全文获取类型
收费全文 | 4804篇 |
免费 | 241篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 366篇 |
妇产科学 | 107篇 |
基础医学 | 589篇 |
口腔科学 | 194篇 |
临床医学 | 321篇 |
内科学 | 812篇 |
皮肤病学 | 76篇 |
神经病学 | 279篇 |
特种医学 | 123篇 |
外科学 | 598篇 |
综合类 | 112篇 |
一般理论 | 3篇 |
预防医学 | 273篇 |
眼科学 | 217篇 |
药学 | 663篇 |
中国医学 | 21篇 |
肿瘤学 | 280篇 |
出版年
2023年 | 25篇 |
2022年 | 102篇 |
2021年 | 170篇 |
2020年 | 78篇 |
2019年 | 119篇 |
2018年 | 135篇 |
2017年 | 105篇 |
2016年 | 123篇 |
2015年 | 121篇 |
2014年 | 225篇 |
2013年 | 230篇 |
2012年 | 333篇 |
2011年 | 350篇 |
2010年 | 204篇 |
2009年 | 182篇 |
2008年 | 274篇 |
2007年 | 279篇 |
2006年 | 202篇 |
2005年 | 222篇 |
2004年 | 191篇 |
2003年 | 161篇 |
2002年 | 135篇 |
2001年 | 112篇 |
2000年 | 100篇 |
1999年 | 84篇 |
1998年 | 34篇 |
1997年 | 33篇 |
1996年 | 22篇 |
1995年 | 17篇 |
1994年 | 12篇 |
1993年 | 15篇 |
1992年 | 67篇 |
1991年 | 56篇 |
1990年 | 58篇 |
1989年 | 52篇 |
1988年 | 47篇 |
1987年 | 40篇 |
1986年 | 53篇 |
1985年 | 38篇 |
1984年 | 27篇 |
1983年 | 22篇 |
1981年 | 13篇 |
1979年 | 16篇 |
1977年 | 16篇 |
1976年 | 11篇 |
1974年 | 18篇 |
1973年 | 19篇 |
1972年 | 15篇 |
1970年 | 9篇 |
1969年 | 10篇 |
排序方式: 共有5055条查询结果,搜索用时 31 毫秒
51.
OBJECTIVE AND IMPORTANCE: Posterior fossa endodermal cysts are rare. They are located in the midline, in ventral or ventrolateral locations, or intrinsic to the neural axis. Accordingly, various theories of embryogenesis have been proposed. We report the first case of an extradural, dorsolaterally situated endodermal cyst. CLINICAL PRESENTATION: An adult male patient presented with a short history of headache and cerebellar ataxia. Neuroimaging revealed an extra-axial cystic posterior fossa mass. INTERVENTION: An entirely extradural cyst was found and was totally excised. Immunohistochemistry confirmed the diagnosis of endodermal cyst. CONCLUSION: The extradural, dorsal location of the endodermal cyst suggests gaps at the cranial end of the notochord causing ectodermal-endodermal adhesions during early gastrulation and the persistence of endodermal remnants in the dorsal mesenchyme of the blastemal cranium. The literature is reviewed, and proposed theories of embryogenesis are discussed. 相似文献
52.
Naveen K. Jain Chandrashekhar S. Patil R. E. Kartasasmita M. Decker J. Lehmann Shrinivas K. Kulkarni 《Drug development research》2004,61(2):66-78
Naproxen‐2‐nitrooxyethylester (S‐(+)‐2‐(6‐methoxy‐2‐naphthyl)propanoic acid‐2‐nitrooxyethylester, LE‐EK06) was synthesized from naproxen and 2‐nitrooxyethylbromide as a novel nitric oxide–releasing derivative of naproxen. Molar equivalents of LE‐EK06 (6.93–27.73 mg/kg, p.o.) to naproxen dose‐dependently exhibited greater antinociceptive activity in comparison to naproxen in a writhing assay. The compound (5.54–22.18 mg/kg, p.o.) showed greater anti‐inflammatory activity at 2 h after as comparable to its effect at 4 h after carrageenan challenge in rats. Further, LE‐EK06 (9.45 mg/kg, p.o.) was more potent in the carrageenan‐evoked hyperalgesia. LE‐EK06 (11.09 mg/kg, p.o.) and naproxen (8.0 mg/kg, p.o.) showed a comparable inhibitory effect on exudate formation and migration of polymorphonuclear leukocytes (PMNs) in a carrageenan‐induced pleurisy test. Further, the compound (11.09 mg/kg, p.o.) significantly reduced myeloperoxidase activity in carrageenan‐treated paw and demonstrated significantly less gastrotoxicity in acute and chronic (21 days) studies. The scanning electron microscopy revealed that LE‐EK06 showed only mild gastric damage (slight disruption of mucus layer) in comparison to naproxen. The present study suggested that naproxen‐2‐nitrooxyethylester (LE‐EK06) represents a novel gastric sparing NSAID. Drug Dev. Res. 61:66–78, 2004. © 2004 Wiley‐Liss, Inc. 相似文献
53.
