bacterial f-type membrane: Topics by WorldWideScience.org

Dipyrone-induced changes in DNA repair and other cell membrane associated processes in Escherichia coli

The analgesic, dipyrone (1,phenyl-2,3-dimethyl-5-pyrazolone-4-methylamino methane sulphonate sodium), at 20 mM concentration, inhibited the rejoining of single-strand scissions in DNA of Escherichia coli B/r cells induced by 20 krad gamma-radiation. The chemical altered the cell membrane structure as evidenced from the uptake of acriflavin, the efflux of potassium ions from the bacterial cells and the inhibition of alkaline phosphatase-a cell membrane associated enzyme. (author). 18 refs., 6 figures.

1982-09-01

4

[Study on denitrification characteristics of dynamic membrane based on nitrate liquid-membrane microelectrodes].

The analgesic, dipyrone (1,phenyl-2,3-dimethyl-5-pyrazolone-4-methylamino methane sulphonate sodium), at 20 mM concentration, inhibited the rejoining of single-strand scissions in DNA of Escherichia coli B/r cells induced by 20 krad gamma-radiation. The chemical altered the cell membrane structure as evidenced from the uptake of acriflavin, the efflux of potassium ions from the bacterial cells and the inhibition of alkaline phosphatase-a cell membrane associated enzyme. (author).

5

Nature and distribution of mucosal lesions associated with enteropathogenic and enterohemorrhagic Escherichia coli in piglets and the role of plasmid-mediated factors.

Nitrate microelectrodes and ORP microelectrodes were fabricated to study the denitrification characteristics of dynamic membrane at different COD loadings. The denitrification process was found at 0.6-1 mm depth beneath the interface of biofilm/bulk. The results of ORP microelectrode also demonstrated that the ORP value in the range of denitrification area was between 88.6 approximately -128.4 mV which was appropriate to denitrification. When the COD loading was 0.45 kg/(m3 x d), the denitrification rate (NO3- -N) was the maximum of 0.6347 x 10(-6 mol/(L x s). With the increase of COD loading, the denitrification area was increasing and two layers with different denitrification rates emerged in the dynamic membrane. The phenomenon implied the effect of organic concentration, oxygen concentration and bacterial competition on the denitrification rate. PMID:17117632

2006-09-01

6

Identification of sucrose binding, membrane proteins using a photolyzable sucrose analog. [P. saccharophila

Bacterial attachment-effacement (att-eff) is emerging as an important virulence characteristic common to both enteropathogenic Escherichia coli (EPEC) and enterohemorrhagic E. coli (EHEC). The contribution of the plasmid-encoded EPEC adherence factor to the production of mucosal lesions and diarrhea was investigated in gnotobiotic piglets. Bacterial att-aff in the intestinal mucosa of piglets infected with plasmid-cured EPEC strain E2348/69 (O127) was indistinguishable from that in piglets infected with the parent strain, but the distribution of lesions was different; it occurred in the small intestines of 6 of 7 piglets infected with the parent strain compared with only 2 of 11 (P = 0.006) infected with the plasmid-cured strain. Plasmid-encoded factors in EPEC and EHEC strains did not appear to contribute to bacterial competition with normal gut microflora. Of 13 strains belonging to five EPEC serogroups, O55, O142, O26, ...

1989-04-01

7

Steady-state levels of G-protein beta-subunit expression are regulated by treatment of cells with bacterial toxins

The sucrose derivative 6'-deoxy-6'-(2-hydroxy-4-azido)benzamidosucrose (6'-HABS) was prepared from sucrose (via 6'-deoxy-6'-aminosucrose) and 4-amino-salicylic acid. 6'-HABS is a competitive inhibitor of sucrose influx into protoplasts from developing soybean cotyledons and of sucrose binding to membranes from the bacteria P. saccharophila. The Ki for inhibition in the soybean protoplasts was 75..mu..M. 6'-Deoxy-6'-(2-hydroxy-3-/sup 125/Iodo-4-azido)benzamidosucrose was prepared by lactoperoxidase iodination of 6'-HABS. Upon photolysis in the presence of membranes from P saccharophila, label from the photoprobe is incorporated into a sucrose inducible polypeptide of mass 84 KD in SDS-PAGE. The polypeptide is protected from labeling by the inclusion of sucrose in the photolysis mixture. Photolysis conditions which lead to specific labeling of the sucrose protectable ...

1986-04-01

8

Cultures of 3T3-L1 cells were incubated with either 10 ng/ml cholera toxin or 10 ng/ml pertussis toxin from 4 days prior to the initiation of differentiation and throughout the subsequent incubation. Toxin concentrations were sufficient to completely prevent the labelling of alpha-subunits with ["3"2P]NAD"+ and pertussis toxin and to prevent by more than 90% the labelling with ["3"2P]NAD"+ and cholera toxin in membranes prepared from these cells. Neither toxin prevented the differentiation to the adipocyte phenotype. Neither toxin prevented the increases in the relative amounts of G-proteins which occur upon differentiation. Both toxins dramatically decreased the amount of beta-subunits. As measured by quantitative immunoblotting with antisera specific for both the 35 kDa and 36 kDa beta-subunits, levels of beta-subunit were decreased by more than 50% of steady-state level of control cells. Thus, bacterial toxins which modifies G-protein ...

1987-06-07

9

Bacterial conjunctivitis

Sodium-driven motor of the polar flagellum in marine bacteria Vibrio

Clinical questionWhat is the best treatment for bacterial conjunctivitis?ResultsTopical antibiotics expedite recovery from bacterial conjunctivitis....Full Text Available

2010-01-01

10

British Library Electronic Table of Contents (United Kingdom)

The Na+-driven bacterial flagellar motor is a molecular machine powered by an electrochemical potential gradient of sodium ions across the cytoplasmic membrane. The marine bacterium Vibrio alginolyticus has a single polar flagellum that enables it to swim in liquid. The flagellar motor contains a basal body and a stator complexes, which are composed of several proteins. PomA, PomB, MotX, and MotY are thought to be essential components of the stator that are required to generate the torque of the rotation. Several mutations have been investigated to understand the characteristics and function of the ion channel in the stator and the mechanism of its assembly around the rotor to complete the motor. In this review, we summarize recent results of the Na+-driven motor in the polar flagellum of ...

2011-01-01

11

Bacterial radiosensitization by using radiation processing in combination with essential oil: Mechanism of action

Defect creation by electronic processes in MgO bombarded with GeV heavy ions

Spice extracts under the form of essential oils were tested for their efficiency to increase the relative radiosensitivity of Listeria monocytogenes and Escherichia coli O157H7 in culture media. The two pathogens were treated by gamma-irradiation alone or in combination with oregano essential oil to evaluate their mechanism of action. The membrane murein composition, and the intracellular and extracellular concentration of ATP was determined. The bacterial strains were treated with two irradiation doses: 1.2 kGy to induce cell damage and 3.5 kGy to cause cell death for L. monocytogenes. A dose of 0.4 kGy to induce cell damages, 1.1 kGy to obtain viable but nonculturable (VBNC) state and 1.3 kGy to obtain a lethal dose was also applied on E. coli O157H7. Oregano essential oil was used at 0.020% and 0.025% (w/v), which is the minimum inhibitory concentration (MIC) for L. monocytogenes. For E. coli O157H7, a concentration of 0.006% and 0.025% ...

2009-07-15

12

Computing with cells advances in membrane computing

To study the defect creation induced by electronic processes in refractory oxides, MgO single crystals were irradiated with high energy tin, uranium and lead ions. Optical absorption measurements showed that F-type centers (oxygen vacancies with trapped electrons) were created during irradiation. The total number of centers per unit area of bombarded sample increases linearly with irradiating fluence. The main part of the point defects was found to arise from electronic processes. The concentration of F-type centers induced by ionization increases with the electronic energy losses. Assuming a saturation of point defect concentration at high fluences, F-type center creation cross sections could be estimated. The influence of irradiation temperature and of the velocity of the bombarding ions are discussed.

1996-12-31

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Factors Linked to Bacterial Vaginosis in Nonpregnant Women

Computing with cells

2009-01-01

14

Bacterial chemoreceptors: high-performance signaling in networked arrays

Objectives. The purposes of this study were to test the hypothesis that vaginal douching is linked to bacterial vaginosis in both symptomatic and asymptomatic women and to identify...Full Text Available

2001-10-01

15

Bilayer Lipid Membranes for Light Converters

Chemoreceptors are crucial components in the bacterial sensory systems that mediate chemotaxis. Chemotactic responses exhibit exquisite sensitivity, extensive dynamic range and precise adaptation....Full Text Available

2008-01-01

16

International Science & Technology Center (ISTC)

Bilayer Lipid Membrane Supported Novel Photoelectrochemical Converter for Light Trapping

17

Immunological characterization of a basement membrane-specific chondroitin sulfate proteoglycan

Sexual intercourse association with asymptomatic bacterial vaginosis and Trichomonas vaginalis treatment in relationship to preterm birth.

Reichert's membrane, an extraembryonic membrane present in developing rodents, has been proposed as an in vivo model for the study of basement membranes. We have used this membrane as a source for isolation...Full Text Available

1989-12-01

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Effect of Chitosan Solution on the Inhibition of Pseudomonas fluorescens Causing Bacterial Head Rot of Broccoli

PMID:12439520

2002-11-01

19

Does oral metronidazole prevent preterm delivery in normal-risk pregnant women with asymptomatic bacterial vaginosis (BV)?

Full Text Available

2010-06-01

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Application of Quantitative Real-Time PCR for Enumeration of Total Bacterial, Archaeal, and Yeast Populations in Kimchi

PMID:10923545

2000-06-01

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Impregnation of silver nanoparticles into bacterial cellulose for antimicrobial wound dressing

Full Text Available

2009-12-01

22

British Library Electronic Table of Contents (United Kingdom)

Bacterial cellulose was produced by Acetobacter xylinum (strain TISTR 975). Bacterial cellulose is an interesting material for using as a wound dressing since it provides moist environment to a wound resulting in a better wound healing. However, bacterial cellulose itself has no antimicrobial activity to prevent wound infection. To achieve antimicrobial activity, silver nanoparticles were impregnated into bacterial cellulose by immersing bacterial cellulose in silver nitrate solution. Sodium borohydride was then used to reduce the absorbed silver ion (Ag+) inside of bacterial cellulose to the metallic silver nanoparticles (Ag0). Silver nanoparticles displayed the optical absorption band around 420nm. The red-shift and broadening of the optical absorption band was observed when the mole rat...

2008-01-01

23

Surgical treatment of subretinal neovascular membrane.

Stable and Unstable Lipid Domains in Ceramide-Containing Membranes

Full Text Available

1999-06-01

24

Parameter Optimization for a Polymer Electrolyte Membrane Fuel Cell Model

Not Available

2011-05-01

25

Overcoming the challenges of membrane protein crystallography

Not Available

2010-11-01

26

Membrane protein biosensing with plasmonic nanopore arrays and pore-spanning lipid membranes

Membrane protein structural biology is still a largely unconquered area, given that approximately 25% of all proteins are membrane proteins and yet less than 150 unique structures are available. Membrane...Full Text Available

2008-10-01

27

METHOD FOR ASSAYING PROTEASE ACTIVITY USING POLYMER MEMBRANE

Integration of solid-state biosensors and lipid bilayer membranes is important for membrane protein research and drug discovery. In these sensors, it is critical that the solid-state sensing...Full Text Available

2010-01-01

28

J-STORE (Japan)

Full Text Available

2007-09-14

29

A novel application of amniotic membrane in patients with bullous keratopathy.

Toll-like receptor 2 polymorphism and gram-positive bacterial infections after liver transplantation

Full Text Available

2006-04-01

30

British Library Electronic Table of Contents (United Kingdom)

Abstract Toll-like receptor 2 (TLR2) is an immune sensor for gram-positive bacterial cell wall components. Single-nucleotide polymorphisms (SNPs) in the TLR2 gene that impair its function may, therefore, influence the risk and outcomes of gram-positive bacterial infections. In a cohort of 694 liver transplant recipients, we assessed the TLR2 SNP that is translated into an amino acid substitution of arginine for glutamine at position 753 (R753Q), and we found that its presence was associated with the clinical characteristics and outcomes of gram-positive bacterial infections. The proportions of patients with the TLR2 R753Q SNP did not significantly differ between those with gram-positive bacterial infections and those without gram-positive bacterial infections (9.6% versus 9.6%, P = 0.999)....

2011-01-01

31

Interaction of antimicrobial peptides with lipid membranes

The bacterial signal indole increases epithelial-cell tight-junction resistance and attenuates indicators of inflammation

This study aims to investigate the difference in the interaction of antimicrobial peptides with two classes of zwitterionic peptides, phosphatidylethanolamines (PE) and phosphatidylcholines (PC). Further experiments were performed on model membranes prepared from specific bacterial lipids, lipopolysaccharides (LPS) isolated from Salmonella minnesota. The structure of the lipid-peptide aqueous dispersions was studied by small-and wide-angle X-ray diffraction during heating and cooling from 5 to 85 C. The lipids and peptides were mixed at lipid-to-peptide ratios 10-10000 (POPE and POPC) or 2-50 (LPS). All experiments were performed at synchrotron soft condensed matter beamline A2 in Hasylab at Desy in Hamburg, Germany. The phases were identified and the lattice parameters were calculated. Alamethicin and melittin interact in similar ways with the lipids. Pure POPC forms only lamellar phases. POPE forms lamellar phases at low temperatures that ...

32

The Mammalian Neuroendocrine Hormone Norepinephrine Supplies Iron for Bacterial Growth in the Presence of Transferrin or Lactoferrin

Interkingdom signaling is established in the gastrointestinal tract in that human hormones trigger responses in bacteria; here, we show that the corollary is true, that a specific bacterial signal,...Full Text Available

2010-01-05

33

Studying bacterial transcriptomes using RNA-seq

Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI...Full Text Available

2000-11-01

34

Stable-Carbon-Isotope Composition of Fatty Acids in Hydrothermal Vent Mussels Containing Methanotrophic and Thiotrophic Bacterial Endosymbionts

Genome-wide studies of bacterial gene expression are shifting from microarray technology to second generation sequencing platforms. RNA-seq has a number of advantages over hybridization-based techniques,...Full Text Available

2010-10-01

35

Separation of the bacterial species, Escherichia coli, from mixed-species microbial communities for transcriptome analysis

Fatty acid biomarker analysis coupled with gas chromatography-isotope ratio mass spectrometry was used to confirm the presence of methanotrophic and thiotrophic bacterial endosymbionts in the tissues...Full Text Available

1998-01-01

36

Sensitivity of Freshly Isolated Bacterial Pathogens to Certain Antibiotics and Nitrofurazone

BackgroundThe study of bacterial species interactions in a mixed-species community can be facilitated by transcriptome analysis of one species in the community using cDNA microarray...Full Text Available

37

Racial differences in cervical cytokine concentrations between pregnant women with and without bacterial vaginosis

The results of antibiotic tests on bacterial pathogens freshly isolated from avian tissues and bovine milk are presented. Coliform isolates from the avian species showed an increased resistance to...Full Text Available

1969-01-01

38

Pretreatment with the gram-positive bacterial cell wall molecule peptidoglycan improves bacterial clearance and decreases inflammation and mortality in mice challenged with Pseudomonas aeruginosa

We have examined the association between cytokine, chemokine and growth factor concentrations with bacterial vaginosis (BV) in pregnant white and black women. A nested case-control analysis...Full Text Available

2008-07-01

39

Persistence of Free-Living Protozoan Communities across Rearing Cycles in Commercial Poultry Houses ?

The objective of this study was to determine if inflammatory tolerance and enhancement of innate immune function could be induced by the gram-positive cell wall component peptidoglycan (PGN)....Full Text Available

2008-10-01

40

Pericardiectomy for Pleuropericardial Effusion Complicating Bacterial Pneumonia

The introduction and survival of zoonotic bacterial pathogens in poultry farming have been linked to bacterial association with free-living protozoa. To date, however, no information is available on...Full Text Available

2011-03-01

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Nonlinearity in bacterial population dynamics: Proposal for experiments for the observation of abrupt transitions in patches

Severe pericardial effusion is a rare complication of bacterial pneumonia and it usually disappears under medical treatment. Herein we report a case of a girl with a congenital immunodeficient syndrome...Full Text Available

2010-01-01

42

Neonatal E. coli infection alters glial, cytokine, and neuronal gene expression in response to acute amphetamine in adolescent rats

An explicit proposal for experiments leading to abrupt transitions in spatially extended bacterial populations in a Petri dish is presented on the basis of an exact formula obtained through an analytic...Full Text Available

2008-12-02

43

Lethal protein produced in response to competition between sibling bacterial colonies

Neonatal bacterial infection in rats alters the responses to a variety of subsequent challenges later in life. Here we explored the effects of neonatal bacterial infection on a subsequent drug...Full Text Available

2010-04-19

44

Interactions of Antibiotics and Methanolic Crude Extracts of Afzelia Africana (Smith.) Against Drug Resistance Bacterial Isolates

Sibling Paenibacillus dendritiformis bacterial colonies grown on low-nutrient agar medium mutually inhibit growth through secretion of a lethal factor. Analysis of secretions reveals...Full Text Available

2010-04-06

45

Improved Understanding of the Bacterial Vaginal Microbiota of Women before and after Probiotic Instillation

Infection due to multidrug resistance pathogens is difficult to manage due to bacterial virulence factors and because of a relatively limited choice of antimicrobial agents. Thus, it is imperative to...Full Text Available

46

IL-6-Dependent Mucosal Protection Prevents Establishment of a Microbial Niche for Attaching/Effacing Lesion-Forming Enteric Bacterial Pathogens1

The vaginal bacterial microbiota of 19 premenopausal women was examined by PCR-denaturing gradient gel electrophoresis (DGGE) and sequencing of the V2-V3 region of the 16S rRNA gene. Ten of the women...Full Text Available

2003-01-01

47

Generation of Novel Bacterial Regulatory Proteins That Detect Priority Pollutant Phenols

Enteric infections with attaching/effacing lesion-inducing bacterial pathogens are a worldwide health problem. A murine infection model with one such pathogen, Citrobacter rodentium,...Full Text Available

2008-05-15

48

FIRST TRIMESTER BACTERIAL VAGINOSIS, INDIVIDUAL MICROORGANISM LEVELS AND RISK OF SECOND TRIMESTER PREGNANCY LOSS AMONG URBAN WOMEN

The genetic systems of bacteria that have the ability to use organic pollutants as carbon and energy sources can be adapted to create bacterial biosensors for the detection of industrial pollution....Full Text Available

2000-01-01

49

Evaluations of bacterial contaminated full thickness burn wound healing in Sprague Dawley rats Treated with Tualang honey

ObjectiveTo examine the role of first trimester bacterial vaginosis (BV) and level of BV-associated microorganisms diagnosed using the Nugent’s Gram stain...Full Text Available

2007-11-01

50

Euryarchaeal ?-CASP Proteins with Homology to Bacterial RNase J Have 5?- to 3?-Exoribonuclease Activity*

Aim:The effect of Tualang honey on wound healing in bacterial contaminated full-thickness burn wounds was evaluated in 36 male Sprague Dawley rats.Materials...Full Text Available

2011-01-01

51

Comparison of oral and vaginal metronidazole for treatment of bacterial vaginosis in pregnancy: impact on fastidious bacteria

In the Archaea only a handful of ribonucleases involved in RNA processing and degradation have been characterized. One potential group of archaeal ribonucleases are homologues of the bacterial RNase...Full Text Available

2010-06-04

52

Comparative genomics of the bacterial genus Listeria: Genome evolution is characterized by limited gene acquisition and limited gene loss

BackgroundBacterial vaginosis (BV) is a common condition that is associated with preterm birth and acquisition of complex communities of vaginal bacteria that include several fastidious...Full Text Available

53

Bacterial Particle Endocytosis by Epithelial Cells Is Selective and Enhanced by Tumor Necrosis Factor Receptor Ligands?

BackgroundThe bacterial genus Listeria contains pathogenic and non-pathogenic species, including the pathogens L. monocytogenes and L. ivanovii,...Full Text Available

54

Bacterial Oxidation of Sulfide Minerals in Column Leaching Experiments at Suboptimal Temperatures

Bacterial pathogens use virulence strategies to invade epithelial barriers, but active processes of epithelial cells may also contribute to the endocytosis of microbial particles. To focus on the latter,...Full Text Available

2009-03-01

55

Bacterial Fouling in a Model Core System

The purpose of the work was to quantitatively characterize temperature effects on the bacterial leaching of sulfide ore material containing several sulfide minerals. The leaching was tested at eight...Full Text Available

1992-02-01

56

Bacterial Competition for Human Nasal Cavity Colonization: Role of Staphylococcal agr Alleles

We have used a sintered glass bead core to simulate the spaces and surfaces of reservoir rock in studies of the bacterial plugging phenomenon that affects waterflood oil recovery operations. The passage...Full Text Available

1985-03-01

57

Bacterial Artificial Chromosome Mutagenesis Using Recombineering

We examined the bacterial aerobic nasal flora of 216 healthy volunteers to identify potential competitive interactions among different species, with special emphasis on the influence of staphylococcal...Full Text Available

2003-01-01

58

Association between bacterial vaginosis or chlamydial infection and miscarriage before 16 weeks' gestation: prospective community based cohort study

Gene expression from bacterial artificial chromosome (BAC) clones has been demonstrated to facilitate physiologically relevant levels compared to viral and nonviral cDNA vectors. BACs are large enough...Full Text Available

2011-01-01

59

Application of tumor, bacterial and parasite susceptibility assays to study immune alterations induced by environmental chemicals

ObjectivesTo assess whether bacterial vaginosis or chlamydial infection before 10 weeks' gestation is associated with miscarriage before 16 weeks.DesignProspective...Full Text Available

2002-12-07

60

ACCEPTABILITY OF A SELF-SAMPLING TECHNIQUE TO COLLECT VAGINAL SMEARS FOR GRAM STAIN DIAGNOSIS OF BACTERIAL VAGINOSIS

Model systems to study the effects of chemicals of environmental concern on bacterial and parasitic diseases as well as the immunosurveillance and destruction of transplantable tumor cells were described...Full Text Available

1982-02-01

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61

A bacterial amber suppressor in Saccharomyces cerevisiae is selectively recognized by a bacterial aminoacyl-tRNA synthetase.

To diagnose asymptomatic bacterial vaginosis (BV), self-sampled vaginal smears were collected during a study of risk factors for preterm birth in African American women. More than 90% of those...Full Text Available

2004-01-01

62

Preparation of reactor tube by welding a porous membrane with a non-porous ceramic tube

Little is known about the conservation of determinants for the identities of tRNAs between organisms. We showed previously that Escherichia coli tyrosine tRNA synthetase can charge the Saccharomyces...Full Text Available

1990-04-01

63

Removal of Organic Load from Olive Washing Water by an Aerated Submerged Biofilter and Profiling of the Bacterial Community Involved in the Process

In the course of designing a catalytic porous membrane reactor for experimental studies, both inside and outside of the non-reaction zones as well as the two ends of the membrane need to be completely sealed to ensure that there is no flow across the membrane in the non-reaction zone. Experiments show that up to 50% of the total flow across the membrane may be contributed by the axial flow along the wall of the non-reaction zones if only one side of the membrane is sealed. Another problem that cannot be solved by sealing is the capillary flow of the catalyst along the tube wall into the non-reaction zones when the catalyst is doped on the membrane. One of the best ways to avoid this axial flow of catalyst would be to use non-porous tubes in the non-reaction zones and join them with the porous membrane tube. In doing so, the cost of the ...

1994-12-31

64

Prediction of Bacterial Proteins Carrying A Nuclear Localization Signal and Nuclear Targeting of HsdM from Klebsiella pneumoniae

Full Text Available

2007-05-01

65

Toxicity of N-substituted aromatics to acetoclastic methanogenic activity in granular sludge

Full Text Available

2009-10-01

66

Pteromalus puparum venom impairs host cellular immune responses by decreasing expression of its scavenger receptor gene.

N-substituted aromatics are important priority pollutants entering the environment primarily through anthropogenic activities associated associated with the industrial production of dyes, explosives, pestides, and pharmaceuticals. Anaerobic treatment of wastewaters discharged by these industries could potentially be problematical as a result of the high toxicity of N-substituted aromatics. The objective of this study was to examine the structure-toxicity relationship of N-substituted aromatic compounds to acetoclastic methanogenic bacteria. The toxicity was assayed to serum flasks by measuring methane production in granular sludge. Unacclimated cultures were used to minimize the biotransformation of the toxic organic chemicals during the test. The nature and the degree of the aromatic substitution were observed to have a profound effect on the toxicity of the test compound. Nitroaromatic compounds were, on the average, over 500-fold more toxic than their corresponding aromatic amines. ...

1995-11-01

67

Manganite reduction by Shewanella putrefaciens MR-4

Insect host/parasitoid interactions are co-evolved systems in which host defenses are balanced by parasitoid mechanisms to disable or hide from host immune effectors. Although there is a rich literature on these systems, parasitoid immune-disabling mechanisms have not been fully elucidated. Here we report on a newly discovered immune-disabling mechanism in the Pieris rapae/Pteromalus puparum host/parasitoid system. Because venom injections and parasitization suppresses host phagocytosis, we turned attention to the P. rapae scavenger receptor (Pr-SR), posing the hypothesis that P. puparum venom suppresses expression of the host Pr-SR gene. To test our hypothesis, we cloned a full-length cDNA of the Pr-SR. Multiple sequences alignment showed the deduced amino acid sequence of Pr-SR is similar to scavenger receptors of other lepidopterans. Bacterial and bead injections induced Pr-SR mRNA and protein expression, which peaked at 4h post-bead injection. Venom injection ...

2011-07-22

68

Impacts of membrane properties on reactive dye removal from dye/salt mixtures by asymmetric cellulose acetate and composite polyamide nanofiltration membranes

Previous studies have documented dissimilatory growth of bacteria on solid Mn{sup 4+} oxide, but Mn{sup 3+} oxides have not been previously studied; here the authors have demonstrated for the first time the bacterial reduction of manganite. Strain MR-4 of Shewanella putrefaciens was able to grow on and rapidly reduce insoluble needle-shaped crystals of synthetic manganite (MnOOH), converting them to soluble Mn{sup 2+} in the process. The rate of Mn{sup 3+} reduction was optimal at pH of 7.0 and 26 C consistent with an enzymatic reaction. In addition the rates of reduction were in proportion to the amount of manganite added, but nearly independent of the cell concentration present (e.g., cell number had only a small effect on the rate of Mn{sup 3+} reduction at early stages of growth) suggesting that surface properties were dictating the rates of metal reduction. This thesis was supported by major differences in reduction rates when Mn oxides of different surface ...

1998-11-01

69

British Library Electronic Table of Contents (United Kingdom)

This paper aims to study fundamentally the impacts of membrane properties on the reactive dye removal from dye/salt mixtures by nanofiltration membranes. To begin with, two types of nanofiltration membranes of similar pore size, namely asymmetric cellulose acetate membrane and thin-film composite polyamide membrane were fabricated, and their key physical, chemical and performance properties were characterized. After that, these resultant membranes were employed to perform dye removal experiments with aqueous solutions of reactive black 5 and NaCl under different operational parameters. The dye removal rate and steady permeate flux were determined and correlated with the measured membrane properties. It was found that there were significant differences between the dye removal performances o...

2010-01-01

70

Electrolytic membrane formation of fluoroalkyl polymer using a UV-radiation-based grafting technique and sulfonation

The binding of polyribosomes to smooth and rough endoplasmic-reticulum membranes (Short Communication)

A sulfonated fluoroalkyl graft polymer (FGP) membrane was prepared as a polymer electrolyte. First, the FGP membrane was grafted with styrene under UV irradiation. The grafted FGP was then sulfonated to functionalize it for proton conductivity. The grafting degree of the membrane increased with increasing grafting time during UV irradiation. The proton conductivity of the membrane increased with increasing grafting degree. The swelling ratio was independent of the grafting time, however, the water uptake increased with increasing grafting degree. Based on these results, it was found that the UV-initiated styrene grafting occurred along the membrane thickness direction. Moreover, the membrane was embedded within the glass fibers of the composite. This composite electrolytic membrane had 1.15 times the proton conductivity of a Nafion 117 ...

2011-03-01

71

Membrane filtration of food suspensions.

In vitro the binding of polyribosomes to smooth endoplasmic-reticulum membranes is more sensitive to ionic strength than is the binding to rough endoplasmic-reticulum membranes. Polyribosomes...Full Text Available

1973-04-01

72

Mechanism of L-glutamate transport in membrane vesicles from Bacillus stearothermophilus.

Factors affecting the membrane filtration of food suspensions were studied for 58 foods and 13 membrane filters. Lot number within a brand, pore size (0.45 or 0.8 micrometer), and time elapsed before...Full Text Available

1979-01-01

73

Determination of bilayer membrane bending stiffness by tether formation from giant, thin-walled vesicles.

In the presence of electrochemical energy, several branched-chain neutral and acidic amino acids were found to accumulate in membrane vesicles of Bacillus stearothermophilus. The membrane vesicles contained...Full Text Available

1989-02-01

74

Contemporary Diagnosis and Management of Preterm Premature Rupture of Membranes

The curvature elastic modulus (bending stiffness) of stearoyloleoyl phosphatidylcholine (SOPC) bilayer membrane is determined from membrane tether formation experiments. R. E. Waugh and R. M. Hochmuth...Full Text Available

1989-03-01

75

Transcriptional Regulation of Membrane Lipid Homeostasis in Escherichia coli*

Spontaneous rupture of membranes (ROM) is a normal component of labor and delivery. Premature ROM (PROM) refers to rupture of the fetal membranes prior to the onset of labor irrespective of gestational...Full Text Available

2008-01-01

76

Stress Coatings for Large Scale Membrane Mirrors (preprint)

The biophysical properties of membrane phospholipids are controlled by the composition of their constituent fatty acids and are tightly regulated in Escherichia...Full Text Available

2009-12-11

77

Preparation of biodegradable PLA/PLGA membranes with PGA mesh and their application for periodontal guided tissue regeneration

... Mirrors (Preprint) Ryan Conk et al. 15 September 2006 ... 4. TITLE AND SUBTITLE Stress Coatings for Large Scale Membrane Mirrors (Preprint) 5a. ...

2006-09-15

78

Durability of Membrane Electrode Assemblies (MEAs) in PEM Fuel ...

A biodegradable polylactic acid (PLA)/poly(glycolide-co-lactide) copolymer (PLGA) membrane with polyglycolic acid (PGA) mesh was prepared to aid the effective regeneration of defective periodontal tissues. The microporous membrane used in this study consists of biodegradable polymers, and seems to have a structure to provide appropriate properties for periodontal tissue regeneration. Based on the albumin permeation test, it is known that the biodegradable membrane exhibits the suitable permeability of nutrients. The membrane maintained its physical integrity for 6-8 weeks, which could be sufficient to retain space in the periodontal pocket. Cell attachment and cytotoxicity tests were performed with respect to the evaluation of biocompatibility of the membrane. As a result, the membrane did not show any cytotoxicity. The safety and therapeutic efficacies of the ...

