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141.
Yingyongnarongkul BE How SE Díaz-Mochón JJ Muzerelle M Bradley M 《Combinatorial chemistry & high throughput screening》2003,6(7):577-587
Advances in high throughput screening (HTS), together with the rapid progress in combinatorial chemistry, genomic and proteomic sciences have dramatically stimulated the development of a variety tools to enable the drug discovery process to become more efficient. Major future challenges in HTS include obtaining high density and good quality data based on assays that are rapid, reliable, inexpensive, sensitive, simple and miniaturised. This paper reviews the development and role of bead-based assays for HTS including DNA and single nucleotide polymorphism (SNP) assays, particularly from a multiplex perspective and evaluating the recent advances in bead-based arrays. The encoding strategies that are commonly used in bead-based assays are highlighted, while the importance of magnetic beads in genomic and proteomic purifications is discussed. In conclusion, bead-based assays offer a powerful promising approach for many aspects of drug discovery. 相似文献
142.
A method is described for neutron activation analysis of thorium by employing thorium-233. Decontamination steps include anion exchange in 12.5 N HCL, precipitation of fluoride, extraction with mesityl oxide and thorium oxalate precipitation. The time spent is less than 1 h; spurious activities in counting samples amount only to 2% and can easily be corrected for. The sensitivity of the method is ca. 0.02 μg of thorium in a neutron flux of 1012n/cm2/sec with an irradiation time of 5 min. 相似文献
143.
Dr. A. Woppmann 《Monatshefte für Chemie / Chemical Monthly》1974,105(2):419-426
The kinetics of the diazotization of o-, m-, p-chloroaniline in 0.005n- to 0.4n-methanolic HCl-solution at 25, 15, 0, ?10 ?20, and ?30°C was invertigated. It was found that the nitrosation reaction (the same as in1) $$C_6 H_4 ClNH_2 + NOCl \mathop \rightleftharpoons \limits^k C_6 H_4 ClNH_2 NO^ + + Cl^ - $$ is a proceeding advance-back-reaction. The decomposition of C6H4ClNH2NO+ by splitting off a proton is the rate determining step. The free activation enthalpies ΔG * for the nitrosation reaction, the activation entropies ΔS *, the activation enthalpies ΔH * and the activation energiesE a at the given temperatures are calculated. The experimentally found and the calculated velocities are given in Tables 1–6. The equilibrium constants of the o-, m-, p-chloroanilinium ions, and nitrosyl-chloride in methanol are indicated in Table 7, diagram 1. TheK M values (the ionic products of methanol, extrapolated at infinite dilution) together with theK A values of Table 7 give theK B values (p. 2) using the table10. The ΔG B values can be calculated using equation ΔG B = ?RTlnK B Fig 2 shows the linear dependance of the logarithmus of the ΔG * values from the logarithmus of theK B values. 相似文献
144.
The model of Onsager in which a polar molecule undergoes a reaction field due to the polarization of the molecular surroundings is used to evaluate by a S.C.F. calculation (CNDO/2 approximation) the modifications of a molecular structure in the liquid state.Application to water molecule and to three polar dimers for values of the dielectric constant varying between 3 and 78, shows that most of geometric parameters and dipoles moments vary of few per cent when the molecule is inserted in a liquid. In the liquid state dipole moments do not depend very much on the dielectric constant but energies and relative stabilities of isomers are strongly dependent on the medium.[/p] 相似文献
145.
Dr. Marita Fell 《Colloid and polymer science》1967,220(2):107-110
Zusammenfassung Aus einem durch Trypsinabbau von -Keratose erhaltenen Gemisch von Peptiden wurden 15 neutrale, 5 saure und 2 basische Peptide durch Kombination papierchromatographischer und papierelektrophoretischer Methoden getrennt und in sehr geringen Mengen isoliert. Es wurden neben der Aminosäurezusammensetzung 14N-terminale Aminosäuren sowie einige Teilsequenzen in den untersuchten Peptiden ermittelt.Die mittlere Kettenlänge der Peptide beträgt 5,8 Aminosäuren.Mit 1 Tabelle3. Mitt. über Untersuchungen an -Keratose. 2. Mitt.:M. Fell undE. Schnabel, Hoppe-Seyler's Z. physiol. Chem.333, 218 (1963). 相似文献
146.
Dr. R. Franzmair 《Monatshefte für Chemie / Chemical Monthly》1976,107(2):511-520
The reaction of 5-oxo-A-nor-3,5-secocholestan-3-oic acid (1) with simple N-mono and N,N-disubstituted hydrazines including acetylhydrazide was studied. Derivatives of 4-amino-4-aza-cholest-5-ene-3-one (2) were obtained.
