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Results 501 - 550 of 1099
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Högberg A - - 2002
The objectives of this study were to investigate the polar and neutral lipid fatty acid composition, content of retinol, α-tocopherol, γ-tocopherol and level of oxidation of the pig muscle (M. longissimus dorsi). Female and castrated male Hampshire crossbreeds were produced in two systems. One group was raised indoors with a ...
Agroyannis B - - 2002
The aim of this study was to determine the relationship between interdialytic weight gain and acid-base balance pre- and posthemodialysis in uremic patients undergoing hemodialysis with a high bicarbonate dialysate (39 mmol/L). To this end we studied 8 stable uremic patients on regular hemodialysis thrice weekly who had stable hematocrit ...
Lee Ki-Wha - - 2002
An efficient and practical one-pot synthesis of 4,5-diaryl-2,2-dimethyl-3(2H)-furanones has been achieved from 1,2-diarylethanones and 2-bromoisobutyryl cyanide in the presence of excess base, by employing the 'hard soft acid base' principle. The reaction scope of 2-bromoisobutyryl cyanide could be expanded to prepare a variety of 2,2-dimethyl-3(2H)-furanone derivatives other than 4,5-diaryl-2,2-dimethyl-3(2H)-furanones.
Shallom Dalia - - 2002
The alpha-L-arabinofuranosidase from Geobacillus stearothermophilus T-6 (AbfA T-6) belongs to the retaining family 51 glycoside hydrolases. The conserved Glu175 was proposed to be the acid-base catalytic residue. AbfA T-6 exhibits residual activity towards aryl beta-D-xylopyranosides. This phenomenon was used to examine the catalytic properties of the putative acid-base mutant E175A. ...
Yuanqin Zhang - - 2002
The effects of cetyltrimethylammonium (CTAB), sodiumdodecylsulfate (SDS) and pol(oxyethylene)(9.5)p-(1,1,3,3-tetramethyl; Triton X-100) on the dissociation constants, transition points and transition intervals of thymol blue and bromothymol blue were studied. The experimental results indicated that surfactant micelles remarkably affected dissociation constants, transition points and transition intervals of the acid-base indicators, and the ...
Maccà Carlo - - 2002
The suitability of the half-cell Pt/I2, KI in glacial acetic acid as reference electrode for potentiometric titrations of weak bases in the same medium was investigated. This electrode is easily prepared. It has been found very convenient in use and performing at least as well as the best electrodes used ...
Biedermann Wolfgang - - 2002
Determination of specified risk material (SRM) in processed meat products was performed by quantification of brain specific fatty acids using gas chromatography-mass spectrometry (GC-MS). Results from SMP (internal standardised meat products) based analyses showed that absolute concentrations of CNS are correlated (r2 = > 0.97) with the contents of the ...
Maloney D G - - 2002
Anions are the negative components of most chemical structures and play many important physiological and pharmacological roles that are of interest to the anaesthetist. Their relevance is reviewed with a particular emphasis on the inorganic anions (halides, bicarbonate, phosphate and sulphate) and the significance and limitations of the anion gap. ...
DiCesare Nicolas - - 2002
We report the spectroscopic characterization of six fluorescent probes for fluoride sensing and/or monitoring. All probes are based on the ability of the boronic acid group to interact with fluoride. The probes combine electron donor and withdrawing groups and involve the excited charge transfer mechanism. The change between the neutral ...
Bodor Nicholas - - 2002
Brain-targeted delivery of various drugs can be successfully achieved by chemical delivery systems (CDS) that contain a 1,4-dihydropyridine-based redox targetor moiety and undergo a sequential metabolism. However, the susceptibility of this moiety toward hydration in acidic media may limit the shelf-life of such compounds in aqueous formulation. Here, a systematic ...
Boyle Martin - - 2002
The carbonic acid/bicarbonate system, as defined by the Henderson-Hasselbach (H-H) equation, has traditionally formed the centrepiece of the presentation of acid/base physiology in nursing education. However, an alternative approach to describe acid/base physiology was proposed by Peter Stewart in 1983. Stewart determined, using the physiochemical principles of dissociation equilibrium, electroneutrality ...
Sowerby Stephen J - - 2002
Scanning tunneling microscopy and chromatography experiments exploring the potential templating properties of nucleic acid bases adsorbed to the surface of crystalline graphite, revealed that the interactions of amino acids with the bare crystal surface are significantly modulated by the prior adsorption of adenine and hypoxanthine. These bases are the coding ...
