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排序方式: 共有946条查询结果,搜索用时 15 毫秒
61.
PH Ingram GA Bruns VM Regina RE Eisenman PS Gerald 《Canadian Metallurgical Quarterly》1977,15(5-6):455-476
Two types of alpha-D-mannosidase isozymes are present in human white blood cells, human diploid fibroblasts, and HeLa cells. One of these (the S isozyme) constitutes the major alpha-D-mannosidase of the human cells, has a pH optimum of 4.4, and is associated with lysosomes. The other (the F isozyme) is most active at pH 6, is acid labile, and is located in the soluble portion of the cytoplasm. The expression of human lysosomal alpha-D-mannosidase was examined in man-hamster hybrid clones, and was found to be concordant with that of phosphohexose isomerase in 54 of 55 primary clones. A locus specifying human lysosomal alpha-D-mannosidase has therfore been assigned to chromosome 19. 相似文献
62.
Tested the relation between mood (depressed [D], elated [E], or neutral [N]), induced by the Velten (1968) procedure, and college students' responses on a subjectively scored life events questionnaire and measures of perceived and received social support. A manipulation check showed that the mood manipulation was successful. There was a significant mood effect on the number of self-reported negative life events, with E Ss reporting the fewest. However, mood had no significant effect on the number of self-reported positive life events or the rated intensity of negative and positive events. Mood had a significant effect on perceived social support, with D Ss scoring the lowest. Self-report of received social support, however, was not affected by the mood manipulation. The findings challenge the widespread use of life event and perceived social support questionnaires whose independence from a mood-related response bias has not been adequately demonstrated. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
63.
Absorption properties of anisotropic poly(vinyl alcohol) (PVA) films in u.v., Vis, and i.r. spectral regions were investigated. The orientation of the transition moments with respect to the long axis of the chain was determined together with the arrangement of PVA chain. Anisotropic PVA matrices should be considered in terms of binary solvents since together with crystallites, there are regions of amorphous structure. 相似文献
64.
Regina Berg Johannes Straub Ella Schreiner Steffen Mader Frank Rominger Bernd F. Straub 《Advanced Synthesis \u0026amp; Catalysis》2012,354(18):3445-3450
The main feature of the herein presented class of molecularly defined catalysts for the copper‐catalyzed azide–alkyne cycloaddition reaction is the presence of two copper centres in one catalyst molecule. We report the facile three‐step synthesis of two representative bis‐NHC‐dicopper complexes as well as their catalytic performance in the azide–alkyne cycloaddition. A screening with one of these complexes has proved its wide applicability and excellent performance as homogeneous catalyst in various organic solvents and with different alkyne and azide substrates. 相似文献
65.
66.
Maria Regina B. Franco Delia B. Rodriguez-Amaya 《Journal of the science of food and agriculture》1983,34(3):293-299
The trapping technique of Singleton and Pattee, in which the volatiles are swept to a Porapak Q trap by suction rather than by a sweeping gas, was modified and used to isolate soursop juice volatiles. Using fixed, low vacuum and operating conditions determined specifically for soursop volatiles, very high reproducibility was obtained. The majority of the peaks had a coefficient of variation less than 0.10. The relative amounts of the volatile components obtained by direct headspace sampling was fairly well maintained in the Porapak Q concentrate. The chromatograms showed distinct differences between two commercial brands or between lots of the same brand of soursop juice. The trapping technique appear to have wide applicability provided that the operating conditions are adapted to each product studied. 相似文献
67.
Avalanche‐Discharge‐Induced Electrical Forming in Tantalum Oxide‐Based Metal–Insulator–Metal Structures 下载免费PDF全文
Katharina Skaja Christoph Bäumer Oliver Peters Stephan Menzel Marco Moors Hongchu Du Manuel Bornhöfft Christoph Schmitz Vitaliy Feyer Chun‐Lin Jia Claus Michael Schneider Joachim Mayer Rainer Waser Regina Dittmann 《Advanced functional materials》2015,25(46):7154-7162
Oxide‐based metal–insulator–metal structures are of special interest for future resistive random‐access memories. In such cells, redox processes on the nanoscale occur during resistive switching, which are initiated by the reversible movement of native donors, such as oxygen vacancies. The formation of these filaments is mainly attributed to an enhanced oxygen diffusion due to Joule heating in an electric field or due to electrical breakdown. Here, the development of a dendrite‐like structure, which is induced by an avalanche discharge between the top electrode and the Ta2O5‐x layer, is presented, which occurs instead of a local breakdown between top and bottom electrode. The dendrite‐like structure evolves primarily at structures with a pronounced interface adsorbate layer. Furthermore, local conductive atomic force microscopy reveals that the entire dendrite region becomes conductive. Via spectromicroscopy it is demonstrated that the subsequent switching is caused by a valence change between Ta4+ and Ta5+, which takes place over the entire former Pt/Ta2O5‐x interface of the dendrite‐like structure. 相似文献
68.
