全文获取类型
收费全文 | 821篇 |
免费 | 55篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 32篇 |
妇产科学 | 5篇 |
基础医学 | 82篇 |
口腔科学 | 11篇 |
临床医学 | 59篇 |
内科学 | 192篇 |
皮肤病学 | 10篇 |
神经病学 | 22篇 |
特种医学 | 85篇 |
外科学 | 84篇 |
综合类 | 136篇 |
预防医学 | 73篇 |
眼科学 | 6篇 |
药学 | 37篇 |
肿瘤学 | 40篇 |
出版年
2022年 | 2篇 |
2021年 | 31篇 |
2020年 | 2篇 |
2019年 | 8篇 |
2018年 | 11篇 |
2017年 | 4篇 |
2016年 | 7篇 |
2015年 | 12篇 |
2014年 | 10篇 |
2013年 | 13篇 |
2012年 | 22篇 |
2011年 | 18篇 |
2010年 | 29篇 |
2009年 | 28篇 |
2008年 | 36篇 |
2007年 | 33篇 |
2006年 | 33篇 |
2005年 | 25篇 |
2004年 | 37篇 |
2003年 | 23篇 |
2002年 | 28篇 |
2001年 | 21篇 |
2000年 | 21篇 |
1999年 | 25篇 |
1998年 | 39篇 |
1997年 | 24篇 |
1996年 | 32篇 |
1995年 | 16篇 |
1994年 | 35篇 |
1993年 | 12篇 |
1992年 | 8篇 |
1991年 | 14篇 |
1990年 | 15篇 |
1989年 | 21篇 |
1988年 | 20篇 |
1987年 | 22篇 |
1986年 | 23篇 |
1985年 | 22篇 |
1984年 | 15篇 |
1983年 | 16篇 |
1982年 | 7篇 |
1981年 | 11篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 3篇 |
1977年 | 4篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1974年 | 3篇 |
1972年 | 3篇 |
排序方式: 共有878条查询结果,搜索用时 390 毫秒
11.
Development of hatching blastocysts from immature human oocytes following in-vitro maturation and fertilization using a co-culture system 总被引:8,自引:0,他引:8
Hwu YM; Lee RK; Chen CP; Su JT; Chen YW; Lin SP 《Human reproduction (Oxford, England)》1998,13(7):1916-1921
Recently, in-vitro maturation (IVM) of immature human oocytes recovered
from non-stimulated follicles has been applied in the treatment of
infertility. However, in previous reports, very few embryos cultured in
conventional medium have reached the expanded blastocyst stage following
in-vitro maturation and fertilization (IVM/IVF). The objective of this
study was to investigate whether the developmental competence of human
embryos following IVM/IVF could be enhanced by the use of a human ampullary
cell co-culture system. Immature human oocytes were aspirated from small
follicles at Caesarean section and then cultured in medium containing human
menopausal gonadotrophin for 36 to 48 h, followed by insemination. Zygotes
were randomly cultured either in conventional culture medium alone or in
the co-culture system. Of 48 embryos cultured in conventional medium alone,
all arrested at the 2-16- cell stage on day 3 after insemination. Of 46
embryos cultured in the co-culture system, 26 embryos (56.5%) arrested at
the 2-16-cell stage. Six embryos (13%) developed to the morula stage.
Fourteen embryos (30.4%) developed to expanded blastocysts and two
blastocysts were hatching on day 7 after insemination. We conclude that
co-culture significantly enhances the development of blastocysts in embryos
resulting from IVM/IVF.
相似文献
12.
13.
Role of nitric oxide in the biology, physiology and pathophysiology of reproduction 总被引:13,自引:0,他引:13
Following its benchmark discovery, nitric oxide (NO) is nowknown to play important functional roles in a variety of physiologicalsystems. Within the vasculature, NO induces vasodilation, inhibitsplatelet aggregation, prevents neutrophil/platelet adhesionto endothelial cells, inhibits smooth muscle cell proliferationand migration, regulates programmed cell death (apoptosis) andmaintains endothelial cell barrier function. NO generated byneurons acts as a neurotransmitter, whereas NO generated bymacrophages in response to invading microbes acts as an antimicrobialagent. Because neurons, blood vessels and cells of the immunesystem are integral parts of the reproductive organs, and inview of the important functional role that NO plays in thosesystems, it is likely that NO is an important regulator of thebiology and physiology of the reproductive system. Indeed, inthe past 10 years, NO has established itself as a polyvalentmolecule which plays a decisive role in regulating multiplefunctions within the female as well as the male reproductivesystem. This review provides an overview of the role of NO invarious reproductive organs under physiological and pathologicalconditions. 相似文献
14.
A novel aberrant splice site mutation in the APC gene 总被引:3,自引:0,他引:3
Charames GS Cheng H Gilpin CA Hunter AG Berk T Bapat B 《Journal of medical genetics》2002,39(10):754-757
15.
