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Sample records for biological activities electronic

  1. Correlation between biological activity and electron transferring of bovine liver catalase: Osmolytes effects

    International Nuclear Information System (INIS)

    Tehrani, H. Sepasi; Moosavi-Movahedi, A.A.; Ghourchian, H.

    2013-01-01

    Highlights: • Proline increases ET in Bovine Liver Catalase (BLC) whereas histidine decreases it. • Proline also increased the biological activity, whereas histidine decreased it. • Electron transferring and biological activity for BLC are directly correlated. • Proline causes favorable ET for BLC shown by positive E 1/2 (E°′) and negative ΔG. • Histidine makes ET unfavorable for BLC, manifested by E 1/2 (E°′) 0. -- Abstract: Catalase is a crucial antioxidant enzyme that protects life against detrimental effects of H 2 O 2 by disproportionating it into water and molecular oxygen. Effect of proline as a compatible and histidine as a non compatible osmolyte on the electron transferring and midpoint potential of catalase has been investigated. Proline increases the midpoint potential (ΔE m > 0), therefore causing the ΔG ET to be less positive and making the electron transfer reaction more facile whereas histidine decreases the E m (ΔE m ET , thereby rendering the electron transfer reaction less efficient. These results indicate the inhibitory effect of histidine evident by a −37% decrease in the cathodic peak current compared to 16% increase in the case of proline indicative of activation. The insight paves the tedious way towards our ultimate goal of elucidating a correlation between biological activity and electron transferring

  2. Wireless Biological Electronic Sensors.

    Science.gov (United States)

    Cui, Yue

    2017-10-09

    The development of wireless biological electronic sensors could open up significant advances for both fundamental studies and practical applications in a variety of areas, including medical diagnosis, environmental monitoring, and defense applications. One of the major challenges in the development of wireless bioelectronic sensors is the successful integration of biosensing units and wireless signal transducers. In recent years, there are a few types of wireless communication systems that have been integrated with biosensing systems to construct wireless bioelectronic sensors. To successfully construct wireless biological electronic sensors, there are several interesting questions: What types of biosensing transducers can be used in wireless bioelectronic sensors? What types of wireless systems can be integrated with biosensing transducers to construct wireless bioelectronic sensors? How are the electrical sensing signals generated and transmitted? This review will highlight the early attempts to address these questions in the development of wireless biological electronic sensors.

  3. Approaching an experimental electron density model of the biologically active trans -epoxysuccinyl amide group-Substituent effects vs. crystal packing

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Ming W.; Stewart, Scott G.; Sobolev, Alexandre N.; Dittrich, Birger; Schirmeister, Tanja; Luger, Peter; Hesse, Malte; Chen, Yu-Sheng; Spackman, Peter R.; Spackman, Mark A.; Grabowsky, Simon (Heinrich-Heine); (Freie); (UC); (Bremen); (JG-UM); (UWA)

    2017-01-24

    The trans-epoxysuccinyl amide group as a biologically active moiety in cysteine protease inhibitors such as loxistatin acid E64c has been used as a benchmark system for theoretical studies of environmental effects on the electron density of small active ingredients in relation to their biological activity. Here, the synthesis and the electronic properties of the smallest possible active site model compound are reported to close the gap between the unknown experimental electron density of trans-epoxysuccinyl amides and the well-known function of related drugs. Intramolecular substituent effects are separated from intermolecular crystal packing effects on the electron density, which allows us to predict the conditions under which an experimental electron density investigation on trans-epoxysuccinyl amides will be possible. In this context, the special importance of the carboxylic acid function in the model compound for both crystal packing and biological activity is revealed through the novel tool of model energy analysis.

  4. Electron holography of biological samples.

    Science.gov (United States)

    Simon, P; Lichte, H; Formanek, P; Lehmann, M; Huhle, R; Carrillo-Cabrera, W; Harscher, A; Ehrlich, H

    2008-01-01

    In this paper, we summarise the development of off-axis electron holography on biological samples starting in 1986 with the first results on ferritin from the group of Tonomura. In the middle of the 1990s strong interest was evoked, but then stagnation took place because the results obtained at that stage did not reach the contrast and the resolution achieved by conventional electron microscopy. To date, there exist only a few ( approximately 12) publications on electron holography of biological objects, thus this topic is quite small and concise. The reason for this could be that holography is mostly established in materials science by physicists. Therefore, applications for off-axis holography were powerfully pushed forward in the area of imaging, e.g. electric or magnetic micro- and nanofields. Unstained biological systems investigated by means of off-axis electron holography up to now are ferritin, tobacco mosaic virus, a bacterial flagellum, T5 bacteriophage virus, hexagonal packed intermediate layer of bacteria and the Semliki Forest virus. New results of the authors on collagen fibres and surface layer of bacteria, the so-called S-layer 2D crystal lattice are presented in this review. For the sake of completeness, we will shortly discuss in-line holography of biological samples and off-axis holography of materials related to biological systems, such as biomaterial composites or magnetotactic bacteria.

  5. Biological roles of Cytochrome c: mitochondrial electron transport, programmed cell death and gain of peroxidatic activity

    Directory of Open Access Journals (Sweden)

    Victoria Colman

    2015-11-01

    Full Text Available El citocromo c (cyt c es una pequeña proteína monomérica de 13,0 kDa, que posee carga neta positiva a pH fisiológico. En su estructura se destaca un grupo hemo hexa-coordinado siendo la His18 y la Met80 la quinta y sexta posición de coordinación, respectivamente. Es una molécula soluble que se asocia mediante interacciones electrostáticas a la parte externa de la membrana mitocondrial interna, donde cumple una importante función como transportador de electrones entre los complejos III y IV de la cadena respiratoria mitocondrial, formando parte de una de las rutas catabólicas principales que llevan a la generación de ATP. Además, el cyt c participa en otras dos funciones esenciales para la célula: la apoptosis y la peroxidación de la cardiolipina de membrana. La actividad peroxidasa del cyt c es esencial para el inicio de la apoptosis, debido a que provoca la oxigenación específica de la cardiolipina para producir hidroperóxidos de cardiolipina, necesarios para la liberación de otros factores pro-apoptóticos. Durante la apoptosis, el cyt c se libera desde el espacio intermembrana de la mitocondria hacia el citosol, formando un complejo con APAF-1 y ATP, modulando las vías dependientes de caspasas. Esta función del cyt c también es muy importante ya que la muerte celular programada es un proceso celular fundamental para la correcta eliminación de células dañadas, evitando la diseminación de los restos celulares. La presente monografía pretende reunir información sobre estas tres principales funciones del cyt c, que dejan en manifiesto su importancia para la vida celular.

  6. Studies of the electronic structure and biological activity of chosen 1,4-benzodiazepines by 35Cl NQR spectroscopy and DFT calculations

    International Nuclear Information System (INIS)

    Bronisz, K.; Ostafin, M.; Poleshchuk, O. Kh.; Mielcarek, J.; Nogaj, B.

    2006-01-01

    Selected derivatives of 1,4-benzodiazepine: lorazepam, lormetazepam, oxazepam and temazepam, used as active substances in anxiolytic drugs, have been studied by 35 Cl NQR method in order to find the correlation between electronic structure and biological activity. The 35 Cl NQR resonance frequencies (ν Q ) measured at 77 K have been correlated with the following parameters characterising their biological activity: biological half-life period (t 0.5 ), affinity to benzodiazepine receptor (IC 50 ) and mean dose equivalent. The results of experimental study of some benzodiazepine derivatives by nuclear quadrupole resonance of 35 Cl nuclei are compared with theoretical results based on DFT calculations which were carried out by means of Gaussian'98 W software

  7. Studies of the electronic structure and biological activity of chosen 1,4-benzodiazepines by {sup 35}Cl NQR spectroscopy and DFT calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bronisz, K. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland); Ostafin, M. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)], E-mail: ostifnqr@amu.edu.pl; Poleshchuk, O. Kh. [Department of Chemistry, Tomsk Pedagogical University, Komsomolskii 75, 634041 Tomsk (Russian Federation); Mielcarek, J. [Faculty of Pharmacy, University of Medical Sciences, Grunwaldzka 6, 60-780 Poznan (Poland); Nogaj, B. [Department of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznan (Poland)

    2006-11-08

    Selected derivatives of 1,4-benzodiazepine: lorazepam, lormetazepam, oxazepam and temazepam, used as active substances in anxiolytic drugs, have been studied by {sup 35}Cl NQR method in order to find the correlation between electronic structure and biological activity. The {sup 35}Cl NQR resonance frequencies ({nu} {sub Q}) measured at 77 K have been correlated with the following parameters characterising their biological activity: biological half-life period (t {sub 0.5}), affinity to benzodiazepine receptor (IC{sub 50}) and mean dose equivalent. The results of experimental study of some benzodiazepine derivatives by nuclear quadrupole resonance of {sup 35}Cl nuclei are compared with theoretical results based on DFT calculations which were carried out by means of Gaussian'98 W software.

  8. Quantifying electron transfer reactions in biological systems

    DEFF Research Database (Denmark)

    Sjulstok, Emil Sjulstok; Olsen, Jógvan Magnus Haugaard; Solov'yov, Ilia A

    2015-01-01

    to deduce the driving force for the electron transfer reaction and to establish those interactions that play the major role in propelling the electron. The suggested approach is seen as a general recipe to treat electron transfer events in biological systems computationally, and we utilize it to describe...

  9. Biological cryo‐electron microscopy in China

    Science.gov (United States)

    2016-01-01

    Abstract Cryo‐electron microscopy (cryo‐EM) plays an increasingly more important role in structural biology. With the construction of an arm of the Chinese National Protein Science Facility at Tsinghua University, biological cryo‐EM has entered a phase of rapid development in China. This article briefly reviews the history of biological cryo‐EM in China, describes its current status, comments on its impact on the various biological research fields, and presents future outlook. PMID:27534377

  10. Peptide π-Electron Conjugates: Organic Electronics for Biology?

    Science.gov (United States)

    Ardoña, Herdeline Ann M; Tovar, John D

    2015-12-16

    Highly ordered arrays of π-conjugated molecules are often viewed as a prerequisite for effective charge-transporting materials. Studies involving these materials have traditionally focused on organic electronic devices, with more recent emphasis on biological systems. In order to facilitate the transition to biological environments, biomolecules that can promote hierarchical ordering and water solubility are often covalently appended to the π-electron unit. This review highlights recent work on π-conjugated systems bound to peptide moieties that exhibit self-assembly and aims to provide an overview on the development and emerging applications of peptide-based supramolecular π-electron systems.

  11. Molecular ferroelectrics: where electronics meet biology.

    Science.gov (United States)

    Li, Jiangyu; Liu, Yuanming; Zhang, Yanhang; Cai, Hong-Ling; Xiong, Ren-Gen

    2013-12-28

    In the last several years, we have witnessed significant advances in molecular ferroelectrics, with the ferroelectric properties of molecular crystals approaching those of barium titanate. In addition, ferroelectricity has been observed in biological systems, filling an important missing link in bioelectric phenomena. In this perspective, we will present short historical notes on ferroelectrics, followed by an overview of the fundamentals of ferroelectricity. The latest developments in molecular ferroelectrics and biological ferroelectricity will then be highlighted, and their implications and potential applications will be discussed. We close by noting molecular ferroelectric as an exciting frontier between electronics and biology, and a number of challenges ahead are also described.

  12. Connecting Biology to Electronics: Molecular Communication via Redox Modality.

    Science.gov (United States)

    Liu, Yi; Li, Jinyang; Tschirhart, Tanya; Terrell, Jessica L; Kim, Eunkyoung; Tsao, Chen-Yu; Kelly, Deanna L; Bentley, William E; Payne, Gregory F

    2017-12-01

    Biology and electronics are both expert at for accessing, analyzing, and responding to information. Biology uses ions, small molecules, and macromolecules to receive, analyze, store, and transmit information, whereas electronic devices receive input in the form of electromagnetic radiation, process the information using electrons, and then transmit output as electromagnetic waves. Generating the capabilities to connect biology-electronic modalities offers exciting opportunities to shape the future of biosensors, point-of-care medicine, and wearable/implantable devices. Redox reactions offer unique opportunities for bio-device communication that spans the molecular modalities of biology and electrical modality of devices. Here, an approach to search for redox information through an interactive electrochemical probing that is analogous to sonar is adopted. The capabilities of this approach to access global chemical information as well as information of specific redox-active chemical entities are illustrated using recent examples. An example of the use of synthetic biology to recognize external molecular information, process this information through intracellular signal transduction pathways, and generate output responses that can be detected by electrical modalities is also provided. Finally, exciting results in the use of redox reactions to actuate biology are provided to illustrate that synthetic biology offers the potential to guide biological response through electrical cues. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Biological Activities of Hydrazone Derivatives

    Directory of Open Access Journals (Sweden)

    S. Güniz Küçükgüzel

    2007-08-01

    Full Text Available There has been considerable interest in the development of novel compounds with anticonvulsant, antidepressant, analgesic, antiinflammatory, antiplatelet, antimalarial, antimicrobial, antimycobacterial, antitumoral, vasodilator, antiviral and antischistosomiasis activities. Hydrazones possessing an azometine -NHN=CH- proton constitute an important class of compounds for new drug development. Therefore, many researchers have synthesized these compounds as target structures and evaluated their biological activities. These observations have been guiding for the development of new hydrazones that possess varied biological activities.

  14. Brassinosteroids: synthesis and biological activities

    Czech Academy of Sciences Publication Activity Database

    Oklešťková, Jana; Rárová, Lucie; Kvasnica, Miroslav; Strnad, Miroslav

    2015-01-01

    Roč. 14, č. 6 (2015), s. 1053-1072 ISSN 1568-7767 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Brassinosteroids * Chemical synthesis * Plant biological activity Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.686, year: 2015

  15. Quantitative biological measurement in Transmission Electron Tomography

    International Nuclear Information System (INIS)

    Mantell, Judith M; Verkade, Paul; Arkill, Kenton P

    2012-01-01

    It has been known for some time that biological sections shrink in the transmission electron microscope from exposure to the electron beam. This phenomenon is especially important in Electron Tomography (ET). The effect on shrinkage of parameters such as embedding medium or sample type is less well understood. In addition anisotropic area shrinkage has largely been ignored. The intention of this study is to explore the shrinkage on a number of samples ranging in thickness from 200 nm to 500 nm. A protocol was developed to determine the shrinkage in area and thickness using the gold fiducials used in electron tomography. In brief: Using low dose philosophy on the section, a focus area was used prior to a separate virgin study area for a series of known exposures on a tilted sample. The shrinkage was determined by measurements on the gold beads from both sides of the section as determined by a confirmatory tomogram. It was found that the shrinkage in area (approximately to 90-95% of the original) and the thickness (approximately 65% of the original at most) agreed with pervious authors, but that a lmost all the shrinkage was in the first minute and that although the direction of the in-plane shrinkage (in x and y) was sometimes uneven the end result was consistent. It was observed, in general, that thinner samples showed more percentage shrinkage than thicker ones. In conclusion, if direct quantitative measurements are required then the protocol described should be used for all areas studied.

  16. Quantitative biological measurement in Transmission Electron Tomography

    Science.gov (United States)

    Mantell, Judith M.; Verkade, Paul; Arkill, Kenton P.

    2012-07-01

    It has been known for some time that biological sections shrink in the transmission electron microscope from exposure to the electron beam. This phenomenon is especially important in Electron Tomography (ET). The effect on shrinkage of parameters such as embedding medium or sample type is less well understood. In addition anisotropic area shrinkage has largely been ignored. The intention of this study is to explore the shrinkage on a number of samples ranging in thickness from 200 nm to 500 nm. A protocol was developed to determine the shrinkage in area and thickness using the gold fiducials used in electron tomography. In brief: Using low dose philosophy on the section, a focus area was used prior to a separate virgin study area for a series of known exposures on a tilted sample. The shrinkage was determined by measurements on the gold beads from both sides of the section as determined by a confirmatory tomogram. It was found that the shrinkage in area (approximately to 90-95% of the original) and the thickness (approximately 65% of the original at most) agreed with pervious authors, but that a lmost all the shrinkage was in the first minute and that although the direction of the in-plane shrinkage (in x and y) was sometimes uneven the end result was consistent. It was observed, in general, that thinner samples showed more percentage shrinkage than thicker ones. In conclusion, if direct quantitative measurements are required then the protocol described should be used for all areas studied.

  17. Electron Bifurcation: Thermodynamics and Kinetics of Two-Electron Brokering in Biological Redox Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Peng; Yuly, Jonathon L.; Lubner, Carolyn E. [National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Mulder, David W. [National Renewable Energy Laboratory, Golden, Colorado 80401, United States; King, Paul W. [National Renewable Energy Laboratory, Golden, Colorado 80401, United States; Peters, John W. [Institute; Beratan, David N. [Department

    2017-08-23

    How can proteins drive two electrons from a redox active donor onto two acceptors at very different potentials and distances? And how can this transaction be conducted without dissipating very much energy or violating the laws of thermodynamics? Nature appears to have addressed these challenges by coupling thermodynamically uphill and downhill electron transfer reactions, using two-electron donor cofactors that have very different potentials for the removal of the first and second electron. Although electron bifurcation is carried out with near perfection from the standpoint of energy conservation and electron delivery yields, it is a biological energy transduction paradigm that has only come into focus recently. This Account provides an exegesis of the biophysical principles that underpin electron bifurcation.

  18. Electron beam irradiation for biological decontamination of Spirulina platensis

    Energy Technology Data Exchange (ETDEWEB)

    Brasoveanu, Mirela [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor Street, P.O. Box MG-36, RO 76 900 Bucharest-Magurele (Romania)]. E-mail: mirela@infim.ro; Nemtanu, Monica [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor Street, P.O. Box MG-36, RO 76 900 Bucharest-Magurele (Romania); Minea, R. [National Institute for Lasers, Plasma and Radiation Physics, Department of Electron Accelerators, 409 Atomistilor Street, P.O. Box MG-36, RO 76 900 Bucharest-Magurele (Romania); Grecu, Maria Nicoleta [National Institute for Materials Physics, Bucharest-Magurele (Romania); Mazilu, Elena [Hofigal SA (Romania); Radulescu, Nora [Hofigal SA (Romania)

    2005-10-15

    The Cyanobacterium Spirulina is commercialized for its use in health foods and for therapeutic purposes due to its valuable constituents particularly proteins and vitamins. The aim of the paper is to study the Spirulina platensis behaviour when it is electron beam irradiated for biological decontamination. Microbial load, antioxidant activity, enzymatic inhibition, electron spin resonance (ESR) and UV-Vis spectra were measured for doses up to 80 kGy. The results were correlated with doses in order to find where decontamination is efficient, keeping the Spirulina qualities.

  19. Electron beam irradiation for biological decontamination of Spirulina platensis

    Science.gov (United States)

    Brasoveanu, Mirela; Nemtanu, Monica; Minea, R.; Grecu, Maria Nicoleta; Mazilu, Elena; Radulescu, Nora

    2005-10-01

    The Cyanobacterium Spirulina is commercialized for its use in health foods and for therapeutic purposes due to its valuable constituents particularly proteins and vitamins. The aim of the paper is to study the Spirulina platensis behaviour when it is electron beam irradiated for biological decontamination. Microbial load, antioxidant activity, enzymatic inhibition, electron spin resonance (ESR) and UV-Vis spectra were measured for doses up to 80 kGy. The results were correlated with doses in order to find where decontamination is efficient, keeping the Spirulina qualities.

  20. Electron Bifurcation: Thermodynamics and Kinetics of Two-Electron Brokering in Biological Redox Chemistry.

    Science.gov (United States)

    Zhang, Peng; Yuly, Jonathon L; Lubner, Carolyn E; Mulder, David W; King, Paul W; Peters, John W; Beratan, David N

    2017-09-19

    How can proteins drive two electrons from a redox active donor onto two acceptors at very different potentials and distances? And how can this transaction be conducted without dissipating very much energy or violating the laws of thermodynamics? Nature appears to have addressed these challenges by coupling thermodynamically uphill and downhill electron transfer reactions, using two-electron donor cofactors that have very different potentials for the removal of the first and second electron. Although electron bifurcation is carried out with near perfection from the standpoint of energy conservation and electron delivery yields, it is a biological energy transduction paradigm that has only come into focus recently. This Account provides an exegesis of the biophysical principles that underpin electron bifurcation. Remarkably, bifurcating electron transfer (ET) proteins typically send one electron uphill and one electron downhill by similar energies, such that the overall reaction is spontaneous, but not profligate. Electron bifurcation in the NADH-dependent reduced ferredoxin: NADP + oxidoreductase I (Nfn) is explored in detail here. Recent experimental progress in understanding the structure and function of Nfn allows us to dissect its workings in the framework of modern ET theory. The first electron that leaves the two-electron donor flavin (L-FAD) executes a positive free energy "uphill" reaction, and the departure of this electron switches on a second thermodynamically spontaneous ET reaction from the flavin along a second pathway that moves electrons in the opposite direction and at a very different potential. The singly reduced ET products formed from the bifurcating flavin are more than two nanometers distant from each other. In Nfn, the second electron to leave the flavin is much more reducing than the first: the potentials are said to be "crossed." The eventually reduced cofactors, NADH and ferredoxin in the case of Nfn, perform crucial downstream redox

  1. Imidazole: Having Versatile Biological Activities

    Directory of Open Access Journals (Sweden)

    Amita Verma

    2013-01-01

    Full Text Available Imidazoles have occupied a unique position in heterocyclic chemistry, and its derivatives have attracted considerable interests in recent years for their versatile properties in chemistry and pharmacology. Imidazole is nitrogen-containing heterocyclic ring which possesses biological and pharmaceutical importance. Thus, imidazole compounds have been an interesting source for researchers for more than a century. The imidazole ring is a constituent of several important natural products, including purine, histamine, histidine, and nucleic acid. Being a polar and ionisable aromatic compound, it improves pharmacokinetic characteristics of lead molecules and thus is used as a remedy to optimize solubility and bioavailability parameters of proposed poorly soluble lead molecules. There are several methods used for the synthesis of imidazole-containing compounds, and also their various structure reactions offer enormous scope in the field of medicinal chemistry. The imidazole derivatives possess extensive spectrum of biological activities such as antibacterial, anticancer, antitubercular, antifungal, analgesic, and anti-HIV activities. This paper aims to review the biological activities of imidazole during the past years.

  2. Electron Transfer in Chemistry and Biology - The Primary Events in ...

    Indian Academy of Sciences (India)

    electron transfer. (PET) is a very important process, with considerable chemical and biological relevance. GENERAL I ARTICLE of electrons, respectively. This has entirely changed the earlier framework of interpreting reactions in chemistry and biology. This shift in emphasis enables one to understand the elementary.

  3. Electron Transfer in Chemistry and Biology - The Primary Events in ...

    Indian Academy of Sciences (India)

    Electron Transfer in Chemistry and Biology -. The Primary Events in Photosynthesis. V Krishnan. One of the most important chemical reactions is electron transfer from one atomic/molecular unit to another. This reaction, accompanied by proton and hydrogen atom transfers, occurs in a cascade in many biological processes,.

  4. Biological applications of ultraviolet free-electron lasers

    International Nuclear Information System (INIS)

    Sutherland, J.C.

    1997-10-01

    This review examines the possibilities for biological research using the three ultraviolet free-electron lasers that are nearing operational status in the US. The projected operating characteristics of major interest in biological research of the free-electron lasers at Brookhaven National Laboratory, the Thomas Jefferson National Accelerator Facility, and Duke University are presented. Experimental applications in the areas of far- and vacuum ultraviolet photophysics and photochemistry, structural biology, environmental photobiology, and medical research are discussed and the prospects for advances in these areas, based upon the characteristics of the new ultraviolet free-electron lasers, are evaluated

  5. Interactions of electrons with biologically important molecules

    International Nuclear Information System (INIS)

    Pisklova, K.; Papp, P.; Stano, M.

    2012-01-01

    For the study of interactions of low-energy electrons with the molecules in the gas phase, the authors used electron-molecule cross-beam apparatus. The experiment is carried out in high vacuum, where molecules of the tested compound are inducted through a capillary. For purposes of this experiment the sample was electrically heated to 180 Deg C., giving a bundle of GlyGly molecules into the gas phase. The resulting signals can be evaluated in two different modes: mass spectrum - at continuous electron energy (e.g. 100 eV) they obtained the signal of intensity of the ions according to their mass to charge ratio; ionization and resonance spectra - for selected ion mass when the authors received the signal of intensity of the ions, depending on the energy of interacting electron.

  6. e-Biologics: Fabrication of Sustainable Electronics with "Green" Biological Materials.

    Science.gov (United States)

    Lovley, Derek R

    2017-06-27

    The growing ubiquity of electronic devices is increasingly consuming substantial energy and rare resources for materials fabrication, as well as creating expansive volumes of toxic waste. This is not sustainable. Electronic biological materials (e-biologics) that are produced with microbes, or designed with microbial components as the guide for synthesis, are a potential green solution. Some e-biologics can be fabricated from renewable feedstocks with relatively low energy inputs, often while avoiding the harsh chemicals used for synthesizing more traditional electronic materials. Several are completely free of toxic components, can be readily recycled, and offer unique features not found in traditional electronic materials in terms of size, performance, and opportunities for diverse functionalization. An appropriate investment in the concerted multidisciplinary collaborative research required to identify and characterize e-biologics and to engineer materials and devices based on e-biologics could be rewarded with a new "green age" of sustainable electronic materials and devices. Copyright © 2017 Lovley.

  7. Quantum effects in biological electron transfer

    Czech Academy of Sciences Publication Activity Database

    de la Lande, A.; Babcock, N. S.; Řezáč, Jan; Levy, B.; Sanders, B. C.; Salahub, D.

    2012-01-01

    Roč. 14, č. 17 (2012), s. 5902-5918 ISSN 1463-9076 Institutional research plan: CEZ:AV0Z40550506 Keywords : electron transfer * tunnelling * decoherence * semi-classical molecular dynamics * density functional theory Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.829, year: 2012

  8. CMOS biomicrosystems where electronics meets biology

    CERN Document Server

    2011-01-01

    "The book will address the-state-of-the-art in integrated Bio-Microsystems that integrate microelectronics with fluidics, photonics, and mechanics. New exciting opportunities in emerging applications that will take system performance beyond offered by traditional CMOS based circuits are discussed in detail. The book is a must for anyone serious about microelectronics integration possibilities for future technologies. The book is written by top notch international experts in industry and academia. The intended audience is practicing engineers with electronics background that want to learn about integrated microsystems. The book will be also used as a recommended reading and supplementary material in graduate course curriculum"--

  9. Ethnobotanical and biological activities of Leptadenia pyrotechnica ...

    African Journals Online (AJOL)

    Conclusion: This review includes the substance of different ethnobotanical uses, phytochemistry and exclusive capability of this plant in the field of anti-microbial and human disease activities. Key words: Leptadenia pyrotechnica, Biological activities, Desert plant, Ethnobotanical, Phytochemical activity, phytochemistry.

  10. Biomaterials-Based Electronics: Polymers and Interfaces for Biology and Medicine

    Science.gov (United States)

    Muskovich, Meredith; Bettinger, Christopher J.

    2012-01-01

    Advanced polymeric biomaterials continue to serve as a cornerstone of new medical technologies and therapies. The vast majority of these materials, both natural and synthetic, interact with biological matter without direct electronic communication. However, biological systems have evolved to synthesize and employ naturally-derived materials for the generation and modulation of electrical potentials, voltage gradients, and ion flows. Bioelectric phenomena can be interpreted as potent signaling cues for intra- and inter-cellular communication. These cues can serve as a gateway to link synthetic devices with biological systems. This progress report will provide an update on advances in the application of electronically active biomaterials for use in organic electronics and bio-interfaces. Specific focus will be granted to the use of natural and synthetic biological materials as integral components in technologies such as thin film electronics, in vitro cell culture models, and implantable medical devices. Future perspectives and emerging challenges will also be highlighted. PMID:23184740

  11. Synthesis and Biological Activities of Some Benzimidazoles ...

    African Journals Online (AJOL)

    The chemical structures of these compounds were elucidated using NMR and elemental analysis. The biological activity of these compounds as fungicides was tested against three commercially known fungicides (C. albicans, patient isolate C. glabrata and C. krusei).The biological activity of two compounds was found to be ...

  12. Photoelectron spectra and biological activity of cinnamic acid derivatives revisited

    Science.gov (United States)

    Novak, Igor; Klasinc, Leo; McGlynn, Sean P.

    2018-01-01

    The electronic structures of several derivatives of cinnamic acid have been studied by UV photoelectron spectroscopy (UPS) and Green's function quantum chemical calculations. The spectra reveal the presence of dimers in the gas phase for p-coumaric and ferulic acids. The electronic structure analysis has been related to the biological properties of these compounds through the analysis of some structure-activity relationships (SAR).

  13. Advancing Small Satellite Electronics Heritage for Microfluidic Biological Experiments

    Science.gov (United States)

    White, Bruce; Mazmanian, Edward; Tapio, Eric

    2016-01-01

    DLR's Eu:CROPIS (Euglena and Combined Regenerative Organic-Food Production in Space) mission, launching in 2017, will carry multiple biological payloads into a sun-synchronous orbit, including NASA Ames' PowerCell experiment. PowerCell will attempt to characterize the viability of synthetic biology at micro-g, Lunar, and Martian gravity levels. PowerCell experiment requirements demand an electronic system similar to previous microfluidic biology payloads, but with an expanded feature set. As such, the system was based on PharmaSat (Diaz-Aguado et al. 2009), a previous successful biology payload from NASA Ames, and improved upon. Newer, more miniaturized electronics allow for greater capability with a lower part count and smaller size. Two identical PowerCell enclosures will fly. Each enclosure contains two separate and identical experiments with a 48-segment optical density measurement system, grow light system, microfluidic system for nutrient delivery and waste flushing, plus thermal control and environmental sensing/housekeeping including temperature, pressure, humidity, and acceleration. Electronics consist of a single Master PCB that interfaces to the spacecraft bus and regulates power and communication, plus LED, Detector, and Valve Manifold PCBs for each experiment. To facilitate ease of reuse on future missions, experiment electronics were designed to be compatible with a standard 3U small sat form factor and power bus, or to interface with a Master power/comm PCB for use in a larger satellite as in the case of PowerCell's flight on Eu:CROPIS.

  14. Some examples of utilization of electron paramagnetic resonance in biology

    International Nuclear Information System (INIS)

    Bemski, G.

    1982-10-01

    A short outline of the fundamentals of electron paramagnetic resonance (EPR) is presented and is followed by examples of the application of EPR to biology. These include use of spin labels, as well as of ENDOR principally to problems of heme proteins, photosynthesis and lipids. (Author) [pt

  15. Flexible Organic Electronics in Biology: Materials and Devices.

    Science.gov (United States)

    Liao, Caizhi; Zhang, Meng; Yao, Mei Yu; Hua, Tao; Li, Li; Yan, Feng

    2015-12-09

    At the convergence of organic electronics and biology, organic bioelectronics attracts great scientific interest. The potential applications of organic semiconductors to reversibly transmit biological signals or stimulate biological tissues inspires many research groups to explore the use of organic electronics in biological systems. Considering the surfaces of movable living tissues being arbitrarily curved at physiological environments, the flexibility of organic bioelectronic devices is of paramount importance in enabling stable and reliable performances by improving the contact and interaction of the devices with biological systems. Significant advances in flexible organic bio-electronics have been achieved in the areas of flexible organic thin film transistors (OTFTs), polymer electrodes, smart textiles, organic electrochemical ion pumps (OEIPs), ion bipolar junction transistors (IBJTs) and chemiresistors. This review will firstly discuss the materials used in flexible organic bioelectronics, which is followed by an overview on various types of flexible organic bioelectronic devices. The versatility of flexible organic bioelectronics promises a bright future for this emerging area. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Advances in cryo-electron tomography for biology and medicine.

    Science.gov (United States)

    Koning, Roman I; Koster, Abraham J; Sharp, Thomas H

    2018-05-01

    Cryo-electron tomography (CET) utilizes a combination of specimen cryo-fixation and multi-angle electron microscopy imaging to produce three-dimensional (3D) volume reconstructions of native-state macromolecular and subcellular biological structures with nanometer-scale resolution. In recent years, cryo-electron microscopy (cryoEM) has experienced a dramatic increase in the attainable resolution of 3D reconstructions, resulting from technical improvements of electron microscopes, improved detector sensitivity, the implementation of phase plates, automated data acquisition schemes, and improved image reconstruction software and hardware. These developments also greatly increased the usability and applicability of CET as a diagnostic and research tool, which is now enabling structural biologists to determine the structure of proteins in their native cellular environment to sub-nanometer resolution. These recent technical developments have stimulated us to update on our previous review (Koning, R.I., Koster, A.J., 2009. Cryo-electron tomography in biology and medicine. Ann Anat 191, 427-445) in which we described the fundamentals of CET. In this follow-up, we extend this basic description in order to explain the aforementioned recent advances, and describe related 3D techniques that can be applied to the anatomy of biological systems that are relevant for medicine. Copyright © 2018 Elsevier GmbH. All rights reserved.

  17. Electron crystallography--the waking beauty of structural biology.

    Science.gov (United States)

    Pope, Christopher R; Unger, Vinzenz M

    2012-08-01

    Since its debut in the mid 1970s, electron crystallography has been a valuable alternative in the structure determination of biological macromolecules. Its reliance on single-layered or double-layered two-dimensionally ordered arrays and the ability to obtain structural information from small and disordered crystals make this approach particularly useful for the study of membrane proteins in a lipid bilayer environment. Despite its unique advantages, technological hurdles have kept electron crystallography from reaching its full potential. Addressing the issues, recent initiatives developed high-throughput pipelines for crystallization and screening. Adding progress in automating data collection, image analysis and phase extension methods, electron crystallography is poised to raise its profile and may lead the way in exploring the structural biology of macromolecular complexes. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Physical activity and biological maturation: a systematic review

    Directory of Open Access Journals (Sweden)

    Eliane Denise Araújo Bacil

    2015-03-01

    Full Text Available OBJECTIVE: To analyze the association between physical activity (PA and biological maturation in children and adolescents. DATA SOURCE: We performed a systematic review in April 2013 in the electronic databases of PubMed/MEDLINE, SportDiscus, Web of Science and LILACS without time restrictions. A total of 628 potentially relevant articles were identified and 10 met the inclusion criteria for this review: cross-sectional or longitudinal studies, published in Portuguese, English or Spanish, with schoolchildren aged 9-15 years old of both genders. DATA SYNTHESIS: Despite the heterogeneity of the studies, there was an inverse association between PA and biological maturation. PA decreases with increased biological and chronological age in both genders. Boys tend to be more physically active than girls; however, when controlling for biological age, the gender differences disappear. The association between PA and timing of maturation varies between the genders. Variation in the timing of biological maturation affects the tracking of PA in early adolescent girls. This review suggests that mediators (BMI, depression, low self-esteem, and concerns about body weight can explain the association between PA and biological maturation. CONCLUSIONS: There is an association between PA and biological maturation. PA decreases with increasing biological age with no differences between genders. As for the timing of biological maturation, this association varies between genders.

  19. Benzimidazoles: A biologically active compounds

    Directory of Open Access Journals (Sweden)

    Salahuddin

    2017-02-01

    Full Text Available Synthesis of commercially available benzimidazole involves condensation of o-phenylenediamine with formic acid. The most prominent benzimidazole compound in nature is N-riosyldimethylbenzimidazole, which serves as a axial ligand for cobalt in vitamin B12. The benzimidazole and its derivatives play a very important role as a therapeutic agent e.g. antiulcer and anthelmintic drugs. Apart from this the benzimidazole derivatives exhibit pharmacological activities such as antimicrobial, antiviral, anticancer, anti-inflammatory, analgesic, etc. The substituted benzimidazoles are summarized in this review to know about the chemistry as well as pharmacological activities.

  20. Biological activity of liposomal vanillin.

    Science.gov (United States)

    Castan, Leniher; Del Toro, Grisel; Fernández, Adolfo A; González, Manuel; Ortíz, Emilia; Lobo, Daliana

    2013-06-01

    This article presents a study of vanillin encapsulation inside multilamellar liposomes, with emphasis on the evaluation of antioxidant activity, the hemolytic effect, and the antisickling properties of these products. Egg phosphatidylcholine-cholesterol and egg phosphatidylcholine-cholesterol-1-O-decylglycerol liposomes were prepared by mechanical dispersion, all with vanillin included. Vesicles were characterized by determination of encapsulation efficiency and vanillin retention capacity. Antioxidant activity was determined by the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. The hemolytic effect of liposomes was also evaluated by spectrophotometry, as well as the antisickling activity by the Huck test using optical microscopy. Results showed that the lipid composition of liposomes did not significantly affect the encapsulation efficiency. Stable vesicles were obtained with a high retention percentage of vanillin. Liposomes exhibited a high capture of the DPPH radical compared to free vanillin and 1-O-decylglycerol (C10) in solution. Vesicles caused no significant hemolisys in normal erythrocytes, nor in those coming from patients with sickle cell anemia. Vanillin encapsulated in liposomes retained its antisickling activity, with a greater effect for C10-containing vesicles. Our results show that vanillin encapsulation in liposomes is a way to enhance the pharmacologic properties of this molecule using a suitable vehicle.

  1. Applications of Free Electron Lasers in Biology and Medicine

    International Nuclear Information System (INIS)

    Pelka, J.B.; Tybor, K.R.; Nietubyc, R.; Wrochna, G.

    2010-01-01

    The advent of free electron lasers opens up new opportunities to probe the dynamics of ultrafast processes and the structure of matter with unprecedented spatial and temporal resolution. New methods inaccessible with other known types of radiation sources can be developed, resulting in a breakthrough in deep understanding the fundamentals of life as well as in numerous medical and biological applications. In the present work the properties of free electron laser radiation that make the sources excellent for probing biological matter at an arbitrary wavelength, in a wide range of intensities and pulse durations are briefly discussed. A number of biophysical and biomedical applications of the new sources, currently considered among the most promising in the field, are presented. (author)

  2. Elsholtzia: phytochemistry and biological activities

    Directory of Open Access Journals (Sweden)

    Guo Zhiqin

    2012-12-01

    Full Text Available Abstract Plants of the genus Elsholtzia (Lamiaceae have a long history of medicinal use in folk. The phytochemical investigations revealed the presence of flavonoids, phenylpropanoids, terpenoids, and other compounds. Abundant volatile components are also identified. Pure compounds, volatile constituents and crude extracts from the genus exhibited a wide spectrum of in vitro and in vivo pharmacological activities. The aims of this review hopefully provide comprehensive information on the distribution, phytochemistry, volatile components, and pharmacological research of Elsholtzia for exploring the potential and advance researches.

  3. Electron scattering from molecules and molecular aggregates of biological relevance

    Science.gov (United States)

    Gorfinkiel, Jimena D.; Ptasinska, Sylwia

    2017-09-01

    In this Topical Review we survey the current state of the art in the study of low energy electron collisions with biologically relevant molecules and molecular clusters. We briefly describe the methods and techniques used in the investigation of these processes and summarise the results obtained so far for DNA constituents and their model compounds, amino acids, peptides and other biomolecules. The applications of the data obtained is briefly described as well as future required developments.

  4. Transmission electron microscopy in molecular structural biology: A historical survey.

    Science.gov (United States)

    Harris, J Robin

    2015-09-01

    In this personal, historic account of macromolecular transmission electron microscopy (TEM), published data from the 1940s through to recent times is surveyed, within the context of the remarkable progress that has been achieved during this time period. The evolution of present day molecular structural biology is described in relation to the associated biological disciplines. The contribution of numerous electron microscope pioneers to the development of the subject is discussed. The principal techniques for TEM specimen preparation, thin sectioning, metal shadowing, negative staining and plunge-freezing (vitrification) of thin aqueous samples are described, with a selection of published images to emphasise the virtues of each method. The development of digital image analysis and 3D reconstruction is described in detail as applied to electron crystallography and reconstructions from helical structures, 2D membrane crystals as well as single particle 3D reconstruction of icosahedral viruses and macromolecules. The on-going development of new software, algorithms and approaches is highlighted before specific examples of the historical progress of the structural biology of proteins and viruses are presented. Copyright © 2014 Elsevier Inc. All rights reserved.

  5. A national facility for biological cryo-electron microscopy

    International Nuclear Information System (INIS)

    Saibil, Helen R.; Grünewald, Kay; Stuart, David I.

    2015-01-01

    This review provides a brief update on the use of cryo-electron microscopy for integrated structural biology, along with an overview of the plans for the UK national facility for electron microscopy being built at the Diamond synchrotron. Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided of the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback

  6. Active learners in sustainable electronics and it

    DEFF Research Database (Denmark)

    Schultz, Ole

    This poster-presentation is about active learning in a course sustainable wireless electronics and it. Active learning understood as practical lab-exercises and a team chosen project.......This poster-presentation is about active learning in a course sustainable wireless electronics and it. Active learning understood as practical lab-exercises and a team chosen project....

  7. Marine Biology Activities. Ocean Related Curriculum Activities.

    Science.gov (United States)

    Pauls, John

    The ocean affects all of our lives. Therefore, awareness of and information about the interconnections between humans and oceans are prerequisites to making sound decisions for the future. Project ORCA (Ocean Related Curriculum Activities) has developed interdisciplinary curriculum materials designed to meet the needs of students and teachers…

  8. Genus Pouteria: chemistry and biological activity

    Directory of Open Access Journals (Sweden)

    Cíntia A. M. Silva

    Full Text Available The genus Pouteria belongs to the family Sapotaceae and can be widely found around the World. These plants have been used as building material, as food, because the eatable fruits, as well as remedies in folk medicine. Some biological activities have been reported to species of this genus such as antioxidant, anti-inflammatory, antibacterial and antifungal. However, the real potential of this genus as source of new drugs or phytomedicines remains unknown. Therefore, a review of the so far known chemical composition and biological activities of this genus is presented to stimulate new studies about the species already reported moreover that species have no reference about chemistry or biological activities could be found until now.

  9. Synthesis, structure and biological properties of active spirohydantoin derivatives

    Directory of Open Access Journals (Sweden)

    Lazić Anita M.

    2016-01-01

    Full Text Available Spirohidantoins represent an pharmacologically important class of heterocycles since many derivatives have been recognized that display interesting activities against a wide range of biological targets. First synthesis of cycloalkanespiro-5-hydantoins was performed by Bucherer and Lieb 1934 by the reaction of cycloalkanone, potassium cyanide and ammonium-carbonate at reflux in a mixture of ethanol and water. QSAR (Quantitative Structure-Activity Relationship studies showed that a wide range of biological activities of spirohydantoin derivatives strongly depend upon their structure. This paper describes different methods of synthesis of spirohydantoin derivatives, their physico-chemical properties and biological activity. It emphasizes the importance of cycloalkanespiro-5-hydantoins with anticonvulsant, antiproliferative, antipsychotic, antimicrobial and antiinflammatory properties as well as their importance in the treatment of diabetes. Numerous spirohydantoin compounds exhibit physiological activity such as serotonin and fibrinogen antagonist, inhibitors of the glycine binding site of the NMDA receptor also, antagonist of leukocyte cell adhesion, acting as allosteric inhibitors of the protein-protein interactions. Some spirohydantoin derivatives have been identified as antitumor agents. Their activity depends on the substituent presented at position N-3 of the hydantoin ring and increases in order alkene > ester > ether. Besides that, compounds that contain two electron withdrawing groups (e.g. fluorine or chlorine on the third and fourth position of the phenyl ring are better antitumor agents than compounds with a single electron withdrawing group. [Projekat Ministarstva nauke Republike Srbije, br. 172013

  10. Biological activities of substituted trichostatic acid derivatives

    Indian Academy of Sciences (India)

    New substituted trichostatic acid derivatives have been synthesized and evaluated for their biological activities towards the H661 non-small lung cancer cell line. These syntheses were achieved by alkylation of propiophenones to introduce the side chain with a terminal precursor of hydroxamic acid and aminobenzamide ...

  11. Expression and Purification of Soluble, Biologically Active ...

    African Journals Online (AJOL)

    Expression and Purification of Soluble, Biologically Active Recombinant Dipeptidyl Peptidase 4 (DPP4/CD26/ADAbp) Comprising the Extracellular Domain in the Yeast, Pichia ... Purpose: To investigate Pichia pastoris expression system for producing clinically usable, high-quality dipeptidyl peptidase 4 recombinant protein.

  12. Parameters of biological activity in colorectal cancer

    Czech Academy of Sciences Publication Activity Database

    Svobodová, Š.; Topolčan, O.; Holubec jr., L.; Levý, M.; Pecen, Ladislav; Svačina, Š.

    2011-01-01

    Roč. 31, č. 1 (2011), s. 373-378 ISSN 0250-7005 Institutional research plan: CEZ:AV0Z10300504 Keywords : colorectal cancer * biological activity * prognosis * tumor markers * angiogenetic factors * metalloproteinases * adhesion molecules Subject RIV: FD - Oncology ; Hematology Impact factor: 1.725, year: 2011

  13. Biological activity screening of seven Plectranthus species

    OpenAIRE

    Epole Ntungwe N; Joana Marçalo; Catarina Garcia; Catarina Reis; Catarina Teodósio; Carolina Oliveira; Cláudia Oliveira; Amílcar Roberto; Patrícia Rijo

    2017-01-01

    Natural products from Plectranthus spp. plants have an ethnopharmacological use, inspiring several scientific investigations. As such, this work aims to perform a biological activity screening in order to scientifically validate the use of these plants. Assays on in vitro acetylcholinesterase (AChE) inhibition, antioxidant effects, antimicrobial activity and Artemia salina lethality were performed on seven Plectranthus spp. extracts (P. swynnertonii, P. welwischii, P. woodii, P. cylindraceus,...

  14. Biological activity of SV40 DNA

    International Nuclear Information System (INIS)

    Abrahams, P.J.

    1978-01-01

    This thesis deals with a study on the biological activity of SV40 DNA. The transforming activity of SV40 DNA and DNA fragments is investigated in order to define as precisely as possible the area of the viral genome that is involved in the transformation. The infectivity of SV40 DNA is used to study the defective repair mechanisms of radiation damages of human xeroderma pigmentosum cells. (C.F.)

  15. Volume scanning electron microscopy for imaging biological ultrastructure.

    Science.gov (United States)

    Titze, Benjamin; Genoud, Christel

    2016-11-01

    Electron microscopy (EM) has been a key imaging method to investigate biological ultrastructure for over six decades. In recent years, novel volume EM techniques have significantly advanced nanometre-scale imaging of cells and tissues in three dimensions. Previously, this had depended on the slow and error-prone manual tasks of cutting and handling large numbers of sections, and imaging them one-by-one with transmission EM. Now, automated volume imaging methods mostly based on scanning EM (SEM) allow faster and more reliable acquisition of serial images through tissue volumes and achieve higher z-resolution. Various software tools have been developed to manipulate the acquired image stacks and facilitate quantitative analysis. Here, we introduce three volume SEM methods: serial block-face electron microscopy (SBEM), focused ion beam SEM (FIB-SEM) and automated tape-collecting ultramicrotome SEM (ATUM-SEM). We discuss and compare their capabilities, provide an overview of the full volume SEM workflow for obtaining 3D datasets and showcase different applications for biological research. © 2016 Société Française des Microscopies and Société de Biologie Cellulaire de France. Published by John Wiley & Sons Ltd.

  16. Electron probe analysis of biological fluids: Possibilities and limitations

    International Nuclear Information System (INIS)

    Roinel, N.

    1984-01-01

    Physical methods of investigation have become essential to investigations at the cellular or subcellular level. Nuclear magnetic resonance is the most recent and striking example, since it is not only a tool for fundamental physicists and organic chemists, but also an extraordinary powerful imaging tool for physicians. The absorption properties of X rays were used immediately after their discovery to image the bones of skeletons. Later, X rays were also found to be extremely efficient in the measurement of the elemental content of microvolumes irradiated by electron probes. The electron probe analyzer (EPA) was immediately adopted by numerous laboratories of metallurgy, geology, and mineral sciences. In the last fifteen years, since the use of this instrument was suggested for liquid analysis, and a preparative technique was developed, the EPA has been used by an increasing number of biological laboratories for measuring the concentrations of the elements contained in subnanoliter volumes of biological fluids. The so-called microdroplet technique has become a routine laboratory method, the only one able to measure the concentrations of an unlimited number of elements in a single 0.1-nl sample. This explains its use in fields as various as renal, reproductive, digestive, and plant physiology, zoology, etc. Several review papers discuss these applications. The possibilities and limitations of the technique are discussed below

  17. Biomaterials-based electronics: polymers and interfaces for biology and medicine.

    Science.gov (United States)

    Muskovich, Meredith; Bettinger, Christopher J

    2012-05-01

    Advanced polymeric biomaterials continue to serve as a cornerstone for new medical technologies and therapies. The vast majority of these materials, both natural and synthetic, interact with biological matter in the absence of direct electronic communication. However, biological systems have evolved to synthesize and utilize naturally-derived materials for the generation and modulation of electrical potentials, voltage gradients, and ion flows. Bioelectric phenomena can be translated into potent signaling cues for intra- and inter-cellular communication. These cues can serve as a gateway to link synthetic devices with biological systems. This progress report will provide an update on advances in the application of electronically active biomaterials for use in organic electronics and bio-interfaces. Specific focus will be granted to covering technologies where natural and synthetic biological materials serve as integral components such as thin film electronics, in vitro cell culture models, and implantable medical devices. Future perspectives and emerging challenges will also be highlighted. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Low Voltage Transmission Electron Microscopy in Cell Biology.

    Science.gov (United States)

    Bendayan, Moise; Paransky, Eugene

    2015-07-01

    Low voltage transmission electron microscopy (LVTEM) was employed to examine biological tissues with accelerating voltages as low as 5kV. Tissue preparation was modified to take advantage of the low-voltage techniques. Treatments with heavy metals, such as post-fixation with osmium tetroxide, on block and counterstaining were omitted. Sections (40nm) were thinner than usual and generated highly contrasted images. General appearance of the cells remains similar to that of conventional TEM. New features were however revealed. The matrix of the pancreatic granules displays heterogeneity with partitions that may correspond to the inner-segregation of their secretory proteins. Mitochondria revealed the presence of the ATP synthase granules along their cristea. The nuclear dense chromatin displayed a honeycomb organization while distinct beads, nucleosomes, aligned along thin threads were seen in the dispersed chromatin. Nuclear pore protein complexes revealed their globular nature. The intercalated disks in cardiac muscle displayed their fine structural organization. These features correlate well with data described or predicted by cell and molecular biology. These new aspects are not revealed when thicker and conventionally osmicated tissue sections were examined by LVTEM, indicating that major masking effects are associated with standard TEM techniques. Immunogold was adapted to LVTEM further enhancing its potential in cell biology. Copyright © 2015 Elsevier GmbH. All rights reserved.

  19. Three-Dimensional scanning transmission electron microscopy of biological specimens

    KAUST Repository

    De Jonge, Niels

    2010-01-18

    A three-dimensional (3D) reconstruction of the cytoskeleton and a clathrin-coated pit in mammalian cells has been achieved from a focal-series of images recorded in an aberration-corrected scanning transmission electron microscope (STEM). The specimen was a metallic replica of the biological structure comprising Pt nanoparticles 2-3 nm in diameter, with a high stability under electron beam radiation. The 3D dataset was processed by an automated deconvolution procedure. The lateral resolution was 1.1 nm, set by pixel size. Particles differing by only 10 nm in vertical position were identified as separate objects with greater than 20% dip in contrast between them. We refer to this value as the axial resolution of the deconvolution or reconstruction, the ability to recognize two objects, which were unresolved in the original dataset. The resolution of the reconstruction is comparable to that achieved by tilt-series transmission electron microscopy. However, the focal-series method does not require mechanical tilting and is therefore much faster. 3D STEM images were also recorded of the Golgi ribbon in conventional thin sections containing 3T3 cells with a comparable axial resolution in the deconvolved dataset. © 2010 Microscopy Society of America.

  20. Glycosides from Marine Sponges (Porifera, Demospongiae): Structures, Taxonomical Distribution, Biological Activities and Biological Roles

    Science.gov (United States)

    Kalinin, Vladimir I.; Ivanchina, Natalia V.; Krasokhin, Vladimir B.; Makarieva, Tatyana N.; Stonik, Valentin A.

    2012-01-01

    Literature data about glycosides from sponges (Porifera, Demospongiae) are reviewed. Structural diversity, biological activities, taxonomic distribution and biological functions of these natural products are discussed. PMID:23015769

  1. Investigating Biological Activity Spectrum for Novel Styrylquinazoline Analogues

    Directory of Open Access Journals (Sweden)

    Jaroslaw Polanski

    2009-10-01

    Full Text Available In this study, series of ring-substituted 2-styrylquinazolin-4(3H-one and 4-chloro-2-styrylquinazoline derivatives were prepared. The syntheses of the discussed compounds are presented. The compounds were analyzed by RP-HPLC to determine lipophilicity. They were tested for their inhibitory activity on photosynthetic electron transport (PET in spinach (Spinacia oleracea L. chloroplasts. Primary in vitro screening of the synthesized compounds was also performed against four mycobacterial strains and against eight fungal strains. Several compounds showed biological activity comparable with or higher than that of the standard isoniazid. It was found that the electronic properties of the R substituent, and not the total lipophilicity of the compound, were decisive for the photosynthesis-inhibiting activity of tested compounds.

  2. Isoflavones: estrogenic activity, biological effect and bioavailability.

    Science.gov (United States)

    Vitale, Daniela Cristina; Piazza, Cateno; Melilli, Barbara; Drago, Filippo; Salomone, Salvatore

    2013-03-01

    Isoflavones are phytoestrogens with potent estrogenic activity; genistein, daidzein and glycitein are the most active isoflavones found in soy beans. Phytoestrogens have similarity in structure with the human female hormone 17-β-estradiol, which can bind to both alpha and beta estrogen receptors, and mimic the action of estrogens on target organs, thereby exerting many health benefits when used in some hormone-dependent diseases. Numerous clinical studies claim benefits of genistein and daidzein in chemoprevention of breast and prostate cancer, cardiovascular disease and osteoporosis as well as in relieving postmenopausal symptoms. The ability of isoflavones to prevent cancer and other chronic diseases largely depends on pharmacokinetic properties of these compounds, in particular absorption and distribution to the target tissue. The chemical form in which isoflavones occur is important because it influences their bioavailability and, therefore, their biological activity. Glucose-conjugated isoflavones are highly polar, water-soluble compounds. They are hardly absorbed by the intestinal epithelium and have weaker biological activities than the corresponding aglycone. Different microbial families of colon can transform glycosylated isoflavones into aglycones. Clinical studies show important differences between the aglycone and conjugated forms of genistein and daidzein. The evaluation of isoflavone metabolism and bioavailability is crucial to understanding their biological effects. Lipid-based formulations such as drug incorporation into oils, emulsions and self-microemulsifying formulations have been introduced to increase bioavailability. Complexation with cyclodextrin also represent a valid method to improve the physicochemical characteristics of these substances in order to be absorbed and distributed to target tissues. We review and discuss pharmacokinetic issues that critically influence the biological activity of isoflavones.

  3. Monitoring Biological Activity at Geothermal Power Plants

    Energy Technology Data Exchange (ETDEWEB)

    Peter Pryfogle

    2005-09-01

    The economic impact of microbial growth in geothermal power plants has been estimated to be as high as $500,000 annually for a 100 MWe plant. Many methods are available to monitor biological activity at these facilities; however, very few plants have any on-line monitoring program in place. Metal coupon, selective culturing (MPN), total organic carbon (TOC), adenosine triphosphate (ATP), respirometry, phospholipid fatty acid (PLFA), and denaturing gradient gel electrophoresis (DGGE) characterizations have been conducted using water samples collected from geothermal plants located in California and Utah. In addition, the on-line performance of a commercial electrochemical monitor, the BIoGEORGE?, has been evaluated during extended deployments at geothermal facilities. This report provides a review of these techniques, presents data on their application from laboratory and field studies, and discusses their value in characterizing and monitoring biological activities at geothermal power plants.

  4. Direct Electron Transfer of Enzymes in a Biologically Assembled Conductive Nanomesh Enzyme Platform.

    Science.gov (United States)

    Lee, Seung-Woo; Lee, Ki-Young; Song, Yong-Won; Choi, Won Kook; Chang, Joonyeon; Yi, Hyunjung

    2016-02-24

    Nondestructive assembly of a nanostructured enzyme platform is developed in combination of the specific biomolecular attraction and electrostatic coupling for highly efficient direct electron transfer (DET) of enzymes with unprecedented applicability and versatility. The biologically assembled conductive nanomesh enzyme platform enables DET-based flexible integrated biosensors and DET of eight different enzyme with various catalytic activities. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Silychristin: Skeletal Alterations and Biological Activities

    Czech Academy of Sciences Publication Activity Database

    Biedermann, David; Buchta, M.; Holečková, Veronika; Sedlák, David; Valentová, Kateřina; Cvačka, Josef; Bednárová, Lucie; Křenková, Alena; Kuzma, Marek; Škuta, Ctibor; Peikerová, Žaneta; Bartůněk, Petr; Křen, Vladimír

    2016-01-01

    Roč. 79, č. 12 (2016), s. 3086-3092 ISSN 0163-3864 R&D Projects: GA ČR(CZ) GA15-03037S; GA MZd(CZ) NV16-27317A; GA MŠk LO1220; GA MŠk LM2015063; GA MŠk(CZ) LD15081 Institutional support: RVO:61388971 ; RVO:68378050 ; RVO:61388963 Keywords : Silychristin * skeletal alterations * biological activities Subject RIV: CC - Organic Chemistry Impact factor: 3.281, year: 2016

  6. Exploring the biological activities of Echeveria leucotricha.

    Science.gov (United States)

    Martínez Ruiz, María G; Gómez-Velasco, Anaximandro; Juárez, Zaida N; Hernández, Luis R; Bach, Horacio

    2013-01-01

    Echeveria leucotricha J. A. Purpus (Crassulaceae) was evaluated for its potential antibacterial, antifungal, antiparasitic, cytotoxic and anti-inflammatory bioactivities. Aerial parts were extracted with hexane, methanol and chloroform, and fractionated accordingly. Biological activity was assessed in vitro against five Gram-positive and four Gram-negative bacteria, four human pathogenic fungi and the protozoan Leishmania donovani. Extracts and fractions showing bioactivities were further investigated for their cytotoxic activities on macrophages. Results show that several extracts and fractions exhibited significant antibacterial, antifungal, and antiparasitic activities, but no anti-inflammatory activity was recorded. Here, we report for the first time, and to the best of our knowledge, these bioactivities, which suggest that this plant can be used in the traditional Mexican medicine.

  7. A national facility for biological cryo-electron microscopy.

    Science.gov (United States)

    Saibil, Helen R; Grünewald, Kay; Stuart, David I

    2015-01-01

    Three-dimensional electron microscopy is an enormously powerful tool for structural biologists. It is now able to provide an understanding of the molecular machinery of cells, disease processes and the actions of pathogenic organisms from atomic detail through to the cellular context. However, cutting-edge research in this field requires very substantial resources for equipment, infrastructure and expertise. Here, a brief overview is provided of the plans for a UK national three-dimensional electron-microscopy facility for integrated structural biology to enable internationally leading research on the machinery of life. State-of-the-art equipment operated with expert support will be provided, optimized for both atomic-level single-particle analysis of purified macromolecules and complexes and for tomography of cell sections. The access to and organization of the facility will be modelled on the highly successful macromolecular crystallography (MX) synchrotron beamlines, and will be embedded at the Diamond Light Source, facilitating the development of user-friendly workflows providing near-real-time experimental feedback.

  8. Biological Activities of Royal Jelly - Review

    Directory of Open Access Journals (Sweden)

    Crenguţa I. Pavel

    2011-10-01

    Full Text Available Royal jelly is a secretion product of the cephalic glands of nurse bees that has been used for centuries for itsextraordinary properties and health effects. This bibliographic study aims to review many of the scientific findingsand research that prove many of the remarkable various actions, effects and some uses of royal jelly. There are takeninto consideration numerous biological properties and effects of royal jelly: antioxidant, neurotrophic, hipoglicemiant, hipocholesterolemiant and hepatoprotective, hypotensive and blood pressure regulatory, antitumor, antibiotic, anti-inflammatory, immunomodulatory and anti-allergic, general tonic and antiaging. Royal jelly is one ofthe most studied bee products, but there still remains much to reveal about its biochemistry and biological activity infuture research for our health and life benefit.

  9. Fluid dynamics in biological active nematics

    Science.gov (United States)

    Tan, Amanda; Hirst, Linda

    We use biological materials to form a self-mixing active system that consists of microtubules driven by kinesin clusters. Microtubules are rigid biopolymers that are a part of the cytoskeleton. Kinesin motors are molecular motors that walk along microtubules to transport cellular cargo. In this system, microtubules are bundled together, and as the kinesin clusters walk along the filaments, the microtubule bundles move relative to each other. As microtubules shear against each other, they extend, bend, buckle and fracture. When confined in a 2D water-oil interface, the system becomes an active nematic that self-mixes due to the buckling and fracturing. To quantify this self-mixing, we attached beads to the microtubules, and tracked their motion. We quantify the quality of mixing using the bead trajectories. This new active material has potential applications as a self-mixing solvent. CCBM NSF-CREST, UC Merced Health Science Research Institute.

  10. Biological activities of Curcuma longa L.

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    Araújo CAC

    2001-01-01

    Full Text Available There are several data in the literature indicating a great variety of pharmacological activities of Curcuma longa L. (Zingiberaceae, which exhibit anti-inflammatory, anti-human immunodeficiency virus, anti-bacteria, antioxidant effects and nematocidal activities. Curcumin is a major component in Curcuma longa L., being responsible for its biological actions. Other extracts of this plant has been showing potency too. In vitro, curcumin exhibits anti-parasitic, antispasmodic, anti-inflammatory and gastrointestinal effects; and also inhibits carcinogenesis and cancer growth. In vivo, there are experiments showing the anti-parasitic, anti-inflammatory potency of curcumin and extracts of C. longa L. by parenteral and oral application in animal models. In this present work we make an overview of the pharmacological activities of C. longa L., showing its importance.

