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   652篇
  免费   38篇
  国内免费   8篇
耳鼻咽喉   5篇
儿科学   49篇
妇产科学   11篇
基础医学   64篇
口腔科学   15篇
临床医学   73篇
内科学   134篇
皮肤病学   6篇
神经病学   29篇
特种医学   140篇
外科学   36篇
综合类   31篇
预防医学   35篇
眼科学   2篇
药学   25篇
肿瘤学   43篇
  2021年   4篇
  2020年   1篇
  2019年   4篇
  2018年   10篇
  2017年   7篇
  2016年   10篇
  2015年   11篇
  2014年   20篇
  2013年   25篇
  2012年   15篇
  2011年   11篇
  2010年   13篇
  2009年   12篇
  2008年   13篇
  2007年   13篇
  2006年   19篇
  2005年   18篇
  2004年   27篇
  2003年   15篇
  2002年   23篇
  2001年   16篇
  2000年   19篇
  1999年   20篇
  1998年   33篇
  1997年   35篇
  1996年   37篇
  1995年   33篇
  1994年   35篇
  1993年   20篇
  1992年   9篇
  1991年   8篇
  1990年   6篇
  1989年   16篇
  1988年   21篇
  1987年   16篇
  1986年   18篇
  1985年   21篇
  1984年   8篇
  1983年   11篇
  1982年   5篇
  1981年   9篇
  1980年   6篇
  1979年   4篇
  1978年   5篇
  1977年   4篇
  1976年   5篇
  1975年   2篇
  1968年   2篇
  1966年   1篇
  1964年   1篇
排序方式: 共有698条查询结果,搜索用时 500 毫秒
1.
2.
Primary tuberculous pathology in nasolpolypi is a rare condition. A case of bilateral ethmoidal polypi with tubercular lesion diagnosed on histopathologlcal examination is being reported and the available relevant literature has been reviewed.  相似文献   
3.
目的:对临床确诊糖尿病患同时测定血清葡萄糖(Glu)及糖化血清蛋白(GSP)的含量,观察二的关系,以及糖化血清蛋白水平对于评价近期(2—3周)糖尿病患血糖在体内变化的临床意义进行了观察。方法:血清葡萄糖、糖化血清蛋白测定均采用酶法测定。结果:178例糖尿病患Glu、GSP均正常3l例占17.4%;Glu、GSP均增高107例占60.1%;Glu正常、GSP增高15例占8.43%;Glu增高、GSP正常25例占14%。结论:糖化血清蛋白的含量不受即时血糖的影响,二的变化不成比例性,对评价糖尿病患2~3周病情的控制是一项灵敏可靠的指标,尤其对于住院病人的治疗与监控有一定的意义。  相似文献   
4.
In the present study we evaluated the protective activity of pyridoxol L,2-pyrrolidon-5 carboxylate (metadoxine) against CCl4 intoxication in rats, especially in relation to liver fibrosis. After 6 consecutive weeks of CCl4 treatment, the animals developed liver fibrosis and inflammation as revealed by histological analysis which also included semiquantitative scoring of these features. In addition the serum levels of the immunoreactive prolyl hydroxylase (SIRPH), an enzyme involved in the hydroxylation of the procollagen molecule, were significantly higher (44.2 +/- 16.3 micrograms/ml; P less than 0.005) in this group of animals than in controls (26.1 +/- 8.06). On the contrary, animals treated with CCl4 + metadoxine (200 mg/kg i.p.) had less severe liver fibrosis and normal SIRPH levels (21.5 +/- 14.6). These data suggest that metadoxine may be an effective pharmacological tool for preventing the progression of liver disease in rats exposed to CCl4 to cirrhosis.  相似文献   
5.
From January 1988 to December 1991, 55 elderly patients (14 pretreated and 41 previously untreated) with non-Hodgkin's lymphoma (NHL) entered a prospective study to evaluate the feasibility of a combination of mitoxantrone (7-9 mg/m2), VP 16-213 (150 mg, 2-hour infusion on day 1, and 200 mg per os on days 3 and 5) and low-dose prednisone (25 mg days 1-5) (MVP regimen), recycling every 21-28 days. The median age was 75 (range 64-93). All but 4 pretreated patients had intermediate- or high-grade lymphomas. Complete remissions were obtained in 22 of 40 (55%) evaluable previously untreated patients, and partial remissions in 10 (2 of these obtained complete remissions after radiotherapy), for an overall response rate of 80%. The median duration of response was 12 months. At 24 months the overall survival was 52% and the relapse-free survival was 31%. Of 14 pretreated patients complete remissions were obtained in 4 (29%) and partial remissions in 3. Granulocytopenia and fever were the most important side effects; two patients contracted bronchopneumonia and one of them died. Other toxicities were mild. We conclude that this combination chemotherapy is effective as first-line and salvage treatment in elderly patients with intermediate- and high-grade NHL, and that it is feasible on an outpatient basis, with manageable toxicity.  相似文献   
6.
7.
8.
Steroid 21-hydroxylase deficiency is among the most common inborn errors of metabolism in man. Characterization of mutations in the 21- hydroxylase gene (CYP21) has permitted genetic diagnosis, facilitated by the polymerase chain reaction (PCR). The most common mutation is conversion of an A or C at nt656 to a G in the second intron causing aberrant splicing of mRNA. Homozygosity for nt656G is associated with profoundly deficient adrenal cortisol and aldosterone synthesis, secondary hypersecretion of adrenal androgens, and a severe form of congenital adrenal hyperplasia (CAH) characterized by ambiguous genitalia and/or sodium wasting in newborns. During the course of genetic analysis of CYP21 mutations in CAH families, we and others have noticed a number of relatives genotyped as nt656G homozygotes, yet showing no clinical signs of disease. A number of lines of evidence have led us to propose that the putative asymptomatic nt656G/G individuals are incorrectly typed due to dropout of one haplotype during PCR amplification of CYP21. For prenatal diagnosis, we recommend that microsatellite typing be used as a supplement to CYP21 genotyping in order to resolve ambiguities at nt656.   相似文献   
9.
Fifty-three families with at least one IDD patient were genotyped for 5 markers of the HLA complex including Bf and DR. In 8 families one of the parents was also affected and in 12 families more than two children were diseased. In total, 76 patients were genotyped. Their haplotypes were compared with those of 106 unrelated controls (the parents of 53 genotyped families).
  • 1) 

