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941.
OCRL1 Modulates Cilia Length in Renal Epithelial Cells 总被引:1,自引:0,他引:1
Rbaibi Y Cui S Mo D Carattino M Rohatgi R Satlin LM Szalinski CM Swanhart LM Fölsch H Hukriede NA Weisz OA 《Traffic (Copenhagen, Denmark)》2012,13(9):1295-1305
Lowe syndrome is an X-linked disorder characterized by cataracts at birth, mental retardation and progressive renal malfunction that results from loss of function of the OCRL1 (oculocerebrorenal syndrome of Lowe) protein. OCRL1 is a lipid phosphatase that converts phosphatidylinositol 4,5-bisphosphate to phosphatidylinositol 4-phosphate. The renal pathogenesis of Lowe syndrome patients has been suggested to result from alterations in membrane trafficking, but this cannot fully explain the disease progression. We found that knockdown of OCRL1 in zebrafish caused developmental defects consistent with disruption of ciliary function, including body axis curvature, pericardial edema, hydrocephaly and impaired renal clearance. In addition, cilia in the proximal tubule of the zebrafish pronephric kidney were longer in ocrl morphant embryos. We also found that knockdown of OCRL1 in polarized renal epithelial cells caused elongation of the primary cilium and disrupted formation of cysts in three-dimensional cultures. Calcium release in response to ATP was blunted in OCRL1 knockdown cells, suggesting changes in signaling that could lead to altered cell function. Our results suggest a new role for OCRL1 in renal epithelial cell function that could contribute to the pathogenesis of Lowe syndrome. 相似文献
942.
Hotta T Kong Z Ho CM Zeng CJ Horio T Fong S Vuong T Lee YR Liu B 《The Plant cell》2012,24(4):1494-1509
Plant cells assemble the bipolar spindle and phragmoplast microtubule (MT) arrays in the absence of the centrosome structure. Our recent findings in Arabidopsis thaliana indicated that AUGMIN subunit3 (AUG3), a homolog of animal dim γ-tubulin 3, plays a critical role in γ-tubulin-dependent MT nucleation and amplification during mitosis. Here, we report the isolation of the entire plant augmin complex that contains eight subunits. Among them, AUG1 to AUG6 share low sequence similarity with their animal counterparts, but AUG7 and AUG8 share homology only with proteins of plant origin. Genetic analyses indicate that the AUG1, AUG2, AUG4, and AUG5 genes are essential, as stable mutations in these genes could only be transmitted to heterozygous plants. The sterile aug7-1 homozygous mutant in which AUG7 expression is significantly reduced exhibited pleiotropic phenotypes of seriously retarded vegetative and reproductive growth. The aug7-1 mutation caused delocalization of γ-tubulin in the mitotic spindle and phragmoplast. Consequently, spindles were abnormally elongated, and their poles failed to converge, as MTs were splayed to discrete positions rendering deformed arrays. In addition, the mutant phragmoplasts often had disorganized MT bundles with uneven edges. We conclude that assembly of MT arrays during plant mitosis depends on the augmin complex, which includes two plant-specific subunits. 相似文献
943.
The functional significance of E-β-Farnesene: Does it influence the populations of aphid natural enemies in the fields? 总被引:1,自引:0,他引:1
Liang-Liang Cui Frédéric Francis Stéphanie Heuskin Georges Lognay Ying-Jie Liu Jie Dong Ju-Lian Chen Xu-Ming Song Yong Liu 《Biological Control》2012,60(2):108-112
Aphids cause much damage to Chinese cabbage in northern China. Over reliance on pesticides have large environmental and human health costs that compel researchers to seek alternative management tactics for aphid control. The component of aphid alarm pheromone, E-β-Farnesene (EβF), extracted from Matricaria chamomilla L., which attracts natural enemies in the laboratory, may have significant implications for the design of cabbage aphid control strategies. The purpose of this paper is to understand the effects of EβF on natural enemies to cabbage aphid control in Chinese cabbage fields. Ladybeetles on Chinese cabbage leaves in EβF released plots and Aphidiidae in EβF released yellow traps were significantly higher than those of in controls. No significant differences were detected in the interactions of different treatments and the two years for all natural enemies. More important, lower aphid densities were found in EβF released plots. Our results suggested that the EβF extracted from M. chamomilla L. could attract natural enemies to reduce cabbage aphids in the Chinese cabbage fields. 相似文献
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947.
The phosphatidylinositol 3-kinase/AKT (PI3K/AKT) pathway plays a critical role in human cancer. We determined the expression
patterns of class I PI3K catalytic subunits and evaluated their importance in the development or progression of colorectal
cancer (CRC). For this purpose, expression of class I PI3K isoforms was evaluated in 82 primary CRC and paired non-cancerous
mucosa samples by qRT-PCR. P-AKT-Ser473 and P-AKT-Thr308 expression were measured by western blot. We found that, compared
with paired non-cancerous mucosa samples, mRNA expression of p110α and p110β in CRCs was significantly increased to 2.02-fold
(95% confidence interval [CI] 1.25–3.28 fold) and 1.76-fold (95% CI 1.19–2.60 fold), respectively; while slight differences
were found regarding the expression of p110δ (0.57-fold; 95% CI 0.31–1.07 fold) and p110γ (0.97-fold; 95% CI 0.50–1.88 fold).