Hohsaka Takahiro - - 2002
Various four-base codons had been developed for introduction of nonnatural amino acids into proteins in an E. coli in vitro translation system. Here, the four-base codon mediated incorporation of nonnatural amino acids was investigated in a rabbit reticulocyte lysate. Mutated streptavidin mRNAs containing four-base codons were prepared and expressed in ...
Unver Beate - - 2002
For the first time, long-term use of regional citrate anticoagulation for high-flux haemodialysis is reported in a patient with heparin-induced thrombocytopenia type II. A simple, flow-independent, citrate infusion protocol allowed efficient anticoagulation. Excellent solute removal, indicated by KT/V values of 1.52 to 1.98, was achieved. Electrolyte and acid-base balance as ...
Ksiazek Piotr - - 2002
The concept adequate includes blood purification, maintenance of electrolyte fluid, and acid-base equilibrium. Dialysis can completely reverse the retention of some small molecules, electrolytes (K, Na, Mg), water and acid-base, and has no effect on anemia, hypertension, arteriosclerosis, cardiomyopathies, malnutrition, bleeding, or partial effect on Ca-P balances. Other therapeutic interventions ...
Igawa Manabu - - 2002
We have collected and analyzed fogwater on the mountainside of Mt. Oyama (1252 m) in the Tanzawa Mountains of Japan and observed the fog event frequency from the base of the mountain with a video camera. The fog event frequency increased with elevation and was observed to be present 46% ...
Shafiee M A - - 2002
We shall illustrate that management of patients with an acid-base disorder could be improved if the acid-base analysis was based on a better understanding of basic concepts of physiology. Three concepts of acid-base physiology and their clinical implications are emphasized in a patient with diabetic ketoacidosis. First, when an acid ...
Sowerby Stephen J - - 2002
The hypothesis that life originated and evolved from linear informational molecules capable of facilitating their own catalytic replication is deeply entrenched. However, widespread acceptance of this paradigm seems oblivious to a lack of direct experimental support. Here, we outline the fundamental objections to the de novo appearance of linear, self-replicating ...
Sahin A - - 2002
BACKGROUND: Intraoperative hypothermia is a major adverse effect of general anesthesia. The different anesthetics may influence thermoregulation differently. Proteins or amino acids have been postulated to stimulate heat production. The purpose of this study is to compare the effects of intraoperative administration of amino acid solutions on intraoperative hypothermia and ...
Brutscher B - - 2001
A three-dimensional MQ-TROSY-HCN pulse sequence is presented which provides intra-base and sugar-to-base correlations for 13C, 15N labeled nucleic acids (RNA, DNA). The experiment simultaneously exploits the favorable relaxation properties of 1H-13C multiple quantum coherence for sugar carbons and of 13C TROSY-type spin evolution for base carbons. MQ-TROSY-HCN thus combines the ...
Ishiwata H - - 2001
The mean concentration and daily intake of five preservatives were estimated based on the results of an analysis of 89,927 samples of food obtained in official inspections by Japanese local governments in fiscal year 1998. The mean concentration of benzoic acid was 9.5% of the allowable limit, and those of ...
Di Giulio M - - 2001
Ronneberg et al. (Proc Natl Acad Sci USA 97:13690-13695, 2000) recently suggested abandoning the coevolution theory of genetic code origin on the basis of two pieces of evidence. They (1) criticize the use of several pairs of amino acids in a precursor-product relationship to support this theory and (2) suggest ...
Liu W - - 2001
The acid-base properties of natural illites from different areas were studied by potentiometric titrations. The acidimetric supernatant was regarded as the system blank to calculate the surface site concentration due to consideration of substrate dissolution during the prolonged acidic titration. The following surface complexation model could give a good interpretation ...
García B - - 2001
The protonation equilibria of N-phenylbenzohydroxamic, benzohydroxamic, salicylhydroxamic, and N-p-tolylcinnamohydroxamic acids have been studied at 25 degrees C in concentrated sulfuric, hydrochloric, and perchloric acid media; the UV-vis spectral measurements were analyzed using the Hammett equation and the Bunnett-Olsen and excess acidity methods. The medium effects observed in the UV spectral ...
Maier J - - 2001
For the case of ionic crystals it is shown to be most straightforward and consistent to define acidity/basicity by the (electro-)chemical potential of the respective ion, in a similar fashion to the way that the Fermi level (i.e.. electrochemical potential of the electron) characterizes the redox state. The isomorphy is ...
