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   37108篇
  免费   1959篇
  国内免费   71篇
耳鼻咽喉   449篇
儿科学   1120篇
妇产科学   851篇
基础医学   5137篇
口腔科学   884篇
临床医学   3032篇
内科学   6934篇
皮肤病学   683篇
神经病学   3564篇
特种医学   1290篇
外国民族医学   1篇
外科学   5487篇
综合类   123篇
现状与发展   1篇
一般理论   13篇
预防医学   3813篇
眼科学   697篇
药学   2579篇
中国医学   118篇
肿瘤学   2362篇
  2023年   270篇
  2022年   274篇
  2021年   651篇
  2020年   426篇
  2019年   627篇
  2018年   1027篇
  2017年   805篇
  2016年   848篇
  2015年   881篇
  2014年   972篇
  2013年   1540篇
  2012年   2320篇
  2011年   2574篇
  2010年   1271篇
  2009年   930篇
  2008年   1978篇
  2007年   2127篇
  2006年   1964篇
  2005年   2024篇
  2004年   1900篇
  2003年   1836篇
  2002年   1677篇
  2001年   845篇
  2000年   925篇
  1999年   688篇
  1998年   219篇
  1997年   197篇
  1996年   165篇
  1992年   376篇
  1991年   350篇
  1990年   362篇
  1989年   337篇
  1988年   320篇
  1987年   310篇
  1986年   326篇
  1985年   337篇
  1984年   267篇
  1983年   230篇
  1982年   148篇
  1979年   255篇
  1978年   168篇
  1975年   167篇
  1974年   205篇
  1973年   202篇
  1972年   215篇
  1971年   175篇
  1970年   154篇
  1969年   196篇
  1968年   171篇
  1967年   163篇
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
101.
In Hungary valve replacement is still a major indication for heart surgery in adults. In the Cardiovascular Surgical Clinic of Semmelweis Medical University of Budapest from 1976 to 1990 2435 patients were operated for valve disease. Majority of the cases had single (aortic n = 856, mitral n = 912) or double (aortic + mitral n = 513) valve replacement. Over this 15 years period there have been many alterations in patients characteristics and surgical technique as well. In spite of the increasing mean age of patients the operative mortality has decreased (in the last 5 years period it was 2.7%, 5.5% and 7.9% in the three groups respectively). At the same time the number of patients requiring valve re-replacement or combined valve + coronary procedure has increased. The use of bioprosthetic valves has fallen below 10 percent from the 60--80 percent observed between 1976--1980. The analysis showes excellent surgical results in the field of valve replacement in Hungary.  相似文献   
102.
When all-ceramic systems are used, a respect for biocompatibility, an understanding of the patient's esthetic demands, and a justifiable reliance on the strength of the selected system are integral to success. Severely damaged molar teeth in two patients were restored with all-ceramic onlays that were prepared with a copy-milling system for ceramics. The onlay patterns were fabricated directly in the mouth with autopolymerizing resin. For these patients, the use of biologic, all-ceramic, copy-milled restorations resulted in clinical success as well as recovered function and esthetics.  相似文献   
103.
Hydatid cysts of central nervous system are rare and comprise only 2% to 3% of all hydatid cysts reported. Orbital localization is very uncommon and has been reported less than 1 % of all hydatid diseases. The primary treatment of hydatid disease is surgical. The most important complication of the surgical treatment is secondary hydatidosis due to spillage of the cyst contents. Because of the difficulties of the orbital localization, total extirpation of the cysts without rupture is almost impossible. Preventing spontaneous rupture of the cysts during surgery and postoperative antihelmintic treatment should be taken into consideration in these cases.This study includes four cases who underwent surgery for orbital hydatid cysts. Radiological characteristics, operative technique and postoperative medical therapy are discussed.  相似文献   
104.
105.
106.
Background :
The aim of this study was to examine nuclear p53 overexpression in transitional cell carcinoma of the bladder, adenocarcinoma of the prostate, and renal cell carcinoma.
