The synthesised organic molecules are mainly based on two motifs, the obigo(phenyleneethynylenes) (OPE)s and tetrathiafulvalene (TTF) as shown below. These two scaffolds (OPE and TTF...... transistors (Part 2). The synthetic protocols rely on stepwise Sonogashira coupling reactions. Conductivity studies on various OPE-based molecular wires reveal that mere OPE compounds have a higher electrical resistance compared to the cruciform based wires (up to 9 times higher). The most spectacular result...... be potential candidates for future molecular electronics Synthesis of a new donor-acceptor chromophore based on a benzoquinone- TTF motif (QuinoneDTF) is also described herein (Part 2). Reaction of this molecule with acid induces a colour change from purple to orange. The purple colour can be restored...

  13. Quantification of the molecular species of acylglycerols containing hydroxy fatty acids in lesquerella oils using high-performance liquid chromatography and mass spectrometry

    Science.gov (United States)

    Ten molecular species of diacylglycerols (DAG), 54 of triacylglycerols (TAG) and 13 of tetraacylglycerols (tetraAG, triacylglycerol estolides) containing hydroxy fatty acids (FA) as well as 20 of TAG containing three normal FA (non-hydroxylated) in lesquerella oil were quantified by a newly improved...

  14. Liquid chromatography/mass spectrometry and liquid chromatography/nuclear magnetic resonance as complementary analytical techniques for unambiguous identification of polymethoxylated flavones in residues from molecular distillation of orange peel oils (Citrus sinensis).

    Science.gov (United States)

    Weber, Berthold; Hartmann, Beate; Stöckigt, Detlef; Schreiber, Klaus; Roloff, Michael; Bertram, Heinz-Jürgen; Schmidt, Claus O

    2006-01-25

    Liquid chromatography/mass spectrometry and liquid chromatography/nuclear magnetic resonance techniques with ultraviolet/diode array detection were used as complementary analytical tools for the reliable identification of polymethoxylated flavones in residues from molecular distillation of cold-pressed peel oils of Citrus sinensis. After development of a liquid chromatographic separation procedure, the presence of several polymethoxy flavones such as sinensetin, nobiletin, tangeretin, quercetogetin, heptamethoxyflavone, and other derivatives was unambiguously confirmed. In addition, proceranone, an acetylated tetranortriterpenoid with limonoid structure, was identified for the first time in citrus.

  15. Modifications induced by swift heavy ions in poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) and poly({epsilon}-caprolactone) (PCL) films. Part 1. Thermal behaviour and molecular mass modifications

    Energy Technology Data Exchange (ETDEWEB)

    Rouxhet, L.; Legras, R. E-mail: legras@poly.ucl.ac.be

    2000-12-01

    Modifications induced by different energetic heavy ions in poly({epsilon}-caprolactone) (PCL) and poly(hydroxybutyrate-hydroxyvalerate) (PHB/HV) have been investigated by the differential scanning calorimetry (DSC) and steric exclusion chromatography (SEC). A certain dose of damages, depending mainly on the charge and mass of the ion and on the intensity of irradiation, has to be overcome in order to detect any effect on PHB/HV. Actually, at a given intensity of irradiation, superior to 10{sup 10} ions/cm{sup 2}, the level of damage intensity increased with the increase in charge and mass of the ion. Moreover, according to the SEC results, there seems to be a critical mass and/or charge threshold above which the dominant type of damages changes. As a matter of fact, high-density irradiation with Ar{sup 9+} and Kr{sup 15+} resulted mainly in chain scission whereas cross-linking was dominant when irradiating the polymer with Xe{sup 24+} and Pb{sup 56+}. The irradiation of PCL in the conditions studied did not modify significantly the values of the melting point, the crystallisation temperature and the molecular masses of the system studied. The main effect of the irradiation detected by the DSC is the cross-linking of the polymer chains.

  16. Low-molecular-weight model study of peroxide cross-linking of ethylene-propylene (-diene) rubber using gas chromatography and mass spectrometry: I. Combination reactions of alkanes

    NARCIS (Netherlands)

    Peters, R.; Tonoli, D.; van Duin, M.; Mommers, J.; Mengerink, Y.; Wilbers, A.T.M.; van Benthem, R.; de Koster, C.; Schoenmakers, P.J.; van der Wal, S.

    2008-01-01

    The combination reaction of linear and branched alkanes, initiated by dicumyl peroxide, has been studied as a model for the combination cross-linking reaction of peroxide-cured terpolymerised ethylene, propylene and diene monomer. Both gas chromatography-mass spectrometry (GC-MS) and comprehensive

  17. Molecular fountain.

    Energy Technology Data Exchange (ETDEWEB)

    Strecker, Kevin E.; Chandler, David W.

    2009-09-01

    A molecular fountain directs slowly moving molecules against gravity to further slow them to translational energies that they can be trapped and studied. If the molecules are initially slow enough they will return some time later to the position from which they were launched. Because this round trip time can be on the order of a second a single molecule can be observed for times sufficient to perform Hz level spectroscopy. The goal of this LDRD proposal was to construct a novel Molecular Fountain apparatus capable of producing dilute samples of molecules at near zero temperatures in well-defined user-selectable, quantum states. The slowly moving molecules used in this research are produced by the previously developed Kinematic Cooling technique, which uses a crossed atomic and molecular beam apparatus to generate single rotational level molecular samples moving slowly in the laboratory reference frame. The Kinematic Cooling technique produces cold molecules from a supersonic molecular beam via single collisions with a supersonic atomic beam. A single collision of an atom with a molecule occurring at the correct energy and relative velocity can cause a small fraction of the molecules to move very slowly vertically against gravity in the laboratory. These slowly moving molecules are captured by an electrostatic hexapole guiding field that both orients and focuses the molecules. The molecules are focused into the ionization region of a time-of-flight mass spectrometer and are ionized by laser radiation. The new molecular fountain apparatus was built utilizing a new design for molecular beam apparatus that has allowed us to miniaturize the apparatus. This new design minimizes the volumes and surface area of the machine allowing smaller pumps to maintain the necessary background pressures needed for these experiments.

  18. Fuel Class Higher Alcohols

    KAUST Repository

    Sarathy, Mani

    2016-08-17

    This chapter focuses on the production and combustion of alcohol fuels with four or more carbon atoms, which we classify as higher alcohols. It assesses the feasibility of utilizing various C4-C8 alcohols as fuels for internal combustion engines. Utilizing higher-molecular-weight alcohols as fuels requires careful analysis of their fuel properties. ASTM standards provide fuel property requirements for spark-ignition (SI) and compression-ignition (CI) engines such as the stability, lubricity, viscosity, and cold filter plugging point (CFPP) properties of blends of higher alcohols. Important combustion properties that are studied include laminar and turbulent flame speeds, flame blowout/extinction limits, ignition delay under various mixing conditions, and gas-phase and particulate emissions. The chapter focuses on the combustion of higher alcohols in reciprocating SI and CI engines and discusses higher alcohol performance in SI and CI engines. Finally, the chapter identifies the sources, production pathways, and technologies currently being pursued for production of some fuels, including n-butanol, iso-butanol, and n-octanol.

  19. Monitoring of in vitro deamidation of gliadin peptic fragment by mass spectrometry may reflect one of the molecular mechanisms taking place in celiac disease development

    Czech Academy of Sciences Publication Activity Database

    Novák, Petr; Man, Petr; Tučková, Ludmila; Tlaskalová, Helena; Bezouška, Karel; Havlíček, Vladimír

    2002-01-01

    Roč. 37, - (2002), s. 507-511 ISSN 1076-5174 R&D Projects: GA MŠk ME 416; GA ČR GA310/00/1373; GA MZd NI5264 Institutional research plan: CEZ:AV0Z5020903; CEZ:MSM 113100001 Keywords : mass spectrometry * sequencing * gliadin Subject RIV: EE - Microbiology, Virology Impact factor: 2.781, year: 2002

  20. Absorption Mode FT-ICR Mass Spectrometry Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Donald F.; Kilgour, David P.; Konijnenburg, Marco; O' Connor, Peter B.; Heeren, Ronald M.

    2013-12-03

    Fourier transform ion cyclotron resonance mass spectrometry offers the highest mass resolving power for molecular imaging experiments. This high mass resolving power ensures that closely spaced peaks at the same nominal mass are resolved for proper image generation. Typically higher magnetic fields are used to increase mass resolving power. However, a gain in mass resolving power can also be realized by phase correction of the data for absorption mode display. In addition to mass resolving power, absorption mode offers higher mass accuracy and signal-to-noise ratio over the conventional magnitude mode. Here we present the first use of absorption mode for Fourier transform ion cyclotron resonance mass spectrometry imaging. The Autophaser algorithm is used to phase correct each spectrum (pixel) in the image and then these parameters are used by the Chameleon work-flow based data processing software to generate absorption mode ?Datacubes? for image and spectral viewing. Absorption mode reveals new mass and spatial features that are not resolved in magnitude mode and results in improved selected ion image contrast.

  1. H-type bovine spongiform encephalopathy-complex molecular featrues and similarities with some human prion diseases

    NARCIS (Netherlands)

    Biacabe, A.G.; Jacobs, J.G.; Bencsik, A.; Langeveld, J.P.M.; Baron, T.G.M.

