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   11651篇
  免费   597篇
  国内免费   98篇
耳鼻咽喉   107篇
儿科学   254篇
妇产科学   120篇
基础医学   1498篇
口腔科学   310篇
临床医学   702篇
内科学   3314篇
皮肤病学   187篇
神经病学   899篇
特种医学   297篇
外科学   1640篇
综合类   83篇
预防医学   329篇
眼科学   349篇
药学   892篇
中国医学   21篇
肿瘤学   1344篇
  2023年   60篇
  2022年   129篇
  2021年   225篇
  2020年   149篇
  2019年   174篇
  2018年   263篇
  2017年   214篇
  2016年   217篇
  2015年   264篇
  2014年   322篇
  2013年   418篇
  2012年   678篇
  2011年   761篇
  2010年   418篇
  2009年   353篇
  2008年   651篇
  2007年   749篇
  2006年   683篇
  2005年   628篇
  2004年   631篇
  2003年   638篇
  2002年   677篇
  2001年   308篇
  2000年   269篇
  1999年   260篇
  1998年   166篇
  1997年   110篇
  1996年   144篇
  1995年   119篇
  1994年   96篇
  1993年   85篇
  1992年   159篇
  1991年   128篇
  1990年   113篇
  1989年   119篇
  1988年   118篇
  1987年   110篇
  1986年   112篇
  1985年   89篇
  1984年   74篇
  1983年   51篇
  1982年   30篇
  1981年   28篇
  1980年   39篇
  1979年   41篇
  1977年   20篇
  1975年   34篇
  1974年   24篇
  1972年   22篇
  1967年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Our aim was to evaluate the long-term skeletal stability of the mandible in 21 patients after orthognathic surgery with physiological positioning. The measurement points SNB, B point (X, Y), Pog (X, Y), and the angle of the ramus were measured on cephalometric photographs to assess skeletal stability preoperatively, immediately after operation, and one and two years postoperatively. In addition, we evaluated the clinical symptoms of disorders of the temporomandibular joint (TMJ). The analysis of the cephalometric photographs showed that SNB, B point X, and Pog X showed no significant differences among the postoperative time points. On the other hand, B point Y and Pog Y showed no significant differences throughout the study period. We compared the angle of the ramus before operation and two years postoperatively, and no significant difference was found. In addition, no cases showed any pathological symptoms of disorders of the TMJ two years postoperatively. The long-term stability after orthognathic surgery with physiological positioning was confirmed, and it seems to be a reliable orthognathic treatment in patients with mandibular prognathism.  相似文献   
3.
4.
Antipsychotics have been found to induce recurrent psychotic episodes lasting minutes to hours, mostly accompanied by oculogyric crisis (OGC). To characterize this side effect, antipsychotic-induced and postencephalitic OGCs that were reported in the literature were compared to find out common characteristics of OGCs and their associated symptoms. Both postencephalitic and antipsychotic-induced OGCs were found to occur late in the day and at regular intervals, and were associated with autonomic symptoms such as profuse sweating, facial flushing, transitory hypertension and difficulty in micturition. They were often associated also with transient psychiatric episodes: visual hallucinations and illusions, auditory hallucinations, delusions, catatonic phenomena, obsessive thoughts and panic attacks. These (OGC) characteristics will be useful in recognizing antipsychotic-induced psychiatric episodes. The associated psychiatric episodes were noted to recur occasionally also without OGC in a few postencephalic cases, and during gradual dose reduction or after a switch to a novel or low-potency antipsychotic in drug-induced cases. These findings suggest that episodes with the OGC characteristics but without OGC per se, may be less severe reactions to antipsychotic medication than those with OGC, and may represent manifestations of subclinical OGC.  相似文献   
5.
From April 1989 to December 2004, we performed liver biopsy on 475 patients and obtained biopsy proven 35 cases of non-alcoholic fatty liver. Among them, 18 cases were diagnosed as non-alcoholic steatohepatitis (NASH). During the last three years, we have tried to detect NASH using ultrasonography and elevated value of serum ferritin (> 300 ng/ml). All of the eligible 7 cases biopsied during the course were diagnosed as NASH. In these 7 cases, ALT levels improved after the body weight loss accompanied by the parallel decrease of serum ferritin levels. Measurement of serum ferritin is useful in the detection of NASH but the normal value of ferritin cannot rule out the possibility of NASH.  相似文献   
6.