Sandford R; Sgotto B; Aparicio S; Brenner S; Vaudin M; Wilson RK; Chissoe S; Pepin K; Bateman A; Chothia C; Hughes J; Harris P 《Human molecular genetics》1997,6(9):1483-1489
PKD1 is the major locus of the common genetic disorder autosomal dominant
polycystic kidney disease (ADPKD). Analysis of the predicted protein
sequence of the human PKD1 gene, polycystin, shows a large molecule with a
unique arrangement of extracellular domains and multiple putative
transmembrane regions. The precise function of polycystin remains unclear
with a paucity of mutations to define key structural and functional
domains. To refine the structure of this protein we have cloned the genomic
region encoding the Fugu PKD1 gene. Fugu PKD1 spans 36 kb of genomic DNA
and has greater complexity with 54 exons compared with 46 in man.
Comparative analysis of the predicted protein sequences shows a lower level
of homology than in similar studies with identity of 40 and 59% similarity.
However key structural motifs including leucine rich repeats (LRR), a
C-type lectin and LDL-A like domains and 16 PKD repeats are maintained. A
region of homology with the sea urchin REJ protein was also confirmed in
Fugu but found to extend over 1000 amino acids. Several highly conserved
intra- and extra- cellular regions, with no known sequence homologies, that
are likely to be of functional importance were detected. The likely
structure of the membrane associated region has been refined with
similarity to the PKD2 protein and voltage gated Ca2+ and Na+ channels
highlighted over part of this area. The overall protein structure has
therefore been clarified and this comparative analysis derived structure
will form the basis for the functional study of polycystin and its
individual domains.
相似文献
16.
Renal transplant (RT) is now a therapy of choice for end stage renal disease (ESRD). The Nephrology Unit, Asvini started functioning in Dec 90 and to date 1298 sittings of hemodialysis have been given to 45 patients. Of these, 35 were in ESRD and 11 patients underwent renal transplantation at this hospital during the period Jan 91 – Dec 93. One patient expired after 18 months of transplantation due to infection. Early experience in screening patients for RT, use of immunosuppression, management of rejection episodes and protocol are presented with special emphasis on its relevance to the Armed Forces.KEY WORDS: Transplantation, Renal Failure, Immunosuppression, Rejection 相似文献
17.
Pediatric health screening procedures, both prenatal and postnatal, have a tremendous potential in improving the health status of children and in turn reducing the resource burden on the parents and the State. The existing recommendations, inherent problems and different screening procedures are discussed. The need for suitable mass screening pediatric procedures in the Indian context is stressed.KEY WORDS: Pediatric screening procedures 相似文献
18.
BACKGROUND: Cigars have been heavily promoted in recent years. The nature and extent of the resultant increase in cigar smoking needs to be understood before the public health implications can be assessed. METHODS: Data are from population-based surveys conducted in California adults (> or = 18 years) in 1990 (n = 24,296) and 1996 (n = 24,266). Trends in current (every day or some days) cigar use are described for demographic subgroups and by cigarette smoking status. RESULTS: Current cigar use has doubled in California, from 2.5% in 1990 to 4.9% in 1996. In 1996, fewer than 5% of cigar smokers smoked cigars daily; essentially all of the increase was from nondaily use in those under 45 years of age of both genders, particularly in 18- to 24-year-olds. Among males, increased cigar use was observed in all racial/ethnic groups except Asians, and was observed in those with higher educational attainment and higher incomes. In both years, current and former cigarette smokers had higher rates of cigar use than never smokers, but the increase in current cigar smoking was observed regardless of cigarette smoking status. In 1996, daily cigar smokers were more likely to be former cigarette smokers than nondaily cigar smokers. CONCLUSION: If more people begin to smoke cigars daily, or if cigar use leads young people to initiate cigarette smoking or leads former cigarette smokers to relapse to cigarette smoking, the recent trends in cigar use may have public health implications. 相似文献
19.
20.
Liu JM; Chen YM; Chao Y; Liu SM; Tiu CM; Wu HW; Chiou TC; Hsieh RK; Chen LT; Whang-Peng J 《Japanese journal of clinical oncology》1998,28(7):431-435
BACKGROUND: To evaluate the efficacy and toxicity of cisplatin/etoposide
continuous infusion chemotherapy for cancer of unknown primary site in
Taiwan, a region with a high prevalence of endemic viral infections.
METHOD: Between April 1994 and February 1996, 20 patients with a diagnosis
of CUPS were treated, including 15 males and five females, of average age
63.3 years (range 41-83 years). Continuous intravenous infusion of
etoposide 80 mg/m2 and cisplatin 25 mg/m2 was given for 3 days every 3
weeks. Pretreatment tumor marker and viral serology studies were performed
for baseline evaluation. Nearly two-thirds of the patients had poorly
differentiated carcinoma. The average number of metastatic sites was 2.65
(range 1-4), with liver and lymph node involvement predominating. RESULTS:
The overall response rate was 25% (95% CI 17.7-32.3%); 30.7% for poorly
differentiated cancers and 25% for well differentiated cancers. Median
survival was 4 months (range 1-12 months), 4.8 months for patients
attaining partial response. Toxicity was moderate, grade 3 and 4
neutropenia occurred in 55% and grade 3 and 4 thrombocytopenia in 40%;
other toxicities were mild. CA125 and CA199 were elevated in more than 50%
of patients. Viral serology studies were not significantly different from
those of the indigenous population. CONCLUSION: Etoposide and cisplatin
combination chemotherapy has modest activity in patients with extensive
CUPS and, at the schedule and dosage given, it is associated with moderate
toxicity.
相似文献