    2007-01-01

    We previously reported that some cattle affected by bovine spongiform encephalopathy (BSE) showed distinct molecular features of the protease-resistant prion protein (PrPres) in Western blot, with a 1-2 kDa higher apparent molecular mass of the unglycosylated PrPres associated with labelling by

  2. L-Phenylalanine catabolism and 2-phenylethanol synthesis in Yarrowia lipolytica--mapping molecular identities through whole-proteome quantitative mass spectrometry analysis.

    Science.gov (United States)

    Celińska, Ewelina; Olkowicz, Mariola; Grajek, Włodzimierz

    2015-08-01

    A world-wide effort is now being pursued towards the development of flavors and fragrances (F&F) production independently from traditional sources, as well as autonomously from depleting fossil fuel supplies. Biotechnological production of F&F by microbes has emerged as a vivid solution to the current market limitations. Amongst a wide variety of fragrant chemicals, 2-PE is of significant interest to both scientific and industrial community. Although the general overview of the 2-PE synthesis pathway is commonly known, involvement of particular molecular identities in this pathway has not been elucidated in Yarrowia lipolytica to date. The aim of this study was mapping molecular identities involved in 2-PE synthesis in Y. lipolytica. To acquire a comprehensive landscape of the proteins that are directly and indirectly involved in L-Phe degradation and 2-PE synthesis, we took advantage of comprehensibility and sensitivity of high-throughput LC-MS/MS-quantitative analysis. Amongst a number of proteins involved in amino acid turnover and the central carbon metabolism, enzymes involved in L-Phe conversion to 2-PE have been identified. Results on yeast-to-hyphae transition in relation to the character of the provided nitrogen source have been presented. © FEMS 2015. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  3. Characterization of angiotensin-I converting enzyme inhibiting peptide from Venerupis philippinarum with nano-liquid chromatography in combination with orbitrap mass spectrum detection and molecular docking

    Science.gov (United States)

    Shi, Lei; Wu, Tizhi; Sheng, Naijuan; Yang, Li; Wang, Qian; Liu, Rui; Wu, Hao

    2017-06-01

    The complexity and diversity of peptide mixture from protein hydrolysates make their characterization difficult. In this study, a method combining nano LC-MS/MS with molecular docking was applied to identifying and characterizing a peptide with angiotensin-I converting enzyme (ACE-I) inhibiting activity from Venerupis philippinarum hydrolysate. Firstly, ethanol supernatant of V. philippinarum hydrolysate was separated into active fractions with chromatographic methods such as ion-exchange chromatography and high performance liquid chromatography in combination. Then seven peptides from active fraction were identified according to the searching result of the MS/MS spectra against protein databases. Peptides were synthesized and subjected to ACE-I-inhibition assay. The peptide NTLTLIDTGIGMTK showed the highest potency with an IC50 of 5.75 μmol L-1. The molecular docking analysis showed that the ACE-I inhibiting peptide NTLTLIDTGIGMTK bond with residues Glu123, Glu403, Arg522, Glu376, Gln281 and Asn285 of ACE-I. Therefore, active peptides could be identified with the present method rather than the traditional purification and identification strategies. It may also be feasible to identify other food-derived peptides which target other enzymes and receptors with the method developed in this study.

  4. Comparative evaluation of low-molecular-mass proteins from Mycobacterium tuberculosis identifies members of the ESAT-6 family as immunodominant T-cell antigens

    DEFF Research Database (Denmark)

    Skjøt, R L; Oettinger, T; Rosenkrands, I

    2000-01-01

    in cultures of peripheral blood mononuclear cells from human tuberculosis (TB) patients, Mycobacterium bovis BCG-vaccinated donors, and nonvaccinated donors. The two ESAT-6 family members, TB10.4 and CFP10, were very strongly recognized and induced gamma interferon release at the same level (CFP10......Culture filtrate from Mycobacterium tuberculosis contains protective antigens of relevance for the generation of a new antituberculosis vaccine. We have identified two previously uncharacterized M. tuberculosis proteins (TB7.3 and TB10.4) from the highly active low-mass fraction of culture filtrate...

  5. The Dark Molecular Gas

    Science.gov (United States)

    Wolfire, Mark G.; Hollenbach, David; McKee, Christopher F.

    2010-06-01

    The mass of molecular gas in an interstellar cloud is often measured using line emission from low rotational levels of CO, which are sensitive to the CO mass, and then scaling to the assumed molecular hydrogen H2 mass. However, a significant H2 mass may lie outside the CO region, in the outer regions of the molecular cloud where the gas-phase carbon resides in C or C+. Here, H2 self-shields or is shielded by dust from UV photodissociation, whereas CO is photodissociated. This H2 gas is "dark" in molecular transitions because of the absence of CO and other trace molecules, and because H2 emits so weakly at temperatures 10 K mass such as gamma rays produced in cosmic-ray collisions with the gas and far-infrared/submillimeter wavelength dust continuum radiation. In this paper, we theoretically model this dark mass and find that the fraction of the molecular mass in this dark component is remarkably constant (~0.3 for average visual extinction through the cloud \\bar{A}_V ≃ 8) and insensitive to the incident ultraviolet radiation field strength, the internal density distribution, and the mass of the molecular cloud as long as \\bar{A}_V, or equivalently, the product of the average hydrogen nucleus column and the metallicity through the cloud, is constant. We also find that the dark mass fraction increases with decreasing \\bar{A}_V, since relatively more molecular H2 material lies outside the CO region in this case.

  6. Molecular recognition: Comparative study of a tunable host-guest system by using a fluorescent model system and collision-induced dissociation mass spectrometry on dendrimers

    DEFF Research Database (Denmark)

    Pittelkow, M.; Nielsen, C.B.; Broeren, A.C.

    2005-01-01

    Host-guest interactions between the periphery of adamantylurea-functionalized dendrimers (host) and ureido acetic acid derivatives (guest) were shown to be specific, strong and spatially well-defined. The binding becomes stronger when using phosphonic or sulfonic acid derivatives. In the present...... of the acidic part of the guest. The formation of hydrogen bonds gives, in all cases, higher association constants, demonstrating that the host is more than a proton sensor. The host with the longer spacer (propyl) shows higher association constants than the host with the shorter spacer (ethyl). The gain...

  7. Photo-alignment of low-molecular mass nematic liquid crystals on photochemically bifunctional chalcone-epoxy film by irradiation of a linearly polarized UV light

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Dong Hoon; Cha, Young Kwan [Kyunghee Univ., Yongin (Korea, Republic of)

    2002-04-01

    Photocrosslinkable chalcone-epoxy compound comprising 1,3-bis-(4-hydroxy-phenyl)-propenone was synthesized for fabricating the photo-alignment layer of liquid crystals. Chalcone group was introduced into the main chain unit of the epoxy oligomer. We observed a photodimerization behavior and an optical anisotropy of this material by irradiation of a linearly polarized UV(LP-UV) light. With a trace amount of cationic photo initiator (TRS-HFA), polymerization of epoxy groups was also conducted at the similar wavelength range used for photodimerization . Linearly polarized UV irradiation on the chalcone-epoxy films with cationic photoinitiator induced optical anisotropy of the film and the resultant film can be used for alignment layers for low molecular weight nematic liquid crystals.

  8. Photo-alignment of low-molecular mass nematic liquid crystals on photochemically bifunctional chalcone-epoxy film by irradiation of a linearly polarized UV light

    CERN Document Server

    Choi, D H

    2002-01-01

    Photocrosslinkable chalcone-epoxy compound comprising 1,3-bis-(4-hydroxy-phenyl)-propenone was synthesized for fabricating the photo-alignment layer of liquid crystals. Chalcone group was introduced into the main chain unit of the epoxy oligomer. We observed a photodimerization behavior and an optical anisotropy of this material by irradiation of a linearly polarized UV(LP-UV) light. With a trace amount of cationic photo initiator (TRS-HFA), polymerization of epoxy groups was also conducted at the similar wavelength range used for photodimerization . Linearly polarized UV irradiation on the chalcone-epoxy films with cationic photoinitiator induced optical anisotropy of the film and the resultant film can be used for alignment layers for low molecular weight nematic liquid crystals.

  9. Effects of surface vibrations on interlayer mass transport: Ab initio molecular dynamics investigation of Ti adatom descent pathways and rates from TiN/TiN(001) islands

    Science.gov (United States)

    Sangiovanni, D. G.; Mei, A. B.; Edström, D.; Hultman, L.; Chirita, V.; Petrov, I.; Greene, J. E.

    2018-01-01

    We carried out density-functional ab initio molecular dynamics (AIMD) simulations of Ti adatom (T iad ) migration on, and descent from, square TiN 〈100 〉 epitaxial islands on TiN(001) at temperatures (T ) ranging from 1200 to 2400 K. Adatom-descent energy barriers determined via ab initio nudged-elastic-band calculations at 0 Kelvin suggest that Ti interlayer transport on TiN(001) occurs essentially exclusively via direct hopping onto a lower layer. However, AIMD simulations reveal comparable rates for T iad descent via direct hopping vs push-out/exchange with a Ti island-edge atom for T ≥1500 K . We demonstrate that this effect is due to surface vibrations, which yield considerably lower activation energies at finite temperatures by significantly modifying the adatom push-out/exchange reaction pathway.

