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Results 351 - 400 of 1100
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Wang Xiaoyan - - 2005
Haloacetic acids are an important class of disinfection byproducts that are being regulated. In this paper we report novel instrumentation for continuous monitoring of the nine haloacetic acids. Hollow fiber liquid-liquid membrane extraction (LLME) and supported liquid membrane extraction (SLME) followed by on-line HPLC-UV detection were studied. With continuous LLME, ...
Bernasconi Claude F - - 2005
[reaction: see text] Acidity constants and rates of reversible deprotonation of acetonyltriphenylphosphonium ion (1H+), phenacyltriphenylphosphonium ion (2H+), N-methyl-4-phenacylpyridinium ion (3H+), and N-methyl-4-(phenylsulfonylmethyl)pyridinium ion (4H+) by amines in water, 50% DMSO-50% water (v/v), and 90% DMSO-10% water (v/v) have been determined. From the respective Brønsted plots, log k(o) values for the ...
Nagy Noémi M - - 2006
Five bentonite samples (35-47% montmorillonite) from a Sarmatian sediment series with bentonite sites around Sajóbábony (Hungary) is studied. Some of these samples were tuffogenic bentonite (sedimentary), the others were bentonitized tuff with volcano sedimentary origin. The acid-base properties of the edge sites were studied by potentiometric titrations and surface complexation ...
Bandini Elisa - - 2005
Fluorescence and trans-->cis photoisomerization are the main deactivation paths following excitation of trans-1-(2'-naphthyl)-2-(3'-hydroxyphenyl)ethene (trans-2,3NOH) in cyclohexane, methanol and acetonitrile. The quantum yield of both processes is wavelength dependent: this is due to the presence of conformational isomers deriving from rotation of the naphthyl group around the single bond with ethene. ...
Robert S. Egan
In North America, the common and abundant coastal, corticolous species currently known as Parmotrema rigidum (Lynge) Hale, is shown to be morphologically distinct from the South American type and other South American representatives of the species based on both ascospore and conidial size. We describe the North American taxon as ...
Simpson Gavin L - - 2005
Analogue matching is a palaeolimnological technique that aims to find matches for fossil sediment samples from a set of modern surface sediment samples. Modern analogues were identified that closely matched the pre-disturbance conditions of eight of the UK Acid Waters Monitoring Network (AWMN) lakes using diatom- and cladoceran-based analogue matching. ...
Buvári-Barcza A - - 2005
The use and importance of formic acid and acetic anhydride (Ac2O) is increasing in nonaqueous acid-base titrations, but their interaction with the solutes is poorly understood. This paper attempts to clarify the effect of the solvents; NMR and spectrophotometric investigations were done to reveal the interactions between some bases and ...
Paulev P E - - 2005
This report describes the historical development in the clinical application of chemical variables for the interpretation of acid-base disturbances. The pH concept was already introduced in 1909. Following World War II, disagreements concerning the definition of acids and bases occurred, and since then two strategies have been competing. Danish scientists ...
Duc Myriam - - 2005
The effects of experimental procedures on the acid-base consumption titration curves of montmorillonite suspension were studied using continuous potentiometric titration. For that purpose, the hysteresis amplitudes between the acid and base branches were found to be useful to systematically evaluate the impacts of storage conditions (wet or dried), the atmosphere ...
Davies J J L - - 2005
Analysis of water chemistry data from 15 years of monitoring at 22 acid-sensitive lakes and streams in the UK reveals coherent national chemical trends indicative of recovery from acidification. Excess sulphate and base cations exhibit significant decline, often accompanied by an increase in an alkalinity-based determination of acid neutralising capacity ...
Duffin James - - 2005
This paper uses a steady-state modeling approach to describe the effects of changes in acid-base balance on the chemoreflex control of breathing. First, a mathematical model is presented, which describes the control of breathing by the respiratory chemoreflexes; equations express the dependence of pulmonary ventilation on Pco(2) and Po(2) at ...
Gunnerson Kyle J - - 2005
Acid-base abnormalities are common in critically ill patients. Our ability to describe acid-base disorders must be precise. Small differences in corrections for anion gap, different types of analytical processes, and the basic approach used to diagnose acid-base aberrations can lead to markedly different interpretations and treatment strategies for the same ...