Increased p110α and p110β expression correlated with primary tumor size, regional lymph node metastases, and AJCC stage. Increased
p110β expression also correlated with distant metastasis. P-AKT-Thr308 and P-AKT-Ser473 expression showed significant direct
correlations with p110α and p110β mRNA expression. Besides, CRC patients with p110β mRNA overexpression had a worse disease-free
survival after radical surgery compared with those with normal or decreased levels (P = 0.043). It was, therefore, concluded that the altered p110α and p110β expression might contribute to the CRC development
or progression. 相似文献
948.
Ochratoxin A (OTA) is nephrotoxic, immunosuppressive, and teratogenic in many species and is a possible human carcinogen. In this study, we investigated the OTA pollution situations of grains in northern China and the signaling pathway that mediated OTA-induced apoptosis in human tubular kidney cells (HKCs). Samples of grains collected from three representative areas were determined by using high-performance liquid chromatography fluorescence method. The effects of OTA on cell apoptosis, caspase-3, Bax, and Bcl-2 expression, and phosphorylation of c-Jun NH(2) terminal kinase (JNK) were detected in cultured HKCs via flow cytometry (FCM), Hoechst 33258 staining, and Western blot. It showed that OTA pollution of edible grains was very common in north China. OTA could affect caspase-3, Bax, and Bcl-2 expression and increased cell apoptosis in cultured HKCs. The JNK signalling pathway might play an important role during these cellular events. 相似文献
949.
Zhao X Chao Y Chen P Liu D Su P Sun J Cui X Tang Y 《Journal of physiology and biochemistry》2012,68(1):129-139
The 26S proteasome is a key component of the ubiquitin-proteasome system, a process responsible for the majority of cellular
protein degradation. The function of the proteasomal ubiquitin receptor hRpn13, a component of the 26S proteasome, is not
completely understood. To investigate the role of hRpn13 in the ubiquitin-proteasome system in osteoblasts, the effects of
suppressing and overexpressing the hRpn13 gene on proliferation, differentiation, and function of human osteoblast-like MG63
cells were examined. After knockdown of hRpn13 by small interfering RNA, changes in osteoblast proliferation were evaluated
by methyl-thiazolyl-tetrazolium assay. There was an increase in markers for osteoblast proliferation, specifically alkaline
phosphatase activity, and elevated protein levels of osteocalcin, proliferating cell nuclear antigen (PCNA), and ubiquitin.
Furthermore, hRpn13 knockdown also resulted in a decrease in the ratio between the gene expressions of RANKL and OPG, key
players in the pathogenesis of bone diseases that influence the normal balance between bone formation and resorption. In contrast,
overexpression of hRpn13 inhibited the proliferation of MG63 cells, and decreased alkaline phosphatase activity as well as
protein levels of osteocalcin, PCNA, and ubiquitin while the ratio of RANKL to OPG expression increased. To confirm the function
of hRpn13 in the ubiquitin-proteasome pathway, osteoblast proliferation enhancement and ubiquitin accumulation after hRpn2
knockdown was assessed. The results suggest that overexpression of hRpn13 negatively influences proliferation and osteogenic
differentiation in MG63 cells. The evidence implies that hRpn13 modulates the influence of osteoblasts on osteoclasts by controlling
the stability of regulatory proteins in osteoblasts. In summary, overexpression of hRpn13 promoted the activity of the ubiquitin-proteasome
system. 相似文献
950.
N Mao Y Ji Z Xie H Wang H Wang J An X Zhang Y Zhang Z Zhu A Cui S Xu K Shen C Liu W Yang W Xu 《PloS one》2012,7(8):e43893
The relevance of human parainfluenza viruses (HPIVs) to the epidemiology of acute respiratory infections (ARI) in China is unclear. From May 2008 to September 2010, 443 nasopharyngeal aspirates (NPAs) from hospitalized pediatric patients (age from 1 to 93 months) in Beijing were collected and screened for HPIVs and other common respiratory viruses by real-time RT-PCR. Sixty-two of 443 samples were positive for HPIVs with 4 positive for HPIV-2 and 58 positive for HPIV-3, indicating that HPIV-3 was the predominant virus present during the study period. A phylogenetic tree based on all the available HN (hemagglutinin-neuraminidase) sequences of HPIV-3 indicated that three distinct clusters (A,B, and C) were circulating with some temporal and regional clustering. Cluster C was further divided into sub-clusters, C1, C2, C3 and C4. HPIV-3 from Beijing isolates belonged to sub-cluster C3, and were grouped with the isolates from two Provinces of China and the neighboring country of Japan. Genetic analysis based on entire HN gene revealed that the HPIV-3 isolates from Beijing were highly similar with 97.2%-100% identity at the nucleotide level and these could be divided into two closely related lineages, C3a and C3b. These findings suggested that there was co-circulation of multiple lineages of HPIV-3 in the Beijing region during the study period. This is the first study to describe the epidemiology and molecular characterization of HPIVs in China. 相似文献