全文获取类型
收费全文 | 633篇 |
免费 | 28篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 60篇 |
妇产科学 | 23篇 |
基础医学 | 65篇 |
口腔科学 | 18篇 |
临床医学 | 52篇 |
内科学 | 89篇 |
皮肤病学 | 11篇 |
神经病学 | 29篇 |
特种医学 | 180篇 |
外国民族医学 | 1篇 |
外科学 | 35篇 |
综合类 | 6篇 |
预防医学 | 17篇 |
眼科学 | 11篇 |
药学 | 29篇 |
肿瘤学 | 42篇 |
出版年
2019年 | 6篇 |
2018年 | 6篇 |
2015年 | 17篇 |
2014年 | 12篇 |
2013年 | 11篇 |
2012年 | 18篇 |
2011年 | 7篇 |
2010年 | 17篇 |
2009年 | 17篇 |
2008年 | 15篇 |
2007年 | 16篇 |
2006年 | 11篇 |
2005年 | 7篇 |
2004年 | 14篇 |
2003年 | 15篇 |
2002年 | 15篇 |
2001年 | 9篇 |
2000年 | 24篇 |
1999年 | 12篇 |
1998年 | 27篇 |
1997年 | 42篇 |
1996年 | 28篇 |
1995年 | 18篇 |
1994年 | 15篇 |
1993年 | 6篇 |
1992年 | 15篇 |
1991年 | 5篇 |
1990年 | 12篇 |
1989年 | 21篇 |
1988年 | 20篇 |
1986年 | 14篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1983年 | 15篇 |
1982年 | 8篇 |
1981年 | 7篇 |
1980年 | 10篇 |
1979年 | 7篇 |
1978年 | 10篇 |
1977年 | 15篇 |
1976年 | 12篇 |
1975年 | 10篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1971年 | 6篇 |
1970年 | 8篇 |
1969年 | 12篇 |
1968年 | 6篇 |
1967年 | 7篇 |
1966年 | 5篇 |
排序方式: 共有674条查询结果,搜索用时 0 毫秒
1.
2.
3.
Laboratory test form design influences test ordering by general practitioners in The Netherlands. 总被引:5,自引:0,他引:5
The effect of listing fewer laboratory tests on the test request form on test-ordering behavior of a group of 47 Dutch general practitioners was studied. The number of laboratory tests ordered by this experimental group during a 12-month period was recorded. The usual, old standard form was used by a control group of 28 general practitioners in a different region. After having used the old, standard form with 178 tests for 5 months, the experimental group received forms listing only 15 hematological and chemical tests plus several urine and feces tests, and space was allowed for "others." A comparison of the experimental and control periods showed that the number of tests ordered monthly in the experimental group was reduced by 18%. When the usual standard form was re-introduced, the general practitioners quickly returned to their old pattern. Results revealed that fixed and often unsound routine influences the use of additional diagnostic procedures. In addition, limiting and restructuring the test-ordering forms may break the routine but does not essentially modify the rationale of test-ordering behavior. 相似文献
4.
A comparison of Skirrow's, Butzler's, Blaser's, Campy-BAP and Preston media for Campylobacter spp was made using human, animal and environmental specimens. Butzler's medium gave the lowest isolation rate and Preston medium, which was the most selective, the highest isolation rate. Enrichment culture using Preston enrichment broth gave a higher isolation rate than direct plating onto Preston medium. 相似文献
5.
Youssef N Carbonell N Bonte H Serfaty L Poupon R Fléjou JF 《Annales de pathologie》2004,24(3):256-258
Dieulafoy's ulcer is a particular form of gastric ulcer confined to a persistent caliber artery and may lead to severe hemorrhage. We report a case of fatal gastric bleeding in a woman with benign biclonal gammapathy. Autopsy found a typical Dieulafoy's ulcer centered by a persistent caliber artery which wall was thickened by AL-amyloid deposits. Amyloidosis involved the gastric wall, but also middle caliber arteries of the liver, the lung, the pancreas, the kidney and the myocardium. AL-amyloidosis is a rare and late complication of monoclonal gammapathy and may be asymptomatic. Pathogenesis of Dieulafoy's ulcer remains unclear. In our case, local ischemia may have facilitated gastric ulceration, and amyloid deposits may have contributed to arterial rupture. 相似文献
6.
7.
Frataxin is reduced in Friedreich ataxia patients and is associated with mitochondrial membranes 总被引:17,自引:8,他引:17
Campuzano V; Montermini L; Lutz Y; Cova L; Hindelang C; Jiralerspong S; Trottier Y; Kish SJ; Faucheux B; Trouillas P; Authier FJ; Durr A; Mandel JL; Vescovi A; Pandolfo M; Koenig M 《Human molecular genetics》1997,6(11):1771-1780
Friedreich ataxia is a progressive neurodegenerative disorder caused by
loss of function mutations in the frataxin gene. In order to unravel
frataxin function we developed monoclonal antibodies raised against
different regions of the protein. These antibodies detect a processed 18
kDa protein in various human and mouse tissues and cell lines that is
severely reduced in Friedreich ataxia patients. By immunocytofluorescence
and immunocytoelectron microscopy we show that frataxin is located in
mitochondria, associated with the mitochondrial membranes and crests.
