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Results 301 - 350 of 3182
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Montero J A - - 2010
Interdigital tissue regression during embryonic development is one of the most representative model systems of morphogenetic cell death, but the degenerative cascade accounting for this process awaits clarification. Although the canonical apoptotic caspase pathway appears to be activated in the interdigital mesenchyme committed to die, neither genetic nor chemical blockage ...
Shellis R P - - 2010
The aims of this study were to determine the effects of pH and acid concentration on the dissolution of enamel, dentine, and compressed hydroxyapatite (HA) in citric acid solutions (15.6 and 52.1 mmol l(-1) ; pH 2.45, 3.2, and 3.9), using a pH-stat system. After an initial adjustment period, the ...
Martinez A R AR Center for Oral Biology, University of Rochester Medical Center, Rochester, NY 14642, - - 2010
Streptococcus mutans and Streptococcus sobrinus are considered the primary organisms responsible for human dental caries. The ability to generate acids and to adapt to low pH conditions is directly associated with the cariogenic potential of these bacteria. To survive acidic conditions, both species have been shown to mount an acid-tolerance ...
Zhou J - - 2011
Aims:  A major problem in industrial fermentation of organic acids with micro-organisms is to ensure a suitable pH in the culture broth. To circumvent this problem, we investigated the effect of citrate, which is a widely used auxiliary energy co-substrate, on cell growth, organic acid production and pH homeostasis among ...
Rodríguez-Llansola Francisco - - 2010
A structurally simple low molecular weight hydrogelator derived from isophthalic acid forms robust pH-responsive hydrogels capable of highly efficient and selective dye adsorption.
Linhares Iara M - - 2011
Ever since the pH of the vagina was found to be much more acidic than blood and interstitial fluids, a belief going back more than a century has persisted that the vagina is protected from pathogenic organisms by the high level of hydronium ions present. A corollary of this belief ...
Jin Junhua - - 2011
The acid adaption is commonly used as a strategy to enhance the acid tolerance of bifidobacteria. However, the acid tolerance response (ATR) mechanism elicited by this method is unclear. Real-time relative-quantitative PCR was applied to analyze the changes in the expressions of ffh, uvrA, groES, and dnaK involved in the ...
Gross Erin L - - 2010
Previous studies have confirmed the association of the acid producers Streptococcus mutans and Lactobacillus spp. with childhood caries, but they also suggested these microorganisms are not sufficient to explain all cases of caries. In addition, health-associated bacterial community profiles are not well understood, including the importance of base production and ...
Akiba Yasutada - - 2010
Luminal acid or CO₂ induces a hyperemic response in the esophagus, via activation of acid sensors on capsaicin-sensitive afferent nerves (CSAN). Since disruption of the hyperemic response to luminal CO₂ acidifies the interstitium of the esophageal mucosa, the hyperemic response may maintain interstitial pH (pH(int)). We hypothesized that acid-related hyperemia ...
Weld Richard J - - 2011
A thermophilic anaerobic digester (AD) was combined with a microbial fuel cell (MFC) to evaluate whether either component had increased stability when operated in combination as a hybrid system, perturbed by the addition of acetic acid. The MFC and the anaerobic digester were able to operate effectively together. The MFC ...
Xu Rongzuo - - 2010
Amphiphilic lipids are promising for efficient intracellular delivery of nucleic acids. In this study, two new amphiphilic carriers, EKHCO and EHHKCO, were designed and synthesized as multifunctional carriers for efficient intracellular delivery of nucleic acids. The critical micelle concentrations of EKHCO and EHHKCO were 9.50 and 6.87 microM, respectively. Dynamic ...
Wilken Lisa R - - 2010
Producing economically competitive recombinant human lysozyme from transgenic rice demands an inexpensive purification process for nonpharmaceutical applications. Human lysozyme is a basic protein, and thus, cation exchange chromatography was the selected method for lysozyme purification. Similar to other protein production systems, the identification of critical impurities in the rice extract ...
Reese Kristen L KL Department of Biological Sciences, University of Delaware, Newark, Delaware 19716, - - 2010
The molecular mechanisms underlying sperm penetration of the physical barriers surrounding the oocyte have not been completely delineated. Although neutral-active or "reproductive" hyaluronidases (hyases), exemplified by Sperm Adhesion Molecule 1 (SPAM1), are thought to be responsible for hyaluronan digestion in the egg vestments and for sperm-zona binding, their roles in ...