Braga D - - 2001
Exposure of the solid zwitterion [CoIII(eta 5-C5H4CO2H)(eta 5-C5H4CO2)] to hydrated vapours of volatile acids (HCl, CF3CO2H, HBF4) or bases (NH3, NMe3, NH2Me) quantitatively produces the corresponding salts; the heterogeneous reactions are fully reversible, as the acid or base molecules can be removed by thermal treatment, regenerating the starting material.
Gargallo R - - 2001
2-Aminopurine (P) is a mutagen causing A.T to G.C transitions in prokaryotic systems. To study the base-pairing schemes between P and cytosine (C) or thymine (T), two self-complementary dodecamers containing P paired with either C or T were synthesized, and their protonation equilibria were studied by acid-base titrations and melting ...
Reed D R - - 2001
Hydrogen-deuterium exchange at non-labile sites is reported. The conjugate bases of isophthalic acid (m-C6H4(CO2H)2), 2-oxoglutaric acid (HO2CCOCH2CH2CO2H), and 2-methylisophthalic acid (2-CH3-1,3-C6H4(CO2H)2) undergo scrambling with 1, 2, and 3 carbon-centered hydrogens under a variety of conditions. Likewise, protonated 2-(m-methoxyphenyl)-ethylamine ((m-CH3OC6H4)CH2CH2NH2) undergoes up to 5 H/D exchanges upon gentle activation whereas the ...
Messa P - - 2001
Uremic acidosis is due to impaired excretion of ammonium ions in the presence of unchanged acid production. However, the degree of acidosis is quite variable among uremic patients and pre-dialytic bicarbonate levels are mainly independent of dialytic base supply. These observations strengthen the suggestion that extra-renal mechanisms may play a ...
Rubash J M - - 2001
Acid-base homeostasis is an important determinant of many physiologic functions. Nowhere is understanding the mechanisms and significance of hydrogen ion (H+) imbalance more important than in critical care management, where patients are threatened with a physiochemical disorder that is often as complex as it is dangerous. Although there may be ...
Ha-Duong N T - - 2001
Experiments using recombinant yeast-expressed human liver cytochromes P450 confirmed previous literature data indicating that ticlopidine is an inhibitor of CYP 2C19. The present studies demonstrated that ticlopidine is selective for CYP 2C19 within the CYP 2C subfamily. UV-visible studies on the interaction of a series of ticlopidine derivatives with CYP ...
Khan M I - - 2001
The hydrothermal reaction of V2O5, V2O3, 2,2'-bpy and Na2SO4 in dilute sulfuric acid yields a novel hybrid, [VIVO(mu 3-SO4)(2,2'-bpy)]infinity, which demonstrates the potential of constructing a new class of robust composite solids composed of a (V/O/SO4)-based framework decorated with organic functionalities by combining appropriate vanadyl sulfate motifs with a variety ...
Riond J L - - 2001
In domestic animals, acid-base balance may be influenced by nutrition. The major research effort in this area has been made on the prevention of hypocalcemic postparturient paresis in dairy cows. This disorder is caused by the sudden increase of calcium secretion into the colostrum. The manipulation of the dietary cation-anion ...
Manz F - - 2001
In the 17th century the notion of nutrition and diet changed in northern European countries. First chemical experiments fostered the idea that salts resulted from a union of acids and bases. Digestion was no more regarded as a process of cooking but a succession of fermentations controlled by a balanced ...
Springsteen G - - 2001
Boronic acids bind certain 1,2- and 1,3-diols with high affinity through reversible formation of boronate esters. They have been utilized as the recognition moiety for artificial receptors, particularly receptors for carbohydrates that have cis-diol moieties. Therefore, sensors for boronic acids could serve as universal reporters for monitoring boronate formation. This ...
Mioni R - - 2001
Acid generation and elimination processes were compared with total base (bicarbonate plus metabolizable anions) turnover in 18 anuric patients undergoing post-dilutional haemofiltration. The study was conducted during the second haemodialysis session of the week by means of a whole-body base balance technique. The results showed that the mean rates of ...
Sanchez A P - - 2001
The respiratory control in land vertebrates (Tetrapoda) is mainly linked to regulation of acid-base status, which involves peripheral and central chemoreceptors. The lungfish (Dipnoi) might constitute the sister group of all land vertebrates (Tetrapoda) and possess a combination of real lungs and reduced gills. In this context, we evaluated the ...