RRM1 and PTEN as prognostic parameters for overall and disease-free survival in patients with non-small-cell lung cancer. 总被引:21,自引:0,他引:21
Gerold Bepler Swati Sharma Alan Cantor Ashish Gautam Eric Haura George Simon Anupama Sharma Eric Sommers Lary Robinson 《Journal of clinical oncology》2004,22(10):1878-1885
PURPOSE: RRM1 has important functions in the determination of the malignant phenotype. It controls cell proliferation through deoxynucleotide production and metastatic propensity through PTEN induction. It is located in a region of loss of heterozygosity in non-small-cell lung cancer (NSCLC), which is a predictor of poor survival. We hypothesized that RRM1 expression would be a significant predictor of outcome in NSCLC. PATIENTS AND METHODS: A retrospective data set of 49 patients and a prospective data set of 77 patients with resectable NSCLC were studied. RNA was extracted from tumor and normal lung tissue, and expression of the genes RRM1, PTEN, and RRM2 was determined by real-time quantitative polymerase chain reaction. RESULTS: RRM1 expression was significantly correlated with PTEN and RRM2 expression in tumor tissue. RRM1 and PTEN expression in tumor tissue was highly predictive of overall (P =.011 and.018, respectively) and disease-free survival (P =.002 and.026, respectively). Patients with high levels of expression lived longer and had disease recurrence later than patients with low levels of RRM1 and PTEN. In a multivariate analysis, high RRM1 expression was predictive of long survival independent of tumor stage, performance status, and weight loss. CONCLUSION: RRM1 is a biologically and clinically important determinant of malignant behavior in NSCLC. Knowing the level of expression of this gene adds significant information to management decisions independent of the currently used outcome predictors of tumor stage, performance status, and weight loss. Future clinical trials should stratify patients based on expression of this gene to avoid unwanted biases. 相似文献
54.
P. M. Parikh S. H. Advani J. S. Nadkarni S. Kulkarni G. Kapoor P. S. R. K. Sastry M. Anand T. K. Saikia R. Gopal 《Cancer investigation》1997,15(4):326-328
Hepatic veno-occlusive disease (VOD) is the second most common cause of death after autologous bone marrow transplantation (ABMT). A patient with multiple myeloma undergoing ABMT developed classic features of hepatic VOD. He responded to treatment with pentoxiphyllin. Serum tumor necrosis factor (TNF) levels showed remarkable correlation with the severity of VOD and response to therapy. 相似文献
55.
56.
Kulkarni P 《JAMA》2000,284(12):1512; author reply 1512-1512; author reply 1513
57.
58.
A model to explore the interaction between muscle insulin resistance and beta-cell dysfunction in the development of type 2 diabetes 总被引:2,自引:0,他引:2
Mauvais-Jarvis F Virkamaki A Michael MD Winnay JN Zisman A Kulkarni RN Kahn CR 《Diabetes》2000,49(12):2126-2134
Type 2 diabetes is a polygenic disease characterized by defects in both insulin secretion and insulin action. We have previously reported that isolated insulin resistance in muscle by a tissue-specific insulin receptor knockout (MIRKO mouse) is not sufficient to alter glucose homeostasis, whereas beta-cell-specific insulin receptor knockout (betaIRKO) mice manifest severe progressive glucose intolerance due to loss of glucose-stimulated acute-phase insulin release. To explore the interaction between insulin resistance in muscle and altered insulin secretion, we created a double tissue-specific insulin receptor knockout in these tissues. Surprisingly, betaIRKO-MIRKO mice show an improvement rather than a deterioration of glucose tolerance when compared to betaIRKO mice. This is due to improved glucose-stimulated acute insulin release and redistribution of substrates with increased glucose uptake in adipose tissue and liver in vivo, without a significant decrease in muscle glucose uptake. Thus, insulin resistance in muscle leads to improved glucose-stimulated first-phase insulin secretion from beta-cells and shunting of substrates to nonmuscle tissues, collectively leading to improved glucose tolerance. These data suggest that muscle, either via changes in substrate availability or by acting as an endocrine tissue, communicates with and regulates insulin sensitivity in other tissues. 相似文献
59.