首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   16044篇
  免费   1221篇
  国内免费   52篇
耳鼻咽喉   277篇
儿科学   489篇
妇产科学   346篇
基础医学   2182篇
口腔科学   284篇
临床医学   1689篇
内科学   3391篇
皮肤病学   325篇
神经病学   1697篇
特种医学   508篇
外国民族医学   1篇
外科学   2189篇
综合类   162篇
一般理论   12篇
预防医学   1378篇
眼科学   305篇
药学   1125篇
  1篇
中国医学   11篇
肿瘤学   945篇
  2023年   161篇
  2022年   212篇
  2021年   477篇
  2020年   278篇
  2019年   418篇
  2018年   425篇
  2017年   310篇
  2016年   383篇
  2015年   411篇
  2014年   513篇
  2013年   670篇
  2012年   1013篇
  2011年   961篇
  2010年   499篇
  2009年   477篇
  2008年   744篇
  2007年   779篇
  2006年   790篇
  2005年   699篇
  2004年   686篇
  2003年   560篇
  2002年   496篇
  2001年   369篇
  2000年   359篇
  1999年   310篇
  1998年   116篇
  1997年   111篇
  1996年   81篇
  1995年   86篇
  1992年   226篇
  1991年   218篇
  1990年   203篇
  1989年   247篇
  1988年   192篇
  1987年   188篇
  1986年   194篇
  1985年   195篇
  1984年   135篇
  1983年   153篇
  1982年   92篇
  1981年   86篇
  1980年   90篇
  1979年   152篇
  1978年   96篇
  1975年   80篇
  1974年   94篇
  1973年   80篇
  1972年   86篇
  1971年   82篇
  1969年   81篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
51.
Galactosyl transferase knock-out pig lungs fail rapidly in baboons. Based on previously identified lung xenograft injury mechanisms, additional expression of human complement and coagulation pathway regulatory proteins, anti-inflammatory enzymes and self-recognition receptors, and knock-down of the β4Gal xenoantigen were tested in various combinations. Transient life-supporting GalTKO.hCD46 lung function was consistently observed in association with either hEPCR (n = 15), hTBM (n = 4), or hEPCR.hTFPI (n = 11), but the loss of vascular barrier function in the xenograft and systemic inflammation in the recipient typically occurred within 24 h. Co-expression of hEPCR and hTBM (n = 11) and additionally blocking multiple pro-inflammatory innate and adaptive immune mechanisms was more consistently associated with survival >1 day, with one recipient surviving for 31 days. Combining targeted genetic modifications to the lung xenograft with selective innate and adaptive immune suppression enables prolonged initial life-supporting lung function and extends lung xenograft recipient survival, and illustrates residual barriers and candidate treatment strategies that may enable the clinical application of other organ xenografts.  相似文献   
52.
Smoking and alcohol exposure continue to be the dominant risk factors for the development of head and neck squamous cell carcinoma (SCCHN) worldwide. Moreover, human papillomavirus (HPV) is associated with SCCHN, particularly SCC of the oropharynx (SCCOP). Body mass index (BMI) has been reported as a possible risk factor for SCCHN, yet the data available so far about the relationship between BMI and SCCHN risk have been mixed. We sought to clarify this relationship. BMI and demographic, clinical, and epidemiological information at diagnosis were collected from 2310 SCCHN cases and 1915 controls (who were cancer-free) from October 2001 through May 2013. The odds ratios (ORs) and 95 percent confidence intervals (95% CI) were determined using the logistic regression process. Multivariable models were used to evaluate the strength of the relation between BMI and SCCHN risk. At diagnosis, 64 (2.8%) of the cases were underweight (BMI <18.5 kg/m2), 661 (28.6%) were normal weight (BMI 18.5<25 kg/m2), 833 (36.1%) were overweight (BMI 25<30 kg/m2), and 752 (32.6%) were obese (BMI ≥30 kg/m2). Comparatively, the ORs (95% CIs) for SCCHN associated with being underweight, overweight, and obese were 2.6 (1.54.7), 0.7 (0.6-0.8), and 0.8 (0.7-0.9), respectively, after adjusting for age, gender, race/ethnicity, smoking, and alcohol consumption. On analysis stratified by tumor sites, the risk of SCCOP among patients seropositive for HPVE6 and/or HPVE7 was higher among the overweight (OR, 5.4, 95% CI, 1.3-23.1) and obese patients (OR, 2.4, 95% CI, 1.1-7.6) compared to the normal weight patients. These findings suggest that pretreatment BMI could be a major risk factor for SCCHN, and the association between BMI and HPV may increase the risk of SCCOP.  相似文献   
53.
54.
55.
Cancer Causes & Control - Disparate clinical outcomes for pharyngeal squamous cell carcinoma (PSCC) of the oropharynx (OPSCC) and hypopharynx (HPSCC) have been observed in Black compared with...  相似文献   
56.
57.
58.
59.
60.
Idiopathic hypogonadotropic hypogonadism (IHH) with anosmia (Kallmann syndrome; KS) or with a normal sense of smell (normosmic IHH; nIHH) are heterogeneous genetic disorders associated with deficiency of gonadotropin-releasing hormone (GnRH). While loss-of-function mutations in FGF receptor 1 (FGFR1) cause human GnRH deficiency, to date no specific ligand for FGFR1 has been identified in GnRH neuron ontogeny. Using a candidate gene approach, we identified 6 missense mutations in FGF8 in IHH probands with variable olfactory phenotypes. These patients exhibited varied degrees of GnRH deficiency, including the rare adult-onset form of hypogonadotropic hypogonadism. Four mutations affected all 4 FGF8 splice isoforms (FGF8a, FGF8b, FGF8e, and FGF8f), while 2 mutations affected FGF8e and FGF8f isoforms only. The mutant FGF8b and FGF8f ligands exhibited decreased biological activity in vitro. Furthermore, mice homozygous for a hypomorphic Fgf8 allele lacked GnRH neurons in the hypothalamus, while heterozygous mice showed substantial decreases in the number of GnRH neurons and hypothalamic GnRH peptide concentration. In conclusion, we identified FGF8 as a gene implicated in GnRH deficiency in both humans and mice and demonstrated an exquisite sensitivity of GnRH neuron development to reductions in FGF8 signaling.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号