全文获取类型
收费全文 | 4503篇 |
免费 | 233篇 |
国内免费 | 49篇 |
专业分类
耳鼻咽喉 | 68篇 |
儿科学 | 71篇 |
妇产科学 | 93篇 |
基础医学 | 618篇 |
口腔科学 | 110篇 |
临床医学 | 414篇 |
内科学 | 763篇 |
皮肤病学 | 150篇 |
神经病学 | 322篇 |
特种医学 | 203篇 |
外科学 | 577篇 |
综合类 | 32篇 |
一般理论 | 3篇 |
预防医学 | 243篇 |
眼科学 | 67篇 |
药学 | 576篇 |
中国医学 | 110篇 |
肿瘤学 | 365篇 |
出版年
2023年 | 31篇 |
2022年 | 113篇 |
2021年 | 183篇 |
2020年 | 90篇 |
2019年 | 116篇 |
2018年 | 143篇 |
2017年 | 105篇 |
2016年 | 140篇 |
2015年 | 195篇 |
2014年 | 255篇 |
2013年 | 277篇 |
2012年 | 388篇 |
2011年 | 404篇 |
2010年 | 222篇 |
2009年 | 167篇 |
2008年 | 269篇 |
2007年 | 256篇 |
2006年 | 225篇 |
2005年 | 190篇 |
2004年 | 165篇 |
2003年 | 140篇 |
2002年 | 107篇 |
2001年 | 97篇 |
2000年 | 78篇 |
1999年 | 82篇 |
1998年 | 33篇 |
1997年 | 18篇 |
1996年 | 22篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 31篇 |
1991年 | 29篇 |
1990年 | 25篇 |
1989年 | 22篇 |
1988年 | 10篇 |
1987年 | 12篇 |
1986年 | 5篇 |
1985年 | 17篇 |
1984年 | 5篇 |
1983年 | 6篇 |
1979年 | 5篇 |
1974年 | 8篇 |
1972年 | 5篇 |
1971年 | 8篇 |
1970年 | 4篇 |
1969年 | 6篇 |
1968年 | 14篇 |
1967年 | 5篇 |
1966年 | 4篇 |
排序方式: 共有4785条查询结果,搜索用时 31 毫秒
991.
992.
The Bac-T-Screen was used to process 795 urine specimens. Tests for urine specimens took slightly more than two minutes. The Bac-T-Screen predicted with 99 per cent accuracy if a specimen was negative for bacteriuria or pyuria. Thus, approximately one half of all carefully collected urine specimens need no further laboratory culture. In addition, the Bac-T-Screen detected bacteriuria with a sensitivity of 96 per cent at the 10(5) CFU/ml level of probability. Pyuria (1 +) was detected with a sensitivity of 98 per cent. The Bac-T-Screen can be used in an office practice as well as in the clinical laboratory. 相似文献
993.
Metabolic Syndrome Is Associated with Impaired Long-term Renal Allograft Function; Not All Component criteria Contribute Equally 总被引:4,自引:0,他引:4
Aiko P. J. de Vries Stephan J. L. Bakker Willem J. van Son Jaap J. Homan van der Heide Rutger J. Ploeg Hauw T. The Paul E. de Jong Reinold O. B. Gans 《American journal of transplantation》2004,4(10):1675-1683
Chronic renal transplant dysfunction (CRTD) remains a leading cause of renal allograft loss. Evidence suggests that immunological and ischemic insults are mainly associated with CRTD occurring within the first year after transplantation, whereas nonimmunological insults are predominantly associated with CRTD beyond the first year. Several cardiovascular risk factors, such as obesity, dyslipidemia, hypertension, and diabetes mellitus have been identified as important nonimmunological risk factors for CRTD. These risk factors constitute the metabolic syndrome (MS). As renal allograft function is a surrogate marker of renal allograft loss, we investigated the association of MS with impairment of renal allograft function beyond the first year after transplantation in a cross-sectional study of 606 renal transplant outpatients. Metabolic syndrome was defined using the definition of the National Cholesterol Education Program. Renal allograft function was assessed as the 24-h urinary creatinine clearance. A total of 383 out of 606 patients (63%) suffered from MS at a median time of 6 years (2.6-11.4) post-transplant. Presence of MS was associated with impaired renal allograft function beyond 1 year post-transplant [-4.1 mL/min, 95%CI (-7.1, -1.1)]. The impact of MS did not change appreciably after adjustment for established risk factors for CRTD [-3.1 mL/min, 95%CI (-6.0, -0.2)]. However, not all component criteria of MS contributed equally. Only systolic blood pressure and hypertriglyceridemia were independently associated with impaired renal allograft function beyond 1 year post-transplant in multivariate analyses. 相似文献
994.
W J van Son F J van der Woude G K van der Hem T H The T Ockhuizen A M Tegzess 《Transplantation》1985,39(5):510-514
In 20 patients with a cadaveric renal allograft, serial measurements were made of the serum complement factors C3, C4, factor B (FB), and C3d, the stable conversion product of C3. Measurements were started immediately before transplantation and continued thereafter once a week to investigate whether these assays help to differentiate between acute allograft rejection (R) and an active cytomegalovirus (CMV) infection. Fifteen patients had one or more R episodes, and 9 patients suffered from an active CMV infection. Six patients had an R episode and subsequently a CMV infection 13-64 days after R. No significant changes were found in the levels of C3, C4, and FB during R or CMV infection. C3d levels remained unchanged or decreased slightly during R. However, there was a 43-500% increase in the C3d level during CMV infection. This difference in the behavior of levels of C3d during R and CMV infection is significant (P less than 0.01), and suggests that serial measurements of C3d may be useful in differentiating CMV infection from R after renal transplantation. 相似文献
995.