2009-10-01

79

Dialysis membrane for separation on microchips

Proton exchange membrane (PEM) fuel cells are energy sources that have the ... for H2 /02 PEM fuel cells because their catalysts have properties suitable for 0 ...

80

Calcium-Actin Waves and Oscillations of Cellular Membranes

Laser-induced phase-separation polymerization of a porous acrylate polymer is used for in-situ fabrication of dialysis membranes inside glass microchannels. A shaped 355 nm laser beam is used to produce a porous polymer membrane with a thickness of about 15 .mu.m, which bonds to the glass microchannel and forms a semi-permeable membrane. Differential permeation through a membrane formed with pentaerythritol triacrylate was observed and quantified by comparing the response of the membrane to fluorescein and fluorescently tagging 200 nm latex microspheres. Differential permeation was observed and quantified by comparing the response to rhodamine 560 and lactalbumin protein in a membrane formed with SPE-methylene bisacrylamide. The porous membranes illustrate the capability for the present technique to integrate sample cleanup into chip-based ...

2010-07-13

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81

Proton exchange membranes prepared by grafting of styrene/divinylbenzene into crosslinked PTFE membranes

AbstractWe propose a mechanism for the formation of membrane oscillations and traveling waves, which arise due to the coupling between the actin cytoskeleton and the calcium flux through...Full Text Available

2009-09-16

82

Plasma membrane as the target site of cholic acid analogs.

Thin PTFE membranes were prepared by coating the PTFE dispersion onto the aluminum films. Thus the thin crosslinked PTFE (RX-PTFE) membranes were obtained by means of electron beam irradiation above the melting temperature of PTFE under oxygen-free atmosphere. The RX-PTFE membranes were pre-irradiated and grafted by styrene with or without divinylbenzene (DVB) in liquid phase. The existence of DVB accelerated the initial grafting rate. The styrene grafted RX-PTFE membranes are white colored, on the other hand, the styrene/DVB grafted RX-PTFE membranes are colorless. The proton exchange membranes (PEMs) were obtained by sulfonating the grafted membranes using chlorosulfonic acid. The ion exchange capacity (IEC) values of the PEMs ranging from 1.5 to 2.8 meq/g were obtained. The PEMs made from the styrene/DVB grafted ...

2005-07-01

83

Quantitative variations in the vaginal bacterial population associated with asymptomatic infections: a real-time polymerase chain reaction study.

Although the mechanism is unknown, Calculus Bovis and its active components, cholic acid analogs (CAAs), have been used in China to treat a wide range of diseases. Based on the previous finding that the potency of CAA is strongly dependent on the intrinsic surface activity, this paper aimed to investigate the role of the plasma membrane in the pharmacological activity of CAAs. First, CAAs (0.1 mM) caused a surface activity-dependent depression on ATPase activity in the cell membrane extract, but it had no effects on other cellular extracts, suggesting an indispensable role of the membrane environment for pharmacological activity. Second, CAAs lowered the membrane fluidity of cultured Caco-2 cells with the same rank-order of potency sequence. Third, the hypothesis that any functional protein located on the membrane is influenced by changes in cellular membrane ...

2011-08-03

84

Quantitative variations in the vaginal bacterial population associated with asymptomatic infections: a real-time polymerase chain reaction study

The real-time polymerase chain reaction (PCR) quantification of several vaginal bacterial groups in healthy women and patients developing asymptomatic bacterial vaginosis (BV) and candidiasis (CA) was performed. Statistical analysis revealed that the BV condition is characterised by a great variability among subjects and that it is associated with a significant increase of Prevotella, Atopobium, Veillonella and Gardnerella vaginalis, and a drop in Lactobacillus. On the contrary, the vaginal microflora of healthy women and patients developing CA was found to be homogeneous and stable over time. PMID:18762999

2008-09-02

85

British Library Electronic Table of Contents (United Kingdom)

The real-time polymerase chain reaction (PCR) quantification of several vaginal bacterial groups in healthy women and patients developing asymptomatic bacterial vaginosis (BV) and candidiasis (CA) was performed. Statistical analysis revealed that the BV condition is characterised by a great variability among subjects and that it is associated with a significant increase of Prevotella, Atopobium, Veillonella and Gardnerella vaginalis, and a drop in Lactobacillus. On the contrary, the vaginal microflora of healthy women and patients developing CA was found to be homogeneous and stable over time.

2009-01-01

86

Acceleration of Emergence of Bacterial Antibiotic Resistance in Connected Microenvironments.

Small Regulatory RNA and Legionella pneumophila

The emergence of bacterial antibiotic resistance is a growing problem, yet the variables that influence the rate of emergence of resistance are not well understood. In a microfluidic device designed to mimic naturally occurring bacterial niches, resistance of Escherichia coli to the antibiotic ciprofloxacin developed within 10 hours. Resistance emerged with as few as 100 bacteria in the initial inoculation. Whole-genome sequencing of the resistant organisms revealed that four functional single-nucleotide polymorphisms attained fixation. Knowledge about the rapid emergence of antibiotic resistance in the heterogeneous conditions within the mammalian body may be helpful in understanding the emergence of drug resistance during cancer chemotherapy. PMID:21940899

2011-09-23

87

Metronidazole to prevent preterm delivery in pregnant women with asymptomatic bacterial vaginosis. National Institute of Child Health and Human Development Network of Maternal-Fetal Medicine Units.

Legionella pneumophila is a gram-negative bacterial species that is ubiquitous in almost any aqueous environment. It is the agent of Legionnaires’ disease, an acute and often...Full Text Available

88

J ji Y - NASA Technical Reports Server

PMID:10684911

2000-02-24

89

Interaction of legionella pneumophila and helicobacter pylori with bacterial species isolated from drinking water biofilms

could be attributed either to removal of bacterial competition. (the reason for adding antibiotics before adding additional carbon and ...

90

Expression and regulation of the NALP3 inflammasome complex in periodontal diseases

BackgroundIt is well established that Legionella pneumophila is a waterborne pathogen; by contrast, the mode of Helicobacter pylori transmission...Full Text Available

91

Effect of Photosynthetic Bacterial Addition to Chlorella or ${\\omega}-Yeast$ on Growth of Rotifer, Brachionus plicatilis, and its Dietary Value for Flounder, Paralichthys olivaceus, Larvae

Periodontitis is an infectious process characterized by inflammation affecting the supporting structures of the teeth. Porphyromonas gingivalis is a major oral bacterial species implicated...Full Text Available

2009-09-01

92

Diversity of Dominant Bacterial Taxa in Activated Sludge Promotes Functional Resistance following Toxic Shock Loading

Full Text Available

2000-03-01

93

British Library Electronic Table of Contents (United Kingdom)

Examining the relationship between biodiversity and functional stability (resistance and resilience) of activated sludge bacterial communities following disturbance is an important first step towards developing strategies for the design of robust biological wastewater treatment systems. This study investigates the relationship between functional resistance and biodiversity of dominant bacterial taxa by subjecting activated sludge samples, with different levels of biodiversity, to toxic shock loading with cupric sulfate (Cu[II]), 3,5-dichlorophenol (3,5-DCP), or 4-nitrophenol (4-NP). Respirometric batch experiments were performed to determine the functional resistance of activated sludge bacterial community to the three toxicants. Functional resistance was estimated as the 30?min IC50 or th...

2011-01-01

94

CURRICULUM VITAE

Bacterial flora-typing with targeted, chip-based Pyrosequencing

... 84. Fields BS, Haupt T, Davis JP, Arduino MJ, Butler JC. Pontiac fever due to Legionella micdadei from a whirlpool spa: Possible role of bacterial endotoxin. ...

95

BackgroundThe metagenomic analysis of microbial communities holds the potential to improve our understanding of the role of microbes in clinical conditions. Recent, dramatic improvements...Full Text Available

96

Bacterial body plans

Antimicrobial activity and mechanism of action of Nu-3, a protonated modified nucleotide

The bacterium Serratia marcescens produces a plethora of multicellular shapes of different colorations on solid substrates, allowing immediate visual detection of varieties. Such a...Full Text Available

2008-07-01

97

Alpha-toxin of Staphylococcus aureus.

Background"Nubiotics" are synthetic oligonucleotides and nucleotides with nuclease-resistant backbones, and are fully protonated for enhanced ability to be taken up by bacterial...Full Text Available

98

9902631 - Lysozyme - NASA

Alpha-toxin, the major cytotoxic agent elaborated by Staphylococcus aureus, was the first bacterial exotoxin to be identified as a pore former. The protein is secreted as a single-chain, water-soluble...Full Text Available

1991-12-01

99

Transfer of lead through the rats intestinal wall

Protein isolated from hen egg-white and functions as a bacteriostatic enzyme by degrading bacterial cell walls. First enzyme ever characterized by protein ...

100

Simultaneous Measurement of Phagosome and Plasma Membrane Potentials in Human Neutrophils By Di-8-Anepps and SEER

... females in vitro intestines lead 203 mucous membranes radionuclide kinetics

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101

Matrix metalloproteinase-9 and tensile strength of fetal membranes in uncomplicated labor.

Not Available

2010-01-01

102

MEASURING DEVICE AND MEASURING METHOD FOR MEASURING PERMEATION CHARACTERISTIC OF MEMBRANE BY USING NUCLEAR MAGNETIC RESONANCE METHOD

PMID:10831980

2000-06-01

103

J-STORE (Japan)

Full Text Available

2007-03-09

104

In-plane resolved in-situ measurements of the membrane resistance in PEFCs

Identifying Contributing Degradation Phenomena in PEM Fuel Cell Membrane Electrode Assemblies Via Electron Microscopy

The conductivity of the membrane is a limiting factor for the efficiency and power density of PEFCs. Because this conductivity is strongly dependent on the membrane hydration, water management is an important aspect of PEFC optimisation. Single cell model experiments were made in order to determine the in-plane hydration of a Nafion{sup R} membrane under fuel cell conditions as function of the gas humidities. (author) 4 fig., 3 refs.

1999-08-01

105

Hydrolysis of Olive Oil Catalyzed by Surfactant-Coated Candida rugosa Lipase in a Hollow Fiber Membrane Reactor

No abstract prepared.

2006-10-01

106

Electrospun Nanofibrous Polyacrylonitrile(PAN)/ Fe2O3 Membrane as Co2Gas Sensor

Full Text Available

2007-04-01

107

Crosslinked sulfonated poly (bis-A)-sulfones as proton exchange membrane for PEM fuel cell application

Full Text Available

2007-04-01

108

Coupled Growth and Division of Model Protocell Membranes

Not Available

2010-02-01

109

The use of fibrous, supramolecular membranes and human tubular cells for renal epithelial tissue engineering: towards a suitable membrane for a bioartificial kidney.

The generation of synthetic forms of cellular life requires solutions...Full Text Available

2009-04-22

110

Physicochemical study of poly(ether ether ketone) electrolyte membranes sulfonated with mixtures of fuming sulfuric acid and sulfuric acid for direct methanol fuel cell application

A bioartificial kidney, which is composed of a membrane cartridge with renal epithelial cells, can substitute important kidney functions in patients with renal failure. A particular challenge is the maintenance of monolayer integrity and specialized renal epithelial cell functions ex vivo. We hypothesized that this can be improved by electro-spun, supramolecular polymer membranes which show clear benefits in ease of processability. We found that after 7?d, in comparison to conventional microporous membranes, renal tubular cells cultured on top of our fibrous supramolecular membranes formed polarized monolayers, which is prerequisite for a well-functioning bioartificial kidney. In future, these supramolecular membranes allow for incorporation of peptides that may increase cell function even further. PMID:20715132

2010-11-10

111

Membranes for carbon dioxide recovery from power plants

Sulfonated poly(ether ether ketone) (SPEEK) membranes with various degrees of sulfonation (DS) have been prepared as a potential membrane material for proton exchange membrane by sulfonation process using mixtures of (15-30% concentration) fuming sulfuric acid and (95-98%) concentrated sulfuric acid as the sulfonating agent. The sulfonation process was conducted at room temperature by varying the acid ratio and reaction time. The produced membranes were then characterized by evaluating the ion exchange capacity (IEC), water uptake, thermal stability, proton conductivity and methanol permeability as a function of degree of sulfonation. The proton conductivity of the sulfonated PEEK membranes with various DS was within the magnitude of 10"-"3 and 10"-"2 S cm"-"1 at room temperature and the methanol permeability was in the range of 3.45 x 10"-"7 to 2.73 x 10"-"6 cm"2 s"-"1. The overall ...

2007-07-15

112

Impedance spectroscopy study with H-doped ammonium uranylphosphate self supported membranes

During the past decades polymer membrane technology has been applied in various industries for a myriad of separation duties. They are also an important candidate for the solution of separation problems associated with the recovery of carbon dioxide in power plants. The application of membrane technology for carbon dioxide removal is discussed for two different ways of operation in present and future power plants. First, pressure driven operations are discussed, followed by a discussion of the use of membranes in absorbers. The pressure driven processes based on currently available gas separation membranes are shown to have poor separation characteristics. Further membrane development work appears to be necessary, especially in the area of temperature resistant membranes. Membrane selectivity goals are presented for present and future power ...

1994-12-31

113

Fundamental study on CO{sub 2} removal from the flue gas of thermal power plant by hollow-fiber gas-liquid contactor

Equivalent circuit and electrical parameters for H-doped NH_4UO_2PO_4.3H_2O self supported membranes have been determined by impedance spectroscopy. The measurements were carried out with a dry membrane, at different temperatures, and a wet membrane in contact with different electrolyte solutions. Resistance values for the dry membrane decrease with temperature increase, which agrees with the weak protonic character of the H-doped ammonium uranylphosphate. On the other hand, differences in the electrical parameters, depending on the electrolyte considered were also obtained and are attributed to different conduction mechanisms. (Author).

114

Newer systems for bacterial resistances to toxic heavy metals.

Microporous membranes are suitable for the CO{sub 2}-MEA (monoethanolamine) system because the overall mass transfer coefficient K of the membrane is approximately 10 times larger than that of composite membranes consisting of microporous membranes and homogeneous membranes. The overall volumetric mass transfer coefficient K{center_dot} of the hollow-fiber contact is more than 5 times larger than that of a conventional packed bed, which suggests that adorption using the present method has the advantage of making the absorption more compact. 8 refs., 7 figs., 4 tabs.

1994-12-31

115

Nature of plant stimulators in the production of Acetobacter xylinum ({open_quotes}Tea fungas{close_quotes}) biofilm used in skin therapy

Bacterial plasmids contain specific genes for resistances to toxic heavy metal ions including Ag+, AsO2-, AsO4(3-), Cd2+, Co2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, Sb3+, and Zn2+. Recent progress with...Full Text Available

1994-09-01

116

Crystal Structure of the Mycobacterium fortuitum Class A ?-Lactamase: Structural Basis for Broad Substrate Specificity

Caffeine and related xanthines were identified as potent stimulators for the bacterial cellulose production in A. xylinum. These compounds are present in several plants whose infusions are useful as culture-medium supplements for this acetobacterium. The proposed target for these native purine-like inhibitory substances is the novel diguanyl nucleotide phosphodiesterase(s) that participates in the bacterial cellulogenic complex.

1991-12-31

117

Introduction of microbial nutrients in a nuclear fuel waste disposal vault as a result of excavation and operation activities

β-Lactamases are the main cause of bacterial resistance to penicillins and cephalosporins. Class A β-lactamases, the largest group of β-lactamases, have been found in many bacterial...Full Text Available

2006-07-01

118

Bacterial Pili exploit integrin machinery to promote immune activation and efficient blood-brain barrier penetration.

A nuclear fuel waste disposal vault would not likely be a sterile environment. Bacterial activity would be expected in those areas of the vault conducive to bacterial life, i.e., where effects of heat, moisture content, radiation and compaction would not prevent or severely restrict bacterial life and where suitable and sufficient nutrients would be present. An inventory of bacterial nutrients that would be emplaced 'intentionally' with vault materials (fuel waste, waste containers, buffer and backfill materials) has been made previously. This report assesses bacterial nutrients that would be added 'inadvertently' to a vault in the form of residues of materials used to excavate and operate a vault. Measurements of blasting material residues in the various water supplies, excavated broken rock (muck) and in cores drilled in old and new tunnel walls were made at AECL's Underground ...

1987-08-27

119

X-radiation effects on muscle cell membrane electrical parameters

Group B Streptococcus (GBS) is the leading cause of meningitis in newborn infants. Bacterial cell surface appendages, known as pili, have been recently described in streptococcal pathogens, including GBS. The pilus tip adhesin, PilA, contributes to GBS adherence to blood-brain barrier (BBB) endothelium; however, the host receptor and the contribution of PilA in central nervous system (CNS) disease pathogenesis are unknown. Here we show that PilA binds collagen, which promotes GBS interaction with the ?(2)?(1) integrin resulting in activation of host chemokine expression and neutrophil recruitment during infection. Mice infected with the PilA-deficient mutant exhibit delayed mortality, a decrease in neutrophil infiltration and bacterial CNS dissemination. We find that PilA-mediated virulence is dependent on neutrophil influx as neutrophil depletion results in a decrease in BBB permeability and GBS-BBB penetration. Our results suggest that the ...

2011-09-06

120

Preparation of new proton exchange membrane based on self-assembly of poly(styrene-co-styrene sulfonic acid)-b-poly(methyl methacrylate)/poly(vinylidene fluoride) blend

Early effects of 100 Kilorads of X-rays on muscle cell membrane properties have been measured in sartorius muscles from Leptodactylus ocellatus. Threshold strength for rectangular current pulses increased 10% after irradiation, and action potential propagation velocity decreased 10%. Passive membrane parameters were calculated from potential responses to sub-threshold current pulses, assuming conventional cable theory. Specific membrane conductance increased to 18% after irradiation, membrane capacitance increased 14%, and length constant decreased 10% but membrane time constant was unchanged. Cell diameter decreased 5%, and resting membrane potential decreased 8%. Membrane parameters during an action potential were also evaluated by the phase-plane and current-voltage plot techniques. Irradiation significantly decreased the action potential ...

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121

Effect of Lactobacillus supplementation with and without arginine on liver damage and bacterial translocation in an acute liver injury model in the rat.

Amphiphilic block copolymers are synthesized by sulfonation of poly(styrene-b-methyl methacrylate) (PS-b-PMMA) using acetyl sulfate, and are blended with poly(vinylidene fluoride) (PVDF) to prepare a new proton exchange membrane, in which PMMA is miscible with PVDF. The morphology and the transport properties of the membranes are investigated as functions of the degree of sulfonation as well as the blend ratio. Notable transition of phase-separated morphology is observed as the PVDF content of the blend is increased. Both the proton conductivity and the ion-exchange capacity (IEC) of the membrane increase with increasing the degree of sulfonation of PS-b-PMMA, and they are also enhanced as the phase-separated domains of blend membrane are well-ordered. Unlike the Nafion membrane, the proton conductivity of the blend membrane increases up to 90 C, indicating the ...

2009-03-01

122

The effect of oxygen enriched air obtained by gas separation membranes from the emission gas of diesel engines

In acute liver failure following hepatitis, toxic insults, or after major liver surgery, there is an increased bacterial translocation from the gut. This may explain some of the infectious complications seen in these conditions. To elucidate mechanisms and find possible preventive measures, we investigated the effect of rectal administration of arginine and probiotic bacteria (Lactobacillus spp.) on bacterial translocation and the extent of liver failure. Sprague-Dawley rats were used and five different Lactobacillus strains (Lb. reuteri R2LC, Lb. rhamnosus DSM 6594 (= strain 271), Lb. plantarum DSM 9843 (= strain 299v), Lb. fermentum 8704:3 (= strain 245), and Lb. reuteri (= strain 108) were administered rectally once daily for 8 days with and without 2% arginine. Acute liver injury (ALI) was induced on the eighth day by intraperitoneal injection of D-galactosamine (1.1 g/kg body weight), and samples were collected after 24 and 48 hours. ...

1997-03-01

123

British Library Electronic Table of Contents (United Kingdom)

Gas separation membranes with polydimethylsiloxane(PDMS)/polystyrene(PS) were prepared by using the sequential interpenetrating polymer network (IPN) method with various PS contents (10?70wt%). These gas separation membranes can be applied to reduce the smoke density in the emission gas of diesel engines. PS content has a pronounced effect on the membrane performance. It was found that the optimized PS contents in the final membrane were 50wt%. The emission capacities of diesel engines used in this study were 632 cc and 11,149 cc. When the oxygen separation membrane was used in the diesel engines, the smoke density of both diesel engines was remarkably reduced (35?73%). The oxygen concentration in the inlet air affects the composition of the emission gases. Especially, hydrocarbon (HC) dec...

2006-01-01

124

Membrane barriers for radon gas flow restrictions

The mammalian neuroendocrine hormone norepinephrine supplies iron for bacterial growth in the presence of transferrin or lactoferrin.

Research was performed to assess the feasibility of barrier membrane substances, for use within mining or associated high risk environments, in restricting the diffusion transport of radon gas quantities. Specific tests were conducted to determine permeability parameters of a variety of membrane materials with reference to radon flow capabilities. Tests were conducted both within laboratory and in-situ emanation environments where concentrations and diffusion flows of radon gas were known to exist. Equilibrium radon gas concentrations were monitored in initially radon-free chambers adjacent to gas sources, but separated by specified membrane substances. Membrane barrier effectiveness was demonstrated to result in reduced emanation concentrations of radon gas within the sampling chamber atmosphere. Minimum gas concentrations were evidenced where the barrier membrane material was ...

125

Tyrosine-derived polycarbonate membrane in treating mandibular bone defects. An experimental study

Norepinephrine stimulates the growth of a range of bacterial species in nutritionally poor SAPI minimal salts medium containing 30% serum. Addition of size-fractionated serum components to SAPI medium indicated that transferrin was required for norepinephrine stimulation of growth of Escherichia coli. Since bacteriostasis by serum is primarily due to the iron-withholding capacity of transferrin, we considered the possibility that norepinephrine can overcome this effect by supplying transferrin-bound iron for growth. Incubation with concentrations of norepinephrine that stimulated bacterial growth in serum-SAPI medium resulted in loss of bound iron from iron-saturated transferrin, as indicated by the appearance of monoferric and apo- isoforms upon electrophoresis in denaturing gels. Norepinephrine also caused the loss of iron from lactoferrin. The pharmacologically inactive metabolite norepinephrine 3-O-sulfate, by contrast, did not result in ...

2000-11-01

126

The Pseudoreceptor BMP and Activin Membrane-bound Inhibitor Positively Modulates Wnt/?-Catenin Signaling*

This study was designed to evaluate the suitability of a novel bioabsorbable material in treating bone defects. A poly(desaminotyrosyl-tyrosine-ethyl ester carbonate) (PDTE carbonate) membrane (thickness...Full Text Available

2006-10-22

127

Taking the plunge: integrating structural, enzymatic and computational insights into a unified model for membrane-immersed rhomboid proteolysis

The canonical Wnt/β-catenin pathway plays a pivotal role in regulating embryogenesis and tumorigenesis by promoting cell proliferation. BAMBI (BMP and activin membrane-bound inhibitor) has...Full Text Available

2008-11-28

128

Sodium ion-dependent amino acid transport in membrane vesicles of Bacillus stearothermophilus.

SYNOPSISRhomboid proteases are a fascinating class of enzymes that combine a serine protease active site within the core of an integral membrane protein. Despite having key roles...Full Text Available

129

Role of plasma membrane calcium ATPase 2 in spinal cord pathology

Amino acid transport in membrane vesicles of Bacillus stearothermophilus was studied. A relatively high concentration of sodium ions is needed for uptake of L-alanine (Kt = 1.0 mM) and L-leucine (Kt...Full Text Available

1991-01-01

130

Pressure driven spinning: A multifaceted approach for preparing nanoscaled functionalized fibers, scaffolds, and membranes with advanced materials

A number of studies have indicated that plasma membrane calcium ATPases (PMCAs) are expressed in the brain and spinal cord and could play important roles not only in the maintenance of cellular calcium...Full Text Available

2010-05-26

131

Membrane nanotubes induced by aqueous phase separation and stabilized by spontaneous curvature

Electrospinning, a flexible jet-based fiber, scaffold, and membrane fabrication approach, has been elucidated as having significance to the heath sciences. Its capabilities have been most impressive...Full Text Available

132

Membrane alteration is necessary but not sufficient for effective glutamate secretion in Corynebacterium glutamicum.

Tubular membrane structures are widespread in eukaryotic cells, but the mechanisms underlying their formation and stability are not well understood. Previous work has focused on tube extrusion from...Full Text Available

2011-03-22

133

Localization of gold in synovial membrane of rheumatoid arthritis treated with sodium aurothiomalate. Studies by electron microscope and electron probe x-ray microanalysis.

We showed recently that secretion of glutamate in biotin-limited cells of Corynebacterium glutamicum is mediated by carrier systems in the plasma membrane (C. Hoischen and R. Krämer, Arch. Microbiol....Full Text Available

1990-06-01

134

K⁺ Channels Are Responsible for an Inwardly Rectifying Current in the Plasma Membrane of Mesophyll Protoplasts of Avena sativa 12

The localization of gold in the synovial membrane of rheumatoid arthritis patients treated with sodium aurothiomalate was examined and quantitative analysis of epon-embedded sections was carried out...Full Text Available

1977-06-01

135

Imaging of membranous dysmenorrhea

In whole-cell recording, the conductance of the plasma membrane of protoplasts isolated from mesophyll cells of leaves of oat (Avena sativa) was greater for inward than outward current....Full Text Available

1992-03-01

136

Identification of novel monosodium urate crystal regulated mRNAs by transcript profiling of dissected murine air pouch membranes

Membranous dysmenorrhea is an unusual clinical entity. It is characterized by the expulsion of huge fragments of endometrium during the menses, favored by hormonal abnormality or drug intake. This report describes a case with clinical, US, and MRI findings before the expulsion. Differential diagnoses are discussed. (orig.)

2001-06-01

137

How cells tiptoe on adhesive surfaces before sticking

IntroductionThe murine air pouch is a bursa-like space that resembles the human synovial membrane. Injection of monosodium urate (MSU) crystals into the pouch elicits an acute inflammatory...Full Text Available

2008-01-01

138

Functional properties of membrane cofactor protein of complement.

Cell membranes are studded with protrusions that were thoroughly analyzed with electron microscopy. However, the nanometer-scale three-dimensional motions generated by cell membranes to fit the topography of foreign surfaces and initiate adhesion remain poorly understood. Here, we describe the dynamics of surface deformations displayed by monocytic cells bumping against fibronectin-coated surfaces. We observed membrane undulations with typically 5 nm amplitude and 5-10 second lifetime. Cell membranes behaved as independent units of micrometer size. Cells detected the presence of foreign surfaces at 50 nm separation, resulting in time-dependent amplification of membrane undulations. Molecular contact then ensued with apparent cell-membrane separation of 30-40 nm, and this distance steadily decreased during the following tens of seconds. Contact maturation was ...

2008-01-01

139

Fluorine-19 NMR Chemical Shift Probes Molecular Binding to Lipid Membranes

Membrane cofactor protein (MCP or gp45-70) of the complement system is a cofactor for factor I-mediated cleavage of fluid-phase C3b and C3b-like C3, which opens the thioester bond. In the present study...Full Text Available

1989-12-01

140

Erythrocyte Membrane Fatty Acid Content in Infants Consuming Formulas Supplemented with Docosahexaenoic Acid (DHA) and Arachidonic Acid (ARA): an Observational Study

The binding of amphiphilic molecules to lipid bilayers is followed by ¹⁹F NMR using chemical shift and line shape differences between the solution and membrane-tethered states of...Full Text Available

2008-05-22

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141

Epigallocatechin-3-gallate affects the growth of LNCaP cells via membrane fluidity and distribution of cellular zinc^*

In this observational study, we compared erythrocyte membrane fatty acids in infants consuming formula supplemented with docosahexaenoic acid (DHA) and arachidonic acid (ARA) with those consuming...Full Text Available

2010-10-01

142

Energetic constraints on the creation of cell membrane pores by magnetic particles.

Objective: To evaluate effects of epigallocatechin-3-gallate (EGCG) on the viability, membrane properties, and zinc distribution, with and without the presence of Zn²⁺, in human prostate...Full Text Available

2009-06-01

143

Electron Spin Resonance Studies of Ionic Permeability Properties of Thylakoid Membranes of Beta vulgaris and Avicennia germinans1

Naturally occurring and contaminant ferromagnetic and ferrimagnetic particles have been found within or near cells, and might allow pulsed magnetic fields to create transient cell membrane opening ("pores")....Full Text Available

1996-08-01

144

Effect of lead on erythrocyte membranes.

Measurement of intrathylakoid aqueous volumes by electron spin resonance spectroscopy was used to study ionic permeability properties of thylakoid membranes isolated from Beta vulgaris...Full Text Available

1985-05-01

145

ESR studies of spin-labeled membranes aligned by isopotential spin-dry ultracentrifugation: lipid-protein interactions.

The effect of blood lead on erythrocyte membrane proteins was studied in 28 workers from a scrap lead refining factory and in 18 controls working in railway construction. Sodium dodecyl sulphate-polyacrylamide...Full Text Available

1983-05-01

146

Dynamic SpoIIIE assembly mediates septal membrane fission during Bacillus subtilis sporulation

Electron spin resonance (ESR) studies have been performed on spin-labeled model membranes aligned using the isopotential spin-dry ultracentrifugation (ISDU) method of Clark and Rothschild. This method...Full Text Available

1994-12-01

147

Dependence of thermal responses of seeds on membrane transitions

SpoIIIE is an FtsK-related protein that transports the forespore chromosome across the Bacillus subtilis sporulation septum. We use membrane photobleaching and protoplast assays to...Full Text Available

2010-06-01

148

Characterization of amino acid transport in membrane vesicles from the thermophilic fermentative bacterium Clostridium fervidus.

Transitions at 28-32°C in membranes of many kinds of seeds influence their germination and subsequent growth. Changes at 28-32°C in the rates of loss of endogenous amino acids from imbibed...Full Text Available

1979-02-01

149

Characteristics of the molecular diversity of the outer membrane protein A gene of Haemophilus parasuis

Amino acid transport was studied in membrane vesicles of the thermophilic anaerobic bacterium Clostridium fervidus. Neutral, acidic, and basic as well as aromatic amino acids were transported at 40...Full Text Available

1989-07-01

150

Carrier-mediated Potassium Efflux Across the Cell Membrane of Red Beet

The molecular diversity of the gene encoding the outer membrane protein A (OmpA) of Haemophilus parasuis has been unclear. In this study, the structural characteristics, sequence types,...Full Text Available

2010-07-01

151

Basement membrane chondroitin sulfate proteoglycan alterations in a rat model of polycystic kidney disease.

The flux ratio (influx/efflux) of K⁺ across the plasmalemma of beet cells at an external potassium concentration of 0.6 mm does not respond to changes of membrane potential in the...Full Text Available

1969-04-01

152

Accelerated interleaflet transport of phosphatidylcholine molecules in membranes under deformation.