  11. Biologically active compounds of semi-metals.

    Science.gov (United States)

    Rezanka, Tomás; Sigler, Karel

    2008-02-01

    Semi-metals (boron, silicon, arsenic and selenium) form organo-metal compounds, some of which are found in nature and affect the physiology of living organisms. They include, e.g., the boron-containing antibiotics aplasmomycin, borophycin, boromycin, and tartrolon or the silicon compounds present in "silicate" bacteria, relatives of the genus Bacillus, which release silicon from aluminosilicates through the secretion of organic acids. Arsenic is incorporated into arsenosugars and arsenobetaines by marine algae and invertebrates, and fungi and bacteria can produce volatile methylated arsenic compounds. Some prokaryotes can use arsenate as a terminal electron acceptor while others can utilize arsenite as an electron donor to generate energy. Selenium is incorporated into selenocysteine that is found in some proteins. Biomethylation of selenide produces methylselenide and dimethylselenide. Selenium analogues of amino acids, antitumor, antibacterial, antifungal, antiviral, anti-infective drugs are often used as analogues of important pharmacological sulfur compounds. Other metalloids, i.e. the rare and toxic tellurium and the radioactive short-lived astatine, have no biological significance.

  12. Polysulfides as biologically active ingredients of garlic.

    Science.gov (United States)

    Münchberg, Ute; Anwar, Awais; Mecklenburg, Susanne; Jacob, Claus

    2007-05-21

    Garlic has long been considered as a natural remedy against a range of human illnesses, including various bacterial, viral and fungal infections. This kind of antibiotic activity of garlic has mostly been associated with the thiosulfinate allicin. Even so, recent studies have pointed towards a significant biological activity of trisulfides and tetrasulfides found in various Allium species, including a wide range of antibiotic properties and the ability of polysulfides to cause the death of certain cancer cells. The chemistry underlying the biological activity of these polysulfides is currently emerging. It seems to include a combination of several distinct transformations, such as oxidation reactions, superoxide radical and peroxide generation, decomposition with release of highly electrophilic S(x) species, inhibition of metalloenzymes, disturbance of metal homeostasis and membrane integrity and interference with different cellular signalling pathways. Further research in this area is required to provide a better understanding of polysulfide reactions within a biochemical context. This knowledge may ultimately form the basis for the development of 'green' antibiotics, fungicides and possibly anticancer agents with dramatically reduced side effects in humans.

  13. Electron reactions in model liquids and biological systems

    International Nuclear Information System (INIS)

    Bakale, G.; Gregg, E.C.

    1982-01-01

    Progress is reported in the following studies: (1) Field-dependent electron attachment; (2) Dependence of electron attachment rate on electron-acceptor dipole moment; (3) Electron attachment in i-octane/TMS mixtures; (4) Electron attachment/detachment equilibria; (5) Electron attachment to reversed micelles; (6) Electron attachment to chemical carcinogens; (7) Radiation-induced bacterial mutagenesis; and (8) Bacterial mutagenicity of nitrobenzene derivatives. 14 references

  14. Biological Activities of Polyphenols from Grapes

    Directory of Open Access Journals (Sweden)

    Hua-Bin Li

    2010-02-01

    Full Text Available The dietary consumption of grape and its products is associated with a lower incidence of degenerative diseases such as cardiovascular disease and certain types of cancers. Most recent interest has focused on the bioactive phenolic compounds in grape. Anthocyanins, flavanols, flavonols and resveratrol are the most important grape polyphenols because they possess many biological activities, such as antioxidant, cardioprotective, anticancer, anti-inflammation, antiaging and antimicrobial properties. This review summarizes current knowledge on the bioactivities of grape phenolics. The extraction, isolation and identification methods of polyphenols from grape as well as their bioavailability and potential toxicity also are included.

  15. Biological Activities of Polyphenols from Grapes

    Science.gov (United States)

    Xia, En-Qin; Deng, Gui-Fang; Guo, Ya-Jun; Li, Hua-Bin

    2010-01-01

    The dietary consumption of grape and its products is associated with a lower incidence of degenerative diseases such as cardiovascular disease and certain types of cancers. Most recent interest has focused on the bioactive phenolic compounds in grape. Anthocyanins, flavanols, flavonols and resveratrol are the most important grape polyphenols because they possess many biological activities, such as antioxidant, cardioprotective, anticancer, anti-inflammation, antiaging and antimicrobial properties. This review summarizes current knowledge on the bioactivities of grape phenolics. The extraction, isolation and identification methods of polyphenols from grape as well as their bioavailability and potential toxicity also are included. PMID:20386657

  16. Urine: Waste product or biologically active tissue?

    Science.gov (United States)

    2018-03-01

    Historically, urine has been viewed primarily as a waste product with little biological role in the overall health of an individual. Increasingly, data suggest that urine plays a role in human health beyond waste excretion. For example, urine might act as an irritant and contribute to symptoms through interaction with-and potential compromise of-the urothelium. To explore the concept that urine may be a vehicle for agents with potential or occult bioactivity and to discuss existing evidence and novel research questions that may yield insight into such a role, the National Institute of Diabetes and Digestive and Kidney Disease invited experts in the fields of comparative evolutionary physiology, basic science, nephrology, urology, pediatrics, metabolomics, and proteomics (among others) to a Urinology Think Tank meeting on February 9, 2015. This report reflects ideas that evolved from this meeting and current literature, including the concept of urine quality, the biological, chemical, and physical characteristics of urine, including the microbiota, cells, exosomes, pH, metabolites, proteins, and specific gravity (among others). Additionally, the manuscript presents speculative, and hopefully testable, ideas about the functional roles of urine constituents in health and disease. Moving forward, there are several questions that need further understanding and pursuit. There were suggestions to consider actively using various animal models and their biological specimens to elaborate on basic mechanistic information regarding human bladder dysfunction. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.

  17. Reconstructing Causal Biological Networks through Active Learning.

    Directory of Open Access Journals (Sweden)

    Hyunghoon Cho

    Full Text Available Reverse-engineering of biological networks is a central problem in systems biology. The use of intervention data, such as gene knockouts or knockdowns, is typically used for teasing apart causal relationships among genes. Under time or resource constraints, one needs to carefully choose which intervention experiments to carry out. Previous approaches for selecting most informative interventions have largely been focused on discrete Bayesian networks. However, continuous Bayesian networks are of great practical interest, especially in the study of complex biological systems and their quantitative properties. In this work, we present an efficient, information-theoretic active learning algorithm for Gaussian Bayesian networks (GBNs, which serve as important models for gene regulatory networks. In addition to providing linear-algebraic insights unique to GBNs, leading to significant runtime improvements, we demonstrate the effectiveness of our method on data simulated with GBNs and the DREAM4 network inference challenge data sets. Our method generally leads to faster recovery of underlying network structure and faster convergence to final distribution of confidence scores over candidate graph structures using the full data, in comparison to random selection of intervention experiments.

  18. Electron energy loss spectroscopy microanalysis and imaging in the transmission electron microscope: example of biological applications

    International Nuclear Information System (INIS)

    Diociaiuti, Marco

    2005-01-01

    This paper reports original results obtained in our laboratory over the past few years in the application of both electron energy loss spectroscopy (EELS) and electron spectroscopy imaging (ESI) to biological samples, performed in two transmission electron microscopes (TEM) equipped with high-resolution electron filters and spectrometers: a Gatan model 607 single magnetic sector double focusing EEL serial spectrometer attached to a Philips 430 TEM and a Zeiss EM902 Energy Filtering TEM. The primary interest was on the possibility offered by the combined application of these spectroscopic techniques with those offered by the TEM. In particular, the electron beam focusing available in a TEM allowed us to perform EELS and ESI on very small sample volumes, where high-resolution imaging and electron diffraction techniques can provide important structural information. I show that ESI was able to improve TEM performance, due to the reduced chromatic aberration and the possibility of avoiding the sample staining procedure. Finally, the analysis of the oscillating extended energy loss fine structure (EXELFS) beyond the ionization edges characterizing the EELS spectra allowed me, in a manner very similar to the extended X-ray absorption fine structure (EXAFS) analysis of the X-ray absorption spectra, to obtain short-range structural information for such light elements of biological interest as O or Fe. The Philips EM430 (250-300 keV) TEM was used to perform EELS microanalysis on Ca, P, O, Fe, Al and Si. The assessment of the detection limits of this method was obtained working with well-characterized samples containing Ca and P, and mimicking the actual cellular matrix. I applied EELS microanalysis to Ca detection in bone tissue during the mineralization process and to P detection in the cellular membrane of erythrocytes treated with an anti-tumoral drug, demonstrating that the cellular membrane is a drug target. I applied EELS microanalysis and selected area electron

  19. Biologically Active Secondary Metabolites from the Fungi.

    Science.gov (United States)

    Bills, Gerald F; Gloer, James B

    2016-11-01

    Many Fungi have a well-developed secondary metabolism. The diversity of fungal species and the diversification of biosynthetic gene clusters underscores a nearly limitless potential for metabolic variation and an untapped resource for drug discovery and synthetic biology. Much of the ecological success of the filamentous fungi in colonizing the planet is owed to their ability to deploy their secondary metabolites in concert with their penetrative and absorptive mode of life. Fungal secondary metabolites exhibit biological activities that have been developed into life-saving medicines and agrochemicals. Toxic metabolites, known as mycotoxins, contaminate human and livestock food and indoor environments. Secondary metabolites are determinants of fungal diseases of humans, animals, and plants. Secondary metabolites exhibit a staggering variation in chemical structures and biological activities, yet their biosynthetic pathways share a number of key characteristics. The genes encoding cooperative steps of a biosynthetic pathway tend to be located contiguously on the chromosome in coregulated gene clusters. Advances in genome sequencing, computational tools, and analytical chemistry are enabling the rapid connection of gene clusters with their metabolic products. At least three fungal drug precursors, penicillin K and V, mycophenolic acid, and pleuromutilin, have been produced by synthetic reconstruction and expression of respective gene clusters in heterologous hosts. This review summarizes general aspects of fungal secondary metabolism and recent developments in our understanding of how and why fungi make secondary metabolites, how these molecules are produced, and how their biosynthetic genes are distributed across the Fungi. The breadth of fungal secondary metabolite diversity is highlighted by recent information on the biosynthesis of important fungus-derived metabolites that have contributed to human health and agriculture and that have negatively impacted crops

  20. Biologically Active Metabolites Synthesized by Microalgae

    Directory of Open Access Journals (Sweden)

    Michele Greque de Morais

    2015-01-01

    Full Text Available Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences.

  1. Biologically Active Metabolites Synthesized by Microalgae.

    Science.gov (United States)

    de Morais, Michele Greque; Vaz, Bruna da Silva; de Morais, Etiele Greque; Costa, Jorge Alberto Vieira

    2015-01-01

    Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences.

  2. Biologically Active Metabolites Synthesized by Microalgae

    Science.gov (United States)

    Costa, Jorge Alberto Vieira

    2015-01-01

    Microalgae are microorganisms that have different morphological, physiological, and genetic traits that confer the ability to produce different biologically active metabolites. Microalgal biotechnology has become a subject of study for various fields, due to the varied bioproducts that can be obtained from these microorganisms. When microalgal cultivation processes are better understood, microalgae can become an environmentally friendly and economically viable source of compounds of interest, because production can be optimized in a controlled culture. The bioactive compounds derived from microalgae have anti-inflammatory, antimicrobial, and antioxidant activities, among others. Furthermore, these microorganisms have the ability to promote health and reduce the risk of the development of degenerative diseases. In this context, the aim of this review is to discuss bioactive metabolites produced by microalgae for possible applications in the life sciences. PMID:26339647

  3. Biological activity screening of seven Plectranthus species

    Directory of Open Access Journals (Sweden)

    Epole Ntungwe N

    2017-07-01

    Full Text Available Natural products from Plectranthus spp. plants have an ethnopharmacological use, inspiring several scientific investigations. As such, this work aims to perform a biological activity screening in order to scientifically validate the use of these plants. Assays on in vitro acetylcholinesterase (AChE inhibition, antioxidant effects, antimicrobial activity and Artemia salina lethality were performed on seven Plectranthus spp. extracts (P. swynnertonii, P. welwischii, P. woodii, P. cylindraceus, P. spicatus, P. ramosior and P. petiolaris. Acetonic extracts were obtained by sonication (10% w/v, where P. ramosior had the highest yield of dry extract (13.49% w/w. In the AChE inhibition assay, only P. cylindraceus extract decreased enzymatic activity (30.2 ± 3.78%. The antimicrobial activity was screened using the well diffusion method, against Gram positive and negative bacteria and yeast. P. ramosior extract showed not only an inhibition zone against S. aureus and C. albicans (15 and 11 mm, respectively, but also the highest scavenging activity (DPPH method, 36.4 ± 0.04%. On the lethality test in A. salina, P. swynnertonnii extract was the most toxic (LC50 = 0.036 mg/L. These preliminary results showed that P. cylindraceus, P. ramosior and P. swynnertonnii are potential bioactive extracts for further isolation and antimicrobial and cytotoxic studies.

  4. Urban Biomining: Biological Extraction of Metals and Materials from Electronics Waste Using a Synthetic Biology Approach

    Science.gov (United States)

    Urbina-Navarrete, J.; Rothschild, L.

    2016-12-01

    End-of-life electronics waste (e-waste) containing toxic and valuable materials is a rapidly progressing human health and environmental issue. Using synthetic biology tools, we have developed a recycling method for e-waste. Our innovation is to use a recombinant version of a naturally-occurring silica-degrading enzyme to depolymerize the silica in metal- and glass- containing e-waste components, and subsequently, to use engineered bacterial surfaces to bind and separate metals from a solution. The bacteria with bound metals can then be used as "bio-ink" to print new circuits using a novel plasma jet electronics printing technology. Here, we present the results from our initial studies that focus on the specificity of metal-binding motifs for a cognate metal. The candidate motifs that show high affinity and specificity will be engineered into bacterial surfaces for downstream applications in biologically-mediated metal recycling. Since the chemistry and role of Cu in metalloproteins is relatively well-characterized, we are using Cu as a proxy to elucidate metal and biological ligand interactions with various metals in e-waste. We assess the binding parameters of 3 representative classes of Cu-binding motifs using isothermal titration calorimetry; 1) natural motifs found in metalloproteins, 2) consensus motifs, and 3) rationally designed peptides that are predicted, in silico, to bind Cu. Our results indicate that naturally-occurring motifs have relative high affinity and specificity for Cu (association constant for Cu Ka 104 M-1, Zn Ka 103 M-1) when competing ions are present in the aqueous milieu. However, motifs developed through rational design by applying quantum mechanical methods that take into account complexation energies of the elemental binding partners and molecular geometry of the cognate metal, not only show high affinity for the cognate metal (Cu Ka 106 M-1), but they show specificity and discrimination against other metal ions that would be

  5. NBS activities in biological reference materials

    Energy Technology Data Exchange (ETDEWEB)

    Rasberry, S.D.

    1988-12-01

    NBS activities in biological reference materials during 1986-1988 are described with a preview of plans for future certifications of reference materials. During the period, work has been completed or partially completed on about 40 reference materials of importance to health, nutrition, and environmental quality. Some of the reference materials that have been completed during the period and are described include: creatinine (SRM 914a), bovine serum albumin (SRM 927a), cholesterol in human serum (SRM's 1951-1952), aspartate aminotransferase (RM 8430), cholesterol and fat-soluble vitamins in coconut oil (SRM 1563), wheat flour (SRM 1567a), rice flour (SRM 1568a), mixed diet (RM 8431a), dinitropyrene isomers and 1-nitropyrene (SRM 1596), and complex PAH's from coal tar (SRM 1597). Oyster tissue (SRM 1566a) is being analyzed and should be available in 1988.

  6. Biologically Active and Antimicrobial Peptides from Plants

    Directory of Open Access Journals (Sweden)

    Carlos E. Salas

    2015-01-01

    Full Text Available Bioactive peptides are part of an innate response elicited by most living forms. In plants, they are produced ubiquitously in roots, seeds, flowers, stems, and leaves, highlighting their physiological importance. While most of the bioactive peptides produced in plants possess microbicide properties, there is evidence that they are also involved in cellular signaling. Structurally, there is an overall similarity when comparing them with those derived from animal or insect sources. The biological action of bioactive peptides initiates with the binding to the target membrane followed in most cases by membrane permeabilization and rupture. Here we present an overview of what is currently known about bioactive peptides from plants, focusing on their antimicrobial activity and their role in the plant signaling network and offering perspectives on their potential application.

  7. ACTIVE AND PARTICIPATORY METHODS IN BIOLOGY: MODELING

    Directory of Open Access Journals (Sweden)

    Brînduşa-Antonela SBÎRCEA

    2011-01-01

    Full Text Available By using active and participatory methods it is hoped that pupils will not only come to a deeper understanding of the issues involved, but also that their motivation will be heightened. Pupil involvement in their learning is essential. Moreover, by using a variety of teaching techniques, we can help students make sense of the world in different ways, increasing the likelihood that they will develop a conceptual understanding. The teacher must be a good facilitator, monitoring and supporting group dynamics. Modeling is an instructional strategy in which the teacher demonstrates a new concept or approach to learning and pupils learn by observing. In the teaching of biology the didactic materials are fundamental tools in the teaching-learning process. Reading about scientific concepts or having a teacher explain them is not enough. Research has shown that modeling can be used across disciplines and in all grade and ability level classrooms. Using this type of instruction, teachers encourage learning.

  8. Mass determination based on electron scattering in electron probe X-ray microanalysis of thin biological specimens

    International Nuclear Information System (INIS)

    Linders, P.W.J.

    1984-01-01

    This thesis describes the development of a method for mass determination of thin biological objects by quantitative electron microscopy. The practical realization of the mass determination consists of photographical recording with subsequent densitometry. (Auth.)

  9. Biologically active extracts with kidney affections applications

    Science.gov (United States)

    Pascu (Neagu), Mihaela; Pascu, Daniela-Elena; Cozea, Andreea; Bunaciu, Andrei A.; Miron, Alexandra Raluca; Nechifor, Cristina Aurelia

    2015-12-01

    This paper is aimed to select plant materials rich in bioflavonoid compounds, made from herbs known for their application performances in the prevention and therapy of renal diseases, namely kidney stones and urinary infections (renal lithiasis, nephritis, urethritis, cystitis, etc.). This paper presents a comparative study of the medicinal plant extracts composition belonging to Ericaceae-Cranberry (fruit and leaves) - Vaccinium vitis-idaea L. and Bilberry (fruit) - Vaccinium myrtillus L. Concentrated extracts obtained from medicinal plants used in this work were analyzed from structural, morphological and compositional points of view using different techniques: chromatographic methods (HPLC), scanning electronic microscopy, infrared, and UV spectrophotometry, also by using kinetic model. Liquid chromatography was able to identify the specific compounds of the Ericaceae family, present in all three extracts, arbutosid, as well as specific components of each species, mostly from the class of polyphenols. The identification and quantitative determination of the active ingredients from these extracts can give information related to their therapeutic effects.

  10. BIOLOGICALLY ACTIVE SUBSTANCES OF SPIRIT PRODUCTION WASTE

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    A. S. Kayshev

    2014-01-01

    Full Text Available A content of biologically active compounds (BAC with signified pharmacological activity in distillers grains was proved. It is prospective for applications of these grains as a raw material resource of pharmaceuticals. A composition of BAC distillers grains received from wheat, corn, barley, millet at different spirit enterprises which use hydro fermentative grain processing. Considering polydispersity of distillers grains they were separated on solid and liquid phases preliminary. Physical and chemical characteristics of distillers grains' liquid base were identified. Elementary composition of distillers grains is signified by active accumulation of biogenic elements (phosphorus, potassium, magnesium, calcium, sodium, iron and low content of heavy metals. The solid phase of distillers grains accumulates carbon, hydrogen and nitrogen in high concentration. The liquid phase of distillers grains contains: proteins and amino acids (20-46%, reducing sugars (5,6%-17,5%, galacturonides (0,8-1,4%, ascorbic acid (6,2-11,4 mg%. The solid base of distillers grains contains: galacturonides (3,4-5,3%, fatty oil (8,4-11,1% with predomination of essential fatty acids, proteins and amino acids (2,1-2,5%, flavonoids (0,4-0,9%, tocopherols (3,4-7,7 mg%. A method of complex processing of distillers grains based on application of membrane filtering of liquid phase and liquid extraction by inorganic and organic solvents of solid phase, which allows almost full extraction of the sum of biologically active compounds (BAC from liquid phase (Biobardin BM and solid phase (Biobardin UL. Biobardin BM comprises the following elements: proteins and amino acids (41-69%, reducing sugars (3,5-15,6%, fatty oil (0,2-0,3%, flavonoids (0,2-0,7%, ascorbic acid (17-37 mg%. Biobardin UL includes: oligouronids (16,4-19,5%, proteins and amino acids (11-21%, fatty oil (3,2-4,9% which includes essential acids; flavonoids (0,6-1,5%, tocopherols (6,6-10,2 mg%, carotinoids (0,13-0,21 mg

  11. INVERSE ELECTRON TRANSFER IN PEROXYOXALATE CHEMIEXCITATION USING EASILY REDUCIBLE ACTIVATORS

    NARCIS (Netherlands)

    Bartoloni, Fernando Heering; Monteiro Leite Ciscato, Luiz Francisco; Augusto, Felipe Alberto; Baader, Wilhelm Josef

    2010-01-01

    INVERSE ELECTRON TRANSFER IN PEROXYOXALATE CHEMIEXCITATION USING EASILY REDUCIBLE ACTIVATORS. Chemiluminescence properties of the peroxyoxalate reaction in the presence of activators bearing electron withdrawing substituents were studied, to evaluate the possible occurrence of an inverse electron

  12. Biological activity of Serratia marcescens cytotoxin

    Directory of Open Access Journals (Sweden)

    G.V. Carbonell

    2003-03-01

    Full Text Available Serratia marcescens cytotoxin was purified to homogeneity by ion-exchange chromatography on a DEAE Sepharose Fast Flow column, followed by gel filtration chromatography on a Sephadex G100 column. The molecular mass of the cytotoxin was estimated to be about 50 kDa. Some biological properties of the cytotoxin were analyzed and compared with well-characterized toxins, such as VT1, VT2 and CNF from Escherichia coli and hemolysin produced by S. marcescens. The sensitivity of the cell lines CHO, HeLa, HEp-2, Vero, BHK-21, MA 104 and J774 to the cytotoxin was determined by the cell viability assay using neutral red. CHO and HEp-2 were highly sensitive, with massive cellular death after 1 h of treatment, followed by BHK-21, HeLa, Vero and J774 cells, while MA 104 was insensitive to the toxin. Cytotoxin induced morphological changes such as cell rounding with cytoplasmic retraction and nuclear compactation which were evident 15 min after the addition of cytotoxin. The cytotoxic assays show that 15 min of treatment with the cytotoxin induced irreversible intoxication of the cells, determined by loss of cell viability. Concentrations of 2 CD50 (0.56 µg/ml of purified cytotoxin did not present any hemolytic activity, showing that the cytotoxin is distinct from S. marcescens hemolysin. Antisera prepared against S. marcescens cytotoxin did not neutralize the cytotoxic activity of VT1, VT2 or CNF toxin, indicating that these toxins do not share antigenic determinants with cytotoxin. Moreover, we did not detect gene sequences for any of these toxins in S. marcescens by PCR assay. These results suggest that S. marcescens cytotoxin is not related to any of these toxins from E. coli.

  13. Activation analysis of biological materials at the Activation Analysis Centre

    International Nuclear Information System (INIS)

    Kukula, F.; Obrusnik, I.; Simkova, M.; Kucera, J.; Krivanek, M.

    1976-01-01

    A review is presented of the work of the Activation Analysis Centre of the Nuclear Research Institute for different fields of the Czechoslovak economy, aimed primarily at analyzing biological materials with the purpose of determining the contents of the so-called vital trace elements and of elements which already have a toxic effect on the organism in trace concentrations. Another important field of research is the path of trace elements from the environment to the human organism. A destructive method for the simultaneous determination of 12 trace elements in 11 kinds of human tissue has been studied. (Z.M.)

  14. Protease activated receptors (PARS) mediation in gyroxin biological activity

    International Nuclear Information System (INIS)

    Silva, Jose Alberto Alves da

    2009-01-01

    Gyroxin is a serine protease enzyme from the South American rattlesnake (Crotalus durissus terrificus) venom; it is only partially characterized and has multiple activities. Gyroxin induces blood coagulation, blood pressure decrease and a neurotoxic behavior named barrel rotation. The mechanisms involved in this neurotoxic activity are not known. Whereas gyroxin is a member of enzymes with high potential to become a new drug with clinical applications such as thrombin, batroxobin, ancrod, tripsyn and kalicrein, it is important to find out how gyroxin works. The analysis on agarose gel electrophoresis and circular dichroism confirmed the molecules' integrity and purity. The gyroxin intravenous administration in mice proved its neurotoxicity (barrel rotation). In vivo studies employing intravital microscopy proved that gyroxin induces vasodilation with the participation of protease activated receptors (PARs), nitric oxide and Na+K+ATPase. The leukocytes' adherence and rolling counting indicated that gyroxin has no pro inflammatory activity. Gyroxin induced platelet aggregation, which was blocked by inhibitors of PAR1 and PAR4 receptors (SCH 79797 and tcY-NH 2 , respectively). Finally, it was proved that the gyroxin temporarily alter the permeability of the blood brain barrier (BBB). Our study has shown that both the protease-activated receptors and nitric oxide are mediators involved in the biological activities of gyroxin. (author)

  15. Biologically active extracts with kidney affections applications

    International Nuclear Information System (INIS)

    Pascu, Mihaela; Pascu, Daniela-Elena; Cozea, Andreea; Bunaciu, Andrei A.; Miron, Alexandra Raluca; Nechifor, Cristina Aurelia

    2015-01-01

    Highlights: • The paper highlighted the compositional similarities and differences between the three extracts of bilberry and cranberry fruit derived from the same Ericaceae family. • A method of antioxidant activity, different cellulose membranes, a Whatman filter and Langmuir – kinetic model were used. • Arbutoside presence in all three extracts of bilberry and cranberry fruit explains their use in urinary infections – cystitis and colibacillosis. • Following these research studies, it was established that the fruits of bilberry and cranberry (fruit and leaves) significantly reduce the risk of urinary infections, and work effectively to protect against free radicals and inflammation. - Abstract: This paper is aimed to select plant materials rich in bioflavonoid compounds, made from herbs known for their application performances in the prevention and therapy of renal diseases, namely kidney stones and urinary infections (renal lithiasis, nephritis, urethritis, cystitis, etc.). This paper presents a comparative study of the medicinal plant extracts composition belonging to Ericaceae-Cranberry (fruit and leaves) – Vaccinium vitis-idaea L. and Bilberry (fruit) – Vaccinium myrtillus L. Concentrated extracts obtained from medicinal plants used in this work were analyzed from structural, morphological and compositional points of view using different techniques: chromatographic methods (HPLC), scanning electronic microscopy, infrared, and UV spectrophotometry, also by using kinetic model. Liquid chromatography was able to identify the specific compounds of the Ericaceae family, present in all three extracts, arbutosid, as well as specific components of each species, mostly from the class of polyphenols. The identification and quantitative determination of the active ingredients from these extracts can give information related to their therapeutic effects.

  16. Biologically active extracts with kidney affections applications

    Energy Technology Data Exchange (ETDEWEB)

    Pascu, Mihaela, E-mail: mihhaela_neagu@yahoo.com [SC HOFIGAL S.A., Analytical Research Department, 2 Intr. Serelor, Bucharest-4 042124 (Romania); Politehnica University of Bucharest, Faculty of Applied Chemistry and Material Science, 1-5 Polizu Street, 11061 Bucharest (Romania); Pascu, Daniela-Elena [Politehnica University of Bucharest, Faculty of Applied Chemistry and Material Science, 1-5 Polizu Street, 11061 Bucharest (Romania); Cozea, Andreea [SC HOFIGAL S.A., Analytical Research Department, 2 Intr. Serelor, Bucharest-4 042124 (Romania); Transilvania University of Brasov, Faculty of Food and Tourism, 148 Castle Street, 500036 Brasov (Romania); Bunaciu, Andrei A. [SCIENT – Research Center for Instrumental Analysis, S.C. CROMATEC-PLUS S.R.L., 18 Sos. Cotroceni, Bucharest 060114 (Romania); Miron, Alexandra Raluca; Nechifor, Cristina Aurelia [Politehnica University of Bucharest, Faculty of Applied Chemistry and Material Science, 1-5 Polizu Street, 11061 Bucharest (Romania)

    2015-12-15

    Highlights: • The paper highlighted the compositional similarities and differences between the three extracts of bilberry and cranberry fruit derived from the same Ericaceae family. • A method of antioxidant activity, different cellulose membranes, a Whatman filter and Langmuir – kinetic model were used. • Arbutoside presence in all three extracts of bilberry and cranberry fruit explains their use in urinary infections – cystitis and colibacillosis. • Following these research studies, it was established that the fruits of bilberry and cranberry (fruit and leaves) significantly reduce the risk of urinary infections, and work effectively to protect against free radicals and inflammation. - Abstract: This paper is aimed to select plant materials rich in bioflavonoid compounds, made from herbs known for their application performances in the prevention and therapy of renal diseases, namely kidney stones and urinary infections (renal lithiasis, nephritis, urethritis, cystitis, etc.). This paper presents a comparative study of the medicinal plant extracts composition belonging to Ericaceae-Cranberry (fruit and leaves) – Vaccinium vitis-idaea L. and Bilberry (fruit) – Vaccinium myrtillus L. Concentrated extracts obtained from medicinal plants used in this work were analyzed from structural, morphological and compositional points of view using different techniques: chromatographic methods (HPLC), scanning electronic microscopy, infrared, and UV spectrophotometry, also by using kinetic model. Liquid chromatography was able to identify the specific compounds of the Ericaceae family, present in all three extracts, arbutosid, as well as specific components of each species, mostly from the class of polyphenols. The identification and quantitative determination of the active ingredients from these extracts can give information related to their therapeutic effects.

  17. SYNTHESIS AND BIOLOGICAL ACTIVITIES OF 3,6 ...

    African Journals Online (AJOL)

    SYNTHESIS AND BIOLOGICAL ACTIVITIES OF 3,6-DISUBSTITUTED-1,2,4-. TRIAZOLO-1,3 ... Thus, many chemists reported synthesis and antimicrobial activity of some 1,2,4-triazolothiadiazole derivatives in ..... N.H. Synthesis and biological activity of oxadiazole and triazolothiadiazole derivatives as tyrosinase inhibitors.

  18. Office of Biological Informatics and Outreach geospatial technology activities

    Science.gov (United States)

    ,

    1998-01-01

    The U.S. Geological Survey (USGS) Office of Biological Informatics and Outreach (OBIO) in Reston, Virginia, and its Center for Biological Informatics (CBI) in Denver, Colorado, provide leadership in the development and use of geospatial technologies to advance the Nation's biological science activities.

  19. Monitoring Chemical and Biological Electron Transfer Reactions with a Fluorogenic Vitamin K Analogue Probe.

    Science.gov (United States)

    Belzile, Mei-Ni; Godin, Robert; Durantini, Andrés M; Cosa, Gonzalo

    2016-12-21

    We report herein the design, synthesis, and characterization of a two-segment fluorogenic analogue of vitamin K, B-VK Q , prepared by coupling vitamin K 3 , also known as menadione (a quinone redox center), to a boron-dipyrromethene (BODIPY) fluorophore (a lipophilic reporter segment). Oxidation-reduction reactions, spectroelectrochemical studies, and enzymatic assays conducted in the presence of DT-diaphorase illustrate that the new probe shows reversible redox behavior on par with that of vitamin K, provides a high-sensitivity fluorescence signal, and is compatible with biological conditions, opening the door to monitor remotely (i.e., via imaging) redox processes in real time. In its oxidized form, B-VK Q is non-emissive, while upon reduction to the hydroquinone form, B-VK QH 2 , BODIPY fluorescence is restored, with emission quantum yield values of ca. 0.54 in toluene. Density functional theory studies validate a photoinduced electron transfer intramolecular switching mechanism, active in the non-emissive quinone form and deactivated upon reduction to the emissive dihydroquinone form. Our results highlight the potential of B-VK Q as a fluorogenic probe to study electron transfer and transport in model systems and biological structures with optimal sensitivity and desirable chemical specificity. Use of such a probe may enable a better understanding of the role that vitamin K plays in biological redox reactions ubiquitous in key cellular processes, and help elucidate the mechanism and pathological significance of these reactions in biological systems.

  20. Advances in imaging and electron physics time resolved electron diffraction for chemistry, biology and material science

    CERN Document Server

    Hawkes, Peter W

    2014-01-01

    Advances in Imaging & Electron Physics merges two long-running serials-Advances in Electronics & Electron Physics and Advances in Optical & Electron Microscopy. The series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains. Contributions from leading authorities Informs and updates on all the latest developments in the field.

  1. Biological activities of substituted trichostatic acid derivatives

    Indian Academy of Sciences (India)

    Administrator

    , although weaker zinc ligands than the hydroxamic acids, generally lead to bioactive molecules and pos- sess higher stability in biological environments. In this respect we prepared both hydroxamic acids and benzamide versions of the target ...

  2. Fundamental Technical Elements of Freeze-fracture/Freeze-etch in Biological Electron Microscopy

    Science.gov (United States)

    Freeze-fracture/freeze-etch describes a process whereby specimens, typically biological or nanomaterial in nature, are frozen, fractured, and replicated to generate a carbon/platinum "cast" intended for examination by transmission electron microscopy. Specimens are subjected to u...

  3. Electron and Proton Transfer by the Grotthuss Mechanism in Aqueous Solution and in Biological Systems

    International Nuclear Information System (INIS)

    Horne, R.A.; Courant, R.A.; Johnson, D.S.

    1965-01-01

    TheFe ll -Fe III electron-exchange reaction and certain long-range biological redox reactions involve the transfer of electrons by a Grotthuss-type mechanism over water bridges. The Grotthuss mechanism is also responsible for the anomalously great electrical conductivity of acidic aqueous solutions. At ordinary pressures the rate-determining step of the Grotthuss mechanism is the rotation of H 2 O, or possibly H 3 O+, and not the actual proton flip itself. The Grotthuss mechanism is confined to the ''free'' rotatable monomeric water between the Frank-Wen clusters in liquid water and avoids areas of relative order. The concentration dependence of protonic conduction can be represented by an equation based upon a cube root of concentration extrapolation and containing Arrhenius terms in which the activation energies are those for the rotation of and the formation of ''holes'' in the solvent water. Thus chemical energy and/or electrical energy can be transmitted rapidly over relatively great distances by the Grotthuss mechanism. Such processes are involved in a variety of phenomena of biological significance, examples being muscular contraction and the chemistry of the respiratory pigments. (author) [fr

  4. Electron Transfer Studies of Ruthenium(II) Complexes with Biologically Important Phenolic Acids and Tyrosine.

    Science.gov (United States)

    Rajeswari, Angusamy; Ramdass, Arumugam; Muthu Mareeswaran, Paulpandian; Rajagopal, Seenivasan

    2016-03-01

    The ruthenium(II) complexes having 2,2'-bipyridine and phenanthroline derivatives are synthesized and characterized. The photophysical properties of these complexes at pH 12.5 are studied. The electron transfer reaction of biologically important phenolic acids and tyrosine are studied using absorption, emission and transient absorption spectral techniques. Semiclassical theory is applied to calculate the rate of electron transfer between ruthenium(II) complexes and biologically important phenolic acids.

  5. Instrumental neutron activation analysis of biological samples

    International Nuclear Information System (INIS)

    Guinn, V.P.; Gavrilas, M.

    1990-01-01

    The elemental compositions of 18 biological reference materials have been processed, for 14 stepped combinations of irradiation/decay/counting times, by the INAA Advance Prediction Computer Program. The 18 materials studied include 11 plant materials, 5 animal materials, and 2 other biological materials. Of these 18 materials, 14 are NBS Standard Reference Materials and four are IAEA reference materials. Overall, the results show that a mean of 52% of the input elements can be determined to a relative standard deviation of ±10% or better by reactor flux (thermal plus epithermal) INAA

  6. Dew formation and activity of biological crusts

    NARCIS (Netherlands)

    Veste, M.; Heusinkveld, B.G.; Berkowicz, S.M.; Breckle, S.W.; Littmann, T.; Jacobs, A.F.G.

    2008-01-01

    Biological soil crusts are prominent in many drylands and can be found in diverse parts of the globe including the Atacama desert, Chile, the Namib desert, Namibia, the Succulent-Karoo desert, South Africa, and the Negev desert, Israel. Because precipitation can be negligible in deserts ¿ the

  7. Biological activities of synthesized silver nanoparticles from ...

    Indian Academy of Sciences (India)

    Nanotechnology is interdisciplinary which includes physics, chemistry, biology, material science and medicine. Nanotechnology is a universal term for the creation, manip ... range of medical devices including bone cement, surgical instruments, surgical masks, etc. Synthesis of noble metal na- noparticles, in particular, silver ...

  8. Methanol as electron donor for thermophilic biological sulfate and sulfite reduction

    NARCIS (Netherlands)

    Weijma, J.

    2000-01-01

    Sulfur oxyanions (e.g. sulfate, sulfite) can be removed from aqueous waste- and process streams by biological reduction with a suitable electron donor to sulfide, followed by partial chemical or biological oxidation of sulfide to elemental sulfur. The aim of the research described in this

  9. Physical aspects of biological activity and cancer

    Czech Academy of Sciences Publication Activity Database

    Pokorný, Jiří

    2012-01-01

    Roč. 2, č. 1 (2012), s. 011207 ISSN 2158-3226 R&D Projects: GA ČR(CZ) GAP102/11/0649 Institutional support: RVO:67985882 Keywords : Electromagnetic fields * Cellular biophysics * Cancer Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 1.349, year: 2012

  10. Egg yolk proteins and peptides with biological activity

    Directory of Open Access Journals (Sweden)

    Aleksandra Zambrowicz

    2014-12-01

    Full Text Available Many proteins of food reveal biological activity. In the sequence of these proteins also numerous biologically active peptides are encrypted. These peptides are released during proteolysis naturally occurring in the gastrointestinal tract, food fermentation or during designed enzymatic hydrolysis in vitro. Biopeptides may exert multiple activities, affecting the cardiovascular, endocrine, nervous and immune systems. An especially rich source of bioactive proteins and biopeptides is egg. Bioactive peptides released from egg white proteins have been well described, whereas egg yolk proteins as precursors of biopeptides are less well characterized. This manuscript describes biologically active proteins and peptides originating from egg yolk and presents their potential therapeutic role.

  11. Galloylation of polyphenols alters their biological activity

    Czech Academy of Sciences Publication Activity Database

    Karas, D.; Ulrichová, J.; Valentová, Kateřina

    2017-01-01

    Roč. 105, JUL 2017 (2017), s. 223-240 ISSN 0278-6915 R&D Projects: GA MŠk(CZ) LD15082; GA MŠk(CZ) LD15084; GA MŠk(CZ) LO1304 Grant - others:GA ČR(CZ) GAP303/12/G163 Program:GA Institutional support: RVO:61388971 Keywords : Polyphenols * Gallic acid * Galloylation Subject RIV: CE - Biochemistry OBOR OECD: Biochemistry and molecular biology Impact factor: 3.778, year: 2016

  12. Biological activities of substituted trichostatic acid derivatives

    Indian Academy of Sciences (India)

    Administrator

    as 6-fluoro trichostatin A, with antiproliferative activities in the micromolar range and with histone deacetylase inhibitory activity. Keywords. Trichostatic acid; HDAC; inhibitor. 1. Introduction. Reversible chemical modifications of DNA and his- tones are important cellular events that promote activation or repression of DNA ...

  13. Ficus carica L. (Moraceae): Phytochemistry, Traditional Uses and Biological Activities

    Science.gov (United States)

    Mawa, Shukranul; Husain, Khairana; Jantan, Ibrahim

    2013-01-01

    This paper describes the botanical features of Ficus carica L. (Moraceae), its wide variety of chemical constituents, its use in traditional medicine as remedies for many health problems, and its biological activities. The plant has been used traditionally to treat various ailments such as gastric problems, inflammation, and cancer. Phytochemical studies on the leaves and fruits of the plant have shown that they are rich in phenolics, organic acids, and volatile compounds. However, there is little information on the phytochemicals present in the stem and root. Reports on the biological activities of the plant are mainly on its crude extracts which have been proven to possess many biological activities. Some of the most interesting therapeutic effects include anticancer, hepatoprotective, hypoglycemic, hypolipidemic, and antimicrobial activities. Thus, studies related to identification of the bioactive compounds and correlating them to their biological activities are very useful for further research to explore the potential of F. carica as a source of therapeutic agents. PMID:24159359

  14. SYNTHESIS, REACTIVITY AND BIOLOGICAL ACTIVITY OF QUINOXALIN-2-ONE DERIVATIVES

    OpenAIRE

    El Mokhtar Essassi; R. Bouhfid; Y. Kandri Rodi; S. Ferfra; H. Benzeid; Y. Ramli

    2010-01-01

    Quinoxalines have a great interest in various fields and particularly in chemistry, biology and pharmacology. It enabled the researchers to develop many methods for their preparations and to seek new fields of application. In this review, we’ll expose different methods of synthesis of the quinoxalin-2-one, its reactivity and finally we’ll discuss the various biological activities of its derivatives.

  15. Biological denitrification using poly(butanediol succinate) as electron donor.

    Science.gov (United States)

    Shen, Zhiqiang; Yin, Yanan; Wang, Jianlong

    2016-07-01

    Poly(butanediol succinate) (PBS), a biodegradable polymer, was used as both solid carbon source and biofilm carrier for biological nitrate removal process, in which PBS was filled in a packed-bed bioreactor. The denitrification performance and the microbial diversity of biofilm attached on the surface of PBS were investigated. The experimental results showed that the volumetric denitrification rate was 0.60 kg m(-3) day(-1) when NO3-N loading rate was 0.63 kg m(-3) day(-1), and the average NO2-N concentration was below 0.20 mg L(-1). The effluent pH value decreased slightly from a range of 6.98-7.87 to 6.46-7.18. The analysis of microbial community structure of biofilm by pyrosequencing method showed that Proteobacteria was the most abundant phylum (89.87 %), and β-Proteobacteria represented the most abundant class. Among the 76 identified genera, Dechloromonas (10.26 %), Alicycliphilus (9.15 %), Azospira (8.92 %), and Sinobacteraceae-uncultured (8.75 %) were the abundant genera. PBS, as a promising alternative carbon source, is a suitable solid carbon source and biofilm carrier for nitrate removal.

  16. Biological activities of Croton palanostigma Klotzsch.

    Science.gov (United States)

    Mota, Eduardo Ferreira; Rosario, Diele Magno; Silva Veiga, Andreza Socorro; Barros Brasil, Davi Do Socorro; Silveira, Fernando Tobias; Dolabela, Maria Fâni

    2016-01-01

    Different species of Croton are used in traditional Amazonian medicine. Among the popular uses are treatment of bacterial diseases, poorly healing wounds and fevers. This study evaluated the antileishmanial, antiplasmodial and antimicrobial activities of the extracts and diterpenes of Croton palanostigma Klotzsch (Euphorbiaceae). Leaves and bark were extracted with dichloromethane and methanol. The bark dichloromethane extract (BDE) was chromatographed on a column, obtaining cordatin and aparisthman. The extracts and diterpenes were assayed thought agar disk diffusion method and their bactericidal or fungicidal effects were evaluated by minimum bactericidal or fungicidal concentration. The antiplasmodial activity was evaluated after 24 and 72 h of exposition. The antileishmanial activity was performed on promastigotes forms of Leishmania amazonensis. The bark methanol extract (BME) and cordatin were not active against any microbial strains tested; BDE and leaves methanol extract (LME) were positive for Pseudomonas aeruginosa and aparisthman was positive for Candida albicans. In the determination of the minimum bactericidal concentration, neither of them were active in the highest concentration tested. The extracts and diterpenes were inactive in Plasmodium falciparum, except the LME in 72 h. Any extract was shown to be active in promastigote forms of L. amazonensis. These results indicate that the BDE and LME did not inhibit the bacterial growth, then they probably had bacteriostatic effect. LME presented activity in P. falciparum.

  17. Flexible biological arsenite oxidation utilizing NOxand O2as alternative electron acceptors.

    Science.gov (United States)

    Wang, Jie; Wan, Junfeng; Wu, Zihao; Li, Hongli; Li, Haisong; Dagot, Christophe; Wang, Yan

    2017-07-01

    The feasibility of flexible microbial arsenite (As III ) oxidation coupled with the reduction of different electron acceptors was investigated. The results indicated the acclimated microorganisms could oxidize As III with oxygen, nitrate and nitrite as the alternative electron acceptors. A series of batch tests were conducted to measure the kinetic parameters of As III oxidation and to evaluate the effects of environmental conditions including pH and temperature on the activity of biological As III oxidation dependent on different electron acceptors. Kinetic results showed that oxygen-dependent As III oxidation had the highest oxidation rate (0.59 mg As g -1  VSS min -1 ), followed by nitrate- (0.40 mg As g -1  VSS min -1 ) and nitrite-dependent As III oxidation (0.32 mg As g -1  VSS min -1 ). The kinetic data of aerobic As III oxidation were fitted well with the Monod kinetic model, while the Haldane substrate inhibition model was better applicable to describe the inhibition of anoxic As III oxidation. Both aerobic and anoxic As III oxidation performed the optimal activity at the near neutral pH. Besides, the optimal temperature for oxygen-, nitrate- and nitrite-dependent As III oxidation was 30 ± 1 °C, 40 ± 1 °C and 20 ± 1 °C, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Synthesis and biological activities of substituted N ...

    African Journals Online (AJOL)

    use

    2011-12-07

    Dec 7, 2011 ... The present study describes the synthesis, antioxidant and antibacterial activities of substituted N'- benzoylhydrazone derivatives, to ... addition, the dramatically rising prevalence of multidrug- resistant microbial infections has ...... extract of Chinese green tea (Camellia sinensis) on Listeria monocytogenes.

  19. Active electronic personal dosemeter in interventional radiology

    International Nuclear Information System (INIS)

    Prlic, I.; Suric Mihic, M.; Vucic, Z.

    2008-01-01

    A recently developed active electronic personal dosemeter (AEPD) was utilised in order to measure the levels and the structure of occupational exposure to scattered X-ray radiation of medical staff who performed percutaneous revascularisation therapy that involves interventional radiology (IR) on the pelvis and upper leg arteries. The AEPDs, placed on the operators' and assistants' chests, that is, above the protective apron, continuously measured and recorded the received doses and, as a novelty, dose rates as a function of time, thus yielding a unique record of occupational doses and dose rates pattern at the working place. This paper presents and discusses one typical daily pattern in which seven percutaneous interventions were performed. (authors)

  20. Biological activities of Castela coccinea Griseb. extracts

    OpenAIRE

    Campagna, María Noel; Ratti, María Soledad; Sciara, Mariela; García Vescovi, Eleonora; Gattuso, Martha; Martínez, María Laura

    2011-01-01

    Infusions of leaf and bark of Castela coccinea Griseb. (Simaroubaceae) were traditionally used against dysentery. In this work, anti-bacterial and antioxidant activity were studied in C. coccinea extracts. The higest DPPH scavenging activity was detected in ethanolic leaf extracts with an IC50= 0.015 mg/ml. Bark ethanolic extracts showed inhibition of lipoperoxidation and free radical scavenging. However, a previous work evidenced that this extract is toxic at a concentration needed ...

  1. Synthetic Approaches and Biological Activities of 4-Hydroxycoumarin Derivatives

    Directory of Open Access Journals (Sweden)

    Oee-Sook Park

    2009-11-01

    Full Text Available The main purpose of this review is to summarize recent chemical syntheses and structural modifications of 4-hydroxycoumarin and its derivatives, of interest due to their characteristic conjugated molecular architecture and biological activities.

  2. Baltic cyanobacteria- A source of biologically active compounds

    Digital Repository Service at National Institute of Oceanography (India)

    Mazur-Marzec, H.; Błaszczyk, A.; Felczykowska, A.; Hohlfeld, N.; Kobos, J.; Toruńska-Sitarz, A.; PrabhaDevi; Montalva`o, S.; DeSouza, L.; Tammela, P.; Mikosik, A.; Bloch, S.; Nejman-Faleńczyk, B.; Węgrzyn, G.

    Cyanobacteria are effective producers of bioactive metabolites, including both acute toxins and potential pharmaceuticals. In the current work, the biological activity of 27 strains of Baltic cyanobacteria representing different taxonomic groups...

  3. Biologically active substances from Zanthoxylum capense(thumb.) Harv.

    CSIR Research Space (South Africa)

    Steyn, PS

    1998-08-01

    Full Text Available A chemical investigation into the composition of Zanthoxylum capense yielded several biologically active compounds, including pellitorine. A convenient HPLC method was developed to determine the presence of pellitorine in crude extracts from plants...

  4. Triazoles: a valuable insight into recent developments and biological activities.

    Science.gov (United States)

    Sahu, Jagdish K; Ganguly, Swastika; Kaushik, Atul

    2013-09-01

    In recent years, heterocyclic compounds, analogs, and derivatives have attracted strong interest due to their useful biological and pharmacological properties. The small and simple triazole nucleus is present in compounds aimed at evaluating new entities that possess anti-microbial, anti-tumor, antitubercular, anti-convulsant, anti-depressant, antimalarial, and anti-inflammatory activities. Triazoles display a broad range of biological activities and are found in many potent, biologically active compounds, such as trazodone (antidepressant drug), rizatriptan (antimigrane drug), hexaconazole (antifungal drug) and alprazolam (hyptonic, sedative and tranquilizer drug). So far, modifications of the triazole ring have proven highly effective with improved potency and lesser toxicity. The present review highlights the recently synthesized triazoles possessing important biological activities. Copyright © 2013 China Pharmaceutical University. Published by Elsevier B.V. All rights reserved.

  5. Biological activity of Herissantia crispa (L. Brizicky

    Directory of Open Access Journals (Sweden)

    Igara Oliveira Lima

    Full Text Available The crude methanol extract (EMeOH of the aerial parts of Herissantia crispa (L. Brizicky, plant riches in flavonoids and without pharmacological studies, was tested to value its activity under the behaviour parameters and to determine the lethal dose (LD50 in mice; antimicrobial and antiulcerogenic activities. The EMeOH (5,000 mg/kg, v.o. or 2,000 mg/kg i.p. did not alter the behaviour parameters and there were not mice deaths. The extract inhibited the bacterial growth. The EMeOH (750 mg/kg showed anti-diarroeal activity. The EMeOH (250, 500 and 750 mg/kg decreased the gastric lesions induced by 0.3 M HCl/ethanol 60% in mice. In conclusion, the EMeOH presents anti-ulcerogenic activity;, however it is necessary to value the antiulcerogenic activity in more specific models and to study the action mechanism by which the vegetable sample protects the gastric mucosa.

  6. Controlled Release of Biologically Active Silver from Nanosilver Surfaces

    OpenAIRE

    Liu, Jingyu; Sonshine, David A.; Shervani, Saira; Hurt, Robert H.

    2010-01-01

    Major pathways in the antibacterial activity and eukaryotic toxicity of nano-silver involve the silver cation and its soluble complexes, which are well established thiol toxicants. Through these pathways, nano-silver behaves in analogy to a drug delivery system, in which the particle contains a concentrated inventory of an active species, the ion, which is transported to and released near biological target sites. Although the importance of silver ion in the biological response to nano-silver ...

  7. Activated Sludge. Student Manual. Biological Treatment Process Control.

    Science.gov (United States)

    Boe, Owen K.; Klopping, Paul H.

    This student manual contains the textual material for a seven-lesson unit on activated sludge. Topic areas addressed in the lessons include: (1) activated sludge concepts and components (including aeration tanks, aeration systems, clarifiers, and sludge pumping systems); (2) activated sludge variations and modes; (3) biological nature of activated…

  8. Raman Optical Activity of Biological Molecules

    Science.gov (United States)

    Blanch, Ewan W.; Barron, Laurence D.

    Now an incisive probe of biomolecular structure, Raman optical activity (ROA) measures a small difference in Raman scattering from chiral molecules in right- and left-circularly polarized light. As ROA spectra measure vibrational optical activity, they contain highly informative band structures sensitive to the secondary and tertiary structures of proteins, nucleic acids, viruses and carbohydrates as well as the absolute configurations of small molecules. In this review we present a survey of recent studies on biomolecular structure and dynamics using ROA and also a discussion of future applications of this powerful new technique in biomedical research.

  9. Synthesis and biological activity of radiolabeled phytosterols

    Energy Technology Data Exchange (ETDEWEB)

    De Palma, A.

    1984-01-01

    /sup 3/H and /sup 14/C-labeled phytosterols were synthesized for the purpose of elucidating insect sterol side-chain dealkylating mechanisms. Sitosterol, stigmasterol, and the 29-fluoro derivatives of these compounds, which are highly toxic, were labeled with /sup 3/H at C-29 in order to study the fate of the two-carbon dealkylation product in vivo and in vitro. The first rapid, reliable in vitro dealkylation bioassay was developed using doubly-labeled (29-/sup 3/H)-(24-/sup 14/C) fucosterol epoxides as the substrates, incubated with midgut preparations from Manduca sexta, the tobacco hornworm. Since C-28 and C-29 are lost in the dealkylation process, the extent of dealkylation is expressed as the change in the isotopic ratio when the system is partitioned between an organic solvent and water after incubation. As predicted, the /sup 3/H//sup 14/C ratio decreases in the organic layer as a function of time, due to loss of /sup 3/H into the aqueous phase as acetate or a biological equivalent. This ratio likewise increases in the aqueous phase for the same reason. The (29-/sup 3/H) phytosterols alone are reliable substrates for the first rapid in vivo bioassay of phytosterol dealkylation.

  10. Synthesis and biological activity of radiolabeled phytosterols

    International Nuclear Information System (INIS)

    De Palma, A.

    1984-01-01

    3 H and 14 C-labeled phytosterols were synthesized for the purpose of elucidating insect sterol side-chain dealkylating mechanisms. Sitosterol, stigmasterol, and the 29-fluoro derivatives of these compounds, which are highly toxic, were labeled with 3 H at C-29 in order to study the fate of the two-carbon dealkylation product in vivo and in vitro. The first rapid, reliable in vitro dealkylation bioassay was developed using doubly-labeled [29- 3 H]-[24- 14 C] fucosterol epoxides as the substrates, incubated with midgut preparations from Manduca sexta, the tobacco hornworm. Since C-28 and C-29 are lost in the dealkylation process, the extent of dealkylation is expressed as the change in the isotopic ratio when the system is partitioned between an organic solvent and water after incubation. As predicted, the 3 H/ 14 C ratio decreases in the organic layer as a function of time, due to loss of 3 H into the aqueous phase as acetate or a biological equivalent. This ratio likewise increases in the aqueous phase for the same reason. The [29- 3 H] phytosterols alone are reliable substrates for the first rapid in vivo bioassay of phytosterol dealkylation

  11. Chitosan to Connect Biology to Electronics: Fabricating the Bio-Device Interface and Communicating Across This Interface

    Directory of Open Access Journals (Sweden)

    Eunkyoung Kim

    2014-12-01

    Full Text Available Individually, advances in microelectronics and biology transformed the way we live our lives. However, there remain few examples in which biology and electronics have been interfaced to create synergistic capabilities. We believe there are two major challenges to the integration of biological components into microelectronic systems: (i assembly of the biological components at an electrode address, and (ii communication between the assembled biological components and the underlying electrode. Chitosan possesses a unique combination of properties to meet these challenges and serve as an effective bio-device interface material. For assembly, chitosan’s pH-responsive film-forming properties allow it to “recognize” electrode-imposed signals and respond by self-assembling as a stable hydrogel film through a cathodic electrodeposition mechanism. A separate anodic electrodeposition mechanism was recently reported and this also allows chitosan hydrogel films to be assembled at an electrode address. Protein-based biofunctionality can be conferred to electrodeposited films through a variety of physical, chemical and biological methods. For communication, we are investigating redox-active catechol-modified chitosan films as an interface to bridge redox-based communication between biology and an electrode. Despite significant progress over the last decade, many questions still remain which warrants even deeper study of chitosan’s structure, properties, and functions.

  12. Synthesis, Physical Characterization and Biological Activity of Some Schiff Base Complexes

    Directory of Open Access Journals (Sweden)

    R. Rajavel

    2008-01-01

    Full Text Available Structural modification of organic molecule has considerable biological relevance. Further, coordination of a biomolecules to the metal ions significantly alters the effectiveness of the biomolecules. In view of the antimicrobial activity ligand [bis-(2-aminobenzaldehyde] malonoyl dihydrazone], metal complexes with Cu(II, Ni(II, Zn(II and oxovanadium(IV have been synthesized and found to be potential antimicrobial agents. An attempt is also made to correlate the biological activities with geometry of the complexes. The complexes have been characterized by elemental analysis, molar conductance, spectra and cyclicvoltammetric measurements. The structural assessment of the complexes has been carried out based on electronic, infrared and molar conductivity values.

  13. Copper Nanoparticles: Synthesis and Biological Activity

    Science.gov (United States)

    Satyvaldiev, A. S.; Zhasnakunov, Z. K.; Omurzak, E.; Doolotkeldieva, T. D.; Bobusheva, S. T.; Orozmatova, G. T.; Kelgenbaeva, Z.

    2018-01-01

    By means of XRD and FESEM analysis, it is established that copper nanoparticles with sizes less than 10 nm are formed during the chemical reduction, which form aggregates mainly with spherical shape. Presence of gelatin during the chemical reduction of copper induced formation of smaller size distribution nanoparticles than that of nanoparticles synthesized without gelatin and it can be related to formation of protective layer. Synthesized Cu nano-powders have sufficiently high activity against the Erwinia amylovora bacterium, and the bacterial growth inhibition depends on the Cu nanoparticles concentration. At a concentration of 5 mg / ml of Cu nanoparticles, the exciter growth inhibition zone reaches a maximum value within 72 hours and the lysis zone is 20 mm, and at a concentration of 1 mg / ml this value is 16 mm, which also indicates the significant antibacterial activity of this sample.

  14. Biological activities of synthesized silver nanoparticles from ...

    Indian Academy of Sciences (India)

    ical scavenging activity was measured by the salicylic acid method [16]. The synthesized AgNPs solution at different concentrations (10 to 80 μg ml. −1. ) was dissolved in 1 ml of distilled water. One millilitre of AgNPs mixed with 1 ml of. 9 mM salicylic acid, 1 ml of 9 mM ferrous sulphate and 1ml of 9 mM hydrogen peroxide.

  15. Heterologous expression of biologically active chicken granulocyte ...

    African Journals Online (AJOL)

    user

    2012-02-07

    Feb 7, 2012 ... CD4+ T cells to enhance the ability of secreting antibody and also enhance the function of CD8+ T cells. (Papatriantafyllou, 2011; Tovey and Lallemand, 2010). GM-CSF also is a key regulator of IL-1beta production. Furthermore, It was reported that GM-CSF play a key role in the activation of Th1 and Th17 ...

  16. Physical aspects of biological activity and cancer

    Science.gov (United States)

    Pokorný, Jiří

    2012-03-01

    Mitochondria are organelles at the boundary between chemical-genetic and physical processes in living cells. Mitochondria supply energy and provide conditions for physical mechanisms. Protons transferred across the inner mitochondrial membrane diffuse into cytosol and form a zone of a strong static electric field changing water into quasi-elastic medium that loses viscosity damping properties. Mitochondria and microtubules form a unique cooperating system in the cell. Microtubules are electrical polar structures that make possible non-linear transformation of random excitations into coherent oscillations and generation of coherent electrodynamic field. Mitochondria supply energy, may condition non-linear properties and low damping of oscillations. Electrodynamic activity might have essential significance for material transport, organization, intra- and inter-cellular interactions, and information transfer. Physical processes in cancer cell are disturbed due to suppression of oxidative metabolism in mitochodria (Warburg effect). Water ordering level in the cell is decreased, excitation of microtubule electric polar oscilations diminished, damping increased, and non-linear energy transformation shifted towards the linear region. Power and coherence of the generated electrodynamic field are reduced. Electromagnetic activity of healthy and cancer cells may display essential differences. Local invasion and metastastatic growth may strongly depend on disturbed electrodynamic activity. Nanotechnological measurements may disclose yet unknown properties and parameters of electrodynamic oscillations and other physical processes in healthy and cancer cells.

  17. Electron spin interactions in chemistry and biology fundamentals, methods, reactions mechanisms, magnetic phenomena, structure investigation

    CERN Document Server

    Likhtenshtein, Gertz

    2016-01-01

    This book presents the versatile and pivotal role of electron spin interactions in nature. It provides the background, methodologies and tools for basic areas related to spin interactions, such as spin chemistry and biology, electron transfer, light energy conversion, photochemistry, radical reactions, magneto-chemistry and magneto-biology. The book also includes an overview of designing advanced magnetic materials, optical and spintronic devices and photo catalysts. This monograph appeals to scientists and graduate students working in the areas related to spin interactions physics, biophysics, chemistry and chemical engineering.

  18. Saponins from Swartzia langsdorffii: biological activities

    Directory of Open Access Journals (Sweden)

    Magalhães Aderbal Farias

    2003-01-01

    Full Text Available The presence of saponins and the molluscicidal activity of the roots, leaves, seeds and fruits of Swartzia langsdorffii Raddi (Leguminosae against Biomphalaria glabrata adults and eggs were investigated. The roots, seeds and fruits were macerated in 95% ethanol. These extracts exerted a significant molluscicidal activity against B. glabrata, up to a dilution of 100 mg/l. Four mixtures (A2, B2, C and D of triterpenoid oleanane type saponins were chromatographically isolated from the seed and fruit extracts. Two known saponins (1 and 2 were identified as beta-D-glucopyranosyl-[alpha-L-rhamnopyranosyl-(1->3- beta-D-glucuronopyranosyl-(1->3]-3beta-hydroxyolean-12-ene-28 -oate, and beta-D-glucopyranosyl-(1->3-beta-D-glucuronopyranosyl-(1 ->3]-3beta-hydroxyolean-12-ene-28-oate, respectively. These two saponins were present in all the mixtures, together with other triterpenoid oleane type saponins, which were shown to be less polar, by reversed-phase HPLC. The saponin identifications were based on spectral evidence, including ¹H-¹H two-dimensional correlation spectroscopy, nuclear Overhauser and exchange spectroscopy, heteronuclear multiple quantum coherence, and heteronuclear multiple-bond connectivity experiments. The toxicity of S. langsdorffii saponins to non-target organisms was prescreened by the brine shrimp lethality test.

