全文获取类型
收费全文 | 6485篇 |
免费 | 496篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 70篇 |
儿科学 | 152篇 |
妇产科学 | 151篇 |
基础医学 | 771篇 |
口腔科学 | 159篇 |
临床医学 | 675篇 |
内科学 | 1432篇 |
皮肤病学 | 74篇 |
神经病学 | 385篇 |
特种医学 | 191篇 |
外国民族医学 | 1篇 |
外科学 | 1323篇 |
综合类 | 147篇 |
一般理论 | 2篇 |
预防医学 | 423篇 |
眼科学 | 158篇 |
药学 | 450篇 |
中国医学 | 34篇 |
肿瘤学 | 412篇 |
出版年
2023年 | 60篇 |
2022年 | 184篇 |
2021年 | 284篇 |
2020年 | 140篇 |
2019年 | 221篇 |
2018年 | 257篇 |
2017年 | 202篇 |
2016年 | 184篇 |
2015年 | 219篇 |
2014年 | 302篇 |
2013年 | 330篇 |
2012年 | 533篇 |
2011年 | 513篇 |
2010年 | 260篇 |
2009年 | 235篇 |
2008年 | 347篇 |
2007年 | 346篇 |
2006年 | 337篇 |
2005年 | 328篇 |
2004年 | 278篇 |
2003年 | 261篇 |
2002年 | 218篇 |
2001年 | 99篇 |
2000年 | 88篇 |
1999年 | 75篇 |
1998年 | 43篇 |
1997年 | 27篇 |
1996年 | 27篇 |
1995年 | 24篇 |
1994年 | 17篇 |
1993年 | 19篇 |
1992年 | 47篇 |
1991年 | 42篇 |
1990年 | 30篇 |
1989年 | 28篇 |
1988年 | 25篇 |
1987年 | 23篇 |
1986年 | 24篇 |
1985年 | 22篇 |
1984年 | 25篇 |
1983年 | 22篇 |
1982年 | 24篇 |
1981年 | 15篇 |
1979年 | 16篇 |
1978年 | 15篇 |
1977年 | 16篇 |
1976年 | 17篇 |
1973年 | 17篇 |
1972年 | 23篇 |
1971年 | 25篇 |
排序方式: 共有7010条查询结果,搜索用时 15 毫秒
1.
Coronavirus disease 2019 (COVID-19) has resulted in many challenges in patient care, especially among high-risk populations such as heart transplant recipients. Patients with heart transplant experience a significantly higher mortality rate with COVID-19 infection, and management is based on extrapolation from clinical trials done on nontransplant patients and from clinical experience. Here we report 4 cases of patients with heart transplant who presented with COVID-19 infection in late 2020. Patients presented with symptoms similar to those seen in the general population. All 4 patients were admitted to the hospital, and they were all treated with dexamethasone. In addition, 2 patients received remdesivir. Immunosuppressive medications were adjusted to maintain adequate levels of immunosuppression but at the same time allow for an adequate immune response against the infection. All patients were discharged alive from the hospital. We then performed a literature review on studies that included heart transplant patients who developed the infection and developed suggestions for a standardized management approach, which we share in this article. 相似文献
2.
Alexander C. Egbe Rosalyn Adigun Vidhu Anand Collin P. West Victor M. Montori Hassan M. Murad Emmanuel Akintoye Karim Osman Heidi M. Connolly 《The Canadian journal of cardiology》2019,35(12):1784-1790
BackgroundAlthough there are robust data about the pathophysiology and prognostic implications of left ventricular (LV) systolic dysfunction in patients with acquired heart disease, similar prognostic data about LV systolic dysfunction are sparse in the tetralogy of Fallot (TOF) population. The purpose of this study was to perform a meta-analysis of all studies that assessed the relationship between LV ejection fraction (LVEF) and cardiovascular adverse events (CAEs) defined as death, aborted sudden death, or sustained ventricular tachycardia.MethodsWe used random-effects models to calculate hazard ratios (HRs) and 95% confidence intervals (CIs).ResultsOf the 1,809 citations, 7 studies with 2,854 patients (age 28 ± 4 years) were included. During 5.6 ± 3.4 years' follow-up, there were 82 deaths, 17 aborted sudden cardiac deaths, and 56 sustained ventricular tachycardia events. Overall, CAEs occurred in 5.1% (144 patients). As a continuous variable, LVEF was a predictor of CAE (HR 1.29, 95% CI, 1.09-1.53, P = 0.001) per 5% decrease in LVEF. Similarly, LVEF < 40% was also a predictor of CAE (HR 3.22, 95% CI, 2.16-4.80, P < 0.001).ConclusionsLV systolic dysfunction was an independent predictor of CAE, and we observed a 30% increase in the risk of CAE for every 5% decrease in LVEF, and a 3-fold increase in the risk of CAE in patients with LVEF <40% compared with other patients. These findings underscore the importance of incorporating LV systolic function in clinical risk stratification of patients with TOF and the need to explore new treatment options to address this problem. 相似文献
3.
4.
5.
Dr. Menon Raj Gopal M.Ch. AlDelamie Taha FRCS Valliathu John FRCS Zacharias Sunny FRCS Lawati Al Adil FRCS Venkatraman M.Ch. 《Indian Journal of Thoracic and Cardiovascular Surgery》2006,22(3):173-177
Background Despite improving surgical techniques, treatment of heart valve disease in children remains controversial. Somatic growth
and adequate anticoagulation are of concern when children undergo valve replacement. We conducted this study to evaluate the
performance of valves in this age group.