    Three haplotypes or segments of them (A2, Cw3, B15, BfS, DR4; Aw30, Cw5, B18, BfF I, DR3; and Al, Cw7, B8, BfS, DR3) were found more frequently in IDD patients.

  • 2) 

    Measured by the 6 formula, the association of the postulated IDD susceptibility gene was very strong with the D-end of two of these haplotypes: BfF1, DR3 and BfS, DR4. However, the association was weak with the DR3 of the haplotype Al, Cw7, B8, BfS, DR3.

  • 3) 

    An excess of HLA-identical affected siblings was found.

  • 4) 

    An excess of DR3/DR4 heterozygotes was observed. By contrast, the observed frequency of patients homozygous for DR3 or DR4 was not increased, but even slightly decreased.


The data support a model of inheritance comprising at least two closely linked specifically "diabetic" loci (most of the time marked by B18, BfFl, DR3 and B15, BfS, DR4) and a non-specifically "diabetic" haplotype favouring auto-immunisation (most of the time marked by B8, BfS, DR3). This model is discussed in the light of the presented data and of those of the literature.  相似文献   
10.
Tuberous sclerosis is an autosomal dominant trait in which the dysregulation of cellular proliferation and differentiation results in the development of hamartomatous growths in many organs. The TSC2 gene is one of two genes determining tuberous sclerosis. Inactivating germline mutations of TSC2 in patients with tuberous sclerosis and somatic loss of heterozygosity at the TSC2 locus in the associated hamartomas indicate that TSC2 functions as a tumour suppressor gene and that loss of function is critical to expression of the tuberous sclerosis phenotype. The TSC2 product, tuberin, has a region of homology with the GTPase activating protein rap1GAP and stimulates the GTPase activity of rap1a and rab5a in vitro. Here we show that the region of homology between tuberin and human rap1GAP and the murine GAP mSpa1 is more extensive than previously reported and spans approximately 160 amino acid residues encoded within exons 34-38 of the TSC2 gene. Single strand conformation polymorphism analysis of these exons in 173 unrelated patients with tuberous sclerosis and direct sequencing of variant conformers together with study of additional family members enabled characterisation of disease associated mutations in 14 cases. Missense mutations, which occurred in exons 36, 37 and 38 were identified in eight cases, four of whom shared the same recurrent change P1675L. Each of the five different missense mutations identified was shown to occur de novo in at least one sporadic case of tuberous sclerosis. The high proportion of missense mutations detected in the region of the TSC2 gene encoding the GAP-related domain supports its key role in the regulation of cellular growth.   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