Velterop J S - - 2001
Sugars and organic acids are important determinants of taste in fruits and vegetables. Based on the enzymatic analyses originally developed by Boehringer-Mannheim, rapid and reliable microplate-based assays were devised for glucose, fructose and sucrose in tomato and orange juice, and citrate and L-malate in tomato. These microplate assays were used ...
McNamara J - - 2001
OBJECTIVE: To review the normal human acid-base physiology and the pathophysiology and management of acid-base disturbances in a two-part presentation. DATA SOURCES: Articles and published peer-review abstracts and a review of studies reported from 1990 to 2000 and identified through a MEDLINE search of the English language literature on acid-base ...
McNamara J - - 2001
OBJECTIVE: To review the normal human acid-base physiology and the pathophysiology and management of acid-base disturbances in a two-part presentation. DATA SOURCES: Articles and published peer-review abstracts and a review of studies reported from 1990 to 2000 and identified through a MEDLINE search of the English language literature on acid-base ...
Erzen E - - 2001
The oxidation of thianthrene 5-oxide, i.e., a mechanistic probe for the assessment of the electronic character of various oxidants, with peroxybenzoic acids in various oxygen bases as solvents was investigated. The nucleophilicity (X(SO)) of peroxy acids was increasing with increasing basicity of the oxygen base. A good linear correlation was ...
Shamsipur M - - 2001
A quantitative structure-property relationship study is suggested for the prediction of acidity constants of some recently synthesized 9,10-anthraquinone derivatives in binary methanol-water mixtures. Modeling of the acidity constant of the anthraquinones as a function of physicochemical parameters and mole fraction of methanol was established by means of the partial least-squares ...
Högberg A - - 2001
The objective of this study was to investigate the polar and neutral lipid fatty acid composition of pig muscle as influenced by rearing conditions and sex. A total of 120 Hampshire crossbreeds were divided in two groups, one reared free-range in a strip grazing fashion and one reared indoors in ...
Ayral X - - 2001
Based on previous experience in inflammatory arthritis, a small number of open studies have evaluated the usefulness of chemical synoviorthesis with osmic acid in haemophilia, with various assessment criteria and a wide range of follow-up periods. Based on these studies, the efficacy of osmic acid seems modest, with 30-44% of ...
Meng M - - 2001
Phosphoglucose isomerase catalyzes the isomerization between glucose 6-phosphate and fructose 6-phosphate in cytoplasm, and functions as autocrine motility factor and neuroleukin outside the cells. A phosphoglucose isomerase from Bacillus stearothermophilus (pgiA) was subjected to mutagenesis study to address the catalytic function of the conserved anionic residues and those probably interacting ...
Story D A - - 2001
Compared with the Henderson-Hasselbalch approach, the Stewart approach may better describe the mechanisms of acid-base physiology and disorders. We prospectively examined the acid-base disorders of 100 routine blood samples from critically ill patients using Stewart's physical chemistry analysis. The median results were pH 7.45, PaCO2 5.5 kPa, bicarbonate 27.2 mmol.l-1 ...
Mulchandani A - - 2001
Direct, selective, rapid and simple determination of organophosphate pesticides has been achieved by integrating organophosphorus hydrolase with electrochemical and opitical transducers. Organophosphorus hydrolase catalyzes the hydrolysis of a wide range of organophosphate compounds, releasing an acid and an alcohol that can be detected directly. This article reviews development, characterization and ...
Chang E E - - 2001
The role of bromide in the formation and speciation of disinfection by-products (DBPs) during chlorination was investigated. The molar ratio of applied chlorine to bromide is an important factor in the formation and speciation of trihalomethanes (THMs) and halogenacetic acids (HAAs). A good relationship exists between the molar fractions of ...
Waldstein D E - - 2001
Fruit damage by obliquebanded leafroller, Choristoneura rosaceana (Harris), was examined on four different apple cultivars during 1997-1999 in heavily infested orchards in New York State. Inital fruit damage occurred 354+/-26 degree-days base 6 degrees C (DD6) after the first moth catch from the overwintering generation and continued to increase until ...
Jie M S - - 2001
Some 1,2- and 1,3-diacyl glycerols (with acyl groups as stearyl, oleyl, linoleyl, or stearolyl) were synthesized by conventional methods. The diacyl glycerols were esterified with 6-bromo-hexanoic acid to give the corresponding bromo-triacylglycerols (of the type AAB and ABA containing a bromo group at the distal part of the hexanoate chain). ...
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