Sun Xuming - - 2010
Proton receptors are G protein-coupled receptors that accept protons as ligands and function as pH sensors. One of the proton receptors, GPR4, is relatively abundant in the kidney, but its potential role in acid-base homeostasis is unknown. In this study, we examined the distribution of GPR4 in the kidney, its ...
Hong Yeon-Ji - - 2010
pH-sensitive liposomes were prepared by modifying the surface of egg phosphatidylcholine (EPC) liposomes with hydrophobically modified silk fibroin (HmSF). For the hydrophobic modification of SF, palmitic acid residues were covalently attached to SF through amide bond. According to the result of TNBS assay, about 90% of amino groups of SF ...
King Thea - - 2010
The food-borne pathogen Escherichia coli O157:H7 is commonly exposed to organic acid in processed and preserved foods, allowing adaptation and the development of tolerance to pH levels otherwise lethal. Since little is known about the molecular basis of adaptation of E. coli to organic acids, we studied K-12 MG1655 and ...
Ling Da-Jiong - - 2010
Acid rain pollution is a serious environmental problem in the world. This study investigated impacts of simulated acid rain (SAR) upon four types of soil enzymes, namely the catalase, acid phosphatase, urease, and amylase, in a latosol. Latosol is an acidic red soil and forms in the tropical rainforest biome. ...
Zhang Li-Wen - - 2010
Ferulic acid (FA) can be used as an antioxidant to prevent damage from ultraviolet (UV) radiation and skin carcinogenesis. To this end, the feasibility of the skin absorption of FA and its derivatives was evaluated in the present study. The percutaneous absorption of five compounds into/across porcine skin was measured ...
Phoeung Thida - - 2010
It has been shown that mixtures of palmitic acid (PA) and cholesterol (Chol) or cholesterol sulfate (Schol) can form fluid bilayers. These bilayers could be extruded using standard extrusion techniques to obtain nonphospholipid large unilamellar vesicles (LUVs). These LUVs displayed a very limited passive permeability, associated with their high sterol ...
Wang Zuohua - - 2010
In this paper, different starches were modified by diethylenetriamine. The native starch reacted with diethylenetriamine giving CAS, whereas the enzymatic hydrolysis starch was modified by diethylenetriamine producing CAES. Adsorption capacities of CAES for four acid dyes, namely, Acid orange 7 (AO7), Acid orange 10 (AO10), Acid green 25 (AG25) and ...
Nierzwicki-Bauer Sandra A - - 2010
The Adirondack Mountains in New York State have a varied surficial geology and chemically diverse surface waters that are among the most impacted by acid deposition in the U.S. No single Adirondack investigation has been comprehensive in defining the effects of acidification on species diversity, from bacteria through fish, essential ...
Vítková Katerina - - 2010
A contribution to the description of electrokinetic effects on the pH boundary formed by sodium borate pH 9.5 and sodium phosphate pH 2.5 electrolytes for on-line preconcentration of weak acids is presented in this article. Simulations of electrokinetic injections together with experimental studies using contactless conductivity detection verified that the ...
Salentinig Stefan - - 2010
In the human digestion process, triglycerides are hydrolyzed by lipases to monoglycerides and the corresponding fatty acids. Here we report the self-assembly of structures in biologically relevant, emulsified oleic acid-monoolein mixtures at various pH values and oleic acid concentrations. Small-angle X-ray scattering, cryogenic transmission electron microscopy, and dynamic light scattering ...
Rhee Yun-Seok - - 2010
The aims of the present study were to elucidate the potential mechanism of propofol emulsion destabilization following the addition of lidocaine, and to evaluate the effects of various electrokinetic stabilizers on the physicochemical properties of lidocaine-propofol emulsions. The assessments included pH observations and determination of the maximum globule diameter (MGD) ...
Erlandsson Martin - - 2010
This study examined the spatiotemporal patterns of episodic acidification in 87 weakly buffered streams in Sweden at a monthly sampling frequency during a ten-year study period (1998-2007). Time series of pre-industrial pH (pH(0)) were reconstructed from the acidification model Meta(MAGIC), and the acidification impact was defined by the difference between ...