Kellum John A - - 2005
Recent advances in acid-base physiology and in the epidemiology of acid-base disorders have refined our understanding of the basic control mechanisms that determine blood pH in health and disease. These refinements have also brought parity between the newer, quantitative and older, descriptive approaches to acid-base physiology. This review explores how ...
Masuda Toshinobu - - 2005
A new method for the sensitive and selective determination of stronger acids, such as methanesulfonic acid, based on an acid-base interaction with N-methylacridone fluorophore (1), is proposed. The fluorescence spectrum of 1 was changed drastically by the addition of methanesulfonic acid in methanol. A ratiometric analysis of methanesulfonic acid by ...
Takatori Toshihito - - 2005
Controlled-release morphine suppositories were prepared by utilizing polyglycerol ester of fatty acid (PGEF). The addition of PGEF to fatty suppository base Witepsol H15 resulted in a decrease of morphine release rate from suppositories. Among PGEFs examined, decaglycerol heptabehenate (HB750) was the most effective additive for the controlled-release of morphine from ...
Overland M - - 2005
A total of 48 pigs (11.4 and 107.2 kg initial and final weight) were used to evaluate increasing dietary levels of bacterial protein meal (BPM) produced on natural gas (0, 50, 100, or 150 g kg(-1)) on fatty acid composition, sensory properties, and susceptibility of pork to lipid oxidation. Increasing ...
Wang Zhuo - - 2005
[reaction: see text] A new saccharide sensor based on a tetrathiafulvalene-anthracene dyad with a boronic acid group was designed and synthesized. Our study employed the tetrathiafulvalene (TTF) unit as the electron-rich group in the saccharide sensor instead of an amine group, and this new sensor detects fructose with good selectivity.
Trakhtenberg Sofia - - 2005
Horseradish peroxidase has been demonstrated to catalyze the oxidative polymerization of aniline to form conductive polyaniline. This process is facilitated by the presence of a macromolecular template with sulfonic acid groups that provide a unique environment for the formation of the conducting polymer. Here we report the use of a ...
Zhao G M - - 2005
Sixty experimental Jinhua hams were processed by a traditional method. The potential alanyl aminopeptidase (AAP) activity in biceps femoris was determined. The effects of temperature, salt content, sodium nitrate content and pH on muscle AAP were evaluated using response surface methodology. Porcine muscle was found to possess very strong potential ...
Zhu S - - 2005
Crystals of partially neutralized stearic acid with triethanolamine (TEA) were prepared by mixing these two materials above 80 degrees C and then cooling. The crystalline composition and the structure and melting behavior of the resultant products were characterized with small-angle and wide-angle X-ray diffraction, thermal analysis, microscopy, and infrared spectroscopy. ...
Hackbarth Richard M - - 2005
Infants requiring CRRT present a unique challenge due to the large circuit volume to blood volume ratio. Blood priming is often used, but some patients can become unstable during the initiation of CRRT due to electrolyte and acid-base imbalance. We postulated that using Z-BUF we could normalize electrolytes and improve ...
Funk Georg-Christian - - 2005
BACKGROUND AND AIMS: Conflicting results exist with regard to metabolic acid-base status in liver cirrhosis, when the classic concept of acid-base analysis is applied. The influence of the common disturbances of water, electrolytes and albumin on acid-base status in cirrhosis has not been studied. The aim of this study was ...
Schück Otto - - 2005
Acid-base balance evaluation according to the Henderson-Hasselbalch equation enable us to assess the contribution of respiratory (pCO2) and/or non-respiratory (metabolic, HCO3(-)) components to the acid-base balance status. A new approach to acid-base balance evaluation according to Stewart-Fencl, which is based on a detailed physical-chemical analysis of body fluids shows that ...
Newton Estelle E - - 2005
The neonatal Fc receptor, FcRn, transports proteins through cells, avoiding degradative compartments. FcRn is used in many physiological processes where proteins must remain intact while they move through cells. These contexts include the transport of IgG antibodies from mother to offspring, and the protection of IgG and albumin from catabolism. ...
Nuernberg Karin - - 2005
The aim of this study was to alter the fatty acid composition of porcine tissue by accumulating essential fatty acids without adversely affecting carcass composition, muscle structure or meat eating quality. A total of 13 female and 12 castrated Pietrain×German Landrace pigs were fed a basal concentrate diet supplemented with ...
