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181.
Salivary gland duct ligation is an alternative to gland excision for treating sialorrhea or reducing salivary gland size prior to tumor excision. Duct ligation also is used as an approach to study salivary gland aging, regeneration, radiotherapy, sialolithiasis and sialadenitis. Reports conflict about the contribution of each salivary cell population to gland size reduction after ductal ligation. Certain cell populations, especially acini, reportedly undergo atrophy, apoptosis and proliferation during reduction of gland size. Acini also have been reported to de-differentiate into ducts. These contradictory results have been attributed to different animal or salivary gland models, or to methods of ligation. We report here a bilateral double ligature technique for rabbit parotid glands with histologic observations at 1, 7, 14, 30, 60 days after ligation. A large battery of special stains and immunohistochemical procedures was employed to define the cell populations. Four stages with overlapping features were observed that led to progressive shutdown of gland activities: 1) marked atrophy of the acinar cells occurred by 14 days, 2) response to and removal of the secretory material trapped in the acinar and ductal lumens mainly between 30 and 60 days, 3) reduction in the number of parenchymal (mostly acinar) cells by apoptosis that occurred mainly between 14–30 days, and 4) maintenance of steady-state at 60 days with a low rate of fluid, protein, and glycoprotein secretion, which greatly decreased the number of leukocytes engaged in the removal of the luminal contents. The main post- ligation characteristics were dilation of ductal and acinar lumens, massive transient infiltration of mostly heterophils (rabbit polymorphonuclear leukocytes), acinar atrophy, and apoptosis of both acinar and ductal cells. Proliferation was uncommon except in the larger ducts. By 30 days, the distribution of myoepithelial cells had spread from exclusively investing the intercalated ducts pre-ligation to surrounding a majority of the residual duct-like structures, many of which clearly were atrophic acini. Thus, both atrophy and apoptosis made major contributions to the post-ligation reduction in gland size. Structures also occurred with both ductal and acinar markers that suggested acini differentiating into ducts. Overall, the reaction to duct ligation proceeded at a considerably slower pace in the rabbit parotid glands than has been reported for the salivary glands of the rat. 相似文献
182.
Wei Cui Zaijun Zhang Wenming Li Shinghung Mak Shengquan Hu Huan Zhang Shuai Yuan Jianhui Rong Tony Chunglit Choi Simon M. Y. Lee Yifan Han 《PloS one》2012,7(9)
SU5416 was originally designed as a potent and selective inhibitor of vascular endothelial growth factor receptor-2 (VEGFR-2) for cancer therapy. In this study, we have found for the first time that SU5416 unexpectedly prevented 1-methyl-4-phenylpyridinium ion (MPP+)-induced neuronal apoptosis in cerebellar granule neurons, and decreased 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced loss of dopaminergic neurons and impairment of swimming behavior in zebrafish in a concentration-dependent manner. However, VEGFR-2 kinase inhibitor II, another specific VEGFR-2 inhibitor, failed to reverse neurotoxicity at the concentration exhibiting anti-angiogenic activity, strongly suggesting that the neuroprotective effect of SU5416 is independent from its anti-angiogenic action. SU5416 potently reversed MPP+-increased intracellular nitric oxide level with an efficacy similar to 7-nitroindazole, a specific neuronal nitric oxide synthase (nNOS) inhibitor. Western blotting analysis showed that SU5416 reduced the elevation of nNOS protein expression induced by MPP+. Furthermore, SU5416 directly inhibited the enzyme activity of rat cerebellum nNOS with an IC50 value of 22.7 µM. In addition, knock-down of nNOS expression using short hairpin RNA (shRNA) abolished the neuroprotective effects of SU5416 against MPP+-induced neuronal loss. Our results strongly demonstrate that SU5416 might exert its unexpected neuroprotective effects by concurrently reducing nNOS protein expression and directly inhibiting nNOS enzyme activity. In view of the capability of SU5416 to cross the blood-brain barrier and the safety for human use, our findings further indicate that SU5416 might be a novel drug candidate for neurodegenerative disorders, particularly those associated with NO-mediated neurotoxicity. 相似文献
183.
Kim JH Jung WS Choi NJ Kim DO Shin DH Kim YJ 《The Journal of nutritional biochemistry》2009,20(4):298-303
Bovine colostrum (BC) has been reported to enhance immune function, reduce fat accumulation and facilitate the movement of glucose to the muscle. However, very few attempts have been made to examine its anti-diabetic effects in diabetes patients. The aim of this study was to evaluate whether BC decreases blood glucose, as well as cholesterol, triglyceride (TG) and ketones levels, which can be elevated by obesity and stress in Type 2 diabetic patients. Sixteen patients (men=8, women=8) with Type 2 diabetes were randomized into the study. Each ingested 5 g of BC on an empty stomach every morning and night for 4 weeks. Blood glucose, ketones (beta-hydroxybutyric acid), total cholesterol and TGs were measured every week. In both the men and women, blood glucose levels at 2 and 8 h postprandial decreased continually during the experimental period. The rate of decrease in blood glucose at 8 h postprandial was not different between the men and women, but was higher in the women (14.25+/-2.66) than in the men (10.96+/-1.82%) at 2 h postprandial. Total cholesterol and TG levels decreased significantly in both the men and women after 4 weeks. Also, beta-hydroxybutyric acid level decreased with BC ingestion, but this was not significant. These results suggest that BC can decrease levels of blood glucose and ketones, as well as reduce cholesterol and TGs, all of which may cause complications in Type 2 diabetic patients. 相似文献
184.
