全文获取类型
收费全文 | 15541篇 |
免费 | 1414篇 |
国内免费 | 711篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 530篇 |
妇产科学 | 227篇 |
基础医学 | 1588篇 |
口腔科学 | 45篇 |
临床医学 | 1125篇 |
内科学 | 3396篇 |
皮肤病学 | 52篇 |
神经病学 | 1356篇 |
特种医学 | 324篇 |
外国民族医学 | 4篇 |
外科学 | 2120篇 |
综合类 | 2210篇 |
现状与发展 | 3篇 |
预防医学 | 970篇 |
眼科学 | 87篇 |
药学 | 1808篇 |
中国医学 | 1251篇 |
肿瘤学 | 534篇 |
出版年
2024年 | 76篇 |
2023年 | 294篇 |
2022年 | 571篇 |
2021年 | 648篇 |
2020年 | 527篇 |
2019年 | 501篇 |
2018年 | 453篇 |
2017年 | 491篇 |
2016年 | 533篇 |
2015年 | 521篇 |
2014年 | 730篇 |
2013年 | 1041篇 |
2012年 | 709篇 |
2011年 | 830篇 |
2010年 | 719篇 |
2009年 | 621篇 |
2008年 | 610篇 |
2007年 | 647篇 |
2006年 | 671篇 |
2005年 | 562篇 |
2004年 | 529篇 |
2003年 | 511篇 |
2002年 | 412篇 |
2001年 | 429篇 |
2000年 | 381篇 |
1999年 | 288篇 |
1998年 | 287篇 |
1997年 | 249篇 |
1996年 | 291篇 |
1995年 | 280篇 |
1994年 | 258篇 |
1993年 | 221篇 |
1992年 | 201篇 |
1991年 | 156篇 |
1990年 | 171篇 |
1989年 | 171篇 |
1988年 | 143篇 |
1987年 | 105篇 |
1986年 | 91篇 |
1985年 | 117篇 |
1984年 | 94篇 |
1983年 | 89篇 |
1982年 | 85篇 |
1981年 | 71篇 |
1980年 | 76篇 |
1979年 | 48篇 |
1978年 | 39篇 |
1977年 | 27篇 |
1976年 | 22篇 |
1974年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Eglantina Idrizaj Rachele Garella Roberta Squecco Maria Caterina Baccari 《World journal of gastroenterology : WJG》2020,26(20):2472-2478
The regulation of food intake is a complex mechanism, and the hypothalamus is the main central structure implicated. In particular, the arcuate nucleus appears to be the most critical area in the integration of multiple peripheral signals.Among these signals, those originating from the white adipose tissue and the gastrointestinal tract are known to be involved in the regulation of food intake.The present paper focuses on adiponectin, an adipokine secreted by white adipose tissue, which is reported to have a role in the control of feeding by acting centrally. The recent observation that adiponectin is also able to influence gastric motility raises the question of whether this action represents an additional peripheral mechanism that concurs with the central effects of the hormone on food intake. This possibility, which represents an emerging aspect correlating the central and peripheral effects of adiponectin in the hunger-satiety cycle, is discussed in the present paper. 相似文献
2.
3.
Aaron Pitzele Mohammad Rahimi Eric Armbrecht 《The journal of maternal-fetal & neonatal medicine》2015,28(15):1770-1773
Objective: To determine whether packed red blood cell (PRBC) transfusion affects post-prandial superior mesenteric artery blood flow velocities (SMA BFVs) in very-low birth weight (VLBW) neonates and if so, at what time point after transfusion restoration of previous SMA BFV patterns occurs.Design/Methods: VLBW pre-term neonates, older than 14 days and tolerating bolus enteral feedings administered every 3?h were enrolled in this prospective observational study. Pulsed Doppler ultrasound was used to measure pre- and post-prandial (at 45?min) time-averaged mean, peak and end diastolic velocities (TAMV, PSV, EDV) immediately before and after 15?ml/kg of PRBC transfusion was given over 3?h; patent ductus arteriosus (PDA) status was also evaluated. Subsequent pre- and post-prandial SMA BFVs were recorded 24 and 48?h after the transfusion.Results: Pre- and post-prandial measurements were obtained for 21 out of 25 enrolled infants. Post-prandial SMA BFVs were attenuated during the feedings immediately after transfusion; at 24 and 48?h after transfusion, changes in post-prandial SMA BFVs were similar to those measured prior to transfusion; the presence of the PDA did not affect results.Conclusions: PRBC transfusion blunted SMA BFV responses to feedings immediately after the transfusion with normalization observed 24?h post-transfusion. 相似文献
4.