  19. A short comparison of electron and proton transfer processes in biological systems

    International Nuclear Information System (INIS)

    Bertrand, Patrick

    2005-01-01

    The main differences between electron and proton transfers that take place in biological systems are examined. The relation between the distance dependence of the rate constant and the mass of the transferred particle is analyzed in detail. Differences between the two processes have important consequences at the experimental level, which are discussed. The various mechanisms that ensure the coupling between electron and proton transfers are briefly described

  20. Dynamical "in situ" observation of biological samples using variable pressure scanning electron microscope

    Czech Academy of Sciences Publication Activity Database

    Neděla, Vilém

    2008-01-01

    Roč. 126, - (2008), 012046:1-4 ISSN 1742-6588. [Electron Microscopy and Analysis Group Conference 2007 (EMAG 2007). Glasgow, 03.09.2007-07.09.2007] R&D Projects: GA ČR(CZ) GA102/05/0886; GA AV ČR KJB200650602 Institutional research plan: CEZ:AV0Z20650511 Keywords : biological sample * VP-SEM * dynamical experiments Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering

  1. 2. Brazilian Congress on Cell Biology and 7. Brazilian Colloquium on Electron Microscopy - Abstracts

    International Nuclear Information System (INIS)

    1980-01-01

    Immunology, virology, bacteriology, genetics and protozoology are some of the subjects treated in the 2. Brazilian Congress on Cell Biology. Studies using radioisotopic techniques and ultrastructural cytological studies are presented. Use of optical - and electron microscopy in some of these studies is discussed. In the 7. Brazilian Colloquium on Electron Microscopy, the application of this technique to materials science is discussed (failure analysis in metallurgy, energy dispersion X-ray analysis, etc). (I.C.R.) [pt

  2. Biological activities of radiation-degraded carrageenan

    Energy Technology Data Exchange (ETDEWEB)

    Relleve, Lorna; Dela Rosa, Alumanda; ABAD, Lucille; Aranilla, Charito; Aliganga, Anne Kathrina [Philippine Nuclear Research Institute, Quezon City (Philippines); Yoshii, Fumio; Kume, Tamikazu; Nagasawa, Naotsugu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment

    2001-03-01

    Carrageenans were irradiated in solid state to doses 50-1000 kGy in air at ambient temperature. Changes in their molecular weight and functional properties with respect to their FT-IR and UV spectra were evaluated. Irradiation of carrageenans resulted in a rapid decrease of molecular weight indicating main chain scission in their polymeric structures. Formations of some compounds were evident by new absorption peaks in their UV and FT-IR spectra and quantitative analyses of the FT-IR spectra which, in addition, support that there is a breakdown in the carrageenan structure. Irradiated carrageenans were investigated for their plant growth-promoting activity. Carrageenans were added to the nutrient solutions for rice seedlings under non-circulating hydroponics cultivation. Irradiated carrageenan induced weight gain in treated rice seedlings. Maximum weight gain was obtained with KC irradiated at 100 kGy while treatment with IC at 500 kGy. IC exhibited less growth promoting properties than KC. The growth of fungi on the roots disappeared with treatment of IC and KC irradiated at 500 kGy. Growth promotion of some leafy vegetables was also observed with application of degraded KC. The carrageenan molecule has been broken down to smaller molecule (s) or compound (s) that can be absorbed effectively as nourishment factors and anti-microbial agents by plants. (author)

  3. Biological activities of radiation-degraded carrageenan

    International Nuclear Information System (INIS)

    Relleve, Lorna; Dela Rosa, Alumanda; ABAD, Lucille; Aranilla, Charito; Aliganga, Anne Kathrina; Yoshii, Fumio; Kume, Tamikazu; Nagasawa, Naotsugu

    2001-01-01

    Carrageenans were irradiated in solid state to doses 50-1000 kGy in air at ambient temperature. Changes in their molecular weight and functional properties with respect to their FT-IR and UV spectra were evaluated. Irradiation of carrageenans resulted in a rapid decrease of molecular weight indicating main chain scission in their polymeric structures. Formations of some compounds were evident by new absorption peaks in their UV and FT-IR spectra and quantitative analyses of the FT-IR spectra which, in addition, support that there is a breakdown in the carrageenan structure. Irradiated carrageenans were investigated for their plant growth-promoting activity. Carrageenans were added to the nutrient solutions for rice seedlings under non-circulating hydroponics cultivation. Irradiated carrageenan induced weight gain in treated rice seedlings. Maximum weight gain was obtained with KC irradiated at 100 kGy while treatment with IC at 500 kGy. IC exhibited less growth promoting properties than KC. The growth of fungi on the roots disappeared with treatment of IC and KC irradiated at 500 kGy. Growth promotion of some leafy vegetables was also observed with application of degraded KC. The carrageenan molecule has been broken down to smaller molecule (s) or compound (s) that can be absorbed effectively as nourishment factors and anti-microbial agents by plants. (author)

  4. [Oregano: properties, composition and biological activity].

    Science.gov (United States)

    Arcila-Lozano, Cynthia Cristina; Loarca-Piña, Guadalupe; Lecona-Uribe, Salvador; González de Mejía, Elvira

    2004-03-01

    The oregano spice includes various plant species. The most common are the genus Origanum, native of Europe, and the Lippia, native of Mexico. Among the species of Origanum. their most important components are the limonene, gamma-cariofilene, rho-cymenene, canfor, linalol, alpha-pinene, carvacrol and thymol. In the genus Lippia, the same compounds can be found. The oregano composition depends on the specie, climate, altitude, time of recollection and the stage of growth. Some of the properties of this plant's extracts are being currently studied due to the growing interest for substituting synthetic additives commonly found in foods. Oregano has a good antioxidant capacity and also presents antimicrobial activity against pathogenic microorganisms like Salmonella typhimurium, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, among others. These are all characteristics of interest for the food industry because they may enhance the safety and stability of foods. There are also some reports regarding the antimutagenic and anticarcinogenic effect of oregano; representing an alternative for the potential treatment and/or prevention of certain chronic ailments, like cancer.

  5. Azaglycomimetics: Natural Occurrence, Biological Activity, and Application

    Science.gov (United States)

    Asano, Naoki

    A large number of alkaloids mimicking the structures of monosaccharides or oligosaccharides have been isolated from plants and microorganisms. The sugar mimicking alkaloids with a nitrogen in the ring are called azasugars or iminosugars. Naturally occurring azasugars are classified into five structural classes: polyhydroxylated piperidines, pyrrolidines, indolizidines, pyrrolizidines, and nortropanes. They are easily soluble in water because of their polyhydroxylated structures and inhibit glycosidases because of a structural resemblance to the sugar moiety of the natural substrate. Glycosidases are involved in a wide range of anabolic and catabolic processes, such as digestion, lysosomal catabolism of glycoconjugates, biosynthesis of glycoproteins, and the endoplasmic reticulum (ER) quality control and ER-associated degradation of glycoproteins. Hence, modifying or blocking these processes in vivo by inhibitors is of great interest from a therapeutic point of view. Azasugars are an important class of glycosidase inhibitors and are arousing great interest for instance as antidiabetics, antiobesity drugs, antivirals, and therapeutic agents for some genetic disorders. This review describes the recent studies on isolation, characterization, glycosidase inhibitory activity, and therapeutic application of azaglycomimetics.

  6. Comparative study of biological activity of glutathione, sodium ...

    African Journals Online (AJOL)

    Glutathione (GSH) and sodium tungstate (Na2WO4) are important pharmacological agents. They provide protection to cells against cytotoxic agents and thus reduce their cytotoxicity. It was of interest to study the biological activity of these two pharmacological active agents. Different strains of bacteria were used and the ...

  7. Assessing Student Behaviors and Motivation for Actively Learning Biology

    Science.gov (United States)

    Moore, Michael Edward

    2017-01-01

    Vision and Change states that one of the major changes in the way we design biology courses should be a switch in approach from teacher-centered learning to student-centered learning and identifies active learning as a recommended methods. Studies show performance benefits for students taking courses that use active learning. What is unknown is…

  8. Multifunctional biomaterial coatings: synthetic challenges and biological activity.

    Science.gov (United States)

    Pagel, Mareen; Beck-Sickinger, Annette G

    2017-01-01

    A controlled interaction of materials with their surrounding biological environment is of great interest in many fields. Multifunctional coatings aim to provide simultaneous modulation of several biological signals. They can consist of various combinations of bioactive, and bioinert components as well as of reporter molecules to improve cell-material contacts, prevent infections or to analyze biochemical events on the surface. However, specific immobilization and particular assembly of various active molecules are challenging. Herein, an overview of multifunctional coatings for biomaterials is given, focusing on synthetic strategies and the biological benefits by displaying several motifs.

  9. SYNTHESIS, REACTIVITY AND BIOLOGICAL ACTIVITY OF QUINOXALIN-2-ONE DERIVATIVES

    Directory of Open Access Journals (Sweden)

    El Mokhtar Essassi

    2010-04-01

    Full Text Available Quinoxalines have a great interest in various fields and particularly in chemistry, biology and pharmacology. It enabled the researchers to develop many methods for their preparations and to seek new fields of application. In this review, we’ll expose different methods of synthesis of the quinoxalin-2-one, its reactivity and finally we’ll discuss the various biological activities of its derivatives.

  10. Surface Immobilized His-tagged Azurin as a Model Interface for the Investigation of Vectorial Electron Transfer in Biological Systems

    International Nuclear Information System (INIS)

    Casalini, Stefano; Berto, Marcello; Kovtun, Alessandro; Operamolla, Alessandra; Di Rocco, Giulia; Facci, Paolo; Liscio, Andrea; Farinola, Gianluca M.; Borsari, Marco; Bortolotti, Carlo A.

    2015-01-01

    A model system for the electrochemical investigation of vectorial electron transfer in biological systems was designed, assembled and characterized. Gold electrodes, functionalized with a -OCH 3 terminated, aromatic self-assembled monolayer, were used as a substrate for the adsorption of variants of copper-containing, redox metalloprotein azurin. The engineered azurin bears a polyhistidine tag at its C-terminus. Thanks to the presence of the solvent exposed tag, which chelates Cu 2+ ions in solution, we introduced an exogenous redox centre. The different reduction potentials of the two redox centres and their positioning with respect to the surface are such that electron transfer from the exogenous copper centre and the electrode is mediated by the native azurin active site, closely paralleling electron transfer processes in naturally occurring multicentre metalloproteins.

  11. Monitoring of biological odour filtration in closed environments with olfactometry and an electronic nose

    NARCIS (Netherlands)

    Willers, H.C.; Gijsel, de P.; Ogink, N.W.M.; Amico, D' A.; Martinelli, E.; Natale, Di C.; Ras, van N.; Waarde, van der J.

    2004-01-01

    Air treatment with a compact biological membrane filter, and air quality monitoring with an electronic nose were tested in the laboratory on air from a cage containing six mice. Additional analyses of air to and from the filter were performed using olfactometry and ammonia and hydrogen sulphide gas

  12. Electron Transfer in Chemistry and Biology-The Primary Events in ...

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 2; Issue 12. Electron Transfer in Chemistry and Biology – The Primary Events in Photosynthesis. V Krishnan. General Article Volume 2 Issue 12 December 1997 pp 77-86. Fulltext. Click here to view fulltext PDF. Permanent link:

  13. How to observe small biological objects in low voltage electron microscope

    Czech Academy of Sciences Publication Activity Database

    Nebesářová, Jana; Vancová, Marie

    2007-01-01

    Roč. 13, č. 3 (2007), s. 248-249 ISSN 1431-9276 R&D Projects: GA AV ČR 1QS600220501 Institutional research plan: CEZ:AV0Z60220518 Keywords : low voltage electron microscope * negative staining * flagella * Borrelia burgdorferi Subject RIV: EA - Cell Biology Impact factor: 1.941, year: 2007

  14. Energy-filtered transmission electron microscopy of biological samples on highly transparent carbon nanomembranes

    International Nuclear Information System (INIS)

    Rhinow, Daniel; Bueenfeld, Matthias; Weber, Nils-Eike; Beyer, Andre; Goelzhaeuser, Armin; Kuehlbrandt, Werner; Hampp, Norbert; Turchanin, Andrey

    2011-01-01

    Ultrathin carbon nanomembranes (CNM) comprising crosslinked biphenyl precursors have been tested as support films for energy-filtered transmission electron microscopy (EFTEM) of biological specimens. Due to their high transparency CNM are ideal substrates for electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) of stained and unstained biological samples. Virtually background-free elemental maps of tobacco mosaic virus (TMV) and ferritin have been obtained from samples supported by ∼1 nm thin CNM. Furthermore, we have tested conductive carbon nanomembranes (cCNM) comprising nanocrystalline graphene, obtained by thermal treatment of CNM, as supports for cryoEM of ice-embedded biological samples. We imaged ice-embedded TMV on cCNM and compared the results with images of ice-embedded TMV on conventional carbon film (CC), thus analyzing the gain in contrast for TMV on cCNM in a quantitative manner. In addition we have developed a method for the preparation of vitrified specimens, suspended over the holes of a conventional holey carbon film, while backed by ultrathin cCNM. -- Research highlights: → We examine ultrathin carbon nanomembranes (CNM) as supports for biological TEM. → CNM comprise crosslinked biphenyl precursors. → CNM supports enable background-free elemental mapping of heavy and light elements. → We perform cryoEM of ice-embedded biological samples on graphene-like conductive CNM.

  15. Distorted wave calculations for electron loss process induced by bare ion impact on biological targets

    International Nuclear Information System (INIS)

    Monti, J.M.; Tachino, C.A.; Hanssen, J.; Fojón, O.A.; Galassi, M.E.; Champion, C.; Rivarola, R.D.

    2014-01-01

    Distorted wave models are employed to investigate the electron loss process induced by bare ions on biological targets. The two main reactions which contribute to this process, namely, the single electron ionization as well as the single electron capture are here studied. In order to further assess the validity of the theoretical descriptions used, the influence of particular mechanisms are studied, like dynamic screening for the case of electron ionization and energy deposition on the target by the impacting projectile for the electron capture one. Results are compared with existing experimental data. - Highlights: ► Distorted wave models are used to investigate ion-molecule collisions. ► Differential and total cross-sections for capture and ionization are evaluated. ► The influence of dynamic screening is determined. ► Capture reaction dominates the mean energy deposited by the projectile on the target

  16. Biological activity of antitumoural MGBG: the structural variable.

    Science.gov (United States)

    Marques, M P M; Gil, F P S C; Calheiros, R; Battaglia, V; Brunati, A M; Agostinelli, E; Toninello, A

    2008-05-01

    The present study aims at determining the structure-activity relationships (SAR's) ruling the biological function of MGBG (methylglyoxal bis(guanylhydrazone)), a competitive inhibitor of S-adenosyl-L-methionine decarboxylase displaying anticancer activity, involved in the biosynthesis of the naturally occurring polyamines spermidine and spermine. In order to properly understand its biochemical activity, MGBG's structural preferences at physiological conditions were ascertained, by quantum mechanical (DFT) calculations.

  17. Electron processing at low energies: from basics to environmental and biological applications.

    Science.gov (United States)

    Illenberger, Eugen

    2006-10-01

    Electron initiated reactions play a key role in nearly any field of pure and applied sciences, in the gas phase as well as in condensed phases or at interfaces. This include substrate induced photochemistry, radiation damage of biological material (and, accordingly, the molecular mechanisms, how radio sensitizers used in tumour therapy operate), reactions induced by electrons in surface tunnelling microscopy (STM), or any kind of plasma used in industrial plasma processing. In each of these fields the electron-molecule interaction represents a key step within an eventually complex reaction sequence. A particularly interesting field is the interaction of electrons with molecules at energies below the level of electronic excitation. In this range many molecules exhibit large cross sections for resonant electron capture, often followed by the decomposition of the transient negative compound (M^-# ) according to e^- + M --> M^-# --> R + X^-.^ We report on such dissociative electron attachment (DEA) processes studied at different stages of aggregation, namely in single molecules under collision free conditions, in clusters formed by supersonic gas expansion, and on the surface of solids or in molecular nanofilms. In the meantime it has also been recognised that in the damage of living cells by high energy radiation the attachment of low energy secondary electrons to DNA is a key initial process leading to strand breaks. These secondary electrons are created along the ionisation track of the primary high-energy quantum. Apart from that, bio-molecular systems exhibit unique features in DEA, like bond and site selective decompositions.

  18. Secondary metabolites in grasses: characterization and biological activity

    Directory of Open Access Journals (Sweden)

    Aldo Tava

    2007-12-01

    Full Text Available In a series of studies dealing on the nutritional value of forage species, more attention was focussed on several compounds, named secondary metabolites, that are important in determining nutritional characteristics. Secondary metabolites are compounds detected in the green materials in low concentration compared to primary metabolites (proteins, sugars, lipids, fibers, but of fundamental importance for the plant physiology. The possess several biological activities and this contribute to their possible pharmacological use. In the present paper studies on secondary metabolites from herbaceous plants are reviewed. Indications of the chemical methods used for their analyses, their presence in the green material and their biological activity are also reported.

  19. Secondary metabolites in grasses: characterization and biological activity

    Directory of Open Access Journals (Sweden)

    Aldo Tava

    2011-02-01

    Full Text Available In a series of studies dealing on the nutritional value of forage species, more attention was focussed on several compounds, named secondary metabolites, that are important in determining nutritional characteristics. Secondary metabolites are compounds detected in the green materials in low concentration compared to primary metabolites (proteins, sugars, lipids, fibers, but of fundamental importance for the plant physiology. The possess several biological activities and this contribute to their possible pharmacological use. In the present paper studies on secondary metabolites from herbaceous plants are reviewed. Indications of the chemical methods used for their analyses, their presence in the green material and their biological activity are also reported.

  20. Biological Activity of Curcuminoids Isolated from Curcuma longa

    Directory of Open Access Journals (Sweden)

    Simay Çıkrıkçı

    2008-04-01

    Full Text Available Curcumin is the most important fraction of turmeric which is responsible for its biological activity. In this study, isolation and biological assessment of turmeric and curcumin have been discussed against standard bacterial and mycobacterial strains such as E.coli , S.aureus, E.feacalis, P.aeuroginosa, M.smegmatis, M.simiae, M.kansasii, M. terrae, M.szulgai and the fungi Candida albicans. The antioxidant activity of curcumin and turmeric were also determined by the CUPRAC method.

  1. Dawning of a new era in TRP channel structural biology by cryo-electron microscopy.

    Science.gov (United States)

    Madej, M Gregor; Ziegler, Christine M

    2018-02-01

    Cryo-electron microscopy (cryo-EM) permits the determination of atomic protein structures by averaging large numbers of individual projection images recorded at cryogenic temperatures-a method termed single-particle analysis. The cryo-preservation traps proteins within a thin glass-like ice layer, making literally a freeze image of proteins in solution. Projections of randomly adopted orientations are merged to reconstruct a 3D density map. While atomic resolution for highly symmetric viruses was achieved already in 2009, the development of new sensitive and fast electron detectors has enabled cryo-EM for smaller and asymmetrical proteins including fragile membrane proteins. As one of the most important structural biology methods at present, cryo-EM was awarded in October 2017 with the Nobel Prize in Chemistry. The molecular understanding of Transient-Receptor-Potential (TRP) channels has been boosted tremendously by cryo-EM single-particle analysis. Several near-atomic and atomic structures gave important mechanistic insights, e.g., into ion permeation and selectivity, gating, as well as into the activation of this enigmatic and medically important membrane protein family by various chemical and physical stimuli. Lastly, these structures have set the starting point for the rational design of TRP channel-targeted therapeutics to counteract life-threatening channelopathies. Here, we attempt a brief introduction to the method, review the latest advances in cryo-EM structure determination of TRP channels, and discuss molecular insights into the channel function based on the wealth of TRP channel cryo-EM structures.

  2. Electron-beam-induced-current and active secondary-electron voltage-contrast with aberration-corrected electron probes

    Energy Technology Data Exchange (ETDEWEB)

    Han, Myung-Geun, E-mail: mghan@bnl.gov [Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Garlow, Joseph A. [Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Materials Science and Engineering Department, Stony Brook University, Stony Brook, NY 11794 (United States); Marshall, Matthew S.J.; Tiano, Amanda L. [Department of Chemistry, Stony Brook University, Stony Brook, NY 11974 (United States); Wong, Stanislaus S. [Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States); Department of Chemistry, Stony Brook University, Stony Brook, NY 11974 (United States); Cheong, Sang-Wook [Department of Physics and Astronomy, Rutgers Center for Emergent Materials, Rutgers University, Piscataway, NJ 08854 (United States); Walker, Frederick J.; Ahn, Charles H. [Department of Applied Physics and Center for Research on Interface Structures and Phenomena, Yale University, New Haven, CT 06520 (United States); Department of Mechanical Engineering and Materials Science, Yale University, New Haven, CT 06520 (United States); Zhu, Yimei [Condensed Matter Physics & Materials Science, Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2017-05-15

    Highlights: • Electron-beam-induced-current (EBIC) and active secondary-electron voltage-contrast (SE-VC) are demonstrated in STEM mode combined with in situ electrical biasing in a TEM. • Electrostatic potential maps in ferroelectric thin films, multiferroic nanowires, and single crystals obtained by off-axis electron holography were compared with EBIC and SE-VC data. • Simultaneous EBIC and active SE-VC performed with atomic resolution STEM are demonstrated. - Abstract: The ability to map out electrostatic potentials in materials is critical for the development and the design of nanoscale electronic and spintronic devices in modern industry. Electron holography has been an important tool for revealing electric and magnetic field distributions in microelectronics and magnetic-based memory devices, however, its utility is hindered by several practical constraints, such as charging artifacts and limitations in sensitivity and in field of view. In this article, we report electron-beam-induced-current (EBIC) and secondary-electron voltage-contrast (SE-VC) with an aberration-corrected electron probe in a transmission electron microscope (TEM), as complementary techniques to electron holography, to measure electric fields and surface potentials, respectively. These two techniques were applied to ferroelectric thin films, multiferroic nanowires, and single crystals. Electrostatic potential maps obtained by off-axis electron holography were compared with EBIC and SE-VC to show that these techniques can be used as a complementary approach to validate quantitative results obtained from electron holography analysis.

  3. Relationship between electronic properties and drug activity of seven quinoxaline compounds: A DFT study

    Science.gov (United States)

    Behzadi, Hadi; Roonasi, Payman; Assle taghipour, Khatoon; van der Spoel, David; Manzetti, Sergio

    2015-07-01

    The quantum chemical calculations at the DFT/B3LYP level of theory were carried out on seven quinoxaline compounds, which have been synthesized as anti-Mycobacterium tuberculosis agents. Three conformers were optimized for each compound and the lowest energy structure was found and used in further calculations. The electronic properties including EHOMO, ELUMO and related parameters as well as electron density around oxygen and nitrogen atoms were calculated for each compound. The relationship between the calculated electronic parameters and biological activity of the studied compounds were investigated. Six similar quinoxaline derivatives with possible more drug activity were suggested based on the calculated electronic descriptors. A mechanism was proposed and discussed based on the calculated electronic parameters and bond dissociation energies.

  4. Gemini ester quat surfactants and their biological activity.

    Science.gov (United States)

    Łuczyński, Jacek; Frąckowiak, Renata; Włoch, Aleksandra; Kleszczyńska, Halina; Witek, Stanisław

    2013-03-01

    Cationic gemini surfactants are an important class of surface-active compounds that exhibit much higher surface activity than their monomeric counterparts. This type of compound architecture lends itself to the compound being easily adsorbed at interfaces and interacting with the cellular membranes of microorganisms. Conventional cationic surfactants have high chemical stability but poor chemical and biological degradability. One of the main approaches to the design of readily biodegradable and environmentally friendly surfactants involves inserting a bond with limited stability into the surfactant molecule to give a cleavable surfactant. The best-known example of such a compound is the family of ester quats, which are cationic surfactants with a labile ester bond inserted into the molecule. As part of this study, a series of gemini ester quat surfactants were synthesized and assayed for their biological activity. Their hemolytic activity and changes in the fluidity and packing order of the lipid polar heads were used as the measures of their biological activity. A clear correlation between the hemolytic activity of the tested compounds and their alkyl chain length was established. It was found that the compounds with a long hydrocarbon chain showed higher activity. Moreover, the compounds with greater spacing between their alkyl chains were more active. This proves that they incorporate more easily into the lipid bilayer of the erythrocyte membrane and affect its properties to a greater extent. A better understanding of the process of cell lysis by surfactants and of their biological activity may assist in developing surfactants with enhanced selectivity and in widening their range of application.

  5. Recent Advances in Momordica charantia: Functional Components and Biological Activities.

    Science.gov (United States)

    Jia, Shuo; Shen, Mingyue; Zhang, Fan; Xie, Jianhua

    2017-11-28

    Momordica charantia L. ( M. charantia ), a member of the Cucurbitaceae family, is widely distributed in tropical and subtropical regions of the world. It has been used in folk medicine for the treatment of diabetes mellitus, and its fruit has been used as a vegetable for thousands of years. Phytochemicals including proteins, polysaccharides, flavonoids, triterpenes, saponins, ascorbic acid and steroids have been found in this plant. Various biological activities of M. charantia have been reported, such as antihyperglycemic, antibacterial, antiviral, antitumor, immunomodulation, antioxidant, antidiabetic, anthelmintic, antimutagenic, antiulcer, antilipolytic, antifertility, hepatoprotective, anticancer and anti-inflammatory activities. However, both in vitro and in vivo studies have also demonstrated that M. charantia may also exert toxic or adverse effects under different conditions. This review addresses the chemical constituents of M. charantia and discusses their pharmacological activities as well as their adverse effects, aimed at providing a comprehensive overview of the phytochemistry and biological activities of M. charantia .

  6. Recent Advances in Momordica charantia: Functional Components and Biological Activities

    Directory of Open Access Journals (Sweden)

    Shuo Jia

    2017-11-01

    Full Text Available Momordica charantia L. (M. charantia, a member of the Cucurbitaceae family, is widely distributed in tropical and subtropical regions of the world. It has been used in folk medicine for the treatment of diabetes mellitus, and its fruit has been used as a vegetable for thousands of years. Phytochemicals including proteins, polysaccharides, flavonoids, triterpenes, saponins, ascorbic acid and steroids have been found in this plant. Various biological activities of M. charantia have been reported, such as antihyperglycemic, antibacterial, antiviral, antitumor, immunomodulation, antioxidant, antidiabetic, anthelmintic, antimutagenic, antiulcer, antilipolytic, antifertility, hepatoprotective, anticancer and anti-inflammatory activities. However, both in vitro and in vivo studies have also demonstrated that M. charantia may also exert toxic or adverse effects under different conditions. This review addresses the chemical constituents of M. charantia and discusses their pharmacological activities as well as their adverse effects, aimed at providing a comprehensive overview of the phytochemistry and biological activities of M. charantia.

  7. Simple glycolipids of microbes: Chemistry, biological activity and metabolic engineering

    Directory of Open Access Journals (Sweden)

    Ahmad Mohammad Abdel-Mawgoud

    2018-03-01

    Full Text Available Glycosylated lipids (GLs are added-value lipid derivatives of great potential. Besides their interesting surface activities that qualify many of them to act as excellent ecological detergents, they have diverse biological activities with promising biomedical and cosmeceutical applications. Glycolipids, especially those of microbial origin, have interesting antimicrobial, anticancer, antiparasitic as well as immunomodulatory activities. Nonetheless, GLs are hardly accessing the market because of their high cost of production. We believe that experience of metabolic engineering (ME of microbial lipids for biofuel production can now be harnessed towards a successful synthesis of microbial GLs for biomedical and other applications. This review presents chemical groups of bacterial and fungal GLs, their biological activities, their general biosynthetic pathways and an insight on ME strategies for their production.

  8. Traditional uses, phytochemistry and biological activities of Cotula ...

    African Journals Online (AJOL)

    Cotula cinerea contains a wide range of phytochemical compounds such as saponins, essential oils, tannins, flavonoids, steroids, and terpenoids. This paper reviews information pertaining its traditional uses, phytochemistry and biological activities such as antibacterial, antifungal, antioxidant, herbicidal, anti-diarrheal and ...

  9. Polysaccharies of higher fungi: Biological role, structure and antioxidative activity

    NARCIS (Netherlands)

    Kozarski, M.S.; Klaus, A.; Niksic, M.; Griensven, van L.J.L.D.; Vrvic, M.M.; Jakovljevic, D.M.

    2014-01-01

    The fungal polysaccharides attract a lot of attention due to their multiple challenging bio-logical properties, such as: anti-tumor, anti-viral, anticomplementary, anticoagulant, hypo-lipidemic, immunomodulatory and immune-stimulatory activities, which all together make them suitable for application

  10. Occurrence, biological activity and synthesis of drimane sesquiterpenoids

    NARCIS (Netherlands)

    Jansen, B.J.M.; Groot, de Æ.

    2004-01-01

    In this review the names, structures and occurrence of all new drimanes and rearranged drimanes, which have been published between January 1990 and January 2003 have been collected. Subjects that have been treated are biosynthesis, analysis, biological activities, with special attention to cytotoxic

  11. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...

  12. A Review on Chemical Constituents and Biological Activities of the ...

    African Journals Online (AJOL)

    The current review is aimed to deliver some updates on the ethnobotany, phytochemistry and biological activities of Beilschmiedia species in order to throw more light on their therapeutic potentials and future research priorities. Phytochemical studies on Beilschmiedia genus yielded essential oils, endiandric acid ...

  13. Design, Synthesis, and Biological Evaluation of Isothiosemicarbazones with Antimycobacterial Activity

    Czech Academy of Sciences Publication Activity Database

    Novotná, E.; Waisser, K.; Kuneš, J.; Palát, K.; Skálová, L.; Szotáková, B.; Buchta, V.; Stolaříková, J.; Ulmann, V.; Pávová, Marcela; Weber, Jan; Komrsková, J.; Hašková, P.; Vokřál, I.; Wsól, V.

    2017-01-01

    Roč. 350, č. 8 (2017), č. článku e1700020. ISSN 0365-6233 Institutional support: RVO:61388963 Keywords : biological activity * cytotoxicity * isocitrate lyase * isothiosemicarbazone * tuberculosis Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 1.994, year: 2016

  14. Solar Energy Education. Renewable energy activities for biology

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    An instructional aid for teachers is presented that will allow biology students the opportunity to learn about renewable energy sources. Some of the school activities include using leaves as collectors of solar energy, solar energy stored in wood, and a fuel value test for green and dry woods. A study of organic wastes as a source of fuel is included. (BCS)

  15. SYNTHESIS OF BIOLOGICALLY-ACTIVE 2-BENZOYL PACLITAXEL ANALOGS

    DEFF Research Database (Denmark)

    GEORG, GI; ALI, SM; BOGE, TC

    1995-01-01

    The influence of aromatic substitution at the 2-benzoyl moiety of paclitaxel on biological activity was investigated, following the Topliss Operational Scheme. Twelve paclitaxel derivatives were synthesized and evaluated in a microtubule assembly assay and for cytotoxicity against B16 melanoma ce...

  16. Biological activities of species in the genus Tulbaghia : A review ...

    African Journals Online (AJOL)

    Species of the genus Tulbaghia has been widely used in traditional medicine to treat various ailments such rheumatism, fits, fever, earache, tuberculosis etc. It is believed that the species possess several therapeutic properties. This paper evaluates some of the biological activities of the genus Tulbaghia. It is evident from ...

  17. Physio-chemical evaluation and biological activity of Ajuga ...

    African Journals Online (AJOL)

    Physio-chemical evaluation and biological activity of Ajuga bracteosa wall and Viola odoroto Linn. Anwar Ali Shad, M. Zeeshan, Hina Fazal, Hamid Ullah Shah, Shabir Ahmed, Hasem Abeer, E. F. Abd_Allah, Riaz Ullah, Hamid Afridi, Akash tariq, Muhammad Adnan Asma ...

  18. Traditional uses, phytochemistry and biological activities of Cotula ...

    African Journals Online (AJOL)

    Keywords: Asteraceae, Cotula cinerea, Traditional uses, Phytochemistry, Biological activities. This is an Open .... desert conditions with an average annual rainfall .... Desert area between. Cairo and. Ismailia. (Egypt). Not stated. [33]. The essential oil of C. cinerea has also been subjected to many studies. The essential oil.

  19. Volatile compounds and biological activities of aerial parts of ...

    African Journals Online (AJOL)

    Volatile compounds and biological activities of aerial parts of Pituranthos scoparius (Coss and ... mg/mL. Conclusion: These findings indicate that the essential oil of P.scoparius has a potential for use as a preservative and flavorant in ..... Values are expressed as mean ± standard deviation (n=3). Key: control (♢), BHT (□) ...

  20. Students' Learning Activities While Studying Biological Process Diagrams

    Science.gov (United States)

    Kragten, Marco; Admiraal, Wilfried; Rijlaarsdam, Gert

    2015-01-01

    Process diagrams describe how a system functions (e.g. photosynthesis) and are an important type of representation in Biology education. In the present study, we examined students' learning activities while studying process diagrams, related to their resulting comprehension of these diagrams. Each student completed three learning tasks. Verbal…

  1. Biological activity of phenolic compounds present in buckwheat plants

    Czech Academy of Sciences Publication Activity Database

    Kalinová, J.; Tříska, Jan; Vrchotová, Naděžda

    2005-01-01

    Roč. 16, č. 1 (2005), s. 123-129 ISSN 0971-4693 Institutional research plan: CEZ:AV0Z60870520 Keywords : biological activity, extract, Fagopyrum esculenthum Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 0.686, year: 2005

  2. The Biological Activities of Moltkia aurea; an Endemic Species to ...

    African Journals Online (AJOL)

    Neslihan BALPINAR

    inclination that studies on medicinal plants, which are basis for the development of new biologically active molecules for pharmaceuticals, have rapidly increased. Recent studies associated with medicinal plants make possible to better understand their properties, safety and efficiency. In this study, Moltkia aurea Boiss.

  3. Synthesis, characterization and evaluation of biological activities of ...

    African Journals Online (AJOL)

    Original Research Article. Synthesis, characterization and evaluation of biological activities of manganese-doped zinc oxide nanoparticles. Shakeel Ahmad Khan1*, Sammia Shahid1, Waqas Bashir1, Sadia Kanwal2 and. Ahsan Iqbal3. 1Department of Chemistry, University of Management and Technology, Lahore-54000, ...

  4. BIOLOGICALLY ENHANCED OXYGEN TRANSFER IN THE ACTIVATED SLUDGE PROCESS (JOURNAL)

    Science.gov (United States)

    Biologically enhanced oxgyen transfer has been a hypothesis to explain observed oxygen transfer rates in activated sludge systems that were well above that predicted from aerator clean-water testing. The enhanced oxygen transfer rates were based on tests using BOD bottle oxygen ...

  5. Biological activities of some Fluoroquinolones-metal complexes ...

    African Journals Online (AJOL)

    Background: Metal ions play a vital role in the design of more biologically active drugs. Aim: The paper reviewed the antimicrobial, toxicological and DNA cleavage studies of some synthesized metal complexes of fluoroquinolone antibiotics. Materials and Methods: Literature searches were done using scientific databases.

  6. Biological Activities of the Essential Oil from Erigeron floribundus

    OpenAIRE

    Riccardo Petrelli; Giuseppe Orsomando; Leonardo Sorci; Filippo Maggi; Farahnaz Ranjbarian; Prosper C. Biapa Nya; Dezemona Petrelli; Luca A. Vitali; Giulio Lupidi; Luana Quassinti; Massimo Bramucci; Anders Hofer; Loredana Cappellacci

    2016-01-01

    Erigeron floribundus (Asteraceae) is an herbaceous plant widely used in Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study, we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucle...

  7. Secondary Metabolites from Inula britannica L. and Their Biological Activities

    Directory of Open Access Journals (Sweden)

    Yoon-Ha Kim

    2010-03-01

    Full Text Available Inula britannica L., family Asteraceae, is used in traditional Chinese and Kampo Medicines for various diseases. Flowers or the aerial parts are a rich source of secondary metabolites. These consist mainly of terpenoids (sesquiterpene lactones and dimmers, diterpenes and triterpenoids and flavonoids. The isolated compounds have shown diverse biological activities: anticancer, antioxidant, anti-inflammatory, neuroprotective and hepatoprotective activities. This review provides information on isolated bioactive phytochemicals and pharmacological potentials of I. britannica.

  8. Secondary metabolites from Inula britannica L. and their biological activities.

    Science.gov (United States)

    Khan, Abdul Latif; Hussain, Javid; Hamayun, Muhammad; Gilani, Syed Abdullah; Ahmad, Shabir; Rehman, Gauhar; Kim, Yoon-Ha; Kang, Sang-Mo; Lee, In-Jung

    2010-03-10

    Inula britannica L., family Asteraceae, is used in traditional Chinese and Kampo Medicines for various diseases. Flowers or the aerial parts are a rich source of secondary metabolites. These consist mainly of terpenoids (sesquiterpene lactones and dimmers, diterpenes and triterpenoids) and flavonoids. The isolated compounds have shown diverse biological activities: anticancer, antioxidant, anti-inflammatory, neuroprotective and hepatoprotective activities. This review provides information on isolated bioactive phytochemicals and pharmacological potentials of I. britannica.

  9. Assessing Student Behaviors and Motivation for Actively Learning Biology

    Science.gov (United States)

    Moore, Michael Edward

    Vision and Change states that one of the major changes in the way we design biology courses should be a switch in approach from teacher-centered learning to student-centered learning and identifies active learning as a recommended methods. Studies show performance benefits for students taking courses that use active learning. What is unknown is why active learning is such an effective instructional tool and the limits of this instructional method’s ability to influence performance. This dissertation builds a case in three steps for why active learning is an effective instructional tool. In step one, I assessed the influence of different types of active learning (clickers, group activities, and whole class discussions) on student engagement behavior in one semester of two different introductory biology courses and found that active learning positively influenced student engagement behavior significantly more than lecture. For step two, I examined over four semesters whether student engagement behavior was a predictor of performance and found participation (engagement behavior) in the online (video watching) and in-class course activities (clicker participation) that I measure were significant predictors of performance. In the third, I assessed whether certain active learning satisfied the psychological needs that lead to students’ intrinsic motivation to participate in those activities when compared over two semesters and across two different institutions of higher learning. Findings from this last step show us that student’s perceptions of autonomy, competency, and relatedness in doing various types of active learning are significantly higher than lecture and consistent across two institutions of higher learning. Lastly, I tie everything together, discuss implications of the research, and address future directions for research on biology student motivation and behavior.

  10. Photo-induced regeneration of hormones by electron transfer processes: Potential biological and medical consequences

    Energy Technology Data Exchange (ETDEWEB)

    Getoff, Nikola, E-mail: nikola.getoff@univie.ac.a [Section of Radiation Biology, Faculty of Life Sciences, University of Vienna, A-1090 Vienna (Austria); Hartmann, Johannes [Department of Gynecologic Endocrinology and Reproduction, Medical University of Vienna, A-1090 Vienna (Austria); Schittl, Heike [Section of Radiation Biology, Faculty of Life Sciences, University of Vienna, A-1090 Vienna (Austria); Gerschpacher, Marion [Department of Gynecologic Endocrinology and Reproduction, Medical University of Vienna, A-1090 Vienna (Austria); Quint, Ruth Maria [Section of Radiation Biology, Faculty of Life Sciences, University of Vienna, A-1090 Vienna (Austria)

    2011-08-15

    Based on the previous results concerning electron transfer processes in biological substances, it was of interest to investigate if hormone transients resulting by e.g. electron emission can be regenerated. The presented results prove for the first time that the hormone transients originating by the electron emission process can be successfully regenerated by the transfer of electrons from a potent electron donor, such as vitamin C (VitC). Investigations were performed using progesterone (PRG), testosterone (TES) and estrone (E1) as representatives of hormones. By irradiation with monochromatic UV light ({lambda}=254 nm) in a media of 40% water and 60% ethanol, the degradation as well as the regeneration of the hormones was studied with each hormone individually and in the mixture with VitC as a function of the absorbed UV dose, using HPLC. Calculated from the obtained initial yields, the determined regeneration of PRG amounted to 52.7%, for TES to 58.6% and for E1 to 90.9%. The consumption of VitC was determined in the same way. The reported results concerning the regeneration of hormones by the transfer of electrons from an electron donor offer a new, promising method for the therapy with hormones. As a consequence of the regeneration of hormones, a decreased formation of carcinogenic metabolites is expected.

  11. Photo-induced regeneration of hormones by electron transfer processes: Potential biological and medical consequences

    International Nuclear Information System (INIS)

    Getoff, Nikola; Hartmann, Johannes; Schittl, Heike; Gerschpacher, Marion; Quint, Ruth Maria

    2011-01-01

    Based on the previous results concerning electron transfer processes in biological substances, it was of interest to investigate if hormone transients resulting by e.g. electron emission can be regenerated. The presented results prove for the first time that the hormone transients originating by the electron emission process can be successfully regenerated by the transfer of electrons from a potent electron donor, such as vitamin C (VitC). Investigations were performed using progesterone (PRG), testosterone (TES) and estrone (E1) as representatives of hormones. By irradiation with monochromatic UV light (λ=254 nm) in a media of 40% water and 60% ethanol, the degradation as well as the regeneration of the hormones was studied with each hormone individually and in the mixture with VitC as a function of the absorbed UV dose, using HPLC. Calculated from the obtained initial yields, the determined regeneration of PRG amounted to 52.7%, for TES to 58.6% and for E1 to 90.9%. The consumption of VitC was determined in the same way. The reported results concerning the regeneration of hormones by the transfer of electrons from an electron donor offer a new, promising method for the therapy with hormones. As a consequence of the regeneration of hormones, a decreased formation of carcinogenic metabolites is expected.

  12. Modelling low energy electron and positron tracks in biologically relevant media

    International Nuclear Information System (INIS)

    Blanco, F.; Munoz, A.; Almeida, D.; Ferreira da Silva, F.; Limao-Vieira, P.; Fuss, M.C.; Sanz, A.G.; Garcia, G.

    2013-01-01

    This colloquium describes an approach to incorporate into radiation damage models the effect of low and intermediate energy (0-100 eV) electrons and positrons, slowing down in biologically relevant materials (water and representative biomolecules). The core of the modelling procedure is a C++ computing programme named 'Low Energy Particle Track Simulation (LEPTS)', which is compatible with available general purpose Monte Carlo packages. Input parameters are carefully selected from theoretical and experimental cross section data and energy loss distribution functions. Data sources used for this purpose are reviewed showing examples of electron and positron cross section and energy loss data for interactions with different media of increasing complexity: atoms, molecules, clusters and condense matter. Finally, we show how such a model can be used to develop an effective dosimetric tool at the molecular level (i.e. nanodosimetry). Recent experimental developments to study the fragmentation induced in biologically material by charge transfer from neutrals and negative ions are also included. (authors)

  13. Cryo-electron tomography-the cell biology that came in from the cold.

    Science.gov (United States)

    Wagner, Jonathan; Schaffer, Miroslava; Fernández-Busnadiego, Rubén

    2017-09-01

    Cryo-electron tomography (cryo-ET) provides high-resolution 3D views into cells pristinely preserved by vitrification. Recent technical advances such as direct electron detectors, the Volta phase plate and cryo-focused ion beam milling have dramatically pushed image quality and expanded the range of cryo-ET applications. Cryo-ET not only allows mapping the positions and interactions of macromolecules within their intact cellular context, but can also reveal their in situ structure at increasing resolution. Here, we review how recent work using cutting-edge cryo-ET technologies is starting to provide fresh views into different aspects of cellular biology at an unprecedented level of detail. We anticipate that these developments will soon make cryo-ET a fundamental technique in cell biology. © 2017 Federation of European Biochemical Societies.

  14. Generalized Fokker-Planck theory for electron and photon transport in biological tissues: application to radiotherapy.

    Science.gov (United States)

    Olbrant, Edgar; Frank, Martin

    2010-12-01

    In this paper, we study a deterministic method for particle transport in biological tissues. The method is specifically developed for dose calculations in cancer therapy and for radiological imaging. Generalized Fokker-Planck (GFP) theory [Leakeas and Larsen, Nucl. Sci. Eng. 137 (2001), pp. 236-250] has been developed to improve the Fokker-Planck (FP) equation in cases where scattering is forward-peaked and where there is a sufficient amount of large-angle scattering. We compare grid-based numerical solutions to FP and GFP in realistic medical applications. First, electron dose calculations in heterogeneous parts of the human body are performed. Therefore, accurate electron scattering cross sections are included and their incorporation into our model is extensively described. Second, we solve GFP approximations of the radiative transport equation to investigate reflectance and transmittance of light in biological tissues. All results are compared with either Monte Carlo or discrete-ordinates transport solutions.

  15. Controlled release of biologically active silver from nanosilver surfaces.

    Science.gov (United States)

    Liu, Jingyu; Sonshine, David A; Shervani, Saira; Hurt, Robert H

    2010-11-23

    Major pathways in the antibacterial activity and eukaryotic toxicity of nanosilver involve the silver cation and its soluble complexes, which are well established thiol toxicants. Through these pathways, nanosilver behaves in analogy to a drug delivery system, in which the particle contains a concentrated inventory of an active species, the ion, which is transported to and released near biological target sites. Although the importance of silver ion in the biological response to nanosilver is widely recognized, the drug delivery paradigm has not been well developed for this system, and there is significant potential to improve nanosilver technologies through controlled release formulations. This article applies elements of the drug delivery paradigm to nanosilver dissolution and presents a systematic study of chemical concepts for controlled release. After presenting thermodynamic calculations of silver species partitioning in biological media, the rates of oxidative silver dissolution are measured for nanoparticles and macroscopic foils and used to derive unified area-based release kinetics. A variety of competing chemical approaches are demonstrated for controlling the ion release rate over 4 orders of magnitude. Release can be systematically slowed by thiol and citrate ligand binding, formation of sulfidic coatings, or the scavenging of peroxy-intermediates. Release can be accelerated by preoxidation or particle size reduction, while polymer coatings with complexation sites alter the release profile by storing and releasing inventories of surface-bound silver. Finally, the ability to tune biological activity is demonstrated through a bacterial inhibition zone assay carried out on selected formulations of controlled release nanosilver.

  16. Graphene as a transparent conductive support for studying biological molecules by transmission electron microscopy

    International Nuclear Information System (INIS)

    Nair, R. R.; Anissimova, S.; Novoselov, K. S.; Blake, P.; Blake, J. R.; Geim, A. K.; Zan, R.; Bangert, U.; Golovanov, A. P.; Morozov, S. V.; Latychevskaia, T.

    2010-01-01

    We demonstrate the application of graphene as a support for imaging individual biological molecules in transmission electron microscope (TEM). A simple procedure to produce free-standing graphene membranes has been designed. Such membranes are extremely robust and can support practically any submicrometer object. Tobacco mosaic virus has been deposited on graphene samples and observed in a TEM. High contrast has been achieved even though no staining has been applied.

  17. RGB color coded images in scanning electron microscopy of biological surfaces

    Czech Academy of Sciences Publication Activity Database

    Kofroňová, Olga; Benada, Oldřich

    2017-01-01

    Roč. 61, č. 3 (2017), s. 349-352 ISSN 0001-723X R&D Projects: GA MŠk(CZ) LO1509; GA ČR(CZ) GA16-20229S Institutional support: RVO:61388971 Keywords : Biological surfaces * Color image s * Scanning electron microscopy Subject RIV: EE - Microbiology, Virology OBOR OECD: Microbiology Impact factor: 0.673, year: 2016

  18. Biological activities of phenolic compounds present in virgin olive oil.

    Science.gov (United States)

    Cicerale, Sara; Lucas, Lisa; Keast, Russell

    2010-02-02

    The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, neurodegenerative diseases and certain types of cancer. The apparent health benefits have been partially ascribed to the dietary consumption of virgin olive oil by Mediterranean populations. Much research has focused on the biologically active phenolic compounds naturally present in virgin olive oils to aid in explaining reduced mortality and morbidity experienced by people consuming a traditional Mediterranean diet. Studies (human, animal, in vivo and in vitro) have demonstrated that olive oil phenolic compounds have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, antimicrobial activity and bone health. This paper summarizes current knowledge on the bioavailability and biological activities of olive oil phenolic compounds.

  19. Biological Activities of Phenolic Compounds Present in Virgin Olive Oil

    Directory of Open Access Journals (Sweden)

    Russell Keast

    2010-02-01

    Full Text Available The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, neurodegenerative diseases and certain types of cancer. The apparent health benefits have been partially ascribed to the dietary consumption of virgin olive oil by Mediterranean populations. Much research has focused on the biologically active phenolic compounds naturally present in virgin olive oils to aid in explaining reduced mortality and morbidity experienced by people consuming a traditional Mediterranean diet. Studies (human, animal, in vivo and in vitro have demonstrated that olive oil phenolic compounds have positive effects on certain physiological parameters, such as plasma lipoproteins, oxidative damage, inflammatory markers, platelet and cellular function, antimicrobial activity and bone health. This paper summarizes current knowledge on the bioavailability and biological activities of olive oil phenolic compounds.

  20. Should Soil Testing Services Measure Soil Biological Activity?

    Directory of Open Access Journals (Sweden)

    Alan J. Franzluebbers

    2016-02-01

    Full Text Available Health of agricultural soils depends largely on conservation management to promote soil organic matter accumulation. Total soil organic matter changes slowly, but active fractions are more dynamic. A key indicator of healthy soil is potential biological activity, which could be measured rapidly with soil testing services via the flush of CO during 1 to 3 d following rewetting of dried soil. The flush of CO is related to soil microbial biomass C and has repeatedly been shown strongly related to net N mineralization during standard aerobic incubations. New research is documenting the close association with plant N uptake in semicontrolled greenhouse conditions ( = 0.77, = 36. Field calibrations are underway to relate the flush of CO to the need for in-season N requirement in a variety of crops. An index of soil biological activity can and should be determined to help predict soil health and soil N availability.

  1. Structural Diversity and Biological Activities of Cyclic Depsipeptides from Fungi

    Directory of Open Access Journals (Sweden)

    Xiaohan Wang

    2018-01-01

    Full Text Available Cyclic depsipeptides (CDPs are cyclopeptides in which amide groups are replaced by corresponding lactone bonds due to the presence of a hydroxylated carboxylic acid in the peptide structure. These peptides sometimes display additional chemical modifications, including unusual amino acid residues in their structures. This review highlights the occurrence, structures and biological activities of the fungal CDPs reported until October 2017. About 352 fungal CDPs belonging to the groups of cyclic tri-, tetra-, penta-, hexa-, hepta-, octa-, nona-, deca-, and tridecadepsipeptides have been isolated from fungi. These metabolites are mainly reported from the genera Acremonium, Alternaria, Aspergillus, Beauveria, Fusarium, Isaria, Metarhizium, Penicillium, and Rosellina. They are known to exhibit various biological activities such as cytotoxic, phytotoxic, antimicrobial, antiviral, anthelmintic, insecticidal, antimalarial, antitumoral and enzyme-inhibitory activities. Some CDPs (i.e., PF1022A, enniatins and destruxins have been applied as pharmaceuticals and agrochemicals.

  2. Structural complexities in the active layers of organic electronics.

    Science.gov (United States)

    Lee, Stephanie S; Loo, Yueh-Lin

    2010-01-01

    The field of organic electronics has progressed rapidly in recent years. However, understanding the direct structure-function relationships between the morphology in electrically active layers and the performance of devices composed of these materials has proven difficult. The morphology of active layers in organic electronics is inherently complex, with heterogeneities existing across multiple length scales, from subnanometer to micron and millimeter range. A major challenge still facing the organic electronics community is understanding how the morphology across all of the length scales in active layers collectively determines the device performance of organic electronics. In this review we highlight experiments that have contributed to the elucidation of structure-function relationships in organic electronics and also point to areas in which knowledge of such relationships is still lacking. Such knowledge will lead to the ability to select active materials on the basis of their inherent properties for the fabrication of devices with prespecified characteristics.

  3. Direct observation of unstained wet biological samples by scanning-electron generation X-ray microscopy

    International Nuclear Information System (INIS)

    Ogura, Toshihiko

    2010-01-01

    Analytical tools of nanometre-scale resolution are indispensable in the fields of biology, physics and chemistry. One suitable tool, the soft X-ray microscope, provides high spatial resolution of visible light for wet specimens. For biological specimens, X-rays of water-window wavelength between carbon (284 eV; 4.3 nm) and oxygen (540 eV; 2.3 nm) absorption edges provide high-contrast imaging of biological samples in water. Among types of X-ray microscope, the transmission X-ray microscope using a synchrotron radiation source with diffractive zone plates offers the highest spatial resolution, approaching 15-10 nm. However, even higher resolution is required to measure proteins and protein complexes in biological specimens; therefore, a new type of X-ray microscope with higher resolution that uses a simple light source is desirable. Here we report a novel scanning-electron generation X-ray microscope (SGXM) that demonstrates direct imaging of unstained wet biological specimens. We deposited wet yeasts in the space between two silicon nitride (Si 3 N 4 ) films. A scanning electron beam of accelerating voltage 5 keV and current 1.6 nA irradiates the titanium (Ti)-coated Si 3 N 4 film, and the soft X-ray signal from it is detected by an X-ray photodiode (PD) placed below the sample. The SGXM can theoretically achieve better than 5 nm resolution. Our method can be utilized easily for various wet biological samples of bacteria, viruses, and protein complexes.

  4. Inverse electron transfer in peroxyoxalate chemiexcitation using easily reducible activators

    OpenAIRE

    BARTOLONI, Fernando Heering; CISCATO, Luiz Francisco Monteiro Leite; AUGUSTO, Felipe Alberto; BAADER, Wilhelm Josef

    2010-01-01

    Chemiluminescence properties of the peroxyoxalate reaction in the presence of activators bearing electron withdrawing substituents were studied, to evaluate the possible occurrence of an inverse electron transfer, from the peroxide intermediate to the activator, in its chemiexcitation step. Relative catalytic rate constants and singlet quantum yields were obtained for the peroxyoxalate reaction, using 9-chloro, 9,10-dichloro, 9-cyano and 9,10-dicyanoanthracenes as activators. The linear free-...

  5. Indonesian propolis: chemical composition, biological activity and botanical origin.

    Science.gov (United States)

    Trusheva, Boryana; Popova, Milena; Koendhori, Eko Budi; Tsvetkova, Iva; Naydenski, Christo; Bankova, Vassya

    2011-03-01

    From a biologically active extract of Indonesian propolis from East Java, 11 compounds were isolated and identified: four alk(en)ylresorcinols (obtained as an inseparable mixture) (1-4) were isolated for the first time from propolis, along with four prenylflavanones (6-9) and three cycloartane-type triterpenes (5, 10 and 11). The structures of the components were elucidated based on their spectral properties. All prenylflavanones demonstrated significant radical scavenging activity against diphenylpicrylhydrazyl radicals, and compound 6 showed significant antibacterial activity against Staphylococcus aureus. For the first time Macaranga tanarius L. and Mangifera indica L. are shown as plant sources of Indonesian propolis.

  6. A stochastic model of protein conformational dynamics and electronic-conformational coupling in biological energy transduction

    Science.gov (United States)

    Cartling, Bo

    1985-11-01

    The principles of biological energy transduction are discussed by means of a mathematical model of a donor-acceptor system of electron transfer enzymes in which electronic and conformational states are coupled. The internal nuclear motion of the enzymes is considered to be composed of transitions between local potential energy wells, which define conformational states, and vibrations within these. The conformational transitions are treated as a stochastic process of the diffusion type on a conformational potential energy surface. Dissipative processes are avoided by restricting electron transfer with respect to conformational states and molecular mechanisms of such electron gating are discussed. Different types of transient kinetics, determined by the relative rates of electronic and conformational transitions, are demonstrated in terms of probability density functions, which describe the probability for the system to be in different electronic and conformational states as a function of time. The experimental basis for the concepts and mechanisms introduced is discussed and further experiments are proposed. The applicability of the mathematical model to other systems is indicated.

  7. Electron transfer behaviour of biological macromolecules towards the single-molecule level

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Grubb, Mikala; Hansen, Allan Glargaard

    2003-01-01

    electron transfer (ET) function retained. In situ STM can also address the microscopic mechanisms for electron tunnelling through the biomolecules and offers novel notions such as coherent multi-ET between the substrate and tip via the molecular redox levels. This differs in important respects from...... is combined with state-of-the-art physical electrochemistry with emphasis on single-crystal, atomically planar electrode surfaces, in situ scanning tunnelling microscopy (STM) and other surface techniques. These approaches have brought bioelectrochemistry important steps forward towards the nanoscale...... electrochemical ET at a single metal/electrolyte interface. Similar data for a short oligonucleotide immobilized on Au(111) show that oligonucleotides can be characterized with comparable detail, with novel perspectives for addressing DNA electronic conduction mechanisms and for biological screening towards...

  8. QSAR Study of the Biologically Active Organosulfurs in Natural Products

    Directory of Open Access Journals (Sweden)

    Fakhr M. Abu-Awwad

    2010-01-01

    Full Text Available The biological activities of two sets of a total of 30 different polysulfides were investigated using QSAR. The semiempirical AM1 in Gaussian 2003 for windows was used to optimize the structures whereas a subsequent calculation of hundreds of various types of descriptors at the density functional (B3LYP/6-31G* using CODESSA package was employed. The known 15-lipoxygenase inhibitory activity data (IC50 of 19 polysulfides out of the whole data set were correlated in a multiple linear regression procedures with the computed descriptors. Statistically, the most significant overall correlations were five- and four- parameter equations with good statistical parameters; R2= 0.9981, R2CV = 0.9970 and R2=9967, R2CV = 0.9933 respectively. The models concluded that biological activity of polysulfides is mainly attributed to quantum-chemical, geometrical and topological descriptors with neither electrostatic contribution nor chief role of sulfur atoms. Also sulfur related descriptors were not the most significant contributors in the concluded models. The obtained models were efficiently employed to estimate the biological activities of the other 11 polysulfides available in natural products such as garlic and mushroom.

  9. Biological activity and photostability of biflorin micellar nanostructures.

    Science.gov (United States)

    Santana, Edson R B; Ferreira-Neto, João P; Yara, Ricardo; Sena, Kêsia X F R; Fontes, Adriana; Lima, Cláudia S A

    2015-05-13

    Capraria biflora L. is a shrub from the Scrophulariaceae family which produces in its roots a compound named biflorin, an o-naphthoquinone that shows activity against Gram-positive bacteria and fungi and also presents antitumor and antimetastatic activities. However, biflorin is hydrophobic and photosensitive. These properties make its application difficult. In this work we prepared biflorin micellar nanostructures looking for a more effective vehiculation and better preservation of the biological activity. Biflorin was obtained, purified and characterized by UV-Vis, infrared (IR) and 1H- and 13C-NMR. Micellar nanostructures of biflorin were then assembled with Tween 80®, Tween 20® and saline (0.9%) and characterized by UV-Vis spectroscopy and dynamic light scattering (DLS). The results showed that the micellar nanostructures were stable and presented an average size of 8.3 nm. Biflorin micellar nanostructures' photodegradation was evaluated in comparison with biflorin in ethanol. Results showed that the biflorin in micellar nanostructures was better protected from light than biflorin dissolved in ethanol, and also indicated that biflorin in micelles were efficient against Gram-positive bacteria and yeast species. In conclusion, the results showed that the micellar nanostructures could ensure the maintenance of the biological activity of biflorin, conferring photoprotection. Moreover, biflorin vehiculation in aqueous media was improved, favoring its applicability in biological systems.

  10. Biological Activity and Photostability of Biflorin Micellar Nanostructures

    Directory of Open Access Journals (Sweden)

    Edson R. B. Santana

    2015-05-01

    Full Text Available Capraria biflora L. is a shrub from the Scrophulariaceae family which produces in its roots a compound named biflorin, an o-naphthoquinone that shows activity against Gram-positive bacteria and fungi and also presents antitumor and antimetastatic activities. However, biflorin is hydrophobic and photosensitive. These properties make its application difficult. In this work we prepared biflorin micellar nanostructures looking for a more effective vehiculation and better preservation of the biological activity. Biflorin was obtained, purified and characterized by UV-Vis, infrared (IR and 1H- and 13C-NMR. Micellar nanostructures of biflorin were then assembled with Tween 80®, Tween 20® and saline (0.9% and characterized by UV-Vis spectroscopy and dynamic light scattering (DLS. The results showed that the micellar nanostructures were stable and presented an average size of 8.3 nm. Biflorin micellar nanostructures’ photodegradation was evaluated in comparison with biflorin in ethanol. Results showed that the biflorin in micellar nanostructures was better protected from light than biflorin dissolved in ethanol, and also indicated that biflorin in micelles were efficient against Gram-positive bacteria and yeast species. In conclusion, the results showed that the micellar nanostructures could ensure the maintenance of the biological activity of biflorin, conferring photoprotection. Moreover, biflorin vehiculation in aqueous media was improved, favoring its applicability in biological systems.

  11. A Review of the Composition of the Essential Oils and Biological Activities of Angelica Species

    Directory of Open Access Journals (Sweden)

    Kandasamy Sowndhararajan

    2017-09-01

    Full Text Available A number of Angelica species have been used in traditional systems of medicine to treat many ailments. Especially, essential oils (EOs from the Angelica species have been used for the treatment of various health problems, including malaria, gynecological diseases, fever, anemia, and arthritis. EOs are complex mixtures of low molecular weight compounds, especially terpenoids and their oxygenated compounds. These components deliver specific fragrance and biological properties to essential oils. In this review, we summarized the chemical composition and biological activities of EOs from different species of Angelica. For this purpose, a literature search was carried out to obtain information about the EOs of Angelica species and their bioactivities from electronic databases such as PubMed, Science Direct, Wiley, Springer, ACS, Google, and other journal publications. There has been a lot of variation in the EO composition among different Angelica species. EOs from Angelica species were reported for different kinds of biological activities, such as antioxidant, anti-inflammatory, antimicrobial, immunotoxic, and insecticidal activities. The present review is an attempt to consolidate the available data for different Angelica species on the basis of major constituents in the EOs and their biological activities.