Herrn Prof. Dr.H. Bretschneider mit den besten Wünschen zum 70. Geburtstag gewidmet. 相似文献
Herrn Prof. Dr.H. Bretschneider mit den besten Wünschen zum 70. Geburtstag gewidmet. 相似文献
147.
Zusammenfassung Die durch Umsetzung von 5-Methyltryptamin, 5-Äthoxytryptamin und 5-Methylmercapto-tryptamin (I, R=CH3, OC2H5 bzw. SCH3) mit dem racemischen Aldehyd-Ester II entstandenenSchiffschen Basen wurden durch Natriumborhydrid-Reduktion in Methanol unter gleichzeitiger Cyclisierung und Desacetylierung in die entsprechenden 10-substituiertendl-Methyl-2,3-seco-3-oxodeserpidate (IV) übergeführt. Die bei der Einwirkung von 3,4,5-Trimethoxybenzoylchlorid in Pyridin erhaltenen Ester V wurden weiter mit Phosphoroxychlorid cyclisiert und die Produkte als Perchlorate (VI) mit Zink in sauerer Lösung zu den entsprechenden 10-substituiertendl-Deserpidinen (VII, R=CH3, OC2H5 bzw. SCH3) reduziert. Mit Hilfe der Chromatographie gelang es in zwei Fällen, aus den Rohprodukten auch die entsprechendendl-3-Isodeserpidine (VIII, R=CH3 bzw. OC2H5) zu isolieren. Zum Unterscheiden der Produkte der normalen Reihe (VII) und der 3-Iso-Reihe (VIII) wurden IR-Spektren und die Papierchromatographie angewendet.Mit 2 Abbildungen 相似文献
148.
López-García I Merino Meroño B Campillo N Hernández-Córdoba M 《Analytical and bioanalytical chemistry》2002,373(1-2):98-102
Two manifolds were assessed for the purpose of determining both the total chromium content and that present as a soluble form in industrial effluents by flow injection flame atomic absorption spectrometry (FI-FAAS). To determine the chromium content in the soluble fraction the samples were used without additional treatment, a 0.45 microm filter being included in the FI system. To determine the total chromium content, the samples were acidified with nitric acid 20% (v/v) and heated for 30 s in a microwave oven (temperatures of about 70 degrees C were reached). The problem posed by the very different concentration range in which total and soluble chromium are present was overcome by using programmed flow rate methodology and by only partially emptying the sample loop. A personal computer controlled both the rotation speed of a peristaltic pump and the volume of sample injected into the system, thus obtaining the dispersion degree required. Using the manifold proposed, the chromium content in the soluble fraction can be determined in the 0.5-20 microg mL(-1) range using a 10 microg mL(-1) single standard for calibration. To determine the total chromium content, a calibration line in the 20-200 microg mL(-1) range was obtained using a single 50 microg mL(-1) chromium standard solution. The reliability of the semi-automatic devices was verified by comparing the results obtained with those found by treating the samples and using both FAAS in a conventional way and a spectrophotometric method using diphenylcarbazide at the 95% confidence level (ANOVA test). The proposed procedures showed a RSD lower than +/-3%. 相似文献
149.
R. González-Ramírez H. Jiménez-Domínguez O. Solorza-Feria E. Ordóñez-Regil A. Cabral-Prieto S. Bulbulian 《Journal of Radioanalytical and Nuclear Chemistry》1993,174(2):291-298
Conditions for the electrodeposition of59Co and57Co on stainless steel foils have been studied. A set of electrolytic parameters has been determined to get a reasonably good electrodeposited sample. The57Co electrodeposited foil was then introduced in a quartz tube to be annealed in an argon flow. The final product was a 11 Ci Mössbauer source for college experiments which was succesfully tested by obtaining spectra of stainless steel and sodium nitroprusside. 相似文献
150.
M. Pospíšil 《Journal of Thermal Analysis and Calorimetry》1984,29(1):49-59
The reduction of mixed oxides NiO-CeO2 of various composition with hydrogen was studied at 290–470° by means of thermogravimetry. Some physicochemical properties of the system were also investigated and compared with earlier studied analogous samples of different “origin”. The degree of mutual interaction of the two components, the reduction kinetics and the sensitivity to the different sorts of radiation (gamma-rays, fast neutrons and electrons), applied in different doses, are strongly affected by the “pre-history” and by the composition in both compared series of mixed oxides. 相似文献