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Sample records for macromolecules jai press

  1. Frontón Euskal Jai Berri Huarte-Pamplona España

    Directory of Open Access Journals (Sweden)

    Guibert Tabar, Javier

    1979-06-01

    Full Text Available The Euskal Jai Berri sports pavilion in Huarte substitutes for the old Pamplona «pelota» court, and is located a few kilometers outside the city in ample grounds providing sufficient room for the building and car park area. The vast complex design plan includes from the regulationsized court, through the grandstand and boxes for the audience, to a number of facilities and services for payers, audience and staff, such as locker rooms, payers lounge, press room and book-makers hall, administration office, manager's living quarters, players lodging, a bar on each floor, cafeteria and restaurant with kitchen and a number of rest rooms. The building was designed based on three main points, namely: natural lighting, modular structure and clear visibility from all angles. Emphasis was placed on integration of the building into the surrounding landscape in an effort to avoid the contrast between the inevitable prismatic shape of the court and the rounded contour of the hails surrounding it.

    El pabellón deportivo de Euskal Jal Berrl, en Huarte, destinado a sustituir al antiguo frontón de Pamplona, se encuentra emplazado a pocos kilómetros de esta ciudad, en unos amplios terrenos que proporcionan suficiente espacio para la edificación y para una extensa zona de aparcamientos. Su complejo y vasto programa abarca desde la concha reglamentaria y las gradas y palcos para espectadores, fiesta una variada serie de instalaciones y servicios para jugadores, público y personal, tales como: vestuarios, salas para pelotaris, corredores y prensa; oficinas administrativas; vivienda para el gerente; residencias para jugadores; bares en cada planta; cafetería y restaurante con cocina; así como los correspondientes aseos. En su diseño, fundamentado en tres puntos principales —iluminación natural, modulación estructural y perfecta visibilidad—, se tuvo especial cuidado en armonizar la construcción con el paisaje circundante, con el fin de

  2. Vinac Marijana Jaića Molitvenik ili dio kućne baštine

    OpenAIRE

    Blažević, Krešimir

    2006-01-01

    U ovom članku želio sam pokazati kako se mnoge stvari mogu i moraju redefinirati i nanovo razjasniti u recentno vrijeme. Marijan Jaić, vjerojatno najtiražniji hrvatski pisac, dugo godina je bio u zapećku proučavanja hrvatske književnosti. Iako je zanimanje za Jaića u posljednjih desetak ili petnaest godina naraslo (napisano je puno knjiga o njemu i njegovu radu), još uvijek nije njegov rad do kraja obrađen i prostora za istraživanje o Jaićevu radu još uvijek ima. Jaić možda i nije književnik ...

  3. 番茄突变体jai1-1高效筛选—再生体系的建立%Establishment of High Efficient Screening and Regeneration System of Tomato mutant jai1-1 in Vitro

    Institute of Scientific and Technical Information of China (English)

    范锡麟; 王少岭; 肖应辉; 王志龙

    2013-01-01

    Tomato(Lycopersicon esculentum Mill.)wild type JAIl and mutant jail-1 screened by different concentrations of MeJA were used as the materials in the study.The cotyledon and hypocotyl of wild type JAI1 and mutant jai1-1 were cultured in vitro to research the effects of genetype and different hormone combinations on tomato callus induction,adventition bud differentiation and rooting,and then identified the results with PCR reaction.The results show that 1/2 MS + MeJA 50 μM/L was the proper media to screen the mutant jai1-1,and that MS + ZT 1.0 mg/L + IAA 0.1 mg/L and MS + ZT 2.0 mg/L + IAA 0.2 mg/L were the best media for adventition bud differentiation for JAI1 and jai1-1 respectively.MS + 6-BA 2.0 mg/L + IAA 0.2 mg/L and 1/2MS + NAA 0.1 mg/L were the best media for callus induction and root induction for both JAI1 and jai1-1,respectively.%利用番茄野生型JAI1和通过不同浓度茉莉酸甲酯(MeJA)处理筛选得到的突变体jai1-1的子叶和下胚轴为材料进行离体组织培养,以探究不同激素组合对愈伤组织的诱导、不定芽分化及生根的影响,最后利用PCR反应验证筛选得到的材料的准确性.结果表明,1/2 MS+ 50 μM/L MeJA是突变体jai1-1筛选的有效培养基.野生型JAI1和突变体jai1-1在MS+ 6-BA 2.0 mg/L+ IAA 0.2 mg/L诱导愈伤组织的效果最好;JAI1在MS+ ZT 1.0mg/L+ IAA 0.1mg/L诱导分化不定芽的效率最高,而jai1-1则以MS+ ZT 2.0 mg/L+ IAA 0.2 mg/L为佳;1/2 MS+ NAA 0.1 mg/L是两者诱导生根的理想培养基.

  4. Biological Macromolecule Crystallization Database

    Science.gov (United States)

    SRD 21 Biological Macromolecule Crystallization Database (Web, free access)   The Biological Macromolecule Crystallization Database and NASA Archive for Protein Crystal Growth Data (BMCD) contains the conditions reported for the crystallization of proteins and nucleic acids used in X-ray structure determinations and archives the results of microgravity macromolecule crystallization studies.

  5. Ion specificities of artificial macromolecules.

    Science.gov (United States)

    Liu, Lvdan; Kou, Ran; Liu, Guangming

    2016-12-21

    Artificial macromolecules are well-defined synthetic polymers, with a relatively simple structure as compared to naturally occurring macromolecules. This review focuses on the ion specificities of artifical macromolecules. Ion specificities are influenced by solvent-mediated indirect ion-macromolecule interactions and also by direct ion-macromolecule interactions. In aqueous solutions, the role of water-mediated indirect ion-macromolecule interactions will be discussed. The addition of organic solvents to aqueous solutions significantly changes the ion specificities due to the formation of water-organic solvent complexes. For direct ion-macromolecule interactions, we will discuss specific ion-pairing interactions for charged macromolecules and specific ion-neutral site interactions for uncharged macromolecules. When the medium conditions change from dilute solutions to crowded environments, the ion specificities can be modified by either the volume exclusion effect, the variation of dielectric constant, or the interactions between ions, macromolecules, and crowding agents.

  6. Ikgadējais apmaksātais atvaļinājums

    OpenAIRE

    Kauliņš, Edgars

    2010-01-01

    Ikgadējais apmaksātais atvaļinājums ir viena no cilvēka svarīgākajām dzīves daļām. Tas ir atpūtas laiks no darba ikdienas, ko darbinieks ir tiesīgs izmantot tieši tā, kā to darbinieks vēlas. Liela loma ikgadējā apmaksātā atvaļinājuma piemērošanā ir darba devējiem. Kā arī būtiska loma ir gan starptautiskajām organizācijām, kas veido tiesību normas, kuras valstis ievieš savā tiesību sistēmā, gan nacionālajām tiesām un starptautiskajām tiesām, kas veido praksi, tādējādi rodas izpratne par to, ka...

  7. Analysis of macromolecules, ligands and macromolecule-ligand complexes

    Science.gov (United States)

    Von Dreele, Robert B [Los Alamos, NM

    2008-12-23

    A method for determining atomic level structures of macromolecule-ligand complexes through high-resolution powder diffraction analysis and a method for providing suitable microcrystalline powder for diffraction analysis are provided. In one embodiment, powder diffraction data is collected from samples of polycrystalline macromolecule and macromolecule-ligand complex and the refined structure of the macromolecule is used as an approximate model for a combined Rietveld and stereochemical restraint refinement of the macromolecule-ligand complex. A difference Fourier map is calculated and the ligand position and points of interaction between the atoms of the macromolecule and the atoms of the ligand can be deduced and visualized. A suitable polycrystalline sample of macromolecule-ligand complex can be produced by physically agitating a mixture of lyophilized macromolecule, ligand and a solvent.

  8. A Course on Macromolecules.

    Science.gov (United States)

    Horta, Arturo

    1985-01-01

    Describes a senior-level course that: (1) focuses on the structure and reactions of macromolecules; (2) treats industrial polymers in a unified way; and (3) uses analysis of conformation and conformational statistics as a unifying approach. Also discusses course topics, including polysaccharides, proteins, nucleic acids, and others. (JN)

  9. Construction with macromolecules

    Directory of Open Access Journals (Sweden)

    Stefan Hecht

    2005-03-01

    Full Text Available The generation of nanosized features via the bottom-up organization of individual atoms and molecules represents one of the most rapidly emerging fields in modern science and technology. In order to gain general and modular access to nanostructures, a construction kit consisting of molecular building blocks with defined nanoscale dimensions, shape, and functionality is required. While nature has developed a hierarchical strategy to construct sophisticated and complex nanostructures, chemistry is just starting to explore artificial macromolecules as a means to synthesize specific nano-objects. In this review, recent advances in achieving control over conformation within macromolecules and the interconnection of conformationally defined subunits by either covalent bonds or self-assembly are discussed in analogy to natural structure evolution.

  10. Diffusion of macromolecules through sclera.

    Science.gov (United States)

    Miao, Heng; Wu, Bi-Dong; Tao, Yong; Li, Xiao-Xin

    2013-02-01

    To quantify the in vitro permeability coefficient over different topographical locations of porcine sclera to macromolecules with different molecular weight. Fresh equatorial and posterior superotemporal porcine sclera was mounted in a two-chamber diffusion apparatus, and its permeability to fluorescein isothiocyanate (FITC)-conjugated dextrans ranging in molecular weight from 40 kDa to 150 kDa was determined by fluorescence spectrophotometry. The sclera was processed as frozen sections and viewed with a fluorescence microscope. The thickness of the area and the thickness that macromolecules enriched in the surface of sclera were measured. The permeability coefficient (Pc) of porcine sclera to macromolecules was significantly higher (40 kDa, p = 0.028; 70 kDa, p = 0.033; 150 kDa, p = 0.007) in equatorial region than posterior, which could be attributed to the significant difference of thickness (p macromolecules enriched in the scleral surface was thicker for those with larger MW (p macromolecules. Larger macromolecules are more likely to accumulate in scleral surface. The difference between topographical locations may have pharmacokinetic implications when considering transscleral diffusion of macromolecules. © 2012 The Authors. Acta Ophthalmologica © 2012 Acta Ophthalmologica Scandinavica Foundation.

  11. [Pēdējais karš. Atmiņa un traumas kominikācija] / Eva-Clarita Pettai

    Index Scriptorium Estoniae

    Pettai, Eva-Clarita, 1971-

    2012-01-01

    Arvustus: Pēdējais karš. Atmiņa un traumas kominikācija. Hrsg. von Mārtiņš Kaprāns, Vita Zelče. Latvijas Universitāte - Sociālo zinātņu fakultāte - Sociālo un politisko pētījumu institūts (Riga 2010)

  12. [Pēdējais karš. Atmiņa un traumas kominikācija] / Eva-Clarita Pettai

    Index Scriptorium Estoniae

    Pettai, Eva-Clarita, 1971-

    2012-01-01

    Arvustus: Pēdējais karš. Atmiņa un traumas kominikācija. Hrsg. von Mārtiņš Kaprāns, Vita Zelče. Latvijas Universitāte - Sociālo zinātņu fakultāte - Sociālo un politisko pētījumu institūts (Riga 2010)

  13. Macromolecules in Undergraduate Physical Chemistry.

    Science.gov (United States)

    Mattice, Wayne L.

    1981-01-01

    Suggests the topic of macromolecules and synthetic polymers be included in undergraduate courses. Two macromolecular systems (polyethylene in a state unperturbated by long-range interactions and a polypeptide undergoing a helix-coil transition) are described which are suitable for inclusion in the statistical mechanics section of physical…

  14. Ion binding to biological macromolecules.

    Science.gov (United States)

    Petukh, Marharyta; Alexov, Emil

    2014-11-01

    Biological macromolecules carry out their functions in water and in the presence of ions. The ions can bind to the macromolecules either specifically or non-specifically, or can simply to be a part of the water phase providing physiological gradient across various membranes. This review outlines the differences between specific and non-specific ion binding in terms of the function and stability of the corresponding macromolecules. Furthermore, the experimental techniques to identify ion positions and computational methods to predict ion binding are reviewed and their advantages compared. It is indicated that specifically bound ions are relatively easier to be revealed while non-specifically associated ions are difficult to predict. In addition, the binding and the residential time of non-specifically bound ions are very much sensitive to the environmental factors in the cells, specifically to the local pH and ion concentration. Since these characteristics differ among the cellular compartments, the non-specific ion binding must be investigated with respect to the sub-cellular localization of the corresponding macromolecule.

  15. DNA compaction by nonbinding macromolecules

    NARCIS (Netherlands)

    Vries, de R.J.

    2012-01-01

    Compaction of DNA by nonbinding macromolecules such as uncharged flexible polymer chains and negatively charged globular proteins is thought to have various applications in biophysics, for example in the formation of a nucleoid structure in bacteria. A simple experimental model that has been very

  16. DNA compaction by nonbinding macromolecules

    NARCIS (Netherlands)

    Vries, de R.J.

    2012-01-01

    Compaction of DNA by nonbinding macromolecules such as uncharged flexible polymer chains and negatively charged globular proteins is thought to have various applications in biophysics, for example in the formation of a nucleoid structure in bacteria. A simple experimental model that has been very we

  17. INFLUENCE OF MACROMOLECULES ON CHEMICAL TRANSPORT

    Science.gov (United States)

    Macromolecules in the pore fluid influence the mobility of hydrophobic compounds through soils. his study evaluated the significance of macromolecules in facilitating chemical transport under laboratory conditions. Partition coefficients between 14C-labeled hexachlorobenzene and ...

  18. El "Canto del Jai"

    Directory of Open Access Journals (Sweden)

    Luis Guillermo Vasco Uribe

    2010-04-01

    Full Text Available El texto que presento a continuación, constituye el primer capítulo de un trabajo, mucho más extenso, de análisis del fenómeno del jaibanismo, de importancia primordial entre los indígenas embera. Dicho trabajo está siendo elaborado con miras a mi promoción como profesor en la Universidad. Se trata de la descripción de una ceremonia de curación y ha sido tomado casi textualmente de mi diario de campo de diciembre de 1976. Sin embargo, he agregado algunos detalles y circunstancias tomados de diarios correspondientes a otras curaciones que he presenciado, con la finalidad de dar una visión lo más completa posible de su desarrollo. Tales agregados no introducen, según mi criterio, ninguna variación esencial en el carácter de la curación tomada como base para la elaboración del capítulo, ni en la forma cómo son realizadas por el jaibaná a quién aquí me refiero.

  19. The radiation chemistry of macromolecules

    CERN Document Server

    1973-01-01

    The Radiation Chemistry of Macromolecules, Volume II is a collection of papers that discusses radiation chemistry of specific systems. Part 1 deals with radiation chemistry of substituted vinyl polymers, particularly polypropylene (PP) as its structure is intermediate between polyethylene and polyisobutylene. This part also discusses polypropylene oxide (PPOx) for it can be prepared in the atactic, isotactic, and optically active forms. One paper focuses on the fundamental chemical processes and the changes in physical properties that give rise to many different applications of polystyrene. An

  20. Configurational diffusion of coal macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Guin, J.A.; Curtis, C.W.; Tarrer, A.R.; Kim, S.; Hwang, D.; Chen, C.C.; Chiou, Z.

    1991-01-01

    The objective of our research was to obtain fundamental information regarding the functional dependence of the diffusion coefficient of coal molecules on the ratio of molecule to pore diameter. That is, the objective of our study was to examine the effect of molecule size and configuration on hindered diffusion of coal macromolecules through as porous medium. To best accomplish this task, we circumvented the complexities of an actual porous catalyst by using a well defined porous matrix with uniform capillaric pores, i.e., a track-etched membrane. In this way, useful information was obtained regarding the relationship of molecular size and configuration on the diffusion rate of coal derived macromolecules through a pore structure with known geometry. Similar studies were performed using a pellet formed of porous alumina, to provide a link between the idealized membranes and the actual complex pore structure of real catalyst extrudates. The fundamental information from our study will be useful toward the tailoring of catalysts to minimize diffusional influences and thereby increase coal conversion and selectivity for desirable products. (VC)

  1. Relaxation Dynamics of Semiflexible Fractal Macromolecules

    Directory of Open Access Journals (Sweden)

    Jonas Mielke

    2016-07-01

    Full Text Available We study the dynamics of semiflexible hyperbranched macromolecules having only dendritic units and no linear spacers, while the structure of these macromolecules is modeled through T-fractals. We construct a full set of eigenmodes of the dynamical matrix, which couples the set of Langevin equations. Based on the ensuing relaxation spectra, we analyze the mechanical relaxation moduli. The fractal character of the macromolecules reveals itself in the storage and loss moduli in the intermediate region of frequencies through scaling, whereas at higher frequencies, we observe the locally-dendritic structure that is more pronounced for higher stiffness.

  2. Bond Tension in Tethered Macromolecules.

    Science.gov (United States)

    Sheiko, Sergei S; Panyukov, Sergey; Rubinstein, Michael

    2011-06-14

    The paper presents scaling analysis of mechanical tension generated in densely branched macromolecules tethered to a solid substrate with a short linker. Steric repulsion between branches results in z-fold amplification of tension in the linker, where z is the number of chain-like arms. At large z ~ 100-1000, the generated tension may exceed the strength of covalent bonds and sever the linker. Two types of molecular architectures were considered: polymer stars and polymer "bottlebrushes" tethered to a solid substrate. Depending on the grafting density, one distinguishes the so-called mushroom, loose grafting, and dense grafting regimes. In isolated (mushroom) and loosely tethered bottlebrushes, the linker tension is by a factor of [Formula: see text] smaller than the tension in a tethered star with the same number of arms z. In densely tethered stars, the effect of interchain distance (d) and number of arms (z) on the magnitude of linker tension is given by f ≅ f0z(3/2)(b/d) for stars in a solvent environment and f ≅ f0z(2) (b/d)(2) for dry stars, where b is the Kuhn length and f0 ≅ kBT/b is intrinsic bond tension. These relations are also valid for tethered bottlebrushes with long side chains. However, unlike molecular stars, bottlebrushes demonstrate variation of tension along the backbone f ≅ f0s z(1/2) / d as a function of distance s from the free end of the backbone. In dense brushes [Formula: see text] with z ≅ 1000, the backbone tension increases from f ≅ f0 = 1 pN at the free end of the backbone (s ≅ b) to its maximum f ≅ zf0 ≅ 1 nN at the linker to the substrate (s ≅ zb).

  3. Macromolecule-Assisted de novo Protein Folding

    Science.gov (United States)

    Choi, Seong Il; Son, Ahyun; Lim, Keo-Heun; Jeong, Hotcherl; Seong, Baik L.

    2012-01-01

    In the processes of protein synthesis and folding, newly synthesized polypeptides are tightly connected to the macromolecules, such as ribosomes, lipid bilayers, or cotranslationally folded domains in multidomain proteins, representing a hallmark of de novo protein folding environments in vivo. Such linkage effects on the aggregation of endogenous polypeptides have been largely neglected, although all these macromolecules have been known to effectively and robustly solubilize their linked heterologous proteins in fusion or display technology. Thus, their roles in the aggregation of linked endogenous polypeptides need to be elucidated and incorporated into the mechanisms of de novo protein folding in vivo. In the classic hydrophobic interaction-based stabilizing mechanism underlying the molecular chaperone-assisted protein folding, it has been assumed that the macromolecules connected through a simple linkage without hydrophobic interactions and conformational changes would make no effect on the aggregation of their linked polypeptide chains. However, an increasing line of evidence indicates that the intrinsic properties of soluble macromolecules, especially their surface charges and excluded volume, could be important and universal factors for stabilizing their linked polypeptides against aggregation. Taken together, these macromolecules could act as folding helpers by keeping their linked nascent chains in a folding-competent state. The folding assistance provided by these macromolecules in the linkage context would give new insights into de novo protein folding inside the cell. PMID:22949867

  4. Alignment of synaptic vesicle macromolecules with the macromolecules in active zone material that direct vesicle docking.

    Science.gov (United States)

    Harlow, Mark L; Szule, Joseph A; Xu, Jing; Jung, Jae Hoon; Marshall, Robert M; McMahan, Uel J

    2013-01-01

    Synaptic vesicles dock at active zones on the presynaptic plasma membrane of a neuron's axon terminals as a precondition for fusing with the membrane and releasing their neurotransmitter to mediate synaptic impulse transmission. Typically, docked vesicles are next to aggregates of plasma membrane-bound macromolecules called active zone material (AZM). Electron tomography on tissue sections from fixed and stained axon terminals of active and resting frog neuromuscular junctions has led to the conclusion that undocked vesicles are directed to and held at the docking sites by the successive formation of stable connections between vesicle membrane proteins and proteins in different classes of AZM macromolecules. Using the same nanometer scale 3D imaging technology on appropriately stained frog neuromuscular junctions, we found that ∼10% of a vesicle's luminal volume is occupied by a radial assembly of elongate macromolecules attached by narrow projections, nubs, to the vesicle membrane at ∼25 sites. The assembly's chiral, bilateral shape is nearly the same vesicle to vesicle, and nubs, at their sites of connection to the vesicle membrane, are linked to macromolecules that span the membrane. For docked vesicles, the orientation of the assembly's shape relative to the AZM and the presynaptic membrane is the same vesicle to vesicle, whereas for undocked vesicles it is not. The connection sites of most nubs on the membrane of docked vesicles are paired with the connection sites of the different classes of AZM macromolecules that regulate docking, and the membrane spanning macromolecules linked to these nubs are also attached to the AZM macromolecules. We conclude that the luminal assembly of macromolecules anchors in a particular arrangement vesicle membrane macromolecules, which contain the proteins that connect the vesicles to AZM macromolecules during docking. Undocked vesicles must move in a way that aligns this arrangement with the AZM macromolecules for docking

  5. Molecular Imprinting of Macromolecules for Sensor Applications.

    Science.gov (United States)

    Saylan, Yeşeren; Yilmaz, Fatma; Özgür, Erdoğan; Derazshamshir, Ali; Yavuz, Handan; Denizli, Adil

    2017-04-19

    Molecular recognition has an important role in numerous living systems. One of the most important molecular recognition methods is molecular imprinting, which allows host compounds to recognize and detect several molecules rapidly, sensitively and selectively. Compared to natural systems, molecular imprinting methods have some important features such as low cost, robustness, high recognition ability and long term durability which allows molecularly imprinted polymers to be used in various biotechnological applications, such as chromatography, drug delivery, nanotechnology, and sensor technology. Sensors are important tools because of their ability to figure out a potentially large number of analytical difficulties in various areas with different macromolecular targets. Proteins, enzymes, nucleic acids, antibodies, viruses and cells are defined as macromolecules that have wide range of functions are very important. Thus, macromolecules detection has gained great attention in concerning the improvement in most of the studies. The applications of macromolecule imprinted sensors will have a spacious exploration according to the low cost, high specificity and stability. In this review, macromolecules for molecularly imprinted sensor applications are structured according to the definition of molecular imprinting methods, developments in macromolecular imprinting methods, macromolecular imprinted sensors, and conclusions and future perspectives. This chapter follows the latter strategies and focuses on the applications of macromolecular imprinted sensors. This allows discussion on how sensor strategy is brought to solve the macromolecules imprinting.

  6. Recent Patents in Pulmonary Delivery of Macromolecules.

    Science.gov (United States)

    Ray, Animikh; Mandal, Abhirup; Mitra, Ashim K

    2015-01-01

    Pulmonary delivery is a non-invasive form of delivery that holds tremendous therapeutic promise for topical and systemic administration of several macromolecules. Oral administration of macromolecules has several limitations such as low bioavailability, degradation of drug before reaching circulation and insufficient absorption across intestinal membrane. Administration of macromolecules such as proteins, peptides and nucleic acids via inhalation offers great potential due to the avoidance of first pass metabolism, higher surface area and rapid clinical response. However, delivery of reproducible, uniform and safe doses of inhaled particles remains a major challenge for clinical translation. Recent advances in the fields of biotechnology and particle engineering led to progress in novel pulmonary drug delivery systems. Moreover, significant developments in carriers and delivery devices prevent denaturation of macromolecules and control their release within the lungs. This article reviews the advances in pulmonary drug delivery systems by focusing on the recent patents in delivery of macromolecules. Furthermore, recent patents in gene delivery to the lungs have also been discussed. List of patents included in this review is comprehensive in terms of pulmonary delivery of therapeutics. It includes inventions related to proteins and peptides, DNA therapeutics, siRNA and other genetic materials with therapeutic applications. The diseases targeted by these therapeutic molecules are varied including but not limited to different forms of cancer, respiratory diseases etc.

  7. Macromolecular crowding: Macromolecules friend or foe.

    Science.gov (United States)

    Mittal, Shruti; Chowhan, Rimpy Kaur; Singh, Laishram Rajendrakumar

    2015-09-01

    Cellular interior is known to be densely crowded due to the presence of soluble and insoluble macromolecules, which altogether occupy ~40% of the total cellular volume. This results in altered biological properties of macromolecules. Macromolecular crowding is observed to have both positive and negative effects on protein folding, structure, stability and function. Significant data has been accumulated so far on both the aspects. However, most of the review articles so far have focused on the positive aspect of macromolecular crowding and not much attention has been paid on the deleterious aspect of crowding on macromolecules. In order to have a complete knowledge of the effect of macromolecular crowding on proteins and enzymes, it is important to look into both the aspects of crowding to determine its precise role under physiological conditions. To fill the gap in the understanding of the effect of macromolecular crowding on proteins and enzymes, this review article focuses on the deleterious influence of crowding on macromolecules. Macromolecular crowding is not always good but also has several deleterious effects on various macromolecular properties. Taken together, the properties of biological macromolecules in vivo appears to be finely regulated by the nature and level of the intracellular crowdedness in order to perform their biological functions appropriately. The information provided here gives an understanding of the role played by the nature and level of cellular crowdedness in intensifying and/or alleviating the burden of various proteopathies. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. PlaMoM: a comprehensive database compiles plant mobile macromolecules.

    Science.gov (United States)

    Guan, Daogang; Yan, Bin; Thieme, Christoph; Hua, Jingmin; Zhu, Hailong; Boheler, Kenneth R; Zhao, Zhongying; Kragler, Friedrich; Xia, Yiji; Zhang, Shoudong

    2017-01-04

    In plants, various phloem-mobile macromolecules including noncoding RNAs, mRNAs and proteins are suggested to act as important long-distance signals in regulating crucial physiological and morphological transition processes such as flowering, plant growth and stress responses. Given recent advances in high-throughput sequencing technologies, numerous mobile macromolecules have been identified in diverse plant species from different plant families. However, most of the identified mobile macromolecules are not annotated in current versions of species-specific databases and are only available as non-searchable datasheets. To facilitate study of the mobile signaling macromolecules, we compiled the PlaMoM (Plant Mobile Macromolecules) database, a resource that provides convenient and interactive search tools allowing users to retrieve, to analyze and also to predict mobile RNAs/proteins. Each entry in the PlaMoM contains detailed information such as nucleotide/amino acid sequences, ortholog partners, related experiments, gene functions and literature. For the model plant Arabidopsis thaliana, protein-protein interactions of mobile transcripts are presented as interactive molecular networks. Furthermore, PlaMoM provides a built-in tool to identify potential RNA mobility signals such as tRNA-like structures. The current version of PlaMoM compiles a total of 17 991 mobile macromolecules from 14 plant species/ecotypes from published data and literature. PlaMoM is available at http://www.systembioinfo.org/plamom/. © The Author(s) 2016. Published by Oxford University Press on behalf of Nucleic Acids Research.

  9. General Differential Contact Identities for Macromolecules.

    Science.gov (United States)

    Landy, Jonathan; Pincus, P A; Jho, YongSeok

    2015-10-16

    We discuss general Maxwell identities relating a macromolecule's charge, the forces acting at its surface, and the osmotic pressure of the solution in which it sits. The identities are closely related to the contact value relations that hold for certain special geometries, but are more general. In particular, the Maxwell identities can be applied to any macromolecule geometry, and they hold both within and outside of mean-field theory. Examples illustrate that combining the identities with approximate treatments of screening can often return simple, accurate osmotic pressure estimates.

  10. The Place of Macromolecules in Freshman Chemistry

    Science.gov (United States)

    Wunderlich, Bernhard

    1973-01-01

    Discusses the inclusion of knowledge on macromolecules into a freshman chemistry course which emphasizes topics in organic chemistry, polymer science and biochemistry, atoms, chemical thermodynamics, and inorganic chemistry. Indicates that the program is the only way to keep chemistry education up to date. (CC)

  11. Macromolecule diffusion and confinement in prokaryotic cells

    NARCIS (Netherlands)

    Mika, Jacek T.; Poolman, Bert

    We review recent observations on the mobility of macromolecules and their spatial organization in live bacterial cells. We outline the major fluorescence microscopy-based methods to determine the mobility and thus the diffusion coefficients (D) of molecules, which is not trivial in small cells. The

  12. Macromolecule diffusion and confinement in prokaryotic cells

    NARCIS (Netherlands)

    Mika, Jacek T.; Poolman, Bert

    2011-01-01

    We review recent observations on the mobility of macromolecules and their spatial organization in live bacterial cells. We outline the major fluorescence microscopy-based methods to determine the mobility and thus the diffusion coefficients (D) of molecules, which is not trivial in small cells. The

  13. Macromolecule diffusion and confinement in prokaryotic cells

    NARCIS (Netherlands)

    Mika, Jacek T.; Poolman, Bert

    2011-01-01

    We review recent observations on the mobility of macromolecules and their spatial organization in live bacterial cells. We outline the major fluorescence microscopy-based methods to determine the mobility and thus the diffusion coefficients (D) of molecules, which is not trivial in small cells. The

  14. Professional WordPress

    CERN Document Server

    Stern, Hal; Williams, Brad

    2010-01-01

    An in-depth look at the internals of the WordPress system.As the most popular blogging and content management platform available today, WordPress is a powerful tool. This exciting book goes beyond the basics and delves into the heart of the WordPress system, offering overviews of the functional aspects of WordPress as well as plug-in and theme development. What is covered in this book?: WordPress as a Content Management System; Hosting Options; Installing WordPress Files; Database Configuration; Dashboard Widgets; Customizing the Dashboard; Creating and Managing Content; Categorizing Your Cont

  15. Macromolecules Inquiry: Transformation of a Standard Biochemistry Lab

    Science.gov (United States)

    Unsworth, Elizabeth

    2014-01-01

    Identification of macromolecules in food is a standard introductory high school biology lab. The intent of this article is to describe the conversion of this standard cookbook lab into an inquiry investigation. Instead of verifying the macromolecules found in food, students use their knowledge of the macromolecules in food to determine the…

  16. News/Press Releases

    Data.gov (United States)

    Office of Personnel Management — A press release, news release, media release, press statement is written communication directed at members of the news media for the purpose of announcing programs...

  17. The Global University Press

    Science.gov (United States)

    Dougherty, Peter J.

    2012-01-01

    The modern world's understanding of American university press has long been shaped by university-press books. American university-press books are good international advertisements for the universities whose logos grace their spines. The growth of transnational scholarship and the expansion of digital communications networks are converging in ways…

  18. Persistence Length of DNA Macromolecule with Kinks

    CERN Document Server

    Simonov, Kyrylo

    2014-01-01

    The study of configurational parameters of deformed DNA is a relevant problem in research of such important biological process as double helix compactization in cell. The deformations accompanied with local disruptions of the regular macromolecule structure cause significant bending of the double helix, or kinks. In this paper an approach for Kratky-Porod model to calculate persistence length of DNA macromolecule with kinks is developed. The presented approach considers kinks of arbitrary configuration, including two basic types of kinks, type 1 - sharp kink caused by unstacking a single base pair step, and type 2 - intrinsic-induced kink that involves several base pairs. Within developed approach analytical expressions for persistence length, coil size and gyration radius of kinky double helix were obtained.

  19. Sperm macromolecules associated with bull fertility.

    Science.gov (United States)

    Kaya, Abdullah; Memili, Erdoğan

    2016-06-01

    Bull fertility, ability of the sperm to fertilize and activate the egg that sustain embryo development, is vitally important for effective and efficient production of cattle. Fertility is a complex trait with low heritability. Despite recent advances in genomic selection and possibility of enormous paternal benefits to profitable cattle production, there exist no reliable tests for evaluating semen quality and predicting bull fertility. This review focuses on sperm macromolecules such as transcripts, proteins and the epigenome, i.e., the functional genome that are associated with bull fertility. Generating new information in these systems is important beyond agriculture because such progress advances the fundamental science of the mammalian male gamete while at the same time introduces biotechnology into livestock production. Sperm macromolecules and epigenome markers associated with bull fertility can be used alone or in combination with the current SNP microarrays to determine sperm quality and to indicate bull fertility.

  20. An Overview of Biological Macromolecule Crystallization

    Science.gov (United States)

    Krauss, Irene Russo; Merlino, Antonello; Vergara, Alessandro; Sica, Filomena

    2013-01-01

    The elucidation of the three dimensional structure of biological macromolecules has provided an important contribution to our current understanding of many basic mechanisms involved in life processes. This enormous impact largely results from the ability of X-ray crystallography to provide accurate structural details at atomic resolution that are a prerequisite for a deeper insight on the way in which bio-macromolecules interact with each other to build up supramolecular nano-machines capable of performing specialized biological functions. With the advent of high-energy synchrotron sources and the development of sophisticated software to solve X-ray and neutron crystal structures of large molecules, the crystallization step has become even more the bottleneck of a successful structure determination. This review introduces the general aspects of protein crystallization, summarizes conventional and innovative crystallization methods and focuses on the new strategies utilized to improve the success rate of experiments and increase crystal diffraction quality. PMID:23727935

  1. Behavior of macromolecules in adsorbed layers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A model for describing the behavior of macromolecules in adsorbed layers is developed by introducing a concept of distribution density of layer thickness U based on stochastic process and probabilistic statistics. The molecular behavior of layers adsorbed on clay particle surfaces is discussed; the random distribution and its statistics of the layer thickness are given by incorporating experimental results with an ionic polyelectrolyte with the molecular weight of 1.08×106 and chain charged density of 0.254.

  2. Identifiability, reducibility, and adaptability in allosteric macromolecules.

    Science.gov (United States)

    Bohner, Gergő; Venkataraman, Gaurav

    2017-05-01

    The ability of macromolecules to transduce stimulus information at one site into conformational changes at a distant site, termed "allostery," is vital for cellular signaling. Here, we propose a link between the sensitivity of allosteric macromolecules to their underlying biophysical parameters, the interrelationships between these parameters, and macromolecular adaptability. We demonstrate that the parameters of a canonical model of the mSlo large-conductance Ca(2+)-activated K(+) (BK) ion channel are non-identifiable with respect to the equilibrium open probability-voltage relationship, a common functional assay. We construct a reduced model with emergent parameters that are identifiable and expressed as combinations of the original mechanistic parameters. These emergent parameters indicate which coordinated changes in mechanistic parameters can leave assay output unchanged. We predict that these coordinated changes are used by allosteric macromolecules to adapt, and we demonstrate how this prediction can be tested experimentally. We show that these predicted parameter compensations are used in the first reported allosteric phenomena: the Bohr effect, by which hemoglobin adapts to varying pH. © 2017 Bohner and Venkataraman.

  3. Shape transformation of lipid vesicles induced by diffusing macromolecules.

    Science.gov (United States)

    Góźdź, W T

    2011-01-14

    The attachment of macromolecules to the surface of a lipid vesicle may cause its deformations such as budding or creation of cylindrical protrusions. Diffusion of the macromolecules in the membranes may cause its shape transformations. The process of shrinking the protrusions due to diffusion of the macromolecules is investigated. It is assumed that macromolecules modify locally the spontaneous curvature and bending rigidity of the lipid membrane. Both spontaneous curvature and bending rigidities depend on the concentration of membrane components. It has been shown that cylindrical protrusions are created when the macromolecules which induce large spontaneous curvature are accumulated at a piece of the vesicle surface. It has been observed that here the elastic constants influence very little the evolution of the vesicle shape caused by diffusing macromolecules and the most important is the value the spontaneous curvature imposed by the macromolecules.

  4. High School Press Freedom.

    Science.gov (United States)

    Maurer, Diana J.

    This report focuses on controversial articles written by the high school press, decisions made by the courts regarding students' press freedoms, and reactions to the articles and rulings. Particular attention is given to two rulings concerning censorship of articles about students' sexual atttiudes and activities, the issue of prior restraint of…

  5. Hydraulic hoist-press

    Energy Technology Data Exchange (ETDEWEB)

    Babayev, Z.B.; Abashev, Z.V.

    1982-01-01

    The efficiency expert of the Angrenskiy production-technological administration of the production association Sredazugol A. V. Bubnov has suggested a hydraulic hoist-press for repairing road equipment which is a device consisting of lifting mechanism, press and test stand for verifying the high pressure hoses and pumps.

  6. Flexibility and Stability of Metal Coordination Macromolecules.

    Science.gov (United States)

    Jiang, Heyan; Geng, Diya; Liu, Dapeng; Lanigan, Nicholas; Wang, Xiaosong

    2017-06-16

    The effect of chain structure on flexibility and stability of macromolecules containing weak P-Fe metal coordination bonds is studied. Migration insertion polymerization (MIP) of FpCX Fp (1) and PR2 CY PR2 (2) (Fp: CpFe(CO)2 ; CX and CY : alkyl spacers; P: phosphine; R: phenyl or isopropyl) generates P(1/2), in which the P-Fe and Fe-P bonds with opposite bonding direction are alternatively arranged in the backbone. On the other hand, P(FpCX P) synthesized from AB-type monomers (FpCX P) has P-Fe bonds arranged in the same direction. P(1/2) is more rigid and stable than P(FpCX P), which is attributed to the chain conformation resulting from the P-Fe bonding direction. In addition, the longer spacers render P(1/2) relatively flexible; the phenyl substituents, as compared with the isopropyl groups, improves the rigidity, thermal, and solution stability of P(1/2). It is therefore possible to incorporate weak metal coordination bonds into macromolecules with improved stability and adjustable flexibility for material processing. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Hybrid Opto-electric Manipulation of Macromolecules

    Science.gov (United States)

    Wereley, Steve

    2013-11-01

    Recently our research group has developed an innovative method for capturing, concentrating, manipulating and sorting populations of micro- and nanometer-scaled entities-particles, cells, macro-molecules, etc. These populations range from individual particles to thousands of particles (Lab-on-a-Chip, 2008; Microfluidics and Nanofluidics, 2008) while the sizes range from microns to nanometers. This novel technique combines features of optical trapping and dielectrophoresis in an innovative, dynamic way using a simple parallel plate electrode configuration. Transparent electrodes comprised of Indium Tin Oxide (ITO) on glass substrates are used to generate an electric field in the fluid while at the same time allowing light into and out of the fluid. Near-IR optical illumination causes subtle localized heating, creating an electric permittivity gradient that in turn drives a microscopic toroidal vortex. The vortex efficiently transports particles to a preferred location, usually the surface of the electrode. Recent advances have extended have allowed us to apply this technique to macromolecules (DNA, proteins) as well as nanoscale particles (quantum dots, nanowires and PSL particles).

  8. WordPress Bible

    CERN Document Server

    Brazell, Aaron

    2011-01-01

    Get the latest word on the biggest self-hosted blogging tool on the marketWithin a week of the announcement of WordPress 3.0, it had been downloaded over a million times. Now you can get on the bandwagon of this popular open-source blogging tool with WordPress Bible, 2nd Edition. Whether you're a casual blogger or programming pro, this comprehensive guide covers the latest version of WordPress, from the basics through advanced application development. If you want to thoroughly learn WordPress, this is the book you need to succeed.Explores the principles of blogging, marketing, and social media

  9. Controlled doping by self-assembled dendrimer-like macromolecules.

    Science.gov (United States)

    Wu, Haigang; Guan, Bin; Sun, Yingri; Zhu, Yiping; Dan, Yaping

    2017-02-01

    Doping via self-assembled macromolecules might offer a solution for developing single atom electronics by precisely placing individual dopants at arbitrary location to meet the requirement for circuit design. Here we synthesize dendrimer-like polyglycerol macromolecules with each carrying one phosphorus atom in the core. The macromolecules are immobilized by the coupling reagent onto silicon surfaces that are pre-modified with a monolayer of undecylenic acid. Nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) are employed to characterize the synthesized macromolecules and the modified silicon surfaces, respectively. After rapid thermal annealing, the phosphorus atoms carried by the macromolecules diffuse into the silicon substrate, forming dopants at a concentration of 10(17) cm(-3). Low-temperature Hall effect measurements reveal that the ionization process is rather complicated. Unlike the widely reported simple ionization of phosphorus dopants, nitrogen and carbon are also involved in the electronic activities in the monolayer doped silicon.

  10. Controlled doping by self-assembled dendrimer-like macromolecules

    Science.gov (United States)

    Wu, Haigang; Guan, Bin; Sun, Yingri; Zhu, Yiping; Dan, Yaping

    2017-02-01

    Doping via self-assembled macromolecules might offer a solution for developing single atom electronics by precisely placing individual dopants at arbitrary location to meet the requirement for circuit design. Here we synthesize dendrimer-like polyglycerol macromolecules with each carrying one phosphorus atom in the core. The macromolecules are immobilized by the coupling reagent onto silicon surfaces that are pre-modified with a monolayer of undecylenic acid. Nuclear magnetic resonance (NMR) and X-ray photoelectron spectroscopy (XPS) are employed to characterize the synthesized macromolecules and the modified silicon surfaces, respectively. After rapid thermal annealing, the phosphorus atoms carried by the macromolecules diffuse into the silicon substrate, forming dopants at a concentration of 1017 cm‑3. Low-temperature Hall effect measurements reveal that the ionization process is rather complicated. Unlike the widely reported simple ionization of phosphorus dopants, nitrogen and carbon are also involved in the electronic activities in the monolayer doped silicon.

  11. Discovery of Reversible Crystallization of Macromolecules

    Science.gov (United States)

    Wunderlich, Bernhard

    2004-03-01

    For 10 years "reversing melting" was observed with temperature-modulated differential scanning calorimetry, TMDSC. This reversing melting is the first harmonic response beyond that caused by the heat capacity of a metastable, semicrystalline macromolecular sample. Before one can identify "reversible melting," the calorimeter response must be corrected for loss of linearity, stationarity, frequency, amplitude, and instrument lag, or proper experiment-design must avoid these problems. Using quasi-isothermal TMDSC, the following observations were made [Prog. Polymer Sci. 28 (2003) 383-450]: Equilibrium crystals of polymers may melt at the equilibrium melting-temperature, but crystallization needs supercooling, even in the presence of crystal nuclei, making the overall process irreversible. Metastable, folded-chain crystals of the same molecules also melt irreversibly, however, may have some specific reversibility. Flexible, linear molecules of up to 10 nm length may melt fully reversibly. Macromolecules of less flexibility may lose the ability to melt reversibly. Decoupling of molecular segments, molecular nucleation, segregation of molar masses, rigid amorphous fractions, effects of equilibrium point defects in crystals and glasses, and transition-less ordering and solidification will be discussed in some detail. Supported by NSF, Polymers Program, DMR-0312233, and the Div. of Mat. Sci., BES, of DOE at ORNL, managed by UT-Battelle, LLC, for the U.S. Department of Energy, DOE-AC05-00OR22725.

  12. Second Harmonic Light Scattering from Macromolecules: Collagen.

    Science.gov (United States)

    Roth, Shmuel

    In this work we present the theory and practice of optical second harmonic generation (SHG) as applied to rat-tail tendon collagen. Our work is the first quantitative application of SHG to biological systems. The angular dependence of SHG is found to display a sharp, intense, forward peak superimposed on a broad background. The sharp peak is shown to imply long-range polar order, while the broad background corresponds to that predicted for the random "up"/"down" array of collagen fibrils seen with the electron microscope. The dependence of fibril diameter distribution on age and state of hydration is measured. Our experiments also reveal information concerning the structure of the fibrils and their arrangement in the tendon. The degree of polar order, the coherence length of tendon for harmonic generation and the absolute magnitude of the nonlinear susceptibility of the collagen fibril are also determined. The biological significance of these findings and the many advantages of SHG for the structural study of biological macromolecules and tissues are discussed.

  13. PREMIER MEETS THE PRESS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    On March 14, Premier Wen Jiabao addressed the Chinese and foreign media at a press conference after the closing meeting of the Third Session of the 11th National People’s Congress. Edited highlights on a number of economic and social issues follow:

  14. PREMIER MEETS THE PRESS

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    @@ March 14.Premier Wen Jiabao addressed the Chinese and foreign media at a press conference after the closing meeting of the Third Session of the 1 lth National People's Congress.Edited highlights on a number of economic and social issues follow:

  15. bbPress complete

    CERN Document Server

    Wynne, Rhys

    2013-01-01

    A concise guide, written in an easy-to-follow format.This book is aimed at ambitious website or blog owners looking to add a forum to their site quickly and easily. Basic experience in WordPress and with managing a website is expected. Knowledge of HTML and PHP will be a bonus, though it isn't necessary.

  16. ALUMINUM BOX BUNDLING PRESS

    Directory of Open Access Journals (Sweden)

    Iosif DUMITRESCU

    2015-05-01

    Full Text Available In municipal solid waste, aluminum is the main nonferrous metal, approximately 80- 85% of the total nonferrous metals. The income per ton gained from aluminum recuperation is 20 times higher than from glass, steel boxes or paper recuperation. The object of this paper is the design of a 300 kN press for aluminum box bundling.

  17. Sandwich complex-containing macromolecules: property tunability through versatile synthesis.

    Science.gov (United States)

    Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola

    2014-03-01

    Sandwich complexes feature unique properties as the physical and electronic properties of a hydrocarbon ligand or its derivative are integrated into the physical, electronic, magnetic, and optical properties of a metal. Incorporation of these complexes into macromolecules results in intriguing physical, electrical, and optical properties that were hitherto unknown in organic-based macromolecules. These properties are tunable through well-designed synthetic strategies. This review surveys many of the synthetic approaches that have resulted in tuning the properties of sandwich complex-containing macromolecules. While the past two decades have seen an ever-growing number of research publications in this field, gaps remain to be filled. Thus, we expect this review to stimulate research interest towards bridging these gaps, which include the insolubility of some of these macromolecules as well as expanding the scope of the sandwich complexes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. Ligand Binding to Macromolecules: Allosteric and Sequential Models of Cooperativity.

    Science.gov (United States)

    Hess, V. L.; Szabo, Attila

    1979-01-01

    A simple model is described for the binding of ligands to macromolecules. The model is applied to the cooperative binding by hemoglobin and aspartate transcarbamylase. The sequential and allosteric models of cooperative binding are considered. (BB)

  19. Organized monolayers of biological macromolecules on Au(111) surfaces

    DEFF Research Database (Denmark)

    Zhang, Jingdong; Chi, Qijin; Nielsen, Jens Ulrik

    2002-01-01

    Single-crystal electrochemistry and scanning tunneling microscopy directly in aqueous electrolyte solution (in situ STM) are established in physical electrochemistry but new in studies of adsorption and interfacial electrochemistry of biological macromolecules. These high-resolution techniques have...

  20. Effect of anionic macromolecules on intestinal permeability of furosemide.

    Science.gov (United States)

    Valizadeh, Hadi; Fahimfar, Hadi; Ghanbarzadeh, Saeed; Islambulchilar, Ziba; Zakeri-Milani, Parvin

    2015-02-01

    Furosemide is an anionic molecule and has very low absorption in gastro intestinal tract. The aim of this study was to investigate the effect of anionic macromolecules on the intestinal permeability of Furosemide. The intestinal permeability of Furosemide was determined using single-pass intestinal perfusion technique in rats. Briefly a jejunal segment of ∼10 cm was isolated and cannulated in both ends for inlet and outlet solution. The perfusate was collected every 10 min and samples were analyzed using the RP-HPLC method. Test samples containing furosemide and two anionic macromolecules, sodium carboxy methyl cellulose and sodium alginate, at different concentrations were used. The obtained data showed that existence of Sodium carboxy methyl cellulose significantly increased the Peff values in all three investigated concentrations (p macromolecules at specific concentrations could alter the permeability of anionic drugs across the biological membranes. Donnan phenomenon and chelating property of macromolecules could be attributed to the observed effect.

  1. A general method to study equilibrium partitioning of macromolecules

    DEFF Research Database (Denmark)

    The distribution of macromolecules between a confined microscopic solution and a macroscopic bulk solution plays an important role in understanding separation processes such as Size Exclusion Chromatography (SEC). In this study, we have developed an efficient computational algorithm for obtaining...

  2. Electrically assisted delivery of macromolecules into the corneal epithelium

    OpenAIRE

    HAO, JINSONG; Li, S. Kevin; Liu, Chia-Yang; Kao, Winston W. Y.

    2009-01-01

    Electrically assisted delivery is noninvasive and has been investigated in a number of ocular drug delivery studies. The objectives of this study were to examine the feasibility of electrically assisted delivery of macromolecules such as small interfering RNA (siRNA) into the corneal epithelium, to optimize the iontophoresis and electroporation methods, and to study the mechanisms of corneal iontophoresis for macromolecules. Anodal and cathodal iontophoresis, electroporation and their combina...

  3. Macromolecule-Induced Clustering of Hard Spheres.

    Science.gov (United States)

    Chatterjee, Avik Prasun

    2001-06-01

    The connectivity Ornstein-Zernike formalism, together with the polymer reference interaction site model (PRISM), is employed to describe connectivity and network formation in mixtures of spheres and polymers. Results are presented for the percolation of spheres induced by both flexible coil-like and rigid rod-like linear polymers; the Percus-Yevick (PY) approximation is used throughout. Our results are compared with predictions based on the adhesive hard sphere (AHS) model, and correlations with the polymer-mediated second virial coefficient between spheres are discussed. Copyright 2001 Academic Press.

  4. Submillimeter wave spectroscopy of biological macromolecules

    Science.gov (United States)

    Globus, Tatiana

    2005-03-01

    The recently emergence of submillimeter-wave or terahertz (THz) spectroscopy of biological molecules has demonstrated the capability to detect low-frequency internal molecular vibrations involving the weakest hydrogen bonds of the DNA base pairs and/or non-bonded interactions. These multiple bonds, although having only ˜ 5% of the strength of covalent bonds, stabilize the structure of bio-polymers, by holding the two strands of the DNA double helix together, or polypeptides together in different secondary structure conformations. There will be a review of THz-frequency transmission (absorption) results for biological materials obtained from Fourier Transform Infrared (FTIR) spectroscopy during the last few years^1,2. Multiple resonances, due to low frequency vibrational modes within biological macromolecules, have been unambiguously demonstrated in qualitative agreement with theoretical prediction, thereby confirming the fundamental physical nature of observed resonance features. The discovery of resonance character of interaction between THz radiation and biological materials opens many possible applications for THz spectroscopy technique in biological sensing and biomedicine using multiple resonances as distinctive spectral fingerprints. However, many issues still require investigation. Kinetics of interactions with radiation at THz has not been studied and vibrational lifetimes have not been measured directly as a function of frequency. The strength of resonant modes of bio-molecules in aqueous environment and strong dependence of spectra on molecular orientation need explanation. Vibrational modes have not been assigned to specific motions within molecules. THz spectroscopy of bio-polymers makes it only in first steps. 1. T. Globus, D. Woolard, M. Bykhovskaia, B. Gelmont, L. Werbos, A. Samuels. International Journal of High Speed Electronics and Systems (IJHSES), 13, No. 4, 903-936 (2003). 2. T. Globus, T. Khromova, D. Woolard and B. Gelmont. Proceedings of

  5. Electrically assisted delivery of macromolecules into the corneal epithelium.

    Science.gov (United States)

    Hao, Jinsong; Li, S Kevin; Liu, Chia-Yang; Kao, Winston W Y

    2009-12-01

    Electrically assisted delivery is noninvasive and has been investigated in a number of ocular drug delivery studies. The objectives of this study were to examine the feasibility of electrically assisted delivery of macromolecules such as small interfering RNA (siRNA) into the corneal epithelium, to optimize the iontophoresis and electroporation methods, and to study the mechanisms of corneal iontophoresis for macromolecules. Anodal and cathodal iontophoresis, electroporation and their combinations were the methods examined with mice in vivo. Cyanine 3 (Cy3)-labeled glyceraldehyde-3-phosphate dehydrogenase (GAPDH) siRNA and fluorescein isothiocyanate (FITC)-labeled dextran of different molecular weights (4-70 kDa) were the macromolecules studied. Microscopy and histology after cryostat sectioning were used to analyze and compare the delivery of the macromolecules to the cornea. Iontophoresis was effective in delivering siRNA and dextran up to 70 kDa into the cornea. The electroporation method studied was less effective than that of iontophoresis. Although both iontophoresis and electroporation alone can deliver the macromolecules into the cornea, these methods alone were not as effective as the combination of iontophoresis and electroporation (iontophoresis followed by electroporation). The significant enhancement of dextran delivery in anodal iontophoresis suggests that electroosmosis can be a significant flux-enhancing mechanism during corneal iontophoresis. These results illustrate the feasibility of electrically assisted delivery of macromolecules such as siRNA into the cornea.

  6. ISS Expedition 09 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 09 from 04/2004-10/2004. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  7. ISS Expedition 05 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 05 from 06/2002-12/2002. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  8. ISS Expedition 10 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 10 from 10/2004-04/2005. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  9. ISS Expedition 02 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 02 from 03/2001-08/2001. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  10. ISS Expedition 37 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 37 from 05/2013-11/2013. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  11. ISS Expedition 23 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 23 from 12/2009-09/2010. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  12. ISS Expedition 24 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 24 from 04/2010-11/2010. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  13. ISS Expedition 42 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 42 from 09/2014-03/2015. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  14. ISS Expedition 34 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 34 from 12/2012-03/2013. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  15. ISS Expedition 16 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 16 from 10/2007-04/2008. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  16. ISS Expedition 03 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 03 from 08/2001-12/2001. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  17. ISS Expedition 06 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 06 from 11/2002-05/2003. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  18. ISS Expedition 11 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 11 from 04/2005-10/2005. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  19. ISS Expedition 35 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 35 from 03/2013-09/2013. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  20. ISS Expedition 38 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 38 from 09/2013-03/2014. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  1. ISS Expedition 20 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 20 from 05/2009-10/2009. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  2. ISS Expedition 08 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 08 from 10/2003-04/2004. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  3. ISS Expedition 30 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 30 from 11/2011-07/2012. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  4. ISS Expedition 39 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 39 from 11/2013-05/2014. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  5. ISS Expedition 01 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 01 from 10/2000-03/2001. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  6. ISS Expedition 36 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 36 from 03/2013-09/2013. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  7. ISS Expedition 04 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 04 from 12/2001-06/2002. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  8. ISS Expedition 32 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 32 from 05/2012-09/2012. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  9. ISS Expedition 12 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 12 from 10/2005-04/2006. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  10. ISS Expedition 41 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 41 from 05/2014-11/2014. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  11. ISS Expedition 17 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 17 from 04/2008-10/2008. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  12. ISS Expedition 26 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 26 from 10/2010-05/2011. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  13. ISS Expedition 28 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 28 from 04/2011-11/2011. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  14. ISS Expedition 40 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 40 from 03/2014-11/2014. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  15. ISS Expedition 31 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 31 from 12/2011-07/2012. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  16. ISS Expedition 18 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 18 from 10/2008-04/2009. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  17. Press rate card: Paralympic Games

    OpenAIRE

    2013-01-01

    This catalogue provides a general overview of the press rate card programme, in an effort to make it as user-friendly as possible for the accredited written and photographic press and non-rights-holding broadcasters.