Alterations in basement membrane components, notably proteoglycans, in a rat model of polycystic kidney disease have been investigated. Rats were fed phenol II (2-amino-4-hydroxyphenyl-5-phenyl thiazole)...Full Text Available

1994-03-01

153

A new analysis for membrane noise. The integral spectrum.

Biological membranes are lamellar structures composed of two leaflets capable of supporting different mechanical stresses. Stress differences between leaflets were generated during micromechanical experiments...Full Text Available

1996-09-01

154

Polarized neutron diffraction study of CePd{sub 3}

A new method of random data analysis has been developed with special implications for membrane noise. The integral spectrometer uses overlapping broad-band filters of simple design, whose bandwidth...Full Text Available

1976-07-01

155

We have performed polarized neutron diffraction measurements on the intermediate valence compound CePd{sub 3} using the D3 spectrometer at the ILL. The results show that at low temperatures, 1.7 K, as well as at 100 K, the field-induced magnetic amplitudes measured in a field of 4.6 T could be interpreted in terms of two contributions: a 4f-type contribution with a Ce{sup 3+} form factor, and an extra delocalized contribution (relatively narrow in q-extent). In particular, we find that the values of the 4f moment deduced from the extrapolation of the neutron data to Q=0 are systematically lower than the values deduced from bulk magnetization measurements performed on the same sample. This difference can be ascribed to a possible positive polarization of the conduction band which is similar at both temperatures.

2004-07-15

156

lipids - GCMD

Photolabelling reveals differences between cholera toxin and ricin toxin insertion mechanisms

The data set consists of the following: - Biochemical analysis of Deschampsia leaves and root; - Chromatographic Analysis of membrane lipids (lipid profile) ...

157

Modeling and Experimental Study of Carbon Dioxide Absorption in a Membrane Contactor

... carbon 14 cholera gels labelling membranes molecules proteins receptors

1982-07-28

158

Fabrication of a MnCo2O4/gadolinia-doped Ceria (GDC) Dual-phase Composite Membrane for Oxygen Separation

This dissertation deals with membrane gas absorption in the application of CO{sub 2} removal by aqueous alkanolamines, using microporous PTFE hollow fiber membranes. A new lab-scale apparatus was constructed and an extensive experimental study executed to determine the performance of the membrane gas absorber, with aqueous solutions of monoethanolamine (MEA) and methyldiethanolamine (MDEA) as absorbents. The important operation parameters CO{sub 2} partial pressure, gas velocity, liquid velocity, temperature and liquid CO{sub 2} loading were systematically varied within the range typically experienced in a process for exhaust gas CO{sub 2}-removal

2003-03-15

159

Cleaning Aged EPDM Rubber Roofing Membrane Material for ...

Full Text Available

2010-03-01

160

Thermokinetic investigation of effects of carbon source on petroleum bacterial growth

... 5. The results of the bond strength measurements were compared to the surface cleanness of the aged EPDM as determined by the specified ...

1992-08-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

161

The utilization of polysaccharides by heterotrophic bacterioplankton in the Bay of Biscay (North Atlantic Ocean)

The growth power-time curves of a strain of petroleum bacteria, B-2, in various kinds of cultures containing different kinds of carbon sources, glucose, n-tetradecane, n-hexadecane and n-octadecane, and different kinds of microemulsions have been determined by using a 2277 Thermal Activity Monitor. The curves showed a single peak for cultures containing a single carbon source, glucose, and two peaks for cultures containing two kinds of carbon sources, glucose and one of the n-alkanes. The first peak indicated that bacteria grew by consuming glucose and the second peak indicated that bacteria grew by consuming n-alkane. The curves were complex when the bacterium grows in a microemulsion culture. According to a kinetic equation of bacterial growth under limited conditions, the rate constants of bacterial growth were obtained. The results showed that the microemulsion culture was more appropriate to bacteria to grow on n-alkanes.

2002-02-07

162

British Library Electronic Table of Contents (United Kingdom)

This study investigates the turnover of polysaccharides by heterotrophic bacterioplankton in the northern Bay of Biscay, a productive marine system on the continental margin of the temperate Atlantic Ocean. Bacterial biomass production (BBP) near the surface ranged from 0.5 to 25.7 nmol C L?1 h?1 during small phytoplankton blooms in May and June that occurred after the main spring bloom. A direct relationship between BBP and total polysaccharides strongly suggests the dependence of bacterial growth on the availability of semi-labile organic matter. Concentrations of combined glucose as well as rate constants of extracellular glucosidase activity and glucose uptake were determined to estimate the actual carbon fluxes from bacterial polysaccharide turnover. Results reveal that ...

2011-01-01

163

Bacterial vaginosis and other asymptomatic vaginal infections in pregnancy.

Bacterial adhesion reduction on a biocompatible Si^+ ion implanted austenitic stainless steel

Preterm birth is a common cause of neonatal morbidity and mortality. Many asymptomatic genital infections have been associated with preterm birth, but attempts to determine a causal relationship between specific infections and preterm birth have been disappointing. Treatment trials of specific infections have generally failed to show a positive effect, and in some trials have shown a deleterious effect. Although there is a strong association between the presence of bacterial vaginosis and Trichomonas vaginalis in pregnancy and preterm birth, randomized treatment trials have failed to show a benefit of treatment of these organisms. Treatment of asymptomatic bacterial vaginosis or T. vaginalis to prevent preterm birth is not warranted. PMID:12112946

2001-08-01

164

British Library Electronic Table of Contents (United Kingdom)

The colonization of an implant surface by bacteria is an extremely important medical problem, which often leads to the failure of medical devices. Modern surface modification techniques, such as ion implantation, can confer to the surfaces very different properties from those of the bulk underlying material. In this work, austenitic stainless steel 316 LVM has been superficially modified by Si^+ ion implantation. The effect of surface modification on the biocompatibility and bacterial adhesion to 316 LVM stainless steel has been investigated. To this aim, human mesenchymal stem cells (hMSCs), as precursor of osteoblastic cells, and bacterial strains relevant in infections related to orthopedic implants, i.e., Staphylococcus aureus and Staphylococcus epidermidis, have been assayed. For the ...

2011-01-01

165

Allelochemicals produced by Caribbean macroalgae and cyanobacteria have species-specific effects on reef coral microorganisms

British Library Electronic Table of Contents (United Kingdom)

Coral populations have precipitously declined on Caribbean reefs while algal abundance has increased, leading to enhanced competitive damage to corals, which likely is mediated by the potent allelochemicals produced by both macroalgae and benthic cyanobacteria. Allelochemicals may affect the composition and abundance of coral-associated microorganisms that control host responses and adaptations to environmental change, including susceptibility to bacterial diseases. Here, we demonstrate that extracts of six Caribbean macroalgae and two benthic cyanobacteria have both inhibitory and stimulatory effects on bacterial taxa cultured from the surfaces of Caribbean corals, macroalgae, and corals exposed to macroalgal extracts. The growth of 54 bacterial isolates was monitored in the presence of l...

2011-01-01

166

cDNA Cloning of the Basement Membrane Chondroitin Sulfate Proteoglycan Core Protein, Bamacan: A Five Domain Structure Including Coiled-Coil Motifs

Use of ceramic porous membranes in molten carbonate fuel cells

Basement membranes contain several proteoglycans, and those bearing heparan sulfate glycosaminoglycans such as perlecan and agrin usually predominate. Most mammalian basement membranes also contain...Full Text Available

1997-01-27

167

Toughness of membranes applied in polymer electrolyte fuel cells

The diffusion of alkali vapours in the anode compartment of a DIR-MCFC produces the deactivation of the internal reforming catalyst. Sets of ceramic porous membranes purposed to limit the diffusion have been manufactured by different techniques and the influence of the preparation technique and of the preparative variables on the morphological characteristics of the membranes structures has been studied.

1996-12-31

168

Stakeholder acceptance analysis: In-well vapor stripping, in-situ bioremediation, gas membrane separation system (membrane separation)

Since several years we apply the radiation-grafting technique to prepare polymeric membranes for application in polymer electrolyte fuel cells (PEFCs). Our investigations presented here focus on changes in toughness of these materials after the various synthesis steps and the importance of membrane toughness for their application in PEFCs. (author) 2 figs., 4 refs.

1999-08-01

169

Ion-Track Membranes and Their Use in Biological and Medical Applications

This document provides stakeholder evaluations on innovative technologies to be used in the remediation of volatile organic compounds from soils and ground water. The technologies evaluated are; in-well vapor stripping, in-situ bioremediation, and gas membrane separation.

1995-12-01

170

High resolution neutron imaging of water in the polymer electrolyte fuel cell membrane

This report is a brief review of biological and medical applications of ion-track membranes. The review aims at informing nuclear physicists about alternative (i.e. non-fundamental-science) use of heavy ion accelerators such as production of micro- and nano-porous materials. The ion-track membranes produced this way are employed in life sciences and numerous technological applications. The author focuses on recent results from the Flerov laboratory in co-operation with other scientific institutions and industrial partners.

2007-05-22

171

Worlds within worlds: evolution of the vertebrate gut microbiota

Water transport in the ionomeric membrane, typically Nafion{reg_sign}, has profound influence on the performance of the polymer electrolyte fuel cell, in terms of internal resistance and overall water balance. In this work, high resolution neutron imaging of the Nafion{reg_sign} membrane is presented in order to measure water content and through-plane gradients in situ under disparate temperature and humidification conditions.

2009-01-01

172

Transcriptome Profiling of a Toxic Dinoflagellate Reveals a Gene-Rich Protist and a Potential Impact on Gene Expression Due to Bacterial Presence

Here we use published 16S rRNA gene sequences to compare the bacterial assemblages associated with humans, other mammals, other metazoa, and free-living microbial communities spanning a range...Full Text Available

2008-10-01

173

The inhibition of staphylococcus epidermidis biofilm formation by vancomycin-modified titanium alloy and implications for the treatment of periprosthetic infection

BackgroundDinoflagellates are unicellular, often photosynthetic protists that play a major role in the dynamics of the Earth's oceans and climate. Sequencing of dinoflagellate nuclear...Full Text Available

174

The antimicrobial resistance patterns and associated determinants in Streptococcus suis isolated from humans in southern Vietnam, 1997-2008

Peri-prosthetic infections are notoriously difficult to treat as the biomaterial implant is ideal for bacterial adhesion and biofilm formation, resulting in decreased antibiotic sensitivity....Full Text Available

2008-12-01

175

The Subtilisin-Like Protease AprV2 Is Required for Virulence and Uses a Novel Disulphide-Tethered Exosite to Bind Substrates

BackgroundStreptococcus suis is an emerging zoonotic pathogen and is the leading cause of bacterial meningitis in adults in Vietnam. Systematic data on the antimicrobial...Full Text Available

176

Single-Step Production of a Recyclable Nanobiocatalyst for Organophosphate Pesticides Biodegradation Using Functionalized Bacterial Magnetosomes

Many bacterial pathogens produce extracellular proteases that degrade the extracellular matrix of the host and therefore are involved in disease pathogenesis. Dichelobacter nodosus...Full Text Available

2010-11-01

177

Seasonal and Spatial Variability of Bacterial and Archaeal Assemblages in the Coastal Waters near Anvers Island, Antarctica

Enzymes are versatile catalysts in laboratories and on an industrial scale; improving their immobilization would be beneficial to broadening their applicability and ensuring their (re)use. Lipid-coated...Full Text Available

178

Relationship between Hydroxy Fatty Acids and Prostaglandin E₂ in Gingival Tissue

A previous report of high levels of members of the domain Archaea in Antarctic coastal waters prompted us to investigate the ecology of Antarctic planktonic prokaryotes. rRNA hybridization...Full Text Available

1998-07-01

179

Pseudomonas aeruginosa selective adherence to and entry into human endothelial cells.

Bacterial hydroxy fatty acids and alpha-hydroxy fatty acids have been demonstrated in complex lipid extracts of subgingival plaque and gingival tissue. However, little is known about the relationship...Full Text Available

1998-12-01

180

Plant and algal interference in bacterial beta-D-galactosidase and beta-D-glucuronidase assays.

The pathogenesis of Pseudomonas aeruginosa disseminated infections depends on bacterial interaction with blood vessels. We have hypothesized that in order to traverse the endothelial barrier, bacteria...Full Text Available

1994-12-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

181

Parallel Evolution of a Type IV Secretion System in Radiating Lineages of the Host-Restricted Bacterial Pathogen Bartonella

Several commonly occurring freshwater and marine plants and algae were screened for beta-D-galactosidase and beta-D-glucuronidase activities by using a 60-min enzyme assay based on the hydrolysis by...Full Text Available

1994-11-01

182

Overexpression of bacterial ethylene-forming enzyme gene in Trichoderma reesei enhanced the production of ethylene

Adaptive radiation is the rapid origination of multiple species from a single ancestor as the result of concurrent adaptation to disparate environments. This fundamental evolutionary process is considered...Full Text Available

2011-02-01

183

OmpA of Uropathogenic Escherichia coli Promotes Postinvasion Pathogenesis of Cystitis?

In order to efficiently utilize natural cellulose materials to produce ethylene, three expression vectors containing the ethylene-forming enzyme (efe) gene from Pseudomonas...Full Text Available

184

Occurrence and distribution of bacterial indicators and pathogens in canal communities along the Texas coast.

Type 1 pilus directs bladder epithelial binding and invasion by uropathogenic Escherichia coli (UPEC) in the initial stage of cystitis, but the bacterial determinants of postinvasion...Full Text Available

2009-12-01

185

Nuclear receptor ERR? and coactivator PGC-1? are effectors of IFN-?-induced host defense

Increased construction of residential canal communities along the southern coastline of the United States has led to a concern about their impact on water quality. Pollution of such dead-end canals...Full Text Available

1977-08-01

186

Molecular Evidence of Bartonella Infection in Domestic Dogs from Algeria, North Africa, by Polymerase Chain Reaction (PCR)

Macrophage activation by the proinflammatory cytokine interferon-γ (IFN-γ) is a critical component of the host innate response to bacterial pathogenesis. However, the precise nature...Full Text Available

2007-08-01

187

Modification of Spatial Distribution of 2,4-Dichlorophenoxyacetic Acid Degrader Microhabitats during Growth in Soil Columns

Bartonella species are being recognized as important bacterial human and canine pathogens, and are associated with multiple arthropod vectors. Bartonella DNA extracted...Full Text Available

2010-08-05

188

Measurement of the Water Potential of Stored Potato Tubers ¹

Bacterial processes in soil, including biodegradation, require contact between bacteria and substrates. Knowledge of the three-dimensional spatial distribution of bacteria at the microscale is necessary...Full Text Available

2004-05-01

189

LOUSE-BORNE BACTERIAL PATHOGENS IN LICE (PHTHIRAPTERA) OF RODENTS AND CATTLE FROM EGYPT

A method of measuring the water potential of stored potato tubers (Solanum tuberosum L.) was needed to investigate the relationship of bacterial soft rot in tubers to water potential....Full Text Available

1985-11-01

190

Intragenomic conflict in populations infected by Parthenogenesis Inducing Wolbachia ends with irreversible loss of sexual reproduction

... were erroneous. The oriental rat flea, Xenopsylla cheopis Rothschild, is considered to be the primary vector of ... laboratory and production of Weigl's exanthematous typhus vaccine. In Maintenance of hum...

191

Insights into Genome Plasticity and Pathogenicity of the Plant Pathogenic Bacterium Xanthomonas campestris pv. vesicatoria Revealed by the Complete Genome Sequence

BackgroundThe maternally inherited, bacterial symbiont, parthenogenesis inducing (PI) Wolbachia, causes females in some haplodiploid insects to produce daughters...Full Text Available

192

Induction of nonspecific tolerance to endotoxins reduces the alveolar bone resorption in ligature-treated rats.

The gram-negative plant-pathogenic bacterium Xanthomonas campestris pv. vesicatoria is the causative agent of bacterial spot disease in pepper and tomato plants, which leads to economically...Full Text Available

2005-11-01

193

In vivo expression and mitochondrial targeting of yeast apoiso-1-cytochrome c fusion proteins.

Previous experimental data from various laboratories indicate that endotoxin of gram-negative oral microorganisms might be one of the most important bacterial products involved in bone resorption during...Full Text Available

1983-02-01

194

Identification of plasmid and Bacillus subtilis chromosomal recombination sites used for pE194 integration.

To define the import pathway for apoiso-1-cytochrome c in vivo, the coding region for bacterial chloramphenicol acetyltransferase (CAT) or yeast copper metallothionein (CuMT) was fused to the carboxy...Full Text Available

1990-11-01

195

Identification of genomic differences between Campylobacter jejuni subsp. jejuni and C. jejuni subsp. doylei at the nap locus leads to the development of a C. jejuni subspeciation multiplex PCR method

The plasmid pE194 (3.7 kilobases) is capable of integrating into the genome of the bacterial host Bacillus subtilis in the absence of the major homology-dependent RecE recombination system. Multiple...Full Text Available

1989-05-01

196

Heavy metals alter the electrokinetic properties of bacteria, yeasts, and clay minerals.

BackgroundThe human bacterial pathogen Campylobacter jejuni contains two subspecies: C. jejuni subsp. jejuni (Cjj)...Full Text Available

197

Gingival crevicular fluid levels of clindamycin compared with its minimal inhibitory concentrations for periodontal bacteria.

The electrokinetic patterns of four bacterial species (Bacillus subtilis, Bacillus megaterium, Pseudomonas aeruginosa, and Agrobacterium radiobacter), two yeasts (Saccharomyces cerevisiae and Candida...Full Text Available

1992-05-01

198

Genomic Evidence for the Evolution of Streptococcus equi: Host Restriction, Increased Virulence, and Genetic Exchange with Human Pathogens

Clindamycin concentrations in gingival crevicular fluid and in blood were determined over a 7-h period and were related to the minimal inhibitory concentrations of this agent for 340 bacterial strains...Full Text Available

1981-05-01

199

Genome-Wide Transcriptional Response of Chemostat-Cultured Escherichia coli to Zinc

The continued evolution of bacterial pathogens has major implications for both human and animal disease, but the exchange of genetic material between host-restricted pathogens is rarely considered....Full Text Available

2009-03-01

200

Genetic Heterogeneity in Severe Congenital Neutropenia: How Many Aberrant Pathways Can Kill a Neutrophil?

Zinc is an essential trace metal ion for growth, but an excess of Zn is toxic and microorganisms express diverse resistance mechanisms. To understand global bacterial responses to excess Zn, we conducted...Full Text Available

2005-02-01

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201

Genetic Evidence for Inhibition of Bacterial Division Protein FtsZ by Berberine

Purpose of reviewSevere congenital neutropenia (SCN) is a primary immunodeficiency in which lack of neutrophils causes inadequate innate immune host response to bacterial...Full Text Available

2007-12-01

202

Factors Affecting Daughter Cells' Arrangement during the Early Bacterial Divisions

BackgroundBerberine is a plant alkaloid that is widely used as an anti-infective in traditional medicine. Escherichia coli exposed to berberine form filaments, suggesting...Full Text Available

203

Evaluating the Involvement of Alternative Sigma Factors SigF and SigG in Clostridium perfringens Sporulation and Enterotoxin Synthesis?

On agar plates, daughter cells of Escherichia coli mutually slide and align side-by-side in parallel during the first round of binary fission. This phenomenon has been previously attributed...Full Text Available

204

Endometrial biopsy in Holstein-Friesian dairy cows. III. Bacteriological analysis and correlations with histological findings.

Clostridium perfringens type A food poisoning is the second most commonly identified bacterial food-borne illness. Sporulation contributes to this disease in two ways: (i) most food-poisoning...Full Text Available

2010-10-01

205

Endogenous Nitric Oxide Protects Bacteria Against a Wide Spectrum of Antibiotics

This study examines the results of bacterial culture from 159 endometrial biopsy samples from 97 commercial dairy cows and correlations between bacteriological and histological findings. Bacteria were...Full Text Available

1991-04-01

206

Effect of Wastewater Treatment Plant Effluent on Microbial Function and Community Structure in the Sediment of a Freshwater Stream with Variable Seasonal Flow?

Bacterial nitric oxide synthases (bNOS) are present in many Gram-positive species and have been demonstrated to synthesize NO from arginine in vitro and in vivo. However, the physiological role...Full Text Available

2009-09-11

207

Effect of Feeding Cows Genetically Modified Maize on the Bacterial Community in the Bovine Rumen?

We investigated the effects of wastewater treatment plant (WWTP) discharge on the ecology of bacterial communities in the sediment of a small, low-gradient stream in South Australia. The quantification...Full Text Available

2008-05-01

208

Distribution Frequency of Pathogenic Bacteria Isolated from Cutaneus Leishmaniasis Lesions

Rumen-cannulated cows (n = 4) were fed successively silage made from either conventional or genetically modified (GM) maize. Results revealed no effects of GM maize on the dynamics...Full Text Available

2007-12-01

209

Distinct signatures of diversifying selection revealed by genome analysis of respiratory tract and invasive bacterial populations

Cutaneous leishmaniasis (CL) is a parasitic disease characterized by single or multiple ulcerations. Secondary bacterial infections are one of the complications that can increase the tissue destruction...Full Text Available

2008-09-01

210

Display of Recombinant Proteins on Bacillus subtilis Spores, Using a Coat-Associated Enzyme as the Carrier?

Many pathogens colonize different anatomical sites, but the selective pressures contributing to survival in the diverse niches are poorly understood. Group A Streptococcus (GAS) is...Full Text Available

2011-03-22

211

Detection of Streptococcus mutans Genomic DNA in Human DNA Samples Extracted from Saliva and Blood

The display of proteins such as feed enzymes at the surface of bacterial spore systems has a great potential use for animal feed. Feed enzymes increase the digestibility of nutrients, leading to greater...Full Text Available

2010-09-01

212

Detection of Atopobium vaginae in Postmenopausal Women by Cultivation-Independent Methods Warrants Further Investigation

Caries is a multifactorial disease, and studies aiming to unravel the factors modulating its etiology must consider all known predisposing factors. One major factor is bacterial colonization,...Full Text Available

2011-01-01

213

Delineating Bacteriostatic and Bactericidal Targets in Mycobacteria Using IPTG Inducible Antisense Expression

We sequenced 16S rRNA genes from the vaginal swab contents of a postmenopausal woman with asymptomatic bacterial vaginosis (BV). Sequences from Atopobium vaginae were the most commonly...Full Text Available

2004-04-01

214

Biotransformation of Explosives by the Old Yellow Enzyme Family of Flavoproteins

In order to identify novel high value antibacterial targets it is desirable to delineate whether the inactivation of the target enzyme will lead to bacterial death or stasis. This knowledge is particularly...Full Text Available

215

Biological processing and interactions with coal: Summary of activities for the period January 1, 1988--March 31, 1988

Several independent studies of bacterial degradation of nitrate ester explosives have demonstrated the involvement of flavin-dependent oxidoreductases related to the old yellow enzyme (OYE) of yeast....Full Text Available

2004-06-01

216

Binary Bacterial Toxins: Biochemistry, Biology, and Applications of Common Clostridium and Bacillus Proteins

Biodegradation/solubilization of coal is described. The degradation of dibenzothiophene by two bacterial strains is reported. The effects of adding salicylate to the treatments was also investigated. 2 figs., 5 tabs. (CBS)

1988-01-01

217

Bacterial response to siderophore and quorum-sensing chemical signals in the seawater microbial community

Certain pathogenic species of Bacillus and Clostridium have developed unique methods for intoxicating cells that employ the classic enzymatic “A-B” paradigm for protein toxins. The binary...Full Text Available

2004-09-01

218

Bacterial lipopolysaccharide induces an endocrine switch from prostaglandin F_2? to prostaglandin E₂ in bovine endometrium

BackgroundOceans are iron-deficient and nutrient-poor environments. These conditions impart limitations on our understanding of and our ability to identify microorganisms from the...Full Text Available

219

Bacterial infections in suspected cutaneous leishmaniasis lesions.

Escherichia coli infection of the endometrium causes uterine disease after parturition and is associated with prolonged luteal phases of the ovarian cycle in cattle. Termination...Full Text Available

2009-04-01

220

Bacterial indicators of risk of diarrhoeal disease from drinking-water in the Philippines.

In Iran, microscopic examination of skin scrapings from 2202 individuals with clinically diagnosed cutaneous leishmaniasis (CL) lesions revealed the presence of amastigotes in 1123 cases (51.0%). Bacteriological...Full Text Available

1990-01-01

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221

Bacterial glycolipids and analogs as antigens for CD1d-restricted NKT cells

Inadequate measures of water quality have been used in many studies of the health effects associated with water supplies in developing countries. The present 1-year epidemiological-microbiological study...Full Text Available

1991-01-01

222

Association of Nasophyaryngeal Bacterial Colonization during Upper Respiratory Tract Infection and the Development of Acute Otitis Media

The CD1 family of proteins binds self and foreign glycolipids for presentation to CD1-restricted T cells. To identify previously uncharacterized active CD1 ligands, especially those of microbial origin,...Full Text Available

2005-02-01

223

Association between skin diseases and severe bacterial infections in children: case-control study

Acute Otitis Media occurs mostly after upper respiratory tract infection; the causative bacteria are those colonized in the nasopharynx. We studied 709 URI episodes and found that children with...Full Text Available

2008-02-15

224

Antimicrobial susceptibilities of bacteria associated with periodontal disease.

BackgroundSepsis or bacteraemia, however rare, is a significant cause of high mortality and serious complications in children. In previous studies skin disease or skin infections...Full Text Available

225

Analysis of the Sulfate-Reducing Bacterial and Methanogenic Archaeal Populations in Contrasting Antarctic Sediments

A total of 193 bacterial strains were tested for their susceptibilities to 14 antimicrobial agents. Penicillin G was active at 2 U/ml against 98% of the oral isolates. Other antibiotics with good activity...Full Text Available

1983-03-01

226

Allosteric regulation of glycerol kinase by enzyme IIIglc of the phosphotransferase system in Escherichia coli and Salmonella typhimurium.

The distribution and activity of communities of sulfate-reducing bacteria (SRB) and methanogenic archaea in two contrasting Antarctic sediments were investigated. Methanogenesis dominated in freshwater...Full Text Available

2003-06-01

227

Adrenaline modulates the global transcriptional profile of Salmonella revealing a role in the antimicrobial peptide and oxidative stress resistance responses

The mechanism by which enzyme IIIglc of the bacterial phosphotransferase system regulates the activity of crystalline glycerol kinase from Escherichia coli has been studied, and the inhibitory effects...Full Text Available

1985-05-01

228

Actinobacillus actinomycetemcomitans Lipopolysaccharide-Mediated Experimental Bone Loss Model for Aggressive Periodontitis

BackgroundThe successful interaction of bacterial pathogens with host tissues requires the sensing of specific chemical and physical cues. The human gut contains a huge number of...Full Text Available

229

Acetic Acid Bacterial Biota of the Pink Sugar Cane Mealybug, Saccharococcus sacchari, and Its Environs

BackgroundBacterial constituents, such as Gram-negative derived lipopolysaccharide (LPS), can initiate inflammatory bone loss through induction of host-derived inflammatory...Full Text Available

2007-03-01

230

ADP-Glucose Pyrophosphorylase, a Regulatory Enzyme for Bacterial Glycogen Synthesis

Saccharococcus sacchari is the primary colonizer of the developing “sterile” tissue between the leaf sheath and stem of sugar cane. The honeydew secreted by the mealybugs...Full Text Available

1990-03-01

231

A report of clinical trial conducted on Toto ointment and soap products.

The accumulation of α-1,4-polyglucans is an important strategy to cope with transient starvation conditions in the environment. In bacteria and plants, the synthesis of glycogen and starch occurs...Full Text Available

2003-06-01

232

A Marker-Dense Physical Map of the Bradyrhizobium japonicum Genome

OBJECTIVE: The efficacy of Toto ointment and soap on common skin disorders was tested. METHODOLOGY: A cohort of Nigerians with common skin conditions such as fungal and bacterial skin infections, scabies,...Full Text Available

2003-01-01

233

A Coxiella burnetti repeated DNA element resembling a bacterial insertion sequence.

Bacterial artificial chromosome (BAC) clones are effective mapping and sequencing reagents for use with a wide variety of small and large genomes. This report describes the development of a physical...Full Text Available

2001-08-01

234

Simulation and design of membrane plants with AspenPlus

A DNA fragment located on the 3' side of the Coxiella burnetii htpAB operon was determined by Southern blotting to exist in approximately 19 copies in the Nine Mile I genome. The DNA sequences of this...Full Text Available

1992-09-01

235

Positron annihilation study on thin-film composite pervaporation membranes: Correlation between polyamide fine structure and different interfacial polymerization conditions

In this paper the simulation of hybrid processes containing membrane units will be discussed. For this purpose a user-defined module for simulation and design of membrane processes was implemented into the simulation program AspenPlus. The advantages can be summarized as follows: - any combination of membrane processes with all other units already implemented in AspenPlus is possible, including internal recycle streams, - utilization of the physical property models and data bases of AspenPlus is possible, - cost and sensitivity analysis can be performed. These benefits are demonstrated in detail for a membrane vapor recovery unit for the treatment of tank farm off-gas, for a two-stage reverse osmosis plant for organic/-organic separations and for a combination of distillation and pervaporation for the separation of a dimethylcarbonate/methanol mixture. (orig.)

1996-10-01

236

British Library Electronic Table of Contents (United Kingdom)

To investigate the variation in the fine structure of polyamide thin-film composite (TFC) membranes prepared via two different interfacial polymerization conditions (IP-I and IP-II), experiments on Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), water contact angle, and positron annihilation spectroscopy (PAS) coupled to a slow positron beam were conducted. Polyamide TFC membranes were prepared via the interfacial polymerization reaction between triethylenetetramine (TETA) and trimesoyl chloride (TMC) on the surface of a modified polyacrylonitrile (mPAN) membrane. Compared with the polyamide TFC membrane prepared via IP-I, the polyamide layer prepared via IP-II showed a shorter S plateau length (thinner thickness), a higher o-Ps intensity I3 value (higher free-volume con...

2010-01-01

237

Kinetics of gypsum crystal growth on a reverse osmosis membrane

British Library Electronic Table of Contents (United Kingdom)

The development of calcium sulfate dihydrate (gypsum) mineral scale in reverse osmosis (RO) membrane desalting was investigated by direct real-time observation of crystal growth. Gypsum scaling studies were conducted in a specially modified plate-and-frame reverse osmosis cell fitted with an optical window, with dark-field membrane lighting arrangement within the membrane cell to enhance crystal boundaries and allow recording of digital surface images magnified through an optical microscope. The evolution of the surface number density (SND) of gypsum crystals resembled a sigmoidal population growth process with an increasing rate of crystal formation at higher solution supersaturation (with respect to gypsum) at the membrane surface. The rate of formation of new crystals declined as the su...

2008-01-01

238

Impedance spectroscopy study with H-doped ammonium uranylphosphate self supported membranes

Electrochemistry Modeling of Proton Exchange Membrane (PEM) Water Electrolysis for Hydrogen Production

Equivalent circuit and electrical parameters for H-doped NH{sub 4}UO{sub 2}PO{sub 4}.3H{sub 2}O self supported membranes have been determined by impedance spectroscopy. The measurements were carried out with a dry membrane, at different temperatures, and a wet membrane in contact with different electrolyte solutions. Resistance values for the dry membrane decrease with temperature increase, which agrees with the weak protonic character of the H-doped ammonium uranylphosphate. On the other hand, differences in the electrical parameters, depending on the electrolyte considered were also obtained and are attributed to different conduction mechanisms. (Author).

