全文获取类型
收费全文 | 994篇 |
免费 | 32篇 |
国内免费 | 75篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 46篇 |
妇产科学 | 14篇 |
基础医学 | 76篇 |
口腔科学 | 15篇 |
临床医学 | 153篇 |
内科学 | 234篇 |
皮肤病学 | 34篇 |
神经病学 | 25篇 |
特种医学 | 259篇 |
外科学 | 47篇 |
综合类 | 28篇 |
预防医学 | 43篇 |
眼科学 | 22篇 |
药学 | 60篇 |
中国医学 | 3篇 |
肿瘤学 | 41篇 |
出版年
2023年 | 5篇 |
2021年 | 2篇 |
2020年 | 4篇 |
2019年 | 7篇 |
2018年 | 7篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 12篇 |
2014年 | 16篇 |
2013年 | 17篇 |
2012年 | 19篇 |
2011年 | 18篇 |
2010年 | 33篇 |
2009年 | 48篇 |
2008年 | 19篇 |
2007年 | 53篇 |
2006年 | 21篇 |
2005年 | 23篇 |
2004年 | 12篇 |
2003年 | 14篇 |
2002年 | 16篇 |
2001年 | 23篇 |
2000年 | 20篇 |
1999年 | 10篇 |
1998年 | 83篇 |
1997年 | 71篇 |
1996年 | 60篇 |
1995年 | 53篇 |
1994年 | 43篇 |
1993年 | 45篇 |
1992年 | 24篇 |
1991年 | 15篇 |
1990年 | 23篇 |
1989年 | 34篇 |
1988年 | 34篇 |
1987年 | 27篇 |
1986年 | 24篇 |
1985年 | 25篇 |
1984年 | 18篇 |
1983年 | 11篇 |
1982年 | 17篇 |
1981年 | 9篇 |
1980年 | 13篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 16篇 |
1976年 | 13篇 |
1975年 | 13篇 |
1958年 | 2篇 |
1900年 | 2篇 |
排序方式: 共有1101条查询结果,搜索用时 0 毫秒
991.
Schollen E; Pardon E; Heykants L; Renard J; Doggett NA; Callen DF; Cassiman JJ; Matthijs G 《Human molecular genetics》1998,7(2):157-164
The search for the carbohydrate-deficient glycoprotein syndrome type I
(CDG1) gene has revealed the existence of a family of phosphomannomutase
(PMM) genes in humans. Two expressed PMM genes, PMM1 and PMM2 , are located
on chromosome bands 22q13 and 16p13, respectively, and a processed
pseudogene PMM2 psi is located on chromosome 18p. Mutations in PMM2 are the
cause of CDG type IA whereas no disorder has been associated with defects
in PMM1 as yet. Here, we describe the genomic organization of these
paralogous genes. There is a 65% identity of the coding sequence, and all
intron/exon boundaries have been conserved. The processed pseudogene is
more closely related to PMM2 . Remarkably, several base substitutions in
PMM2 that are associated with disease are also present at the corresponding
positions in the pseudogene. Thus, mutations that occur at a slow rate in
the active gene in the population have also accumulated in the pseudogene.
相似文献
992.
Prognostic factors for an unsatisfactory primary methotrexate treatment of cervical pregnancy: a quantitative review 总被引:17,自引:0,他引:17
Hung TH; Shau WY; Hsieh TT; Hsu JJ; Soong YK; Jeng CJ 《Human reproduction (Oxford, England)》1998,13(9):2636-2642
To determine the risks when the primary methotrexate (MTX) treatment of
cervical pregnancy has an unsatisfactory outcome, we conducted a Medline
search on relevant literature published from January 1983 to June 1997. The
search yielded 28 publications of 48 cases of cervical pregnancy. These and
four new cases from our institutions were used in our study. A cervical
pregnancy that presented with a serum beta-human chorionic gonadotrophin
concentration of > or = 10,000 mIU/ml [odds ratio (OR) 10.82, 95%
confidence interval (CI) 2.59, 45.14], gestational age at > or = 9 weeks
(OR 6.44, 95% CI 1.46, 28.52), embryonic cardiac activity (OR 14.29, 95% CI
2.95, 76.92), and crown- rump length of >10 mm (OR 13.33, 95% CI 1.46,
120.48) was considered to be associated with a higher unsatisfactory rate
of primary MTX treatment. A concomitant feticide was found to enhance the
therapeutic effect of MTX treatment if embryonic cardiac activity was
evident (OR 0.13, 95% CI 0.02, 0.68). Administration of a high dose of MTX
did not seem to be more effective than a lower one. Our findings supported
some previous observations and, more importantly, provided useful clinical
information in selecting appropriate candidates for MTX treatment in cases
of cervical pregnancy.