Analysis of cellular localization of various truncated forms of frataxin
expressed in cultured cells and evidence of removal of an N-terminal
epitope during protein maturation demonstrated that the mitochondrial
targetting sequence is encoded by the first 20 amino acids. Given the
shared clinical features between Friedreich ataxia, vitamin E deficiency
and some mitochondriopathies, our data suggest that a reduction in frataxin
results in oxidative damage.
相似文献
8.
Dithiothreitol prevents age-associated decrease in oocyte/conceptus viability in vitro 总被引:2,自引:0,他引:2
The present study was designed to ascertain whether the negative effects on
reproductive potential of post-ovulatory ageing in vitro of oocytes can be
prevented by antioxidant therapy. Mouse metaphase II (MII) oocytes were
aged in vitro for 12 h prior to insemination in the presence of varying
concentrations of L-ascorbic acid, 6-methoxy-
2,5,7,8-tetramethylchromane-2-carboxylic acid (Trolox), L-cystine
dihydrochloride, ethylenediaminetetraacetic acid (EDTA), beta-
mercaptoethanol and DL-dithiothreitol (DTT). In-vitro ageing of oocytes was
associated with lower fertilization rate, higher proportion of concepti
exhibiting cellular fragmentation at 24 h post-insemination and lower
percentage of concepti reaching the blastocyst stage. Ascorbic acid, Trolox
and EDTA had no effect on cellular fragmentation or potential of oocytes
for development. However, the probability of an oocyte reaching the
blastocyst stage was decreased (P < or = or = 0.05) in oocytes incubated
in the presence of L-cystine (50 and 500 microM) and beta-mercaptoethanol
(5, 50 and 500 microM) when compared to control aged oocytes.
Age-associated cellular fragmentation at 24 h post-insemination was
partially prevented (P < or = 0.05) by incubating oocytes in the
presence of beta-mercaptoethanol (500 microM). DTT (50 and 500 microM)
increased (P < or = 0.05) fertilization rate and number of cells at 81 h
post-insemination to levels similar to those exhibited by control oocytes.
Furthermore, both age-associated fragmentation at 24 h post-insemination (P
< or = 0.05) and decreased potential of oocytes for development to the
blastocyst stage (P < or = 0.05) were prevented, at least in part, by
culturing oocytes in the presence of DTT (50 microM). Although the
mechanism by which DTT exerts its beneficial effects on aged oocytes
remains to be elucidated, it may protect oocytes by preventing oxidation of
free thiol groups and/or altering a redox-independent signalling pathway
that mediates cellular fragmentation and death.
相似文献
9.
TaqMan amplification system with an internal positive control for HCV RNA quantitation. 总被引:6,自引:0,他引:6
10.
Y chromosome microdeletions, in azoospermic or near-azoospermic subjects, are located in the AZFc (DAZ) subregion 总被引:9,自引:2,他引:9
Submicroscopic deletions of the Y chromosome and polymorphisms of the
androgen receptor (AR) gene in the X chromosome have been observed in men
with defective spermatogenesis. To further define the subregions/genes in
the Y chromosome causing male infertility and its relationship to
polymorphisms of the AR polyglutamine tract, we screened the genomic DNA of
202 subfertile males and 101 healthy fertile controls of predominantly
Chinese ethnic origin. Y microdeletions were examined with 16
sequence-tagged site (STS) probes, including the RBM and DAZ genes,
spanning the AZFb and AZFc subregions of Yq11, and related to the size of
trinucleotide repeat encoding the AR polyglutamine tract. Y microdeletions
were detected and confirmed in three out of 44 (6.8%) of azoospermic and
three out of 86 (3.5%) severely oligozoospermic patients. No deletions were
detected in any of the patients with sperm counts of >0.5 x 10(6)/ml,
nor in any of the 101 fertile controls. All six affected patients had
almost contiguous Y microdeletions spanning the entire AZFc region
including the DAZ gene. The AZFb region, containing the RBM1 gene, was
intact in five of the six subjects. Y deletions were not found in those
with long AR polyglutamine tracts. Our study, the first in a Chinese
population, suggest a cause and effect relationship between Y
microdeletions in the AZFc region (possibly DAZ), and azoospermia or
near-azoospermia. Y microdeletions and long AR polyglutamine tracts appear
to be independent contributors to male infertility.
相似文献