Dussy Franz E - - 2005
A simple procedure based on a common silica gel column chromatography for the isolation of Delta9-tetrahydrocannabinolic acid A (Delta9-THCA-A) from hemp in a multi-milligram scale is presented. Further, the decarboxylation reaction of Delta9-THCA-A to the toxicologically active Delta9-tetrahydrocannabinol (Delta9-THC) at different analytical and under-smoking conditions is investigated. Maximal conversion in ...
Ayers Paul W - - 2005
The hard/soft-acid/base (HSAB) principle indicates that hard acids prefer binding to hard bases (often forming bonds with substantial ionic character) while soft acids prefer binding to soft bases (often forming bonds with substantial covalent character). Though the HSAB principle is a foundational concept of the modern theory of acids and ...
Napolitano Michael J - - 2005
Quantitation of cellular adenylate levels (i.e., ATP, ADP, AMP) has widespread applications in physiological, metabolic and energetic studies. We have compared classical adenylate extraction procedures (i.e., perchloric acid, boiling) with a previously unreported proteinase K-based extraction technique. Our results suggest that all three techniques are comparable in soft animal tissue, ...
Kellum John A - - 2005
An advanced understanding of acid-base physiology is central to the practice of critical care medicine. Intensivists spend much of their time managing problems that are related to fluids, electrolytes, and blood pH. Recent advances in the understanding of acid-base physiology occurred as the result of the application of basic physical-chemical ...
Villar Susana E Jorge - - 2005
Twenty-three highly-coloured lichen specimens belonging to the genera Candelariella, Aspicilia and Xanthoria from high altitude sites in the Atacama Desert, Chile, 2300-4500 metres, have been analysed non-destructively by Raman spectroscopy. The vibrational band assignments in the spectra of the specimens, which were still attached to their limestone or sandstone substrata, ...
Zhou Yanxiu - - 2005
A potentiometric chemosensor for selective determination of dipicolinic acid (2,6-pyridinedicarboxylic acid, DPA) was developed based on the surface imprinting technique coupled with a nanoscale transducer: an indium tin oxide (ITO)-coated glass plate. The sensor fabrication conditions, optimal recognition condition, as well as selectivity, sensitivity, and stability of the DPA sensor ...
Copley Shelley D - - 2005
The genetic code has certain regularities that have resisted mechanistic interpretation. These include strong correlations between the first base of codons and the precursor from which the encoded amino acid is synthesized and between the second base of codons and the hydrophobicity of the encoded amino acid. These regularities are ...
Handy Scott T - - 2005
The 2-position of imidazolium cations is known to be relatively acidic, leading to the useful Arduengo-type carbenes. At the same time, the acidity of this site can lead to undesired side reactions when using imidazolium-based ionic liquids as solvents. In this note, we describe the surprisingly facile deuterium exchange at ...
Purchas R W - - 2005
The concentrations of fatty acids were measured in intramuscular fat from the longissimus lumborum (LL) and triceps brachii (TB) muscles of Angus-cross heifers finished either on a high-concentrate ration in Washington, USA, (US cattle, n=15) or on pasture in New Zealand (NZ cattle, n=16). Half of the NZ cattle were ...
Zupan Jure - - 2005
An algorithm for encoding long strings of building blocks, like 4 DNA bases (adenine-A, cytosine-C, thymine-T, and guanidine-G), 20 natural amino acids (from Alanine Ala to Valine-Val, plus the stop triplet), or all 64 possible base triplets (from AAA to TTT), into "zigzag" or "spectrum-like" representations is suggested. The new ...
Reed Christopher A - - 2005
Icosahedral carborane anions such as CHB11Cl11- are amongst the least coordinating, most chemically inert anions known. They are also amongst the least basic, so their conjugate acids, H(carborane), are superacids (i.e. stronger than 100% H2SO4). Acidity scale measurements indicate that H(CHB11Cl11) is the strongest pure Brønsted acid presently known, surpassing ...
Jiao Tifeng - - 2005
A bolaform Schiff base, N,N'-bis(salicylidene)-1,10-decanediamine (BSC10), has been synthesized and its interfacial hydrogen bond formation or molecular recognition with barbituric acid was investigated in comparison with that of a single chain Schiff base, 2-hydroxybenzaldehyde-octadecylamine (HBOA). It has been found that while HBOA formed a monolayer at the air/water interface, the ...