  18. ISS Expedition 25 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 25 from 06/2010-03/2011. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  19. ISS Expedition 14 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 14 from 09/2006-04/2007. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  20. ISS Expedition 27 Press Kit

    Data.gov (United States)

    National Aeronautics and Space Administration — Press kit for ISS mission Expedition 27 from 12/2010-09/2011. Press kits contain information about each mission overview, crew, mission timeline, benefits, and media...

  1. WordPress multisite administration

    CERN Document Server

    Longren, Tyler

    2013-01-01

    This is a simple, concise guide with a step-by-step approach, packed with screenshots and examples to set up and manage a network blog using WordPress.WordPress Multisite Administration is ideal for anyone wanting to familiarize themselves with WordPress Multisite. You'll need to know the basics about WordPress, and having at least a broad understanding of HTML, CSS, and PHP will help, but isn't required.

  2. Physicochemical Properties of Ion Pairs of Biological Macromolecules.

    Science.gov (United States)

    Iwahara, Junji; Esadze, Alexandre; Zandarashvili, Levani

    2015-09-30

    Ion pairs (also known as salt bridges) of electrostatically interacting cationic and anionic moieties are important for proteins and nucleic acids to perform their function. Although numerous three-dimensional structures show ion pairs at functionally important sites of biological macromolecules and their complexes, the physicochemical properties of the ion pairs are not well understood. Crystal structures typically show a single state for each ion pair. However, recent studies have revealed the dynamic nature of the ion pairs of the biological macromolecules. Biomolecular ion pairs undergo dynamic transitions between distinct states in which the charged moieties are either in direct contact or separated by water. This dynamic behavior is reasonable in light of the fundamental concepts that were established for small ions over the last century. In this review, we introduce the physicochemical concepts relevant to the ion pairs and provide an overview of the recent advancement in biophysical research on the ion pairs of biological macromolecules.

  3. Tailoring liquid crystalline lipid nanomaterials for controlled release of macromolecules.

    Science.gov (United States)

    Bisset, Nicole B; Boyd, Ben J; Dong, Yao-Da

    2015-11-10

    Lipid-based liquid crystalline materials are being developed as drug delivery systems. However, the use of these materials for delivery of large macromolecules is currently hindered by the small size of the water channels in these structures limiting control over diffusion behaviour. The addition of the hydration-modulating agent, sucrose stearate, to phytantriol cubic phase under excess water conditions incrementally increased the size of these water channels. Inclusion of oleic acid enabled further control of swelling and de-swelling of the matrix via a pH triggerable system where at low pH the hexagonal phase is present and at higher pH the cubic phase is present. Fine control over the release of various sized model macromolecules is demonstrated, indicating future application to controlled loading and release of large macromolecules such as antibodies. Copyright © 2015 Elsevier B.V. All rights reserved.

  4. A general method to study equilibrium partitioning of macromolecules

    DEFF Research Database (Denmark)

    The distribution of macromolecules between a confined microscopic solution and a macroscopic bulk solution plays an important role in understanding separation processes such as Size Exclusion Chromatography (SEC). In this study, we have developed an efficient computational algorithm for obtaining...... the equilibrium partition coefficient (pore-to-bulk concentration ratio) and the concentration profile inside the confining geometry. The algorithm involves two steps. First, certain characteristic structure properties of the studied macromolecule are obtained by sampling its configuration space, and second those...... data are used for the computation of partition coefficient and concentration profile for any confinement size. Our algorithm is versatile to the model and type of the macromolecule studied, and is capable of handling three types of confining geometries (slit, rectangular channel and rectangular box...

  5. WordPress for dummies

    CERN Document Server

    Sabin-Wilson, Lisa

    2014-01-01

    The bestselling WordPress guide, fully updated to cover the 2013 enhancements WordPress has millions of users, and this popular guide has sold more than 105,000 copies in its previous editions. With the newest releases of WordPress, author and WordPress expert Lisa Sabin-Wilson has completely updated the book to help you use and understand all the latest features. You'll learn about both the hosted WordPress.com version and the more flexible WordPress.org, which requires third-party hosting. Whether you're switching to WordPress from another blogging platform or just beginning to blog, you'll

  6. Intellective high-precision macromolecule resistance temperature/humidity instrument

    Science.gov (United States)

    Liu, Guixiong; Zhou, Qinhe; Kuang, Yongcong; Xu, Jing; Zeng, Zhixin

    2001-09-01

    Considering that the resistance of macromolecule resistor varies in a wide range and humidity sensor component is sensitive to temperature as well, a intelligent high- precision macromolecule resistance temperature/humidity instrument was proposed in this paper, the instrument is based on the integration of frequency-and-period-measuring method, and sensing characteristic calculation and compensation using interpolation. Practical applications show that the instrument has the advantages of high precision, simple peripheral circuit, low cost, suitability for remote measurement, strong ability of anti-interference and wide operation range.

  7. ASPHERICITY AND PROLATENESS OF LINEAR AND CIRCULAR MACROMOLECULES

    Institute of Scientific and Technical Information of China (English)

    WEI Gaoyuan

    1995-01-01

    The shape asymmetry of gaussian models of linear and circular macromolecules has been numerically invesigated in terms of asphericity and prolateness parameters. These parameters are found to decrease with increasing length for the macromolecule either confined to a plane or in three dimensions. The effect of dimensionality on these parameters is visible only for low dimensions and is generally weak. As dimensionality goes to infinity, it is found that asphericity and prolateness for both chains and rings approach slowly yet descendingly values of corresponding asphericity and prolateness factors, with the exception of the chain which shows a minimum value of asphericity when the embedding space has a dimensionality of four.

  8. Effects of high hydrostatic pressures on living cells: a consequence of the properties of macromolecules and macromolecule-associated water.

    Science.gov (United States)

    Mentré, P; Hui Bon Hoa, G

    2001-01-01

    Sixty percent of the Earth's biomass is found in the sea, at depths greater than 1000 m, i.e., at hydrostatic pressures higher than 100 atm. Still more surprising is the fact that living cells can reversibly withstand pressure shifts of 1000 atm. One explanation lies in the properties of cellular water. Water forms a very thin film around macromolecules, with a heterogeneous structure that is an image of the heterogeneity of the macromolecular surface. The density of water in contact with macromolecules reflects the physical properties of their different domains. Therefore, any macromolecular shape variations involving the reorganization of water and concomitant density changes are sensitive to pressure (Le Chatelier's principle). Most of the pressure-induced changes to macromolecules are reversible up to 2000 atm. Both the effects of pressure shifts on living cells and the characteristics of pressure-adapted species are opening new perspectives on fundamental problems such as regulation and adaptation.

  9. Repetitious-Hot-Pressing Technique in Hot-Pressing Process

    Institute of Scientific and Technical Information of China (English)

    Shixue SONG; Xing AI; Wei GAO; Jun ZHAO

    2003-01-01

    A new pressing method was proposed for hot-pressing process. Experimental results indicated that the porosity in Al2O3/TiC/Ni/Mo (hereafter called Al2O3/TiC composite) composite compacts decreases by 6% after adopting this new technique,compared to traditional hot-pressing technique under the same sintering temperature. The flexural strength and Vickerhardness increase from 883 MPa to 980 MPa and from 16 GPa to 21.1 GPa, respectively. A theoretical model was given toanalyze the densification mechanism of the composite in the process of repetitious-hot-pressing.

  10. Insulin facilitates transport of macromolecules and nutrients to muscles

    DEFF Research Database (Denmark)

    Christensen, N J; Hilsted, J

    1993-01-01

    , systolic blood pressure and plasma noradrenaline. These changes were absent or attenuated in diabetic patients (without neuropathy) after an oral glucose load. These responses were normalized by insulin infusion. Our results suggest that insulin facilitates the transfer of macromolecules and nutrients from...

  11. DEDUCTION OF EVOLUTIONARY RELATIONSHIPS FROM THE STRUCTURE OF MACROMOLECULES

    NARCIS (Netherlands)

    BEINTEMA, JJ

    1992-01-01

    Macromolecules can be used to derive evolutionary relationships. This discovery has led to the development of a new discipline in biology, molecular evolution. A brief survey of several aspects of this new field of investigation is presented, together with references to historical and more recent li

  12. Crystallogenesis of biological macromolecules. Biological, microgravity and other physicochemical aspects

    NARCIS (Netherlands)

    Giege, R; Drenth, J; Ducruix, A; McPherson, A; Saenger, W

    1995-01-01

    After an historical introduction and justification of the importance of proteins (as well as other macromolecules or macromolecular assemblies of biological origin) in modern biology but also in physics, this review presents the state of the field of macromolecular crystallogenesis. The basic questi

  13. Reduced adipose tissue lymphatic drainage of macromolecules in obese subjects

    DEFF Research Database (Denmark)

    Arngrim, N; Simonsen, L; Holst, Jens Juul

    2012-01-01

    The aim of this study was to investigate subcutaneous adipose tissue lymphatic drainage (ATLD) of macromolecules in lean and obese subjects and, furthermore, to evaluate whether ATLD may change in parallel with adipose tissue blood flow. Lean and obese male subjects were studied before and after ...... online publication, 3 July 2012; doi:10.1038/ijo.2012.98....

  14. Chaperoning roles of macromolecules interacting with proteins in vivo.

    Science.gov (United States)

    Choi, Seong Il; Lim, Keo-Heun; Seong, Baik L

    2011-01-01

    The principles obtained from studies on molecular chaperones have provided explanations for the assisted protein folding in vivo. However, the majority of proteins can fold without the assistance of the known molecular chaperones, and little attention has been paid to the potential chaperoning roles of other macromolecules. During protein biogenesis and folding, newly synthesized polypeptide chains interact with a variety of macromolecules, including ribosomes, RNAs, cytoskeleton, lipid bilayer, proteolytic system, etc. In general, the hydrophobic interactions between molecular chaperones and their substrates have been widely believed to be mainly responsible for the substrate stabilization against aggregation. Emerging evidence now indicates that other features of macromolecules such as their surface charges, probably resulting in electrostatic repulsions, and steric hindrance, could play a key role in the stabilization of their linked proteins against aggregation. Such stabilizing mechanisms are expected to give new insights into our understanding of the chaperoning functions for de novo protein folding. In this review, we will discuss the possible chaperoning roles of these macromolecules in de novo folding, based on their charge and steric features.

  15. Dermal and transdermal delivery of pharmaceutically relevant macromolecules.

    Science.gov (United States)

    Münch, S; Wohlrab, J; Neubert, R H H

    2017-10-01

    The skin offers an attractive way for dermal and transdermal drug delivery that is why the drug still needs certain qualities to transcend the outermost layer of the skin, the stratum corneum. The requirements are: drugs with a maximum molecular weight of 1kDa, high lipophilicity and a certain polarity. This would restrict the use of a transdermal delivery of macromolecules, which would make the drug more effective in therapeutic administration. Various studies have shown that macromolecules without support do not penetrate the human skin. This effect can be achieved using physical and chemical methods, as well as biological peptides. The most popular physical method is the use of microneedles to create micropores in the skin and release the active agent in different sections. But also, other methods have been tested. Microjets, lasers, electroporation, sonophoresis and iontophoresis are also promising methods to successfully deliver dermal and transdermal macromolecules. Additionally, there are different penetration enhancer groups and biological peptides, which are also considered to be interesting approaches of enabling macromolecules to travel along the skin. All these methods will be described and evaluated in this review article. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Antimicrobial resistance challenged with metal-based antimicrobial macromolecules.

    Science.gov (United States)

    Abd-El-Aziz, Alaa S; Agatemor, Christian; Etkin, Nola

    2017-02-01

    Antimicrobial resistance threatens the achievements of science and medicine, as it deactivates conventional antimicrobial therapeutics. Scientists respond to the threat by developing new antimicrobial platforms to prevent and treat infections from these resistant strains. Metal-based antimicrobial macromolecules are emerging as an alternative to conventional platforms because they combine multiple mechanisms of action into one platform due to the distinctive properties of metals. For example, metals interact with intracellular proteins and enzymes, and catalyse various intracellular processes. The macromolecular architecture offers a means to enhance antimicrobial activity since several antimicrobial moieties can be conjugated to the scaffold. Further, these macromolecules can be fabricated into antimicrobial materials for contact-killing medical implants, fabrics, and devices. As volatilization or leaching out of the antimicrobial moieties from the macromolecular scaffold is reduced, these medical implants, fabrics, and devices can retain their antimicrobial activity over an extended period. Recent advances demonstrate the potential of metal-based antimicrobial macromolecules as effective platforms that prevent and treat infections from resistant strains. In this review these advances are thoroughly discussed within the context of examples of metal-based antimicrobial macromolecules, their mechanisms of action and biocompatibility. Copyright © 2016 Elsevier Ltd. All rights reserved.

  17. Microfluidic device and method for processing of macromolecules

    DEFF Research Database (Denmark)

    2012-01-01

    to the first set of outlets is guided through the reaction channels, and second inlet and outlet channels for feeding an enzymatic reagent to the reaction chamber essentially without displacing the macromolecule containers trapped in the reaction channels, wherein the second set of inlets and outlets...

  18. Crystallization of biological macromolecules in a reduced gravity environment

    Science.gov (United States)

    Meehan, E. J., Jr.

    1979-01-01

    A battery of micro techniques were developed which allow the screening of a large number of conditions using only a small amount of the macromolecule. The need to develop methodologies for growing large crystals required for neutron diffraction studies is discussed.

  19. Interactions between adsorbed macromolecules : measurements on emulsions and liquid films

    NARCIS (Netherlands)

    Vliet, van T.

    1977-01-01

    The aim of this study was to gain more insight into the factors, determining the inter- and intramolecular interactions between adsorbed macromolecules. To that end several experimental and theoretical approaches were followed, using well-defined systems. It was shown that these interactions could c

  20. Synthesis of main-chain metal carbonyl organometallic macromolecules (MCMCOMs).

    Science.gov (United States)

    Cao, Kai; Murshid, Nimer; Wang, Xiaosong

    2015-04-01

    Synthesis of main-chain metal carbonyl organometallic macromolecules (MCMCOMs) is difficult, mainly due to the instability of metal carbonyl complexes. Despite its challenge a number of MCMCOMs has been prepared by strategically using organometallic, organic, and polymer synthetic chemistry. Main contributions to this research field were reported by the groups of Tyler, Pannell, and Wang and are briefly summarized in this article.

  1. Adsorption of charged macromolecules on a gold electrode

    NARCIS (Netherlands)

    Barten, D.

    2003-01-01

    In this thesis we have examined the role of electrostatic interactions in the adsorption of charged macromolecules from aqueous solution to a solid surface and the possibilitiesfor manipulatingthis process through the electric potential

  2. Bioenergetic aspects of the translocation of macromolecules across bacterial membranes

    NARCIS (Netherlands)

    Palmen, Ronald; Driessen, Arnold J.M.; Hellingwerf, K

    1994-01-01

    Bacteria are extremely versatile in the sense that they have gained the ability to transport all three major classes of biopolymers through their cell envelope: proteins, nucleic acids, and polysaccharides. These macromolecules are translocated across membranes in a large number of cellular processe

  3. Chaperoning Roles of Macromolecules Interacting with Proteins in Vivo

    Directory of Open Access Journals (Sweden)

    Baik L. Seong

    2011-03-01

    Full Text Available The principles obtained from studies on molecular chaperones have provided explanations for the assisted protein folding in vivo. However, the majority of proteins can fold without the assistance of the known molecular chaperones, and little attention has been paid to the potential chaperoning roles of other macromolecules. During protein biogenesis and folding, newly synthesized polypeptide chains interact with a variety of macromolecules, including ribosomes, RNAs, cytoskeleton, lipid bilayer, proteolytic system, etc. In general, the hydrophobic interactions between molecular chaperones and their substrates have been widely believed to be mainly responsible for the substrate stabilization against aggregation. Emerging evidence now indicates that other features of macromolecules such as their surface charges, probably resulting in electrostatic repulsions, and steric hindrance, could play a key role in the stabilization of their linked proteins against aggregation. Such stabilizing mechanisms are expected to give new insights into our understanding of the chaperoning functions for de novo protein folding. In this review, we will discuss the possible chaperoning roles of these macromolecules in de novo folding, based on their charge and steric features.

  4. WordPress For Dummies

    CERN Document Server

    Sabin-Wilson, Lisa

    2011-01-01

    The bestselling guide to WordPress, fully updated to help you get your blog going! Millions of bloggers rely on WordPress, the popular, free blogging platform. This guide covers all the features and improvements in the most up-to-date version of WordPress. Whether you are switching to WordPress from another blogging platform or just starting your first blog, you'll find the advice in this friendly guide gets you up to speed on both the free-hosted WordPress.com version and WordPress.org, which requires the purchase of web hosting services, and figure out which version is best for you. You'll b

  5. Light-Switchable Azobenzene-Containing Macromolecules: From UV to Near Infrared.

    Science.gov (United States)

    Weis, Philipp; Wu, Si

    2017-06-23

    Azobenzene-containing macromolecules (azo-macromolecules) such as azobenzene-containing polymers (azopolymers) and azobenzene-functionalized biomacromolecules are photoswitchable macromolecules. Trans-to-cis photoisomerization in conventional azo-macromolecules is induced by ultraviolet (UV) light. However, UV light cannot penetrate deeply into issue and has a very small fraction in sunlight. Therefore, conventional azo-macromolecules are problematic for biomedical and solar-energy-related applications. In this Feature Article, the strategies for constructing visible and near-infrared (NIR) light-responsive azo-macromolecules are reviewed, and the potential applications of visible- and NIR-light-responsive azo-macromolecules in biomedicine and solar energy conversion are highlighted. The remaining challenges in the field of photoswitchable azo-macromolecules are discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Surface Characteristics and Adhesion Behavior of Escherichia coli O157:H7: Role of Extracellular Macromolecules

    Science.gov (United States)

    Surface macromolecule cleavage experiments were conducted on enterohaemorrhagic Escherichia coli O157:H7 cells to investigate the influence of these macromolecules on cell surface properties. Electrophoretic mobility, hydrophobicity, and titration experiments were carried out on proteinase K treate...

  7. Vesicular uptake of macromolecules by human placental amniotic epithelial cells.

    Science.gov (United States)

    Sharshiner, Rita; Brace, Robert A; Cheung, Cecilia Y

    2017-09-01

    Studies in animal models have shown that unidirectional vesicular transport of amniotic fluid across the amnion plays a primary role in regulating amniotic fluid volume. Our objective was to explore vesicle type, vesicular uptake and intracellular distribution of vesicles in human amnion cells using high- and super-resolution fluorescence microscopy. Placental amnion was obtained at cesarean section and amnion cells were prepared and cultured. At 20%-50% confluence, the cells were incubated with fluorophore conjugated macromolecules for 1-30 min at 22 °C or 37 °C. Fluorophore labeled macromolecules were selected as markers of receptor-mediated caveolar and clathrin-coated vesicular uptake as well as non-specific endocytosis. After fluorophore treatment, the cells were fixed, imaged and vesicles counted using Imaris(®) software. Vesicular uptake displayed first order saturation kinetics with half saturation times averaging 1.3 min at 37 °C compared to 4.9 min at 22 °C, with non-specific endocytotic uptake being more rapid at both temperatures. There was extensive cell-to-cell variability in uptake rate. Under super-resolution microscopy, the pattern of intracellular spatial distribution was distinct for each macromolecule. Co-localization of fluorescently labeled macromolecules was very low at vesicular dimensions. In human placental amnion cells, 1) vesicular uptake of macromolecules is rapid, consistent with the concept that vesicular transcytosis across the amnion plays a role in the regulation of amniotic fluid volume; 2) uptake is temperature dependent and variable among individual cells; 3) the unique intracellular distributions suggest distinct functions for each vesicle type; 4) non-receptor mediated vesicular uptake may be a primary vesicular uptake mechanism. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. WordPress Top Plugins

    CERN Document Server

    Corbin, Brandon

    2010-01-01

    Time flies when you're having fun. This is the right way to describe this WordPress Top Plugins book by Brandon Corbin. With real world examples and by showing you the perks of having these plugins installed on your websites, the author is all set to captivate your interest from start to end. Regardless of whether this is your first time working with WordPress, or you're a seasoned WordPress coding ninja, WordPress Top Plugins will walk you through finding and installing the best plugins for generating and sharing content, building communities and reader base, and generating real advertising r

  9. Beginning WordPress 3

    CERN Document Server

    Leary, Stephanie

    2009-01-01

    One of the most popular open source blogging and content management systems, WordPress lets you create a website to promote yourself or your business quickly and easilyi' "and better yet, it's free. WordPress is a flexible, user-friendly system, and it can be extended with a variety of themes and plugins. Beginning WordPress 3 is a complete guide for the beginning developer who wants to start using WordPress. You'll learn how to publish and manage online content, add media, create widgets and plugins, and much more. What you'll learn * How to get started with Wordpress, create new content

  10. Macromolecule Mediated Transport and Retention of Escherichia coli O157:H7 in Saturated Porous Media

    Science.gov (United States)

    The role of extracellular macromolecules on Escherichia coli O157:H7 transport and retention was investigated in saturated porous media. To compare the relative transport and retention of E. coli cells that are macromolecule rich and deficient, macromolecules were partially cleaved using a proteolyt...

  11. Measuring Equilibrium Binding Affinity of Biological Macromolecules in Solution by Thermophoresis

    Science.gov (United States)

    2015-05-18

    Approved for Public Release; Distribution Unlimited Final Report: Measuring Equilibrium Binding Affinity of Biological Macromolecules in Solution by...Equilibrium Binding Affinity of Biological Macromolecules in Solution by Thermophoresis Report Title The primary research focus of the San Diego State...equilibrium binding affinities of biological macromolecules in solution. This qauntitative information plays a vital role in supporting the static

  12. Indre spenninger og ytre press

    DEFF Research Database (Denmark)

    Ibsen, Bjarne

    2011-01-01

    Anmeldelse af bogen 'Norsk idrett. Indre spenninger og ytre press' redigeret af Dag Vidar Hanstad, Gunnar Breivik, Mari Kristin Sisjord og Hans B. Skaset og udgivet af forlaet akilles.......Anmeldelse af bogen 'Norsk idrett. Indre spenninger og ytre press' redigeret af Dag Vidar Hanstad, Gunnar Breivik, Mari Kristin Sisjord og Hans B. Skaset og udgivet af forlaet akilles....

  13. The CIA and the Press.

    Science.gov (United States)

    Carvalho, Bernardo A.

    The involvement of the Central Intelligence Agency (CIA) with both United States and foreign news media has been recorded in numerous publications. This report reviews the important aspects of the CIA-press relationships as they have appeared in print and discusses the implications of these relationsihps for the credibility of the press. Media…

  14. Warpage of rubber pressed composites

    NARCIS (Netherlands)

    Wijskamp, Sebastiaan; Lamers, E.A.D.; Akkerman, Remko; van de Ven, Erik

    2002-01-01

    The rubber pressing process is applied for the rapid production of thermoplastic composite products. However, rubber pressed products show geometrical distortions, such as warpage, due to process-induced residual stresses. It is believed that these stresses build up as a result of the large thermal

  15. BuddyPress theme development

    CERN Document Server

    Lister, Tammie

    2013-01-01

    This book is a hands-on tutorial guide to using BuddyPress.This book is great for designers and developers who are looking to learn how to develop BuddyPress themes. It's assumed that the reader has some understanding of Wordpress and is familiar with CSS and HTML.

  16. Head First WordPress

    CERN Document Server

    Siarto, Jeff

    2010-01-01

    Whether you're promoting your business or writing about your travel adventures, Head First WordPress will teach you not only how to make your blog look unique and attention-grabbing, but also how to dig into the more complex features of WordPress 3.0 to make your website work well, too. You'll learn how to move beyond the standard WordPress look and feel by customizing your blog with your own URL, templates, plugin functionality, and more. As you learn, you'll be working with real WordPress files: The book's website provides pre-fab WordPress themes to download and work with as you follow al

  17. Isothermal Titration Calorimetry for Measuring Macromolecule-Ligand Affinity

    Science.gov (United States)

    Duff,, Michael R.; Grubbs, Jordan; Howell, Elizabeth E.

    2011-01-01

    Isothermal titration calorimetry (ITC) is a useful tool for understanding the complete thermodynamic picture of a binding reaction. In biological sciences, macromolecular interactions are essential in understanding the machinery of the cell. Experimental conditions, such as buffer and temperature, can be tailored to the particular binding system being studied. However, careful planning is needed since certain ligand and macromolecule concentration ranges are necessary to obtain useful data. Concentrations of the macromolecule and ligand need to be accurately determined for reliable results. Care also needs to be taken when preparing the samples as impurities can significantly affect the experiment. When ITC experiments, along with controls, are performed properly, useful binding information, such as the stoichiometry, affinity and enthalpy, are obtained. By running additional experiments under different buffer or temperature conditions, more detailed information can be obtained about the system. A protocol for the basic setup of an ITC experiment is given. PMID:21931288

  18. High and low thermal conductivity of amorphous macromolecules

    Science.gov (United States)

    Xie, Xu; Yang, Kexin; Li, Dongyao; Tsai, Tsung-Han; Shin, Jungwoo; Braun, Paul V.; Cahill, David G.

    2017-01-01

    We measure the thermal conductivity, heat capacity and sound velocity of thin films of five polymers, nine polymer salts, and four caged molecules to advance the fundamental understanding of the lower and upper limits to heat conduction in amorphous macromolecules. The thermal conductivities vary by more than one order of magnitude, from 0.06 W m-1K-1 for [6,6]-phenyl-C71-butyric acid methyl ester to 0.67 W m-1K-1 for poly(vinylphosphonic acid calcium salt). Minimum thermal conductivity calculated from the measured sound velocity and effective atomic density is in good agreement with the thermal conductivity of macromolecules with various molecular structures and intermolecular bonding strength.

  19. Plasmodesmata: intercellular tunnels facilitating transport of macromolecules in plants.

    Science.gov (United States)

    Kragler, Friedrich

    2013-04-01

    In plants, intercellular structures named plasmodesmata (PD) form a continuous cytoplasmic network between neighboring cells. PD pores provide channels for intercellular symplasmic (cell-to-cell) transport throughout most tissues of the plant body. Cell-defining proteins, such as transcription factors, and regulatory non-coding sequences, such as short interfering RNA, micro RNA, protein-encoding messenger RNAs, viroids, and viral RNA/DNA genomes move via PD channels to adjacent cells. PD-mediated intercellular transport of macromolecules is a regulated process depending on the tissue, developmental stage, and nature of the transported macromolecule. In this review, PD channels and their similarity to tunneling nanotubes present in animals are highlighted. In addition, homeodomain protein movement and cellular components regulating transport are discussed.

  20. Comment j'ai pourri le web

    Directory of Open Access Journals (Sweden)

    Loys Bonod

    2012-04-01

    Full Text Available Ce texte décrit l’expérience pédagogique faite par un professeur de Lycée, à Paris, qui pour prouver la dépendance de la pensée vis-à-vis du numérique, a piégé ses élèves. Il a publié sur différents sites (Wikipédia, entre autres des commentaires – vrais et faux – sur un poème relativement rare, puis il a interrogé ses étudiants. Le but était de démontrer aux élèves qu’ils ne sont pas assez mûrs pour analyser sainement tous les contenus internet car leur curiosité, sélection  et jugement restent trop restreints.

  1. Synthesis, Characterisation and Application of 68Ga-labelled Macromolecules

    OpenAIRE

    Velikyan, Irina

    2005-01-01

    The positron emitting radionuclide 68Ga (T1/2 = 68 min) might become of practical interest for clinical positron emission tomography (PET). The metallic cation, 68Ga(III), is suitable for complexation with chelators, either naked or conjugated with biological macromolecules. Such labelling procedures require pure and concentrated preparations of 68Ga(III), which cannot be sufficiently fulfilled by the presently available 68Ge/68Ga generator eluate. This thesis presents methods to increase the...

  2. MEASURING THE SHAPES OF MACROMOLECULES – AND WHY IT MATTERS

    Directory of Open Access Journals (Sweden)

    Jie Li

    2013-09-01

    Full Text Available The molecular basis of life rests on the activity of biological macromolecules, mostly nucleic acids and proteins. A perhaps surprising finding that crystallized over the last handful of decades is that geometric reasoning plays a major role in our attempt to understand these activities. In this paper, we address this connection between geometry and biology, focusing on methods for measuring and characterizing the shapes of macromolecules. We briefly review existing numerical and analytical approaches that solve these problems. We cover in more details our own work in this field, focusing on the alpha shape theory as it provides a unifying mathematical framework that enable the analytical calculations of the surface area and volume of a macromolecule represented as a union of balls, the detection of pockets and cavities in the molecule, and the quantification of contacts between the atomic balls. We have shown that each of these quantities can be related to physical properties of the molecule under study and ultimately provides insight on its activity. We conclude with a brief description of new challenges for the alpha shape theory in modern structural biology.

  3. Localization of intracrystalline organic macromolecules in mollusk shells

    Science.gov (United States)

    Suzuki, Michio; Okumura, Taiga; Nagasawa, Hiromichi; Kogure, Toshihiro

    2011-12-01

    As a crucial first step for understanding the organic-inorganic interaction in biomineralization of mollscan shells, localization of the intracrystalline organic macromolecules in biogenic calcium carbonate crystals of the nacreous, prismatic ( Pinctada fucata) and foliated ( Cellana toreuma) microstructures were investigated using Fresnel contrast analysis in a transmission electron microscope. Spherular Fresnel contrasts in the crystals correspond to organic substances, which was confirmed by the detection of 1s→π * (CC) transition peak at 284 eV in electron energy loss spectroscopy. Nano-sized (5-10 nm) spherules in the aragonite tablets constituting the nacreous layer of P. fucata specifically concentrate in the vicinity of the interlamellar membrane between the aragonite tablets. The dominant sizes of the organic macromolecules extracted by dissolving the aragonite tablets in the nacreous layer of P. fucata were estimated using the gel-filtration analysis to be roughly 10 and 4 nm, which dimensionally corresponds to the sizes observed by Fresnel contrast imaging in the tablets. These results will serve for understanding the functions of intracrystalline organic macromolecules in mollusk shells.

  4. Measuring the shapes of macromolecules – and why it matters

    Directory of Open Access Journals (Sweden)

    Jie Li

    2013-09-01

    Full Text Available The molecular basis of life rests on the activity of biological macromolecules, mostly nucleic acids and proteins. A perhaps surprising finding that crystallized over the last handful of decades is that geometric reasoning plays a major role in our attempt to understand these activities. In this paper, we address this connection between geometry and biology, focusing on methods for measuring and characterizing the shapes of macromolecules. We briefly review existing numerical and analytical approaches that solve these problems. We cover in more details our own work in this field, focusing on the alpha shape theory as it provides a unifying mathematical framework that enable the analytical calculations of the surface area and volume of a macromolecule represented as a union of balls, the detection of pockets and cavities in the molecule, and the quantification of contacts between the atomic balls. We have shown that each of these quantities can be related to physical properties of the molecule under study and ultimately provides insight on its activity. We conclude with a brief description of new challenges for the alpha shape theory in modern structural biology.

  5. Measuring the shapes of macromolecules - and why it matters.

    Science.gov (United States)

    Li, Jie; Mach, Paul; Koehl, Patrice

    2013-01-01

    The molecular basis of life rests on the activity of biological macromolecules, mostly nucleic acids and proteins. A perhaps surprising finding that crystallized over the last handful of decades is that geometric reasoning plays a major role in our attempt to understand these activities. In this paper, we address this connection between geometry and biology, focusing on methods for measuring and characterizing the shapes of macromolecules. We briefly review existing numerical and analytical approaches that solve these problems. We cover in more details our own work in this field, focusing on the alpha shape theory as it provides a unifying mathematical framework that enable the analytical calculations of the surface area and volume of a macromolecule represented as a union of balls, the detection of pockets and cavities in the molecule, and the quantification of contacts between the atomic balls. We have shown that each of these quantities can be related to physical properties of the molecule under study and ultimately provides insight on its activity. We conclude with a brief description of new challenges for the alpha shape theory in modern structural biology.

  6. Self-organization of amphiphilic macromolecules with local helix structure in concentrated solutions.

    Science.gov (United States)

    Glagolev, M K; Vasilevskaya, V V; Khokhlov, A R

    2012-08-28

    Concentrated solutions of amphiphilic macromolecules with local helical structure were studied by means of molecular dynamic simulations. It is shown that in poor solvent the macromolecules are assembled into wire-like aggregates having complex core-shell structure. The core consists of a hydrophobic backbone of the chains which intertwine around each other. It is protected by the shell of hydrophilic side groups. In racemic mixture of right-hand and left-hand helix macromolecules the wire-like complex is a chain of braid bundles of macromolecules with the same chirality stacking at their ends. The average number of macromolecules in the wire cross-section is close to that of separate bundles observed in dilute solutions of such macromolecules. The effects described here could serve as a simple model of self-organization in solutions of macromolecules with local helical structure.

  7. The Press Research Centre, 1956-1976.

    Science.gov (United States)

    Press Research Centre, Krakow (Poland).

    In 1956, the Press Research Centre was established in Cracow, Poland by a group of journalists and publishers, for the purpose of instituting press research that would have practical applications. The aims of the Centre were to conduct studies on the history of the Polish press, the contemporary press, press readership, and editorial techniques.…

  8. A comparison of impulse drying to double felted pressing on pilot- scale shoe presses and roll presses

    Energy Technology Data Exchange (ETDEWEB)

    Orloff, D.I.

    1992-08-01

    Pilot-scale shoe press and roll press experiments have been conducted to compare impulse drying and double felted pressing. Both ceramic coated and Beloit Type C press rolls have been evaluated. The experiments show that impulse drying can provide significantly higher outgoing solids than double felled pressing at the same impulse. For example, at an impulse of 0.234 MPa seconds (34 psi seconds), sheets at an ingoing solids of 52% were impulse dried (using the Beloit Type C press roll) to 68% solids while optimized double felled pressing could only yield press dryness of, at most, 60%.

  9. Heuristic modeling of macromolecule release from PLGA microspheres

    Directory of Open Access Journals (Sweden)

    Szlęk J

    2013-12-01

    Full Text Available Jakub Szlęk,1 Adam Pacławski,1 Raymond Lau,2 Renata Jachowicz,1 Aleksander Mendyk11Department of Pharmaceutical Technology and Biopharmaceutics, Jagiellonian University Medical College, Krakow, Poland; 2School of Chemical and Biomedical Engineering, Nanyang Technological University (NTU, SingaporeAbstract: Dissolution of protein macromolecules from poly(lactic-co-glycolic acid (PLGA particles is a complex process and still not fully understood. As such, there are difficulties in obtaining a predictive model that could be of fundamental significance in design, development, and optimization for medical applications and toxicity evaluation of PLGA-based multiparticulate dosage form. In the present study, two models with comparable goodness of fit were proposed for the prediction of the macromolecule dissolution profile from PLGA micro- and nanoparticles. In both cases, heuristic techniques, such as artificial neural networks (ANNs, feature selection, and genetic programming were employed. Feature selection provided by fscaret package and sensitivity analysis performed by ANNs reduced the original input vector from a total of 300 input variables to 21, 17, 16, and eleven; to achieve a better insight into generalization error, two cut-off points for every method was proposed. The best ANNs model results were obtained by monotone multi-layer perceptron neural network (MON-MLP networks with a root-mean-square error (RMSE of 15.4, and the input vector consisted of eleven inputs. The complicated classical equation derived from a database consisting of 17 inputs was able to yield a better generalization error (RMSE of 14.3. The equation was characterized by four parameters, thus feasible (applicable to standard nonlinear regression techniques. Heuristic modeling led to the ANN model describing macromolecules release profiles from PLGA microspheres with good predictive efficiency. Moreover genetic programming technique resulted in classical equation with

  10. Bending dynamics of semi-flexible macromolecules in isotropic turbulence

    CERN Document Server

    Ali, Aamir; Vincenzi, Dario

    2014-01-01

    We study the Lagrangian dynamics of semi-flexible macromolecules in laminar as well as in homogeneous and isotropic turbulent flows by means of analytically solvable stochastic models and direct numerical simulations. The statistics of the bending angle is qualitatively different in laminar and turbulent flows and exhibits a strong dependence on the topology of the velocity field. In particular, in two-dimensional turbulence, particles are either found in a fully extended or in a fully folded configuration; in three dimensions, the predominant configuration is the fully extended one.

  11. Conformations of Macromolecules and their Complexes from Heterogeneous Datasets

    CERN Document Server

    Schwander, P; Ourmazd, A

    2014-01-01

    We describe a new generation of algorithms capable of mapping the structure and conformations of macromolecules and their complexes from large ensembles of heterogeneous snapshots, and demonstrate the feasibility of determining both discrete and continuous macromolecular conformational spectra. These algorithms naturally incorporate conformational heterogeneity without resort to sorting and classification, or prior knowledge of the type of heterogeneity present. They are applicable to single-particle diffraction and image datasets produced by X-ray lasers and cryo-electron microscopy, respectively, and particularly suitable for systems not easily amenable to purification or crystallization.

  12. Arrangement of a nanostructure array to control equilibrium and nonequilibrium transports of macromolecules.

    Science.gov (United States)

    Yasui, Takao; Kaji, Noritada; Ogawa, Ryo; Hashioka, Shingi; Tokeshi, Manabu; Horiike, Yasuhiro; Baba, Yoshinobu

    2015-05-13

    Exploiting the nonequilibrium transport of macromolecules makes it possible to increase the separation speed without any loss of separation resolution. Here we report the arrangement of a nanostructure array in microchannels to control equilibrium and nonequilibrium transports of macromolecules. The direct observation and separation of macromolecules in the nanopillar array reported here are the first to reveal the nonequilibrium transport, which has a potential to overcome the intrinsic trade-off between the separation speed and resolution.

  13. Dual Use of Amphiphilic Macromolecules As Cholesterol Efflux Triggers and Inhibitors of Macrophage Athero-inflammation

    Science.gov (United States)

    Iverson, Nicole; Plourde, Nicole M.; Sparks, Sarah M.; Wang, Jinzhong; Patel, Ekta; Shah, Pratik; Lewis, Daniel R.; Zablocki, Kyle; Nackman, Gary B.; Uhrich, Kathryn E.; Moghe, Prabhas V.

    2011-01-01

    Activated vascular wall macrophages can rapidly internalize modified lipoproteins and escalate the growth of atherosclerotic plaques. This article proposes a biomaterials-based therapeutic intervention for depletion of non-regulated cholesterol accumulation and inhibition of inflammation of macrophages. Macromolecules with high scavenger receptor (SR)-binding activity were investigated for SR-mediated delivery of agonists to cholesterol-trafficking nuclear liver-X receptors. From a diverse feature space of a family of amphiphilic macromolecules of linear and aromatic mucic acid backbones modified with varied aliphatic chains and conjugated with differentially branched poly(ethylene glycol), a key molecule (carboxyl-terminated, C12-derivatized, linear mucic acid backbone) was selected for its ability to preferentially bind scavenger receptor A (SR-A) as the key target. At a basal level, this macromolecule suppressed the pro-inflammatory signaling of activated THP-1 macrophages while competitively lowering oxLDL uptake in vitro through scavenger receptor SRA-1 targeting. To further deplete intracellular cholesterol, the core macromolecule structure was exploited to solubilize a hydrophobic small molecule agonist for nuclear Liver-X Receptors, which regulate the efflux of intracellular cholesterol. The macromolecule-encapsulated agonist system was found to reduce oxLDL accumulation by 88% in vitro in comparison to controls. In vivo studies were designed to release the macromolecules (with or without encapsulated agonist) to injured carotid arteries within Sprague Dawley rats fed a high fat diet, conditions that yield enhanced cholesterol accumulation and macrophage recruitment. The macromolecules lowered intimal levels of accumulated cholesterol (50% for macromolecule alone; 70% for macromolecule-encapsulated agonist) and inhibited macrophage retention (92% for macromolecule; 96% for macromolecule-encapsulated agonist; 4 days) relative to non-treated controls. Thus

  14. WordPress 3 Cookbook

    CERN Document Server

    Shreves, Ric

    2011-01-01

    This is a Packt Cookbook, which means it contains step-by-step instructions to achieve a particular goal or solve a particular problem. There are plenty of screenshots and explained practical tasks to make comprehension quick and easy. This book is not specifically for developers or programmers; rather it can be used by anyone who wants to get more out of their WordPress blog by following step-by-step instructions. A basic knowledge of PHP/XHTML/CSS/WordPress is desirable but not necessary.

  15. Selective extraction of proteins and other macromolecules from biological samples using molecular imprinted polymers.

    Science.gov (United States)

    Stevenson, Derek; El-Sharif, Hazim F; Reddy, Subrayal M

    2016-11-01

    The accurate determination of intact macromolecules in biological samples, such as blood, plasma, serum, urine, tissue and feces is a challenging problem. The increased interest in macromolecules both as candidate drugs and as biomarkers for diagnostic purposes means that new method development approaches are needed. This review charts developments in the use of molecularly imprinted polymers first for small-molecular-mass compounds then for proteins and other macromolecules. Examples of the development of molecularly imprinted polymers for macromolecules are highlighted. The two main application areas to date are sensors and separation science, particularly SPE. Examples include peptides and polypeptides, lysozyme, hemoglobin, ovalbumin, bovine serum albumin and viruses.

  16. Genetically targeted fluorogenic macromolecules for subcellular imaging and cellular perturbation.

    Science.gov (United States)

    Magenau, Andrew J D; Saurabh, Saumya; Andreko, Susan K; Telmer, Cheryl A; Schmidt, Brigitte F; Waggoner, Alan S; Bruchez, Marcel P

    2015-10-01

    The alteration of cellular functions by anchoring macromolecules to specified organelles may reveal a new area of therapeutic potential and clinical treatment. In this work, a unique phenotype was evoked by influencing cellular behavior through the modification of subcellular structures with genetically targetable macromolecules. These fluorogen-functionalized polymers, prepared via controlled radical polymerization, were capable of exclusively decorating actin, cytoplasmic, or nuclear compartments of living cells expressing localized fluorgen-activating proteins. The macromolecular fluorogens were optimized by establishing critical polymer architecture-biophysical property relationships which impacted binding rates, binding affinities, and the level of internalization. Specific labeling of subcellular structures was realized at nanomolar concentrations of polymer, in the absence of membrane permeabilization or transduction domains, and fluorogen-modified polymers were found to bind to protein intact after delivery to the cytosol. Cellular motility was found to be dependent on binding of macromolecular fluorogens to actin structures causing rapid cellular ruffling without migration. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Terahertz spectroscopy of dry, hydrated, and thermally denatured biological macromolecules

    Science.gov (United States)

    Lipscomb, Dawn; Echchgadda, Ibtissam; Ibey, Bennett L.; Beier, Hope; Thomas, Robert J.; Peralta, Xomalin; Wilmink, Gerald J.

    2012-03-01

    Terahertz time-domain spectroscopy (THz-TDS) is an effective technique to probe the intermolecular and collective vibrational modes of biological macromolecules at THz frequencies. To date, the vast majority of spectroscopic studies have been performed on dehydrated biomolecular samples. Given the fact that all biochemical processes occur in aqueous environments and water is required for proper protein folding and function, we hypothesize that valuable information can be gained from spectroscopic studies performed on hydrated biomolecules in their native conformation. In this study, we used a THz-TDS system that exploits photoconductive techniques for THz pulse generation and freespace electro-optical sampling approaches for detection. We used the THz spectrometer to measure the time-dependent electric field of THz waves upon interaction with water, phosphate buffered saline (PBS), and collagen gels. By comparing these waveforms with references, we simultaneously determined each sample's index of refraction (n) and absorption coefficients (μa) as a function of frequency. Our data show that the properties we measure for the water, PBS and collagen are comparable to those reported in the literature. In the future, we plan to examine the effect that both temperature and pH have on the optical properties of other biological macromolecules. Studies will also be performed to compare our results to those generated using molecular dynamics simulations.

  18. 7 CFR 550.29 - Press releases.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 6 2010-01-01 2010-01-01 false Press releases. 550.29 Section 550.29 Agriculture... Program Management § 550.29 Press releases. Press releases or other forms of public notification will be... opportunity to review, in advance, all written press releases and any other written information to be...

  19. Local and international press digest

    CERN Multimedia

    2008-01-01

    The following are the top stories in the Maltese and the international press today. The Times gives prominence to the Prime Minister's flying visit to Geneva yesterday, where he signed a research cooperation agreement with CERN, the European nuclear research organisation.

  20. Law and the Student Press.

    Science.gov (United States)

    Stevens, George E.; Webster, John B.

    Court cases and legal decisions involving the student press in the late 1960s and early 1970s are brought together in this book in order to show how the law has been applied to school officials and student journalists in high school, college, and the underground. The ten chapters cover the following topics: censorship, libel, obscenity, contempt,…

  1. A new approach to determine press stiffness

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Wanheim, Tarras

    2004-01-01

    A new procedure is proposed for measuring press stiffness, including separated horizontal and vertical loading of the press frame. The load can be eccentrically positioned for measuring rotational stiffnesses. Two loading devices and corresponding measuring equipment for registration of press...... deflections are designed. The press stiffness is presented as a 6 by 6 flexibility matrix. The approach has been tested by measuring the stiffness of a 5000 kN O-frame, ring element, hydraulic press, a 10000 kN O-frame, pillar element, hydraulic press and a 10000 kN O-frame, ring element mechanical press...

  2. Recent Advances in Non-Invasive Delivery of Macromolecules using Nanoparticulate Carriers System.

    Science.gov (United States)

    Shadab, Md; Haque, Shadabul; Sheshala, Ravi; Meng, Lim Wei; Meka, Venkata Srikanth; Ali, Javed

    2017-01-01

    The drug delivery of macromolecules such as proteins and peptides has become an important area of research and represents the fastest expanding share of the market for human medicines. The most common method for delivering macromolecules is parenterally. However parenteral administration of some therapeutic macromolecules has not been effective because of their rapid clearance from the body. As a result, most macromolecules are only therapeutically useful after multiple injections, which causes poor compliance and systemic side effects. Therefore, there is a need to improve delivery of therapeutic macromolecules to enable non-invasive delivery routes, less frequent dosing through controlled-release drug delivery, and improved drug targeting to increase efficacy and reduce side effects. Non-invasive administration routes such as intranasal, pulmonary, transdermal, ocular and oral delivery have been attempted intensively by formulating macromolecules into nanoparticulate carriers system such as polymeric and lipidic nanoparticles. This review discusses barriers to drug delivery and current formulation technologies to overcome the unfavorable properties of macromolecules via non-invasive delivery (mainly intranasal, pulmonary, transdermal oral and ocular) with a focus on nanoparticulate carrier systems. This review also provided a summary and discussion of recent data on non-invasive delivery of macromolecules using nanoparticulate formulations. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  3. The Origin and the Future of Macromolecule Ionization by Laser Irradiation

    Institute of Scientific and Technical Information of China (English)

    KoichiTanaka

    2004-01-01

    Starting in 1984,a Shimadzu Corporation Central Research Laboratory development team set about the challenge of developinng an instrument for analyzing macromolecules such as proteins. At the time, the conventional consensus among chemists was that, “laser ionization of macromolecules exceeding a molecular weight of 10,000 is imposible”. However, not being a chemist, I was unaware of this widelyheld belief.

  4. Organometallic macromolecules with piano stool coordination repeating units: chain configuration and stimulated solution behaviour.

    Science.gov (United States)

    Cao, Kai; Ward, Jonathan; Amos, Ryan C; Jeong, Moon Gon; Kim, Kyoung Taek; Gauthier, Mario; Foucher, Daniel; Wang, Xiaosong

    2014-09-11

    Theoretical calculations illustrate that organometallic macromolecules with piano stool coordination repeating units (Fe-acyl complex) adopt linear chain configuration with a P-Fe-C backbone surrounded by aromatic groups. The macromolecules show molecular weight-dependent and temperature stimulated solution behaviour in DMSO.

  5. The flavonoid herbacetin diglucoside as a constituent of the lignan macromolecule from flaxseed hulls

    NARCIS (Netherlands)

    Struijs, K.; Vincken, J.P.; Verhoef, R.P.; Oostveen, van W.H.M.; Voragen, A.G.J.; Gruppen, H.

    2007-01-01

    Lignans in flaxseed are known to be part of a macromolecule in which they are connected through the linker-molecule hydroxy-methyl-glutaric acid (HMGA). In this study, the lignan macromolecule was extracted from flaxseed hulls and degraded to its monomeric constituents by complete saponification. Be

  6. Responsive inverse opal hydrogels for the sensing of macromolecules.

    Science.gov (United States)

    Couturier, Jean-Philippe; Sütterlin, Martin; Laschewsky, André; Hettrich, Cornelia; Wischerhoff, Erik

    2015-05-26

    Dual responsive inverse opal hydrogels were designed as autonomous sensor systems for (bio)macromolecules, exploiting the analyte-induced modulation of the opal's structural color. The systems that are based on oligo(ethylene glycol) macromonomers additionally incorporate comonomers with various recognition units. They combine a coil-to-globule collapse transition of the LCST type with sensitivity of the transition temperature toward molecular recognition processes. This enables the specific detection of macromolecular analytes, such as glycopolymers and proteins, by simple optical methods. While the inverse opal structure assists the effective diffusion even of large analytes into the photonic crystal, the stimulus responsiveness gives rise to strong shifts of the optical Bragg peak of more than 100 nm upon analyte binding at a given temperature. The systems' design provides a versatile platform for the development of easy-to-use, fast, and low-cost sensors for pathogens.

  7. Covalent binding of foreign chemicals to tissue macromolecules. [Acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Thorgeirsson, S.S.; Wirth, P.J.

    1977-03-01

    In vivo and in vitro covalent binding of foreign chemicals to tissue macromolecules via metabolic activation is described, using the analgesic acetaminophen as an example. Acetaminophen is metabolized through a variety of pathways. The arylating metabolite is formed by a cytochrome P-450 dependent N-hydroxylation process. The resulting hydroxamic acid is then conjugated with glutathione, and the resulting conjugate is subsequently excreted as the mercapturic acid in the urine. It is not until the glutathione concentration is reduced to about 20% of the initial concentration that covalent binding of acetaminophen to amino acids of proteins occurs and subsequent liver necrosis is seen. The extent of in vitro binding correlates with treatments that alter hepatic necrosis and in vivo binding, indicating that in vitro binding is a valid index of acetaminophen hepatotoxicity. A simple bacterial test system for detecting chemical carcinogens as mutagens is described.

  8. Novel macromolecules derived from coumarin: synthesis and antioxidant activity

    Science.gov (United States)

    Al-Amiery, Ahmed A.; Al-Majedy, Yasameen K.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

    2015-07-01

    The rational design of 4-hydroxycoumarins with tailor-made antioxidant activities is required nowadays due to the wide variety of pharmacologically significant, structurally interesting of coumarins and researcher orientation toward green chemistry and natural products. A simple and unique coumarins have been achieved by reaction of 4-hydroxycoumarin with aromatic aldehyde accompanied with the creation of a macromolecules have 2-aminothiazolidin-4-one. The molecular structures of the compounds were characterized by the Fourier transformation infrared and Nuclear magnetic resonance spectroscopies, in addition to CHN analysis. The scavenging abilities of new compounds against stable DPPH radical (DPPH•) and hydrogen peroxide were done and the results show that the compounds exhibited high antioxidant activates.

  9. Surface induced self-organization of comb-like macromolecules

    Science.gov (United States)

    Popov, Konstantin I; Palyulin, Vladimir V; Möller, Martin; Khokhlov, Alexei R

    2011-01-01

    Summary We present a review of the theoretical and experimental evidence for the peculiar properties of comb copolymers, demonstrating the uniqueness of these materials among other polymer architectures. These special properties include an increase in stiffness upon increasing side-chain length, the spontaneous curvature of adsorbed combs, rod–globule transition, and specific intramolecular self-assembly. We also propose a theory of chemically heterogeneous surface nanopattern formation in ultrathin films of comblike macromolecules containing two different types (A and B) of incompatible side chains (so-called binary combs). Side chains of the binary combs are strongly adsorbed on a surface and segregated with respect to the backbone. The thickness of surface domains formed by the B side chains is controlled by the interaction with the substrate. We predict the stability of direct and inverse disc-, torus- and stripelike nanostructures. Phase diagrams of the film are constructed. PMID:22003463

  10. Supramolecular Chemistry and Mechanochemistry of Macromolecules: Recent Advances by Single-Molecule Force Spectroscopy.

    Science.gov (United States)

    Cheng, Bo; Cui, Shuxun

    2015-01-01

    Atomic force spectroscopy (AFM)-based single-molecule force spectroscopy (SMFS) was invented in the 1990s. Since then, SMFS has been developed into a powerful tool to study the inter- and intra-molecular interactions of macromolecules. Using SMFS, a number of problems in the field of supramolecular chemistry and mechanochemistry have been studied at the single-molecule level, which are not accessible by traditional ensemble characterization methods. In this review, the principles of SMFS are introduced, followed by the discussion of several problems of contemporary interest at the interface of supramolecular chemistry and mechanochemistry of macromolecules, including single-chain elasticity of macromolecules, interactions between water and macromolecules, interactions between macromolecules and solid surface, and the interactions in supramolecular polymers.

