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401.
Background
The native extracellular matrix (ECM) consists of a highly complex, tissue-specific network of proteins and polysaccharides, which help regulate many cellular functions. Despite the complex nature of the ECM, in vitro cell-based studies traditionally assess cell behavior on single ECM component substrates, which do not adequately mimic the in vivo extracellular milieu.Methodology/Principal Findings
We present a simple approach for developing naturally derived ECM coatings for cell culture that provide important tissue-specific cues unlike traditional cell culture coatings, thereby enabling the maturation of committed C2C12 skeletal myoblast progenitors and human embryonic stem cells differentiated into cardiomyocytes. Here we show that natural muscle-specific coatings can (i) be derived from decellularized, solubilized adult porcine muscle, (ii) contain a complex mixture of ECM components including polysaccharides, (iii) adsorb onto tissue culture plastic and (iv) promote cell maturation of committed muscle progenitor and stem cells.Conclusions
This versatile method can create tissue-specific ECM coatings, which offer a promising platform for cell culture to more closely mimic the mature in vivo ECM microenvironment. 相似文献402.
Gleb Slobodin Mohammad Sheikh Ahmad Itzhak Rosner Michael Rozenbaum Elias Toubi 《Cellular immunology》2010,261(2):77-80
Background
The role and function of T regulatory (Treg) cells have not been fully investigated in patients with systemic sclerosis (SSc).Methods
Ten patients with SSc donated 20 ml of peripheral blood. Activity (Valentini) and severity (Medsger) scores for SSc were calculated for all patients. Healthy volunteers (controls) were matched to each patient by gender and age. CD4+ cells were separated using the MACS system. The numbers of Treg cells were estimated by flow cytometry after staining for CD4, CD25, and FoxP3 and calculated as patient-to-control ratio separately for each experiment. Correlations with activity and severity indices of the disease were performed. Twenty-four-hour production of TGF-β and IL-10 by activated CD4+ cells was measured by ELISA in culture supernatants.Results
The numbers of Treg cells, expressed as patient-to-control ratio, correlated significantly with both activity and severity indices (r = 0.71, p = 0.034 and r = 0.67, p = 0.044, respectively). ELISA-measured production of TGF-β and IL-10 by CD4+ cells was similar in patients and controls.Conclusions
Increased numbers of Treg cells are present in patients with SSc, correlating with activity and severity of the disease. This expansion of Treg cells was not accompanied, however, by heightened TGF-β or IL-10 production. Further studies to elaborate the causes and functional significance of Treg cell expansion in SSc are needed. 相似文献403.
Lu SY Sheikh F Sheppard PC Fresnoza A Duckworth ML Detillieux KA Cattini PA 《Biochemical and biophysical research communications》2008,373(2):270-274
Fibroblast growth factor 16 (FGF-16) expression has previously been detected in mouse heart at mid-gestation in the endocardium and epicardium, suggesting a role in embryonic heart development. More specifically, exogenously applied FGF-16 has been shown to stimulate growth of embryonic myocardial cells in tissue explants. We have generated mice lacking FGF-16 by targeting the Fgf16 locus on the X chromosome. Elimination of Fgf16 expression resulted in embryonic death as early as day 11.5 (E11.5). External abnormalities, including hemorrhage in the heart and ventral body region as well as facial defects, began to appear in null embryos from E11.5. Morphological analysis of FGF-16 null hearts revealed cardiac defects including chamber dilation, thinning of the atrial and ventricular walls, and poor trabeculation, which were visible at E10.5 and more pronounced at E11.5. These findings indicate FGF-16 is required for embryonic heart development in mid-gestation through its positive effect on myocardial growth. 相似文献
404.
Kinetic analysis of the MAPK and PI3K/Akt signaling pathways 总被引:1,自引:0,他引:1
Computational modeling of signal transduction is currently attracting much attention as it can promote the understanding of complex signal transduction mechanisms. Although several mathematical models have been used to examine signaling pathways, little attention has been given to crosstalk mechanisms. In this study, an attempt was made to develop a computational model for the pathways involving growth-factor-mediated mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3'-kinase/protein kinase B (PI3K/Akt). In addition, the dynamics of the protein activities were analyzed based on a set of kinetic data. The simulation approach integrates the information on several levels and predicts systems behavior. The in-silico analysis conducted revealed that the Raf and Akt pathways act independently. 相似文献
405.
Effect of radiation on gene expression of rat liver chemokines: in vivo and in vitro studies 总被引:1,自引:0,他引:1
Moriconi F Christiansen H Raddatz D Dudas J Hermann RM Rave-Fränk M Sheikh N Saile B Hess CF Ramadori G 《Radiation research》2008,169(2):162-169
The aim of the study was to analyze the effect of a single irradiation on chemokine gene expression in the rat liver and in isolated rat hepatocytes. RNA extracted from livers and from hepatocytes within the first 48 h after irradiation was analyzed by real-time PCR and the Northern blot assay. The chemokine concentrations in the serum of irradiated rats were measured quantitatively by ELISA. A significant radiation-induced increase of CINC1, IP10, MCP1, MIP3alpha, MIP3beta, MIG and ITAC gene expression could be detected at the RNA level in the liver. CINC1, MCP1 and IP10 serum levels were significantly increased. In rat hepatocytes in vitro, only MIP3alpha showed a radiation-induced increase in expression, while CINC1, IP10, MIP3beta, MIG, MIP1alpha, ITAC and SDF1 RNA levels were significantly down-regulated. However, incubation of irradiated hepatocytes in vitro with either TNF-alpha, IL1beta, or IL6 plus TNF-alpha led to up-regulation of MCP1, IP10 and MCP1 or CINC1 and MIP3beta, respectively. Irradiation of the liver induces up-regulation of the genes of the main proinflammatory chemokines, probably through the action of locally synthesized proinflammatory cytokines. The reason for the lack of liver inflammation in this model has still to be clarified. 相似文献
406.