Sam Sik Kang Ju Sun Kim Kun Ho Son Chong Ock Lee Young Hee Kim 《Archives of pharmacal research》1996,19(5):406-410
The flowers ofChrysanthemum boreale afforded handelin, a unique guaianolide dimer and a mixture ofn-hydrocarbons andn-hydrocarbon alcohols in addition to β-sitosterol and β-sitosterol glucoside. Detailed analysis of the1H-and11C-NMR spectra of handelin was carried out by the application of two-dimensional1H-1H-COSY and1H-11C multiple-bond, multiplequantum sepctroscopic correlation techniques. Handelin was inactive in thein vitro anti-tumor activity. 相似文献
996.
997.
The detailed mechanisms underlying long-term potentiation (LTP) are not known. In hippocampal CA1, translocation of protein kinase C (PKC) activity from cytosol to membrane and subsequent phosphorylation of growth associated protein (GAP)-43 have been demonstrated to be critical events for the maintenance phase of LTP. LTP in mossy fiber (MF)-CA3 pathway and the Schaffer collateral/commissural (SC)-CA1 pathway differ in a number of ways: SC-CA1 LTP depends on NMDA receptors while MF-CA3 LTP does not, and SC-CA1 LTP is primarily postsynaptic while MF-CA3 LTP is primarily presynaptic. The role of PKC in MF-CA3 LTP has not been studied. We investigated the role of PKC in CA3 and show that PKC inhibitors prevent LTP, but that PKC activators produce a reversible synaptic potentiation, indicating that PKC activation is an essential but not sufficient component of LTP in CA3. Then using antibodies against specific PKC isozymes we have determined the membrane vs. cytosolic distribution of various PKC isozymes in slices subjected to low or tetanic stimulation, or perfused with phorbol esters (PDAc). Compared with control, LTP and PDAc slices show greater PKC-α and -ε immunoreactivity in the membrane fraction, indicating that both LTP and phorbol ester treatment induce translocation of PKC-α and -ε from cytosol to membrane. However, with PKC-β and PKC-γ the only detectable translocation from cytosol to membrane was in the phorbol ester-treated slices. Thus, while phorbol ester treatment causes translocation of PKC-α, -β, -γ and -ε, the only detectable translocation associated with CA3 LTP is that of PKC-α and -ε. 相似文献
998.
Afoakwah Clifford Nghiem Son Scuffham Paul Byrnes Joshua 《The European journal of health economics》2021,22(4):643-658
The European Journal of Health Economics - Cardiovascular diseases (CVDs) remain a global health challenge due to number of deaths and use of healthcare services related to the condition.... 相似文献
999.
Sae Byul Lee Seung Sang Ko Chan Heun Park Seok Jin Nam Jung Eun Choi Yong Sik Jung Woo-Chan Park Byung Ho Son 《Breast cancer research and treatment》2018,171(2):273-282
Purpose
The purpose of the study was to evaluate protein expression of PD-L1 and CD20 as prognostic biomarkers of patient outcome in inflammatory breast cancer (IBC) samples.Methods
PD-L1 and CD20 protein expression was measured by immunohistochemistry in 221 pretreatment IBC biopsies. PD-L1 was assessed in tumor cells (PD-L1+ tumor cells) and tumor stromal infiltrating lymphocytes (PD-L1+ TILs); CD20 was scored in tumor-infiltrating B cells. Kaplan–Meier curves and Cox proportional hazard models were used for survival analysis.Results
PD-L1+ tumor cells, PD-L1+ TILs, and CD20+ TILs were found in 8%, 66%, and 62% of IBC, respectively. PD-L1+ tumor cells strongly correlated with high TILs, pathological complete response (pCR), CD20+ TILs, but marginally with breast cancer-specific survival (BCSS, P?=?0.057). PD-L1+ TILs strongly correlated with high TILs, CD20+ TILs, and longer disease-free survival (DFS) in all IBC and in triple-negative (TN) IBC (P?<?0.035). IBC and TN IBC patients with tumors containing both CD20+ TILs and PD-L1+ TILs (CD20+TILs/PD-L1+TILs) showed longer DFS and improved BCSS (P?<?0.002) than patients lacking both, or those with either CD20+ TILs or PD-L1+ TILs alone. In multivariate analyses, CD20+TILs/PD-L1+TILs status was an independent prognostic factor for DFS in IBC (hazard ratio (HR): 0.53, 95% CI 0.37–0.77) and TN IBC (HR: 0.39 95% CI 0.17–0.88), and for BCSS in IBC (HR: 0.60 95% CI 0.43–0.85) and TN IBC (HR: 0.38 95% CI 0.17–0.83).Conclusion
CD20+TILs/PD-L1+TILs status represents an independent favorable prognostic factor in IBC and TN IBC, suggesting a critical role for B cells in antitumor immune responses. Anti-PD-1/PD-L1 and B cell-activating immunotherapies should be explored in these settings.1000.
Eunhae Um Ji-Won Kang SaeByul Lee Hee Jeong Kim Tae in Yoon Guiyun Sohn Il Yong Chung Jisun Kim Jong Won Lee Byung Ho Son Sei Hyun Ahn Beom Seok Ko 《Clinical breast cancer》2018,18(5):e1087-e1091