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排序方式: 共有237条查询结果,搜索用时 15 毫秒
31.
In high active steroid producing cells of the human corpus luteum we can find in the cytoplasm a well developed smooth endoplasmic reticulum in form of smooth tubules and homogenously spread vesicles resulting from an active metabolic process. We also find specific concertinalike folded membrane complexes which too belong to the endoplasmic reticulum. Numerous mainly tubular mitochondria contain dense lipoid inclusions. Their close conection with the endoplasmic vesicles is expression of a direct interaction of both cell organelles in progesterone production. The transport of the intracellular formed steroid hormones to the capillary takes place via locally enlarged intercellular spaces which communicate with the pericapillary space. On the other hand there are pericellular canaliculi which are coated with a membrane. They have no direct connection to the pericapillar space. 相似文献
32.
The author explores Andie Knutson's plea for a more appropriate term to describe the positive aspects of mental health (see record 1964-01167-001) and suggest the term mental fitness. She provides the definition of fitness and explains that this concept of mental fitness carries much of the connotation we are groping for. It forms an excellent counterpart for the late President Kennedy's program for physical fitness. At the same time, it avoids the unfortunate connotation of illness, and consequent restriction to medical care. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
33.
Aaron J. Marcus Dorothea Zucker-Franklin 《Journal of the American Oil Chemists' Society》1965,42(6):500-504
There is now reasonable agreement on the sequence of physiological and biochemical events leading to fibrin formation, and
phospholipids are an important part of this process. The phosphatides are ordinarily provided by platelets, and it appears
that a lipoprotein complex is responsible for this activity. The anatomic site of this complex is not known, but evidence
is presented that it may be a property of the platelet membrane. Methods for the study of platelet lipids including fatty
acids and aldehydes are described, and include silicic acid column and paper chromatography, as well as thin-layer and gas-liquid
chromatographic procedures. These are also being utilized in studies of subcellular platelet particles, where only limited
amts of biological material are available for study. It is stressed that experimental results obtained from studies on isolated
lipids should be interpreted with a certain degree of caution. It is unlikely that they are available as such in in vivo coagulation,
and the drastic procedures used for their extraction and isolation may alter their basic physiological properties. 相似文献
34.
35.
Dr. Andreas Gollner Dr. Harald Weinstabl Dr. Julian E. Fuchs Dr. Dorothea Rudolph Dr. Geraldine Garavel Karin S. Hofbauer Jale Karolyi-Oezguer Gerhard Gmaschitz Wolfgang Hela Dr. Nina Kerres Elisabeth Grondal Patrick Werni Dr. Juergen Ramharter Dr. Joachim Broeker Dr. Darryl B. McConnell 《ChemMedChem》2019,14(1):88-93
Mouse double minute 2 (MDM2) is a main and direct inhibitor of the crucial tumor suppressor p53. Reports from initial clinical trials showed that blocking this interaction with a small-molecule inhibitor can have great value in the treatment of cancer for patients with p53 wild-type tumors; however, it also revealed dose-limiting hematological toxicities and drug-induced resistance as main issues. To overcome the former, an inhibitor with superior potency and pharmacokinetic properties to ultimately achieve full efficacy with less-frequent dosing schedules is required. Toward this aim, we optimized our recently reported spiro-oxindole inhibitors by focusing on the crucial interaction with the amino acid side chain of His96MDM2. The designed molecules required the targeted synthesis of structurally complex spiro[indole-3,2′-pyrrolo[2,3-c]pyrrole]-2,4′-diones for which we developed an unprecedented intramolecular azomethine ylide cycloaddition and investigated the results by computational methods. One of the new compounds showed superior cellular potency over previously reported BI-0252. This finding is a significant step toward an inhibitor suitable to potentially mitigate hematological on-target adverse effects. 相似文献
36.
Matthias Schulz Frank Balzer Dorothea Scheunemann Oriol Arteaga Arne Lützen Stefan C. J. Meskers Manuela Schiek 《Advanced functional materials》2019,29(16)
A facile route to soft matter self‐powered bulk heterojunction photodiode detectors sensitive to the circular polarization state of light is shown based on the intrinsic excitonic circular dichroism of the photoactive layer blend. As light detecting materials, enantiopure semiconducting small molecular squaraine derivates of opposite handedness are employed. Via Mueller matrix ellipsometry, the circular dichroism is proven to be of H‐type excitonic nature and not originating from mesoscopic structural ordering. Within the green spectral range, the photodiodes convert circular polarized light into a handedness‐dependent photocurrent with a maximum dissymmetry factor of ±0.1 corresponding to 5% overall efficiency for the polarization discrimination under short circuit conditions. On the basis of transfer matrix optical simulations, it is rationalized that the optical dissymmetry fully translates into a photocurrent dissymmetry for ease of device design. Thereby, the photodiode's ability to efficiently distinguish between left and right circularly polarized light without the use of external optical elements and voltage bias is demonstrated. This allows a straightforward and sustainable future design of flexible, lightweight, and compact integrated platforms for chiroptical imaging and sensing. 相似文献
37.
