全文获取类型
收费全文 | 9472篇 |
免费 | 731篇 |
国内免费 | 184篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 182篇 |
妇产科学 | 131篇 |
基础医学 | 1008篇 |
口腔科学 | 229篇 |
临床医学 | 1240篇 |
内科学 | 1610篇 |
皮肤病学 | 85篇 |
神经病学 | 623篇 |
特种医学 | 261篇 |
外科学 | 840篇 |
综合类 | 872篇 |
一般理论 | 10篇 |
预防医学 | 1525篇 |
眼科学 | 105篇 |
药学 | 635篇 |
3篇 | |
中国医学 | 337篇 |
肿瘤学 | 635篇 |
出版年
2024年 | 9篇 |
2023年 | 239篇 |
2022年 | 227篇 |
2021年 | 520篇 |
2020年 | 388篇 |
2019年 | 433篇 |
2018年 | 391篇 |
2017年 | 364篇 |
2016年 | 361篇 |
2015年 | 367篇 |
2014年 | 596篇 |
2013年 | 842篇 |
2012年 | 550篇 |
2011年 | 555篇 |
2010年 | 478篇 |
2009年 | 430篇 |
2008年 | 471篇 |
2007年 | 400篇 |
2006年 | 335篇 |
2005年 | 274篇 |
2004年 | 278篇 |
2003年 | 237篇 |
2002年 | 184篇 |
2001年 | 178篇 |
2000年 | 135篇 |
1999年 | 110篇 |
1998年 | 111篇 |
1997年 | 103篇 |
1996年 | 91篇 |
1995年 | 81篇 |
1994年 | 75篇 |
1993年 | 46篇 |
1992年 | 60篇 |
1991年 | 47篇 |
1990年 | 43篇 |
1989年 | 42篇 |
1988年 | 44篇 |
1987年 | 34篇 |
1986年 | 32篇 |
1985年 | 37篇 |
1984年 | 33篇 |
1983年 | 28篇 |
1982年 | 15篇 |
1981年 | 22篇 |
1980年 | 19篇 |
1979年 | 16篇 |
1978年 | 11篇 |
1976年 | 12篇 |
1974年 | 8篇 |
1973年 | 6篇 |
排序方式: 共有10000条查询结果,搜索用时 671 毫秒
41.
Martin Grosse Holtforth Louis G. Castonguay Thomas D. Borkovec 《Clinical psychology》2004,11(4):396-404
The conceptual and methodological framework proposed by Doss (this issue) makes valuable suggestions for strategic choices in future research. This commentary addresses conceptual and terminological distinctions adopted by Doss, as well as his criticism of add-on/ dismantling studies. We also suggest research topics and methodological developments that could be integrated in Doss's framework to further expand understanding of therapeutic change. 相似文献
42.
43.
展望分子谱系地理学在道地药材研究中的应用 总被引:4,自引:3,他引:1
作者在介绍分子谱系地理学的概念、研究方法和研究现状的基础上,探讨了分子谱系地理学推断的3种植物遗传分化模式--异域片断化、受距离影响的有限基因流和分布区快速扩展与道地性形成的相关性;阐述了基于分子谱系地理学研究的道地药材分子鉴定对以往分子鉴定局限的突破;阐明了分子谱系地理学在道地药材产地变迁历史研究中的应用;论述了分子谱系地理学在解决道地药材栽培中种质退化问题等方面的作用.这些方面的应用展现了分子谱系地理学在道地药材研究中的应用前景,为道地药材的研究提供了新的理论和方法. 相似文献
44.
Motoaki Nakamura Dean F Salisbury Yoshio Hirayasu Sylvain Bouix Kilian M Pohl Takeshi Yoshida Min-Seong Koo Martha E Shenton Robert W McCarley 《Neuropsychopharmacology》2007,62(7):773-783
BACKGROUND: Overall neocortical gray matter (NCGM) volume has not been studied in first-episode schizophrenia (FESZ) at first hospitalization or longitudinally to evaluate progression, nor has it been compared with first-episode affective psychosis (FEAFF). METHODS: Expectation-maximization/atlas-based magnetic resonance imaging (MRI) tissue segmentation into gray matter, white matter (WM), or cerebrospinal fluid (CSF) at first hospitalization of 29 FESZ and 34 FEAFF, plus 36 matched healthy control subjects (HC), and, longitudinally approximately 1.5 years later, of 17 FESZ, 21 FEAFF, and 26 HC was done. Manual editing separated NCGM and its lobar parcellation, cerebral WM (CWM), lateral ventricles (LV), and sulcal CSF (SCSF). RESULTS: At first hospitalization, FESZ and FEAFF showed smaller NCGM volumes and larger SCSF and LV than HC. Longitudinally, FESZ showed NCGM volume reduction (-1.7%), localized to frontal (-2.4%) and temporal (-2.6%) regions, and enlargement of SCSF (7.2%) and LV (10.4%). Poorer outcome was associated with these LV and NCGM changes. FEAFF showed longitudinal NCGM volume increases (3.6%) associated with lithium or valproate administration but without clinical correlations and regional localization. CONCLUSIONS: Longitudinal NCGM volume reduction and CSF component enlargement in FESZ are compatible with post-onset progression. Longitudinal NCGM volume increase in FEAFF may reflect neurotrophic effects of mood stabilizers. 相似文献
45.
