全文获取类型
收费全文 | 33484篇 |
免费 | 1907篇 |
国内免费 | 335篇 |
专业分类
耳鼻咽喉 | 550篇 |
儿科学 | 349篇 |
妇产科学 | 462篇 |
基础医学 | 5564篇 |
口腔科学 | 875篇 |
临床医学 | 2675篇 |
内科学 | 6344篇 |
皮肤病学 | 1317篇 |
神经病学 | 2450篇 |
特种医学 | 2246篇 |
外国民族医学 | 1篇 |
外科学 | 4130篇 |
综合类 | 166篇 |
一般理论 | 5篇 |
预防医学 | 1578篇 |
眼科学 | 583篇 |
药学 | 3318篇 |
中国医学 | 444篇 |
肿瘤学 | 2669篇 |
出版年
2024年 | 23篇 |
2023年 | 244篇 |
2022年 | 774篇 |
2021年 | 1238篇 |
2020年 | 559篇 |
2019年 | 798篇 |
2018年 | 974篇 |
2017年 | 798篇 |
2016年 | 1155篇 |
2015年 | 1528篇 |
2014年 | 1802篇 |
2013年 | 2061篇 |
2012年 | 3076篇 |
2011年 | 3017篇 |
2010年 | 1723篇 |
2009年 | 1512篇 |
2008年 | 2093篇 |
2007年 | 1889篇 |
2006年 | 1686篇 |
2005年 | 1559篇 |
2004年 | 1204篇 |
2003年 | 1054篇 |
2002年 | 896篇 |
2001年 | 787篇 |
2000年 | 720篇 |
1999年 | 511篇 |
1998年 | 201篇 |
1997年 | 129篇 |
1996年 | 113篇 |
1995年 | 78篇 |
1994年 | 90篇 |
1993年 | 74篇 |
1992年 | 145篇 |
1991年 | 153篇 |
1990年 | 171篇 |
1989年 | 133篇 |
1988年 | 119篇 |
1987年 | 110篇 |
1986年 | 93篇 |
1985年 | 64篇 |
1984年 | 43篇 |
1983年 | 38篇 |
1982年 | 28篇 |
1981年 | 36篇 |
1979年 | 23篇 |
1978年 | 22篇 |
1977年 | 23篇 |
1975年 | 18篇 |
1974年 | 17篇 |
1970年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
71.
Gordon Nicole T. Alberty-Oller Jaime J. Fei Kezhen Greco Giampaolo Gallagher Emily J. LeRoith Derek Feldman Sheldon M. Killilea Bridgid Boolbol Susan K. Choi Lydia Friedman Neil Pilewskie Melissa Port Elisa Tiersten Amy Bickell Nina A. 《Annals of surgical oncology》2021,28(11):5941-5947
Annals of Surgical Oncology - Black women with breast cancer have a worse overall survival compared with White women; however, no difference in Oncotype DX? (ODX) recurrence scores has been... 相似文献
72.
Clinical and Experimental Nephrology - 相似文献
73.
74.
75.
Hye-Sung Jo Jae Hyun Han Yoon Young Choi Jin-I Seok Young-In Yoon Dong-Sik Kim 《肝胆外科与营养》2021,10(3):325
BackgroundExcessive portal pressure after massive hepatectomy can cause hepatic sinusoidal injury and have deleterious impacts on hepatic functional recovery, contributing to developing post-hepatectomy liver failure. This study aimed to assess the effects of splanchnic vasoactive agents on hepatic functional recovery and regeneration while clarifying the underlying mechanism, using a 70% hepatectomy porcine model.MethodsEighteen pigs undergoing 70% hepatectomy were involved in this study and divided into three groups: control (n=6), terlipressin (n=6), and octreotide (n=6). Terlipressin (0.5 mg) and octreotide (0.2 mg) were administered 3 times a day for each group with the first dose starting just before surgery until the 7th postoperative day, at which time the surviving pigs were sacrificed. During the period, portal pressure, liver weight, biochemical analysis, histological injury score, and molecular markers were evaluated and compared between groups.ResultsThe 7-day survival rates in the octreotide, terlipressin, and control groups were 100%, 83.3%, and 66.7%, respectively. The portal pressures decreased in both terlipressin and octreotide groups than the control group at 30 minutes, 1 hour and 6 hours after hepatectomy. The amount of regeneration measured by liver weight to body weight ratio at the time of sacrifice in the terlipressin group was smaller than that in the control group (117% vs. 129%, P=0.03). Serum aspartate aminotransferase (AST) and total bilirubin levels at 1 and 6 hours after hepatectomy and prothrombin time/international normalized ratio (PT/INR) at 6 hours after hepatectomy were significantly improved in the terlipressin and octreotide groups compared to the control group. Serum endothelin-1 (ET-1) was significantly lower in the terlipressin group than that in the control group 6 hours after hepatectomy (P<0.01). The histological injury score in the control group was significantly higher than that in the terlipressin group on the 7th postoperative day (P<0.01).ConclusionsSplanchnic vasoactive agents, such as terlipressin and octreotide, could effectively decrease portal pressure and attenuate liver injury after massive hepatectomy. 相似文献
76.