相似文献
993.
994.
Molecular defects in Sanfilippo syndrome type A 总被引:2,自引:2,他引:2
Sanfilippo A syndrome (mucopolysaccharidosis type IIIA, MPS-IIIA) is an
autosomal recessive neurodegenerative disorder due to an enzymatic defect
of the lysosomal enzyme sulphamidase (EC 3.10.1.1) required for the
degradation of heparan sulphate. In this study, molecular defects in the
sulphamidase gene of MPS-IIIA patients were investigated in a group of 10
patients of Australian and American origin. The entire coding region of the
sulphamidase gene was RT-PCR amplified and one polymorphism (R456H), four
novel mutations (S66W, R245H, E447K, 1307 del 9) and one previously
described mutation (1284 del 11) were identified by direct PCR sequencing.
R245H was present in six patients including one severely affected
homozygote. In three of the other patients with R245H, second mutant
alleles were identified as S66W, 1284 del 11 and E447K, respectively. S66W
was also detected in another patient where the other mutant allele remains
undefined. In addition, 1307 del 9 was also detected in a patient with the
other mutant allele remaining undefined. Allele specific oligonucleotide
hybridisation was used to determine the incidence of these in a population
of 26 MPS-IIIA patients (Australian and American) and 60 normal controls
(Australian). R245H represented 27% (14/52 alleles) in this total patient
population, while the other three changes ranged from 1.9 to 9.6% (1-5 of
52 alleles). The sequence variant, R456H, was shown to be polymorphic as it
was present in 55% of normal and 38% of patient alleles. The total combined
incidence of these five is 46% of alleles. This is the first study of the
molecular defects in MPS-IIIA patients and will greatly assist the
development of molecular analysis for MPS-IIIA patients and studies
concerned with genotype to phenotype relationships.
相似文献
995.
996.
RK Mukherjee MF Back JJ Lu TP Shakespeare CJ Wynne 《Journal of Medical Imaging and Radiation Oncology》2003,47(2):143-145
In February 2003, one woman returned from Hong Kong to Singapore with a previously undescribed atypical pneumonia. Two months later, Singapore is facing its greatest ever threat to its population's health and the country's economy. The government has taken strong action to break the chain of infection of Severe Acute Respiratory Syndrome (SARS). As a radiation oncology department in Singapore, we have faced challenges in keeping staff and patients safe while continuing to provide a service to our patients. In this article, we outline the measures taken to curb SARS in Singapore and discuss the implications for Australasian radiation oncology departments. 相似文献
997.
瑞格列奈治疗 2型糖尿病 68例疗效观察 总被引:1,自引:0,他引:1
目的 :观察瑞格列奈降低 2型糖尿病人的空腹血糖 ,餐后 2h血糖的作用。方法 :2型糖尿病人 68例 ,随机分为治疗组 3 4例 (男 1 8,女 1 6)及对照组 3 4例 (男 1 7,女 1 7)。采用瑞格列奈 0 .5mgpotid× 4周。结果 :能有效降低 2型糖尿病人的空腹血糖 ,餐后 2h血糖的作用。有非常显著性差异 (P <0 .0 1 ) ,尚能降低糖化血红蛋白 (P <0 .0 1 )。结论 :瑞格列奈能有效降低 2型糖尿病人的空腹血糖 ,餐后 2h血糖 ,降低血脂及糖化血红蛋白 ,且无明显副作用。 相似文献
998.
Diarrhoea and perianal excoriation occur frequently after the endorectal pull-through operation for Hirschsprung's disease. A new method of faecal analysis was performed on 3-day stool collections in 17 postoperative Hirschsprung patients and in 14 normal children, in order to define the faecal abnormality and to establish the cause of perianal excoriation in these patients. Loose stools in postoperative patients were deficient in dry solid content and contained an excess of extractable faecal water. This also had a raised electrolyte concentration, particularly with respect to sodium. Total daily output of faecal water was normal. Formed stools from postoperative patients were also deficient in drysolids but had a normal extractable water content. Excess extractable faecal water, the main abnormality of loose stools in these patients, is the result of abnormal water absorption from the distal colon. Perianal excoriation in these patients is most closely associated with the concentration of sodium in faecal water. 相似文献
999.
The effect of continuous positive airway pressure (CPAP) on lung mechanics was investigated in 12 babies after operation for severe congenital heart disease. At the time of study all babies were receiving or being weaned from ventilatory support and had abnormally low lung volume or compliance. During CPAP there was a fall in the pulmonary resistance which, with a slight decrease in minute ventilation, resulted in a significant decrease in the work of breathing. It is suggested that lowering the oxygen cost of breathing may contribute to the improvement in arterial oxygenation seen when CPAP is used. 相似文献
1000.