Tian Yanqing - - 2010
A series of new naphthalimide derivatives were synthesized and studied. Three of the materials (SM1, SM2, and SM3) possess methacrylate(s) moieties as pH sensor monomers, enabling these compounds to be polymerized with other monomers for thin film preparation for extracellular pH sensing. Herein, poly(2-hydroxyethyl methacrylate)-co-poly(acrylamide) (PHEMA-co-PAM) was chosen as the ...
Matthies Romy - - 2010
A full-scale passive treatment system (PTS) was commissioned in 2003 to treat two net-acidic coal mine water discharges in the Durham coalfield, UK. The principal aim of the PTS was to decrease concentrations of iron (<177 mg L(-1)) and aluminium (<85 mg L(-1)) and to increase pH (>3.2) and alkalinity ...
Huo Mingqun - - 2011
Particles with aerodynamic diameters <10 [Formula: see text]m (PM(10)) and particles with aerodynamic diameters <2.5 [Formula: see text]m (PM(2.5)) were sampled during summer 2006 in Beijing and mass concentrations, water-soluble ionic compounds concentrations, and acidic buffer capacity were analyzed. Results show that the mass concentration ranges of PM(10) and PM(2.5) were from ...
Sriranganadane Dev - - 2010
Aspergillus fumigatus grows well at neutral and acidic pH in a medium containing protein as the sole nitrogen source by secreting two different sets of proteases. Neutral pH favors the secretion of neutral and alkaline endoproteases, leucine aminopeptidases (Laps) which are nonspecific monoaminopeptidases, and an X-prolyl dipeptidase (DppIV). Acidic pH ...
Alan Emel - - 2010
Mucus normally protects the airway epithelium from dehydration and inhaled infectious agents and possibly toxic substances. Two components of mucus, mucin and water play major roles in the elimination of inhaled foreign material. Mucins are large carbohydrates rich glycoprotein. The objective of the present study was to determine the histochemical ...
Sateesha Sb - - 2010
The matrix tablets of diltiazem hydrochloride were prepared by direct compression using hydroxypropyl methyl cellulose (HPMC) and various amounts (2.5%, 5.0%, 10% and 20%) of citric acid, malic acid and succinic acid. The characterization of physical mixture of drug and organic acids was performed by Infra-red spectroscopy. An organic acid ...
Mykytczuk N C S - - 2010
Strain variation in the acidophile Acidithiobacillus ferrooxidans was examined as a product of membrane adaptation in response to pH stress. We tested the effects of sub and supra-optimal pH in two type strains and four strains isolated from acid mine drainage water around Sudbury, Ontario, Canada. Growth rate, membrane fluidity ...
Lin Yen-Ling - - 2010
This report describes the design and synthesis of a new series of degradable, pH-sensitive, membrane-destabilizing, comb-like polymers that can enhance the intracellular delivery of therapeutic nucleic acids. These comb-like polymers are based on a diblock polymer backbone where the first block is a copolymer of pH-sensitive ethyl acrylic acid (EAA) ...
Rand Danielle - - 2011
Reactions of short sugars under mild, plausibly prebiotic conditions yield organic microspherules that may have played a role in prebiotic chemistry as primitive reaction vessels. It has been widely thought that nitrogen chemistry, in particular Amadori rearrangement, is central to this process, Here we show that microspherules form in the ...
Fukamachi Toshihiko - - 2010
In tumor cell masses, the extracellular pH decreases below 6.5. The effect of external acidic pH on the efficacy of 24 chemical compounds including molecular-targeted inhibitors and anti-tumor reagents was investigated in human cancer cells. Lovastatin showed no cytotoxicity in mesothelioma or pancreatic carcinoma cells at concentrations up to 10 ...
Laudon Hjalmar - - 2010
Despite decades of research about episodic acidification in many regions of the world, the understanding of what controls the transient changes in stream water chemistry occurring during rain and snow melt events is still limited. Here, we use 20 years of hydrological and stream chemical data from the paired watershed ...
Kwon Taek Kwan - - 2011
Monoolein (MO) cubic phase containing acidic proteinoid was prepared for a pH-dependent release. The acidic proteinoid was prepared by a thermal-condensation reaction of Asp and Leu (9.85/0.15 in molar ratio). To prepare MO cubic phase, molten MO was hydrated with the proteinoid solution in distilled water. For pH-dependent release experiment, ...
