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981.
Cuixia Di Ming Li Feng Long Muqun Bai Yajie liu Xiaolin Zheng Shijian Xu Yun Xiang Zhenglong Sun Lizhe An 《Planta》2009,231(1):169-178
Polygalacturonase-inhibiting proteins (PGIPs) are plant defense proteins. To date, no spatial distribution of PGIPs and interaction between PGIPs and nitric oxide (NO) in plant were described. Here, we first reported the full-length cDNA sequence of PGIP of Chorispora bungeana (CbPGIP1). Notably, immunofluorescence localization showed that the CbPGIP was evenly distributed in leaves but it was mainly localized in epidermis and vascular bundle in stems and roots. Further studies indicated that CbPGIP had higher abundance in roots than in stems and leaves. Conversely, the bulk PGIP of C. bungeana showed a higher activity in leaves than in stems and roots. In addition, quantitative real-time polymerase chain reaction demonstrated that CbPGIP1 expression was induced by Stemphylium solani, salicylic acid (SA), 4, ?4°C and NO. This is a first report attempting to predict if NO can induce the PGIP expression. Taken together, these findings showed that the gene was spatially regulated and NO and SA might take part in CbPGIP1 expression induced by biotic and abiotic stresses. This study highlighted the potential importance of CbPGIP1 and NO in plant resistance. 相似文献
982.
983.
Aiping Bai Zdzislaw M. Szulc Jacek Bielawski Nalini Mayroo Xiang Liu James Norris Yusuf A. Hannun Alicja Bielawska 《Bioorganic & medicinal chemistry》2009,17(5):1840-1848
Novel ω-N-amino analogs of B13 (Class E) were designed, synthesized and tested as inhibitors of acid ceramidase (ACDase) and potential anticancer agents deprived of unwanted lysosomal destabilization and ACDase proteolytic degradation properties of LCL204 [Szulc, Z. M.; Mayroo, N.; Bai, A.; Bielawski, J.; Liu, X.; Norris, J. S.; Hannun, Y. A.; Bielawska, A. Bioorg. Med. Chem. 2008, 16, 1015].Representative analog LCL464, (1R,2R)-2-N-(12′-N,N-dimethylaminododecanoyl amino)-1-(4″-nitrophenyl)-1,3-propandiol, inhibited ACDase activity in vitro, with a similar potency as B13 but higher than LCL204. LCL464 caused an early inhibition of this enzyme at a cellular level corresponding to decrease of sphingosine and specific increase of C14- and C16-ceramide. LCL464 did not induce lysosomal destabilization nor degradation of ACDase, showed increased cell death demonstrating inherent anticancer activity in a wide range of different cancer cell lines, and induction of apoptosis via executioner caspases activation. LCL464 represents a novel structural lead as chemotherapeutic agent acting via the inhibition of ACDase. 相似文献
984.
Establishment and characterization of a fibroblast cell line from the Mongolian horse 总被引:1,自引:0,他引:1
Lin-feng Li Wei-jun Guan Yue Hua Xiu-juan Bai Yue-hui Ma 《In vitro cellular & developmental biology. Animal》2009,45(7):311-316
A fibroblast line was successfully established from Mongolian horse ear marginal tissue by using a primary explant technique
and cell cryogenic preservation technology. Biological analysis showed the following: The cells were adherent and exhibited
density-dependent inhibition of proliferation; assays of microbial contamination from bacteria, fungi, and mycoplasma were
negative; the population doubling time of the cells was 33.9 h; and a 2n chromosome number of 64 at a frequency higher than
80%. A lack of cross-contamination of this cell line with other species was confirmed by isoenzyme analysis of lactic and
malic dehydrogenases. In order to study exogenous gene expression, four fluorescent proteins, pEGFP-N3, pEGFP-C1, pDsRed1-N1,
and pEYFP-N1, were transfected into the cells. The corresponding fluorescence was distributed throughout the cytoplasm and
nucleus 12 h after transfection. This cell line not only preserves the genetic resources of the Mongolian horse at the cellular
level but also provides valuable materials for genomic, postgenomic, and somacloning research in this species. 相似文献
985.