1995-01-01

239

Artificial kidney engineering-Dialysis membrane and dialyzer for blood purification-

An electrochemistry model was developed to analyse the J-V characteristics of a Proton Exchange Membrane (PEM) water electrolyzer for hydrogen production. The Butler-Volmer equation and water transport characteristics through electrolyte membrane were employed to simulate the electrode activation over-potential and membrane ohmic over-potential, respectively. The modeling results are found to agree reasonably well with experimental data published in the literature. The parametric simulations show that the ohmic over-potential is relatively small with typical water content in the membrane. Compared with the cathode over-potential, the anode over-potential is more significant and constitutes the major source of voltage loss. The high anode over-potential is due to the relatively slow oxidation kinetics, which is related to anode material property and microstructure. This model can be integrated with a ...

2006-06-13

240

Effect of tetracycline hydrochloride treatment on the critical thermal maximum of common shiners

Since artificial organs are intended to replicate chemical processes, knowledge of chemical engineering is essential in their design so that they will function with the maximum efficiency. The most commonly used artificial organ is the artificial kidney, a machine that performs a treatment known as hemodialysis. This process cleanses the bodies of renal failure patients by dialysis and filtration which are simple physiochemical processes. Hemodialysis membranes act to remove accumulated uremia toxins, excess ions and water from the patient via the dialysate, and to supply from the dialysate those ions that are insufficient. This paper describes dialysis membranes and dialyzers for blood purification, the solute transport mechanism of the membrane, and a technical evaluation of the dialysis membrane. Lastly, the next generation of artificial kidney is reviewed. 71 refs., 12 figs., 7 tabs.

1997-08-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

241

Sulfonated poly(ether ether ketone) based composite membranes for nanofiltration of acidic and alkaline media

The transfer of fish from field to laboratory facilities or their propagation in closed or restricted systems frequently results in bacterial infection and ultimately large-scale mortality. In attemps to alleviate this problem, we have added tetracycline hydrochloride to the water prophylactically (pretreating tanks before wild fish were added) and therapeutically (treating tanks after bacterial outbreaks were detected.) In the present study, we examined the effect of tetracyline hydrochloride on the critical thermal maximum (CTM) of the common shiner (Notropis cornutus).

1980-01-01

242

British Library Electronic Table of Contents (United Kingdom)

Several thin film composite nanofiltration membranes have been prepared by spin coating a sulfonated poly(ether ether ketone) solution on a polyethersulfone support, followed by thermal treatment. The most optimal developed nanofiltration membrane shows a clean water permeance of ~4.5Lm^-^2h^-^1bar^-^1 and a molecular weight cut off (MWCO) of ~500gmol^-^1. No irreversible changes in membrane performance have been observed after prolonged exposure (up to several weeks) of this membrane to solutions with a pH in the range 0-14. Compared to Desal-5-DK, the developed membrane displays a similar water permeance and a higher NaCl retention. In comparison to commercially available pH stable membranes, MPF-34 and NP030P, it reveals a higher water permeance. Permeance and MWCO analysis at varying p...

2011-01-01

243

Radiosynthesis of hydrogel confined to hollow-fiber membranes for the design of a bioartificial extra-corporeal liver

Radiation inactivation target size of rat adipocyte glucose transporters in the plasma membrane and intracellular pools

Current bioartificial extra-corporeal systems are bioreactors where cells are separated from the surrounding media by porous polymeric membranes. The present work focuses on the design of membranes that allow the differential diffusion of plasma metabolites and proteins such as immunoglobulin (IgG). This design will improve catabolites removal and reduce possible immune response and virus infection. We demonstrate the feasibility to synthesize the hydrogels confined to the macroporous structure of membranes by radiation-induced in situ polymerization. The hollow-fiber membranes were soaked in aqueous monomeric solution, rinsed and irradiated while submerged in oil. This procedure confined the hydrogel to the void internal volume of the pores of the membrane. Hydrogels of polyacrylamide and polyHEMA were synthesized this way by irradiation at 10 kGy. Hydraulic permeability and ...

2007-08-15

244

Proteomic analysis of the shistosome tegument and its surface membranes

The in situ assembly states of the glucose transport carrier protein in the plasma membrane and in the intracellular (microsomal) storage pool of rat adipocytes were assessed by studying radiation-induced inactivation of the D-glucose-sensitive cytochalasin B binding activities. High energy radiation inactivated the glucose-sensitive cytochalasin B binding of each of these membrane preparations by reducing the total number of the binding sites without affecting the dissociation constant. The reduction in total number of binding sites was analyzed as a function of radiation dose based on target theory, from which a radiation-sensitive mass (target size) was calculated. When the plasma membranes of insulin-treated adipocytes were used, a target size of approximately 58,000 daltons was obtained. For adipocyte microsomal membranes, we obtained target sizes of approximately 112,000 and 109,000 daltons prior ...

1987-06-15

245

Scientific Electronic Library Online (English)

Abstract in english The tegument surface of the adult schistosome, bounded by a normal plasma membrane overlain by a secreted membranocalyx, holds the key to understanding how schistosomes evade host immune responses. Recent advances in mass spectrometry (MS), and the sequencing of the Schistosoma mansoni transcriptome/genome, have facilitated schistosome proteomics. We detached the tegument from the worm body and enriched its surface membranes by differential extraction, before subjecting t (more) he preparation to liquid chromatography-based proteomics to identify its constituents. The most exposed proteins on live worms were labelled with impearmeant biotinylation reagents, and we also developed methods to isolate the membranocalyx for analysis. We identified transporters for sugars, amino acids, inorganic ions and water, which confirm the importance of the tegument plasma membrane in nutrient acquisition and solute ...

2006-10-01

246

Proteins of the kidney microvillar membrane

Characterisation of a re-cast composite Nafion 1100 series of proton exchange membranes incorporating inert inorganic oxide particles

Two methods were used to label pig kidney microvillar membrane proteins from the luminal and cytoplasmic surfaces of closed membrane vesicles. The first method was lactoperoxidase-catalysed radioiodination. Lactoperoxidase and glucose oxidase were positioned inside or outside the vesicles, iodination being initiated by adding glucose and "1"2"5I. After electrophoresis of the proteins, asymmetric labelling patterns on radioautographs were observed. However the major disadvantage of this method was the high degree of intramembrane labelling of the fatty acid chains of membrane lipids. The second method overcame this disadvantage. A new hydophilic photoreagent, 3,5-di("1"2"5I)iodo-4-azidobenzenesulphonate, was transported by a Na"+-dependent system into microvillar vesicles, thus permitting labelling from either side of the membrane when the vesicles were photolysed. The activity of several microvillar ...

247

The Relationships between Xylem Safety and Hydraulic Efficiency in the Cupressaceae: The Evolution of Pit Membrane Form and Function1[W][OA

A series of cation exchange membranes was produced by impregnating and coating both sides of a quartz web with a Nafion solution (1100 EW, 10%wt in water). Inert filler particles (SiO_2, ZrO_2 or TiO_2; 5-20%wt) were incorporated into the aqueous Nafion solution to produce robust, composite membranes. Ion-exchange capacity/equivalent weight, water take-up, thickness change on hydration and ionic and electrical conductivity were measured in 1 mol dm"-"3 sulfuric acid at 298 K. The TiO_2 filler significantly impacted on these properties, producing higher water take-up and increased conductivity. Such membranes may be beneficial for proton exchange membrane (PEM) fuel cell operation at low humidification. The PEM fuel cell performance of the composite membranes containing SiO_2 fillers was examined in a Ballard Mark 5E unit cell. While the use of composite ...

2010-09-01

248

Experimental validation of upgraded designs for PERMCAT reactors considering mechanical behaviour of Pd/Ag membranes under H{sub 2} atmosphere

Water transport in conifers occurs through single-celled tracheids that are connected to one another via intertracheid pit membranes. These membranes have two components: the porous margo, which allows water to pass through the membrane, and the impermeable torus, which functions to isolate gas-filled tracheids. During drought, tracheids can become air filled and thus hydraulically dysfunctional, a result of air entering through the pit membrane and nucleating cavitation in the water column. What are the hydraulic tradeoffs associated with cavitation resistance at the pit level, and how do they vary within the structural components of the intertracheid pit? To address these questions, we examined pit structure in 15 species of Cupressaceae exhibiting a broad range of cavitation resistances. Across species, cavitation resistance was most closely correlated to the ratio of the torus to pit aperture ...

2010-08-15

249

Experimental validation of upgraded designs for PERMCAT reactors considering mechanical behaviour of Pd/Ag membranes under H_2 atmosphere

The PERMCAT process chosen for the final clean-up stage of the Tokamak Exhaust Processing system of the ITER tritium plant combines in a single component a catalytic reactor and a permeator using Pd/Ag membranes. This study covers the mechanical behaviour of a Pd/Ag membrane under different operating conditions. The consequences of hydrogen uptake by the membrane during nominal operation but also during off-normal events are presented. Depending on the operating conditions, expansions around 2% and significant deformations are observed. Different mechanical designs of PERMCAT reactors are then discussed. The first generation comprises finger-type membranes and two new mechanical designs use either additional edge welded bellows or a special corrugated Pd/Ag membrane. These upgraded designs improve the robustness and simplify the geometry of the component. The experimental validation ...

2007-10-15

250

ELECTROLYTIC MEMBRANE DIALYSIS FOR TREATING WASTEWATER STREAMS

The PERMCAT process chosen for the final clean-up stage of the Tokamak Exhaust Processing system of the ITER tritium plant combines in a single component a catalytic reactor and a permeator using Pd/Ag membranes. This study covers the mechanical behaviour of a Pd/Ag membrane under different operating conditions. The consequences of hydrogen uptake by the membrane during nominal operation but also during off-normal events are presented. Depending on the operating conditions, expansions around 2% and significant deformations are observed. Different mechanical designs of PERMCAT reactors are then discussed. The first generation comprises finger-type membranes and two new mechanical designs use either additional edge welded bellows or a special corrugated Pd/Ag membrane. These upgraded designs improve the robustness and simplify the geometry of the component. The experimental validation ...

2007-10-01

251

Development of a new evaporator using hydrophobic membrane for radioactive liquid waste

This project will determine whether electrolytic dialysis has promise in the separation of charged particles in an aqueous solution. The ability to selectively move ions from one aqueous solution to another through a semipermeable membrane will be studied as a function of emf, amperage, and particle electrical charge. The ions selected for the study are Cl{sup -} and SO{sub 4}{sup 2-}. These ions are of particular interest because of their electrical conduction properties in aqueous solution resulting with their association with the corrosive action of metals. The studies will be performed with commercial membranes on solutions prepared in the laboratory from reagent salts. pH adjustments will be made with dilute reagent acid and base. Specific objectives of the project include testing a selected membrane currently available for electrolytic dialysis, membrane resistance to extreme pH conditions, the ...

2000-04-01

252

Antenna organization in green photosynthetic bacteria. Progress report, March 1986--February 1987

An evaporator using a hydrophobic membrane made from a polytetrafluoroethylene (PTFE) was developed to improve DF (Decontamination Factor) and to reduce evaporator size. The membrane distillation, provided by the evaporator, is a new technique for liquid purification. Fundamental experiments were carried out to develop the membrane filter (tube type, outer diameter, 8 mm; membrane thickness, 500 {mu}m) for radioactive liquid treatment. The continuous operation test using actual liquid waste was also made during about 3,000 h. (This is almost equal to the operation time of an actual evaporator per year.) The evaporation rate decreased with increase an operation time due to contamination of waste impurity. But the rate was recovered by washing the membrane with hot water and then drying it. DF was over 10{sup 4} which is ten times larger than that for a conventional system. A pilot ...

1996-10-01

253

Static potential of open bosonic membranes

This project is concerned with the structure and function of the unique antenna system found in the green photosynthetic bacteria. The antenna system in these organisms is contained within a vesicle known as a chlorosome, which is attached to the cytoplasmic side of the cell membrane. Additional antenna pigments and reaction centers are contained in integral membrane proteins. Energy absorbed by the bacteriochlorophyll c (BChl c) pigments in the chlorosome is transferred via a ``baseplate`` array of BChl a antenna pigments into the membrane and to the reaction center. This system is similar in some respects to the phycobilisome antenna system found in cyanobacteria and some types of algae, in that a membrane-associated structure absorbs light and transfers it to the membrane where conversion to chemical energy takes place. However, the overall structure, the type of pigments ...

1987-12-31

254

Expression of bacterial luciferase in eukaryotic cells

We study the static potential of open bosonic membranes in the 1/d approximation, where d is the space-time dimensionality. For a fixed square boundary of side length R we find, in contrast to the string potential, no critical distance below which tachyons appear. Instead, we find a correction factor to the classical potential, V/sub cl/=kR/sup 2/, which for small distances shifts the perturbative ground state energy by a positive constant. We interpret the shift as the mass gap of this quantum membrane.

1989-03-30

255

[Changes in the mucous membrane of the esophagus and stomach in patients with chronic alcoholism during the period of acute alcoholic intoxication (according to fiber endoscopy and spot biopsy data)].

Expression of Bacterial luciferase enzyme (lux) in mammalian cells would be a powerful bioreporter protein system for in vivo imaging because eukaryotic luciferases need expensive substrates. However, only a few efforts have been made to express bacterial luciferase enzyme in mammalian cells. As the result of this, we attempted to construct bicistronic vector including two bacterial luciferase genes (LuxA and LuxB) for assessing the potential to be visualized in vitro or in vivo by optical imaging system after transfection to mammalian cells. We designed and synthesized luxA and luxB genes from Photorhabdus Luminescens. To co-express both luxA and luxB genes from a single promoter, we cloned as a bicistronic transcript fused with an internal ribosomal entry site (IRES). This bicistronic transcript was transfected by Superfect to HEK 293T cell line. We also transfected lux A and lux B vector to HEK 293T cells separately. To ...

2005-11-18

256

Uncoupling action of polychlorinated biphenyls (Kanechlor-400) on oxidative phosphorylation in rat liver mitochondria

PMID:4428360

1974-01-01

257

The effect of SEM preparation on pit membrane remnants in vessel element end-walls of primitive angiosperms

A study was made of the uncoupling action of polychlorinated biphenyls (Kanechlor-400) on oxidative phosphorylation in rat liver mitochondria. Kanechlor-400 (KC-400) at 20 ..mu..g/ml stimulated state 4 respiration of rat liver mitochondria more than 4-fold with ..cap alpha..-ketoglutarate/malate as a substrate, and released the oligomycin-inhibited state 3 respiration. KC-400 also dissipated the membrane potential across the mitochondrial membranes; thus, it acts as an uncoupler of oxidative phosphorylation in rat liver mitochondria. KC-400 altered the permeability properties of mitochondrial membranes as evidenced by the release of endogenous K/sup +/ and the oxidation of exogenously supplied NADH. It is concluded that KC-400 produces a nonspecific increase in mitochondrial ion permeability, thereby dissipating membrane potential, which leads to the uncoupling.

1984-03-01

258

British Library Electronic Table of Contents (United Kingdom)

Scanning electron microscope (SEM) is necessary to demonstrate presence or absence of pit membranes in possible perforations or the type of pit membrane remnants in perforations in vessel element end-walls of angiosperms, but it was unconfirmed and questionable whether pit membrane absence in pits was affected by the processing and handling before SEM observations. To solve this question, the secondary xylem of four woody species from primitive angiosperms, Illicium henryi Diels. (Illiciaceae), Schisandra rubriflora (Franch.) Rehd. et Wils. (Schisandraceae), Tetracentron sinensis Oliv. and Trochodendron aralioides Sieb. & Zucc. (Trochodendraceae) was chosen and the following techniques were used: (1) fresh materials were examined in low-vacuum with ESEM. (2) Air-dried materials were examin...

2011-01-01

259

Subcellular localization of ammonium transporters in Dictyostelium discoideum

Study on polyamide thin-film composite nanofiltration membrane by interfacial polymerization of polyvinylamine (PVAm) and isophthaloyl chloride (IPC)

BackgroundWith the exception of vertebrates, most organisms have plasma membrane associated ammonium transporters which primarily serve to import a source of nitrogen for nutritional...Full Text Available

260

British Library Electronic Table of Contents (United Kingdom)

A novel thin-film composite polyamide nanofiltration membrane was prepared through interfacial polymerization of polymeric polyamine polyvinylamine (PVAm) with isophthaloyl chloride (IPC) on a polysulfone supporting film. The composite membranes were prepared under different conditions and characterized in terms of chemical and morphological structures, surface zeta potential, pure water permeability, and rejection to different solutes including electrolytes and sucrose. The results showed that the membrane performance was significantly affected by the content of amine units of PVAm and the concentrations of PVAm and IPC. The increase of the content of amine units of PVAm and the concentration of IPC resulted in an augment in salt rejection and a decrease in permeability, while the increas...

2011-01-01

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261

Stearic acid and carcinogenesis.

Solution structure and dynamics of sugarcane defensin 5: the role of dynamics in the interaction with lipid membranes

Decreased membrane rigidity is one of the characteristics of malignant cells, resulting in part from the desaturation of stearic acid into oleic acid. In this study we investigated the influence of...Full Text Available

1987-10-01

262

Preparation and Characterization of a Novel Polyamide Charged Mosaic Membrane

English 2009 p. 161-162 Brazil Paula, Viviane Silva de Almeida, Fabio

2009-05-04

263

British Library Electronic Table of Contents (United Kingdom)

A novel composite charged mosaic membrane (CCMM) was prepared via interfacial polymerization (IP) of polyamine [poly(epichlorohydrin amine)] and trimesoyl chloride (TMC) on the polyethersulfone (PES) support. Fourier transform infrared spectroscopy (FT-IR), environmental scanning electron microscopy (ESEM), atomic force microscopy (AFM) and water contact angle analysis were applied to characterize the resulted CCMM. The FT-IR spectrum indicates that TMC reacts sufficiently with polyamine. ESEM and AFM pictures show that the IP process produces a dense selective layer on the support membrane. The water contact angle of the CCMM is smaller than that of the substrate membrane because of the cross-linked hydrophilic polyamine network. Several factors affecting the IP reaction and the performan...

2010-01-01

264

Predicting the proton conductivity of perfluorosulfonic acid membrane via combining statistical thermodynamics and molecular dynamics simulation

British Library Electronic Table of Contents (United Kingdom)

Abstract The electrochemical properties of a perfluorosulfonic acid (PFSA) membrane are estimated using a combination of molecular dynamics simulation and statistical thermodynamic model. We obtain all parameters in an ionic conductivity model from an atomistic simulation and remove all adjusted model parameters. From a microscopic point of view, the hydrated PFSA membrane shows micro-phase segregation which separated into hydrophilic and hydrophobic phases. Our present work originates with this phenomenon and we treat this phase segregation as if it is a continuous phase for each of which the proton (H+) is transported inside the PFSA membrane/solvent (water and alcohols) mixture. The chemical potential for a given system is estimated using a molecular simulation technique to predict the ...

2011-01-01

265

Pd based membrane reactor for ultra pure hydrogen production through the dry reforming of methane. Experimental and modeling studies

British Library Electronic Table of Contents (United Kingdom)

A dense Pd-Ag membrane reactor (MR) with 100% hydrogen selectivity packed with either Rh/La2O3 or Rh/La2O3-SiO2 as catalysts was used to carry out the dry reforming of methane. The membrane reactor simulation was performed using a well-known reactor model. For this purpose, we employed the equations derived from complete kinetic studies of the dry reforming of methane reaction in connection with both catalysts. In addition, we developed the kinetic equation for the reverse water gas shift reaction (RWGS). The combination of detailed kinetic studies with the measured permeation flux for the Pd-Ag membrane allowed a complete comparison between experimental and simulated operation variables. The variables studied for both catalysts were methane conversion and hydrogen permeation as a function...

2011-01-01

266

On the spontaneous emergence of cell polarity

Molecular Microscopy of Brain Gangliosides: Illustrating their Distribution in Hippocampal Cell Layers

Diverse cell polarity networks require positive feedback for locally amplifying distributions of signalling molecules at the plasma membrane1. Additional...Full Text Available

2008-08-14

267

Molecular Aspects of Thyroid Hormone Actions

Gangliosides are amphiphilic molecules found in the outer layer of plasma membranes of all vertebrate...Full Text Available

2011-02-21

268

Mode of action of membrane-disruptive lytic compounds from the marine dinoflagellate Alexandrium tamarense

Cellular actions of thyroid hormone may be initiated within the cell nucleus, at the plasma membrane, in cytoplasm, and at the mitochondrion. Thyroid hormone nuclear receptors (TRs) mediate the biological...Full Text Available

2010-04-01

269

British Library Electronic Table of Contents (United Kingdom)

Certain allelochemicals of the marine dinoflagellate Alexandrium tamarense cause lysis of a broad spectrum of target protist cells but the lytic mechanism is poorly defined. We first hypothesized that membrane sterols serve as molecular targets of these lytic compounds, and that differences in sterol composition among donor and target cells may cause insensitivity of Alexandrium and sensitivity of targets to lytic compounds. We investigated Ca^2^+ influx after application of lytic fractions to a model cell line PC12 derived from a pheochromocytoma of the rat adrenal medulla to establish how the lytic compounds affect ion flux associated with lysis of target membranes. The lytic compounds increased permeability of the cell membrane for Ca^2^+ ions even during blockade of Ca^2^+ channels wit...

2011-01-01

270

Mechanical design of a PERMCAT reactor module

Hydrophobic labelling of membrane-embedded proteins with lipophilic reagents

The PERMCAT is a membrane reactor proposed for processing fusion reactor plasma exhaust gas: tritium removal is obtained by isotopic swamping operating in counter-current mode. In this work, a membrane reactor using a permeator tube of length about 500 mm produced via diffusion welding of Pd-Ag thin foils is described. An appropriate mechanical design of the membrane module has been developed in order to avoid any significant compressive and bending stresses on the very long and thin wall permeator tube: two expanded bellows have been applied to the Pd-Ag tube, so that it has been pre-tensioned before operating. The elongation of the metal permeator under hydrogenation has been theoretically estimated and experimentally verified for properly designing the membrane reactor.

2007-02-01

271

Hyaluronan-Dependent Pericellular Matrix

Hydrophobic labelling is frequently used in the study of membrane-inserted domains of intrinsic proteins. However, the published procedures, fail to incorporate sufficient radioactivity into membrane immunoglobulins of B lymhocytes to permit investigation of their subunit structures and associations with other proteins. In order to increase the specific radioactivity of ["1"2"5I]iodonaphtylazide ["1"2"5I]INA), an improved method for the synthesis of the reagent was developed. In addition, the optimal conditions for labelling B lymhpocytes with ["1"2"5I]INA and commercially available reagent 3-(trifluoromethyl)-3-(trifluoromethyl)-3-(3'-["1"2"5Iliodophenyl)diazirine (["1"2"5I]TID were isolated and analysed in detail by SDS-PAGE. The usefulness of the two reagents for the investigation of lipid-embedded domains of membrane proteins is discussed. (author). 28 refs.; 4 figs.

272

Examination of Iotophoretic Transport of Ionic Drugs across ...

Hyaluronan is a multifunctional glycosaminoglycan that forms the structural basis of the pericellular matrix. Hyaluronan is extruded directly through the plasma membrane by one of three hyaluronan...Full Text Available

2007-11-10

273

Detection of glycoproteins in the Acanthamoeba plasma membrane

... derived and which describes fundamentally flux enhancement across an artificial membrane or skin: Keywords: Transdermal drug delivery system. ...

1986-07-30

274

Design and fabrication of large ultra-thin PIN detector with membrane stress deviation

In the present study the authors have shown that glycoproteins are present in the plasma membrane of Acanthamoeba castellanii by utilizing different radioactive labeling techniques. Plasma membrane proteins in the amoeba were iodinated by "1"2"5I-lactoperoxidase labeling and the solubilized radiolabeled glycoproteins were separated by lectin-Sepharose affinity chromatography followed by polyacrylamide gel electrophoresis. The periodate/NaB"3H_4 and galactose oxidase/NaB"3H_4 labeling techniques were used for labeling of surface carbohydrates in the amoeba. Several surface-labeled glycoproteins were observed in addition to a diffusely labeled region with M_r of 55,000-75,000 seen on electrophoresis, which could represent glycolipids. The presence of glycoproteins in the plasma membrane of Acanthamoeba castellanii was confirmed by metabolic labeling with ["3"5S]methionine followed by lectin-Sepharose affinity chromatography ...

275

Comparative study of functional properties of commercial and membrane processed yellow pea protein isolates

In this paper, the design of large thin PIN detector with a membrane stress avoidance configuration is proposed, and the related device fabrication process is developed. Ultra-thin PIN detector {approx} 1.13 cm{sup 2} in area is fabricated on a thin ( {approx} 35{mu}m) silicon membrane, and characterized. Detector performance improvement has been successfully demonstrated. With the membrane stress avoidance design, the improved detector exhibits a leakage of 6nA, which is at least 5 times lower than that of detector of identical junction area. The new detector features a full depleted capacitance of 110 pF, and a FWHM of 40.86 keV energy resolution for 5.486 MeV alpha particle spectrography.

2010-09-15

276

British Library Electronic Table of Contents (United Kingdom)

Functional properties of commercial and membrane processed pea protein isolates (PPI) prepared from yellow peas were investigated. Four protein isolates were prepared from yellow pea flour using water and KCl extractions at 25^oC followed by ultrafiltration and diafiltration (UF and DF) at pHs of 7.5 and 7.5 or 6 respectively. Following assessment of compositional attributes; solubility, foaming, flow and dynamic rheology, emulsification ability and heat-induced textural and rheological properties of prepared PPIs and a commercially available PPI were tested and compared. Membrane purification of proteins resulted in 28% to 68% reduction in phytic acid and enhanced, comparatively, the tested functional properties. Solubility of membrane processed PPIs, at all tested pHs, was superior and t...

2011-01-01

277

Biogenesis of the Protein Storage Vacuole Crystalloid

Accelerated aging of catalytically airblown asphalt membranes under simulated uranium mill tailings impoundment conditions

We identify new organelles associated with the vacuolar system in plant cells. These organelles are defined biochemically by their internal content of three integral membrane proteins: a chimeric reporter...Full Text Available

2000-08-21

278

AMPA-receptor trafficking and injury-induced cell death

This paper evaluates the performance of asphalt membranes by examining the chemical and permeability changes experienced by the asphalt during aging tests. The aging process was accelerated by exposing the asphalt to elevated temperatures, high oxygen concentrations, and increased strengths of aqueous oxidizing agents. The synergistic effects of the variables are evaluated by using a fractional factorial experimental design. The installation costs for a catalytically airblown asphalt liner are roughly half that of the typical polymeric materials, and also less than the rubberized asphalt membrane. The results of the initial accelerated aging tests of the asphalt membranes indicate that this material will provide stable, long-term leachate isolation in a mill tailings environment.

1982-12-01

279

A mathematical model of mitochondrial swelling

AMPA receptors (AMPARs) are critical for synaptic plasticity, and are subject to alterations based on subunit composition and receptor trafficking to and from the plasma membrane. One of the...Full Text Available

2010-07-01

280

A SYMMETRICAL, EXTRACELLULAR FIBRIL

BackgroundThe permeabilization of mitochondrial membranes is a decisive event in apoptosis or necrosis culminating in cell death. One fundamental mechanism by which...Full Text Available

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281

Quantification of antibiotic drug potency by a two-compartment radioassay of bacterial growth

Symmetrical, extracellular fibrils, which are related to the "special fibrils" of the dermis described by Palade and Farquhar, have been found along the outer surface of the basement membrane covering...Full Text Available

1969-08-01

282

Comparison of newer synthetic and biological wound dressings.

The two-compartment radioassay for microbial kinetics based on continuous measurement of the {sup 14}CO{sub 2} released by bacterial metabolism of 14C-labeled substrate offers a valuable approach to testing the potency of antimicrobial drugs. By using a previously validated radioassay with gram-positive and gram-negative bacteria, a group of protein synthesis inhibitors was evaluated for their effect on microbial growth kinetics. All tested drugs induced changes in both the slopes and intercepts of the growth curves. An exponential growth model was applied to quantify the drug effect on the processes of bacterial {sup 14}CO{sub 2} liberation and cell generation. The response was measured in terms of a generation rate constant. A linear dependence of the generation rate constant on the dose of spectinomycin was observed with Escherichia coli. Sigmoidal-shaped curves were found in the assays of chloramphenicol and tetracycline. The implications ...

1990-06-01

283

Analysis of S-adenosylmethionine and related sulfur metabolites in bacterial isolates of Pseudomonas aeruginosa (BAA-47) by liquid chromatography/electrospray ionization coupled to a hybrid linear quadrupole ion trap and Fourier transform ion cyclotron resonance mass spectrometry

In 18 piglets, weighing 10-15 kg, third-degree burns or full-thickness skin excisions of 4 X 4 cm were inflicted. The effect of five dressing materials on adhesiveness to the wounds, appearance, conformability, wound contraction, bacterial count, and morphology of the wound was studied at the end of the seventh and fourteenth days without dressing changes. In 11 piglets with a burn wound, the most adherent dressing was collagen sponge(CS), followed by polyurethane sponge (PU), pigskin xenograph (PS), and xeroform. CS more effectively debrided the wound from coagulated necrotic tissue than the other dressings. Wound contraction was maximal with CS dressing (52%), followed by PU (44%), xeroform (32%), and PS (27%). In another seven piglets with full-thickness excised wounds, a velour dressing made of polytetrafluoroethylene (PTFE) or PU adhered significantly more than CS or PS. Wound contraction was greater with CS (37%) or PTFE (35%) than with PS (23%) or PU (18%). ...

1981-06-01

284

British Library Electronic Table of Contents (United Kingdom)

A comprehensive and highly selective method for detecting in bacterial supernatants a modified sulfur nucleoside, S-adenosyl-L-methionine (SAM), and its metabolites, i.e., S-adenosylhomocysteine (SAH), adenosine (Ado), 5prime-deoxy-5prime-methylthioadenosine (MTA), adenine (Ade), S-adenosyl-methioninamine (dcSAM), homocysteine (Hcy) and methionine (Met), was developed. The method is based on reversed-phase liquid chromatography with positive electrospray ionization (ESI+) coupled to a hybrid linear quadrupole ion trap (LTQ) and 7-T Fourier transform ion cyclotron resonance mass spectrometry (FTICRMS). A gradient elution was employed with a binary solvent of 0.05 M ammonium formate at pH 4 and acetonitrile. The assay involves a simultaneous cleanup of cell-free bacterial broths by solid-pha...

2009-01-01

285

Effects of human serum on bacterial competition with neutrophils for molecular oxygen.