  10. CLOUD–CLOUD COLLISION AS A TRIGGER OF THE HIGH-MASS STAR FORMATION: A MOLECULAR LINE STUDY IN RCW 120

    Energy Technology Data Exchange (ETDEWEB)

    Torii, K.; Hasegawa, K.; Hattori, Y.; Sano, H.; Ohama, A.; Yamamoto, H.; Tachihara, K.; Soga, S.; Shimizu, S.; Fukui, Y. [Department of Physics, Nagoya University, Chikusa-ku, Nagoya, Aichi 464-8601 (Japan); Okuda, T.; Mizuno, N. [National Astronomical Observatory of Japan, Mitaka, Tokyo 181-8588 (Japan); Onishi, T. [Department of Astrophysics, Graduate School of Science, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531 (Japan); Mizuno, A., E-mail: torii@a.phys.nagoya-u.ac.jp [Solar-Terrestrial Environment Laboratory, Nagoya University, Chikusa-ku, Nagoya 464-8601 (Japan)

    2015-06-10

    RCW 120 is a Galactic H ii region that has a beautiful ring shape that is bright in the infrared. Our new CO J = 1–0 and J = 3–2 observations performed with the NANTEN2, Mopra, and ASTE telescopes have revealed that two molecular clouds with a velocity separation of 20 km s{sup −1} are both physically associated with RCW 120. The cloud at −8 km s{sup −1} apparently traces the infrared ring, while the other cloud at −28 km s{sup −1} is distributed just outside the opening of the infrared ring, interacting with the H ii region as suggested by the high kinetic temperature of the molecular gas and by the complementary distribution with the ionized gas. A spherically expanding shell driven by the H ii region is usually considered to be the origin of the observed ring structure in RCW 120. Our observations, however, indicate no evidence of the expanding motion in the velocity space, which is inconsistent with the expanding shell model. We postulate an alternative that, by applying the model introduced by Habe and Ohta, the exciting O star in RCW 120 was formed by a collision between the present two clouds at a collision velocity of ∼30 km s{sup −1}. In the model, the observed infrared ring can be interpreted as the cavity created in the larger cloud by the collision, whose inner surface is illuminated by the strong ultraviolet radiation after the birth of the O star. We discuss that the present cloud–cloud collision scenario explains the observed signatures of RCW 120, i.e., its ring morphology, coexistence of the two clouds and their large velocity separation, and absence of the expanding motion.

  11. Multiresidue analysis of cephalosporin antibiotics in bovine milk based on molecularly imprinted polymer extraction followed by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Baeza, A N; Urraca, J L; Chamorro, R; Orellana, G; Castellari, M; Moreno-Bondi, M C

    2016-11-25

    This work reports the preparation of molecularly imprinted polymers (MIPs) selective to cephalosporin (CF) antibiotics, and their application as molecularly imprinted solid-phase extraction (MISPE) sorbents for the determination of these antimicrobials in milk samples. Several functional monomers and cross-linkers have been screened to select the best combination that provides high selectivity for the simultaneous multiresidue extraction of cefthiofur (THIO), cefazolin (AZO), cefquinome (QUI), cephapirin (API), cephalexin (ALE) and cephalonium (ALO) from the samples. The novel MIPs were prepared by a non-covalent imprinting approach in the form of spherical microparticles using the synthetic surrogate molecule sodium 7-(2-biphenylylcarboxamido)-3-methyl-3-cepheme-4-carboxylate, N-3,5-bis(trifluoromethyl)phenyl-N'-4-vinylphenyl urea (VPU) as functional monomer, and divinylbenzene (DVB) as crosslinking agent in a 1:2:20 molar ratio. The optimized MISPE method allowed the extraction of the target antimicrobials from raw cow milk samples using a selective washing with 5mL methanol/2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES) buffer (0.1M, pH 7.5) (2:98, v/v) to remove the non-specifically retained compounds, followed by elution with 1mL of trifluoroacetic acid (TFA) in methanol (0.1:99.9, v/v). The extracts have been analysed by UHPLC-MS/MS and the analytical method has been validated according to EU guideline 2002/657/EC. The limits of quantification (S/N=10) were in the 1.7-12.5μgkg-1 range, well below the maximum residue limits (MRLs) currently established for the quantified cephalosporins in milk samples. The developed MIP allows mutiresidual determination of the six cephalosporin antibiotics mentioned above, significantly broadening the application to food analysis of MISPE methods. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. In Vitro Mass Multiplication and Assessment of Genetic Stability of In Vitro Raised Artemisia absinthium L. Plants Using ISSR and SSAP Molecular Markers

    Directory of Open Access Journals (Sweden)

    B. Kour

    2014-01-01

    Full Text Available The present investigations were made attempting to develop a rapid, reliable, and reproducible in vitro regeneration protocol for Artemisia absinthium L., a medicinal plant of Kashmir Himalayas. Out of several auxin-cytokinin combinations tested, Murashige and Skoog’s (MS medium supplemented with 0.5 mgL−1 2,4-dichlorophenoxyacetic acid (2,4-D and 0.5 mgL−1 kinetin (Kn was found to be the best for the callus induction. On the other hand, 4.5 mgL−1 6-benzylaminopurine (BAP and 0.5 mgL−1 1-α-naphthaleneacetic acid (NAA in the medium resulted in maximum shoot induction from the callus. Similarly, BAP and NAA at a concentration of 1.5 mgL−1 and 0.5 mgL−1, respectively, proved to be the best for the multiple shoot induction from nodal explants. Numerous shoots were obtained from nodal explants after third subculture. In vitro rooting was maximum on medium containing indole-3-butyric acid (IBA at 0.5 mgL−1. The genetic stability of the in vitro raised plants of Artemisia absinthium was assessed using the intersimple sequence repeat (ISSR and sequence-specific amplification polymorphism (SSAP molecular markers. Both markers were able to detect the somaclonal variations in the callus regenerated plants, while no variation was detected in the plants regenerated from the nodal explants. SSAP has been found to be more useful in detection of variability as compared to ISSR molecular marker. The results of present study concluded that the direct regeneration protocol will be useful for the production of true to type plants of this medicinally important plant. This will go a long way in reducing the pressure on the natural populations for the secondary metabolite production, especially for extraction of essential oils.

  13. Influence of Low Molecular Weight Polymers on the Rheology of Bentonite Suspensions Influence de polymères de faible masse moléculaire sur la rhéologie de suspensions de bentonite

    Directory of Open Access Journals (Sweden)

    Rossi S.

    2006-12-01

    Full Text Available In this communication we demonstrate how relatively low molecular weight synthetic polymers significantly alter the rheological properties of Bentonite/water suspensions depending upon the polymer dosage and/or degree of surface coverage on the clay particle. The behaviour of two types of nonionic polymers are reported; a series of nonylphenol poly(propylene oxide poly(ethylene oxide polymers with varying EO chain length and a series consisting of an ABA block copolymer of poly(propylene oxide-poly(ethylene oxide with varying EO chain length. Adsorption isotherms of dilute clay suspensions showed a higher uptake of the lowest molecular weight polymer (in µmol/m² for each series. The adsorbed amount G increases in the order NPE > PEO > PE. The oscillatory shear and steady state shear stress-shear rate measurements of concentrated clay suspensions (3-6% w/v facilitate the interpretation of the particle-particle interactions. The yield stress, plastic viscosity and elastic modulus showed a maximum at about 50% surface coverage by the NPE polymers, and a subsequent decrease due to stabilisation of the suspension. For the PE polymers these parameters continously decreased as the surface of the clay particle was covered. Scaling of the elastic modulus with increasing clay content allows the determination of the exponent n from a power-law fit G = Kon which qualitatively describes the degree of dispersion for the different polymers. Preliminary results of the effect of temperature and pressure on Bentonite/polymer suspensions are also presented. Dans cette communication, nous démontrons comment les polymères synthétiques de masse moléculaire relativement faible modifient notablement les propriétés rhéologiques de suspensions de bentonite dans l'eau en fonction de polymère et/ou du degré de couverture superficielle de la particule d'argile. Les comportements de deux types de polymères non ioniques sont décrits: une série de polymères

  14. Mass Separation by Metamaterials

    Science.gov (United States)

    Restrepo-Flórez, Juan Manuel; Maldovan, Martin

    2016-02-01

    Being able to manipulate mass flow is critically important in a variety of physical processes in chemical and biomolecular science. For example, separation and catalytic systems, which requires precise control of mass diffusion, are crucial in the manufacturing of chemicals, crystal growth of semiconductors, waste recovery of biological solutes or chemicals, and production of artificial kidneys. Coordinate transformations and metamaterials are powerful methods to achieve precise manipulation of molecular diffusion. Here, we introduce a novel approach to obtain mass separation based on metamaterials that can sort chemical and biomolecular species by cloaking one compound while concentrating the other. A design strategy to realize such metamaterial using homogeneous isotropic materials is proposed. We present a practical case where a mixture of oxygen and nitrogen is manipulated using a metamaterial that cloaks nitrogen and concentrates oxygen. This work lays the foundation for molecular mass separation in biophysical and chemical systems through metamaterial devices.

  15. Assay of labile estrogen o-quinones, potent carcinogenic molecular species, by high performance liquid chromatography-electrospray ionization tandem mass spectrometry with phenazine derivatization.

