全文获取类型
收费全文 | 9508篇 |
免费 | 997篇 |
国内免费 | 31篇 |
专业分类
耳鼻咽喉 | 61篇 |
儿科学 | 276篇 |
妇产科学 | 180篇 |
基础医学 | 1398篇 |
口腔科学 | 288篇 |
临床医学 | 1061篇 |
内科学 | 1953篇 |
皮肤病学 | 112篇 |
神经病学 | 984篇 |
特种医学 | 541篇 |
外科学 | 1188篇 |
综合类 | 211篇 |
一般理论 | 2篇 |
预防医学 | 914篇 |
眼科学 | 304篇 |
药学 | 550篇 |
中国医学 | 9篇 |
肿瘤学 | 504篇 |
出版年
2021年 | 140篇 |
2020年 | 92篇 |
2019年 | 139篇 |
2018年 | 175篇 |
2017年 | 154篇 |
2016年 | 145篇 |
2015年 | 180篇 |
2014年 | 252篇 |
2013年 | 378篇 |
2012年 | 481篇 |
2011年 | 417篇 |
2010年 | 291篇 |
2009年 | 288篇 |
2008年 | 378篇 |
2007年 | 393篇 |
2006年 | 403篇 |
2005年 | 341篇 |
2004年 | 354篇 |
2003年 | 273篇 |
2002年 | 331篇 |
2001年 | 267篇 |
2000年 | 213篇 |
1999年 | 221篇 |
1998年 | 193篇 |
1997年 | 167篇 |
1996年 | 195篇 |
1995年 | 144篇 |
1994年 | 147篇 |
1993年 | 102篇 |
1992年 | 227篇 |
1991年 | 203篇 |
1990年 | 191篇 |
1989年 | 223篇 |
1988年 | 203篇 |
1987年 | 187篇 |
1986年 | 171篇 |
1985年 | 185篇 |
1984年 | 144篇 |
1983年 | 127篇 |
1982年 | 92篇 |
1981年 | 76篇 |
1980年 | 81篇 |
1979年 | 110篇 |
1978年 | 91篇 |
1977年 | 89篇 |
1976年 | 71篇 |
1975年 | 79篇 |
1974年 | 85篇 |
1973年 | 79篇 |
1972年 | 70篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Mutations in the retinal guanylate cyclase (RETGC-1) gene in dominant cone-rod dystrophy 总被引:3,自引:0,他引:3
Kelsell RE; Gregory-Evans K; Payne AM; Perrault I; Kaplan J; Yang RB; Garbers DL; Bird AC; Moore AT; Hunt DM 《Human molecular genetics》1998,7(7):1179-1184
The dominant cone-rod dystrophy gene CORD6 has previously been mapped to
within an 8 cM interval on chromosome 17p12-p13. The retinal- specific
guanylate cyclase gene (RETGC-1), which maps to within this genetic
interval and previously was implicated in Leber's congenital amaurosis, was
screened for mutations within this family and in a panel of small families
and individuals with various cone and cone- rod dystrophy phenotypes. A
missense mutation (E837D) was identified in affected members of the CORD6
family, as well as a second missense mutation (R838C) in three other
families with dominant cone-rod dystrophy. RETGC-1 is only the fourth gene
to be implicated in cone-rod dystrophy and this is the first report of
dominant mutations in this gene.
相似文献
72.
73.
Localization of a gene for otosclerosis to chromosome 15q25-q26 总被引:5,自引:0,他引:5
Tomek MS; Brown MR; Mani SR; Ramesh A; Srisailapathy CR; Coucke P; Zbar RI; Bell AM; McGuirt WT; Fukushima K; Willems PJ; Van Camp G; Smith RJ 《Human molecular genetics》1998,7(2):285-290
Among white adults otosclerosis is the single most common cause of hearing
impairment. Although the genetics of this disease are controversial, the
majority of studies indicate autosomal dominant inheritance with reduced
penetrance. We studied a large multi- generational family in which
otosclerosis has been inherited in an autosomal dominant pattern. Five of16
affected persons have surgically confirmed otosclerosis; the remaining nine
have a conductive hearing loss but have not undergone corrective surgery.
To locate the disease- causing gene we completed genetic linkage analysis
using short tandem repeat polymorphisms (STRPs) distributed over the entire
genome. Multipoint linkage analysis showed that only one genomic region, on
chromosome 15q, generated a lod score >2.0. Additional STRPs were typed
in this area, resulting in a lod score of 3.4. STRPs FES (centromeric) and
D15S657 (telomeric) flank the 14. 5 cM region that contains an otosclerosis
gene.
相似文献
74.
75.
Rapid differentiation of the major causative agents of bacterial meningitis by use of frequency-pulsed electron capture gas-liquid chromatograph: analysis of acids. 下载免费PDF全文
The major causative agents of bacterial meningitis, Haemophilus influenzae serogroup B, Neisseria meningitidis serogroups B and C, Klebsiella pneumoniae, Streptococcus pneumoniae, and two types of Escherichia coli, were cultured in a modified chemically defined Catlin medium and in a commercial version of the unmodified Catlin medium. The spent media were extracted under acidic conditions, and electron-capturing derivatives were prepared by derivatization with trichloroethanol or haptafluorobutyric anhydride. The derivatives were analyzed on a gas chromatograph equipped with a frequency-pulsed electron capture detector and a PEP-2 computer. The data obtained from the study show that these organisms can be easily distinguished from each other on the basis of metabolic products detected in either type of medium. Three different metabolic groups were detected within two serogroups of N. meningitidis. The methods are practical, and the new technique should offer clinical laboratories and hospitals a better method for rapid identification of this important group of pathogens. 相似文献
76.