  11. Teach yourself visually WordPress

    CERN Document Server

    Majure, Janet

    2012-01-01

    Get your blog up and running with the latest version of WordPress WordPress is one of the most popular, easy-to-use blogging platforms and allows you to create a dynamic and engaging blog, even if you have no programming skills or experience. Ideal for the visual learner, Teach Yourself VISUALLY WordPress, Second Edition introduces you to the exciting possibilities of the newest version of WordPress and helps you get started, step by step, with creating and setting up a WordPress site. Author and experienced WordPress user Janet Majure shares advice, insight, and best practices for taking full

  12. Smashing WordPress Beyond the Blog

    CERN Document Server

    Hedengren, Thord Daniel

    2012-01-01

    The ultimate guide to WordPress, from the world's most popular resource for web designers and developers As one of the hottest tools on the web today for creating a blog, WordPress has evolved to be much more that just a blogging platform and has been pushed beyond its original purpose. With this new edition of a perennially popular WordPress resource, Smashing Magazine offers you the information you need so you can maximize the potential and power of WordPress. WordPress expert Thord Daniel Hedengren takes you beyond the basic blog to show you how to leverage the capabilities of WordPress to

  13. Prediction of Pressing Quality for Press-Fit Assembly Based on Press-Fit Curve and Maximum Press-Mounting Force

    Directory of Open Access Journals (Sweden)

    Bo You

    2015-01-01

    Full Text Available In order to predict pressing quality of precision press-fit assembly, press-fit curves and maximum press-mounting force of press-fit assemblies were investigated by finite element analysis (FEA. The analysis was based on a 3D Solidworks model using the real dimensions of the microparts and the subsequent FEA model that was built using ANSYS Workbench. The press-fit process could thus be simulated on the basis of static structure analysis. To verify the FEA results, experiments were carried out using a press-mounting apparatus. The results show that the press-fit curves obtained by FEA agree closely with the curves obtained using the experimental method. In addition, the maximum press-mounting force calculated by FEA agrees with that obtained by the experimental method, with the maximum deviation being 4.6%, a value that can be tolerated. The comparison shows that the press-fit curve and max press-mounting force calculated by FEA can be used for predicting the pressing quality during precision press-fit assembly.

  14. Synthesis of biocontrol macromolecules by derivative of chitosan with surfactin and antifungal evaluation.

    Science.gov (United States)

    Yuan, Bo; Xu, Pei-Yuan; Zhang, Yue-Ji; Wang, Pei-Pei; Yu, Hong; Jiang, Ji-Hong

    2014-05-01

    A derivative of chitosan was prepared with chitosan and β-cyclodextrins, which was synthesized by the immobilization reaction, as a carrier to adsorb surfactin produced from Bacillus amyloliquefaciens and got biological macromolecules. The antifungal activity against three sapstain fungi by a combination of macromolecules was tested. The results showed that the macromolecules inhibited the mycelium growth of sapstain fungi Lasiodiplodia rubropurpurea, L. crassispora, and L. theobromae by about 73.22%, 76.72%, and 70.22%, respectively. The macromolecules were relatively thermally stable with more than 50% of the antifungal activity even after being held at 121°C for 30 min. Meanwhile, the activity of the macromolecules remained more than 55% at a pH value ranging from 4 to 12. The macromolecules were resistant to hydrolysis by most protein-denaturing detergents and other enzymes. The results indicated the macromolecules might provide an alternative bioresource for the bio-control of sapstain. Copyright © 2014. Published by Elsevier B.V.

  15. Transpapillary (Nipple) Delivery of Macromolecules to the Breast: Proof of Concept Study.

    Science.gov (United States)

    Dave, Kaushalkumar; Alsharif, Fahd M; Perumal, Omathanu

    2016-11-07

    Localized drug delivery to the breast can maximize drug concentration at the target site and minimize systemic drug distribution. To this end, the study explored the feasibility of delivering macromolecules to the breast through mammary papilla (nipple). The in vitro penetration of model macromolecules (inulin, dextran, ovalbumin, and bovine serum albumin) varying in molecular weight from 5 to 67 kDa was studied using excised porcine and human mammary papilla. The penetration of macromolecules decreased with increase in molecular weight. The penetration of the macromolecules was significantly higher through the mammary papilla in comparison to breast skin. In vitro penetration of the macromolecules was similar in human and porcine mammary papilla. Iontophoresis was used to enhance the transport of bovine serum albumin (BSA) through the mammary papilla. The flux and cumulative amount permeated was increased by 2- to 4-fold by iontophoresis. The macromolecules were transported through the ducts and the surrounding connective tissue in the mammary papilla. Overall, the results from this study for the first time demonstrate the feasibility of delivering macromolecules through the mammary papilla. These findings have implications for developing safe and effective localized therapeutic approaches for breast cancer.

  16. WordPress Website Development

    OpenAIRE

    Lassila, Joonas

    2016-01-01

    The aim of this Bachelor’s thesis was to develop a WordPress mobile-first style website for the customer, Pohjois-Suomen Pesis. The main purpose of the development was to learn website designing principles and create a responsive website for the mobile and desktop platforms. The development process began defining the requirements of the website and creating the requirements document. Then next step was learning how to design a website layout and to choose the colour scheme for the site. T...

  17. 7 CFR 58.421 - Press.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Press. 58.421 Section 58.421 Agriculture Regulations... Plants Approved for USDA Inspection and Grading Service 1 Equipment and Utensils § 58.421 Press. The cheese press should be constructed of stainless steel and all joints welded and all surfaces, seams...

  18. 28 CFR 540.64 - Press pools.

    Science.gov (United States)

    2010-07-01

    ... 28 Judicial Administration 2 2010-07-01 2010-07-01 false Press pools. 540.64 Section 540.64... PERSONS IN THE COMMUNITY Contact With News Media § 540.64 Press pools. (a) The Warden may establish a press pool whenever he or she determines that the frequency of requests for interviews and...

  19. Incremental Pressing Technique in Explosive Charge

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    A pressing technique has become available that might be useful for compressing granular explosives. If the height-diameter ratio of the charge is unfavorable,the high quality charge can not be obtained with the common single-action pressing. This paper presents incremental pressing technique, which can obtain the charge with higher overall density and more uniform density.

  20. Yale University Press: Disseminating "Lux et Veritas"?

    Science.gov (United States)

    Parrott, John B.

    2010-01-01

    America's university presses are situated within a network of over one hundred universities, learned societies, and scholarly associations. According to a pamphlet put out by the American Association of University Presses, these presses "make available to the broader public the full range and value of research generated by university faculty."…

  1. The Small Book Press: A Cultural Essential.

    Science.gov (United States)

    Henderson, Bill

    1984-01-01

    Discussion of small literary book publishers notes works of small-press authors (Thomas Paine, Washington Irving, Walt Whitman, Mark Twain, Upton Sinclair, Anais Nin); today's outstanding presses (Creative Arts Book Company, Persea Books, Full Court Press, Reed and Cannon Company, Tuumba Books); and role of little magazines. Thirty-seven…

  2. Physical Delivery of Macromolecules using High-Aspect Ratio Nanostructured Materials.

    Science.gov (United States)

    Lee, Kunwoo; Lingampalli, Nithya; Pisano, Albert P; Murthy, Niren; So, Hongyun

    2015-10-28

    There is great need for the development of an efficient delivery method of macromolecules, including nucleic acids, proteins, and peptides, to cell cytoplasm without eliciting toxicity or changing cell behavior. High-aspect ratio nanomaterials have addressed many challenges present in conventional methods, such as cell membrane passage and endosomal degradation, and have shown the feasibility of efficient high-throughput macromolecule delivery with minimal perturbation of cells. This review describes the recent advances of in vitro and in vivo physical macromolecule delivery with high-aspect ratio nanostructured materials and summarizes the synthesis methods, material properties, relevant applications, and various potential directions.

  3. Channel-Forming Bacterial Toxins in Biosensing and Macromolecule Delivery

    Directory of Open Access Journals (Sweden)

    Philip A. Gurnev

    2014-08-01

    Full Text Available To intoxicate cells, pore-forming bacterial toxins are evolved to allow for the transmembrane traffic of different substrates, ranging from small inorganic ions to cell-specific polypeptides. Recent developments in single-channel electrical recordings, X-ray crystallography, protein engineering, and computational methods have generated a large body of knowledge about the basic principles of channel-mediated molecular transport. These discoveries provide a robust framework for expansion of the described principles and methods toward use of biological nanopores in the growing field of nanobiotechnology. This article, written for a special volume on “Intracellular Traffic and Transport of Bacterial Protein Toxins”, reviews the current state of applications of pore-forming bacterial toxins in small- and macromolecule-sensing, targeted cancer therapy, and drug delivery. We discuss the electrophysiological studies that explore molecular details of channel-facilitated protein and polymer transport across cellular membranes using both natural and foreign substrates. The review focuses on the structurally and functionally different bacterial toxins: gramicidin A of Bacillus brevis, α-hemolysin of Staphylococcus aureus, and binary toxin of Bacillus anthracis, which have found their “second life” in a variety of developing medical and technological applications.

  4. Channel-forming bacterial toxins in biosensing and macromolecule delivery.

    Science.gov (United States)

    Gurnev, Philip A; Nestorovich, Ekaterina M

    2014-08-21

    To intoxicate cells, pore-forming bacterial toxins are evolved to allow for the transmembrane traffic of different substrates, ranging from small inorganic ions to cell-specific polypeptides. Recent developments in single-channel electrical recordings, X-ray crystallography, protein engineering, and computational methods have generated a large body of knowledge about the basic principles of channel-mediated molecular transport. These discoveries provide a robust framework for expansion of the described principles and methods toward use of biological nanopores in the growing field of nanobiotechnology. This article, written for a special volume on "Intracellular Traffic and Transport of Bacterial Protein Toxins", reviews the current state of applications of pore-forming bacterial toxins in small- and macromolecule-sensing, targeted cancer therapy, and drug delivery. We discuss the electrophysiological studies that explore molecular details of channel-facilitated protein and polymer transport across cellular membranes using both natural and foreign substrates. The review focuses on the structurally and functionally different bacterial toxins: gramicidin A of Bacillus brevis, α-hemolysin of Staphylococcus aureus, and binary toxin of Bacillus anthracis, which have found their "second life" in a variety of developing medical and technological applications.

  5. Graphical Methods for Quantifying Macromolecules through Bright Field Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Hang; DeFilippis, Rosa Anna; Tlsty, Thea D.; Parvin, Bahram

    2008-08-14

    Bright ?eld imaging of biological samples stained with antibodies and/or special stains provides a rapid protocol for visualizing various macromolecules. However, this method of sample staining and imaging is rarely employed for direct quantitative analysis due to variations in sample fixations, ambiguities introduced by color composition, and the limited dynamic range of imaging instruments. We demonstrate that, through the decomposition of color signals, staining can be scored on a cell-by-cell basis. We have applied our method to Flbroblasts grown from histologically normal breast tissue biopsies obtained from two distinct populations. Initially, nuclear regions are segmented through conversion of color images into gray scale, and detection of dark elliptic features. Subsequently, the strength of staining is quanti?ed by a color decomposition model that is optimized by a graph cut algorithm. In rare cases where nuclear signal is significantly altered as a result of samplepreparation, nuclear segmentation can be validated and corrected. Finally, segmented stained patterns are associated with each nuclear region following region-based tessellation. Compared to classical non-negative matrix factorization, proposed method (i) improves color decomposition, (ii) has a better noise immunity, (iii) is more invariant to initial conditions, and (iv) has a superior computing performance

  6. Quantification of the Molecular Topology for Hierarchical Macromolecules

    Science.gov (United States)

    Beaucage, Gregory

    2009-03-01

    Hierarchical structures are often produced from ramified macromolecules such as comb, star, hyperbranched and dendritic polymers. We have recently derived a method for the description of complex molecular and nanostructural topologies based on a statistical analysis [1,2]. The method has been applied to a wide range of hierarchical materials from long chain branched polyolefins, hyperbranched polymers [3], star polymers, H-branched polymers to cyclics, biopolymers [4], and branched nanostructured aggregates. This method, when applied to neutron scattering data, yields the mole fraction of a structure involved in branching, the number of branch sites, the average branch length, and the number if inner chain segments. Further, quantitative measures of the convolution or tortuosity of the structure and the connectivity of the branching network can be made, opening a new window for our understanding of complex molecular topologies. This understanding has recently been applied to biological chain molecules to understand protein and RNA folding [4] for example as well as to aggregated, nanostructured, carbon soot. [0pt] [1] Beaucage, G, Phys. Rev. E 2004, 70, 031401. [2] Kulkarni, AS & Beaucage, G, J. Polym. Sci. Part B: Polym. Phys. 2006, 44, 1395. [3] Kulkarni, AS & Beaucage, G, Macromol. Rapid Comm. 2007, 28, 1312.?4) Beaucage, G, Biophysical J. 2008, 95, 503.

  7. The Circle of Dust: From Nanoparticles to Macromolecules and Beyond

    Science.gov (United States)

    Micelotta, E.; Jones, A.; Bocchio, M.; Cami, J.; Peeters, E.; Bernard-Salas, J.

    There is increasing observational evidence that a non-negligible fraction of the cosmic carbon is locked up into macromolecules and nanoparticles. Carbonaceous nanoparticles and Hydrogenated Amorphous Carbon (HAC) nanoparticles represent one of the main components of interstellar dust. HAC nanoparticles have been proposed as a viable carrier for the Unidentified InfraRed (UIR) bands, which dominate the mid-infrared spectrum of almost any astronomical object. Fullerene molecules C60 and C70 have been detected in various circumstellar and interstellar environments. We present some of our recent results about the evolution of such carbonaceous structures and the possible connections between each other. We show how photo-processing of HAC nanoparticles can lead to the formation of C60 and C70 in space. There the low density of the gas precludes the formation of fullerene materials following known vaporization or combustion synthesis routes, even on astronomical timescales. We then discuss the processing of small hydrocarbon dust by energetic ions and electrons under extreme conditions, e.g., in shocked regions. Finally, we derive the astrophysical implications of such processing in terms of the observed emission.

  8. Professional WordPress design and development

    CERN Document Server

    Williams, Brad; Stern, Hal

    2014-01-01

    The highest rated WordPress development and design book on the market is back with an all new third edition. Professional WordPress is the only WordPress book targeted to developers, with advanced content that exploits the full functionality of the most popular CMS in the world. Fully updated to align with WordPress 4.1, this edition has updated examples with all new screenshots, and full exploration of additional tasks made possible by the latest tools and features. You will gain insight into real projects that currently use WordPress as an application framework, as well as the basic usage a

  9. RELATIONSHIP BETWEEN COMPACTING PRESSURE AND CONDITIONS IN PRESSING CHAMBER DURING BIOMASS PRESSING

    Directory of Open Access Journals (Sweden)

    Peter Križan

    2016-02-01

    Full Text Available In this paper, we will present the impact of the conditions in pressing chambers during the pressing of wooden briquettes. The conditions in pressing chambers can significantly impact the resulting compacting pressure required for the pressing of briquettes. In the introduction, we show which parameters of the pressing chamber during pressing can impact the resulting compacting pressure. The experiment results which are shown in this paper described the detected impact of some important pressing chamber parameters. This experiment aims to detect the pressing chamber length impact and the impact of the way of pressing. By setting the pressing conditions, we will be able to achieve the suitable resulting compacting pressure with respect to the required final briquettes quality.

  10. COMPUTATIONAL METHODS FOR STUDYING THE INTERACTION BETWEEN POLYCYCLIC AROMATIC HYDROCARBONS AND BIOLOGICAL MACROMOLECULES

    Science.gov (United States)

    Computational Methods for Studying the Interaction between Polycyclic Aromatic Hydrocarbons and Biological Macromolecules .The mechanisms for the processes that result in significant biological activity of PAHs depend on the interaction of these molecules or their metabol...

  11. Electric Birefringence: A Simple Apparatus for Determining Physical Parameters of Macromolecules and Colloids.

    Science.gov (United States)

    Trimm, Harold H.; And Others

    1984-01-01

    Describes a birefringence apparatus that can be assembled for less than $100 and can be used to measure both the dimensions and dipole moments of many macromolecules. Details are given of the construction and manipulation of the apparatus. (JN)

  12. Development of modified release gliclazide biological macromolecules using natural biodegradable polymers.

    Science.gov (United States)

    Prajapati, Vipulkumar D; Mashru, Krupa H; Solanki, Himanshu K; Jani, Girish K

    2013-04-01

    Modified release biological macromolecules (beads) of gliclazide using sodium alginate combined with either gellan gum or pectin in different ratios were prepared by Ionotropic gelation method. Biological macromolecules were evaluated for different physico-chemical parameters. Increase in polymers proportion showed difficulty in production of biological macromolecules due to high viscosity of dispersion. As the polymer concentration increases, the swelling and entrapment efficiency of drug increased. Compared to all other batches and commercial modified release gliclazide tablet, formulated biological macromolecules of sodium alginate with pectin (2:1 ratio) and with gellan gum (6:0.75 ratio) exhibited spherical shape, biphasic in vitro release profile and initial high drug release followed by moderate release up to 12 h as matrix diffusion kinetics and Higuchi model as well as Korsmeyer model. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. IDEAL: ACADEMIC PRESS JOURNALS ONLINE

    CERN Multimedia

    The Library

    2001-01-01

    All Academic Press journals are available online to CERN users for a test period which will last until the end of July. The service 'IDEALIBRARY' includes 174 scientific journals that cover several domains, ranging from engineering to mathematics, computing and physics. Titles covered are among others 'Atomic Data and Nuclear Data Tables', 'Nuclear Data Sheets', 'Annals of Physics', 'Journal of Parallel and Distributed Computing'. Reference citations present in each article are linked to the corresponding full text, when the latter is published by a member of the CrossRef consortium (members are: Elsevier, APS, AIP and others). Therefore, the navigation between articles and references is uninterrupted. A search engine allows queries by author, title and publication year. See http://www.idealibrary.com. At present the Library is evaluating a site license offer proposed by the publisher.

  14. [The press and family planning].

    Science.gov (United States)

    Abraham De D'ornellas, R

    1987-01-01

    The treatment in the press of family planning hinges on two fundamental factors: the taboo of the leftist groups and the taboo of the Catholic Church, whose head is against abortion under any circumstances. Leftist views insinuate that family planning is the genocidal plan of North American imperialists against the Third World and, in particular, against Latin America. This genocidal plan is supposed to subject poor populations to international schemes. In the press family planning is often treated in a sanctimonious fashion, lumping it together with topics like pornography, sex, and violence. In 1983 the daily newspaper Expreso published a supplement running every week for almost three months about the issue of population, which dealt fairly extensively with such topics as population and housing, education, employment, and urban proliferation, as well as responsible parenthood and child survival. In addition, there was a detailed description of contraceptive methods. In October 1986 another surprising thing happened: the President of Peru talked about the topic of family planning, which at the time was an act of courage. Since then much has changed; the whole world is interested in family planning and certain aspects of population. Since October 1986 more has been published in this domain than during the preceding 20 years. In contrast, the Church reacted differently to this issue: after some initial caution, the conference of Peruvian bishops attacked all methods of modern contraceptives and private institutions of family planning. The information boom in family planning will certainly continue. At the moment this flood of articles and editorials about the issue is an expression of the anxiety of families related to uncontrolled reproduction and the fear of overpopulation in large cities devoid of minimal services.

  15. Insights and Lessons from a Scientific Conference on Non-Invasive Delivery of Macromolecules.

    Science.gov (United States)

    Savla, Ronak; Mrsny, Randall J; Park, Kinam; Aubert, Isabelle; Stamoran, Cornell

    2017-06-01

    A growing share of the pharmaceutical development pipeline is occupied by macromolecule drugs, which are primarily administered by injection. Despite decades of attempts, non-invasive delivery of macromolecules has seen only a few success stories. Potential benefits of non-invasive administration include better patient acceptance and adherence and potentially better efficacy and safety. Greater inter-disciplinary dialogue and collaboration are integral to realizing these benefits.

  16. Community Satisfaction of Sundanese Language Press

    Directory of Open Access Journals (Sweden)

    Parulian Sitompul

    2014-07-01

    Full Text Available The 1960s could be called the golden age of Sunda press. At the present time the press Sunda suffered a setback in a various of activities. While in the middle of advancements in printing and layout technology, Sundanese language press is currently lagging far behind the national press. The research problem is how people's satisfaction to Sundanese language press. Therefore, the purpose of the study was to determine the motive, knowledge, and community satisfaction of the Sundanese language press. Method used is descriptive quantitative. Sample of 50 respondents which is 10% of the entire community reading Sundanese language press in the two districts of Bogor City. The results showed that the communitiy's motivation to read the Sundanese language press because of the Sundanese language used, and used by all members of the family. In addition, community already knows the function of the Sundanese language press. Eventhough it has not met their expectations, but the people are satisfied with the existence of Sundanese language press that they read.

  17. Sub-terahertz resonance spectroscopy of biological macromolecules and cells

    Science.gov (United States)

    Globus, Tatiana; Moyer, Aaron; Gelmont, Boris; Khromova, Tatyana; Sizov, Igor; Ferrance, Jerome

    2013-05-01

    Recently we introduced a Sub-THz spectroscopic system for characterizing vibrational resonance features from biological materials. This new, continuous-wave, frequency-domain spectroscopic sensor operates at room temperature between 315 and 480 GHz with spectral resolution of at least 1 GHz and utilizes the source and detector components from Virginia Diode, Inc. In this work we present experimental results and interpretation of spectroscopic signatures from bacterial cells and their biological macromolecule structural components. Transmission and absorption spectra of the bacterial protein thioredoxin, DNA and lyophilized cells of Escherichia coli (E. coli), as well as spores of Bacillus subtillis and B. atrophaeus have been characterized. Experimental results for biomolecules are compared with absorption spectra calculated using molecular dynamics simulation, and confirm the underlying physics for resonance spectroscopy based on interactions between THz radiation and vibrational modes or groups of modes of atomic motions. Such interactions result in multiple intense and narrow specific resonances in transmission/absorption spectra from nano-gram samples with spectral line widths as small as 3 GHz. The results of this study indicate diverse relaxation dynamic mechanisms relevant to sub-THz vibrational spectroscopy, including long-lasting processes. We demonstrate that high sensitivity in resolved specific absorption fingerprints provides conditions for reliable detection, identification and discrimination capability, to the level of strains of the same bacteria, and for monitoring interactions between biomaterials and reagents in near real-time. Additionally, it creates the basis for the development of new types of advanced biological sensors through integrating the developed system with a microfluidic platform for biomaterial samples.

  18. The flavonoid herbacetin diglucoside as a constituent of the lignan macromolecule from flaxseed hulls.

    Science.gov (United States)

    Struijs, Karin; Vincken, Jean-Paul; Verhoef, René; van Oostveen-van Casteren, Willemiek H M; Voragen, Alphons G J; Gruppen, Harry

    2007-04-01

    Lignans in flaxseed are known to be part of a macromolecule in which they are connected through the linker-molecule hydroxy-methyl-glutaric acid (HMGA). In this study, the lignan macromolecule was extracted from flaxseed hulls and degraded to its monomeric constituents by complete saponification. Besides secoisolariciresinol diglucoside (SDG), the phenolic compounds p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeAG) were isolated, which was expected based on indications from the literature. Also the flavonoid herbacetin diglucoside (HDG) was found. The presence of HDG was confirmed by NMR following preparative RP-HPLC purification. Also the presence of the three other constituents (CouAG, FeAG and SDG) was confirmed by NMR. To prove that HDG is a substructure of the lignan macromolecule, the macromolecule was fragmented by partial saponification. A fragment consisting of HDG and HMGA was indicated. This fragment was isolated by preparative RP-HPLC and its identity was confirmed by NMR. It is concluded that the flavonoid HDG is a substructure of the lignan macromolecule from flaxseed hulls and that it is incorporated in the macromolecule via the same linker-molecule as SDG.

  19. PlaMoM: a comprehensive database compiles plant mobile macromolecules

    Science.gov (United States)

    Guan, Daogang; Yan, Bin; Thieme, Christoph; Hua, Jingmin; Zhu, Hailong; Boheler, Kenneth R.; Zhao, Zhongying; Kragler, Friedrich; Xia, Yiji; Zhang, Shoudong

    2017-01-01

    In plants, various phloem-mobile macromolecules including noncoding RNAs, mRNAs and proteins are suggested to act as important long-distance signals in regulating crucial physiological and morphological transition processes such as flowering, plant growth and stress responses. Given recent advances in high-throughput sequencing technologies, numerous mobile macromolecules have been identified in diverse plant species from different plant families. However, most of the identified mobile macromolecules are not annotated in current versions of species-specific databases and are only available as non-searchable datasheets. To facilitate study of the mobile signaling macromolecules, we compiled the PlaMoM (Plant Mobile Macromolecules) database, a resource that provides convenient and interactive search tools allowing users to retrieve, to analyze and also to predict mobile RNAs/proteins. Each entry in the PlaMoM contains detailed information such as nucleotide/amino acid sequences, ortholog partners, related experiments, gene functions and literature. For the model plant Arabidopsis thaliana, protein–protein interactions of mobile transcripts are presented as interactive molecular networks. Furthermore, PlaMoM provides a built-in tool to identify potential RNA mobility signals such as tRNA-like structures. The current version of PlaMoM compiles a total of 17 991 mobile macromolecules from 14 plant species/ecotypes from published data and literature. PlaMoM is available at http://www.systembioinfo.org/plamom/. PMID:27924044

  20. Determination of 6 stiffnesses for a press

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Eriksen, Morten; Wanheim, Tarras

    2000-01-01

    the workpiece will result in deflections of the press, which will decrease the tolerances of the component. At present, it is possible to measure the reaction forces from the workpiece, for instance by use of the model material technique as described in [1-2]. If the stiffness and clearances of the press...... is known too, the final dimensions can be predicted by divide the force by the stiffness and add the clearance. If the stiffness of the press is known, it is possible to optimize the orientation of the workpiece too, so the direction, in which the best tolerances is demanded, is equal to the direction...... in which the press has the highest stiffness. Furthermore, knowledge about the stiffnesses of all presses in a production system makes it possible to choose the press which best fit to a specific process....

  1. Smashing WordPress Beyond the Blog

    CERN Document Server

    Hedengren, Thord Daniel

    2011-01-01

    Smashing WordPress shows you how to utilize the power of the WordPress platform, and provides a creative spark to help you build WordPress-powered sites that go beyond the obvious. The second edition of Smashing WordPress has been updated for WordPress 3.1+, which includes internal, custom post types, the admin bar, and lots of other useful new features. You will learn the core concepts used to post types, the admin bar, and lots of other useful new features. You will learn the core concepts used to build just about anything in WordPress, resulting in fast deployments and greater design flexib

  2. PRESS FREEDOM IN SINGAPORE AND MALAYSIA: DEFAMATION

    OpenAIRE

    Georgia Kate Chapman

    2015-01-01

    This paper focuses on the arguments around restriction on freedom of the press in the Strong States of Singapore and Malaysia. It assesses the presence of constraints on press freedoms in democratic western countries imposed by corporation rather than state and the similar effects that these constraints may have on bias present in publicly accessible news reporting. It argues that independence of the press does not just require protection from legal and executive regulation, but also protecti...

  3. WordPress 3.7 complete

    CERN Document Server

    Król, Karol

    2013-01-01

    WordPress 3.5 Complete: Third Edition is a comprehensive and step-by-step tutorial packed with screenshots and examples to make it easy and quick to pick it up.This WordPress book is a guide to WordPress for online publishers and web developers. If you are new to blogging and want to create your own blog or website from scratch, then ""WordPress 3.5 Complete: Third Edition"" is for you. No prior knowledge of HTML/CSS or PHP is required.

  4. Activation of Selected Core Muscles during Pressing

    Directory of Open Access Journals (Sweden)

    Thomas W. Nesser

    2015-10-01

    Full Text Available Introduction: Unstable surface training is often used to activate core musculature during resistance training. Unfortunately, unstable surface training is risky and leads to detraining. Purpose: The purpose of this study was to determine core muscle activation during stable surface ground-based lifts. Methods: Fourteen recreational trained and former NCAA DI athletes (weight 84.2 ± 13.3 kg; height 176.0 ± 9.5 cm; age 20.9 ± 2.0 years volunteered for participation. Subjects completed two ground-based lifts: overhead press and push-press. Surface EMG was recorded from 4 muscles on the right side of the body (Rectus Abdominus (RA, External Oblique (EO, Transverse Abdominus (TA, and Erector Spinae (ES. Results: Paired sample T-tests identified significant muscle activation differences between the overhead press and the push-press included ES and EO. Average and peak EMG for ES was significantly greater in push-press (P<0.01. Anterior displacement of COP was significantly greater in push-press compared to overhead press during the eccentric phase. Conclusion: The push-press was identified as superior in core muscle activation when compared to the overhead pressing exercise. Keywords: torso, stability, weight lifting, resistance training

  5. Towards a more responsible press

    Directory of Open Access Journals (Sweden)

    Taimur ul Hassan

    2012-12-01

    Full Text Available The article analyses Pakistan’s newspapers’ performance with regard to civil society in2003 by using content analysis approach. There is no gainsaying that a strong civil society guaranteesa strong democracy. In Pakistan, spells of military rule have stunted the growth of democracy,adversely affecting civil society. Media too has suffered as a result. Normative theories of media callfor laying down norms and conventions for media. In democracy, all sections of society should berepresented in media. In Pakistan’s case, due to military regimes and quasi democratic governments,combined with the demands of market economy, the media have largely not been able to fulfill thisresponsibility towards society. Social Responsibility demands that the media must fulfill itsresponsibility towards society, while giving a free space to all voices of society. In Pakistan, whethernewspapers played that role in 2003 when civil society had accelerated its campaign to end honorkillings and crimes against women is investigated. The findings show that newspapers did supportcivil society, showing a gradual movement towards a more responsible press.

  6. A closure relation to molecular theory of solvation for macromolecules

    Science.gov (United States)

    Kobryn, Alexander E.; Gusarov, Sergey; Kovalenko, Andriy

    2016-10-01

    We propose a closure to the integral equations of molecular theory of solvation, particularly suitable for polar and charged macromolecules in electrolyte solution. This includes such systems as oligomeric polyelectrolytes at a finite concentration in aqueous and various non-aqueous solutions, as well as drug-like compounds in solution. The new closure by Kobryn, Gusarov, and Kovalenko (KGK closure) imposes the mean spherical approximation (MSA) almost everywhere in the solvation shell but levels out the density distribution function to zero (with the continuity at joint boundaries) inside the repulsive core and in the spatial regions of strong density depletion emerging due to molecular associative interactions. Similarly to MSA, the KGK closure reduces the problem to a linear equation for the direct correlation function which is predefined analytically on most of the solvation shells and has to be determined numerically on a relatively small (three-dimensional) domain of strong depletion, typically within the repulsive core. The KGK closure leads to the solvation free energy in the form of the Gaussian fluctuation (GF) functional. We first test the performance of the KGK closure coupled to the reference interaction site model (RISM) integral equations on the examples of Lennard-Jones liquids, polar and nonpolar molecular solvents, including water, and aqueous solutions of simple ions. The solvation structure, solvation chemical potential, and compressibility obtained from RISM with the KGK closure favorably compare to the results of the hypernetted chain (HNC) and Kovalenko-Hirata (KH) closures, including their combination with the GF solvation free energy. We then use the KGK closure coupled to RISM to obtain the solvation structure and thermodynamics of oligomeric polyelectrolytes and drug-like compounds at a finite concentration in electrolyte solution, for which no convergence is obtained with other closures. For comparison, we calculate their solvation

  7. Macromolecule simulation and CH4 adsorption mechanism of coal vitrinite

    Science.gov (United States)

    Yu, Song; Yan-ming, Zhu; Wu, Li

    2017-02-01

    The microscopic mechanism of interactions between CH4 and coal macromolecules is of significant practical and theoretical importance in CBM development and methane storage. Under periodic boundary conditions, the optimal energy configuration of coal vitrinite, which has a higher torsion degree and tighter arrangement, can be determined by the calculation of molecular mechanics (MM) and molecular dynamics (MD), and annealing kinetics simulation based on ultimate analysis, 13C NMR, FT IR and HRTEM. Macromolecular stabilization is primarily due to the van der Waals energy and covalent bond energy, mainly consisting of bond torsion energy and bond angle energy. Using the optimal configuration as the adsorbent, GCMC simulation of vitrinite adsorption of CH4 is conducted. A saturated state is reached after absorbing 17 CH4s per coal vitrinite molecule. CH4 is preferentially adsorbed on the edge, and inclined to gathering around the branched chains of the inner vitrinite sites. Finally, the adsorption parameters are calculated through first principle DFT. The adsorbability order is as follows: aromatic structure> heteroatom rings > oxygen functional groups. The adsorption energy order is as follows: Top < Bond < Center, Up < Down. The order of average RDF better reflects the adsorption ability and that of [-COOH] is lower than those of [sbnd Cdbnd O] and [Csbnd Osbnd C]. CH4 distributed in the distance of 0.99-16 Å to functional groups in the type of monolayer adsorption and the average distance order manifest as [sbnd Cdbnd O] (1.64 Å) < [Csbnd Osbnd C] (1.89 Å) < [sbnd COOH] (3.78 Å) < [-CH3] (4.11 Å) according to the average RDF curves. CH4 enriches around [sbnd Cdbnd O] and [Csbnd O-C] whereas is rather dispersed about [-COOH] and [CH3]. Simulation and experiment data are both in strong agreement with the Langmuir and D-A isothermal adsorption model and the D-A model fit better than Langmuir model. Preferential adsorption sites and orientations in vitrinite are

  8. Regulation of synaptic vesicle docking by different classes of macromolecules in active zone material.

    Science.gov (United States)

    Szule, Joseph A; Harlow, Mark L; Jung, Jae Hoon; De-Miguel, Francisco F; Marshall, Robert M; McMahan, Uel J

    2012-01-01

    The docking of synaptic vesicles at active zones on the presynaptic plasma membrane of axon terminals is essential for their fusion with the membrane and exocytosis of their neurotransmitter to mediate synaptic impulse transmission. Dense networks of macromolecules, called active zone material, (AZM) are attached to the presynaptic membrane next to docked vesicles. Electron tomography has shown that some AZM macromolecules are connected to docked vesicles, leading to the suggestion that AZM is somehow involved in the docking process. We used electron tomography on the simply arranged active zones at frog neuromuscular junctions to characterize the connections of AZM to docked synaptic vesicles and to search for the establishment of such connections during vesicle docking. We show that each docked vesicle is connected to 10-15 AZM macromolecules, which fall into four classes based on several criteria including their position relative to the presynaptic membrane. In activated axon terminals fixed during replacement of docked vesicles by previously undocked vesicles, undocked vesicles near vacated docking sites on the presynaptic membrane have connections to the same classes of AZM macromolecules that are connected to docked vesicles in resting terminals. The number of classes and the total number of macromolecules to which the undocked vesicles are connected are inversely proportional to the vesicles' distance from the presynaptic membrane. We conclude that vesicle movement toward and maintenance at docking sites on the presynaptic membrane are directed by an orderly succession of stable interactions between the vesicles and distinct classes of AZM macromolecules positioned at different distances from the membrane. Establishing the number, arrangement and sequence of association of AZM macromolecules involved in vesicle docking provides an anatomical basis for testing and extending concepts of docking mechanisms provided by biochemistry.

  9. Surface characteristics and adhesion behavior of Escherichia coli O157:H7: role of extracellular macromolecules.

    Science.gov (United States)

    Kim, Hyunjung N; Hong, Yongsuk; Lee, Ilkeun; Bradford, Scott A; Walker, Sharon L

    2009-09-14

    Experiments were conducted using enterohemorrhagic Escherichia coli O157:H7 cells to investigate the influence of extracellular macromolecules on cell surface properties and adhesion behavior to quartz sand. Partial removal of the extracellular macromolecules on cells by a proteolytic enzyme (proteinase K) was confirmed using Fourier transform infrared spectroscopy analyses. The proteinase K treated cells exhibited more negative electrophoretic mobility (EPM) at an ionic strength (IS) macromolecules resulted in polymeric layers outside the cell surface that were less electrophoretically soft. The more negative mobility for the treated cells was likely due to the combined effects of a change in the distribution of functional groups and an increase in the charges per unit volume after enzyme treatment and not just removal of extracellular macromolecules. The proteolytic digestion of extracellular macromolecules led to a significant difference in the cell adhesion to quartz sand. The adhesion behavior for treated cells was consistent with DLVO theory and increased with IS due to less negativity in the EPM. In contrast, the adhesion behavior of untreated cells was much more complex and exhibited a maximum at IS = 1 mM. The treated cells exhibited less adhesion than the untreated cells when the IS or = 10 mM, a sudden decrease in the removal efficiency was observed only for the untreated cells even through EPM values were similar for both treated and untreated cells. This result suggested that an additional non-DLVO type interaction, electrosteric repulsion, occurred at higher IS (> or =10 mM in this study) for the untreated cells due to the presence of extracellular macromolecules that hindered cell adhesion to the quartz surface. This finding provides important insight into the role of macromolecule-induced E. coli O157:H7 interactions in aquatic environments.

  10. In the Stocks: Perilous Press Releases.

    Science.gov (United States)

    Morton, Linda P.; Loving, Bill

    1994-01-01

    Reviews some of the legal responsibilities of public relations practitioners in the preparation of press releases. Discusses legal criteria for judging the fraudulence of press releases and discusses the timeframe for fraudulent action. Concludes with lessons that practitioners need to understand. (SR)

  11. Evaluating the aluminum content of pressed dross

    Science.gov (United States)

    Kevorkijan, V.

    2002-02-01

    Pressing of skimmed hot drosses in a press is a very popular technology for cooling hot dross and obtaining the maximum in-house recovery of aluminum alloy. As a result of the pressing action, part of the molten aluminum alloy is squeezed out, while the rest of the free metal remains in the pressed skulls. Thus, pressed skulls are a valuable waste product, consisting of 30 70 wt.% free aluminum. Other constituents are aluminum oxide and oxides of alloying metals. Pressed skulls are generally valued on a free-metal recovery basis, which necessarily involves practical determination of their free aluminum content. Because most analytical methods are limited to the laboratory level and representative sub-samples, there is a practical interest in developing a routine, cost-effective, and non-destructive method to predict the free aluminum content in entire pressed skulls, based on their density. To develop such a method, a relation between the bulk density, porosity, and free aluminum content of pressed skulls was established. This article offers a review of those experiments and an analysis of their results.

  12. Assessment of permeability barriers to macromolecules in the rodent endometrium at the onset of implantation.

    Science.gov (United States)

    Bany, Brent M; Hamilton, G Scot

    2011-01-01

    In rodents, embryo implantation is an invasive process, which begins with its attachment to the uterine wall and culminates in the formation of the definitive placenta several days later. It is critical that the endometrium provide a supportive environment for the implanting embryo during this process, as the placenta is not yet established. The concept of changing permeability barriers to macromolecules between different extracellular compartments in the rodent uterus at the onset of implantation has been established. This chapter provides protocols that can be used to assess this changing permeability barrier and the associated redistribution of macromolecules during the early phases of implantation in rodents. An increased permeability of the endometrial vasculature to plasma proteins occurs in areas adjacent to the implanting blastocyst. In addition, alterations in the extracellular matrix enhance the accumulation of fluid and extravasated macromolecules. We describe several protocols proven to be effective in studying and quantifying early vascular and extravascular responses to natural and artificial "implantation stimuli." The first three protocols represent qualitative and quantitative methods to assess the early endometrial "vascular permeability" response. On the contrary, the fourth protocol addresses the onset of decidualization and the arising permeability barrier, which restricts the movement of macromolecules through the extracellular space. This barrier is believed to provide transient protection for the implanting embryo against potentially harmful maternal serum proteins. This protocol describes assessment of resistance of the primary decidual zone to the movement of macromolecules across the compartments of the extracellular space.

  13. Nanoscale amphiphilic macromolecules as lipoprotein inhibitors: the role of charge and architecture

    Science.gov (United States)

    Wang, Jinzhong; Plourde, Nicole M; Iverson, Nicole; Moghe, Prabhas V; Uhrich, Kathryn E

    2007-01-01

    A series of novel amphiphilic macromolecules composed of alkyl chains as the hydrophobic block and poly(ethylene glycol) as the hydrophilic block were designed to inhibit highly oxidized low density lipoprotein (hoxLDL) uptake by synthesizing macromolecules with negatively charged moieties (ie, carboxylic acids) located in the two different blocks. The macromolecules have molecular weights around 5,500 g/mol, form micelles in aqueous solution with an average size of 20–35 nm, and display critical micelle concentration values as low as 10−7 M. Their charge densities and hydrodynamic size in physiological buffer solutions correlated with the hydrophobic/hydrophilic block location and quantity of the carboxylate groups. Generally, carboxylate groups located in the hydrophobic block destabilize micelle formation more than carboxylate groups in the hydrophilic block. Although all amphiphilic macromolecules inhibited unregulated uptake of hoxLDL by macrophages, inhibition efficiency was influenced by the quantity and location of the negatively charged-carboxylate on the macromolecules. Notably, negative charge is not the sole factor in reducing hoxLDL uptake. The combination of smaller size, micellar stability and charge density is critical for inhibiting hoxLDL uptake by macrophages. PMID:18203436

  14. Active macromolecules of honey form colloidal particles essential for honey antibacterial activity and hydrogen peroxide production.

    Science.gov (United States)

    Brudzynski, Katrina; Miotto, Danielle; Kim, Linda; Sjaarda, Calvin; Maldonado-Alvarez, Liset; Fukś, Henryk

    2017-08-09

    Little is known about the global structure of honey and the arrangement of its main macromolecules. We hypothesized that the conditions in ripened honeys resemble macromolecular crowding in the cell and affect the concentration, reactivity, and conformation of honey macromolecules. Combined results from UV spectroscopy, DLS and SEM showed that the concentration of macromolecules was a determining factor in honey structure. The UV spectral scans in 200-400 nm visualized and allowed quantification of UV-absorbing compounds in the following order: dark > medium > light honeys (p macromolecules promoted their self-assembly to micron-size superstructures, visible in SEM as two-phase system consisting of dense globules distributed in sugar solution. These particles showed increased conformational stability upon dilution. At the threshold concentration, the system underwent phase transition with concomitant fragmentation of large micron-size particles to nanoparticles in hierarchical order. Honey two-phase conformation was an essential requirement for antibacterial activity and hydrogen peroxide production. These activities disappeared beyond the phase transition point. The realization that active macromolecules of honey are arranged into compact, stable multicomponent assemblies with colloidal properties reframes our view on global structure of honey and emerges as a key property to be considered in investigating its biological activity.

  15. Receptor-mediated endocytosis of macromolecules and strategy to enhance their transport in alveolar epithelial cells.

    Science.gov (United States)

    Takano, Mikihisa; Kawami, Masashi; Aoki, Ayako; Yumoto, Ryoko

    2015-05-01

    Pulmonary delivery is an attractive administration route for therapeutic proteins and peptides. In this context, endocytosis/transcytosis at the distal lung epithelial barrier is an important process in the pulmonary absorption of therapeutic macromolecules. The alveolar epithelium is comprised of type I and type II cells. Understanding the transport mechanisms in these cells is essential for the development of efficient pulmonary delivery systems of therapeutic macromolecules. Endocytic pathways for albumin and insulin in alveolar epithelial cells and possible receptors for the endocytosis are discussed. Strategies to enhance the endocytosis and pulmonary absorption of macromolecules are also discussed, by focusing on the effects of cationic poly(amino acid)s. Although the surface area occupied by type II cells in alveoli is much smaller than that covered by type I cells, type II cells may significantly contribute to the endocytosis/transcytosis of macromolecules such as albumin. Identification of the receptors involved in the cellular uptake of each macromolecule is prerequisite for the understanding and regulation of its transport into and across alveolar epithelial cells. Establishment of novel in-vitro culture cell models of type I and type II cells would be a great help for the future advance of this research field.

  16. Cathepsin B degradable star-shaped peptidic macromolecules for delivery of 2-methoxyestradiol.

    Science.gov (United States)

    Shankar, Ravi; Samykutty, Abhilash; Riggin, Corinne; Kannan, Sneha; Wenzel, Ursula; Kolhatkar, Rohit

    2013-10-07

    2-Methoxyestradiol (2ME), a natural metabolite of estradiol, has antiproliferative and antiangiogenic activity. However, its clinical success is limited due to poor water solubility and poor pharmacokinetic parameters suggesting the need for a delivery vehicle. In this study we evaluated cathepsin B degradable star-shaped peptidic macromolecules (SPMs) that can potentially be used to create higher generation and high molecular weight peptidic polymer as delivery vehicle of 2ME. Two peptidic macromolecules having positively charged amine (ASPM) or negatively charged carboxyl surface groups (CSPM) were synthesized and evaluated for their degradation in the presence of cathepsin B and stability in the presence of neutral or acidic buffer and serum. Both ASPM and CSPM degraded rapidly in the presence of cathepsin B. Both were stable in neutral and acidic buffer whereas only CSPM exhibited substantial stability in the presence of serum. Both macromolecules were nontoxic toward breast cancer cells whereas 2ME-containing macromolecules exhibited antiproliferative activity in the micromolar range. Overall, results from the current study indicate that tetrapeptide GFLG can be used to create star-shaped macromolecules that are degraded in the presence of cathepsin B and have the potential to be developed as delivery vehicles of 2ME.

  17. Locust bean gum in the development of sustained release mucoadhesive macromolecules of aceclofenac.

    Science.gov (United States)

    Prajapati, Vipul D; Jani, Girish K; Moradiya, Naresh G; Randeria, Narayan P; Maheriya, Pankaj M; Nagar, Bhanu J

    2014-11-26

    The study shows the development and optimization of locust bean gum (LBG)-alginate mucoadhesive macromolecules containing aceclofenac through ionotropic-gelation using 3(2) factorial design. The effect of amount of LBG and sodium alginate on drug entrapment efficiency (%DEE), % mucoadhesion at 8h (M8) and % in vitro drug release at 10h (%Q10h) were optimized. The percentage yield, average size and DEE of macromolecules were found within the range of 93.19 to 96.65%, 1.328 ± 0.11 to 1.428 ± 0.13 μm, and 56.37 to 68.54%, respectively. The macromolecules were also characterized by SEM, FTIR and DSC. The in vitro drug release from these macromolecules (84.95 ± 2.02 to 95.33 ± 1.56% at 10h) exhibited sustained release (first-order) pattern with super case-II transport mechanism. The swelling and mucoadhesivity of these macromolecules were affected by pH of the medium. The design established the role of derived polynomial equations and plots in predicting the values of dependent variables for the preparation and optimization. Copyright © 2014 Elsevier Ltd. All rights reserved.

  18. Mechanoporation of living cells for delivery of macromolecules using nanoneedle array.

    Science.gov (United States)

    Matsumoto, Daisuke; Yamagishi, Ayana; Saito, Megumi; Sathuluri, Ramachandra Rao; Silberberg, Yaron R; Iwata, Futoshi; Kobayashi, Takeshi; Nakamura, Chikashi

    2016-12-01

    Efficient and rapid delivery of macromolecule probes, such as quenchbodies and other large biomarkers that cannot readily pass through the plasma membrane, is necessary for live-cell imaging and other intracellular analyses. We present here an alternative, simple method for delivery of macromolecules into live cells. In this method, which we term here mechanoporation, a nanoneedle array is used for making transient pores in the plasma membrane to allow access of desired macromolecules into thousands of live cells, simultaneously. This rapid, 3-step method facilitates an efficient delivery by adding macromolecules into the medium, inserting nanoneedles into the cells and oscillating the nanoneedle array, a process that takes no more than 5 min in total. In addition, we demonstrate here how this method can repeatedly and reproducibly deliver molecules into specifically-selected locations on a given cell culture dish. The results presented here show how this unique mechanoporation method enables rapid and high-throughput bio-macromolecule delivery and live-cell imaging. Copyright © 2016 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

  19. A comparison of impulse drying to double felted pressing on pilot- scale shoe presses and roll presses. Progress report, No. 6

    Energy Technology Data Exchange (ETDEWEB)

    Orloff, D.I.

    1992-08-01

    Pilot-scale shoe press and roll press experiments have been conducted to compare impulse drying and double felted pressing. Both ceramic coated and Beloit Type C press rolls have been evaluated. The experiments show that impulse drying can provide significantly higher outgoing solids than double felled pressing at the same impulse. For example, at an impulse of 0.234 MPa seconds (34 psi seconds), sheets at an ingoing solids of 52% were impulse dried (using the Beloit Type C press roll) to 68% solids while optimized double felled pressing could only yield press dryness of, at most, 60%.

  20. The effect of composition on diffusion of macromolecules in a crowded environment.

    Science.gov (United States)

    Kondrat, Svyatoslav; Zimmermann, Olav; Wiechert, Wolfgang; von Lieres, Eric

    2015-05-28

    We study diffusion of macromolecules in a crowded cytoplasm-like environment, focusing on its dependence on composition and its crossover to the anomalous subdiffusion. The crossover and the diffusion itself depend on both the volume fraction and the relative concentration of macromolecules. In accordance with previous theoretical and experimental studies, diffusion slows down when the volume fraction increases. Contrary to expectations, however, the diffusion is also strongly dependent on the molecular composition. The crossover time decreases and diffusion slows down when the smaller macromolecules start to dominate. Interestingly, diffusion is faster in a cytoplasm-like (more polydisperse) system than it is in a two-component system, at comparable packing fractions, or even when the cytoplasm packing fraction is larger.

  1. Anisotropic diffusion of macromolecules in the contiguous nucleocytoplasmic fluid during eukaryotic cell division.

    Science.gov (United States)

    Pawar, Nisha; Donth, Claudia; Weiss, Matthias

    2014-08-18

    Character and rapidity of protein diffusion in intracellular fluids are key determinants of the dynamics and steady state of a plethora of biochemical reactions. So far, an anomalous diffusion in cytoplasmic fluids with viscoelastic and even glassy characteristics has been reported in a variety of organisms on several length scales and timescales. Here, we show that the contiguous fluid of former cytoplasm and nucleoplasm features an anisotropically varying diffusion of macromolecules during eukaryotic cell division. In metaphase, diffusion in the contiguous nucleocytoplasmic fluid appears less anomalous along the spindle axis as compared to perpendicular directions. As a consequence, the long-time diffusion of macromolecules preferentially points along the spindle axis, leading to prolonged residence of macromolecules in the spindle region. Based on our experimental data, we suggest that anisotropic diffusion facilitates the encounter and interaction of spindle-associated proteins, e.g., during the formation of a dynamic spindle matrix. Copyright © 2014 Elsevier Ltd. All rights reserved.

  2. Nonuniform elastic properties of macromolecules and effect of prestrain on their continuum nature.

    Science.gov (United States)

    Aggarwal, Ankush; May, Eric R; Brooks, Charles L; Klug, William S

    2016-01-01

    Many experimental and theoretical methods have been developed to calculate the coarse-grained continuum elastic properties of macromolecules. However, all of those methods assume uniform elastic properties. Following the continuum mechanics framework, we present a systematic way of calculating the nonuniform effective elastic properties from atomic thermal fluctuations obtained from molecular dynamics simulation at any coarse-grained scale using a potential of the mean-force approach. We present the results for a mutant of Sesbania mosaic virus capsid, where we calculate the elastic moduli at different scales and observe an apparent problem with the chosen reference configuration in some cases. We present a possible explanation using an elastic network model, where inducing random prestrain results in a similar behavior. This phenomenon provides a novel insight into the continuum nature of macromolecules and defines the limits on details that the elasticity theory can capture. Further investigation into prestrains could elucidate important aspects of conformational dynamics of macromolecules.

  3. Scalable synthesis of sequence-defined, unimolecular macromolecules by Flow-IEG.

    Science.gov (United States)

    Leibfarth, Frank A; Johnson, Jeremiah A; Jamison, Timothy F

    2015-08-25

    We report a semiautomated synthesis of sequence and architecturally defined, unimolecular macromolecules through a marriage of multistep flow synthesis and iterative exponential growth (Flow-IEG). The Flow-IEG system performs three reactions and an in-line purification in a total residence time of under 10 min, effectively doubling the molecular weight of an oligomeric species in an uninterrupted reaction sequence. Further iterations using the Flow-IEG system enable an exponential increase in molecular weight. Incorporating a variety of monomer structures and branching units provides control over polymer sequence and architecture. The synthesis of a uniform macromolecule with a molecular weight of 4,023 g/mol is demonstrated. The user-friendly nature, scalability, and modularity of Flow-IEG provide a general strategy for the automated synthesis of sequence-defined, unimolecular macromolecules. Flow-IEG is thus an enabling tool for theory validation, structure-property studies, and advanced applications in biotechnology and materials science.

  4. Improved microchip design and application for in situ transmission electron microscopy of macromolecules.

    Science.gov (United States)

    Dukes, Madeline J; Thomas, Rebecca; Damiano, John; Klein, Kate L; Balasubramaniam, Sharavanan; Kayandan, Sanem; Riffle, Judy S; Davis, Richey M; McDonald, Sarah M; Kelly, Deborah F

    2014-04-01

    Understanding the fundamental properties of macromolecules has enhanced the development of emerging technologies used to improve biomedical research. Currently, there is a critical need for innovative platforms that can illuminate the function of biomedical reagents in a native environment. To address this need, we have developed an in situ approach to visualize the dynamic behavior of biomedically relevant macromolecules at the nanoscale. Newly designed silicon nitride devices containing integrated "microwells" were used to enclose active macromolecular specimens in liquid for transmission electron microscopy imaging purposes.We were able to successfully examine novel magnetic resonance imaging contrast reagents, micelle suspensions, liposome carrier vehicles, and transcribing viral assemblies. With each specimen tested, the integrated microwells adequately maintained macromolecules in discrete local environments while enabling thin liquid layers to be produced.

  5. Equilibrium partitioning of macromolecules in confining geometries: Improved universality with a new molecular size parameter

    DEFF Research Database (Denmark)

    Wang, Yanwei; Peters, Günther H.J.; Hansen, Flemming Yssing

    2008-01-01

    We present a new framework for the description of macromolecules subject to confining geometries. The two main ingredients are a new computational method and the definition of a new molecular size parameter. The computational method, hereafter referred to the confinement analysis from bulk...... structures (CABS), allows the computation of equilibrium partition coefficients as a function of confinement size solely based on a single sampling of the configuration space of a macromolecule in bulk. Superior in computational speed to previous computational methods, CABS is capable of handling slits...... parameter for characterization of spatial confinement effects on macromolecules. Results for the equilibrium partition coefficient in the weak confinement regime depend only on the ratio ofR-s to the confinement size regardless of molecular details....