The purpose of this study was to determine the relative inactivation of MS2 coliphage (American Type Culture Collection strain 15597-B1) and heterotrophic plate count bacteria using raw surface water under a variety of naturally occurring conditions. It was found that the applied ozone dose and dissolved organic carbon had the most impact on ozone disinfection of MS2 coliphage and HPC bacteria. The dissolved organic carbon was found to compete for the ozone and significantly reduce the inactivation of both the coliphage and the bacteria. Furthermore, it was observed that the presence of any ozone residual inactivated greater than 4 logs MS2 coliphage and 2 logs heterotrophic plate count bacteria within a 30 second contact time. Ozone residuals greater than 0.20 mg/L inactivated greater than 5 logs MS2 coliphage and 3 logs heterotrophic plate count bacteria also within 30 second contact time. Comparison of inactivation studies indicate that MS2 coliphage is probably more sensitive to ozone than enteric viruses. It was concluded that the regulatory agencies should reevaluate their recommendations for using MS2 coliphage as an ozone disinfection indicator of enteric viruses. 相似文献
38.
Maria Pilarska Dorothea Bartels Ewa Niewiadomska 《International journal of molecular sciences》2021,22(19)
Reactive oxygen species (ROS) signalling is crucial in modulating stress responses in plants, and NADPH oxidases (NOXs) are an important component of signal transduction under salt stress. The goal of this research was to investigate whether the regulation of NOX-dependent signalling during mild and severe salinity differs between the halophyte Eutrema salsugineum and the glycophyte Arabidopsis thaliana. Gene expression analyses showed that salt-induced expression patterns of two NOX genes, RBOHD and RBOHF, varied between the halophyte and the glycophyte. Five days of salinity stimulated the expression of both genes in E. salsugineum leaves, while their expression in A. thaliana decreased. This was not accompanied by changes in the total NOX activity in E. salsugineum, while the activity in A. thaliana was reduced. The expression of the RBOHD and RBOHF genes in E. salsugineum leaves was induced by abscisic acid (ABA) and ethephon spraying. The in silico analyses of promoter sequences of RBOHD and RBOHF revealed multiple cis-acting elements related to hormone responses, and their distribution varied between E. salsugineum and A. thaliana. Our results indicate that, in the halophyte E. salsugineum, the maintenance of the basal activity of NOXs in leaves plays a role during acclimation responses to salt stress. The different expression patterns of the RBOHD and RBOHF genes under salinity in E. salsugineum and A. thaliana point to a modified regulation of these genes in the halophyte, possibly through ABA- and/or ethylene-dependent pathways. 相似文献
39.
Sebastian Wilken Dorothea ScheunemannVerena Wilkens Jürgen ParisiHolger Borchert 《Organic Electronics》2012,13(11):2386-2394
In this study, we report on the improvement of ITO-free inverted polymer/fullerene solar cells by introducing a zinc oxide (ZnO) layer between the active layer and the cathode. The ZnO layers are deposited from solution, using colloidal ZnO nanocrystals with a rodlike shape, which are obtained using a wet-chemical synthesis route at low temperature. The nanocrystals are widely characterized with respect to their structural, optical, and electronic properties. In particular, simulations of powder X-ray diffraction data based on Rietveld refinement are shown to be a suitable method to characterize the average crystallite shape and particle size. Cyclic voltammetry reveals that nanocrystalline ZnO is an appropriate choice as electron-selective buffer layer in organic solar cells based on a bulk heterojunction of poly (3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM). Using ITO-free inverted solar cells in substrate configuration with an opaque Cr/Al/Cr bottom electrode, we demonstrate that introducing a cathodic interlayer of ZnO nanocrystals leads to a notable enhancement in photovoltaic performance. The magnitude of the effect is found to depend on the solvents used to process the active layer. In case of absorber blends processed from o-dichlorobenzene, we show an almost threefold increase in efficiency from 0.8 to 2.2% at an active area of 1 cm2. 相似文献
40.
The use of microwave irradiation for the easy synthesis of graphene-supported transition metal nanoparticles in ionic liquids 总被引:1,自引:0,他引:1
Dorothea Marquardt Christian Vollmer Ralf Thomann Peter Steurer Rolf Mülhaupt Engelbert Redel Christoph Janiak 《Carbon》2011,(4):1326-1332
Stable ruthenium or rhodium metal nanoparticles were supported on chemically derived graphene (CDG) surfaces with small and uniform particle sizes (Ru 2.2 ± 0.4 nm and Rh 2.8 ± 0.5 nm) by decomposition of their metal carbonyl precursors by rapid microwave irradiation in a suspension of CDG in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate. The graphene-supported hybrid nanoparticles were shown to be active and could be re-used at least 10 times as catalysts for the hydrogenation of cyclohexene and benzene under organic-solvent-free conditions with constant activities up to 1570 mol cyclohexane × (mol metal)−1 × h−1 at 4 bar and 75 °C. 相似文献