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排序方式: 共有170条查询结果,搜索用时 31 毫秒
131.
Carolina J. Jorgez Jill A. Rosenfeld Nathan R. Wilken Hima V. Vangapandu Aysegul Sahin Dung Pham Claudia M. B. Carvalho Anne Bandholz Amanda Miller David D. Weaver Barbara Burton Deepti Babu John S. Bamforth Timothy Wilks Daniel P. Flynn Elizabeth Roeder Ankita Patel Sau W. Cheung James R. Lupski Dolores J. Lamb 《PloS one》2014,9(9)
132.
Kim Guan Saw Sau Siong Tneh Gaik Leng Tan Fong Kwong Yam Sha Shiong Ng Zainuriah Hassan 《PloS one》2014,9(1)
The current-voltage characteristics of Ni contacts with the surfaces of ZnO thin films as well as single crystal (0001) ZnO substrate are investigated. The ZnO thin film shows a conversion from Ohmic to rectifying behavior when annealed at 800°C. Similar findings are also found on the Zn-polar surface of (0001) ZnO. The O-polar surface, however, only shows Ohmic behavior before and after annealing. The rectifying behavior observed on the Zn-polar and ZnO thin film surfaces is associated with the formation of nickel zinc oxide (Ni1-xZnxO, where x = 0.1, 0.2). The current-voltage characteristics suggest that a p-n junction is formed by Ni1-xZnxO (which is believed to be p-type) and ZnO (which is intrinsically n-type). The rectifying behavior for the ZnO thin film as a result of annealing suggests that its surface is Zn-terminated. Current-voltage measurements could possibly be used to determine the surface polarity of ZnO thin films. 相似文献
133.
Roberto Depasquale Sau L. Lee Bhawana Saluja Jagdeep Shur Robert Price 《AAPS PharmSciTech》2015,16(3):589-600
This study investigated the structural relaxation of micronized fluticasone propionate (FP) under different lagering conditions and its influence on aerodynamic particle size distribution (APSD) of binary and tertiary carrier-based dry powder inhaler (DPI) formulations. Micronized FP was lagered under low humidity (LH 25 C, 33% RH [relative humidity]), high humidity (HH 25°C, 75% RH) for 30, 60, and 90 days, respectively, and high temperature (HT 60°C, 44% RH) for 14 days. Physicochemical, surface interfacial properties via cohesive-adhesive balance (CAB) measurements and amorphous disorder levels of the FP samples were characterized. Particle size, surface area, and rugosity suggested minimal morphological changes of the lagered FP samples, with the exception of the 90-day HH (HH90) sample. HH90 FP samples appeared to undergo surface reconstruction with a reduction in surface rugosity. LH and HH lagering reduced the levels of amorphous content over 90-day exposure, which influenced the CAB measurements with lactose monohydrate and salmeterol xinafoate (SX). CAB analysis suggested that LH and HH lagering led to different interfacial interactions with lactose monohydrate but an increasing adhesive affinity with SX. HT lagering led to no detectable levels of the amorphous disorder, resulting in an increase in the adhesive interaction with lactose monohydrate. APSD analysis suggested that the fine particle mass of FP and SX was affected by the lagering of the FP. In conclusion, environmental conditions during the lagering of FP may have a profound effect on physicochemical and interfacial properties as well as product performance of binary and tertiary carrier-based DPI formulations.
Electronic supplementary material
The online version of this article (doi:10.1208/s12249-014-0222-8) contains supplementary material, which is available to authorized users.KEY WORDS: cohesive-adhesive balance, laagering, mechanical activation, particle adhesion, process-induced structural disorder 相似文献134.
Linterman MA Pierson W Lee SK Kallies A Kawamoto S Rayner TF Srivastava M Divekar DP Beaton L Hogan JJ Fagarasan S Liston A Smith KG Vinuesa CG 《Nature medicine》2011,17(8):975-982
Follicular helper (T(FH)) cells provide crucial signals to germinal center B cells undergoing somatic hypermutation and selection that results in affinity maturation. Tight control of T(FH) numbers maintains self tolerance. We describe a population of Foxp3(+)Blimp-1(+)CD4(+) T cells constituting 10-25% of the CXCR5(high)PD-1(high)CD4(+) T cells found in the germinal center after immunization with protein antigens. These follicular regulatory T (T(FR)) cells share phenotypic characteristics with T(FH) and conventional Foxp3(+) regulatory T (T(reg)) cells yet are distinct from both. Similar to T(FH) cells, T(FR) cell development depends on Bcl-6, SLAM-associated protein (SAP), CD28 and B cells; however, T(FR) cells originate from thymic-derived Foxp3(+) precursors, not naive or T(FH) cells. T(FR) cells are suppressive in vitro and limit T(FH) cell and germinal center B cell numbers in vivo. In the absence of T(FR) cells, an outgrowth of non-antigen-specific B cells in germinal centers leads to fewer antigen-specific cells. Thus, the T(FH) differentiation pathway is co-opted by T(reg) cells to control the germinal center response. 相似文献
135.
