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981.
982.
We present a centrifugal process for the extraction of plasma from sediment by a decanting structure, terminating with metered plasma which is readily available for subsequent on-disk processing. Our technique supplies 2 microl plasma from 5 microl of whole blood at moderate spinning frequencies of 40 Hz within 20 s, only. The residual cell concentration in the purified plasma amounts to less than 0.11%, independent of the frequency of rotation. A capillary duct connects the extracted plasma to subsequent on-disk processing units. 相似文献
983.
The efficiency of the photoinduced radical addition of tertiary amines to olefinic double bonds is significantly enhanced and the stereoselectivity is influenced when thiocarbonyl compounds are added to the reaction mixture. 相似文献
984.
Wackerbarth H Larsen FB Hansen AG McKenzie CJ Ulstrup J 《Dalton transactions (Cambridge, England : 2003)》2006,(28):3438-3444
Densely packed Self-Assembled Monolayers (SAMs) of a peroxide-bridged dicobalt complex, [Co2(O2)(bpbp)(O2CCH2CH2S)]2+, 3, (bpbp- = 2,6-bis((N,N-bis-(2-picolyl)amino)-methyl)-4-tert-butylphenolato) have been prepared on atomically planar Au(111) surfaces. Surface voltammetric and interfacial capacitance data, along with electrochemical scanning tunnelling microscopy (in situ STM) imaging, support the formation of a densely packed adlayer of 3 attached via a gold-thiolate bond. In solution, the disulfide linked precursor for 3 reversibly binds dioxygen with high affinity. Electrochemical measurements show that the redox potential of the O22-/O2*- couple of the monolayer of 3 is cathodically shifted by nearly 500 mV compared to the precursor in solution. This is attributed to the close proximity of the O2 binding site to the gold surface. Since the redox potential of the O22-/O2*- couple reflects tentatively the binding affinity of O2 to the deoxygenated CoII2 binding site, the potential of the O22-/O2*- couple of the SAM of 3 suggests a much higher affinity towards O2 compared to the solution precursor. 相似文献
985.
Hunger J Beta IA Böhlig H Ling C Jobic H Hunger B 《The journal of physical chemistry. B》2006,110(1):342-353
Diffuse reflectance infrared Fourier transform spectroscopic (DRIFTS) measurements (4000-1500 cm(-1)) and the results of neutron powder diffraction have been combined to study the structure of adsorption complexes of water in a NaX zeolite at different water loadings (25, 48, 72, and 120 water molecules per unit cell, respectively). Sharp bands corresponding to non-hydrogen-bonded OH groups of water molecules and broad associate bands due to hydrogen-bonded molecules are observed in the DRIFT spectra. We observe a remarkable downshift of the high-frequency associate band in a narrow temperature interval when the water amount decreases from 120 to 72 molecules per unit cell, which could signify some kind of "phase transition" for the water inside the zeolite cavities. Neutron powder diffraction results show that water molecules are predominantly localized in or near the 12-ring windows. Water molecules with hydrogen-bonded and non-hydrogen-bonded OH groups were found, in agreement with the observation of sharp and broad bands in the DRIFT spectra. We find strong evidence for the formation of cyclic hexamers of water molecules localized in the 12-ring windows, which are further stabilized by hydrogen bonds to framework oxygen atoms. 相似文献
986.
987.
988.
The 2-nitrophenylhydrazones 2 of D-arabino-2-hexulopyranosonic acid, D-arabinose, D-galactose and D-galacturonic acid are used as precursors to form chiral functionalized 1,2,4-benzotriazines and benzimidazoles by reductive cyclization methods. Catalytic hydrogenation provided the amine derivatives which are cyclized and air oxidized in alkaline solution to yield the novel 1,2,4-benzotriazines 3 as the main products, while on acid catalysis the benzimidazoles 4 are formed. 相似文献
989.
Cover Picture: Crystal Engineering with the New Linker Tolanedisulfonic Acid (H2TDS): Helical Chains in Zn(TDS)(DMA)3, Linear Chains in Zn(TDS)(NMP)3, and Complex Anions in [HDMA]2[Zn(TDS)2(DMA)3](DMA)2 (Chem. Asian J. 6/2015) 下载免费PDF全文
990.