  6. Extracellular matrix macromolecules: potential tools and targets in cancer gene therapy.

    Science.gov (United States)

    Sainio, Annele; Järveläinen, Hannu

    2014-01-01

    Tumour cells create their own microenvironment where they closely interact with a variety of soluble and non-soluble molecules, different cells and numerous other components within the extracellular matrix (ECM). Interaction between tumour cells and the ECM is bidirectional leading to either progression or inhibition of tumourigenesis. Therefore, development of novel therapies targeted primarily to tumour microenvironment (TME) is highly rational. Here, we give a short overview of different macromolecules of the ECM and introduce mechanisms whereby they contribute to tumourigenesis within the TME. Furthermore, we present examples of individual ECM macromolecules as regulators of cell behaviour during tumourigenesis. Finally, we focus on novel strategies of using ECM macromolecules as tools or targets in cancer gene therapy in the future.

  7. Intracellular uptake of macromolecules by brain lymphatic endothelial cells during zebrafish embryonic development.

    Science.gov (United States)

    van Lessen, Max; Shibata-Germanos, Shannon; van Impel, Andreas; Hawkins, Thomas A; Rihel, Jason; Schulte-Merker, Stefan

    2017-05-12

    The lymphatic system controls fluid homeostasis and the clearance of macromolecules from interstitial compartments. In mammals brain lymphatics were only recently discovered, with significant implications for physiology and disease. We examined zebrafish for the presence of brain lymphatics and found loosely connected endothelial cells with lymphatic molecular signature covering parts of the brain without forming endothelial tubular structures. These brain lymphatic endothelial cells (BLECs) derive from venous endothelium, are distinct from macrophages, and are sensitive to loss of Vegfc. BLECs endocytose macromolecules in a selective manner, which can be blocked by injection of mannose receptor ligands. This first report on brain lymphatic endothelial cells in a vertebrate embryo identifies cells with unique features, including the uptake of macromolecules at a single cell level. Future studies will address whether this represents an uptake mechanism that is conserved in mammals and how these cells affect functions of the embryonic and adult brain.

  8. Silicification and biosilicification: The role of macromolecules in bioinspired silica synthesis

    Science.gov (United States)

    Patwardhan, Siddharth Vijay

    Diatoms, sponges and grasses are all known to produce ornate biogenic silica structures under ambient conditions. Some aspects of the molecular mechanism controlling biosilicification have recently been elucidated. The entrapment of the catalyzing/templating/scaffolding biomacromolecules enables them to be recovered by selective dissolution of biosilica. The proteins extracted from the diatom Cylindrotheca fusiformis (silaffins) and the sponge Tethya aurantia (silicateins) have been shown to precipitate silica from silica precursors in vitro. The identification of synthetic macromolecules that can act as catalysts/templates/scaffolds for silica formation gives exciting possibilities for bioinspired silica synthesis. Herein, the role of various synthetic (bio)macromolecules in silicification is studied. Attempts have also been made to understand the mechanism(s) governing (bio)macromolecule mediated (bio)silicification. Furthermore, the results and the understanding gained from various synthetic systems are used to demonstrate the potential of such bioinspired routes to develop new materials.

  9. Global analysis of fluorescence decays to probe the internal dynamics of fluorescently labeled macromolecules.

    Science.gov (United States)

    Duhamel, Jean

    2014-03-11

    The aim of this review is to introduce the reader first to the mathematical complexity associated with the analysis of fluorescence decays acquired with solutions of macromolecules labeled with a fluorophore and its quencher that are capable of interacting with each other via photophysical processes within the macromolecular volume, second to the experimental and mathematical approaches that have been proposed over the years to handle this mathematical complexity, and third to the information that one can expect to retrieve with respect to the internal dynamics of such fluorescently labeled macromolecules. In my view, the ideal fluorophore-quencher pair to use in studying the internal dynamics of fluorescently labeled macromolecules would involve a long-lived fluorophore, a fluorophore and a quencher that do not undergo energy migration, and a photophysical process that results in a change in fluorophore emission upon contact between the excited fluorophore and quencher. Pyrene, with its ability to form an excimer on contact between excited-state and ground-state species, happens to possess all of these properties. Although the concepts described in this review apply to any fluorophore and quencher pair sharing pyrene's exceptional photophysical properties, this review focuses on the study of pyrene-labeled macromolecules that have been characterized in great detail over the past 40 years and presents the main models that are being used today to analyze the fluorescence decays of pyrene-labeled macromolecules reliably. These models are based on Birks' scheme, the DMD model, the fluorescence blob model, and the model free analysis. The review also provides a step-by-step protocol that should enable the noneducated user to achieve a successful decay analysis exempt of artifacts. Finally, some examples of studies of pyrene-labeled macromolecules are also presented to illustrate the different types of information that can be retrieved from these fluorescence decay

  10. Hydrodynamic Forces on Macromolecules Protruding from Lipid Bilayers Due to External Liquid Flows.

    Science.gov (United States)

    Jönsson, Peter; Jönsson, Bengt

    2015-11-24

    It has previously been observed that an externally applied hydrodynamic shear flow above a fluid lipid bilayer can change the local concentration of macromolecules that are associated with the lipid bilayer. The external liquid flow results in a hydrodynamic force on molecules protruding from the lipid bilayer, causing them to move in the direction of the flow. However, there has been no quantitative study about the magnitude of these forces. We here use finite element simulations to investigate how the magnitude of the external hydrodynamic forces varies with the size and shape of the studied macromolecule. The simulations show that the hydrodynamic force is proportional to the effective hydrodynamic area of the studied molecule, Ahydro, multiplied by the mean hydrodynamic shear stress acting on the membrane surface, σhydro. The parameter Ahydro depends on the size and shape of the studied macromolecule above the lipid bilayer and scales with the cross-sectional area of the molecule. We also investigate how hydrodynamic shielding from other surrounding macromolecules decreases Ahydro when the surface coverage of the shielding macromolecules increases. Experiments where the protein streptavidin is anchored to a supported lipid bilayer on the floor of a microfluidic channel were finally performed at three different surface concentrations, Φ = 1%, 6%, and 10%, where the protein is being moved relative to the lipid bilayer by a liquid flow through the channel. From photobleaching measurements of fluorescently labeled streptavidin we found the experimental drift data to be within good accuracy of the simulated results, less than 12% difference, indicating the validity of the results obtained from the simulations. In addition to giving a deeper insight into how a liquid flow can affect membrane-associated molecules in a lipid bilayer, we also see an interesting potential of using hydrodynamic flow experiments together with the obtained results to study the size and

  11. Synthesis and Characterization of a Chondroitin Sulfate Based Hybrid Bio/Synthetic Biomimetic Aggrecan Macromolecule

    Science.gov (United States)

    Sarkar, Sumona

    Lower back pain resulting from intervertebral disc degeneration is one of the leading musculoskeletal disorders confronting our health system. In order to mechanically stabilize the disc early in the degenerative cascade and prevent the need for spinal fusion surgeries, we have proposed the development of a hybrid-bio/synthetic biomimetic proteoglycan macromolecule for injection into the disc in the early stages of degeneration. The goal of this thesis was to incorporate natural chondroitin sulfate (CS) chains into bottle brush polymer synthesis strategies for the fabrication of CS-macromolecules which mimic the proteoglycan structure and function while resisting enzymatic degradation. Both the "grafting-to" and "grafting-through" techniques of bottle brush synthesis were explored. CS was immobilized via a terminal primary amine onto a model polymeric backbone (polyacrylic acid) for investigation of the "grafting-to" strategy and an epoxy-amine step-growth polymerization technique was utilized for the "grafting-through" synthesis of CS-macromolecules with polyethylene glycol backbone segments. Incorporation of a synthetic polymeric backbone at the terminal amine of CS was confirmed via biochemical assays, 1H-NMR and FTIR spectroscopy, and CS-macromolecule size was demonstrated to be higher than that of natural CS via gel permeation chromatography, transmission electron microscopy and viscosity measurements. Further analysis of CS-macromolecule functionality indicated maintenance of natural CS properties such as high fixed charge density, high osmotic potential and low cytotoxicity with nucleus pulposus cells. These studies are the first attempt at the incorporation of natural CS into biomimetic bottle brush structures. CS-macromolecules synthesized via the methods developed in these studies may be utilized in the treatment and prevention of debilitating back pain as well as act as mimetics for other proteoglycans implicated in cartilage, heart valve, and nervous

  12. WordPress web application development

    CERN Document Server

    Ratnayake, Rakhitha Nimesh

    2013-01-01

    An extensive, practical guide that explains how to adapt WordPress features, both conventional and trending, for web applications.This book is intended for WordPress developers and designers who have the desire to go beyond conventional website development to develop quality web applications within a limited time frame and for maximum profit. Experienced web developers who are looking for a framework for rapid application development will also find this to be a useful resource. Prior knowledge with of WordPress is preferable as the main focus will be on explaining methods for adapting WordPres

  13. Teach yourself visually complete WordPress

    CERN Document Server

    Majure, Janet

    2013-01-01

    Take your WordPress skills to the next level with these tips, tricks, and tasks Congratulations on getting your blog up and running with WordPress! Now are you ready to take it to the next level? Teach Yourself VISUALLY Complete WordPress takes you beyond the blogging basics with expanded tips, tricks, and techniques with clear, step-by-step instructions accompanied by screen shots. This visual book shows you how to incorporate forums, use RSS, obtain and review analytics, work with tools like Google AdSense, and much more.Shows you how to use mobile tools to edit a

  14. WordPress 24-Hour Trainer

    CERN Document Server

    Plumley, George

    2011-01-01

    The eagerly anticipated second edition, completely updated for WordPress 3.1 As an open source content management system, WordPress allows users to easily build feature-rich web sites with no programming experience. This unique book-and-video package is a friendly, self-paced beginners guide to the latest release of WordPress. Lessons are focused on practical, everyday tasks that users will need to create and maintain their sites: entering new content, creating new pages, managing menus, making content search-engine friendly. Plus you'll find lots of tips based on years of experience teaching

  15. Professional WordPress Plugin Development

    CERN Document Server

    Williams, Brad; Tadlock, Justin

    2011-01-01

    Taking WordPress to the next level with advanced plugin developmentWordPress is used to create self-hosted blogs and sites, and it's fast becoming the most popular content management system (CMS) on the Web. Now you can extend it for personal, corporate and enterprise use with advanced plugins and this professional development guide. Learn how to create plugins using the WordPress plugin API: utilize hooks, store custom settings, craft translation files, secure your plugins, set custom user roles, integrate widgets, work with JavaScript and AJAX, create custom post types. You'll find a practic

  16. WordPress web design for dummies

    CERN Document Server

    Sabin-Wilson, Lisa

    2013-01-01

    Updated, full-color guide to creating dynamic websites with WordPress 3.6 In this updated new edition, bestselling For Dummies author and WordPress expert Lisa Sabin-Wilson makes it easy for anyone with a basic knowledge of the WordPress software to create a custom site using complementary technologies such as CSS, HTML, PHP, and MySQL. You'll not only get up to speed on essential tools and technologies and further advance your own design skills, this book also gives you pages of great case studies, so you can see just how other companies and individuals are creating compelling, customized, a

  17. "Bio"-macromolecules: polymer-protein conjugates as emerging scaffolds for therapeutics.

    Science.gov (United States)

    Borchmann, Dorothee E; Carberry, Tom P; Weck, Marcus

    2014-01-01

    Polymer-protein conjugates are biohybrid macromolecules derived from covalently connecting synthetic polymers with polypeptides. The resulting materials combine the properties of both worlds: chemists can engineer polymers to stabilize proteins, to add functionality, or to enhance activity; whereas biochemists can exploit the specificity and complexity that Nature has bestowed upon its macromolecules. This has led to a wealth of applications, particularly within the realm of biomedicine. Polymer-protein conjugation has expanded to include scaffolds for drug delivery, tissue engineering, and microbial inhibitors. This feature article reflects upon recent developments in the field and discusses the applications of these hybrids from a biomaterials standpoint.

  18. Single molecule optical measurements of orientation and rotations of biological macromolecules

    Science.gov (United States)

    Shroder, Deborah Y.; Lippert, Lisa G.; Goldman, Yale E.

    2016-12-01

    Subdomains of macromolecules often undergo large orientation changes during their catalytic cycles that are essential for their activity. Tracking these rearrangements in real time opens a powerful window into the link between protein structure and functional output. Site-specific labeling of individual molecules with polarized optical probes and measurement of their spatial orientation can give insight into the crucial conformational changes, dynamics, and fluctuations of macromolecules. Here we describe the range of single molecule optical technologies that can extract orientation information from these probes, review the relevant types of probes and labeling techniques, and highlight the advantages and disadvantages of these technologies for addressing specific inquiries.

  19. Templated and self-limiting calcite formation directed by coccolith organic macromolecules.

    Science.gov (United States)

    Gal, Assaf; Wirth, Richard; Barkay, Zahava; Eliaz, Noam; Scheffel, André; Faivre, Damien

    2017-07-06

    The formation of intricately shaped crystalline minerals by organisms is orchestrated by specialized biomacromolecules. The macromolecules associated with coccoliths, nanometer-sized calcite crystal arrays produced by marine microalgae, can form a distinct calcium-rich phase via macromolecular recognition. Here, we show that this calcium-rich phase can be mineralized into a thin film of single-crystalline calcite by the balanced addition of carbonate ions. Such a crystallization process provides a strategy to direct crystalline products via local interactions between soluble macromolecules and compatible templates.

  20. Method for selective immobilization of macromolecules on self assembled monolayer surfaces

    Science.gov (United States)

    Laskin, Julia [Richland, WA; Wang, Peng [Billerica, MA

    2011-11-29

    Disclosed is a method for selective chemical binding and immobilization of macromolecules on solid supports in conjunction with self-assembled monolayer (SAM) surfaces. Immobilization involves selective binding of peptides and other macromolecules to SAM surfaces using reactive landing (RL) of mass-selected, gas phase ions. SAM surfaces provide a simple and convenient platform for tailoring chemical properties of a variety of substrates. The invention finds applications in biochemistry ranging from characterization of molecular recognition events at the amino acid level and identification of biologically active motifs in proteins, to development of novel biosensors and substrates for stimulated protein and cell adhesion.

  1. Click chemistry approach to functionalize two-dimensional macromolecules of graphene oxide nanosheets

    Institute of Scientific and Technical Information of China (English)

    Liang Kou; Hongkun He; Chao Gao

    2010-01-01

    A facile “click chemistry” approach to functionalize 2D macromolecules of graphene oxide nanosheets with poly (ethylene glycol) of different molecular weights, polystyrene, palmitic acid and various amino acids was presented. FTIR, TGA, Raman spectroscopy, XPS, XRD, TEM, AFM and SEM were utilized to characterize the products. High degree of functionalization was achieved on the flat surfaces of graphene oxide, affording polymer-grafted 2D brushes and amino acids-immobilized nanosheets, which show improved solubility in organic solvents. The click chemistry strategy reported herein provides a facile and general method for functionalization of graphene oxide with macromolecules and desired biomolecules.

  2. A new bead-spring model for simulation of semi-flexible macromolecules

    Science.gov (United States)

    Saadat, Amir; Khomami, Bamin

    2016-11-01

    A bead-spring model for semi-flexible macromolecules is developed to overcome the deficiencies of the current coarse-grained bead-spring models. Specifically, model improvements are achieved through incorporation of a bending potential. The new model is designed to accurately describe the correlation along the backbone of the chain, segmental length, and force-extension behavior of the macromolecule even at the limit of 1 Kuhn step per spring. The relaxation time of different Rouse modes is used to demonstrate the capabilities of the new model in predicting chain dynamics.

  3. Determination of 6 stiffnesses for a press

    DEFF Research Database (Denmark)

    Arentoft, Mogens; Eriksen, Morten; Wanheim, Tarras

    2000-01-01

    The industry is increasingly demanding for better tolerances at cold forged products caused by the tough competition at the market. Near net-shape or net-shape production save resources for machining and reduce therefore also the material costs. During the forming process, the reaction forces fro...... in which the press has the highest stiffness. Furthermore, knowledge about the stiffnesses of all presses in a production system makes it possible to choose the press which best fit to a specific process....... is known too, the final dimensions can be predicted by divide the force by the stiffness and add the clearance. If the stiffness of the press is known, it is possible to optimize the orientation of the workpiece too, so the direction, in which the best tolerances is demanded, is equal to the direction...

  4. Denmark, Democracy and the Free Press

    DEFF Research Database (Denmark)

    Breiting, Søren

    2006-01-01

    What's important to Danish people in Denmark and in the world - most will argue for the importance of a free critical press, solidarity with people who need help and a peaceful world.......What's important to Danish people in Denmark and in the world - most will argue for the importance of a free critical press, solidarity with people who need help and a peaceful world....

  5. The Liberal Struggle for Press Freedom

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    In this paper, the public debate following the re-ligion-motivated assassination of Dutch filmmaker Theo van Gogh in November 2004 is examined. The paper aims at describ-ing religious as well as secular positions in the Danish debate about freedom of speech and press in relation to religious issues....... Historically, the concept of press freedom was linked to a fight for religious freedom in London, as described by Siebert....

  6. The Liberal Struggle for Press Freedom

    DEFF Research Database (Denmark)

    Mogensen, Kirsten

    In this paper, the public debate following the religion-motivated assassination of Dutch filmmaker Theo van Gogh in November 2004 is examined. The paper aims at describing religious as well as secular positions in the Danish debate about freedom of speech and press in relation to religious issues....... Historically, the concept of press freedom was linked to a fight for religious freedom in London, as described by Siebert....

  7. Denmark, Democracy and the Free Press

    DEFF Research Database (Denmark)

    Breiting, Søren

    2006-01-01

    What's important to Danish people in Denmark and in the world - most will argue for the importance of a free critical press, solidarity with people who need help and a peaceful world.......What's important to Danish people in Denmark and in the world - most will argue for the importance of a free critical press, solidarity with people who need help and a peaceful world....

  8. Research on Web Press Tension Control System

    OpenAIRE

    Chen Sheng Jiang; Zhang Chun Feng; Wang Zhong You; Li Qing Lin

    2016-01-01

    Tension control of press is a key and difficult point of the whole machine control. The stand or fall of tension is directly related to the quality of the products. According to the characteristics of the web press tension control, this paper expounds the main factors influencing tension and the purpose of tension control, researches on the tension control principle of web tape, analyzes control rule and control circuit of tension control system, illustrates the advantages of PID control law ...

  9. WordPress 3 For Business Bloggers

    CERN Document Server

    Thewlis, Paul

    2011-01-01

    This is a practical, hands-on book based around a fictitious case study blog, which you will build on a development server using WordPress. The case study grows chapter by chapter, from installing your local development server, right up to the finished blog. This book is for anybody running or starting a business blog using WordPress, whether you plan to use your blog for PR and marketing, or want to profit directly from blogging.

  10. Induced liquid-crystalline ordering in solutions of stiff and flexible amphiphilic macromolecules: Effect of mixture composition.

    Science.gov (United States)

    Glagolev, Mikhail K; Vasilevskaya, Valentina V; Khokhlov, Alexei R

    2016-07-28

    Impact of mixture composition on self-organization in concentrated solutions of stiff helical and flexible macromolecules was studied by means of molecular dynamics simulation. The macromolecules were composed of identical amphiphilic monomer units but a fraction f of macromolecules had stiff helical backbones and the remaining chains were flexible. In poor solvents the compacted flexible macromolecules coexist with bundles or filament clusters from few intertwined stiff helical macromolecules. The increase of relative content f of helical macromolecules leads to increase of the length of helical clusters, to alignment of clusters with each other, and then to liquid-crystalline-like ordering along a single direction. The formation of filament clusters causes segregation of helical and flexible macromolecules and the alignment of the filaments induces effective liquid-like ordering of flexible macromolecules. A visual analysis and calculation of order parameter relaying the anisotropy of diffraction allow concluding that transition from disordered to liquid-crystalline state proceeds sharply at relatively low content of stiff components.

  11. Effects of Several Natural Macromolecules on the Stability and Controlled Release Properties of Water-in-Oil-in-Water Emulsions.

    Science.gov (United States)

    Li, Jinlong; Shi, Yiheng; Zhu, Yunping; Teng, Chao; Li, Xiuting

    2016-05-18

    Water-in-oil-in-water (W/O/W) emulsions are effective vehicles for embedding application of active compounds but limited by their thermodynamic instability and rapid release properties. The present study added bovine serum albumin, whey protein isolate, whey protein hydrolysate, sodium caseinate, carboxymethylcellulose sodium, fish gelatin, apple pectin, gum arabic, ι-carrageenan, and hydroxypropyl chitosan separately to the internal or external aqueous phase to investigate their effects on the physical stabilities and controlled release properties of W/O/W emulsions. The effects of the natural macromolecules in the internal and external aqueous phases were different and depended upon the macromolecule structure and its mass fraction. The addition of the natural macromolecule strengthened the interfaces of emulsions, which improved the physical stability. The natural macromolecules that improved the stability often did not improve controlled release. Therefore, the balance between these properties needs to be considered when adding natural macromolecules to a W/O/W emulsion.

  12. Synthesis and Characterization of Tailored Macromolecules via Stable Free Radical Polymerization Methodologies

    OpenAIRE

    2003-01-01

    The stable free radical polymerization methodology for production of controlled macromolecules was investigated using a novel monomer, 2-vinylnaphthalene. Initial polymerizations resulted in molecular weight distributions typical of conventional free radical polymerization techniques (>2.0). Manipulation of the initiator concentration and the molar ratio of initiator to nitroxide demonstrated no significant control over the resulting polymer products. Analysis of the polymerization kinetics...

  13. A novel method for imaging sites of paracellular passage of macromolecules in epithelial sheets.

    Science.gov (United States)

    Richter, Jan F; Schmauder, Ralf; Krug, Susanne M; Gebert, Andreas; Schumann, Michael

    2016-05-10

    Understanding the dynamics of intestinal barrier function is key to elucidating oral delivery routes of therapeutics as well as to understanding various diseases that involve the mucosal immune system. Passage of macromolecules across barrier-forming epithelia is classically analyzed by means of various tracer flux measurements. This approach averages over contributions from many cells and lacks labeling of passage-sites. Thus, abundance and nature of involved cells have remained unidentified. We present a novel method that allowed for optical analysis of passage of various macromolecules on large-scale and single-cell level. To achieve tracking of passage loci in epithelia at submicrometer resolution we used biotinylated and fluorescent macromolecules that bind to basolateral membranes pre-labeled with cell-adherent avidin. We applied this method to epithelial cell lines and isolated mucosae in order to 3-dimensionally determine barrier leak properties over time. Tracer passage was found in all epithelia examined. However, it was infrequent, strikingly inhomogeneous, depended on culture duration and tightness of the monolayer. Stimulating passage with barrier-perturbing agents increased the number of leaks exposition time-dependently in cell lines and explanted mucosae. After stepwise opening of the paracellular passage pathway, integrated tracer-signal measured by our assay strictly correlated to simultaneously performed standard fluxes. Thus, our assay allows for the study of transepithelial macromolecule passage in various physiological and pathological conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. New strategy to create ultra-thin surface layer of grafted amphiphilic macromolecules.

    Science.gov (United States)

    Lazutin, A A; Govorun, E N; Vasilevskaya, V V; Khokhlov, A R

    2015-05-14

    It was found first that macromolecules made of amphiphilic monomer units could form spontaneously an ultra-thin layer on the surface which the macromolecules are grafted to. The width of such layer is about double size of monomer unit consisting of hydrophilic A (repulsive) and hydrophobic (attractive) B beads. The hydrophilic A beads are connected in a polymer chain while hydrophobic B beads are attached to A beads of the backbone as side groups. Three characteristic regimes are distinguished. At low grafting density, the macromolecules form ultra-thin micelles of the shape changing with decrease of distance d between grafting points as following: circular micelles-prolonged micelles-inverse micelles-homogeneous bilayer. Those micelles have approximately constant height and specific top-down A-BB-A structure. At higher grafting density, the micelles start to appear above the single bilayer of amphiphilic macromolecules. The thickness of grafted layer in these cases is different in different regions of grafting surface. Only at rather high density of grafting, the height of macromolecular layer becomes uniform over the whole grafting surface. The study was performed by computer modeling experiments and confirmed in framework of analytical theory.

  15. Prospective frequency correction for macromolecule-suppressed GABA editing at 3T

    DEFF Research Database (Denmark)

    Edden, Richard A E; Oeltzschner, Georg; Harris, Ashley D

    2016-01-01

    PURPOSE: To investigate the effects of B0 field offsets and drift on macromolecule (MM)-suppressed GABA-editing experiments, and to implement and test a prospective correction scheme. "Symmetric" editing schemes are proposed to suppress unwanted coedited MM signals in GABA editing. MATERIALS...

  16. Stress growth and relaxation of dendritically branched macromolecules in shear and uniaxial extension

    DEFF Research Database (Denmark)

    Huang, Qian; Costanzo, S.; Das, C.

    2017-01-01

    of the remarkable properties of these highly branched macromolecules. In particular, we address three questions pertinent to the specific molecular structure: (i) is steady state attainable during uniaxial extension? (ii) what is the respective transient response in simple shear? and (iii) how does stress relax...

  17. A Method for Decomposition of the Basic Reaction of Biological Macromolecules into Exponential Components.

    Science.gov (United States)

    Barabash, Yu M; Lyamets, A K

    2016-12-01

    The structural and dynamical properties of biological macromolecules under non-equilibrium conditions determine the kinetics of their basic reaction to external stimuli. This kinetics is multiexponential in nature. This is due to the operation of various subsystems in the structure of macromolecules, as well as the effect of the basic reaction on the structure of macromolecules. The situation can be interpreted as a manifestation of the stationary states of macromolecules, which are represented by monoexponential components of the basic reaction (Monod-Wyman-Changeux model) Monod et al. (J Mol Cell Biol 12:88-118, 1965). The representation of multiexponential kinetics of the basic reaction in the form of a sum of exponential functions [Formula: see text] is a multidimensional optimization problem. To solve this problem, a gradient method of optimization with software determination of the amount of exponents and reasonable calculation time is developed. This method is used to analyze the kinetics of photoinduced electron transport in the reaction centers (RC) of purple bacteria and the fluorescence induction in the granum thylakoid membranes which share a common function of converting light energy.

  18. Intermediate scattering function for macromolecules in solutions probed by neutron spin echo.

    Science.gov (United States)

    Liu, Yun

    2017-02-01

    The neutron-spin-echo method (NSE) is a powerful technique for studying internal dynamics of macromolecules in solutions because it can simultaneously probe length and time scales comparable to intramolecular density fluctuations of macromolecules. Recently, there has been increased, strong interest in studying protein internal motions using NSE. The coherent intermediate scattering function (ISF) measured by NSE depends on internal, rotational, and translational motions of macromolecules in solutions. It is thus critical, but highly nontrivial, to separate the internal motion from other motions in order to properly understand protein internal dynamics. Even though many experiments are performed at relatively high concentrations, current theories of calculating the ISF of concentrated protein solutions are either inaccurate or flawed by incorrect assumptions for realistic protein systems with anisotropic shapes. Here, a theoretical framework is developed to establish the quantitative relationship of different motions included in the ISF. This theory based on the dynamic decoupling approximation is applicable to a wide range of protein concentrations, including dilute cases. It is also, in general, useful for studying many other types of macromolecule systems studied by NSE.

  19. The spectral properties of DNA and RNA macromolecules at low temperatures: fundamental and applied aspects.

    Science.gov (United States)

    Yashchuk, Valeriy M; Kudrya, Vladislav Yu

    2017-01-18

    This paper summarizes the results of studies of the spectral properties-optical absorption, fluorescence and phosphorescence-of DNA and RNA macromolecules and synthetic poly-, oligo- and mono-nucleotides, which have been carried out in our laboratory. The system of first excited singlet and triplet energy levels for DNA and RNA is evaluated using low-temperature (4.2 K-77 K) luminescent measurements. The traps of the singlet and triplet electronic excitations in these compounds are identified. An important self-protection mechanism against photo-damage of DNA and RNA by UV photons or penetrative radiation based on the capture of triplet electronic-energy excitations by the most photostable centers-in DNA, the complex formed by neighboring adenosine (A) and thymidine (T) links; in RNA, the adenosine links-is described. It is confirmed that despite similarities in the chemical and partly energy structures DNA is more stable than RNA. The spectral manifestation of the telomeres (the important functional system) in DNA macromolecules is examined. The results obtained on telomere fragments provide the possibility of finding the configuration peculiarities of the triplet excitations traps in DNA macromolecules. The resulting spreading length of the migrating singlet (l s) and triplet (l t) excitations for DNA and RNA macromolecules are evaluated.

  20. Theory of Brushes Formed by Ψ-Shaped Macromolecules at Solid-Liquid Interfaces.

    Science.gov (United States)

    Zhulina, Ekaterina B; Leermakers, Frans A M; Borisov, Oleg V

    2015-06-16

    We present a theoretical analysis targeted to describe the structural properties of brushes formed by Ψ-shaped macromolecules tethered by terminal segment of stem to planar surface while exposing multiple free branches to the surrounding solution. We use an analytical self-consistent field approach based on the strong stretching approximation, and the assumption of Gaussian elasticity for linear chain fragments of the tethered macromolecules. The effect of weak and strong polydispersity of branches is analyzed. In the case of weakly polydisperse macromolecules, variations in length of branches lead to a more uniform polymer density distribution with slight increase in the brush thickness compared to the case of monodisperse chains with the same degree of polymerization. We demonstrate that in contrast to linear chains, strong polydispersity of Ψ-shaped macromolecules does not necessarily lead to strong perturbations in polymer density distribution. In particular, mixed brushes of the so-called "mirror" dendrons (in which number of stem monomers in one component coincides with number of monomers in a branch of the other component, and vice versa) give rise to a unified polymer density distribution with shape independent of the brush composition. The predictions of analytical theory are systematically compared to the results of numerical self-consistent field modeling based on the Scheutjens-Fleer approach.

  1. Tonal Interface to MacroMolecules (TIMMol): A Textual and Tonal Tool for Molecular Visualization

    Science.gov (United States)

    Cordes, Timothy J.; Carlson, C. Britt; Forest, Katrina T.

    2008-01-01

    We developed the three-dimensional visualization software, Tonal Interface to MacroMolecules or TIMMol, for studying atomic coordinates of protein structures. Key features include audio tones indicating x, y, z location, identification of the cursor location in one-dimensional and three-dimensional space, textual output that can be easily linked…

  2. Preface: Special Topic on Coarse Graining of Macromolecules, Biopolymers, and Membranes.

    Science.gov (United States)

    Holm, Christian; Gompper, Gerhard; Dill, Ken A

    2015-12-28

    This special issue highlights new developments in theory and coarse-graining in biological and synthetic macromolecules and membranes. Such approaches give unique insights into the principles and design of the structures, dynamics, and assembly processes of these complex fluids and soft materials, where the length and time scales are often prohibitively long for fully atomistic modeling.

  3. Preface: Special Topic on Coarse Graining of Macromolecules, Biopolymers, and Membranes

    Energy Technology Data Exchange (ETDEWEB)

    Holm, Christian [Institut für Computerphysik, Universität Stuttgart, Allmandring 3, 70569 Stuttgart (Germany); Gompper, Gerhard [Theoretical Soft Matter and Biophysics, Institute of Complex Systems and Institute for Advanced Simulation, Forschungszentrum Jülich, 52428 Jülich (Germany); Dill, Ken A. [Department of Chemistry, Stony Brook University, Stony Brook, New York 11794 (United States)

    2015-12-28

    This special issue highlights new developments in theory and coarse-graining in biological and synthetic macromolecules and membranes. Such approaches give unique insights into the principles and design of the structures, dynamics, and assembly processes of these complex fluids and soft materials, where the length and time scales are often prohibitively long for fully atomistic modeling.

  4. A screening-corrected additivity rule for the calculation of electron scattering from macro-molecules

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, F [Departamento de Fisica Atomica Molecular y Nuclear, Facultad de Ciencias Fisicas. Universidad Complutense, Avda. Complutense s/n, E-28040 Madrid (Spain); Garcia, G [Instituto de Matematicas y Fisica Fundamental, Consejo Superior de Investigaciones CientIficas, Serrano 121, 28006 Madrid (Spain)], E-mail: pacobr@fis.ucm.es

    2009-07-28

    A simplified form of the well-known screening-corrected additivity rule procedure for the calculation of electron-molecule cross sections is proposed for the treatment of some very large macro-molecules. While the comparison of the standard and simplified treatments for a DNA dodecamer reveals very similar results, the new treatment presents some important advantages for large molecules.

  5. Distribution of various forms of organic nitrogen in a lignite macromolecule

    Energy Technology Data Exchange (ETDEWEB)

    Platonov, V.V.; Proskuryakov, V.A.; Polovetskaya, O.S.; Shavyrina, O.A.; Ryl' tsova, S.V. [Lev Tolstoi State Pedalogical University, Tula (Russian Federation)

    2001-07-01

    The chemical composition of organic bases from tars of stepwise semicoking of lignite was studied. The features of distribution of organic nitrogen in a coal macromolecule and the most probable pathways of thermal degradation of the nitrogen-containing fragments were examined.

  6. Advances in industrial prospective of cellulosic macromolecules enriched banana biofibre resources: A review.

    Science.gov (United States)

    Pappu, Asokan; Patil, Vikas; Jain, Sonal; Mahindrakar, Amit; Haque, Ruhi; Thakur, Vijay Kumar

    2015-08-01

    Biological macromolecules enriched resources are rapidly emerging as sustainable, cost effective and environmental friendly materials for several industrial applications. Among different biological macromolecules enriched resources, banana fibres are one of the unexplored high potential bio-resources. Compared to various natural fibres such as jute, coir, palm etc., the banana fibres exhibits a better tensile strength i.e. 458 MPa with 17.14 GPa tensile modulus. Traditionally used petroleum based synthetic fibres have been proven to be toxic, non-biodegradable and energy intensive for manufacturing. Cellulosic banana fibres are potential engineering materials having considerable scope to be used as an environmental friendly reinforcing element for manufacturing of polymer based green materials. This paper summarizes the world scenario of current production of biological macromolecules rich banana residues and fibres; major user's of banana fibres. The quality and quantity of biological macromolecules especially the cellulose, hemicellulose, lignin, wax, engineering and mechanical properties of banana biofibre resources are reported and discussed. Subsequently, the findings of the recent research on bio resource composites, materials performance and opportunities have been discussed which would be a real challenge for the tomorrow world to enhance the livelihood environmental friendly advancement. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Intermediate scattering function for macromolecules in solutions probed by neutron spin echo

    Science.gov (United States)

    Liu, Yun

    2017-02-01

    The neutron-spin-echo method (NSE) is a powerful technique for studying internal dynamics of macromolecules in solutions because it can simultaneously probe length and time scales comparable to intramolecular density fluctuations of macromolecules. Recently, there has been increased, strong interest in studying protein internal motions using NSE. The coherent intermediate scattering function (ISF) measured by NSE depends on internal, rotational, and translational motions of macromolecules in solutions. It is thus critical, but highly nontrivial, to separate the internal motion from other motions in order to properly understand protein internal dynamics. Even though many experiments are performed at relatively high concentrations, current theories of calculating the ISF of concentrated protein solutions are either inaccurate or flawed by incorrect assumptions for realistic protein systems with anisotropic shapes. Here, a theoretical framework is developed to establish the quantitative relationship of different motions included in the ISF. This theory based on the dynamic decoupling approximation is applicable to a wide range of protein concentrations, including dilute cases. It is also, in general, useful for studying many other types of macromolecule systems studied by NSE.

  8. The spectral properties of DNA and RNA macromolecules at low temperatures: fundamental and applied aspects

    Science.gov (United States)

    Yashchuk, Valeriy M.; Kudrya, Vladislav Yu

    2017-03-01

    This paper summarizes the results of studies of the spectral properties—optical absorption, fluorescence and phosphorescence—of DNA and RNA macromolecules and synthetic poly-, oligo- and mono-nucleotides, which have been carried out in our laboratory. The system of first excited singlet and triplet energy levels for DNA and RNA is evaluated using low-temperature (4.2 K-77 K) luminescent measurements. The traps of the singlet and triplet electronic excitations in these compounds are identified. An important self-protection mechanism against photo-damage of DNA and RNA by UV photons or penetrative radiation based on the capture of triplet electronic-energy excitations by the most photostable centers—in DNA, the complex formed by neighboring adenosine (A) and thymidine (T) links; in RNA, the adenosine links—is described. It is confirmed that despite similarities in the chemical and partly energy structures DNA is more stable than RNA. The spectral manifestation of the telomeres (the important functional system) in DNA macromolecules is examined. The results obtained on telomere fragments provide the possibility of finding the configuration peculiarities of the triplet excitations traps in DNA macromolecules. The resulting spreading length of the migrating singlet (l s) and triplet (l t) excitations for DNA and RNA macromolecules are evaluated.

  9. Classification of the ejection mechanisms of charged macromolecules from liquid droplets

    Science.gov (United States)

    Consta, Styliani; Malevanets, Anatoly

    2013-01-01

    The relation between the charge state of a macromolecule and its ejection mechanism from droplets is one of the important questions in electrospray ionization methods. In this article, effects of solvent-solute interaction on the manifestation of the charge induced instability in a droplet are examined. We studied the instabilities in a prototype system of a droplet comprised of charged poly(ethylene glycol) and methanol, acetonitrile, and water solvents. We observed instances of three, previously only conjectured, [S. Consta, J. Phys. Chem. B 114, 5263 (2010), 10.1021/jp912119v] mechanisms of macroion ejection. The mechanism of ejection of charged macroion in methanol is reminiscent of "pearl" model in polymer physics. In acetonitrile droplets, the instability manifests through formation of solvent spines around the solvated macroion. In water, we find that the macroion is ejected from the droplet through contiguous extrusion of a part of the chain. The difference in the morphology of the instabilities is attributed to the interplay between forces arising from the macroion solvation energy and the surface energy of the droplet interface. For the contiguous extrusion of a charged macromolecule from a droplet, we demonstrate that the proposed mechanism leads to ejection of the macromolecule from droplets with sizes well below the Rayleigh limit. The ejected macromolecule may hold charge significantly higher than that suggested by prevailing theories. The simulations reveal new mechanisms of macroion evaporation that differ from conventional charge residue model and ion evaporation mechanisms.

  10. A Method for Decomposition of the Basic Reaction of Biological Macromolecules into Exponential Components

    Science.gov (United States)

    Barabash, Yu. M.; Lyamets, A. K.

    2016-12-01

    The structural and dynamical properties of biological macromolecules under non-equilibrium conditions determine the kinetics of their basic reaction to external stimuli. This kinetics is multiexponential in nature. This is due to the operation of various subsystems in the structure of macromolecules, as well as the effect of the basic reaction on the structure of macromolecules. The situation can be interpreted as a manifestation of the stationary states of macromolecules, which are represented by monoexponential components of the basic reaction (Monod-Wyman-Changeux model) Monod et al. (J Mol Cell Biol 12:88-118, 1965). The representation of multiexponential kinetics of the basic reaction in the form of a sum of exponential functions (A(t)={sum}_{i=1}^n{a}_i{e}^{-{k}_it}) is a multidimensional optimization problem. To solve this problem, a gradient method of optimization with software determination of the amount of exponents and reasonable calculation time is developed. This method is used to analyze the kinetics of photoinduced electron transport in the reaction centers (RC) of purple bacteria and the fluorescence induction in the granum thylakoid membranes which share a common function of converting light energy.

  11. A chip sustem for size separation of macromolecules and particles by hydrodynamic chromatography

    NARCIS (Netherlands)

    Chmela, Emil; Tijssen, Robert; Blom, M.T.; Gardeniers, Johannes G.E.; van den Berg, Albert

    2002-01-01

    For the first time, a miniaturized hydrodynamic chromatography chip system has been developed and tested on separation of fluorescent nanospheres and macromolecules. The device can be applied to size characterization of synthetic polymers, biopolymers, and particles, as an attractive alternative to

  12. Hollow fiber membrane modification with functional zwitterionic macromolecules for improved thromboresistance in artificial lungs.

    Science.gov (United States)

    Ye, Sang-Ho; Arazawa, David T; Zhu, Yang; Shankarraman, Venkat; Malkin, Alexander D; Kimmel, Jeremy D; Gamble, Lara J; Ishihara, Kazuhiko; Federspiel, William J; Wagner, William R

    2015-03-03

    Respiratory assist devices seek optimized performance in terms of gas transfer efficiency and thromboresistance to minimize device size and reduce complications associated with inadequate blood biocompatibility. The exchange of gas with blood occurs at the surface of the hollow fiber membranes (HFMs) used in these devices. In this study, three zwitterionic macromolecules were attached to HFM surfaces to putatively improve thromboresistance: (1) carboxyl-functionalized zwitterionic phosphorylcholine (PC) and (2) sulfobetaine (SB) macromolecules (mPC or mSB-COOH) prepared by a simple thiol-ene radical polymerization and (3) a low-molecular weight sulfobetaine (SB)-co-methacrylic acid (MA) block copolymer (SBMAb-COOH) prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization. Each macromolecule type was covalently immobilized on an aminated commercial HFM (Celg-A) by a condensation reaction, and HFM surface composition changes were analyzed by X-ray photoelectron spectroscopy. Thrombotic deposition on the HFMs was investigated after contact with ovine blood in vitro. The removal of CO2 by the HFMs was also evaluated using a model respiratory assistance device. The HFMs conjugated with zwitterionic macromolecules (Celg-mPC, Celg-mSB, and Celg-SBMAb) showed expected increases in phosphorus or sulfur surface content. Celg-mPC and Celg-SBMAb experienced rates of platelet deposition significantly lower than those of unmodified (Celg-A, >95% reduction) and heparin-coated (>88% reduction) control HFMs. Smaller reductions were seen with Celg-mSB. The CO2 removal rate for Celg-SBMAb HFMs remained comparable to that of Celg-A. In contrast, the rate of removal of CO2 for heparin-coated HFMs was significantly reduced. The results demonstrate a promising approach to modifying HFMs using zwitterionic macromolecules for artificial lung devices with improved thromboresistance without degradation of gas transfer.

  13. Inhalation therapy of macromolecules%大分子的吸入治疗

    Institute of Scientific and Technical Information of China (English)

    周煜

    2001-01-01

    随着重组DNA技术和分子生物学的发展,以蛋白质和多肽为主的大分子成为一类新型药物,并越来越受到重视,新兴的基因治疗技术使得核酸大分子也有可能成为药物。目前,绝大部分大分子药物都是通过注射途径给药, 病人在医院注射费用昂贵且不方便,因而许多注射替代给药途径成为研究热门,通过肺部吸入给药就是一种很有吸引力的非侵入性给药途径。本文介绍了肺吸收大分子的可能机制和大分子吸入治疗的临床与基础研究以及面临的问题。%Advances in molecular biology and recombinant DNA technology have led to the development of macromolecule as therapeutic agents for a variety of diseases including proteins, peptides and even nucleic acids. At present most of macromolecules are delivered by injection. Other routes of drug administration are being actively investigated. The inhalation therapy of macromolecule is an attractive noninvasive drug delivery method. In this review we describe the possible mechanisms of macromolecule absorption by the lung, then discuss the clinical and basic research of macromolecular inhalation therapy and analyze the problems of macromolecule inhalation delivery.

  14. Permselectivity of the liver blood-lymph (ascitic fluid) barrier to macromolecules in decompensated cirrhosis: relation to calculated pore-size

    DEFF Research Database (Denmark)

    Henriksen, Jens Henrik Sahl

    1983-01-01

    ) exchange of endogeneous macromolecules. A significant 'sieving' is present in this barrier to the largest macromolecule (IgM). Calculations of pore-size equivalent to the observed permselectivity of macromolecules suggest microvascular gaps (or channels) with an average radius about 300 A, i...

  15. Serbian press about refugees: 1990–2005

    Directory of Open Access Journals (Sweden)

    Grujić Jelena

    2005-01-01

    Full Text Available In this paper Serbian press’ approach toward refugees as a topic, for period of last fifteen years is analyzed. The analyses is built up on huge database of all articles about refugees published in progovernment and independent daily and weekly Serbian press, in mentioned period. Results of this research are crushing: differences of approaches in pro-government and independent press are minor; both press profiles, despite of what was expected, were shown equal lack of understanding toward the topic, contributing to social marginalization of refugees. Professional ethical codex have been remarkably violated all the time. These findings are part of a forthcoming book "Political framing of refugees: 1990. – 2005.".

  16. CSR-communication in the Business Press

    DEFF Research Database (Denmark)

    Morsing, Mette; Langer, Roy

    is systematically maintained in the business press. We refer to this process as strategic ambiguity. The paper discusses the potential value and limitations of framing CSR in a state of strategic ambiguity in the context of the concurrent rethinking of the role of business in modern welfare societies.......In this paper we analyze the construction of corporate social responsibility in the business press as an act of strategic ambiguity. While corporate social responsibility (CSR) generally evokes positive associations in public opinion, this paper demonstrates that these associations are based...... on a broadly encompassing and ambiguous definition of CSR. Our empirical data shows how the business press in its discourse on CSR provides no clarity on the definition of CSR in terms of a coherent motive, a dominant stakeholder or a consistent issue, but rather maintains ambiguity and imprecision about...

  17. PRESS FREEDOM IN SINGAPORE AND MALAYSIA: DEFAMATION

    Directory of Open Access Journals (Sweden)

    Georgia Kate Chapman

    2015-04-01

    Full Text Available This paper focuses on the arguments around restriction on freedom of the press in the Strong States of Singapore and Malaysia. It assesses the presence of constraints on press freedoms in democratic western countries imposed by corporation rather than state and the similar effects that these constraints may have on bias present in publicly accessible news reporting. It argues that independence of the press does not just require protection from legal and executive regulation, but also protection from large media corporations and their political alignments. This report will assess the bias of reporting and news media publication that exists in Malaysia and Singapore due to legislative and regulatory constraints as opposed to bias that exist in the western liberal democratic nations of the United Kingdom (UK and the United States of America (USA due to Media Organisation control.

  18. Bullying the media : Cultural and climato-economic readings of press repression versus press freedom

    NARCIS (Netherlands)

    Van de Vliert, E.

    Journalists and media assistants in many places are murdered, imprisoned, censored, threatened, and similarly harrassed. Here I document that, and explain why, there are three climato-economic niches of press repression versus press freedom as part of broader syndromes of national culture. A

  19. AUPress: A Comparison of an Open Access University Press with Traditional Presses

    Science.gov (United States)

    McGreal, Rory; Chen, Nian-Shing

    2011-01-01

    This study is a comparison of AUPress with three other traditional (non-open access) Canadian university presses. The analysis is based on the rankings that are correlated with book sales on Amazon.com and Amazon.ca. Statistical methods include the sampling of the sales ranking of randomly selected books from each press. The results of one-way…

  20. UCL Press: the UK’s 'first fully open access' university press

    Directory of Open Access Journals (Sweden)

    Paul Ayris

    2015-11-01

    Full Text Available The purpose of this article is to set in context the launch of University College London Press (UCL Press, which describes itself as the UK’s first fully open access (OA university press. The drivers for this launch are bound up with the global movement towards open access and open science – developments in which UCL is acknowledged as a European leader. The first part of the article looks at these movements and relates them to the relaunch in May 2015 of the UCL Press imprint as an OA imprint. This analysis has been undertaken by Dr Paul Ayris, Director of UCL Library Services and Chief Executive of UCL Press.  The second half of the article is a personal account by Lara Speicher, Publishing Manager at UCL Press, of the relaunch of the Press. This section looks at staffing structures, business models, technical infrastructures, publishing programmes and content.  In the final part of the article, Paul Ayris draws some conclusions from the history of the relaunch of UCL Press and sets these in the context of the global open science discussion.

  1. THE ROLE OF PRESS FABRIC PRESSURE UNIFORMITY AND PORE SIZE ON DEWATERING AND REWET DURING PRESSING

    Institute of Scientific and Technical Information of China (English)

    Xiaolin Fan; Mary Toney; Jorgen Gullbrand; Fawaad Qamar

    2004-01-01

    New procedures for measuring the pressure uniformity and pore size of press fabrics have been developed to study their role in the dewatering efficiency of a wet paper sheet and fabric system during pressing. The press nip profile of a single nip can be simulated in the laboratory using a custom built Servo-hydraulic Press Nip Simulator (SPNS) and is used to evaluate the final dryness and rewet of a handsheet with press fabric(s). Pressure uniformity can be measured with a flexible high-resolution transducer and pore size; both tests measured using water as the fluid are performed on compressed press fabric samples. A strong correlation is found between pressure uniformity parameters, mean flow pore size and final dryness for different sheets. Rewet is measured "directly" using a tracer fluid in the press fabric in our SPNS tester. Preliminary results indicate a significant reduction in rewet for some sheets with the use of an anti-rewet layer in combination withcertain press fabric designs.

  2. Speaking of a Free Press: 200 Years of Notable Quotations about Press Freedoms.

    Science.gov (United States)

    American Newspaper Publishers Association Foundation, Washington, DC.

    Intended to summarize the ideals underlying the struggle for freedom of the press and to reinforce the basic Constitutional principles upon which the United States functions, this collection of quotations reflects the beliefs of prominent people throughout history who have championed press freedom, as well as the ideas of some who have opposed it.…

  3. AUPress: A Comparison of an Open Access University Press with Traditional Presses

    Science.gov (United States)

    McGreal, Rory; Chen, Nian-Shing

    2011-01-01

    This study is a comparison of AUPress with three other traditional (non-open access) Canadian university presses. The analysis is based on the rankings that are correlated with book sales on Amazon.com and Amazon.ca. Statistical methods include the sampling of the sales ranking of randomly selected books from each press. The results of one-way…

  4. Hydroxycinnamic acids are ester-linked directly to glucosyl moieties within the lignan macromolecule from flaxseed hulls.

    Science.gov (United States)

    Struijs, Karin; Vincken, Jean-Paul; Verhoef, René; Voragen, Alphons G J; Gruppen, Harry

    2008-03-01

    In flaxseed hulls, lignans are present in an oligomeric structure. Secoisolariciresinol diglucoside (SDG), ester-linked to hydroxy-methyl-glutaric acid (HMGA), forms the backbone of this lignan macromolecule. The hydroxycinnamic acids p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeAG) are also part of the lignan macromolecule. However, their position and type of linkage are still unknown. The aim of this study was to investigate how CouAG and FeAG are linked within the lignan macromolecule from flaxseed hulls. Fragments of the lignan macromolecule were obtained by partial saponification. After isolation of the fragments by preparative RP-HPLC, several key structures were identified by MS and NMR. Within the lignan macromolecule, CouAG is attached to the C-6 position of a glucosyl moiety of SDG. FeA is linked to the C-2 position of a glucosyl moiety of SDG. FeAG is ester-linked within the lignan macromolecule with its carboxyl group, but it remains unclear whether FeAG links to the C-2 or C-6 position of SDG. Attachment of HMGA to the glucosyl moiety of CouAG or FeAG was not observed. The results clearly show that within the lignan macromolecule, the hydroxycinnamic acids are linked directly via an ester bond to the glucosyl moiety of SDG.

  5. WordPress 24-hour trainer

    CERN Document Server

    Plumley, George

    2015-01-01

    Create and expand feature-rich sites with no programming experience Ready to build, maintain, and expand your web site with WordPress but have no prior programming experience? WordPress 24-Hour Trainer, 3rd Edition is your book-and-video learning solution that walks you step-by-step through all the important features you will need to know. Lessons range from focused, practical everyday tasks to more advanced, creative features. Learn from an industry professional how to enter content, create pages, manage menus, utilize plug-ins, connect to social media, create membership and e-commerce site

  6. Internet Marketing with WordPress

    CERN Document Server

    Mercer, David

    2011-01-01

    The book's accompanying Interactive learning environment on siteprebuilder.com gives you an online place to enhance and extend your practical experience through exercises, consolidate your learning and theoretical knowledge with marked quizzes, interaction with your WordPress marketing community, and fun and exciting extras such as challenges and competitions. This book is for people already using WordPress, who want more visitors, better visitors, and to convert more of them into paying customers. No prior marketing experience is required, although a basic understanding of either hosted or se

  7. Research on Web Press Tension Control System

    Directory of Open Access Journals (Sweden)

    Chen Sheng Jiang

    2016-01-01

    Full Text Available Tension control of press is a key and difficult point of the whole machine control. The stand or fall of tension is directly related to the quality of the products. According to the characteristics of the web press tension control, this paper expounds the main factors influencing tension and the purpose of tension control, researches on the tension control principle of web tape, analyzes control rule and control circuit of tension control system, illustrates the advantages of PID control law adopted in the tension control system, and concludes the influencing factors of paper tape tension control system and the corresponding problems needed to solve in the control.

  8. Scholarly publishing : The challenges facing the African university press

    NARCIS (Netherlands)

    Ngobeni, S.

    2012-01-01

    This paper seeks to examine the challenges that face the university press in Africa in general and South Africa in particular. It will start by examining the state of the university press in Africa, the state of the university press in South Africa, the challenges that face university presses, such

  9. Free Press in a Constitutional Democracy

    Science.gov (United States)

    Lucianek, Christine

    2014-01-01

    This article describes a lesson in which students will examine several views expressed by the founders to understand the context for including freedom of the press in the First Amendment. Students will be asked to think about the role that the news media and the need to be an informed citizen continue to play in our democracy. Students will…

  10. Brownsville: The Reaction of the Negro Press

    Science.gov (United States)

    Wynne, Lewis N.

    1972-01-01

    Describes the events that followed subsequent to the assignment of an all-black regimental unit to the Fort Brown military installation on the outskirts of Brownsville, Texas, in 1906, with reference to the reactions of the Brownsville residents, the Negro press, and white champions of the black cause, and to the actions of President Theodore…

  11. World Press Photo'98 / Priit Brennel

    Index Scriptorium Estoniae

    Brennel, Priit

    1998-01-01

    Pressifoto ülemaailmsest konkursist ja aastaringselt järgnevatest üritustest, mida korraldab World Press Photo Foundation (peakorter Amsterdamis) 1955. aastast. 1998. a. peapreemia - France Pressi fotograafi Hocine'i töö 23. septembri ööl toimunud massimõrvast Alžeerias, Benthalas. Eestist osalesid Tiit Räis, Viktor Vesterinen.

