首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   587篇
  免费   54篇
  国内免费   5篇
耳鼻咽喉   8篇
儿科学   23篇
妇产科学   13篇
基础医学   46篇
口腔科学   14篇
临床医学   81篇
内科学   136篇
皮肤病学   21篇
神经病学   14篇
特种医学   97篇
外科学   61篇
综合类   25篇
预防医学   41篇
眼科学   8篇
药学   16篇
肿瘤学   42篇
  2023年   6篇
  2021年   15篇
  2020年   8篇
  2019年   5篇
  2018年   14篇
  2017年   16篇
  2016年   10篇
  2015年   18篇
  2014年   30篇
  2013年   41篇
  2012年   9篇
  2011年   13篇
  2010年   33篇
  2009年   19篇
  2008年   20篇
  2007年   19篇
  2006年   12篇
  2005年   9篇
  2004年   8篇
  2003年   4篇
  2002年   11篇
  2001年   13篇
  2000年   5篇
  1999年   13篇
  1998年   25篇
  1997年   33篇
  1996年   29篇
  1995年   17篇
  1994年   19篇
  1993年   12篇
  1992年   9篇
  1991年   3篇
  1990年   6篇
  1989年   9篇
  1988年   9篇
  1987年   8篇
  1986年   8篇
  1985年   10篇
  1984年   9篇
  1983年   5篇
  1982年   13篇
  1981年   7篇
  1980年   11篇
  1979年   5篇
  1978年   6篇
  1977年   8篇
  1976年   6篇
  1975年   5篇
  1973年   3篇
  1957年   3篇
排序方式: 共有646条查询结果,搜索用时 15 毫秒
1.
2.

Background  

Pulmonary dysfunction following cardiac surgery is believed to be caused, at least in part, by a lung vascular injury and/or atelectasis following cardiopulmonary bypass (CPB) perfusion and collapse of non-ventilated lungs.  相似文献   
3.