    Science.gov (United States)

    Yamashita, Kouwa; Masuda, Akina; Hoshino, Yuka; Komatsu, Sachiko; Numazawa, Mitsuteru

    2010-04-01

    A sensitive and selective assay method for labile estrogen o-quinones, estrone (E(1))-2,3-quinone (Q), E(1)-3,4-Q, estradiol (E(2))-2,3-Q and E(2)-3,4-Q, based on the use of phenazine (Phz) derivatization with o-phenylenediamine and high performance liquid chromatography-electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS) was described. The Phz derivatives of four estrogen o-quinones were purified by solid phase extraction and analyzed by HPLC-ESI-MS/MS. The protonated molecule was observed as a base peak for all Phz derivatives in their ESI-mass spectra (positive mode). In multiple reaction monitoring, the transition from [M+H]+ to m/z 231 was chosen for quantification. Calibration curves for the o-quinones were obtained using standard catechol estrogens after sodium metaperiodate treatment and Phz derivatization. Using this method, these four estrogen o-quinones were analyzed with the limit of quantification of 5 ng/ml in acetonitrile (MeCN)-blank matrix (1:4, v/v), respectively, on a basis of the weight of catechol estrogens. Assay accuracy and precision for four estrogen o-quinones were 89.6-113.0% and 3.1-12.6% (5, 125 and 2000 ng/ml in MeCN-blank matrix). Applications of this method enabled to determine the catalytic activities on hydroxylation and subsequent oxidation of E(1) and E(2) of Mushroom tyrosinase and rat liver microsomal fraction. It was confirmed by this method that tyrosinase exhibited 2- and 4-hydroxylation and further oxidation activities for catechols in the ring-A of estrogens. Whereas rat liver microsomal fraction possessed only 2- and 4-hydroxylation activities, and further oxidation activity for catechol estrogens was low. 2010 Elsevier Ltd. All rights reserved.

  16. MUSCLE W49: A multi-scale continuum and line exploration of the most luminous star formation region in the Milky Way. I. Data and the mass structure of the giant molecular cloud

    Energy Technology Data Exchange (ETDEWEB)

    Galván-Madrid, R.; Pineda, J. E.; Peng, T.-C. [European Southern Observatory, Karl-Schwarzschild-Str. 2, D-85748 Garching (Germany); Liu, H. B.; Ho, P. T. P. [Academia Sinica Institute of Astronomy and Astrophysics, P.O. Box 23-141, Taipei 106, Taiwan (China); Zhang, Z.-Y. [Max-Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn (Germany); Zhang, Q.; Keto, E. R. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Rodríguez, L. F.; Zapata, L. [Centro de Radioastronomía y Astrofísica, UNAM, A.P. 3-72 Xangari, Morelia 58089 (Mexico); Peters, T. [Institut für Theoretische Physik, Universität Zürich, Winterthurerstrasse 190, CH-8057 Zürich (Switzerland); De Pree, C. G. [Department of Physics and Astronomy, Agnes Scott College, Decatur, GA 30030 (United States)

    2013-12-20

    The Multi-scale Continuum and Line Exploration of W49 is a comprehensive gas and dust survey of the giant molecular cloud (GMC) of W49A, the most luminous star-formation region in the Milky Way. The project covers, for the first time, the entire GMC at different scales and angular resolutions. In this paper, we present (1) an all-configuration Submillimeter Array mosaic in the 230 GHz (1.3 mm) band covering the central ∼3' × 3' (∼10 pc, known as W49N), where most of the embedded massive stars reside and (2) Purple Mountain Observatory 14 m telescope observations in the 90 GHz band, covering the entire GMC with maps of up to ∼35' × 35' in size, or ∼113 pc. We also make use of archival data from the Very Large Array, JCMT-SCUBA, the IRAM 30 m telescope, and the Caltech Submillimeter Observatory BOLOCAM Galactic Plane Survey. We derive the basic physical parameters of the GMC at all scales. Our main findings are as follows. (1) The W49 GMC is one of the most massive in the Galaxy, with a total mass M {sub gas} ∼ 1.1 × 10{sup 6} M {sub ☉} within a radius of 60 pc. Within a radius of 6 pc, the total gas mass is M {sub gas} ∼ 2 × 10{sup 5} M {sub ☉}. At these scales, only ∼1% of the material is photoionized. The mass reservoir is sufficient to form several young massive clusters (YMCs) as massive as a globular cluster. (2) The mass of the GMC is distributed in a hierarchical network of filaments. At scales <10 pc, a triple, centrally condensed structure peaks toward the ring of HC H II regions in W49N. This structure extends to scales from ∼10 to 100 pc through filaments that radially converge toward W49N and its less-prominent neighbor W49S. The W49A starburst most likely formed from global gravitational contraction with localized collapse in a 'hub-filament' geometry. (3) Currently, feedback from the central YMCs (with a present mass M {sub cl} ≳ 5 × 10{sup 4} M {sub ☉}) is still not enough to entirely disrupt

  17. Emerging and Future Applications of Matrix-Assisted Laser Desorption Ionization Time-of-Flight (MALDI-TOF) Mass Spectrometry in the Clinical Microbiology Laboratory: A Report of the Association for Molecular Pathology.

    Science.gov (United States)

    Doern, Christopher D; Butler-Wu, Susan M

    2016-11-01

    The performance of matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MS) for routine bacterial and yeast identification as well as direct-from-blood culture bottle identification has been thoroughly evaluated in the peer-reviewed literature. Microbiologists are now moving beyond these methods to apply MS to other areas of the diagnostic process. This review discusses the emergence of advanced matrix-assisted laser desorption ionization time-of-flight MS applications, including the identification of filamentous fungi and mycobacteria and the current and future state of antimicrobial resistance testing. Copyright © 2016 American Society for Investigative Pathology and the Association for Molecular Pathology. Published by Elsevier Inc. All rights reserved.

  18. The Mass Attenuation Coefficients, Electronic, Atomic, and Molecular Cross Sections, Effective Atomic Numbers, and Electron Densities for Compounds of Some Biomedically Important Elements at 59.5 keV

    Directory of Open Access Journals (Sweden)

    Burcu Akça

    2014-01-01

    Full Text Available The mass attenuation coefficients for compounds of biomedically important some elements (Na, Mg, Al, Ca, and Fe have been measured by using an extremely narrow collimated-beam transmission method in the energy 59.5 keV. Total electronic, atomic, and molecular cross sections, effective atomic numbers, and electron densities have been obtained by using these results. Gamma-rays of 241Am passed through compounds have been detected by a high-resolution Si(Li detector and by using energy dispersive X-ray fluorescence spectrometer (EDXRF. Obtained results have been compared with theoretically calculated values of WinXCom and FFAST. The relative difference between the experimental and theoretical values are −9.4% to +11.9% with WinXCom and −11.8% to +11.7% FFAST. Results have been presented and discussed in this paper.

  19. A strategy based on gas chromatography-mass spectrometry and virtual molecular docking for analysis and prediction of bioactive composition in natural product essential oil.

    Science.gov (United States)

    Wang, Haiyang; Gu, Dongyu; Wang, Miao; Guo, Hong; Wu, Huijuan; Tian, Guangliang; Li, Qian; Yang, Yi; Tian, Jing

    2017-06-09

    The discovery of leads from medicinal plants is crucial to drug development. The present study presents a strategy based on GC-MS coupled with molecular docking for analysis, identification and prediction of protein tyrosine phosphatase 1B inhibitors in the essential oil from Himalayan Cedar (HC). The essential oil with IC50 value of 120.71±0.26μg/mL exhibited potential activity against protein tyrosine phosphatase 1B (PTP1B) in vitro. After GC-MS analysis, 35 compounds were identified from this oil. The identified compounds were individually docked with PTP1B. Caryophyllene oxide with the lowest binding energy of -6.28kcal/mol was completely wrapped by the active site of PTP1B. The docking results indicated that caryophyllene oxide has potential PTP1B inhibitory activity and may be responsible for the PTP1B inhibitory activity of the essential oil. Caryophyllene oxide in the essential oil of Himalayan Cedar was isolated by HSCCC and the PTP1B inhibitory activity of this compound was then evaluated; the IC50 value was 31.32±0.38μM. The result revealed that the present strategy can effectively discover the active composition from the complex mixture of medicinal plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Molecularly imprinted polymer-sol-gel tablet toward micro-solid phase extraction: II. Determination of amphetamine in human urine samples by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    El-Beqqali, Aziza; Andersson, Lars I; Jeppsson, Amin Dadoun; Abdel-Rehim, Mohamed

    2017-09-15

    Amphetamine selective molecularly imprinted sol-gel polymer tablets, MIP-tablets, for solid-phase microextraction of biofluid samples were prepared. An acetonitrile solution of deuterated amphetamine template and silane precursor, 3-(propylmethacrylate) trimethoxysilane, was soaked into the pores of polyethylene tablet substrates and polymerized by an acid-catalysed sol-gel process. Application of the resultant MIP-tablets to extract amphetamine from human urine samples followed by LC-MS/MS analysis was investigated. The extraction protocol was optimised with respect to pH of sample, addition of sodium chloride, extraction time, desorption solvent and desorption time. The final analysis method determined amphetamine in human urine with a limit of detection (LOD) of 1.0ng/mL and a lower limit of quantification (LLOQ) of 5ng/mL. Validation demonstrated accuracy of the method was 91.0-104.0% and inter-assay precision was 4.8-8.5% (RSD). Extraction recovery was 80%. The MIP-tablets could be re-used and the same tablet could be employed for more than twenty extractions. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Molecular characterisation of a bio-based active packaging containing Origanum vulgare L. essential oil using pyrolysis gas chromatography-mass spectrometry.