5.
6.
7.
目的探究N6-甲基腺嘌呤(m6A)去甲基化酶ALKBH5与弱精症的相关性。方法收集精液标本30份,包括弱精症患者与健康者精液标本各15份,密度梯度离心纯化精子,使用液相色谱与质谱联用(LC-MS/MS)检测精子RNA的m6A水平,使用实时荧光定量PCR法检测ALKBH5相对表达水平。结果弱精症患者m6A水平明显高于健康者,ALKBH5相对表达水平低于健康者,差异均有统计学意义(P<0.05)。精子活动度参数相关性分析结果显示,ALKBH5相对表达水平与前向运动精子数和非前向运动精子数呈正相关(r=0.512、0.377,P<0.05),与不动精子数呈负相关(r=-0.497,P<0.05);m6A与前向运动精子数和非前向运动精子数呈负相关(r=-0.442、-0.425,P<0.05),与不动精子数呈正相关(r=0.528,P<0.05)。结论在弱精症患者中,m6A及其去甲基化酶ALKBH5与精子活动度具有相关性。 相似文献
8.
BackgroundPercutaneous endoscopic gastrostomy (PEG) is required for Levodopa/Carbidopa Intestinal Gel (LCIG) delivery in patients with advanced Parkinson's disease (PD) as well as for enteral feeding in a variety of neurological disorders. Buried Bumper Syndrome (BBS) is a serious complication of PEG. The frequency of BBS in patients receiving LCIG treatment has never been reported.ObjectivesTo compare the frequency of BBS in patients on LCIG treatment or on enteral feeding over the past 12 years and identify possible risk factors.MethodsWe reviewed prospectively recorded data from 2009 to 2020 on two case-series: LCIG-treated PD patients and non-PD patients on enteral nutrition. We identified all BBS incidences. Patients’ characteristics, clinical manifestations, BBS management, possible risk factors and outcomes were analyzed.ResultsDuring the 12 years, 35 PD patients underwent PEG insertion for LCIG infusion, and 123 non-PD patients for nutritional support. There were eight cases of BBS in six PD patients (17.1%). Six of them were effectively managed without treatment discontinuation. Of the enteral feeding patients, only one developed BBS (0.8%) (p < 0.001). We identified inappropriate PEG site aftercare, weight gain, early onset PD, longer survival, treatment duration, dementia and PEG system design as potential risk factors for BBS development.ConclusionsBBS occurs more frequently in LCIG patients than in patients receiving enteral feeding. If detected early, it can be successfully managed, and serious sequalae or treatment discontinuation can be avoided. Regular endoscopic follow-up visits of LCIG-treated patients and increased awareness in patients and clinicians are recommended. 相似文献
9.
Joseane Balan Da Silva Gleison Daion Piovezana Bossolani Camila Piva Greicy Brisa Malaquias Dias Jancarlo Gomes Ferreira Diogo Francisco Rossoni 《International journal of environmental health research》2016,26(5-6):578-588
The spatial distribution of enteroparasitosis in an indigenous village from Paraná was evaluated to identify areas of risk for these infections. A cross-sectional study (from November 2010 to June 2011) was performed using Three Faecal Test® and Kato &; Katz method and a questionnaire on housing and hygiene conditions was administered. Local geostatistical analyses were performed to determine the spatial distribution of intestinal parasitic infections. The overall prevalence of enteroparasites was 67.2?% (457/680), and the most prevalent taxa were Ascaris lumbricoides (48.8?%) and Trichuris trichiura (44.7?%). The prevalence of heavy infection by soil-transmitted helminths was 3.6?% and the families lived in houses with an average of 5.1 residents and < 2 bedrooms per household. The average number of species per individual present spatial heterogeneity with the highest values (≥0.8) in areas with high clustering of residences. The visualization of the spatial distribution of intestinal parasites in this indigenous village is an important contribution to determining health risk areas and planning decisions and services. 相似文献
10.