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   1579467篇
  免费   107691篇
  国内免费   3382篇
耳鼻咽喉   22974篇
儿科学   48289篇
妇产科学   43920篇
基础医学   221924篇
口腔科学   45569篇
临床医学   132340篇
内科学   315944篇
皮肤病学   36681篇
神经病学   128206篇
特种医学   61086篇
外国民族医学   556篇
外科学   239501篇
综合类   32107篇
现状与发展   6篇
一般理论   499篇
预防医学   113958篇
眼科学   36214篇
药学   117146篇
  3篇
中国医学   3709篇
肿瘤学   89908篇
  2019年   12202篇
  2018年   19367篇
  2017年   14627篇
  2016年   15737篇
  2015年   17609篇
  2014年   22890篇
  2013年   35202篇
  2012年   49592篇
  2011年   51591篇
  2010年   29222篇
  2009年   26789篇
  2008年   47964篇
  2007年   51873篇
  2006年   51496篇
  2005年   50228篇
  2004年   48409篇
  2003年   46324篇
  2002年   45121篇
  2001年   69836篇
  2000年   71669篇
  1999年   60984篇
  1998年   15750篇
  1997年   14338篇
  1996年   13748篇
  1995年   12987篇
  1994年   12124篇
  1992年   45946篇
  1991年   44143篇
  1990年   43302篇
  1989年   42104篇
  1988年   39372篇
  1987年   38642篇
  1986年   37019篇
  1985年   34990篇
  1984年   26218篇
  1983年   22227篇
  1982年   13365篇
  1979年   25110篇
  1978年   17890篇
  1977年   15610篇
  1976年   14030篇
  1975年   16028篇
  1974年   19040篇
  1973年   18543篇
  1972年   17733篇
  1971年   16649篇
  1970年   15779篇
  1969年   15292篇
  1968年   14287篇
  1967年   12745篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
991.
Summary Adrenaline, when administered in dental local anaesthetic solutions, significantly reduces the plasma potassium concentration in young healthy adults. This effect occurs within 10 min of extravascular injections into the maxillary buccal sulcus and may influence the choice of local anaesthetic solution for patients receiving kaliuretic diuretics.  相似文献   
992.
993.
Recently, food intake in Japan has been characterized by an increase in fat intake, especially animal-fat intake and the maintenance of excess salt (sodium chloride) intake. It is generally accepted that the increase in fat intake is closely related to atherosclerosis, and excess salt intake is a high risk factor for the development of hypertension and cerebrovascular lesions. So far, in almost all reports, the increase in fat intake and excess salt intake have been studied independently, and there have been few reports on the combined effects of these two factors. Taking the above things into consideration, it would seem to be very interesting to investigate the effect of excess salt intake on lipid metabolism. In this paper, we studied the effects of excess salt intake on lipoprotein and apolipoprotein metabolisms, using stroke-prone spontaneously hypertensive rats (SHRSP) and normotensive Kyo: Wistar rats (WKY) as model animals. The results obtained were as follows: A significant increase in the concentration of serum total cholesterol (TC) was observed in SHRSP and WKY, when the rats were given a regular diet (CE-2, Clea Japan Inc.) and 1% sodium chloride solution (1% NaCl) as drinking water for 4 weeks. This was accompanied by a tendency toward increases in the concentrations of serum apolipoproteins in both strains. These results suggest that excess salt intake could accelerate the production of serum total lipoproteins in SHRSP and WKY, when the rats are fed a regular diet. Next, 1% NaCl and a high-fat and high-cholesterol diet (HFC diet) were simultaneously given to SHRSP and WKY for 6 weeks. The effects of simultaneous administration on lipoprotein and apolipoprotein metabolisms were compared with those of HFC feeding. One percent NaCl did not markedly affect hypercholesterolemia in WKY, while it induced more marked hypercholesterolemia in SHRSP that was associated with extreme elevations of serum TC and the atherogenic index (A.I.). This deleterious effect of 1% NaCl in SHRSP was due to drastic elevations of cholesterol contents in the very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL) and low density lipoprotein (LDL) fractions. This was also associated with marked increases in apo B contents in the VLDL, IDL and LDL fractions and significant increases in apo E contents in the VLDL and IDL fractions. These results indicate that 1% NaCl induced much larger increases in serum atherogenic beta-lipoproteins in SHRSP.(ABSTRACT TRUNCATED AT 400 WORDS)  相似文献   
994.