    Science.gov (United States)

    Llana-Ruíz-Cabello, María; Pichardo, Silvia; Jiménez-Morillo, Nicasio T; Bermúdez, José M; Aucejo, Susana; González-Vila, Francisco J; Cameán, Ana M; González-Pérez, José A

    2016-07-01

    Environmental, economic and safety challenges motivate shift towards safer materials for food packaging. New bioactive packaging techniques, i.e. addition of essential plant oils (EOs), are gaining attention by creating barriers to protect products from spoilage. Analytical pyrolysis gas chromatography-mass spectrometry (Py-GC-MS) was used to fingerprint a bioactive polylactic acid (PLA) with polybutylene succinate (PBS) (950 g kg(-1) :50 g kg(-1) ) film extruded with variable quantities (0, 20, 50 and 100 g kg(-1) ) of Origanum vulgare EO. Main PLA:PBS pyrolysis products were lactide enantiomers and monomer units from the major PLA fraction and succinic acid anhydride from the PBS fraction. Oregano EO pyrolysis released cymene, terpinene and thymol/carvacrol peaks as diagnostic peaks for EO. In fact, linear correlation coefficients better than 0.950R(2) value (P < 0.001) were found between the chromatographic area of the diagnostic peaks and the amount of oregano EO in the bioplastic. The pyrolytic behaviour of a bio-based active package polymer including EO is studied in detail. Identified diagnostic compounds provide a tool to monitor the quantity of EO incorporated into the PLA:PBS polymeric matrix. Analytical pyrolysis is proposed as a rapid technique for the identification and quantification of additives within bio-based plastic matrices. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  2. Determination of steroidal oestrogens in tap water samples using solid-phase extraction on a molecularly imprinted polymer sorbent and quantification with gas chromatography-mass spectrometry (GC-MS).

    Science.gov (United States)

    Zacs, D; Perkons, I; Bartkevics, V

    2016-07-01

    An analytical method was established and validated for the analysis of steroidal oestrogens in tap water samples. Gas chromatography coupled to high-resolution mass spectrometry (GC-HRMS) and gas chromatography coupled to tandem mass spectrometry (GC-MS/MS) were used for the identification/quantification of selected compounds and the analytical performance of these techniques was evaluated. Liquid-liquid extraction (LLE) and solid-phase extraction (SPE) with a molecularly imprinted polymer (MIP) stationary phase that was highly selective for oestrogens were used for the extraction of 100-mL aliquots of water samples. The recoveries of analytes with the described methods ranged from 92 to 114 %, while the repeatability in terms of relative standard deviations (RSDs) was in the range from 2.1 to 15.2 % (n = 5). It was concluded that SPE with MIP that was highly selective for oestrogens in combination with GC-HRMS detection is more preferable for the analysis of oestrogens in tap water samples. The typical oestrogen, 17β-estradiol (17β-E2), was detected above the method limit of quantification (m-LOQ) in 5 of 14 analysed tap water samples at concentrations from 0.09 to 0.15 ng L(-1). Despite that 17α-ethynylestradiol (17α-EE2) was not quantified in this study above m-LOQ, the presence of this chemical was qualitatively confirmed in some of the analysed samples.

  3. Three-phase molecularly imprinted sol-gel based hollow fiber liquid-phase microextraction combined with liquid chromatography-tandem mass spectrometry for enrichment and selective determination of a tentative lung cancer biomarker.

    Science.gov (United States)

    Moein, Mohammad Mahdi; Javanbakht, Mehran; Karimi, Mohammad; Akbari-Adergani, Behrouz; Abdel-Rehim, Mohamed

    2015-07-15

    In the present study, the modification of a polysulfone hollow fiber membrane with in situ molecularly imprinted sol-gel process (as a novel and one-step method) was prepared and investigated. 3-(propylmethacrylate)trimethoxysilane (3PMTMOS) as an inorganic precursor was used for preparation of molecularly imprinted sol-gel. The modified molecularly imprinted sol-gel hollow fiber membrane (MSHM) was used for the liquid-phase microextraction (LPME) of hippuric acid (HA) in human plasma and urine samples. MSHM as a selective, robust, and durable tool was used for at least 50 extractions without significant decrease in the extraction efficiency. The non-molecularly imprinted sol-gel hollow fiber membrane (NSHM) as blank hollow fiber membrane was prepared by the same process, only without HA. To achieve the best condition, influential parameters on the extraction efficiency were thoroughly investigated. The capability of this robust, green, and simple method for extraction of HA was successfully accomplished with LC/MS/MS. The limits of detection (LOD) and quantification (LOQ) in human plasma and urine samples were 0.3 and 1.0nmolL(-1), respectively. The standard calibration curves were obtained within the concentration range 1-2000nmolL(-1) for HA in human plasma and urine. The coefficients of determination (r(2)) were ≥0.998. The obtained data exhibited recoveries were higher than 89% for the extraction of HA in human plasma and urine samples. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. Interrogating the molecular details of the peroxiredoxin activity of the Escherichia coli bacterioferritin comigratory protein using high-resolution mass spectrometry.

    Science.gov (United States)

    Clarke, David J; Mackay, C Logan; Campopiano, Dominic J; Langridge-Smith, Pat; Brown, Alan R

    2009-05-12

    Bacterioferritin comigratory protein (BCP) is a bacterial thioredoxin-dependent thiol peroxidase that reduces a variety of peroxide substrates. Using high-resolution Fourier transform ion cyclotron resonance mass spectrometry coupled with top-down fragmentation techniques, we have analyzed the mechanistic details of hydrogen peroxide reduction by E. coli BCP. We show here that catalysis occurs via an atypical two-cysteine peroxiredoxin pathway. A transient sulfenic acid is initially formed on Cys-45, before resolution by the formation of an intramolecular disulfide bond between Cys-45 and Cys-50. This oxidized BCP intermediate is shown to be a substrate for reduction by thioredoxin, completing the catalytic cycle. Although we invoke Cys-50 in the catalytic cycle of Escherichia coli bacterioferritin comigratory protein (BCP), a previous study had shown that this residue was not absolutely required for peroxiredoxin activity. In order to explain these apparently conflicting phenomena, we analyzed the reaction of a C50S BCP mutant with peroxide. We show that this mutant BCP enzyme adopts a different and novel mechanistic pathway. The C50S BCP mutant reacts with peroxide to form a sulfenic acid on Cys-45, in the same manner as wild-type BCP. However, the nascent intermediate is then resolved by reaction with Cys-45 from a second BCP molecule, resulting in a dimeric intermediate containing an intermolecular disulfide bond. We further show that this novel resolving complex is a substrate for reduction by thioredoxin. The importance of our results in furthering the understanding of catalysis within BCP family is discussed.

  5. Assessment of the Molecular Expression and Structure of Gangliosides in Brain Metastasis of Lung Adenocarcinoma by an Advanced Approach Based on Fully Automated Chip-Nanoelectrospray Mass Spectrometry

    Science.gov (United States)

    Zamfir, Alina D.; Serb, Alina; Vukeli, Željka; Flangea, Corina; Schiopu, Catalin; Fabris, Dragana; Kalanj-Bognar, Svjetlana; Capitan, Florina; Sisu, Eugen

    2011-12-01

    Gangliosides (GGs), sialic acid-containing glycosphingolipids, are known to be involved in the invasive/metastatic behavior of brain tumor cells. Development of modern methods for determination of the variations in GG expression and structure during neoplastic cell transformation is a priority in the field of biomedical analysis. In this context, we report here on the first optimization and application of chip-based nanoelectrospray (NanoMate robot) mass spectrometry (MS) for the investigation of gangliosides in a secondary brain tumor. In our work a native GG mixture extracted and purified from brain metastasis of lung adenocarcinoma was screened by NanoMate robot coupled to a quadrupole time-of-flight MS. A native GG mixture from an age-matched healthy brain tissue, sampled and analyzed under identical conditions, served as a control. Comparative MS analysis demonstrated an evident dissimilarity in GG expression in the two tissue types. Brain metastasis is characterized by many species having a reduced N-acetylneuraminic acid (Neu5Ac) content, however, modified by fucosylation or O-acetylation such as Fuc-GM4, Fuc-GM3, di- O-Ac-GM1, O-Ac-GM3. In contrast, healthy brain tissue is dominated by longer structures exhibiting from mono- to hexasialylated sugar chains. Also, significant differences in ceramide composition were discovered. By tandem MS using collision-induced dissociation at low energies, brain metastasis-associated GD3 (d18:1/18:0) species as well as an uncommon Fuc-GM1 (d18:1/18:0) detected in the normal brain tissue could be structurally characterized. The novel protocol was able to provide a reliable compositional and structural characterization with high analysis pace and at a sensitivity situated in the fmol range.

  6. Molecular-mass heterogeneity of Griffonia simplicifolia lectin IV subunits. Differences in the oligosaccharide moieties in the N-terminal region.

