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排序方式: 共有1119条查询结果,搜索用时 718 毫秒
991.
Sodium‐ion capacitors (SICs) are emerging energy storage devices with high energy, high power, and durable life. Sn is a promising anode material for lithium storage, but the poor conductivity of the a‐NaSn phase upon sodaition hinders its implementation in SICs. Herein, a superior Sn‐based anode material consisting of plum pudding‐like Co2P/Sn yolk encapsulated with nitrogen‐doped carbon nanobox (Co2P/Sn@NC) for high‐performance SICs is reported. The 8–10 nm metallic nanoparticles produced in situ are uniformly dispersed in the amorphous Sn matrix serving as conductive fillers to facilitate electron transfer in spite of the formation of electrically resistive a‐NaSn phase during cycling. Meanwhile, the carbon shell buffers the large expansion of active Sn and provides a stable electrode–electrolyte interface. Owing to these merits, the yolk–shell Co2P/Sn@NC demonstrates a large capacity of 394 mA h g?1 at 100 mA g?1, high rate capability of 168 mA h g?1 at 5000 mA g?1, and excellent cyclability with 87% capacity retention after 10 000 cycles. By integrating the Co2P/Sn@NC anode with a peanut shell‐derived carbon cathode in the SIC, high energy densities of 112.3 and 43.7 Wh kg?1 at power densities of 100 and 10 000 W kg?1 are achieved.  相似文献   
992.
Exosomes are membrane‐bound vesicles that traffic small molecular cargos. These cargos participate in cell–cell communication and contribute to the pathogenesis of many disease including cancer. How these mechanisms contribute to communication within the pancreatic adenocarcinoma (PDAC) microenvironment and how they contribute to PDAC biology are poorly understood. Performed in this study are comprehensive, quantitative comparisons of the proteomes of three PDAC cell lines to those of the exosomes they produce. Approximately 35% of whole cell proteins sort into exosomes. Analysis of composition of microbiomes (ANCOM) determined a cluster of 98 enriched pancreatic cancer exosome core proteins (ePC‐ECPs). Further, these proteins are predicted by ingenuity pathway analysis (IPA) as actively involved in signaling pathways regulating cell death and survival, cellular movement, and cell‐to‐cell signaling and interaction in particular (top three p‐value significant pathways). Significant enrichment of canonical pathways of acute phase response signaling (inflammatory response signaling pathways) and FXR and RXR activation in biosynthetic pathways are also predicted; 97 ePC‐ECPs are associated with cancer and among them, 34 are specifically associated with PDAC. In conclusion, exosomes from PDAC are enriched with cancer‐associated signaling proteins. Further assessment of these proteins as PDAC biomarkers or therapeutic targets is warranted.  相似文献   
993.
To understand the early heat shock (HS)‐regulated cellular responses that influence the tolerance of rice plant to high environmental temperatures, two‐dimensional difference gel electrophoresis (2D‐DIGE) is performed to explore the early HS‐regulated proteome. Multiple proteins that show abundance changes after 1 and 5 min of HS treatment are identified. Of the early HS‐regulated proteins identified, the abundance of a ubiquitin‐specific protease, OsUBP21, and its Arabidopsis homolog, AtUBP13, is found to be upregulated by 5 min of HS treatment. Further, knocking the expression of OsUBP21 or AtUBP13 down or out increases the tolerance of rice and Arabidopsis plants to HS stress, suggesting that the function of these ubiquitin‐specific proteases in regulating plant HS responses is conserved between monocots and dicots. 2D‐DIGE showed a group of proteins are differentially regulated in wild‐type and ubp21 mutant after 30 min of HS treatment. Among these proteins, 11 are found to interact directly with OsUBP21; thus, they may be targets of OsUBP21. Future analyses of the roles of these OsUBP21‐interacting proteins in plant HS responses will help reveal the protein ubiquitination/deubiquitination‐regulated cellular responses induced by HS in rice.  相似文献   
994.
Heat stress can restrict plant growth,development,and crop yield.As essential plant antioxidants,carotenoids play significant roles in plant stress resistance.b-carotene hydroxylase(BHY)and b-carotene ketolase(BKT),which catalyze the conversions of b-carotene to zeaxanthin and b-carotene to canthaxanthin,respectively,are key enzymes in the carotenoid biosynthetic pathway,but little is known about their potential functions in stress resistance.Here,we investigated the roles of b-carotene hydroxylase and b-carotene ketolase during heat stress in Physcomitrella patens through expressing a b-carotene ketolase gene from Chlamydomonas reinhardtii(Cr BKT)and a b-carotene hydroxylase gene from Haematococcus pluvialis(Hp BHY)in the moss P.patens.In transgenic moss expressing these genes,carotenoids content increased(especially lutein content),and heat stress tolerance increased,with reduced leafy tissue necrosis.To investigate the mechanism of this heat stress resistance,we measured various physiological indicators and found a lower malondialdehyde level,higher peroxidase and superoxide dismutase activities,and higher endogenous abscisic acid and salicylate content in the transgenic plants in response to high-temperature stress.These results demonstrate that Cr BKT and Hp BHY increase plant heat stress resistance through the antioxidant and damage repair metabolism,which is related to abscisic acid and salicylate signaling.  相似文献   
995.