  12. Characterization of biologically active substances from Calendula officinalis.

    Science.gov (United States)

    Lovecka, Petra; Lipov, Jan; Thumova, Kamila; Macurkova, Anna

    2018-02-26

    The aim of this work was to compare water and organic extracts, infusions and tinctures from flowers and leaves of Calendula officinalis in terms of their biological activity and composition. The purpose of work was investigation whether the leaves and stems are really the waste or they contain interesting substances which could be utilized. Antimicrobial, antifungal, antioxidant and anti-inflammatory activities were studied. Then the ability to inhibit collagenase was studied as well. Cytotoxicity was tested for all the samples on mammalian cell lines. To determine the composition of extracts, infusions and tinctures phytochemical analysis (the set of colour reactions for detection of groups of biologically active compounds) was carried out and shown that samples from flowers and leaves contain the same groups of biologically active substances (proteins and amino acids, reducing sugars, flavonoids, saponins, phenolics, terpenoids, steroids, glycosides). The antimicrobial activity of tested samples was proved, where the most sensitive bacterium was Micrococcus luteus and the most sensitive yeast was Geotrichum candidum. The study of anti - collagenase activity has shown that the enzymatic reaction of collagenase was affected by all tested samples and their effect was concentration dependent. Cytotoxicity of water and methanol extracts at cell lines HEK 293T and HepG2 was observed. Cells HepG2 were more sensitive than cells HEK 293T. Using cell line RAW 264.7 anti-inflammatory activity of all samples was observed. Tincture of leaves was the most effective. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  13. Biological activity of selected plants with adaptogenic effect

    Directory of Open Access Journals (Sweden)

    Eva Ivanišová

    2016-05-01

    Full Text Available The aim of this study was to determine biological activity of plants with adaptogenic effect: Panax ginseng Mayer., Withania somnifera L., Eleuterococcus senticosus Rupr. et Maxim., Astragallus membranaceus Fisch. and Codonopsis pilosulae Franch. The antioxidant activity was detected by DPPH and phosphomolybdenum method, total polyphenol content with Folin – Ciocalteu reagent, flavonoids content by aluminium chloride method. The detection of antimicrobial activity was carried out by disc diffusion method against three species of Gram-negative bacteria: Escherichia coli CCM 3988, Salmonella enterica subsp. enterica CCM 3807, Yersinia enterocolitica CCM 5671 and two Gram-positive bacteria: Bacillus thuringiensis CCM 19, Stapylococcus aureus subsp. aureus CCM 2461. Results showed that plants with adaptogenic effect are rich for biologically active substances. The highest antioxidant activity by DPPH method was determined in the sample of Eleuterococcus senticosus (3.15 mg TEAC – Trolox equivalent antioxidant capacity per g of sample and by phosphomolybdenum method in the sample of Codonopsis pilosulae (188.79 mg TEAC per g of sample. In the sample of Panax ginseng was measured the highest content of total polyphenols (8.10 mg GAE – galic acid equivalent per g of sample and flavonoids (3.41 μg QE – quercetin equivalent per g of sample. All samples also showed strong antimicrobial activity with the best results in Panax ginseng and Withania somnifera in particular for species Yersinia enterocolitica CCM 5671 and Salmonella enterica subsp. enterica CCM 3807. The analyzed species of plant with high value of biological activity can be used more in the future, not only in food, but also in cosmetics and pharmaceutical industries.

  14. Marine Sponge Lectins: Actual Status on Properties and Biological Activities

    Directory of Open Access Journals (Sweden)

    Sandro Mascena Gomes Filho

    2014-12-01

    Full Text Available Marine sponges are primitive metazoans that produce a wide variety of molecules that protect them against predators. In studies that search for bioactive molecules, these marine invertebrates stand out as promising sources of new biologically-active molecules, many of which are still unknown or little studied; thus being an unexplored biotechnological resource of high added value. Among these molecules, lectins are proteins that reversibly bind to carbohydrates without modifying them. In this review, various structural features and biological activities of lectins derived from marine sponges so far described in the scientific literature are discussed. From the results found in the literature, it could be concluded that lectins derived from marine sponges are structurally diverse proteins with great potential for application in the production of biopharmaceuticals, especially as antibacterial and antitumor agents.

  15. MILK KEFIR: COMPOSITION, MICROBIAL CULTURES, BIOLOGICAL ACTIVITIES AND RELATED PRODUCTS

    Directory of Open Access Journals (Sweden)

    Maria Rosa Prado

    2015-10-01

    Full Text Available In recent years, there has been a strong focus on beneficial foods with probiotic microorganisms and functional organic substances. In this context, there is an increasing interest in the commercial use of kefir, since it can be marketed as a natural beverage that has health promoting bacteria. There are numerous commercially available kefir based-products. Kefir may act as a matrix in the effective delivery of probiotic microorganisms in different types of products. Also, the presence of kefir’s exopolysaccharides, known as kefiran, which has biological activity, certainly adds value to products. Kefiran can also be used separately in other food products and as a coating film for various food and pharmaceutical products. This article aims to update the information about kefir and its microbiological composition, biological activity of the kefir’s microflora and the importance of kefiran as a beneficial health substance.

  16. Milk kefir: composition, microbial cultures, biological activities, and related products.

    Science.gov (United States)

    Prado, Maria R; Blandón, Lina Marcela; Vandenberghe, Luciana P S; Rodrigues, Cristine; Castro, Guillermo R; Thomaz-Soccol, Vanete; Soccol, Carlos R

    2015-01-01

    In recent years, there has been a strong focus on beneficial foods with probiotic microorganisms and functional organic substances. In this context, there is an increasing interest in the commercial use of kefir, since it can be marketed as a natural beverage that has health promoting bacteria. There are numerous commercially available kefir based-products. Kefir may act as a matrix in the effective delivery of probiotic microorganisms in different types of products. Also, the presence of kefir's exopolysaccharides, known as kefiran, which has biological activity, certainly adds value to products. Kefiran can also be used separately in other food products and as a coating film for various food and pharmaceutical products. This article aims to update the information about kefir and its microbiological composition, biological activity of the kefir's microflora and the importance of kefiran as a beneficial health substance.

  17. Charged particle activation analysis of phosphorus in biological materials

    International Nuclear Information System (INIS)

    Masumoto, K.; Yagi, M.

    1983-01-01

    Charged particle activation analysis of phosphorus in biological materials using the 31 P(α,n) sup(34m)Cl reaction has been studied. Since sup(34m)Cl is also produced by the 32 S(α,pn) and the 35 Cl(α,α'n) reactions, the thick-target yield curves on phosphorus, sulfur and chlorine were determined in order to choose the optimum irradiation conditions. As a result, it was found that the activation analysis for phosphorus without interferences from sulfur and chlorine is possible by bombarding with less than 17 MeV alphas. The applicability of this method to biological samples was then examined by irradiating several standard reference materials. It was confirmed that phosphorus can readily be determined at the detection limit of 1μg free from interferences due to the matrix elements. (author)

  18. Biological activities of secondary metabolites of the order Zoanthids

    Directory of Open Access Journals (Sweden)

    Zahra Aminikhoei

    2015-11-01

    Full Text Available The phylum Cnidaria is a large, diverse and ecologically important group of marine invertebrates, which produce powerful toxins and venoms. The number of marine natural product from cnidarians isolated from class Anthozoa. Among the Anthozoa, the order of zoanthids are sessile, clonal and mostly brightly colored invertebrate which produce high biodiversity of cytolitic, neurotoxic and cardiotoxic compounds. Zoanthids containing palytoxins are reportedly among the most toxic marine organisms known. In addition, a high concentration of zoanthamine alkaloids extracted from this group.The zoanthamine alkaloids were isolated over 20 years ago, exhibit a broad range of biological activities.The best studied and most well-known biological activity of zoanthamine derivative significantly suppressed bone resorption and enhanced bone formation.

  19. Biological activities and medicinal properties of Cajanus cajan (L) Millsp.

    Science.gov (United States)

    Pal, Dilipkumar; Mishra, Pragya; Sachan, Neetu; Ghosh, Ashoke K

    2011-10-01

    Cajanus cajan (L) Millsp. (Sanskrit: Adhaki, Hindi: Arhar, English: Pigeon pea, Bengali: Tur) (family: Fabaceae) is the most important grain legume crop of rain-fed agriculture in semi-arid tropics. It is both a food crop and a cover/forage crop with high levels of proteins and important amino acids like methionine, lysine and tryptophan. During the last few decades extensive studies have been carried out regarding the chemistry of C. cajan and considerable progress has been achieved regarding its biological activities and medicinal applications. This review article gives an overview on the biological activities of the compounds isolated, pharmacological actions and clinical studies of C. cajan extracts apart from its general details.

  20. Biological activities and medicinal properties of Cajanus cajan (L Millsp.

    Directory of Open Access Journals (Sweden)

    Dilipkumar Pal

    2011-01-01

    Full Text Available Cajanus cajan (L Millsp. (Sanskrit: Adhaki, Hindi: Arhar, English: Pigeon pea, Bengali: Tur (family: Fabaceae is the most important grain legume crop of rain-fed agriculture in semi-arid tropics. It is both a food crop and a cover/forage crop with high levels of proteins and important amino acids like methionine, lysine and tryptophan. During the last few decades extensive studies have been carried out regarding the chemistry of C. cajan and considerable progress has been achieved regarding its biological activities and medicinal applications. This review article gives an overview on the biological activities of the compounds isolated, pharmacological actions and clinical studies of C. cajan extracts apart from its general details.

  1. Biological activities and medicinal properties of Gokhru (Pedalium murex L.).

    Science.gov (United States)

    Rajashekar, V; Rao, E Upender; P, Srinivas

    2012-07-01

    Bada Gokhru (Pedalium murex L.) is perhaps the most useful traditional medicinal plant in India. Each part of the neem tree has some medicinal property and is thus commercially exploitable. During the last five decades, apart from the chemistry of the Pedalium murex compounds, considerable progress has been achieved regarding the biological activity and medicinal applications of this plant. It is now considered as a valuable source of unique natural products for development of medicines against various diseases and also for the development of industrial products. This review gives a bird's eye view mainly on the biological activities of some of this compounds isolated, pharmacological actions of the extracts, clinical studies and plausible medicinal applications of gokharu along with their safety evaluation.

  2. Propolis volatile compounds: chemical diversity and biological activity: a review

    OpenAIRE

    Bankova, Vassya; Popova, Milena; Trusheva, Boryana

    2014-01-01

    Propolis is a sticky material collected by bees from plants, and used in the hive as building material and defensive substance. It has been popular as a remedy in Europe since ancient times. Nowadays, propolis use in over-the-counter preparations, “bio”-cosmetics and functional foods, etc., increases. Volatile compounds are found in low concentrations in propolis, but their aroma and significant biological activity make them important for propolis characterisation. Propolis is a plant-derived...

  3. Secondary metabolites in grasses: characterization and biological activity

    OpenAIRE

    Aldo Tava

    2007-01-01

    In a series of studies dealing on the nutritional value of forage species, more attention was focussed on several compounds, named secondary metabolites, that are important in determining nutritional characteristics. Secondary metabolites are compounds detected in the green materials in low concentration compared to primary metabolites (proteins, sugars, lipids, fibers), but of fundamental importance for the plant physiology. The possess several biological activities and this contribute to th...

  4. Polymer application for separation/filtration of biological active compounds

    Science.gov (United States)

    Tylkowski, B.; Tsibranska, I.

    2017-06-01

    Membrane technology is an important part of the engineer's toolbox. This is especially true for industries that process food and other products with their primary source from nature. This review is focused on ongoing development work using membrane technologies for concentration and separation of biologically active compounds, such as polyphenols and flavonoids. We provide the readers not only with the last results achieve in this field but also, we deliver detailed information about the membrane types and polymers used for their preparation.

  5. Biological Activities of Phenolic Compounds Present in Virgin Olive Oil

    OpenAIRE

    Cicerale, Sara; Lucas, Lisa; Keast, Russell

    2010-01-01

    The Mediterranean diet is associated with a lower incidence of atherosclerosis, cardiovascular disease, neurodegenerative diseases and certain types of cancer. The apparent health benefits have been partially ascribed to the dietary consumption of virgin olive oil by Mediterranean populations. Much research has focused on the biologically active phenolic compounds naturally present in virgin olive oils to aid in explaining reduced mortality and morbidity experienced by people consuming a trad...

  6. Recent Advances in Momordica charantia: Functional Components and Biological Activities

    OpenAIRE

    Jia, Shuo; Shen, Mingyue; Zhang, Fan; Xie, Jianhua

    2017-01-01

    Momordica charantia L. (M. charantia), a member of the Cucurbitaceae family, is widely distributed in tropical and subtropical regions of the world. It has been used in folk medicine for the treatment of diabetes mellitus, and its fruit has been used as a vegetable for thousands of years. Phytochemicals including proteins, polysaccharides, flavonoids, triterpenes, saponins, ascorbic acid and steroids have been found in this plant. Various biological activities of M. charantia have been report...

  7. Structural Diversity and Biological Activities of Cyclic Depsipeptides from Fungi

    OpenAIRE

    Xiaohan Wang; Xiao Gong; Peng Li; Daowan Lai; Ligang Zhou

    2018-01-01

    Cyclic depsipeptides (CDPs) are cyclopeptides in which amide groups are replaced by corresponding lactone bonds due to the presence of a hydroxylated carboxylic acid in the peptide structure. These peptides sometimes display additional chemical modifications, including unusual amino acid residues in their structures. This review highlights the occurrence, structures and biological activities of the fungal CDPs reported until October 2017. About 352 fungal CDPs belonging to the groups of cycli...

  8. Biological Activities and Phytochemicals of Swietenia macrophylla King

    Directory of Open Access Journals (Sweden)

    Habsah Abdul Kadir

    2013-08-01

    Full Text Available Swietenia macrophylla King (Meliaceae is an endangered and medicinally important plant indigenous to tropical and subtropical regions of the World. S. macrophylla has been widely used in folk medicine to treat various diseases. The review reveals that limonoids and its derivatives are the major constituents of S. macrophylla. There are several data in the literature indicating a great variety of pharmacological activities of S. macrophylla, which exhibits antimicrobial, anti-inflammatory, antioxidant effects, antimutagenic, anticancer, antitumor and antidiabetic activities. Various other activities like anti-nociceptive, hypolipidemic, antidiarrhoeal, anti-infective, antiviral, antimalarial, acaricidal, antifeedant and heavy metal phytoremediation activity have also been reported. In view of the immense medicinal importance of S. macrophylla, this review aimed at compiling all currently available information on its ethnomedicinal uses, phytochemistry and biological activities of S. macrophylla, showing its importance.

  9. Chemical composition and biological activities of the Agaricus mushrooms

    Directory of Open Access Journals (Sweden)

    L Munkhgerel

    2014-10-01

    Full Text Available Two species of Agaricus mushroom grown in Mongolia were analyzed for their element content. Biological activity and chemical components study of Agaricus, grown in the Mongolian flora has been investigated for the first time. The ethanol extracts of dried Agaricus sp. mushrooms were analyzed for antioxidant activity on 1,1-diphenyl-2- picrylhydrazyl (DPPH radicals and interferon-like activity. The ethanol extracts from Agaricus arvensis showed the most potent radical scavenging activity. The IC50 of A. silvaticus and A. arvensis were 216 and 17.75 g/ml respectively. Among the twenty three mushroom extracts, the extracts from A. silvatisus and A. arvensis have shown the interferon-like activity. DOI: http://dx.doi.org/10.5564/mjc.v14i0.197Mongolian Journal of Chemistry 14 (40, 2013, p41-45

  10. Expression of biologically active murine interleukin-18 in Lactococcus lactis.

    Science.gov (United States)

    Feizollahzadeh, Sadegh; Khanahmad, Hossein; Rahimmanesh, Ilnaz; Ganjalikhani-Hakemi, Mazdak; Andalib, Alireza; Sanei, Mohammad Hossein; Rezaei, Abbas

    2016-11-01

    The food-grade bacterium Lactococcus lactis is increasingly used for heterologous protein expression in therapeutic and industrial applications. The ability of L. lactis to secrete biologically active cytokines may be used for the generation of therapeutic cytokines. Interleukin (IL)-18 enhances the immune response, especially on mucosal surfaces, emphasizing its therapeutic potential. However, it is produced as an inactive precursor and has to be enzymatically cleaved for maturation. We genetically manipulated L. lactis to secrete murine IL-18. The mature murine IL-18 gene was inserted downstream of a nisin promoter in pNZ8149 plasmid and the construct was used to transform L. lactis NZ3900. The transformants were selected on Elliker agar and confirmed by restriction enzyme digestion and sequencing. The expression and secretion of IL-18 protein was verified by SDS-PAGE, western blotting and ELISA. The biological activity of recombinant IL-18 was determined by its ability to induce interferon (IFN)-γ production in L. lactis co-cultured with murine splenic T cells. The amounts of IL-18 in bacterial lysates and supernatants were 3-4 μg mL -1 and 0.6-0.7 ng mL -1 , respectively. The successfully generated L. lactis strain that expressed biologically active murine IL-18 can be used to evaluate the possible therapeutic effects of IL-18 on mucosal surfaces. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  11. Ethnobotany, chemistry, and biological activities of the genus Tithonia (Asteraceae).

    Science.gov (United States)

    Chagas-Paula, Daniela A; Oliveira, Rejane B; Rocha, Bruno A; Da Costa, Fernando B

    2012-02-01

    The genus Tithonia is an important source of diverse natural products, particularly sesquiterpene lactones, diterpenes, and flavonoids. The collected information in this review attempts to summarize the recent developments in the ethnobotany, biological activities, and secondary metabolite chemistry of this genus. More than 100 structures of natural products from Tithonia are reported in this review. The species that has been most investigated in this genus is T. diversifolia, from which ca. 150 compounds were isolated. Biological studies are described to evaluate the anti-inflammatory, analgesic, antimalarial, antiviral, antidiabetic, antidiarrhoeal, antimicrobial, antispasmodic, vasorelaxant, cancer-chemopreventive, cytotoxic, toxicological, bioinsecticide, and repellent activities. A few of these studies have been carried out with isolated compounds from Tithonia species, but the majority has been conducted with different extracts. The relationship between the biological activity and the toxicity of compounds isolated from the plants of this genus as well as T. diversifolia extracts still remains unclear, and mechanisms of action remain to be determined. Copyright © 2012 Verlag Helvetica Chimica Acta AG, Zürich.

  12. Biologically active and biomimetic dual gelatin scaffolds for tissue engineering.

    Science.gov (United States)

    Sánchez, P; Pedraz, J L; Orive, G

    2017-05-01

    We have designed, developed and optimized Genipin cross-linked 3D gelatin scaffolds that were biologically active and biomimetic, show a dual activity both for growth factor and cell delivery. Type B gelatin powder was dissolved in DI water. 100mg of genipin was dissolved in 10ml of DI water. Three genipin concentrations were prepared: 0.1%, 0.2% and 0.3% (w/v). Solutions were mixed at 40°C and under stirring and then left crosslinking for 72h. Scaffolds were obtained by punching 8 mm-cylinders into ethanol 70% solution for 10min and then freeze-drying. Scaffolds were biologically, biomechanically and morphologically evaluated. Cell adhesion and morphology of D1-Mesenchymal stem cells (MSCs) and L-929 fibroblast was studied. Vascular endothelial grwoth factor (VEGF) and Sonic hedgehog (SHH) were used as model proteins. Swelling ratio increased and younǵs module decreased along with the concentration of genipin. All scaffolds were biocompatible according to the toxicity test. MSC and L-929 cell adhesion improved in 0.2% of genipin, obtaining better results with MSCs. VEGF and SHH were released from the gels. This preliminary study suggest that the biologically active and dual gelatin scaffolds may be used for tissue engineering approaches like bone regeneration. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Adsorption of Heavy Metals on Biologically Activated Brown Coal Sludge

    Directory of Open Access Journals (Sweden)

    Mária Praščáková

    2005-11-01

    Full Text Available Adsorption of cooper (II and zinc (II ions from aqueous solutions on a biologically activated brown coal sludge was investigated. Four families of adsorbents were prepared from the brown coal sludge bya microorganism’s activity. There were used microscopic fungi such as Aspergillus niger, Aspergillus clavatus, Penicillium glabrum and Trichoderma viride. Prepared sorbents were capable of removing Cu (II and Zn (II. The sorption isotherm has been constructed and the specific metal uptake and the maximum capacity of the adsorbent have been determined.

  14. Synthesis, crystal structure and biological activity of novel diester cyclophanes

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Pengfei; Yang, Bingqin; Fang, Xianwen; Cheng, Zhao; Yang, Meipan, E-mail: yangbq@nwu.edu.cn [Department of Chemistry, Key Laboratory of Synthetic and Natural Functional Molecule Chemistry, Northwest University, Shaanxi (China)

    2012-10-15

    A series of novel diester cyclophanes was synthesized by esterification of 1,2-benzenedicarbonyl chloride with eight different diols under high dilution conditions. The structures of the compounds were verified by elemental analysis, {sup 1}H nuclear magnetic resonance (NMR), IR spectroscopy and high resolution mass spectrometry (HRMS). The crystal structures of two compounds were characterized by single crystal X-ray diffractometry (XRD). All the new cyclophanes were evaluated for biological activities and the results showed that some of these compounds have low antibacterial or antifungal activities (author)

  15. Cryo-electron microscopy for structural analysis of dynamic biological macromolecules.

    Science.gov (United States)

    Murata, Kazuyoshi; Wolf, Matthias

    2018-02-01

    Since the introduction of what became today's standard for cryo-embedding of biological macromolecules at native conditions more than 30years ago, techniques and equipment have been drastically improved and the structure of biomolecules can now be studied at near atomic resolution by cryo-electron microscopy (cryo-EM) while capturing multiple dynamic states. Here we review the recent progress in cryo-EM for structural studies of dynamic biological macromolecules. We provide an overview of the cryo-EM method and introduce contemporary studies to investigate biomolecular structure and dynamics, including examples from the recent literature. Cryo-EM is a powerful tool for the investigation of biological macromolecular structures including analysis of their dynamics by using advanced image-processing algorithms. The method has become even more widely applicable with present-day single particle analysis and electron tomography. The cryo-EM method can be used to determine the three-dimensional structure of biomacromolecules in near native condition at close to atomic resolution, and has the potential to reveal conformations of dynamic molecular complexes. This article is part of a Special Issue entitled "Biophysical Exploration of Dynamical Ordering of Biomolecular Systems" edited by Dr. Koichi Kato. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  16. The integrative role of cryo electron microscopy in molecular and cellular structural biology.

    Science.gov (United States)

    Orlov, Igor; Myasnikov, Alexander G; Andronov, Leonid; Natchiar, S Kundhavai; Khatter, Heena; Beinsteiner, Brice; Ménétret, Jean-François; Hazemann, Isabelle; Mohideen, Kareem; Tazibt, Karima; Tabaroni, Rachel; Kratzat, Hanna; Djabeur, Nadia; Bruxelles, Tatiana; Raivoniaina, Finaritra; Pompeo, Lorenza di; Torchy, Morgan; Billas, Isabelle; Urzhumtsev, Alexandre; Klaholz, Bruno P

    2017-02-01

    After gradually moving away from preparation methods prone to artefacts such as plastic embedding and negative staining for cell sections and single particles, the field of cryo electron microscopy (cryo-EM) is now heading off at unprecedented speed towards high-resolution analysis of biological objects of various sizes. This 'revolution in resolution' is happening largely thanks to new developments of new-generation cameras used for recording the images in the cryo electron microscope which have much increased sensitivity being based on complementary metal oxide semiconductor devices. Combined with advanced image processing and 3D reconstruction, the cryo-EM analysis of nucleoprotein complexes can provide unprecedented insights at molecular and atomic levels and address regulatory mechanisms in the cell. These advances reinforce the integrative role of cryo-EM in synergy with other methods such as X-ray crystallography, fluorescence imaging or focussed-ion beam milling as exemplified here by some recent studies from our laboratory on ribosomes, viruses, chromatin and nuclear receptors. Such multi-scale and multi-resolution approaches allow integrating molecular and cellular levels when applied to purified or in situ macromolecular complexes, thus illustrating the trend of the field towards cellular structural biology. © 2016 The Authors. Biology of the Cell published by Wiley-VCH Verlag GmbH & Co. KGaA on behalf of Société Française des Microscopies and Société de Biologie Cellulaire de France.

  17. On the mechanism of biological activation by tritium.

    Science.gov (United States)

    Rozhko, T V; Badun, G A; Razzhivina, I A; Guseynov, O A; Guseynova, V E; Kudryasheva, N S

    2016-06-01

    The mechanism of biological activation by beta-emitting radionuclide tritium was studied. Luminous marine bacteria were used as a bioassay to monitor the biological effect of tritium with luminescence intensity as the physiological parameter tested. Two different types of tritium sources were used: HTO molecules distributed regularly in the surrounding aqueous medium, and a solid source with tritium atoms fixed on its surface (tritium-labeled films, 0.11, 0.28, 0.91, and 2.36 MBq/cm(2)). When using the tritium-labeled films, tritium penetration into the cells was prevented. The both types of tritium sources revealed similar changes in the bacterial luminescence kinetics: a delay period followed by bioluminescence activation. No monotonic dependences of bioluminescence activation efficiency on specific radioactivities of the films were found. A 15-day exposure to tritiated water (100 MBq/L) did not reveal mutations in bacterial DNA. The results obtained give preference to a "non-genomic" mechanism of bioluminescence activation by tritium. An activation of the intracellular bioluminescence process develops without penetration of tritium atoms into the cells and can be caused by intensification of trans-membrane cellular processes stimulated by ionization and radiolysis of aqueous media. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Distribution and biological activities of the flavonoid luteolin.

    Science.gov (United States)

    López-Lázaro, Miguel

    2009-01-01

    Epidemiological evidence suggests that flavonoids may play an important role in the decreased risk of chronic diseases associated with a diet rich in plant-derived foods. Flavonoids are also common constituents of plants used in traditional medicine to treat a wide range of diseases. The purpose of this article is to summarize the distribution and biological activities of one of the most common flavonoids: luteolin. This flavonoid and its glycosides are widely distributed in the plant kingdom; they are present in many plant families and have been identified in Bryophyta, Pteridophyta, Pinophyta and Magnoliophyta. Dietary sources of luteolin include, for instance, carrots, peppers, celery, olive oil, peppermint, thyme, rosemary and oregano. Preclinical studies have shown that this flavone possesses a variety of pharmacological activities, including antioxidant, anti-inflammatory, antimicrobial and anticancer activities. The ability of luteolin to inhibit angiogenesis, to induce apoptosis, to prevent carcinogenesis in animal models, to reduce tumor growth in vivo and to sensitize tumor cells to the cytotoxic effects of some anticancer drugs suggests that this flavonoid has cancer chemopreventive and chemotherapeutic potential. Modulation of ROS levels, inhibition of topoisomerases I and II, reduction of NF-kappaB and AP-1 activity, stabilization of p53, and inhibition of PI3K, STAT3, IGF1R and HER2 are possible mechanisms involved in the biological activities of luteolin.

  19. Radiation degradation of carbohydrates and their biological activities for plants

    International Nuclear Information System (INIS)

    Kume, T.; Nagasawa, N.; Matsuhashi, S.

    2000-01-01

    Radiation effects on carbohydrates such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to improve the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities such as anti-bacterial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Pectic fragments obtained from degraded pectin induced the phytoalexins such as glyceollins in soybean and pisatin in pea. The irradiated chitosan shows the higher elicitor activity for pisatin than that of pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. Kappa and iota carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa irradiated at 100 kGy. Some radiation degraded carbohydrates suppressed the damage of heavy metals on plants. The effects of irradiated carbohydrates on transportation of heavy metals have been investigated by PETIS (Positron Emitting Tracer Imaging System) and autoradiography using 48 V and 62 Zn. (author)

  20. Radiation degradation of carbohydrates and their biological activities for plants

    Energy Technology Data Exchange (ETDEWEB)

    Kume, T.; Nagasawa, N.; Matsuhashi, S. [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment] [and others

    2000-03-01

    Radiation effects on carbohydrates such as chitosan, sodium alginate, carrageenan, cellulose, pectin have been investigated to improve the biological activities. These carbohydrates were easily degraded by irradiation and induced various kinds of biological activities such as anti-bacterial activity, promotion of plant growth, suppression of heavy metal stress, phytoalexins induction. Pectic fragments obtained from degraded pectin induced the phytoalexins such as glyceollins in soybean and pisatin in pea. The irradiated chitosan shows the higher elicitor activity for pisatin than that of pectin. For the plant growth promotion, alginate derived from brown marine algae, chitosan and ligno-cellulosic extracts show a strong activity. Kappa and iota carrageenan derived from red marine algae can promote growth of rice and the highest effect was obtained with kappa irradiated at 100 kGy. Some radiation degraded carbohydrates suppressed the damage of heavy metals on plants. The effects of irradiated carbohydrates on transportation of heavy metals have been investigated by PETIS (Positron Emitting Tracer Imaging System) and autoradiography using {sup 48}V and {sup 62}Zn. (author)

  1. Characterization of the corrosion resistance of several alloys to dilute biologically active solutions

    Science.gov (United States)

    Walsh, Daniel W.

    1990-01-01

    Sulfate reducing bacteria and acid producing bacteria/fungi detected in hygiene waters increased the corrosion rate in aluminum alloy. Biologically active media enhanced the formation of pits on metal coupons. Direct observation of gas evolved at the corrosion sample, coupled with scanning electron microscopy (SEM) and energy dispersive x-ray analysis of the corrosion products indicates that the corrosion rate is increased because the presence of bacteria favor the reduction of hydrogen as the cathodic reaction through the reaction of oxygen and water. SEM verifies the presence of microbes in a biofilm on the surface of corroding samples. The bacterial consortia are associated with anodic sites on the metal surface, aggressive pitting occurs adjacent to biofilms. Many pits are associated with triple points and inclusions in the aluminum alloy microstructure. Similar bacterial colonization was found on the stainless steel samples. Fourier transform Infrared Spectroscopy confirmed the presence of carbonyl groups in pitted areas of samples exposed to biologically active waters.

  2. Biological Activities of Phenolic Compounds of Extra Virgin Olive Oil

    Directory of Open Access Journals (Sweden)

    Maurizio Servili

    2013-12-01

    Full Text Available Over the last few decades, multiple biological properties, providing antioxidant, anti-inflammatory, chemopreventive and anti-cancer benefits, as well as the characteristic pungent and bitter taste, have been attributed to Extra Virgin Olive Oil (EVOO phenols. In particular, growing efforts have been devoted to the study of the antioxidants of EVOO, due to their importance from health, biological and sensory points of view. Hydrophilic and lipophilic phenols represent the main antioxidants of EVOO, and they include a large variety of compounds. Among them, the most concentrated phenols are lignans and secoiridoids, with the latter found exclusively in the Oleaceae family, of which the drupe is the only edible fruit. In recent years, therefore, we have tackled the study of the main properties of phenols, including the relationships between their biological activity and the related chemical structure. This review, in fact, focuses on the phenolic compounds of EVOO, and, in particular, on their biological properties, sensory aspects and antioxidant capacity, with a particular emphasis on the extension of the product shelf-life.

  3. Biological Activities of Phenolic Compounds of Extra Virgin Olive Oil.

    Science.gov (United States)

    Servili, Maurizio; Sordini, Beatrice; Esposto, Sonia; Urbani, Stefania; Veneziani, Gianluca; Di Maio, Ilona; Selvaggini, Roberto; Taticchi, Agnese

    2013-12-20

    Over the last few decades, multiple biological properties, providing antioxidant, anti-inflammatory, chemopreventive and anti-cancer benefits, as well as the characteristic pungent and bitter taste, have been attributed to Extra Virgin Olive Oil (EVOO) phenols. In particular, growing efforts have been devoted to the study of the antioxidants of EVOO, due to their importance from health, biological and sensory points of view. Hydrophilic and lipophilic phenols represent the main antioxidants of EVOO, and they include a large variety of compounds. Among them, the most concentrated phenols are lignans and secoiridoids, with the latter found exclusively in the Oleaceae family, of which the drupe is the only edible fruit. In recent years, therefore, we have tackled the study of the main properties of phenols, including the relationships between their biological activity and the related chemical structure. This review, in fact, focuses on the phenolic compounds of EVOO, and, in particular, on their biological properties, sensory aspects and antioxidant capacity, with a particular emphasis on the extension of the product shelf-life.

  4. Summary of diamino pyrazoles derived and study their biological activities

    International Nuclear Information System (INIS)

    Hagui, Marwa

    2016-01-01

    The work involves the synthesis of new heterocyclic structures diamino pyrazoles derivatives that are present in many natural products and products of pharmacological and therapeutic interests and study their biological activities. In order to develop a radiotracer interest and use in diagnostic nuclear medicine, we are interested to synthesis a pyrazole derivative with the precursor [Re(CO)5Br] and studying the antibacterial and antifungal activity of 3.5-diamino pyrazole and even thioamide complex rhenium. The objectives of our workout: 1/ Synthesis of molecules 3,5-diamino pyrazole and thioamide. 2/ Synthesis of 3,5-diamino pyrazole-rhenium complex. 3/ The in vitro study: Bacteriological Tests (Study of antibacterial and antifungal activity of 3,5-diamino pyrazole and thioamide). The first part of this work concerns the chemical synthesis of molecules such as: thioamide, Amp z1 Ampz2 and then we had synthesized the complex 3,5-diamino pyrazole-rhenium. Similarly we determined the physicochemical characteristics of the compounds synthesized by CLHP, CCM and RMN ( 1 H, 13 C). The second part is devoted to the study in vitro of biological activities of the synthesized molecules and complex 3,5 diaminopyrazole-rhenium with concentration 1 mg/mL and 2 mg/mL. The results allow us to say that the thioamide and Ampz2 have antibacterial activity against S. enterica and Ampz2 has low activity against S. aureus and P. aeruginossa. Other pyrazole derivatives have no significant antibacterial and antifungal activity. The results also show that the synthesized compounds of concentration 2 mg/mL in relation to the inhibition zones of amoxicillin and DMSO: 1/ Escherichia coli, there is antibacterial activity for thioamide, and the Amp z1-Re Ampz2 compound. 2/ Staphylococcus aureus, the complex Ampz 1-Re and the thioamide have significant antibacterial activity. 3/ Salmonella, we observe that the thioamide molecules, Ampz2 and Amp z1-Re have significant antibacterial activity

  5. The cell biology of T-dependent B cell activation

    DEFF Research Database (Denmark)

    Owens, T; Zeine, R

    1989-01-01

    The requirement that CD4+ helper T cells recognize antigen in association with class II Major Histocompatibility Complex (MHC) encoded molecules constrains T cells to activation through intercellular interaction. The cell biology of the interactions between CD4+ T cells and antigen-presenting cells...... includes multipoint intermolecular interactions that probably involve aggregation of both polymorphic and monomorphic T cell surface molecules. Such aggregations have been shown in vitro to markedly enhance and, in some cases, induce T cell activation. The production of T-derived lymphokines that have been...... implicated in B cell activation is dependent on the T cell receptor for antigen and its associated CD3 signalling complex. T-dependent help for B cell activation is therefore similarly MHC-restricted and involves T-B intercellular interaction. Recent reports that describe antigen-independent B cell...

  6. Biological activities of triazine derivatives. Combining DFT and QSAR results

    Directory of Open Access Journals (Sweden)

    Majdouline Larif

    2017-02-01

    Full Text Available In order to investigate the relationship between activities and structures, a 3D-QSAR study is applied to a set of 43 molecules based on triazines. This study was conducted using the principal component analysis (PCA method, the multiple linear regression method (MLR and the artificial neural network (ANN. The predicted values of activities are in good agreement with the experimental results. The artificial neural network (ANN techniques, considering the relevant descriptors obtained from the MLR, showed a correlation coefficient of 0.9 with an 8-3-1 ANN model which is a good result. As a result of quantitative structure–activity relationships, we found that the model proposed in this study is constituted of major descriptors used to describe these molecules. The obtained results suggested that the proposed combination of several calculated parameters could be useful to predict the biological activity of triazine derivatives.

  7. A comparison of the biological activities of four prostaglandins

    Science.gov (United States)

    Horton, E. W.; Main, I. H. M.

    1963-01-01

    The biological activities of prostaglandins E1, E2, E3 and F1α have been compared. Prostaglandins E1, E2, E3 were qualitatively similar; E1 and E2 were about equiactive, but E3 was less active on all preparations. Prostaglandin F1α was a less potent vasodilator than E1 on the cat gastrocnemius muscle blood flow and skin blood flow and a less potent depressor drug on rabbit blood pressure. On the rabbit isolated jejunum F1α was twice as active as E1 but on the guinea-pig isolated ileum E1 was about forty times more active than F1α. One qualitative difference between these prostaglandins was observed; on the rabbit fallopian tube in vivo prostaglandins of the E series decreased both the tone and the peristalsis of the tube whereas prostaglandin F1α increased tubal tone. ImagesFig. 2Fig. 3Fig. 5 PMID:14066143

  8. Biological activities of water-soluble fullerene derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, S; Mashino, T [Department of Pharmaceutical Sciences, Faculty of Pharmacy, Keio University, 1-5-30 Shiba-koen, Minato-ku, Tokyo 105-8512 (Japan)], E-mail: mashino-td@pha.keio.ac.jp

    2009-04-01

    Three types of water-soluble fullerene derivatives were synthesized and their biological activities were investigated. C{sub 60}-dimalonic acid, an anionic fullerene derivative, showed antioxidant activity such as quenching of superoxide and relief from growth inhibition of E. coli by paraquat. C{sub 60}-bis(7V,7V-dimethylpyrrolidinium iodide), a cationic fullerene derivative, has antibacterial activity and antiproliferative effect on cancer cell lines. The mechanism is suggested to be respiratory chain inhibition by reactive oxygen species produced by the cationic fullerene derivative. Proline-type fullerene derivatives showed strong inhibition activities on HIV-reverse transcriptase. The IC{sub 50} values were remarkably lower than nevirapine, a clinically used anti-HIV drug. Fullerene derivatives have a big potential for a new type of lead compound to be used as medicine.

  9. Electron Bio-Imaging Centre (eBIC): the UK national research facility for biological electron microscopy.

    Science.gov (United States)

    Clare, Daniel K; Siebert, C Alistair; Hecksel, Corey; Hagen, Christoph; Mordhorst, Valerie; Grange, Michael; Ashton, Alun W; Walsh, Martin A; Grünewald, Kay; Saibil, Helen R; Stuart, David I; Zhang, Peijun

    2017-06-01

    The recent resolution revolution in cryo-EM has led to a massive increase in demand for both time on high-end cryo-electron microscopes and access to cryo-electron microscopy expertise. In anticipation of this demand, eBIC was set up at Diamond Light Source in collaboration with Birkbeck College London and the University of Oxford, and funded by the Wellcome Trust, the UK Medical Research Council (MRC) and the Biotechnology and Biological Sciences Research Council (BBSRC) to provide access to high-end equipment through peer review. eBIC is currently in its start-up phase and began by offering time on a single FEI Titan Krios microscope equipped with the latest generation of direct electron detectors from two manufacturers. Here, the current status and modes of access for potential users of eBIC are outlined. In the first year of operation, 222 d of microscope time were delivered to external research groups, with 95 visits in total, of which 53 were from unique groups. The data collected have generated multiple high- to intermediate-resolution structures (2.8-8 Å), ten of which have been published. A second Krios microscope is now in operation, with two more due to come online in 2017. In the next phase of growth of eBIC, in addition to more microscope time, new data-collection strategies and sample-preparation techniques will be made available to external user groups. Finally, all raw data are archived, and a metadata catalogue and automated pipelines for data analysis are being developed.

  10. Resonant enhancement of relativistic electron fluxes during geomagnetically active periods

    Directory of Open Access Journals (Sweden)

    I. Roth

    Full Text Available The strong increase in the flux of relativistic electrons during the recovery phase of magnetic storms and during other active periods is investigated with the help of Hamiltonian formalism and simulations of test electrons which interact with whistler waves. The intensity of the whistler waves is enhanced significantly due to injection of 10-100 keV electrons during the substorm. Electrons which drift in the gradient and curvature of the magnetic field generate the rising tones of VLF whistler chorus. The seed population of relativistic electrons which bounce along the inhomogeneous magnetic field, interacts resonantly with the whistler waves. Whistler wave propagating obliquely to the magnetic field can interact with energetic electrons through Landau, cyclotron, and higher harmonic resonant interactions when the Doppler-shifted wave frequency equals any (positive or negative integer multiple of the local relativistic gyrofrequency. Because the gyroradius of a relativistic electron may be the order of or greater than the perpendicular wavelength, numerous cyclotron, harmonics can contribute to the resonant interaction which breaks down the adiabatic invariant. A similar process diffuses the pitch angle leading to electron precipitation. The irreversible changes in the adiabatic invariant depend on the relative phase between the wave and the electron, and successive resonant interactions result in electrons undergoing a random walk in energy and pitch angle. This resonant process may contribute to the 10-100 fold increase of the relativistic electron flux in the outer radiation belt, and constitute an interesting relation between substorm-generated waves and enhancements in fluxes of relativistic electrons during geomagnetic storms and other active periods.

    Key words. Magnetospheric physics (energetic particles · trapped; plasma waves and instabilities; storms and substorms

  11. Removal of diclofenac from surface water by electron beam irradiation combined with a biological aerated filter

    Science.gov (United States)

    He, Shijun; Wang, Jianlong; Ye, Longfei; Zhang, Youxue; Yu, Jiang

    2014-12-01

    The degradation of DCF was investigated in aqueous solution by using electron beam (EB) technology. When the initial concentration was between 10 and 40 mg/L, almost 100% of the DCF was degraded at a dose of 0.5 kGy. However, only about 6.5% of DCF was mineralized even at 2 kGy according to total organic carbon (TOC) measurements. A combined process of EB and biological aerated filter (BAF) was therefore developed to enhance the treatment of DCF contaminated surface water. The effluent quality of combined process was substantially improved by EB pretreatment due to the degradation of DCF and related intermediates. Both irradiation and biological treatment reduced the toxicity of the treated water. The experimental results showed that EB is effective for removing DCF from artificial aqueous solution and real surface water.

  12. Nano-Bio Electrochemical Interfacing-Linking Cell Biology and Micro-Electronics

    Science.gov (United States)

    Shacham-Diamand, Y.; Popovtzer, R.; Rishpon, Y.

    Integration of biological substance within electronic devices is an innovative and challenging area combining recent progress in molecular biology and micro technology. First, we introduce the concept of integrating living cells with Micro Electro Mechanical Systems (MEMS). Following a brief overview on "whole cell based biosensors" we describe the design, fabrication, and process of a biocompatible electrochemical "Lab-on-a-Chip" system. Demonstrating the application of electrochemical interfacing based whole cell bio chips, we present two different configurations: a. integration of prokaryotic cells (bacteria) for water toxicity detection, and b. integration of eukaryotic cells (human colon cancer cells) for rapid evaluation of the effectiveness of drug treatments. Both applications, with either microbes or mammalian cells integrated onto MEMS based biochips with liquid volume in the range of 100 nL-1 μL, function well and yield a detectable signal much higher than noise level after few minutes.

  13. Emerging opportunities in structural biology with X-ray free-electron lasers

    Science.gov (United States)

    Schlichting, Ilme; Miao, Jianwei

    2012-01-01

    X-ray free-electron lasers (X-FELs) produce X-ray pulses with extremely brilliant peak intensity and ultrashort pulse duration. It has been proposed that radiation damage can be “outrun” by using an ultra intense and short X-FEL pulse that passes a biological sample before the onset of significant radiation damage. The concept of “diffraction-before-destruction” has been demonstrated recently at the Linac Coherent Light Source, the first operational hard X-ray FEL, for protein nanocrystals and giant virus particles. The continuous diffraction patterns from single particles allow solving the classical “phase problem” by the oversampling method with iterative algorithms. If enough data are collected from many identical copies of a (biological) particle, its three-dimensional structure can be reconstructed. We review the current status and future prospects of serial femtosecond crystallography (SFX) and single-particle coherent diffraction imaging (CDI) with X-FELs. PMID:22922042

  14. A geometric initial guess for localized electronic orbitals in modular biological systems

    Energy Technology Data Exchange (ETDEWEB)

    Beckman, P. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Univ. of Chicago, IL (United States); Fattebert, J. L. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Lau, E. Y. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Osei-Kuffuor, D. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-09-11

    Recent first-principles molecular dynamics algorithms using localized electronic orbitals have achieved O(N) complexity and controlled accuracy in simulating systems with finite band gaps. However, accurately deter- mining the centers of these localized orbitals during simulation setup may require O(N3) operations, which is computationally infeasible for many biological systems. We present an O(N) approach for approximating orbital centers in proteins, DNA, and RNA which uses non-localized solutions for a set of fixed-size subproblems to create a set of geometric maps applicable to larger systems. This scalable approach, used as an initial guess in the O(N) first-principles molecular dynamics code MGmol, facilitates first-principles simulations in biological systems of sizes which were previously impossible.

  15. European activities in space radiation biology and exobiology

    International Nuclear Information System (INIS)

    Horneck, G.

    1996-01-01

    In view of the space station era, the European Space Agency has initiated a review and planning document for space life sciences. Radiation biology includes dosimetry of the radiation field and its modification by mass shielding, studies on the biological responses to radiation in space, on the potential impact of space flight environment on radiation effects, and assessing the radiation risks and establishing radiation protection guidelines. To reach a better understanding of the processes leading to the origin, evolution and distribution of life, exobiological activities include the exploration of the solar system, the collection and analysis of extraterrestrial samples and the utilization of space as a tool for testing the impact of space environment on organics and resistant life forms. (author)

  16. Chemical constituents and biological activities of the genus Linaria (Scrophulariaceae).

    Science.gov (United States)

    Cheriet, Thamere; Mancini, Ines; Seghiri, Ramdane; Benayache, Fadila; Benayache, Samir

    2015-01-01

    This is a review on 95 references dealing with the genus Linaria (Scrophularioideae-Antirrhineae tribe), a known genus of the Scrophulariaceae family, which comprises about 200 species mainly distributed in Europe, Asia and North Africa. The use of some Linaria species in folk medicine has attracted the attention for chemical and biological studies. This report is aimed to be a comprehensive overview on the isolated or identified known and often new metabolites from the 41 Linaria species so far cited. It is organised presenting first the phytochemical classes of alkaloids, polyphenols including flavonoids, the latter being quite diffused and mostly present as flavones, flavonols and their glycosides, and terpenoids including iridoids and steroids. Second, the results from biological investigation on plant extracts, pure natural products isolated from Linaria species and some synthetic derivatives are reported, with antitumour, anti-acetylcholinesterase, anti-inflammatory and analgesic, antioxidant and antibacterial activities.

  17. 76 FR 9024 - Agency Information Collection Activities; Proposed Collection; Comment Request; Electronic...

    Science.gov (United States)

    2011-02-16

    ...] Agency Information Collection Activities; Proposed Collection; Comment Request; Electronic Records; Electronic Signatures AGENCY: Food and Drug Administration, HHS. ACTION: Notice. SUMMARY: The Food and Drug... relating to FDA's electronic records and electronic signatures. DATES: Submit either electronic or written...

  18. The BIOSCI electronic newsgroup network for the biological sciences. Final report, October 1, 1992--June 30, 1996

    Energy Technology Data Exchange (ETDEWEB)

    Kristofferson, D.; Mack, D.

    1996-10-01

    This is the final report for a DOE funded project on BIOSCI Electronic Newsgroup Network for the biological sciences. A usable network for scientific discussion, major announcements, problem solving, etc. has been created.

  19. Quality control of the documentation process in electronic economic activities

    Directory of Open Access Journals (Sweden)

    Krutova A.S.

    2017-06-01

    Full Text Available It is proved that the main tool that will provide adequate information resources e economic activities of social and economic relations are documenting quality control processes as the basis of global information space. Directions problems as formation evaluation information resources in the process of documentation, namely development tools assess the efficiency of the system components – qualitative assessment; development of mathematical modeling tools – quantitative evaluation. A qualitative assessment of electronic documentation of economic activity through exercise performance, efficiency of communication; document management efficiency; effectiveness of flow control operations; relationship management effectiveness. The concept of quality control process documents electronically economic activity to components which include: the level of workflow; forms adequacy of information; consumer quality documents; quality attributes; type of income data; condition monitoring systems; organizational level process documentation; attributes of quality, performance quality consumer; type of management system; type of income data; condition monitoring systems. Grounded components of the control system electronic document subjects of economic activity. Detected components IT-audit management system economic activity: compliance audit; audit of internal control; detailed multilevel analysis; corporate risk assessment methodology. The stages and methods of processing electronic transactions economic activity during condition monitoring of electronic economic activity.

  20. THREE-DIMENSIONAL OBSERVATIONS ON THICK BIOLOGICAL SPECIMENS BY HIGH VOLTAGE ELECTRON MICROSCOPY

    Directory of Open Access Journals (Sweden)

    Tetsuji Nagata

    2011-05-01

    Full Text Available Thick biological specimens prepared as whole mount cultured cells or thick sections from embedded tissues were stained with histochemical reactions, such as thiamine pyrophosphatase, glucose-6-phosphatase, cytochrome oxidase, acid phosphatase, DAB reactions and radioautography, to observe 3-D ultrastructures of cell organelles producing stereo-pairs by high voltage electron microscopy at accerelating voltages of 400-1000 kV. The organelles demonstrated were Golgi apparatus, endoplasmic reticulum, mitochondria, lysosomes, peroxisomes, pinocytotic vesicles and incorporations of radioactive compounds. As the results, those cell organelles were observed 3- dimensionally and the relative relationships between these organelles were demonstrated.

  1. Antiproliferative Pt(IV) complexes: synthesis, biological activity, and quantitative structure-activity relationship modeling.

    Science.gov (United States)

    Gramatica, Paola; Papa, Ester; Luini, Mara; Monti, Elena; Gariboldi, Marzia B; Ravera, Mauro; Gabano, Elisabetta; Gaviglio, Luca; Osella, Domenico

    2010-09-01

    Several Pt(IV) complexes of the general formula [Pt(L)2(L')2(L'')2] [axial ligands L are Cl-, RCOO-, or OH-; equatorial ligands L' are two am(m)ine or one diamine; and equatorial ligands L'' are Cl- or glycolato] were rationally designed and synthesized in the attempt to develop a predictive quantitative structure-activity relationship (QSAR) model. Numerous theoretical molecular descriptors were used alongside physicochemical data (i.e., reduction peak potential, Ep, and partition coefficient, log Po/w) to obtain a validated QSAR between in vitro cytotoxicity (half maximal inhibitory concentrations, IC50, on A2780 ovarian and HCT116 colon carcinoma cell lines) and some features of Pt(IV) complexes. In the resulting best models, a lipophilic descriptor (log Po/w or the number of secondary sp3 carbon atoms) plus an electronic descriptor (Ep, the number of oxygen atoms, or the topological polar surface area expressed as the N,O polar contribution) is necessary for modeling, supporting the general finding that the biological behavior of Pt(IV) complexes can be rationalized on the basis of their cellular uptake, the Pt(IV)-->Pt(II) reduction, and the structure of the corresponding Pt(II) metabolites. Novel compounds were synthesized on the basis of their predicted cytotoxicity in the preliminary QSAR model, and were experimentally tested. A final QSAR model, based solely on theoretical molecular descriptors to ensure its general applicability, is proposed.

  2. Ab Initio Calculations of the Electronic Structures and Biological Functions of Protein Molecules

    Science.gov (United States)

    Zheng, Haoping

    2003-04-01

    The self-consistent cluster-embedding (SCCE) calculation method reduces the computational effort from M3 to about M1 (M is the number of atoms in the system) with unchanged calculation precision. So the ab initio, all-electron calculation of the electronic structure and biological function of protein molecule becomes a reality, which will promote new proteomics considerably. The calculated results of two real protein molecules, the trypsin inhibitor from the seeds of squash Cucurbita maxima (CMTI-I, 436 atoms) and the Ascaris trypsin inhibitor (912 atoms, two three-dimensional structures), are presented. The reactive sites of the inhibitors are determined and explained. The precision of structure determination of inhibitors are tested theoretically.

  3. Quantitative analysis of biological fluids by electron probe and X ray spectrometry

    International Nuclear Information System (INIS)

    Girod, Chantal

    1986-01-01

    In order to know the kidney normal operation and to have an insight on cellular transport mechanisms and hormonal regulations at the nephron level, a technique based on the use of an electron probe has been developed for the elemental analysis of micro-volumes of biological fluids. This academic document reports applications of this technique on animals on which such fluids have been sampled at different levels of the nephron. As these samples are available in too small volumes to be dosed by conventional methods, they have been quantitatively analysed by using an electronic probe based analyser in order to determine concentrations of all elements with an atomic number greater than that of carbon. After a presentation of the implemented method and hardware, the author thus describes how an analysis is performed, and reports and discusses an example (analysis conditions, data acquisition, data processing, minimum detectable concentration, reasons for measurement scattering)

  4. Ultrastable gold substrates: Properties of a support for high-resolution electron cryomicroscopy of biological specimens

    Science.gov (United States)

    Russo, Christopher J.; Passmore, Lori A.

    2016-01-01

    Electron cryomicroscopy (cryo-EM) allows structure determination of a wide range of biological molecules and specimens. All-gold supports improve cryo-EM images by reducing radiation-induced motion and image blurring. Here we compare the mechanical and electrical properties of all-gold supports to amorphous carbon foils. Gold supports are more conductive, and have suspended foils that are not compressed by differential contraction when cooled to liquid nitrogen temperatures. These measurements show how the choice of support material and geometry can reduce specimen movement by more than an order of magnitude during low-dose imaging. We provide methods for fabrication of all-gold supports and preparation of vitrified specimens. We also analyse illumination geometry for optimal collection of high resolution, low-dose data. Together, the support structures and methods herein can improve the resolution and quality of images from any electron cryomicroscope. PMID:26592474

  5. Hydrogen, metals, bifurcating electrons, and proton gradients: the early evolution of biological energy conservation.

    Science.gov (United States)

    Martin, William F

    2012-03-09

    Life is a persistent, self-specified set of far from equilibrium chemical reactions. In modern microbes, core carbon and energy metabolism are what keep cells alive. In very early chemical evolution, the forerunners of carbon and energy metabolism were the processes of generating reduced carbon compounds from CO(2) and the mechanisms of harnessing energy as compounds capable of doing some chemical work. The process of serpentinization at alkaline hydrothermal vents holds promise as a model for the origin of early reducing power, because Fe(2+) in the Earth's crust reduces water to H(2) and inorganic carbon to methane. The overall geochemical process of serpentinization is similar to the biochemical process of methanogenesis, and methanogenesis is similar to acetogenesis in that both physiologies allow energy conservation from the reduction of CO(2) with electrons from H(2). Electron bifurcation is a newly recognized cytosolic process that anaerobes use generate low potential electrons, it plays an important role in some forms of methanogenesis and, via speculation, possibly in acetogenesis. Electron bifurcation likely figures into the early evolution of biological energy conservation. Copyright © 2011. Published by Elsevier B.V.

  6. Biochemical studies on certain biologically active nitrogenous compounds

    International Nuclear Information System (INIS)

    Abdel kader, S.M.; El Sayed, M.M.; El Malt, E.A.; Shaker, E.S.; Abdel Aziz, H.G.

    2010-01-01

    Certain biologically active nitrogenous compounds such as alkaloids are widely distributed in many wild and medicinal plants such as peganum harmala L. (Phycophyllaceae). However, less literature cited on the natural compounds was extracted from the aerial parts of this plant; therefore this study was conducted on harmal leaves using several solvents. Data indicated that methanol extract was the inhibitoriest effect against some pathogenic bacteria, particularly Streptococcus pyogenus. Chromatographic separation illustrated that presence of four compounds; the most active one was the third compound (3). Elementary analysis (C, H, N) revealed that the primary chemical structure of the active antibacterial compound (C3) was: C17 H21 N3 O7 S with molecular weight 411. Spectroscopic analysis proved that coninical structure was = 1- thioformyl, 8?- D glucoperanoside- Bis- 2, 3 dihydroisopyridino pyrrol. This new compound is represented as a noval ?- carboline alkaloid compound

  7. Pereskia aculeata Muller (Cactaceae Leaves: Chemical Composition and Biological Activities

    Directory of Open Access Journals (Sweden)

    Lucèia Fàtima Souza

    2016-09-01

    Full Text Available The aims of this work were to study the chemical composition of the essential oil from the leaves of Pereskia aculeata and to evaluate some biological activities of three leaf extracts. The phenolic content, antioxidant activity, and in vitro antimicrobial and antifungal activities were determined. The methanol extract showed antioxidant activity (EC50 7.09 mg/mL and high polyphenols content (15.04 ± 0.31 mg gallic acid equivalents (GAE/g. The petroleum ether extract exhibited potent antibacterial activity against Escherichia coli, whereas the chloroform extract showed inhibitory activity against Bacillus cereus and Staphylococcus aureus. The petroleum ether and methanol extracts were more effective in inhibiting the growth of Aspergillus versicolor. The possible cytotoxicity of extracts on neuroblastoma SH-SY5Y cancer cell line and the influence on adenylate cyclase (ADCY expression was also studied. P. aculeata chloroform extract showed antiproliferative activity with an IC50 value of 262.83 µg/mL. Treatments of SH-SY5Y neuroblastoma cells with 100 µg/mL of methanol extract significantly reduced ADCY1 expression.

  8. Activating and inhibiting connections in biological network dynamics

    Directory of Open Access Journals (Sweden)

    Knight Rob

    2008-12-01

    Full Text Available Abstract Background Many studies of biochemical networks have analyzed network topology. Such work has suggested that specific types of network wiring may increase network robustness and therefore confer a selective advantage. However, knowledge of network topology does not allow one to predict network dynamical behavior – for example, whether deleting a protein from a signaling network would maintain the network's dynamical behavior, or induce oscillations or chaos. Results Here we report that the balance between activating and inhibiting connections is important in determining whether network dynamics reach steady state or oscillate. We use a simple dynamical model of a network of interacting genes or proteins. Using the model, we study random networks, networks selected for robust dynamics, and examples of biological network topologies. The fraction of activating connections influences whether the network dynamics reach steady state or oscillate. Conclusion The activating fraction may predispose a network to oscillate or reach steady state, and neutral evolution or selection of this parameter may affect the behavior of biological networks. This principle may unify the dynamics of a wide range of cellular networks. Reviewers Reviewed by Sergei Maslov, Eugene Koonin, and Yu (Brandon Xia (nominated by Mark Gerstein. For the full reviews, please go to the Reviewers' comments section.

  9. Biological activity of lactoferrin-functionalized biomimetic hydroxyapatite nanocrystals

    Directory of Open Access Journals (Sweden)

    Nocerino N

    2014-03-01

    Full Text Available Nunzia Nocerino,1 Andrea Fulgione,1 Marco Iannaccone,1 Laura Tomasetta,1 Flora Ianniello,1 Francesca Martora,1 Marco Lelli,2 Norberto Roveri,2 Federico Capuano,3 Rosanna Capparelli1 1Department of Agriculture Special Biotechnology Center Federico II, CeBIOTEC Biotechnology, University of Naples Federico II, Naples, 2Department of Chemistry, G Ciamician, Alma Mater Studiorum, University of Bologna, Bologna, 3Department of Food Inspection IZS ME, Naples, Italy Abstract: The emergence of bacterial strains resistant to antibiotics is a general public health problem. Progress in developing new molecules with antimicrobial properties has been made. In this study, we evaluated the biological activity of a hybrid nanocomposite composed of synthetic biomimetic hydroxyapatite surface-functionalized by lactoferrin (LF-HA. We evaluated the antimicrobial, anti-inflammatory, and antioxidant properties of LF-HA and found that the composite was active against both Gram-positive and Gram-negative bacteria, and that it modulated proinflammatory and anti-inflammatory responses and enhanced antioxidant properties as compared with LF alone. These results indicate the possibility of using LF-HA as an antimicrobial system and biomimetic hydroxyapatite as a candidate for innovative biomedical applications. Keywords: lactoferrin, hydroxyapatite nanocrystals, biomimetism, biological activity, drug delivery

  10. Synthesis and biological activities of turkesterone 11?-acyl derivatives

    Directory of Open Access Journals (Sweden)

    Laurence Dinan

    2003-02-01

    Full Text Available Turkesterone is a phytoecdysteroid possessing an 11alpha-hydroxyl group. It is an analogue of the insect steroid hormone 20-hydroxyecdysone. Previous ecdysteroid QSAR and molecular modelling studies predicted that the cavity of the ligand-binding domain of the ecdysteroid receptor would possess space in the vicinity of C-11/C-12 of the ecdysteroid. We report the regioselective synthesis of a series of turkesterone 11alpha-acyl derivatives in order to explore this possibility. The structures of the analogues have been unambiguously determined by spectroscopic means (NMR and low-resolution mass spectrometry. Purity was verified by HPLC. Biological activities have been determined in Drosophila melanogaster BII cell-based bioassay for ecdysteroid agonists and in an in vitro radioligand-displacement assay using bacterially expressed D. melanogaster EcR/USP receptor proteins. The 11alpha-acyl derivatives do retain a significant amount of biological activity relative to the parent ecdysteroid. Further, although activity initially drops with the extension of the acyl chain length (C2 to C4, it then increases (C6 to C10, before decreasing again (C14 and C20. The implications of these findings for the interaction of ecdysteroids with the ecdysteroid receptor and potential applications in the generation of affinity-labelled and fluorescently-tagged ecdysteroids are discussed.