Huang Chao - - 2010
Polyhalo isophthalonitriles were reacted with substituted anilines and subsequently cyclocondensed in the presence of sulfuric acid to give polyhalo acridones. These polyhalo acridones were proven to be useful as pH-sensitive fluorescent probes for a wide range of acidic and basic conditions.
Vardhanabhuti Bongkosh - - 2010
Whey protein gels have a weak/brittle texture when formed at pH <or= 4.5, yet this pH is required to produce a high-protein, shelf-stable product. We investigated if gels could be made under conditions that produced strong/elastic textural properties then adjusted to pH <or= 4.5 and maintain textural properties. Gels were ...
Dhareshwar Sundeep S - - 2010
The C-phosphoryloxymethyl (POM) and phosphoryloxymethyloxymethyl (POMOM) prodrugs resulting from derivatization at the reactive alpha-carbon of beta-dicarbonyl carbon acid drugs represent a unique approach for improving their chemical stability and aqueous solubility. This work evaluates the physicochemical and in vitro enzymatic bioconversion lability of selected prodrugs of phenylbutazone and phenindione. The ...
Hermans D - - 2010
Campylobacter jejuni is the most common cause of bacterial-mediated diarrheal disease worldwide. Because poultry and poultry products are a major source of C. jejuni infections in humans, efforts should be taken to develop strategies to decrease Campylobacter shedding during primary production. For this purpose, the efficacy of medium-chain fatty acids ...
Katz P O - - 2010
In patients with Los Angeles (LA) grade C or D oesophagitis, a positive relationship has been established between the duration of intragastric acid suppression and healing. To determine whether there is an apparent optimal time of intragastric acid suppression for maximal healing of reflux oesophagitis. Post hoc analysis of data ...
Kampe Heike - - 2010
As extreme environmental conditions strongly affect bacterial community composition (BCC), we examined whether differences in pH-even at low pH-and in iron and sulfate concentrations lead to changes in BCC of acidic mining lakes. Thereby, we tested the following hypotheses: (1) diversity of the bacterial community in acidic lakes decreases with ...
Duret Guillaume - - 2010
The trimeric OmpU and OmpT porins form large, triple-barrel hydrophilic channels in the outer membrane of the pathogen Vibrio cholerae. They have distinct pore properties, such as conductance, block by deoxycholic acid, and sensitivity to acidic pH. Their three-dimensional structures are unknown, but they share significant sequence homologies. To gain ...
Chi Lina - - 2010
New ethynylated triphenylamine boronic acid sensors 1 and 2 were designed and the photophysical properties, as well as the binding with tartaric acid and mandelic acid were studied. We found the emission intensity of the sensors is sensitive to the polarity of the solvents and the emission of sensor 2 ...
Talbot Colleen - - 2010
The colon is believed to absorb NaCl via the coupled operation of apical Na/H exchanger-3 (NHE3) and Cl/HCO(3) exchanger SLC26A3 (DRA). Efficient coupling requires that NHE3 and DRA operate in close proximity within common luminal and cytosolic microenvironments. Thus we examined whether these proteins coexist along the apical margin of ...
Fang Yapeng - - 2010
Electron paramagnetic resonance (EPR) is here used to study the interaction between gum arabic and a fatty acid. The EPR spectra of 5-doxyl stearic acid (5-DSA), a spin-labeled fatty acid analog, displayed increasingly anisotropic line features upon addition of gum arabic, indicating a strong immobilization of the nitroxyl moiety when ...
Axelsson-Olsson Diana - - 2010
Campylobacter jejuni is a recognized and common gastrointestinal pathogen in most parts of the world. Human infections are often food borne, and the bacterium is frequent among poultry and other food animals. However, much less is known about the epidemiology of C. jejuni in the environment and what mechanisms the ...
Verma Shikha - - 2010
Saccharomyces cerevisiae is widely known for its catalytic activity on substrates such as aldehyde and ketone. Interestingly, the activity of S. cerevisiae on heptanal (C(6)H(13)CHO), in spite of its being a very common aldehyde, has not been explored. The main objective of this study was therefore to investigate the bioconversion ...
Molatová Z - - 2010
Organic acids can be used as feed supplements or for treatment of poultry carcasses in processing plants. The antimicrobial activity of nineteen organic acids and two monoacylglycerols in cultures of Campylobacter jejuni CCM 6214(T) (ATCC 33560) was determined using a SYBR Green-based real-time PCR assay. The IC(50) was a concentration ...
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