    Science.gov (United States)

    Nikrad, P V; Pearlstone, J R; Carpenter, M R; Lemieux, R U; Smillie, L B

    1990-12-01

    Lectin IV of Griffonia simplicifolia (Mr approximately 56,000), which has a strong affinity for both the Lewis b and Y blood-group determinants, is a dimeric protein of two subunits, alpha (29 kDa) and beta (27 kDa), separable by SDS/PAGE and containing covalently linked oligosaccharide. After digestion with N-glycanase, the protein migrates as a single band with a mobility identical with that of the beta-subunit. After cleavage with hydroxylamine of 3H-labelled, but otherwise intact, lectin, the radioactively labelled oligosaccharide was found to be associated with two blocked N-terminal peptides separable by h.p.l.c. and having identical amino acid compositions. One of these had three or four glucosamine residues per molecule, whereas the other had only one or two. Sequence analyses of these, as well as of a 21 kDa hydroxylamine-cleaved fragment and of the intact lectin pretreated with pyroglutamate aminopeptidase, have provided a unique sequence for residues 1-62 of the two subunits. Evidence is presented for two sites of N-linked oligosaccharide attachment at Asn-5 and Asn-18. Whereas the alpha-subunit has oligosaccharide linked to both sites, the beta-subunit has carbohydrate associated with only one (Asn-18). Sugar analyses of the whole lectin reveal a monosaccharide composition of (Xyl)3(Fuc)2(Man)10(GlcNAc)6, representing 6.4% of the mass of the molecule. Taken together with the susceptibility of the Asn-5 linkage (but not of Asn-18) to N-glycanase digestion, the observations indicate that the structures of the oligosaccharides at residues 5 and 18 are different.

  7. Molecular mass spectrometry in metallodrug development: A case of mapping transferrin-mediated transformations for a ruthenium(III) anticancer drug

    Energy Technology Data Exchange (ETDEWEB)

    Jarosz, Maciej [Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego St. 3, 00-664 Warsaw (Poland); Matczuk, Magdalena, E-mail: mmatczuk@ch.pw.edu.pl [Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego St. 3, 00-664 Warsaw (Poland); Pawlak, Katarzyna [Chair of Analytical Chemistry, Faculty of Chemistry, Warsaw University of Technology, Noakowskiego St. 3, 00-664 Warsaw (Poland); Timerbaev, Andrei R. [Vernadsky Institute of Geochemistry and Analytical Chemistry, Russian Academy of Sciences, Kosygin St. 19, 119991 Moscow (Russian Federation)

    2014-12-03

    Highlights: • Extra- and intra-cellular interactions of Ru(III) anticancer drug candidate. • ESI-TOF-MS mapping of the ruthenium species bound to transferring. • ESI-QqQ-MS identification of released Ru species under cytosol simulated conditions. - Abstract: Electrospray ionization mass spectrometry (ESI-MS) techniques have been used to characterize the speciation of a Ru(III) anticancer drug, indazolium trans-[tetrachloridobis(1H-indazole) ruthenate(III)], upon its binding to transferrin and the impact of cellular reducing components on drug–transferrin adducts. Using time-of-flight ESI-MS, the polymorphism of apo- (iron-free) and holo-form (iron-saturated) of the protein was confirmed. While the ruthenium moieties bound to each of five isoforms under simulated extracellular conditions are essentially identical in numbers for apo- and holo-transferrin, distinct differences were found in the composition of Ru(III) species attached to either of the protein forms, which are dominated by differently coordinated aquated complexes. On the other hand, at least one of the Ru-N bonds in metal-organic framework remains intact even after prolonged interaction with the protein. Triple quadrupole tandem ESI-MS measurements demonstrated that the ruthenium species released from drug adducts with holo-transferrin in simulated cancer cytosol are underwent strong ligand exchange (as compared to the protein-bound forms) but most strikingly, they contain the metal center in the reduced Ru(II) state. In vitro probing the extra- and intracellular interactions of promising Ru(III) drug candidate performed by ESI-MS is thought to shed light on the transportation to tumor cells by transferrin and on the activation to more reactive species by the reducing environment of solid tumors.

  8. TANGO I: Interstellar medium in nearby radio galaxies. Molecular gas

    Science.gov (United States)

    Ocaña Flaquer, B.; Leon, S.; Combes, F.; Lim, J.

    2010-07-01

    Context. Powerful radio-AGN are hosted by massive elliptical galaxies that are usually very poor in molecular gas. Nevertheless, gas is needed at their very center to feed the nuclear activity. Aims: We study the molecular gas properties (i.e., mass, kinematics, distribution, origin) of these objects, and compare them with results for other known samples. Methods: At the IRAM-30m telescope, we performed a survey of the CO(1-0) and CO(2-1) emission from the most powerful radio galaxies of the Local Universe, selected only on the basis of their radio continuum fluxes. Results: The main result of our survey is that the molecular gas content of these galaxies is very low compared to spiral or FIR-selected galaxies. The median value of the molecular gas mass, including detections and upper limits, is 2.2 × 108 M⊙. When separated into FR-I and FR-II types, a difference in their H2 masses is found. The median value of FR-I galaxies is about 1.9 × 108 M⊙ and higher for FR-II galaxies, at about 4.5 × 108 M⊙. Which is probably entirely because of a Malmquist bias. Our results contrast with those of previous surveys, whose targets were mainly selected by means of their FIR emission, implying that we measure higher observed masses of molecular gas. Moreover, the shape of CO spectra suggest that a central molecular gas disk exists in 30% of these radio galaxies, a lower rate than in other active galaxy samples. Conclusions: We find a low level of molecular gas in our sample of radio-selected AGNs, indicating that galaxies do not need much molecular gas to host an AGN. The presence of a molecular gas disk in some galaxies and the wide range of molecular gas masses may be indicative of different origins for the gas, which we can not exclude at present (e.g., minor/major mergers, stellar mass loss, or accretion). Appendices and Figure 15 are only available in electronic form at http://www.aanda.org

  9. Higher Education and European Regionalism.

    Science.gov (United States)

    Paterson, Lindsay

    2001-01-01

    Speculates about the relationship between two fundamental social changes occurring in Europe: the development of a mass higher education system and the slow decay of the old states that were inherited from the 19th century, eroded from below by various movements for national and regional autonomy, and eroded from above by the growing power and…

  10. Recent improvements of ISOLTRAP Absolute mass measurements of exotic nuclides at $10^{-8}$ precision

    CERN Document Server

    Kellerbauer, A G

    2003-01-01

    In the past three years, the sensitivity and the performance of the Penning trap mass spectrometer ISOLTRAP have been enhanced significantly. These improvements, which range from technical developments to systematic studies of the various factors contributing to the uncertainty of the final mass result, now allow mass measurements of short-lived radionuclides with half-lives of less than 100 ms and with a precision of better than 10$^{-8}$. Using a newly developed carbon cluster ion source, ISOLTRAP can perform absolute mass measurements relative to the microscopic mass standard $^{12}$C. These developments are reviewed as pertaining to the extension of ISOLTRAP mass measurements to higher precision and shorter half-lives and to molecular mass measurements.

  11. HERSCHEL KEY PROGRAM, ''DUST, ICE, AND GAS IN TIME'' (DIGIT): THE ORIGIN OF MOLECULAR AND ATOMIC EMISSION IN LOW-MASS PROTOSTARS IN TAURUS

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jeong-Eun; Lee, Seokho [Department of Astronomy and Space Science, Kyung Hee University, Yongin-shi, Kyungki-do 449-701 (Korea, Republic of); Lee, Jinhee [Department of Physics and Astronomy, The University of Georgia, Athens, GA 30602-2451 (United States); Evans II, Neal J.; Green, Joel D., E-mail: jeongeun.lee@khu.ac.kr [Department of Astronomy, University of Texas at Austin, 2515 Speedway, Stop C1400, Austin, TX 78712-1205 (United States)

    2014-10-01

    Six low-mass embedded sources (L1489, L1551-IRS5, TMR1, TMC1-A, L1527, and TMC1) in Taurus have been observed with Herschel-PACS to cover the full spectrum from 50 to 210 μm as part of the Herschel key program, ''Dust, Ice, and Gas In Time''. The relatively low intensity of the interstellar radiation field surrounding Taurus minimizes contamination of the [C II] emission associated with the sources by diffuse emission from the cloud surface, allowing study of the [C II] emission from the source. In several sources, the [C II] emission is distributed along the outflow, as is the [O I] emission. The atomic line luminosities correlate well with each other, as do the molecular lines, but the atomic and molecular lines correlate poorly. The relative contribution of CO to the total gas cooling is constant at ∼30%, while the cooling fraction by H{sub 2}O varies from source to source, suggesting different shock properties resulting in different photodissociation levels of H{sub 2}O. The gas with a power-law temperature distribution with a moderately high density can reproduce the observed CO fluxes, indicative of CO close to LTE. However, H{sub 2}O is mostly subthermally excited. L1551-IRS5 is the most luminous source (Ł{sub bol} = 24.5 L {sub ☉}) and the [O I] 63.1 μm line accounts for more than 70% of its FIR line luminosity, suggesting complete photodissociation of H{sub 2}O by a J shock. In L1551-IRS5, the central velocity shifts of the [O I] line, which exceed the wavelength calibration uncertainty (∼70 km s{sup –1}) of PACS, are consistent with the known redshifted and blueshifted outflow direction.

  12. Isobar Separation in a Multiple-Reflection Time-of-Flight Mass Spectrometer by Mass-Selective Re-Trapping.

    Science.gov (United States)

    Dickel, Timo; Plaß, Wolfgang R; Lippert, Wayne; Lang, Johannes; Yavor, Mikhail I; Geissel, Hans; Scheidenberger, Christoph

    2017-06-01

    A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. Graphical Abstract ᅟ.