An aqueous extract of Platycodi radix inhibits LPS-induced NF-kappaB nuclear translocation in human cultured airway epithelial cells 总被引:5,自引:0,他引:5
We investigated the effects of aqueous extract from Platycodi radix (AEPR), a traditional drug used to treat acute lung inflammatory disease, on lipopolysaccharide (LPS)-induced inflammation in A549 human cultured airway epithelial cells. Nuclear factor-kappaB (NF-kappaB) and its inhibitory regulator, inhibitory kappaB (I-kappaB), play crucial roles in LPS-induced inflammatory response. We show that LPS-induced nuclear translocation of NF-kappaBp65 is inhibited by AEPR. LPS-induced expression of I-kappaBalpha, which is expressed by LPS-induced activation of NF-kappaB, is inhibited by AEPR as well. Besides LPS-induced expression of a group of genes, such as tumor necrosis factor-alpha (TNF-alpha), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), are repressed by AEPR. We also found that expression of heat shock protein 70 (Hsp70), which has an anti-inflammatory activity, is increased by AEPR plus LPS. These results suggest that AEPR may act as a therapeutic agent for inflammatory disease through regulating the activity of NF-kappaB and expression of inflammatory genes. 相似文献
77.
Akt/PKB activation in gastric carcinomas correlates with clinicopathologic variables and prognosis 总被引:23,自引:0,他引:23
Nam SY Lee HS Jung GA Choi J Cho SJ Kim MK Kim WH Lee BL 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2003,111(12):1105-1113
Akt/protein kinase B (PKB) plays an important role in cell survival. However, the role of Akt in the biology of gastric cancer has not been well studied. We sought to investigate the expression of Akt or phosphorylated Akt (pAkt) in human gastric carcinomas and to analyze the relationship between Akt or pAkt and the clinicopathologic parameters. The expressions of Akt and pAkt were evaluated immunohistochemically in 311 gastric carcinomas using the tissue array method. Akt expression was detected in 74% of the tumors and pAkt expression in 78%. pAkt was highly expressed in the early stage of pTNM (p=0.011). We also found an inverse association between pAkt and lymphatic invasion (p=0.01) or lymph node metastasis (p=0.008). pAkt expression was significantly correlated with a higher survival in patients with stage I carcinomas (p=0.0003). Interestingly, combined evaluation revealed that the group with pAkt-positive and lymph node-negative carcinomas showed a better prognosis than the other groups (p<0.0001). In addition, pAkt was shown to correlate positively with APC (p=0.002) and Smad4 (p<0.0001) expression. These findings suggest that pAkt expression may help to predict the clinical outcome of gastric cancer patients. 相似文献
78.
S S Yoon H D Youn C Suh Y J Bang S J Choi B K Kim N K Kim E C Kim 《Journal of Korean medical science》1987,2(4):255-258
One case of arthritis complicating leukemia is described in which leukemic cells were identified in synovial fluid by light microscopy. Although arthritis is a well-known manifestation of leukemia with an incidence of 13.5%, the pathogenesis often is unclear, and the direct demonstration of leukemic cells in synovial fluid has been very uncommon. A 16 year-old male patient was admitted due to left elbow joint pain and swelling. Synovial fluid examination revealed blast cells and this finding has directed to a final diagnosis of acute lymphoblastic leukemia. 相似文献
79.
Gene delivery to glioma cells in rat brain by grafting of a retrovirus packaging cell line 总被引:9,自引:0,他引:9
M P Short B C Choi J K Lee A Malick X O Breakefield R L Martuza 《Journal of neuroscience research》1990,27(3):427-439
Retrovirus vectors only integrate into the genome of dividing cells and can thus be used to selectively infect tumor cells in the adult rat brain. Gene delivery was assessed by using the retrovirus BAG vector, which bears the Escherichia coli lacZ gene under the MoMLV LTR promoter-enhancer element, and by histochemical staining for bacterial beta-galactosidase activity. Direct injection of this vector (90-900 cfu) into the adult rat brain, with or without prior inoculation of C6 glioma cells (2 x 10(5) cells) resulted in labeling of only a few cells as assessed 1 week later. When the psi 2-BAG packaging line was grafted into the brain, labeled psi 2-BAG cells could be found after 1 day, but not after 5 days, following grafting, suggesting that the grafted cells had been rejected and that no endogenous cells had integrated released vector, or that expression of lacZ had been turned off. In contrast, when the psi 2-BAG packaging line was grafted into a brain region, which had been inoculated previously with rat C6 glioma cells (2 x 10(5) cells), beta-galactosidase labeling of these tumor cells, identified by immunocytochemistry for glial fibrillary acidic protein and S100, could be demonstrated 10 days later. Thus, grafting of retrovirus packaging lines into adult brain provides a mean to infect tumor cells in situ. The grafted packaging cells may continue to release retrovirus particles for an extended period, thus infecting more cells at the stage of division appropriate for viral integration, as compared to inoculation of the virus alone. Grafting of retrovirus packaging cell lines could be used to selectively deliver "killer" or "suppressor" genes to tumor cells in the brain to curtail their growth. 相似文献
80.
From the roasted seeds ofCassia tora L., a new naphthopyrone glycoside was isolated and characterized as 10-[(β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl)oxyl-5-hydroxy-8-methoxy-2-methyl-4H-naphtho
[1,2-b]pyran-4-one(isorubrofusarin gentiobioside). Along with isorubrofusarin gentiobioside, alaternin and adenosine were isolated
and identified. 相似文献