全文获取类型
收费全文 | 490篇 |
免费 | 24篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 10篇 |
妇产科学 | 1篇 |
基础医学 | 30篇 |
口腔科学 | 2篇 |
临床医学 | 31篇 |
内科学 | 77篇 |
皮肤病学 | 9篇 |
神经病学 | 20篇 |
特种医学 | 44篇 |
外科学 | 95篇 |
综合类 | 123篇 |
一般理论 | 1篇 |
预防医学 | 15篇 |
眼科学 | 12篇 |
药学 | 19篇 |
中国医学 | 1篇 |
肿瘤学 | 22篇 |
出版年
2022年 | 5篇 |
2021年 | 13篇 |
2020年 | 4篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 6篇 |
2016年 | 2篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 11篇 |
2012年 | 24篇 |
2011年 | 20篇 |
2010年 | 9篇 |
2009年 | 21篇 |
2008年 | 32篇 |
2007年 | 16篇 |
2006年 | 30篇 |
2005年 | 13篇 |
2004年 | 22篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 19篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 23篇 |
1997年 | 28篇 |
1996年 | 21篇 |
1995年 | 5篇 |
1994年 | 11篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 10篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 3篇 |
1974年 | 1篇 |
1971年 | 4篇 |
1970年 | 2篇 |
排序方式: 共有516条查询结果,搜索用时 15 毫秒
121.
122.
Purpose
It is a widely held view that anterior resection (AR) for rectal cancer is an oncologically superior operation to abdominoperineal excision (APE). However, some centres have demonstrated better outcomes with APE. We conducted a systematic review of high-quality studies within the total mesorectal excision (TME) era comparing outcomes of AR and APE.Methods
A literature search was performed to identify studies within the TME era comparing AR and APE with regard to the following: circumferential resection margin (CRM) status, tumour perforation rates, specimen quality, local recurrence, overall survival (OS; 3 or 5 year), cancer-specific survival (CSS) and disease-free survival (DFS). Additional data regarding patient demographics and tumour characteristics was collected.Results
Twenty four studies fulfilled the eligibility criteria with Newcastle–Ottawa scores of six or greater. Where a significant difference was found, all studies reported lower and more advanced tumours for APE and 4/5 studies observed more frequent use of neoadjuvant and adjuvant therapies in APE patients. Tumour perforation rates and CRM involvement where reported, were significantly greater for APE. 8 out of 10 studies showing significant differences in local recurrence reported higher rates for APE but no differences were observed with distant recurrence. Where differences were noted, AR was reported to have increased DFS, CSS and OS compared to APE.Conclusions
Patients treated with AR have lower rates of tumour perforation and CRM involvement and tend to have better outcomes with regard to disease recurrence and survival. However, tumours treated by APE are lower and more locally advanced. 相似文献123.
Background: Cation exchange high performance liquid chromatography (HPLC) is emerging as the method of choice for initial screening and diagnosis of haemoglobinopathies. The use of alkaline and acid gel electrophoresis in the developing countries may result in incorrect diagnosis of haemoglobinopathies. The aim of the study is to assess the accuracy and precision of diagnosis of haemoglobinopathies by HPLC and its possible advantage over conventional techniques. 相似文献
124.
Introduction
The Armed Forces personnel are exposed to various kinds of injuries due to the nature of their duties. Increase in motorized population without taking protective measures and rise in violence has contributed towards maxillofacial injuries. The aim of this study was to determine the incidence, aetiology and management of injuries resulting in fracture of the Zygomatic complex in Armed Forces personnel and their families.Methods
This study was conducted at Command Military Dental Centre (EC). Out of 90 maxillofacial injuries, 40 individuals (44.4%) were treated for Zygomatic complex fractures, majority were in their third decade of life and RTA was the leading cause.Result
Thirty seven individuals (92.5%) recovered uneventfully, while three (7.5%) patients had post operative complications such as enophthalmos, paraesthesia, diplopia, facial asymmetry, palpability of implants and facial nerve paresis. These complications were subsequently treated successfully.Conclusion
The midface is composed of fragile bones which get fractured easily. It is imperative to educate people regarding the use of protective headgears/seat belts while travelling in motorized transport.Key Words: Zygomatic complex, Road traffic accident (RTA) 相似文献125.
