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91.
Chiral high performance liquid chromatography was used for the enantiometric separation of leucovorin. The optimal separation conditions recommended after optimizing the mobile phase composition, flow rate, and temperature are described. Achiral reversed-phase chromatographic method was applied for the simultaneous separation of methotrexate and leucovorin in clinical samples. Column-switching system including achiral short pre-column and chiral analytical column based on immobilized bovine serum albumin were used for simultaneous determination of leucovorin and methotrexate patients treated at the National Cancer Institute.  相似文献   
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93.
Wheat bran is multi-layered and consists of different cell types with different chemical compositions. The relatively high content of protein as well as the small amount of lignin is the key differentiator to other lignocellulose containing biomasses. Following the classical route of a biorefinery, bran may be disintegrated to a high extent and separated into fractions of high purity in order to build up new chemicals which serve as precursors for higher polymerized compounds. Secondly, bran contains substances that are per se valuables, but need to be further separated and purified.  相似文献   
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Bei “Monitored Natural Attenuation” (MNA)-Ma?nahmen werden anhand von Felddaten Prognosen zur Schadensentwicklung erstellt. Zur überprüfung der Aussagef?higkeit von Felddaten hinsichtlich MNA wurden an einer Grundwasserkontamination durch BTEX hydrogeologische Untersuchungen durchgeführt. Hierzu wurden Pumpversuchsdaten, geologische Bohrdaten und Niederschlagsdaten berücksichtigt, daneben die zeitliche Entwicklung der Grundwasserst?nde, der Schadstoffgehalte sowie der hydraulischen Gradienten des Grundwassers. Es zeigte sich eine signifikante Abh?ngigkeit der Schadstoffgehalte für BTEX maximal |r|=0,89 von einem bis zu ±1,4m schwankenden Grundwasserstand, der sich unterschiedlich auswirkt: bei hohem Grundwasserstand sind die Schadstoffgehalte in Herdn?he verringert, gleichzeitig erfolgt eine Ausdehnung der Fahne in Abstromrichtung. Die hydraulischen Gradienten schwanken zwischen 1,5‰ und 15,1‰. Im herdnahen Bereich ist bei hohem Grundwasserstand eine Gradientenverflachung, im Abstrom eine Gradientenversteilung festzustellen. Die Richtungen der horizontalen hydraulischen Gradienten variieren von 12° bis 67°. Unter Berücksichtigung dieser Abh?ngigkeiten ist eine differenzierte Betrachtung der Felddaten für eine nachfolgende Auswertung hinsichtlich MNA erforderlich. Die hydrogeologische und die hydraulische Erkundung ist eine wichtige Voraussetzung zum Verst?ndnis der hydrochemischen Prozesse bei NA in kontaminierten Grundwasserleitern. Die Ergebnisse zeigen, dass hydraulische und hydrogeologische Aspekte bei den in den USA gebr?uchlichen Protokollen zur Anwendung von NA eine zu geringe Beachtung finden.  相似文献   
96.
The carboxy-terminal domain (CTD) of RNA polymerase II consists of multiple repeats of the unique heptad sequence -(Ser-Pro-Thr-Ser-Pro-Ser-Tyr)- which may interact with DNA through the intercalation of adjacent tyrosine aromatic rings. We have examined details of the interaction of this motif with calf thymus DNA through analysis of peptide analogues that contain (1) an amino-terminal tyrosine which mimics the presence of an adjacent heptad repeat and (2) positively-charged lysine residues which facilitate the initial contact between peptide and DNA. Results of fluorescence experiments, NMR titrations, and viscometric analyses indicate that these peptides bind to the DNA helix through a non-classical intercalation mode involving partial aromatic stacking of the tyrosine rings with the Watson-Crick base pairs.  相似文献   
97.
After all medical and audiological treatments have failed, tinnitus patients often get the advise to "learn to live with it". The aim of psycho-social treatment is assisting patients in the identification of tinnitus aggravating factors and teaching them various coping skills. Treating these problems is primarily recommended for patients suffering from other disorders, even related to tinnitus. Motivation for psycho-social treatment depends on the ability of patients to accept tinnitus as a fundamental fact in their existence.  相似文献   
98.
Electrolyte addition to nonionic contrast media has been suggested to further reduce the incidence of ventricular fibrillation during coronary arteriography. The present study was designed to investigate the effects of adding 30 mM NaCl, 0.9 mM KCl, 0.15 mM CaCl2 and 0.1 mM MgCl2 to iohexol on cardiac electrophysiology and hemodynamics (iohexol+electrolytes = IPE). Contrast media were injected into the left main coronary artery in 9 open-chest, anesthetized dogs before and after induction of acute ischemic heart failure. IPE increased left ventricular inotropy (LV dP/dtmax) with no initial decrease, even during heart failure. During heart failure IPE induced the same hemodynamic effects as iohexol without electrolyte addition. IPE slightly lengthened epicardial monophasic action potential duration before heart failure. We conclude that IPE appears to be well tolerated hemodynamically. The electrophysiologic differences between IPE and iohexol are small when the injection time is not longer than 5 s.  相似文献   
99.
100.
Adult varicella can be a severe illness complicated by pneumonia, encephalitis, or prolonged fever. This study measured levels of tumor necrosis factor (TNF)-alpha, interleukin-2 (IL-2), and interferon gamma (IFN-G) in a consecutive group of 31 adult varicella patients presenting within 24 hours of rash onset. All cytokines were assayed using an ELISA technique. TNF-alpha was detectable in 71% of patients with a mean level of 52 pg/ml. IL-2 was detectable in 29% with a mean level of 1040 pg/ml. IFN-gamma was detectable in only 9%. There was no correlation between TNF, IL-2, or IFN-G level and clinical severity as determined by duration and severity of cutaneous findings, duration of fever, frequency of hepatitis, or thrombocytopenia.  相似文献   
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