Between 1-1-1982 and 1-1-1988 52 children with an end-stage liver disease were evaluated to determine whether orthotopic liver transplantation (OLT) would be appropriate. 24 children were accepted as candidates in the long term. Twelve were not accepted as potential recipients. The parents of 3 decided not to accept OLT as treatment for their children. Two children died before a suitable donor liver was available, so that OLT was carried out in 11 children. Two of these children needed a second transplant. In 3 children only a part of a donor liver was transplanted. Shortage of donor livers of small size is partly alleviated by using a part of a larger liver. The underlying diseases of the transplanted children were cryptogenic cirrhosis (1x), biliary atresia with a hepatoportoenterostomy (8x) and cirrhosis following neonatal hepatitis (2x). Ten children with OLT are clinically and physically well. Postoperatively a primary graft dysfunction occurred in one child. He was retransplanted. The median waiting time for a donor liver was 5 months. The timing for OLT has to take this in account. In treating children with end-stage liver disease (partial) OLT should be considered.  相似文献   
995.
A case of systemic lupus erythematosus (SLE) with focal involvement of the rectum is reported. The lesion roentgenologically resembled a malignant tumour and was resected. Histologic examination disclosed only typical SLE changes in a very restricted area, with the remaining gastrointestinal tract unaffected. This appears to be the first report of focal colitis as a complication of SLE. The case points the importance of suspecting symptoms from any organ system in patients with connective tissue disorders to be manifestations of that underlying pathology.  相似文献   
996.
The authors' 5-year experience in the management and care of prostatic carcinoma are summarized. Their method differs essentially from earlier practice. They have found a new diagnostic and therapeutic method by introducing the TECO irradiation therapy, extensively using bone scintigraphy, by introducing cytostatics, extensively applying the prostate-specific acid phosphatase and by performing rectal biopsy of the prostate. They describe their own observations on the diagnostics and therapy of prostatic carcinoma. They stress that none of the therapies is the method of choice, the use of the various kinds of treatment are defined by strict indications. They state that care of prostatic cancer patients is highly important because only observation of the course of the disease may ensure the evaluation of treatment results and the indication of the adequate therapeutic method.  相似文献   
997.
To evaluate diabetic microangiopathy in the subcutaneous fatty tissue objectively and to clarify the relation between pathogenesis of membranocystic lesion (MCL) and diabetic microangiopathy, specimens obtained from 23 diabetics and 23 nondiabetics were examined histologically. Ten of 23 diabetics and 7 of 23 non-diabetics were examined electron microscopically. Using electron micrographs measurements were made of the following areas; entire microvessel section, basal laminae, luminal space, endothelial cells, pericytes, and we scored the following findings: veil cells, cellular debris and vacuoles in the thickened basal laminae, abnormal densities of the endothelial cells. In diabetics, the area of luminal space was smaller and the area of basal laminae was larger than those of non-diabetics. Scored assessment of the veil cells, cellular debris and vacuoles in the thickened basal laminae were statistically significant in diabetics. Veil cells around the subcutaneous microvessels were less frequent and possessed fewer cytoplasmic processes than those around the dermal microvessels. Histologically, MCLs were frequently demonstrated in skin disorders resulting from diabetic microangiopathy, including 3 cases of pigmented pretibial patches, and 1 case of diabetic bulla. MCLs were more frequently demonstrated in diabetic cases with retinopathy, neuropathy, and nephropathy than those without complications. MCLs were detected only on the shins and the feet. MCLs were more frequently seen in cases with larger area of basal laminae than those with smaller area of basal laminae in morphometric measurement of electron micrographs. The present studies suggest that microangiopathy in the subcutaneous tissue is a pathological feature of diabetes mellitus and is a contributory factor to the formation of MCL.  相似文献   
998.
999.
Circulating immune complexes (CIC), adult schistosome antibody, and total immunoglobulin concentrations were estimated in sera from 35 chronic Schistosoma mansoni patients with different infection intensities and different pathological complications. High CIC levels were present in about one-third (10/35) of the sera. Most of the patients (9/10) with elevated CIC levels also had hepatomegaly or hepatosplenomegaly. This finding is significant in the pathogenesis of schistosomal liver fibrosis and may also apply to other liver diseases, especially cirrhosis. No correlation was found between infection intensity as judged by stool egg counts and CIC levels. A reverse relationship was observed between the level of anti-adult worm IgG and CIC levels. CIC levels were elevated within 7 and 28 days after treatment in most patients. Hypergammaglobulinaemia was detected in most sera.  相似文献   
1000.
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