A Srour AM El Tantawi N Khouja A Zouaoui J-P Lassau J Philippon Ph Cornu 《Surgical and radiologic anatomy : SRA》1994,16(1):117-119
Summary The anterior interhemispheric approach for aneurysms of the anterior communicating artery was studied in ten cadavers. This approach presents several advantages over the pterional approach widely used in neurosurgery. It allows direct access to the region of the anterior communicating artery complex with minimal retraction of the brain and preservatioin of the olfactory tract and the gyrus rectus.
Bases anatomiques de l'abord inter-hémisphérique antérieur lors de la chirurgie des anévrysmes de l'artère communicante antérieure
Résumé Ce travail concerne l'abord neurochirurgical des anévrysmes de l'artére communicante antérieure par voie frontale interhémisphérique. L'étude anatomique a été réalisée sur dix sujets. Cette exposition possède de nombreux avantages comparée à la voie ptérionale habituelle : voie d'abord reduite médiane permettant une visualisation directe et symétrique du complexe artériel de l'artére communicante antérieure ; avec le moindre manipulation et retraction du cerveau en respectant les voies olfactives et le gyrus rectus.相似文献
77.
T. R. Brooks 《Journal of the National Medical Association》1996,88(5):300-304
This study was undertaken to determine the association between health providers'' stress and performances, and patients who presented with disability forms that the providers did not feel were justified. Two questionnaires were given to health-care providers at the Family Practice Clinic, Martin Luther King/Drew Medical Center, Los Angeles, California. One questionnaire assessed the level of stress they suffered from, and a second questionnaire assessed how these types of patients may affect their general performance. The data suggested that the performance of providers was definitely affected by hostile, demanding, threatening, and malingering patients. The students, residents, nurses, and clinic administrative staff were all affected. Third-year medical students and foreign-trained doctors appeared not to be affected as much, probably because of a lack of knowledge about the "system" or because they preferred not to "rock the boat". 相似文献
78.
Murine neurotropic retrovirus spongiform polioencephalomyelopathy: acceleration of disease by virus inoculum concentration. 总被引:4,自引:1,他引:4 下载免费PDF全文
A 10-fold reduction in the incubation period of murine neurotropic retrovirus spongiform polioencephalomyelopathy was effected by a 1,000-fold concentration of the cloned virus inoculum. 相似文献
79.
Atm is a stress-induced DNA damage checkpoint protein kinase with multiple roles in cell-cycle progression. Recent evidence indicates that Atm also plays a role in stem cell maintenance and self-renewal. It is not known whether Atm has a role during tissue regeneration. Using liver regeneration as a model system, we examined the role of Atm in this process. Here, we show that the expression levels of Atm protein were gradually increased during liver regeneration and this was correlated with the onset of DNA replication. The induction of Stat3 and JNK signaling, which are essential processes in normal regeneration response, was attenuated during the early phases of liver regeneration in Atm-deficient mice. P53 was transiently phosphorylated at serine 23 during liver regeneration in an Atm-dependent manner. In addition, we found that cyclin A induction was delayed and p21 was over-expressed, both of these processes were correlated with reduced and delayed DNA replication in Atm(-/-) mice during liver regeneration. Finally, we show that increased apoptosis was observed in Atm(-/-) mice in response to partial hepatectomy, indicating that Atm is required for the survival of hepatocytes. Collectively, these data indicate that liver regeneration is impaired in Atm-deficient mice. Given that liver is the first line of defense against environmental toxins, the elucidation of the function of Atm and Atm-mediated signaling pathways in liver metabolism and in response to environmental toxins is of fundamental interest. 相似文献
80.
The effects of co-culture with human fibroblasts on human embryo development in vitro and implantation 总被引:5,自引:0,他引:5
Wetzels AM; Bastiaans BA; Hendriks JC; Goverde HJ; Punt-van der Zalm AP; Verbeet JG; Braat DD 《Human reproduction (Oxford, England)》1998,13(5):1325-1330
In a human in-vitro fertilization (IVF) programme, the effect of co-
culture of embryos with human fibroblasts was evaluated with respect to
pregnancy rate and embryo development. Patients were included in the study
after giving informed written consent. The IVF treatments were randomly
assigned by stratification of both age (<36 versus > or =36 years)
and previous IVF attempts (yes versus no). After fertilization was
established, the zygotes were transferred to a 4-well dish with or without
fibroblasts and cultured for 2 days. On the third day after ovum pick-up
(OPU), cell number and quality [5 (good) to 1 (poor)] of the embryos were
scored and a maximum of three embryos was transferred. Supernumerary
embryos of good quality were cryopreserved. The design of this study was a
group sequential trial with the objective of detecting differences between
pregnancy rates following IVF with conventional incubation or incubation in
co-culture with fibroblasts. This design included one evaluation at
half-way data collection. In the study, 148 patients had an OPU, of whom 77
were allocated to the co-culture group. There was no statistically
significant difference in pregnancy rate, cell number and embryo quality
between the two groups. The ongoing pregnancy rate per embryo transfer was
27% in co-culture and 30% in the conventional culture group. The
implantation rates per transferred embryo were 17 and 18% respectively.
Using a multivariate logistic regression model for the probability of
ongoing pregnancies, the odds ratio of co-culture, adjusted for age and
previous IVF attempts, was not statistically significant. In conclusion,
co-culture with human fibroblasts does not contribute to an improvement of
embryo quality nor to a higher pregnancy rate after IVF in an unselected
group of patients.
相似文献