  13. MOLECULAR PROPERTIES OF SELECTED POLYSACCHARIDES DETERMINED BY SEC CHROMATOGRAPHY AND THEIR IMPACT ON WATER ABSORPTION OF WHEAT FLOUR

    Directory of Open Access Journals (Sweden)

    Krzysztof Buksa

    2012-02-01

    Full Text Available Chemical composition and solubility in water of selected polysaccharides as β-glucan, arabinoxylan and inulin preparation were determined. All these preparation were of good purity, they consist of at least 71% of polysaccharide of intrest. Solubility in water was the highest in the case of inulin and the lowest in the case of β-glucan. Molecular properties of examined preparations were determined by SEC chromatography. β-glucan and arabinoxylan were of much higher molecular mass than inulin. Molecular mass of examined polysacharides was corelated with increase of water absorption of the flour caused by 2% addition of each polysaccharide.doi:10.5219/173   

  14. Webometrics Ranking in the Context of Accessibility of Higher Education

    Science.gov (United States)

    Bershadskaya, Margarita; Voznesenskaya, Yulia; Karpenko, Olga

    2016-01-01

    The purpose of this study is a comparative assessment of the development of mass higher education in the regions and countries on the basis of the results of Webometrics. Main tasks: Comparison of national educational systems in terms of the scale of mass higher education; assessment of the quality of mass higher education; study of the growth of…

  15. Nominal Mass?

    Science.gov (United States)

    Attygalle, Athula B.; Pavlov, Julius

    2017-08-01

    The current IUPAC-recommended definition of the term "nominal mass," based on the most abundant naturally occurring stable isotope of an element, is flawed. We propose that Nominal mass should be defined as the sum of integer masses of protons and neutrons in any chemical species. In this way, all isotopes and isotopologues can be assigned a definitive identifier.

  16. Mulheres com síndrome dos ovários policísticos apresentam maior frequência de síndrome metabólica independentemente do índice de massa corpóreo Women with polycystric ovary syndrome have a higher frequency of metabolic syndrome regardless of body mass index

    Directory of Open Access Journals (Sweden)

    Anderson Sanches Melo

    2012-01-01

    Full Text Available OBJETIVO: Avaliar a prevalência de síndrome metabólica e dos seus critérios definidores em mulheres com síndrome dos ovários policísticos do Sudeste brasileiro, estratificadas de acordo com o índice de massa corpóreo e comparadas com controles ovulatórias. MÉTODOS: Estudo transversal, realizado com 332 mulheres em idade reprodutiva, que foram divididas em dois grupo: Controle, constituído por 186 mulheres com ciclos menstruais regulares, sintomas ovulatórios e sem diagnóstico de síndrome dos ovários policísticos ou outra anovulação crônica; e Síndrome dos ovários policísticos, composto por 146 mulheres com o diagnóstico de síndrome dos ovários policísticos - Consenso de Rotterdam ASRM/ESHRE. Cada um destes grupos foi estratificado de acordo com o índice de massa corpóreo (PURPOSE: To assess the prevalence of metabolic syndrome and of its defining criteria in women with polycystic ovary syndrome from the Brazilian Southeast, who were stratified according to body mass index and compared to ovulatory controls. METHODS: This was a cross-sectional study conducted on 332 women of reproductive age, who were divided into two groups: Control, consisting of 186 women with regular menstrual cycles and ovulatory symptoms and without a diagnosis of polycystic ovary syndrome or other type of chronic anovulation, and the Polycystic ovary syndrome,Group, consisting of 146 women with a diagnosis of polycystic ovary syndrome (Rotterdam Consensus ASRM/ESHRE. Each group was stratified according to the body mass index, as follows: body mass index ( < 25 ≥25 and <30, and ≥ 30 kg/m². The frequencies of metabolic syndrome and of its defining criteria and the clinical and hormonal characteristics (follicle stimulating hormone, total testosterone, dehydroepiandrostenedione sulfate were analyzed. RESULTS: The frequency of metabolic syndrome was six times higher in the obese Polycystic ovary syndrome Group than among control women with the

  17. The Novel Functions of High-Molecular-Mass Complexes Containing Insulin Receptor Substrates in Mediation and Modulation of Insulin-Like Activities: Emerging Concept of Diverse Functions by IRS-Associated Proteins.

    Science.gov (United States)

    Hakuno, Fumihiko; Fukushima, Toshiaki; Yoneyama, Yosuke; Kamei, Hiroyasu; Ozoe, Atsufumi; Yoshihara, Hidehito; Yamanaka, Daisuke; Shibano, Takashi; Sone-Yonezawa, Meri; Yu, Bu-Chin; Chida, Kazuhiro; Takahashi, Shin-Ichiro

    2015-01-01

    Insulin-like peptides, such as insulin-like growth factors (IGFs) and insulin, induce a variety of bioactivities, such as growth, differentiation, survival, increased anabolism, and decreased catabolism in many cell types and in vivo. In general, IGFs or insulin bind to IGF-I receptor (IGF-IR) or insulin receptor (IR), activating the receptor tyrosine kinase. Insulin receptor substrates (IRSs) are known to be major substrates of receptor kinases, mediating IGF/insulin signals to direct bioactivities. Recently, we discovered that IRSs form high-molecular-mass complexes (referred to here as IRSomes) even without IGF/insulin stimulation. These complexes contain proteins (referred to here as IRSAPs; IRS-associated proteins), which modulate tyrosine phosphorylation of IRSs by receptor kinases, control IRS stability, and determine intracellular localization of IRSs. In addition, in these complexes, we found not only proteins that are involved in RNA metabolism but also RNAs themselves. Thus, IRSAPs possibly contribute to modulation of IGF/insulin bioactivities. Since it is established that disorder of modulation of insulin-like activities causes various age-related diseases including cancer, we could propose that the IRSome is an important target for treatment of these diseases.

  18. The circulating concentration and ratio of total and high molecular weight adiponectin in post-menopausal women with and without osteoporosis and its association with body mass index and biochemical markers of bone metabolism.

    Science.gov (United States)

    Sodi, R; Hazell, M J; Durham, B H; Rees, C; Ranganath, L R; Fraser, W D

    2009-09-01

    There is increasing evidence suggesting that adiponectin plays a role in the regulation of bone metabolism. This was a cross-sectional study of 34 post-menopausal women with and 37 without osteoporosis. All subjects had body mass index (BMI), bone mineral density (BMD), total-, high molecular weight (HMW)-adiponectin and their ratio, osteoprotegerin (OPG), a marker of bone resorption (betaCTX) and formation (P1NP) measured. We observed a positive correlation between BMI and BMD (r=0.44, p<0.001). When normalised for BMI, total-, HMW-adiponectin concentrations and HMW/total-adiponectin ratio were significantly lower in obese compared to lean subjects but there was no difference between those with or without osteoporosis. There were significant negative correlations between HMW/total-adiponectin ratio and BMI (r=-0.27, p=0.030) and with OPG (r=-0.44, p<0.001). Our data suggests that there is no significant difference in the circulating concentration of fasting early morning total- or HMW-adiponectin in post-menopausal women with or without osteoporosis. The correlation between HMW/total-adiponectin ratio and OPG may indicate that adiponectin could influence bone metabolism by altering osteoblast production of OPG thereby affecting osteoclasts mediated bone resorption.

  19. A comparison of laser ablation-inductively coupled plasma-mass spectrometry and high-resolution continuum source graphite furnace molecular absorption spectrometry for the direct determination of bromine in polymers

    Science.gov (United States)

    de Gois, Jefferson S.; Van Malderen, Stijn J. M.; Cadorim, Heloisa R.; Welz, Bernhard; Vanhaecke, Frank

    2017-06-01

    This work describes the development and comparison of two methods for the direct determination of Br in polymer samples via solid sampling, one using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) and the other using high-resolution continuum source graphite furnace molecular absorption spectrometry with direct solid sample analysis (HR-CS SS-GF MAS). The methods were optimized and their accuracy was evaluated by comparing the results obtained for 6 polymeric certified reference materials (CRMs) with the corresponding certified values. For Br determination with LA-ICP-MS, the 79Br+ signal could be monitored interference-free. For Br determination via HR-CS SS-GF MAS, the CaBr molecule was monitored at 625.315 nm with integration of the central pixel ± 1. Bromine quantification by LA-ICP-MS was performed via external calibration against a single CRM while using the 12C+ signal as an internal standard. With HR-CS SS-GF MAS, Br quantification could be accomplished using external calibration against aqueous standard solutions. Except for one LA-ICP-MS result, the concentrations obtained with both techniques were in agreement with the certified values within the experimental uncertainty as evidenced using a t-test (95% confidence level). The limit of quantification was determined to be 100 μg g- 1 Br for LA-ICP-MS and 10 μg g- 1 Br for HR-CS SS-GF MAS.

  20. Comparison of microbial communities in Lake Tahoe surface sample with Tonga Trench water column samples using High Pressure Liquid Chromatography - Electrospray Ionization - Mass Spectroscopy (HPLC - ESI - MS) and Global Natural Products Social Molecular Network (GNPS)

    Science.gov (United States)

    Belmonte, M. A.