  11. X-rays in the Cryo-Electron Microscopy Era: Structural Biology's Dynamic Future.

    Science.gov (United States)

    Shoemaker, Susannah C; Ando, Nozomi

    2018-01-23

    Over the past several years, single-particle cryo-electron microscopy (cryo-EM) has emerged as a leading method for elucidating macromolecular structures at near-atomic resolution, rivaling even the established technique of X-ray crystallography. Cryo-EM is now able to probe proteins as small as hemoglobin (64 kDa) while avoiding the crystallization bottleneck entirely. The remarkable success of cryo-EM has called into question the continuing relevance of X-ray methods, particularly crystallography. To say that the future of structural biology is either cryo-EM or crystallography, however, would be misguided. Crystallography remains better suited to yield precise atomic coordinates of macromolecules under a few hundred kilodaltons in size, while the ability to probe larger, potentially more disordered assemblies is a distinct advantage of cryo-EM. Likewise, crystallography is better equipped to provide high-resolution dynamic information as a function of time, temperature, pressure, and other perturbations, whereas cryo-EM offers increasing insight into conformational and energy landscapes, particularly as algorithms to deconvolute conformational heterogeneity become more advanced. Ultimately, the future of both techniques depends on how their individual strengths are utilized to tackle questions at the frontiers of structural biology. Structure determination is just one piece of a much larger puzzle: a central challenge of modern structural biology is to relate structural information to biological function. In this perspective, we share insight from several leaders in the field and examine the unique and complementary ways in which X-ray methods and cryo-EM can shape the future of structural biology.

  12. Investigating the Spectrum of Biological Activity of Ring-Substituted Salicylanilides and Carbamoylphenylcarbamates

    Directory of Open Access Journals (Sweden)

    Josef Jampilek

    2010-11-01

    Full Text Available In this study, a series of twelve ring-substituted salicylanilides and carbamoylphenylcarbamates were prepared and characterized. The compounds were analyzed using RP-HPLC to determine lipophilicity. They were tested for their activity related to the inhibition of photosynthetic electron transport (PET in spinach (Spinacia oleracea L. chloroplasts. Moreover, their site of action in the photosynthetic apparatus was determined. Primary in vitro screening of the synthesized compounds was also performed against mycobacterial, bacterial and fungal strains. Several compounds showed biological activity comparable with or higher than the standards 3-(3,4-dichlorophenyl-1,1-dimethylurea, isoniazid, penicillin G, ciprofloxacin or fluconazole. The most active compounds showed minimal anti-proliferative activity against human cells in culture, indicating they would have low cytotoxicity. For all compounds, the relationships between lipophilicity and the chemical structure are discussed.

  13. Human laminin isolated in a nearly intact, biologically active form from placenta by limited proteolysis

    DEFF Research Database (Denmark)

    Wewer, U; Albrechtsen, R; Manthorpe, M

    1983-01-01

    fragments cross-reacted with rat laminin in immunodiffusion and enzyme immunoassay, and a polyclonal antiserum against the fragments reacted with basement membranes in tissues in a manner identical with the 4E10 antibody. Electron microscopic images of the human peptic fragments showed structures similar...... to the cross-shaped images of murine laminins, although the short arms were truncated to various degrees or even absent. The isolated peptic fragments also displayed biological activity similar to that of murine laminins in that the outgrowth of neurites by neuronal cells was promoted on plates coated...... with the fragments....

  14. Nanodiamonds as Carriers for Address Delivery of Biologically Active Substances

    Directory of Open Access Journals (Sweden)

    Petunin AI

    2010-01-01

    Full Text Available Abstract Surface of detonation nanodiamonds was functionalized for the covalent attachment of immunoglobulin, and simultaneously bovine serum albumin and Rabbit Anti-Mouse Antibody. The nanodiamond-IgGI125 and RAM-nanodiamond-BSAI125 complexes are stable in blood serum and the immobilized proteins retain their biological activity. It was shown that the RAM-nanodiamond-BSAI125 complex is able to bind to the target antigen immobilized on the Sepharose 6B matrix through antibody–antigen interaction. The idea can be extended to use nanodiamonds as carriers for delivery of bioactive substances (i.e., drugs to various targets in vivo.

  15. Detection of biologically active diterpenoic acids by Raman Spectroscopy

    DEFF Research Database (Denmark)

    Talian, Ivan; Orinak, Andrej; Efremov, Evtim V.

    2010-01-01

    is not suitable for their unambiguous identification, especially not in solution. We attempted to increase the sensitivity by applying UV-resonance Raman spectroscopy and surface-enhanced Raman spectroscopy (SERS) techniques. The UV-Raman spectra of the three compounds in ethanol/water 50 : 50 showed only very......Three poorly detectable, biologically active diterpenoic acids, kaurenoic, abietic, and gibberellic acid, were studied by using different modes of Raman spectroscopy. Because of their structural similarities, in the absence of strongly polarizable groups, conventional Raman spectroscopy...

  16. New enamine derivatives of lapachol and biological activity.

    Science.gov (United States)

    Oliveira, Mailcar F; Lemos, Telma G; de Mattos, Marcos C; Segundo, Taciana A; Santiago, Gilvandete M P; Braz-Filho, Raimundo

    2002-06-01

    A convenient synthesis of the new enamine derivatives 2-(4-morpholinyl)-3-(3-methyl-2-butenyl)-1,4-naphthalenedione, 2-(1-piperidinyl)-3-(3-methyl-2-butenyl)-1,4-naphtalenedione and 2-(1-pyrrolidinyl)-3-(3-methyl-2-butenyl)-1,4-naphthalenedione was carried out from natural 2-hydroxy-3-(3-methyl-2-butenyl)-1,4-naphthalenedione (lapachol) and morpholine, piperidine and pyrrolidine. The structures of the products were established mainly by NMR analysis, including 2D experiments. Biological activities of these products were evaluated against Artemia salina, Aedes aegypti and cytotoxicity using A549 human breast cells.

  17. New enamine derivatives of lapachol and biological activity

    Directory of Open Access Journals (Sweden)

    OLIVEIRA MAILCAR F.

    2002-01-01

    Full Text Available A convenient synthesis of the new enamine derivatives 2-(4-morpholinyl-3-(3-methyl-2-butenyl-1,4-naphthalenedione, 2-(1-piperidinyl-3-(3-methyl-2-butenyl-1,4-naphtalenedione and 2-(1-pyrrolidinyl-3-(3-methyl-2-butenyl-1,4-naphthalenedione was carried out from natural 2-hydroxy-3-(3-methyl-2-butenyl-1,4-naphthalenedione (lapachol and morpholine, piperidine and pyrrolidine. The structures of the products were established mainly by NMR analysis, including 2D experiments. Biological activities of these products were evaluated against Artemia salina, Aedes aegypti and cytotoxicity using A549 human breast cells.

  18. Secondary metabolites and biological activity of Pentas species: A minireview

    Directory of Open Access Journals (Sweden)

    Heba-tollah M. Sweelam

    2018-03-01

    Full Text Available The genus Pentas belongs to the Rubiaceae family, which contains approximately 40 species. Several Pentas species were reported to be used as a folk treatment by African indigenous people in treating some diseases such as malaria, tapeworms, dysentery, gonorrhea, syphilis and snake poisoning. This article covers the period from 1962 to 2017 and presents an overview of the biological activity of different Pentas species and describes their phytochemical traits. As a conclusion, the main secondary metabolites from Pentas species are quinones, highly oxygenated chromene-based structures, and iridoids. Pentas species are widely used in folk medicine but they have to be more investigated for their medicinal properties.

  19. Radio-active waste disposal and deep-sea biology

    International Nuclear Information System (INIS)

    Rice, A.L.

    1978-01-01

    The deep-sea has been widely thought of as a remote, sparsely populated, and biologically inactive environment, well suited to receive the noxious products of nuclear fission processes. Much of what is known of abyssal biology tends to support this view, but there are a few disquieting contra-indications. The realisation, in recent years, that many animal groups show a previously unsuspected high species diversity in the deep-sea emphasized the paucity of our knowledge of this environment. More dramatically, the discovery of a large, active, and highly mobile abysso-bentho-pelagic fauna changed the whole concept of abyssal life. Finally, while there is little evidence for the existence of vertical migration patterns linking the deep-sea bottom communities with those of the overlying water layers, there are similarly too few negative results for the possibility of such transport mechanisms to be dismissed. In summary, biological knowledge of the abyss is insufficient to answer the questions raised in connection with deep-sea dumping, but in the absence of adequate answers it might be dangerous to ignore the questions

  20. Biological shielding design and qualification of concreting process for construction of electron beam irradiation facility

    International Nuclear Information System (INIS)

    Petwal, V.C.; Kumar, P.; Suresh, N.; Parchani, G.; Dwivedi, J.; Thakurta, A.C.

    2011-01-01

    A technology demonstration facility for irradiation of food and agricultural products is being set-up by RRCAT at Indore. The facility design is based on linear electron accelerator with maximum beam power of 10 kW and can be operated either in electron mode at 10 MeV or photon modes at 5/7.5 MeV. Biological shielding has been designed in accordance with NCRP 51 to achieve dose rate at all accessible points outside the irradiation vault less than the permissible limit of 0.1 mR/hr. In addition to radiation attenuation property, concrete must have satisfactory mechanical properties to meet the structural requirements. There are number of site specific variables which affect the structural, thermal and radiological properties of concrete, leading to considerable difference in actual values and design values. Hence it is essential to establish a suitable site and environmental specific process to cast the concrete and qualify the process by experimental measurement. For process qualification we have cast concrete test blocks of different thicknesses up to 3.25 m and evaluated the radiological and mechanical properties by radiometry, ultrasonic and mechanical tests. In this paper we describe the biological shielding design of the facility and analyse the results of tests carried out for qualification of the process. (author)

  1. Novel Triazole Hybrids of Betulin: Synthesis and Biological Activity Profile.

    Science.gov (United States)

    Bębenek, Ewa; Jastrzębska, Maria; Kadela-Tomanek, Monika; Chrobak, Elwira; Orzechowska, Beata; Zwolińska, Katarzyna; Latocha, Małgorzata; Mertas, Anna; Czuba, Zenon; Boryczka, Stanisław

    2017-11-01

    Betulin derivatives containing a 1,2,3-triazole ring possess a wide spectrum of biological activities, including antiviral, anticancer, and antibacterial activity. A series of novel triazoles were prepared by the 1,3-dipolar cycloaddition reaction between the alkyne derivatives of betulin and organic azides. The chemical structures of the obtained compounds were defined by ¹H and 13 C NMR, IR, and high-resolution mass spectrometry (HR-MS) analysis. The target triazoles were screened for their antiviral activity against DNA and RNA viruses. The cytotoxic activity of the obtained compounds 5a - k and 6a - h was determined using five human cancer cell lines (T47D, MCF-7, SNB-19, Colo-829, and C-32) by a WST-1 assay. The bistriazole 6b displayed a promising IC 50 value (0.05 μM) against the human ductal carcinoma T47D (500-fold higher potency than cisplatin). The microdilution method was applied for an evaluation of the antimicrobial activity of all of the compounds. The triazole 5e containing a 3'-deoxythymidine-5'-yl moiety exhibited antibacterial activity against two gram-negative bacteria vz. Klebsiella pneumoniae and Escherichia coli (minimal inhibitory concentration (MIC) range of 0.95-1.95 μM).

  2. Novel Triazole Hybrids of Betulin: Synthesis and Biological Activity Profile

    Directory of Open Access Journals (Sweden)

    Ewa Bębenek

    2017-11-01

    Full Text Available Betulin derivatives containing a 1,2,3-triazole ring possess a wide spectrum of biological activities, including antiviral, anticancer, and antibacterial activity. A series of novel triazoles were prepared by the 1,3-dipolar cycloaddition reaction between the alkyne derivatives of betulin and organic azides. The chemical structures of the obtained compounds were defined by 1H and 13C NMR, IR, and high-resolution mass spectrometry (HR-MS analysis. The target triazoles were screened for their antiviral activity against DNA and RNA viruses. The cytotoxic activity of the obtained compounds 5a–k and 6a–h was determined using five human cancer cell lines (T47D, MCF-7, SNB-19, Colo-829, and C-32 by a WST-1 assay. The bistriazole 6b displayed a promising IC50 value (0.05 μM against the human ductal carcinoma T47D (500-fold higher potency than cisplatin. The microdilution method was applied for an evaluation of the antimicrobial activity of all of the compounds. The triazole 5e containing a 3′-deoxythymidine-5′-yl moiety exhibited antibacterial activity against two gram-negative bacteria vz. Klebsiella pneumoniae and Escherichia coli (minimal inhibitory concentration (MIC range of 0.95–1.95 μM.

  3. Hippeastrum reticulatum (Amaryllidaceae: Alkaloid Profiling, Biological Activities and Molecular Docking

    Directory of Open Access Journals (Sweden)

    Luciana R. Tallini

    2017-12-01

    Full Text Available The Amaryllidaceae family has proven to be a rich source of active compounds, which are characterized by unique skeleton arrangements and a broad spectrum of biological activities. The aim of this work was to perform the first detailed study of the alkaloid constituents of Hippeastrum reticulatum (Amaryllidaceae and to determine the anti-parasitological and cholinesterase (AChE and BuChE inhibitory activities of the epimers (6α-hydroxymaritidine and 6β-hydroxymaritidine. Twelve alkaloids were identified in H. reticulatum: eight known alkaloids by GC-MS and four unknown (6α-hydroxymaritidine, 6β-hydroxymaritidine, reticulinine and isoreticulinine by NMR. The epimer mixture (6α-hydroxymaritidine and 6β-hydroxymaritidine showed low activity against all protozoan parasites tested and weak AChE-inhibitory activity. Finally, a molecular docking analysis of AChE and BuChE proteins showed that isoreticulinine may be classified as a potential inhibitory molecule since it can be stabilized in the active site through hydrogen bonds, π-π stacking and hydrophobic interactions.

  4. Biological Applications and Transmission Electron Microscopy Investigations of Mesoporous Silica Nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Trewyn, Brian G. [Iowa State Univ., Ames, IA (United States)

    2006-01-01

    The research presented and discussed within involves the development of novel biological applications of mesoporous silica nanoparticles (MSN) and an investigation of mesoporous material by transmission electron microscopy (TEM). Mesoporous silica nanoparticles organically functionalized shown to undergo endocytosis in cancer cells and drug release from the pores was controlled intracellularly and intercellularly. Transmission electron microscopy investigations demonstrated the variety of morphologies produced in this field of mesoporous silica nanomaterial synthesis. A series of room-temperature ionic liquid (RTIL) containing mesoporous silica nanoparticle (MSN) materials with various particle morphologies, including spheres, ellipsoids, rods, and tubes, were synthesized. By changing the RTIL template, the pore morphology was tuned from the MCM-41 type of hexagonal mesopores to rotational moire type of helical channels, and to wormhole-like porous structures. These materials were used as controlled release delivery nanodevices to deliver antibacterial ionic liquids against Escherichia coli K12. The involvement of a specific organosiloxane function group, covalently attached to the exterior of fluorescein doped mesoporous silica nanoparticles (FITC-MSN), on the degree and kinetics of endocytosis in cancer and plant cells was investigated. The kinetics of endocystosis of TEG coated FITC-MSN is significantly quicker than FITC-MSN as determined by flow cytometry experiments. The fluorescence confocal microscopy investigation showed the endocytosis of TEG coated-FITC MSN triethylene glycol grafted fluorescein doped MSN (TEG coated-FITC MSN) into both KeLa cells and Tobacco root protoplasts. Once the synthesis of a controlled-release delivery system based on MCM-41-type mesoporous silica nanorods capped by disulfide bonds with superparamagnetic iron oxide nanoparticles was completed. The material was characterized by general methods and the dosage and kinetics of the

  5. Direct electron imaging in electron microscopy with monolithic active pixel sensors

    Energy Technology Data Exchange (ETDEWEB)

    Deptuch, G. [Brookhaven National Laboratory, Upton, NY 11973 (United States)], E-mail: deptuch@ieee.org; Besson, A. [IPHC, CNRS-IN2P3/ULP, 23 rue du Loess, BP 28, 67037 Strasbourg Cedex 02 (France); Rehak, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Szelezniak, M. [IPHC, CNRS-IN2P3/ULP, 23 rue du Loess, BP 28, 67037 Strasbourg Cedex 02 (France); Wall, J. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Winter, M. [IPHC, CNRS-IN2P3/ULP, 23 rue du Loess, BP 28, 67037 Strasbourg Cedex 02 (France); Zhu, Y. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2007-08-15

    A new imaging device for dynamic electron microscopy is in great demand. The detector should provide the experimenter with images having sufficient spatial resolution at high speed. Immunity to radiation damage, accumulated during exposures, is critical. Photographic film, a traditional medium, is not adequate for studies that require large volumes of data or rapid recording and charge coupled device (CCD) cameras have limited resolution, due to phosphor screen coupling. CCD chips are not suitable for direct recording due to their extreme sensitivity to radiation damage. This paper discusses characterization of monolithic active pixel sensors (MAPS) in a scanning electron microscope (SEM) as well as in a transmission electron microscope (TEM). The tested devices were two versions of the MIMOSA V (MV) chip. This 1 M pixel device features pixel size of 17x17 {mu}m{sup 2} and was designed in a 0.6 {mu}m CMOS process. The active layer for detection is a thin (less than 20 {mu}m) epitaxial layer, limiting the broadening of the electron beam. The first version of the detector was a standard imager with electronics, passivation and interconnection layers on top of the active region; the second one was bottom-thinned, reaching the epitaxial layer from the bottom. The electron energies used range from a few keV to 30 keV for SEM and from 40 to 400 keV for TEM. Deterioration of the image resolution due to backscattering was quantified for different energies and both detector versions.

  6. Study by transmission electron microcospy of activated saponite

    OpenAIRE

    Suárez Barrios, M.; Romero, E.; Santiago, C. de; Martín Pozas, J. M.

    1999-01-01

    This work studies the modifications undergone by the Creen Clays Saponite in the Tagus Basin subjected to activation treatments, and stresses the influence of the development of the electronic microscopy technique for studying these materials. Acid treatment with HCI and pillaring treatment with All3 were performed. Characterization of the samples was carried out by DRX, chemical analysis of major elements and Transmission Electronic Microscopy. Add treament causes the delamination and fragme...

  7. New versatile staining reagents for biological transmission electron microscopy that substitute for uranyl acetate.

    Science.gov (United States)

    Nakakoshi, Masamichi; Nishioka, Hideo; Katayama, Eisaku

    2011-12-01

    Aqueous uranyl acetate has been extensively used as a superb staining reagent for transmission electron microscopy of biological materials. However, recent regulation of nuclear fuel material severely restricts its use even for purely scientific purposes. Since uranyl salts are hazardous due to biological toxicity and remaining radioactivity, development of safe and non-radioactive substitutes is greatly anticipated. We examined two lanthanide salts, samarium triacetate and gadolinium triacetate, and found that 1-10% solution of these reagents was safe but still possess excellent capability for staining thin sections of plastic-embedded materials of animal and plant origin. Although post-fixation with osmium tetroxide was essential for high-contrast staining, post-staining with lead citrate could be eliminated if a slow-scan CCD camera is available for observation. These lanthanide salts can also be utilized as good negative-staining reagents to study supramolecular architecture of biological macromolecules. They were not as effective as a fixative of protein assembly, reflecting the non-hazardous nature of the reagents.

  8. Biological activity of lactoferrin-functionalized biomimetic hydroxyapatite nanocrystals.

    Science.gov (United States)

    Nocerino, Nunzia; Fulgione, Andrea; Iannaccone, Marco; Tomasetta, Laura; Ianniello, Flora; Martora, Francesca; Lelli, Marco; Roveri, Norberto; Capuano, Federico; Capparelli, Rosanna

    2014-01-01

    The emergence of bacterial strains resistant to antibiotics is a general public health problem. Progress in developing new molecules with antimicrobial properties has been made. In this study, we evaluated the biological activity of a hybrid nanocomposite composed of synthetic biomimetic hydroxyapatite surface-functionalized by lactoferrin (LF-HA). We evaluated the antimicrobial, anti-inflammatory, and antioxidant properties of LF-HA and found that the composite was active against both Gram-positive and Gram-negative bacteria, and that it modulated proinflammatory and anti-inflammatory responses and enhanced antioxidant properties as compared with LF alone. These results indicate the possibility of using LF-HA as an antimicrobial system and biomimetic hydroxyapatite as a candidate for innovative biomedical applications.

  9. Facile Chemical Access to Biologically Active Norcantharidin Derivatives from Biomass

    Directory of Open Access Journals (Sweden)

    Konstantin I. Galkin

    2017-12-01

    Full Text Available Reductive amination of 2,5-diformylfuran (DFF was used to implement the transition from bio-derived 5-hydroxymethylfurfural (HMF to pharmaceuticals. The synthesized bis(aminomethylfurans were utilized as building blocks for the construction of new derivatives with structural cores of naturally occurring biologically active compounds. Using the one-pot procedure, which included the Diels–Alder reaction followed by hydrogenation of the double bond, bio-derived analogues of the anticancer drug norcantharidin were obtained. The cyclization process was diastereoselective, and resulted in the formation of tricyclic products with the endo configuration. Analysis of cytotoxycity for the resulting tricyclic amine-containing compounds showed an increase of anticancer activity as compared with the unsubstituted norcantharimide.

  10. Structural Diversity and Biological Activities of the Cyclodipeptides from Fungi

    Directory of Open Access Journals (Sweden)

    Xiaohan Wang

    2017-11-01

    Full Text Available Cyclodipeptides, called 2,5-diketopiperazines (2,5-DKPs, are obtained by the condensation of two amino acids. Fungi have been considered to be a rich source of novel and bioactive cyclodipeptides. This review highlights the occurrence, structures and biological activities of the fungal cyclodipeptides with the literature covered up to July 2017. A total of 635 fungal cyclodipeptides belonging to the groups of tryptophan-proline, tryptophan-tryptophan, tryptophan–Xaa, proline–Xaa, non-tryptophan–non-proline, and thio-analogs have been discussed and reviewed. They were mainly isolated from the genera of Aspergillus and Penicillium. More and more cyclodipeptides have been isolated from marine-derived and plant endophytic fungi. Some of them were screened to have cytotoxic, phytotoxic, antimicrobial, insecticidal, vasodilator, radical scavenging, antioxidant, brine shrimp lethal, antiviral, nematicidal, antituberculosis, and enzyme-inhibitory activities to show their potential applications in agriculture, medicinal, and food industry.

  11. Established and emerging biological activity markers of inflammatory bowel disease

    DEFF Research Database (Denmark)

    Nielsen, O H; Vainer, B; Madsen, S M

    2000-01-01

    Assessment of disease activity in inflammatory bowel disease (IBD), i.e., ulcerative colitis (UC) and Crohn's disease (CD), is done using clinical parameters and various biological disease markers. Ideally, a disease marker must: be able to identify individuals at risk of a given disorder......, be disease specific, mirror the disease activity and, finally, be easily applicable for routine clinical purposes. However, no such disease markers have yet been identified for IBD. In this article, classical disease markers including erythrocyte sedimentation rate, acute phase proteins (especially...... orosomucoid and CRP), leukocyte and platelet counts, albumin, neopterin, and beta2-microglobulin will be reviewed together with emerging disease markers such as antibodies of the ANCA/ASCA type, cytokines (e.g., IL-1, IL-2Ralpha, IL-6, IL-8, TNF-alpha, and TNF-alpha receptors) and with various adhesion...

  12. Enhanced biological activity of carotenoids stabilized by phenyl groups.

    Science.gov (United States)

    You, Ji Suk; Jeon, Sunhwa; Byun, Youn Jung; Koo, Sangho; Choi, Shin Sik

    2015-06-15

    Carotenoids are lipid soluble food ingredients with multifunction including antioxidant and anticancer activities. However, carotenoids are destructively oxidized upon reaction with radicals resulting in toxic effects on biological systems. Two synthetic carotenoids (BAS and BTS) containing the aromatic phenyl groups with a para-substituent (OMe and Me, respectively) at C-13 and C-13' position were prepared in order to overcome a structural instability of carotenoid. Both BAS and BTS exerted stronger radical scavenging activity than β-carotene in DPPH and ABTS assays. In particular, BTS significantly reduced in vivo ROS (reactive oxygen species) levels and improved body growth and reproduction of Caenorhabditiselegans. BTS has a great potential for the advanced and modified carotenoid material with stability leading to enhanced bioavailability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Synthesis and Biological Activity of Reversed Pyrimidine Nucleosides

    Directory of Open Access Journals (Sweden)

    Nataša Župančić

    2015-03-01

    Full Text Available An efficient approach to reversed nucleosides which enables their synthesis in gram quantities is described. N-1′-Pyrimidine reversed nucleosides were prepared by treating of the sodium salt of pyrimidine bases with protected 5-tosyl ribose. Additionally, N-1′,N-3′-disubstituted reversed nucleosides were isolated in the condensation reactions with the 5-halogen pyrimidines. Using the Sonogashira coupling of 5′-iodouracil reversed nucleoside with ethynyltrimethyl silane gave 5′-ethynyl derivative which was further transformed into 5′-acetyl reversed nucleoside. Biological activity of deprotected reversed nucleosides was validated on the panel of six human carcinoma cell lines (HeLa, MIAPaCa2, Hep2, NCI-H358, CaCo-2, and HT-29. 5′-Iodouracil derivative displayed moderate growth inhibition activity against human colon carcinoma (CaCo-2 cells.

  14. Established and emerging biological activity markers of inflammatory bowel disease

    DEFF Research Database (Denmark)

    Nielsen, O H; Vainer, B; Madsen, S M

    2000-01-01

    orosomucoid and CRP), leukocyte and platelet counts, albumin, neopterin, and beta2-microglobulin will be reviewed together with emerging disease markers such as antibodies of the ANCA/ASCA type, cytokines (e.g., IL-1, IL-2Ralpha, IL-6, IL-8, TNF-alpha, and TNF-alpha receptors) and with various adhesion......Assessment of disease activity in inflammatory bowel disease (IBD), i.e., ulcerative colitis (UC) and Crohn's disease (CD), is done using clinical parameters and various biological disease markers. Ideally, a disease marker must: be able to identify individuals at risk of a given disorder......, be disease specific, mirror the disease activity and, finally, be easily applicable for routine clinical purposes. However, no such disease markers have yet been identified for IBD. In this article, classical disease markers including erythrocyte sedimentation rate, acute phase proteins (especially...

  15. Fruit cuticular waxes as a source of biologically active triterpenoids.

    Science.gov (United States)

    Szakiel, Anna; Pączkowski, Cezary; Pensec, Flora; Bertsch, Christophe

    2012-06-01

    The health benefits associated with a diet rich in fruit and vegetables include reduction of the risk of chronic diseases such as cardiovascular disease, diabetes and cancer, that are becoming prevalent in the aging human population. Triterpenoids, polycyclic compounds derived from the linear hydrocarbon squalene, are widely distributed in edible and medicinal plants and are an integral part of the human diet. As an important group of phytochemicals that exert numerous biological effects and display various pharmacological activities, triterpenoids are being evaluated for use in new functional foods, drugs, cosmetics and healthcare products. Screening plant material in the search for triterpenoid-rich plant tissues has identified fruit peel and especially fruit cuticular waxes as promising and highly available sources. The chemical composition, abundance and biological activities of triterpenoids occurring in cuticular waxes of some economically important fruits, like apple, grape berry, olive, tomato and others, are described in this review. The need for environmentally valuable and potentially profitable technologies for the recovery, recycling and upgrading of residues from fruit processing is also discussed.

  16. Template Synthesis of Tubular Nanostructures for Loading Biologically Active Molecules.

    Science.gov (United States)

    Karatas, Aysegul; Algan, Aslıhan Hilal

    2017-01-01

    The template synthesis is a low cost, simple and versatile nanofabrication method to produce cylindrical/tubular nanostructures with controllable dimensions such as length, diameter and aspect ratio. This method utilizes nanoporous membranes such as anodized aluminum oxide (AAO) or polycarbonate (PC) as templates which have nanosized specific, cylindrical and uniform inner pores to be coated with the desired material. Template synthesized nanotubular structures have been produced from variety of materials including ceramics, polymers and proteins for loading biologically active molecules. Available procedures of material deposition into the template nanopores consist of several techniques like wetting (melt or solution wetting), layer-by-layer (LbL) assembly and sol-gel chemistry. Template synthesis enables not only control of the geometry of the resulting nanostructures but also provides nanovehicles having separated inner and outer surfaces which can be variously functionalized. Tubular nanostructures fabricated by this method have numerous potential applications including delivery of biologically active molecules such as drugs, gene, enzymes and proteins. In this review we aimed to present up-to-date works on the template based synthesis which has greatly facilitated the fabrication of polymer and protein tubular nanostructures, principally. The strategies regarding the synthesis and designing of these promising tubular nanostructures together with recent approaches relevant of drug delivery was also presented. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Phytochemical Constituents and Biological Activities of Salvia suffruticosa

    Directory of Open Access Journals (Sweden)

    Arezoo Rustaie

    2018-03-01

    Full Text Available Background and objectives: Salvia suffruticosa is a perennial plant from Lamiaceae family. Many Salvia species have been employed as medicinal plants; despite the medicinal potentials of S. suffruticosa, there is limited studies regarding its phytochemical profile or biological properties. The aim of the present study was to investigate the chemical constituents of the essential oil and extract of the plant and evaluate its biological activities. Methods: Essential oil from the aerial parts of the plant was extracted by hydrodistillation and analyzed using gas chromatography/mass spectroscopy. Isolation of compounds from methanol and petroleum ether fractions was achieved by using column chromatography with different stationary phases. The structures of the isolated compounds were elucidated by NMR techniques. Cytotoxicity potentials were evaluated using MTT assay and acridine orange/ethidium bromide staining method. Antioxidant activity was assessed by DPPH method. Results: Hydrocarbon sesquiterpenes were identified as the predominant components of the oil, with β-caryophyllene (27.35%, bicyclogermacrene (22.15%, germacrene-D (9.49% and β-farnesene (9.08% as the major constituents. Phytochemical analysis of the extract resulted in isolation of lupeol (1, β-sitosterol (2, stigmasterol (3, caffeic acid (4 and 1-feruloyl-β-D-glucopyranose (5. Among the tested samples, lupeol demonstrated the most potent inhibitory activity toward breast cancer cell lines including MCF-7, T-47D and MDA-MB-231 with IC50 values equal to 33.38±2.6, 36.70±3.1 and 23.66±1.4 μg/mL, respectively; caffeic acid with IC50 value of 12.1±1.2 μg/mL showed the most potent radical scavenging activity. Conclusion: The results of this study suggested S. suffruticosa as a promising source of bioactive compounds useful in prevention and treatment of cancer.

  18. The in vitro biological activity of Lepidium meyenii extracts.

    Science.gov (United States)

    Valentová, K; Buckiová, D; Kren, V; Peknicová, J; Ulrichová, J; Simánek, V

    2006-03-01

    The biological activity of methanolic and aqueous extracts from dehydrated hypocotyls of Lepidium meyenii (Brassicaceae, vernacular name "maca"), was studied on rat hepatocytes and human breast cancer MCF-7 cells. The extracts did not exhibit cytotoxicity in hepatocyte primary cultures up to 10 mg/ml as measured by the MTT viability test, and lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) leakage. Moreover, after 72 h, extracts inhibited LDH and AST leakage from the hepatocytes. When hepatocytes were intoxicated by t-butyl hydroperoxide, neither extract prevented oxidative damage. Both extracts showed weak antioxidant activity in the DPPH radical scavenging test with IC(50) values of 3.46 +/- 0.16 and 0.71 +/- 0.10 mg/ml, for aqueous and methanolic extracts, respectively. Thus, the observed effect on spontaneous enzyme leakage is probably mediated through mechanisms other than antioxidant activity. Both methanolic and aqueous extracts have shown estrogenic activity comparable with that of silymarin in MCF-7 cell line. Maca estrogenicity was exhibited in the range from 100 to 200 mug of extract per ml. The findings in the present study show that maca does not display in vitro hepatotoxicity. In contrast, a slight cytoprotective effect, probably not mediated by antioxidant capacity, was noted. Maca extracts exhibited estrogenic activity comparably to the effect of silymarin in MCF-7 cells.

  19. Characterization of chickpea (Cicer arietinum L.) lectin for biological activity.

    Science.gov (United States)

    Gautam, Ajay Kumar; Gupta, Neha; Narvekar, Dakshita T; Bhadkariya, Rajni; Bhagyawant, Sameer S

    2018-05-01

    Lectins are proteins that are subject of intense investigations. Information on lectin from chickpea ( Cicer arietinum L.) with respect to its biological activities are very limited. In this study, we purified lectin from the seeds of chickpea employing DEAE-cellulose and SP-Sephadex ion exchange chromatography and identified its molecular subunit mass as 35 kDa. The free radical scavenging activity of lectin measured by the DPPH assay has IC 50 of 0.88 µg/mL. Lectin exerted antifungal activity against Candida krusei , Fusarium oxysporium oxysporium , Saccharomyces cerevisiae and Candida albicans , while antibacterial activity against E. coli , B. subtilis , S. marcescens and P. aeruginosa. The minimum inhibitory concentrations were 200, 240, 160 and 140 µg for C. krusei, F. oxysporium , S. cerevisiae and C. albicans respectively. Lectin was further examined for its antiproliferative potential against cancerous cell line. The cell viability assay indicated a high inhibition activity on Ishikawa, HepG2, MCF-7 and MDA-MB-231 with IC 50 value of 46.67, 44.20, 53.58 and 37.46 µg/mL respectively. These results can provide a background for future research into the benefits of chickpea lectin to pharmacological perspective.

  20. Avoiding artefacts during electron microscopy of silver nanomaterials exposed to biological environments.

    Science.gov (United States)

    Chen, S; Goode, A E; Skepper, J N; Thorley, A J; Seiffert, J M; Chung, K F; Tetley, T D; Shaffer, M S P; Ryan, M P; Porter, A E

    2016-02-01

    Electron microscopy has been applied widely to study the interaction of nanomaterials with proteins, cells and tissues at nanometre scale. Biological material is most commonly embedded in thermoset resins to make it compatible with the high vacuum in the electron microscope. Room temperature sample preparation protocols developed over decades provide contrast by staining cell organelles, and aim to preserve the native cell structure. However, the effect of these complex protocols on the nanomaterials in the system is seldom considered. Any artefacts generated during sample preparation may ultimately interfere with the accurate prediction of the stability and reactivity of the nanomaterials. As a case study, we review steps in the room temperature preparation of cells exposed to silver nanomaterials (AgNMs) for transmission electron microscopy imaging and analysis. In particular, embedding and staining protocols, which can alter the physicochemical properties of AgNMs and introduce artefacts thereby leading to a misinterpretation of silver bioreactivity, are scrutinized. Recommendations are given for the application of cryogenic sample preparation protocols, which simultaneously fix both particles and diffusible ions. By being aware of the advantages and limitations of different sample preparation methods, compromises or selection of different correlative techniques can be made to draw more accurate conclusions about the data. © 2015 The Authors Journal of Microscopy © 2015 Royal Microscopical Society.

  1. Bone Scan in Detection of Biological Activity in Nonhypertrophic Fracture Nonunion

    OpenAIRE

    Gandhi, Sunny J.; Rabadiya, Bhavdeep

    2017-01-01

    Biological activity of the fracture site is very important factor in treatment planning of fracture nonunion. If no biological activity is detected, then an autologous bone graft can be supplemented or osteogenic supplementations, such as bone morphogenetic protein is given. If biological activity is present, then secure fixation is sufficient to achieve bony union. Biological activity of nonunions is usually assessed by conventional radiographs. The presence of callus formation is usually as...

  2. Preparation and characterization of new biologically active polyurethane foams.

    Science.gov (United States)

    Savelyev, Yuri; Veselov, Vitali; Markovskaya, Ludmila; Savelyeva, Olga; Akhranovich, Elena; Galatenko, Natalya; Robota, Ludmila; Travinskaya, Tamara

    2014-12-01

    Biologically active polyurethane foams are the fast-developed alternative to many applications of biomedical materials. Due to the polyurethane structure features and foam technology it is possible to incorporate into their structure the biologically active compounds of target purpose via structural-chemical modification of macromolecule. A series of new biologically active polyurethane foams (PUFs) was synthesized with polyethers (MM 2500-5000), polyesters MM (500-2200), 2,4(2,6) toluene diisocyanate, water as a foaming agent, catalysts, foam stabilizers and functional compounds. Different functional compounds: 1,4-di-N-oxy-2,3-bis-(oxymethyl)-quinoxaline (DOMQ), partial sodium salt of poly(acrylic acid) and 2,6-dimethyl-N,N-diethyl aminoacetatanilide hydrochloride were incorporated into the polymer structure/composition due to the chemical and/or physical bonding. Structural peculiarities of PUFs were studied by FTIR spectroscopy and X-ray scattering. Self-adhesion properties of PUFs were estimated by measuring of tensile strength at break of adhesive junction. The optical microscopy method was performed for the PUF morphology studies. Toxicological estimation of the PUFs was carried out in vitro and in vivo. The antibacterial action towards the Gram-positive and Gram-negative bacteria (Escherichia coli ATC 25922, E. coli ATC 2150, Klebsiella pneumoniae 6447, Staphylococcus aureus 180, Pseudomonas aeruginosa 8180, Proteus mirabilis F 403, P. mirabilis 6054, and Proteus vulgaris 8718) was studied by the disc method on the solid nutrient. Physic-chemical properties of the PUFs (density, tensile strength and elongation at break, water absorption and vapor permeability) showed that all studied PUFs are within the operational requirements for such materials and represent fine-cellular foams. Spectral studies confirmed the incorporation of DOMQ into the PUF's macrochain. PUFs are characterized by microheterogeneous structure. They are antibacterially active, non

  3. Imaging and elemental mapping of biological specimens with a dual-EDS dedicated scanning transmission electron microscope

    Science.gov (United States)

    Wu, J.S.; Kim, A. M.; Bleher, R.; Myers, B.D.; Marvin, R. G.; Inada, H.; Nakamura, K.; Zhang, X.F.; Roth, E.; Li, S.Y.; Woodruff, T. K.; O'Halloran, T. V.; Dravid, Vinayak P.

    2013-01-01

    A dedicated analytical scanning transmission electron microscope (STEM) with dual energy dispersive spectroscopy (EDS) detectors has been designed for complementary high performance imaging as well as high sensitivity elemental analysis and mapping of biological structures. The performance of this new design, based on a Hitachi HD-2300A model, was evaluated using a variety of biological specimens. With three imaging detectors, both the surface and internal structure of cells can be examined simultaneously. The whole-cell elemental mapping, especially of heavier metal species that have low cross-section for electron energy loss spectroscopy (EELS), can be faithfully obtained. Optimization of STEM imaging conditions is applied to thick sections as well as thin sections of biological cells under low-dose conditions at room- and cryogenic temperatures. Such multimodal capabilities applied to soft/biological structures usher a new era for analytical studies in biological systems. PMID:23500508

  4. Structure-biological activity relationship of synthetic trihydroxilated chalcones

    Directory of Open Access Journals (Sweden)

    Devia Cristina M.

    1998-01-01

    Full Text Available The bacteriostatic activity of 2?,4?,2-trihydroxychalcone; 2?,4?,3-trihydroxychalcone and 2?,4?,4-trihydroxychalcone, prepared by condensation of 2,4-dihydroxyacetophenone and benzaldehyde substituted, against Staphylococcus aureus ATCC 25923 was assayed by agar plate method. The three compounds presented important inhibition halos. In order to elucidate structure-activity relationships, the minimal inhibitory concentrations against S. aureus were determined by the broth dilution method and the results obtained were compared to that of 2',4'-dihydroxychalcone. The sequence observed was: MIC 2?,4?,3-(OH3 > MIC 2?,4?-(OH2 > MIC 2?,4?,4-(OH3 > > MIC 2?,4?,2-(OH3. These results showed that the introduction of an electron donating group (-OH in the aromatic B-ring causes an increase in bioactivity, and that the intensity of action depends on the position of the OH substitute.

  5. Biological activity of soil contaminated with cobalt, tin, and molybdenum.

    Science.gov (United States)

    Zaborowska, Magdalena; Kucharski, Jan; Wyszkowska, Jadwiga

    2016-07-01

    In this age of intensive industrialization and urbanization, mankind's highest concern should be to analyze the effect of all metals accumulating in the environment, both those considered toxic and trace elements. With this aim in mind, a unique study was conducted to determine the potentially negative impact of Sn(2+), Co(2+), and Mo(5+) in optimal and increased doses on soil biological properties. These metals were applied in the form of aqueous solutions of Sn(2+) (SnCl2 (.)2H2O), Co(2+) (CoCl2 · 6H2O), and Mo(5+) (MoCl5), each in the doses of 0, 25, 50, 100, 200, 400, and 800 mg kg(-1) soil DM. The activity of dehydrogenases, urease, acid phosphatase, alkaline phosphatase, arylsulfatase, and catalase and the counts of twelve microorganism groups were determined on the 25th and 50th day of experiment duration. Moreover, to present the studied problem comprehensively, changes in the biochemical activity and yield of spring barley were shown using soil and plant resistance indices-RS. The study shows that Sn(2+), Co(2+), and Mo(5+) disturb the state of soil homeostasis. Co(2+) and Mo(5+) proved the greatest soil biological activity inhibitors. The residence of these metals in soil, particularly Co(2+), also generated a drastic decrease in the value of spring barley resistance. Only Sn(2+) did not disrupt its yielding. The studied enzymes can be arranged as follows for their sensitivity to Sn(2+), Co(2+), Mo(5+): Deh > Ure > Aryl > Pal > Pac > Cat. Dehydrogenases and urease may be reliable soil health indicators.

  6. Catalytically and biologically active silver nanoparticles synthesized using essential oil

    Science.gov (United States)

    Vilas, Vidya; Philip, Daizy; Mathew, Joseph

    2014-11-01

    There are numerous reports on phytosynthesis of silver nanoparticles and various phytochemicals are involved in the reduction and stabilization. Pure explicit phytosynthetic protocol for catalytically and biologically active silver nanoparticles is of importance as it is an environmentally benign green method. This paper reports the use of essential oil of Myristica fragrans enriched in terpenes and phenyl propenes in the reduction and stabilization. FTIR spectra of the essential oil and the synthesized biogenic silver nanoparticles are in accordance with the GC-MS spectral analysis reports. Nanosilver is initially characterized by an intense SPR band around 420 nm, followed by XRD and TEM analysis revealing the formation of 12-26 nm sized, highly pure, crystalline silver nanoparticles. Excellent catalytic and bioactive potential of the silver nanoparticles is due to the surface modification. The chemocatalytic potential of nanosilver is exhibited by the rapid reduction of the organic pollutant, para nitro phenol and by the degradation of the thiazine dye, methylene blue. Significant antibacterial activity of the silver colloid against Gram positive, Staphylococcus aureus (inhibition zone - 12 mm) and Gram negative, Escherichia coli (inhibition zone - 14 mm) is demonstrated by Agar-well diffusion method. Strong antioxidant activity of the biogenic silver nanoparticles is depicted through NO scavenging, hydrogen peroxide scavenging, reducing power, DPPH and total antioxidant activity assays.

  7. Chemistry and Biological Activities of Flavonoids: An Overview

    Science.gov (United States)

    Kumar, Shashank; Pandey, Abhay K.

    2013-01-01

    There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. The bioavailability, metabolism, and biological activity of flavonoids depend upon the configuration, total number of hydroxyl groups, and substitution of functional groups about their nuclear structure. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. Most recent researches have focused on the health aspects of flavonoids for humans. Many flavonoids are shown to have antioxidative activity, free radical scavenging capacity, coronary heart disease prevention, hepatoprotective, anti-inflammatory, and anticancer activities, while some flavonoids exhibit potential antiviral activities. In plant systems, flavonoids help in combating oxidative stress and act as growth regulators. For pharmaceutical purposes cost-effective bulk production of different types of flavonoids has been made possible with the help of microbial biotechnology. This review highlights the structural features of flavonoids, their beneficial roles in human health, and significance in plants as well as their microbial production. PMID:24470791

  8. Biological Activities of the Essential Oil from Erigeron floribundus.

    Science.gov (United States)

    Petrelli, Riccardo; Orsomando, Giuseppe; Sorci, Leonardo; Maggi, Filippo; Ranjbarian, Farahnaz; Biapa Nya, Prosper C; Petrelli, Dezemona; Vitali, Luca A; Lupidi, Giulio; Quassinti, Luana; Bramucci, Massimo; Hofer, Anders; Cappellacci, Loredana

    2016-08-13

    Erigeron floribundus (Asteraceae) is an herbaceous plant widely used in Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study, we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD), a promising new target for developing novel antibiotics, and Trypanosoma brucei, the protozoan parasite responsible for Human African trypanosomiasis. The essential oil composition was dominated by spathulenol (12.2%), caryophyllene oxide (12.4%) and limonene (8.8%). The E. floribundus oil showed a good activity against Staphylococcus aureus (inhibition zone diameter, IZD of 14 mm, minimum inhibitory concentration, MIC of 512 µg/mL). Interestingly, it inhibited the NadD enzyme from S. aureus (IC50 of 98 µg/mL), with no effects on mammalian orthologue enzymes. In addition, T. brucei proliferation was inhibited with IC50 values of 33.5 µg/mL with the essential oil and 5.6 µg/mL with the active component limonene. The essential oil exhibited strong cytotoxicity on HCT 116 colon carcinoma cells with an IC50 value of 14.89 µg/mL, and remarkable ferric reducing antioxidant power (tocopherol-equivalent antioxidant capacity, TEAC = 411.9 μmol·TE/g).

  9. Soil degradation effect on biological activity in Mediterranean calcareous soils

    Science.gov (United States)

    Roca-Pérez, L.; Alcover-Sáez, S.; Mormeneo, S.; Boluda, R.

    2009-04-01

    Soil degradation processes include erosion, organic matter decline, compaction, salinization, landslides, contamination, sealing and biodiversity decline. In the Mediterranean region the climatological and lithological conditions, together with relief on the landscape and anthropological activity are responsible for increasing desertification process. It is therefore considered to be extreme importance to be able to measure soil degradation quantitatively. We studied soil characteristics, microbiological and biochemical parameters in different calcareous soil sequences from Valencia Community (Easter Spain), in an attempt to assess the suitability of the parameters measured to reflect the state of soil degradation and the possibility of using the parameters to assess microbiological decline and soil quality. For this purpose, forest, scrubland and agricultural soil in three soil sequences were sampled in different areas. Several sensors of the soil biochemistry and microbiology related with total organic carbon, microbial biomass carbon, soil respiration, microorganism number and enzyme activities were determined. The results show that, except microorganism number, these parameters are good indicators of a soil biological activity and soil quality. The best enzymatic activities to use like indicators were phosphatases, esterases, amino-peptidases. Thus, the enzymes test can be used as indicators of soil degradation when this degradation is related with organic matter losses. There was a statistically significant difference in cumulative O2 uptake and extracellular enzymes among the soils with different degree of degradation. We would like to thank Spanish government-MICINN for funding and support (MICINN, project CGL2006-09776).

  10. Biological Activities of Oleanolic Acid Derivatives from Calendula officinalis Seeds.

    Science.gov (United States)

    Zaki, Ahmed; Ashour, Ahmed; Mira, Amira; Kishikawa, Asuka; Nakagawa, Toshinori; Zhu, Qinchang; Shimizu, Kuniyoshi

    2016-05-01

    Phytochemical examination of butanol fraction of Calendula officinalis seeds led to the isolation of two compounds identified as 28-O-β-D-glucopyranosyl-oleanolic acid 3-O-β-D-glucopyranosyl (1→3)-β-D-glucopyranosiduronic acid (CS1) and oleanolic acid 3-O-β-D-glucopyranosyl (1→3)-β-D-glucopyranosiduronic acid (CS2). Biological evaluation was carried out for these two compounds such as melanin biosynthesis inhibitory, hyaluronic acid production activities, anti obesity using lipase inhibition and adipocyte differentiation as well as evaluation of the protective effect against hydrogen peroxide induced neurotoxicity in neuro-2A cells. The results showed that, compound CS2 has a melanin biosynthesis stimulatory activity; however, compound CS1 has a potent stimulatory effect for the production of hyaluronic acid on normal human dermal fibroblast from adult (NHDF-Ad). Both compounds did not show any inhibitory effect on both lipase and adipocyte differentiation. Compound CS2 could protect neuro-2A cells and increased cell viability against H2 O2 . These activities (melanin biosynthesis stimulatory and protective effect against H2 O2 of CS2 and hyaluronic acid productive activities of these triterpene derivatives) have been reported for the first time. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Biological Activities of the Essential Oil from Erigeron floribundus

    Directory of Open Access Journals (Sweden)

    Riccardo Petrelli

    2016-08-01

    Full Text Available Erigeron floribundus (Asteraceae is an herbaceous plant widely used in Cameroonian traditional medicine to treat various diseases of microbial and non-microbial origin. In the present study, we evaluated the in vitro biological activities displayed by the essential oil obtained from the aerial parts of E. floribundus, namely the antioxidant, antimicrobial and antiproliferative activities. Moreover, we investigated the inhibitory effects of E. floribundus essential oil on nicotinate mononucleotide adenylyltransferase (NadD, a promising new target for developing novel antibiotics, and Trypanosoma brucei, the protozoan parasite responsible for Human African trypanosomiasis. The essential oil composition was dominated by spathulenol (12.2%, caryophyllene oxide (12.4% and limonene (8.8%. The E. floribundus oil showed a good activity against Staphylococcus aureus (inhibition zone diameter, IZD of 14 mm, minimum inhibitory concentration, MIC of 512 µg/mL. Interestingly, it inhibited the NadD enzyme from S. aureus (IC50 of 98 µg/mL, with no effects on mammalian orthologue enzymes. In addition, T. brucei proliferation was inhibited with IC50 values of 33.5 µg/mL with the essential oil and 5.6 µg/mL with the active component limonene. The essential oil exhibited strong cytotoxicity on HCT 116 colon carcinoma cells with an IC50 value of 14.89 µg/mL, and remarkable ferric reducing antioxidant power (tocopherol-equivalent antioxidant capacity, TEAC = 411.9 μmol·TE/g.

  12. Chemistry and Biological Activities of Flavonoids: An Overview

    Directory of Open Access Journals (Sweden)

    Shashank Kumar

    2013-01-01

    Full Text Available There has been increasing interest in the research on flavonoids from plant sources because of their versatile health benefits reported in various epidemiological studies. Since flavonoids are directly associated with human dietary ingredients and health, there is need to evaluate structure and function relationship. The bioavailability, metabolism, and biological activity of flavonoids depend upon the configuration, total number of hydroxyl groups, and substitution of functional groups about their nuclear structure. Fruits and vegetables are the main dietary sources of flavonoids for humans, along with tea and wine. Most recent researches have focused on the health aspects of flavonoids for humans. Many flavonoids are shown to have antioxidative activity, free radical scavenging capacity, coronary heart disease prevention, hepatoprotective, anti-inflammatory, and anticancer activities, while some flavonoids exhibit potential antiviral activities. In plant systems, flavonoids help in combating oxidative stress and act as growth regulators. For pharmaceutical purposes cost-effective bulk production of different types of flavonoids has been made possible with the help of microbial biotechnology. This review highlights the structural features of flavonoids, their beneficial roles in human health, and significance in plants as well as their microbial production.

  13. Using a Redox Modality to Connect Synthetic Biology to Electronics: Hydrogel-Based Chemo-Electro Signal Transduction for Molecular Communication.

    Science.gov (United States)

    Liu, Yi; Tsao, Chen-Yu; Kim, Eunkyoung; Tschirhart, Tanya; Terrell, Jessica L; Bentley, William E; Payne, Gregory F

    2017-01-01

    A hydrogel-based dual film coating is electrofabricated for transducing bio-relevant chemical information into electronical output. The outer film has a synthetic biology construct that recognizes an external molecular signal and transduces this input into the expression of an enzyme that converts redox-inactive substrate into a redox-active intermediate, which is detected through an amplification mechanism of the inner redox-capacitor film. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Biological regeneration of para-nitrophenol loaded activated carbon

    International Nuclear Information System (INIS)

    Durrani, M.A.Q.; Martin, R.J.

    1997-01-01

    Biological regeneration is one of several methods that may be used to restore the adsorptive capacity of exhausted granular activated carbon (GAC). This study deals with in-situ biological regeneration on a pilot scale. The principal objective of this research was to ascertain whether biological regeneration of GAC could occur under conditions typical of water treatment. The important parameters which may have the greatest impact on bio regeneration of a given adsorbate were studied. The research investigated the extent of bio regeneration for para-nitrophenol (PNP) of concentration 50 mg/L. Bio regeneration in the total exhaustion system was evaluated in terms of regeneration efficiency and the substrate removal. A three mode procedure was followed for each bio regeneration run. The prepared carbon was initially exhausted with an adsorbate; it was then bio regenerated for para-nitrophenol (PNP) of concentration 50 mg/L. Bio regeneration in he total exhaustion system was evaluated in terms of regeneration efficiency and the substrate removal. A three mode procedure was followed for each bio regeneration run. The prepared carbon was initially exhausted with an adsorbate; it was then bio regenerated with a mixed culture of bacteria, and lastly the carbon was re-saturated. In the totally exhausted GAC system, the bio regeneration was enhanced by increasing the during of regeneration for a fixed initial biomass content of the bioreactor. The bio regeneration efficiency of the totally exhausted (with PNP) GAC the empty bed contact time (EBCT) and the initial concentration of the substrate had a profound effect on the bio regeneration efficiency. Bacterial counts in the effluents of regenerated GAC columns were significantly more than those of fresh carbon effluents. (author)

  15. BIOLOGICALLY ACTIVE SUBSTANCES OF THE LAURUS NOBILIS LEAVES

    Directory of Open Access Journals (Sweden)

    N. M. Nasukhova

    2017-01-01

    Full Text Available Laurus nobilis L. is an evergreen dioecious, rarely monecious plant up to 12-15 m high. The plant’s name is devoted to an Ancient Greek God of Sun Apollo and is a symbol of peace and victory. It was used in making up wreaths for emperors, generals, and poets. Its natural area includes Mediterranean countries with high level of annual precipitation. It is actively cultivated as a decorative plant in Europe, Russia, USA and other countries. It is cultivated in Turkey, Algeria, Morocco, Portugal, Spain, Italy, France, Russia, and Mexico. The aim of the study is the review of available literature about isolation, identification, quantitative determination of biologically active compounds of the Laurus nobilis leaves in the established species and their pharmacological activity. Materialsand methods. The study was carried out using searching (PubMed, CiteSeer, arXiv, library databases (eLibrary, Cyberleninka, and ResearchGate free social network. Results and discussion. We have established that Laurus nobilis leaves have components of essential oil, phenolic compounds, and sesquiterpenic lactones as the principal active substances. Qualitative composition and quantitative content of these compound groups in these raw materials varies depending on the ecological and geographical, edaphic, climatic factors, phase of the plant growth, cultivation technology, drying method etc. The results of the pharmacological studies of the extracts, summary fractions, and individual compounds of Laurus nobilis leaves characterize this type of raw materials as a perspective source for a more profound study. Conclusion. As the available open review data showed, the essential oil components, phenolic compounds (phenolic acids, flavonoids, etc, sesquiterpenic lactones of Laurus nobilis exhibit a diverse spectrum of pharmacological activity. Antimicrobial (widely, anti-virus, anti-inflammatory, anti-diabetic, and cytoxic (anticancer activities, established in extracts

  16. Zoanthid mucus as new source of useful biologically active proteins.

    Science.gov (United States)

    Guarnieri, Míriam Camargo; de Albuquerque Modesto, Jeanne Claíne; Pérez, Carlos Daniel; Ottaiano, Tatiana Fontes; Ferreira, Rodrigo da Silva; Batista, Fabrício Pereira; de Brito, Marlon Vilela; Campos, Ikaro Henrique Mendes Pinto; Oliva, Maria Luiza Vilela

    2018-03-01

    Palythoa caribaeorum is a very common colonial zoanthid in the coastal reefs of Brazil. It is known for its massive production of mucus, which is traditionally used in folk medicine by fishermen in northeastern Brazil. This study identified biologically active compounds in P. caribaerum mucus. Crude mucus was collected during low tides by the manual scraping of colonies; samples were maintained in an ice bath, homogenized, and centrifuged at 16,000 g for 1 h at 4 °C; the supernatant (mucus) was kept at -80 °C until use. The enzymatic (proteolytic and phospholipase A 2 ), inhibitory (metallo, cysteine and serine proteases), and hemagglutinating (human erythrocyte) activities were determined. The results showed high levels of cysteine and metallo proteases, intermediate levels of phosholipase A 2 , low levels of trypsin, and no elastase and chymotrypsin like activities. The mucus showed potent inhibitory activity on snake venom metalloproteases and cysteine proteinase papain. In addition, it showed agglutinating activity towards O + , B + , and A + erythrocyte types. The hemostatic results showed that the mucus prolongs the aPTT and PT, and strongly inhibited platelet aggregation induced by arachidonic acid, collagen, epinephrine, ADP, and thrombin. The antimicrobial activity was tested on 15 strains of bacteria and fungi through the radial diffusion assay in agar, and no activity was observed. Compounds in P. caribaeorum mucus were analyzed for the first time in this study, and our results show potential pharmacological activities in these compounds, which are relevant for use in physiopathological investigations. However, the demonstration of these activities indicates caution in the use of crude mucus in folk medicine. Furthermore, the present or absent activities identified in this mucus suggest that the studied P. caribaeorum colonies were in thermal stress conditions at the time of sample collection; these conditions may precede the bleaching

  17. An introduction to sample preparation and imaging by cryo-electron microscopy for structural biology

    Science.gov (United States)

    Thompson, Rebecca F.; Walker, Matt; Siebert, C. Alistair; Muench, Stephen P.; Ranson, Neil A.

    2016-01-01

    Transmission electron microscopy (EM) is a versatile technique that can be used to image biological specimens ranging from intact eukaryotic cells to individual proteins >150 kDa. There are several strategies for preparing samples for imaging by EM, including negative staining and cryogenic freezing. In the last few years, cryo-EM has undergone a ‘resolution revolution’, owing to both advances in imaging hardware, image processing software, and improvements in sample preparation, leading to growing number of researchers using cryo-EM as a research tool. However, cryo-EM is still a rapidly growing field, with unique challenges. Here, we summarise considerations for imaging of a range of specimens from macromolecular complexes to cells using EM. PMID:26931652

  18. Particle Accelerator Applications: Ion and Electron Irradiation in Materials Science, Biology and Medicine

    Science.gov (United States)

    Rodríguez-Fernández, Luis

    2010-09-01

    Although the developments of particle accelerators are devoted to basic study of matter constituents, since the beginning these machines have been applied with different purposes in many areas also. Today particle accelerators are essential instruments for science and technology. This work presents an overview of the main application for direct particle irradiation with accelerator in material science, biology and medicine. They are used for material synthesis by ion implantation and charged particle irradiation; to make coatings and micromachining; to characterize broad kind of samples by ion beam analysis techniques; as mass spectrometers for atomic isotopes determination. In biomedicine the accelerators are applied for the study of effects by charged particles on cells. In medicine the radiotherapy by electron irradiation is widely used, while hadrontherapy is still under development. Also, they are necessary for short life radioisotopes production required in radiodiagnostic.

  19. Do-it-yourself biology and electronic waste hacking: A politics of demonstration in precarious times.

    Science.gov (United States)

    Delgado, Ana; Callén, Blanca

    2017-02-01

    In recent years, there has been an explosion of do it yourself, maker and hacker spaces in Europe. Through makers and do-it-yourself initiatives, 'hacking' is moving into the everyday life of citizens. This article explores the collective and political nature of those hacks by reporting on empirical work on electronic waste and do-it-yourself biology hacking. Using Dewey's experimental approach to politics, we analyse hacks as 'inquiry' to see how they serve to articulate public and political action. We argue that do-it-yourself and makers' hacks are technical and political demonstrations. What do-it-yourself and makers' hacks ultimately demonstrate is that things can be done otherwise and that 'you' can also do it. In this sense, they have a potential viral effect. The final part of the article explores some potential shortcomings of such politics of demonstration.

  20. Electron beam injection during active experiments. I - Electromagnetic wave emissions

    Science.gov (United States)

    Winglee, R. M.; Kellogg, P. J.

    1990-01-01

    The wave emissions produced in Echo 7 experiment by active injections of electron beams were investigated to determine the properties of the electromagnetic and electrostatic fields for both the field-aligned and cross-field injection in such experiments and to evaluate the sources of free energy and relative efficiencies for the generation of the VLF and HF emissions. It is shown that, for typical beam energies in active experiments, electromagnetic effects do not substantially change the bulk properties of the beam, spacecraft charging, and plasma particle acceleration. Through simulations, beam-generated whistlers; fundamental z-mode and harmonic x-mode radiation; and electrostatic electron-cyclotron, upper-hybrid, Langmuir, and lower-hybrid waves were identified. The characteristics of the observed wave spectra were found to be sensitive to both the ratio of the electron plasma frequency to the cyclotron frequency and the angle of injection relative to the magnetic field.

  1. Laser Polarimeter for Measurement of Optical Activity of Biological Objects

    Science.gov (United States)

    Protasov, E. A.; Protasov, D. E.; Ryzhkova, A. V.

    In this paper has been described the polarimetric device for measurement of optical activity of biological tissues, where the source of radiation is an infrared laser with a wave λ=0.808 micron. The polarizers used are polarizing prisms of Glan - Taylor. To obtain required angular resolution (0.180/cm) has been developed a device that converts the angle of rotation of the analyzer into electrical signal, which is fed to the appropriate scan digital oscilloscope. The passage of the polarized light through the fingers of the hand was established and the angles of rotation of the polarization vector of the transmitted radiation were measured, the values of which may be determined by the content of hemoglobin in the blood.

  2. Relationships between the stereochemistry and biological activity of fungal phytotoxins.

    Science.gov (United States)

    Evidente, Antonio; Andolfi, Anna; Cimmino, Alessio

    2011-10-01

    Toxins produced by phytopathogenic fungi assume great importance because of their involvement in several plant diseases. Although such pathogens are known to have seriously damaged crops, forest, and environmental resources, they represent a very important tool to develop new environmentally friendly herbicides and fungicides. This review deals with the relationships between the biological activity of some phytotoxins produced by pathogenic fungi for major forest plants and for damaging weeds and their stereochemistry. In particular, the methods used to determine their relative and/or absolute configuration will be illustrated. These include the application of Mosher's and Murata's methods, X-ray diffractometric analysis, circular dichroism, and the use of computational methods to determine the theoretical optical rotatory power as well as the CD spectrum. The importance of determining the absolute configuration to achieve the total synthesis of some phytotoxins, interesting for their potential practical application, is also discussed. © 2011 Wiley-Liss, Inc.