  12. TEMPERATURE BEHAVIOUR IN PARTICLEBOARD DURING PRESSING

    Directory of Open Access Journals (Sweden)

    Leandro Calegari

    2010-08-01

    Full Text Available The objective of the present work was to investigate the behaviour of core and face temperatures of particleboard glued with 8% tannin-formaldehyde adhesive. The boards were manufactured with three replication per treatment, with density of 0,7 g/cm³ and 27 kgf/cm² of pressing specific pressure. Pine flakes (40, 75 and 110 mm long and 0,5 and 1,0 mm thick and eucalypt particles were used and two pressing temperatures (140 and 180ºC along with two mat moisture content (17 and 21% were employed. The curves of temperature rise with pressing time indicated a fast temperature rise during the first 100 seconds of pressing, remaining at a plateau possible after reaching water boiling temperature. The temperature increased again, but on a more gradual form, after the lost mat moisture. It was possible to observe that mat formed by flakes of larger thicknesses showed faster initial temperature rise. The main factor that influenced the temperature behaviour at the board core was the mat moisture content. The higher the mat moisture content, the faster the temperature rise.

  13. An Introduction to Bibliographical Press Work.

    Science.gov (United States)

    Richardson, John V., Jr.

    This guide to the literature of bibliographical press work is comprised of brief introductory notes on the field and this bibliography, followed by citations listed in seven categories: (1) book production, (2) handmade paper, (3) printer's ink, (4) type design, (5) book design, (6) hand printing, and (7) hand bookbinding. Introductory as well as…

  14. World Press Photo'98 / Priit Brennel

    Index Scriptorium Estoniae

    Brennel, Priit

    1998-01-01

    Pressifoto ülemaailmsest konkursist ja aastaringselt järgnevatest üritustest, mida korraldab World Press Photo Foundation (peakorter Amsterdamis) 1955. aastast. 1998. a. peapreemia - France Pressi fotograafi Hocine'i töö 23. septembri ööl toimunud massimõrvast Alžeerias, Benthalas. Eestist osalesid Tiit Räis, Viktor Vesterinen.

  15. Metrics for Offset Printing Press Operation.

    Science.gov (United States)

    Cooper, Gloria S., Ed.; Magisos, Joel H., Ed.

    Designed to meet the job-related metric measurement needs of offset printing press operation students, this instructional package is one of six for the communication media occupations cluster, part of a set of 55 packages for metric instruction in different occupations. The package is intended for students who already know the occupational…

  16. The Press, Privacy, and Community Mores.

    Science.gov (United States)

    Glasser, Theodore L.

    Because of judicial indifference and legislative inaction, the conflict between the right of privacy and the freedom of the press is no closer to a resolution than it was a century ago. William Prosser's reduction of the common law of privacy into four separate torts has not solved the problem. The concept of "newsworthiness" has not been helpful…

  17. Free Press in a Constitutional Democracy

    Science.gov (United States)

    Lucianek, Christine

    2014-01-01

    This article describes a lesson in which students will examine several views expressed by the founders to understand the context for including freedom of the press in the First Amendment. Students will be asked to think about the role that the news media and the need to be an informed citizen continue to play in our democracy. Students will…

  18. Neo-Lysenkoism, IQ, and the Press.

    Science.gov (United States)

    Davis, Bernard D.

    1983-01-01

    In "The Mismeasure of Man," a history of efforts to measure intelligence, Stephen Jay Gould is highly selective in his account, and tests for scientific truth by the standards of his own social and political convictions. Specifically, to combat racist approaches to theories of intelligence, Gould presses for equal and opposite bias.…

  19. When should you press the reload button?

    NARCIS (Netherlands)

    Timmer, Judith B.

    2009-01-01

    While surfing on the Internet, you may have observed the following. If a webpage takes a long time to download and you press the reload button then often the page promptly appears on your screen. Hence, the download was not hindered by congestion — then you’d better try again later — but by some

  20. Research Review: The Specialized Business Press.

    Science.gov (United States)

    Endres, Kathleen L.

    1994-01-01

    Reviews scholarly research (from journalism, communication, business, and the humanities) on the specialized business press. Notes the lack of theory building and ties across disciplines, and anticipates that new advances in CD-ROM technology may increase research into the field as well as strengthen ties across disciplines. (SR)

  1. Trial access to Cambridge University Press ebooks

    CERN Multimedia

    CERN Library

    2011-01-01

    From 1 August till 31 October, CERN users are invited to enjoy a trial access to all Cambridge University Press electronic books: http://ebooks.cambridge.org/. Please don't hesitate to send feedback to library.desk@cern.ch.

  2. The Moral Universes of Libertarian Press Theory.

    Science.gov (United States)

    Wuliger, Gregory T.

    1991-01-01

    Uses Kantian logic to analyze the statement of Libertarian press theory "Truth beats falsehood in a free marketplace of ideas" as a definition, an observation, and a universal truth. Notes three corresponding moral universes, with differing ethical obligations. Discusses strengths and weaknesses of each. Cautions media ethics analysts against…

  3. An installation for pressing pasted electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Matsudzava, S.; Sugimoto, K.

    1983-07-13

    The active mass is placed on the current outlet and the electrode is pressed and its thickness is regulated by passing it through rollers. The water and the adhering particles of the active mass are continuously sucked off during rotation of the rollers.

  4. A Journalist's Guide to the Free Press.

    Science.gov (United States)

    Ingelhart, Louis

    1996-01-01

    Summarizes the content of the federal constitution and various state constitutions regarding freedom of the press. Examines certain borderline issues, including actions and expressions, pornography, defamation, libel, and copyrighted material. States that regulation of unprotected material must be reasonable, specific, and clear. Discusses what…

  5. Marine-derived biological macromolecule-based biomaterials for wound healing and skin tissue regeneration.

    Science.gov (United States)

    Chandika, Pathum; Ko, Seok-Chun; Jung, Won-Kyo

    2015-01-01

    Wound healing is a complex biological process that depends on the wound condition, the patient's health, and the physicochemical support given through external materials. The development of bioactive molecules and engineered tissue substitutes to provide physiochemical support to enhance the wound healing process plays a key role in advancing wound-care management. Thus, identification of ideal molecules in wound treatment is still in progress. The discovery of natural products that contain ideal molecules for skin tissue regeneration has been greatly advanced by exploration of the marine bioenvironment. Consequently, tremendously diverse marine organisms have become a great source of numerous biological macromolecules that can be used to develop tissue-engineered substitutes with wound healing properties. This review summarizes the wound healing process, the properties of macromolecules from marine organisms, and the involvement of these molecules in skin tissue regeneration applications.

  6. Mitochondrial transit peptide exhibits cell penetration ability and efficiently delivers macromolecules to mitochondria.

    Science.gov (United States)

    Jain, Aastha; Chugh, Archana

    2016-09-01

    Mitochondrial malfunction under various circumstances can lead to a variety of disorders. Effective targeting of macromolecules (drugs) is important for restoration of mitochondrial function and treatment of related disorders. We have designed a novel cell-penetrating mitochondrial transit peptide (CpMTP) for delivery of macromolecules to mitochondria. Comparison between properties of cell-penetrating peptides (CPPs) and mitochondrial signal sequences enabled prediction of peptides with dual ability for cellular translocation and mitochondrial localization. Among the predicted peptides, CpMTP translocates across HeLa cells and shows successful delivery of noncovalently conjugated cargo molecules to mitochondria. CpMTP may have applications in transduction and transfection of mitochondria for therapeutics. © 2016 Federation of European Biochemical Societies.

  7. Recent Progress in the Design of Monodisperse, Sequence-Defined Macromolecules.

    Science.gov (United States)

    Solleder, Susanne C; Schneider, Rebekka V; Wetzel, Katharina S; Boukis, Andreas C; Meier, Michael A R

    2017-05-01

    This review describes different synthetic strategies towards sequence-defined, monodisperse macromolecules, which are built up by iterative approaches and lead to linear non-natural polymer structures. The review is divided in three parts: solution phase-, solid phase-, and fluorous- and polymer-tethered approaches. Moreover, synthesis procedures leading to conjugated and non-conjugated macromolecules are considered and discussed in the respective sections. A major focus in the evaluation is the applicability of the different approaches in polymer chemistry. In this context, simple procedures for monomer and oligomer synthesis, overall yields, scalability, purity of the oligomers, and the achievable level of control (side-chains, backbone, stereochemistry) are important benchmarks. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. A Stochastic Finite Element Model for the Dynamics of Globular Macromolecules

    CERN Document Server

    Oliver, Robin; Harlen, Oliver G; Harris, Sarah A

    2012-01-01

    We describe a novel coarse-grained simulation method for modelling the dynamics of globular macromolecules, such as proteins. The macromolecule is treated as a continuum that is subject to thermal fluctuations. The model includes a non-linear treatment of elasticity and viscosity with thermal noise that is solved using finite element analysis. We have validated the method by demonstrating that the model provides average kinetic and potential energies that are in agreement with the classical equipartition theorem. In addition, we have performed Fourier analysis on the simulation trajectories obtained for a series of linear beams to confirm that the correct average energies are present in the first two Fourier bending modes. We have then used the new modelling method to simulate the thermal fluctuations of a representative protein over 500ns timescales. Using reasonable parameters for the material properties, we have demonstrated that the overall deformation of the biomolecule is consistent with the results obt...

  9. Biomimetic Transmembrane Channels with High Stability and Transporting Efficiency from Helically Folded Macromolecules.

    Science.gov (United States)

    Lang, Chao; Li, Wenfang; Dong, Zeyuan; Zhang, Xin; Yang, Feihu; Yang, Bing; Deng, Xiaoli; Zhang, Chenyang; Xu, Jiayun; Liu, Junqiu

    2016-08-08

    Membrane channels span the cellular lipid bilayers to transport ions and molecules into cells with sophisticated properties including high efficiency and selectivity. It is of particular biological importance in developing biomimetic transmembrane channels with unique functions by means of chemically synthetic strategies. An artificial unimolecular transmembrane channel using pore-containing helical macromolecules is reported. The self-folding, shape-persistent, pore-containing helical macromolecules are able to span the lipid bilayer, and thus result in extraordinary channel stability and high transporting efficiency for protons and cations. The lifetime of this artificial unimolecular channel in the lipid bilayer membrane is impressively long, rivaling those of natural protein channels. Natural channel mimics designed by helically folded polymeric scaffolds will display robust and versatile transport-related properties at single-molecule level. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Encoding of Primary Structures of Biological Macromolecules Within a Data Mining Perspective

    Institute of Scientific and Technical Information of China (English)

    Mondher Maddouri; Mourad Elloumi

    2004-01-01

    An encoding method has a direct effect on the quality and the representation of the discovered knowledge in data mining systems. Biological macromolecules are encoded by strings of characters, called primary structures. Knowing that data mining systems usually use relational tables to encode data, we have then to reencode these strings and transform them into relational tables. In this paper, we do a comparative study of the existing static encoding methods, that are based on the Biologist know-how, and our new dynamic encoding one,that is based on the construction of Discriminant and Minimal Substrings (DMS). Different classification methods are used to do this study. The experimental results show that our dynamic encoding method is more efficient than the static ones, to encode biological macromolecules within a data mining perspective.

  11. Synthesis and mechanisms of formation of polymers composed of different macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Korshak, V.V.; Askadskii, A.A.; Vointseva, I.I.; Mustafaeva, B.B.; Slonimskii, G.L.; Suprun, A.P.

    1983-02-01

    The fundamental possibility of synthesizing soluble and fusible aggregates of different macromolecules was discovered in the reaction of chlorinated and aromatic polymers under the conditions of the Friedel-Crafts reaction. Such an approach opens the prospects of combining in one macromolecule two or more different types of chain, and of the synthesis of polymers with a new combination of properties. In this reaction poly-1,1,2-trichlorobutadiene (PTCB) and polyvinylcholoride can be used as chlorine-containing compounds, and polystyrene (PS), poly-..cap alpha..-methyl-styrene, polyarylates, polycarbonates, etc., as the aromatic polymers. The mechanism of the reaction of chlorinated and aromatic polymers was studied with PTCB and PS as the model pair of polymers.

  12. Spreading of a chain macromolecule onto a cell membrane by a computer simulation Model

    Science.gov (United States)

    Xie, Jun; Pandey, Ras

    2002-03-01

    Computer simulations are performed to study conformation and dynamics of a relatively large chain macromolecule at the surface of a model membrane - a preliminary attempt to ultimately realistic model for protein on a cell membrane. We use a discrete lattice of size Lx × L × L. The chain molecule of length Lc is modeled by consecutive nodes connected by bonds on the trail of a random walk with appropriate constraints such as excluded volume, energy dependent configurational bias, etc. Monte Carlo method is used to move chains via segmental dynamics, i.e., end-move, kink-jump, crank-shaft, reptation, etc. Membrane substrate is designed by a self-assemble biased short chains on a substrate. Large chain molecule is then driven toward the membrane by a field. We investigate the dynamics of chain macromolecule, spread of its density, and conformation.

  13. Load-release of small and macromolecules from elastomers with reversible gyroid mesoporosity

    DEFF Research Database (Denmark)

    Guo, Fengxiao; Schulte, Lars; Ndoni, Sokol

    2012-01-01

    . However, in the gel state in the presence of a good solvent the swollen matrix did show a nanoporous structure originated from the gyroid block copolymer precursor. Nanopores can be opened or closed depending on the presence or absence of a solvent. Macromolecules like PEG of different molecular weights...... or small molecules like the surfactant SDS were loaded into the opened nanoporous matrix in the presence of a solvent and remained trapped. The loaded molecules could be released again in the presence of a solvent. The load and release of the molecules in deuterated form were monitored by in situ time......-resolved small angle neutron scattering, SANS. The bicontinuous gyroid pore structure is accessible to macromolecules without the need for sample pre-alignment. The materials presented here are model systems for a novel type of load-delivery systems that could show great potential in e.g. diagnostics or drug...

  14. Accuracy of Press Reports in Astronomy

    Science.gov (United States)

    Schaefer, B. E.; Hurley, K.; Nemiroff, R. J.; Branch, D.; Perlmutter, S.; Schaefer, M. W.; Consolmagno, G. J.; McSween, H.; Strom, R.

    1999-12-01

    Most Americans learn about modern science from press reports, while such articles have a bad reputation among scientists. We have performed a study of 403 news articles on three topics (gamma-ray astronomy, supernovae, and Mars) to quantitatively answer the questions 'How accurate are press reports of astronomy?' and 'What fraction of the basic science claims in the press are correct?' We have taken all articles on the topics from five news sources (UPI, NYT, S&T, SN, and 5 newspapers) for one decade (1987-1996). All articles were evaluated for a variety of errors, ranging from the fundamental to the trivial. For 'trivial' errors, S&T and SN were virtually perfect while the various newspapers averaged roughly one trivial error every two articles. For meaningful errors, we found that none of our 403 articles significantly mislead the reader or misrepresented the science. So a major result of our study is that reporters should be rehabilitated into the good graces of astronomers, since they are actually doing a good job. For our second question, we rated each story with the probability that its basic new science claim is correct. We found that the average probability over all stories is 70%, regardless of source, topic, importance, or quoted pundit. How do we reconcile our findings that the press does not make significant errors yet the basic science presented is 30% wrong? The reason is that the nature of news reporting is to present front-line science and the nature of front-line science is that reliable conclusions have not yet been reached. So a second major result of our study is to make the distinction between textbook science (with reliability near 100%) and front-line science which you read in the press (with reliability near 70%).

  15. Ultrasound-enhanced penetration through sclera depends on frequency of sonication and size of macromolecules.

    Science.gov (United States)

    Chau, Ying; Suen, Wai Leung Langston; Tse, Ho Yan; Wong, Hoi Sang

    2017-03-30

    We previously employed ultrasound as a needleless approach to deliver macromolecules via the transscleral route to the back of the eye in live animals (Suen et al., 2013). Here, we investigated the nature of the ultrasound-enhanced transport through sclera, the outermost barrier in the transscleral route. Thus, the possible role of cavitation from ultrasound was explored; its effect during and after sonication on scleral penetration was measured; and the dependence on the size of macromolecules was determined. We applied ultrasound frequency from 40kHz to 3MHz at ISATA (spatial-average-temporal-average intensity) of 0.05W/cm(2) to fresh rabbit sclera ex vivo. Fluorescent dextran of size 20kDa to 150kDa was used as macromolecular probes. We measured the distance of penetration of the probes through the sclera over 30s during sonication and over 15min after sonication from cryosectioned tissue images. Deeper penetration in the sclera was observed with decreasing frequency. The presence of stable cavitation was further verified by passive acoustic detection. The effect during sonication increased penetration distance up to 20 fold and was limited to macromolecular probes ≤70kDa. The effect post sonication increased penetration distance up to 3 fold and attributed to the improved intrasscleral transport of macromolecules ≥70kDa. Post-sonication enhancement diminished gradually in 3h. As the extent of cavitation increased with decreasing frequency, the trend observed supports the contribution of (stable) cavitation to enhancing transport through sclera. Effect during sonication was attributed to flow associated with acoustic microstreaming. Effect post sonication was attributed to the temporary increase in scleral permeability. Flow-associated effect was more pronounced but only applied to smaller macromolecules. Copyright © 2017. Published by Elsevier B.V.

  16. Bioinformatic science and devices for computer analysis and visualization of macromolecules

    Directory of Open Access Journals (Sweden)

    Yu.B. Porozov

    2010-06-01

    Full Text Available The goals and objectives of bioinformatic science are presented in the article. The main methods and approaches used in computer biology are highlighted. Areas in which bioinformatic science can greatly facilitate and speed up the work of practical biologist and pharmacologist are revealed. The features of both the basic packages and software devices for complete, thorough analysis of macromolecules and for development and modeling of ligands and binding centers are described

  17. Asymmetrical flow field-flow fractionation in the study of water-soluble macromolecules

    OpenAIRE

    Yohannes, Gebrenegus

    2007-01-01

    Asymmetrical flow field-flow fractionation (AsFlFFF) was constructed, and its applicability to industrial, biochemical, and pharmaceutical applications was studied. The effect of several parameters, such as pH, ionic strength, temperature and the reactants mixing ratios on the particle sizes, molar masses, and the formation of aggregates of macromolecules was determined by AsFlFFF. In the case of industrial application AsFlFFF proved to be a valuable tool in the characterization of the hydrod...

  18. Application of Symmetry Adapted Function Method for Three-Dimensional Reconstruction of Octahedral Biological Macromolecules

    Directory of Open Access Journals (Sweden)

    Songjun Zeng

    2010-01-01

    Full Text Available A method for three-dimensional (3D reconstruction of macromolecule assembles, that is, octahedral symmetrical adapted functions (OSAFs method, was introduced in this paper and a series of formulations for reconstruction by OSAF method were derived. To verify the feasibility and advantages of the method, two octahedral symmetrical macromolecules, that is, heat shock protein Degp24 and the Red-cell L Ferritin, were utilized as examples to implement reconstruction by the OSAF method. The schedule for simulation was designed as follows: 2000 random orientated projections of single particles with predefined Euler angles and centers of origins were generated, then different levels of noises that is signal-to-noise ratio (S/N =0.1,0.5, and 0.8 were added. The structures reconstructed by the OSAF method were in good agreement with the standard models and the relative errors of the structures reconstructed by the OSAF method to standard structures were very little even for high level noise. The facts mentioned above account for that the OSAF method is feasible and efficient approach to reconstruct structures of macromolecules and have ability to suppress the influence of noise.

  19. Prevention of H-Aggregates Formation in Cy5 Labeled Macromolecules

    Directory of Open Access Journals (Sweden)

    Jing Kang

    2010-01-01

    Full Text Available H-aggregates of the cyanine dye Cy5 are formed during covalent linkage to the cationic macromolecule Poly(allylamine (PAH. The nonfluorescent H-aggregates strongly restrict the usage of the dye for analytical purposes and prevent a quantitative determination of the labeled macromolecules. The behavior of the H-aggregates has been studied by investigation of the absorption and fluorescence spectra of the dye polymer in dependence on solvent, label degree and additional sulfonate groups. H-aggregate formation is caused by an inhomogeneous distribution of the Cy5 molecules on the polymer chain. The H-aggregates can be destroyed by conformational changes of the PAH induced by interactions with polyanions or in organic solvents. It has been found that the polymer labeling process in high content of organic solvents can prevent the formation of H-aggregates. The results offer a better understanding and improvement of the use of the Cy5 dye for labeling purposes in fluorescence detection of macromolecules.

  20. Synthetic mimetics of the endogenous gastrointestinal nanomineral: Silent constructs that trap macromolecules for intracellular delivery.

    Science.gov (United States)

    Pele, Laetitia C; Haas, Carolin T; Hewitt, Rachel E; Robertson, Jack; Skepper, Jeremy; Brown, Andy; Hernandez-Garrido, Juan Carlos; Midgley, Paul A; Faria, Nuno; Chappell, Helen; Powell, Jonathan J

    2017-02-01

    Amorphous magnesium-substituted calcium phosphate (AMCP) nanoparticles (75-150nm) form constitutively in large numbers in the mammalian gut. Collective evidence indicates that they trap and deliver luminal macromolecules to mucosal antigen presenting cells (APCs) and facilitate gut immune homeostasis. Here, we report on a synthetic mimetic of the endogenous AMCP and show that it has marked capacity to trap macromolecules during formation. Macromolecular capture into AMCP involved incorporation as shown by STEM tomography of the synthetic AMCP particle with 5nm ultra-fine iron (III) oxohydroxide. In vitro, organic cargo-loaded synthetic AMCP was taken up by APCs and tracked to lysosomal compartments. The AMCP itself did not regulate any gene, or modify any gene regulation by its cargo, based upon whole genome transcriptomic analyses. We conclude that synthetic AMCP can efficiently trap macromolecules and deliver them to APCs in a silent fashion, and may thus represent a new platform for antigen delivery. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  1. Structure-Correlation NMR Spectroscopy for Macromolecules Using Repeated Bidirectional Photoisomerization of Azobenzene.

    Science.gov (United States)

    Nagashima, Toshio; Ueda, Keisuke; Nishimura, Chiaki; Yamazaki, Toshio

    2015-11-17

    Control over macromolecular structure offers bright potentials for manipulation of macromolecular functions. We here present structure-correlation NMR spectroscopy to analyze the correlation between polymorphic macromolecular structures driven by photoisomerization of azobenzene. The structural conversion of azobenzene was induced within the mixing time of a NOESY experiment using a colored light source, and the reverse structural conversion was induced during the relaxation delay using a light source of another color. The correlation spectrum between trans- and cis-azobenzene was then obtained. To maximize the efficiency of the bidirectional photoisomerization of azobenzene-containing macromolecules, we developed a novel light-irradiation NMR sample tube and method for irradiating target molecules in an NMR radio frequency (rf) coil. When this sample tube was used for photoisomerization of an azobenzene derivative at a concentration of 0.2 mM, data collection with reasonable sensitivity applicable to macromolecules was achieved. We performed isomerization of an azobenzene-cross-linked peptide within the mixing time of a NOESY experiment that produced cross-peaks between helix and random-coil forms of the peptide. Thus, these results indicate that macromolecular structure manipulation can be incorporated into an NMR pulse sequence using an azobenzene derivative and irradiation with light of two types of wavelengths, providing a new method for structural analysis of metastable states of macromolecules.

  2. Nasal Absorption of Macromolecules from Powder Formulations and Effects of Sodium Carboxymethyl Cellulose on Their Absorption.

    Science.gov (United States)

    Tanaka, Akiko; Furubayashi, Tomoyuki; Matsushita, Akifumi; Inoue, Daisuke; Kimura, Shunsuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

    2016-01-01

    The nasal absorption of macromolecules from powder formulations and the effect of sodium carboxymethyl cellulose (CMC-Na) as a pharmaceutical excipient on their absorption were studied. Model macromolecules were fluorescein isothiocyanate-labeled dextran (average molecular weight of 4.4kDa, FD4) and insulin. The plasma concentration of FD4 after application of the powder containing 50% starch (control) was higher than that after application of the solution, and the absorption from 50% starch powder was enhanced by the substitution of starch with CMC-Na. The fractional absorption of FD4 after administration of the CMC-Na powder formulation was 30% and 40% higher than that after administration from the solution and the starch powder, respectively. The nasal absorption of insulin from the powder and the effect of CMC-Na were similar with those of FD4. The effective absorption of FD4 and insulin after application of powder with CMC-Na could be due to the increase in the nasal residence of FD4 and insulin. No damage in the nasal mucosa or dysfunction of the mucociliary clearance was observed after application of the drug powder and CMC-Na. The present findings indicate that nasal delivery of powder formulations with the addition of CMC-Na as an excipient is a promising approach for improving the nasal absorption of macromolecules.

  3. Ordinary-extraordinary transition in dynamics of solutions of charged macromolecules.

    Science.gov (United States)

    Muthukumar, Murugappan

    2016-10-24

    The occurrence of the ubiquitous and intriguing "ordinary-extraordinary" behavior of dynamics in solutions of charged macromolecules is addressed theoretically by explicitly considering counterions around the macromolecules. The collective and coupled dynamics of macromolecules and their counterion clouds in salt-free conditions are shown to lead to the "ordinary" behavior (also called the "fast" mode) where diffusion coefficients are independent of molar mass and polymer concentration and are comparable to those of isolated metallic ions in aqueous media, in agreement with experimental facts observed repeatedly over the past four decades. The dipoles arising from adsorbed counterions on polymer backbones can form many pairwise physical cross-links, leading to microgel-like aggregates. Balancing the swelling from excluded volume effects and counterion pressure with elasticity of the microgel, we show that there is a threshold value of a combination of polymer concentration and electrolyte concentration for the occurrence of the "extraordinary" phase (also called the "slow" mode) and the predicted properties of diffusion coefficient for this phase are in qualitative agreement with well-known experimental data.

  4. Immunomodulatory Properties of Taranjebin (Camel's Thorn) Manna and Its Isolated Carbohydrate Macromolecules.

    Science.gov (United States)

    Hamedi, Azadeh; Farjadian, Shirin; Karami, Mohammad Reza

    2015-10-01

    Taranjebin manna is a substance produced by Poophilus nebulosus Leth. (Aphrophoridae) larva that feed from host plant Alhagi maurorum (Leguminosae). In Persian ethnomedicine, it is used as an antipyretic, antiviral, antimicrobial, demulcent, and adaptogen. But it is contraindicated in acute fever and some infections. This controversy might be due to its immunomodulatory properties. This study evaluated immunomodulatory properties of Taranjebin and its macromolecules. Taranjebin solution was prepared as described in traditional literature. After dialysis and precipitation, the macromolecules were isolated on DEAE Sephadex A-25. The cytotoxic/proliferative properties of Taranjebin and its isolated macromolecules on human Jurkat E6.1 cells were investigated (15.62-1000 μg/mL) using WST-1 reagent. Three of 4 isolated acidic polysaccharides inhibited the proliferation of Jurkat cells in a dose-dependent manner at concentrations higher than 31.25 μg/mL (IC50 range of 44.81-147.97 μg/mL). The crude aqueous Taranjebin solution had proliferative effects. These results indicate the immunomodulatory properties of Taranjebin. © The Author(s) 2015.

  5. Silica-based systems for oral delivery of drugs, macromolecules and cells.

    Science.gov (United States)

    Diab, Roudayna; Canilho, Nadia; Pavel, Ileana A; Haffner, Fernanda B; Girardon, Maxime; Pasc, Andreea

    2017-04-20

    According to the US Food and Drug Administration and the European Food Safety Authority, amorphous forms of silica and silicates are generally recognized to be safe as oral delivery ingredients in amounts up to 1500mg per day. Silica is used in the formulation of solid dosage forms, e.g. tablets, as glidant or lubricant. The synthesis of silica-based materials depends on the payload nature, drug, macromolecule or cell, and on the target release (active or passive). In the literature, most of the examples deal with the encapsulation of drugs in mesoporous silica nanoparticles. Still to date limited reports concerning the delivery of encapsulated macromolecules and cells have been reported in the field of oral delivery, despite the multiple promising examples demonstrating the compatibility of the sol-gel route with biological entities, likewise the interest of silica as an oral carrier. Silica diatoms appear as an elegant, cost-effective and promising alternative to synthetic sol-gel-based materials. This review reports the latest advances silica-based systems and discusses the potential benefits and drawbacks of using silica for oral delivery of drugs, macromolecules or cells. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Diffusion profile of macromolecules within and between human skin layers for (trans)dermal drug delivery.

    Science.gov (United States)

    Römgens, Anne M; Bader, Dan L; Bouwstra, Joke A; Baaijens, Frank P T; Oomens, Cees W J

    2015-10-01

    Delivering a drug into and through the skin is of interest as the skin can act as an alternative drug administration route for oral delivery. The development of new delivery methods, such as microneedles, makes it possible to not only deliver small molecules into the skin, which are able to pass the outer layer of the skin in therapeutic amounts, but also macromolecules. To provide insight into the administration of these molecules into the skin, the aim of this study was to assess the transport of macromolecules within and between its various layers. The diffusion coefficients in the epidermis and several locations in the papillary and reticular dermis were determined for fluorescein dextran of 40 and 500 kDa using a combination of fluorescent recovery after photobleaching experiments and finite element analysis. The diffusion coefficient was significantly higher for 40 kDa than 500 kDa dextran, with median values of 23 and 9 µm(2)/s in the dermis, respectively. The values only marginally varied within and between papillary and reticular dermis. For the 40 kDa dextran, the diffusion coefficient in the epidermis was twice as low as in the dermis layers. The adopted method may be used for other macromolecules, which are of interest for dermal and transdermal drug delivery. The knowledge about diffusion in the skin is useful to optimize (trans)dermal drug delivery systems to target specific layers or cells in the human skin. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Formation and characterization of calcium orthophosphates in the presence of two different acidic macromolecules

    Science.gov (United States)

    Pelin, Irina M.; Maier, Vasilica; Suflet, Dana M.; Popescu, Irina; Darie-Nita, Raluca N.; Aflori, Magdalena; Butnaru, Maria

    2017-10-01

    The synthetic nanocrystalline calcium orthophosphates have a notable bioactivity due to the chemical similarity with biological apatite from calcified tissues. In mineralized tissues, the highly ordered structures come from organized assemblies of biomacromolecules and inorganic nanoparticles. One of the purposes of this work was to study the effect of two types of acidic macromolecules: atelocollagen and phosphorylated curdlan onto calcium orthophosphates formation after 30 days of maturation at 2 ± 2 °C. The resulted samples after a long aging time, either calcium orthophosphates or composites, were first investigated by FT-IR spectroscopy and X-ray diffractometry and the results indicated that precipitated hydroxyapatite with low crystallinity was obtained when the synthesis was performed in the presence of phosphorylated curdlan. The macromolecules influenced the morphology of the particles as shown by scanning and transmission electron microscopy. The presence of macromolecules as demonstrated by thermal investigation also influenced the rheological properties of the samples. The second purpose of the work was to evaluate the cytotoxicity of the samples using the MTT assay, and the results revealed very good cells viability. The preliminary results are encouraging regarding the use of these materials for further tests in order to develop injectable bone substitutes.

  8. Nasal Absorption of Macromolecules from Powder Formulations and Effects of Sodium Carboxymethyl Cellulose on Their Absorption

    Science.gov (United States)

    Tanaka, Akiko; Furubayashi, Tomoyuki; Matsushita, Akifumi; Inoue, Daisuke; Kimura, Shunsuke; Katsumi, Hidemasa; Sakane, Toshiyasu; Yamamoto, Akira

    2016-01-01

    The nasal absorption of macromolecules from powder formulations and the effect of sodium carboxymethyl cellulose (CMC-Na) as a pharmaceutical excipient on their absorption were studied. Model macromolecules were fluorescein isothiocyanate-labeled dextran (average molecular weight of 4.4kDa, FD4) and insulin. The plasma concentration of FD4 after application of the powder containing 50% starch (control) was higher than that after application of the solution, and the absorption from 50% starch powder was enhanced by the substitution of starch with CMC-Na. The fractional absorption of FD4 after administration of the CMC-Na powder formulation was 30% and 40% higher than that after administration from the solution and the starch powder, respectively. The nasal absorption of insulin from the powder and the effect of CMC-Na were similar with those of FD4. The effective absorption of FD4 and insulin after application of powder with CMC-Na could be due to the increase in the nasal residence of FD4 and insulin. No damage in the nasal mucosa or dysfunction of the mucociliary clearance was observed after application of the drug powder and CMC-Na. The present findings indicate that nasal delivery of powder formulations with the addition of CMC-Na as an excipient is a promising approach for improving the nasal absorption of macromolecules. PMID:27598527

  9. Size and average density spectra of macromolecules obtained from hydrodynamic data.

    Science.gov (United States)

    Pavlov, G M

    2007-02-01

    It is proposed to normalize the Mark-Kuhn-Houwink-Sakurada type of equation relating the hydrodynamic characteristics, such as intrinsic viscosity, velocity sedimentation coefficient and translational diffusion coefficient of linear macromolecules to their molecular masses for the values of linear density M(L) and the statistical segment length A. When the set of data covering virtually all known experimental information is normalized for M(L), it is presented as a size spectrum of linear polymer molecules. Further normalization for the A value reduces all data to two regions: namely the region exhibiting volume interactions and that showing hydrodynamic draining. For chains without intachain excluded volume effects these results may be reproduced using the Yamakawa-Fujii theory of wormlike cylinders. Data analyzed here cover a range of contour lengths of linear chains varying by three orders of magnitude, with the range of statistical segment lengths varying approximately 500 times. The plot of the dependence of [eta]M on M represents the spectrum of average specific volumes occupied by linear and branched macromolecules. Dendrimers and globular proteins for which the volume occupied by the molecule in solution is directly proportional to M have the lowest specific volume. The homologous series of macromolecules in these plots are arranged following their fractal dimensionality.

  10. Analysis of Institutional Press Releases and its Visibility in the Press

    Directory of Open Access Journals (Sweden)

    José Antonio Alcoceba-Hernando, Ph.D.

    2010-01-01

    Full Text Available The relationships between institutional communication and media communication influence the shaping of social representations of public issues. This research article analyses these relationships based on the case study of the external communication of a public institution, the press releases of Spain’s Youth Institute (Instituto de la Juventud, aka, Injuve, during three years and their repercussion in the press during the same period of time. The results obtained in this research allowed drawing conclusions on the types of communication production of the aforementioned institution and the news treatment of such pieces of information by the printed and digital media. The press releases and the news items were studied using quantitative media content analysis which focused, especially, in referential issues like the information treatment, the thematic analysis, youth representations in the case of the releases; and the visibility of the press releases in the making of news

  11. Freedom of the Press – two concepts

    Directory of Open Access Journals (Sweden)

    Markus Meckl

    2015-03-01

    Full Text Available In 1644 the debate for freedom of expression started in modern times thanks to John Milton’s Areopagitica, where he still argued about God in order to justify his quest for freedom. With the enlightenment God lost his unifying role for society and could no longer serve as justification. Two arguments were brought then forward to justify freedom of the press: One by the continental movement of the enlightenment; the other from within the movement of utilitarianism, and most influentially by John Stuart Mill. Both underlined the importance of truth; however, they differed in their understanding on what truth was good for. This difference in their arguments had a lasting impact on the debate on the limits of freedom of the press.

  12. Condition monitoring of multistage printing presses

    Science.gov (United States)

    Wang, W.; Golnaraghi, F.; Ismail, F.

    2004-03-01

    The main concern in printing quality in multistage presses is doubling. Doubling is caused by imperfections either within stages (units) or in links connecting different stages, mainly resulting from machine vibration, gear damage, and excessive run-out. In this paper, we propose new means for printing quality control via geared system health condition monitoring. The diagnosis is based on the signals acquired from inexpensive magnetic pickups. A new technique is developed to monitor the gear rotation synchronization among different stages in order to isolate possible sources of the doubling problem. A new approach is proposed to determine the gear run-out. Moreover, gear tooth damage detection is conducted using the beta kurtosis and the continuous wavelet transform based on the overall residual signal. The beta kurtosis of original signal average is also shown here to be useful in detecting excessive gear run-out. Test results from printing presses demonstrated the viability of the proposed methods.

  13. Reducing VOC Press Emission from OSB Manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Gary D. McGinnis; Laura S. WIlliams; Amy E. Monte; Jagdish Rughani: Brett A. Niemi; Thomas M. Flicker

    2001-12-31

    Current regulations require industry to meet air emission standards with regard to particulates, volatile organic compounds (VOCs), hazardous air pollutants (HAPs) and other gases. One of many industries that will be affected by the new regulations is the wood composites industry. This industry generates VOCs, HAPs, and particulates mainly during the drying and pressing of wood. Current air treatment technologies for the industry are expensive to install and operate. As regulations become more stringent, treatment technologies will need to become more efficient and cost effective. The overall objective of this study is to evaluate the use of process conditions and chemical additives to reduce VOC/HAPs in air emitted from presses and dryers during the production of oriented strand board.

  14. Press Freedom on the Media Agenda

    Directory of Open Access Journals (Sweden)

    Terezinha Maria de Carvalho Cruz Pires

    2007-06-01

    Full Text Available This article proposes to present a refl ection on the meanings constructed by the Brazilian written press regarding media and democracy. For this, it was necessary to recompose a specifi c journalistic event: the submission to the Brazilian Congress of a bill to create the Federal Journalism Council by the Brazilian President, Luiz Inácio Lula da Silva, at the request of the National Journalists Federation in August, 2004. This procedure gave rise to something rarely seen: the media were in the spotlight and thus it caused a controversial debate to emerge on the public scene regarding the journalist profession, journalism and press freedom, involving a diversity of political subjects.

  15. Design of jigs, fixtures and press tools

    CERN Document Server

    Venkataraman, K

    2015-01-01

    Textbook presenting the fundamentals of tool design with special focus on jigs, fixtures and die design Covers sections on sheet metal forming processes; turning, grinding, broaching, welding and modular fixtures; principles of clamping; and an Introduction to Presses and Auxiliary Equipment Author has many years' experience in both academic and industrial environments, and presents this work in an easily-accessible style End of chapter questions and answers assist the learning process for both practicing tooling designers and engineers, and manufacturing en

  16. ACTIVATED HOT PRESSING BEHAVIOR OF WC NANOPOWDERS

    Directory of Open Access Journals (Sweden)

    Edwin GEVORKYAN

    2010-06-01

    Full Text Available The questions of consolidation of nanopowders concerning hot compaction by pressing activated by electric current action are considered. Mechanisms of grain boundary creep-sliding which are sequentially prevalent in a forming of compacted structures under influence of temperature factor and in the presence of a direct electric heating are discussed. Structural-transformational sources and conditions of forming of high physical-mechanical properties of nanopowder refractory solid-state products are described.

  17. Magellan Press Conference (2 of 2)

    Science.gov (United States)

    1991-01-01

    Live footage shows the speakers participating in the Magellan Press Conference question and answer session. Speakers include Huntress, Spear, Ledbetter, Johnson, McCarthy, and Saunders. The speakers are shown answering questions from various NASA Centers, and participating audience members from many different industries. They discuss the start and stop date for the mapping. Also shown are animation and radar images of Venus and Artemis. This is tape 2 of 2; tape 1 has a report number NONP-NASA-VT-2000036552.

  18. Natural cold pressed oils as cosmetic products

    Directory of Open Access Journals (Sweden)

    Małgorzata Ligęza

    2016-12-01

    Full Text Available Background. It seems that patients may ask general practitioners about natural cosmetics applied on the skin regarding their safety and suitability. Objectives. The aim of the study was to analyze natural cold pressed oils as potential cosmetic products. Material and methods. Cold pressed oils obtained from selected seeds and fruit stones were analyzed, including: chokeberry seed oil, blackcurrant seed oil, elderberry seed oil, raspberry seed oil, apricot seed oil, tomato seed oil, strawberry seed oil, broccoli seed oil, Nigella sativa seed oil, hemp oil, safflower seed oil, Silybum marianum seed oil and coconut oil. 80 adult volunteers assessed the cosmetic properties of the analyzed oils. Each of the volunteers tested 2 to 4 different oils, by applying them on the skin. In addition, patch tests with all analyzed oils were performed on 23 individuals. Results. The majority of tested oils were positively evaluated by the participants: in the opinion of the participants, oil extracted from safflower had the best appearance (100% positive opinions, coconut oil had the best smell (70% positive opinions, while black currant seed oil showed the best absorbency (85% positive opinions. No irritation was observed within the analyzed product group, albeit one allergic reaction to apricot seed oil was observed with patch testing. Conclusions . Based on the achieved results, it could be suggested that natural cold pressed oils can be applied to the skin as cosmetics. Our observations may be helpful for general practitioners when choosing natural cosmetics.

  19. WordPress all-in-one for dummies

    CERN Document Server

    Sabin-Wilson, Lisa

    2013-01-01

    Top WordPress guide, now fully updated for the latest WordPress release! This updated new edition comprises one of the largest collections of practical intermediate to advanced information on WordPress. Fully updated for the latest WordPress release, this in-depth book covers it all, from setting up your software to publishing your site, using SEO and social media, developing and using plug-ins, running multiple sites with WordPress, and more. Veteran author Lisa Sabin-Wilson is a top authority on WordPress, and she and her co-authors pack this book with essential and easy-to-follo

  20. Inclination of Nations to Control Press and Attitudes on Professionalization.

    Science.gov (United States)

    Merrill, John C.

    1988-01-01

    Interviews official representatives of 58 nations to investigate their "inclination to control" the press. Finds the region most inclined to control the press is the Middle East, whereas regions least inclined are Western Europe and North America. (RS)

  1. Advanced ensemble modelling of flexible macromolecules using X-ray solution scattering.

    Science.gov (United States)

    Tria, Giancarlo; Mertens, Haydyn D T; Kachala, Michael; Svergun, Dmitri I

    2015-03-01

    Dynamic ensembles of macromolecules mediate essential processes in biology. Understanding the mechanisms driving the function and molecular interactions of 'unstructured' and flexible molecules requires alternative approaches to those traditionally employed in structural biology. Small-angle X-ray scattering (SAXS) is an established method for structural characterization of biological macromolecules in solution, and is directly applicable to the study of flexible systems such as intrinsically disordered proteins and multi-domain proteins with unstructured regions. The Ensemble Optimization Method (EOM) [Bernadó et al. (2007 ▶). J. Am. Chem. Soc. 129, 5656-5664] was the first approach introducing the concept of ensemble fitting of the SAXS data from flexible systems. In this approach, a large pool of macromolecules covering the available conformational space is generated and a sub-ensemble of conformers coexisting in solution is selected guided by the fit to the experimental SAXS data. This paper presents a series of new developments and advancements to the method, including significantly enhanced functionality and also quantitative metrics for the characterization of the results. Building on the original concept of ensemble optimization, the algorithms for pool generation have been redesigned to allow for the construction of partially or completely symmetric oligomeric models, and the selection procedure was improved to refine the size of the ensemble. Quantitative measures of the flexibility of the system studied, based on the characteristic integral parameters of the selected ensemble, are introduced. These improvements are implemented in the new EOM version 2.0, and the capabilities as well as inherent limitations of the ensemble approach in SAXS, and of EOM 2.0 in particular, are discussed.

  2. Aqueous self-assembly of hydrophobic macromolecules with adjustable rigidity of the backbone.

    Science.gov (United States)

    Guan, Zhou; Liu, Dapeng; Lin, Jiaping; Wang, Xiaosong

    2017-08-02

    P(FpC3P) (Fp: CpFe(CO)2; C3P: propyl diphenyl phosphine) has a helical backbone, resulting from piano stool metal coordination geometry, which is rigid with intramolecular aromatic interaction of the phenyl groups. The macromolecule is hydrophobic, but the polarized CO groups can interact with water for aqueous self-assembly. The stiffness of P(FpC3P), which is adjustable by temperature, is an important factor influencing the morphologies of kinetically trapped assemblies. P(FpC3P)7 self-assembles in DMSO/water (10/90 by volume) into lamellae at 25 °C, vesicles at 40 °C and irregular aggregates at higher temperatures (60 and 70 °C). The colloidal stability decreases in the order of lamellae, vesicles and irregular aggregates. Dissipative particle dynamics (DPD) simulation reveals the same temperature-dependent self-assembled morphologies with an interior of hydrophobic aromatic groups covered with the metal coordination units. The rigid backbone at 25 °C accounts for the formation of the layered morphology, while the reduced rigidity of the same P(FpC3P)7 at 40 °C curves up the lamellae into vesicles. At a higher temperature (60 or 70 °C), P(FpC3P)7 behaves as a random coil without obvious amphiphilic segregation, resulting in irregular aggregates. The stiffness is, therefore, a crucial factor for the aqueous assembly of macromolecules without obvious amphiphilic segregation, which is reminiscent of the solution behavior observed for many hydrophobic biological macromolecules such as proteins.

  3. Advanced ensemble modelling of flexible macromolecules using X-ray solution scattering

    Directory of Open Access Journals (Sweden)

    Giancarlo Tria

    2015-03-01

    Full Text Available Dynamic ensembles of macromolecules mediate essential processes in biology. Understanding the mechanisms driving the function and molecular interactions of `unstructured' and flexible molecules requires alternative approaches to those traditionally employed in structural biology. Small-angle X-ray scattering (SAXS is an established method for structural characterization of biological macromolecules in solution, and is directly applicable to the study of flexible systems such as intrinsically disordered proteins and multi-domain proteins with unstructured regions. The Ensemble Optimization Method (EOM [Bernadó et al. (2007. J. Am. Chem. Soc. 129, 5656–5664] was the first approach introducing the concept of ensemble fitting of the SAXS data from flexible systems. In this approach, a large pool of macromolecules covering the available conformational space is generated and a sub-ensemble of conformers coexisting in solution is selected guided by the fit to the experimental SAXS data. This paper presents a series of new developments and advancements to the method, including significantly enhanced functionality and also quantitative metrics for the characterization of the results. Building on the original concept of ensemble optimization, the algorithms for pool generation have been redesigned to allow for the construction of partially or completely symmetric oligomeric models, and the selection procedure was improved to refine the size of the ensemble. Quantitative measures of the flexibility of the system studied, based on the characteristic integral parameters of the selected ensemble, are introduced. These improvements are implemented in the new EOM version 2.0, and the capabilities as well as inherent limitations of the ensemble approach in SAXS, and of EOM 2.0 in particular, are discussed.

  4. Impacts of Organic Macromolecules, Chlorophyll and Soot on Arctic Sea Ice

    Science.gov (United States)

    Ogunro, O. O.; Wingenter, O. W.; Elliott, S.; Flanner, M.; Dubey, M. K.

    2014-12-01

    Recent intensification of Arctic amplification can be strongly connected to positive feedback relating black carbon deposition to sea ice surface albedo. In addition to soot deposition on the ice and snow pack, ice algal chlorophyll is likely to compete as an absorber and redistributor of energy. Hence, solar radiation absorption by chlorophyll and some components of organic macromolecules in/under the ice column is currently being examined to determine the level of influence on predicted rate of ice loss. High amounts of organic macromolecules and chlorophyll are produced in global sea ice by the bottom microbial community and also in vertically distributed layers where substantial biological activities take place. Brine channeling in columnar ice can allow for upward flow of nutrients which leads to greater primary production in the presence of moderate light. Modeling of the sea-ice processes in tandem with experiments and field observations promises rapid progress in enhancing Arctic ice predictions. We are designing and conducting global climate model experiments to determine the impact of organic macromolecules and chlorophyll on Arctic sea ice. Influences on brine network permeability and radiation/albedo will be considered in this exercise. Absorption by anthropogenic materials such as soot and black carbon will be compared with that of natural pigments. We will indicate areas of soot and biological absorption dominance in the sense of single scattering, then couple into a full radiation transfer scheme to attribute the various contributions to polar climate change amplification. The work prepares us to study more traditional issues such as chlorophyll warming of the pack periphery and chemical effects of the flow of organics from ice internal communities. The experiments started in the Arctic will broaden to include Antarctic sea ice and shelves. Results from the Arctic simulations will be presented.

  5. Tjekkoslovakisk presse år 2

    Directory of Open Access Journals (Sweden)

    Rudolf Prevratil

    1991-09-01

    Full Text Available Danske teleselskaber overvejer at etablere sig som kabeloperatører i Polen, mens et amerikansk selskab allerede er igang i Warszawa og Krakow. Franske lokalradionetworks opretter filialer i Polen og Tjekko- slovakiet. Den tjekkiske statsradio stiller sendenet til rådighed for Radio Free Europe. Springer-koncernen opretter en "østtysk" pendant til Bild, hvis redaktionelle hovedlinje lægger sig op ad de dybe sociale frustrati- oner, der fulgte med DDR's indlemmelse i BDR. Maxwell, Hersant og Berlusconi m.fl. etablerer sig alene eller med lokale konstellationer inden for trykt presse i flere øst- og mellemeuropæiske stater. Samtidig for- søger den tidligere undergrundspresse at vinde økonomisk og politisk fodfæste inden for markedets og "det legale samfunds" rammer, i kon- kurrence med fortidens mediemutanter og vestlige mediekoncerner. Rudolf Prevratils artikel er en refleksion over en del af de problemer, primært af økonomisk og politisk art, som har tårnet sig op for den tjek- koslovakiske presse efter fløjlsrevolutionen i november 1989. Den giver et billede af dagens situation og får gennem sine analyser påvist, at etab- lingen af en demokratisk presse i Tjekkoslovakiet ikke alene er afhængig af "hjælp udefra", men i nok så høj grad forudsætter et net af sociale og kulturelle udviklingsprocesser, som både anerkender opgøret med for- tiden og vedkender sig den historiske arv. Artiklen er oversat fra engelsk af Per Jauert.

  6. Thermal Test on Target with Pressed Disks

    Energy Technology Data Exchange (ETDEWEB)

    Woloshun, Keith Albert [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dale, Gregory E. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Olivas, Eric Richard [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Romero, Frank Patrick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Dalmas, Dale Allen [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Chemerisov, Sergey [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Gromov, Roman [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Lowden, Rick [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-05-27

    A thorough test of the thermal performance of a target for Mo99 production using solid Mo100 target to produce the Mo99 via a gamma-n reaction has previously been conducted at Argonne National Laboratory (ANL). The results are reported in “Zero Degree Line Mo Target Thermal Test Results and Analysis,” LANL report Number LA-UR-15-23134 dated 3/27/15. This target was comprised of 25 disks 1 mm thick and 12 mm in diameter, separated by helium coolant gaps 0.5 mm wide. The test reported in the above referenced report was conducted with natural Mo disks all cut from commercial rod. The production plant will have Mo100 disks pressed and sintered using a process being developed at Oak Ridge National Laboratory (ORNL). The structural integrity of press-and-sinter disks is of some concern. The test reported herein included 4 disks made by the ORNL process and placed in the high heat, and therefore high thermal stress, region of the target. The electron beam energy was 23 MeV for these tests. Beam spot size was 3.5 mm horizontal and 3 mm vertical, FWHM. The thermal stress test of pressed-and-sintered disks resulted in no mechanical failures. The induced thermal stresses were below yield stress for natural Mo, indicating that up to that stress state no inherent deficiencies in the mechanical properties of the fabricated disks were evident.

  7. Small and Wide Angle X-ray Scattering studies of biological macromolecules in solution.

    Science.gov (United States)

    Liu, Li; Boldon, Lauren; Urquhart, Melissa; Wang, Xiangyu

    2013-01-08

    In this paper, Small and Wide Angle X-ray Scattering (SWAXS) analysis of macromolecules is demonstrated through experimentation. SWAXS is a technique where X-rays are elastically scattered by an inhomogeneous sample in the nm-range at small angles (typically 0.1 - 5°) and wide angles (typically > 5°). This technique provides information about the shape, size, and distribution of macromolecules, characteristic distances of partially ordered materials, pore sizes, and surface-to-volume ratio. Small Angle X-ray Scattering (SAXS) is capable of delivering structural information of macromolecules between 1 and 200 nm, whereas Wide Angle X-ray Scattering (WAXS) can resolve even smaller Bragg spacing of samples between 0.33 nm and 0.49 nm based on the specific system setup and detector. The spacing is determined from Bragg's law and is dependent on the wavelength and incident angle. In a SWAXS experiment, the materials can be solid or liquid and may contain solid, liquid or gaseous domains (so-called particles) of the same or another material in any combination. SWAXS applications are very broad and include colloids of all types: metals, composites, cement, oil, polymers, plastics, proteins, foods, and pharmaceuticals. For solid samples, the thickness is limited to approximately 5 mm. Usage of a lab-based SWAXS instrument is detailed in this paper. With the available software (e.g., GNOM-ATSAS 2.3 package by D. Svergun EMBL-Hamburg and EasySWAXS software) for the SWAXS system, an experiment can be conducted to determine certain parameters of interest for the given sample. One example of a biological macromolecule experiment is the analysis of 2 wt% lysozyme in a water-based aqueous buffer which can be chosen and prepared through numerous methods. The preparation of the sample follows the guidelines below in the Preparation of the Sample section. Through SWAXS experimentation, important structural parameters of lysozyme, e.g. the radius of gyration, can be analyzed.

  8. Key factors regulating the mass delivery of macromolecules to model cell membranes

    DEFF Research Database (Denmark)

    Campbell, Richard A.; Watkins, Erik B.; Jagalski, Vivien

    2014-01-01

    We show that both gravity and electrostatics are key factors regulating interactions between model cell membranes and self-assembled liquid crystalline aggregates of dendrimers and phospholipids. The system is a proxy for the trafficking of reservoirs of therapeutic drugs to cell membranes for slow...... diffusion and continuous delivery. Neutron reflectometry measurements were carried out on supported lipid bilayers of varying charge and on hydrophilic silica surfaces. Translocation of the macromolecule across the membrane and adsorption of the lamellar aggregates occur only when the membrane (1...... of the aggregates to activate endocytosis pathways on specific cell types is discussed in the context of targeted drug delivery applications....