Vaginal Matrix Metalloproteinase Levels in Pregnant Women With Bacterial Vaginosis

A dialyzable factor(s) in human serum is known to stimulate gonococcal oxygen consumption. Its effect on other human pathogens was investigated. A 10% serum solution increased peak O2 consumption for Escherichia coli and Staphylococcus aureus to 157% (P less than 0.05) and 199% (P less than 0.02), respectively, of their O2 consumption when suspended in Hanks balanced salt solution, compared with a 356% increase for Neisseria gonorrhoeae with serum. Dialyzed serum lacked stimulatory capacity. Bacteria, serum, and neutrophils are often incubated to evaluate neutrophil bactericidal activity. Samples of 10(8) N. gonorrhoeae, S. aureus, and E. coli turned resazurin colorless (anaerobic conditions, Eh less than -42 mV) after 7.4, 13.3, and 15.1 min, respectively. Because neutrophil formation of reactive oxygen intermediates requires ambient O2, the effect of live bacteria and serum on this process was explored. After 5 min of incubation of 10(8) N. gonorrhoeae or S. aureus in 10% normal or ...

1986-06-01

286

British Library Electronic Table of Contents (United Kingdom)

Objective To compare matrix metalloproteinase (MMP)-8 and MMP-9 levels in the vaginal secretions of pregnant women with or without asymptomatic bacterial vaginosis (BV). Methods In this study, vaginal levels and molecular forms of MMP-8 and MMP-9 were studied in 36 pregnant women between 28 and 34 weeks of gestation with asymptomatic BV and 41 pregnant women, matched for gestational age, without BV. Results Vaginal MMP-8 concentrations were significantly higher (P = .023) in BV-positive women. There was no significant difference in MMP-9 levels between healthy pregnant controls and BV-positive pregnant women. The presence of MMP-8 was confirmed by a 38-kd band on Western blots. Conclusions Our findings show that BV is associated with increased levels of MMP-8 in vaginal fluid. Increased pr...

2006-01-01

287

Testing an agent-based model of bacterial cell motility: How nutrient concentration affects speed distribution

British Library Electronic Table of Contents (United Kingdom)

We revisit a recently proposed agent-based model of active biological motion and compare its predictions with own experimental findings for the speed distribution of bacterial cells, Salmonella typhimurium. Agents move according to a stochastic dynamics and use energy stored in an internal depot for metabolism and active motion. We discuss different assumptions of how the conversion from internal to kinetic energy d(v) may depend on the actual speed, to conclude that d 2 v ? with either ? = 2 or 1 ? < 2 are promising hypotheses. To test these, we compare the model?s prediction with the speed distribution of bacteria which were obtained in media of different nutrient concentration and at different times. We find that both hypotheses are in line with the experimental observations, with ? bet...

2011-01-01

288

Susceptibility to invasive bacterial infections in children with sickle cell disease

British Library Electronic Table of Contents (United Kingdom)

Individuals with sickle cell disease (SCD) demonstrate an increased susceptibility to invasive bacterial infections (IBI). The most common organisms causing IBI are Streptococcus pneumoniae, nontyphi Salmonella species and Haemophilus influenzae type b (Hib). IBI are the most common causes of death in children below 5 years of age with SCD. Increased susceptibility to IBI is because of several factors including dysfunctional antibody production and opsonophagocytosis as well as defective splenic clearance. Early diagnosis of Hib and pneumococcal infections combined with antibiotic prophylaxis and immunization programs, could lead to significant improvements in mortality, especially in Africa. Pediatr Blood Cancer. 2010;55:401-406. Copyright 2010 Wiley-Liss, Inc.

2010-01-01

289

Regulation and secretion of Xanthomonas virulence factors

British Library Electronic Table of Contents (United Kingdom)

Abstract Plant pathogenic bacteria of the genus Xanthomonas cause a variety of diseases in economically important monocotyledonous and dicotyledonous crop plants worldwide. Successful infection and bacterial multiplication in the host tissue often depend on the virulence factors secreted including adhesins, polysaccharides, LPS and degradative enzymes. One of the key pathogenicity factors is the type III secretion system, which injects effector proteins into the host cell cytosol to manipulate plant cellular processes such as basal defense to the benefit of the pathogen. The coordinated expression of bacterial virulence factors is orchestrated by quorum-sensing pathways, multiple two-component systems and transcriptional regulators such as Clp, Zur, FhrR, HrpX and HpaR. Furthermore, virule...

2010-01-01

290

Nationwide surveillance of bacterial respiratory pathogens conducted by the Japanese Society of Chemotherapy in 2008: general view of the pathogens? antibacterial susceptibility

British Library Electronic Table of Contents (United Kingdom)

For the purpose of nationwide surveillance of the antimicrobial susceptibility of bacterial respiratory pathogens collected from patients in Japan, the Japanese Society of Chemotherapy conducted a third year of nationwide surveillance during the period from January to April 2008. A total of 1,097 strains were collected from clinical specimens obtained from well-diagnosed adult patients with respiratory tract infections. Susceptibility testing was evaluable with 987 strains (189 Staphylococcus aureus, 211 Streptococcus pneumoniae, 6 Streptococcus pyogenes, 187 Haemophilus influenzae, 106 Moraxella catarrhalis, 126 Klebsiella pneumoniae, and 162 Pseudomonas aeruginosa). A total of 44 antibacterial agents, including 26 ?-lactams (four penicillins, three penicillins in combination with ?-lacta...

2011-01-01

291

Leaching of zinc sulfide by Thiobacillus ferrooxidans: Bacterial oxidation of the sulfur product layer increases the rate of zinc sulfide dissolution at high concentrations of ferrous ions

Comparison of iodine and glutaraldehyde as surface disinfectants for red porgy (Pagrus pagrus) and white sea bream (Diplodus sargus sargus) eggs

This paper reports the results of leaching experiments conducted with and without Thiobacillus ferroxidans at the same conditions in solution. The extent of leaching of ZnS with Bacteria is significantly higher than that without bacteria at high concentrations of ferrous ions. A porous layer of elemental sulfur is present on the surfaces of the chemically leached particles, which no sulfur is present on the surfaces of the bacterially leached particles. The analysis of the data using the shrinking-core model shows that the chemical leaching of ZnS is limited by the diffusion of ferrous ions through the sulfur product layer at high concentrations of ferrous ions. The analysis of the data shows that diffusion through the product layer does not limit the rate of dissolution when bacteria are present. This suggests that the action of T.ferroxidans in oxidizing the sulfur formed on the particle surface is to remove the barrier to diffusion by ferrous ions.

1999-12-01

292

British Library Electronic Table of Contents (United Kingdom)

Abstract The efficacy of iodine and glutaraldehyde as fish egg surface disinfectants were assessed in red porgy (Pagrus pagrus) and white sea bream (Diplodus sargus sargus) eggs, two species of interest for Mediterranean aquaculture. Iodine was effective in reducing the bacterial load of the 1-day-old eggs when applied at 50 mg L-1 for 5 min. The same concentration did not cause any significant change in hatching success or survival of the larvae for the first 5 days. Glutaraldehyde failed to reduce the bacterial load of the fish eggs at concentrations that were safe for the eggs (100 mg L-1 for 5 min), as it had a significant effect in preventing hatching of the developed embryo. Disinfecting 0-day-old eggs with iodine resulted in a significant reduction of hatching percentage, while larv...

2007-01-01

293

Biosorption of lead from aqueous solutions by Bacillus strains possessing heavy-metal resistance

British Library Electronic Table of Contents (United Kingdom)

In this study, bacterial strains were investigated in order to determine their heavy metal tolerance. The bacterial strains were identified as Bacillus cereus and Bacillus pumilus. In the batch system, the effects of operating variables such as solution pH, initial metal concentration, contact time, and adsorbent dosage were investigated. Both isolates were highly resistance to copper and lead in comparison with the control strain examined. The adsorption capacities of B. cereus and B. pumilus were found to be 22.1mg/g and 28.06mg/g, respectively. The biosorption follows pseudo-second order kinetics and the isotherm fits well to the Langmuir isotherm model. In column experiments, the biosorption was fitted well by the Thomas model. The breakthrough and exhaustion capacity of each biosorben...

2011-01-01

294

Aerogels from Unaltered Bacterial Cellulose: Application of scCO2 Drying for the Preparation of Shaped, Ultra-Lightweight Cellulosic Aerogels

British Library Electronic Table of Contents (United Kingdom)

Bacterial cellulose produced by the gram-negative bacterium Gluconacetobacter xylinum was found to be an excellent native starting material for preparing shaped ultra-lightweight cellulose aerogels. The procedure comprises thorough washing and sterilization of the aquogel, quantitative solvent exchange and subsequent drying with supercritical carbon dioxide at 40 degreeC and 100 bar. The average density of the obtained dry cellulose aerogels is only about 8 mg cm-3 which is comparable to the most lightweight silica aerogels and distinctly lower than all values for cellulosic aerogels obtained from plant cellulose so far. SEM, ESEM and nitrogen adsorption experiments at 77 K reveal an open-porous network structure that consists of a comparatively high percentage of large mesopores and small...

2010-01-01

295

Ability of a ?minimum?? microbial food web model to reproduce response patterns observed in mesocosms manipulated with N and P, glucose, and Si

British Library Electronic Table of Contents (United Kingdom)

We compared an idealised mathematical model of the lower part of the pelagic food web to experimental data from a mesocosm experiment in which the supplies of mineral nutrients (nitrogen and phosphorous), bioavailable dissolved organic carbon (BDOC, as glucose), and silicate were manipulated. The central hypothesis of the experiment was that bacterial consumption of BDOC depends on whether the growth rate of heterotrophic bacteria is limited by organic-C or by mineral nutrients. In previous work, this hypothesis was examined qualitatively using a conceptual food web model. Here we explore the extent to which a ?simplest possible?? mathematical version of this conceptual model can reproduce the observed dynamics. The model combines algal?bacterial competition for mineral nutrients (phosphor...

2007-01-01

296

The chemical properties of silica particle surface in relation to silica-cell interactions

Physical mechanisms of biological molecular motors

Although silicosis has been studied extensively, the mechanism is still not fully understood. Experiments do provide evidence that the actions of unique properties of silica surface on the cell membrane are the starting point of silicotic processes. This paper summarizes literature on chemical properties of silica surface, and the effect of particle size on silica toxicity. This paper also discusses the ways in which silica dusts are though to interact with the cell membrane, with emphasis on freshness, hydrogen bonding, and free-radical interactions.

1989-01-01

297

Metallic aggregate synthesis by radiolysis of simple or complex salt aqueous solutions. Study by electron microscope of aggregate grafting on carbon membranes

Biological motors generally fall into two categories: (1) those that convert chemical into mechanical energy via hydrolysis of a nucleoside triphosphate, usually adenosine triphosphate, regarded as life's chemical currency of energy and (2) membrane bound motors driven directly by an ion gradient and/or membrane potential. Here we argue that electrostatic interactions play a vital role for both types of motors and, therefore, the tools of physics can greatly contribute to understanding biological motors.

2009-03-01

298

Liquid radwaste processing with spiral wound reverse osmosis

French ... Title Synthese d'agregats metalliques par radiolyse de solutions aqueuses de sels simples ou complexes. Etude par M. E. du greffage des agregats sur membranes de carbone.

1987-05-20

299

Determination by enzyme-linked immunosorbent assay of immunoglobulin G (IgG), IgM, and IgA to Brucella melitensis major outer membrane proteins and whole-cell heat-killed antigens in sera of patients with brucellosis.

Two different reverse osmosis systems were investigated. The first was a 50-element plant-scale system that is used to treat 2200 m"3 of AECL liquid radwastes annually.It uses thin-film composite (TFC) membranes and operates at an applied pressure of 2760 kPa, with a fixed crossflow of about 40 L/min. The other system uses the same thin-film composite membranes for waste processing but is a two-element pilot-scale system. It is operated at pressures m ranging between 1500 and 7000 kPa, at a fixed crossflow of 55 L/min. The average lifetime of the thin-film composite membranes in the plant-scale processing application at AECL is about 3000 h. After this service life has expired the rejection efficiency declines rapidly from 99.5% to about 95% as the membranes become impaired from chemical cleaning procedures that are required after each 100 m"3 of waste is treated. The permeation flux for the plant-scale ...

1996-02-25

300

Conformational Changes in BAK, a Pore-forming Proapoptotic Bcl-2 Family Member, upon Membrane Insertion and Direct Evidence for the Existence of BH3-BH3 Contact Interface in BAK Homo-oligomers*

An enzyme-linked immunosorbent assay was used to compare Brucella melitensis major outer membrane proteins (MOMP) and whole-cell heat-killed antigens (HK) in measuring antibrucella immunoglobulin G...Full Text Available

1989-08-01

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301

Basis for the Specificity and Activation of the Serpin Protein Z-dependent Proteinase Inhibitor (ZPI) as an Inhibitor of Membrane-associated Factor Xa*

During apoptosis, the pro-apoptotic Bcl-2 family proteins BAK and BAX form large oligomeric pores in the mitochondrial outer membrane. Apoptotic factors, including cytochrome c, are...Full Text Available

2010-09-10

302

Lipid domain formation modulates activities of snake venom phospholipase A(2) enzymes.

The serpin ZPI is a protein Z (PZ)-dependent specific inhibitor of membrane-associated factor Xa (fXa) despite having an unfavorable P1 Tyr. PZ accelerates the inhibition reaction ∼2000-fold...Full Text Available

2010-06-25

303

Influence of Ce0.9Gd0.1O2-d particles on microstructure and oxygen permeability of Ba0.5Sr0.5Co0.8Fe0.2O3-d composite membrane

The goal of the present study is to elucidate the effect of lipid domain formation on activities of Naja naja atra and Bungarus multicinctus phospholipase A(2) (PLA(2)) enzymes. Sphingomyelin inhibited enzymatic activity and membrane-damaging activity of PLA(2) against egg yolk phosphatidylcholine (EYPC), while cholesterol and cholesterol sulfate abrogated the inhibitory effect of sphingomyelin. The ability of cholesterol and cholesterol sulfate to abolish the inhibitory effect of sphingomyelin was closely related to their capacity to induce domain formation in EYPC/sphingomyelin vesicles. Laurdan fluorescence measurement revealed that membrane packing of EYPC/sphingomyelin vesicles was differently affected by cholesterol and cholesterol sulfate. Unlike cholesterol, cholesterol sulfate was unable to promote domain formation in dipalmitoylphosphatidylcholine (DPPC) vesicles. Cholesterol increased but cholesterol sulfate reduced PLA(2) activity ...

2010-08-10

304

British Library Electronic Table of Contents (United Kingdom)

This study examined the oxygen permeation behavior of Ce0.9Gd0.1O2-d (Gadolinium-Doped Ceria, GDC)/Ba0.5Sr0.5Co0.8Fe0.2O3-d (BSCF) composite membranes fabricated using a conventional sintering technique. GDC/BSCF composite membranes with a relative density >95% could be obtained when a green compact of BSCF and GDC was sintered at 1150^oC for 5h. It appears that GDC serves as a grain growth inhibitor because the average grain size of the composite decreased with increasing GDC content. The oxygen permeability of the BSCF and GDC/BSCF composite membranes strongly depends on the grain size and membrane thickness. The addition of GDC to BSCF resulted in a small grain size, low thermal expansion coefficient and high hardness. However, it is believed that oxygen permeation was blocked by GDC, a...

2010-01-01

305

High-performance hybrid pervaporation membranes with superior hydrothermal and acid stability

A study of membrane protein defects and alpha hemoglobin chains of red blood cells in human beta thalassemia

A new organic-inorganic hybrid membrane has been prepared with exceptional performance in dewatering applications. The only precursor used in the sol-gel synthesis of the selective layer was organically linked 1,2-bis(triethoxysilyl)ethane (BTESE). The microporous structure of this layer enables selective molecular sieving of small molecules from larger ones. In the dehydration of n-butanol with 5% of water, the membrane shows a high separation factor of over 4000 and ultra-fast water transport at a rate of more than 20 kg m{sup -2} h{sup -1} at 150C. This can be related to the high adsorption capacity of the material and the sub-micron thickness of the selective layer. The selectivity has now remained constant over almost one and a half years under continuous process testing conditions. Apart from the hydrothermal stability, the membrane exhibits a high tolerance for acid contamination. A slow performance decline in flux ...

2009-05-15

306

[Intraspecies antagonism of Sh. flexneri in an HEp-2 cell line model].

The soluble pool of alpha hemoglobin chains present in blood or bone marrow cells was measured with a new affinity method using a specific probe, beta A hemoglobin chain labeled with ["3H]N-ethylmaleimide. This pool of soluble alpha chains was 0.067 #+-# 0.017% of hemoglobin in blood of normal adult, 0.11 #+-# 0.03% in heterozygous beta thalassemia and ranged from 0.26 to 1.30% in homozygous beta thalassemia intermedia. This elevated pool of soluble alpha chains observed in human beta thalassemia intermedia decreased 33-fold from a value of 10% of total hemoglobin in bone marrow cells to 0.3% in the most dense red blood cells. The amount of insoluble alpha chains was measured by using the polyacrylamide gel electrophoresis in urea and Triton X-100. In beta thalassemia intermedia the amount of insoluble alpha chains was correlated with the decreased spectrin content of red cell membrane and was associated with a decrease in ankyrin and with other abnormalities of ...

307

Vertical and Horizontal Variations in the Physiological Diversity of the Aerobic Chemoheterotrophic Bacterial Microflora in Deep Southeast Coastal Plain Subsurface Sediments

The authors describe an effect of suppression of invasion of the guinea pig eye conjunctiva and the HEp-2 epithelial cells by virulent Sh. flexneri bacilli, with a simultaneous administration of the same dose of avirulent shigella mutants, genetically connected with them. The data of morphological study and experiments with 3H-glucose labeled shigellae carried out on the cell species model indicated that the bacterial competition for the specific sites for absorption on the epithelial cells underlay the observed phenomenon. PMID:331774

1977-06-01

308

The hrpK Operon of Pseudomonas syringae pv. tomato DC3000 Encodes Two Proteins Secreted by the Type III (Hrp) Protein Secretion System: HopB1 and HrpK, a Putative Type III Translocator

Aerobic chemoheterotrophic bacteria were isolated from surface soils and coastal plain subsurface (including deep aquifer) sediments (depths to 265 m) at a study site near Aiken, S.C., by plating on...Full Text Available

1989-05-01

309

The ecological role of bacteriocins in bacterial competition.

Pseudomonas syringae is a gram-negative bacterial plant pathogen that is dependent on a type III protein secretion system (TTSS) and the effector proteins it translocates into plant...Full Text Available

2005-01-01

310

Stabilization of Plutonium in Subsursface Environments via Microbial Reduction and Biofilm Formation

Bacteriocins are an abundant class of antimicrobial molecules that appear to mediate population dynamics within species. The bacteriocins of Escherichia coli have served as a model for exploring the ecological role of these potent toxins. Studies suggest that colicins provide a competitive edge in nutrient-poor environments and that there might be a trade-off between the costs and benefits of colicin production. PMID:10203843

1999-03-01

311

Prevalence of Actinobacillus pleuropneumoniae, Actinobacillus suis, Haemophilus parasuis, Pasteurella multocida, and Streptococcus suis in representative Ontario swine herds

Our work is towards mechanistically understanding interactions of unsaturated bacterial biofilms and their extracellular polymeric substances (EPS) with actinide metals and metal surrogates under vadose zone conditions. Because metal contaminants in the vadose zone co-occur with organic pollutants, some of our work has included experiments with organic pollutants.

2005-06-01

312

Phase transitions in multiplicative competitive processes

Tonsillar and nasal swabs were collected from weanling pigs in 50 representative Ontario swine herds and tested for the presence of 5 important bacterial upper respiratory tract pathogens. All but 1...Full Text Available

2008-04-01

313

Nod2 sensing of lysozyme-digested peptidoglycan promotes macrophage recruitment and clearance of S. pneumoniae colonization in mice.

We introduce a discrete multiplicative process as a generic model of competition. Players with different abilities successively join the game and compete for finite resources. Emergence of dominant players and evolutionary development occur as a phase transition. The competitive dynamics underlying this transition is understood from a formal analogy to statistical mechanics. The theory is applicable to bacterial competition, predicting novel population dynamics near criticality.

2005-07-01

314

Mutations Affecting Motifs of Unknown Function in the Central Domain of Nitrogen Regulatory Protein C

Streptococcus pneumoniae colonizes the mucosal surface of the human upper respiratory tract. A colonization event is gradually cleared through phagocytosis by monocytes/macrophages that are recruited to the airway lumen. Here, we sought to define the bacterial and host factors that promote monocyte/macrophage influx and S. pneumoniae clearance using intranasal bacterial challenge in mice. We found that the recruitment of monocytes/macrophages required their expression of the chemokine receptor CCR2 and correlated with expression of the CCR2 ligand CCL2. Production of CCL2 and monocyte/macrophage recruitment were deficient in mice lacking digestion of peptidoglycan by lysozyme (LysM) and cytosolic sensing of the products of digestion by Nod2. Ex vivo macrophages produced CCL2 following bacterial uptake, digestion by LysM, and sensing of peptidoglycan by Nod2. Sensing of digested peptidoglycan by Nod2 also required the ...

2011-08-15

315

Isolation of a bacterial host selective for bacteriophage T4 containing cytosine in its DNA.

The positive control function of the bacterial enhancer-binding protein NtrC resides in its central domain, which is highly conserved among activators of ς⁵⁴ holoenzyme. Previous...Full Text Available

1999-09-01

316

Intrahepatic cholangiocarcinoma presenting as liver abscess: report of two cases

An Escherichia coli B strain, B834 galU56, has been isolated which supports growth of bacteriophage T4 with cytosine in its DNA while restricting growth of T4 with hydroxymethylcytosine. This host is...Full Text Available

1978-09-01

317

Intracellular activity of the peptide antibiotic NZ2114: studies with Staphylococcus aureus and human THP-1 monocytes, and comparison with daptomycin and vancomycin

Intrahepatic cholangiocarcinoma is the second most common primary malignant hepatic neoplasm. We describe two cases of intrahepatic cholangiocarcinoma which initially presented as liver abscess both clinically and radiologically. Mucin-hypersecretion from the tumor cells and extensive necrosis or secondary bacterial infection was responsible for the radiologic appearance of a liver abscess.=20

1998-10-01

318

DEFF Research Database (Denmark)

Staphylococcus aureus survives inside eukaryotic cells. Our objective was to assess the activity of NZ2114, a novel peptidic antibiotic, against intracellular S. aureus in comparison with established antistaphylococcal agents acting on the bacterial envelope with a distinct mechanism.

2010-01-01

319

First Outbreak of Multidrug-Resistant Klebsiella pneumoniae Producing both SHV-12-Type Extended-Spectrum ?-Lactamase and DHA-1-Type AmpC ?-Lactamase at a Korean Hospital

Detection of Atopobium vaginae in postmenopausal women by cultivation-independent methods warrants further investigation.

PurposeCoexistence of different classes of β-lactamases in a single bacterial isolate may pose diagnostic and therapeutic challenges. We investigated a spread of Klebsiella...Full Text Available

2008-02-29

320

Campylobacter jejuni, C. coli, and C. lari naturally present in Leghorn laying hens and the antibiotic resistance profiles of these organisms

We sequenced 16S rRNA genes from the vaginal swab contents of a postmenopausal woman with asymptomatic bacterial vaginosis (BV). Sequences from Atopobium vaginae were the most commonly detected. In a survey of 35 other postmenopausal women, this organism was detected in 44% with BV but not in any subjects deemed healthy. PMID:15071062

2004-04-01

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321

Blockade of catecholamine-induced growth by adrenergic and dopaminergic receptor antagonists in Escherichia coli O157:H7, Salmonella enterica and Yersinia enterocolitica

Campylobacter spp. are present in the intestinal tract and internal tissues of broiler breeder and broiler chickens. Campylobacter spp. are known to cause acute bacterial gastroenteritis in humans and raw poultry products have been implicated as a significant source of these infections. The object...

322

A modeling study by response surface methodology and artificial neural network on culture parameters optimization for thermostable lipase production from a newly isolated thermophilic Geobacillus sp. strain ARM

BackgroundThe ability of catecholamines to stimulate bacterial growth was first demonstrated just over a decade ago. Little is still known however, concerning the nature of the putative...Full Text Available

323

DEVELOPMENT OF PROTOTYPE TITANATE ION EXCHANGE LOADED MEMBRANES FOR STRONTIUM, CESIUM AND ACTINIDE DECONTAMINATION FROM AQUEOUS MEDIA

BackgroundThermostable bacterial lipases occupy a place of prominence among biocatalysts owing to their novel, multifold applications and resistance to high temperature and other...Full Text Available

324

Submerged microfiltration membrane coupled with alum coagulation/powdered activated carbon adsorption for complete decolorization of reactive dyes

We have successfully incorporated high surface area particles of titanate ion exchange materials (monosodium titanate and crystalline silicotitanate) with acceptable particle size distribution into porous and inert support membrane fibrils consisting of polytetrafluoroethylene (Teflon(reg_sign)), polyethylene and cellulose materials. The resulting membrane sheets, under laboratory conditions, were used to evaluate the removal of surrogate radioactive materials for cesium-137 and strontium-90 from high caustic nuclear waste simulants. These membrane supports met the nominal requirement for nonchemical interaction with the embedded ion exchange materials and were porous enough to allow sufficient liquid flow. Some of this 47-mm size stamped out prototype titanium impregnated ion exchange membrane discs was found to remove more than 96% of dissolved cesium-133 and strontium-88 from a caustic nuclear waste ...

2008-05-30

325

British Library Electronic Table of Contents (United Kingdom)

Even the presence of very low concentrations of dyes (1mgL-1) in the effluent is highly visible and is considered aesthetically undesirable. It must be removed from wastewater completely. This study systematically evaluates the performance of adsorption (three kinds of powdered activated carbons), coagulation (AlCl36H2O) and membrane (submerged hollow fiber microfiltration) processes individually in treating two kinds of reactive dyes (Orange 16 and Black 5) and then using a hybrid process with combined coagulation-adsorption-membrane treatment system. Adsorption capacity and kinetics of Orange 16 were much higher and faster than those of Black 5. The dye removal efficiency by coagulation was highly dependent on dye concentration and solution pH. The hybrid process performance was far more...

2006-01-01

326

Strong and Tunable Nonlinear Optomechanical Coupling in a Low-Loss System

Role of natural organic matter (NOM), colloidal particles, and solution chemistry on ultrafiltration performance

A major goal in optomechanics is to observe and control quantum behavior in a system consisting of a mechanical resonator coupled to an optical cavity. Work towards this goal has focused on increasing the strength of the coupling between the mechanical and optical degrees of freedom; however, the form of this coupling is crucial in determining which phenomena can be observed in such a system. Here we demonstrate that avoided crossings in the spectrum of an optical cavity containing a flexible dielectric membrane allow us to realize several different forms of the optomechanical coupling. These include cavity detunings that are (to lowest order) linear, quadratic, or quartic in the membrane's displacement, and a cavity finesse that is linear in (or independent of) the membrane's displacement. All these couplings are realized in a single device with extremely low optical loss and can be tuned over a wide range in situ; in ...

2010-01-01

327

British Library Electronic Table of Contents (United Kingdom)

Mechanistic studies on a charged ultrafiltration (UF) membrane fouled with natural organic matter (NOM) and colloidal particles are systematically investigated to understand the relative role of each NOM fraction and the presence of colloidal particulate to membrane fouling. Humic acid (HA), dextran, and kaolin were employed as surrogate model foulants representing the organic hydrophobic acid NOM, hydrophilic neutral NOM, and inorganic colloidal materials, respectively. The results obtained showed that the organic NOM of hydrophilic surrogate (dextran) plays a primary role in promoting membrane fouling, followed by hydrophobic acids and inorganic kaolin, but to a lesser extent than organic NOM compounds. Significant differences in the extent of fouling between dextran and HA have been obs...

2011-01-01

328

Phase Behavior and Interactions of the Membrane-Protein Bacteriorhodopsin

Pharmaceutical applications of cyclodextrins: effects on drug permeation through biological membranes

We present a synchrotron x-ray diffraction study of melting in stacks of two-dimensional crystalline arrays of the membrane protein bacteriorhodopsin. Two distinct regimes have been found as a function of the intermembrane distance d . In the {open_quotes}coupled{close_quotes} regime for d{lt}250 {Angstrom} the temperature (T{sub m}) of the melting transition decreases with increasing d , demonstrating the effect of the repulsive membrane interactions on the intramembrane protein ordering. For d{gt}250 {Angstrom} a {open_quotes}decoupled{close_quotes} regime is found with higher T{sup *}{sub m} independent of d . Below T{sup *}{sub m} a solid-liquid-solid reentrant behavior is observed as d is increased. {copyright} {ital 1999} {ital The American Physical Society}

1999-04-01

329

British Library Electronic Table of Contents (United Kingdom)

Abstract Objectives- Cyclodextrins are useful solubilizing excipients that have gained currency in the formulator's armamentarium based on their ability to temporarily camouflage undesirable physicochemical properties. In this context cyclodextrins can increase oral bioavailability, stabilize compounds to chemical and enzymatic degradation and can affect permeability through biological membranes under certain circumstances. This latter property is examined herein as a function of the published literature as well as work completed in our laboratories. Key findings- Cyclodextrins can increase the uptake of drugs through biological barriers if the limiting barrier component is the unstirred water layer (UWL) that exists between the membrane and bulk water. This means that cyclodextrins are mo...

2011-01-01

330

Manganese oxide nanowires, films, and membranes and methods of making

Healing of onlay mandibular bone grafts covered with collagen membrane or bovine bone substitutes: A microscopical and immunohistochemical study in the sheep

Nanowires, films, and membranes comprising ordered porous manganese oxide-based octahedral molecular sieves, and methods of making, are disclosed. A single crystal ultra-long nanowire includes an ordered porous manganese oxide-based octahedral molecular sieve, and has an average length greater than about 10 micrometers and an average diameter of about 5 nanometers to about 100 nanometers. A film comprises a microporous network comprising a plurality of single crystal nanowires in the form of a layer, wherein a plurality of layers is stacked on a surface of a substrate, wherein the nanowires of each layer are substantially axially aligned. A free standing membrane comprises a microporous network comprising a plurality of single crystal nanowires in the form of a layer, wherein a plurality of layers is aggregately stacked, and wherein the nanowires of each layer are substantially axially aligned.

2008-10-21

331

British Library Electronic Table of Contents (United Kingdom)

The objective of this study was to evaluate the role of collagen membrane and Bio-Oss coverage in healing of an onlay graft to the mandible. Twelve adult sheep each received an onlay bone graft (experiment 1), bone graft+Bio-Gide (experiment 2), and bone graft+Bio-Oss/Bio-Gide (experiment 3) on the lateral surface of the mandible. The animals were euthanized at 4, 8, 12 or 16 weeks after surgery, and findings were analysed by routine microscopy and immunohistochemistry for proliferation (Ki67) and apoptotic (Caspase-3) markers. Grafts were fully incorporated in all specimens. Pronounced resorption was observed in experiment 1. Minimal loss of graft volume was seen in experiment 2 specimens without membrane displacement. A remarkable increase in the augmented region of the mandible was obse...