Methods 42 children under the age of 13 years who underwent valve replacement were included in this study. Totally, 50 valves were
implanted in 42 patients: 48 were mechanical prostheses, two were bioprosthetic both in pulmonary position. 37 (74%) valves
were implanted in mitral position, 10 (20%) in aortic position, 1 (2%) in tricuspid position and 2 (4%) in pulmonary position.
Preoperatively, 14 (33,3%) patients were in New York Heart Association (NYHA) class IV, while 27 (64.2%) were in NYHA class
III.
Results There were 2 (4.7%) hospital deaths and 2 (4.7%) late deaths while 2 (4.7%) patients were lost to follow up. The mean follow
up period was 9.4 yrs. 35 (83.3%) patients are in NYHA Class I and free of all medications except warfarin. 3 (7.1%) patients
have undergone 5 successful pregnancies. The median INR was 2.23. Major thrombo-embolic episode occurred in 1 (2.3%) patient.
Conclusions In view of the problems of sizing, anticoagulation and need for re-operation at an early age, there is a reluctance to replace
valves in children. This study shows that despite these problems, valve replacement can be undertaken safely and successfully
in children, when repair has failed or not technically feasible. 相似文献
6.
Why is the age-standardized incidence of low-trauma fractures rising in many elderly populations? 总被引:4,自引:0,他引:4
Pekka Kannus Seppo Niemi Jari Parkkari Mika Palvanen Ari Heinonen Harri Siev?nen Teppo J?rvinen Karim Khan Markku J?rvinen 《Journal of bone and mineral research》2002,17(8):1363-1367
Low-trauma fractures of elderly people are a major public health burden worldwide, and as the number and mean age of older adults in the population continue to increase, the number of fractures is also likely to increase. Epidemiologically, however, an additional concern is that, for unknown reasons, the age-standardized incidence (average individual risk) of fracture has also risen in many populations during the recent decades. Possible reasons for this rise include a birth cohort effect, deterioration in the average bone strength by time, and increased average risk of (serious) falls. Literature provides evidence that the rise is not due to a birth cohort effect, whereas no study shows whether bone fragility has increased during this relatively short period of time. This osteoporosis hypothesis could, however, be tested if researchers would now repeat the population measurements of bone mass and density that were made in the late 1980s and the 1990s. If such studies proved that women's and men's age-standardized mean values of bone mass and density have declined over time, the osteoporosis hypothesis would receive scientific support. The third explanation is based on the hypothesis that the number and/or severity of falls has risen in elderly populations during the recent decades. Although no study has directly tested this hypothesis, a great deal of indirect epidemiologic evidence supports this contention. For example, the age-standardized incidence of fall-induced severe head injuries, bruises and contusions, and joint distortions and dislocations has increased among elderly people similarly to the low-trauma fractures. The fall hypothesis could also be tested in the coming years because the 1990s saw many research teams reporting age- and sex-specific incidences of falling for elderly populations, and the same could be done now to provide data comparing the current incidence rates of falls with the earlier ones. 相似文献
7.
O. M. Karim A. E. Boothroyd J. H. Wyllie 《Annals of the Royal College of Surgeons of England》1990,72(5):304-308
Anthropometric measurements were performed on 51 normal, supine, barium enema examinations to determine the position of the lower pole of the caecum and the base of the appendix relative to palpable bony landmarks (the anterior superior iliac spine and the symphysis pubis). Four quadrants were defined (iliac, umbilical, inguinal and pelvic) by the intersection of the right lateral line and the interspinous line (the line joining the left and right anterior superior iliac spines). The position of the lower pole of the caecum was iliac in 12%, inguinal in 37%, and pelvic in 51%. The appendix or appendix stump was visualised on 53% of the barium examinations. The position of the appendix was iliac in 15%, umbilical in 15%, inguinal in 11%, and pelvic in 59%. The positions of the lower pole of the caecum and base of the appendix are lower and more medial than previously described. 70% of appendices were found to lie inferior to the interspinous line, contrary to established surgical teaching, which assumes McBurney's point to be the surface landmark for the appendix. 相似文献
8.
9.
Diagnostic tests for Helicobacter pylori: comparison and influence of non-steroidal anti-inflammatory drugs.
下载免费PDF全文
![点击此处可从《Journal of clinical pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A. S. Taha P. Boothman I. Nakshabendi J. Reid C. Morran C. G. Gemmell F. D. Lee R. D. Sturrock R. I. Russell 《Journal of clinical pathology》1992,45(8):709-712
AIMS: To evaluate the efficacy of culture, histology, CLO-test, Helico-G and Pyloriset tests in diagnosing Helicobacter pylori in the presence or absence of non-steroidal anti-inflammatory drugs (NSAIDs). METHODS: Of 134 patients studied, 75 had taken NSAIDs. At endoscopy, biopsy specimens were taken for culture, histology, and CLO-test. Blood was also taken for enzyme linked immunosorbent assay (ELISA) (Helico-G) and latex agglutination (Pyloriset) tests. RESULTS: The sensitivity, specificity, and predictive values of histology and CLO-test, compared with culture, ranged from 90% to 97%, regardless of NSAID intake. In the 59 patients not taking NSAIDs Helico-G had a sensitivity of 75% (p < 0.05) and a specificity of 61%; Pyloriset's sensitivity and specificity were, respectively, 63% (p < 0.05) and 67%. In the 75 patients taking NSAIDs the sensitivity of Helico-G was 81% and its specificity 45% (p < 0.05); Pyloriset had a sensitivity of 61% (p < 0.05) and a specificity of 50% (p < 0.05). CONCLUSION: These findings suggest that H pylori is more reliably diagnosed by culture, histology, and CLO-test than by the serological tests used in this study, especially in patients treated with NSAIDs. 相似文献
10.