Background  

Shoulder disorders are a common health problem in western societies. Several treatment protocols have been developed for the clinical management of persons with shoulder pain. However available evidence does not support any protocol as being superior over others. Systematic reviews provide some evidence that certain physical therapy interventions (i.e. supervised exercises and mobilisation) are effective in particular shoulder disorders (i.e. rotator cuff disorders, mixed shoulder disorders and adhesive capsulitis), but there is an ongoing need for high quality trials of physical therapy interventions. Usually, physical therapy consists of active exercises intended to strengthen the shoulder muscles as stabilizers of the glenohumeral joint or perform mobilisations to improve restricted mobility of the glenohumeral or adjacent joints (shoulder girdle). It is generally accepted that a-traumatic shoulder problems are the result of impingement of the subacromial structures, such as the bursa or rotator cuff tendons. Myofascial trigger points (MTrPs) in shoulder muscles may also lead to a complex of symptoms that are often seen in patients diagnosed with subacromial impingement or rotator cuff tendinopathy. Little is known about the treatment of MTrPs in patients with shoulder disorders.  相似文献   
4.
BACKGROUND: Nitric oxide (NO) plays a key role in wound repair and S-nitrosothiols like S-nitrosoglutathione (GSNO) are well known NO donors. METHODS: Animals were separated in two groups and submitted to excisional wounds on the dorsal surface at the first day. GSNO (100 microm)-containing hydrogels were topically applied on the wound bed in the GSNO group, daily, during the first 4 days. Control group was topically treated with hydrogel without GSNO for the same period. Wound contraction and re-epithelialization were measured. Animals were sacrificed 21 days after wounding. Samples of lesion and normal tissue were formalin-fixed, paraffin embedded for histological analysis. RESULTS: Wound contraction, measured 14 and 21 days after wounding, was greater in the GSNO group than in the control group (P<0.05 for both). The re-epithelialized wound area, measured 14 days after wounding, was higher in the GSNO group than in the control group (P<0.05). A higher amount of inflammatory cells was observed in superficial and deep areas of the granulation tissue of the control group compared to the GSNO group. Twenty-one days after wounding, thin red-yellow collagen fibers arranged perpendicularly to the surface were found in the granulation tissue of the control group, whereas in the GSNO-treated group collagen fibers were thicker and arranged parallel to the surface. Increased number of mast cells was observed in the GSNO group compared with that in the control group. Vascularization and myofibroblast distribution were similar in both groups. CONCLUSION: Topical application of GSNO-containing hydrogel during the early phases of rat cutaneous wound repair accelerates wound closure and re-epithelialization and affects granulation tissue organization.  相似文献   
5.
Summary: A survey of the medical records and renal biopsy reports of 41 patients with a diagnosis of membranous glomerulonephritis seen at the University Hospital, Faculty of Medicine of Ribeirão Preto, University of São Paulo was undertaken between 1961 and April 1992. Twenty-three of these patients were found to have idiopathic membranous glomerulonephritis (IMG) and 22 of them were treated with corticosteroids and/or immunosuppressants. Data for these 22 patients showed that the age at clinical presentation was 36.3± 17.5 years, white skin colour predominated (14 patients), and 15 were males; nephrotic syndrome was the clinical presentation in 20 patients and proteinuria was accidentally discovered in two patients. On the first hospital visit 11 patients presented proteinuria of up to 3 g/24 h and 16 presented serum creatinine below 1.5 mg/dL, and 14 developed renal hypertension during follow up. Clinicalmorphological correlation permitted us to conclude (in agreement with the literature) that advanced patient age, intensity of proteinuria, serum creatinine levels above 1.5 mg/dL on the occasion of the first hospital visit, and arterial hypertension are clinical-laboratory factors indicating a poor prognosis for IMG. More advanced staging of glomerular damage, presence of segmental mesangial sclerosis and tubulointerstitial involvement are microscopic factors indicating a poor prognosis for IMG.  相似文献   
6.
Life expectancy in British Marfan syndrome populations   总被引:2,自引:0,他引:2  
A total of 206 patients with Marfan syndrome were ascertained throughout genetic clinics in Wales and Scotland during the period 1970–1990. There were 45 deaths representing 22% of the cohort. Mean age at death was 45.3 ± 16.5 years. 50% median cumulative survival in the total cohort (n = 206) was 53 years for males and 72 years for females. Multivariate analysis confirmed severity as the best independent indicator of survival. These findings and survival curves will assist in the counselling of British families and individuals with Marfan syndrome.  相似文献   
7.
8.
Effectiveness of Oximes 2-PAM and HI-6 in Recovery of MuscleFunction Depressed by Organophosphate Agents in the Rat Hemidiaphragm:An in vitro Study. REDDY, V. K., DESHPANDE, S. S., CINTRA, W.M., SCOBLE, G. T., AND ALBUQUERQUE, E. X. (1991). Fundam. Appl.Toxicol. 17, 746–760. Phrenic nerve diaphragm musclesof young adult rats were used to study the ability of the oximes2-PAM and HI-6 to recover muscle function depressed by organophosphate(OP) agents. The single twitch of diaphragm muscles which wereexposed to soman (0.2 mm) recovered after washing with salinefor 3 hr, but the muscles pretreated with sarin (0.4 µM),VX (0.2 µM), or tabun (0.4 µM) showed only partialrecovery. In addition, after 3 hr washing, the muscles pretreatedwith soman as well as with tabun did not recover the tetanussustaining ability (TSA), yet complete recovery was observedwith muscles pretreated with sarin and VX. These results indicatethat the OPs have different effects on muscle contractile propertiesand that VX- and sarin-pretreated muscles recover equally wellafter wash with physiological solution. The recovery of twitchtension of diaphragm muscles by 2-PAM and HI-6 was similar tothat achieved by washing with saline for 3 hr for sarin- andsoman-exposed muscles. The most remarkable differences wereseen in the recovery of TSA. Both 2-PAM and HI-6 recovered theTSA of muscles that were pretreated with sarin and VX. Although2-PAM recovered the TSA after tabun pretreatment, HI-6 had nodiscernible effect. On the other hand, HI-6 recovered the TSAof soman-pretreated muscles but 2-PAM did not. The effectivenessof muscle function recovery was not related to the oximes' abilityto reactivate AChE, thus indicating that the recovery of musclecontractility may be attributed to a direct effect of thesecompounds on the muscle.  相似文献   
9.
Leavitt  SA; DeAngelo  AB; George  MH; Ross  JA 《Carcinogenesis》1997,18(11):2101-2106
Dichloroacetic acid (DCA) is a chlorination byproduct found in finished drinking water. When administered in drinking water this chemical has been shown to produce hepatocellular adenomas and carcinomas in B6C3F1 mice over the animal's lifetime. In this study, we investigated whether mutant frequencies were increased in mouse liver using treatment protocols that yielded significant tumor induction. DCA was administered continuously at either 1.0 or 3.5 g/l in drinking water to male transgenic B6C3F1 mice harboring the bacterial lacI gene. Groups of five or six animals were killed at 4, 10 or 60 weeks and livers removed. At both 4 and 10 weeks of treatment, there was no significant difference in mutant frequency between the treated and control animals at either dose level. At 60 weeks, mice treated with 1.0 g/l DCA showed a 1.3-fold increase in mutant frequency over concurrent controls (P = 0.05). Mice treated with 3.5 g/l DCA for 60 weeks had a 2.3-fold increase in mutant frequency over the concurrent controls (P = 0.002). The mutation spectrum recovered from mice treated with 3.5 g/l DCA for 60 weeks contained G:C-->A:T transitions (32.79%) and G:C-->T:A transversions (21.31%). In contrast, G:C-->A:T transitions comprised 53.19% of the recovered mutants among control animals. Although only 19.15% of mutations among the controls were at T:A sites, 32.79% of the mutations from DCA-treated animals were at T:A sites. This is consistent with the previous observation that the proportion of mutations at T:A sites in codon 61 of the H-ras gene was increased in DCA-induced liver tumors in B6C3F1 mice. The present study demonstrates DCA-associated mutagenicity in the mouse liver under conditions in which DCA produces hepatic tumors.   相似文献   
10.
Female sterilisation is an important component of National Family Welfare Programme. The target group is best motivated during the puerperium for such a procedure. However laparoscopic sterilisation which has got some distinct advantages, is not technically feasible at this time. The authors have used a technique where the advantages of cosmetic appearance, reduced post operative morbidity and reversibility can be conferred on the puerperal women.After trying out the method individually in some cases, a formal case control study design has been made and an evaluation study has been performed in 122 cases. The technique has been found to be cosmetically more acceptable, both at clientele and peer evaluation levels (p<0.001). Though all the four parameters of post operative morbidity have shown better results for the technique evaluated as against the conventional technique, statistical significance has been achieved in two of the parameters (p<0.05).KEY WORDS: Cosmetics, Female sterilisation, Post operative morbidity  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号