全文获取类型
收费全文 | 21398篇 |
免费 | 1562篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 339篇 |
儿科学 | 606篇 |
妇产科学 | 588篇 |
基础医学 | 2597篇 |
口腔科学 | 353篇 |
临床医学 | 2480篇 |
内科学 | 4732篇 |
皮肤病学 | 202篇 |
神经病学 | 1841篇 |
特种医学 | 886篇 |
外国民族医学 | 1篇 |
外科学 | 3169篇 |
综合类 | 246篇 |
一般理论 | 19篇 |
预防医学 | 1726篇 |
眼科学 | 377篇 |
药学 | 1305篇 |
中国医学 | 12篇 |
肿瘤学 | 1527篇 |
出版年
2023年 | 128篇 |
2022年 | 244篇 |
2021年 | 646篇 |
2020年 | 337篇 |
2019年 | 490篇 |
2018年 | 606篇 |
2017年 | 445篇 |
2016年 | 469篇 |
2015年 | 562篇 |
2014年 | 805篇 |
2013年 | 897篇 |
2012年 | 1433篇 |
2011年 | 1509篇 |
2010年 | 776篇 |
2009年 | 599篇 |
2008年 | 1140篇 |
2007年 | 1113篇 |
2006年 | 1099篇 |
2005年 | 1009篇 |
2004年 | 949篇 |
2003年 | 865篇 |
2002年 | 795篇 |
2001年 | 419篇 |
2000年 | 378篇 |
1999年 | 366篇 |
1998年 | 180篇 |
1997年 | 146篇 |
1996年 | 158篇 |
1995年 | 152篇 |
1994年 | 134篇 |
1993年 | 139篇 |
1992年 | 374篇 |
1991年 | 342篇 |
1990年 | 289篇 |
1989年 | 305篇 |
1988年 | 222篇 |
1987年 | 236篇 |
1986年 | 213篇 |
1985年 | 195篇 |
1984年 | 165篇 |
1983年 | 145篇 |
1982年 | 113篇 |
1980年 | 99篇 |
1979年 | 144篇 |
1978年 | 109篇 |
1977年 | 79篇 |
1975年 | 93篇 |
1974年 | 107篇 |
1973年 | 82篇 |
1972年 | 80篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Brittney H. Cotta Margaret F. Meagher Aaron Bradshaw Stephen T. Ryan Gerant Rivera-Sanfeliz 《Expert review of anticancer therapy》2019,19(4):301-308
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.
Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.
Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings. 相似文献
3.
4.
Timo Rath Lukas Pfeifer Clemens Neufert reas Kremer Moritz Leppkes Arthur Hoffman Markus F Neurath Steffen Zopf 《World journal of gastroenterology : WJG》2020,26(16):1962-1970
BACKGROUND The adenoma detection rate(ADR) is inversely associated with the incidence of interval colorectal cancer and serves as a benchmark quality criterion during screening colonoscopy. However, adenoma miss rates reach up to 26% and studies have shown that a second inspection of the right colon in retroflected view(RFV) can increase ADR.AIM To assess whether inspection of the whole colon in RFV compared to standard forward view(SFV) can increase ADR.METHODS Patients presenting for screening or surveillance colonoscopy were invited to participate in this randomized controlled trial and randomized into two arms. In RFV arm colonoscopy was initially performed with SFV, followed by a second inspection of the whole colon in RFV. In the SFV arm first withdrawal was performed with SFV, followed by a second inspection of the whole colon again with SFV. Number, size and morphology of polyps found during first and second inspection in each colonic segment were recorded and all polyps were removed and sent for histopathology in separate containers.RESULTS Two hundred and five patients were randomly assigned to the RFV(n = 101) and SFV(n = 104) arm. In the RFV arm, both polyp detection rate(PDR) and ADR were increased under second inspection in RFV(PDR 1~(st) SFV: 39.8%, PDR 2~(nd)RFV: 46.6%; ADR 1~(st) SFV: 35.2%, ADR 2~(nd) RFV: 42%). Likewise, in the SFV arm,PDR and ADR were increased under second inspection(PDR 1~(st) SFV: 37.5%, PDR 2~(nd) SFV: 46.6%; ADR 1~(st) SFV: 34.1%, ADR 2~(nd)SFV: 44.3%) with no significant differences in ADR and PDR between the SFV and RFV arm. Mean number of adenomas per patient(APP) was increased in the RFV and SFV(APP RFV arm: 1~(st) SFV: 1.71; 2~(nd) RFV: 2.38; APP SFV arm: 1~(st) SFV: 1.83, 2~(nd)SFV:2.2). The majority of adenomas additionally found during second inspection in RFV or in SFV were located in the transverse and left-sided colon and were 5 mm in size.CONCLUSION Second inspection of the whole colon leads to increased adenoma detection with no differences between SFV and RFV. Hence, increased detection is most likely a feature of the second inspection itself but not of the inspection mode. 相似文献
5.
6.
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
7.
8.
9.
10.
A hypothesis for reactivation of pulmonary tuberculosis: How thoracic wall shape affects the epidemiology of tuberculosis 下载免费PDF全文
Aaron R. Casha Liberato Camilleri Alexander Manché Ruben Gatt Daphne Attard Wiktor Wolak Krzysztof Dudek Marilyn Gauci Christopher Giordimaina Joseph N. Grima 《Clinical anatomy (New York, N.Y.)》2015,28(5):614-620
This study was aimed at determining the cause for the high incidence of tuberculosis (TB) reactivation occurring in males with a low body mass index (BMI). Current thinking about pulmonary TB describes infection in the lung apex resulting in cavitation after reactivation. A different hypothesis is put forward for TB infection, suggesting that this occurs in subclinical apical cavities caused by increased pleural stress due to a low BMI body habitus. A finite element analysis (FEA) model of a lung was constructed including indentations for the first rib guided by paramedian sagittal CT reconstructions, and simulations were conducted with varying antero‐posterior (AP) diameters to mimic chests with a different thoracic index (ratio of AP to the transverse chest diameters). A Pubmed search was conducted about gender and thoracic index, and the effects of BMI on TB. FEA modeling revealed a tenfold increase in stress levels at the lung apex in low BMI chests, and a four‐fold increase with a low thoracic index, r2 = 0.9748 P < 0.001. Low thoracic index was related to BMI, P = 0.001. The mean thoracic index was statistically significantly lower in males, P = 0.001, and increased with age in both genders. This article is the first to suggest a possible mechanism linking pulmonary TB reactivation to low BMI due to the flattened thoracic wall shape of young male adults. The low thoracic index in young males may promote TB reactivation due to tissue destruction in the lung apex from high pleural stress levels. Clin. Anat. 28:614–620, 2015. © 2015 Wiley Periodicals, Inc. 相似文献