Bordiga Silvia - - 2005
Zeolitic materials based on the chabazite topology, such as H-SAPO-34, possess unique shape-selectivity properties for converting methanol into light olefins. In addition to the topology, zeolite acidity is inherently linked to catalyst activity and selectivity. The acidic properties of high silica chabazite (H-SSZ-13) have attracted much attention in the past ...
Herd Anthony M - - 2005
To review rules and formulas for solving even the most complex acid-base problems. MEDLINE was searched from January 1966 to December 2003. The search was limited to English-language review articles involving human subjects. Nine relevant review papers were found and provide th background. As this information is well established and ...
Jakmunee Jaroon - - 2005
A new concept for micro-titration using a "lab-on-valve"(LOV) system with sequential injection of mono-segmented flow is proposed. The performance of the system was demonstrated by the assay of acidity in fruit juices which is based on acid-base neutralization. A standard/sample solution containing citric acid, indicator, sodium hydroxide, were sandwiched between ...
Revsbech Niels Peter - - 2005
Electrochemical microsensors for O2, pH, H2S, H2, and N2O are now available commercially, thus it has become a relatively simple task to analyze the microenvironment in stratified microbial communities for several chemical species. In addition, sensors are available for the physical parameters diffusivity and flow, and based on knowledge about ...
Alarcón-Angeles G - - 2005
The time stability of the azomethine-H species was determined not to be better than 10 min in the absence of oxygen and light, however under phosphate buffered conditions the azomethine-H species remained stable for longer periods, as indicated by the spectrophotometric behaviour. Nevertheless, the analysis time still exceeded the stability ...
Yaylayan Varoujan A - - 2005
Earliest reports on the origin of acrylamide in food have confirmed asparagine as the main amino acid responsible for its formation. Available evidence suggests that sugars and other carbonyl compounds play a specific role in the decarboxylation process of asparagine, a necessary step in the generation of acrylamide. It has ...
de Mendoza M Giuffrida - - 2005
Lipid extracts from longissimus dorsi muscles of 64 water buffaloes and 68 zebu-type cattle were used to quantify the amount (mg/g of lipids) of total conjugated linoleic acid (CLA), CLA isomers c9, t11 and t10, c12 and linoleic acid (LA), according to species (buffaloes and cattle), age (slaughter groups at ...
Mortier Siska - - 2005
OBJECTIVES: Peritonitis remains a principal cause of dropout in peritoneal dialysis (PD). The physiological host response to a peritoneal infection involves a rise in numbers of circulating leukocytes to the peritoneal cavity. We evaluated the effects of (1) conventional peritoneal dialysis fluid (PDF), (2) bicarbonate-based PDF, low in glucose degradation ...
Müllegger Johannes - - 2005
Thioglycoligases are recently introduced variants of retaining glycosidases in which the acid-base catalyst has been mutated, rendering them capable of thioglycoside synthesis. The original acid-base mutant of Agrobacterium sp. beta-glucosidase (E170A) was previously shown to be an effective thioglycoligase carrying out glycosyltransfer from 2,4-dinitrophenyl glycosides to several different thio sugar ...
Mukai Junji - - 2004
The purpose of this study was to evaluate quantitatively the taste of the various total enteral nutrients marketed in Japan using human gustatory sensation tests and an artificial taste sensor. In the human gustatory sensation test, four basic taste intensities (sweetness, saltiness, sourness, and bitterness), as well as 15 kinds ...
Lloyd P - - 2004
OBJECTIVE: To review acid-base balance by considering the physical effects of ions in solution and describe the use of a calculator to derive the strong ion difference and Atot and strong ion gap. DATA SOURCES: A review of articles reporting on the use of strong ion difference and Atot in ...
Corey Howard E - - 2005
Complex acid-base disorders arise frequently in critically ill patients, especially in those with multiorgan failure. In order to diagnose and treat these disorders better, some intensivists have abandoned traditional theories in favor of revisionist models of acid-base balance. With claimed superiority over the traditional approach, the new methods have rekindled ...
Landskron Kai - - 2004
We report the synthesis of a new class of materials called periodic mesoporous dendrisilicas. They are prepared from dendrimers with trialkoxysilyl groups at the outmost shell. Dendrimers of various cores and numbers of shells are used. The dendrisilica synthesis is based on acid- or base-catalyzed hydrolysis of the trialkoxysilyl groups ...
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