  9. Controlled uniform coating from the interplay of Marangoni flows and surface-adsorbed macromolecules

    CERN Document Server

    Kim, Hyoungsoo; Um, Eujin; Jacobi, Ian; Button, Ernie; Stone, Howard A

    2016-01-01

    Surface coatings and patterning technologies are essential for various physicochemical applications. In this Letter, we describe key parameters to achieve uniform particle coatings in binary solutions: First, multiple sequential Marangoni flows, set by solute and surfactant simultaneously, prevent non-uniform particle distributions and continuously mix suspended materials during droplet evaporation. Second, we show the importance of particle-surface interactions that can be established by surface-adsorbed macromolecules. To achieve a uniform deposit in a binary mixture a small concentration of surfactant and surface-adsorbed polymer (0.05 wt% each) is sufficient, which offers a new physicochemical avenue for control of coatings.

  10. Differential scanning calorimetry: An invaluable tool for a detailed thermodynamic characterization of macromolecules and their interactions

    Directory of Open Access Journals (Sweden)

    Michael H Chiu

    2011-01-01

    Full Text Available Differential Scanning Calorimetry (DSC is a highly sensitive technique to study the thermotropic properties of many different biological macromolecules and extracts. Since its early development, DSC has been applied to the pharmaceutical field with excipient studies and DNA drugs. In recent times, more attention has been applied to lipid-based drug delivery systems and drug interactions with biomimetic membranes. Highly reproducible phase transitions have been used to determine values, such as, the type of binding interaction, purity, stability, and release from a drug delivery mechanism. This review focuses on the use of DSC for biochemical and pharmaceutical applications.

  11. Isolation of cell nuclei using inert macromolecules to mimic the crowded cytoplasm.

    Directory of Open Access Journals (Sweden)

    Ronald Hancock

    Full Text Available Cell nuclei are commonly isolated and studied in media which include millimolar concentrations of cations, which conserve the nuclear volume by screening the negative charges on chromatin and maintaining its compaction. However, two factors question if these ionic conditions correctly reproduce the environment of nuclei in vivo: the small-scale motion and conformation of chromatin in vivo are not reproduced in isolated nuclei, and experiments and theory suggest that small ions in the cytoplasm are not free in the soluble phase but are predominantly bound to macromolecules. We studied the possible role in maintaining the structure and functions of nuclei in vivo of a further but frequently overlooked property of the cytoplasm, the crowding or osmotic effects caused by diffusible macromolecules whose concentration, measured in several studies, is in the range of 130 mg/ml. Nuclei which conserved their volume in the cell and their ultrastructure seen by electron microscopy were released from K562 cells in media containing the inert polymer 70 kDa Ficoll (50% w/v or 70 kDa dextran (35% w/v to replace the diffusible cytoplasmic molecules which were dispersed on cell lysis with digitonin, with 100 microM K-Hepes buffer as the only source of ions. Immunofluorescence labelling and experiments using cells expressing GFP-fusion proteins showed that internal compartments (nucleoli, PML and coiled bodies, foci of RNA polymerase II were conserved in these nuclei, and nascent RNA transcripts could be elongated. Our observations are consistent with the hypothesis that crowding by diffusible cytoplasmic macromolecules is a crucial but overlooked factor which supports the nucleus in vivo by equilibrating the opposing osmotic pressure cause by the high concentration of macromolecules in the nucleus, and suggest that crowded media provide more physiological conditions to study nuclear structure and functions. They may also help to resolve the long-standing paradox

  12. Cluster of red blood cells in microcapillary flow: hydrodynamic versus macromolecule induced interaction

    CERN Document Server

    Clavería, Viviana; Thiébaud, Marine; Abkarian, Manouk; Coupier, Gwennou; Misbah, Chaouqi; John, Thomas; Wagner, Christian

    2016-01-01

    We present experiments on RBCs that flow through microcapillaries under physiological conditions. We show that the RBC clusters form as a subtle imbrication between hydrodynamics interaction and adhesion forces because of plasma proteins. Clusters form along the capillaries and macromolecule-induced adhesion contribute to their stability. However, at high yet physiological flow velocities, shear stresses overcome part of the adhesion forces, and cluster stabilization due to hydrodynamics becomes the only predominant mechanism. For the case of pure hydrodynamic interaction, cell-to-cell distances have a pronounced bimodal distribution. Our 2D-numerical simulations on vesicles captures the transition between adhesive and non-adhesive clusters at different flow velocities.

  13. Differential scanning calorimetry: An invaluable tool for a detailed thermodynamic characterization of macromolecules and their interactions

    Science.gov (United States)

    Chiu, Michael H.; Prenner, Elmar J.

    2011-01-01

    Differential Scanning Calorimetry (DSC) is a highly sensitive technique to study the thermotropic properties of many different biological macromolecules and extracts. Since its early development, DSC has been applied to the pharmaceutical field with excipient studies and DNA drugs. In recent times, more attention has been applied to lipid-based drug delivery systems and drug interactions with biomimetic membranes. Highly reproducible phase transitions have been used to determine values, such as, the type of binding interaction, purity, stability, and release from a drug delivery mechanism. This review focuses on the use of DSC for biochemical and pharmaceutical applications. PMID:21430954

  14. Macromolecules Mimicking Backbones of Nucleic and Teichoic Acids.Synthesis,Some Properties and Applications

    Institute of Scientific and Technical Information of China (English)

    Stanislaw; Penczek; Julia; B.Pretula; Krzysztof; Kaluzynski

    2007-01-01

    1 Results Several methods have been elaborated in this laboratory allowing preparation of macromolecules with phosphodiester bonds,and having sequence of atoms similar as in the chains of biomacromolecules - nucleic or teichoic acids (TA),namely:-(C)n-O-PO-,where n=2 (for teichoic acids) or 3.These methods,to be discussed in the lecture,are based on the ring-opening polymerization,transesterification,and recently elaborated direct addition of phosphoric acid to diepoxides.For the first time an attempt h...

  15. Interactions between macromolecule-bound antioxidants and Trolox during liposome autoxidation

    DEFF Research Database (Denmark)

    Celik, Ecem Evrim; Amigo Rubio, Jose Manuel; Andersen, Mogens Larsen

    2017-01-01

    The interactions between free and macromolecule-bound antioxidants were investigated in order to evaluate their combined effects on the antioxidant environment. Dietary fiber (DF), protein and lipid-bound antioxidants, obtained from whole wheat, soybean and olive oil products, respectively...... of the simple addition effects of Trolox and bound antioxidants with measured values on lipid oxidation revealed synergetic interactions for DF and refined olive oil-bound antioxidants, and antagonistic interactions for protein and extra virgin olive oil-bound antioxidants with Trolox. A generalized version...

  16. Volume Stamping on Hydraulic Presses (Selected Portions),

    Science.gov (United States)

    1981-07-02

    equipment. Appears need in the criation of tho presses cf even groater efforts/forces than being in the industry . In thq USA are published the s...PAGE 1 IT Fi 0 pesbyt, e ~t frE -00 ffim-l-a , Page- 35.- F--:!.n L vi ceatrt the cr-J .*a contrut icndssig o poerli/tic stmigfahrseil .,-tr /euir-isc...the sate time, that also ir t e USA , were created thq prrssqE with effort/force 30000 and 75000 T. TIs ccnstruction cf these oress-s oreceded

  17. Shape optimization of the modular press body

    Directory of Open Access Journals (Sweden)

    Pabiszczak Stanisław

    2016-12-01

    Full Text Available A paper contains an optimization algorithm of cross-sectional dimensions of a modular press body for the minimum mass criterion. Parameters of the wall thickness and the angle of their inclination relative to the base of section are assumed as the decision variables. The overall dimensions are treated as a constant. The optimal values of parameters were calculated using numerical method of the tool Solver in the program Microsoft Excel. The results of the optimization procedure helped reduce body weight by 27% while maintaining the required rigidity of the body.

  18. Through the Looking Glass: Press Responses to Genocide.

    Science.gov (United States)

    Lipstadt, Deborah E.

    1991-01-01

    Examines press coverage of the Holocaust to analyze the response of the United States and the world to the Jewish extermination. Compares this coverage to earlier press responses to the Armenian genocide and Ukraine famines. Argues the press was unwilling to face the Holocaust's magnitude. Urges teachers to teach about the Holocaust and similar…

  19. Lesquerella Press Cake as an Organic Fertilizer for Greenhouse Tomatoes

    Science.gov (United States)

    Lesquerella press cake is a co-product generated during the processing of the new oilseed crop lesquerella [Lesquerella fendleri (A. Gray) S. Wats.]. As with other new crops, developing commercial uses for the press cake would increase the profitability of growing lesquerella. The press cake conta...

  20. Graphic Arts: The Press and Finishing Processes. Third Edition.

    Science.gov (United States)

    Crummett, Dan

    This document contains teacher and student materials for a course in graphic arts concentrating on printing presses and the finishing process for publications. Seven units of instruction cover the following topics: (1) offset press systems; (2) offset inks and dampening chemistry; (3) offset press operating procedures; (4) preventive maintenance…

  1. Where is the British national press?

    Science.gov (United States)

    MacInnes, John; Rosie, Michael; Petersoo, Pille; Condor, Susan; Kennedy, James

    2007-06-01

    Although globalization has highlighted the danger of conflating state, society and nation, sociologists remain insufficiently alert to such banal nationalism. Newspapers offer a strong test case of the extent of diversity in the construction of state, national and social boundaries, since Billig and Anderson have argued they comprise a special case where their orientation to an audience simultaneously located in a state, society and nation allows them to reproduce a sense of national identity. However, despite the commonsense obviousness of the term, it proves remarkably difficult to define what the 'British national press' might comprise. Circulation density of titles varies substantially across different parts of the UK and editorial copy is altered to address diverse 'national' readerships. 'British' newspapers also circulate in other states, especially the Republic of Ireland. After reviewing how newspapers might be defined as 'national' and/or 'British', we conclude that both Anderson and Billig over-estimate the congruence, relevance and obviousness of state, society and national boundaries. If the conceptualization of such boundaries is problematic in the case of the press, it follows that it must be still more so for most other objects of sociological analysis, including that of 'society' itself.

  2. A metaphor corpus in business press headlines

    Directory of Open Access Journals (Sweden)

    Honesto Herrera Soler

    2008-04-01

    Full Text Available In linguistics a corpus typically involves a finite body of texts which are considered to be representative of a particular variety of language at a specific time (McEnery & Wilson, 2001. Those are the assumptions we have had in mind in this metaphor corpus based on business press headlines. Our body of texts is a finite number of headlines drawn from the specific field of the business sections of three newspapers: Financial Times, El País and El Mundo, published over a period running from January to July 2003. Compiling a small corpus of non-literal instantiations as different authors have done (Cortés de los Ríos, 2001; Kövecses, 2002; Charteris-Black, 2003; Koller, 2004; Deignan, 2005; and others will enable us first to identify whether the contextual meaning of a word or a multiword unit of headline contrasts with its basic meaning and whether the contextual meaning can be understood by comparison with that basic meaning, and then to categorize, both in the Spanish and in the British press, the different linguistic realizations of a headline in terms of their syntactic structure, metaphor foci and source domains.

  3. Academic integrity: "accepted," "in press," or unacceptable?

    Science.gov (United States)

    Mushlin, Stuart B; Katz, Joel T

    2013-11-01

    In this issue, Grimm and Maxfield report the results of an analysis of the outcomes of manuscripts listed as "provisionally accepted," "accepted," "in press," and "submitted" on applications to a university radiology residency program. Their surprising finding that one-third of manuscripts listed as "accepted" or "in press" were not published two years after being included on an application raises questions about the reasons for these discrepancies.The authors of this commentary argue that one explanation for these findings is that some applicants deliberately misrepresented facts in order to be seen as more attractive candidates. After examining the professionalism implications of the study by Grimm and Maxfield, the authors offer recommendations for addressing lapses in students' professionalism early on. They recommend that medical school admissions and teaching faculty establish clear and unshakable expectations that untruths will not be tolerated regardless of the difficult administrative challenges that may ensue. Further, medical school admissions committees should select entrance criteria that reward collaborative behaviors and honesty in addition to academic achievement. The authors encourage more longitudinal, systematic analyses of potential fabrications in residency applications, with the goal of fostering a culture of trust in medicine.

  4. Press Conference: LHC Restart, Season 2

    CERN Document Server

    CERN. Geneva

    2015-01-01

    PRESS BRIEFING ON THE LARGE HADRON COLLIDER (LHC) RE-START, SEASON 2 AT CERN, GLOBE OF SCIENCE AND INNOVATION Where :   http://cern.ch/directions   at the Globe of Science and Innovation When : Thursday, 12 March from 2.30 to 3.30pm - Open seating as from 2.15pm Speakers : CERN’s Director General, Rolf Heuer and Director of Accelerators, Frédérick Bordry, and representatives of the LHC experiments Webcast : https://webcast.web.cern.ch/webcast/ Dear Journalists, CERN is pleased to invite you to the above press briefing which will take place on Thursday 12 March, in the Globe of Science and Innovation, 1st floor, from 2.30 to 3.30pm. The Large Hadron Collider (LHC) is ready to start up for its second three-year run. The 27km LHC is the largest and most powerful particle accelerator in the world operating at a temperature of -217 degrees Centigrade and powered to a current of 11,000 amps. Run 2 of the LHC follows a two-year technical s...

  5. A CONCEPTUAL APPROACH ON PRESS CONFERENCE

    Directory of Open Access Journals (Sweden)

    Ioana Olariu

    2015-07-01

    Full Text Available A press conference is an important tool of public relations. The primary role of public relations is to manage a company’s reputation and help build public consent for its enterprises. The goal of PR is to develop and maintain goodwill with most, if not all, of its publics. Failure to do so may mean loss of customers and revenues, time lost dealing with complaints or lawsuits, and loss of esteem. A company’s publics change constantly. Well-executed public relations is an ongoing process that molds good long-term relationships and plays an important role in relationship marketing and integrated communications. Companies often call press conference when they have significant news to announce, such as the introduction of a new product or advertising campaign. Although used less often by organizations and corporations, this form of delivery can be very effective. The topic must be of major interest to a specific group before it is likely to gain coverage.

  6. [The use of dried grape press cake in pig fattening].

    Science.gov (United States)

    Herzig, I; Tomová, M; Holub, A; Pleskac, Z

    1979-12-01

    In dried grape press cake the content of crude nutrients and ash, overall sugar, amino acids, alpha-tocopherol and gross energy was determined. In biological experiments with pigs (total of 109 animals) 10% of mixture A1 or SOL was replaced by the same amount of dried crushed grape press cake, without affecting negatively the weight gains and consumption of mixtures per unit of weight gain. Nutritional effects of grape press cake are a subject of discussion and comprise three factors: higher content of enrgy (fat and sugars) in mixtures containing press cake, anti-oxidation effect of press cake and the effect of tocopherols on the metabolism of basic nutrients.

  7. Configurational diffusion of coal macromolecules. Final technical report, September 15, 1986--September 14, 1991

    Energy Technology Data Exchange (ETDEWEB)

    Guin, J.A.; Curtis, C.W.; Tarrer, A.R.; Kim, S.; Hwang, D.; Chen, C.C.; Chiou, Z.

    1991-12-31

    The objective of our research was to obtain fundamental information regarding the functional dependence of the diffusion coefficient of coal molecules on the ratio of molecule to pore diameter. That is, the objective of our study was to examine the effect of molecule size and configuration on hindered diffusion of coal macromolecules through as porous medium. To best accomplish this task, we circumvented the complexities of an actual porous catalyst by using a well defined porous matrix with uniform capillaric pores, i.e., a track-etched membrane. In this way, useful information was obtained regarding the relationship of molecular size and configuration on the diffusion rate of coal derived macromolecules through a pore structure with known geometry. Similar studies were performed using a pellet formed of porous alumina, to provide a link between the idealized membranes and the actual complex pore structure of real catalyst extrudates. The fundamental information from our study will be useful toward the tailoring of catalysts to minimize diffusional influences and thereby increase coal conversion and selectivity for desirable products. (VC)

  8. Toward detecting and identifying macromolecules in a cellular context: Template matching applied to electron tomograms

    Science.gov (United States)

    Böhm, Jochen; Frangakis, Achilleas S.; Hegerl, Reiner; Nickell, Stephan; Typke, Dieter; Baumeister, Wolfgang

    2000-01-01

    Electron tomography is the only technique available that allows us to visualize the three-dimensional structure of unfixed and unstained cells currently with a resolution of 6–8 nm, but with the prospect to reach 2–4 nm. This raises the possibility of detecting and identifying specific macromolecular complexes within their cellular context by virtue of their structural signature. Templates derived from the high-resolution structure of the molecule under scrutiny are used to search the reconstructed volume. Here we outline and test a computationally feasible two-step procedure: In a first step, mean-curvature motion is used for segmentation, yielding subvolumes that contain with a high probability macromolecules in the expected size range. Subsequently, the particles contained in the subvolumes are identified by cross-correlation, using a set of three-dimensional templates. With simulated and real tomographic data we demonstrate that such an approach is feasible and we explore the detection limits. Even structurally similar particles, such as the thermosome, GroEL, and the 20S proteasome can be identified with high fidelity. This opens up exciting prospects for mapping the territorial distribution of macromolecules and for analyzing molecular interactions in situ. PMID:11087814

  9. Development of a Non-Aqueous Dispersion to Improve Intestinal Epithelial Flux of Poorly Permeable Macromolecules.

    Science.gov (United States)

    Maher, Sam; Medani, Mekki; Carballeira, Nestor N; Winter, Desmond C; Baird, Alan W; Brayden, David J

    2017-01-01

    Intestinal permeation enhancers (PEs) offer an attractive strategy to enable oral peptide administration. However, optimal presentation of peptide and PE from solid-dosage forms is offset by slow dissolution rates in the small intestine, which reduces the likelihood that the PE can reach the threshold concentration for sufficient permeability enhancement. The purpose of this study was to design a PE-based liquid dispersion that can improve intestinal permeation of macromolecules across Caco-2 monolayers and isolated rat/human intestinal mucosae mounted in Ussing chambers. An enhancer screen in monolayers based on permeability (TEER, Papp [(14)C]-mannitol) and cytotoxicity (MTT assay) initially identified methyl 10-hydroxydecanoate (10-OHC10CH3) as a candidate. 10-OHC10CH3 (20 mM) increased the Papp of fluorescent dextran of 4 kDa (FD4) (167-fold), 10 kDa (FD10) (429-fold), and 40 kDa (FD40) (520-fold) across monolayers. Blends of 10-OHC10CH3 with low molecular weight PEGs (0.2-1 kDa) formed liquid dispersions in which enhancement capacity across monolayers of 10-OHC10CH3 was increased over 10-OHC10CH3 alone in the order PEG200 macromolecules.

  10. Improved Measurement of B(sub 22) of Macromolecules in a Flow Cell

    Science.gov (United States)

    Wilson, Wilbur; Fanguy, Joseph; Holman, Steven; Guo, Bin

    2008-01-01

    An improved apparatus has been invented for use in determining the osmotic second virial coefficient of macromolecules in solution. In a typical intended application, the macromolecules would be, more specifically, protein molecules, and the protein solution would be pumped through a flow cell to investigate the physical and chemical conditions that affect crystallization of the protein in question. Some background information is prerequisite to a meaningful description of the novel aspects of this apparatus. A method of determining B22 from simultaneous measurements of the static transmittance (taken as an indication of concentration) and static scattering of light from the same location in a flowing protein solution was published in 2004. The apparatus used to implement the method at that time included a dual-detector flow cell, which had two drawbacks: a) The amount of protein required for analysis of each solution condition was of the order of a milligram - far too large a quantity for a high-throughput analysis system, for which microgram or even nanogram quantities of protein per analysis are desirable. b) The design of flow cell was such that two light sources were used to probe different regions of the flowing solution. Consequently, the apparatus did not afford simultaneous measurements at the same location in the solution and, hence, did not guarantee an accurate determination of B22.

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

    Science.gov (United States)

    Murata, Kazuyoshi; Wolf, Matthias

    2017-07-27

    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.

  12. Coupled Segmentation of Nuclear and Membrane-bound Macromolecules through Voting and Multiphase Level Set.

    Science.gov (United States)

    Chang, Hang; Wen, Quan; Parvin, Bahram

    2015-03-01

    Membrane-bound macromolecules play an important role in tissue architecture and cell-cell communication, and is regulated by almost one-third of the genome. At the optical scale, one group of membrane proteins expresses themselves as linear structures along the cell surface boundaries, while others are sequestered; and this paper targets the former group. Segmentation of these membrane proteins on a cell-by-cell basis enables the quantitative assessment of localization for comparative analysis. However, such membrane proteins typically lack continuity, and their intensity distributions are often very heterogeneous; moreover, nuclei can form large clump, which further impedes the quantification of membrane signals on a cell-by-cell basis. To tackle these problems, we introduce a three-step process to (i) regularize the membrane signal through iterative tangential voting, (ii) constrain the location of surface proteins by nuclear features, where clumps of nuclei are segmented through a delaunay triangulation approach, and (iii) assign membrane-bound macromolecules to individual cells through an application of multi-phase geodesic level-set. We have validated our method using both synthetic data and a dataset of 200 images, and are able to demonstrate the efficacy of our approach with superior performance.

  13. Effect of poly-L-arginine on intestinal absorption of hydrophilic macromolecules in rats.

    Science.gov (United States)

    Yamaki, Tsutomu; Uchida, Masaki; Kuwahara, Yusuke; Shimazaki, Yohei; Ohtake, Kazuo; Kimura, Mitsutoshi; Uchida, Hiroyuki; Kobayashi, Jun; Ogihara, Masahiko; Morimoto, Yasunori; Natsume, Hideshi

    2013-01-01

    We have already reported that poly-L-arginine (PLA) remarkably enhanced the in vivo nasal absorption of hydrophilic macromolecules without producing any significant epithelial damage in rats. In the present study, we examined whether PLA could enhance the absorption of a model hydrophilic macromolecule, fluorescein isothiocyanate-dextran (FD-4), across the intestinal mucosa, as well as the nasal mucosa, by an in situ closed-loop method using the rat intestine. PLA was found to enhance the intestinal absorption of FD-4 in a concentration-dependent manner within the concentrations investigated in this study, but segment-specific differences were found to be associated with this effect (ileum>jejunum>duodenum≧colon). The factors responsible for the segment-specific differences were also investigated by intestinal absorption studies using aprotinin, a trypsin inhibitor, and an analysis of the expression of occludin, a tight junction protein. In the small intestine, the differences in the effect of PLA on the absorption of FD-4 may be related to the enzymatic degradation of PLA. In the colon, the reduced effect of PLA on the absorption of FD-4 may be related to the smaller surface area for absorption and the higher expression of occludin compared with other segments.

  14. Complexation between a macromolecule and an amphiphile by Monte Carlo technique.

    Science.gov (United States)

    Gharibi, Hussein; Behjatmanesh-Ardakani, Reza; Hashemianzadeh, Majid; Mousavi-Khoshdel, Morteza

    2006-07-13

    Using a simple modified version of Larson's model, we studied the complexation between a macromolecule and an amphiphile in a dilute range of concentrations. The main characteristic of amphiphile molecules, that is, the hydrophobicity of the tails and hydrophilicity of the heads, is used to model the self-assembling process. Contrary to the molecular thermodynamics approaches, no prior shape was considered for the aggregates and the system was allowed to choose the most stable structure. For true ensemble averaging, without any synthetic results, configurational bias Monte Carlo and reptation moves are used to produce a Markov chain of configurations. From the results, it is found that the macromolecule causes the clusters of surfactants to be formed at a concentration much lower than the critical micelle concentration. Furthermore, the shape of the clusters tends to be more spherical, which is in line with theory and experiments. From the results, it is learned how a polymer can change the behavior of an amphiphilic molecule. All of the results are in good qualitative agreement with experimental and molecular thermodynamics results. Furthermore, the model predicts network formation between bound clusters at high concentrations of the surfactant.

  15. Combining modular ligation and supramolecular self-assembly for the construction of star-shaped macromolecules.

    Science.gov (United States)

    Altintas, Ozcan; Muller, Thierry; Lejeune, Elise; Plietzsch, Oliver; Bräse, Stefan; Barner-Kowollik, Christopher

    2012-06-14

    A well-defined random copolymer of styrene (S) and chloromethylstyrene (CMS) featuring lateral chlorine moieties with an alkyne terminal group is prepared (P(S-co-CMS), M(n) = 5500 Da, PDI = 1.13). The chloromethyl groups are converted into Hamilton wedge (HW) entities (P(S-co-HWS), M(n) = 6200 Da, PDI = 1.13). The P(S-co-HWS) polymer is subsequently ligated with tetrakis(4-azidophenyl)methane to give HW-functional star-shaped macromolecules (P(S-co-HWS))(4), M(n) = 25,100 Da, PDI = 1.08). Supramolecular star-shaped copolymers are then prepared via self-assembly between the HW-functionalized four-arm star-shaped macromolecules (P(S-co-HW))(4) and cyanuric acid (CA) end-functionalized PS (PS-CA, M(n) = 3700 Da, PDI = 1.04), CA end-functionalized poly(methyl methacrylate) (PMMA-CA, M(n) = 8500 Da, PDI = 1.13) and CA end-functionalized polyethylene glycol (PEG-CA, M(n) = 1700 Da, PDI = 1.05). The self-assembly is monitored by (1)H NMR spectroscopy and light scattering analyses.

  16. SETOR: hardware-lighted three-dimensional solid model representations of macromolecules.

    Science.gov (United States)

    Evans, S V

    1993-06-01

    SETOR is designed to exploit the hardware lighting capabilities of the IRIS-4D series graphics workstations to render high-quality raster images of macromolecules that can undergo rotation and translation interactively. SETOR can render standard all-atom and backbone models of proteins or nucleic acids, but focuses on displaying protein molecules by highlighting elements of secondary structure. The program has a very friendly user interface that minimizes the number of input files by allowing the user to interactively edit parameters, such as colors, lighting coefficients, and descriptions of secondary structure via mouse activated dialogue boxes. The choice of polymer chain representation can be varied from standard vector models and van der Waal models, to a B-spline fit of polymer backbones that yields a smooth ribbon that approximates the polymer chain, to strict Cardinal splines that interpolate the smoothest curve possible that will precisely follow the polymer chain. The program provides a photograph mode, save/restore facilities, and efficient generation of symmetry-related molecules and packing diagrams. Additionally, SETOR is designed to accept commands and model coordinates from the standard input stream, and to control standard output. Ancillary programs provide a method to interactively edit hardcopy plots of all vector and many solid models generated by SETOR, and to produce standard HPGL or PostScript files. Examples of figures rendered by SETOR of a number of macromolecules of various classes are presented.

  17. ConSurf 2016: an improved methodology to estimate and visualize evolutionary conservation in macromolecules.

    Science.gov (United States)

    Ashkenazy, Haim; Abadi, Shiran; Martz, Eric; Chay, Ofer; Mayrose, Itay; Pupko, Tal; Ben-Tal, Nir

    2016-07-08

    The degree of evolutionary conservation of an amino acid in a protein or a nucleic acid in DNA/RNA reflects a balance between its natural tendency to mutate and the overall need to retain the structural integrity and function of the macromolecule. The ConSurf web server (http://consurf.tau.ac.il), established over 15 years ago, analyses the evolutionary pattern of the amino/nucleic acids of the macromolecule to reveal regions that are important for structure and/or function. Starting from a query sequence or structure, the server automatically collects homologues, infers their multiple sequence alignment and reconstructs a phylogenetic tree that reflects their evolutionary relations. These data are then used, within a probabilistic framework, to estimate the evolutionary rates of each sequence position. Here we introduce several new features into ConSurf, including automatic selection of the best evolutionary model used to infer the rates, the ability to homology-model query proteins, prediction of the secondary structure of query RNA molecules from sequence, the ability to view the biological assembly of a query (in addition to the single chain), mapping of the conservation grades onto 2D RNA models and an advanced view of the phylogenetic tree that enables interactively rerunning ConSurf with the taxa of a sub-tree.

  18. Smooth deuterated cellulose films for the visualisation of adsorbed bio-macromolecules.

    Science.gov (United States)

    Su, Jielong; Raghuwanshi, Vikram S; Raverty, Warwick; Garvey, Christopher J; Holden, Peter J; Gillon, Marie; Holt, Stephen A; Tabor, Rico; Batchelor, Warren; Garnier, Gil

    2016-10-31

    Novel thin and smooth deuterated cellulose films were synthesised to visualize adsorbed bio-macromolecules using contrast variation neutron reflectivity (NR) measurements. Incorporation of varying degrees of deuteration into cellulose was achieved by growing Gluconacetobacter xylinus in deuterated glycerol as carbon source dissolved in growth media containing D2O. The derivative of deuterated cellulose was prepared by trimethylsilylation(TMS) in ionic liquid(1-butyl-3-methylimidazolium chloride). The TMS derivative was dissolved in toluene for thin film preparation by spin-coating. The resulting film was regenerated into deuterated cellulose by exposure to acidic vapour. A common enzyme, horseradish peroxidase (HRP), was adsorbed from solution onto the deuterated cellulose films and visualized by NR. The scattering length density contrast of the deuterated cellulose enabled accurate visualization and quantification of the adsorbed HRP, which would have been impossible to achieve with non-deuterated cellulose. The procedure described enables preparing deuterated cellulose films that allows differentiation of cellulose and non-deuterated bio-macromolecules using NR.

  19. Smooth deuterated cellulose films for the visualisation of adsorbed bio-macromolecules

    Science.gov (United States)

    Su, Jielong; Raghuwanshi, Vikram S.; Raverty, Warwick; Garvey, Christopher J.; Holden, Peter J.; Gillon, Marie; Holt, Stephen A.; Tabor, Rico; Batchelor, Warren; Garnier, Gil

    2016-10-01

    Novel thin and smooth deuterated cellulose films were synthesised to visualize adsorbed bio-macromolecules using contrast variation neutron reflectivity (NR) measurements. Incorporation of varying degrees of deuteration into cellulose was achieved by growing Gluconacetobacter xylinus in deuterated glycerol as carbon source dissolved in growth media containing D2O. The derivative of deuterated cellulose was prepared by trimethylsilylation(TMS) in ionic liquid(1-butyl-3-methylimidazolium chloride). The TMS derivative was dissolved in toluene for thin film preparation by spin-coating. The resulting film was regenerated into deuterated cellulose by exposure to acidic vapour. A common enzyme, horseradish peroxidase (HRP), was adsorbed from solution onto the deuterated cellulose films and visualized by NR. The scattering length density contrast of the deuterated cellulose enabled accurate visualization and quantification of the adsorbed HRP, which would have been impossible to achieve with non-deuterated cellulose. The procedure described enables preparing deuterated cellulose films that allows differentiation of cellulose and non-deuterated bio-macromolecules using NR.

  20. STUDY ON THE EFFECT OF POLYSTYRENE SULFONIC ACID MACROMOLECULES ON THE POLYMERIZATION OF ACRYLAMIDE

    Institute of Scientific and Technical Information of China (English)

    WANG Shenguo; XI Fu; LI Zhifen

    1983-01-01

    The effect of polystyrene sulfonic acid (PSSA) macromolecules on the polymerization of acrylamide (AM) has been studied. It was found that the rates of polymerization of AM were greatly increased in the presence of PSSA in the polymerization system. The maximum value of the rate of polymerization of AM was obtained when the ratio of[-SO3H]: [AM] reached 3:1. When the insoluble crosslinked PSSA was used instead of the soluble one, this effect decreased considerably. The interaction between molecules of PSSA and AM was determined by infrared spectroscopy, elementary analysis and X-ray photoelectron spectroscopy.The combination form, -SO3-NH3+ CO-, formed between sulfonic group and amide group was found to be existed since the infrared absorption band of -NH2 shifted from 3400 cm-1 to 3150cm-1, the binding energy of electron N1S changed from 399.7 eV to 401.3 eV, and the atomic ratio of N to S of the products was similar to the ratio of reagents. Based on these experimental results, the mechanism of AM polymerization in the presence of PSSA is proposed. The initial step is the combination of AM with sulfonic group to form -CONH3+, then followed by polymerization on the PSSA macromolecule. The role of PSSA on the polymerization of AM is discussed.

  1. Food macromolecule based nanodelivery systems for enhancing the bioavailability of polyphenols

    Directory of Open Access Journals (Sweden)

    Bing Hu

    2017-01-01

    Full Text Available Diet polyphenols—primarily categorized into flavonoids (e.g., flavonols, flavones, flavan-3-ols, anthocyanidins, flavanones, and isoflavones and nonflavonoids (with major subclasses of stilbenes and phenolic acids—are reported to have health-promoting effects, such as antioxidant, antiinflammatory, anticarcinoma, antimicrobial, antiviral, and cardioprotective properties. However, their applications in functional foods or medicine are limited because of their inefficient systemic delivery and poor oral bioavailability. Epigallocatechin-3-gallate, curcumin, and resveratrol are the well-known representatives of the bioactive diet polyphenols but with poor bioavailability. Food macromolecule based nanoparticles have been fabricated using reassembled proteins, crosslinked polysaccharides, protein–polysaccharide conjugates (complexes, as well as emulsified lipid via safe procedures that could be applied in food. The human gastrointestinal digestion tract is the first place where the food grade macromolecule nanoparticles exert their effects on improving the bioavailability of diet polyphenols, via enhancing their solubility, preventing their degradation in the intestinal environment, elevating the permeation in small intestine, and even increasing their contents in the bloodstream. We contend that the stability and structure behaviors of nanocarriers in the gastrointestinal tract environment and the effects of nanoencapsulation on the metabolism of polyphenols warrant more focused attention in further studies.

  2. Upgraded ESRF BM29 beamline for SAXS on macromolecules in solution

    Energy Technology Data Exchange (ETDEWEB)

    Pernot, Petra, E-mail: rejma@esrf.fr [ESRF, 6 Jules Horowitz, F-38043 Grenoble (France); Round, Adam [EMBL, 6 Jules Horowitz, F-38042 Grenoble (France); Barrett, Ray; De Maria Antolinos, Alejandro [ESRF, 6 Jules Horowitz, F-38043 Grenoble (France); Gobbo, Alexandre [EMBL, 6 Jules Horowitz, F-38042 Grenoble (France); Gordon, Elspeth [ESRF, 6 Jules Horowitz, F-38043 Grenoble (France); Huet, Julien [EMBL, 6 Jules Horowitz, F-38042 Grenoble (France); Kieffer, Jerôme; Lentini, Mario; Mattenet, Muriel; Morawe, Christian; Mueller-Dieckmann, Christoph; Ohlsson, Staffan; Schmid, Werner; Surr, John; Theveneau, Pascal; Zerrad, Louiza; McSweeney, Sean [ESRF, 6 Jules Horowitz, F-38043 Grenoble (France)

    2013-07-01

    A description of the new ESRF BioSAXS beamline is given. The beamline presented is dedicated to small-angle X-ray scattering of macromolecules in solution operating with a high-throughput sample-changer robot and automated data analysis for quality control and feedback. Small-angle X-ray scattering (SAXS) measurements of proteins in solution are becoming increasingly popular with biochemists and structural biologists owing to the presence of dedicated high-throughput beamlines at synchrotron sources. As part of the ESRF Upgrade program a dedicated instrument for performing SAXS from biological macromolecules in solution (BioSAXS) has been installed at the renovated BM29 location. The optics hutch has been equipped with new optical components of which the two principal elements are a fixed-exit double multilayer monochromator and a 1.1 m-long toroidal mirror. These new dedicated optics give improved beam characteristics (compared with the previous set-up on ID14-3) regarding the energy tunability, flux and focusing at the detector plane leading to reduced parasitic scattering and an extended s-range. User experiments on the beamline have been successfully carried out since June 2012. A description of the new BioSAXS beamline and the set-up characteristics are presented together with examples of obtained data.

  3. Ordered mesoporous polymer-silica hybrid nanoparticles as vehicles for the intracellular controlled release of macromolecules.

    Science.gov (United States)

    Kim, Tae-Wan; Slowing, Igor I; Chung, Po-Wen; Lin, Victor Shang-Yi

    2011-01-25

    A two-dimensional hexagonal ordered mesoporous polymer-silica hybrid nanoparticle (PSN) material was synthesized by polymerization of acrylate monomers on the surface of SBA-15 mesoporous silica nanoparticles. The structure of the PSN material was analyzed using a series of different techniques, including transmission electron microscopy, powder X-ray diffraction, and N(2) sorption analysis. These structurally ordered mesoporous polymer-silica hybrid nanoparticles were used for the controlled release of membrane-impermeable macromolecules inside eukaryotic cells. The cellular uptake efficiency and biocompatibility of PSN with human cervical cancer cells (HeLa) were investigated. Our results show that the inhibitory concentration (IC(50)) of PSN is very high (>100 μg/mL per million cells), while the median effective concentration for the uptake (EC(50)) of PSN is low (EC(50) = 4.4 μg/mL), indicating that PSNs are fairly biocompatible and easily up-taken in vitro. A membrane-impermeable macromolecule, 40 kDa FITC-Dextran, was loaded into the mesopores of PSNs at low pH. We demonstrated that the PSN material could indeed serve as a transmembrane carrier for the controlled release of FITC-Dextran at the pH level inside live HeLa cells. We believe that further developments of this PSN material will lead to a new generation of nanodevices for intracellular controlled delivery applications.

  4. Distribution volumes of macromolecules in human ovarian and endometrial cancers--effects of extracellular matrix structure.

    Science.gov (United States)

    Haslene-Hox, Hanne; Oveland, Eystein; Woie, Kathrine; Salvesen, Helga B; Tenstad, Olav; Wiig, Helge

    2015-01-01

    Elements of the extracellular matrix (ECM), notably collagen and glucosaminoglycans, will restrict part of the space available for soluble macromolecules simply because the molecules cannot occupy the same space. This phenomenon may influence macromolecular drug uptake. To study the influence of steric and charge effects of the ECM on the distribution volumes of macromolecules in human healthy and malignant gynecologic tissues we used as probes 15 abundant plasma proteins quantified by high-resolution mass spectrometry. The available distribution volume (VA) of albumin was increased in ovarian carcinoma compared with healthy ovarian tissue. Furthermore, VA of plasma proteins between 40 and 190 kDa decreased with size for endometrial carcinoma and healthy ovarian tissue, but was independent of molecular weight for the ovarian carcinomas. An effect of charge on distribution volume was only found in healthy ovaries, which had lower hydration and high collagen content, indicating that a condensed interstitium increases the influence of negative charges. A number of earlier suggested biomarker candidates were detected in increased amounts in malignant tissue, e.g., stathmin and spindlin-1, showing that interstitial fluid, even when unfractionated, can be a valuable source for tissue-specific proteins. We demonstrate that the distribution of abundant plasma proteins in the interstitium can be elucidated by mass spectrometry methods and depends markedly on hydration and ECM structure. Our data can be used in modeling of drug uptake, and give indications on ECM components to be targeted to increase the uptake of macromolecular substances.

  5. Bionic design for surface optimization combining hydrophilic and negative charged biological macromolecules.

    Science.gov (United States)

    Ran, Fen; Song, Haiming; Niu, Xiaoqin; Yang, Aimei; Nie, Shengqiang; Wang, Lingren; Li, Jie; Sun, Shudong; Zhao, Changsheng

    2014-06-01

    While polyethersulfone (PES) membrane represents a promising option for blood purification, the blood compatibility must be dramatically enhanced to meet today's ever-increasing demands for many emerging application. In this study, we report a bionic design for optimization and development of a modified PES membrane combining hydrophilic and negative charged biological macromolecules on its surface. The hydrophilic and ionic charged biological macromolecules sulfonated poly(styrene)-b-poly(methyl methacrylate)-b-poly-(styrene) (PSSMSS) and poly(vinyl pyrrolidone)-b-poly(methyl methacrylate)-b-poly-(vinyl pyrrolidone) were synthesized via reversible addition-fragmentation chain transfer polymerization and used together to modify PES membranes by blending method. A hydrophilic membrane surface with negative charged surface coating was obtained, imitating the hydrophilic and negatively charged structure feature of heparin. The modified PES membranes showed suppressed platelet adhesion, and a prolonged blood clotting time, and thereby improved blood compatibility. In addition, the blood clotting time of the modified membranes increased with the blended PSSMSS amounts increment, indicating that both the hydrophilic and negative charged groups play important roles in improving the blood compatibility of PES membranes.

  6. A dural lymphatic vascular system that drains brain interstitial fluid and macromolecules.

    Science.gov (United States)

    Aspelund, Aleksanteri; Antila, Salli; Proulx, Steven T; Karlsen, Tine Veronica; Karaman, Sinem; Detmar, Michael; Wiig, Helge; Alitalo, Kari

    2015-06-29

    The central nervous system (CNS) is considered an organ devoid of lymphatic vasculature. Yet, part of the cerebrospinal fluid (CSF) drains into the cervical lymph nodes (LNs). The mechanism of CSF entry into the LNs has been unclear. Here we report the surprising finding of a lymphatic vessel network in the dura mater of the mouse brain. We show that dural lymphatic vessels absorb CSF from the adjacent subarachnoid space and brain interstitial fluid (ISF) via the glymphatic system. Dural lymphatic vessels transport fluid into deep cervical LNs (dcLNs) via foramina at the base of the skull. In a transgenic mouse model expressing a VEGF-C/D trap and displaying complete aplasia of the dural lymphatic vessels, macromolecule clearance from the brain was attenuated and transport from the subarachnoid space into dcLNs was abrogated. Surprisingly, brain ISF pressure and water content were unaffected. Overall, these findings indicate that the mechanism of CSF flow into the dcLNs is directly via an adjacent dural lymphatic network, which may be important for the clearance of macromolecules from the brain. Importantly, these results call for a reexamination of the role of the lymphatic system in CNS physiology and disease.

  7. EX-PRESS Glaucoma Filtration Device: efficacy, safety, and predictability.

    Science.gov (United States)

    Chan, Jessica E; Netland, Peter A

    2015-01-01

    Trabeculectomy has been the traditional primary surgical therapy for open-angle glaucoma. While trabeculectomy is effective in lowering intraocular pressure, complications associated with the procedure have motivated the development of alternative techniques and devices, including the EX-PRESS Glaucoma Filtration Device. This review describes the efficacy, safety, complication rates, and potential advantages and disadvantages of the EX-PRESS Glaucoma Filtration Device. EX-PRESS implantation is technically simpler compared with that of trabeculectomy, with fewer surgical steps. Vision recovery has been more rapid after EX-PRESS implantation compared with trabeculectomy. Intraocular pressure variation is lower during the early postoperative period, indicating a more predictable procedure. While efficacy of the EX-PRESS implant has been comparable to trabeculectomy, postoperative complications appear less common after EX-PRESS implantation compared with trabeculectomy. The EX-PRESS Glaucoma Filtration Device appears to be safe and effective in the surgical management of open-angle glaucoma.

  8. Effects of press sizes on internal steam pressure during particleboard hot-pressing process

    Science.gov (United States)

    Zhiyong Cai; Michael Birkeland; James M. Wescott; Jane O' Dell; Jerrold E. Winandy

    2009-01-01

    Internal steam pressure produced during the hot-pressing cycle in particleboard production is critical to the newly developed bond strength that will determine the overall performance of particleboard. The difference between the accumulation of internal steam pressure for small panels made in the laboratory and that of large commercial-sized panels makes it difficult...

  9. Actes illocutoires et discours de la presse ecrite (Illocutionary Acts and the Press).

    Science.gov (United States)

    Duda, Richard

    This study investigates the applicability of the speech act theory to written discourse, specifically that of the press. A survey of Searle's taxonomy leads to the suggestion that the constituent statements of most newspaper articles belong to the class of illocutionary acts he calls "representatives." In consideration of the basic characteristic…

  10. Actes illocutoires et discours de la presse ecrite (Illocutionary Acts and the Press).

    Science.gov (United States)

    Duda, Richard

    This study investigates the applicability of the speech act theory to written discourse, specifically that of the press. A survey of Searle's taxonomy leads to the suggestion that the constituent statements of most newspaper articles belong to the class of illocutionary acts he calls "representatives." In consideration of the basic characteristic…

  11. Self-assembly of an amphiphilic macromolecule under spherical confinement: An efficient route to generate hollow nanospheres

    Science.gov (United States)

    Glagoleva, A. A.; Vasilevskaya, V. V.; Yoshikawa, K.; Khokhlov, A. R.

    2013-12-01

    In general, bio-macromolecules are composed of hydrophilic and hydrophobic moieties and are confined within small cavities, such as cell membranes and intracellular organelles. Here, we studied the self-organization of macromolecules having groups with different affinities to solvents under spherical nano-scale confinement by means of computer modeling. It is shown that depending on the interaction parameters of monomer units composed of side- and main-chain monomer groups along a single linear macromolecule and on cavity size, such amphiphilic polymers undergo the conformational transitions between hollow nanospheres, rod-like and folded cylindrical structures, and a necklace conformation with and without a particular ordering of beads. The diagram of the conformations in the variables the incompatibility parameter of monomer units and the cavity radius is constructed.

  12. Thermoelectric properties of pressed bismuth nanoparticles

    Science.gov (United States)

    Hostler, Stephen R.; Qu, Yu Qiao; Demko, Michael T.; Abramson, Alexis R.; Qiu, Xiaofeng; Burda, Clemens

    2008-03-01

    Theory predicts a substantial increase in the dimensionless figure of merit as the dimensionality and characteristic size of a material are decreased. We explore the use of bismuth nanoparticles pressed into pellets as potential increased efficiency thermoelectric materials. The figure of merit of these pellets is determined by independently measuring the electrical conductivity, thermal conductivity and Seebeck coefficient. The results from the nanoparticle sample are compared to microparticle-based samples. Both sample types show a slight reduction in thermal conductivity relative to bulk bismuth and a Seebeck coefficient near or slightly larger in magnitude than bulk bismuth. These changes are dwarfed by a hundred-fold decrease in the electrical conductivity due to porosity and an oxide layer on the particles. The low conductivity leads to figures of merit at least two orders of magnitude smaller than bulk bismuth. Oxide layer removal and reduced pellet porosity will be required to increase the figure of merit.

  13. Hot Isostatic Pressing of 60-Nitinol

    Science.gov (United States)

    Stanford, Malcolm K.

    2015-01-01

    The effects of varying the time, temperature and pressure during consolidation of 60-Nitinol (Nickel Titanium alloy) by hot isostatic pressing (HIP) were examined. Six HIP cycles with a cycle time of either 2 or 20 hours, temperature of 900 or 1000 degrees Centigrade, and a chamber pressure of either 100 or 200 millipascals were used. The cycle representing the shortest cycle time at the highest temperature and pressure (2 hours/1000 degrees Centigrade/200 millipascals) produced material with the highest hardness (720 Vickers Pyramid Number (HV)). A modest increase in average grain size and significant porosity reduction were observed in material subjected to the longest cycle time at the highest temperature, regardless of the pressure applied. The intent of this study is to facilitate the technology transfer involved in the processing of this material.

  14. STS-114: Discovery Launch Readiness Press Conference

    Science.gov (United States)

    2005-01-01

    This press conference, attended by representatives from the national, Florida, and aerospace media, addresses launch, weather, and safety issues related to Space Shuttle Discovery prior to its launch on the STS-114 Return to Flight mission. The Master of Ceremonies is George Diller from NASA Public Affairs, and the panelists are: Space Shuttle Program Manager Bill Parsons, ISS Program Manager (JSC) Bill Gerstenmaier, Space Shuttle Deputy Program Manager Wayne Hale, Director of Shuttle Processing Mike Wetmore, ISS Program Manager (JAXA) Dr. Kuniaki Shiraki, and Launch Weather Officer (USAF) Mindy Chavez. Questions included the following topics: predicted weather conditions at launch, contingency rescue plans, countdown procedures, and risk management, as well as implications of the Return to Flight for the International Space Station (ISS).

  15. STS-114: Post Launch Press Conference

    Science.gov (United States)

    2005-01-01

    Dean Acosta, Deputy Assistant Administrator for Public Affairs hosted this post launch press conference. Present were Mike Griffin, NASA Administrator; William Ready, Associate Administrator for Space Operations; Bill Parsons, Space Shuttle Program Manager; Mike Leinbach, NASA Launch Director; and Wayne Hill, Deputy Program Manager for Space Shuttle Program. Each expressed thanks to all of NASA Officials and employees, contractors, vendors and the crew for their hard work the past two and a half years that resulted the successful and pristine launch of Space Shuttle Discovery. The Panel emphasized that through extensive technical analysis, thorough planning and tremendous amount of public support brought them full circle again to return to flight. Flight safety, debris during rocket separation, sensors, observations from the mission control, launch conditions were some of the topics discussed with the News media.

  16. STS-114: Discovery Launch Postponement Press Briefing

    Science.gov (United States)

    2005-01-01

    This press briefing addresses the problem that occurred prior to the launch of the STS-114. Dean Acosta, Deputy Assistant Administrator of Public Affairs, introduces the panel which consists of Dr. Michael Griffin, NASA Administrator, William Readdy, Associate Administrator for Space Operations, Wayne Hale, Space Shuttle Program Deputy Manager, Steve Poulas, Orbiter Project Manager, Mike Leinbach, NASA Launch Director, and Bill Parsons, Space Shuttle Program Manager. Wayne Hale expresses that a problem occurred with one of the low level sensors in the hydrogen tank and that the cause of the problem must be identified and rectified. Steve Poulos talks about establishing a troubleshooting plan as a part of the scrub effort and Mike Leinbach describes the process of draining the external tank. Wayne Hale answers questions about the sensors and if the Space Shuttle Discovery is safe to fly and Steve Poulos answers questions about the possible suspects for this problem.

  17. MASSIF-1: a beamline dedicated to the fully automatic characterization and data collection from crystals of biological macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Bowler, Matthew W., E-mail: mbowler@embl.fr [European Molecular Biology Laboratory, Grenoble Outstation, 71 avenue des Martyrs, F-38042 Grenoble (France); Université Grenoble Alpes-EMBL-CNRS, 71 avenue des Martyrs, F-38042 Grenoble (France); Nurizzo, Didier, E-mail: mbowler@embl.fr; Barrett, Ray; Beteva, Antonia; Bodin, Marjolaine [European Synchrotron Radiation Facility, 71 avenue des Martyrs, F-38043 Grenoble (France)

    2015-10-03

    MASSIF-1 (ID30A-1) is a new beamline dedicated to the completely automatic characterization and data collection from crystals of biological macromolecules. MASSIF-1 (ID30A-1) is an ESRF undulator beamline operating at a fixed wavelength of 0.969 Å (12.8 keV) that is dedicated to the completely automatic characterization of and data collection from crystals of biological macromolecules. The first of the ESRF Upgrade MASSIF beamlines to be commissioned, it has been open since September 2014, providing a unique automated data collection service to academic and industrial users. Here, the beamline characteristics and details of the new service are outlined.

  18. Press self-regulation in Britain: a critique.

    Science.gov (United States)

    Cohen-Almagor, Raphael

    2015-02-01

    This article reviews the history of press self-regulation in Britain, from the 1947 Ross Commission to the 2012 Leveson Inquiry Commission. It considers the history of the Press Council and the Press Complaints Commission, analysing the ways they developed, their work, and how they have reached their current non-status. It is argued that the existing situation in Britain is far from satisfactory, and that the press should advance more elaborate mechanisms of self-control, establishing a new regulatory body called the Public and Press Council that will be anchored in law, empowering the new regulator with greater and unprecedented authority, and equipping it with substantive sanctioning abilities. The Public and Press Council should be independent and effective, with transparent policies, processes and responsibilities. Its adjudication should be made in accordance with a written, detailed Code of Practice.

  19. Direct drive digital servo press with high parallel control

    Science.gov (United States)

    Murata, Chikara; Yabe, Jun; Endou, Junichi; Hasegawa, Kiyoshi

    2013-12-01

    Direct drive digital servo press has been developed as the university-industry joint research and development since 1998. On the basis of this result, 4-axes direct drive digital servo press has been developed and in the market on April of 2002. This servo press is composed of 1 slide supported by 4 ball screws and each axis has linearscale measuring the position of each axis with high accuracy less than μm order level. Each axis is controlled independently by servo motor and feedback system. This system can keep high level parallelism and high accuracy even with high eccentric load. Furthermore the 'full stroke full power' is obtained by using ball screws. Using these features, new various types of press forming and stamping have been obtained by development and production. The new stamping and forming methods are introduced and 'manufacturing' need strategy of press forming with high added value and also the future direction of press forming are also introduced.

  20. NATO Advanced Research Workshop on Nuclear Magnetic Resonance of Paramagnetic Macromolecules

    CERN Document Server

    1995-01-01

    Since A. Kowalsky's first report of the spectrum of cytochrome c in 1965, interest in the detection, assignment and interpretation of paramagnetic molecules has surged, especially in the last decade. Two classes of systems have played a key role in the development of the field: heme proteins and iron-sulfur proteins. These two systems are unique in many respects, one of which is that they contain well-defined chromophores, each of which can be studied in detail outside the protein matrix. They are the most successfully studied macromolecules, and the first eight and last six of the seventeen contributions to this book deal with heme and/or iron-sulfur proteins. The middle three chapters survey the progress on, and significant promise of, more difficult systems which do not possess a chromophore, but which have nevertheless yielded remarkable insights into their structure.

  1. [Diffusion and diffusion-osmosis models of the charged macromolecule transfer in barriers of biosystems].

    Science.gov (United States)

    Varakin, A I; Mazur, V V; Arkhipova, N V; Serianov, Iu V

    2009-01-01

    Mathematical models of the transfer of charged macromolecules have been constructed on the basis of the classical equations of electromigration diffusion of Helmholtz-Smolukhovskii, Goldman, and Goldman-Hodgkin-Katz. It was shown that ion transfer in placental (mimicking lipid-protein barriers) and muscle barriers occurs by different mechanisms. In placental barriers, the electromigration diffusion occurs along lipid-protein channels formed due to the conformational deformation of phospholipid and protein molecules with the coefficients of diffusion D = (2.6-3.6) x 10(-8) cm2/s. The transfer in muscle barriers is due to the migration across charged interfibrillar channels with the negative diffusion activation energy, which is explained by changes in the structure of muscle fibers and expenditures of thermal energy for the extrusion of Cl- from channel walls with the diffusion coefficient D = (6.0-10.0) x 10(-6) cm2/s.