Sung-Hwan Jo Dal-Hoe Koo Jihyun F Kim Cheol-Goo Hur Sanghyeob Lee Tae-jin Yang Suk-Yoon Kwon Doil Choi 《BMC plant biology》2009,9(1):42
Background
Tandemly repeated DNA, also called as satellite DNA, is a common feature of eukaryotic genomes. Satellite repeats can expand and contract dramatically, which may cause genome size variation among genetically-related species. However, the origin and expansion mechanism are not clear yet and needed to be elucidated. 相似文献185.
Chu H Kang S Ha S Cho K Park SM Han KH Kang SK Lee H Han SH Yun CH Choi Y 《Microbiology and immunology》2005,49(11):941-948
The most common enteric colibacillosis in neonatal and newborns is caused by enterotoxigenic Escherichia coli(ETEC). Colonization of ETEC in the small intestine is associated with adhesions using fimbriae, which is known as a specific adhesion factor and provides highly specific means for anchoring and prerequisite for an infectious agent. In the present study we have engineered Lactobacillus acidophilus to produce recombinant K99 fimbriae, which is used for the colonization to the intestine of pigs. The expression of K99 fimbrial protein was confirmed using SDS-PAGE, immunoblot and agglutination analyses. To evaluate a function of the K99 fimbrial protein, inhibition and competition tests were performed on pre-screened intestinal brush border from pigs. The tests showed that recombinant L. acidophilus, not control L. acidophilus, had a significant inhibitory effect to and competition against K99+ E. coli in a dose dependent manner. In conclusion, we demonstrated that recombinant K99 fimbriae producing L. acidophilus was able to prevent E. coli binding to intestinal brush border. 相似文献
186.
187.
188.
Jungeun Kim Jeongyeo Lee Jae-Pil Choi Inkyu Park Kyungbong Yang Min Keun Kim Young Han Lee Ill-Sup Nou Dae-Soo Kim Sung Ran Min Sang Un Park HyeRan Kim 《BMC genomics》2014,15(1)
Background
The Brassicaceae family is an exemplary model for studying plant polyploidy. The Brassicaceae knowledge-base includes the well-annotated Arabidopsis thaliana reference sequence; well-established evidence for three rounds of whole genome duplication (WGD); and the conservation of genomic structure, with 24 conserved genomic blocks (GBs). The recently released Brassica rapa draft genome provides an ideal opportunity to update our knowledge of the conserved genomic structures in Brassica, and to study evolutionary innovations of the mesohexaploid plant, B. rapa.Results
Three chronological B. rapa genomes (recent, young, and old) were reconstructed with sequence divergences, revealing a trace of recursive WGD events. A total of 636 fast evolving genes were unevenly distributed throughout the recent and young genomes. The representative Gene Ontology (GO) terms for these genes were ‘stress response’ and ‘development’ both through a change in protein modification or signaling, rather than by enhancing signal recognition. In retention patterns analysis, 98% of B. rapa genes were retained as collinear gene pairs; 77% of those were singly-retained in recent or young genomes resulting from death of the ancestral copies, while others were multi-retained as long retention genes. GO enrichments indicated that single retention genes mainly function in the interpretation of genetic information, whereas, multi-retention genes were biased toward signal response, especially regarding development and defense. In the recent genome, 13,302, 5,790, and 20 gene pairs were multi-retained following Brassica whole genome triplication (WGT) events with 2, 3, and 4 homoeologous copies, respectively. Enriched GO-slim terms from B. rapa homomoelogues imply that a major effect of the B. rapa WGT may have been to acquire environmental adaptability or to change the course of development. These homoeologues seem to more frequently undergo subfunctionalization with spatial expression patterns compared with other possible events including nonfunctionalization and neofunctionalization.Conclusion
We refined Brassicaceae GB information using the latest genomic resources, and distinguished three chronologically ordered B. rapa genomes. B. rapa genes were categorized into fast evolving, single- and multi-retention genes, and long retention genes by their substitution rates and retention patterns. Representative functions of the categorized genes were elucidated, providing better understanding of B. rapa evolution and the Brassica genus.Electronic supplementary material
The online version of this article (doi:10.1186/1471-2164-15-606) contains supplementary material, which is available to authorized users. 相似文献189.
Ji-Hyeon Park Ji Hae Seo Hee-Jun Wee Tam Thuy Lu Vo Eun Ji Lee Hoon Choi Jong-Ho Cha Bum Ju Ahn Min Wook Shin Sung-Jin Bae Kyu-Won Kim 《PloS one》2014,9(8)
Arrest defective 1 (ARD1) is an acetyltransferase that is highly conserved across organisms, from yeasts to humans. The high homology and widespread expression of ARD1 across multiple species and tissues signify that it serves a fundamental role in cells. Human ARD1 (hARD1) has been suggested to be involved in diverse biological processes, and its role in cell proliferation and cancer development has been recently drawing attention. However, the subcellular localization of ARD1 and its relevance to cellular function remain largely unknown. Here, we have demonstrated that hARD1 is imported to the nuclei of proliferating cells, especially during S phase. Nuclear localization signal (NLS)-deleted hARD1 (hARD1ΔN), which can no longer access the nucleus, resulted in cell morphology changes and cellular growth impairment. Notably, hARD1ΔN-expressing cells showed alterations in the cell cycle and the expression levels of cell cycle regulators compared to hARD1 wild-type cells. Furthermore, these effects were rescued when the nuclear import of hARD1 was restored by exogenous NLS. Our results show that hARD1 nuclear translocation mediated by NLS is required for cell cycle progression, thereby contributing to proper cell proliferation. 相似文献
190.
Roh-Eul Yoo Seung Hong Choi Hye Rim Cho Bong-sik Jeon Eunbyul Kwon Eung-gyu Kim Juyoung Park Wan-Jae Myeong Jae-Kyung Won Yun-Sang Lee Ji-Hoon Kim Sun-Won Park Chul-Ho Sohn 《PloS one》2014,9(9)