Bushra Rashid Zafar Saleem Tayyab Husnain Sheikh Riazuddin 《Journal of Plant Biology》2008,51(4):248-254
Transgenic plants offer many unique opportunities for managing pest populations. However, the inheritance, integration, and
expression of multiple transgenes are prerequisite for maintaining sustainable resistance against insects in crops. We took
a gene-pyramiding approach to produce Bt cotton expressing two Bt genes,cry1Ac andcry2A. Using sonication-assistedAgrobacterium-mediated transformation (SAAT), we achieved an efficiency of 6.26%. Putative transgenic plants were confirmed via PCR, Southern hybridization,
and western-blotting. Those showing mortality of 75 to 100% for the second instar ofHeliothis armigera (compared with 0% for the control) were considered Bt-positive. Transgenes were segregated according to a 3:1 Mendelian inheritance
pattern in the T1 generation forHeliothis resistance. In our insect bioassay, the control plants showed >95% leaf damage, and insects reached the 4th instar stage of larval growth. In contrast, leaf damage on transgenic plants was limited to only a few bites, and insect
mortality was 75 to 100%. ELISA confirmed transgene expression, and Bt protein was detected in leaf tissue. This performance
was consistent with that of the parent transgenics. PCR and Southern blots verified integration of thecry1Ac andcry2A genes into the progeny. Therefore, this strategy provides a pathway toward cotton improvement and the development of durable
resistance against insect damage. 相似文献
407.
408.
Rahman S Bhatia K Khan AQ Kaur M Ahmad F Rashid H Athar M Islam F Raisuddin S 《Chemico-biological interactions》2008,172(3):195-205
Vitamin E (alpha-tocopherol) is a promising chemopreventive and pharmacologically safe agent, which can be exploited or tested against skin cancer. It is an established antioxidant with an ability to ameliorate the UV-induced skin damage and chemically induced inflammation in lungs. However, there are some conflicting reports about its role as a modulator of chemically induced promotion. We evaluated its efficacy in preventing the inflammatory and oxidative stress responses in a double 12-O-tetradecanoylphorbol-13-acetate (TPA) application tumor skin promotion protocol. Double application of TPA was undertaken to produce massive inflammatory and oxidative stress responses. Topical TPA treatment adversely altered many of the marker responses of stage I skin tumor promotion. Vitamin E application 30 min prior to TPA treatment (10 nmol) inhibited induction of hydrogen peroxide, myeloperoxidase (MPO) activity, xanthine oxidase (XO) activity and lipid peroxidation (LPO). Vitamin E also positively modulated altered antioxidants of mouse skin. Histological examination also revealed marked improvement. These results confirm the efficacy of vitamin E against early inflammatory and oxidative stress responses, which are hallmark of tumor promotion and provide rational basis for chemopreventive action of vitamin E in skin cancer. 相似文献
409.
Field evaluation and risk assessment of transgenic indica basmati rice 总被引:11,自引:1,他引:10
Bashir Khurram Husnain Tayyab Fatima Tahira Latif Zakia Aks Mehdi Syed Riazuddin Sheikh 《Molecular breeding : new strategies in plant improvement》2004,13(4):301-312
We report the first field trial of different transgenic lines of Indica Basmati rice (B-370) expressing cry1Ac and cry2A genes. Different transgenic lines were grown under field conditions for two consecutive years, according to RCBD and Split Plot Design respectively. All the biosafety measures were taken into consideration. Sixty neonate larvae of yellow stem borer were artificially infested into each plant in three installments. Data was recorded in terms of dead hearts and white heads at vegetative and flowering stage respectively. Transgenic lines exhibited inherent ability to protect rice plants from target insects (p<0.01). Natural infestations of rice skipper and rice leaf folder were also observed and transgenic plants were statistically superior to their untransformed counterparts. Green house whole plant bioassays were done by infesting two 2nd instar larvae of rice leaf folder per tiller. Transgenics were 96% more resistant than untransformed control plants. The presence of cry genes was observed with Dot blot, PCR and Southern blot analysis, while ELISA and Western blot analysis confirmed the expression of Cry proteins. All lines expressed higher level of Cry proteins when compared with commercially released cultivars of Bt cotton, maize and potato. It was also observed that although toxin titer substantially decreased with increasing age of the plants, it remained well within the limits to kill the target insects. Morphological studies showed significant variation for days to maturity, plant height and panicle length. Cooking qualities of seeds harvested from these lines were compared with the untransformed control. The transgenic lines had no effect on non-target insects (insects belonging to orders other than diptera and lepidoptera) and germination of three local varieties of wheat. Chances of gene spread were calculated at a level of 0.18% cross pollination in experimental lines. 相似文献
410.