全文获取类型
收费全文 | 401182篇 |
免费 | 34354篇 |
国内免费 | 17222篇 |
专业分类
耳鼻咽喉 | 4564篇 |
儿科学 | 4346篇 |
妇产科学 | 5977篇 |
基础医学 | 72138篇 |
口腔科学 | 9711篇 |
临床医学 | 28665篇 |
内科学 | 61587篇 |
皮肤病学 | 6780篇 |
神经病学 | 23606篇 |
特种医学 | 10743篇 |
外国民族医学 | 184篇 |
外科学 | 36449篇 |
综合类 | 57520篇 |
现状与发展 | 60篇 |
一般理论 | 8篇 |
预防医学 | 17318篇 |
眼科学 | 5225篇 |
药学 | 46624篇 |
76篇 | |
中国医学 | 12014篇 |
肿瘤学 | 49163篇 |
出版年
2024年 | 840篇 |
2023年 | 6236篇 |
2022年 | 13077篇 |
2021年 | 16596篇 |
2020年 | 13681篇 |
2019年 | 12026篇 |
2018年 | 11801篇 |
2017年 | 12622篇 |
2016年 | 13613篇 |
2015年 | 15661篇 |
2014年 | 24106篇 |
2013年 | 26395篇 |
2012年 | 23100篇 |
2011年 | 26616篇 |
2010年 | 21864篇 |
2009年 | 21868篇 |
2008年 | 22019篇 |
2007年 | 21231篇 |
2006年 | 19326篇 |
2005年 | 16909篇 |
2004年 | 13965篇 |
2003年 | 12242篇 |
2002年 | 9778篇 |
2001年 | 8514篇 |
2000年 | 7332篇 |
1999年 | 6329篇 |
1998年 | 5881篇 |
1997年 | 5441篇 |
1996年 | 4875篇 |
1995年 | 4523篇 |
1994年 | 4138篇 |
1993年 | 3439篇 |
1992年 | 2948篇 |
1991年 | 2705篇 |
1990年 | 2289篇 |
1989年 | 2034篇 |
1988年 | 1867篇 |
1987年 | 1598篇 |
1986年 | 1392篇 |
1985年 | 2035篇 |
1984年 | 1872篇 |
1983年 | 1299篇 |
1982年 | 1425篇 |
1981年 | 1150篇 |
1980年 | 994篇 |
1979年 | 842篇 |
1978年 | 574篇 |
1977年 | 458篇 |
1976年 | 416篇 |
1975年 | 217篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
目的 探讨端粒酶逆转录酶(hTERT)和环氧化酶(cox)-2在乳腺浸润性导管癌中的表达及其临床意义.方法 使用免疫组织化学法分别检测45例乳腺浸润性导管癌和22例乳腺良性病变标本的hTERT和COX-2蛋白表达情况.结果 hTERT在乳腺浸润性导管癌中阳性表达率fig71.11%,明显高于乳腺良性病变9.09%,两者比较差异有统计学意义(P<0.05).hTERT阳性表达与乳腺浸润性导管癌患者的年龄、肿瘤大小、腋窝淋巴结转移情况及雌、孕激素表达水平无相关性(P>0.05),与Her-2表达存在显著相关性(P<0.05).COX-2在乳腺浸润性导管癌中的阳性表达率为82.22%,明显高于乳腺良性病变50.00%,两者比较差异有统计学意义(P<0.05).COX-2阳性表达与乳腺浸润性导管癌患者腋窝淋巴结转移情况、Her-2、ER阳性表达有关(P<0.05).在乳腺浸润性导管癌中hTERT阳性表达与COX-2阳性表达呈正相关(r=0.557,P<0.01).结论 hTERT与COX-2在乳腺浸润性导管癌中的表达显著高于在乳腺良性病变中的表达,hTERT与COX-2在乳腺癌的发生、发展中起重要作用.hTERT表达与COX-2表达存在显著相关性,COX-2的过度表达可能是端粒酶激活和调节的机制之一. 相似文献
92.