  3. Radiation degradation of polysaccharides and induced biological activity

    Energy Technology Data Exchange (ETDEWEB)

    Nagasawa, Naotsugu; Yoshii, Fumio; Makuuchi Keizo; Kume Tamikazu [Japan Atomic Energy Research Inst., Takasaki, Gunma (Japan). Takasaki Radiation Chemistry Research Establishment; Mitomo, Hiroshi [Gunma Univ., Kiryu (Japan). Faculty of Engineering

    1999-09-01

    Relationship between irradiation effect of polysaccharides and induced biological activity for plants has been investigated. Sodium alginate was irradiated by gamma-rays from a Co-60 source in liquid state (aqueous solution) and in solid state (powder form). Measurement of molecular weight and analysis of UV spectra of irradiated sodium alginate have been carried out. The molecular weight was decreased by irradiation in both conditions. New absorbance peak derived from double bond or/and carbonyl group was appeared at close to 267 nm by irradiation in UV spectra. It was found that alginate having molecular weight about 10,000 is most suitable to used as growth promoter in plants. To obtain the molecular weight of 10,000 by irradiation, the necessary doses are 100 kGy in liquid state and 500 kGy in solid state, respectively. (author)

  4. Production and biological activities of yellow pigments from Monascus fungi.

    Science.gov (United States)

    Chen, Gong; Wu, Zhenqiang

    2016-08-01

    Monascus yellow pigments (MYPs), are azaphilone compounds and one of the three main components of total Monascus pigments (MPs). Thirty-five hydrophilic or hydrophobic MYPs have been identified, with the majority being hydrophobic. Apart from screening special Monascus strains, some advanced approaches, such as extractive and high-cell-density fermentations, have been applied for developing or producing new MYPs, especially extracellular hydrophilic MYPs. The outstanding performance of MYPs in terms of resistance to photodegradation, as well as tolerance for temperature and pH, give natural MYPs reasonable prospects, compared with the orange and red MPs, for practical use in the present and future. Meanwhile, MYPs have shown promising potential for applications in the food and pharmaceutical industries based on their described bioactivities. This review briefly summarizes the reports to date on chemical structures, biological activities, biosynthetic pathways, production technologies, and physicochemical performances of MYPs. The existing problems for MYPs are discussed and research prospects proposed.

  5. Neutron activation analysis on determination of arsenic in biological matrixes

    International Nuclear Information System (INIS)

    Menezes, Maria Angela de B.C.; Silva, Maria Aparecida

    2013-01-01

    Aiming at giving support to the Worker's Health Awareness Program of the Municipal Department of Health of Belo Horizonte, an assessment related arsenic was carried out in two galvanising factories by means of hair and toenail samples analysis as biomonitors. The arsenic was determined in all matrixes from the factories where gold electrodeposition process was applied. This is because arsenic salts are usually added to gold bath to improve the metal covering. The high concentration results surprised the health surveillance professionals, and alerted for the need of assessing the influence of a long-term exposure. Studies concerning galvanising process have usually been developed broaching many aspects, but so far few works has pointed out the detection and measurement of other elements like arsenic. The k 0 -Instrumental Neutron Activation method was applied confirming to be a suitable technique on determination of arsenic in biological matrixes. (author)

  6. Structure and Biological Activity of Pathogen-like Synthetic Nanomedicines

    Science.gov (United States)

    Lőrincz, Orsolya; Tőke, Enikő R.; Somogyi, Eszter; Horkay, Ferenc; Chandran, Preethi; Douglas, Jack F.; Szebeni, János; Lisziewicz, Julianna

    2011-01-01

    Here we characterize the structure, stability and intracellular mode-of-action of DermaVir nanomedicine that is under clinical development for the treatment of HIV/AIDS. This nanomedicine is comprised of pathogen-like pDNA/PEIm nanoparticles (NPs) having the structure and function resembling spherical viruses that naturally evolved to deliver nucleic acids to the cells. Atomic force microscopy demonstrated spherical 100–200nm NPs with a smooth polymer surface protecting the pDNA in the core. Optical-absorption determined both the NP structural stability and biological activity relevant to their ability to escape from the endosome and release the pDNA at the nucleus. Salt, pH and temperature influence the nanomedicine shelf-life and intracellular stability. This approach facilitates the development of diverse polyplex nanomedicines where the delivered pDNA-expressed antigens induce immune responses to kill infected cells. PMID:21839051

  7. [The release of biologically active compounds from peat peloids].

    Science.gov (United States)

    Babaskin, D V

    2011-01-01

    This work had the objective to study kinetics of the release of flavonoides from peat peloid compositions containing extracts of medicinal herbs in model systems.The key parameters of the process are defined. The rate of liberation of flavonoides is shown to depend on their initial concentration in the compositions being used. The influence of the flavonoide composition of the tested extracts and dimethylsulfoxide on the release of biologically active compounds contained in the starting material in the model environment is estimated. The possibility of the layer-by-layer deposition of the compositions and peat peloids in order to increase the efficacy of flavonoide release from the starting composition and to ensure more rational utilization of the extracts of medicinal plants is demonstrated.

  8. Certification of biological candidates reference materials by neutron activation analysis

    Science.gov (United States)

    Kabanov, Denis V.; Nesterova, Yulia V.; Merkulov, Viktor G.

    2018-03-01

    The paper gives the results of interlaboratory certification of new biological candidate reference materials by neutron activation analysis recommended by the Institute of Nuclear Chemistry and Technology (Warsaw, Poland). The correctness and accuracy of the applied method was statistically estimated for the determination of trace elements in candidate reference materials. The procedure of irradiation in the reactor thermal fuel assembly without formation of fast neutrons was carried out. It excluded formation of interfering isotopes leading to false results. The concentration of more than 20 elements (e.g., Ba, Br, Ca, Co, Ce, Cr, Cs, Eu, Fe, Hf, La, Lu, Rb, Sb, Sc, Ta, Th, Tb, Yb, U, Zn) in candidate references of tobacco leaves and bottom sediment compared to certified reference materials were determined. It was shown that the average error of the applied method did not exceed 10%.

  9. Theoretical description of protein field effects on electronic excitations of biological chromophores

    International Nuclear Information System (INIS)

    Varsano, Daniele; Caprasecca, Stefano; Coccia, Emanuele

    2017-01-01

    Photoinitiated phenomena play a crucial role in many living organisms. Plants, algae, and bacteria absorb sunlight to perform photosynthesis, and convert water and carbon dioxide into molecular oxygen and carbohydrates, thus forming the basis for life on Earth. The vision of vertebrates is accomplished in the eye by a protein called rhodopsin, which upon photon absorption performs an ultrafast isomerisation of the retinal chromophore, triggering the signal cascade. Many other biological functions start with the photoexcitation of a protein-embedded pigment, followed by complex processes comprising, for example, electron or excitation energy transfer in photosynthetic complexes. The optical properties of chromophores in living systems are strongly dependent on the interaction with the surrounding environment (nearby protein residues, membrane, water), and the complexity of such interplay is, in most cases, at the origin of the functional diversity of the photoactive proteins. The specific interactions with the environment often lead to a significant shift of the chromophore excitation energies, compared with their absorption in solution or gas phase. The investigation of the optical response of chromophores is generally not straightforward, from both experimental and theoretical standpoints; this is due to the difficulty in understanding diverse behaviours and effects, occurring at different scales, with a single technique. In particular, the role played by ab initio calculations in assisting and guiding experiments, as well as in understanding the physics of photoactive proteins, is fundamental. At the same time, owing to the large size of the systems, more approximate strategies which take into account the environmental effects on the absorption spectra are also of paramount importance. Here we review the recent advances in the first-principle description of electronic and optical properties of biological chromophores embedded in a protein environment. We show

  10. Theoretical description of protein field effects on electronic excitations of biological chromophores

    Science.gov (United States)

    Varsano, Daniele; Caprasecca, Stefano; Coccia, Emanuele

    2017-01-01

    Photoinitiated phenomena play a crucial role in many living organisms. Plants, algae, and bacteria absorb sunlight to perform photosynthesis, and convert water and carbon dioxide into molecular oxygen and carbohydrates, thus forming the basis for life on Earth. The vision of vertebrates is accomplished in the eye by a protein called rhodopsin, which upon photon absorption performs an ultrafast isomerisation of the retinal chromophore, triggering the signal cascade. Many other biological functions start with the photoexcitation of a protein-embedded pigment, followed by complex processes comprising, for example, electron or excitation energy transfer in photosynthetic complexes. The optical properties of chromophores in living systems are strongly dependent on the interaction with the surrounding environment (nearby protein residues, membrane, water), and the complexity of such interplay is, in most cases, at the origin of the functional diversity of the photoactive proteins. The specific interactions with the environment often lead to a significant shift of the chromophore excitation energies, compared with their absorption in solution or gas phase. The investigation of the optical response of chromophores is generally not straightforward, from both experimental and theoretical standpoints; this is due to the difficulty in understanding diverse behaviours and effects, occurring at different scales, with a single technique. In particular, the role played by ab initio calculations in assisting and guiding experiments, as well as in understanding the physics of photoactive proteins, is fundamental. At the same time, owing to the large size of the systems, more approximate strategies which take into account the environmental effects on the absorption spectra are also of paramount importance. Here we review the recent advances in the first-principle description of electronic and optical properties of biological chromophores embedded in a protein environment. We show

  11. Biological activities of undescribed North American lichen species.

    Science.gov (United States)

    Yeash, Erik A; Letwin, Lyndon; Malek, Lada; Suntres, Zacharias; Knudsen, Kerry; Christopher, Lew P

    2017-11-01

    Lichens provide a large array of compounds with the potential for pharmaceutical development. In the present study, extracts from three previously undescribed North American lichen species were examined for antioxidant, antibacterial and anticancer activities. The results from this study demonstrated the following: (i) Acarospora socialis ethanol extract exhibited significant DPPH antioxidant scavenging activities, which were concentration dependent; (ii) acetone and ethyl acetate extracts of Xanthoparmelia mexicana inhibited Gram-positive bacteria but had no effect on Gram-negative bacteria; X. mexicana acetone extract yielded a minimum inhibitory concentration (MIC) of 20.9 µg mL -1 against Staphylococcus aureus, and 41.9 µg mL -1 against Enterococcus faecalis; (iii) acetone extract of Lobothallia alphoplaca inhibited growth of cultured breast cancer MCF-7 cells with an effective concentration (EC 50 ) of 87 µg mL -1 ; the MCF-7 cell cycle appears arrested in the G2 phase, whereas the DNA synthesis cell cycle (S) may be inhibited. New lichen species that possess strong biological activities have been identified. These lichens comprise secondary metabolites that possess antioxidant, antibacterial and anticancer properties. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  12. BIOLOGICAL ACTIVITY OF APPLE JUICE ENRICHED BY HERBAL EXTRACTS

    Directory of Open Access Journals (Sweden)

    Eva Ivanišová

    2015-02-01

    Full Text Available Herbal phytochemicals have recently become an attractive subject for scientists in many different research areas. The aim of this study was to determine antioxidant activity, total polyphenol and flavonoid content of apple juice enriched by water herbal extracts. Secondary was to evaluate sensory characteristic of enriched apple juice. It was found that applications of water herbal extracts to apple juice increase antioxidant activities, and also total polyphenol and flavonoid content with compare to pure apple juice. The highest biological activities were detected in apple juice with addition of lemon balm (14.42 mg TEAC/L; 84.38 mg TEAC/L; 50.88 mg GAE/L; 36.26 μg QE/L, oregano (14.92 mg TEAC/L; 79.97 mg TEAC/L; 50.51 mg GAE/L; 31.02 μg QE/L and salvia (8.40 mg TEAC/L; 30.40 mg TEAC/L; 23.33 mg GAE/L; 27.67 μg QE/L water extract. Sensorial analysis of samples showed, that enriched juices had better properties for evaluators with compared to pure juice. The aim of this study was also to mention the potential use of medicinal herbs in food industry, because plant bioactive compounds can play an important role in preventing cardiovascular diseases, cancers and reduction inflammatory action.

  13. Evaluation of the biological activity of sunflower hull extracts

    Energy Technology Data Exchange (ETDEWEB)

    Taha, F. S.; Wagdy, S. M.; Hassanein, M. M. M.; Hamed, S. F.

    2012-11-01

    This work was planned with the aim of adding value to sunflower seed hulls, a waste product of the oil industry by preparing a sunflower hull phenolic extract rich in chlorogenic acid (CGA). In order to fulfill this goal, the optimization for the extraction of a phenolic extract from the hulls was investigated. The parameters studied were: type of solvent, solvent to water ratio and hull to solvent ratio. In addition, the solvent mixtures were also studied. The resulting phenolic extracts were evaluated for their biological activities. This included phenolic content determination, evaluation of the antioxidant and antimicrobial activities. Chlorogenic acid was determined in two chosen hull extracts using the UV spectrophotometric method and HPLC analysis. The anti carcinogenic activity of the two chosen extracts was tested on seven different cell line carcinomas. The results revealed that all the phenolic extracts of sunflower hull studied contain between 190-312.5 mg phenolics/ 100 g hulls. The highest phenolic extraction was achieved with 80% methanol (1:30, hull to solvent, w/v ratio) and methanol to ethanol to water (7:7:6 v/v/v) mixture with values of 312.5 and 306.5 mg phenolics/100 g hulls, respectively. The free radical scavenging activity and antioxidant activity of all the samples ranged from 33.6-72.6%. The highest antioxidant activity and free radical scavenging activity were achieved by the same extracts that possessed the highest phenolic content, namely methanol to ethanol to water extract and 80% methanol with values 71.8 and 72.6%, 68.2 and 70.9% respectively, compared to 77.9 and 76.9% respectively for TBHQ. All the phenolic extracts possessed antimicrobial activity but to different levels against different pathogenic bacteria. The two chosen extracts also possessed anti carcinogenic activity, which differed among varying cell line carcinomas. The HPLC analysis indicated that chlorogenic acid was the main phenolic acid in the extract. Thus it can

  14. Optimization of companies’ activity on development of electronic product

    Directory of Open Access Journals (Sweden)

    K.V. Nalivaychenko

    2012-02-01

    Full Text Available The article considers modern processes of informatization of activity for business companies. There are generalized the makes of world companies, which create information technologies in global information environment: the electronic information product containing an universal development algorithm for it, is most effective. It is found that companies prefer opened program codes.

  15. Phytochemical Analysis and Biological Activities of Cola nitida Bark

    Directory of Open Access Journals (Sweden)

    Durand Dah-Nouvlessounon

    2015-01-01

    Full Text Available Kola nut is chewed in many West African cultures and is used ceremonially. The aim of this study is to investigate some biological effects of Cola nitida’s bark after phytochemical screening. The bark was collected, dried, and then powdered for the phytochemical screening and extractions. Ethanol and ethyl acetate extracts of C. nitida were used in this study. The antibacterial activity was tested on ten reference strains and 28 meat isolated Staphylococcus strains by disc diffusion method. The antifungal activity of three fungal strains was determined on the Potato-Dextrose Agar medium mixed with the appropriate extract. The antioxidant activity was determined by DPPH and ABTS methods. Our data revealed the presence of various potent phytochemicals. For the reference and meat isolated strains, the inhibitory diameter zone was from 17.5±0.7 mm (C. albicans to 9.5±0.7 mm (P. vulgaris. The MIC ranged from 0.312 mg/mL to 5.000 mg/mL and the MBC from 0.625 mg/mL to >20 mg/mL. The highest antifungal activity was observed with F. verticillioides and the lowest one with P. citrinum. The two extracts have an excellent reducing free radical activity. The killing effect of A. salina larvae was perceptible at 1.04 mg/mL. The purified extracts of Cola nitida’s bark can be used to hold meat products and also like phytomedicine.

  16. Scanning transmission electron microscopy through-focal tilt-series on biological specimens.

    Science.gov (United States)

    Trepout, Sylvain; Messaoudi, Cédric; Perrot, Sylvie; Bastin, Philippe; Marco, Sergio

    2015-10-01

    Since scanning transmission electron microscopy can produce high signal-to-noise ratio bright-field images of thick (≥500 nm) specimens, this tool is emerging as the method of choice to study thick biological samples via tomographic approaches. However, in a convergent-beam configuration, the depth of field is limited because only a thin portion of the specimen (from a few nanometres to tens of nanometres depending on the convergence angle) can be imaged in focus. A method known as through-focal imaging enables recovery of the full depth of information by combining images acquired at different levels of focus. In this work, we compare tomographic reconstruction with the through-focal tilt-series approach (a multifocal series of images per tilt angle) with reconstruction with the classic tilt-series acquisition scheme (one single-focus image per tilt angle). We visualised the base of the flagellum in the protist Trypanosoma brucei via an acquisition and image-processing method tailored to obtain quantitative and qualitative descriptors of reconstruction volumes. Reconstructions using through-focal imaging contained more contrast and more details for thick (≥500 nm) biological samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. iBET: Immersive visualization of biological electron-transfer dynamics.

    Science.gov (United States)

    Nakano, C Masato; Moen, Erick; Byun, Hye Suk; Ma, Heng; Newman, Bradley; McDowell, Alexander; Wei, Tao; El-Naggar, Mohamed Y

    2016-04-01

    Recently, we presented a computational framework named VizBET to simulate and visualize biological electron-transfer (ET) dynamics. The visualization process was encapsulated as a plugin to the Visual Molecular Dynamics (VMD) software. However, the user's ability to understand complex, multidimensional ET pathways was severely limited when visualized in 2D on traditional computer monitors. To provide a more accurate representation with enhanced depth perception, we here present an extension of VizBET named iBET to render the VMD model of ET dynamics in a commodity virtual reality (VR) platform. The paper describes detailed procedures to export VMD models into the Unity game engine and render it in an Oculus Rift head mounted display. With the increasing availability of low-cost VR systems like the Rift and rich programmability of game engines, the iBET framework provides a powerful means to explore and understand not only biological ET processes but also a unique experiential tool for broad scientific communities. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung Woo; Chung, Byung Yeoup [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Lee, In Chul [Youngdong University, Youngdong (Korea, Republic of)

    2011-10-15

    Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

  19. Removing undesirable color and boosting biological activity in red beet extracts using gamma irradiation

    International Nuclear Information System (INIS)

    Lee, Seung Sik; Lee, Eun Mi; Hong, Sung Hyun; Bai, Hyoung Woo; Chung, Byung Yeoup; Lee, In Chul

    2011-01-01

    Red beet (Beta vulgaris L.) is a traditional and popular vegetable distributed in many part of the world and has been used as a natural colorant in many dairy products, beverages, candies and cattle products. Red beet roots contain two groups of betalain pigments, redviolet betacyanins and yellow betaxanthins. Betalains possess several biological activities such as antioxidant, anti-inflammatory, hepatoprotective, and anticancer properities. Recent trend of using natural products in industries tends toward multifunctional, high quality, and highpriced value foods and cosmetics. To meet the needs of consumers, cosmetics, medicine, and foods should contain the proper amount of natural products. Although the color removal processes such as filtration and absorption by clay are still useful, these procedures are difficult, time-consuming and costly. To overcome this problem, the radiation technology has emerged as a new way. Radiation technology has been applied to the decomposition and decoloration of pigment and is an efficient technique for inactivating pathogens, removing undesirable color in biomaterial extracts and improving or maintaining biological activities. Gamma-irradiation and electron beamirradiation techniques in previous reports were applied in order to remove any undesirable color and to improve or maintain biological activities of various extracts such as green tea leaves, licorice root, and S. chinensis fruits. Latorre et al. reported that betacyanin concentration decreased with the irradiation dose and significantly, in 35%, after 2.0 kGy of gamma-ray, whereas betaxathin concentration increased (about 11%-ratio with respect to control) after 1 kGy but decreased (about 19%) after 2 kGy. However, they did not try to analysis for completed removal of red beet pigments. Therefore, it is necessary to find the optimum irradiation dose for entirely removing red pigments in red beet. The aim of this work was to address the effects of the color removal and

  20. Phenolic Compounds Characterization and Biological Activities of Citrus aurantium Bloom

    Directory of Open Access Journals (Sweden)

    Armin Oskoueian

    2012-01-01

    Full Text Available Citrus plants are known to possess beneficial biological activities for human health. In addition, ethnopharmacological application of plants is a good tool to explore their bioactivities and active compounds. This research was carried out to evaluate the phenolic and flavonoid analysis, antioxidant properties, anti inflammatory and anti cancer activity of Citrus aurantium bloom. The total phenolics and flavonoids results revealed that methanolic extract contained high total phenolics and flavonoids compared to ethanolic and boiling water extracts. The obtained total phenolics value for methanolic Citrus aurantium bloom extract was 4.55 ± 0.05 mg gallic acid equivalent (GAE/g dry weight (DW, and for total flavonoids it was 3.83 ± 0.05 mg rutin equivalent/g DW. In addition, the RP-HPLC analyses of phenolics and flavonoids indicated the presence of gallic acid, pyrogallol, syringic acid, caffeic acid, rutin, quercetin and naringin as bioactive compounds. The antioxidant activity of Citrus aurantium bloom were examined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH assay and the ferric reducing/antioxidant potential (FRAP. The free radical scavenging and ferric reducing power activities were higher for the methanolic extract of Citrus aurantium bloom at a concentration of 300 μg/mL, with values of 55.3% and 51.7%, respectively, as compared to the corresponding boiling water and ethanolic extracts, but the activities were lower than those of antioxidant standards such as BHT and α-tocopherol. Furthermore, the anti-inflammatory result of methanolic extract showed appreciable reduction in nitric oxide production of stimulated RAW 264.7 cells at the presence of plant extract. Apart from that, the anticancer activity of the methanolic extract was investigated in vitro against human cancer cell lines (MCF-7; MDA-MB-231, human colon adenocarcinoma (HT-29 and Chang cell as a normal human hepatocyte. The obtained result demonstrated the moderate to

  1. Preliminary Phytochemical and Biological activities on Russelia juncea Zucc

    Directory of Open Access Journals (Sweden)

    Maryam Bibi

    2017-12-01

    Full Text Available To probe the ethnomedicinal claims of Russelia juncea Zucc. (Plantaginaceae as prescribed traditionally in the folklore history of medicines. Methods: The dichloromethane and methanol extracts of aerial parts and roots were examined for antimicrobial, antioxidant, antiglycation, insecticidal, leishmanicidal, cytotoxic and phytotoxic activities. Different phytochemical tests were also performed to confirm the presence of various groups of secondary metabolites such as alkaloids, glycosides, saponins, tannins, flavonoids and terpenoids. Results: Phytochemical screening of this plant confirmed the presence of alkaloids, saponins, tannins, flavonoids and terpenoids. Antibacterial activity was only shown by RJRD with 80% inhibition at the concentration of 150µg/ml against Shigella flexneri. Among the tested samples, RJAM and RJRM displayed significant radical scavenging activity up to 93% and 89% with IC50 values of 184.75 ± 4.05µM and 263.01 ± 9.36µM. The significant antiglycation potential was exhibited by RJAD, RJAM and RJRM with 55.35%, 62.25% and 59.22% inhibition and IC50 values of 0.84 ± 0.08mg/ml, 1.37 ± 0.15mg/ml and 1.52 ± 0.10mg/ml respectively. Moderate leishmanicidal activity was exposed by RJAD and RJRM with IC50 values of 73.04 ± 1.05µg/ml and 77.66 ± 0.23µg/ml while RJAM was found to be more potent and exposed significant leishmanicidal activity having IC50 of 48 ± 0.39µg/ml. However, prominent cytotoxic activity was displayed by RJRM with 66.08% inhibition and IC50 of 31.20 ± 3µg/ml. Non-significant antifungal, insecticidal and phytotoxic activities were demonstrated by all the tested samples. Conclusion: All the above contributions give serious attentiveness to scientists to isolate and purify the biologically active phytoconstituents by using advanced scientific methodologies that serve as lead compounds in the synthesis of new therapeutic agents of desired interest in the world of drug discovery.

  2. Phenolic compounds characterization and biological activities of Citrus aurantium bloom.

    Science.gov (United States)

    Karimi, Ehsan; Oskoueian, Ehsan; Hendra, Rudi; Oskoueian, Armin; Jaafar, Hawa Z E

    2012-01-30

    Citrus plants are known to possess beneficial biological activities for human health. In addition, ethnopharmacological application of plants is a good tool to explore their bioactivities and active compounds. This research was carried out to evaluate the phenolic and flavonoid analysis, antioxidant properties, anti inflammatory and anti cancer activity of Citrus aurantium bloom. The total phenolics and flavonoids results revealed that methanolic extract contained high total phenolics and flavonoids compared to ethanolic and boiling water extracts. The obtained total phenolics value for methanolic Citrus aurantium bloom extract was 4.55 ± 0.05 mg gallic acid equivalent (GAE)/g dry weight (DW), and for total flavonoids it was 3.83 ± 0.05 mg rutin equivalent/g DW. In addition, the RP-HPLC analyses of phenolics and flavonoids indicated the presence of gallic acid, pyrogallol, syringic acid, caffeic acid, rutin, quercetin and naringin as bioactive compounds. The antioxidant activity of Citrus aurantium bloom were examined by the 1,1-diphenyl-2-picryl-hydrazyl (DPPH) assay and the ferric reducing/antioxidant potential (FRAP). The free radical scavenging and ferric reducing power activities were higher for the methanolic extract of Citrus aurantium bloom at a concentration of 300 μg/mL, with values of 55.3% and 51.7%, respectively, as compared to the corresponding boiling water and ethanolic extracts, but the activities were lower than those of antioxidant standards such as BHT and α-tocopherol. Furthermore, the anti-inflammatory result of methanolic extract showed appreciable reduction in nitric oxide production of stimulated RAW 264.7 cells at the presence of plant extract. Apart from that, the anticancer activity of the methanolic extract was investigated in vitro against human cancer cell lines (MCF-7; MDA-MB-231), human colon adenocarcinoma (HT-29) and Chang cell as a normal human hepatocyte. The obtained result demonstrated the moderate to appreciable

  3. Enhanced Physicochemical and Biological Properties of Ion-Implanted Titanium Using Electron Cyclotron Resonance Ion Sources

    Directory of Open Access Journals (Sweden)

    Csaba Hegedűs

    2016-01-01

    Full Text Available The surface properties of metallic implants play an important role in their clinical success. Improving upon the inherent shortcomings of Ti implants, such as poor bioactivity, is imperative for achieving clinical use. In this study, we have developed a Ti implant modified with Ca or dual Ca + Si ions on the surface using an electron cyclotron resonance ion source (ECRIS. The physicochemical and biological properties of ion-implanted Ti surfaces were analyzed using various analytical techniques, such as surface analyses, potentiodynamic polarization and cell culture. Experimental results indicated that a rough morphology was observed on the Ti substrate surface modified by ECRIS plasma ions. The in vitro electrochemical measurement results also indicated that the Ca + Si ion-implanted surface had a more beneficial and desired behavior than the pristine Ti substrate. Compared to the pristine Ti substrate, all ion-implanted samples had a lower hemolysis ratio. MG63 cells cultured on the high Ca and dual Ca + Si ion-implanted surfaces revealed significantly greater cell viability in comparison to the pristine Ti substrate. In conclusion, surface modification by electron cyclotron resonance Ca and Si ion sources could be an effective method for Ti implants.

  4. Role of Muramyl Dipeptide in Lipopolysaccharide-Mediated Biological Activity and Osteoclast Activity

    Directory of Open Access Journals (Sweden)

    Hideki Kitaura

    2018-01-01

    Full Text Available Lipopolysaccharide (LPS is an endotoxin and bacterial cell wall component that is capable of inducing inflammation and immunological activity. Muramyl dipeptide (MDP, the minimal essential structural unit responsible for the immunological activity of peptidoglycans, is another inflammation-inducing molecule that is ubiquitously expressed by bacteria. Several studies have shown that inflammation-related biological activities were synergistically induced by interactions between LPS and MDP. MDP synergistically enhances production of proinflammatory cytokines that are induced by LPS exposure. Injection of MDP induces lethal shock in mice challenged with LPS. LPS also induces osteoclast formation and pathological bone resorption; MDP enhances LPS induction of both processes. Furthermore, MDP enhances the LPS-induced receptor activator of NF-κB ligand (RANKL expression and toll-like receptor 4 (TLR4 expression both in vivo and in vitro. Additionally, MDP enhances LPS-induced mitogen-activated protein kinase (MAPK signaling in stromal cells. Taken together, these findings suggest that MDP plays an important role in LPS-induced biological activities. This review discusses the role of MDP in LPS-mediated biological activities, primarily in relation to osteoclastogenesis.

  5. Evaluation of Biological Activities of Chemically Synthesized Silver Nanoparticles

    Directory of Open Access Journals (Sweden)

    Ashraf A. Mostafa

    2015-01-01

    Full Text Available Silver nanoparticles were synthesized by the earlier reported methods. The synthesized nanoparticles were characterized using ultraviolet-visible spectrophotometry (UV/Vis, transmission electron microscopy (TEM, energy dispersive X-ray spectroscopy (EDX, and X-ray powder diffraction (XRD. The synthesized materials were also evaluated for their antibacterial activity against Gram positive and Gram negative bacterial strains. TEM micrograph showed the spherical morphology of AgNPs with size range of 40–60 nm. The synthesized nanoparticles showed a strong antimicrobial activity and their effect depends upon bacterial strain as AgNPs exhibited greater inhibition zone for Pseudomonas aeruginosa (19.1 mm followed by Staphylococcus aureus (14.8 mm and S. pyogenes (13.6 mm while the least activity was observed for Salmonella typhi (12.5 mm at concentration of 5 µg/disc. The minimum inhibitory concentration (MIC of AgNPs against S. aureus was 2.5 µg/disc and less than 2.5 µg/disc for P. aeruginosa. These results suggested that AgNPs can be used as an effective antiseptic agent for infectious control in medical field.

  6. Evaluation of Biological Activities of Chemically Synthesized Silver Nanoparticles

    International Nuclear Information System (INIS)

    Mostafa, A. A.; Solkamy, E.N.; Sayed, Sh. R. M.; Khan, M.; Shaik, M.R.; Al-Warthan, A.; Adil, S.F.

    2015-01-01

    Silver nanoparticles were synthesized by the earlier reported methods. The synthesized nanoparticles were characterized using ultraviolet-visible spectrophotometry (UV/Vis), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), and X-ray powder diffraction (XRD). The synthesized materials were also evaluated for their antibacterial activity against Gram positive and Gram negative bacterial strains. TEM micrograph showed the spherical morphology of AgNPs with size range of 40-60 nm. The synthesized nanoparticles showed a strong antimicrobial activity and their effect depends upon bacterial strain as AgNPs exhibited greater inhibition zone for Pseudomonas aeruginosa (19.1 mm) followed by Staphylococcus aureus (14.8?mm) and S. pyogenes (13.6 mm) while the least activity was observed for Salmonella typhi (12.5 mm) at concentration of 5 μg/disc. The minimum inhibitory concentration (MIC) of AgNPs against S. aureus was 2.5 μg/disc and less than 2.5 μg/disc for P. aeruginosa. These results suggested that AgNPs can be used as an effective antiseptic agent for infectious control in medical field.

  7. Biosynthesis, Characterization, and Biological Activities of Iron Nanoparticles using Sesamum indicum Seeds Extract

    Science.gov (United States)

    Bano, Farah; Baber, Muhammad; Ali, Amjad; Shah, Ziaullah; Muhammad, Syed Aun

    2017-01-01

    Background: Iron nanoparticles (FeNPs) have got many biomedical and health applications because of biocompatible and nontoxic nature to humans. Objective: To synthesize the FeNPs using natural sources. Materials and Methods: In this study, simple and economical procedure was adopted for FeNPs synthesis. Sesame seeds were processed to obtain seed extract as a biological material for FeNPs production. FeNPs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopic. Results: The average diameter of these FeNPs was 99 nm. These nanoparticles showed significant anti-typhoid activity (30 mm zone of inhibition) as compared to ciprofloxacin (32 mm) as standard. Furthermore, in vitro alpha-amylase inhibitory assay also showed moderate antidiabetic activity with more than 50% inhibition. Conclusion: This study would be helpful in understanding of nanoparticles synthesis from natural sources and ultimately will be used as potential alternative therapeutic agents. SUMMARY Iron nanoparticles (FeNPs) were synthesized by Sesamum indicum seedsFeNPs were characterized by scanning electron microscope with average diameter of 99 nmThese FeNPs are effective against Salmonella typhi, a causative agent of typhoidThese FeNPs can be used as antidiabetic agent. Abbreviations used: FeNPs: Iron Nano Particles; SEM: Scanning Electron Microscopy; MIC: Minimum Inhibitory Concentration; S. indicum: Sesamum Indicum. PMID:28479723

  8. Biosynthesis, Characterization, and Biological Activities of Iron Nanoparticles usingSesamum indicumSeeds Extract.

    Science.gov (United States)

    Bano, Farah; Baber, Muhammad; Ali, Amjad; Shah, Ziaullah; Muhammad, Syed Aun

    2017-01-01

    Iron nanoparticles (FeNPs) have got many biomedical and health applications because of biocompatible and nontoxic nature to humans. To synthesize the FeNPs using natural sources. In this study, simple and economical procedure was adopted for FeNPs synthesis. Sesame seeds were processed to obtain seed extract as a biological material for FeNPs production. FeNPs were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopic. The average diameter of these FeNPs was 99 nm. These nanoparticles showed significant anti-typhoid activity (30 mm zone of inhibition) as compared to ciprofloxacin (32 mm) as standard. Furthermore, in vitro alpha-amylase inhibitory assay also showed moderate antidiabetic activity with more than 50% inhibition. This study would be helpful in understanding of nanoparticles synthesis from natural sources and ultimately will be used as potential alternative therapeutic agents. Iron nanoparticles (FeNPs) were synthesized by Sesamum indicum seedsFeNPs were characterized by scanning electron microscope with average diameter of 99 nmThese FeNPs are effective against Salmonella typhi , a causative agent of typhoidThese FeNPs can be used as antidiabetic agent. Abbreviations used: FeNPs: Iron Nano Particles; SEM: Scanning Electron Microscopy; MIC: Minimum Inhibitory Concentration; S. indicum : Sesamum Indicum .

  9. Influence of Bicarbonate, Sulfate, and Electron Donors on Biological reduction of Uranium and Microbial Community Composition

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Wensui [ORNL; Zhou, Jizhong [ORNL; Wu, Weimin [ORNL; Yan, Tingfen [ORNL; Criddle, Craig [ORNL; Jardine, Philip M [ORNL; Gu, Baohua [ORNL

    2007-01-01

    A microcosm study was performed to investigate the effect of ethanol and acetate on uranium(VI) biological reduction and microbial community changes under various geochemical conditions. Each microcosm contained an uranium-contaminated sediment (up to 2.8 g U/kg) suspended in buffer with bicarbonate at concentrations of either 1 mM or 40 mM and sulfate at either 1.1 or 3.2 mM. Ethanol or acetate was used as an electron donor. Results indicate that ethanol yielded in significantly higher U(VI) reduction rates than acetate. A low bicarbonate concentration (1 mM) was favored for U(VI) bioreduction to occur in sediments, but high concentrations of bicarbonate (40 mM) and sulfate (3.2 mM) decreased the reduction rates of U(VI). Microbial communities were dominated by species from the Geothrix genus and Proteobacteria phylum in all microcosms. However, species in the Geobacteraceae family capable of reducing U(VI) were significantly enriched by ethanol and acetate in low bicarbonate buffer. Ethanol increased the population of unclassified Desulfuromonales, while acetate increased the population of Desulfovibrio. Additionally, species in the Geobacteraceae family were not enriched in high bicarbonate buffer, but the Geothrix and the unclassified Betaproteobacteria species were enriched. This study concludes that ethanol could be a better electron donor than acetate for reducing U(VI) under given experimental conditions, and electron donor and geoundwater geochemistry alter microbial communities responsible for U(VI) reduction.

  10. Influence of bicarbonate, sulfate, and electron donors on biological reduction of uranium and microbial community composition

    Energy Technology Data Exchange (ETDEWEB)

    Luo Wensui [Oak Ridge Inst. for Science and Education, TN (United States); Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Wu Wei-Min; Criddle, C.S. [Stanford Univ., CA (United States). Dept. of Civil and Environmental Engineering; Yan Tingfen [Oak Ridge Inst. for Science and Education, TN (United States); Jardine, P.M.; Gu Baohua [Oak Ridge National Lab., TN (United States). Environmental Sciences Div.; Zhou Jizhong [Oklahoma Univ., Norman, OK (United States). Dept. of Botany and Microbiology

    2007-12-15

    A microcosm study was performed to investigate the effect of ethanol and acetate on uranium(VI) biological reduction and microbial community changes under various geochemical conditions. Each microcosm contained an uranium-contaminated sediment (up to 2.8 g U/kg) suspended in buffer with bicarbonate at concentrations of either 1 or 40 mM and sulfate at either 1.1 or 3.2 mM. Ethanol or acetate was used as an electron donor. Results indicate that ethanol yielded in significantly higher U(VI) reduction rates than acetate. A low bicarbonate concentration (1 mM) was favored for U(VI) bioreduction to occur in sediments, but high concentrations of bicarbonate (40 mM) and sulfate (3.2 mM) decreased the reduction rates of U(VI). Microbial communities were dominated by species from the Geothrix genus and Proteobacteria phylum in all microcosms. However, species in the Geobacteraceae family capable of reducing U(VI) were significantly enriched by ethanol and acetate in low-bicarbonate buffer. Ethanol increased the population of unclassified Desulfuromonales, while acetate increased the population of Desulfovibrio. Additionally, species in the Geobacteraceae family were not enriched in high-bicarbonate buffer, but the Geothrix and the unclassified Betaproteobacteria species were enriched. This study concludes that ethanol could be a better electron donor than acetate for reducing U(VI) under given experimental conditions, and electron donor and groundwater geochemistry alter microbial communities responsible for U(VI) reduction. (orig.)

  11. [Composition and content of biologically active substances in rose hips].

    Science.gov (United States)

    Dubtsova, G N; Negmatulloeva, R N; Bessonov, V V; Baĭkov, V G; Sheviakova, L V; Makhova, N N; Perederiaev, O I; Bogachuk, M N; Baĭgarin, E K

    2012-01-01

    The paper studies the chemical composition of the powders obtained from the pulp with the skins and seeds of fruits of wild rose hips. Research results have shown that the main fraction of the powder is dietary fiber, powder of seeds of insoluble fiber in 1,6 and 2,3 higher than in the powder of the fruit with a thin skin and pulp, respectively. The greatest amount of carbohydrates and protein found in powders and pulp of the fruit with a thin skin, and lipids predominate in the powder from the seeds. Found that the lipid powder rosehip richest in oleic, linoleic and linolenic acids, the share of oleic acid has 6,4-19,2%, linoleic and linolenic 19,7-45,8 and 23,3-33,9% of the amount of fatty acids. Lipids powders of hips and seeds of rose have higher levels of essential linoleic acid and powder from the pulp with the skins - linolenic acid. In the study established the presence of sterols 7 fractions, the predominant of which is the beta-sitosterol. In the powder from the pulp with the skins found the greatest amount of ascorbic acid, carotenoids, and the powder of seeds - vitamin E. Carotenoids in powders are beta-carotene and lycopene. The high content of ascorbic acid, vitamin E and carotenoids in powder from wild rose hips makes them a good source of antioxidants. Therefore, we studied the possibility of using vegetable powders obtained from hips of wild rose, to enrich biologically active substances such as vitamins C, E and carotenoids, food supply, particularly of health care use. Rosehip powder from the pulp with the skins had the highest antioxidant activity, antioxidant activity of hips powders was 74% of the activity of powder from the pulp with the skins, the lowest antioxidant activity was observed in the powder from the wild rose seeds. That's way, based on the analysis of the chemical composition of rose hip powder found high levels they ascorbic acid, carotenoids, flavonoids,found their high antioxidant activity. It allows to recommend powders

  12. A Conceptual Framework for Organizing Active Learning Experiences in Biology Instruction

    Science.gov (United States)

    Gardner, Joel; Belland, Brian R.

    2012-01-01

    Introductory biology courses form a cornerstone of undergraduate instruction. However, the predominantly used lecture approach fails to produce higher-order biology learning. Research shows that active learning strategies can increase student learning, yet few biology instructors use all identified active learning strategies. In this paper, we…

  13. Modeling large scale cohesive sediment transport affected by small scale biological activity

    NARCIS (Netherlands)

    Borsje, Bastiaan Wijnand; de Vries, Mindert; Hulscher, Suzanne J.M.H.; de Boer, Gerben J.

    2008-01-01

    Biological activity on the bottom of the seabed is known to have significant influence on the dynamics of cohesive sediment on a small spatial and temporal scale. In this study, we aim to understand the large-scale effects of small-scale biological activity. Hereto, effects of biology are

  14. A novel conformation of gel grown biologically active cadmium nicotinate

    Science.gov (United States)

    Nair, Lekshmi P.; Bijini, B. R.; Divya, R.; Nair, Prabitha B.; Eapen, S. M.; Dileep Kumar, B. S.; Nishanth Kumar, S.; Nair, C. M. K.; Deepa, M.; Rajendra Babu, K.

    2017-11-01

    The elimination of toxic heavy metals by the formation of stable co-ordination compounds with biologically active ligands is applicable in drug designing. A new crystalline complex of cadmium with nicotinic acid is grown at ambient temperature using the single gel diffusion method in which the crystal structure is different from those already reported. Single crystal x-ray diffraction reveals the identity of crystal structure belonging to monoclinic system, P21/c space group with cell dimensions a = 17.220 (2) Å, b = 10.2480 (2) Å, c = 7.229(9) Å, β = 91.829(4)°. Powder x-ray diffraction analysis confirmed the crystallinity of the sample. The unidentate mode of co-ordination between the metal atom and the carboxylate group is supported by the Fourier Transform Infra Red spectral data. Thermal analysis ensures the thermal stability of the complex. Kinetic and thermodynamic parameters are also calculated. The stoichiometry of the complex is confirmed by the elemental analysis. The UV-visible spectral analysis shows the wide transparency window of the complex in the visible region. The band gap of the complex is found to be 3.92 eV. The complex shows excellent antibacterial and antifungal activity.

  15. Chemical constituents and biological activities of two Iranian Cystoseira species.

    Science.gov (United States)

    Yegdaneh, Afsaneh; Ghannadi, Alireza; Dayani, Ladan

    2016-07-01

    The marine environment represents approximately half of the global biodiversity and could provide unlimited biological resources for the production of therapeutic drugs. Marine seaweeds comprise few thousands of species representing a considerable part of the littoral biomass. Extracts of the Cystoseira indica and Cystoseira merica were subjected to phytochemical and cytotoxicity evaluation. The amount of total phenol was determined with Folin-Ciocalteu reagent. Cytotoxicity was characterized by IC50 of human cancer cell lines including MCF-7 (human breast adenocarcinoma), HeLa (cervical carcinoma), and HT-29 (human colon adenocarcinoma) using Sulforhodamin assay. Antioxidant activities were evaluated using 2,2-diphenylpicrylhydrazyl (DPPH) method. The analysis revealed that tannins, saponins, sterols and triterpenes were the most abundant constituents in these Cystoseira species while cyanogenic and cardiac glycosides were the least ones. C. indica had the higher content of total phenolics and also showed higher antioxidant activity. Cytotoxic results showed that both species inhibited cell growth effectively, especially against MCF-7 cell line. The present findings suggest potential pharmacological applications of selected seaweeds but require further investigation and identification of their bioactive principles.

  16. Pomegranate Fruit as a Rich Source of Biologically Active Compounds

    Science.gov (United States)

    Sreekumar, Sreeja; Sithul, Hima; Muraleedharan, Parvathy; Azeez, Juberiya Mohammed; Sreeharshan, Sreeja

    2014-01-01

    Pomegranate is a widely used plant having medicinal properties. In this review, we have mainly focused on the already published data from our laboratory pertaining to the effect of methanol extract of pericarp of pomegranate (PME) and have compared it with other relevant literatures on Punica. Earlier, we had shown its antiproliferative effect using human breast (MCF-7, MDA MB-231), and endometrial (HEC-1A), cervical (SiHa, HeLa), and ovarian (SKOV3) cancer cell lines, and normal breast fibroblasts (MCF-10A) at concentration of 20–320 μg/mL. The expressions of selected estrogen responsive genes (PR, pS2, and C-Myc) were downregulated by PME. Unlike estradiol, PME did not increase the uterine weight and proliferation in bilaterally ovariectomized Swiss-Albino mice models and its cardioprotective effects were comparable to that of 17β-estradiol. We had further assessed the protective role of PME on skeletal system, using MC3T3-E1 cells. The results indicated that PME (80 μg/mL) significantly increased ALP (Alkaline Phosphatase) activity, supporting its suggested role in modulating osteoblastic cell differentiation. The antiosteoporotic potential of PME was also evaluated in ovariectomized (OVX) rodent model. The results from our studies and from various other studies support the fact that pomegranate fruit is indeed a source of biologically active compounds. PMID:24818149

  17. Soil biological activity as affected by tillage intensity

    Science.gov (United States)

    Gajda, A. M.; Przewłoka, B.

    2012-02-01

    The effect of tillage intensity on changes of microbiological activity and content of particulate organic matter in soil under winter wheat duirng 3 years was studied. Microbial response related to the tillage-induced changes in soil determined on the content of biomass C and N, the rate of CO2 evolution, B/F ratio, the activity of dehydrogenases, acid and alkaline phosphatases, soil C/N ratio and microbial biomass C/N ratio confirmed the high sensitivity of soil microbial populations to the tillage system applied. After three year studies, the direct sowing system enhanced the increase of labile fraction of organic matter content in soil. There were no significant changes in the labile fraction quantity observed in soil under conventional tillage. Similar response related to the tillage intensity was observed in particulate organic matter quantities expressed as a percentage of total organic matter in soil. A high correlation coefficients calculated between contents of soil microbial biomass C and N, particulate organic matter and potentially mineralizable N, and the obtained yields of winter wheat grown on experimental fields indicated on a high importance of biological quality of status of soil for agricultural crop production.

  18. Glutarimides: Biological activity, general synthetic methods and physicochemical properties

    Directory of Open Access Journals (Sweden)

    Popović-Đorđević Jelena B.

    2015-01-01

    Full Text Available Glutarimides, 2,6-dioxopiperidines are compounds that rarely occur in natural sources, but so far isolated ones exert widespread pharmacological activities, which makes them valuable as potential pharmacotherapeutics. Glutarimides act as androgen receptor antagonists, anti-inflammatory, anxiolytics, antibacterials, and tumor suppressing agents. Some synthetic glutarimide derivatives are already in use as immunosuppressive and sedative (e.g., thalidomide or anxiolytics (buspirone drugs. The wide applicability of this class of compounds, justify the interest of scientists to explore new pathways for its syntheses. General methods for synthesis of six-membered imide ring, are presented in this paper. These methods include: a reaction of dicarboxylic acids with ammonia or primary amine, b reactions of cyclization: amido-acids, diamides, dinitriles, nitrilo-acids, amido-nitriles, amido-esters, amidoacyl-chlorides or diacyl-chlorides, c adition of carbon-monoxide on a,b-unsaturated amides, d oxidation reactions, e Michael adition of active methylen compounds on methacrylamide or conjugated amides. Some of the described methods are used for closing glutarimide ring in syntheses of farmacological active compounds sesbanimide and aldose reductase inhibitors (ARI. Analyses of the geometry, as well as, the spectroscopic analyses (NMR and FT-IR of some glutarimides are presented because of their broad spectrum of pharmacological activity. To elucidate structures of glutarimides, geometrical parameters of newly synthesized tert-pentyl-1-benzyl-4-methyl-glutarimide-3-carboxylate (PBMG are analyzed and compared with the experimental data from X-ray analysis for glutarimide. Moreover, molecular electrostatic potential (MEP surface which is plotted over the optimized geometry to elucidate the reactivity of PBMG molecule is analyzed. The electronic properties of glutarimide derivatives are explained on the example of thalidomide. The Frontier Molecular Orbital

  19. Actinobacteria from arid and desert habitats: diversity and biological activity

    Directory of Open Access Journals (Sweden)

    Joachim eWink

    2016-01-01

    Full Text Available Abstract The lack of new antibiotics in the pharmaceutical pipeline guides more and more researchers to leave the classical isolation procedures and to look in special niches and ecosystems. Bioprospecting of extremophilic Actinobacteria through mining untapped strains and avoiding resiolation of known biomolecules is among the most promising strategies for this purpose. With this approach, members of acidtolerant, alkalitolerant, psychrotolerant, thermotolerant, halotolerant and xerotolerant Actinobacteria have been obtained from respective habitats. Among these, little survey exists on the diversity of Actinobacteria in arid areas, which are often adapted to relatively high temperatures, salt concentrations, and radiation. Therefore, arid and desert habitats are special ecosystems which can be recruited for the isolation of uncommon Actinobacteria with new metabolic capability.At the time of this writing, members of Streptomyces, Micromonospora, Saccharothrix, Streptosporangium, Cellulomonas, Amycolatopsis, Geodermatophilus, Lechevalieria, Nocardia and Actinomadura are reported from arid habitats. However, metagenomic data present dominant members of the communities in desiccating condition of areas with limited water availability that are not yet isolated. Furthermore, significant diverse types of polyketide synthase (PKS and nonribosomal peptide synthetase (NRPS genes are detected in xerophilic and xerotolerant Actinobacteria and some bioactive compounds are reported from them. Rather than pharmaceutically active metabolites, molecules with protection activity against drying such as Ectoin and Hydroxyectoin with potential application in industry and agriculture have also been identified from xerophilic Actinobacteria. In addition, numerous biologically active small molecules are expected to be discovered from arid adapted Actinobacteria in the future. In the current survey, the diversity and biotechnological potential of Actinobacteria

  20. Actinobacteria from Arid and Desert Habitats: Diversity and Biological Activity.

    Science.gov (United States)

    Mohammadipanah, Fatemeh; Wink, Joachim

    2015-01-01

    The lack of new antibiotics in the pharmaceutical pipeline guides more and more researchers to leave the classical isolation procedures and to look in special niches and ecosystems. Bioprospecting of extremophilic Actinobacteria through mining untapped strains and avoiding resiolation of known biomolecules is among the most promising strategies for this purpose. With this approach, members of acidtolerant, alkalitolerant, psychrotolerant, thermotolerant, halotolerant and xerotolerant Actinobacteria have been obtained from respective habitats. Among these, little survey exists on the diversity of Actinobacteria in arid areas, which are often adapted to relatively high temperatures, salt concentrations, and radiation. Therefore, arid and desert habitats are special ecosystems which can be recruited for the isolation of uncommon Actinobacteria with new metabolic capability. At the time of this writing, members of Streptomyces, Micromonospora, Saccharothrix, Streptosporangium, Cellulomonas, Amycolatopsis, Geodermatophilus, Lechevalieria, Nocardia, and Actinomadura are reported from arid habitats. However, metagenomic data present dominant members of the communities in desiccating condition of areas with limited water availability that are not yet isolated. Furthermore, significant diverse types of polyketide synthase (PKS) and non-ribosomal peptide synthetase (NRPS) genes are detected in xerophilic and xerotolerant Actinobacteria and some bioactive compounds are reported from them. Rather than pharmaceutically active metabolites, molecules with protection activity against drying such as Ectoin and Hydroxyectoin with potential application in industry and agriculture have also been identified from xerophilic Actinobacteria. In addition, numerous biologically active small molecules are expected to be discovered from arid adapted Actinobacteria in the future. In the current survey, the diversity and biotechnological potential of Actinobacteria obtained from arid ecosystems

  1. Isolation, Biological Activities and Synthesis of Indoloquinoline Alkaloids: Cryptolepine, Isocryptolepine and Neocryptolepine

    Digital Repository Service at National Institute of Oceanography (India)

    Parvatkar, P.T.; Parameswaran, P.S.; Tilve, S.G.

    of biological properties. This review describes the isolation, brief biological activities and various synthetic methodologies developed during recent years for the preparation of this important class of alkaloids, with special emphasis on preparation...

  2. [Biologically active substances of black currant of new varieties].

    Science.gov (United States)

    Miasishcheva, N V; Artemova, E N

    2013-01-01

    The assortment of black currant actively replenishes and is constantly updated as a result of successful work of domestic and foreign selectors. New grades of black currant are characterized by the raised content of biologically active substances, including vitamin C, P-active agents, pectin and are of special interest for studying. Fresh berries of seven grades (Azhurnaya, Arapka, Iskushenie, Kreolka, Ladushka, Orel serenade, Ocharovanie) of black currant which were selected by the All-Russian research institute of selection of fruit crops and are perspective for cultivation in the Central Chernozem Region of Russia were chosen as objects for research. The nutritional value of fresh berries was found to vary. Average content of soluble solids was 14.1%, while those below the average were observed in Kreolka (12.1%). The maximum amount of sugars characterized Ladushka grade (11.05%), minimum--Kreolka (9.00%). It has been found that most varieties have fairly high acidity. It is worth noting grade Ladushka, which had the highest sugar-acid index (4.39), with the lowest acidity (2.51%). The highest content of ascorbic acid was found in varieties Orel Serenade--183.7 mg/100 g, the smallest--Ocharovanie--110 mg/100 g, grade Azhurnaya, Kreolka, Ladushka exceeded this indicator average value (144.9 mg/100 g). In terms of the amount of P-active substances stood grades having values above the average (722.2 mg/100 g): Azhurnaya (789.8 mg/100 g), Kreolka (864.5 mg/100 g), Oryol serenade (765.6 mg/100 g). The average content of pectin in the studied berries of black currant was 7.92%, with a minimum of 6.30% was observed in grades Azhurnaya, maximum 9.90%--the kind Oryol serenade. High values of this index were characterized by grade Ladushka, Ocharovanie. Azhurnaya varieties, Creole, Orel serenade had high levels of ascorbic acid and P-active substances. Sort Ladushka marked as a dessert due to the largest sugar-acid ratio. Ladushka, Orel Serenade, Ocharovanie have the

  3. A Survey of Biology Teachers Use of Activity-Oriented, Laboratory Practical Exercises to Promote Functional Biology Education

    Directory of Open Access Journals (Sweden)

    Abigail Mgboyibo Osuafor

    2016-08-01

    Full Text Available A major goal of science education is fostering students’ intellectual competencies such as independent learning, problem-solving, decision-making and critical thinking. This goal can only be achieved when students are actively involved in the teaching-learning process through activity-based, practical-oriented instructional methods involving the use of laboratories. This study therefore, investigated the extent to which the biology teachers employ activity-oriented, laboratory/practical instructional methods in order to improve the learning outcome of their students. The descriptive survey involved 73 Biology teachers randomly selected from all the six education zones of Anambra state, Nigeria. Four research questions were posed and four hypotheses were formulated to guide the conduct of the study. A 32-item structured questionnaire which has reliability co-efficient of 0.82 was used to collect data. Data were analyzed using mean, standard deviation and t-tests. Results show that Biology teachers adopt practical-oriented strategies in teaching biology, conduct practical activities to a high extent, and perceive practical exercises as essential to effective teaching and learning of the subject. Provision of adequate number of laboratory materials, employment of adequate number of biology teachers, making provision for well designed laboratory activities in the curriculum and training of teachers on how to effectively combine theory with practical are some of the strategies that will encourage biology teachers to conduct practical lessons. There was no significant difference between male and female biology teachers in their responses to the different aspects investigated. Based on these findings, some recommendations were made that include that curriculum designers should incorporate guides for practical activities that go with each topic in the curriculum so as to encourage the teachers to teach theory with practical as a unified whole to

  4. Antimycobacterial and Photosynthetic Electron Transport Inhibiting Activity of Ring-Substituted 4-Arylamino-7-Chloroquinolinium Chlorides

    Directory of Open Access Journals (Sweden)

    Alois Cizek

    2013-09-01

    Full Text Available In this study, a series of twenty-five ring-substituted 4-arylamino-7-chloroquinolinium chlorides were prepared and characterized. The compounds were tested for their activity related to inhibition of photosynthetic electron transport (PET in spinach (Spinacia oleracea L. chloroplasts and also primary in vitro screening of the synthesized compounds was performed against mycobacterial species. 4-[(2-Bromophenylamino]-7-chloroquinolinium chloride showed high biological activity against M. marinum, M. kansasii, M. smegmatis and 7-chloro-4-[(2-methylphenylamino]quinolinium chloride demonstrated noteworthy biological activity against M. smegmatis and M. avium subsp. paratuberculosis. The most effective compounds demonstrated quite low toxicity (LD50 > 20 μmol/L against the human monocytic leukemia THP-1 cell line within preliminary in vitro cytotoxicity screening. The tested compounds were found to inhibit PET in photosystem II. The PET-inhibiting activity expressed by IC50 value of the most active compound 7-chloro-4-[(3-trifluoromethylphenylamino]quinolinium chloride was 27 μmol/L and PET-inhibiting activity of ortho-substituted compounds was significantly lower than this of meta- and para-substituted ones. The structure-activity relationships are discussed for all compounds.

  5. Essential Oils from Neotropical Piper Species and Their Biological Activities

    Science.gov (United States)

    da Trindade, Rafaela; Alves, Nayara Sabrina; Figueiredo, Pablo Luís; Maia, José Guilherme S.; Setzer, William N.

    2017-01-01

    The Piper genus is the most representative of the Piperaceae reaching around 2000 species distributed in the pantropical region. In the Neotropics, its species are represented by herbs, shrubs, and lianas, which are used in traditional medicine to prepare teas and infusions. Its essential oils (EOs) present high yield and are chemically constituted by complex mixtures or the predominance of main volatile constituents. The chemical composition of Piper EOs displays interspecific or intraspecific variations, according to the site of collection or seasonality. The main volatile compounds identified in Piper EOs are monoterpenes hydrocarbons, oxygenated monoterpenoids, sesquiterpene hydrocarbons, oxygenated sesquiterpenoids and large amounts of phenylpropanoids. In this review, we are reporting the biological potential of Piper EOs from the Neotropical region. There are many reports of Piper EOs as antimicrobial agents (fungi and bacteria), antiprotozoal (Leishmania spp., Plasmodium spp., and Trypanosoma spp.), acetylcholinesterase inhibitor, antinociceptive, anti-inflammatory and cytotoxic activity against different tumor cells lines (breast, leukemia, melanoma, gastric, among others). These studies can contribute to the rational and economic exploration of Piper species, once they have been identified as potent natural and alternative sources to treat human diseases. PMID:29240662

  6. Isoflavone profile and biological activity of soy bread.

    Science.gov (United States)

    Zhang, Yu Chu; Albrecht, Daniel; Bomser, Joshua; Schwartz, Steven J; Vodovotz, Yael

    2003-12-17

    The present study examines the ability of isoflavone extracts from whole soy bread and two soy bread fractions, crumb and crust, to modulate the proliferation of human prostate cancer PC-3 cells. Total isoflavone content in the two fractions of soy bread were similar (3.17 micromol/g dry basis). However, their conjugate patterns were altered. Both fractions of soy bread contained a similar level of isoflavone aglycones ( approximately 24%). Low concentrations of soy bread extracts increased PC-3 cell proliferation as much as 47% compared to untreated control. This proliferative effect in cell growth was reduced at higher extract concentration. Soy bread crust extract (10 mg/mL) reduced PC-3 cell proliferation by 15% compared to untreated control. Interestingly, wheat bread extracts increased cell proliferation at all concentrations tested. Although extracts from both breads possessed biological activity, only soy bread crust extract reduced PC-3 cell proliferation. This observation may be related to the presence of soy in this bread.

  7. Nonoxidized, biologically active parathyroid hormone determines mortality in hemodialysis patients

    DEFF Research Database (Denmark)

    Tepel, Martin; Armbruster, Franz Paul; Grön, Hans Jürgen

    2013-01-01

    Background: It was shown that nonoxidized PTH (n-oxPTH) is bioactive, whereas the oxidation of PTH results in a loss of biological activity. Methods: In this study we analyzed the association of n-oxPTH on mortality in hemodialysis patients using a recently developed assay system. Results......: Hemodialysis patients (224 men, 116 women) had a median age of 66 years. One hundred seventy patients (50%) died during the follow-up period of 5 years. Median n-oxPTH levels were higher in survivors (7.2 ng/L) compared with deceased patients (5.0 ng/L; P = .002). Survival analysis showed an increased survival...... in the highest n-oxPTH tertile compared with the lowest n-oxPTH tertile (χ(2), 14.3; P = .0008). Median survival was 1702 days in the highest n-oxPTH tertile, whereas it was only 453 days in the lowest n-oxPTH tertile. Multivariable-adjusted Cox regression showed that higher age increased odds for death, whereas...

  8. Synthesis of Combretastatin A-4 Analogs and their Biological Activities.

    Science.gov (United States)

    Siebert, Agnieszka; Gensicka, Monika; Cholewinski, Grzegorz; Dzierzbicka, Krystyna

    2016-01-01

    Combretastatin A-4 (CA-4) is a natural product, which consists of two phenyl rings, linked by an ethylene bridge. CA-4, inhibitor of polymerization of tubulin to microtubules, possesses a strong antitumor and anti-vascular properties both in vitro and in vivo. Previous studies showed that disodium phosphate salt of CA-4, a water-soluble prodrug is well tolerated at therapeutically useful doses. However, it should be noted that the cis-configuration of the double bond and the 3,4,5-trimethoxy group on ring A is necessary for the biological activity of CA-4. Structure of CA-4 renders the compound readily susceptible to isomerization, which reduces the potency and bioavailability. To circumvent this problem, a lot of scientists in the world synthesized a series of cis-restricted CA-4 analogs, where the double bond has been replaced by introduction of non-heterocyclic groups or heterocyclic groups like β -lactam and oxadiazole. This paper reviews the most important approaches in analogs of combretastatin synthesis and presents structure-reactivity relationships for these compounds. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  9. Biological Activities of Three Essential Oils of the Lamiaceae Family

    Directory of Open Access Journals (Sweden)

    Gema Nieto

    2017-08-01

    Full Text Available Herbs and spices have been used since ancient times to improve the sensory characteristics of food, to act as preservatives and for their nutritional and healthy properties. Herbs and spices are generally recognized as safe (GRAS and are excellent substitutes for chemical additives. Essential oils are mixtures of volatile compounds obtained, mainly by steam distillation, from medicinal and aromatic plants. They are an alternative to synthetic additives for the food industry, and they have gained attention as potential sources for natural food preservatives due to the growing interest in the development of safe, effective, natural food preservation. Lamiaceae is one of the most important families in the production of essential oils with antioxidants and antimicrobial properties. Aromatic plants are rich in essential oils and are mainly found in the Mediterranean region, where the production of such oils is a profitable source of ecological and economic development. The use of essential oils with antimicrobial and antioxidant properties to increase the shelf life of food is a promising technology, and the essential oils of the Lamiaceae family, such as rosemary, thyme, and sage, have been extensively studied with respect to their use as food preservatives. Regarding the new applications of essential oils, this review gives an overview of the current knowledge and recent trends in the use of these oils from aromatic plants as antimicrobials and antioxidants in foods, as well as their biological activities, future potential, and challenges.