Methods :
Forty-four pathologic specimens from 39 bladder cancer patients, 41 prostatic adenocarcinoma, and 39 renal cell carcinoma specimens were analyzed immunohistochemically with D07 monoclonal antibody to detect the expression of the mutant p53 gene. Overexpression was said to occur when the number of positively-stained tumor nuclei were≥ 10% in each specimen. p53 overexpression was correlated with the clinical and histopathological features of these cancers.
Results :
Nuclear p53 overexpression occurred in 18.2% of transitional cell bladder cancer specimens, 12.2% of prostate cancer specimens, and 17.9% of renal cell cancer specimens. Statistical analyses showed that grade, vascular invasion, and necrosis in bladder cancer, a high Gleason score in prostate cancer, and the 1-year mortality rate in renal cancer were significantly related with p53 nuclear overexpression (P<0.05).
Conclusion :
Using the D07 monoclonal antibody, nuclear p53 overexpression is relatively uncommon in urologic malignancies, and moderately correlates with several histopathological and clinical features of urologic malignancies.  相似文献   
107.
P Berk?  I Molnár 《Orvosi hetilap》1992,133(50):3199-3203
The authors have examined the incidence of intrauterine growth retardation at a country level for the first time both in local and international aspect. Using the nomenclature of NDN-system they have found the frequency of WL-(proportional) retardation 7.95% and that of N-(disproportional) retardation 5.99%. They show incidence of retardation from county to county, as well. Examining the correlation between retardation and perinatal mortality they've stated that while the frequency of still-birth among the average developed and proportionally nutrified fetus is 0.34% and the frequency of perinatal mortality among them is 1.23%, that of the N-retardated newborns is 0.88% and 2.08%, respectively, and that of the WL-retarded is higher than the latter: 2.03% and 3.90% respectively. Regarding the incidence and mortality ratio among the two types of retardation the difference is significant.  相似文献   
108.
Water-suppressed 1H magnetic resonance spectra were recorded from two brain regions of psychiatric patients and normal volunteers. The two regions studied were (a) the basal ganglia structures surrounding the anterior horn of the lateral ventricle and (b) the occipital cortex. N-Acetylaspartate (NAA), phosphocreatine-creatine (PCr-Cr), choline and inositol resonances were seen in both regions. Ratios of metabolite peak integrals to PCr-Cr peak integral were calculated for each spectrum. To control for partial volume effects, comparisons between patients and controls were made only from identical regions i.e. basal ganglia vs basal ganglia, and likewise for occipital cortex. Metabolite ratios from the occipital region of patients were similar to those from the occipital region of normal subjects. Bipolar patients being treated with lithium had elevated NAA/PCr-Cr in the basal ganglia region when compared to normals. These patients also demonstrated elevated choline/PCr-Cr and inositol/PCr-Cr ratios in the basal ganglia region.  相似文献   
109.
Introduction and background A 3-year-old Bosnian girl with a large symptomatic brainstem and multiple supratentorial cavernous angiomas, who underwent neurosurgical treatment, is presented. As multiple cavernomas are more common in familial cases, genetic analyses and neuroradiological imaging were performed in the patient and her parents to see whether there was any evidence for inheritance. This information is important for genetic counseling and provision of medical care for at-risk relatives. Currently, no recommendation is available on how to manage these cases.Results Genetic analyses demonstrated a novel CCM1 frameshift mutation (c.1683_1684insA; p.V562SfsX6) in the child and the asymptomatic 27-year-old mother. Sensitive gradient-echo magnetic resonance imaging of the mother revealed multiple supratentorial lesions, whereas analogous imaging of the father showed no pathological findings.Conclusion This case exemplifies that seemingly sporadic cases with multiple lesions might well be hereditary and that presymptomatic genetic testing of family members may identify relatives for whom clinical and neuroradiological monitoring is indicated.  相似文献   
110.
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