Wang F Feng M Xu P Xiao H Niu P Yang X Bai Y Peng Y Yao P Tan H Tanguay RM Wu T 《Cell stress & chaperones》2009,14(3):245-251
Heat shock proteins (Hsps) can protect cells, organs, and whole organisms against damage caused by abnormal environmental
hazards. Some studies have reported that lymphocyte Hsps may serve as biomarkers for evaluating disease status and exposure
to environmental stresses; however, few epidemiologic studies have examined the associations between lymphocyte Hsps levels
and lung cancer risk. We examined lymphocyte levels of Hsp27 and Hsp70 in 263 lung cancer cases and age- and gender-matched
cancer-free controls by flow cytometry. Multivariate logistic regression models were used to estimate the association between
lymphocyte Hsps levels and lung cancer risk. Our results showed that Hsp27 levels were significantly lower in lung cancer
cases than in controls (16.5 vs 17.8 mean fluorescence intensity, P < 0.001). This was not observed for Hsp70 levels. Further stratification analysis revealed that lymphocyte Hsp27 levels were
negatively associated with lung cancer risk especially in males and heavy smokers. There was a statistical trend of low odd
ratios (95% confidence intervals) and upper tertile levels of Hsp27 [1.000, 0.904 (0.566–1.444) and 0.382 (0.221–0.658, P
trend = 0.001) in males and 1.000, 0.9207 (0.465–1.822) and 0.419 (0.195–0.897, P
trend = 0.036) in heavy smokers] after adjustment for confounding factors. These results suggest that lower lymphocyte Hsp27 levels
might be associated with an increased risk of lung cancer. Our findings need to be validated in a large prospective study.
Feng Wang and Maohui Feng contributed equally to this work. 相似文献
986.
The resurrection flowering plant Ramonda serbica inhabits the shallow organo-mineral soil that develops in crevices on northern-facing carbonate rocks in the gorges in the
Balkan Peninsula. This type of soil represents a complex substrate whose physical and chemical properties were found to be
well suited to the most important requirements for the growth and development of R. serbica as well as for the plant’s survival in the state of anhydrobiosis in periods of drought stress. Considerable amount of organic
matter (39.4%) in the soil resulted in the high field capacity (134 ml/100 g soil) as well as the slow changes in the amount
of its available water. The suitable soil hydric status, based on the organic remains, supports the slow dehydration of this
poikilohydric plant, which is extremely important in allowing the activation of the plant’s protective mechanisms. The pH
of the soil solution was slighty alkaline (7.7) mostly due to carbonates in its crystallographic structure. The large amount
of incompletely decomposed organic debris resulted in a marked difference between total and available nutrient concentration
in the soil. Still, the adequate content of nutrients in the leaves points to efficient mineral consumption by the plant roots.
The sufficient bioavailability of nutrients and water was also improved by vesicular–arbuscular mycorrhiza detected in R. serbica roots. 相似文献
987.
Vincent Popoff Gonzalo A. Mardones Siau-Kun Bai Valérie Chambon Danièle Tenza Patricia V. Burgos Anbing Shi Philippe Benaroch Sylvie Urbé Christophe Lamaze Barth D. Grant Graça Raposo Ludger Johannes 《Traffic (Copenhagen, Denmark)》2009,10(12):1868-1880
Clathrin and retromer have key functions for retrograde trafficking between early endosomes and the trans -Golgi network (TGN). Previous studies on Shiga toxin suggested that these two coat complexes operate in a sequential manner. Here, we show that the curvature recognition subunit component sorting nexin 1 (SNX1) of retromer interacts with receptor-mediated endocytosis-8 (RME-8) protein, and that RME-8 and SNX1 colocalize on early endosomes together with a model cargo of the retrograde route, the receptor-binding B-subunit of Shiga toxin (STxB). RME-8 has previously been found to bind to the clathrin uncoating adenosine triphosphatase (ATPase) Hsc70, and we now report that depletion of RME-8 or Hsc70 affects retrograde trafficking at the early endosomes–TGN interface of STxB and the cation-independent mannose 6-phosphate receptor, an endogenous retrograde cargo protein. We also provide evidence that retromer interacts with the clathrin-binding protein hepatocyte growth factor-regulated tyrosine kinase substrate (Hrs) not only via SNX1, as previously published (Chin Raynor MC, Wei X, Chen HQ, Li L. Hrs interacts with sorting nexin 1 and regulates degradation of epidermal growth factor receptor. J Biol Chem 2001;276:7069–7078), but also via the core complex component Vps35. Hrs codistributes at the ultrastructural level with STxB on early endosomes, and interfering with Hrs function using antibodies or mild overexpression inhibits retrograde transport. Our combined data suggest a model according to which the functions in retrograde sorting on early endosomes of SNX1/retromer and clathrin are articulated by RME-8, and possibly also by Hrs. 相似文献
988.