Background and purpose:
It has been previously shown that high levels of nitric oxide (NO), from NO donors, kill neurones, but the mechanisms are unclear.Experimental approach:
The effects of NO donors on the electrical properties of rat cultured cerebellar granule cells (CGC neurones) were investigated using the whole-cell patch-clamp technique.Key results:
The NO donor (Z)-1-[2-(2-aminoethyl)-N-(2-ammonioethyl)amino]diazen-1-ium-1,2-diolate (DETA-NONOate or NOC-18) caused a rapid, persistent, but fully reversible inward current that was associated with an increase in baseline noise and was concentration dependent (100 µM–10 mM). The response to 3 mM DETA-NONOate was completely inhibited by 1 mM gadolinium, but not by NO scavengers (1 mM haemoglobin or 1 mM PTIO) or glutamate receptor antagonists (10 µM MK-801 or 60 µM CNQX). Application of decomposed 3 mM DETA-NONOate or 3 mM nitrite had no effect. In contrast, the NO donor S-nitrosoglutathione (GSNO) caused a rapid, persistent, but fully reversible outward current that was also concentration dependent (1–10 mM). The 3 mM GSNO response was unaltered by NO scavengers, glutamate antagonists or gadolinium, but was mimicked by decomposed 3 mM GSNO and 3 mM oxidized glutathione.Conclusions and implications:
These results suggest that DETA-NONOate directly activates cation-selective channels, causing an inward current in CGCs. In contrast, GSNO causes an outward current in these cells. Some of the effects of these NO donors are independent of NO, and thus caution is required in interpreting results when using high concentrations of these compounds. 相似文献126.
127.
128.
J Coresh RD Toto KA Kirk PK Whelton S Massry C Jones L Agodoa F Van Lente 《American journal of kidney diseases》1998,32(1):32-42
Serum creatinine and endogenous creatinine clearance (CrCl) are widely used measures of renal function. This study compares the precision, bias, and sources of error in using different CrCl measures to estimate the glomerular filtration rate (GFR) in 118 men and women screened for the African-American Study of Kidney Disease and Hypertension (AASK) pilot study. We measured serum creatinine, 24-hour CrCl, and CrCl during timed clearance periods conducted simultaneously with an 125I-iothalamate GFR study. Serum creatinine was measured using two different kinetic rate Jaffe methods (CX3 and Hitachi). After standardization for body surface area, the different measures of renal function available for each individual were compared with the 125I-iothalamate GFR simultaneous to the CrCl. In a subset of 50 participants, the CrCl measures were compared with a follow-up GFR (fGFR). The mean 125I-iothalamate GFR was 65.2 (SD, 26.4), with a range of 11 to 122 mL/min/1.73 m2. The mean +/- SD percentage differences from the GFR were -9%+/-22% for the Cockcroft-Gault estimated CrCl, 1%+/-29% for the 24-hour CrCl, and 8%+/-16% for the CX3 simultaneous CrCl. The Hitachi method overestimated serum creatinine and underestimated GFR. Compared with an fGFR, the mean +/- SD differences were 2%+/-19% for the first GFR, -6%+/-20% for the Cockcroft-Gault estimated CrCl, 10%+/-28% for the 24-hour CrCl, and 14%+/-29% for the CX3 simultaneous CrCl. Thus, the increased precision with which the timed CrCl predicted its simultaneous GFR did not extend to improved ability to predict a future GFR. The fractional excretion of creatinine, measured as the ratio of the CX3 simultaneous CrCl to 125I-iothalamate clearance, increased with decreasing GFR but was lower than expected (mean +/- SD of 1.21+/-0.16 for GFRs between 20 and 40 mL/min/1.73 m2). The lower fractional excretion explains why the 24-hour and Cockcroft-Gault CrCls did not overestimate GFR, but the reasons for this lower excretion are uncertain. Creatinine assay specificity and calibration are important sources of variability that must be examined in any CrCl measure of GFR. We conclude that despite requiring substantially more time and effort, neither the outpatient 24-hour urine nor the timed CrCl offered increased precision over a calculation based on serum creatinine, sex, age, and weight in predicting GFR. 相似文献
129.
MG Venugopal R Sinha PS Menon PK Chattopadhyay SK Roy Chowdhury 《Medical Journal Armed Forces India》2010
Introduction: The incidence of maxillofacial injuries is on the rise due to motor vehicle accidents and increased incidence of violence in recent times. The aim of this retrospective study was to determine the incidence, aetiology, the pattern of fractures, their management with open reduction and internal fixation (ORIF) and complications, if any. 相似文献
130.
In this study, we explored the antioxidant and anti-inflammatory properties of the medicinal herb Andrographis paniculata using in vitro as well as in vivo systems. Methanolic extract of Andrographis paniculata was found to inhibit formation of oxygen derived free radicals such as superoxide (32%) hydroxyl radicals (80%) lipid peroxidation (80%) and nitric oxide (42.8%) in in vitro system. In vivo studies using BALB/c mice models also showed significant inhibition in PMA induced superoxide (32.4%) and nitric oxide (65.3%) formation. Interestingly we also found that, administration of Andrographis paniculata extract produced complete inhibition of carageenan induced inflammation compared with control models. 相似文献