Rodica Pop-Busui Jiang Lu Neuza Lopes Teresa L. Z. Jones and the BARI D Investigators 《Journal of the peripheral nervous system : JPNS》2009,14(1):1-13
Abstract We evaluated the associations between glycemic therapies and prevalence of diabetic peripheral neuropathy (DPN) at baseline among participants in the Bypass Angioplasty Revascularization Investigation 2 Diabetes (BARI 2D) trial on medical and revascularization therapies for coronary artery disease (CAD) and on insulin-sensitizing vs. insulin-providing treatments for diabetes. A total of 2,368 patients with type 2 diabetes and CAD was evaluated. DPN was defined as clinical examination score >2 using the Michigan Neuropathy Screening Instrument (MNSI). DPN odds ratios across different groups of glycemic therapy were evaluated by multiple logistic regression adjusted for multiple covariates including age, sex, hemoglobin A1c (HbA1c), and diabetes duration. Fifty-one percent of BARI 2D subjects with valid baseline characteristics and MNSI scores had DPN. After adjusting for all variables, use of insulin was significantly associated with DPN (OR = 1.57, 95% CI: 1.15–2.13). Patients on sulfonylurea (SU) or combination of SU/metformin (Met)/thiazolidinediones (TZD) had marginally higher rates of DPN than the Met/TZD group. This cross-sectional study in a cohort of patients with type 2 diabetes and CAD showed association of insulin use with higher DPN prevalence, independent of disease duration, glycemic control, and other characteristics. The causality between a glycemic control strategy and DPN cannot be evaluated in this cross-sectional study, but continued assessment of DPN and randomized therapies in BARI 2D trial may provide further explanations on the development of DPN. 相似文献
93.
C. Oprea P.J. Szalanski M.V. Gustova I.A. Oprea V. Buzguta 《Applied radiation and isotopes》2009,67(12):2142-2145
R-mode factor analysis was applied to characterize the chemical composition of human teeth investigated by particle induced X-ray emission (PIXE), Rutherford backscattering spectrometry (RBS) and X-ray fluorescence (XRF) techniques. The approach developed in this study enabled the separation between essential mineral teeth components and the pollutants deposited in teeth tissues during the human life. The three independent sources of metals incorporated in human teeth were found. The first source, representing about 43% of the variance of the concentration data, was characterized by pollutant elements of power industry emissions. The second factor was loaded with toxic elements of general urban pollution. The third factor represented the tooth source as it contained mainly large fractions of the mineral components of the tooth tissue as Ca and K. 相似文献
94.
Ho-Seong Han Jai Young Cho Yoo-Seok Yoon 《Journal of hepato-biliary-pancreatic sciences》2009,16(4):427-432
Many studies have recently reported on laparoscopic liver resection, although its development has been slow compared to laparoscopy in other fields. The indications for the location of laparoscopic liver resection have previously been limited to easily accessible lesions. Performing laparoscopic liver resection in the posterior and superior parts of the liver has been considered difficult due to inadequate exposure, the poor operative field and the difficulty with parenchymal dissection. Flexible endoscopy, high definition imaging and various kinds of equipment for parenchymal transection have been introduced for clinical use. In addition, much experience with this procedure has been accumulated at many centers. Accordingly, there are an increasing number of reports on laparoscopic liver resection in difficult locations. At our institution, the location of the tumor is no longer a limitation to laparoscopic liver resection. However, for safer laparoscopic liver resection, the patient positioning and trocar placement should be individualized according to the tumor location. The type of resection also may depend on the remaining liver’s functional capacity. We describe here the technical considerations for performing laparoscopic liver resection, including the technical considerations for performing laparoscopic liver resection for lesions located in the postero-superior segments of the liver. 相似文献
95.
蛋白质组学是研究细胞内所有蛋白质及其动态变化规律的科学,近年来它被广泛应用于生命科学的各个领域.二维聚丙烯酰胺凝胶电泳法(2D PAGE)是蛋白质组学核心技术.就蛋白质组学在皮肤病学基础研究和临床皮肤病中的应用进行综述. 相似文献
96.
Severe myoclonic epilepsy (SMEI) or Dravet syndrome is caused by mutations of the SCN1A gene that encodes voltage-gated sodium channel alpha-1 subunit. Recently, we generated and characterized a knock-in (KI) mice with an SCN1A nonsense mutation that appeared in three independent SMEI patients. The SCN1A-KI mice well reproduced the SMEI disease phenotypes. Both homozygous and heterozygous knock-in mice developed epileptic seizures within the first postnatal month. In heterozygous knock-in mice, trains of evoked action potentials in inhibitory neurons exhibited pronounced spike amplitude decrement late in the burst but not in pyramidal neurons. We further showed that in wild-type mice the Nav1.1 protein is expressed dominantly in axons and moderately in somata of parbalbumin (PV) – positive inhibitory interneurons. Our immunohistochemical observations of the Nav1.1 are clearly distinct to the previous studies, and our findings has corrected the view of the Nav1.1 protein distribution. The data indicate that Nav1.1 plays critical roles in the spike output from PV interneurons and further, that the specifically altered function of these inhibitory circuits may contribute to epileptic seizures in the mice. These information should contribute to the understanding of molecular pathomechanism of SMEI and to develop its effective therapies. 相似文献
97.