  2. Enhanced ileal absorption of a hydrophilic macromolecule, pentosan polysulfate sodium (PPS).

    Science.gov (United States)

    Dong, Liang; Yum, Alicia; Nguyen, Joe; Wong, Pat

    2004-01-01

    An in situ gelling, bioadhesive liquid formulation was developed to enhance the bioavailbility (BA) of a polysaccharide, pentosan polysulfate sodium (PPS). The formulation was tested to determine its bioavailability enhancement in a non-flush/non-ligated rat ileal model. A potent synergistic effect was found with a gelling agent Cremophor and a permeation enhancer sodium salicylate. The absolute bioavailabilities were 1.9%, 4.6%, 6.3% and 46.4%, respectively, for the PPS solution in saline, sodium salicylate/PPS, Cremophor/PPS and Cremophor/sodium salicylate/PPS. Therefore, we successfully demonstrated the approach of utilizing an in situ gelling/bioadhesive liquid carrier to enhancing the bioavailability of a hydrophilic macromolecule at the distal small intestine.

  3. Specific features of 5S rRNA structure - its interactions with macromolecules and possible functions.

    Science.gov (United States)

    Smirnov, A V; Entelis, N S; Krasheninnikov, I A; Martin, R; Tarassov, I A

    2008-12-01

    Small non-coding RNAs are today a topic of great interest for molecular biologists because they can be regarded as relicts of a hypothetical "RNA world" which, apparently, preceded the modern stage of organic evolution on Earth. The small molecule of 5S rRNA (approximately 120 nucleotides) is a component of large ribosomal subunits of all living beings (5S rRNAs are not found only in mitoribosomes of fungi and metazoans). This molecule interacts with various protein factors and 23S (28S) rRNA. This review contains the accumulated data to date concerning 5S rRNA structure, interactions with other biological macromolecules, intracellular traffic, and functions in the cell.

  4. Dielectric many-body effects in arrays of charged cylindrical macromolecules

    Science.gov (United States)

    Sinkovits, Daniel W.; Barros, Kipton; Dobnikar, Jure; Kandu&{Caron; C}, Matej; Naji, Ali; Podgornik, Rudolf; Luijten, Erik

    2012-02-01

    Nonuniform dielectric constants are a ubiquitous aspect of condensed-matter systems, but nevertheless widely ignored in simulations. Analytical work suggests that the polarization effects resulting from these inhomogeneities can produce many-body interactions that qualitatively alter the behavior of systems driven by electrostatic interactions, but such work relies on approximations. Recently, we have developed an algorithm that computes the fluctuating polarization charge at the interface between dielectric materials during a molecular dynamics simulation, without approximation. Here, we apply this approach to investigate arrays of charged cylindrical macromolecules in the presence of explicit counterions. We study the dielectric many-body effects as a function of separation, dielectric constant variation, and counterion valency. Our findings have implications for the aggregation of polyelectrolytes such as F-actin or DNA.

  5. A Biology Laboratory Exercise Using Macromolecule Assays to Distinguish Four Types of Milk

    Directory of Open Access Journals (Sweden)

    Charlotte W. Pratt

    2011-03-01

    Full Text Available One of the drawbacks of cookbook-style laboratory exercises for General Biology courses is that students are not challenged to develop skills in scientific reasoning, such as formulating hypotheses and designing and carrying out experiments. Several traditional laboratory curricula include exercises involving semi-quantitative colorimetric assays to detect proteins (biuret test, reducing sugars (Benedict’s test, starch (Lugol’s test, and lipids (Sudan red test in a variety of easily prepared solutions (glucose, albumin, glycine, etc. and familiar food items (lemon juice, cornstarch, egg white, etc.. An extension of this lab exercise was developed to allow students to use their knowledge of the macromolecule assays to design an experiment to distinguish four types of “milk”: whole milk, skim milk, cream, and soy milk (rice milk or almond milk could also be included.

  6. Spirulina cultivation with a CO2 absorbent: Influence on growth parameters and macromolecule production.

    Science.gov (United States)

    Rosa, Gabriel Martins da; Moraes, Luiza; de Souza, Michele da Rosa Andrade Zimmermann; Costa, Jorge Alberto Vieira

    2016-01-01

    The objective of this study was to select a concentration of CO2 absorbents to supplement Spirulina sp. LEB 18 cultivation and to evaluate the effect of these compounds on the growth and production of macromolecules. Three initial biomass concentrations (X0), eight concentrations of monoethanolamine (MEA), and three NaOH concentrations were tested. The selected MEA concentrations did not inhibit the growth of Spirulina and doubled the dissolved inorganic carbon concentration in the assay medium in relation to the concentration of NaOH. The protein concentration in the biomass grown with MEA was, on average, 17% higher than that obtained with NaOH. Thus, it was found that MEA did not reduce the productivity of Spirulina sp. LEB 18, and its use can be further explored as a means for converting the carbon dissolved in the medium to biomolecules.

  7. Enzyme kinetics and transport in a system crowded by mobile macromolecules.

    Science.gov (United States)

    Echeverria, Carlos; Kapral, Raymond

    2015-11-21

    The dynamics of an elastic network model for the enzyme 4-oxalocrotonate tautomerase is studied in a system crowded by mobile macromolecules, also modeled by elastic networks. The system includes a large number of solvent molecules, as well as substrate and product molecules which undergo catalytic reactions with this hexameric protein. The time evolution of the entire system takes place through a hybrid dynamics that combines molecular dynamics for solute species and multiparticle collision dynamics for the solvent. It is shown that crowding leads to subdiffusive dynamics for the protein, in accord with many studies of diffusion in crowded environments, and increases orientational relaxation times. The enzyme reaction kinetics is also modified by crowding. The effective Michaelis constant decreases with crowding volume fraction, and this decrease is attributed to excluded volume effects, which dominate over effects due to reduced substrate diffusion that would cause the Michaelis constant to increase.

  8. Microwave-assisted extraction of Shenfu coal and its macromolecule structure

    Institute of Scientific and Technical Information of China (English)

    CHEN Hong; LI Jian-wei; LEI Zhao; GE Ling-mei

    2009-01-01

    Coals consist of some molecules trapped within an organic matrix from which some organic compounds can be extracted by solvents. The Soxhlet technique has been widely used for extracting organic compounds. Microwave heating methods may be successfully applied in the field of coal science. Acetone extraction yields and the chemical composition of the extract were inves-tigated using a typical Chinese coal, Shenfu coal, with microwave-assisted extraction. The acetone extract and residue were ana-lyzed by GC/MS and carbon-13 nuclear magnetic resonance spectroscopy respectively. The carbon spectra were converted into several numerical parameters, fa, Ha, Xb, which indicate the difference in macromolecular structure between Shenfu coal and its residue. Furthermore, a hybrid genetic algorithm was employed using these parameters to approximate a coal macromolecule by assembling the structural fragments or functional groups into a large and complicated structure.

  9. Press conference of the 15 october 2002; Conference de presse du 15 octobre 2002

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2002-10-01

    Facing the public hostile purposes of october 2002, concerning the renewable energies, Andre Antolini, President of the renewable energies syndicate, proposed a press conference to give information, data and realizations on the renewable energies. The text of the conference is presented, as data on employment, biofuels, the wind energy, the hydro-electricity the greenhouse effect fight, the public opinion, the solar heating, the photovoltaic and the future projects and electric power supply for 2010. (A.L.B.)

  10. Concentration in the French Press Media Industry: Quantitative Analysis. The Case of the French Press Industry

    OpenAIRE

    Badillo, Patrick-Yves; Lesourd, Jean-Baptiste

    2010-01-01

    This work aims at studying the concentration of the French press industry, using as quantitative benchmarks several concentration indexes, such as the Herfindahl-Hirschman index, and the diversity index adapted to the media sector recently introduced by Noam (2003). This Noam index has, so far, not been used extensively, at least to our knowledge. Our paper is organised as follows. The second part begins by a media industry-oriented discussion various statistical indexes of concentration, and...

  11. Ex vitro experimental study on concentration polarization of macromolecules (LDL) at an arterial stenosis.

    Science.gov (United States)

    Zhang, ZhiGuo; Deng, XiaoYan; Fan, YuBo; Li, DeYu

    2007-08-01

    To verify the previous theoretical prediction that the disturbed flow distal to a stenosis enhances lipid accumulation at the blood/arterial wall interface, we designed a canine carotid arterial stenosis model and measured ex vitro the luminal surface concentration of bovine serum albumin (as a tracer macromolecule) by directly taking liquid samples from the luminal surface of the artery. The experimental results showed that due to the presence of a filtration flow, the luminal surface albumin concentration c(w) was higher than the bulk concentration c(0) as predicted by our theory. The measurement revealed that the luminal surface concentration of macromolecules was indeed enhanced significantly in regions of the disturbed flow. At Re = 50, the relative luminal surface concentration c(w)/c(0) was 1.66 +/- 0.10 in the vortex region, while the c(w)/c(0) was 1.37 +/- 0.06 in the laminar flow region. When Re increased to 100, the c(w)/c(0) in the vortex flow region and the laminar flow region reduced to 1.39 +/- 0.07 and 1.24 +/- 0.04, respectively. The effect of the filtration rate, v(w), on the luminal surface concentration of albumin was remarkably apparent. At Re = 50 and 100, when v(w) = 8.9 +/- 1.7 x 10(-6) cm/s, c(w) in the vortex region was 77% and 52% higher than c(0) respectively, meanwhile when v(w) = 4.8 +/- 0.6 x 10(-6) cm/s, c(w) in the vortex region was only 66% and 39% higher than c(0) respectively. In summary, the present study has provided further experimental evidence that concentration polarization can occur in the arterial system and fluid layer with highly concentrated lipids in the area of flow separation point may be responsible for the formation and development of atherosclerosis.

  12. Enhanced Sampling Methods for the Computation of Conformational Kinetics in Macromolecules

    Science.gov (United States)

    Grazioli, Gianmarc

    Calculating the kinetics of conformational changes in macromolecules, such as proteins and nucleic acids, is still very much an open problem in theoretical chemistry and computational biophysics. If it were feasible to run large sets of molecular dynamics trajectories that begin in one configuration and terminate when reaching another configuration of interest, calculating kinetics from molecular dynamics simulations would be simple, but in practice, configuration spaces encompassing all possible configurations for even the simplest of macromolecules are far too vast for such a brute force approach. In fact, many problems related to searches of configuration spaces, such as protein structure prediction, are considered to be NP-hard. Two approaches to addressing this problem are to either develop methods for enhanced sampling of trajectories that confine the search to productive trajectories without loss of temporal information, or coarse-grained methodologies that recast the problem in reduced spaces that can be exhaustively searched. This thesis will begin with a description of work carried out in the vein of the second approach, where a Smoluchowski diffusion equation model was developed that accurately reproduces the rate vs. force relationship observed in the mechano-catalytic disulphide bond cleavage observed in thioredoxin-catalyzed reduction of disulphide bonds. Next, three different novel enhanced sampling methods developed in the vein of the first approach will be described, which can be employed either separately or in conjunction with each other to autonomously define a set of energetically relevant subspaces in configuration space, accelerate trajectories between the interfaces dividing the subspaces while preserving the distribution of unassisted transition times between subspaces, and approximate time correlation functions from the kinetic data collected from the transitions between interfaces.

  13. Opinion: hazards faced by macromolecules when confined to thin aqueous films.

    Science.gov (United States)

    Glaeser, Robert M; Han, Bong-Gyoon

    2017-01-01

    Samples prepared for single-particle electron cryo-microscopy (cryo-EM) necessarily have a very high surface-to-volume ratio during the short period of time between thinning and vitrification. During this time, there is an obvious risk that macromolecules of interest may adsorb to the air-water interface with a preferred orientation, or that they may even become partially or fully unfolded at the interface. In addition, adsorption of macromolecules to an air-water interface may occur even before thinning. This paper addresses the question whether currently used methods of sample preparation might be improved if one could avoid such interfacial interactions. One possible way to do so might be to preemptively form a surfactant monolayer over the air-water interfaces, to serve as a structure-friendly slide and coverslip. An alternative is to immobilize particles of interest by binding them to some type of support film, which-to continue using the analogy-thus serves as a slide. In this case, the goal is not only to prevent the particles of interest from diffusing into contact with the air-water interface but also to increase the number of particles seen in each image. In this direction, it is natural to think of developing various types of affinity grids as structure-friendly alternatives to thin carbon films. Perhaps ironically, if precautions are not taken against adsorption of particles to air-water interfaces, sacrificial monolayers of denatured protein may take the roles of slide, coverslip, or even both.

  14. A mathematical model for filtration and macromolecule transport across capillary walls.

    Science.gov (United States)

    Facchini, L; Bellin, A; Toro, E F

    2014-07-01

    Metabolic substrates, such as oxygen and glucose, are rapidly delivered to the cells of large organisms through filtration across microvessels walls. Modelling this important process is complicated by the strong coupling between flow and transport equations, which are linked through the osmotic pressure induced by the colloidal plasma proteins. The microvessel wall is a composite media with the internal glycocalyx layer exerting a strong sieving effect on macromolecules, with respect to the external layer composed by the endothelial cells. The physiological structure of the microvessel is represented as the superimposition of two membranes with different properties; the inner membrane represents the glycocalyx, while the outer membrane represents the surrounding endothelial cells. Application of the mass conservation principle and thermodynamic considerations lead to a model composed of two coupled second-order ordinary differential equations for the hydrostatic and osmotic pressures, one, expressing volumetric mass conservation and the other, which is non-linear in the unknown osmotic pressure, expressing macromolecules mass conservation. Despite the complexity of the system, the assumption that the properties of the layers are piece-wise constant allows us to obtain analytical solutions for the two pressures. This solution is in agreement with experimental observations, which contrary to common belief, show that flow reversal cannot occur in steady-state conditions unless the hydrostatic pressure in the lumen drops below physiologically plausible values. The observed variations of the volumetric flux and the solute mass flux in case of a significant reduction of the hydrostatic pressure at the lumen are in qualitative agreement with observed variations during detailed experiments reported in the literature. On the other hand, homogenising the microvessel wall into a single-layer membrane with equivalent properties leads to a very different distribution of

  15. Ex vitro experimental study on concentration polari-zation of macromolecules (LDL) at an arterial stenosis

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    To verify the previous theoretical prediction that the disturbed flow distal to a stenosis enhances lipid accumulation at the blood/arterial wall interface, we designed a canine carotid arterial stenosis model and measured ex vitro the luminal surface concentration of bovine serum albumin (as a tracer mac-romolecule) by directly taking liquid samples from the luminal surface of the artery. The experimental results showed that due to the presence of a filtration flow, the luminal surface albumin concentration cw was higher than the bulk concentration co as predicted by our theory. The measurement revealed that the luminal surface concentration of macromolecules was indeed enhanced significantly in re-gions of the disturbed flow. At Re = 50, the relative luminal surface concentration cw/co was 1.66 ± 0.10 in the vortex region, while the cw/co was 1.37 ± 0.06 in the laminar flow region. When Re increased to 100, the cw/co in the vortex flow region and the laminar flow region reduced to 1.39 ± 0.07 and 1.24 ± 0.04, respectively. The effect of the filtration rate, vw, on the luminal surface concentration of albumin was remarkably apparent. At Re = 50 and 100, when vw = 8.9 ± 1.7 × 10-6 cm/s, cw in the vortex region was 77% and 52% higher than co respectively, meanwhile when vw = 4.8 ± 0.6 × 10-6 cm/s, cw in the vortex region was only 66 % and 39% higher than co respectively. In summary, the present study has provided further experimental evidence that concentration polarization can occur in the arterial system and fluid layer with highly concentrated lipids in the area of flow separation point may be responsible for the formation and development of atherosclerosis.

  16. Ex vitro experimental study on concentration polarization of macromolecules (LDL) at an arterial stenosis

    Institute of Scientific and Technical Information of China (English)

    ZHANG ZhiGuo; DENG XiaoYan; FAN YuBo; LI DeYu

    2007-01-01

    To verify the previous theoretical prediction that the disturbed flow distal to a stenosis enhances lipid accumulation at the blood/arterial wall interface, we designed a canine carotid arterial stenosis model and measured ex vitro the luminal surface concentration of bovine serum albumin (as a tracer macromolecule) by directly taking liquid samples from the luminal surface of the artery. The experimental results showed that due to the presence of a filtration flow, the luminal surface albumin concentration cw was higher than the bulk concentration co as predicted by our theory. The measurement revealed that the luminal surface concentration of macromolecules was indeed enhanced significantly in regions of the disturbed flow. At Re = 50, the relative luminal surface concentration cw/co was 1.66±0.10 in the vortex region, while the cw/co was 1.37±0.06 in the laminar flow region. When Re increased to 100,the cw/co in the vortex flow region and the laminar flow region reduced to 1.39±0.07 and 1.24±0.04,respectively. The effect of the filtration rate, vw, on the luminal surface concentration of albumin was remarkably apparent. At Re=50 and 100, when vw=8.9±1.7×10-6 cm/s, cw in the vortex region was 77% and 52% higher than co respectively, meanwhile when vw = 4.8±0.6×10-6 cm/s, cw in the vortex region was only 66% and 39% higher than co respectively. In summary, the present study has provided further experimental evidence that concentration polarization can occur in the arterial system and fluid layer with highly concentrated lipids in the area of flow separation point may be responsible for the formation and development of atherosclerosis.

  17. Exciton scattering approach for optical spectra calculations in branched conjugated macromolecules

    Science.gov (United States)

    Li, Hao; Wu, Chao; Malinin, Sergey V.; Tretiak, Sergei; Chernyak, Vladimir Y.

    2016-12-01

    The exciton scattering (ES) technique is a multiscale approach based on the concept of a particle in a box and developed for efficient calculations of excited-state electronic structure and optical spectra in low-dimensional conjugated macromolecules. Within the ES method, electronic excitations in molecular structure are attributed to standing waves representing quantum quasi-particles (excitons), which reside on the graph whose edges and nodes stand for the molecular linear segments and vertices, respectively. Exciton propagation on the linear segments is characterized by the exciton dispersion, whereas exciton scattering at the branching centers is determined by the energy-dependent scattering matrices. Using these ES energetic parameters, the excitation energies are then found by solving a set of generalized "particle in a box" problems on the graph that represents the molecule. Similarly, unique energy-dependent ES dipolar parameters permit calculations of the corresponding oscillator strengths, thus, completing optical spectra modeling. Both the energetic and dipolar parameters can be extracted from quantum-chemical computations in small molecular fragments and tabulated in the ES library for further applications. Subsequently, spectroscopic modeling for any macrostructure within a considered molecular family could be performed with negligible numerical effort. We demonstrate the ES method application to molecular families of branched conjugated phenylacetylenes and ladder poly-para-phenylenes, as well as structures with electron donor and acceptor chemical substituents. Time-dependent density functional theory (TD-DFT) is used as a reference model for electronic structure. The ES calculations accurately reproduce the optical spectra compared to the reference quantum chemistry results, and make possible to predict spectra of complex macromolecules, where conventional electronic structure calculations are unfeasible.

  18. Anti-Arrhenius cleavage of covalent bonds in bottlebrush macromolecules on substrate.

    Science.gov (United States)

    Lebedeva, Natalia V; Nese, Alper; Sun, Frank C; Matyjaszewski, Krzysztof; Sheiko, Sergei S

    2012-06-12

    Spontaneous degradation of bottlebrush macromolecules on aqueous substrates was monitored by atomic force microscopy. Scission of C ─ C covalent bonds in the brush backbone occurred due to steric repulsion between the adsorbed side chains, which generated bond tension on the order of several nano-Newtons. Unlike conventional chemical reactions, the rate of bond scission was shown to decrease with temperature. This apparent anti-Arrhenius behavior was caused by a decrease in the surface energy of the underlying substrate upon heating, which results in a corresponding decrease of bond tension in the adsorbed macromolecules. Even though the tension dropped minimally from 2.16 to 1.89 nN, this was sufficient to overpower the increase in the thermal energy (k(B)T) in the Arrhenius equation. The rate constant of the bond-scission reaction was measured as a function of temperature and surface energy. Fitting the experimental data by a perturbed Morse potential V = V(0)(1 - e(-βx))(2) - fx, we determined the depth and width of the potential to be V(0) = 141 ± 19 kJ/mol and β(-1) = 0.18 ± 0.03 Å, respectively. Whereas the V(0) value is in reasonable agreement with the activation energy E(a) = 80-220 kJ/mol of mechanical and thermal degradation of organic polymers, it is significantly lower than the dissociation energy of a C ─ C bond D(e) = 350 kJ/mol. Moreover, the force constant K(x) = 2β(2)V(0) = 1.45 ± 0.36 kN/m of a strained bottlebrush along its backbone is markedly larger than the force constant of a C ─ C bond K(l) = 0.44 kN/m, which is attributed to additional stiffness due to deformation of the side chains.

  19. Do column frits contribute to the on-column, flow-induced degradation of macromolecules?

    Science.gov (United States)

    Striegel, André M

    2014-09-12

    Flow-induced, on-column degradation is a major hindrance to the accurate characterization of ultra-high molar mass macromolecules and colloids. This degradation is a direct result of the large shear rates which are generated within the column, which cause chain scission to occur both in the interstitial medium and, it has been postulated, at the packing particle pore boundary. An additional putative source of degradation has been the column frits, though little experimental evidence exists to either support or refute this claim. To this effect, the present experiments examine the role of the frits in the degradation of high molar mass macromolecules. Two narrow dispersity polystyrene standards, the molar mass of which differs by a factor of two, were analyzed on three different size-exclusion chromatography (SEC) columns, each with frits of different pore size, at various flow rates. In the smallest pore size column, which also contained the smallest frits and which was packed with the smallest diameter particles, the larger standard was forced to degrade by increasing the flow rate of the mobile phase. During the course of the latter portion of the study, the inlet and the outlet frits were removed from the column, in stepwise fashion. It was concluded that neither frit played any appreciable role in the degradation. Results of our studies were applied to explain previously observed degradation in ultra-high pressure liquid chromatography of polymers. The general conclusion arrived at herein is that the column frits are likely to have a secondary role (as compared to interstitial and pore boundary stresses), or no role at all, in polymer degradation for cases where the frit radius is larger than or equal to the hydraulic radius rcof the column.

  20. Selling a Story: How to Write a Successful Press Release

    Science.gov (United States)

    Pearson, E.

    2016-12-01

    Press releases are an important part of communicating new discoveries with the general public. However, if they are confusing or difficult to read then they are unlikely to be picked up by media outlets. This article details how to create a successful press release by addressing a series of points: learning how to identify the audience; writing text that is both eye catching and clear; including multimedia and contact details; getting your press release to the media; and timing.

  1. Dynamic Multiaxial Response of a Hot-Pressed Aluminum Nitride

    Science.gov (United States)

    2012-01-05

    Dynamic Multiaxial Response of a Hot-Pressed Aluminum Nitride by Guangli Hu, C. Q. Chen, K. T. Ramesh, and J. W. McCauley ARL-RP-0487...Laboratory Aberdeen Proving Ground, MD 21005-5066 ARL-RP-0487 June 2014 Dynamic Multiaxial Response of a Hot-Pressed Aluminum Nitride...3. DATES COVERED (From - To) January 2010–January 2013 4. TITLE AND SUBTITLE Dynamic Multiaxial Response of a Hot-Pressed Aluminum Nitride 5a

  2. WordPress all-in-one for dummies

    CERN Document Server

    Sabin-Wilson, Lisa; Palmer, Kevin

    2011-01-01

    A convenient how-to guide for maximizing your WordPress experience. WordPress is a state-of-the-art blog publishing platform with nearly ten million active installations. Eight minibooks provide you with expanded coverage of the most important topics to the WordPress community, such as WordPress basics, theme designs, plug-in development, social media integration, SEO, customization, and running multiple sites. Veteran author Lisa Sabin-Wilson leads an authoritative team of authors who offer their unique knowledge and skillset while sharing invaluable advice for maximizing your site's potentia

  3. The small academic press in the land of giants

    Directory of Open Access Journals (Sweden)

    Frances Pinter

    2015-11-01

    Full Text Available Mergers and acquisitions, for example the merger of Macmillan Science and Education with Springer Science+Business Media, might suggest that large is the future for academic publishing.  It might seem that giant players will dominate the future of scholarly publishing, but, at the same time, this year has seen the launch of UCL Press, the University’s in-house publishing arm. Goldsmiths, University of London, has also announced it is preparing to launch Goldsmiths Press, a new university press built on digital-first publishing, especially around unconventional projects traditionally excluded by publishers. Some of the more established university presses also seem to be increasing their scope. For example, Stanford University Press launched a new trade imprint and Manchester University Press has announced it has acquired forward titles from Bloomsbury Publishing.  'Insights 'asked two experts if there really is scope for the small academic press in the modern scholarly publishing environment. Frances Pinter has provided the perspective of the small university press. She is realistic about the challenges small academic publishers face, but concludes that there is space and opportunity for them to coexist with the giants. Michael Magoulias is equally realistic about the challenges of small, but sees the university press as a necessary, not to say, vital, alternative to commercial publishing.

  4. Legal Protection To The Infotainment Of Press Development In Indonesia

    Directory of Open Access Journals (Sweden)

    Anwar Fuadi

    2015-08-01

    Full Text Available Abstract In the socio-political life the press has become an integral part in democratic life. The press has become one of the means for citizens to bring their thoughts and opinions. Nowadays there is a tendency to increase the quantity of press publications sharp but not accompanied by a statement of the quality of journalism. The objective of this research is to understand the essence of the infotainment liability as a mass media in order to construct a freedom of the press principle which has legitimacy within the legal system of the press in Indonesia. The type of research used in this paper is normative research or also known as doctrinal research by reviewing the legal protection to the infotainment as a mass media in Indonesia. The outcomes of the research indicate that the role of infotainment in the legal system of the press in Indonesia refers to the legal construction of institutional and infotainment organizers itself. Legal liability of Infotainment essentially can be seen from the press obligations stipulated in the Law No. 40 of 1999 regarding the Press Law No. 32 of 2002 regarding Broadcasting as well as the Journalists Code of Ethics which support freedom of the press and expression.

  5. Comparison of gold nanoparticle mediated photoporation: vapor nanobubbles outperform direct heating for delivering macromolecules in live cells.

    Science.gov (United States)

    Xiong, Ranhua; Raemdonck, Koen; Peynshaert, Karen; Lentacker, Ine; De Cock, Ine; Demeester, Jo; De Smedt, Stefaan C; Skirtach, Andre G; Braeckmans, Kevin

    2014-06-24

    There is a great interest in delivering macromolecular agents into living cells for therapeutic purposes, such as siRNA for gene silencing. Although substantial effort has gone into designing nonviral nanocarriers for delivering macromolecules into cells, translocation of the therapeutic molecules from the endosomes after endocytosis into the cytoplasm remains a major bottleneck. Laser-induced photoporation, especially in combination with gold nanoparticles, is an alternative physical method that is receiving increasing attention for delivering macromolecules in cells. By allowing gold nanoparticles to bind to the cell membrane, nanosized membrane pores can be created upon pulsed laser illumination. Depending on the laser energy, pores are created through either direct heating of the AuNPs or by vapor nanobubbles (VNBs) that can emerge around the AuNPs. Macromolecules in the surrounding cell medium can then diffuse through the pores directly into the cytoplasm. Here we present a systematic evaluation of both photoporation mechanisms in terms of cytotoxicity, cell loading, and siRNA transfection efficiency. We find that the delivery of macromolecules under conditions of VNBs is much more efficient than direct photothermal disturbance of the plasma membrane without any noticeable cytotoxic effect. Interestingly, by tuning the laser energy, the pore size could be changed, allowing control of the amount and size of molecules that are delivered in the cytoplasm. As only a single nanosecond laser pulse is required, we conclude that VNBs are an interesting photoporation mechanism that may prove very useful for efficient high-throughput macromolecular delivery in live cells.

  6. Application of flow field-flow fractionation for the characterization of macromolecules of biological interest: a review

    NARCIS (Netherlands)

    Qureshi, R.N.; Kok, W.T.

    2011-01-01

    An overview is given of the recent literature on (bio) analytical applications of flow field-flow fractionation (FlFFF). FlFFF is a liquid-phase separation technique that can separate macromolecules and particles according to size. The technique is increasingly used on a routine basis in a variety

  7. Effect of adsorption of charged macromolecules on streaming and membrane potential values measured with a microporous polysulfone membrane

    DEFF Research Database (Denmark)

    Benavente, J.; Jonsson, Gunnar Eigil

    1997-01-01

    Changes in streaming and membrane potentials measured across a commercial microporous polysulfone membrane as a result of the adsorption of differently charged macromolecules were studied. Measurements were carried out with different NaCl solutions (10(-3) M to 5 x 10(-2) M) and their mixtures...

  8. Hydroxycinnamic acids are ester-linked directly to glucosyl moieties within the lignan macromolecule from flaxseed hulls

    NARCIS (Netherlands)

    Struijs, K.; Vincken, J.P.; Verhoef, R.P.; Voragen, A.G.J.; Gruppen, H.

    2008-01-01

    In flaxseed hulls, lignans are present in an oligomeric structure. Secoisolariciresinol diglucoside (SDG), ester-linked to hydroxy-methyl-glutaric acid (HMGA), forms the backbone of this lignan macromolecule. The hydroxycinnamic acids p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeA

  9. Application of flow field-flow fractionation for the characterization of macromolecules of biological interest: a review

    NARCIS (Netherlands)

    R.N. Qureshi; W.T. Kok

    2011-01-01

    An overview is given of the recent literature on (bio) analytical applications of flow field-flow fractionation (FlFFF). FlFFF is a liquid-phase separation technique that can separate macromolecules and particles according to size. The technique is increasingly used on a routine basis in a variety o

  10. Quality of cold-pressed organic oils

    Directory of Open Access Journals (Sweden)

    Monika Skwarek

    2013-09-01

    Full Text Available The aim of this study was to assess the quality of the traditional cold-pressed oils made from organic materials in a small farm. Scope of the study included evaluation of canola, flax, camelina and poppy oil immediately after manufacture and during storage under various conditions (light, temperature. Fatty acid composition, oxidability rate, an acid value, peroxide value, anisidine value and colour values in CIE L*a*b* were marked. It has been shown that immediately after the production all oils were characterised by a high quality and fatty acid composition suitable for each type of oil. Among the examined oils, the highest content of saturated fatty acids characterised flax oil, the lowest canola oil. Oils: camelina, poppy and flax compared with canola oil, contained approximately twice the amount of polyunsaturated fatty acids. The fastest rate of oxidative changes, both in the room temperature conditions and cooling, showed poppy oil. Among the oils stored in room temperature, canola oil was the most oxidatively stable.

  11. Hot isostatic press waste option study report

    Energy Technology Data Exchange (ETDEWEB)

    Russell, N.E.; Taylor, D.D.

    1998-02-01

    A Settlement Agreement between the Department of Energy and the State of Idaho mandates that all high-level radioactive waste now stored at the Idaho Chemical Processing Plant be treated so that it is ready to move out of Idaho for disposal by the target date of 2035. This study investigates the immobilization of all Idaho Chemical Processing Plant calcine, including calcined sodium bearing waste, via the process known as hot isostatic press, which produces compact solid waste forms by means of high temperature and pressure (1,050 C and 20,000 psi), as the treatment method for complying with the settlement agreement. The final waste product would be contained in stainless-steel canisters, the same type used at the Savannah River Site for vitrified waste, and stored at the Idaho National Engineering and Environmental Laboratory until a national geological repository becomes available for its disposal. The waste processing period is from 2013 through 2032, and disposal at the High Level Waste repository will probably begin sometime after 2065.

  12. [Gender and health in the daily press].

    Science.gov (United States)

    Revuelta, Gemma; Alonso, Inma; Tomás, Sonia; Guerrero, Marcela; Rohlfs, Izabella

    2004-05-01

    To have a better understanding on the role of the press in the communication of gender and health issues, the content of the five most spread newspapers in Spain was studied (El País, ABC, El Mundo, La Vanguardia and El Periódico de Catalunya) for five years (1997-2001) and the electronic version of The New York Times of the period 1990-1999. An unequal distribution was observed in the responsibility as for the information related to three aspects: positions of responsibility in the newspapers (out of 71 main posts, 67 were men and 4 women); the authors of the articles on health issues (61.2% men and 38,8% women, among the articles that include the author) and the mentioned information sources (81.43% men and 17.77% women). Among the 120 health issues that were covered during the period of the study, only 20 explicitly mentioned a woman (16.67%). Those subjects that included more frequently explicit references were: ablation, iatrogenics, sterilization, sexual and reproductive health, incontinence, beauty and domestic violence. The analysis of the approach to these subjects helped to identify the stereotypes of gender inequality, in the language as well as in the approach.

  13. [Health information in the daily local press].

    Science.gov (United States)

    Unzueta Zamalloa, L; Najarro Ajuria, G; Mendíbil Crespo, I; Galán Morales, F; Garay Narvarte, F J

    1998-04-15

    To know how much health-related information is published in the daily local press, type of information; pathologies; practical help offered, and sources. Crossover descriptive study. Community. Health articles (events and publicity excluded) published in the newspapers of Bizkaia: Deia, Egin, Egunkaria, El Correo and El Mundo; sample included all issues from one fortnight of June and one fortnight of September of 1996. 501 articles, which occupied 1.57% of the impressed surface, were published. 90% of the issues had health articles. 19.8% appeared in once-weekly health sections. Subjects considered as health culture were 49.9% scientific and technical information and 9.8% health habits and vaccinations. When compared with the rest of the newspaper, health sections gave more explicit advice (p = 0.04) and diferred in sources of information (p < 0.01). Health articles are almost daily published. The most frequent type was the spread of scientific and technical information. Current information topics are dominant. A few articles give explicit advice or referred to health habits. Acknowledgement of the sources could be improved. It would be desirable to investigate the quality of contents.

  14. Structural and Electrical Properties of PZT/PVDF Piezoelectric Nanocomposites Prepared by Cold-Press and Hot-Press Routes

    Institute of Scientific and Technical Information of China (English)

    ZHANG De-Qing; WANG Da-Wei; YUAN Jie; ZHAO Quan-Liang; WANG Zhi-Ying; CAO Mao-Sheng

    2008-01-01

    @@ The 0-3 PZT/PVDF piezoelectric composites are prepared separately by hot-press and cold-press processes. The effects of the PZT content and the shaping-process on the composites are studied. The experimental results indicate that composites with 70% PZT nanopowders prepared by the hot-press method exhibit excellent piezo-electric and dielectric properties. The maxima of daa and e of the composites prepared by hot-press method are about 30% and 65% higher than those prepared by the cold-press method, respectively. This is mainly attributed to the favourable coupling of the two materials in the process of the hot press and the formation of the β-type PVDF, which possesses better electric properties.

  15. A comparative study between spiral-filter press and belt press implemented in a cloudy apple juice production process.

    Science.gov (United States)

    De Paepe, Domien; Coudijzer, Katleen; Noten, Bart; Valkenborg, Dirk; Servaes, Kelly; De Loose, Marc; Diels, Ludo; Voorspoels, Stefan; Van Droogenbroeck, Bart

    2015-04-15

    In this study, advantages and disadvantages of the innovative, low-oxygen spiral-filter press system were studied in comparison with the belt press, commonly applied in small and medium size enterprises for the production of cloudy apple juice. On the basis of equivalent throughput, a higher juice yield could be achieved with spiral-filter press. Also a more turbid juice with a higher content of suspended solids could be produced. The avoidance of enzymatic browning during juice extraction led to an attractive yellowish juice with an elevated phenolic content. Moreover, it was found that juice produced with spiral-filter press demonstrates a higher retention of phenolic compounds during the downstream processing steps and storage. The results demonstrates the advantage of the use of a spiral-filter press in comparison with belt press in the production of a high quality cloudy apple juice rich in phenolic compounds, without the use of oxidation inhibiting additives.

  16. Distal clavicular osteolysis in adults: association with bench pressing intensity

    Energy Technology Data Exchange (ETDEWEB)

    Nevalainen, Mika T.; Morrison, William B.; Zoga, Adam C.; Roedl, Johannes B. [Sidney Kimmel Medical College at Thomas Jefferson University, Division of Musculoskeletal Imaging and Interventions, Department of Radiology, Thomas Jefferson University Hospital, Philadelphia, PA (United States); Ciccotti, Michael G. [Sidney Kimmel Medical College at Thomas Jefferson University, Division of Sports Medicine, Department of Orthopedic Surgery, Thomas Jefferson University Hospital, Rothman Institute, Philadelphia, PA (United States)

    2016-11-15

    To investigate the association between distal clavicular osteolysis (DCO) and bench pressing intensity. From a retrospective review of MRI shoulder reports of individuals between 20 and 40 years of age, 262 male patients with DCO and 227 age-matched male patients without DCO were selected. All patients had completed a bench pressing questionnaire. The patients' bench pressing frequency (times per week), duration (years of bench pressing), bench pressing weight (maximum bench pressing weight with one repetition = 1RM) and the ratio of bench pressing weight to body weight were compared between both groups using Chi-square and Mann-Whitney tests. The results showed that 56 % (146/262) of patients with DCO were high-intensity bench pressers (1RM more than 1.5 times the body weight) compared to 6 % (14/227) in patients without DCO. High-intensity bench pressing was a risk factor for DCO (OR = 19; 95 %CI = 11-35; p < 0.001). Low-intensity bench pressing (1RM less than 1.5 times the body weight) was not a risk factor for DCO (OR = 0.6; 95 % CI = 0.4-0.8). High frequency (>1 x /week) and duration (>5 years) of bench pressing were risk factors. In bench pressers who suffered from DCO, the mean 1RM was 283 lbs (±SD 57) compared to 209 lbs (±SD 60) in bench pressers not affected by DCO (p < 0.001, Mann-Whitney). High-intensity, but not low-intensity bench pressing is a risk factor for DCO. (orig.)

  17. New Realities for Scholarly Presses in Trying Economic Times

    Science.gov (United States)

    Blakesley, David

    2014-01-01

    The author explains that Parlor Press is an independent publisher and distributor of scholarly and trade books in print and digital formats. It was founded in 2002 to address the need for an alternative scholarly, academic press attentive to emergent ideas and forms while maintaining the highest possible standards of quality, credibility, and…

  18. Letting The Nasa Press Engine Work For You

    Science.gov (United States)

    Weaver, Kimberly A.

    2006-09-01

    You have an amazing result based on NASA data or a NASA mission, you have written your seminal paper and submitted it to your favorite journal. You believe it has press potential and maybe you've even gotten help from your PR folks in writing a press release. Now you would really like NASA to issue this as a press release. But how do you do that? This presentation will illustrate the steps required to engage NASA in helping promote your story. What are NASA's requirements for newsworthiness? Should your news be released as a web feature story or in the local media? Does your news rise to the level of a full-blown press conference or will it be a media teleconference? How do you obtain approval for a NASA press event? Once your result is scheduled to be issued as a press release, how can you improve your chances of getting the best possible coverage for your story? I will discuss the NASA press process and suggest how to consider factors like timing, working with your collaborating institutions in an efficient way, and not letting the cat out of the bag until the press event.

  19. University Presses See Opportunities in Shakeup in the Publishing World.

    Science.gov (United States)

    McMillen, Liz

    1997-01-01

    Recent closings in the commercial publishing industry and reduction in serious nonfiction publications may open doors for university presses to fill the gap. University presses are already anticipating the changing market, reviewing book lists, and looking at new areas for publication development. Changes in the commercial publishing industry are…

  20. Coeducation and the Women's Rights Press, 1849-1920.

    Science.gov (United States)

    Butcher, Patricia Smith

    The role of the women's rights press in reporting on and advancing coeducation in the United States is considered. The women's rights press was linked to the women's rights movement and articulated the goal that women should enjoy full participation in all aspects of U.S. life, including higher education. This analysis is based on 12 of the most…

  1. Criticism of the Press: Its Social, Psychological and Political Origins.

    Science.gov (United States)

    Becker, Lee B.; And Others

    This study examines data from several national polls about press coverage during the Watergate scandal, in order to assess the origins of press criticism. The polls were conducted between 28 September and 6 October 1973, during June 1974, and in August 1974. The data suggest that political variables--particularly support of Nixon, party…

  2. Press Releases vs. Newspaper Coverage of California Supreme Court Decisions.

    Science.gov (United States)

    Hale, F. Dennis

    1978-01-01

    A study comparing the coverage in newspapers and press releases regarding one year's decisions of the California Supreme Court revealed that the press releases influenced the kinds of decisions that were reported but not the quantity of coverage by the newspapers. (GT)

  3. Multiple Measures in the Study of Press Response.

    Science.gov (United States)

    Charlebois, Carol

    1979-01-01

    Surveys measures of press behavior; reports on the testing of J. Galtung and M. Ruge's theory about the structure of news. Concludes that there are three major dimensions to press response to events: the decision to record the event, and considerations regarding space allocation and reader attention. (GT)

  4. The printed press and the Tunisian revolution: issues and challenges

    Directory of Open Access Journals (Sweden)

    Zeineb TOUATI

    2012-01-01

    Full Text Available Our presentation will show the minor role played by the Tunisian printed press during the revolutionary process of 2011. We will also raise the main evolutions that have taken place in that field. Issues raised by the new situation and the challenges faced by the press will also be examined..

  5. Raman spectra of hot-pressed boron suboxide

    CSIR Research Space (South Africa)

    Machaka, R

    2011-01-01

    Full Text Available Despite hot pressing being the most popular method of consolidating B6O powder, the Raman spectrum of polycrystalline hot-pressed B6O was until now poorly understood. Yet, recent reports have contributed to the understanding of only high...

  6. News from the Library: PressDisplay on mobile devices!

    CERN Document Server

    CERN Library

    2013-01-01

    You are probably already using PressDisplay to read newspapers online, but for those of you who are not yet aware of this service, PressDisplay is an online portal where you can browse and read online articles from more than 1,900 newspapers from 95 countries, as soon as they are published.   Whether you are an experienced user or a beginner, we have good news concerning PressDisplay: our license now permits you to download complete newspaper issues to your mobile devices and read them offline wherever you like. To do that, you have to use the mobile app PressReader. Instructions on how to install the PressReader app are available here: For Ipad For Android smartphone For Android tablet For Windows 8 devices For BlackBerry Playbook For Android eReader Your feedback is welcome! Please contact us by e-mail.

  7. Synthesis and application of functional branched macromolecules: From site isolation and energy harvesting to catalysis

    Science.gov (United States)

    Hecht, Stefan

    The symbiosis of our understanding of structure property relationships in many biological macromolecules and our increased ability to prepare large synthetic macromolecules with exquisite structural precision has generated a new area of research where chemistry and materials science join with biology. For example, numerous biological systems utilize the concept of site isolation whereby an active center or catalytic site is encapsulated, frequently within a protein, to afford properties that would not be encountered in the bulk state. The ability of a dendritic shell to encapsulate functional core moieties and to create specific site-isolated nanoenvironments, thereby affecting molecular properties, not only mimics natural systems but affords novel materials with unique characteristics. Furthermore, introduction of donor chromophores at periphery of dendrimers having a central acceptor dye enables spatial and spectral energy concentration at the core. Continuing the effort towards designing bio-inspired macromolecules, this dissertation describes the use of different polymer architectures to encapsulate active sites that have either photophysical, photochemical, or catalytic functions and the evaluation of site isolation using a variety of different techniques. While the first part is mainly concerned with different synthetic approaches towards site isolation of porphyrin moieties, the second part describes the design of light-driven catalytic systems incorporating both light harvesting and energy conversion. The fundamental knowledge that can be gleaned from such investigations has implications that range from the preliminary design of artificial enzymes to the construction of molecular-scale devices. After an overview of dendritically encapsulated functions (Chapter 1) and a brief account of a novel synthetic approach to benzene core dendrimers (Chapter 2), site isolation of porphyrin moieties within dendrimers, their linear structural isomers, and branched star

  8. Surface behavior and kinetic analysis of macromolecules separated from beer in aqueous solution; Biru yori bunrishita kobunshi no suiyoeki deno hyomen kyodo to sono sokudo ronteki kaiseki

    Energy Technology Data Exchange (ETDEWEB)

    Segawa, S.; Mitani, Y. [Sapporo Breweries Ltd., Tokyo (Japan). Brewing Research Lab.; Ogaki, K. [Osaka Univ., Osaka (Japan). Division of Chemical Engineering

    2000-09-10

    In a solution of macromolecules such as proteins that have surface activity, the macromolecules stabilize the foam by adsorbing at the bubble surface. These surface-active macromolecules at the gas/liquid interface lower surface energy. The macromolecules adhere to the gas/liquid interface, and then change their shapes. Hydrophobic groups in the molecule turn to the gas phase and hydrophilic groups turn to the liquid phase. The macromolecules separated from beer were dissolved in an acetic acid buffer solution, and then the surface behavior was speculated by the surface tension change. Their surface tension did not reach a constant value for several seconds, not like the low molecular solutions such as ethanol. The decrease in this surface tension could be kinetically analyzed. The surface tension decreased by the adsorption of macromolecules on the liquid surface, and by the shape changes in the molecule (the extension of molecule at the surface). In the {beta}-casein solution, the surface tension decreased in 2 steps that were more clear than in the beer macromolecule solution. This surface tension decrease is also supposed to show the adsorption of protein molecules and the shape change at the liquid surface. (author)

  9. The chain length of lignan macromolecule from flaxseed hulls is determined by the incorporation of coumaric acid glucosides and ferulic acid glucosides.

    Science.gov (United States)

    Struijs, Karin; Vincken, Jean-Paul; Doeswijk, Timo G; Voragen, Alphons G J; Gruppen, Harry

    2009-01-01

    Lignan macromolecule from flaxseed hulls is composed of secoisolariciresinol diglucoside (SDG) and herbacetin diglucoside (HDG) moieties ester-linked by 3-hydroxy-3-methylglutaric acid (HMGA), and of p-coumaric acid glucoside (CouAG) and ferulic acid glucoside (FeAG) moieties ester-linked directly to SDG. The linker molecule HMGA was found to account for 11% (w/w) of the lignan macromolecule. Based on the extinction coefficients and RP-HPLC data, it was determined that SDG contributes for 62.0% (w/w) to the lignan macromolecule, while CouAG, FeAG, and HDG contribute for 12.2, 9.0, and 5.7% (w/w), respectively. Analysis of fractions of lignan macromolecule showed that the higher the molecular mass, the higher the proportion of SDG was. An inverse relation between the molecular mass and the proportion (%) CouAG+FeAG was found. Together with the structural information of oligomers of lignan macromolecule obtained after partial saponification, it is hypothesized that the amount of CouAG+FeAG present during biosynthesis determines the chain length of lignan macromolecule. Furthermore, the chain length was estimated from a model describing lignan macromolecule based on structural and compositional data. The average chain length of the lignan macromolceule was calculated to be three SDG moieties with CouAG or FeAG at each of the terminal positions, with a variation between one and seven SDG moieties.

  10. Effect of cAMP on macromolecule synthesis in the pathogenic protozoa Trypanosoma cruzi

    Directory of Open Access Journals (Sweden)

    Dilvani O. Santos

    1988-09-01

    Full Text Available Macromolecule synthesis of Trypanosoma cruzi in culture was monitored using radioactive tracers. Cells of different days in culture displayed a preferential incorporation of precursors as follows: 1 day for (³H-thymidine cells; 3 days for (³H-uridine cells, and 4 days for (³H-leucine cells. Autoradiographic studies showed that (³H-thymidine was incorporated in the DNA of both kinetoplast and nucleus in this order. Shifts in the intracellular content of cAMP either by addition of dibutyryl-cAMP or by stimulation of the adenylcyclase by isoproterenol, caused an inhibition in the synthesis of DNA, RNA and proteins. Addition to the T. cruzi cultures of these agents which elevate the intracellular content ofcAMP provoked an interruption of cell proliferation as a result of the impairment of macromolecule synthesis. A discrimination was observed among the stereoisomers of isoproterenol, the L configuration showing to be most active.A síntese de macromoléculas de T. cruzi em cultura foi monitorada usando traçadores radioativos. Células de diferentes dias em cultura mostraram uma incorporação preferencial de precursores comco se seguez: 1 dia para (3H-timidina; 3 dias para (3H-uridina e 4 dias para (3H-leucina. Estudos autoradiográficos mostraram que (3H-leucina. Estudos autoradiográficos mostraram que (3H-timidina foi incorporada no DNA de ambos, cinetoplasto e núcleo, nesta ordem. Alterações no conteúdo intracelular de cAMP seja por adição de dibutiril-cAMP ou por estimulação de adenilciclase por isoproterenol, causav am inibição na síntese de DNA, RNA e proteínas. A adição destes agentes que elevam o conteúdo intracelular de cAMP em culturas de T.cruzi provocou inibição de crescimento, com resultado da síntese macromolecular imperfeita. Foi observada uma discriminação entre os estereoisômeros de isoproterenol, sendo a configuração L, a mais ativa.

  11. A statistical model of macromolecules dynamics for Fluorescence Correlation Spectroscopy data analysis

    Directory of Open Access Journals (Sweden)

    Dmitri Koroliouk

    2016-08-01

    Full Text Available In this paper, we propose a new mathematical model to describe the mechanisms of biological macromolecules interactions. Our model consists of a discrete stationary random sequence given by a solution of difference stochastic equation, characterized by a drift predictive component and by a diffusion term. The relative statistical estimations are very simple and effective, promising to be a good tool for the mathematical description of collective biological reactions. This paper presents the mathematical model and its verification on a simulated data set, obtained on the basis of the well-known Stokes-Einsteinmodel. In particular, we considered several mix of particles of different diffusion coefficient, respectively: D1=10 mm2/sec and D2=100 mm2/sec. The parameters evaluated by this new mathematical model on simulated data show good estimation accuracy, in comparison with the prior parameters used in the simulations. Furthermore, when analyzing the data for the mix of particles with different diffusion coefficient, the proposed model parameters  (regression and  (square variance of the stochastic component have a good discriminative ability for the molar fraction determination.  In this paper, we propose a new mathematical model to describe the mechanisms of biological macromolecules interactions. Our model consists of a discrete stationary random sequence given by a solution of difference stochastic equation, characterized by a drift predictive component and by a diffusion term. The relative statistical estimations are very simple and effective, promising to be a good tool for mathematical description of collective biological reactions. This paper presents the mathematical model and its verification on simulated data set, obtained on the basis of the well-known Stokes-Einsteinmodel. In particular we considered several mix of particles of different diffusion coefficient, respectively: D1=10 mm2/sec and D2=100 mm2/sec. The parameters

  12. Cobalt-mediated radical coupling (CMRC): an unusual route to midchain-functionalized symmetrical macromolecules.

    Science.gov (United States)

    Debuigne, Antoine; Poli, Rinaldo; De Winter, Julien; Laurent, Pascal; Gerbaux, Pascal; Dubois, Philippe; Wathelet, Jean-Paul; Jérôme, Christine; Detrembleur, Christophe

    2010-02-01

    Cobalt-mediated radical coupling (CMRC) is a straightforward approach to the synthesis of symmetrical macromolecules that relies on the addition of 1,3-diene compounds onto polymer precursors preformed by cobalt-mediated radical polymerization (CMRP). Mechanistic features that make this process so efficient for radical polymer coupling are reported here. The mechanism was established on the basis of NMR spectroscopy and MALDI-MS analyses of the coupling product and corroborated by DFT calculations. A key feature of CMRC is the preferential insertion of two diene units in the middle of the chain of the coupling product mainly according to a trans-1,4-addition pathway. The large tolerance of CMRC towards the diene structure is demonstrated and the impact of this new coupling method on macromolecular engineering is discussed, especially for midchain functionalization of polymers. It is worth noting that the interest in CMRC goes beyond the field of polymer chemistry, since it constitutes a novel carbon-carbon bond formation method that could be applied to small organic molecules.

  13. Controlled method of reducing electrophoretic mobility of macromolecules, particles, or cells

    Science.gov (United States)

    Vanalstine, James M. (Inventor)

    1992-01-01

    A method of reducing electrophoretic mobility of macromolecules, particles, cells, and other substances is provided which comprises interacting in a conventional electrophoretic separating procedure, the substances with a polymer-linked affinity compound comprised of a hydrophilic neutral polymer such as polyethylene glycol bound to a second component such as a hydrophobic compound, an immunocompound such as an antibody or antibody active fragment, or a ligand such as a hormone, drug, antigen, or a hapten. The reduction of electrophoretic mobility achieved is directly proportional to the concentration of the polymer-linked affinity compound employed, and such reduction can comprise up to 100 percent for particular particles and cells. The present invention is advantageous in that electrophoretic separation can now be achieved for substances whose native surface charge structure had prevented them from being separated by normal electrophoretic means. Depending on the affinity component utilized, separation can be achieved on the basis of the specific/irreversible, specific/reversible, semi-specific/reversible, relatively nonspecific/reversible, or relatively nonspecific/irreversible ligand-substance interactions.

  14. Rappertk: a versatile engine for discrete restraint-based conformational sampling of macromolecules

    Directory of Open Access Journals (Sweden)

    Karmali Anjum M

    2007-03-01

    Full Text Available Abstract Background Macromolecular structures are modeled by conformational optimization within experimental and knowledge-based restraints. Discrete restraint-based sampling generates high-quality structures within these restraints and facilitates further refinement in a continuous all-atom energy landscape. This approach has been used successfully for protein loop modeling, comparative modeling and electron density fitting in X-ray crystallography. Results Here we present a software toolkit (Rappertk which generalizes discrete restraint-based sampling for use in structural biology. Modular design and multi-layered architecture enables Rappertk to sample conformations of any macromolecule at many levels of detail and within a variety of experimental restraints. Performance against a Cα-tracing benchmark shows that the efficiency has not suffered despite the overhead required by this flexibility. We demonstrate the toolkit's capabilities by building high-quality β-sheets and by introducing restraint-driven sampling. RNA sampling is demonstrated by rebuilding a protein-RNA interface. Ability to construct arbitrary ligands is used in sampling protein-ligand interfaces within electron density. Finally, secondary structure and shape information derived from EM are combined to generate multiple conformations of a protein consistent with the observed density. Conclusion Through its modular design and ease of use, Rappertk enables exploration of a wide variety of interesting avenues in structural biology. This toolkit, with illustrative examples, is freely available to academic users from http://www-cryst.bioc.cam.ac.uk/~swanand/mysite/rtk/index.html.