Min Xu Lin Bai Yong Gong Wei Xie Haiying Hang Tao Jiang 《The Journal of biological chemistry》2009,284(31):20457-20461
Cellular DNA lesions are efficiently countered by DNA repair in conjunction with delays in cell cycle progression. Previous studies have demonstrated that Rad9, Hus1, and Rad1 can form a heterotrimeric complex (the 9-1-1 complex) that plays dual roles in cell cycle checkpoint activation and DNA repair in eukaryotic cells. Although the 9-1-1 complex has been proposed to form a toroidal structure similar to proliferating cell nuclear antigen (PCNA), which plays essential roles in DNA replication and repair, the structural basis by which it performs different functions has not been elucidated. Here we report the crystal structure of the human 9-1-1 complex at 3.2 Å resolution. The crystal structure, together with biochemical assays, reveals that the interdomain connecting loops (IDC loop) of hRad9, hHus1, and hRad1 are largely divergent, and further cocrystallization study indicates that a PCNA-interacting box (PIP box)-containing peptide derived from hFen1 binds tightly to the interdomain connecting loop of hRad1, providing the molecular basis for the damage repair-specific activity of the 9-1-1 complex in contrast to PCNA. Furthermore, structural comparison with PCNA reveals other unique structural features of the 9-1-1 complex that are proposed to contribute to DNA damage recognition.Cellular DNA damage triggers the activation of the cell cycle checkpoint, leading to a delay or arrest in cell cycle progression to prevent replication and inducing DNA damage repair (1, 2). In response to DNA damage, the 9-1-13 complex can be loaded onto DNA lesion sites by Rad17-RFC2–5 (which consists of one large subunit, Rad17, and four small subunits, RFC2–5), where it triggers the activation of the cell cycle checkpoint (3, 4). Moreover, the 9-1-1 complex can also directly participate in DNA repair via physical association with many factors involved in base excision repair (BER), translesion synthesis, homologous recombination, and mismatch repair pathways (5–9).Although both the 9-1-1 and the PCNA complexes perform critical functions in eukaryotic cells with predicted similar structures (10), their specific roles are distinct. First, the 9-1-1 complex is a DNA damage sensor in the cell cycle checkpoint but does not function as a scaffold for the major DNA replication factors; however, PCNA plays exactly the opposite role (1, 11). Second, although both the complexes function in DNA repair, their specific activities are different. Previous observations indicated that some BER enzymes, such as MYH (MutY glycosylate homolog) (12), TDG (thymine DNA glycosylate) (7), and NEIL (Nei-like glycosylate) (8), interact with the 9-1-1 complex via motifs that are located outside the conserved PCNA-interacting box (the PIP box), implying that the 9-1-1 complex functions as a damage repair-specific clamp, in contrast to PCNA. However, the structural basis for this hypothesis remains unclear. Another important unresolved issue concerns the damage-sensing mechanism of the 9-1-1 complex. During the DNA replication process, the PCNA·RFC clamp·clamp loader specifically recognizes the primer-template junction (13). However, the molecular basis by which the 9-1-1·Rad17-RFC2–5 clamp·clamp loader specifically recognizes the damaged DNA is little known. To address these questions, we performed structural and biochemical studies on the 9-1-1 complex. 相似文献
989.
990.
In hermaphroditic plants, female reproductive success often varies among different positions within an inflorescence.However, few studies have evaluated the relative importance of underlying causes such as pollen limitation, resource limitation or architectural effect, and few have compared male allocation. During a 2-year investigation, we found that female reproductive success of an acropetally flowering species, Corydalis remota Fisch. ex Maxim. var. Iineariloba Maxim. was significantly lower in the upper late developing flowers when compared with the lower early flowers. Supplementation with outcross pollen did not improve female reproductive success of the upper flowers, while removal of the lower developing fruits significantly increased female reproductive success of the upper flowers in both years, evidencing resource limitation of the upper flowers. Female production in upper flowers was greatly improved by simultaneous pollen supplementation of the upper flowers and removal of the lower fruits, suggesting that, when resources are abundant, pollen may limit the female reproductive success of the upper flowers. The less seed mass in the upper flowers didn't increase in all treatments due to architecture. In the upper flowers, ovule production was significantly lower and the pollen : ovule ratio was significantly higher. These results suggest that male-biased sex allocation in the upper flowers may lead to increased male reproductive success, whereas the lower flowers have higher female reproductive success. 相似文献