2008-01-01

332

Evaluation of Neonatal Membrane Oxygenators With Respect to Gaseous Microemboli Capture and Transmembrane Pressure Gradients

British Library Electronic Table of Contents (United Kingdom)

Abstract A series of studies performed at our center demonstrates that gaseous microemboli (GME) remain a challenge in cardiac surgical procedures. Evaluation of novel oxygenators must address hemodynamic parameters and microemboli capture capability. The objective of this study is to compare two neonatal membrane oxygenators, the Quadrox i (MAQUET Cardiopulmonary AG, Hirrlingen, Germany) and the Capiox RX05 (Terumo Corporation, Tokyo, Japan), with respect to GME capture and hemodynamic energy delivery. The experimental circuit included a Maquet HL 20 heart lung machine, a Heater Cooler Unit HCU 30 (MAQUET Cardiopulmonary AG), a membrane oxygenator (Quadrox i Neonatal or Capiox RX05), and inch tubing from the COBE Heart/Lung Perfusion Pack (COBE Cardiovascular, Inc., Arvada, CO, USA). A Ca...

2010-01-01

333

Development of ultrafiltration and adsorbents: October 1979-March 1980

Conductivity studies on commercially available proton-conducting membranes with different equivalent weight

Tests on a sample of trench water from the Maxey Flats burial ground effectively demonstrated the new Reverse Osmosis Pilot Plant. The effluent from the 50% salt-rejection membrane was decontaminated well enough with the exception of tritium to be discharged to the environment. The performance of the 97% salt-rejection membrane was superior to that of the 50% membrane. A breakthrough and capacity experiment was conducted with Durasil 10 on a simulated Three Mile Island solution. The maximum decontamination factor was extrapolated to be 10/sup 6/, which would reduce the cesium level of TMI water to below the discard limit. Capacity (1/DF = 0.5) was reached at 1260 column volumes. Several adsorbents were tested in the engineering columns for decontamination of cesium-bearing solutions. Under the conditions of the experiment, these adsorbents were ineffective in removing cesium from the solution.

1980-07-02

334

Computed tomography of middle ear cholesteatomas without tympanic membrane perforation

Two perfluorosulfonic acid membranes, Nafion{sup R} 105 and Nafion{sup R} 115 with the same thickness but different equivalent weights (EW = 1000 g/eq. resp. 1100 g/eq.) were characterised by conductivity measurements at different water vapour activities in the temperature range of 25-70{sup o}C. The results demonstrate that a lower membrane equivalent weight opens the possibility to obtain the needed proton conductivity at lower water vapour activity. This is especially important for those fuel cell applications, in which the cell is operated without external humidification of the fuel gases. (author) 5 figs., 5 refs.

1999-08-01

335

Characterization of the platelet-aggregating activity of tumor cells. [Mice

The growth of a middle ear cholesteatoma behind a normal tympanic membrane is a rate though possible event. In such cases, CT may provide useful information for diagnosis. The results are presented of a CT study carried out on 14 patients affected with unilateral conductive hearing loss and with normal tympanic membrane. CT allowed the diagnosis of meddle ear cholesteatoma to be made in all cases. All patients were treated with surgery: 8 of them underwent tympanoplasty and 6 explorative tympanotomy. While the diagnosis of cholesteatoma was confirmed in 13 patients, in 1 case tympanosclerosis was diagnosed. CT diagnosis of middle ear cholesteatoma is based on the demonstration of a low-density soft-tissue mass, in association with bone erosion or ossicular dislocation. The author emphasizes the difficulty of a CT diagnosis of cholesteatoma in the patients with middle ear soft-tissue masses in the absence of bone alterations.

1991-01-01

336

A method for measuring effective radon diffusion coefficients in radon barriers by using modified Lucas cells

Two lines of mouse tumor cells were shown to be capable of aggregating mouse and rabbit platelets in vitro. This process required higher Mg/sup 2 +/ concentrations than were needed by other commonly used platelet-aggregating agents. Platelet-aggregating activity was also found in tumor cell membrane fragments. This membrane-bound platelet-aggregating material contained protein, lipid, and carbohydrate moieties. The presence of all three appeared to be essential for stimulating platelet aggregation. Destruction of any component abolished its activity. Platelet aggregation induced by tumor cell membrane fragments was associated with a secretory release reaction. In this process, growth-promoting activity for tumor cells was also released from platelets. These results underline the importance of platelets in establishing tumor metastases.

1980-04-01

337

When autophagy meets viruses: a double-edged sword with functions in defense and offense

Radon proof barriers are used for lowering of radon transport from the soil into the house and the determination of the radon diffusion coefficient is an important parameter to be determined in order to design the minimal thickness of the radon proof insulation. A method has been developed in our laboratory by using modified Lucas cells connected to a radon source and tightly closed onto the top by the tested membranes whose radon diffusion coefficients are being measured. Solving the time-dependent differential equation for radon diffusion in the membrane for well-defined experimental conditions the effective radon diffusion coefficient of the insulating material can be evaluated by comparing the radon concentration decrease in the cell for the first hours with the well-known radioactive decay. First results obtained in several preliminary tests carried out with a parafilm M barrier and two polyethylene membranes are shown ...

2005-01-01

338

What can we learn about the lipid vesicle structure from the small-angle neutron scattering experiment? (Investigation DMPC vesicle structure by small angle neutron scattering)

Autophagy is a ubiquitous catabolic process that ensures organism’s well-being by sequestering a wide array of undesired intracellular constituents into double-membrane vesicles termed...Full Text Available

2010-12-01

339

Use of Lipophilic Cations to Measure the Membrane Potential of Oat Leaf Protoplasts 1

Small angle neutron scattering (SANS) on the unilamellar vesicle populations (diameter 500 and 1000 angstrom) was used to characterize lipid vesicles from dimyristoylphosphatidylcholine (DMPC) at three phases (gel, ripple, and liquid). Parameters of vesicle populations and internal structure of the DMPC bilayer were characterized on the basis of the Separated Form Factor (SFF) model. Parameters of the internal bilayer structure (thickness of the membrane and the hydrophobic core, hydration, and surface area of lipid molecule) were determined on the basis of the Hydrophobic-Hydrophilic (HH) approximation of neutron scattering length density across the bilayer r(x) and of the Step Function (SF) approximation of r(x). It was demonstrated in frame of HH approximation that DMPC membrane thickness in liquid phase (T=30 degrees) depends on the membrane curvature. The dependence of the DMPC membrane thickness ...

2005-01-01

340

The LW blood group glycoprotein is homologous to intercellular adhesion molecules.

Uptake of the lipophilic cation triphenylmethylphosphonium into mesophyll protoplasts of oat (Avena sativa L. cv. “Garry”) approaches equilibrium at 3 to 4 hours. The...Full Text Available

1978-12-01

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341

The Cytokinin Receptors of Arabidopsis Are Located Mainly to the Endoplasmic Reticulum¹^[W]^[OA]

The LW blood group antigens reside on a 42-kDa erythrocyte membrane glycoprotein that was purified by immunoaffinity and partially sequenced. From this information, a specific PCR-amplified DNA fragment...Full Text Available

1994-06-07

342

The ATP-Binding Cassette Transporter ABCA4: Structural and Functional Properties and Role in Retinal Disease

The plant hormone cytokinin is perceived by membrane-located sensor histidine kinases. Arabidopsis (Arabidopsis thaliana) possesses three cytokinin receptors: ARABIDOPSIS HISTIDINE...Full Text Available

2011-08-01

343

Technical and clinical assessment of oxygen concentrators.

ATP-binding cassette transporters (ABC transporters) utilize the energy of ATP hydrolysis to translocate an unusually diverse set of substrates across cellular membranes. ABCA4, also known as...Full Text Available

2010-01-01

344

Study on the property of snow when sliding off membrane structure roof. Makukozobutsu ni okeru kassetsuji no seijo ni kansuru kenkyu

One membrane oxygen enricher (Oxygen Enrichment Company OE-4E) and four molecular sieve (MS) concentrators (Mountain Medical Econo2, De Vilbiss MINI DeVO2, Cryogenic Roomate III, and Mountain Medical...Full Text Available

1985-11-01

345

Stochastic simulation of the transducin GTPase cycle.

Since membrane structures such as domes have been constructed in snowy regions, how to dispose snow on the roof has become a big problem. In the case of disposing snow on the roof by sliding off, it is required to know the distance and range of snow dispersion after the fall from the roof from the aspect of disaster prevention. This paper describes the experimental study on the effects of snow depth, sliding distance and angle on the distance and range of snow dispersion using an outdoor apparatus to slide the snow off which can adjust the conditions for sliding. As a result, the distance of snow dispersion was influenced not only by the sliding distance and angle but also the depth (as well as the weight) of the snow. When the snow was sliding on the membrane structure, it was neccesary to consider viscostic resisting force of water between the snow and the membrane in addition to kinetic friction force. After the fall ...

1992-07-30

346

Stem Cell Therapies Benefit Alport Syndrome

On rod disc membranes, single photoactivated rhodopsin (R*) molecules catalytically activate many copies of the G-protein (Gt), which in turn binds and activates the effector (phosphodiesterase). We...Full Text Available

1996-12-01

347

Soluble Variants of Rhodobacter capsulatus Membrane-anchored Cytochrome c_y Are Efficient Photosynthetic Electron Carriers*

Patients with Alport syndrome progressively lose renal function as a result of defective type IV collagen in their glomerular basement membrane. In mice lacking the α3 chain of type IV collagen...Full Text Available

2009-11-01

348

Septum Formation in Escherichia coli: Characterization of Septal Structure and the Effects of Antibiotics on Cell Division

Photosynthetic (Ps) electron transport pathways often contain multiple electron carriers with overlapping functions. Here we focus on two c-type cytochromes (cyt) in facultative phototrophic...Full Text Available

2008-05-16

349

Semiempirical model based on thermodynamic principles for determining 6 kW proton exchange membrane electrolyzer stack characteristics

Septa can be demonstrated in sections of Escherichia coli strains B and B/r after fixation with acrolein and glutaraldehyde. The septum consists of an ingrowth of the cytoplasmic membrane...Full Text Available

1974-07-01

350

Rhabdomere biogenesis in Drosophila photoreceptors is acutely sensitive to phosphatidic acid levels

The performance of a 6 kW proton exchange membrane (PEM) electrolyzer was modeled using a semiempirical equation. Total cell voltage was represented as a sum of the Nernst voltage, activation overpotential and ohmic overpotential. A temperature and pressure dependent Nernst potential, derived from thermodynamic principles, was used to model the 20 cell PEM electrolyzer stack. The importance of including the temperature dependence of various model components is clearly demonstrated. The reversible potential without the pressure effect decreases with increasing temperature in a linear fashion. The exchange current densities at both the electrodes and the membrane conductivity were the coefficients of the semiempirical equation. An experimental system designed around a 6 kW PEM electrolyzer was used to obtain the current-voltage characteristics at different stack temperatures. A nonlinear curve fitting method was employed to determine the equation ...

2008-12-01

351

Relative potencies for barbiturate binding to the Torpedo acetylcholine receptor.

Phosphatidic acid (PA) is postulated to have both structural and signaling functions during membrane dynamics in animal cells. In this study, we show that before a critical time period during rhabdomere...Full Text Available

2009-04-06

352

Regulation of basal cellular physiology by the homeostatic unfolded protein response

1. The structural requirements of an allosteric barbiturate binding site on acetylcholine receptor-rich membranes isolated from Torpedo electroplaques have been characterized by the ability of fourteen...Full Text Available

1990-11-01

353

Regulation of Vacuolar H⁺-Pyrophosphatase by Free Calcium ¹

The extensive membrane network of the endoplasmic reticulum (ER) is physically juxtaposed to and functionally entwined with essentially all other cellular compartments. Therefore, the ER must sense...Full Text Available

2010-05-31

354

Receptor Binding Sites and Antigenic Epitopes on the Fiber Knob of Human Adenovirus Serotype 3

The H⁺-translocating inorganic pyrophosphatase (H⁺-PPase) associated with vesicles of the vacuolar membrane (tonoplast) isolated from beet (Beta vulgaris L.) is...Full Text Available

1992-12-01

355

Purification and Characterization of a Membrane-Bound Protease from Chlamydomonas reinhardtii 1

The adenovirus fiber knob causes the first step in the interaction of adenovirus with cell membrane receptors. To obtain information on the receptor binding site(s), the interaction of labeled cell...Full Text Available

1998-11-01

356

Properties of rare-gas solids. [Diffusion rate of xenon through epithelial tissue

In Chlamydomonas reinhardtii y-1, newly synthesized chlorophyll a/b-binding apoproteins are degraded when chlorophylls are not present for assembly of stable light-harvesting...Full Text Available

1992-07-01

357

Propagation of human embryonic and induced pluripotent stem cells in an indirect co-culture system

Results are reported from studies of the diffusion rate of xenon through frog abdominal skin and toad urinary bladders, typical epithelial membranes. It was concluded that intracellular water serves as the principal barrier for xenon passage through epithelial tissue.

1977-01-01

358

Probing a Membrane Matrix Regulating Hormone Action

We have developed and validated a microporous poly(ethylene terephthalate) membrane-based indirect co-culture system for human pluripotent stem cell (hPSC) propagation, which allows real-time...Full Text Available

2010-03-05

359

Prenatal diagnosis for recessive dystrophic epidermolysis bullosa in 10 families by mutation and haplotype analysis in the type VII collagen gene (COL7A1).

Auxin-induced pea (Pisum sativum) stem section elongation is enhanced at levels of 3 to 40 micromolar by six new classes of alkane derivatives additional to those described earlier,...Full Text Available

1971-11-01

360

Pore-forming toxins trigger shedding of receptors for interleukin 6 and lipopolysaccharide.

BACKGROUND: Epidermolysis bullosa (EB) is a group of heritable diseases that manifest as blistering and erosions of the skin and mucous membranes. In the dystrophic forms of EB (DEB), the diagnostic...Full Text Available

1996-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

361

Peripartal changes in serum alkaline phosphatase activity and lactate dehydrogenase activity in dairy cows.

Cleavage of membrane-associated proteins with the release of biologically active macromolecules is an emerging theme in biology. However, little is known about the nature and regulation of the involved...Full Text Available

1996-07-23

362

Passive immunity to feline leukemia: evaluation of immunity from dams naturally infected and experimentally vaccinated.

Peripartal serum alkaline phosphatase activity and lactate dehydrogenase activity were measured in 30 dairy cows in order to examine the association between retained fetal membranes and enzyme activity....Full Text Available

1987-10-01

363

PRELIMINARY STUDY ON MODIFICATION OF YOLK SAC OF ZEBRAFISH EMBRYOS (DANIO RERIO) USING MICROINJECTION

Antibodies against feline leukemia virus (FeLV) and the feline oncornavirus-associated cell membrane antigen (FOCMA) were transferred from pregnant cats to their suckling kittens. All of these kittens...Full Text Available

1977-04-01

364

PAS Domain of the Aer Redox Sensor Requires C-Terminal Residues for Native-Fold Formation and Flavin Adenine Dinucleotide Binding

Low membrane permeability is one of the major obstacles to the successful cryopreservation of zebrafish embryos. The aim of the present study was to explore if this could be overcome by yolk...Full Text Available

2006-01-01

365

Osterix Overexpression in Mesenchymal Stem cells Stimulates Healing of Critical-Sized Defects in Murine Calvarial Bone

The Aer protein in Escherichia coli is a membrane-bound, FAD-containing aerotaxis and energy sensor that putatively monitors the redox state of the electron transport system. Binding...Full Text Available

2004-10-01

366

Osmotically Induced Removal of Water from Fungal Cells as Determined by a Spin Probe Technique 1

Osterix (Osx) is a zinc-finger-containing transcription factor that is expressed in osteoblasts of all endochondral and membranous bones. In Osx null ...Full Text Available

2007-10-01

367

Osmotic Shock Inhibits Auxin-stimulated Acidification and Growth ¹

Effects of physical environment on plasma membrane semipermeability and osmotic induction of changes in aqueous cytoplasmic volume were studied in vegetative and spore cells of a plant pathogenic fungus,...Full Text Available

1978-11-01

368

Nylon biodegradation by lignin-degrading fungi.

Cells of oat coleoptiles (Avena sativa L. cv. “Garry”) have been osmotically shocked in order to observe the effect of alterations of the plasma membrane on some auxin...Full Text Available

1977-03-01

369

Neurobehavioral effects of power-frequency electromagnetic fields.

The biodegradation of nylon by lignin-degrading fungi was investigated. The fungus IZU-154 significantly degraded nylon-66 membrane under ligninolytic conditions. Nuclear magnetic resonance analysis...Full Text Available

1997-01-01

370

Nano-engineered PtVFe catalysts in proton exchange membrane fuel cells: Electrocatalytic performance

Some laboratory experiments have suggested that power-frequency electric and magnetic fields (EMF) may be capable of influencing calcium efflux from cell membranes, pineal function, and circadian rhythms....Full Text Available

1993-12-01

371

Mycobacterium tuberculosis Chaperonin 10 Is Secreted in the Macrophage Phagosome: Is Secretion Due to Dissociation and Adoption of a Partially Helical Structure at the Membrane?

Proton exchange membrane fuel cells (PEMFCs) are attractive because of their high conversion efficiency, low pollution, lightweight, and high power density. A major area of challenges is the design and engineering of active, robust, and low-cost electrocatalysts. This report discusses recent findings of our investigations of the design and nano-engineering of platinum-vanadium-iron catalysts for use in PEMFC. The membrane electrode assembly was prepared using nano-engineered PtVFe nanoparticles with controlled composition and size supported on carbon as cathode electrocatalysts. The electrocatalytic activity and stability of the catalysts have been characterized by both rotating disk electrode and membrane electrode assembly measurements. The trimetallic catalysts have been shown to exhibit excellent electrocatalytic performance in PEMFC in comparison with commercial platinum catalysts. The results exhibited a good ...

2010-11-30

372

Multiple Functions of the 37/67-kd Laminin Receptor Make It a Suitable Target for Novel Cancer Gene Therapy

To confirm that Mycobacterium tuberculosis chaperonin 10 (Cpn10) is secreted outside the live bacillus, infected macrophages were examined by electron microscopy. This revealed that...Full Text Available

2003-07-01

373

Modulation of B-cell endoplasmic reticulum calcium homeostasis by Epstein-Barr virus Latent Membrane Protein-1

The 37/67-kd laminin receptor, LAMR, is a multifunctional protein that associates with the 40S ribosomal subunit and also localizes to the cell membrane to interact with the extracellular matrix. LAMR...Full Text Available

2010-01-01

374

Model for phase III autografts of epidermal cells cultured on a collagen-proteoglycan biomatrix.

BackgroundCalcium signaling plays an important role in B lymphocyte survival and activation, and is critically dependent on the inositol-1,4,5-tris-phosphate-induced...Full Text Available

375

Mitochondrial DNA repair and association with aging - an update

The primary aim of this study was to develop a model system that uses epidermal cells (keratinocytes and accessory pigmented cells) cultured on a reconstituted basement membrane biomatrix for use in...Full Text Available

1989-10-01

376

Metabolic labeling and direct imaging of choline phospholipids in vivo

Mitochondrial DNA is constantly exposed to oxidative injury. Due to its location close to the main site of reactive oxygen species, the inner mitochondrial membrane, mtDNA is more susceptible...Full Text Available

2010-08-01

377

Membrane Efflux and Influx Modulate both Multidrug Resistance and Virulence of Klebsiella pneumoniae in a Caenorhabditis elegans Model?

Choline (Cho)-containing phospholipids are the most abundant phospholipids in cellular membranes and play fundamental structural as well as regulatory roles in cell metabolism and signaling. Although...Full Text Available

2009-09-08

378

Mechanism of Na(+)-dependent citrate transport in Klebsiella pneumoniae.

Cross-resistance to cefoxitin (FOX), chloramphenicol (CMP), and quinolones (nalidixic acid [NAL]) related to a putative efflux system overexpression has recently been reported for Klebsiella...Full Text Available

2010-10-01

379

Malolactic fermentation: electrogenic malate uptake and malate/lactate antiport generate metabolic energy.

Citrate transport via CitS of Klebsiella pneumoniae has been shown to depend on the presence of Na+. This transport system has been expressed in Escherichia coli, and uptake of citrate in E. coli membrane...Full Text Available

1992-08-01

380

Lack of association between polymorphisms in C4b-binding protein and atypical haemolytic uraemic syndrome in the Spanish population

The mechanism of metabolic energy production by malolactic fermentation in Lactococcus lactis has been investigated. In the presence of L-malate, a proton motive force composed of a membrane potential...Full Text Available

1991-10-01

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381

Lack of Influence of Phytochrome on Membrane Permeability to Tritiated Water ¹

Dysregulation of the alternative pathway of complement activation, caused by mutations or polymorphisms in the genes encoding factor H, membrane co-factor protein, factor I or factor B, is associated...Full Text Available

2009-01-01

382

Kinetics of the Vacuolar H⁺-Pyrophosphatase ¹

The water permeability of tissues was investigated by measuring the efflux of ³HHO from previously loaded (in darkness) etiolated bean buds (Phaseolus vulgaris L. var. Red...Full Text Available

1976-02-01

383

Introduction of the CIITA gene into tumor cells produces exosomes with enhanced anti-tumor effects

The responses of the vacuolar membrane (tonoplast) proton-pumping inorganic pyrophosphatase (H⁺-PPase) from oat (Avena sativa L.) roots to changes in Mg²⁺ and...Full Text Available

1992-12-01

384

Intracellular pH in adipocytes: effects of free fatty acid diffusion across the plasma membrane, lipolytic agonists, and insulin.

Exosomes are small membrane vesicles secreted from various types of cells. Tumor-derived exosomes contain MHC class I molecules and tumor-specific antigens, receiving attention as a potential cancer...Full Text Available

2011-05-31

385

Interaction of Platelet Membrane Receptors with von Willebrand Factor, Ristocetin, and the Fc Region of Immunoglobulin G

The main function of white adipose tissue is to store nutrient energy in the form of triglycerides. The mechanism by which free fatty acids (FFA) move into and out of the adipocyte has not been resolved....Full Text Available

1996-09-17

386

Initial Development and Characterization of PLGA Nanospheres Containing Ropivacaine

The agglutination of human platelets by ristocetin and von Willebrand factor was inhibited by aggregated immunoglobulin (Ig)G and by Fc fragments of IgG, but not by Fab, F(ab′)₂ or...Full Text Available

1978-11-01

387

In vitro selection of RNA molecules that displace cocaine from the membrane-bound nicotinic acetylcholine receptor

Local anesthetics are able to induce pain relief by binding to the sodium channels of excitable membranes, blocking the influx of sodium ions and the propagation of the nervous impulse. Ropivacaine...Full Text Available

2007-12-01

388

Impact of sphingomyelin levels on coronary heart disease and left ventricular systolic function in humans

The nicotinic acetylcholine receptor (AChR) controls signal transmission between cells in the nervous system. Abused drugs such as cocaine inhibit this receptor. Transient kinetic investigations indicate...Full Text Available

1998-11-24

389

Immunochemical Analysis of the Temporal and Tissue-Specific Expression of an Avena sativa Plasma Membrane Determinant 1

Sphingomyelin (SM) is an abundant phospholipid in cell membranes and in lipoproteins. In human plasma, SM is mainly found in atherogenic lipoproteins; therefore, higher levels of SM may promote atherogenesis....Full Text Available

390

IgE antibodies to D. pteronyssinus in atopic patients.

An immunoglobulin Mk monoclonal (F8IVE9) antibody raised against oat (Avena sativa cv Garry) root homogenate has been produced and characterized. The predominant target...Full Text Available

1992-01-01

391

Homology of SMP domains to the TULIP superfamily of lipid-binding proteins provides a structural basis for lipid exchange between ER and mitochondria

An aqueous house dust mite extract was separated by SDS-PAGE and transferred to nitrocellulose membranes by Western Blotting. Two major allergens, Der pI and Der pII associated with the mite faeces...Full Text Available

1988-06-01

392

Highly efficient concentration of lenti- and retroviral vector preparations by membrane adsorbers and ultrafiltration

Mitochondria must uptake some phospholipids from the endoplasmic reticulum (ER) for the biogenesis of their membranes. They convert one of these lipids, phosphatidylserine, to phosphatidylethanolamine,...Full Text Available

2010-08-15

393

High temperature electrochemical polishing of H{sub 2}S from coal gasification process streams. Quarterly progress report, October 1, 1995--December 31, 1995

BackgroundLentiviral vectors (LVs) can efficiently transduce a broad spectrum of cells and tissues, including dividing and non-dividing cells. So far the most widely used method...Full Text Available

394

Further assembly required: construction and dynamics of the endoplasmic reticulum network

An advanced process for the separation of hydrogen sulfide (H{sub 2}S) from coal gasification product streams through an electrochemical membrane is being developed. H{sub 2}S is removed from the syn-gas stream, split into hydrogen, which enriches the exiting syn-gas, and sulfur, which is condensed from an inert sweep gas stream. The process allows removal of H{sub 2}S without cooling the gas stream and with negligible pressure loss through the separator. The process is made economically attractive by the lack of need for a Claus process for sulfur recovery. Membrane manufacturing coupled with full-cell experimentation was the primary focus this quarter. A tape-casted zirconia membrane was developed and utilized in one full-cell experiment (run 25); run 24 utilized a fabricated membrane purchased from Zircar Corporation. Results are discussed.

1995-12-31

395

Free Fatty Acids Regulate Two Galactosyltransferases in Chloroplast Envelope Membranes Isolated from Spinach Leaves

The endoplasmic reticulum (ER) is a continuous membrane system comprising the nuclear envelope, ribosome-studded peripheral sheets and an interconnected network of smooth tubules extending throughout...Full Text Available

2010-07-01

396

Exit from the Golgi Is Required for the Expansion of the Autophagosomal Phagophore in Yeast Saccharomyces cerevisiae

Effects of MgCl₂ and free fatty acids (FFA) on galactolipid:galactolipid galactosyltransferase (GGGT) and UDP-galactose: 1,2-diacylglycerol galactosyltransferase (UDGT) in chloroplast envelope...Full Text Available

1990-10-01

397

Evolutionary conservation of a microbody targeting signal that targets proteins to peroxisomes, glyoxysomes, and glycosomes

The delivery of proteins and organelles to the vacuole by autophagy involves membrane rearrangements that result in the formation of large vesicles called autophagosomes. The mechanism underlying autophagosome...Full Text Available

2010-07-01

398

Entropic effects in channel-facilitated transport: Inter-particle interactions break the flux symmetry

Peroxisomes, glyoxysomes, glycosomes, and hydrogenosomes have each been classified as microbodies, i.e., subcellular organelles with an electron-dense matrix that is bound by a single membrane. We investigated...Full Text Available

1991-09-01

399

Electric-field-induced deformation of biological cells

We analyze transport through conical channels due to the difference in particle concentration on the two sides of the membrane. Because of the detailed balance, fluxes of non-interacting particles...Full Text Available

2009-08-01

400

Effects of Perfluorocarbons on surfactant exocytosis and membrane properties in isolated alveolar type II cells

The cell is modeled as an ellipsoid with shell and the surface stress distribution calculated by means of the Maxwell Stress Tensor. The cell membrane is treated as incompressible material having both bending and shear energies of deformation. Employing the principle of virtual work, cell volume (and hence shape) is computed as a function of the external field strength and orientation with respect to the field. The following results were obtained: (1) The surface stresses that develop or the cell membrane are distributed having both normal and tangential components that act together to produce a rounding of the cell. (2) If the tangential component of the stress is ignored, then higher field strengths are needed to produce similar deformation (shape change) of cells. (3) The threshold value of the applied field, i.e, the field strength at which the volume (shape) of the cell changes abruptly, occurs at approximately 55V/cm. Above the threshold ...

1989-01-01

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

401

Effects of PKA phosphorylation on the conformation of the Na,K-ATPase regulatory protein FXYD1

BackgroundPerfluorocarbons (PFC) are used to improve gas exchange in diseased lungs. PFC have been shown to affect various cell types. Thus, effects on alveolar type II (ATII) cells...Full Text Available

2010-01-01

402

Effects of ?-Cyclodextrin on the Structure of Sphingomyelin/Cholesterol Model Membranes

FXYD1 (phospholemman) is a member of an evolutionarily conserved family of membrane proteins that regulate the function of the Na,K-ATPase enzyme complex in specific tissues and specific physiological...Full Text Available

2009-11-01

403

Dosing Recommendations for Continuous Venovenous Hemodiafiltration with AN69 Filter Membranes and Prismaflex Dialyzers

The interaction of β-cyclodextrin (β-CD) with mixed bilayers composed of sphingomylein and cholesterol (Chol) above and below the accepted stable complexation...Full Text Available

2010-09-08

404

Distribution of lead-203 in human peripheral blood in vitro.

Background:Continuous renal replacement therapy is used to manage fluid and solute imbalances in critically ill patients but may affect the clearance of concurrently administered...Full Text Available

2009-11-01

405

Diminished osmotic fragility of human erythrocytes following the membrane insertion of oxygenated sterol compounds

In-vitro experiments using 203Pb were performed to identify the lead binding components in human peripheral blood. The distribution of lead in plasma, in the red cell membrane, and within the red cell...Full Text Available

1980-02-01

406

Dimeric subunit stoichiometry of the human voltage-dependent proton channel Hv1

Oxygenated sterol compounds (OSC), when incubated for 1 hr with human erythrocytes in lipoprotein-depleted medium at concentrations of 0.625-5 x 10/sup -5/M, are inserted into the cell membrane and remain there despite subsequent washing of the cells. The insertion results in expansion of the surface area of the red cell ghost membrane, an increase in critical hemolytic volume, and as a consequence, in dimished osmotic fragility of the erythrocytes. This effect is seen with echinocyte-forming as well as with non-echinocyte-forming OSC. Erythrocytes treated with OSC do not differ from control cells with respect to their mean cell volume (MCV) in isotonic solution, water content, ion fluxes, and filterability through polycarbonate filters. The shift of the osmotic fragility curve toward lower NaCl concentrations is proportional to the amount of OSC inserted into the red cell membrane. 7BETA-Hydroxycholesterol, ...

1981-08-01

407

Differential effects of procaine and phenethyl alcohol on excision repair of DNA in u. v. -irradiated Escherichia coli

In voltage-gated Na⁺, K⁺, and Ca²⁺ channels, four voltage-sensor domains operate on a central pore domain in response to membrane voltage. In contrast, the voltage-gated...Full Text Available

2008-06-03

408

Different distribution of fluorinated anesthetics and nonanesthetics in model membrane: a 19F NMR study.

Experiments were performed to investigate the involvement of the cell membrane in the excision DNA repair process in Escherichia coli. Two membrane-binding drugs, procaine and phenethyl alcohol (PEA), inhibited liquid-holding recovery (LBR) in u.v.-irradiated E. coli wild-type and recA strains. In uvrB and polA strains where, after u.v.-irradiation, LHR was absent the two drugs had no effect. Both drugs markedly reduced the removal of u.v.-induced thymine dimers in the DNA of wild-type cells (H/r30). Analysis by alkaline sucrose gradients revealed that PEA inhibited the incision step in excision repair. In contrast, procaine had no effect on incision but apparently inhibited the late steps in excision repair. PEA dissociated DNA from the cell membrane, whereas procaine did not. The results suggest that the two drugs PEA and procaine inhibit LHR and the excision repair process operating on u.v.-induced damage in E. coli by ...