  10. Biological Activities of Three Essential Oils of the Lamiaceae Family.

    Science.gov (United States)

    Nieto, Gema

    2017-08-23

    Herbs and spices have been used since ancient times to improve the sensory characteristics of food, to act as preservatives and for their nutritional and healthy properties. Herbs and spices are generally recognized as safe (GRAS) and are excellent substitutes for chemical additives. Essential oils are mixtures of volatile compounds obtained, mainly by steam distillation, from medicinal and aromatic plants. They are an alternative to synthetic additives for the food industry, and they have gained attention as potential sources for natural food preservatives due to the growing interest in the development of safe, effective, natural food preservation. Lamiaceae is one of the most important families in the production of essential oils with antioxidants and antimicrobial properties. Aromatic plants are rich in essential oils and are mainly found in the Mediterranean region, where the production of such oils is a profitable source of ecological and economic development. The use of essential oils with antimicrobial and antioxidant properties to increase the shelf life of food is a promising technology, and the essential oils of the Lamiaceae family, such as rosemary, thyme, and sage, have been extensively studied with respect to their use as food preservatives. Regarding the new applications of essential oils, this review gives an overview of the current knowledge and recent trends in the use of these oils from aromatic plants as antimicrobials and antioxidants in foods, as well as their biological activities, future potential, and challenges.

  11. Polyphenols from Bee Pollen: Structure, Absorption, Metabolism and Biological Activity

    Directory of Open Access Journals (Sweden)

    Anna Rzepecka-Stojko

    2015-12-01

    Full Text Available Bee pollen constitutes a natural source of antioxidants such as phenolic acids and flavonoids, which are responsible for its biological activity. Research has indicated the correlation between dietary polyphenols and cardioprotective, hepatoprotective, anti-inflammatory, antibacterial, anticancerogenic, immunostimulating, antianaemic effects, as well as their beneficial influence on osseous tissue. The beneficial effects of bee pollen on health result from the presence of phenolic acids and flavonoids which possess anti-inflammatory properties, phytosterol and linolenic acid which play an anticancerogenic role, and polysaccharides which stimulate immunological activity. Polyphenols are absorbed in the alimentary tract, metabolised by CYP450 enzymes, and excreted with urine and faeces. Flavonoids and phenolic acids are characterised by high antioxidative potential, which is closely related to their chemical structure. The high antioxidant potential of phenolic acids is due to the presence and location of hydroxyl groups, a carboxyl group in the immediate vicinity of ortho-diphenolic substituents, and the ethylene group between the phenyl ring and the carboxyl group. As regards flavonoids, essential structural elements are hydroxyl groups at the C5 and C7 positions in the A ring, and at the C3′ and C4′ positions in the B ring, and a hydroxyl group at the C3 position in the C ring. Furthermore, both, the double bond between C2 and C3, and a ketone group at the C4 position in the C ring enhance the antioxidative potential of these compounds. Polyphenols have an ideal chemical structure for scavenging free radicals and for creating chelates with metal ions, which makes them effective antioxidants in vivo.

  12. Sustainable production of biologically active molecules of marine based origin.

    Science.gov (United States)

    Murray, Patrick M; Moane, Siobhan; Collins, Catherine; Beletskaya, Tanya; Thomas, Olivier P; Duarte, Alysson W F; Nobre, Fernando S; Owoyemi, Ifeloju O; Pagnocca, Fernando C; Sette, L D; McHugh, Edward; Causse, Eric; Pérez-López, Paula; Feijoo, Gumersindo; Moreira, Ma T; Rubiolo, Juan; Leirós, Marta; Botana, Luis M; Pinteus, Susete; Alves, Celso; Horta, André; Pedrosa, Rui; Jeffryes, Clayton; Agathos, Spiros N; Allewaert, Celine; Verween, Annick; Vyverman, Wim; Laptev, Ivan; Sineoky, Sergei; Bisio, Angela; Manconi, Renata; Ledda, Fabio; Marchi, Mario; Pronzato, Roberto; Walsh, Daniel J

    2013-09-25

    The marine environment offers both economic and scientific potential which are relatively untapped from a biotechnological point of view. These environments whilst harsh are ironically fragile and dependent on a harmonious life form balance. Exploitation of natural resources by exhaustive wild harvesting has obvious negative environmental consequences. From a European industry perspective marine organisms are a largely underutilised resource. This is not due to lack of interest but due to a lack of choice the industry faces for cost competitive, sustainable and environmentally conscientious product alternatives. Knowledge of the biotechnological potential of marine organisms together with the development of sustainable systems for their cultivation, processing and utilisation are essential. In 2010, the European Commission recognised this need and funded a collaborative RTD/SME project under the Framework 7-Knowledge Based Bio-Economy (KBBE) Theme 2 Programme 'Sustainable culture of marine microorganisms, algae and/or invertebrates for high value added products'. The scope of that project entitled 'Sustainable Production of Biologically Active Molecules of Marine Based Origin' (BAMMBO) is outlined. Although the Union is a global leader in many technologies, it faces increasing competition from traditional rivals and emerging economies alike and must therefore improve its innovation performance. For this reason innovation is placed at the heart of a European Horizon 2020 Strategy wherein the challenge is to connect economic performance to eco performance. This article provides a synopsis of the research activities of the BAMMBO project as they fit within the wider scope of sustainable environmentally conscientious marine resource exploitation for high-value biomolecules. Copyright © 2013 Elsevier B.V. All rights reserved.

  13. Distinguishing Biologically Controlled Calcareous Biomineralization in Fossil Organisms Using Electron Backscatter Diffraction (EBSD)

    Science.gov (United States)

    Päßler, Jan-Filip; Jarochowska, Emilia; Bestmann, Michel; Munnecke, Axel

    2018-02-01

    Although carbonate-precipitating cyanobacteria are ubiquitous in aquatic ecosystems today, the criteria used to identify them in the geological record are subjective and rarely testable. Differences in the mode of biomineralization between cyanobacteria and eukaryotes, i.e. biologically induced calcification (BIM) vs. biologically controlled calcification (BCM), result in different crystallographic structures which might be used as a criterion to test cyanobacterial affinities. Cyanobacteria are often used as a ‘wastebasket taxon’, to which various microfossils are assigned. The lack of a testable criterion for the identification of cyanobacteria may bias their fossil record severely. We employed electron backscatter diffraction (EBSD) to investigate the structure of calcareous skeletons in two microproblematica widespread in Palaeozoic marine ecosystems: Rothpletzella, hypothesized to be a cyanobacterium, and an incertae sedis microorganism Allonema. We used a calcareous trilobite shell as a BCM reference. The mineralized structure of Allonema has a simple single-layered structure of acicular crystals perpendicular to the surface of the organism. The c-axes of these crystals are parallel to the elongation and thereby normal to the surface of the organism. EBSD pole figures and misorientation axes distribution reveal a fibre texture around the c-axis with a small degree of variation (up to 30°), indicating a highly ordered structure. A comparable pattern was found in the trilobite shell. This structure allows excluding biologically induced mineralization as the mechanism of shell formation in Allonema. In Rothpletzella, the c-axes of the microcrystalline sheath show a broader clustering compared to Allonema, but still reveal crystals tending to be perpendicular to the surface of the organism. The misorientation axes of adjacent crystals show an approximately random distribution. Rothpletzella also shares morphological similarities with extant cyanobacteria. We

  14. Distinguishing Biologically Controlled Calcareous Biomineralization in Fossil Organisms Using Electron Backscatter Diffraction (EBSD

    Directory of Open Access Journals (Sweden)

    Jan-Filip Päßler

    2018-02-01

    Full Text Available Although carbonate-precipitating cyanobacteria are ubiquitous in aquatic ecosystems today, the criteria used to identify them in the geological record are subjective and rarely testable. Differences in the mode of biomineralization between cyanobacteria and eukaryotes, i.e., biologically induced calcification (BIM vs. biologically controlled calcification (BCM, result in different crystallographic structures which might be used as a criterion to test cyanobacterial affinities. Cyanobacteria are often used as a “wastebasket taxon,” to which various microfossils are assigned. The lack of a testable criterion for the identification of cyanobacteria may bias their fossil record severely. We employed electron backscatter diffraction (EBSD to investigate the structure of calcareous skeletons in two microproblematica widespread in Palaeozoic marine ecosystems: Rothpletzella, hypothesized to be a cyanobacterium, and an incertae sedis microorganism Allonema. We used a calcareous trilobite shell as a BCM reference. The mineralized structure of Allonema has a simple single-layered structure of acicular crystals perpendicular to the surface of the organism. The c-axes of these crystals are parallel to the elongation and thereby normal to the surface of the organism. EBSD pole figures and misorientation axes distribution reveal a fiber texture around the c-axis with a small degree of variation (up to 30°, indicating a highly ordered structure. A comparable pattern was found in the trilobite shell. This structure allows excluding biologically induced mineralization as the mechanism of shell formation in Allonema. In Rothpletzella, the c-axes of the microcrystalline sheath show a broader clustering compared to Allonema, but still reveal crystals tending to be perpendicular to the surface of the organism. The misorientation axes of adjacent crystals show an approximately random distribution. Rothpletzella also shares morphological similarities with extant

  15. Artemisinin inhibits chloroplast electron transport activity: mode of action.

    Directory of Open Access Journals (Sweden)

    Adyasha Bharati

    Full Text Available Artemisinin, a secondary metabolite produced in Artemisia plant species, besides having antimalarial properties is also phytotoxic. Although, the phytotoxic activity of the compound has been long recognized, no information is available on the mechanism of action of the compound on photosynthetic activity of the plant. In this report, we have evaluated the effect of artemisinin on photoelectron transport activity of chloroplast thylakoid membrane. The inhibitory effect of the compound, under in vitro condition, was pronounced in loosely and fully coupled thylakoids; being strong in the former. The extent of inhibition was drastically reduced in the presence of uncouplers like ammonium chloride or gramicidin; a characteristic feature described for energy transfer inhibitors. The compound, on the other hand, when applied to plants (in vivo, behaved as a potent inhibitor of photosynthetic electron transport. The major site of its action was identified to be the Q(B; the secondary quinone moiety of photosystemII complex. Analysis of photoreduction kinetics of para-benzoquinone and duroquinone suggest that the inhibition leads to formation of low pool of plastoquinol, which becomes limiting for electron flow through photosystemI. Further it was ascertained that the in vivo inhibitory effect appeared as a consequence of the formation of an unidentified artemisinin-metabolite rather than by the interaction of the compound per se. The putative metabolite of artemisinin is highly reactive in instituting the inhibition of photosynthetic electron flow eventually reducing the plant growth.

  16. Are Prompts Provided by Electronic Books as Effective for Teaching Preschoolers a Biological Concept as Those Provided by Adults?

    Science.gov (United States)

    Strouse, Gabrielle A.; Ganea, Patricia A.

    2016-01-01

    Research Findings: Prior research indicates that shared book reading is an effective method for teaching biological concepts to young children. Adult questioning during reading enhances children's comprehension. We investigated whether adult prompting during the reading of an electronic book enhanced children's understanding of a biological…

  17. Electron Cryo-Tomography of Vitreous Cryo-Sections : Towards Imaging Biological Nanomachines in their Cellular Environment

    NARCIS (Netherlands)

    Pierson, J.

    2011-01-01

    The field of biological electron microcopy (EM) has evolved into a reliable imaging technique for examining the ultrastructure of cells and their constituents at molecular, and, in some cases, atomic1, 2 resolution. Conventional EM techniques are being overshadowed by cryo-techniques, which ensure a

  18. Main activities of the Latin American Network of Biological Dosimetry (LBDNet)

    International Nuclear Information System (INIS)

    Di Giorgio, M.; Vallerga, M.B.; Radl, A.; Taja, M.R.; Stuck Oliveira, M.; Valdivia, P.; Garcia Lima, O.; Lamadrid, A.; Gonzalez Mesa, J.E.; Romero Aguilera, I.; Mandina Cardoso, T.; Guerrero Carbajal, C.; Arceo Maldonado, C.; Espinoza, M.; Martinez Lopez, W.; Di Tomasso, M.; Barquinero, F.; Roy, L.

    2010-01-01

    The Latin American Biological Dosimetry Network (LBDNET) was constituted in 2007 for mutual assistance in case of a radiation emergency in the region supported by IAEA Technical Cooperation Projects RLA/9/054 and RLA/9/061. The main objectives are: a) to strengthen the technical capacities of Biological Dosimetry Services belonging to laboratories existing in the region (Argentine, Brazil, Chile, Cuba, Mexico, Peru and Uruguay) integrated in National Radiological Emergency Plans to provide a rapid biodosimetric response in a coordinated manner between countries and with RANET-IAEA/BioDoseNet-WHO, b) to provide support to other countries in the region lacking Biological Dosimetry laboratories, c) to consolidate the organization of the Latin American Biological Dosimetry Network for mutual assistance. The activities developed include technical meetings for protocols and chromosomal aberration scoring criteria unification, blood samples cultures exercises, chromosomal aberrations analysis at microscope, discussion of statistical methods and specialized software for dose calculation, the intercomparison between laboratory data after the analysis of slides with irradiated material and the intercomparison of the analysis of captured images distributed electronically in the WEB. The last exercise was the transportation of an irradiated human blood sample to countries inside and outside of the region. At the moment the exercises are concluded and they are pending to be published in reference journals. Results obtained show the capacity in the region for a biodosimetric response to a radiological accident. In the future the network will integrate techniques for high dose exposure evaluation and will enhance the interaction with other emergency systems in the region. (authors) [es

  19. Active silicon x-ray for measuring electron temperature

    International Nuclear Information System (INIS)

    Snider, R.T.

    1994-07-01

    Silicon diodes are commonly used for x-ray measurements in the soft x-ray region between a few hundred ev and 20 keV. Recent work by Cho has shown that the charge collecting region in an underbiased silicon detector is the depletion depth plus some contribution from a region near the depleted region due to charge-diffusion. The depletion depth can be fully characterized as a function of the applied bias voltage and is roughly proportional to the squart root of the bias voltage. We propose a technique to exploit this effect to use the silicon within the detector as an actively controlled x-ray filter. With reasonable silicon manufacturing methods, a silicon diode detector can be constructed in which the sensitivity of the collected charge to the impinging photon energy spectrum can be changed dynamically in the visible to above the 20 keV range. This type of detector could be used to measure the electron temperature in, for example, a tokamak plasma by sweeping the applied bias voltage during a plasma discharge. The detector samples different parts of the energy spectrum during the bias sweep, and the data collected contains enough information to determine the electron temperature. Benefits and limitations of this technique will be discussed along with comparisons to similar methods for measuring electron temperature and other applications of an active silicon x-ray filter

  20. Production of biologically active recombinant human factor H in Physcomitrella.

    Science.gov (United States)

    Büttner-Mainik, Annette; Parsons, Juliana; Jérôme, Hanna; Hartmann, Andrea; Lamer, Stephanie; Schaaf, Andreas; Schlosser, Andreas; Zipfel, Peter F; Reski, Ralf; Decker, Eva L

    2011-04-01

    The human complement regulatory serum protein factor H (FH) is a promising future biopharmaceutical. Defects in the gene encoding FH are associated with human diseases like severe kidney and retinal disorders in the form of atypical haemolytic uremic syndrome (aHUS), membranoproliferative glomerulonephritis II (MPGN II) or age-related macular degeneration (AMD). There is a current need to apply intact full-length FH for the therapy of patients with congenital or acquired defects of this protein. Application of purified or recombinant FH (rFH) to these patients is an important and promising approach for the treatment of these diseases. However, neither protein purified from plasma of healthy individuals nor recombinant protein is currently available on the market. Here, we report the first stable expression of the full-length human FH cDNA and the subsequent production of this glycoprotein in a plant system. The moss Physcomitrella patens perfectly suits the requirements for the production of complex biopharmaceuticals as this eukaryotic system not only offers an outstanding genetical accessibility, but moreover, proteins can be produced safely in scalable photobioreactors without the need for animal-derived medium compounds. Transgenic moss lines were created, which express the human FH cDNA and target the recombinant protein to the culture supernatant via a moss-derived secretion signal. Correct processing of the signal peptide and integrity of the moss-produced rFH were verified via peptide mapping by mass spectrometry. Ultimately, we show that the rFH displays complement regulatory activity comparable to FH purified from plasma. © 2010 The Authors. Plant Biotechnology Journal © 2010 Society for Experimental Biology, Association of Applied Biologists and Blackwell Publishing Ltd.

  1. Relationship between electronic structure and radioprotective activity of some indazoles

    International Nuclear Information System (INIS)

    Sokolov, Yu.A.

    2000-01-01

    The quantum-chemical study of electronic structure of 29 indasoles with complete optimization of geometry and search of quantitative link between the established characteristics and radioprotective activity (RPA) was carried out through the MNDO method with application of multiple linear and nonlinear regression analysis and the basic component method. The equations of correlation relationship between the RPA and electronic characteristics are presented. 10 indasole structures, the forecasted RPA values whereof (survival rate, %) equal 50% and above, are selected. The statistic significance of the obtained correlation equations and their regression coefficients make it possible to conclude, that the established relationships are not accidental and are prospective for forecasting RPA of other close compounds of the indasole series [ru

  2. Characterization of biological macromolecules by electrophoresis and neutron activation

    International Nuclear Information System (INIS)

    Stone, S.F.; Hancock, D.; Zeisler, R.

    1987-01-01

    A procedure combining polyacrylamide gel electrophoresis (PAGE) with INAA and autoradiography was developed to study biological macromolecules and their associated trace elements. Results from the application of this method to several metalloproteins are presented. (author)

  3. Biology

    Indian Academy of Sciences (India)

    I am particularly happy that the Academy is bringing out this document by Professor M S. Valiathan on Ayurvedic Biology. It is an effort to place before the scientific community, especially that of India, the unique scientific opportunities that arise out of viewing Ayurveda from the perspective of contemporary science, its tools ...

  4. Systems Biology Graphical Notation: Activity Flow language Level 1 Version 1.2.

    Science.gov (United States)

    Mi, Huaiyu; Schreiber, Falk; Moodie, Stuart; Czauderna, Tobias; Demir, Emek; Haw, Robin; Luna, Augustin; Le Novère, Nicolas; Sorokin, Anatoly; Villéger, Alice

    2015-09-04

    The Systems Biological Graphical Notation (SBGN) is an international community effort for standardized graphical representations of biological pathways and networks. The goal of SBGN is to provide unambiguous pathway and network maps for readers with different scientific backgrounds as well as to support efficient and accurate exchange of biological knowledge between different research communities, industry, and other players in systems biology. Three SBGN languages, Process Description (PD), Entity Relationship (ER) and Activity Flow (AF), allow for the representation of different aspects of biological and biochemical systems at different levels of detail. The SBGN Activity Flow language represents the influences of activities among various entities within a network. Unlike SBGN PD and ER that focus on the entities and their relationships with others, SBGN AF puts the emphasis on the functions (or activities) performed by the entities, and their effects to the functions of the same or other entities. The nodes (elements) describe the biological activities of the entities, such as protein kinase activity, binding activity or receptor activity, which can be easily mapped to Gene Ontology molecular function terms. The edges (connections) provide descriptions of relationships (or influences) between the activities, e.g., positive influence and negative influence. Among all three languages of SBGN, AF is the closest to signaling pathways in biological literature and textbooks, but its well-defined semantics offer a superior precision in expressing biological knowledge.

  5. Polysaccharides from Traditional Chinese Medicines: Extraction, Purification, Modification, and Biological Activity.

    Science.gov (United States)

    Chen, Yun; Yao, Fangke; Ming, Ke; Wang, Deyun; Hu, Yuanliang; Liu, Jiaguo

    2016-12-13

    Traditional Chinese Medicine (TCM) has been used to treat diseases in China for thousands of years. TCM compositions are complex, using as their various sources plants, animals, fungi, and minerals. Polysaccharides are one of the active and important ingredients of TCMs. Polysaccharides from TCMs exhibit a wide range of biological activities in terms of immunity- modifying, antiviral, anti-inflammatory, anti-oxidative, and anti-tumor properties. With their widespread biological activities, polysaccharides consistently attract scientist's interests, and the studies often concentrate on the extraction, purification, and biological activity of TCM polysaccharides. Currently, numerous studies have shown that the modification of polysaccharides can heighten or change the biological activities, which is a new angle of polysaccharide research. This review highlights the current knowledge of TCM polysaccharides, including their extraction, purification, modification, and biological activity, which will hopefully provide profound insights facilitating further research and development.

  6. Global electron content: a new conception to track solar activity

    Directory of Open Access Journals (Sweden)

    E. L. Afraimovich

    2008-02-01

    Full Text Available We developed a method and programs for estimation of the global electron content (GEC from GPS measurements, using the ionosphere models IRI-2001 and NeQuick. During the 23rd cycle of solar activity, the value of GEC varied from 0.8 to 3.2×1032 electrons, following changes in the solar extreme ultra violet (EUV radiation and solar radio emission at 10.7-cm wavelength. We found a strong resemblance of these variations, with discernible 11-year and 27-day periodicities. A saturation effect of GEC is found when F10.7 increases. We found that GEC is characterized by strong seasonal (semiannual variations with maximum relative amplitude at about 10% during the rising and falling parts of the solar activity and up to 30% during the period of maximum. It was found that the relative difference between model and experimental GEC series increase as the smoothing time window decreases. We found that GEC-IRI seasonal variations are out-of-phase with experimental GEC values. The lag between model and experimental maximum of GEC values can reach several tens of days. The variations of GEC lag, on average, 2 days after those of F10.7 and UV. GEC completely reflects the dynamics of the active regions on the solar surface. The amplitude of the 27-day GEC variations decreases from 8% at the rising and falling solar activity to 2% at the maximum and at the minimum. We also found that the lifetime of contrast long-living active formations on the Sun's surface in EUV range for more than 1 month exceeds the one in radio range (10.7 cm.

  7. Global electron content: a new conception to track solar activity

    Directory of Open Access Journals (Sweden)

    E. L. Afraimovich

    2008-02-01

    Full Text Available We developed a method and programs for estimation of the global electron content (GEC from GPS measurements, using the ionosphere models IRI-2001 and NeQuick. During the 23rd cycle of solar activity, the value of GEC varied from 0.8 to 3.2×1032 electrons, following changes in the solar extreme ultra violet (EUV radiation and solar radio emission at 10.7-cm wavelength. We found a strong resemblance of these variations, with discernible 11-year and 27-day periodicities. A saturation effect of GEC is found when F10.7 increases. We found that GEC is characterized by strong seasonal (semiannual variations with maximum relative amplitude at about 10% during the rising and falling parts of the solar activity and up to 30% during the period of maximum. It was found that the relative difference between model and experimental GEC series increase as the smoothing time window decreases. We found that GEC-IRI seasonal variations are out-of-phase with experimental GEC values. The lag between model and experimental maximum of GEC values can reach several tens of days. The variations of GEC lag, on average, 2 days after those of F10.7 and UV. GEC completely reflects the dynamics of the active regions on the solar surface. The amplitude of the 27-day GEC variations decreases from 8% at the rising and falling solar activity to 2% at the maximum and at the minimum. We also found that the lifetime of contrast long-living active formations on the Sun's surface in EUV range for more than 1 month exceeds the one in radio range (10.7 cm.

  8. Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications.

    Science.gov (United States)

    Zhu, Hongli; Luo, Wei; Ciesielski, Peter N; Fang, Zhiqiang; Zhu, J Y; Henriksson, Gunnar; Himmel, Michael E; Hu, Liangbing

    2016-08-24

    goal of this study is to review the fundamental structures and chemistries of wood and wood-derived materials, which are essential for a wide range of existing and new enabling technologies. The scope of the review covers multiscale materials and assemblies of cellulose, hemicellulose, and lignin as well as other biomaterials derived from wood, in regard to their major emerging applications. Structure-properties-application relationships will be investigated in detail. Understanding the fundamental properties of these structures is crucial for designing and manufacturing products for emerging applications. Today, a more holistic understanding of the interplay between the structure, chemistry, and performance of wood and wood-derived materials is advancing historical applications of these materials. This new level of understanding also enables a myriad of new and exciting applications, which motivate this review. There are excellent reviews already on the classical topic of woody materials, and some recent reviews also cover new understanding of these materials as well as potential applications. This review will focus on the uniqueness of woody materials for three critical applications: green electronics, biological devices, and energy storage and bioenergy.

  9. Wood-Derived Materials for Green Electronics, Biological Devices, and Energy Applications

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Hongli; Luo, Wei; Ciesielski, Peter N.; Fang, Zhiqiang; Zhu, J. Y.; Henriksson, Gunnar; Himmel, Michael E.; Hu, Liangbing

    2016-08-24

    goal of this study is to review the fundamental structures and chemistries of wood and wood-derived materials, which are essential for a wide range of existing and new enabling technologies. The scope of the review covers multiscale materials and assemblies of cellulose, hemicellulose, and lignin as well as other biomaterials derived from wood, in regard to their major emerging applications. Structure-properties-application relationships will be investigated in detail. Understanding the fundamental properties of these structures is crucial for designing and manufacturing products for emerging applications. Today, a more holistic understanding of the interplay between the structure, chemistry, and performance of wood and wood-derived materials is advancing historical applications of these materials. This new level of understanding also enables a myriad of new and exciting applications, which motivate this review. There are excellent reviews already on the classical topic of woody materials, and some recent reviews also cover new understanding of these materials as well as potential applications. This review will focus on the uniqueness of woody materials for three critical applications: green electronics, biological devices, and energy storage and bioenergy.

  10. Urban biomining meets printable electronics: end-to-end at destination biological recycling and reprinting

    Data.gov (United States)

    National Aeronautics and Space Administration — Space missions rely utterly on metallic components, from the spacecraft to electronics. Yet, metals add mass, and electronics have the additional problem of a...

  11. Activities in biological radiation research at the AGF

    International Nuclear Information System (INIS)

    1984-01-01

    The AGF is working on a wide spectrum of biological radiation research, with the different scientific disciplines contributing different methodologies to long-term research projects. The following fields are studied: 1. Molecular and cellular modes of action of radiation. 2. Detection and characterisation of biological radiation damage, especially in humans. 3. Medical applications of radiation effects. 4. Concepts and methods of radiation protection. The studies will lead to suggestions for radiation protection and improved radiotherapy. They may also contribute to the development of environmental protection strategies. (orig./MG) [de

  12. Bioactivity of marine organisms. Part 3. Screening of marine algae of Indian coast for biological activity

    Digital Repository Service at National Institute of Oceanography (India)

    Kamat, S.Y.; Wahidullah, S.; Naik, C.G.; DeSouza, L.; Jayasree, V.; Ambiye, V.; Bhakuni, D.S.; Goel, A.K.; Garg, H.S.; Srimal, R.C.

    Ethanolic extracts from Indian marine algae have been tested for anti-viral, anti-bacterial, anti-fungal, anti-fertility, hypoglycaemic and a wide range of pharmacological activities. Of 34 species investigated 17 appeared biologically active. Six...

  13. Screening of some marine plants from the Indian coast for biological activity

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A; Solimabi; Kamat, S.Y.; De; Reddy, C.V.G.; Bhakuni, D.S.; Dhawan, B

    Extracts of twenty five seaweeds from Indian coast have been put through a broad biological screen which includes tests for antiviral, antibacterial, antifungal, antiprotozoal, antifertility activities and a wide range of pharmacological activities...

  14. Determination of biologically active phenols and polyphenols in various objects by chromatographic techniques

    International Nuclear Information System (INIS)

    Kochetova, M V; Semenistaya, E N; Larionov, Oleg G; Revina, A A

    2007-01-01

    Chromatographic techniques for determination of biologically active phenols and polyphenols are considered. Various methods for sample preparation and detection are compared. The advantages of high performance liquid chromatography with spectrophotometric detection for determination of antioxidants are demonstrated. Data on determination of biologically active phenols and polyphenols published in the period from 1995 to 2005 are analysed.

  15. Biologically Active Macrocyclic Compounds – from Natural Products to Diversity‐Oriented Synthesis

    DEFF Research Database (Denmark)

    Madsen, Charlotte Marie; Clausen, Mads Hartvig

    2011-01-01

    Macrocyclic compounds are attractive targets when searching for molecules with biological activity. The interest in this compound class is increasing, which has led to a variety of methods for tackling the difficult macrocyclization step in their synthesis. This microreview highlights some recent...... developments in the synthesis of macrocycles, with an emphasis on chemistry developed to generate libraries of putative biologically active compounds....

  16. Sideritis scardica Griseb., an endemic species of Balkan peninsula: traditional uses, cultivation, chemical composition, biological activity.

    Science.gov (United States)

    Todorova, Milka; Trendafilova, Antoaneta

    2014-03-14

    Sideritis scardica Griseb. is an endemic species in the Balkan Peninsula. It is used in traditional medicine as a loosening agent in bronchitis and bronchial asthma; against the common cold and lung emphysema; in the treatment of inflammation, gastrointestinal disorders and coughs; and as an active constituent of dietary supplements for the prevention of anemia. This review aims to provide a comprehensive overview of the traditional use, phytochemistry, biological activity, cultivation, and extraction of Sideritis scardica and to highlight the gaps in our knowledge which deserves further research. The present review is based on information collected from scientific journals, books, and electronic search. These sources include Scopus, Pubmed, Web of Science, and Google scholar as well as local books on ethnopharmacology and botany of this plant. The reported data on phytochemical studies, biological activity, cultivation, extraction, and traditional uses have been reviewed. Variability in essential oil composition of wild growing and cultivated taxa depending on ecological conditions was discussed. Flavonoids, phenylethanoids, diterpenoids, aliphatic compounds, etc. identified so far have been summarized. A comparative study on the effectiveness of different methods, solvents, and parameters of extraction has also been discussed. A broad range of activities of plant extracts and fractions as antimicrobial, anti-inflammatory, cytotoxic, antioxidant, gastroprotective, antiglioma, and triple monoamine reuptake inhibition as well as cultivation of the species as an approach for conservation of the natural habitats and provision of herb with high and permanent quality has also been presented. Sideritis scardica has become very popular and widely advertised herb in Europe. Although some of ethnobotanical uses have been proved through in vitro experiments, further studies of the individual compounds or chemical class of compounds responsible for the pharmacological effects

  17. Synthesis and biological activity of new homolupanes and homolupane saponins

    Czech Academy of Sciences Publication Activity Database

    Sidoryk, K.; Korda, A.; Rárová, Lucie; Oklešťková, Jana; Strnad, Miroslav; Cmoch, P.; Pakulski, Z.; Gwardiak, K.; Karczewski, R.; Luboradzki, R.

    2015-01-01

    Roč. 71, č. 13 (2015), s. 2004-2012 ISSN 0040-4020 R&D Projects: GA MŠk(CZ) LO1204 Institutional support: RVO:61389030 Keywords : Homobetulin * Homobetulinic acid * Glycosylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.645, year: 2015

  18. Biological activities of Peganum harmala leaves | Hayet | African ...

    African Journals Online (AJOL)

    The antioxidant activity was evaluated using ammonium thiocyanate method. Among tested extracts, methanol and chloroform extracts displayed a higher antibacterial activity against gram-positive than gram-negative bacteria. The methanol extract demonstrated the highest antioxidant activity and good antiviral activity ...

  19. Electron Resonance Decay into a Biological Function: Decrease in Viability of E. coli Transformed by Plasmid DNA Irradiated with 0.5-18 eV Electrons.

    Science.gov (United States)

    Kouass Sahbani, S; Cloutier, P; Bass, A D; Hunting, D J; Sanche, L

    2015-10-01

    Transient negative ions (TNIs) are ubiquitous in electron-molecule scattering at low electron impact energies (0-20 eV) and are particularly effective in damaging large biomolecules. Because ionizing radiation generates mostly 0-20 eV electrons, TNIs are expected to play important roles in cell mutagenesis and death during radiotherapeutic cancer treatment, although this hypothesis has never been directly verified. Here, we measure the efficiency of transforming E. coli bacteria by inserting into the cells, pGEM-3ZfL(-) plasmid DNA that confers resistance to the antibiotic ampicillin. Before transformation, plasmids are irradiated with electrons of specific energies between 0.5 and 18 eV. The loss of transformation efficiency plotted as a function of irradiation energy reveals TNIs at 5.5 and 9.5 eV, corresponding to similar states observed in the yields of DNA double strand breaks. We show that TNIs are detectable in the electron-energy dependence of a biological process and can decrease cell viability.

  20. Preparation, Spectroscopic Investigation and Biological Activity of New Mixed Ligand Chelates

    International Nuclear Information System (INIS)

    Alassbaly, F.S.; Ajaily, M.M.E.

    2014-01-01

    Preparation and investigation of new Co(II), Ni(II), Zn(II) and Cr(III) chelates with mixed ligands including Schiff base (L1) formed from the condensation of 4-dimethylaminobenzaldehyde with 2-aminophenol and anthranilic acid (L2) were studied. The obtained Schiff base and mixed ligand chelates were subjected to several physiochemical techniques, in terms of CHN elemental analyses, molar conductivity, magnetic moment measurements, infrared, proton nuclear magnetic resonance, electronic and mass spectra. The analytical data showed the formation of the Schiff base compound and the ratio of metal to ligands of the chelates are 1:1:1(M:L1:L2). The infrared spectral data exhibited that the used ligands behaving as bidentate ligands towards the metal ions. The proton nuclear magnetic resonance spectral data showed the signals of the active groups in the ligands which entered in chelation with Zn(II) metal ion. The electronic spectral results showed the existence of pie (phenyl ring) and n = pie (C=N) of the ligands and suggested the geometrical structures of the chelates. Meanwhile, the mass spectral data revealed the fragmentations of the Schiff base, anthranilic acid and their Ni(II) mixed ligand chelate has been preformed the only chelate conducted for justification. All the prepared mixed chelates were non-electrolyte in nature. The antibacterial activity of the Schiff base, anthranilic acid, metal salts and mixed ligand chelates were studied and found to be that mixed ligand chelates have the most biological activity in comparison to the free ligands and salts. (author)

  1. Systems Biology Graphical Notation: Activity Flow language Level 1 Version 1.2

    Directory of Open Access Journals (Sweden)

    Mi Huaiyu

    2015-06-01

    Full Text Available The Systems Biological Graphical Notation (SBGN is an international community effort for standardized graphical representations of biological pathways and networks. The goal of SBGN is to provide unambiguous pathway and network maps for readers with different scientific backgrounds as well as to support efficient and accurate exchange of biological knowledge between different research communities, industry, and other players in systems biology. Three SBGN languages, Process Description (PD, Entity Relationship (ER and Activity Flow (AF, allow for the representation of different aspects of biological and biochemical systems at different levels of detail.

  2. Synthesis, biological activities, and quantitative structure-activity relationship (QSAR) study of novel camptothecin analogues.

    Science.gov (United States)

    Wu, Dan; Zhang, Shao-Yong; Liu, Ying-Qian; Wu, Xiao-Bing; Zhu, Gao-Xiang; Zhang, Yan; Wei, Wei; Liu, Huan-Xiang; Chen, An-Liang

    2015-05-13

    In continuation of our program aimed at the development of natural product-based pesticidal agents, three series of novel camptothecin derivatives were designed, synthesized, and evaluated for their biological activities against T. Cinnabarinus, B. brassicae, and B. xylophilus. All of the derivatives showed good-to-excellent activity against three insect species tested, with LC50 values ranging from 0.00761 to 0.35496 mmol/L. Remarkably, all of the compounds were more potent than CPT against T. Cinnabarinus, and compounds 4d and 4c displayed superior activity (LC50 0.00761 mmol/L and 0.00942 mmol/L, respectively) compared with CPT (LC50 0.19719 mmol/L) against T. Cinnabarinus. Based on the observed bioactivities, preliminary structure-activity relationship (SAR) correlations were also discussed. Furthermore, a three-dimensional quantitative structure-activity relationship (3D-QSAR) model using comparative molecular field analysis (CoMFA) was built. The model gave statistically significant results with the cross-validated q2 values of 0.580 and correlation coefficient r2 of 0.991 and  of 0.993. The QSAR analysis indicated that the size of the substituents play an important in the activity of 7-modified camptothecin derivatives. These findings will pave the way for further design, structural optimization, and development of camptothecin-derived compounds as pesticidal agents.

  3. Investigations in space-related molecular biology. [cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens

    Science.gov (United States)

    Fernandez-Moran, H.; Pritzker, A. N.

    1974-01-01

    Improved instrumentation and preparation techniques for high resolution, high voltage cryo-electron microscopic and diffraction studies on terrestrial and extraterrestrial specimens are reported. Computer correlated ultrastructural and biochemical work on hydrated and dried cell membranes and related biological systems provided information on membrane organization, ice crystal formation and ordered water, RNA virus linked to cancer, lunar rock samples, and organometallic superconducting compounds. Apollo 11, 12, 14, and 15 specimens were analyzed

  4. Enhanced biological phosphorus removal. Carbon sources, nitrate as electron acceptor, and characterization of the sludge community

    Energy Technology Data Exchange (ETDEWEB)

    Christensson, M.

    1997-10-01

    Enhanced biological phosphorus removal (EBPR) was studied in laboratory scale experiments as well as in a full scale EBPR process. The studies were focused on carbon source transformations, the use of nitrate as an electron acceptor and characterisation of the microflora. A continuous anaerobic/aerobic laboratory system was operated on synthetic wastewater with acetate as sole carbon source. An efficient EBPR was obtained and mass balances over the anaerobic reactor showed a production of 1.45 g poly-{beta}-hydroxyalcanoic acids (PHA), measured as chemical oxygen demand (COD), per g of acetic acid (as COD) taken up. Furthermore, phosphate was released in the anaerobic reactor in a ratio of 0.33 g phosphorus (P) per g PHA (COD) formed and 0.64 g of glycogen (COD) was consumed per g of acetic acid (COD) taken up. Microscopic investigations revealed a high amount of polyphosphate accumulating organisms (PAO) in the sludge. Isolation and characterisation of bacteria indicated Acinetobacter spp. to be abundant in the sludge, while sequencing of clones obtained in a 16S rDNA clone library showed a large part of the bacteria to be related to the high mole % G+C Gram-positive bacteria and only a minor fraction to be related to the gamma-subclass of proteobacteria to which Acinetobacter belongs. Operation of a similar anaerobic/aerobic laboratory system with ethanol as sole carbon source showed that a high EBPR can be achieved with this compound as carbon source. However, a prolonged detention time in the anaerobic reactor was required. PHA were produced in the anaerobic reactor in an amount of 1.24 g COD per g of soluble DOC taken up, phosphate was released in an amount of 0.4-0.6 g P per g PHA (COD) produced and 0.46 g glycogen (COD) was consumed per g of soluble COD taken up. Studies of the EBPR in the UCT process at the sewage treatment plant in Helsingborg, Sweden, showed the amount of volatile fatty acids (VFA) available to the PAO in the anaerobic stage to be

  5. In search of new biological activities of isolates from Odontoglossum Harvengtense 'Tutu'.

    Science.gov (United States)

    Suzuki, Ryuichiro; Tanaka, Tomohiro; Yamamoto, Miki; Sakagami, Hiroshi; Tomomura, Mineko; Tomomura, Akito; Satoh, Kazue; Shirataki, Yoshiaki

    2012-01-01

    In the current study, we isolated four known compounds, two phenanthrenes, 2,5-dihydroxy-4,9-dimethoxy phenanthrene [1] and 4-methoxyphenanthrene-2,7-diol (flavanthrinin) [2], one phenanthrenequinone, 5-hydroxy-2,3-dimethoxy-1,4-phenanthrenequinone [3], and one flavone, 3,5,7-trihydroxyflavone (galangin) [4], from the ethyl acetate (EtOAc) extract of Odontoglossum Harvengtense 'Tutu' through bioassay-guided fractionation, and investigated their biological activities. The isolated compounds were identified with spectroscopic analysis and through comparison to literature values. Cytotoxic activity towards human tumor and normal cells was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Nitric oxide (NO) was determined by the Griess method. Radical scavenging activity was determined by electron spin resonance (ESR) spectroscopy. Osteoclastogenesis was monitored by tartrate-resistant acid phosphatase (TRAP) activity. The compounds had slightly higher cytotoxicity towards human oral squamous cell carcinoma and leukemia cell lines as compared with human normal oral cells, yielding a tumor specificity value of 1.1-2.7. Among these four compounds, 1 most potently inhibited the lipopolysaccharide (LPS)-stimulated NO production and the receptor activator of nuclear factor-κB ligand (RANKL)-stimulated osteoclastogenesis by mouse macrophage-like RAW264.7 cells. Micromolar concentrations of 1 scavenged the NO radical produced from 1-hydroxy-2-oxo-3-(N-3-methyl-3-aminopropyl)-3-methyl-1-triazene. The present study demonstrated, for the first time, that 1 inhibited both macrophage activation and osteoclast differentiation, suggesting its possible anti-inflammatory action.

  6. Pharmacological and biological activities of Mirabilis jalapa L.

    Directory of Open Access Journals (Sweden)

    Rozina Rozina

    2016-05-01

    Full Text Available AbstractPlants have been used for health care and medical purposes for several thousands of years. The number of higher plant species on earth is about 250000. It is estimated that 35000 to 70000 species have, at one time or another, been used in some cultures for medicinal purposes. One of these is Mirabilis jalapa L. which is traditionally used as Purgative and emetic, for treatment of many gastrointestinal disorders, including dysentery, diarrhea, muscle pain and abdominal colic. Besides this it also exhibits certain useful activities like Antiviral activity, Antimicrobial activity, Antimalarial activity, Anthelmintic activity, Antioxidant activity, Aytotoxic activity Anti-tubercular drugs induced hepatotoxicity, Antinociceptive activity, Antifungal activity, Anti-corrosion activity, Antispasmodic activity, Anti-inflammatory activity and many others. Pharmacologically active compounds include active alcoholic extract, ether compound-3,3’-Methylenebis (4- hydroxycoumarin N-D-alpha-Phenylyglycinelaminaribiitol-3-(4-(dimethylamino cinnamoyl 4hydroxycoumarin. The purpose of my review is to find out the areas of scope and to give the detail of the work done on Mirabilis Jalapa L. for future research work.

  7. Modelling of electron transport and of sawtooth activity in tokamaks

    Energy Technology Data Exchange (ETDEWEB)

    Angioni, C

    2001-10-01

    Transport phenomena in tokamak plasmas strongly limit the particle and energy confinement and represent a crucial obstacle to controlled thermonuclear fusion. Within the vast framework of transport studies, three topics have been tackled in the present thesis: first, the computation of neoclassical transport coefficients for general axisymmetric equilibria and arbitrary collisionality regime; second, the analysis of the electron temperature behaviour and transport modelling of plasma discharges in the Tokamak a configuration Variable (TCV); third, the modelling and simulation of the sawtooth activity with different plasma heating conditions. The work dedicated to neoclassical theory has been undertaken in order to first analytically identify a set of equations suited for implementation in existing Fokker-Planck codes. Modifications of these codes enabled us to compute the neoclassical transport coefficients considering different realistic magnetic equilibrium configurations and covering a large range of variation of three key parameters: aspect ratio, collisionality, and effective charge number. A comparison of the numerical results with an analytical limit has permitted the identification of two expressions for the trapped particle fraction, capable of encapsulating the geometrical effects and thus enabling each transport coefficient to be fitted with a single analytical function. This has allowed us to provide simple analytical formulae for all the neoclassical transport coefficients valid for arbitrary aspect ratio and collisionality in general realistic geometry. This work is particularly useful for a correct evaluation of the neoclassical contribution in tokamak scenarios with large bootstrap cur- rent fraction, or improved confinement regimes with low anomalous transport and for the determination of the plasma current density profile, since the plasma conductivity is usually assumed neoclassical. These results have been included in the plasma transport code

  8. The half-lives of biological activity of some pesticides in water

    OpenAIRE

    Kyaw Myint Oo,

    2001-01-01

    In the absence of analytical methods, the half-lives of biological activity of pesticides can be estimated by bioassays. To determine the half-lives of biological acivity of pesticides to fish, static bioassays were conducted in the laboratory with ten different formulations of pesticides using Labeo rohita as a bio-indicator. The half-lives of biological activity for ten different pesticides in soft water at pH 7.5 and 27░C, ranged from 4.6 days to 11.8 days. The half-life of biological acti...

  9. FINASOL OSR 52 active components biodegradation by using the biologic activator Biolen IG 30

    International Nuclear Information System (INIS)

    Bergueiro, J. R.; Luengo, M. C.; Socias, S.; Perez, F.; Laseca, D.; Perez-Navarro, A.; Morales, N.

    1997-01-01

    Degradation of the active ingredients in the FINASOL OSR 52, a commonly used dispersant in the treatment of marine oil spills, was studied. BIOLEN IG 30, comprising a mixture of bacteria, specially selected for their ability to degrade a wide range of chemical compounds, was used as the biodegrading agent. The kinetic coefficients of the degradation process were determined at different conditions, at ambient temperature, and at controlled 20 degrees C. BIOLEN IC 10 biologic activator was found to be adequate for total ionic and anionic dispersant degradation of the FINASOL OSR 52 at room temperature and at controlled 20 degrees C. Weekly addition of one gram of BIOLEN IG 30 was observed to improve biodegradation percentages for both ionic and anionic dispersants at controlled 20 degrees C. 12 refs., 5 tabs., 4 figs

  10. An active electron polarized scintillating GSO target for neutrino physics

    Energy Technology Data Exchange (ETDEWEB)

    Baiboussinov, B. [INFN, Sez. di Padova, Via Marzolo 8, 35131 Padova (Italy); Braggio, C., E-mail: braggio@pd.infn.it [INFN, Sez. di Padova, Via Marzolo 8, 35131 Padova (Italy); Dipartimento di Fisica, Universita di Padova, Via Marzolo 8, 35131 Padova (Italy); Cardini, A. [INFN, Sez. di Cagliari, S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari) (Italy); Carugno, G. [INFN, Sez. di Padova, Via Marzolo 8, 35131 Padova (Italy); Congiu, F. [Dipartimento di Fisica, Universita di Cagliari, S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari) (Italy); Gain, S. [St. Petersburg State Polytechnical University, 195251 St. Petersburg, Polytekhnicheskaya 29 (Russian Federation); Galeazzi, G. [INFN, Laboratori Nazionali di Legnaro, Viale dell Universita, 2 35020 Legnaro (PD) (Italy); Lai, A. [INFN, Sez. di Cagliari, S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari) (Italy); Lehman, A.; Mocci, P.; Mura, A.; Quochi, F.; Saba, M. [Dipartimento di Fisica, Universita di Cagliari, S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari) (Italy); Saitta, B. [INFN, Sez. di Cagliari, S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari) (Italy); Dipartimento di Fisica, Universita di Cagliari, S.P. per Sestu Km 0.700, 09042 Monserrato (Cagliari) (Italy); Sartori, G. [INFN, Sez. di Padova, Via Marzolo 8, 35131 Padova (Italy)

    2012-12-01

    The feasibility of an electron-polarized, active target to be used as detector in neutrino scattering experiments, suggested by several theoretical papers, has been investigated. We report on the properties of the paramagnetic crystal Gd{sub 2}SiO{sub 5} (GSO), in which 7.7% of the total number of electrons present can be polarized by lowering the temperature and applying an intense external magnetic field. The material magnetic susceptibility has been measured down to cryogenic temperatures showing that for H=5 T and T=4 K about 80% of the maximum allowed magnetization can be attained. Also the spectral and time response of the crystal have been characterized and the scintillation process has been studied using a photomultiplier to measure the response to gamma rays irradiation and cosmic rays operating the GSO crystal at 13.5 K. An avalanche photodiode (APD) readout of the scintillation signal from the GSO crystal has also been performed, since the magnetic field-independent response of this device allows it to be placed close to the crystal in the cryogenic environment.

  11. Anti-inflammatory activity of electron-deficient organometallics.

    Science.gov (United States)

    Zhang, Jingwen; Pitto-Barry, Anaïs; Shang, Lijun; Barry, Nicolas P E

    2017-11-01

    We report an evaluation of the cytotoxicity of a series of electron-deficient (16-electron) half-sandwich precious metal complexes of ruthenium, osmium and iridium ([Os/Ru( η 6 - p -cymene)(1,2-dicarba- closo -dodecarborane-1,2-dithiolato)] ( 1/2 ), [Ir( η 5 -pentamethylcyclopentadiene)(1,2-dicarba- closo -dodecarborane-1,2-dithiolato)] ( 3 ), [Os/Ru( η 6 - p -cymene)(benzene-1,2-dithiolato)] ( 4/5 ) and [Ir( η 5 -pentamethylcyclopentadiene)(benzene-1,2-dithiolato)] ( 6 )) towards RAW 264.7 murine macrophages and MRC-5 fibroblast cells. Complexes 3 and 6 were found to be non-cytotoxic. The anti-inflammatory activity of 1-6 was evaluated in both cell lines after nitric oxide (NO) production and inflammation response induced by bacterial endotoxin lipopolysaccharide (LPS) as the stimulus. All metal complexes were shown to exhibit dose-dependent inhibitory effects on LPS-induced NO production on both cell lines. Remarkably, the two iridium complexes 3 and 6 trigger a full anti-inflammatory response against LPS-induced NO production, which opens up new avenues for the development of non-cytotoxic anti-inflammatory drug candidates with distinct structures and solution chemistry from that of organic drugs, and as such with potential novel mechanisms of action.

  12. Holography and coherent diffraction with low-energy electrons: A route towards structural biology at the single molecule level

    Energy Technology Data Exchange (ETDEWEB)

    Latychevskaia, Tatiana; Longchamp, Jean-Nicolas; Escher, Conrad; Fink, Hans-Werner, E-mail: hwfink@physik.uzh.ch

    2015-12-15

    The current state of the art in structural biology is led by NMR, X-ray crystallography and TEM investigations. These powerful tools however all rely on averaging over a large ensemble of molecules. Here, we present an alternative concept aiming at structural analysis at the single molecule level. We show that by combining electron holography and coherent diffraction imaging estimations concerning the phase of the scattered wave become needless as the phase information is extracted from the data directly and unambiguously. Performed with low-energy electrons the resolution of this lens-less microscope is just limited by the De Broglie wavelength of the electron wave and the numerical aperture, given by detector geometry. In imaging freestanding graphene, a resolution of 2 Å has been achieved revealing the 660.000 unit cells of the graphene sheet from a single data set. Once applied to individual biomolecules the method shall ultimately allow for non-destructive imaging and imports the potential to distinguish between different conformations of proteins with atomic resolution. - Highlights: • Structural biology of single proteins. • Radiation damage-free imaging of individual biomolecules. • Holography. • Low-energy electrons. • Coherent diffraction and phase retrieval.

  13. Transmission microscopy of unmodified biological materials: comparative radiation dosages with electrons and ultrasoft X-ray photons

    International Nuclear Information System (INIS)

    Sayre, D.; Feder, R.; Spiller, E.; Kirz, J.; Kim, D.M.

    1977-01-01

    The minimum radiation dosage in a specimen consistent with transmission microscopy at resolution d and specimen thickness t is calculated for model specimens resembling biological materials in their natural state. The calculations cover 10 4 -10 7 eV electrons and 1.3-90 A photons in a number of microscopy modes. The results indicate that over a considerable part of the (t,d)-plane transmission microscopy on such specimens can be carried out at lower dosage with photons than with electrons. Estimates of the maximum resolutions obtainable with electrons and photons, consistent with structural survival of the specimen, are obtained, as are data on optimal operating conditions for microscopy with the two particles

  14. Biological activity of Stevia rebaudiana Bertoni and their relationship to health.

    Science.gov (United States)

    Ruiz-Ruiz, Jorge Carlos; Moguel-Ordoñez, Yolanda Beatriz; Segura-Campos, Maira Rubi

    2017-08-13

    The leaves of Stevia rebaudiana Bertoni has nutrients and phytochemicals, which make it an adequate source for the extraction and production of functional food ingredients. Preclinical and clinical studies suggest therapeutic and pharmacological applications for stevia and their extracts because they are not toxic and exhibit several biological activities. This review presents the biological activity of Stevia rebaudiana Bertoni and their relationship to antidiabetic, anticariogenic, antioxidant, hypotensive, antihypertensive, antimicrobial, anti-inflammatory and antitumor activities. Consumption and adverse effects were also reviewed.

  15. Cryo-electron microscopy and X-ray crystallography: complementary approaches to structural biology and drug discovery.

    Science.gov (United States)

    Vénien-Bryan, Catherine; Li, Zhuolun; Vuillard, Laurent; Boutin, Jean Albert

    2017-04-01

    The invention of the electron microscope has greatly enhanced the view scientists have of small structural details. Since its implementation, this technology has undergone considerable evolution and the resolution that can be obtained for biological objects has been extended. In addition, the latest generation of cryo-electron microscopes equipped with direct electron detectors and software for the automated collection of images, in combination with the use of advanced image-analysis methods, has dramatically improved the performance of this technique in terms of resolution. While calculating a sub-10 Å resolution structure was an accomplishment less than a decade ago, it is now common to generate structures at sub-5 Å resolution and even better. It is becoming possible to relatively quickly obtain high-resolution structures of biological molecules, in particular large ones (>500 kDa) which, in some cases, have resisted more conventional methods such as X-ray crystallography or nuclear magnetic resonance (NMR). Such newly resolved structures may, for the first time, shed light on the precise mechanisms that are essential for cellular physiological processes. The ability to attain atomic resolution may support the development of new drugs that target these proteins, allowing medicinal chemists to understand the intimacy of the relationship between their molecules and targets. In addition, recent developments in cryo-electron microscopy combined with image analysis can provide unique information on the conformational variability of macromolecular complexes. Conformational flexibility of macromolecular complexes can be investigated using cryo-electron microscopy and multiconformation reconstruction methods. However, the biochemical quality of the sample remains the major bottleneck to routine cryo-electron microscopy-based determination of structures at very high resolution.

  16. ELECTRONIC EQUIPMENT TO MONITORIZE SOME BIOLOGICAL PROCESS OF ECONOMIC IMPORTANCE IN HONEYBEE COLONY AND ITS ENVIRONMENT

    Directory of Open Access Journals (Sweden)

    A. SICEANU

    2007-10-01

    Full Text Available The electronic hive is the result of the scientific researches carried out between2003-2006 by a research project funded by MEdC through the National ProgramRELANSIN, being accomplished by Institute for Beekeeping Research andDevelopment –Bucharest in cooperation with the Polytechnics University fromBucharest –The Center for Electronic Technology and Interconnection Techniquesand the Radio Consult CompanyTo achieve the great complexity of the electronic model adapted to the hive –the“smart” hive, it was necessary to establish the all electronic details which to makepossible to monitorize some very important information from the bee colony andits environment with the help of the honeybees and which to eliminate the errorsthat may occur in the information collection process.Thus, the project aimed to conceive the electronic system in order to collectinformation from inside the hive and from environment too, to storage andtransmit it to a data basis by GSM network in order to be analyzed and processedby users.By this complex electronic system, composed by electronic equipment and thehoney bee colony, which is dynamic and strong related with natural evolution ofvegetation correlated with the climate factors, is possible to identify instantaneousor periodically a large palette of aggression factors as well naturals (acids rains,extreme temperatures, calamities as anthropic factors –accidental chemical orbiologic pollution. The obtained data, electronically quantified and taken out intothe data basis, could offer accurate information about the moisturized areas atdifferent time intervals.

  17. Biologically Active Chorionic Gonadotropin: Synthesis by the Human Fetus

    Science.gov (United States)

    McGregor, W. G.; Kuhn, R. W.; Jaffe, R. B.

    1983-04-01

    The kidney, and to a slight extent the liver, of human fetuses were found to synthesize and secrete the α subunit common to glycoprotein hormones. Fetal lung and muscle did not synthesize this protein. Since fetal kidney and liver were previously found to synthesize β chorionic gonadotropin, their ability to synthesize bioactive chorionic gonadotropin was also determined. The newly synthesized hormone bound to mouse Leydig cells and elicited a biological response: namely, the synthesis of testosterone. These results suggest that the human fetus may participate in metabolic homeostasis during its development.

  18. Physiochemical, optical and biological activity of chitosan-chromone derivative for biomedical applications.

    Science.gov (United States)

    Kumar, Santosh; Koh, Joonseok

    2012-01-01

    This paper describes the physiochemical, optical and biological activity of chitosan-chromone derivative. The chitosan-chromone derivative gels were prepared by reacting chitosan with chromone-3-carbaldehyde, followed by solvent exchange, filtration and drying by evaporation. The identity of Schiff base was confirmed by UV-Vis absorption spectroscopy and Fourier-transform infrared (FTIR) spectroscopy. The chitosan-chromone derivative was evaluated by X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), photoluminescence (PL) and circular dichroism (CD). The CD spectrum showed the chitosan-chromone derivative had a secondary helical structure. Microbiological screening results demonstrated the chitosan-chromone derivative had antimicrobial activity against Escherichia coli bacteria. The chitosan-chromone derivative did not have any adverse effect on the cellular proliferation of mouse embryonic fibroblasts (MEF) and did not lead to cellular toxicity in MEFs. These results suggest that the chitosan-chromone derivative gels may open a new perspective in biomedical applications.

  19. Nickel removal from nickel plating waste water using a biologically active moving-bed sand filter.

    Science.gov (United States)

    Pümpel, Thomas; Macaskie, Lynne E; Finlay, John A; Diels, Ludo; Tsezos, Marios

    2003-12-01

    Efficient removal of dissolved nickel was observed in a biologically active moving-bed 'MERESAFIN' sand filter treating rinsing water from an electroless nickel plating plant. Although nickel is fully soluble in this waste water, its passage through the sand filter promoted rapid removal of approximately 1 mg Ni/l. The speciation of Ni in the waste water was modelled; the most probable precipitates forming under the conditions in the filter were predicted using PHREEQC. Analyses of the Ni-containing biosludge using chemical, electron microscopical and X-ray spectroscopic techniques confirmed crystallisation of nickel phosphate as arupite (Ni3(PO4)2 x 8H2O), together with hydroxyapatite within the bacterial biofilm on the filter sand grains. Biosorption contributed less than 1% of the overall sequestered nickel. Metabolising bacteria are essential for the process; the definitive role of specific components of the mixed population is undefined but the increase in pH promoted by metabolic activity of some microbial components is likely to promote nickel desolubilisation by others.

  20. Electron Transfer in Chemistry and Biology – The Primary Events in ...

    Indian Academy of Sciences (India)

    molecular unit to another. This reaction, accompanied by proton and hydrogen atom trans- fers, occurs in a cascade in many biological processes, includ- ing photosynthesis. The key chemical steps involved in photo- synthesis and the many ...

  1. Dynamical 'in situ' observation of biological samples using variable pressure scanning electron microscope

    International Nuclear Information System (INIS)

    Nedela, V

    2008-01-01

    Possibilities of 'in-situ' observation of non-conductive biological samples free of charging artefacts in dynamically changed surrounding conditions are the topic of this work. The observed biological sample, the tongue of a rat, was placed on a cooled Peltier stage. We studied the visibility of topographical structure depending on transition between liquid and gas state of water in the specimen chamber of VP SEM.

  2. The effect of biologically active feed additives of humilid substances on the antioxidant system in liver mitochondria of gerbils

    Directory of Open Access Journals (Sweden)

    O. O. Dyomshina

    2017-04-01

    products, catalase activation, and an increase in the concentration of cytochrome C. Also, an increase in the amount of cytochrome C, which is a direct participant in the mitochondrial respiratory chain and provides efficient electron transport, indicates the acceleration of energy supply processes. The functional activity of mitochondria was accompanied by increased activity of aspartate aminotransferase involved in the shuttle of malate-aspartate transport of electrons through the mitochondrial membrane. The results obtained indicate the positive reaction of gerbil liver mitochondria under the influence of the biologically active feed additives of humic substance.

  3. Dynamic Processes in Biology, Chemistry, and Materials Science: Opportunities for UltraFast Transmission Electron Microscopy - Workshop Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Kabius, Bernd C.; Browning, Nigel D.; Thevuthasan, Suntharampillai; Diehl, Barbara L.; Stach, Eric A.

    2012-07-25

    This report summarizes a 2011 workshop that addressed the potential role of rapid, time-resolved electron microscopy measurements in accelerating the solution of important scientific and technical problems. A series of U.S. Department of Energy (DOE) and National Academy of Science workshops have highlighted the critical role advanced research tools play in addressing scientific challenges relevant to biology, sustainable energy, and technologies that will fuel economic development without degrading our environment. Among the specific capability needs for advancing science and technology are tools that extract more detailed information in realistic environments (in situ or operando) at extreme conditions (pressure and temperature) and as a function of time (dynamic and time-dependent). One of the DOE workshops, Future Science Needs and Opportunities for Electron Scattering: Next Generation Instrumentation and Beyond, specifically addressed the importance of electron-based characterization methods for a wide range of energy-relevant Grand Scientific Challenges. Boosted by the electron optical advancement in the last decade, a diversity of in situ capabilities already is available in many laboratories. The obvious remaining major capability gap in electron microscopy is in the ability to make these direct in situ observations over a broad spectrum of fast (µs) to ultrafast (picosecond [ps] and faster) temporal regimes. In an effort to address current capability gaps, EMSL, the Environmental Molecular Sciences Laboratory, organized an Ultrafast Electron Microscopy Workshop, held June 14-15, 2011, with the primary goal to identify the scientific needs that could be met by creating a facility capable of a strongly improved time resolution with integrated in situ capabilities. The workshop brought together more than 40 leading scientists involved in applying and/or advancing electron microscopy to address important scientific problems of relevance to DOE’s research

  4. Biological Activities of Essential Oils from Plants Growing in Tanzania

    African Journals Online (AJOL)

    Most of the oils showed anti-candida activity, with oils from Ocimum species being the most active compared to the others. Thus, Ocimum suave oils merit further investigation towards the development of safe and biodegradable larvicides. Furthermore, oils from Ocimum basilicum and Ocimum kilimandscharicum could offer ...