136.
Triplex forming oligonucleotides (TFOs) are the most commonly used approach for site-specific targeting of double stranded DNA (dsDNA). Important parameters describing triplex formation include equilibrium binding constants (K(eq)) and association/dissociation rate constants (k(on) and k(off)). The 'fluorescent intercalator displacement replacement' (FIDR) assay is introduced herein as an operationally simple approach toward determination of these parameters for triplexes involving TC-motif TFOs. Briefly described, relative rate constants are determined from fluorescence intensity changes upon: (i) TFO-mediated displacement of pre-intercalated and fluorescent ethidium from dsDNA targets (triplex association) and (ii) Watson-Crick complement-mediated displacement of the TFO and replacement with ethidium (triplex dissociation). The assay is used to characterize triplexes between purine-rich dsDNA targets and TC-motif TFOs modified with six different locked nucleic acid (LNA) monomers, i.e. conventional and C5-alkynyl-functionalized LNA and α-L-LNA pyrimidine monomers. All of the studied monomers increase triplex stability by decreasing the triplex dissociation rate. LNA-modified TFOs form more stable triplexes than α-L-LNA-modified counterparts owing to slower triplex dissociation. Triplexes modified with C5-(3-aminopropyn-1-yl)-LNA-U monomer Z are particularly stable. The study demonstrates that three affinity-enhancing features can be combined into one high-affinity TFO monomer: conformational restriction of the sugar ring, expansion of the pyrimidine π-stacking surface and introduction of an exocyclic amine. 相似文献
137.
138.
Dolezal P Aili M Tong J Jiang JH Marobbio CM Marobbio CM Lee SF Schuelein R Belluzzo S Binova E Mousnier A Frankel G Giannuzzi G Palmieri F Gabriel K Naderer T Hartland EL Lithgow T 《PLoS pathogens》2012,8(1):e1002459
The Mitochondrial Carrier Family (MCF) is a signature group of integral membrane proteins that transport metabolites across the mitochondrial inner membrane in eukaryotes. MCF proteins are characterized by six transmembrane segments that assemble to form a highly-selective channel for metabolite transport. We discovered a novel MCF member, termed Legionellanucleotide carrier Protein (LncP), encoded in the genome of Legionella pneumophila, the causative agent of Legionnaire's disease. LncP was secreted via the bacterial Dot/Icm type IV secretion system into macrophages and assembled in the mitochondrial inner membrane. In a yeast cellular system, LncP induced a dominant-negative phenotype that was rescued by deleting an endogenous ATP carrier. Substrate transport studies on purified LncP reconstituted in liposomes revealed that it catalyzes unidirectional transport and exchange of ATP transport across membranes, thereby supporting a role for LncP as an ATP transporter. A hidden Markov model revealed further MCF proteins in the intracellular pathogens, Legionella longbeachae and Neorickettsia sennetsu, thereby challenging the notion that MCF proteins exist exclusively in eukaryotic organisms. 相似文献
139.
140.
Swagata Chatterjee Gopi Ballav Sau Samir Kumar Mukherjee 《World journal of microbiology & biotechnology》2009,25(10):1829-1836
This article reports on the isolation and characterization of a Cr(VI) resistant bacterial strain, having plant growth promoting
properties to improve general growth of plant in chromium-contaminated soil through rhizosphere colonization. The strain was
isolated from the sludge of waste canal carrying industrial effluents. The minimum inhibitory concentration of chromium to
this strain was found to be 450 and 400 mM in complex and minimal media, respectively. The strain also showed varied degree
of resistance to Cd, Co, As, Ni and Zn. It exhibited potential Cr(VI) reducing ability under aerobic culture conditions, and
the factors affecting Cr(VI) reduction by this strain were evaluated. The optimum pH and temperature required to achieve maximum
Cr(VI) reduction values were 7 and 35°C, respectively. Higher concentration of Cr(VI) slowed down the reduction, but with
longer incubation time it reduced nearly all detectable amount of Cr(VI). The strain showed positive response to IAA production
and phosphate solubilization. It promoted the growth of chilli plants in waste-fed soil with or without additional Cr through
its establishment in rhizosphere. The successful establishment of KUCr3 in the rhizosphere of chilli plants helped to reduce
Cr uptake by the test plant. This strain shows a promise that the multifarious role of this strain would be useful in the
Cr-contaminated rhizosphere soil as a good bioremediation and plant growth promoting agent as well. Through biochemical characterization
and 16S rDNA sequence analysis, the strain KUCr3, as the name given to it, was identified as a strain of Cellulosimicrobium cellulans. 相似文献