A 69-year-old man was admitted to our kidney center with endstage renal failure. We started intermittent peritoneal dialysis immediately because of severe azotemia, hyperkalemia, and metabolic acidosis. Two weeks after admission, he developed uremic pericarditis with frequent ventricular premature contractions and supraventricular premature contractions. The intermittent peritoneal dialysis was then replaced by intensive hemodialysis, and oral administration of 300 mg/d of cibenzoline was started. Four days later, he developed thirst, weakness, and dyspnea due to respiratory muscular paralysis. We initiated respiratory support with a respirator because analysis of his blood gases revealed marked hypercapnia and hypoxia. He also developed hypoglycemia and prolonged PQ and QRS intervals on the electrocardiogram, which we believed were due to cibenzoline intoxication; we discontinued the cibenzoline immediately. All symptoms improved, and he was extubated 5 days later. After 2 months, his pericardial effusion disappeared. He now continues maintenance hemodialysis as an outpatient. We suspect that the cibenzoline induced the respiratory muscular paralysis for 2 reasons: 1) the patient experienced the respiratory muscular paralysis, at the same time he also experienced thirst, weakness, hypoglycemia, and prolonged PQ and QRS intervals on electrocardiogram, and all of these symptoms improved after the discontinuation of cibenzoline, and 2) his plasma concentration of cibenzoline became remarkably elevated, to 20 times above the standard therapeutic level. This patient's clinical course indicates that hemodialysis might be superior to intermittent peritoneal dialysis for treatment of cibenzoline intoxication.  相似文献   
7.
CYP2E1 and ALDH2 Genotypes and Alcohol Dependence in Japanese   总被引:2,自引:0,他引:2  
The genotypes of the CYP2E1 and ALDH2 loci of alcoholic (alcohol dependence) and nonalcoholic (healthy) Japanese were investigated to examine the relationship between the polymorphism of CYP2E1 (C1/C2) and ALDH2 ( ALDH2*1/ALDH2*2 ), and the susceptibility to alcoholism. There was no significant difference in C2 gene frequency between alcoholics (0.19) and nonalcoholics (controls) (0.20), whereas there was a significant difference in ALDH2 allele frequency, suggesting that, in Japanese, the C2 genotype of CYP2E1 may have nothing to do with the risk of developing alcohol dependence. However, the ALDH2*1 allele may influence drinking behavior and the development of alcohol dependence. Furthermore, racial interethnic differences in the frequency of the mutated allele of the CYP2E1 gene (CJ were found, like the ALDH2 gene. Japanese healthy controls showed a significantly higher frequency of the C2 allele than did Swedish healthy controls (0.05; reported by Persson et al., FEBS Lett. 319:207-211,1993).  相似文献   
8.
K Nagai  T Suda  K Kawasaki  S Mathuura 《Surgery》1986,100(5):815-821
In rats treat-given hydrocortisone to suppress healing, tensile strength of the skin at the site of an incision wound was significantly higher in rats locally treated with carnosine than in untreated animals. Similar effects on the tensile strength of the skin were observed by the administration of beta-alanine and histidine, but not of beta-alanine alone. Exogenous carnosine was degraded in the body by carnosinase and histidine decarboxylase to yield histamine. Since beta-alanine, the other degradation product of carnosine, was found to stimulate the biosynthesis of nucleic acids and collagen, histamine derived from carnosine is considered to have enhanced the process of wound healing by stimulating effusion at the initial stage of inflammation. Thus, the enhancement by carnosine of wound healing may be ascribed to stimulation of early effusion by histamine and of collagen biosynthesis by beta-alanine. The wound-healing effects of carnosine were further demonstrated by the observation that carnosine significantly increased granulation suppressed by cortisone, mitomycin C, 5-fluorouracil, and bleomycin.  相似文献   
9.
Lithium was administered to a 15-year-old boy who had four episodes of hypersomnia following his recovery from influenza. The episodes lasted about a week and were not associated with depression, hypomania or polyphagia, but were heralded by depersonalization. The episode did not recur during prophylactic lithium administration in the latter half of 1983, but recurred later on three occasions when lithium was discontinued or taken less than prescribed. This finding, together with a few cases reported in the literature, appear to indicate that lithium is potentially effective in preventing hypersomnia even in cases unassociated with affective symptoms. However, its preventive effect may not always be complete, as depersonalization recurred in the present case in March 1985 when the serum lithium level was in the therapeutic range.  相似文献   
10.
Mediastinal cystic tumors are well-marginated round lesions that comprise 12% to 18% of all mediastinal masses. These lesions include a variety of diseases with overlapping radiologic appearances and variable prognoses. Pathological examinations are almost always required for differential diagnosis. We encountered a case of anterior mediastinal tumor discovered in the process of investigation of Raynaud's phenomenon. Taking into account the tumor location, a pericardial cyst was initially suspected. However, the tumor was surgically resected and histopathological examinations demonstrated thymus-like tissue in the cyst walls. Raynaud's phenomenon greatly improved after surgery. These findings suggested that cystic thymoma originated from ectopic thymic tissue and is accompanied by paraneoplastic syndrome.  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