Kathleen Hawker 《Annals of Indian Academy of Neurology》2009,12(4):221-225
B cells have recently been identified as an integral component of the immune system; they play a part in autoimmunity through antigen presentation, antibody secretion, and complement activation. Animal models of multiple sclerosis (MS) suggest that myelin destruction is partly mediated through B cell activation (and plasmablasts). MS patients with evidence of B cell involvement, as compared to those without, tend to have a worse prognosis. Finally, the significant decrease in new gadolinium-enhancing lesions, new T2 lesions, and relapses in MS patients treated with rituximab (a monoclonal antibody against CD20 on B cells) leads us to the conclusion that B cells play an important role in MS and that immune modulation of these cells may ameliorate the disease. This article will explore the role of B cells in MS and the rationale for the development of B cell–targeted therapeutics. MS is an immune-mediated disease that affects over 2 million people worldwide and is the number one cause of disability in young patients. Most therapeutic targets have focused on T cells; however, recently, the focus has shifted to the role of B cells in the pathogenesis of MS and the potential of B cells as a therapeutic target. 相似文献
98.
Parastoo Jangouk Thomas Dehmel Gerd Meyer Zu Hörste Andreas Ludwig Helmar C. Lehmann Bernd C. Kieseier 《Glia》2009,57(16):1765-1774
The disintegrin and metalloproteinase 10 (ADAM10) is a membrane‐anchored metalloproteinase with both proteolytic and disintegrin characteristics. Here, we investigate the expression, regulation, and functional role of ADAM10 in axonal outgrowth and myelination of the peripheral nerve. Expression pattern analysis of 11 ADAM family members in co‐cultures of rat dorsal root ganglia (DRG) neurons and Schwann cells (SCs) demonstrated the most pronounced mRNA expression for ADAM10. In further studies, ADAM10 was found to be consistently upregulated in DRG‐SC co‐cultures before the induction of myelination. Neurons as well as SCs widely expressed ADAM10 at the protein level. In neurons, the expression of ADAM10 was exclusively limited to the axons before the induction of myelination. Inhibition of ADAM10 activity by the hydroxamate‐based inhibitors GI254023X and GW280264X resulted in a significant decrease in the mean axonal length. These data suggest that ADAM10 represents a prerequisite for myelination, although its activity is not required during the process of myelination itself as demonstrated by expression analysis of myelin protein zero (P0) and Sudan black staining. Hence, during the process of myelin formation, ADAM10 is highly upregulated and appears to be critically involved in axonal outgrowth that is a requirement for myelination in the peripheral nerve. © 2009 Wiley‐Liss, Inc. 相似文献
99.
100.
G Gaitanis K Nomikos E Vava EC Alexopoulos ID Bassukas 《Journal of the European Academy of Dermatology and Venereology》2009,23(12):1427-1431
Background/aim Theoretical considerations support the combination of cryosurgery and topical imiquimod to treat basal cell carcinomas (BCC). The aim of the present study was to test the feasibility and efficacy of 'cryosurgery during continued imiquimod application' ('immunocryosurgery') to treat 'high-risk-for-recurrence' BCCs.
Methods Thirteen patients with 21 biopsy-proven tumours (4 of 21 relapses after prior surgery) were included. After 2–5 weeks (median, 3) of daily 5% imiquimod cream application, the tumours were treated by liquid N2 cryosurgery (spray, two cycles, 10–20 s) and imiquimod was continued for additional 2–12 weeks (median, 4). The outcome after at least 18 months of follow-up (18–24 months) is currently reported.
Results Nineteen of 21 tumours responded promptly to immunocryosurgery; two tumours required additional treatment cycles to clear. Thus, the clinical clearance rate was 100%. Only 1 of 21(5%) tumour relapsed after at least 18 months of follow-up (cumulative efficacy: 95%).
Conclusions 'Immunocryosurgery' is a promising non-surgical combination modality to treat 'high-risk-for-recurrence BCCs'. Initial evidence is suggestive of an at least additive effect of the two combined modalities. Further studies comparing immunocryosurgery directly with cryosurgery and imiquimod monotherapies will confirm the reported results. 相似文献
Methods Thirteen patients with 21 biopsy-proven tumours (4 of 21 relapses after prior surgery) were included. After 2–5 weeks (median, 3) of daily 5% imiquimod cream application, the tumours were treated by liquid N
Results Nineteen of 21 tumours responded promptly to immunocryosurgery; two tumours required additional treatment cycles to clear. Thus, the clinical clearance rate was 100%. Only 1 of 21(5%) tumour relapsed after at least 18 months of follow-up (cumulative efficacy: 95%).
Conclusions 'Immunocryosurgery' is a promising non-surgical combination modality to treat 'high-risk-for-recurrence BCCs'. Initial evidence is suggestive of an at least additive effect of the two combined modalities. Further studies comparing immunocryosurgery directly with cryosurgery and imiquimod monotherapies will confirm the reported results. 相似文献