  5. Synthesis and biological activity of some heterocyclic compounds ...

    Indian Academy of Sciences (India)

    A number of 1-substituted-2-methyl benzimidazole derivatives have been synthesized and tested for their antibacterial activities. The chemical structures of the newly synthesized compounds were verified on the basis of spectral and elemental methods of analyses. Investigation of antimicrobial activity of the compounds ...

  6. Biological activities and nutritional value of Tapinanthus bangwensis ...

    African Journals Online (AJOL)

    In the brine shrimp lethality assay, the ethyl acetate and dichloromethane fractions showed cytotoxic activity with LD50 values of 11.22 and 15.84 μg/ml, respectively. ... These results demonstrate the cytotoxic and antioxidant activities of T. bangwensis leaves and support the traditional use of the plant in cancer treatment.

  7. Upshot of the ripening time on biological activities, phenol content ...

    African Journals Online (AJOL)

    Anis

    2013-10-02

    Oct 2, 2013 ... Total phenol content and the antioxidant activities of three cultivars of Opuntia ficus-indica (L.) Mill. were evaluated. The results show that the ecotypes were significantly different according to their fatty acid composition, antioxidant and antibacterial activity, as well as their polyphenol profiles. Rossa fruit.

  8. Synthesis and biological activity of some heterocyclic compounds ...

    Indian Academy of Sciences (India)

    Administrator

    antiprotozoal. 20,21 and anti-hepatitis B virus activity. 22. In addition, a large number of antibiotics contain the 2-azetidinone. (commonly known as β-lactam) moiety. 23 such as penicillin, cephalosporin and carbapenem (figure 2). It is also associated with a variety of therapeutic activities. 24–28. In continuation of our work to.

  9. Upshot of the ripening time on biological activities, phenol content ...

    African Journals Online (AJOL)

    Total phenol content and the antioxidant activities of three cultivars of Opuntia ficus-indica (L.) Mill. were evaluated. The results show that the ecotypes were significantly different according to their fatty acid composition, antioxidant and antibacterial activity, as well as their polyphenol profiles. Rossa fruit collected in August ...

  10. BIOLOGICAL VALUE OF PUNY FRUITS RELATED TO THEIR ANTIRADICAL ACTIVITY

    Directory of Open Access Journals (Sweden)

    M. BALOGHOVÁ

    2007-05-01

    Full Text Available All analysed species of puny fruits (red currant (Ribes rubrum L variant Jonkheervan Tets, white currant (Ribes vulgare L. variant Blanka, black currant (Ribesnigrum L. variant Eva, blueberry (Vaccinium myrtilis variant Berkeley, elderberry(Sambucus nigra L. variant Sambo, hawthorn (Crataegus oxyacantha, mulberry(Morus nigra L. genotypes M152 and M047 are natural sources of anthocyanpigments and vitamin C with a high antiradical activity. Due to the fact that thehighest antiradical activity is not accompanied by the highest content of anthocyansand vitamin C in puny fruits, we suppose that the antiradical activity of plantmaterials is also connected with the presence of other compounds with antioxidantand antiradical activity. From our results follows that all studied puny fruits with ahigh antiradical activity increase the antioxidant value of human nutrition and alsoits prophylactic and medicinal effect.

  11. Phytochemical prospection and biological activity of Duroia macrophylla (Rubiaceae

    Directory of Open Access Journals (Sweden)

    Daiane Martins

    2014-12-01

    Full Text Available Context: Duroia macrophylla (Rubiaceae is endemic from the Amazon Rainforest. Aims: To perform phytochemical profile of Duroia macrophylla extracts and to evaluate them as antioxidant, insecticidal and cytotoxic. Methods: Dichloromethane and methanol extracts of leaves and branches (collected three times were subjected to phytochemical screening by comparative thin layer chromatography and NMR analyses. The extracts were assayed to antioxidant (DPPH and Fe-phenanthroline, at 10 μg/mL, insecticidal on Sitophilus zeamais (by ingestion of stored grains and contact, both at 10 mg/mL and toxic activities on Artemia salina (1000 μg/mL. Results: There were found evidences of terpenes, phenolic substances (phenols and flavonoids and alkaloids, with differences between the vegetal part, collection period and solvent used. Antioxidant evaluations showed three of twelve were active and two were considered moderately active, with a relationship dependently of concentration. All methanol extracts showed the presence of phenolic substances (phenols and flavonoids but one showed only phenols. For insecticidal activity, there were three most active extracts, two of which showed only presence of terpenes and the other, besides terpenes, phenolic substances (phenols and flavonoids. For Artemia salina toxicity assay, the five most active were all from the 2nd and 3rd collections. Conclusions: The active extracts of D. macrophylla in each test were different. Three methanol extracts showed antioxidant activity; three extracts showed insecticidal activity and the presence of terpenic substances and five extracts presented cytotoxic activity, but it was not possible to correlate it with any specific secondary metabolite.

  12. A glimpse on biological activities of tellurium compounds

    Directory of Open Access Journals (Sweden)

    Rodrigo L. O. R. Cunha

    2009-09-01

    Full Text Available Tellurium is a rare element which has been regarded as a toxic, non-essential trace element and its biological role is not clearly established to date. Besides of that, the biological effects of elemental tellurium and some of its inorganic and organic derivatives have been studied, leading to a set of interesting and promising applications. As an example, it can be highlighted the uses of alkali-metal tellurites and tellurates in microbiology, the antioxidant effects of organotellurides and diorganoditellurides and the immunomodulatory effects of the non-toxic inorganic tellurane, named AS-101, and the plethora of its uses. Inasmuch, the nascent applications of organic telluranes (organotelluranes as protease inhibitors and its applications in disease models are the most recent contribution to the scenario of the biological effects and applications of tellurium and its compounds discussed in this manuscript.O telúrio é um elemento não-essencial raro que vem sendo considerado tóxico, e o seu papel biológico é ainda pouco esclarecido. Apesar disso, os efeitos biológicos do telúrio elementar e de alguns derivados inorgânicos e orgânicos que têm sido estudados revelam um conjunto de aplicações diversificadas interessantes e promissoras. Como exemplo, pode-se destacar os usos de teluritos e teluratos de metais alcalinos em microbiologia, o efeito antioxidante de teluretos e diteluretos orgânicos, os efeitos imunomodulatórios e a diversidade de usos correlacionados a este efeito de uma telurana inorgânica denominada AS-101. Ademais, as aplicações de teluranas orgânicas (organoteluranas como inibidoras de proteases e as aplicações em modelos de doenças compõem a mais recente contribuição ao cenário dos efeitos e aplicações biológicas do telúrio e seus compostos discutidas neste manuscrito.

  13. Quinones from plants of northeastern Brazil: structural diversity, chemical transformations, NMR data and biological activities.

    Science.gov (United States)

    Lemos, Telma L G; Monte, Francisco J Q; Santos, Allana Kellen L; Fonseca, Aluisio M; Santos, Hélcio S; Oliveira, Mailcar F; Costa, Sonia M O; Pessoa, Otilia D L; Braz-Filho, Raimundo

    2007-05-20

    The present review focus in quinones found in species of Brazilian northeastern Capraria biflora, Lippia sidoides, Lippia microphylla and Tabebuia serratifolia. The review cover ethnopharmacological aspects including photography of species, chemical structure feature, NMR datea and biological properties. Chemical transformations of lapachol to form enamine derivatives and biological activities are discussed.

  14. Learning Activity Package, Biology, LAPs 20, 30, 31, 32, and 33.

    Science.gov (United States)

    Rhoden, Bruce

    Included is a set of five teacher-prepared Learning Activity Packages (LAPs) for individualized instruction in topics in biology. The units cover the topics of genetic continuity, methods of investigation, cell biology, genetics, and animal physiology. Each unit contains a rationale for the material; a list of behavioral objectives for the unit; a…

  15. An Introduction to Biological Modeling Using Coin Flips to Predict the Outcome of a Diffusion Activity

    Science.gov (United States)

    Butcher, Greg Q.; Rodriguez, Juan; Chirhart, Scott; Messina, Troy C.

    2016-01-01

    In order to increase students' awareness for and comfort with mathematical modeling of biological processes, and increase their understanding of diffusion, the following lab was developed for use in 100-level, majors/non-majors biology and neuroscience courses. The activity begins with generation of a data set that uses coin-flips to replicate…

  16. Biologically Active Organic Matter in Soils of European Russia

    Science.gov (United States)

    Semenov, V. M.; Kogut, B. M.; Zinyakova, N. B.; Masyutenko, N. P.; Malyukova, L. S.; Lebedeva, T. N.; Tulina, A. S.

    2018-04-01

    Experimental and literature data on the contents and stocks of active organic matter in 200 soil samples from the forest-tundra, southern-taiga, deciduous-forest, forest-steppe, dry-steppe, semidesert, and subtropical zones have been generalized. Natural lands, agrocenoses, treatments of long-term field experiments (bare fallow, unfertilized and fertilized crop rotations, perennial plantations), and different layers of soil profile are presented. Sphagnum peat and humus-peat soil in the tundra and forest-tundra zones are characterized by a very high content of active organic matter (300-600 mg C/100 g). Among the zonal soils, the content of active organic matter increases from the medium (75-150 mg C/100 g) to the high (150-300 mg C/100 g) level when going from soddy-podzolic soil to gray forest and dark-gray forest soils and then to leached chernozem. In the series from typical chernozem to ordinary and southern chernozem and chestnut and brown semidesert soils, a decrease in the content of active organic matter to the low (35-75 mg C/100 g) and very low (<35 mg C/100 g) levels is observed. Acid brown forest soil in the subtropical zone is characterized by a medium supply with active organic matter. Most arable soils are mainly characterized by low or very low contents of active organic matter. In the upper layers of soils, active organic matter makes up 1.2-11.1% of total Corg. The profile distribution of active organic matter in the studied soils coincides with that of Corg: their contents appreciably decrease with depth, except for brown semidesert soil. The stocks of active organic matter vary from 0.4 to 5.4 t/ha in the layer of 0-20 cm and from 1.0 to 12.4/ha in the layer of 0-50 cm of different soil types.

  17. Chemical Constituents of Descurainia sophia L. and its Biological Activity

    Directory of Open Access Journals (Sweden)

    Nawal H. Mohamed

    2009-01-01

    Full Text Available Seven coumarin compounds were isolated for the first time from the aerial parts of DescurainiaSophia L. identified as scopoletine, scopoline, isoscopoline, xanthtoxol, xanthtoxin, psoralene and bergaptane.Three flavonoids namely kaempferol, quercetine and isorhamnetine and three terpenoid compounds -sitosterol-amyrine and cholesterol were also isolated and identified by physical and chemical methods; melting point, Rfvalues, UV and 1H NMR spectroscopy. Qualitative and quantitative analyses of free and protein amino acidsusing amino acid analyzer were performed. The plant contains 15 amino acids as free and protein amino acidswith different range of concentrations. Fatty acid analysis using GLC, revealed the presence of 10 fatty acids,the highest percentage was palmitic acid (27.45 % and the lowest was lauric acid (0.13%. Biological screeningof alcoholic extract showed that the plant is highly safe and has analgesic, antipyretic and anti-inflammatoryeffects.

  18. Effects of different external carbon sources and electron acceptors on interactions between denitrification and phosphorus removal in biological nutrient removal processes.

    Science.gov (United States)

    Hu, Xiang; Sobotka, Dominika; Czerwionka, Krzysztof; Zhou, Qi; Xie, Li; Makinia, Jacek

    The effects of two different external carbon sources (acetate and ethanol) and electron acceptors (dissolved oxygen, nitrate, and nitrite) were investigated under aerobic and anoxic conditions with non-acclimated process biomass from a full-scale biological nutrient removal-activated sludge system. When acetate was added as an external carbon source, phosphate release was observed even in the presence of electron acceptors. The release rates were 1.7, 7.8, and 3.5 mg P/(g MLVSS·h) (MLVSS: mixed liquor volatile suspended solids), respectively, for dissolved oxygen, nitrate, and nitrite. In the case of ethanol, no phosphate release was observed in the presence of electron acceptors. Results of the experiments with nitrite showed that approximately 25 mg NO 2 -N/L of nitrite inhibited anoxic phosphorus uptake regardless of the concentration of the tested external carbon sources. Furthermore, higher denitrification rates were obtained with acetate (1.4 and 0.8 mg N/(g MLVSS·h)) compared to ethanol (1.1 and 0.7 mg N/ (g MLVSS·h)) for both anoxic electron acceptors (nitrate and nitrite).

  19. The Evolution of Selection Activities for Electronic Resources.

    Science.gov (United States)

    Davis, Trisha L.

    1997-01-01

    Selection of electronic resources--CD-ROMs, dial access databases, electronic journals, and World Wide Web products--requires a more extensive set of criteria than do print resources. Discusses two factors influencing collection development of electronic products: technology options and licensing issues, and outlines how traditional selection…

  20. Three-dimensional electron microscopy of macromolecular assemblies: visualization of biological molecules in their native state

    National Research Council Canada - National Science Library

    Frank, J

    2006-01-01

    ... Clusters 2.8 Support Grids 33 33 3 Principle of Image Formation in the Transmission Electron Microscope 34 3.1 Introduction 34 3.2 The Weak-Phase Object Approximation 35 3.3 The Contrast Transfer...

  1. Biological versus chemical leaching of electronic waste for copper and gold recovery

    OpenAIRE

    Isildar , Arda

    2016-01-01

    The well-being of the society depends on a number of metals, including base metals, precious metals and increasingly rare earth elements (REE). The usage of these metals increased in numerous applications, including electrical and electronic equipment (EEE), and their interrupted supply is at stake. There is an increasing interest in the secondary sources of these metals, particularly waste electrical and electronic equipment (WEEE) in order to compensate their potential supply deficit. This ...

  2. Biological activity of camel milk casein following enzymatic digestion.

    Science.gov (United States)

    Salami, Maryam; Moosavi-Movahedi, Ali Akbar; Moosavi-Movahedi, Faezeh; Ehsani, Mohammad Reza; Yousefi, Reza; Farhadi, Mohammad; Niasari-Naslaji, Amir; Saboury, Ali Akbar; Chobert, Jean-Marc; Haertlé, Thomas

    2011-11-01

    The aim of this study was to investigate the effects of enzymatic hydrolysis with digestive enzymes of camel whole casein and beta-casein (β-CN) on their antioxidant and Angiotensin Converting Enzyme (ACE)-inhibitory properties. Peptides in each hydrolysate were fractionated with ultra-filtration membranes. The antioxidant activity was determined using a Trolox equivalent antioxidant capacity (TEAC) scale. After enzymatic hydrolysis, both antioxidant and ACE-inhibitory activities of camel whole casein and camel β-CN were enhanced. Camel whole casein and β-CN showed significant ACE-inhibitory activities after hydrolysis with pepsin alone and after pepsinolysis followed by trypsinolysis and chymotrypsinolysis. Camel β-CN showed high antioxidant activity after hydrolysis with chymotrypsin. The results of this study suggest that when camel milk is consumed and digested, the produced peptides start to act as natural antioxidants and ACE-inhibitors.

  3. CHARACTERIZATION ADN BIOLOGICAL ACTIVITY OF SECONDARY METABOLITES FROM ARMILLARIA TABESCENS

    Science.gov (United States)

    Ethyl acetate extracts from liquid cultures of Armillaria tabescens showed good antimicrobial activity against Candida albicans, Cryptococcus neoformans, Escherichia coli and Mycobacterium intracellulare. Chemical analyses of extract constituents led to the isolation and identification of two new co...

  4. Synthesis and Antiplatelet Activity of Antithrombotic Thiourea Compounds: Biological and Structure-Activity Relationship Studies

    Directory of Open Access Journals (Sweden)

    André Luiz Lourenço

    2015-04-01

    Full Text Available The incidence of hematological disorders has increased steadily in Western countries despite the advances in drug development. The high expression of the multi-resistance protein 4 in patients with transitory aspirin resistance, points to the importance of finding new molecules, including those that are not affected by these proteins. In this work, we describe the synthesis and biological evaluation of a series of N,N'-disubstituted thioureas derivatives using in vitro and in silico approaches. New designed compounds inhibit the arachidonic acid pathway in human platelets. The most active thioureas (compounds 3d, 3i, 3m and 3p displayed IC50 values ranging from 29 to 84 µM with direct influence over in vitro PGE2 and TXA2 formation. In silico evaluation of these compounds suggests that direct blockage of the tyrosyl-radical at the COX-1 active site is achieved by strong hydrophobic contacts as well as electrostatic interactions. A low toxicity profile of this series was observed through hemolytic, genotoxic and mutagenic assays. The most active thioureas were able to reduce both PGE2 and TXB2 production in human platelets, suggesting a direct inhibition of COX-1. These results reinforce their promising profile as lead antiplatelet agents for further in vivo experimental investigations.

  5. Tests of biological activity of metabolites from Penicillium expansum (Link Thom various isolates

    Directory of Open Access Journals (Sweden)

    Halina Borecka

    2013-12-01

    Full Text Available Aqrobacterium tumefaciens and cucumber, mustard and linseeds were compared as test organisms for evaluation of the biological activity of patulin. It was found that the reaction of cucumber seeds and linseed to the patulin concentrations was more pronounced than that of mustard and Aqrobacterium tumefaciens. The activity of metabolites produced by Penicillium expansum was investigated with the use of cucumber seeds. As measure of activity served the percentage of radicule growth inhibition was compared with the growth in control seeds. The biological activity of the metabolites was specific for the isolates, those from apples being more active. Thirty two isolates from pears and 34 from apples were examined.

  6. Bioactive components and functional properties of biologically activated cereal grains: A bibliographic review.

    Science.gov (United States)

    Singh, Arashdeep; Sharma, Savita

    2017-09-22

    Whole grains provide energy, nutrients, fibers, and bioactive compounds that may synergistically contribute to their protective effects. A wide range of these compounds is affected by germination. While some compounds, such as β-glucans are degraded, others, like antioxidants and total phenolics are increased by means of biological activation of grains. The water and oil absorption capacity as well as emulsion and foaming capacity of biologically activated grains are also improved. Application of biological activation of grains is of emerging interest, which may significantly enhance the nutritional, functional, and bioactive content of grains, as well as improve palatability of grain foods in a natural way. Therefore, biological activation of cereals can be a way to produce food grains enriched with health-promoting compounds and enhanced functional attributes.

  7. The chemical structures, plant origins, ethnobotany and biological activities of homoisoflavanones.

    Science.gov (United States)

    du Toit, Karen; Drewes, Siegfried E; Bodenstein, Johannes

    2010-03-01

    This work reviews the four basic structural types of homoisoflavanones. The relationships between the various structures of homoisoflavanones and their plant origins, ethnobotany and biological activities are put into perspective.

  8. Biological activities of Suaeda heterophylla and Bergenia stracheyi

    Directory of Open Access Journals (Sweden)

    Iftikhar Ali

    2014-09-01

    Full Text Available Objective: To evaluate the antioxidant, phytotoxic, antimicrobial, insecticidal, cytotoxic, antiglycative, and xanthine oxidase activities of different extracts of Suaeda heterophylla (S. heterophylla and Bergenia stracheyi (B. stracheyi. Methods: The extracts of S. heterophylla and B. stracheyi were evaluated for antioxidant, phytotoxic, antimicrobial, insecticidal, cytotoxic, antiglycative, and xanthine oxidase activities using standard experimental methods. Results: The overall antioxidant potential of ethyl acetate extract of S. heterophylla was the strongest, followed by chloroform extract, methanolic extract and n-hexane extract. It is interesting to note that ethyl acetate fraction showed 94.98% inhibition at concentration of 60 µg/mL while standard ascorbic acid showed 98.49% inhibition at same concentration. The crude methanol extracts of S. heterophylla and B. stracheyi showed significant phytotoxic activity at the highest dose. Moreover, methanol extract of B. stracheyi possessed strong activity in xanthine oxidase enzyme inhibition. Conclusions: Antioxidant, phytotoxic, and xanthine oxidase activities of different fractions of S. heterophylla and B. stracheyi clearly demonstrate that these fractions possess great potential for the food, cosmetic and pharmaceutical industries.

  9. INFLUENCE OF BIOLOGICALLY ACTIVE SUBSTANCES ON TOMATO YIELD AND QUALITY

    Directory of Open Access Journals (Sweden)

    G. I. Yarovoy

    2017-01-01

    Full Text Available The study of influence of growth regulators and biopreparations affecting on decrease of disease development, increase of yield capacity and final product quality was carried out in tomato. It was shown that all preparations were effective in decreasing the process of diseases development and increasing the yield capacity and product quality. The studies were carried out in the experimental fields at the Institute of Vegetables and Melons NAAS, in Ukraine in 2011-2012. The field studies were performed according to ‘Methodology of Experimental Work in Vegetable and Melon Growing’ on area sown with cultivars ‘Karas’ and ‘Kremenchugskiy’. The fungicides ‘Mars U 77%’, ‘Vimpel with Fitotsid’, ‘Vermistim’ wth ‘Azotofit’ and ‘Bioglobin’ with ‘Azotofit’ were used on cultivars of tomato, as control were the plants without treatment. It was determined that all preparations decreased the development of diseases. On average, the development of early dry spot had decreased by 12.2–16.1% and anthracnose by 10.0–12.6% in the cultivars ‘Kremenchugskiy’ and ‘Karas’. Thus, biopreparations used on the varieties ‘Kremenchugskiy’ and ‘Karas’ were effective in decrease of disease development, such as early dry spot, anthracnose, in a range of 39.1–52.7 %. Generally, during observation period the efficacy index of the preparations ‘Vermistim’ with ‘Azotofit’, ‘Bioglobin’ with ‘Azotofit’ was higher than others preparations on the varieties ‘Kremenchug and ‘Karas’ against early dry spot (48.3–50.9%, 50.3–52.7% and anthracnose (46.1–47.0%, 47.6–48.5%. The results showed that the vast majority of biological preparations, phytohormones used against diseases in tomato crops of varieties ‘Kremenchugskiy’ and ‘Karas’, were effective in a range of 39.1-52.7% and also maintained the tomato yield within 2.8-5.1 t/ha or 8.1- 13.9%. The biological preparations, phytohormones improved

  10. Methods for chemical synthesis of biologically active compounds using supramolecular protective groups and novel compounds obtainable Thereby

    NARCIS (Netherlands)

    Herrmann, Andreas; Bastian, Andreas Alexander; Marcozzi, Alessio

    2014-01-01

    The invention relates to drug development and synthetic chemistry, in particular to the manufacture of biologically active compounds based on naturally occurring molecules. It also relates to novel biologically active compounds, for example aminoglycoside antibiotics, in a substantially pure

  11. Research and Teaching: Instructor Use of Group Active Learning in an Introductory Biology Sequence

    Science.gov (United States)

    Auerbach, Anna Jo; Schussler, Elisabeth E.

    2016-01-01

    Active learning (or learner-centered) pedagogies have been shown to enhance student learning in introductory biology courses. Student collaboration has also been shown to enhance student learning and may be a critical part of effective active learning practices. This study focused on documenting the use of individual active learning and group…

  12. Using Active Learning in a Studio Classroom to Teach Molecular Biology

    Science.gov (United States)

    Nogaj, Luiza A.

    2013-01-01

    This article describes the conversion of a lecture-based molecular biology course into an active learning environment in a studio classroom. Specific assignments and activities are provided as examples. The goal of these activities is to involve students in collaborative learning, teach them how to participate in the learning process, and give…

  13. Biological activity of Terminalia arjuna on Human Pathogenic Microorganisms

    Directory of Open Access Journals (Sweden)

    Tariq Javed

    2016-01-01

    Full Text Available World’s population relies chiefly on traditional medicinal plants, using their extracts or active constituents. Terminalia arjuna of family Combretaceae reported to be effective as aphrodisiac, expectorant, tonic, styptic, antidysenteric, sweet, acrid, purgative, laxative, astringent, diuretic, astringent, cirrhosis, cardioprotective and cancer treatment.   In present study, antibacterial, antifungal, brine shrimp lethality and phytotoxic effect of Terminalia arjuna was performed. Our results showed that methanolic extract of Terminalia arjuna leaves has moderate antifungal effect against Microsporm canis and fruit extract possess good antibacterial activity against Staphylococus aureus  and  Preudomonas aeroginosa. Moreover, Dichloromethane extract of Terminalia arjuna bark and fruit posses moderate phytotoxic activity

  14. Phytochemical components and biological activities of Silene arenarioides Desf.

    Science.gov (United States)

    Golea, Lynda; Benkhaled, Mohammed; Lavaud, Catherine; Long, Christophe; Haba, Hamada

    2017-12-01

    In this study, six known compounds 1-6 were isolated from the aerial parts of Silene arenarioides Desf. using different chromatographic methods. The structures of these compounds were identified as maltol glycoside (1), soyacerebroside I (2), chrysin (3), apigenin (4), quercetin (5) and stigmasterol glucoside (6). The compounds (1) and (2) are reported for the first time from this genus. The isolated compounds were determined using NMR techniques ( 1 H NMR, 13 C NMR, COSY, HSQC and HMBC) and mass spectroscopy (ESI-MS). The antibacterial and antioxidant activities of extracts and of compound (1) have been evaluated. The antioxidant activity was performed by DPPH radical scavenging method, which showed that methanol extract possesses a good antioxidant activity with value of IC 50  = 8.064 ± 0.005 μg/mL.

  15. Synthesis and biological activities of diflunisal hydrazide-hydrazones.

    Science.gov (United States)

    Küçükgüzel, S Güniz; Mazi, Adil; Sahin, Fikrettin; Oztürk, Suzan; Stables, James

    2003-01-01

    Several diflunisal hydrazide-hydrazone derivatives namely 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylic acid [(5-nitro-2-furyl/substitutedphenyl)methylene] hydrazide (3a-o) have been synthesised. Methyl 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylate (1) and 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylic acid hydrazide (2) were also synthesised and used as intermediate compounds. All synthesised compounds were screened for their antimycobacterial activity against Mycobacterium tuberculosis H37 Rv, antimicrobial activities against various bacteria, fungi and yeast species. Compound 3a have shown activity against Staphylococcus epidermis HE-5 and Staphylococcus aureus HE-9 at 18.75 and 37.5 microg mL(-1), respectively. Compound 3o have exhibited activity against Acinetobacter calcoaceticus IO-16 at a concentration of 37.5 microg mL(-1), whereas Cefepime, the drug used as standard, have been found less active against the microorganisms mentioned above. The synthesised compounds were found to provide 12-34% inhibition of mycobacterial growth of M. tuberculosis H37 Rv in the primary screen at 6.25 microg mL(-1). Anticonvulsant activity of the compounds were also determined by maximal electroshock (MES) and subcutaneous metrazole (scMET) tests in mice and rats following the procedures of antiepileptic drug development (ADD) program of the National Institutes of Health (NIH). Compound 3k showed 25% protection against MES induced seizures in p.o. rat screening at a dose level of 30 mg kg(-1) whereas 3n and 3o showed neurotoxicity after 4 and 0.5 h at a dose level of 100 and 300 mg kg(-1), respectively.

  16. Capturing Biological Activity in Natural Product Fragments by Chemical Synthesis.

    Science.gov (United States)

    Crane, Erika A; Gademann, Karl

    2016-03-14

    Natural products have had an immense influence on science and have directly led to the introduction of many drugs. Organic chemistry, and its unique ability to tailor natural products through synthesis, provides an extraordinary approach to unlock the full potential of natural products. In this Review, an approach based on natural product derived fragments is presented that can successfully address some of the current challenges in drug discovery. These fragments often display significantly reduced molecular weights, reduced structural complexity, a reduced number of synthetic steps, while retaining or even improving key biological parameters such as potency or selectivity. Examples from various stages of the drug development process up to the clinic are presented. In addition, this process can be leveraged by recent developments such as genome mining, antibody-drug conjugates, and computational approaches. All these concepts have the potential to identify the next generation of drug candidates inspired by natural products. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  17. Bio-templated CdSe quantum dots green synthesis in the functional protein, lysozyme, and biological activity investigation

    International Nuclear Information System (INIS)

    Wang, Qisui; Li, Song; Liu, Peng; Min, Xinmin

    2012-01-01

    Bifunctional fluorescence (CdSe Quantum Dots) – protein (Lysozyme) nanocomposites were synthesized at room temperature by a protein-directed, solution-phase, green-synthetic method. Fluorescence (FL) and absorption spectra showed that CdSe QDs were prepared successfully with Lyz. The average particle size and crystalline structure of QDs were investigated by high-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD), respectively. With attenuated total reflection-fourier transform infrared (ATR-FTIR) spectra and thermogravimetric (TG) analysis, it was confirmed that there is interaction between QDs and amide I, amide II groups in Lyz. FL polarization was measured and FL imaging was done to monitor whether QDs could be responsible for possible changes in the conformation and activity of Lyz. Interestingly, the results showed Lyz still retain the biological activity after formation of QDs, but the secondary structure of the Lyz was changed. And the advantage of this synthesis method is producing excellent fluorescent QDs with specifically biological function. -- Highlights: ► Lysozyme-directed green synthesis of CdSe quantum dots. ► Lysozyme still retain the biological activity after formation of CdSe. ► The method is the production of fluorescent QDs with highly specific and functions.

  18. Development of a Free-Electron Laser Center and Research in Medicine, Biology and Materials Science,

    Science.gov (United States)

    1992-05-14

    where enhanced nonproton ion movements can be observed during the photocycle ( Marinetti and Mauzerall, 1986). We do not have the possibility to measure...Biological Membranes. C.L. 17 Bolis, E.J.M. Helmreich and H. Passow, editors. Alan R. Liss Inc., NY 39-50. Marinetti , T., and D. Mauzerall 1986. Large

  19. Predicting Drug Use at Electronic Music Dance Events: Self-Reports and Biological Measurement

    Science.gov (United States)

    Johnson, Mark B.; Voas, Robert A.; Miller, Brenda A.; Holder, Harold D.

    2009-01-01

    Most information on the prevalence of drug use comes from self-report surveys. The sensitivity of such information is cause for concern about the accuracy of self-report measures. In this study, self-reported drug use in the last 48 hr is compared to results from biological assays of saliva samples from 371 young adults entering clubs. The…

  20. Phenolic compounds and biological activity of Capsicum annuum L ...

    African Journals Online (AJOL)

    The objective of this study was to evaluate antifungal and antioxidant activities of vegetable extracts (Capsicum annuum L. cv. Dora, cv. Strizanka, cv. Morava), grown in Serbia. Different experimental models have included the determination content of total phenolics, total flavonoids, antioxidant capacity and minimum ...

  1. Ultrasonic-Assisted Extraction and Evaluation of Biological Activities ...

    African Journals Online (AJOL)

    Flemingia philippinensis and to investigate the antioxidant and anti-tumor activities of the extracts of the materials from various locations in China. Methods: The total flavonoids in F. philippinensis were obtained by ultrasonic-assisted conventional solvent extraction method, and the extraction conditions were optimized by ...

  2. Some biological activities of Pycnanthus angolensis (Welw.) Warb ...

    African Journals Online (AJOL)

    These findings indicate a correlation in the activities of the leaves and as such serve as panacea for infectious diseases and therefore scientific justification to some of the folkloric uses of the plant. Keywords: Antimicrobial; Larvicidal; Brine shrimp lethality; Pycnanthus angolensis. Journal of Pharmacy and Bioresources Vol.

  3. Research on prokaryocyte expression and biological activity of the ...

    African Journals Online (AJOL)

    Furthermore, the ATPase activity of the protein was also assayed using ultraviolet spectrophotometry based on PiColorLock Gold reagent. An effective expression method was established for BLM protein in E. coli. The obvious bioactivities of the protein were observed in binding to ssDNA or dsDNA, unwinding the dsDNA in ...

  4. Volatile compounds and biological activities of aerial parts of ...

    African Journals Online (AJOL)

    ... and β-carotene-linoleic acid assays while antimicrobial activity was screened using the disk diffusion method against a panel of six bacterial (Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Klebseilla pneumonia, Agrobacterium tumefaciens) and four fungal strains (Candida albicans, ...

  5. Phytoconstituents and biological activities of essential Oil from Rhus ...

    African Journals Online (AJOL)

    The present study determined the major phytoconstituents, the antioxidant and the antimicrobial activities of Rhus lancea essential oil against eight bacterial and four fungal species. The yield was 0.18% and the major phytoconstituents found were µ-pinene, benzene and d-3-carene. The oil exhibited remarkable ...

  6. Biological activities of four essential oils against Anopheles gambiae ...

    African Journals Online (AJOL)

    The control of malaria is still a challenge partly due to mosquito's resistance to current available insecticides. The aim of this work was to evaluate the ovicidal, larvicidal and repellent activities of Lantana camara, Hyptis suaveolens, Hyptis spicigera and Ocimum canum essential oils against Anopheles gambiae s.l. ...

  7. Determination of cephalosporin acylase activity by biological and ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-01

    Dec 1, 2009 ... microorganisms with cephalosporin acylase activity was developed. The core part of cephalosporin was replaced by 6-amino penicillinic acid (6-APA) to generate new substrates glutaryl-6-APA and adipoyl-6-APA for screen- ing. Serratia marcescens that is sensitive to 6-APA and resistant to penicillin G, ...

  8. chemical constituents and biological activity of three tanzanian wild

    African Journals Online (AJOL)

    Mgina

    antimicrobial activities infer that the three mushroom species are potential functional food substrates. INTRODUCTION. Termitomyces is a tropical edible ... extract (32 g) on cooling in the fridge at -. 4°C formed white crystals of mannitol and ... against the bacteria Vibrio cholerae and. Escherichia coli, and the fungus Candida.

  9. Biological activities of Rumex dentatus L: Evaluation of methanol ...

    African Journals Online (AJOL)

    PRECIOUS

    2009-12-15

    Dec 15, 2009 ... solani, respectively by methanol extracts of roots and leaves. Phytochemical analysis of hexane extracts showed presence of flavor-noids as major constituents, which might be responsible for antifungal activity. (Atindehou et al., 2002). Previously, fungitoxic surface flavonoids (Isoflavonoids) have been ...

  10. Programming biological operating systems: genome design, assembly and activation.

    Science.gov (United States)

    Gibson, Daniel G

    2014-05-01

    The DNA technologies developed over the past 20 years for reading and writing the genetic code converged when the first synthetic cell was created 4 years ago. An outcome of this work has been an extraordinary set of tools for synthesizing, assembling, engineering and transplanting whole bacterial genomes. Technical progress, options and applications for bacterial genome design, assembly and activation are discussed.

  11. Chemical composition and biological activities of essential oils from ...

    African Journals Online (AJOL)

    2-ol (19.4%), transp- mentha-2,8-dien-1-ol (16.4%) and limonene (13.7%). The major components identified in the oil of Cymbopogon schoenanthus were piperitone (68.4%), and ä-2-carene (11.5%). The antimicrobial activity of the essential ...

  12. Biological activities of extracts from cultivated Granadilla Passiflora alata.

    Science.gov (United States)

    Vasic, Sava M; Stefanovic, Olgica D; Licina, Braho Z; Radojevic, Ivana D; Comic, Ljiljana R

    2012-01-01

    Research conducted in this study showed the influence of ethanol, acetone and ethyl acetate extracts of the outgrowth of cultivated Passiflora alata on microorganisms, as well as the antioxidant activity and the concentrations of total phenols, flavonoids and tannins. In vitro antimicrobial activities of extracts were studied on 27 species of microorganisms, of which 17 species of bacteria and 10 species of fungi. The strongest antimicrobial activity was detected on G+ bacteria while the activities on other species were moderate. Ethyl acetate extract showed the strongest effect. The concentrations of total phenols were examined by using Folin-Ciocalteu reagent and the obtained values ranged from 14.04 to 34.22 mg GA/g. By using aluminium chloride method, the concentrations of flavonoids were obtained and the values ranged from 33.19 to 62.30 mg RU/g. In determining the amount of tannins we used the method with buthanol-HCl reagent and the obtained value was 5.1 % of dry matter. The efficiency of antioxidation, which we identified through the reduction of DPPH, was in the range from 808.69 to 1107.79 µg/ml for a particular IC50, and AAI values were between 0.07 and 0.10. The best parameters were shown by ethanol extract. All data were statistically analyzed. Overall, extracts showed potential for further investigation and use.

  13. Evaluation of some biological activities of Abelia triflora R Br ...

    African Journals Online (AJOL)

    Purpose: To investigate the antioxidant, anti-inflammatory, antidiabetic, cardiovascular and cytotoxic activities of the leaf extract and major compounds isolated from Abelia triflora R. Br. (Caprifoliaceae) Methods: The chloroform soluble fraction of A. triflora leaves was subjected to several column chromatographic ...

  14. Phytochemical profile and some biological activities of three ...

    African Journals Online (AJOL)

    Purpose: To characterise the phytochemical profile of whole plants of Centaurea balsamita, C. depressa and C. lycopifolia with LC-ESI-MS/MS, and as well as their antioxidant, anticholinesterase and antimicrobial activities. Methods: Organic and aqueous extracts of the three Centaurea species were evaluated for DPPH ...

  15. Biologically Active Compounds of Plant Foods: Prospective Impact ...

    African Journals Online (AJOL)

    Harmful compounds interfere with normal growth, reproduction, or health and reduce protein and carbohydrate utilization. The health benefits of selected substances from Ethiopian food crops need to be studied. Active compounds need to be isolated, identified and produced to explore their potential benefits with emphasis ...

  16. Biological activity and phytoconstituents of essential oil from fresh ...

    African Journals Online (AJOL)

    Essential oil was extracted from fresh leaves of Eriosema englerianum by hydrodistillation and its major phytoconstituents determined by GC-MS. The major phytoconstituents were O-cymene, terpinolene and ascaridole with a yield of 0.28%. Antimicrobial activity of the oil was tested against nine human bacterial pathogens ...

  17. Activated Sludge. Instructor's Guide. Biological Treatment Process Control.

    Science.gov (United States)

    Boe, Owen K.

    This instructor's guide contains the materials needed to teach a seven-lesson unit on activated sludge. These materials include an overview of the unit, lesson plans, lecture outlines (keyed to slides designed for use with the lessons), student worksheets for each of the seven lessons (with answers), and two copies of a final quiz (with and…

  18. Biological activities and phytochemical constituents of the gray ...

    African Journals Online (AJOL)

    In vitro assessment of the antibacteriophage, antibacterial and anticandidal activities as well as cytotoxicity were evaluated for both aqueous and ethanol extracts prepared from roots, cotyledons, leaves and stems of Avicennia marina. Aqueous extracts of both shoots and roots of the seedlings demonstrated ...

  19. Synthesis, characterization, biological activity and DNA cleavage studies of tridentate Schiff bases and their Co(II complexes

    Directory of Open Access Journals (Sweden)

    P. Kavitha

    2016-01-01

    Full Text Available In the present study a series of Co(II complexes of formyl chromone Schiff bases have been synthesized characterized by analytical, molar conductance, IR, electronic, magnetic susceptibility, thermal, fluorescence and powder XRD measurements and screened for various biological activities (antimicrobial, antioxidant, nematicidal, DNA cleavage and cytotoxicity. In all the Co(II complexes 1:2 metal to ligand molar ratio was obtained from analytical data. The molar conductance data confirm that all complexes are non-electrolytic in nature. Based on the electronic and magnetic data, an octahedral geometry is ascribed for all the Co(II complexes. Thermal behaviour of the synthesized complexes illustrates the general decomposition patterns of the complexes. The X-ray analysis data show that all the Co(II complexes have triclinic crystal system with different unit cell parameters. Metal complexes have greater antimicrobial activity than ligands. Antioxidant and nematicidal activities indicate that the ligands exhibit greater activity when compared to their respective Co(II complexes. All ligands and Co(II complexes of HL1 and HL2 showed considerable anticancer activity against Raw, MCF-7 and COLO 205 cell lines. All ligands and their Co(II complexes showed more pronounced DNA cleavage activity in the presence of H2O2.

  20. Biologically active dibenzofurans from Pilidiostigma glabrum, an endemic Australian Myrtaceae.

    Science.gov (United States)

    Shou, Qingyao; Banbury, Linda K; Renshaw, Dane E; Lambley, Eleanore H; Mon, Htwe; Macfarlane, Graham A; Griesser, Hans J; Heinrich, Michael M; Wohlmuth, Hans

    2012-09-28

    In an effort to identify new anti-inflammatory and antibacterial agents with potential application in wound healing, five new dibenzofurans, 1,3,7,9-tetrahydroxy-2,8-dimethyl-4,6-di(2-methylbutanoyl)dibenzofuran (1), 1,3,7,9-tetrahydroxy-2,8-dimethyl-4-(2-methylbutanoyl)-6-(2-methylpropionyl)dibenzofuran (2), 1,3,7,9-tetrahydroxy-2,8-dimethyl-4,6-di(2-methylpropionyl)dibenzofuran (3), 1,3,7,9-tetrahydroxy-4,6-dimethyl-2-(2-methylbutanoyl)-8-(2-methylpropionyl)dibenzofuran (4), and 1,3,7,9-tetrahydroxy-4,6-dimethyl-2,8-di(2-methylpropionyl)dibenzofuran (5), were isolated from the leaves of Pilidiostigma glabrum together with one previously described dibenzofuran. Structure elucidation was achieved by way of spectroscopic measurements including 2D-NMR spectroscopy. Compounds with 2,8-acyl substitutions had potent antibacterial activity against several Gram-positive strains (MIC in the low micromolar range), while compounds with 4,6-acyl substitutions were less active. All compounds except 3 inhibited the synthesis of nitric oxide in RAW264 macrophages with IC(50) values in the low micromolar range. Compounds with 2,8-acyl substitutions also inhibited the synthesis of PGE(2) in 3T3 cells, whereas 4,6-acyl-substituted compounds were inactive. None of the compounds inhibited the synthesis of TNF-α in RAW264 cells. The compounds showed variable but modest antioxidant activity in the oxygen radical absorbance capacity assay. These findings highlight that much of the Australian flora remains unexplored and may yet yield many new compounds of interest. Initial clues are provided on structure/activity relationships for this class of bioactives, which may enable the design and synthesis of compounds with higher activity and/or selectivity.

  1. Biological function of activation-induced cytidine deaminase (AID

    Directory of Open Access Journals (Sweden)

    Ritu Kumar

    2014-10-01

    Full Text Available Activation-induced Cytidine Deaminase (AID is an essential regulator of B cell diversification, but its full range of action has until recently been an enigma. Based on homology, it was originally proposed to be an RNA-editing enzyme, but so far, no RNA substrates are known. Rather, it functions by deaminating cytidine, and in this manner, coupled with base-excision repair or mismatch repair machinery, it is a natural mutator. This allows it to play a central role in adaptive immunity, whereby it initiates the processes of class switch recombination and somatic hypermutation to help generate a diverse and high-affinity repertoire of immunoglobulin isotypes. More recently, it has been appreciated that methylated cytidine, already known as a key epigenetic mark on DNA controlling gene expression, can also be a target for AID modification. Coupled with repair machinery, this can facilitate the active removal of methylated DNA. This activity can impact the process of cellular reprogramming, including transition of a somatic cell to pluripotency, which requires major reshuffling of epigenetic memory. Thus, seemingly disparate roles for AID in controlling immune diversity and epigenetic memory have a common mechanistic basis. However, the very activity that is so useful for B cell diversity and cellular reprogramming is dangerous for the integrity of the genome. Thus, AID expression and activity is tightly regulated, and deregulation is associated with diseases including cancer. Here, we review the range of AID functions with a focus on its mechanisms of action and regulation. Major questions remain to be answered concerning how and when AID is targeted to specific loci and how this impacts development and disease.

  2. Challenges regarding the start-up of an anaerobic biological sulphate reactor using H2 and CO2 as electron donor and carbon sources

    CSIR Research Space (South Africa)

    Roux, SP

    2009-05-01

    Full Text Available Include neutralization and chemical precipitation as well as membrane dependent processes. Biological sulphate reduction is another, environmentally benign option but relies heavily on the availability of an economically viable electron donor...

  3. [Biomechanic and biological activity assessment of concavity-convex amniotic membrane].

    Science.gov (United States)

    Shao, Yi; Yu, Yao; Tan, Gang; Peng, Juan; Zhou, Qiong; Pei, Chonggang; Dong, Wenjia; Gao, Guiping

    2012-12-01

    This paper conducted research on biomechanical characteristics and biological activity of concavity-convex amniotic membrane (CCAM) and discussed its superiority as ocular surface repair material. Folding and compression with vacuum of fresh amniotic membrane were used to prepare CCAM. After cutting the striga of CCAM, sixteen CCAM tissue section were chosen at random to test their tensile strength using electronic universal testing machine. The bilayer amniotic membrane (BAM), the double-deck amniotic membrane (DAM) and the monolayer amniotic membrane (MAM) were as controls. The test parameters included yield strength, tensile strength, elongation at break, elastic modulus and so on. The cytokines of fresh amniotic membrane (FAM), MAM and CCAM were analyzed by radioimmunoassay method. The CCAM was obviously thicker than MAM and DAM. After 15 min in PBS, the CCAM tissue can recover the normal shape. The tensile strength and the elongation at break of CCAM were higher than those of the MAM and the DAM (P biomechanical properties than the MAM and the DAM, showing the superiority as ocular surface repair material.

  4. Synthesis, Spectroscopic Characterization and Biological Activities of Transition Metal Complexes Derived from a Tridentate Schiff Base

    Directory of Open Access Journals (Sweden)

    J. Senthil Kumaran

    2013-01-01

    Full Text Available A new series of Cu (II, Ni (II, Co (II and Zn (II complexes have been synthesized from the Schiff base derived from 4-hydroxy-3-methoxybenzylidine-4-aminoantipyrine and 2-aminophenol. The structural features have been determined from their elemental analysis, magnetic susceptibility, molar conductance, Mass, IR, UV-Vis, 1H-NMR, 13C-NMR and ESR spectral studies. The redox behavior of the copper complex has been studied by cyclic voltammetry. The data confirm that the complexes have composition of ML2 type. The electronic absorption spectral data of the complexes propose an octahedral geometry around the central metal ion. All the metal complexes with DNA structure were guided by the presence of inter-molecular C–H⋯O and C–H⋯N hydrogen bonds. The biological activity of the synthesized compounds were tested against the bacterial species such as Bacillus subtilis, Staphylococcus aureus, Proteus vulgaris and fungal species such as Candida albicans by the well-diffusion method.

  5. Biologic activity of cyclic and caged phosphates: a review.

    Science.gov (United States)

    Lorke, Dietrich E; Stegmeier-Petroianu, Anka; Petroianu, Georg A

    2017-01-01

    The recognition in the early 1960s by Morifusa Eto that tri-o-cresyl phosphate (TOCP) is hydroxylated by the cytochrome P450 system to an intermediate that spontaneously cyclizes to a neurotoxic phosphate (saligenin phosphate ester) ignited the interest in this group of compounds. Only the ortho isomer can cyclize and clinically cause Organo Phosphate Induced Delayed Neurotoxicity (OPIDN); the meta and para isomers of tri-cresyl phosphate are not neuropathic because they are unable to form stable cyclic saligenin phosphate esters. This review identifies the diverse biological effects associated with various cyclic and caged phosphates and phosphonates and their possible use. Cyclic compounds that inhibit acetylcholine esterase (AChE), such as salithion, can be employed as pesticides. Others are neurotoxic, most probably because of inhibition of neuropathy target esterase (NTE). Cyclic phosphates that inhibit lipases, the cyclipostins, possibly represent promising therapeutic avenues for the treatment of type 2 diabetes mellitus and/or microbial infections; those compounds inhibiting β-lactamase may prevent bacterial resistance against β-lactam antibiotics. Naturally occurring cyclic phosphates, such as cyclic AMP, cyclic phosphatidic acid and the ryanodine receptor modulator cyclic adenosine diphosphate ribose, play an important physiological role in signal transduction. Moreover, some cyclic phosphates are GABA-antagonists, while others are an essential component of Molybdenum-containing enzymes. Some cyclic phosphates (cyclophosphamide, ifosfamide) are clinically used in tumor therapy, while the coupling of therapeutic agents with other cyclic phosphates (HepDirect® Technology) allows drugs to be targeted to specific organs. Possible clinical applications of these compounds are considered. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  6. Characterization and biological activity of bacterial glycoconjugates in cold adaptation.

    OpenAIRE

    Casillo, Angela

    2016-01-01

    The cryosphere, covering about one-fifth of the surface of the Earth, comprises several components: snow, river and lake ice, sea ice, ice sheets, ice shelves, glaciers and ice caps, and frozen ground which exist, both on land and beneath the oceans (Vaughan DG, et al. 2013). All these habitats, combining the low temperature and the low liquid water activity, are challenging for all the forms of life (Casanueva et al., 2010). These extreme environments are inhabited by microorganisms of all t...

  7. New Conjugated Benzothiazole-N-oxides: Synthesis and Biological Activity

    Directory of Open Access Journals (Sweden)

    Pavlína Foltínová

    2009-12-01

    Full Text Available Eleven new 2-styrylbenzothiazole-N-oxides have been prepared by aldol – type condensation reactions between 2-methylbenzothiazole–N-oxide and para-substituted benzaldehydes. Compounds with cyclic amino substituents showed typical push-pull molecule properties. Four compounds were tested against various bacterial strains as well as the protozoan Euglena gracilis as model microorganisms. Unlike previously prepared analogous benzothiazolium salts, only weak activity was recorded.

  8. Essential Oils of Oregano: Biological Activity beyond Their Antimicrobial Properties

    Directory of Open Access Journals (Sweden)

    Nayely Leyva-López

    2017-06-01

    Full Text Available Essential oils of oregano are widely recognized for their antimicrobial activity, as well as their antiviral and antifungal properties. Nevertheless, recent investigations have demonstrated that these compounds are also potent antioxidant, anti-inflammatory, antidiabetic and cancer suppressor agents. These properties of oregano essential oils are of potential interest to the food, cosmetic and pharmaceutical industries. The aim of this manuscript is to review the latest evidence regarding essential oils of oregano and their beneficial effects on health.

  9. Biological activities and DNA interactions of Amanita ovoidea.

    Science.gov (United States)

    Doğan, Hasan Hüseyin; Arslan, Emine

    2015-01-01

    Amanita ovoidea (Bull.) Link (Amanitaceae) is a well-known species due to its pleasant aroma and flavor since ancient times in the worldwide. This species is also known in Turkey and people consume it extensively. To evaluate medicinal importance of A. ovoidea for human health, to explain the effect of mushroom extracts on bacterial DNA, and to find preventive role on bacterial disease. Chloroform, acetone, and methanol extracts of A. ovoidea were tested for the antimicrobial activities against four Gram-positive bacteria, five Gram-negative bacteria, and yeast using a micro-dilution method. In addition, DNA binding, DNA cleavage activity, and restriction enzyme digestion of the methanol extract of A. ovoidea were examined at different concentrations (40.000-78.125 µg/mL). The highest minimum inhibitory concentration (MIC) value observed against the test micro-organisms was with the chloroform extract (MIC 19.5 µg/mL concentration) against Candida albicans. Other highest antimicrobial effects observed against the test micro-organisms were with the methanol extracts against Bacillus subtilis, Staphylococcus aureus, Listeria monocytogenes, Streptococcus pyogenes, Candida albicans, Klebsiella pneumoniae, Proteus vulgaris, and Salmonella enteritidis (MICs, 78 µg/mL concentrations). All concentrations reduced the mobility of plasmid DNA. BamHI and HindIII targeted specially to supercoils and cut them. Amanita ovoidea extract prevented cutting with HindIII by binding especially to the AA region in open circular DNA. Present results demonstrated that A. ovoidea has excellent antimicrobial and antifungal activities by its DNA interaction activity on pBR322.

  10. BIOLOGICAL ACTIVITIES AND PHENOLIC-FLAVONOID CONTENTS OF BILBERRY EXTRACTS

    OpenAIRE

    I. HACIBEKİROĞLU, U. KOLAK*, I. HACIBEKİROĞLU, U. KOLAK*

    2014-01-01

    SUMMARYIn this study, the petroleum ether, dichloromethane, methanol and hot water extracts were prepared from bilberry blooms. Total phenolic and flavonoid contents of these extracts were determined as pyrocatechol and quercetin equivalents, respectively. The antioxidant activity of the extracts was investigated by using four methods including DPPH free radical and ABTS cation radical scavenging, β-carotene bleaching and cupric reducing antioxidant capacity (CUPRAC) assays. The methanol ext...

  11. Phytochemical and Biological Activities of Four Wild Medicinal Plants

    OpenAIRE

    Shad, Anwar Ali; Ahmad, Shabir; Ullah, Riaz; AbdEl-Salam, Naser M.; Fouad, H.; Rehman, Najeeb Ur; Hussain, Hidayat; Saeed, Wajid

    2014-01-01

    The fruits of four wild plants, namely, Capparis decidua, Ficus carica, Syzygium cumini, and Ziziphus jujuba, are separately used as traditional dietary and remedial agents in remote areas of Khyber Pakhtunkhwa, Pakistan. The results of our study on these four plants revealed that the examined fruits were a valuable source of nutraceuticals and exhibited good level of antimicrobial activity. The fruits of these four investigated plants are promising source of polyphenols, flavonoids, alkaloid...

  12. Biological activities and phenolic contents of Argania spinosa L ...

    African Journals Online (AJOL)

    Cytotoxic activity was evaluated by methyl-thiazolyldiphenyl-tetrazolium bromide (MTT) assay. Results: The results revealed abundant polyphenols and flavonoids (221.39 ± 5.70 μg GAEq/1 g and 66.86 ± 3.36 μg CAEq/1 g, respectively) in the leaf extract. UPLC-DAD-ESI-QTOF-MS profiling showed the presence of ...

  13. Vouacapane diterpenoids isolated from Pterodon and their biological activities

    Directory of Open Access Journals (Sweden)

    Leandra A.R. Oliveira

    Full Text Available Abstract The Pterodon genus comprises two native species in Brazil, known as “sucupira-branca” or “faveira”. Their fruits have long been used in Brazilian natural medicine, mainly for the treatment of infections and inflammations. The pharmacological properties of these fruits have often been linked with vouacapane diterpenoids. This review evaluated the scientific research in the period from 1973 to February 2017, aiming to answer how difficult it still is to develop a scientifically supported product based on Pterodon vouacapanes. Therefore, this paper reviews purification, identification, and quantification methods applied to vouacapane diterpenoids from Pterodon, as well as the performance of these phytochemicals in pharmacological tests described in the literature. Data analysis results support conventional notions that suggest vouacapane diterpenoids from Pterodon have anti-inflammatory properties. However, the studies carried out so far still represent partial assessment of the vouacapane activities and further studies need to be completed. Pterodon diterpenoids have also been associated with larvicidal, leishmanicidal, cardiovascular, and antitumor activities, which reinforces the genus' potential as a source of phytomedicines. Some remaining gaps about the reviewed activities were mentioned, while trends and perspectives for future research were proposed.

  14. Biological Activity of Vegetal Extracts Containing Phenols on Plant Metabolism

    Directory of Open Access Journals (Sweden)

    Andrea Ertani

    2016-02-01

    Full Text Available The influence of vegetal extracts derived from red grape, blueberry fruits and hawthorn leaves on Zea mays L. plant growth and the activity of phenylalanine ammonia-lyase (PAL, a key enzyme of the phenylpropanoid pathway, was investigated in laboratory experiments. The extracts were characterized using FT-IR and Raman spectroscopies in order to obtain a pattern of the main functional groups. In addition, phenols content was determined by HPLC, whereas the content of indoleacetic acid and isopentenyladenosine hormones was determined by ELISA test and the auxin and gibberellin-like activities by plant-bioassays. The treated maize revealed increased root and leaf biomass, chlorophyll and sugars content with respect to untreated plants. Hawthorn, red grape skin and blueberry at 1.0 mL/L induced high p-coumaric content values, whilst hawthorn also showed high amounts of gallic and p-hydroxybenzoic acids. PAL activity induced by hawthorn at 1.0 mL/L had the highest values (11.1-fold UNT and was strongly and linearly related with the sum of leaf phenols. Our results suggest that these vegetal extracts contain more than one group of plant-promoting substances.

  15. Chemical or biological activity in open chaotic flows

    International Nuclear Information System (INIS)

    Karolyi, G.; Pentek, A.; Toroczkai, Z.; Toroczkai, Z.; Tel, T.; Grebogi, C.

    1999-01-01

    We investigate the evolution of particle ensembles in open chaotic hydrodynamical flows. Active processes of the type A+B→2B and A+B→2C are considered in the limit of weak diffusion. As an illustrative advection dynamics we consider a model of the von Karman vortex street, a time-periodic two-dimensional flow of a viscous fluid around a cylinder. We show that a fractal unstable manifold acts as a catalyst for the process, and the products cover fattened-up copies of this manifold. This may account for the observed filamental intensification of activity in environmental flows. The reaction equations valid in the wake are derived either in the form of dissipative maps or differential equations depending on the regime under consideration. They contain terms that are not present in the traditional reaction equations of the same active process: the decay of the products is slower while the productivity is much faster than in homogeneous flows. Both effects appear as a consequence of underlying fractal structures. In the long time limit, the system locks itself in a dynamic equilibrium state synchronized to the flow for both types of reactions. For particles of finite size an emptying transition might also occur leading to no products left in the wake. copyright 1999 The American Physical Society

  16. Objectives of research activities in Biology Branch, Chalk River Nuclear Laboratories, 1976

    International Nuclear Information System (INIS)

    1977-03-01

    The primary responsibility assigned to the Biology Branch within the framework of CRNL has been an active engagement in basic research related to the assessment of radiation hazards, particularly those to be expected after exposure to relatively low doses of radiation delivered at low dose-rates. The present group is characterized by a broad interest in the entire chain of events by which the initial radiation-induced changes in the living cell are translated into biological effects, with a special focus of attention on the mechanisms by which the initial damage can be largely repaired and by which the risks to man are modified under different circumstances. The basic concepts in radiation biology and risk estimates are reviewed in the light of recent literature on these topics. The current and proposed research activities of the Biology Branch are described. General and specific recommendations for future activities are given. (author)

  17. Electron Transfer in Chemistry and Biology – The Primary Events in ...

    Indian Academy of Sciences (India)

    The ions are embedded in an environment (ligand. Box 2. A few examples of Electron Transfer Proteins. Protein. Metal ions. Cytochromes. Fe a, a3, b, c1, c, etc. cyt. aa3. Ferridoxins. Fe. Rubredoxins. Fe. Xanthine oxidase. Fe/Mo. Aldehyde oxidase. Fe/Mo. Succinate dehydrogenase. Stellacyanin, plastocyanin and azurin.

  18. Perceptions of Prospective Biology Teachers on Scientific Argumentation in Microbiology Inquiry Lab Activities

    Science.gov (United States)

    Roviati, E.; Widodo, A.; Purwianingsih, W.; Riandi, R.

    2017-09-01

    Inquiry laboratory activity and scientific argumentation in science education should be promoted and explicitly experienced by prospective biology teacher students in classes, including in microbiology courses. The goal of this study is to get information about perceptions of prospective biology teachers on scientific argumentation in microbiology inquiry lab activities. This study reported the result of a survey research to prospective biology teachers about how their perception about microbiology lab classes and their perception about inquiry and argumentation in microbiology lab activities should be. The participants of this study were 100 students of biology education department from an institute in Cirebon, West Java taking microbiology lecture during the fifth semester. The data were collected using questionnaire to explore the perceptions and knowledge of prospective biology teachers about microbiology, inquiry lab activities and argumentation. The result showed that students thought that the difficulties of microbiology as a subject were the lack of references and the way lecturer teaching. The students’ perception was that argumentation and inquiry should be implemented in microbiology courses and lab activities. Based on the data from questionnaire, It showed that prospective biology teacher students had very little knowledge about scientific argumentation and its implementation in science education. When the participants made arguments based on the problems given, they showed low quality of arguments.

  19. Using Active Learning to Teach Concepts and Methods in Quantitative Biology.

    Science.gov (United States)

    Waldrop, Lindsay D; Adolph, Stephen C; Diniz Behn, Cecilia G; Braley, Emily; Drew, Joshua A; Full, Robert J; Gross, Louis J; Jungck, John A; Kohler, Brynja; Prairie, Jennifer C; Shtylla, Blerta; Miller, Laura A

    2015-11-01

    This article provides a summary of the ideas discussed at the 2015 Annual Meeting of the Society for Integrative and Comparative Biology society-wide symposium on Leading Students and Faculty to Quantitative Biology through Active Learning. It also includes a brief review of the recent advancements in incorporating active learning approaches into quantitative biology classrooms. We begin with an overview of recent literature that shows that active learning can improve students' outcomes in Science, Technology, Engineering and Math Education disciplines. We then discuss how this approach can be particularly useful when teaching topics in quantitative biology. Next, we describe some of the recent initiatives to develop hands-on activities in quantitative biology at both the graduate and the undergraduate levels. Throughout the article we provide resources for educators who wish to integrate active learning and technology into their classrooms. © The Author 2015. Published by Oxford University Press on behalf of the Society for Integrative and Comparative Biology. All rights reserved. For permissions please email: journals.permissions@oup.com.

  20. Fabrication, Characterization, and Biological Activity of Avermectin Nano-delivery Systems with Different Particle Sizes

    Science.gov (United States)

    Wang, Anqi; Wang, Yan; Sun, Changjiao; Wang, Chunxin; Cui, Bo; Zhao, Xiang; Zeng, Zhanghua; Yao, Junwei; Yang, Dongsheng; Liu, Guoqiang; Cui, Haixin

    2018-01-01

    Nano-delivery systems for the active ingredients of pesticides can improve the utilization rates of pesticides and prolong their control effects. This is due to the nanocarrier envelope and controlled release function. However, particles containing active ingredients in controlled release pesticide formulations are generally large and have wide size distributions. There have been limited studies about the effect of particle size on the controlled release properties and biological activities of pesticide delivery systems. In the current study, avermectin (Av) nano-delivery systems were constructed with different particle sizes and their performances were evaluated. The Av release rate in the nano-delivery system could be effectively controlled by changing the particle size. The biological activity increased with decreasing particle size. These results suggest that Av nano-delivery systems can significantly improve the controllable release, photostability, and biological activity, which will improve efficiency and reduce pesticide residues.