The diet and feeding ecology of a wild subpopulation of black-and-white snub-nosed monkeys (Rhinopithecus bieti) were studied at Xiaochangdu in Honglaxueshan Nature Reserve, Tibet. This region is climatologically harsher than any other inhabited by non-human primates. Black-and-white snub-nosed monkeys fed on 48 parts of 25 plant species, at least three species of lichens and seven species of invertebrates. The number of food items exploited varied markedly among seasons, with dietary diversity being greatest in spring and summer. In winter, black-and-white snub-nosed monkeys had to subsist on fallback foods such as dried grass and bark. Ubiquitous lichens formed a major dietary constituent throughout the year, contributing about 75% of feeding records. Even though lichens act as a staple, our findings signify that the monkeys at Xiaochangdu prefer feeding on foliage, which is higher in protein content than the former. We provide evidence that black-and-white snub-nosed monkeys are able to cope with an array of food items other than lichens and hence can be regarded as feeding generalists. We discuss the results with reference to previous studies on other subpopulations living in habitats that are floristically more diverse and offer more plant food items than the marginal habitat at Xiaochangdu.  相似文献   
996.
997.
This investigation was undertaken to ascertain the antinociceptive activity of Caragana microphylla Lam. seeds and isolate and characterize the constituents. Antinociceptive activity was screened using acetic acid-induced abdominal constriction in ICR mice. The 75% ethanol extract and some fractions showed analgesic activity, but the antinociceptive activity of chloroform fraction was the strongest and was more productive than other fractions. Seven compounds were isolated from it and identified as: (1) machaeric acid, (2) beta-sitosterol, (3) stigmasterol, (4) pratol, (5) dehydrocavidine, (6) formononetin and (7) sucrose. Caragana microphylla Lam. seeds showed analgesic activity, with the chloroform fraction showing the strongest analgesic activity among the fractions.  相似文献   
998.
Transforming growth factor-β1 (TGF-β1) can activate mitogen-activated protein kinases (MAPKs) in many types of cells. The mechanism of this activation is not well elucidated. Here, we explore the role of TGF-β/Smads signaling compounds in TGF-β1-mediated activation of extracellular signal-regulated kinase (ERK) MAPK in human papillomavirus (HPV)-18 immortalized human bronchial epithelial cell line BEP2D and the role of TGF-β1-induced phosphorylation of ERK in proliferation and apoptosis of BEP2D. The cell models of siRNA-mediated silencing of TGF-β receptor type II (TβRII), Smad2, Smad3, Smad4, and Smad7 were employed in this study. Our results demonstrate that TGF-β1 activates ERK in a time-dependent manner with a maximum effect at 60 min; overexpression of Smad7 increased this TGF-β1-mediated phosphorylation of the ERK; and siRNA-mediated silencing of TβRII, Smad3, Smad4, and Smad7 abrogated this effect. Moreover, we observed that overexpression of Smad7 restored TGF-β1-mediated ERK phosphorylation in Smad4 knockdown cells but not in TβRII knockdown cells. In BEP2D cells, TGF-β1 treatment effectively inhibited cells’ proliferation and induced their apoptosis. Pretreatment with U0126, an inhibitor of ERK1/2, significantly enhanced the TGF-β1-mediated antiproliferative and apoptosis induction effects in BEP2D cells. These data revealed that TβRII and Smad7 play the critical roles in TGF-β1-mediated activation of ERK; Smad3 and Smad4 can play an indirect role through up-regulating Smad7 expression; and TGF-β1-induced phosphorylation of ERK may participate in BEP2D cell proliferation and apoptosis regulation.  相似文献   
999.
Huo  Yun-Feng  Li  Yin-Ting  Xia  Wei  Wang  Chong  Xie  Yuan-Yuan  Wang  Yan-Bo  Zhou  Tao  Fu  Ling-Lin 《Glycoconjugate journal》2021,38(5):573-583
Glycoconjugate Journal - To explore effect of the structural properties of porphyra haitanensis polysaccharide on its biological activity, degraded porphyra polysaccharides were separated and...  相似文献   
1000.
Low-grade gliomas (LGGs) are grade III gliomas based on the WHO classification with significant genetic heterogeneity and clinical properties. Traditional histological classification of gliomas has been challenged by the improvement of molecular stratification; however, the reproducibility and diagnostic accuracy of LGGs classification still remain poor. Herein, we identified fatty acid binding protein 5 (FABP5) as one of the most enriched genes in malignant LGGs and elevated FABP5 revealed severe outcomes in LGGs. Functionally, lentiviral suppression of FABP5 reduced malignant characters including proliferation, cloning formation, immigration, invasion and TMZ resistance, contrarily, the malignancies of LGGs were enhanced by exogenous overexpression of FABP5. Mechanistically, epithelial-mesenchymal transition (EMT) was correlated to FABP5 expression in LGGs and tumour necrosis factor α (TNFα)-dependent NF-κB signalling was involved in this process. Furthermore, FABP5 induced phosphorylation of inhibitor of nuclear factor kappa-B kinase α (IKKα) thus activated nuclear factor kappa-B (NF-κB) signalling. Taken together, our study indicated that FABP5 enhances malignancies of LGGs through canonical activation of NF-κB signalling, which could be used as individualized prognostic biomarker and potential therapeutic target of LGGs.  相似文献   
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