  15. Glycoxidation of biological macromolecules: a critical approach to halt the menace of glycation.

    Science.gov (United States)

    Ahmad, Saheem; Khan, M Salman; Akhter, Firoz; Khan, Mohd Sajid; Khan, Amir; Ashraf, J M; Pandey, Ramendra Pati; Shahab, Uzma

    2014-11-01

    Glycation is the result of covalent bonding of a free amino group of biological macromolecules with a reducing sugar, which results in the formation of a Schiff base that undergoes rearrangement, dehydration and cyclization to form a more stable Amadori product. The final products of nonenzymatic glycation of biomacromolecules like DNA, proteins and lipids are known as advanced glycation end products (AGEs). AGEs may be generated rapidly or over long times stimulated by distinct triggering mechanisms, thereby accounting for their roles in multiple settings and disease states. Both Schiff base and Amadori glycation products generate free radicals resulting in decline of antioxidant defense mechanisms and can damage cellular organelles and enzymes. This critical review primarily focuses on the mechanistic insight of glycation and the most probable route for the formation of glycation products and their therapeutic interventions. Furthermore, the prevention of glycation reaction using therapeutic drugs such as metformin, pyridoxamine and aminoguanidine (AG) are discussed with special emphasis on the novel concept of the bioconjugation of these drugs like, AG with gold nanoparticles (GNPs). At or above 10 mM concentration, AG is found to be toxic and therefore has serious health concerns, and the study warrants doing this novel bioconjugation of AG with GNPs. This approach might increase the efficacy of the AG at a reduced concentration with low or no toxicity. Using the concept of synthesis of GNPs with abovementioned drugs, it is assumed that toxicity of various drugs which are used at high doses can be minimized more effectively.

  16. Perspective: On the importance of hydrodynamic interactions in the subcellular dynamics of macromolecules

    Science.gov (United States)

    Skolnick, Jeffrey

    2016-01-01

    An outstanding challenge in computational biophysics is the simulation of a living cell at molecular detail. Over the past several years, using Stokesian dynamics, progress has been made in simulating coarse grained molecular models of the cytoplasm. Since macromolecules comprise 20%-40% of the volume of a cell, one would expect that steric interactions dominate macromolecular diffusion. However, the reduction in cellular diffusion rates relative to infinite dilution is due, roughly equally, to steric and hydrodynamic interactions, HI, with nonspecific attractive interactions likely playing rather a minor role. HI not only serve to slow down long time diffusion rates but also cause a considerable reduction in the magnitude of the short time diffusion coefficient relative to that at infinite dilution. More importantly, the long range contribution of the Rotne-Prager-Yamakawa diffusion tensor results in temporal and spatial correlations that persist up to microseconds and for intermolecular distances on the order of protein radii. While HI slow down the bimolecular association rate in the early stages of lipid bilayer formation, they accelerate the rate of large scale assembly of lipid aggregates. This is suggestive of an important role for HI in the self-assembly kinetics of large macromolecular complexes such as tubulin. Since HI are important, questions as to whether continuum models of HI are adequate as well as improved simulation methodologies that will make simulations of more complex cellular processes practical need to be addressed. Nevertheless, the stage is set for the molecular simulations of ever more complex subcellular processes. PMID:27634243

  17. Antioxidant, antimicrobial, cell viability and enzymatic inhibitory of antioxidant polymers as biological macromolecules.

    Science.gov (United States)

    Hashemi Gahruie, Hadi; Niakousari, Mehrdad

    2017-11-01

    Polymeric antioxidants such as Catechinaldehyde Polycondensates, Catechin-acelaldehydepolycondensates, Flavonoid-grafted chitosan fibers, Ferulate hydrogel, Dextran ferulate hydrogel, Starch-quercetin conjugate, Gallic acid- and Caffeic acid-functionalized chitosan, Gallic acid - chitosan conjugate, Poly(rutin), Gallic acid grafted chitosan, Dextran-Catechin Conjugate belong to biological macromolecules. These kinds of compounds have stronger antioxidant potential and pharmacokinetic activities, as compared to similar low molecular weight preservatives. Most of these compounds sources are either antioxidants with low molecules polymerization, or polymers conjugation such as synthetic or natural preservatives. Additives are well known as being an important ingredient of food products due to their strong preservative potential. Many researchers and industries attempt to find synthesize materials with the same antioxidant potential and higher stability than the similar compounds with low molecular weight. Recently, macromolecular antioxidants have received wide attention as food additives and dietary supplements in functional foods. It seems that the main usage of these compounds is in the food packaging industry. Most of these compounds have strong antioxidant, antimicrobial, cell viability and enzymatic inhibitory properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Coupling of the fusion and budding of giant phospholipid vesicles containing macromolecules.

    Science.gov (United States)

    Terasawa, Hidetoshi; Nishimura, Kazuya; Suzuki, Hiroaki; Matsuura, Tomoaki; Yomo, Tetsuya

    2012-04-17

    Mechanisms that enabled primitive cell membranes to self-reproduce have been discussed based on the physicochemical properties of fatty acids; however, there must be a transition to modern cell membranes composed of phospholipids [Budin I, Szostak JW (2011) Proc Natl Acad Sci USA 108:5249-5254]. Thus, a growth-division mechanism of membranes that does not depend on the chemical nature of amphiphilic molecules must have existed. Here, we show that giant unilamellar vesicles composed of phospholipids can undergo the coupled process of fusion and budding transformation, which mimics cell growth and division. After gaining excess membrane by electrofusion, giant vesicles spontaneously transform into the budded shape only when they contain macromolecules (polymers) inside their aqueous core. This process is a result of the vesicle maximizing the translational entropy of the encapsulated polymers (depletion volume effect). Because the cell is a lipid membrane bag containing highly concentrated biopolymers, this coupling process that is induced by physical and nonspecific interactions may have a general importance in the self-reproduction of the early cellular compartments.

  19. Preparation, characterization and application of a novel biodegradable macromolecule: carboxymethyl zein.

    Science.gov (United States)

    Yin, Huayue; Lu, Tao; Liu, Li; Lu, Chuanhua

    2015-01-01

    Zein, a naturally biocompatible and biodegradable macromolecule, is widely used as plastic film material; however, the poor water solubility limits its other applications. In this study, we aimed to obtain carboxymethyl zein (CM-zein) by modifying it with sodium monochloroacetate in weakly basic environment. CM-zein showed a new FTIR peak of C-O-C bond at 1080 cm(-1), with a new signal region appearing at 4.0-4.05 ppm that assigned to the protons of the CH2 group from a carboxymethyl on (1)H NMR and a Tg of 168.0 °C by thermal analysis. Compared with the -12.3 mV of zeta potential of unmodified zein, CM-zein increased it significantly to -23.9 mV as a consequence of carboxymethylation. 5-Fluorouracil (5-FU), a model drug used in CM-zein-based tablet, was rarely detected in 0.1 mol/L HCl (pH 1.0) but it was released massively and quickly in phosphates buffer (pH 6.8) in vitro assays. The unmodified zein-based tablet illustrated much lower release level in these two fluids. Furthermore, the pharmacokinetic study of rats showed that CM-zein released 5-FU in intestine but not in stomach after dissolving. These findings indicated that CM-zein has the potential to be used for enteric preparation as a novel pH-selective biomaterial.

  20. Introduction to 3D reconstruction of macromolecules using single particle electron microscopy

    Institute of Scientific and Technical Information of China (English)

    Oscar LLORCA

    2005-01-01

    Single-particle electron microscopy has now reached maturity, becoming a commonly used method in the examination ofmacromolecular structure. Using a small amount of purified protein, isolated molecules are observed under the electron microscope and the data collected can be averaged into a 3D reconstruction.Single-particle electron microscopy is an appropriate tool for the analysis of proteins that can only be obtained in modest quantities, like many of the large complexes currently of interest in biomedicine. Whilst the use of electron microscopy expands, new methods are being developed and improved to deal with further challenges, such as reaching higher resolutions and the combination of information at different levels of structural detail. More importantly, present methodology is still not robust enough when studying certain "tricky" proteins like those displaying extensive conformational flexibility and a great deal of user expertise is required, posing a threat to the consistency of the final structure. This mini review describes a brief outline of the methods currently used in the 3D analysis of macromolecules using single-particle electron microscopy, intended for those first approaching this field. A summary of methods, techniques, software, and some recent work is presented. The spectacular improvements to the technique in recent years, its advantages and limitations compared to other structural methods,and its future developments are discussed.

  1. Correction: Membrane-active macromolecules resensitize NDM-1 gram-negative clinical isolates to tetracycline antibiotics.

    Directory of Open Access Journals (Sweden)

    Divakara S S M Uppu

    Full Text Available Gram-negative 'superbugs' such as New Delhi metallo-beta-lactamase-1 (blaNDM-1 producing pathogens have become world's major public health threats. Development of molecular strategies that can rehabilitate the 'old antibiotics' and halt the antibiotic resistance is a promising approach to target them. We report membrane-active macromolecules (MAMsthat restore the antibacterial efficacy (enhancement by >80-1250 fold of tetracycline antibiotics towards blaNDM-1 Klebsiella pneumonia and blaNDM-1 Escherichia coli clinical isolates.Organismic studies showed that bacteria had an increased and faster uptake of tetracyclinein the presence of MAMs which is attributed to the mechanism of re-sensitization. Moreover,bacteria did not develop resistance to MAMs and MAMs stalled the development of bacterial resistance to tetracycline. MAMs displayed membrane-active properties such as dissipation of membrane potential and membrane-permeabilization that enabled higher uptake of tetracycline in bacteria. In-vivo toxicity studies displayed good safety profiles and preliminary in-vivo antibacterial efficacy studies showed that mice treated with MAMs in combination with antibiotics had significantly decreased bacterial burden compared to the untreated mice. This report of re-instating the efficacy of the antibiotics towards blaNDM-1 pathogens using membrane-active molecules advocates their potential for synergistic co-delivery of antibiotics to combat Gram-negative superbugs.

  2. Membrane-active macromolecules resensitize NDM-1 gram-negative clinical isolates to tetracycline antibiotics.

    Directory of Open Access Journals (Sweden)

    Divakara S S M Uppu

    Full Text Available Gram-negative 'superbugs' such as New Delhi metallo-beta-lactamase-1 (blaNDM-1 producing pathogens have become world's major public health threats. Development of molecular strategies that can rehabilitate the 'old antibiotics' and halt the antibiotic resistance is a promising approach to target them. We report membrane-active macromolecules (MAMs that restore the antibacterial efficacy (enhancement by >80-1250 fold of tetracycline antibiotics towards blaNDM-1 Klebsiella pneumonia and blaNDM-1 Escherichia coli clinical isolates. Organismic studies showed that bacteria had an increased and faster uptake of tetracycline in the presence of MAMs which is attributed to the mechanism of re-sensitization. Moreover, bacteria did not develop resistance to MAMs and MAMs stalled the development of bacterial resistance to tetracycline. MAMs displayed membrane-active properties such as dissipation of membrane potential and membrane-permeabilization that enabled higher uptake of tetracycline in bacteria. In-vivo toxicity studies displayed good safety profiles and preliminary in-vivo antibacterial efficacy studies showed that mice treated with MAMs in combination with antibiotics had significantly decreased bacterial burden compared to the untreated mice. This report of re-instating the efficacy of the antibiotics towards blaNDM-1 pathogens using membrane-active molecules advocates their potential for synergistic co-delivery of antibiotics to combat Gram-negative superbugs.

  3. Characterization of magnetically oriented phospholipid micelles for measurement of dipolar couplings in macromolecules.

    Science.gov (United States)

    Ottiger, M; Bax, A

    1998-10-01

    Weak alignment of solute molecules with the magnetic field can be achieved in a dilute liquid crystalline medium, consisting of an aqueous mixture of dimyristoyl-phosphatidylcholine (DMPC) and dihexanoyl-phosphatidylcholine (DHPC). For a certain range of molar ratios, DMPC and DHPC can form large, disc-shaped particles, commonly referred to as bicelles (Sanders and Schwonek, 1992), which cooperatively align in the magnetic field and induce a small degree of alignment on asymmetrically shaped solute molecules. As a result, dipolar couplings between pairs of 1H, 13C or 15N nuclei are no longer averaged to zero by rotational diffusion and they can be readily measured, providing valuable structural information. The stability of these liquid crystals and the degree of alignment of the solute molecules depend strongly on experimental variables such as the DMPC:DHPC ratio and concentration, the preparation protocol of the DMPC/DHPC mixtures, as well as salt, temperature, and pH. The lower temperature limit for which the liquid crystalline phase is stable can be reduced to 20 degrees C by using a ternary mixture of DHPC, DMPC, and 1-myristoyl-2-myristoleoyl-sn-glycero-3-phosphocholine, or a binary mixture of DHPC and ditridecanoyl-phosphatidylcholine. These issues are discussed, with an emphasis on the use of the medium for obtaining weak alignment of biological macromolecules.

  4. Characterization of magnetically oriented phospholipid micelles for measurement of dipolar couplings in macromolecules

    Energy Technology Data Exchange (ETDEWEB)

    Ottiger, Marcel; Bax, Ad [National Institutes of Health, Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases (United States)

    1998-10-15

    Weak alignment of solute molecules with the magnetic field can be achieved in a dilute liquid crystalline medium, consisting of an aqueous mixture of dimyristoyl-phosphatidylcholine (DMPC) and dihexanoyl-phosphatidylcholine (DHPC). For a certain range of molar ratios, DMPC and DHPC can form large, disc-shaped particles, commonly referred to as bicelles (Sanders and Schwonek, 1992), which cooperatively align in the magnetic field and induce a small degree of alignment on asymmetrically shaped solute molecules. As a result, dipolar couplings between pairs of {sup 1}H, {sup 13}C or {sup 15}N nuclei are no longer averaged to zero by rotational diffusion and they can be readily measured, providing valuable structural information. The stability of these liquid crystals and the degree of alignment of the solute molecules depend strongly on experimental variables such as the DMPC:DHPC ratio and concentration, the preparation protocol of the DMPC/DHPC mixtures, as well as salt, temperature, and pH. The lower temperature limit for which the liquid crystalline phase is stable can be reduced to 20 deg. C by using a ternary mixture of DHPC, DMPC, and 1-myristoyl-2-myristoleoyl-sn-glycero-3-phosphocholine, or a binary mixture of DHPC and ditridecanoyl-phosphatidylcholine. These issues are discussed, with an emphasis on the use of the medium for obtaining weak alignment of biological macromolecules.

  5. Suspendable macromolecules are responsible for ice nucleation activity of birch and conifer pollen

    Directory of Open Access Journals (Sweden)

    B. G. Pummer

    2012-03-01

    Full Text Available The ice nucleation of bioaerosols (bacteria, pollen, spores, etc. is a topic of growing interest, since their impact on ice cloud formation and thus on radiative forcing, an important parameter in global climate, is not yet fully understood. Here we show that pollen of different species strongly differ in their ice nucleation behaviour. The average freezing temperatures in laboratory experiments range from 240 to 255 K. As the most efficient nuclei (silver birch, Scots pine and common juniper pollen have a distribution area up to the Northern timberline, their ice nucleation activity might be a cryoprotective mechanism. Far more intriguingly, it has turned out that water, which has been in contact with pollen and then been separated from the bodies, nucleates as good as the pollen grains themselves. The ice nuclei have to be easily-suspendable macromolecules located on the pollen. Once extracted, they can be distributed further through the atmosphere than the heavy pollen grains and so presumably augment the impact of pollen on ice cloud formation even in the upper troposphere. Our experiments lead to the conclusion that pollen ice nuclei, in contrast to bacterial and fungal ice nucleating proteins, are non-proteinaceous compounds.

  6. Electron Microscopy and Image Processing: Essential Tools for Structural Analysis of Macromolecules.

    Science.gov (United States)

    Belnap, David M

    2015-11-02

    Macromolecular electron microscopy typically depicts the structures of macromolecular complexes ranging from ∼200 kDa to hundreds of MDa. The amount of specimen required, a few micrograms, is typically 100 to 1000 times less than needed for X-ray crystallography or nuclear magnetic resonance spectroscopy. Micrographs of frozen-hydrated (cryogenic) specimens portray native structures, but the original images are noisy. Computational averaging reduces noise, and three-dimensional reconstructions are calculated by combining different views of free-standing particles ("single-particle analysis"). Electron crystallography is used to characterize two-dimensional arrays of membrane proteins and very small three-dimensional crystals. Under favorable circumstances, near-atomic resolutions are achieved. For structures at somewhat lower resolution, pseudo-atomic models are obtained by fitting high-resolution components into the density. Time-resolved experiments describe dynamic processes. Electron tomography allows reconstruction of pleiomorphic complexes and subcellular structures and modeling of macromolecules in their cellular context. Significant information is also obtained from metal-coated and dehydrated specimens. Copyright © 2015 John Wiley & Sons, Inc.

  7. Oxidative damage to macromolecules in human Parkinson disease and the rotenone model.

    Science.gov (United States)

    Sanders, Laurie H; Greenamyre, J Timothy

    2013-09-01

    Parkinson disease (PD), the most common neurodegenerative movement disorder, is associated with selective degeneration of nigrostriatal dopamine neurons. Although the underlying mechanisms contributing to neurodegeneration in PD seem to be multifactorial, mitochondrial impairment and oxidative stress are widely considered to be central to many forms of the disease. Whether oxidative stress is a cause or a consequence of dopaminergic death, there is substantial evidence for oxidative stress both in human PD patients and in animal models of PD, especially using rotenone, a complex I inhibitor. There are many indices of oxidative stress, but this review covers the recent evidence for oxidative damage to nucleic acids, lipids, and proteins in both the brain and the peripheral tissues in human PD and in the rotenone model. Limitations of the existing literature and future perspectives are discussed. Understanding how each particular macromolecule is damaged by oxidative stress and the interplay of secondary damage to other biomolecules may help us design better targets for the treatment of PD. Copyright © 2013 Elsevier Inc. All rights reserved.

  8. Film Self-Assembly of Oppositely Charged Macromolecules Triggered by Electrochemistry through a Morphogenic Approach.

    Science.gov (United States)

    Dochter, Alexandre; Garnier, Tony; Pardieu, Elodie; Chau, Nguyet Trang Thanh; Maerten, Clément; Senger, Bernard; Schaaf, Pierre; Jierry, Loïc; Boulmedais, Fouzia

    2015-09-22

    The development of new surface functionalization methods that are easy to use, versatile, and allow local deposition represents a real scientific challenge. Overcoming this challenge, we present here a one-pot process that consists in self-assembling, by electrochemistry on an electrode, films made of oppositely charged macromolecules. This method relies on a charge-shifting polyanion, dimethylmaleic-modified poly(allylamine) (PAHd), that undergoes hydrolysis at acidic pH, leading to an overall switching of its charge. When a mixture of the two polyanions, PAHd and poly(styrenesulfonate) (PSS), is placed in contact with an electrode, where the pH is decreased locally by electrochemistry, the transformation of PAHd into a polycation (PAH) leads to the continuous self-assembly of a nanometric PAH/PSS film by electrostatic interactions. The pH decrease is obtained by the electrochemical oxidation of hydroquinone, which produces protons locally over nanometric distances. Using a negatively charged enzyme, alkaline phosphatase (AP), instead of PSS, this one-pot process allows the creation of enzymatically active films. Under mild conditions, self-assembled PAH/AP films have an enzymatic activity which is adjustable simply by controlling the self-assembly time. The selective functionalization of microelectrode arrays by PAH/AP was achieved, opening the route toward miniaturized biosensors.

  9. A new force-extension formula for stretched macromolecules and polymers based on the Ising model

    Science.gov (United States)

    Chan, Yue; Haverkamp, Richard G.

    2016-12-01

    In this paper, we derive a new force-extension formula for stretched macromolecules and homogeneous polymer matrices. The Ising model arising from paramagnetism is employed, where the magnetic force is replaced by the external force, and the resistance energy is addressed in this model instead of the usual persistent length arising from the freely jointed chain and worm-like chain models. While the force-extension formula reveals the distinctive stretching features for stretched polymers, the resistance energy is found to increase almost linearly with the external force for our two polysaccharides stretching examples with and without ring conformational changes. In particular, a jump in the resistance energy which is caused by a conformational transition is investigated, and the gap between the jump determines the energy barrier between two conformational configurations. Our theoretical model matches well with experimental results undergoing no and single conformational transitions, and a Monte Carlo simulation has also been performed to ensure the correctness of the resistance energy. This technique might also be employed to determine the binding energy from other causes during molecular stretching and provide vital information for further theoretical investigations.

  10. Quantum propagation of electronic excitations in macromolecules: A computationally efficient multiscale approach

    Science.gov (United States)

    Schneider, E.; a Beccara, S.; Mascherpa, F.; Faccioli, P.

    2016-07-01

    We introduce a theoretical approach to study the quantum-dissipative dynamics of electronic excitations in macromolecules, which enables to perform calculations in large systems and cover long-time intervals. All the parameters of the underlying microscopic Hamiltonian are obtained from ab initio electronic structure calculations, ensuring chemical detail. In the short-time regime, the theory is solvable using a diagrammatic perturbation theory, enabling analytic insight. To compute the time evolution of the density matrix at intermediate times, typically ≲ps , we develop a Monte Carlo algorithm free from any sign or phase problem, hence computationally efficient. Finally, the dynamics in the long-time and large-distance limit can be studied combining the microscopic calculations with renormalization group techniques to define a rigorous low-resolution effective theory. We benchmark our Monte Carlo algorithm against the results obtained in perturbation theory and using a semiclassical nonperturbative scheme. Then, we apply it to compute the intrachain charge mobility in a realistic conjugated polymer.

  11. Electric double layer and electrokinetic potential of pectic macromolecules in sugar beet

    Directory of Open Access Journals (Sweden)

    Kuljanin Tatjana A.

    2008-01-01

    Full Text Available Electrokinetic potential is an important property of colloidal particles and, regarding the fact that it is a well defined and easily measurable property, it is considered to be a permanent characteristic of a particular colloidal system. In fact, it is a measure of electrokinetic charge that surrounds the colloidal particle in a solution and is in direct proportion with the mobility of particles in an electric field. Gouy-Chapman-Stern-Graham's model of electric double layer was adopted and it was proven experimentally that the addition of Cu++ ions to sugar beet pectin caused a reduction in the negative electrokinetic potential proportional to the increase of Cu++ concentration. Higher Cu++ concentrations increased the proportion of cation specific adsorption (Cu++ and H+ with regard to electrostatic Coulombic forces. Consequently, there is a shift in the shear plane between the fixed and diffuse layers directed towards the diffuse layer, i.e. towards its compression and decrease in the electrokinetic potential or even charge inversion of pectin macromolecules.

  12. Role of macromolecules in the safety of use of body wash cosmetics.

    Science.gov (United States)

    Bujak, Tomasz; Wasilewski, Tomasz; Nizioł-Łukaszewska, Zofia

    2015-11-01

    One of the most challenging problems related to the use of surfactants in body wash cosmetics is their potential to cause skin irritations. Surfactants can bind with proteins, remove lipids from the epidermal surface, contribute to the disorganization of liquid crystal structures in the intercellular lipids, and interact with living skin cells. These processes can lead to skin irritations and allergic reactions, and impair the epidermal barrier function. The present study is an attempt to assess the effect of polymers and hydrolysed proteins present in the formulations of model body wash cosmetics on product properties. Special attention was given to the safety of use of this product type. The study examined three macromolecules: polyvinylpyrrolidone (PVP), hydrolysed wheat protein (HWP) and polyvinylpyrrolidone/hydrolysed wheat protein crosspolymer (PVP/HWP). The addition of the substances under study was found to improve the foaming properties of body wash cosmetics, increase their stability during storage, and contribute significantly to an improvement in the safety of product use by reducing the irritant potential. The strongest ability to reduce the skin irritation potential was determined for the formula enriched with the PVP/HWP crosspolymer.

  13. Upgraded ESRF BM29 beamline for SAXS on macromolecules in solution.

    Science.gov (United States)

    Pernot, Petra; Round, Adam; Barrett, Ray; De Maria Antolinos, Alejandro; Gobbo, Alexandre; Gordon, Elspeth; Huet, Julien; Kieffer, Jerôme; Lentini, Mario; Mattenet, Muriel; Morawe, Christian; Mueller-Dieckmann, Christoph; Ohlsson, Staffan; Schmid, Werner; Surr, John; Theveneau, Pascal; Zerrad, Louiza; McSweeney, Sean

    2013-07-01

    Small-angle X-ray scattering (SAXS) measurements of proteins in solution are becoming increasingly popular with biochemists and structural biologists owing to the presence of dedicated high-throughput beamlines at synchrotron sources. As part of the ESRF Upgrade program a dedicated instrument for performing SAXS from biological macromolecules in solution (BioSAXS) has been installed at the renovated BM29 location. The optics hutch has been equipped with new optical components of which the two principal elements are a fixed-exit double multilayer monochromator and a 1.1 m-long toroidal mirror. These new dedicated optics give improved beam characteristics (compared with the previous set-up on ID14-3) regarding the energy tunability, flux and focusing at the detector plane leading to reduced parasitic scattering and an extended s-range. User experiments on the beamline have been successfully carried out since June 2012. A description of the new BioSAXS beamline and the set-up characteristics are presented together with examples of obtained data.

  14. Detection of Macromolecules in Desert Cyanobacteria Mixed with a Lunar Mineral Analogue After Space Simulations

    Science.gov (United States)

    Baqué, Mickael; Verseux, Cyprien; Rabbow, Elke; de Vera, Jean-Pierre Paul; Billi, Daniela

    2014-09-01

    In the context of future exposure missions in Low Earth Orbit and possibly on the Moon, two desert strains of the cyanobacterium Chroococcidiopsis, strains CCMEE 029 and 057, mixed or not with a lunar mineral analogue, were exposed to fractionated fluencies of UVC and polychromatic UV (200-400 nm) and to space vacuum. These experiments were carried out within the framework of the BIOMEX (BIOlogy and Mars EXperiment) project, which aims at broadening our knowledge of mineral-microorganism interaction and the stability/degradation of their macromolecules when exposed to space and simulated Martian conditions. The presence of mineral analogues provided a protective effect, preserving survivability and integrity of DNA and photosynthetic pigments, as revealed by testing colony-forming abilities, performing PCR-based assays and using confocal laser scanning microscopy. In particular, DNA and pigments were still detectable after 500 kJ/m2 of polychromatic UV and space vacuum (10-4 Pa), corresponding to conditions expected during one-year exposure in Low Earth Orbit on board the EXPOSE-R2 platform in the presence of 0.1 % Neutral Density (ND) filter. After exposure to high UV fluencies (800 MJ/m2) in the presence of minerals, however, altered fluorescence emission spectrum of the photosynthetic pigments were detected, whereas DNA was still amplified by PCR. The present paper considers the implications of such findings for the detection of biosignatures in extraterrestrial conditions and for putative future lunar missions.

  15. New beamline dedicated to solution scattering from biological macromolecules at the ESRF

    Energy Technology Data Exchange (ETDEWEB)

    Pernot, P; Theveneau, P; Giraud, T; Fernandes, R Nogueira; Nurizzo, D; Spruce, D; Surr, J; McSweeney, S [ESRF, BP 220, Grenoble (France); Round, A; Felisaz, F; Foedinger, L; Gobbo, A; Huet, J; Villard, C; Cipriani, F, E-mail: rejma@esrf.f, E-mail: around@embl.f [EMBL Grenoble, BP 181, Grenoble (France)

    2010-10-01

    The new bio-SAXS beamline (ID14-3 at the ESRF, Grenoble, France) is dedicated exclusively to small-angle scattering experiments of biological macromolecules in solution and has been in user operation since November 2008. Originally a protein crystallography beamline, ID14-3 was refurbished, still as a part of the ESRF Structural Biology group, with the main aim to provide a facility with 'quick and easy' access to satisfy rapidly growing demands from crystallographers, biochemists and structural biologists. The beamline allows manual and automatic sample loading/unloading, data collection, processing (conversion of a 2D image to a normalized 1D X-ray scattering profile) and analysis. The users obtain on-line standard data concerning the size (radius of gyration, maximum dimension and volume) and molecular weight of samples which allow on-the fly ab-inito shape reconstruction in order to provide feedback enabling the data collection strategies to be optimized. Automation of sample loading is incorporated on the beamline using a device constructed in collaboration between the EMBL (Grenoble and Hamburg outstations) and the ESRF. Semi/automated data analysis is implemented following the model of the SAXS facility at X33, EMBL Hamburg. This paper describes the bio-SAXS beamline and set-up characteristics together with the examples of user data obtained.

  16. Electrospun ECM macromolecules as biomimetic scaffold for regenerative medicine: challenges for preserving conformation and bioactivity

    Directory of Open Access Journals (Sweden)

    Chiara Emma Campiglio

    2017-05-01

    Full Text Available The extracellular matrix (ECM, the physiological scaffold for cells in vivo, provides structural support to cells and guaranties tissue integrity. At the same time, however, it represents an extremely complex and finely tuned signaling environment that contributes in regulating tissue homeostasis and repair. ECM can bind, release and activate signaling molecules and also modulate cell reaction to soluble factors. Cell-ECM interactions, as a result, are recognized to be critical for physiological wound healing, and consequently in guiding regeneration. Due to its complexity, mimicking ECM chemistry and architecture appears a straightforward strategy to exploit the benefits of a biologically recognizable and cell-instructive environment. As ECM consists primarily of sub-micrometric fibers, electrospinning, a simple and versatile technique, has attracted the majority efforts aimed at reprocessing of biologically occurring molecules. However, the ability to trigger specific cellular behavior is likely to depend on both the chemical and conformational properties of biological molecules. As a consequence, when ECM macromolecules are electrospun, investigating the effect of processing on their structure, and the extent to which their potential in directing cellular behavior is preserved, appears crucial. In this perspective, this review explores the electrospinning of ECM molecules specifically focusing on the effect of processing on polymer structure and on in vitro or in vivo experiments designed to confirm the maintenance of their instructive role.

  17. Electronic method for autofluorography of macromolecules on two-D matrices

    Science.gov (United States)

    Davidson, Jackson B.; Case, Arthur L.

    1983-01-01

    A method for detecting, localizing, and quantifying macromolecules contained in a two-dimensional matrix is provided which employs a television-based position sensitive detection system. A molecule-containing matrix may be produced by conventional means to produce spots of light at the molecule locations which are detected by the television system. The matrix, such as a gel matrix, is exposed to an electronic camera system including an image-intensifier and secondary electron conduction camera capable of light integrating times of many minutes. A light image stored in the form of a charge image on the camera tube target is scanned by conventional television techniques, digitized, and stored in a digital memory. Intensity of any point on the image may be determined from the number at the memory address of the point. The entire image may be displayed on a television monitor for inspection and photographing or individual spots may be analyzed through selected readout of the memory locations. Compared to conventional film exposure methods, the exposure time may be reduced 100-1000 times.

  18. Microfiberoptic fluorescence photobleaching reveals size-dependent macromolecule diffusion in extracellular space deep in brain.

    Science.gov (United States)

    Zador, Zsolt; Magzoub, Mazin; Jin, Songwan; Manley, Geoffrey T; Papadopoulos, Marios C; Verkman, A S

    2008-03-01

    Diffusion in brain extracellular space (ECS) is important for nonsynaptic intercellular communication, extracellular ionic buffering, and delivery of drugs and metabolites. We measured macromolecular diffusion in normally light-inaccessible regions of mouse brain by microfiberoptic epifluorescence photobleaching, in which a fiberoptic with a micron-size tip is introduced deep in brain tissue. In brain cortex, the diffusion of a noninteracting molecule [fluorescein isothiocyanate (FITC)-dextran, 70 kDa] was slowed 4.5 +/- 0.5-fold compared with its diffusion in water (D(o)/D), and was depth-independent down to 800 microm from the brain surface. Diffusion was significantly accelerated (D(o)/D of 2.9+/-0.3) in mice lacking the glial water channel aquaporin-4. FITC-dextran diffusion varied greatly in different regions of brain, with D(o)/D of 3.5 +/- 0.3 in hippocampus and 7.4 +/- 0.3 in thalamus. Remarkably, D(o)/D in deep brain was strongly dependent on solute size, whereas diffusion in cortex changed little with solute size. Mathematical modeling of ECS diffusion required nonuniform ECS dimensions in deep brain, which we call "heterometricity," to account for the size-dependent diffusion. Our results provide the first data on molecular diffusion in ECS deep in brain in vivo and demonstrate previously unrecognized hindrance and heterometricity for diffusion of large macromolecules in deep brain.

  19. DESIGN OF A BUSH PRESSING MACHINE FOR PUMPS

    Directory of Open Access Journals (Sweden)

    AMITH KALEKAR

    2015-03-01

    Full Text Available Bearings are among the most important components in the vast majority of machines. Bush is an independent plain bearing that is inserted into a housing to provide a bearing surface for rotary applications. Bushes are fitted either by pressing for less interference or by heating the frame or cooling the bushes using dry ice or liquid nitrogen. In the present case, due to uneven cooling using liquid nitrogen or other problems, bush is not fitting easily in some of the pump frames. So there is a need of a bush pressing machine. A ‘C’ frame type hydraulic bush pressing machine is designed in this work.

  20. Mannes of Forging and Perspectives of Knuckle Joint Presses Modernization

    Directory of Open Access Journals (Sweden)

    A. A. Antsifirov

    2014-01-01

    Full Text Available The article raises an issue to enhance technological forging capabilities on the known knuckle joint presses. It provides an illustrated overview of main design types of presses with crank-knuckle, toggle-knuckle, and knuckle joint mechanisms. The article also shows the advantages of the modernization way and improvement just of the active press equipment in terms of quality-to-price ratio, for example, as compared to the similar new foreign press equipment.It gives an overview of features, which provide forging processes owing to kinetic energy accumulated with the moving parts of the known designs of the knuckle joint presses depending on the drive actuating mechanism. Focused attention is drawn to forging on the knuckle joint presses for a time of contact with a work piece to be comparable with the duration of the work piece deformation process on hydraulic forging hammers. This allows us to forge thin-wall products with process automation compared to the forging hammers.Analysis of accumulating processes of kinetic energy by the moving parts of the knuckle joint presses has shown that presses driven by hydraulic cylinders or two screw hydraulic cylinder are the most optimal for technological operations as evidenced by references to domestic and foreign invention certificates and patents. The article presents disadvantages of forging on presses with hydraulic or pneumatic drive. It is a dependence of the deformation force, caused, mainly, by a force of the drive cylinder. The article gives linear movement rate quantities of press moving members depending on the drives of the actuating mechanism. Based on the above analysis of the features to manufacture work pieces on the knuckle joint presses, the article gives the rationale for the relevance of forging in a short period of time, provided that the moving parts of the press accumulate the required kinetic energy. This can be achieved only through modernization and improvement of forging

  1. Combining Two Methods of Sequence Definition in a Convergent Approach: Scalable Synthesis of Highly Defined and Multifunctionalized Macromolecules.

    Science.gov (United States)

    Solleder, Susanne C; Martens, Steven; Espeel, Pieter; Du Prez, Filip; Meier, Michael A R

    2017-08-23

    The straightforward convergent synthesis of sequence-defined and multifunctionalized macromolecules is described herein. The first combination of two efficient approaches for the synthesis of sequence-defined macromolecules is reported: thiolactone chemistry and the Passerini three-component reaction (P-3CR). The thiolactone moiety was used as protecting group for the thiol, allowing the synthesis of a library of sequence-defined α,ω-functionalized building blocks. These building blocks were subsequently efficiently coupled to oligomers with carboxylic acid functionalities in a P-3CR. Thus, larger oligomers with molecular weights of up to 4629.73 g mol(-1) were obtained in gram quantities in a convergent approach along with the introduction of independently selectable side chains (up to 15), thus clearly demonstrating the high versatility and the efficiency of the reported approach. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  2. Coil-globule transition of macromolecules in mixed solvent: A semi-grand canonical molecular dynamics approach

    Science.gov (United States)

    Mukherji, Debashish; Kremer, Kurt

    2014-03-01

    Conformational transition of macromolecules in mixed solvents are intimately linked to large local concentration fluctuations of solvent components. The numerical studies in the field are limited to the closed boundary schemes, which, however, suffer from severe system size effects. To overcome this discrepancy, we have developed a semi-grand canonical molecular dynamics scheme for complex fluids. Our method makes use of the adaptive resolution scheme (AdResS) with a metropolis particle exchange criterion. In AdResS, an all-atom region, containing macromolecule, is coupled to a coarse-grained (CG) reservoir. The semi-grand canonical particle exchange is performed in the CG region. As the applications of the method, we study the concentration driven reentrant collapse and swelling transition of poly(N-isopropylacrylamide) (PNIPAm) and poly(N,N-diethylacrylamide) (PDEAm) in aqueous methanol and demonstrate the role of the delicate interplay of the different intermolecular interactions.

  3. Solubility and stability of curcumin in solutions containing alginate and other viscosity modifying macromolecules. Studies of curcumin and curcuminoids. XXX.

    Science.gov (United States)

    Tønnesen, H Hjorth

    2006-08-01

    The solubility, chemical- and photochemical stability of curcumin in aqueous solutions containing alginate, gelatin or other viscosity modifying macromolecules have been investigated in order to obtain an alternative to the use of surfactants or cyclodextrins. The solubility of curcumin in aqueous solution at pH 5 increased by a factor > or = 10(4) in the presence of 0.5% (w/v) alginate (various qualities) or gelatin compared to plain buffer, while propylene glycol alginate ester, cesapectin and sodium carboxymethyl cellulose did not have a similar solubilizing effect. The solubilization was slightly influenced by pH, ionic strength and type and concentration of buffer salts. The macromolecules do, however, not stabilize towards hydrolytic- or photolytic degradation of curcumin.

  4. Digital X-ray camera for quality evaluation three-dimensional topographic reconstruction of single crystals of biological macromolecules

    Science.gov (United States)

    Borgstahl, Gloria (Inventor); Lovelace, Jeff (Inventor); Snell, Edward Holmes (Inventor); Bellamy, Henry (Inventor)

    2008-01-01

    The present invention provides a digital topography imaging system for determining the crystalline structure of a biological macromolecule, wherein the system employs a charge coupled device (CCD) camera with antiblooming circuitry to directly convert x-ray signals to electrical signals without the use of phosphor and measures reflection profiles from the x-ray emitting source after x-rays are passed through a sample. Methods for using said system are also provided.

  5. [The contribution of magnetic resonance spectroscopy to the classification of high grade gliomas. The predictive value of macromolecules].

    Science.gov (United States)

    Martínez-Bisbal, M C; Celda-Muñoz, B; Martí-Bonmatí, L; Ferrer-Ripollés, P; Revert-Ventura, A J; Piquer-Belloch, J; Mollá-Olmos, E; Arana-Fernández de Moya, E; Dosdá-Muñoz, R

    1H MRS allows the study of metabolite concentration changes in intracranial tumours, relating them, more or less successfully, to the histological type and grade of the tumour. To analyse the patterns which are useful for classifying the grades of cerebral gliomas by means of various ratios obtained using 1H MRS with two echo times (ET), with and without water suppression, paying special attention to the macromolecules. We studied 8 gliomas (1 grade II, 2 grade III and 5 grade IV) with single volume 1H MRS at ET 31 ms (8/8) and 136 ms (7/8). The intensities of the metabolites, including macromolecules (MMA, 0.9 ppm; MMB, 1.3 ppm), were normalised to water signal intensity for ET 31, to Cr at ET 31 and 136 ms and NAA/Cho for both ET and the ratio MMA/MMB at ET 31. There were significant differences between the three grades on the ratios MMA/MMB (p= 0.000) with descent of the MMA/MMB coefficient as the grade increases, and NNA/Cho at ET 136 (p= 0.018). We found an inverse relationship between the quantity in mI and the increase in grade. No macromolecules were found at ET 136 in any of the tumours of grade II or III. The spectra of gliomas with ET 31 showed macromolecules around 0.9 and 1.3 ppm with different relative ratios for each tumour grade. The ET 136 spectra informs about the content of NNA and Cho. Apart from the increase in MMB (0.9 ppm), with short ET the higher grades showed lower content of mI. The study of gliomas using 1H MRS with ET 31 and 136 ms contributes to the diagnosis of the grade of tumour.

  6. A Redox-Activatable Fluorescent Sensor for the High-Throughput Quantification of Cytosolic Delivery of Macromolecules.

    Science.gov (United States)

    Wang, Zhaohui; Luo, Min; Mao, Chengqiong; Wei, Qi; Zhao, Tian; Li, Yang; Huang, Gang; Gao, Jinming

    2017-01-24

    Efficient delivery of biomacromolecules (e.g., proteins, nucleic acids) into cell cytosol remains a critical challenge for the development of macromolecular therapeutics or diagnostics. To date, most common approaches to assess cytosolic delivery rely on fluorescent labeling of macromolecules with an "always on" reporter and subcellular imaging of endolysosomal escape by confocal microscopy. This strategy is limited by poor signal-to-noise ratio and only offers low throughput, qualitative information. Herein we describe a quantitative redox-activatable sensor (qRAS) for the real-time monitoring of cytosolic delivery of macromolecules. qRAS-labeled macromolecules are silent (off) inside the intact endocytic organelles, but can be turned on by redox activation after endolysosomal disruption and delivery into the cytosol, thereby greatly improving the detection accuracy. In addition to confocal microscopy, this quantitative sensing technology allowed for a high-throughput screening of a panel of polymer carriers toward efficient cytosolic delivery of model proteins on a plate reader. The simple and versatile qRAS design offers a useful tool for the investigation of new strategies for endolysosomal escape of biomacromolecules to facilitate the development of macromolecular therapeutics for a variety of disease indications. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. Combined small angle X-ray solution scattering with atomic force microscopy for characterizing radiation damage on biological macromolecules.

    Science.gov (United States)

    Costa, Luca; Andriatis, Alexander; Brennich, Martha; Teulon, Jean-Marie; Chen, Shu-Wen W; Pellequer, Jean-Luc; Round, Adam

    2016-10-27

    Synchrotron radiation facilities are pillars of modern structural biology. Small-Angle X-ray scattering performed at synchrotron sources is often used to characterize the shape of biological macromolecules. A major challenge with high-energy X-ray beam on such macromolecules is the perturbation of sample due to radiation damage. By employing atomic force microscopy, another common technique to determine the shape of biological macromolecules when deposited on flat substrates, we present a protocol to evaluate and characterize consequences of radiation damage. It requires the acquisition of images of irradiated samples at the single molecule level in a timely manner while using minimal amounts of protein. The protocol has been tested on two different molecular systems: a large globular tetremeric enzyme (β-Amylase) and a rod-shape plant virus (tobacco mosaic virus). Radiation damage on the globular enzyme leads to an apparent increase in molecular sizes whereas the effect on the long virus is a breakage into smaller pieces resulting in a decrease of the average long-axis radius. These results show that radiation damage can appear in different forms and strongly support the need to check the effect of radiation damage at synchrotron sources using the presented protocol.

  8. Supramolecular Assembly of Comb-like Macromolecules Induced by Chemical Reactions that Modulate the Macromolecular Interactions In Situ.

    Science.gov (United States)

    Xia, Hongwei; Fu, Hailin; Zhang, Yanfeng; Shih, Kuo-Chih; Ren, Yuan; Anuganti, Murali; Nieh, Mu-Ping; Cheng, Jianjun; Lin, Yao

    2017-08-16

    Supramolecular polymerization or assembly of proteins or large macromolecular units by a homogeneous nucleation mechanism can be quite slow and require specific solution conditions. In nature, protein assembly is often regulated by molecules that modulate the electrostatic interactions of the protein subunits for various association strengths. The key to this regulation is the coupling of the assembly process with a reversible or irreversible chemical reaction that occurs within the constituent subunits. However, realizing this complex process by the rational design of synthetic molecules or macromolecules remains a challenge. Herein, we use a synthetic polypeptide-grafted comb macromolecule to demonstrate how the in situ modulation of interactions between the charged macromolecules affects their resulting supramolecular structures. The kinetics of structural formation was studied and can be described by a generalized model of nucleated polymerization containing secondary pathways. Basic thermodynamic analysis indicated the delicate role of the electrostatic interactions between the charged subunits in the reaction-induced assembly process. This approach may be applicable for assembling a variety of ionic soft matters that are amenable to chemical reactions in situ.

  9. Membrane-active macromolecules kill antibiotic-tolerant bacteria and potentiate antibiotics towards Gram-negative bacteria.

    Science.gov (United States)

    Uppu, Divakara S S M; Konai, Mohini M; Sarkar, Paramita; Samaddar, Sandip; Fensterseifer, Isabel C M; Farias-Junior, Celio; Krishnamoorthy, Paramanandam; Shome, Bibek R; Franco, Octávio L; Haldar, Jayanta

    2017-01-01

    Chronic bacterial biofilms place a massive burden on healthcare due to the presence of antibiotic-tolerant dormant bacteria. Some of the conventional antibiotics such as erythromycin, vancomycin, linezolid, rifampicin etc. are inherently ineffective against Gram-negative bacteria, particularly in their biofilms. Here, we report membrane-active macromolecules that kill slow dividing stationary-phase and antibiotic tolerant cells of Gram-negative bacteria. More importantly, these molecules potentiate antibiotics (erythromycin and rifampicin) to biofilms of Gram-negative bacteria. These molecules eliminate planktonic bacteria that are liberated after dispersion of biofilms (dispersed cells). The membrane-active mechanism of these molecules forms the key for potentiating the established antibiotics. Further, we demonstrate that the combination of macromolecules and antibiotics significantly reduces bacterial burden in mouse burn and surgical wound infection models caused by Acinetobacter baumannii and Carbapenemase producing Klebsiella pneumoniae (KPC) clinical isolate respectively. Colistin, a well-known antibiotic targeting the lipopolysaccharide (LPS) of Gram-negative bacteria fails to kill antibiotic tolerant cells and dispersed cells (from biofilms) and bacteria develop resistance to it. On the contrary, these macromolecules prevent or delay the development of bacterial resistance to known antibiotics. Our findings emphasize the potential of targeting the bacterial membrane in antibiotic potentiation for disruption of biofilms and suggest a promising strategy towards developing therapies for topical treatment of Gram-negative infections.

  10. Using a water-confined carbon nanotube to probe the electricity of sequential charged segments of macromolecules

    Institute of Scientific and Technical Information of China (English)

    Wang Yu; Zhao Yan-Jiao; Huang Ji-Ping

    2012-01-01

    The detection of macromolecular conformation is particularly important in many physical and biological applications.Here we theoretically explore a method for achieving this detection by probing the electricity of sequential charged segments of macromolecules.Our analysis is based on molecular dynamics simulations,and we investigate a single file of water molecules confined in a half-capped single-walled carbon nanotube (SWCNT) with an external electric charge of +e or -e (e is the elementary charge).The charge is located in the vicinity of the cap of the SWCNT and along the centerline of the SWCNT.We reveal the picosecond timescaie for the re-orientation (namely,from one unidirectional direction to the other) of the water molecules in response to a switch in the charge signal,-e → +e or +e → e.Our results are well understood by taking into account the electrical interactions between the water molecules and between the water molecules and the external charge.Because such signals of re-orientation can be magnified and transported according to Tu et al.[2009 Proc.Natl.Acad.Sci.USA 106 18120],it becomes possible to record fingerprints of electric signals arising from sequential charged segments of a macromolecule,which are expected to be useful for recognizing the conformations of some particular macromolecules.

  11. Diffusion and partitioning of macromolecules in casein microgels: evidence for size-dependent attractive interactions in a dense protein system.

    Science.gov (United States)

    Peixoto, Paulo D S; Bouchoux, Antoine; Huet, Sébastien; Madec, Marie-Noëlle; Thomas, Daniel; Floury, Juliane; Gésan-Guiziou, Geneviève

    2015-02-10

    Understanding the mechanisms that determine the diffusion and interaction of macromolecules (such as proteins and polysaccharides) that disperse through dense media is an important fundamental issue in the development of innovative technological and medical applications. In the current work, the partitioning and diffusion of macromolecules of different sizes (from 4 to 10 nm in diameter) and shapes (linear or spherical) within dispersions of casein micelles (a protein microgel) is studied. The coefficients for diffusion and partition are measured using FRAP (fluorescence recovery after photobleaching) and analyzed with respect to the structural characteristics of the microgel determined by the use of TEM (transmission electron microscopy) tomography. The results show that the casein microgel displays a nonspecific attractive interaction for all macromolecules studied. When the macromolecular probes are spherical, this affinity is clearly size-dependent, with stronger attraction for the larger probes. The current data show that electrostatic effects cannot account for such an attraction. Rather, nonspecific hydration molecular forces appear to explain these results. These findings show how weak nonspecific forces affect the diffusion and partitioning of proteins and polysaccharides in a dense protein environment. These results could be useful to better understand the mechanisms of diffusion and partitioning in other media such as cells and tissues. Furthermore, there arises the possibility of using the casein micelle as a size-selective molecular device.

  12. Volatile organic compound emissions during hot-pressing of southern pine particleboard : panel size effects and trade-off between press time and temperature

    Science.gov (United States)

    Wenlong Wang; Douglas J. Gardner; Melissa G.D. Baumann

    2002-01-01

    In previous research, it was shown that decreasing either press temperature or press time generally resulted in decreased volatile organic compound (VOC) emissions during the hot-pressing of southern pine particleboard. However, because it is impossible to reduce both pressing time and temperature while maintaining panel physical and mechanical properties, this study...

  13. Viietärni sisekujundaja Meelis Press / Kristjan Arunurm

    Index Scriptorium Estoniae

    Arunurm, Kristjan

    2008-01-01

    Tallinnas Tornimäe kaksiktornides asuva Swissotel'i sisekujundusest. Sisekujundaja Meelis Press, tema ja hoone arhitekti Meeli Truu kommentaarid. Swissotel'i kett otsustas Meelis Pressile teha pakkumise kujundada peagi Türgi Swissotel. 8 ill

  14. Fabrication and properties of hot pressed bismuth tungstate

    Energy Technology Data Exchange (ETDEWEB)

    Streicher, W.L.

    1978-01-01

    Bi/sub 2/WO/sub 6/ is a synthetic polar material that is a possible candidate for energy conversion and detection systems. Previous research on this material has been concerned with crystal growth and sintering characteristics of polycrystalline compacts. This study involves itself with the fabrication of polycrystalline compacts by hot pressing techniques. Densities approaching theoretical crystal density were achieved by hot pressing at 850/sup 0/C for one hour with pressures exceeding 35 MPa. Before hot pressing, the sintering range was determined by high temperature dilatometry of unfired Bi/sub 2/WO/sub 6/ ceramics. Hot pressed discs were characterized by scanning electron microscopy, differential scanning calorimetry, and x-ray diffraction. Electrical properties were determined by dc resistivity, capacitance, and conductance measurements, ac poling, dc poling, and current-voltage measurements.

  15. Desenvolvimento de um regulador de pressão microprocessado

    OpenAIRE

    Leonardo de Lucena Martins

    2012-01-01

    Dentre os fatores que afetam a uniformidade de aplicação de água, cita-se a variação de pressão no sistema, causada principalmente pela topografia do terreno e pela inexistência ou operação inadequada de reguladores de pressão. Nesse sentido, têm-se empregado válvulas reguladoras de pressão nos projetos de irrigação com variações topográficas. Contudo, a pressão de saída na válvula nem sempre será correspondente a apresentada no catálogo do fabricante. Com o avanço da eletrônica e a moderniza...

  16. HYBRID CONTROL OF HYDRAULIC PRESS MACHINE BASED ON ROBUST CONTROL

    Institute of Scientific and Technical Information of China (English)

    FANG Yu; YANG Jian; CHAI Xiaodong

    2008-01-01

    A robust control algorithm is proposed to focus on the non-linearity and variables of the hydraulic press machine with the proportional valve. The proposed robust controller does not need to design stable compensator in advance, which is simple in design and has large scope of uncertainty applications. The feedback gains of the proposed robust controller are small, so it is easily implemented in engineering applications. The theoretical and experimental research on the position and speed control of the hydraulic press machine is carried out. The control requirements of the hydraulic press machine during the working process are met in the position and speed at the same time. Experimental results show that the proposed controller has better robustness subject to load variables and adaptability of parameter variations of the hydraulic press machine with the proportional valve.

  17. Optical and mechanical properties of hot-pressed cesium iodide

    Energy Technology Data Exchange (ETDEWEB)

    Kim, H.E.; Moorhead, A.J. (Oak Ridge National Lab., TN (USA). Metals and Ceramics Div.)

    1990-03-01

    This paper reports on polycrystalline CsI disks fabricated by hot-pressing in a nitrogen-purged glove box. Densification during hot-pressing occurred by plastic flow resulting from lattice dislocation glide. Primary recrystallization and extensive grain growth were observed. Both the optical and mechanical properties of this material were significantly affected by grain growth, but in opposite ways. Transmittance increased and strength decreased as grain size increased. The hot-pressed CsI had transmittance of about 85% in the extra-long-wavelength infrared range, a value equivalent to that of single-crystal CsI. The flexural strengths of the CsI that was hot-pressed under conditions that minimized grain growth was about 8 times higher than that of single-crytal CsI.

  18. Ethical Newsgathering Values of the Public and Press Photographers.

    Science.gov (United States)

    Hartley, Craig H.

    1983-01-01

    Compares the reactions of photojournalists and the public to hypothetical ethical dilemmas confronting press photographers. Concludes that the two groups disagree significantly in their reactions to 17 of 19 ethical situations. (FL)

  19. Concept Design of Movable Beam of Hydraulic Press

    Directory of Open Access Journals (Sweden)

    Li Yancong

    2017-01-01

    Full Text Available The hydraulic press movable beam is one of the key components of the hydraulic press; its design quality impacts the accuracy of the workpiece that the press suppressed. In this paper, first, with maximum deflection and material strength as constraints, mechanical model of the movable beam is established; next, the concept design model of the moveable beam structure is established; the relationship among the force of the side cylinder, the thickness of the inclined plate, outer plate is established also. Taking movable beam of the 100MN type THP10-10000 isothermal forging hydraulic press as an example, the conceptual design result is given. This concept design method mentoned in the paper has general meaning and can apply to other similar product design.

  20. Differential Suppression by Punishment of Nonconsummatory Licking and Lever Pressing

    Science.gov (United States)

    Walters, Gary C.; Herring, Barbara

    1978-01-01

    Five experiments investigated the differential effects of shock punishment on nonconsummatory licking (dry licking) and lever pressing. Results support a motivationally based theory of punishment involving the role of incentive stimuli associated with the particular responses studied. (Editor/RK)