    2015-12-01

    Intact polar lipids (IPLs) are lipids composed of a head group, a glycerol, and a fatty acid chain that make up the lipid bilayer of cell membranes in living cells; and the varying head groups can be indicative of the type of microbes present in the environment (Van Mooy 2010). So by distinguishing and identifying the IPL distribution in an environment one can make inferences about the microbial communities in the said environment. In this study, we used High Pressure Liquid Chromatography-Electrospray Ionization- Mass Spectroscopy (HPLC-ESI-MS) and Global Natural Products Social Molecular Networking (GNPS) to compare the IPL distributions of two oligotrophic environments: surface waters of Lake Tahoe in the Sierra Nevada Mountains, and the water column of the Tonga Trench in the South Pacific. We hypothesized that the similar nutrient dynamics of the two oligotrophic environments would result in similar eukaryotic and prokaryotic communities, which would be reflected in the IPL composition of suspended particulate organic matter (POM). For simplicity we focused on the classes of IPLs most commonly observed in the marine environment: phosphotidylglycerol (PG), phosphotidylethanolamine (PE), diacylglyceryl-trimethyl-homoserine (DGTS), diacylglyceryl-hydroxymethyl-trimethylalanine (DGTA), sulfoquinovosyldiacylglycerol (SQDG), monoglycosyldiacylglycerol (MGDG) and diglycosyldiacylglycerol (DGDG). Our results showed that all of the marine IPLs of interest were present in Lake Tahoe which confirms that there are many of the same microbial communities in the fresh waters of Lake Tahoe and the salt waters Tonga Trench.

  1. The novel functions of high-molecular-mass complexes containing insulin receptor substrates in mediation and modulation of insulin-like activities: Emerging concept of diverse function by IRS-associated proteins

    Directory of Open Access Journals (Sweden)

    Fumihiko eHakuno

    2015-05-01

    Full Text Available Insulin-like peptides, such as insulin and insulin-like growth factors (IGFs, induce a variety of bioactivities, such as growth, differentiation, survival, increased anabolism and decreased catabolism in many cell types and in vivo. In general, insulin or IGFs bind to insulin receptor (IR or IGF-I receptor (IGF-IR, activating the receptor tyrosine kinase. Insulin receptor substrates (IRSs are known to be major substrates of receptor kinases, mediating IGF/insulin signals to direct bioactivities. Recently, we discovered that IRSs form high-molecular-mass complexes (referred to here as IRSomes even without IGF/insulin stimulation. These complexes contain proteins (referred to here as IRSAP; IRS-associated protein, which modulate tyrosine phosphorylation of IRSs by receptor kinases, control IRS stability and determine intracellular localization of IRSs. In addition, in these complexes we found not only proteins that are involved in RNA metabolism but also RNAs themselves. Thus IRSAPs possibly contribute to modulation of IGF/insulin bioactivities. Since it is established that disorder of modulation of insulin-like activities causes various age-related diseases including cancer we could propose that the IRSome is an important target for treatment of these diseases.

  2. Geometry of mass.

    Science.gov (United States)

    Dietrich, D D

    2015-08-06

    We study the effect of mass on geometric descriptions of gauge field theories. In an approach in which the massless theory resembles general relativity, the introduction of the mass entails non-zero torsion and the generalization to Einstein-Cartan-Sciama-Kibble theories. The relationships to pure torsion formulations (teleparallel gravity) and to higher gauge theories are also discussed. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

  3. Molecularly imprinted polymer coupled with dispersive liquid-liquid microextraction and injector port silylation: a novel approach for the determination of 3-phenoxybenzoic acid in complex biological samples using gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Mudiam, Mohana Krishna Reddy; Chauhan, Abhishek; Jain, Rajeev; Dhuriya, Yogesh Kumar; Saxena, Prem Narain; Khanna, Vinay Kumar

    2014-01-15

    A novel analytical approach based on molecularly imprinted solid phase extraction (MISPE) coupled with dispersive liquid-liquid microextraction (DLLME), and injector port silylation (IPS) has been developed for the selective preconcentration, derivatization and analysis of 3-phenoxybenzoic acid (3-PBA) using gas chromatography-tandem mass spectrometry (GC-MS/MS) in complex biological samples such as rat blood and liver. Factors affecting the synthesis of MIP were evaluated and the best monomer and cross-linker were selected based on binding affinity studies. Various parameters of MISPE, DLLME and IPS were optimized for the selective preconcentration and derivatization of 3-PBA. The developed method offers a good linearity over the calibration range of 0.02-2.5ngmg(-1) and 7.5-2000ngmL(-1) for liver and blood respectively. Under optimized conditions, the recovery of 3-PBA in liver and blood samples were found to be in the range of 83-91%. The detection limit was found to be 0.0045ngmg(-1) and 1.82ngmL(-1) in liver and blood respectively. SRM transition of 271→227 and 271→197 has been selected as quantifier and qualifier transition for 3-PBA derivative. Intra and inter-day precision for five replicates in a day and for five, successive days was found to be less than 8%. The method developed was successfully applied to real samples, i.e. rat blood and tissue for quantitative evaluation of 3-PBA. The analytical approach developed is rapid, economic, simple, eco-friendly and possess immense utility for the analysis of analytes with polar functional groups in complex biological samples by GC-MS/MS. Copyright © 2013 Elsevier B.V. All rights reserved.

  4. Superbasic alkyl-substituted bisphosphazene proton sponges: a new class of deprotonating matrices for negative ion matrix-assisted ionization/laser desorption mass spectrometry of low molecular weight hardly ionizable analytes.

    Science.gov (United States)

    Calvano, C D; Cataldi, T R I; Kögel, J F; Monopoli, A; Palmisano, F; Sundermeyer, J

    2016-07-30

    Here hardly ionizable and low molecular weight compounds are detected in negative ion mode by using novel superbasic proton sponges based on 1,8-bisphosphazenylnaphthalene (PN) as MALDI matrices. Among the selected proton sponges, 1,8-bis(trispyrrolidinophosphazenyl)naphthalene (TPPN) has shown the best behaviour as matrix since it allows the direct detection of intact cholesterol without derivatization also in real challenging samples. Very weakly acidic compounds such as sterols, steroids, fatty alcohols and saccharides were detected in reflectron negative ion mode by a MALDI TOF/TOF system equipped with a neodymium-doped yttrium lithium fluoride (Nd:YLF) laser (345 nm) with typical mass accuracy of 10 ppm. MS/MS experiments were performed by using ambient air as the collision gas. Contrary to traditional MALDI matrices, superbasic proton sponges allowed the easy deprotonation of an alcohol functional group without a previous chemical derivatization step. Experimental evidence indicates that analyte deprotonation is achieved in the condensed phase, i.e. PN superbasic proton sponges operate according to a recently proposed model named matrix assisted ionization/laser desorption (MAILD). A detection limit of 3 pmol/spot of cholesterol (model compound) with a signal-to-noise ratio ≥ 10 was typically obtained. For the first time, the usefulness of novel superbasic proton sponges is demonstrated for MALDI detection of hardly ionizable compounds such as sterols, steroids, fatty alcohols and saccharides. The leading candidate TPPN has been successfully applied for negative ion MAILD-MS analysis of cholesterol, fatty acids and phospholipids in egg yolk and brain tissue extracts. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  5. Neutrino masses

    CERN Document Server

    Gelmini, Graciela B; Gelmini, Graciela; Roulet, Esteban

    1995-01-01

    This is a review for Reports of Progress in Physics. After an introduction we start by explaining the different neutrino masses corresponding to different types of neutrinos, Dirac or Majorana, in section 2. In section 3 we discuss the main elementary particle models for neutrino masses and their distinctive phenomenological consequences. In section 4 we describe the status of direct mass searches and Majorana mass searches in neutrinoless double beta decays. In section 5 we go over the many cosmological implications of, and constraints on, neutrino properties, mainly masses and lifetimes. Sections 6, 7 and 8 review neutrino oscillations, the solar neutrino problem and the atmospheric neutrino problem, their implications and the current and future experiments. In particular, we explain oscillations in vacuum in section 6 and oscillations in matter in section 7. Section 9 summarizes the main bounds imposed by stars, mainly SN1987A. A few concluding remarks follow.

  6. Mass Society

    DEFF Research Database (Denmark)

    Borch, Christian

    2017-01-01

    the negative features usually ascribed by late nineteenth-century crowd psychology to spontaneous crowds, and attributes these to the entire social fabric. However, in contrast to crowd psychology, theorists of mass society often place greater emphasis on how capitalism, technological advances, or demographic......Mass society is a societal diagnosis that emphasizes – usually in a pejorative, modernity critical manner – a series of traits allegedly associated with modern society, such as the leveling of individuality, moral decay, alienation, and isolation. As such, the notion of mass society generalizes...... developments condition such negative features, and some theorists argue that mass society produces a propensity to totalitarianism. Discussions of mass society culminated in the early and mid-twentieth century....

  7. Fast atom bombardment mass spectral analysis of three new oxidative products of primaquine

    Science.gov (United States)

    Sinha, Sukesh N.; Dua, V. K.

    2004-03-01

    FAB mass spectrum of 5,5-di-[6-methoxy-8-(4'-amino-1'butyl amino)] quinoline (PI) was recorded in three different concentrations to establish the structure of new oxidative products of primaquine and also the effect of matrix on percentage relative abundance of molecular as well as fragment ions which were demonstrated first time. At three concentrations, three different behaviors of matrix, molecular and fragment ions were observed. At higher concentration (>1 nM) molecular ion behaved as a base peak, but due to side reaction with matrix certain extra peak were also obtained. Thus, the higher concentration was interesting to show the side reaction of analyte with m-nitro-benzyl alcohol (NBA) but not for molecular weight determination. At the lowest concentratio