46.
目的:筛选与大肠癌临床分期相关的蛋白,为大肠癌分子分期和预后预测提供依据。方法:将不同临床分期大肠癌组织蛋白进行二维凝胶电泳,选择部分差异表达蛋白进行MALDI-TOF质谱分析和生物信息学分析以鉴定差异表达蛋白;免疫组织化学方法验证筛选结果。结果: 建立了不同临床分期大肠癌组织的二维凝胶电泳图谱,其中Ⅰ,Ⅱ,Ⅲ,Ⅳ大肠癌组织平均蛋白质点数分别为970±41,980±32,1010±43,1240±34;以Ⅰ期大肠癌为参照,Ⅱ期大肠癌差异表达蛋白有52.00±12,Ⅲ期大肠癌差异表达蛋白42.00±11,Ⅳ期大肠癌差异表达蛋白72.00±15,通过进行质谱分析和生物信息学查询,鉴定30个显著差异表达的蛋白点,其中Ⅱ,Ⅲ,Ⅳ均上调的有3种蛋白:AnnexinⅡ,AnnexinⅣ,热休克蛋白27(HSP27)。而仅在Ⅳ期中上调蛋白有1种蛋白,即肝脂肪酸结合蛋白(LFABP)。AnnexinⅡ和肝型脂肪酸结合蛋白表达的免疫组化检测结果与蛋白质筛选结果基本一致。结论:不同临床分期的大肠癌中存在着差异表达蛋白,这些蛋白可能作为大肠癌分子分期和预后的标志物。 相似文献
47.
补益中药对老龄雄性大鼠下丘脑神经递质——甲状腺轴机能作用的研究 总被引:3,自引:0,他引:3
本文通过对3月龄、18月龄、24月龄雄性大鼠下丘脑去甲肾上腺素(NE)、多巴胺(DA)、5-羟色胺(5-HT)、5-羟吲哚乙酸(5-HIAA),和下丘脑垂体促甲状腺释放激素(TRH)、垂体、血甲状腺释放激素(TSH)、血甲状腺激素(T_3、T_4)的测定,研究了大鼠下丘脑神经递质与甲状腺轴机能的增龄性变化,并在此基础上探讨了补益中药对老龄大鼠下丘脑—垂体—甲状腺机能的作用。结果提示:老龄大鼠下丘脑机能的减退是甲状腺轴机能减退的重要原因;补益中药可能改善了老龄大鼠下丘脑的调控机能,进而延缓了甲状腺轴机能的老年性变化。 相似文献
48.
49.
Haruo Ito Zengo Kataumi Shigeyuki Yanagi Kenji Kawamura Hidenori Sumiya Hideki Fuse Jun Shimazaki 《International journal of andrology》1986,9(3):161-169
Testicular development was studied in prepubertal boys with retractile testes. Testicular volume, the diameter of the seminiferous tubules and the number of spermatogonia in the tubules were decreased in cases of unilateral retractile testis, when compared with values for the contralateral normally descended testis. On the other hand, in patients with a unilateral retractile testis and contralateral inguinal testis, there was no difference in the developmental parameters between the two testes. These results suggest that the retractile testis has developmental failures characteristic of a cryptorchid testis and therefore requires orchiopexy. 相似文献
50.
Summary: The present study was undertaken in the hope that conflicting opinions concerning interrelationships among minimal change disease (MCD), mesangial proliferative glomerulonephritis (MPG) and focal segmental glomeruloscierosis (FSGS) might be elucidated by morphometric methods performed by image analysis, as well as to study whether serum creatinine and changes in quantitatively analysed glomeruli could correlate with the interstitial fibrosis in these glomerulopathies. Fifteen renal biopsy specimens from children with MCD, 10 with primary MPG and 12 with FSGS for whom both light and electron microscopy as well as immunofluorescence microscopy and full clinical data were available, were examined quantitatively. As a control five biopsy and 10 autopsy specimens of the normal kidneys were used. Our quantitative study showed that in MCD, MPG and FSGS glomerular and interstitial values differed from normal. Morphometric differences between MPG and both MCD and FSGS groups were also shown. Although the mean values of total glomerular area and relative interstitial volume were increased in FSGS patients, in total glomerular cells per unit of glomerular area and mesangium (% of total glomerular area) were similar in both MCD and FSGS groups. In MPG strong positive correlations existed between interstitial volume and serum creatinine, interstitial volume and total glomerular cells per unit of glomerular area as well as between interstitial volume and glomerular mesangium (% of total glomerular area). In FSGS there was significant positive correlation between interstitial volume and serum creatinine. In the MCD group all correlations were weak and not significant. In conclusion, our morphometric studies suggest a close relationship between MCD and FSGS, and indicate that MPG is a separate morphologic entity in children. 相似文献