Alfredo M. Gravagnuolo Eden Morales‐Narváez Charlene Regina Santos Matos Sara Longobardi Paola Giardina Arben Merkoçi 《Advanced functional materials》2015,25(38):6084-6092
Class I hydrophobin Vmh2, a peculiar surface active and versatile fungal protein, is known to self‐assemble into chemically stable amphiphilic films, to be able to change wettability of surfaces, and to strongly adsorb other proteins. Herein, a fast, highly homogeneous and efficient glass functionalization by spontaneous self‐assembling of Vmh2 at liquid–solid interfaces is achieved (in 2 min). The Vmh2‐coated glass slides are proven to immobilize not only proteins but also nanomaterials such as graphene oxide (GO) and quantum dots (QDs). As models, bovine serum albumin labeled with Alexa 555 fluorophore, anti‐immunoglobulin G antibodies, and cadmium telluride QDs are patterned in a microarray fashion in order to demonstrate functionality, reproducibility, and versatility of the proposed substrate. Additionally, a GO layer is effectively and homogeneously self‐assembled onto the studied functionalized surface. This approach offers a quick and simple alternative to immobilize nanomaterials and proteins, which is appealing for new bioanalytical and nanobioenabled applications. 相似文献
69.
Gerhard Heise Andreas Brner Marcel Dickmann Marina Englmaier Andreas Heiss Matthias Kemnitzer Jan Konrad Regina Moser Jrg Palm Helmut Vogt Heinz P. Huber 《Progress in Photovoltaics: Research and Applications》2015,23(10):1291-1304
In this paper, we present the selective structuring of all three patterns (P1, P2 and P3) of a monolithic interconnection of CIS (Cu(In,Ga)(S,Se)2) thin film solar cells by picosecond laser pulses at a wavelength of 1064 nm. We show results for single pulse ablation threshold values and line scribing of molybdenum films on glass (P1), CIS on molybdenum (P2) and zinc oxide on CIS (P3). The purposes of these processes are the p‐type isolation (P1), cell interconnect (P2) and n‐type isolation (P3), which are required for complete cell architecture. The half micron thick molybdenum back electrode can be structured with a process speed of more than 15 m/s at about 15 W average power without detectable residues and damage by direct induced laser ablation from the back side (P1). The CIS layer can be structured selectively down to the molybdenum at process speeds up to 1 m/s at about 15 W average power, due to the precision of direct laser ablation in the ultrashort pulse regime (P2). The ZnO front electrode layer is separated by clean trenches with straight side walls at process speeds of up to 15 m/s at about 10 W average power, as a result of indirect induced laser ablation (P3). A validation of functionality of all processes is demonstrated on CIS solar cell modules (30 × 30 cm2). By replacing one state‐of‐the‐art process by a picosecond laser process at a time, solar efficiencies could be increased for P1 and P2 and stayed on a similar level for P3. After an optimization of the patterning processes in the R&D pilot line of AVANCIS, we achieved a new record efficiency for an all‐laser‐patterned CIS solar module: 14.7% as best value for the aperture area efficiency of a 30 × 30 cm2 sized CIS module was reached. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
70.
Wieslaw J. Bochenek Peter Weber Regina Slowinska Gexin Tang John B. Rodgers 《Lipids》1990,25(10):665-668
Monosaccharide composition was determined in apolipoprotein B-48 (apoB) of chylomicrons of rat mesenteric lymph. Chylomicrons
were separated into three fractions based on density. Triglyceride and apolipoprotein content were determined in each. ApoB
was isolated and quantified using precipitation with isopropanol. Chylomicrons were collected in lymph under normal conditions,
and with Poloxalene 2930 when chylomicron secretion was inhibited. Most of the triglyceride was carried in the least dense
fraction, while the highest apoB content was in the most dense fraction under normal conditions. Mannose and galactosamine
contents of apoB were similar in all fractions while contents of both glucosamine and galactose were highest in the least
dense fraction. When chylomicron secretion was inhibited by Poloxalene, the amount of triglyceride recovered in the least
dense fraction was significantly reduced. Despite the inhibition of lipid transport in the least dense fraction of chylomicrons
by Poloxalene, there was little change in apoB recoveries and in the relative content of various monosaccharides in the apoB
from each of the three fractions as compared to results obtained during lipid absorption under normal conditions. In conclusion,
carbohydrate composition of apoB of chylomicrons is heterogeneous and varies with chylomicron density. 相似文献