1986-12-01

409

Detection and enumeration of toxin-producing Pasteurella multocida with a colony-blot assay.

Despite their structural resemblance, a pair of cyclic halogenated compounds, 1-chloro-1,2,2-trifluorocyclobutane (F3) and 1,2-dichlorohexafluorocyclobutane (F6), exhibit completely different anesthetic...Full Text Available

1997-04-01

410

Deletion of the Plasmodium falciparum Merozoite Surface Protein 7 Gene Impairs Parasite Invasion of Erythrocytes?

Colonies of toxin-producing Pasteurella multocida were detected with peroxidase-labeled monoclonal antibodies by a membrane assay. Examination of the specificity of the assay with 29 P. multocida cultures...Full Text Available

1991-07-01

411

Cyclophilin B Interacts with Sodium-Potassium ATPase and Is Required for Pump Activity in Proximal Tubule Cells of the Kidney

Merozoite surface proteins have been implicated in the initial attachment to the host red blood cell membrane that begins the process of invasion, an important step in the life cycle of the malaria...Full Text Available

2008-12-01

412

Comparison of membrane filters for recovery of legionellae from water samples.

Cyclophilins (Cyps), the intracellular receptors for Cyclosporine A (CsA), are responsible for peptidyl-prolyl cis-trans isomerisation and for chaperoning several membrane proteins. Those functions...Full Text Available

413

Cleavage of sterol regulatory element binding proteins (SREBPs) by CPP32 during apoptosis.

The procedure currently used for isolating legionellae from environmental samples recommend filtration through a 0.2-microns-pore-size polycarbonate filter. In this study we evaluated the performance...Full Text Available

1993-01-01

414

Chemiosmotic model for plant mitochondria

Cellular cholesterol homeostasis is controlled by sterol-regulated proteolysis of membrane-bound transcription factors called sterol-regulatory element binding proteins (SREBPs). CPP32, a cysteine protease,...Full Text Available

1996-03-01

415

Charge compensation for NADPH oxidase activity in microglia in rat brain slices does not involve a proton current

A balanced application of chemiosmosis to plant mitochondria is presented. Electron transport carriers are sequenced to achieve proton translocation across the inner membrane. The processes of proton translocation, use, and release are integrated to yield a description of the effective proton gradient available for metabolite transport and ATP synthesis. 27 references, 6 figures.

1983-12-01

416

Characterization of genes in the cellulose-synthesizing operon (acs operon) of Acetobacter xylinum: implications for cellulose crystallization.

The membrane properties of isolated cultured microglia have been extensively studied but it is important to understand their properties in situ, where they protect the brain against...Full Text Available

2008-09-01

417

Cd36, a class B scavenger receptor, functions as a monomer to bind acetylated and oxidized low-density lipoproteins

The synthesis of an extracellular ribbon of cellulose in the bacterium Acetobacter xylinum takes place from linearly arranged, membrane-localized, cellulose-synthesizing and extrusion complexes that...Full Text Available

1994-09-01

418

Cadherin Mechanics and Complexation: The Importance of Calcium Binding

Cd36 is a small-molecular-weight integral membrane protein expressed in a diverse, but select, range of cell types. It has an equally diverse range of ligands and physiological functions, which has...Full Text Available

2007-11-01

419

Biosorption of heavy metals by free and immobilised biomass

E-cadherins belong to a family of membrane-bound, cellular adhesion proteins. Their adhesive properties mainly involve the two N-terminal extracellular domains (EC1 and EC2). The junctions between these...Full Text Available

2005-12-01

420

Binding of a Fluorescent Lipid Amphiphile to Albumin and its Transfer to Lipid Bilayer Membranes

A review of the research activities carried out by the authors on biosorption of heavy metals is reported in this work. In particular, biomass characterisation, biosorption equilibrium with single metal system, biomass immobilisation in polymeric matrix and related kinetics, biosorption in membrane reactor systems are the main aspects reported in the paper. (orig.)

2000-07-01

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421

Bif-1 regulates Atg9 trafficking by mediating the fission of Golgi membranes during autophagy

Kinetics and thermodynamics of the binding of a fluorescent lipid amphiphile, Rhodamine Green™-tetradecylamide (RG-C_14:0), to bovine serum albumin were characterized in an equilibrium...Full Text Available

2003-01-01

422

An analysis by low-angle neutron scattering of the structure of the acetylcholine receptor from Torpedo californica in detergent solution.

Atg9 is a transmembrane protein essential for autophagy which cycles between the Golgi network, late endosomes and LC3-positive autophagosomes in mammalian cells during starvation through a mechanism...Full Text Available

2011-01-01

423

Aminoglycoside Efflux in Pseudomonas aeruginosa: Involvement of Novel Outer Membrane Proteins

The acetylcholine receptor from the electric tissue of Torpedo californica is a large, integral membrane protein containing four different types of polypeptide chains. The structure of the purified...Full Text Available

1979-12-01

424

Amino acid transport in the thermophilic anaerobe Clostridium fervidus is driven by an electrochemical sodium gradient.

The expression of tripartite multidrug efflux pumps such as MexA-MexB-OprM in Pseudomonas aeruginosa contributes to intrinsic resistance to a wide variety of antimicrobials, including...Full Text Available

2003-03-01

425

Adhesion of DOPA-Functionalized Model Membranes to Hard and Soft Surfaces

Amino acid transport was studied in membranes of the peptidolytic, thermophilic, anaerobic bacterium Clostridium fervidus. Uptake of the negatively charged amino acid L-glutamate, the neutral amino...Full Text Available

1993-04-01

426

A novel approach for predicting the uptake and toxicity of metallic and metalloid ions

The adhesive proteins secreted by marine mussels form a natural glue that cures rapidly to form strong and durable bonds in aqueous environments. These mussel adhesive proteins contain an unusual...Full Text Available

2009-01-01

427

A membrane-associated progesterone-binding protein, 25-Dx, is regulated by progesterone in brain regions involved in female reproductive behaviors

Electrostatic nature of plant plasma membrane (PM) plays significant roles in the ion uptake and toxicity. Electrical potential at the PM exterior surface (ψ₀^o) influences...Full Text Available

2011-03-01

428

A View of NASA's International Cooperation - External Relations - NASA

The ventromedial hypothalamus (VMH) plays a central role in the regulation of the female reproductive behavior lordosis, a behavior dependent upon the sequential activation of receptors for the ovarian...Full Text Available

2000-11-07

429

A Genomewide RNAi Screen for Genes That Affect the Stability, Distribution and Function of P Granules in Caenorhabditis elegans

international vehicles, control centers, and ground support personnel. ... consists of thin membranes made from a polymer-based film and ..... (including airplanes and submarines), environmental monitoring, and control ...... sciences can use it to analyze the birth and death of stars, the formation of solar ...

430

'Sheltered disruption' of Neurospora crassa MOM22, an essential component of the mitochondrial protein import complex.

P granules are non-membrane-bound organelles found in the germ-line cytoplasm throughout Caenorhabditis elegans development. Like their “germ granule” counterparts in...Full Text Available

2009-12-01

431

Proton exchange membrane fuel cells with chromium nitridenanocrystals as electrocatalysts

MOM22 is a component of the protein import complex of the mitochondrial outer membrane of Neurospora crassa. Using the newly developed procedure of 'sheltered disruption', we created a heterokaryotic...Full Text Available

1995-03-15

432

Photoassisted hydrogen generation by integrated electroactive SPE membrane system

Polymer electrolyte membrane fuel cells (PEMFCs) are energy conversion devices that produce electricity from a supply of fuel, such as hydrogen. One of the major challenges in achieving efficient energy conversion is the development of cost-effective materials that can act as electrocatalysts for PEMFCs. In this letter, we demonstrate that, instead of conventional noble metals, such as platinum, chromium nitride nanocrystals of fcc structure exhibit attractive catalytic activity for PEMFCs. Device testing indicates good stability of nitride nanocrystals in low temperature fuel cell operational environment.

2007-07-01

433

Monoclonal antibodies to antigens on human neutrophils, activated T lymphocytes, and acute leukemia blast cells

Incorporation of TiO{sub 2}, into perfluoroionomer membrane by treatment with TiC1{sub 4}-methanol has been described. Platinum was used as an electrocatalyst. In order to make the system electronically as well as ionically conducting, the electrode was modified with polypyrrole (PPy). Photopolymerisation of pyrrole was accomplished by immersing TiO{sub 2}-Pt-NaF in pyrrole solution. UV-visible and FT-IR Spectroscopic studies were preformed with regards to the formation of the TiO{sub 2}, Pt and PPy within Nafion matrix. We report the construction and evaluation of this integrated system and establish the feasibility of hydrogen generation thereof. (Author)

2000-04-01

434

Effect of Carbon Dioxide in the Air on Zinc-air Cell

The authors describe the production of two mouse hybridomas secreting monoclonal antibodies to antigenic determinants of the surface membranes of human neutrophils, activated T lymphocytes, and acute leukemic blast cells. The degree of lymphocyte stimulation was estimated from incorporation of /sup 3/H-thymidine with parallel microculture. Monoclonal antibodies of supernatants of hybridoma cultures shown here reacted in both immunofluorescence test and cytotoxicity test with surface membrane antigens on the majority of neutrophils and PHA-activated peripheral blood lymphocytes from healthy subjects, but did not give positive reactions with unactivated lymphocytes, adherent monocytes, erythrocytes, and alloantigen-stimulated lymphocytes.

1987-11-01

435

ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

The electrolyte was brought into contact with air and potassium carbonate was measured with various contact time in order to check the defect of carbon dioxide in the air on zinc-air cell. The relationship between potassium carbonate concentration in electrolyte and battery capacity was also studied. The potassium carbonate concentration in the electrolyte. The rate of carbon dioxide absorption was mainly affected by the pore size of hydrophobic membrane. Our study showed that adapting the pore of hydrophobic membrane decreased the loss of cell discharge performance due to the presence of carbon dioxide or water vapor in the atmosphere. 7 refs., 12 figs., 1 tab.

1999-04-01

436

ENGINEERING DEVELOPMENT OF CERAMIC MEMBRANE REACTOR SYSTEM FOR CONVERTING NATURAL GAS TO HYDROGEN AND SYNTHESIS GAS FOR LIQUID TRANSPORTATION FUELS

The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through February 1999.

1999-03-01

437

Dynamics of a reverse osmosis unit with application to pulsating regimes for process optimization

The objective of this contract is to research, develop and demonstrate a novel ceramic membrane reactor system for the low-cost conversion of natural gas to synthesis gas and hydrogen for liquid transportation fuels: the ITM Syngas process. Through an eight-year, three-phase program, the technology will be developed and scaled up to obtain the technical, engineering, operating and economic data necessary for the final step to full commercialization of the Gas-to-Liquids (GTL) conversion technology. This report is a summary of activities through September 1999.

1999-10-01

438

British Library Electronic Table of Contents (United Kingdom)

We propose unsteady-state reverse osmosis cell modelling in two dimensions. The convection-diffusion equation describing the concentration of the relevant chemical species is solved by a finite difference technique, while the velocity field is described by empirical expressions for spiral-wound membrane cells. A non-constant permeability is introduced to take into account the effects of membrane compaction at high operating pressures. The role of concentration polarization is discussed for different values of the parameters describing the global process. Finally, the model is applied to predict the effects of a pulsating flow where a cyclic pressure feed is adopted to enhance the permeate flux. In this context, an experimental validation of the model is proposed.

2011-01-01

439

Coating of metallic membranes by pulsed laser deposition; Beschichtung von metallischen Membranen mittels Pulsed Laser Deposition

Case for applying subnanosecond high-intensity, electrical pulses to biological cells.

There is increasing demand to functionalize meso- and nano-porous materials by coating and make the porous substrate biocompatible or environment friendly. However, coating on a meso-porous substrate poses great challenges, especially if the pore aspect ratio is high. In the current work the pulsed laser deposition (PLD) method is used for coating Ni{sub 3}Al-based meso-porous membranes with diamond-like carbon (DLC) layers of high thickness homogeneity and adhesion. (orig.)

2008-08-15

440

Back-up for high voltage cable pressurizing system

In this paper, model analysis into the time-dependent transmembrane potential at the outer cell membrane is presented, for applied high-intensity electric pulses having durations in the nanosecond range or smaller. It is argued that the frequency-dependent dielectric response of cell membranes could be used to advantage for stronger bioeffects by employing shorter pulses. Our model calculations predict faster transmembrane voltages and larger electroporation densities for a given external energy with pulse durations in the subnanosecond regime. This temporal regime would be used, for example, in the electrotherapy of mixed cell ensembles having different dielectric response properties. PMID:21937300

2011-10-01

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441

Effect of coagulation on fouling rate and cleanability of ultrafiltration membranes

A back-up system is provided for a pumping plant or a pressure reservoir system used to maintain insulating oil under pressure in high voltage submarine power cables which includes a gas driven membrane pump to insure a small outflow of oil at a rupture point in the power cable to prevent water from penetrating the cable. The proper operation of the membrane pump is insured by introducing degasified oil at the drive side of the pump during the stand-by and test modes of operation of the back-up system. 11 drawings.

1982-07-19

442

Development of low-level liquid-waste treatment systems: April-September 1982

Among the membrane filtration techniques, continuous cross-flow ultrafiltration (UF) is an innovative method to separate solid/liquid or liquid/liquid phases at a lower pressure of 5--150 psi compared to reverse osmosis (RO) in which the applied pressure is an order of magnitude higher. Recently, attempts have been made to combine processes of UF and other treatments for many applications. However, there is very little knowledge about the filtration process which combined coagulation and UF, and very few attempts have been made to apply coagulated UF to the treatment of fuel oil contaminated water. During the UF treatment of organic contaminants rapid declines in flux will occur due to the membrane fouling. Oil as a foulant plants an important role in the flux decrease. However, there are very limited pretreatment processes which can effectively remove fuel oil from water and hence solve the fouling problem. The purpose of the study was to ...

1996-11-01

443

Development of low-level liquid-waste treatment systems: April-September 1982

A preliminary investigation was conducted on ion specific membranes. This investigation concentrated on testing candidate organic compounds for transporting cesium ions through a membrane composed of the organic compound supported on a substrate. Solid PVC membranes were initially tried, but were found to be too slow. Thereafter, only liquid membranes were tested. These were faster and cesium concentration factors up to 2.96 were achieved in a single membrane cell. A cell with two membranes achieved a cesium concentration factor of 4.19. Cesium precipitation with sodium tetraphenyl borate in high sodium concentrations was explored. No interference from sodium was found until the sodium nitrite concentration reached 4.5 moles. Concurrently, cesium concentrations as high as 5.4 g/L were precipitated. Potassium tetraphenyl borate is being investigated for use in ...

1982-12-22

444

Temperature and controlled atmosphere effects on efficacy of Muscodor albus as a biofumigant

A preliminary investigation was conducted on ion specific membranes. This investigation concentrated on testing candidate organic compounds for transporting cesium ions through a membrane composed of the organic compound supported on a substrate. Solid PVC membranes were initially tried, but were found to be too slow. Thereafter, only liquid membranes were tested. These were faster and cesium concentration factors up to 2.96 were achieved in a single membrane cell. A cell with two membranes achieved a cesium concentration factor of 4.19. Cesium precipitation with sodium tetraphenyl borate in high sodium concentrations was explored. No interference from sodium was found until the sodium nitrite concentration reached 4.5 moles. Concurrently, cesium concentrations as high as 5.4 g/L were precipitated. Potassium tetraphenyl borate is being investigated for use in ...

445

British Library Electronic Table of Contents (United Kingdom)

Biofumigation with Muscodor albus was investigated to control four fungal decay pathogens (Phytophthora erythroseptica, Sclerotinia sclerotiorum, Botrytis cinerea and Penicillium expansum) and four bacterial pathogens (Erwinia carotovora pv. carotovora, Pseudomonas fluorescens, Escherichia coli, Listeria innocua) in controlled atmosphere conditions (regular air (20.8% O2+0.03% CO2), high CO2 (20.8% O2+15% CO2) or low O2 (1% O2+0.03% CO2)). In vitro experiments involved 48h exposure to M. albus at 3degreeC or 20degreeC, in vivo experiments involved 72h exposure to M. albus at 3degreeC. In vitro biofumigation with M. albus in regular air at 20degreeC killed all the pathogens. Bacterial growth was best controlled by M. albus at 20degreeC regardless of atmospheric conditions whereas fungal gro...

2008-01-01

446

Sulfur and carbon cycling in a flue gas desulfurization sludge disposal site.

Impact of Bifidobacterium animalis subsp. lactis BB-12 and, Lactobacillus acidophilus LA-5-containing yoghurt, on fecal bacterial counts of healthy adults

Products of a power plant flue gas desulfurization scrubber are discharged into a pond as sludge consisting of calcite (initial delta13C 3.2-3.8 per thousand), gypsum (initial delta34S 7.6-8.6 per thousand), and aqueous solution. Reducing conditions exist below a boundary that appears to move vertically as a function of changes in pond water level. Under reducing conditions, bacteria partially reduce aqueous sulfate to low-delta34S sulfide, consuming organic carbon and generating low-delta13C bicarbonate. Under oxidizing conditions, sulfide is converted to sulfate, leading to calcite dissolution, gypsum precipitation, and isotopic re-equilibration of remaining calcite with dissolved bicarbonate near the pond surface. The gypsum has delta34S near 6 per thousand, and calcite has delta13C as low as -1.7 per thousand; the changes from initial values correspond to predictions based on isotopic balance and reaction stoichiometry. The pond largely contains the products of ...

2003-04-01

447

British Library Electronic Table of Contents (United Kingdom)

This randomized, placebo-controlled, double blind, parallel dose-response study investigated the impact of 4-week commercial yoghurt consumption supplemented with Bifidobacterium animalis subsp. lactis (BB-12) and Lactobacillus acidophilus (LA-5) on fecal bacterial counts of healthy adults. Fifty-eight volunteers were randomly assigned to three different groups: 1. placebo (no probiotic, no starter and no green tea extract); 2. Yoptimal (10^9cfu/100g of BB-12 and LA-5 and 40mg of green tea extract) and 3. Yoptimal-10 (10^1^0cfu/100g of BB-12, 10^9cfu/100g of LA-5 and 40mg of green tea extract). These yoghurt products also contained Lactobacillus delbrueckii subsp. bulgaricus (10^7cfu/100g) and Streptococcus thermophilus (10^1^0cfu/100g). The quantitative PCR (qPCR) results showed that ther...

2011-01-01

448

Geochemical study on origin of natural gases in Japanese oil and gas fields

Effect of clindamycin treatment on vaginal inflammatory markers in pregnant women with bacterial vaginosis and a positive fetal fibronectin test

The origin of natural gas in the Japanese oil and gas fields are geochemically studied. Samples are taken from structural natural gas, surface gas seepage, water-dissolved natural gas and coal-field gas of the Japan Sea coast area. The origins of primary hydrocarbons are classified into bacteria gas and thermogenic gas, the latter being subclassified into gas in oil production zone with the per million deviation of the carbon isotope (/sup 13/C/sup 1/) of methane less than -35 and those gases with maturity higher than this. Surface gas seepage is subjected to migration and bacterial oxidation. Coal gas is similar to oil gas. The CO/sub 2/ concentration is 0 - 2% and /sup 13/CO/sub 2/ deviations from -30 - +30. The origin can be barely estimated from the isotopic composition because of the wide secondary change in the composition. The origin and migration of gas from the gas field of northern Niigata are not similar to those in the southern area, which consist of a ...

1988-05-01

449

British Library Electronic Table of Contents (United Kingdom)

Objective To compare the levels of interleukin (IL)-1?, IL-6, and matrix metalloproteinase (MMP)-8 in the vaginal secretions of pregnant women with a positive fetal fibronectin (fFN) test result with or without asymptomatic bacterial vaginosis (BV) before and after treatment with oral clindamycin. Methods A prospective cohort study was conducted among 43 pregnant women with a positive fFN test result. All patients were treated with clindamycin, and the pre- and post-treatment levels of IL-1?, IL-6, and MMP-8 were compared. Results Before treatment, levels of IL-1? and MMP-8 were significantly higher in women with BV compared with women without BV (P<0.05). Vaginal levels of IL-1? and IL-6, but not MMP-8, decreased after treatment in pregnant women with BV. Conclusions The inability of clin...

2009-01-01

450

Complete genome sequence of Conexibacter woesei type strain (ID131577T)

Use of the K88 antigen for in vivo bacterial competition with porcine strains of enteropathogenic Escherichia coli.

The genus Conexibacter (Monciardini et al. 2003) represents the type genus of the family Conexibacteraceae (Stackebrandt 2005, emend. Zhi et al. 2009) with Conexibacter woesei as the type species of the genus. C. woesei is a representative of a deep evolutionary line of des-cent within the class Actinobacteria. Strain ID131577T was originally isolated from temperate forest soil in Gerenzano (Italy). Cells are small, short rods that are motile by peritrichous fla-gella. They may form aggregates after a longer period of growth and, then as a typical charac-teristic, an undulate structure is formed by self-aggregation of flagella with entangled bacteri-al cells. Here we describe the features of the organism, together with the complete sequence and annotation. The 6,359,369 bp long genome of C. woesei contains 5,950 protein-coding and 48 RNA genes and is part of the Genomic Encyclopedia of Bacteria and Archaea project.

2010-01-01

451

The wavelength dependence of ultraviolet enhanced reactivation in a mammalian cell-virus system

Infant mice were used to measure the amount of fluid accumulation (enterosorption) in the intestinal tract after oral inoculation of a porcine strain of enteropathogenic Escherichia coli (K88-+, Ent-+). Significant reduction in the amount of fluid found in the intestinal tract was observed if the mice were first inoculated with a K88-possessing, non-enterotoxigenic strain of E. coli. The protection provided is thought to be due to specific competition for attachment sites on cells of the small intestine. PMID:1095492

1975-07-01

452

Mineral biotechnology. Microbial aspects of mineral beneficiation, metal extraction, and environmental control

The effect of UV radiation in the wavelength region 230 nm to 302 nm on the ability of an irradiated mammalian cell to reactivate UV-irradiated mammalian virus was tested. An action spectrum for radiation enhanced reactivation (RER) is presented. The shape of the action spectrum points to a combined nucleic acid-protein target for UV radiation effects on this cellular parameter. An analysis of the results of others involving the biochemical and photobiological events involved in RER does not allow us to distinguish which macromolecule is the major contributor to this effect. Studies involving an analogous phenomenon in bacteris (Weigle reactivation) imply that RER and WR amy involve similar mechanisms. (author).

453

Effect of microwaves on microorganisms in foods

Papers in this book illustrate the utility of mineral biotechnology with respect to biobeneficiation, bioleaching, bioremediation and biomineralization. Papers of particular interest to the coal industry include: depression of pyrite flotation by yeast and bacteris (S.K. Kawatra and T.C. Eisele); desulfurization of coal by microbial flotation in a semicontinuous system (T. Nagaoka and others); biochemical removal of HAP precursors from coal - INEEL slurry column testing (K.S. Noah and G.J. Olson); microorganisms, biotechnology and acid rock drainage - emphasis on passive-biological control and treatment methods (N. Kuyucak); and utility of bioreagents in mineral processing (P. Somasundaran and others).

2001-07-01

454

Characterisation of anti-Staphylococcus aureus activity of quercetin

The microbial safety of foods cooked in microwave ovens was investigated. The mechanisms of microwave destruction of microorganisms were examined. Effects of time and temperature on microorganisms in different food systems were described. Studies showed that: microwave heating of food is more ''''food dependent'' than conventional heating; recommended microwave treatment time for some foods may not destroy high levels of bacteria; use of microwaves in combination with conventional heating methods results in more uniform heating of foods and destruction of bacteria; and microwaves exert different killing effects on individual bacterial species. (78 references, 2 tables)

1980-08-01

455

British Library Electronic Table of Contents (United Kingdom)

Summary Although many antibiotics are available for the treatment of bacterial infections, the emergence and global spread of antibiotic-resistant bacteria is a community-wide problem. To overcome this problem, we must explore alternative antimicrobials. This study investigated the antibacterial properties of quercetin, a flavonoid present in vegetables and fruits. Quercetin was tested against gram-positive and gram-negative bacteria and was found to exert selective antibacterial activity against Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), and Staphylococcus epidermidis. Some clinical MRSA strains showed remarkable susceptibility to quercetin. In combination with antibiotics, such as oxacillin, ampicillin, vancomycin, gentamicin, and erythromycin, quercetin sho...

2010-01-01

456

X-ray absorption spectroscopy of bacterial sulfur globules

The association of asymptomatic bacterial vaginosis with upper genital tract infection.

Sulfur K-edge X-ray absorption spectroscopy is a powerful in situ probe of sulfur biochemistry in intact cells and tissues. Under favorable circumstances the technique can provide quantitative information on the chemical identify of the sulfur species that are present in a sample. Prange et al. have recently reported an X-ray absorption spectroscopic study of bacterial sulfur storage globules. Unfortunately there are substantial problems with the experimental technique employed that, they contend, lead to completely erroneous conclusions. In the more recent of their two papers Prange et al. employed a curve-fitting method similar to that used by us (for more than 10 years). In essence, the method employs simply fitting a linear combination of the spectra of standard compounds to that of the unknown, in this case cultures of bacterial cells. This type of analysis can provide quantitative estimates of the individual sulfur types in the sample, ...

2002-08-01

457

Nonphotochemical Hole-Burning Studies of Energy Transfer Dynamics in Antenna Complexes of Photosynthetic Bacteria

Objective: To determine whether asymptomatic bacterial vaginosis (BV) is associated with upper genital tract inflammation or bacterial colonization.Methods: Fifty nonpregnant women with intact uteri who planned to undergo gynecologic surgery and had no recent symptoms of vaginal infection were enrolled. We obtained a vaginal swab for Gram stain, endocervical swab for chlamydia and gonorrhea DNA probe testing, and Pipelle endometrial biopsy for aerobic and anaerobic cultures and histology. We correlated surgical findings and histology of available surgical specimens with the microbiologic results. The diagnosis of BV was made according to Speigel's criteria. Bacteria isolated from the uterus were classified as high virulence versus low virulence. Contingency tables were analyzed using the chi-square or Fisher Exact tests.Results: Twenty-one of 50 patients had BV on Gram stain, 3 had intermediate BV, and 3 had unreadable slides. Eleven patients ...

1998-07-01

458

Isolation of imidacloprid degrading bacteria from industrial sites

This thesis contains the candidate's original work on excitonic structure and energy transfer dynamics of two bacterial antenna complexes as studied using spectral hole-burning spectroscopy. The general introduction is divided into two chapters (1 and 2). Chapter 1 provides background material on photosynthesis and bacterial antenna complexes with emphasis on the two bacterial antenna systems related to the thesis research. Chapter 2 reviews the underlying principles and mechanism of persistent nonphotochemical hole-burning (NPHB) spectroscopy. Relevant energy transfer theories are also discussed. Chapters 3 and 4 are papers by the candidate that have been published. Chapter 3 describes the application of NPHB spectroscopy to the Fenna-Matthews-Olson (FMO) complex from the green sulfur bacterium Prosthecochloris aestuarii; emphasis is on determination of the low energy vibrational structure that is important for ...

2002-06-27

459

Purification and characterization of (-)(/sup 125/I)hydroxyphenylisopropyladenosine, an adenosine R-site agonist radioligand and theoretical analysis of mixed stereoisomer radioligand binding

Immidacloprid is a cyclodiene organochlorine used as an insecticide all over the world and possessing a serous environmental threat. It is mostly used for cotton insects (bollworm, aphid and white fly). For isolation of imidacloprid degrading bacteria, two soil samples were collected from industrial contaminated sites of Kala Shah Kahu district sheikupura, having ten year history of use. Soil samples were analyzed by measuring pH and electric conductivity. The isolation of imidacroprid degrading bacteria was performed by enrichment technique. Eight bacterial strains, S/sub 1-a/ S/2-2-b/ S/2-c/ S/2-d/ S/2-e/ S/sub 2-f/ and S/sub 2-g/ and S/sub e-a/ were isolated on the basis of their colony morphologies. The purified colonies were characterized morphologically, physiologically and biochemically. Gram staining was done and Gram negative strain were confirmed on MacConkey agar and Eosin Methylene Blue. Bacterial strains were also checked for ...

460

Insulin-like growth factor II receptor is phosphorylated by a tyrosine kinase in adipocyte plasma membranes

(-)-N6-(R-4-Hydroxyphenylisopropyl)adenosine (HPIA) was iodinated with NaI and trace /sup 125/I. Mono- and diiodinated reaction products and the starting material were separated by high pressure liquid chromatography and the structures of the reaction products were verified by NMR. (-)-N6-(R-Phenylisopropyl)adenosine (PIA), IHPIA, and I2HPIA decreased rat atrial contractility with ED50 values of 24, 28, and 33 nM, respectively. The contractile effects of these compounds were competitively blocked by theophylline (KI . 7.9 microM), but were not affected by adenosine deaminase. IHPIA also inhibited (-)isoproterenol-stimulated cyclic AMP accumulation in adipocytes with an ED50 (10 nM) and to an extent (83%) nearly identical to PIA. (/sup 125/I)HPIA prepared using carrier-free /sup 125/I bound to adenosine receptors on membranes from rat cerebral cortex, adipocyte ghosts, and heart ventricles. Binding was inhibited stereospecifically by PIA and by other adenosine ...

1984-11-01

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461

Fabrication and characterization of poly(phenylene oxide)/SBA-15/carbon molecule sieve multilayer mixed matrix membrane for gas separation

Incorporation of /sup 32/P from (gamma-32P)ATP into tyrosine residues of the insulin-like growth factor (IGF)-II receptor was observed in a Triton X-100-insoluble fraction of rat adipocyte plasma membranes. IGF-II receptor phosphorylation proceeded to a stoichiometry of approximately 0.5 mol of phosphate/IGF-II binding site after 10 min of incubation at 4 degrees C. A Km for ATP of 6 microM was calculated for this phosphorylation reaction. Addition of IGF-II caused an approximately 2-fold increase in tyrosine phosphorylation of the IGF-II receptor in this preparation. In contrast, phosphorylation of angiotensin II by the Triton X-100 washed membranes was not stimulated by IGF-II. Incubation of purified receptor immobilized on IGF-II agarose or of receptor-enriched low density microsomal membranes with (gamma-32P)ATP did not result in appreciable incorporation of (/sup 32/P)phosphate into the IGF-II receptor nor into ...

1986-06-15

462

Distribution of lead-203 in human peripheral blood in vitro

A novel multilayer mixed matrix membrane (MMM), consisting of poly(phenylene oxide) (PPO), large-pore mesoporous silica molecular sieve zeolite SBA-15, and a carbon molecular sieve (CMS)/Al{sub 2}O{sub 3} substrate, was successfully fabricated using the procedure outlined in this paper. The membranes were cast by spin coating and exposed to different gases for the purpose of determining and comparing the permeability and selectivity of PPO/SBA-15 membranes to H{sub 2}, CO{sub 2}, N{sub 2}, and CH{sub 4}. PPO/SBA-15/CMS/Al{sub 2}O{sub 3} MMMs with different loading weights of zeolite SBA-15 were also studied. This new class of PPO/SBA-15/CMS/Al{sub 2}O{sub 3} multilayer MMMs showed higher levels of gas permeability compared to PPO/SBA-15 membranes. The permselectivity of H{sub 2}/N{sub 2} and H{sub 2}/CH{sub 4} combinations increased remarkably, with values at 38.9 and 50.9, respectively, at 10 wt% ...

2010-07-15

463

A single amino acid substitution modulates low-pH-triggered membrane fusion of GP64 protein in Autographa californica and Bombyx mori nucleopolyhedroviruses

In-vitro experiments using "2"0"3Pb were performed to identify the lead binding components in human peripheral blood. The distribution of lead in plasma, in the red cell membrane, and within the red cell was also investigated. Studies of the distribution of "2"0"3Pb in the whole blood showed that at a lead concentration of 2.45 #mu#mol/l (50 #mu#g/100 ml) about 94% of lead had been incorporated by the erythrocytes and 6% remained in the plasma. After extraction of lipid by a methanol/chloroform mixture, about 75% of the lead was found to be associated with the protein fraction. The lipid contained about 21% of the "2"0"3Pb, the remainder being in the aqueous plasma. SDS polyacrylamide gel electrophoresis of blood plasma showed that almost 90% of the "2"0"3Pb was present in the albumin fraction; the remainder was likely to be associated with high molecular weight globulins. Several binding sites were identified on the erythrocyte membrane. The ...

464

Transient radon diffusion through radon-proof membranes: A new technique for more precise determination of the radon diffusion coefficient

We have previously shown that budded viruses of Bombyx mori nucleopolyhedrovirus (BmNPV) enter the cell cytoplasm but do not migrate into the nuclei of non-permissive Sf9 cells that support a high titer of Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) multiplication. Here we show, using the syncytium formation assay, that low-pH-triggered membrane fusion of BmNPV GP64 protein (Bm-GP64) is significantly lower than that of AcMNPV GP64 protein (Ac-GP64). Mutational analyses of GP64 proteins revealed that a single amino acid substitution between Ac-GP64 H155 and Bm-GP64 Y153 can have significant positive or negative effects on membrane fusion activity. Studies using bacmid-based GP64 recombinant AcMNPV harboring point-mutated ac-gp64 and bm-gp64 genes showed that Ac-GP64 H155Y and Bm-GP64 Y153H substitutions decreased and increased, respectively, the multiplication and cell-to-cell spread of progeny viruses. These results ...

2010-09-01

465

The multidrug resistance efflux complex, EmrAB from Escherichia coli forms a dimer in vitro

The following paper is focused on the numerical modelling of the transient radon diffusion through radon-proof membranes during the measurement of their radon diffusion coefficient. The major aim of such numerical modelling is to increase the accuracy of radon diffusion coefficients derived from the measured data sets. The developed complex ''transient'' numerical model is able to calculate the radon diffusion coefficient with sufficient accuracy from almost any data set - even from a short-time measurement with a non-linear course of results. This numerical model can also be used for various analyses of transient radon transfer processes (e.g. for the calculation of radon distribution curves within the membrane). The following paper presents governing equations for the simulation model, together with a brief description of algorithms incorporated in the newly developed software package, which can be used ...

2009-06-15

466

Spectroscopic studies on the interaction of the antibiotic lasalocid A (x-537a) with technetium (V) ions in methanol

Tripartite efflux systems are responsible for the export of toxins across both the inner and outer membranes of Gram negative bacteria. Previous work has indicated that EmrAB-TolC from Escherichia coli is such a tripartite system, comprised of EmrB an MFS transporter, EmrA, a membrane fusion protein and TolC, an outer membrane channel. The whole complex is predicted to form a continuous channel allowing direct export from the cytoplasm to the exterior of the cell. Little is known, however, about the interactions between the individual components of this system. Reconstitution of EmrA + EmrB resulted in co-elution of the two proteins from a gel filtration column indicating formation of the EmrAB complex. Electron microscopic single particle analysis of the reconstituted EmrAB complex revealed the presence of particles approximately 240 x 140 A, likely to correspond to two EmrAB dimers in a back-to-back arrangement, ...

2009-03-06

467

Removal of lead from solution using non-living residual brewery yeast

In the present study, the authors examine the interactions of pentavalent technetium ions (TcO/sup 3+/) with the basic form of the lasalocid A in pure methanol solvent and in methanol-water mixtures. There are a number of reasons for such a study. First, the interactions of technetium ions with biologically important compounds are of considerable importance owing to the widespread use of /sup 99m/Tc in diagnostic radio-imaging. Second, lasalocid A is known to transport metal ions across phospholipid bilayer membranes and between the aqueous cores of phospholipid inverse micelles. Third, lasalocid A is known to bind and solubilize metal ions in bulk organic liquid phases. Fourth, the conformation adopted by lasalocid A on interaction with TcO/sup 3+/ appears to be different than those found in most other cases and circumstances. Fifth, it may also be possible to use the competition of TcO/sup 3+/ with other, physiologically relevant cations (Na/sup +/, K/sup +/, ...

468

Radiation-induced changes in the cell membrane of cultured human endothelial cells

A number of preparations of residual non-living brewery yeast were examined for their ability to remove lead from solution. Those preparations included washed and un-washed intact yeast and washed and un-washed homogenates of the yeast cells. Using biosorption isotherm analysis it was found that the washed and un-washed preparations of intact, non-living yeast exhibited maximum biosorption capacities for lead of 127 and 99 mg/g dry weight biomass, respectively. The washed and un-washed cell homogenates exhibited maximum biosorption capacities of 38 and 139 mg lead/g dry weight biomass, respectively. Since it had previously been shown that these preparations of biomass were capable of removing uranium from solution by combined biosorption and precipitation processes, it was decided to examine removal of lead from solution using a form of equilibrium dialysis in which the biomass was retained within a semi-permeable membrane during contact reactions. The results ...

1998-10-01

469

Precise characterisation of nanochannels in track etched membranes by SAXS and SANS

We investigated the effect of irradiation on the kinetic characteristics of amino acid and glucose transport, and the effect on the activity of the cell membrane-bound enzyme 5'-nucleotidase and on the receptor-mediated stimulation of cyclic adenosine monophosphate synthesis by prostaglandin E1. Irradiation inhibited the sodium-dependent amino acid transport by a reduced binding of the amino acid to the transport unit. The transport of glucose, which appeared to be a sodium-independent process, was temporarily stimulated by increased maximal velocity of the transport. No effect was found on the binding to the transport unit. Irradiation increased the 5'-nucleotidase activity and decreased the prostaglandin E1-stimulated cyclic adenosine monophosphate synthesis 48 h after exposure to 20 Gy. It is concluded that irradiation decreases sodium-dependent transport by impairment of the transport unit, does not impair a sodium-independent process, and has ...

1985-12-01

470

Photochemical energy conversion by membrane-bound photoredox systems. Final report

Poster session: Abstract is full text. Track membranes are thin polymer foils irradiated by heavy ions. The defects created by the heavy ions are located along the ions trajectory, the track. It is possible to open channels by etching with a chemical agent. These channels are very uniform. Small Angle Scattering (of X rays and neutrons) give global information about the characteristics of the channel shape. As the nanochannels are strictly parallel, an excellent sample orientation is required to obtain interpretable spectra. Then shoulders due to the oscillations of the Bessel function (radial part of the channel shape Fourier transform) are easily seen in the scattered intensity in the PXY data treatment software of SAS spectra allow to determine the channel diameter with its dispersion law, to demonstrate the existence of a wall thickness with a linearly varying density, and to assess the roughness. PXY can also detect non cylindric shapes like single or double ...

2003-05-01

471

Phospholipid asymmetry in large unilamellar vesicles induced by transmembrane pH gradients

This project has received DOE support since July 1, 1978. During this period, 40 papers have been published dealing predominantly with chlorophyll-photosensitized electron transfer reactions in a variety of media (solutions, polymer films, lipid bilayer membranes). The overall theme of this work has been to develop mechanistic strategies f or photochemical energy storage via chlorophyll, using the green plant photosynthetic system as a paradigm for designing in vitro systems. Microheterogeneous lipid vesicle suspensions allow ready application of time-resolved optical spectroscopy to follow the course of light-induced electron transfer processes. Both the yields and the lifetimes of electron transfer products were markedly improved in the vesicle systems. In subsequent studies, this compartmentalization was favorably manipulated by controlling the electrical charge on the membrane surface, by controlling the solubility properties of the ...

1994-06-16

472

Multielement determination of major-to-ultratrace elements in salmon egg by ICP-AES and ICP-MS

The influence of membrane pH gradients on the transbilayer distribution of some common phospholipids has been investigated. The authors demonstrate that the transbilayer equilibrium of the acidic phospholipids egg phosphatidylglycerol (EPG) and egg phosphatidic acid (EPA) can be manipulated by membrane proton gradients, whereas phosphatidylethanolamine, a zwitterionic phospholipid, remains equally distributed between the inner and outer monolayers of large unilamellar vesicles (LUVs). Asymmetry of EPG is examined in detail and demonstrated by employing three independent techniques: ion-exchange chromatography, {sup 13}C NMR, and periodic acid oxidation of the (exterior) EPG headgroup. In the absence of a transmembrane pH gradient ({Delta}pH) EPG is equally distributed between the outer and inner monolayers of LuVs. When vesicles composed of either egg phosphatidylcholine (EPC) or DOPC together with 5 mol % EPG are prepared with a transmembrane ...

1989-05-16

473

Membrane compressor for leakfree compression of gaseous fluids; Membranverdichter fuer das leckfreie Verdichten gasfoermiger Fluide

The multielement determination of major-to-ultratrace elements in salmon egg was carried out by ICP-AES and ICP-MS. First, salmon eggs (30 eggs used) were digested with conc. nitric acid and 60% perchloric acid by heating almost to dryness repeatedly. Finally, the residues of salmon eggs were dissolved in 1 M nitric acid and the sample solutions were analyzed by ICP-AES and ICP-MS. About 40 elements could be determined over the concentration range in 9 orders of magnitude. The concentrations of bio-essential elements, such as Zn, Fe, and Cu, in salmon egg were 10-100 times higher than those in human blood serum. In addition, the major-to-ultratrace elements in cell cytoplasm and cell membrane were separately determined in a similar manner to those in whole egg cell. The concentrations of most bio-essential elements were higher in cell cytoplasm than in cell membrane, while those of Fe and Cu were higher in cell membrane ...

2002-04-01

474

Increase of unsaturated fatty acids under high pressure in a deep-sea bacterium; Shinkai kara bunrisareta taiatsusei biseibutsu DSS12 kabu no baiyo ondo, baiyo atsuryoku to kintai shibosan sosei no henka

Leakfree compression of gaseous liquids prevents impurities resulting from entry of lubricants and abrasive particles and is therefore an important requirement on modern compressors. Another requirement voiced increasingly often is the reduction or even prevention of problematic off-gases and contaminated residues of libricating oils. Further, compressors should have high corrosion resistance, low noise, a long service life and high reliability. Membrane compressors are largely able to meet these requirements. The article describes the technical concept and applications of membrane compressors. (orig.) [Deutsch] Umweltschutz und steigende Forderungen der Industrie an die Reinheit technischer Gase verlangen Kompressoren, die weitgehend leckagefrei verdichten und keine Verunreinigungen des Gases durch Schmierstoffe und Abrieb hervorrufen. Immer haeufiger wird in diesem Zusammenhang die Reduzierung oder sogar die Vermeidung von schwer zu ...

1996-09-01

475

High performance protonic ceramic membrane fuel cells (PCMFCs) with Sm_0_._5Sr_0_._5CoO_3_-_#delta# perovskite cathode

A cellular membrane exchanges substances into and from the cell and protects the cell interior by maintaining semi-fluidity rather than be being solid. It is known that microorganisms maintain the fluidity in correspondence with varying environmental temperatures by changing and adjusting the composition of fatty acids which constitute the cellular membrane lipids. As part of the studies to elucidate the pressure withstanding mechanism in deep-sea bacteria, this paper investigates what variations the fatty acid composition, which constitutes cellular membranes of the DSS12 strain, a pressure withstanding bacterium growing well under either normal pressure or high pressures, will show under different culturing temperatures and pressures. Culture under low temperatures and culture under high pressures increase content of unsaturated fatty acids including icosapentanoic acid. Culture under high temperatures or normal pressure ...

1997-03-01

476

Factors affecting actions of ethanol on GABA-activated chloride channels

Protonic ceramic membrane fuel cells (PCMFCs) based on proton-conducting electrolytes have attracted much attention because of many advantages, such as low activation energy and high energy efficiency. A stable, easily sintered perovskite oxide BaCe_0_._5Zr_0_._3Y_0_._1_6Zn_0_._0_4O_3_-_#delta# (BCZYZ) as electrolyte for proton-conducting solid oxide fuel cells (SOFCs) with Sm_0_._5Sr_0_._5CoO_3_-_#delta# (SSC) composite cathode is investigated. By fabricating thin membrane BCZYZ electrolyte (#approx#20 #mu#m) synthesized by a modified Pechini method on NiO-BCZYZ anode support, PCMFCs are assembled and tested by selecting SSC perovskite cathode with high mixed ionic and electronic conductivities. An open-circuit potential of 1.015 V, a maximal power density of 528 mW cm"-"2, and a low polarization resistance of the electrodes of 0.15 #OMEGA# cm"2 is achieved at 700 "oC. The results indicate that BCZYZ proton-conducting electrolyte with SSC ...

2010-04-02

477

Electron spin resonance probe for the solvation of ionomer membranes and other microscopically heterogeneous systems. Cu[sup 2+] in nafion, sephadex and silica gel

Effects of ethanol in vitro on membrane vesicles were evaluated by monitoring "3"6Cl"- influx. Different assay parameters were tested to determine increased or decreased action of ethanol on GABA-activated chloride channels. The ability of 30 mM ethanol to augment "3"6Cl"- flux was seen at 0 degree C, in the absence of GABA, and at 34 degree C in the presence of GABA, using two different assay procedures. Picrotoxin blocked the direct effects of ethanol suggesting GABA_a involvement. Endogenous GABA in the medium surrounding the microsacs was assayed at different temperatures both in the presence and absence of GABA and ethanol. The direct effect of ethanol did not appear to involve the action of endogenous GABA. In addition to temperature effects on the assay, time of membrane storage also influenced ethanol action. Microsacs stored on ice for 2 hours or more lost their ability to respond to ethanol but not to GABA, pentobarbital or ...

478

Effect of Nucleus Pulposus Cells Having Different Phenotypes on Chondrogenic Differentiation of Adipose-Derived Stromal Cells in a Coculture System Using Porous Membranes

Cu[sup 2+] is a sensitive electron spin resonance (ESR) probe for the penetration of various polar solvents in membranes made of Nafion and as an indicator for the replacement of one solvent by another. The ESR parameters (g and [sup 63]Cu hyperfine tensors) can be translated into a structure of the solvent around the cation. The replacement of a solvent in the membrane by another depends on the polarity of the two solvents. The solvent with the largest dielectric constant, N-methylformamide (NMF), can be replaced by water but not by methanol or acetonitrile (dielectric constants 182, 78.5, 32.7, and 37.5, respectively). Preferential solvation of the cation by water in three water/acetonitrile mixtures (9:1, 1:1, and 1:9 by volume) in contact with silica gel, Sephadex, and Nafion has been observed in various degrees. Nafion is most selective, followed by Sephadex and by silica gel. The selectivity appears to be related to electrostatic ...

1992-01-01

479

British Library Electronic Table of Contents (United Kingdom)

In this study, adipose-derived stem cells (ASCs) were cocultured with nucleus pulposus (NP) cells using a porous membrane to investigate the effect of NP cell phenotype on ASC chondrogenic differentiation. Human NP cells were collected from 14 patients and classified into two groups (normal vs. degenerative) depending on the level of type II collagen, aggrecan (AGG), type I collagen, and bax gene expression. Human ASCs were then cocultured with each group of NP cells on porous membranes in the absence of chondrogenic supplements. After 2 weeks, real-time-polymerase chain reaction results showed that ASCs cocultured with normal NP cells had much higher type II collagen and AGG gene expression than ASCs cocultured with degenerative NP cells. The production of AGG was also observed only in th...

2011-01-01

480

Development of a Novel Bioelectrochemical Membrane Reactor for Wastewater Treatment.

Carbon dioxide absorption contactors: hollow fibre membranes and packed absorption columns

A novel bioelectrochemical membrane reactor (BEMR), which takes advantage of a membrane bioreactor (MBR) and microbial fuel cells (MFC), is developed for wastewater treatment and energy recovery. In this system, stainless steel mesh with biofilm formed on it serves as both the cathode and the filtration material. Oxygen reduction reactions are effectively catalyzed by the microorganisms attached on the mesh. The effluent turbidity from the BEMR system was low during most of the operation period, and the chemical oxygen demand and NH(4)(+)-N removal efficiencies averaged 92.4% and 95.6%, respectively. With an increase in hydraulic retention time and a decrease in loading rate, the system performance was enhanced. In this BEMR process, a maximum power density of 4.35 W/m(3) and a current density of 18.32 A/m(3) were obtained at a hydraulic retention time of 150 min and external resister of 100 ?. The Coulombic efficiency was 8.2%. Though the ...

2011-10-01

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481

Behaviour of the de-inked tailings soil cover at the Clinton mining site; Comportement de la couverture de residus de desencrage au site minier Clinton

One of the important aspects in an absorption system is the effectiveness in which the gas and liquid phases come into contact with each other. An effective absorption process will provide sufficient contacting area for the gas and liquid phases to interact upon. With this in mind, work was conducted to evaluate carbon dioxide (CO{sub 2}) absorption into aqueous solutions of monoethanolamine (MEA) using two different types of contacting devices: gas absorption membrane (GAM) modules and traditional packed columns. The performance of these two absorption devices was compared to one another using the overall mass transfer coefficient (K{sub G}a{sub v}) as a basis. The GAM module contained microporous polypropylene hollow fibre membranes and the packed absorption column contained Sulzer DX structured packing. The results indicate that GAM modules tend to have slightly larger K{sub G}a{sub v} values, potentially opening the door for smaller ...

2003-07-01

482

All-atom molecular dynamics simulations using orientational constraints from anisotropic NMR samples

The production of de-inked tailings in Quebec has significantly increased during the last decade. From less than 100,000 wet tons in 1990, the production of de-inked tailings reached 500,000 wet tons in 1995, and 510,000 wet tons in 1999. The geotechnical, hydraulic, and physico-chemical properties of de-inked tailings are favorable for its use as soil cover for the prevention of acid mine drainage at mining sites. In this presentation, the authors discussed the three-year monitoring of the behaviour of a membrane covering an old mining site with the potential to produce acid mine drainage. The site is located at the Clinton Mine, near Woburn, Quebec. The mine shaft was filled with the tailings and waste rock scattered around the site and covered with a protective membrane which included de-inked tailings. The profile of the membrane was discussed, as well as construction details. The results confirmed the good performance ...

2000-07-01

483

All-atom molecular dynamics simulations using orientational constraints from anisotropic NMR samples

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints some deuterium quadrupolar couplings from ...

2007-03-03

484

All-atom molecular dynamics simulations using orientational constraints from anisotropic NMR samples

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints some deuterium quadrupolar couplings from ...

2007-05-15

485

Aging mechanism of Sulfonated poly(aryl ether ketone) (sPAEK) in an hydroperoxide solution and in fuel cell

Orientational constraints obtained from solid state NMR experiments on anisotropic samples are used here in molecular dynamics (MD) simulations for determining the structure and dynamics of several different membrane-bound molecules. The new MD technique is based on the inclusion of orientation dependent pseudo-forces in the COSMOS-NMR force field. These forces drive molecular rotations and re-orientations in the simulation, such that the motional time-averages of the tensorial NMR properties approach the experimentally measured parameters. The orientational-constraint-driven MD simulations are universally applicable to all NMR interaction tensors, such as chemical shifts, dipolar couplings and quadrupolar interactions. The strategy does not depend on the initial choice of coordinates, and is in principle suitable for any flexible molecule. To test the method on three systems of increasing complexity, we used as constraints some deuterium quadrupolar couplings from ...

2007-05-01

486

The Separation of Humic Substances by Membrane Polysulfone Method

Ex situ and in situ fuel cell degradation of a sPAEK membrane were investigated. Post-mortem analyses of the aged membrane and of the degradation products eluted in water were carried out by NMR, IR, SEC and EDX. Ex situ agings were performed in a low concentration H{sub 2}O{sub 2} solution (0.07%) without any metallic catalyst. We exemplify that ex situ accelerated aging tests in such hydrogen peroxide solution are relevant to the chemical degradation in fuel cell. We have shown that a 500 h fuel cell test at moderate temperature (60 C) induces significant modifications on the macromolecules such as a 40% molecular weight reduction. Degradation appears heterogeneous and limited to the cathode side. The model compound approach developed in the previous article (Perrot et al.) has allowed the identification of the aging path in fuel cell. Phenolic and carboxylic acid chain ends have been identified as the main products resulting from polymer ...

2010-01-15

487

Submitochondrial distribution of cAMP in its incubation with rat liver mitochondria

The separation of humic substances by polysulfone has been done. Thisinvestigation aims at separating the humic substances contained in theestuary environment. Because of without sample pre-treatment, cheap and easythis method has been to choice. At preliminary study proved that byincreasing the pressure until 50 psia, the yield of flux was 13.5 l/m"2.jamand the reject coefficient was 90.98%, so that polysulfone membrane isappropriate to be applied. More over the pressure could be increased morethan 50 psia. The feed concentration should be lower than 150 ppm, though thevolume should be greater. The pH condition should be alkaline (pH> 7), sinceat this condition the filtration process is easily conducted and the rejectcoefficient could reach 95.09%. (author)

2000-07-25

488

Structural characterization of liposomes made of diether archaeal lipids and dipalmitoyl-L-a-phosphatidylcholine

When labeled cAMP is incubated with isolated mitochondria from rat liver, it penetrates not only through the outer membrane of the mitochondria but also into the mitoplasts, where it is accumulated chiefly in the matrix. Damage to the mitochondrial membrane by freezing-thawing promotes not an influx but an efflux of cAMP out of the mitoplasts. A substantial part of the labeled nucleotide in all the investigated submitochondrial fractions was identified as intact cAMP by the method of thin-layer chromatography. The transport of cAMP into the mitochondria can explain the activation of their functions by the hormones that activate cytoplasmic adenylate cyclase and by extramitochondrial (cytosol) cAMP, as well as the presence of cAMP-dependent protein kinase and cAMP-phosphodiesterase in the mitochondria.

1986-03-20

489

British Library Electronic Table of Contents (United Kingdom)

The physicochemical properties of binary lipid mixtures of diether C25,25 lipids and dipalmitoyl-L-a-phosphatidylcholine (DPPC) were studied using photon correlation, fluorescence and electron paramagnetic resonance spectroscopy, and transmission electron microscopy. These two types of lipids can be mixed at all molar ratios to form unilamellar and multilamellar liposomes. Fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatrien in mixed liposomes indicates that the abrupt changes in order parameter in the hydrophobic part of bilayer membranes made of DPPC lipids disappears with increasing mol%C25,25 lipids. Electron paramagnetic resonance spectroscopy shows that at temperatures below 50^oC, the interfacial regions of membrane bilayer of mixed liposomes is more fluid than for pure DPPC lipo...

2011-01-01

490

Spatial fluorescence cross correlation spectroscopy by means of a spatial light modulator

Protective nitride formation on stainless steel alloys for proton exchange membrane fuel cell bipolar plates

Spatial Fluorescence Cross Correlation Spectroscopy is a rarely investigated version of Fluorescence Correlation Spectroscopy, in which the fluorescence signals from differ-ent observation volumes are cross-correlated. In the reported experiments, two observation volumes, typically shifted by a few $\\mu$m, are produced, with a Spatial Light Modulator and two adjustable pinholes. We illustrated the feasibility and potentiality of this technique by: i) measuring molecular flows, in the range 0.2 - 1.5 $\\mu$m/ms, of solutions seeded with fluorescent nanobeads or rhodamine molecules (simulating active transport phenomenons); ii) investigating the perme-ability of phospholipidic membrane of Giant Unilamellar Vesicles versus hydrophilic or hydrophobic molecules (in that case the laser spots were set on both sides of the mem-brane). Theoretical descriptions are proposed together with a discussion about FCS based, alternative methods.

2008-01-01

491

British Library Electronic Table of Contents (United Kingdom)

Gas nitridation has shown excellent promise to form dense, electrically conductive and corrosion-resistant Cr-nitride surface layers on Ni-Cr base alloys for use as proton exchange membrane fuel cell (PEMFC) bipolar plates. Due to the high cost of nickel, Fe-base bipolar plate alloys are needed to meet the cost targets for many PEMFC applications. Unfortunately, nitridation of Fe-base stainless steel alloys typically leads to internal Cr-nitride precipitation rather than the desired protective surface nitride layer formation, due to the high permeability of nitrogen in these alloys. This paper reports the finding that it is possible to form a continuous, protective Cr-nitride (CrN and Cr2N) surface layer through nitridation of Fe-base stainless steel alloys. The key to form a protective Cr...

2007-01-01

492

Low temperature surface modifications of polyacrylonitrile ultrafiltration membranes: 1. Plasma treatment effects

Immune responses induced by spirochetal outer membrane lipoproteins and glycolipids

Excitation of low temperature helium or helium/water plasma and subsequent exposure to air of polyacrylonitrile (PAN) ultrafiltration membranes was used to hydrophilize the surface of these materials. We analyzed the effectiveness of this approach as a function of plasma operating variables including gas phase composition, plasma power, treatment time and system pressure. Following the changes in physical and chemical composition of the PAN surface resulting from these modifications was a major aspect of this work. Techniques such as the captive bubble contact angle method, ellipsometry, ESCA, and FTIR-ATR were all used. In addition, the formation and life-time of peroxides during these processes were determined. At low powers (<25W) and short treatment periods ({<=}30 sec), the main chemical conversion of PAN surfaces was simultaneous hydrophilization and stabilization via PAN cyclization. Relatively small water permeability changes were observed as a result ...

1995-12-01

493

British Library Electronic Table of Contents (United Kingdom)

The class of Spirochetes comprises a wide array of clinically important pathogens, including Treponema pallidum causing syphilis as well as Borrelia burgdorferi, the agent of Lyme disease (LD). Diseases caused by spirochetes are characterized by specific sequelae of host reactions, and also by characteristic antibody response patterns. Over the last decades, research on the interaction of spirochetes with the hosts immune system had a strong emphasis on outer membrane lipoproteins. In fact, these structures have been convincingly shown to activate immune cells via CD14 and Toll-like receptor (TLR)-2, and recent data also indicate an interaction with lipopolysaccharide (LPS)-binding protein (LBP). In particular, the interaction of B. burgdorferi with TLR-2 could not only be demonstrated in ...

2008-01-01

494

Hygro-thermal mechanical behavior of Nafion during constrained swelling

British Library Electronic Table of Contents (United Kingdom)

Durability is a major limitation of current proton exchange membrane fuel cells. Mechanical stress due to hygro-thermal cycling is one failure mechanism of the polymer electrolyte membrane. In previous work the cyclic rate, temperature, and hydration dependent elastic-viscoplastic mechanical behavior of Nafion has been extensively investigated in uniaxial and biaxial tension, serving as a data basis and means of validation for a three-dimensional constitutive model. Here, the important effect of loading via constrained swelling is studied. Specifically, two types of loading are investigated: partially constrained swelling via a bimaterial swelling test and hygro-thermal cycling within a fuel cell. The bimaterial swelling conditions are examined via experiments in conjunction with modeling....

2011-01-01

495

Highly-sensitive ion selective electrode based on molecularly imprinted polymer particles for determination of tetracycline in aqueous samples

British Library Electronic Table of Contents (United Kingdom)

In this work, a highly-sensitive polymeric membrane ion selective electrode for determination of tetracycline was constructed by using molecularly imprinted polymer (MIP) particles as quasi-ionophore. The water-compatible MIP particles targeting tetracycline were synthesized with tetracycline as a template molecule, methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, 2,2?-azobisisobutyronitrile as an initiator and lanthanum ion as a mediator. Benefited from the distinctive performance of the quasi-ionophore and the optimized composition of the membrane and the inner filling solution, the lower detection limit of the electrode was decreased to about 1 ? 10?8 mol/l. It exhibited a good electrode slope 59.8 mV/decade near the theoretical Nernstian one, ...

2011-01-01

496

Design and fabrication of a two dimensional valveless micropump

Cooling facility for reactor container

The scale-down of a liquid mini-pump (order of 10 mm) to a micrometre scale has been attempted using a novel valveless nozzle-diffuser design and new application of an organic physical vapor-deposited membrane. The micropump employs no moving parts other than the membrane and accomplishes the rectification of fluid flow due to pressure recovery differences in the nozzle and diffuser flow directions. More specifically, liquids flow with less resistance (i.e. conduct more fluid) in the diffuser direction than the nozzle direction, for a given pressure differential. At the micrometre scale, the fabrication of the critical nozzle and diffuser elements was performed by focused ion beam (FIB) microlithography of glass slides. Etched slides were sandwiched to make two-dimensional venturis. Sternme and Sternme noted the importance of a lower Reynolds Number linfit on the desired pressure recovery which challenged the fabrication of this pump design at ...

1995-12-31

497

Combined bony closure of oroantral fistula and sinus lift with mandibular bone grafts for subsequent dental implant placement

Cooling water is sprayed on the outer surface of an upper portion of a container, and a pool is formed by the cooling water flowing down while cooling the container. Further, the cooling water stored in the cooling water pool is recycled by a pump for spraying the cooling water on the outer surface of the upper portion of the container. Sufficient amount of cooling water is supplied for spraying the cooling water to the outer surface of the upper portion of the container so that the outer surface of the container is free from drying and a liquid membrane is formed on the entire surface. The amount of the cooling water is made greater than that of the cooling water evaporated when the entire amount of the heat generate in the reactor core of the reactor is transferred to the cooling water. Since the liquid membrane is formed on the entire surface of the container with no drying of the outer surface, the area of cooling surface of the container ...

1993-05-07

498

British Library Electronic Table of Contents (United Kingdom)

Sinus lifting and reconstruction of localized alveolar defects are often required after closure of a large oroantral fistula (OAF) to allow for subsequent implant installation. This study describes a combined surgical technique that involves sinus lifting, bony closure, and reconstruction of the alveolar defect at the site of an OAF. The sinus membrane was reconstructed as a continuous layer by combining the residual sinus membrane with a rotated part of oral mucosa around the OAF. Autogenous bone from the chin and/or ramus was grafted into the prepared sinus space and alveolar defect, and the graft was covered by a buccal advancement flap. This technique was used to treat 8 patients who had large OAFs in the posterior maxillary region. The treatment was successful in all cases, and the te...

2011-01-01

499

5,8,11,14-Eicosatetraynoic acid-induced destruction of mitochondria in human prostate cells (PC-3).