全文获取类型
收费全文 | 301篇 |
免费 | 6篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 18篇 |
儿科学 | 37篇 |
妇产科学 | 4篇 |
基础医学 | 36篇 |
口腔科学 | 9篇 |
临床医学 | 56篇 |
内科学 | 29篇 |
皮肤病学 | 4篇 |
神经病学 | 6篇 |
特种医学 | 26篇 |
外科学 | 21篇 |
综合类 | 23篇 |
预防医学 | 14篇 |
眼科学 | 1篇 |
药学 | 16篇 |
中国医学 | 4篇 |
肿瘤学 | 4篇 |
出版年
2021年 | 3篇 |
2019年 | 6篇 |
2017年 | 2篇 |
2016年 | 1篇 |
2015年 | 5篇 |
2014年 | 23篇 |
2013年 | 22篇 |
2012年 | 13篇 |
2011年 | 8篇 |
2010年 | 11篇 |
2009年 | 13篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 7篇 |
2005年 | 4篇 |
2004年 | 2篇 |
2003年 | 8篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 7篇 |
1999年 | 2篇 |
1998年 | 13篇 |
1997年 | 18篇 |
1996年 | 11篇 |
1995年 | 9篇 |
1994年 | 10篇 |
1993年 | 12篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 5篇 |
1989年 | 3篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1981年 | 2篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 3篇 |
1977年 | 1篇 |
1976年 | 1篇 |
1958年 | 1篇 |
1957年 | 2篇 |
1956年 | 2篇 |
1954年 | 2篇 |
1952年 | 16篇 |
1951年 | 23篇 |
1950年 | 2篇 |
排序方式: 共有308条查询结果,搜索用时 0 毫秒
131.
Germline mutations of the MEN1 gene in familial multiple endocrine neoplasia type 1 and related states 总被引:9,自引:0,他引:9
Agarwal SK; Kester MB; Debelenko LV; Heppner C; Emmert-Buck MR; Skarulis MC; Doppman JL; Kim YS; Lubensky IA; Zhuang Z; Green JS; Guru SC; Manickam P; Olufemi SE; Liotta LA; Chandrasekharappa SC; Collins FS; Spiegel AM; Burns AL; Marx SJ 《Human molecular genetics》1997,6(7):1169-1175
Familial multiple endocrine neoplasia type 1 (FMEN1) is an autosomal
dominant trait characterized by tumors of the parathyroids, gastro-
intestinal endocrine tissue, anterior pituitary and other tissues. We
recently cloned the MEN1 gene and confirmed its identity by finding
mutations in FMEN1. We have now extended our mutation analysis to 34 more
unrelated FMEN1 probands and to two related states, sporadic MEN1 and
familial hyperparathyroidism. There was a high prevalence of heterozygous
germline MEN1 mutations in sporadic MEN1 (8/11 cases) and in FMEN1 (47/50
probands). One case of sporadic MEN1 was proven to be a new MEN1 mutation.
Eight different mutations were observed more than once in FMEN1. Forty
different mutations (32 FMEN1 and eight sporadic MEN1) were distributed
across the MEN1 gene. Most predicted loss of function of the encoded menin
protein, supporting the prediction that MEN1 is a tumor suppressor gene. No
MEN1 germline mutation was found in five probands with familial
hyperparathyroidism, suggesting that familial hyperparathyroidism often is
caused by mutation in another gene or gene(s).
相似文献
132.
Nitric oxide synthase activity and localization do not change in uterus and placenta during human parturition 总被引:13,自引:2,他引:13
Thomson AJ; Telfer JF; Kohnen G; Young A; Cameron IT; Greer IA; Norman JE 《Human reproduction (Oxford, England)》1997,12(11):2546-2552
Animal studies have suggested that nitric oxide, a smooth muscle relaxant,
is a fundamental mediator in the initiation of parturition. The purpose of
this study was to test the hypothesis that the onset of human labour is
associated with a reduction in the activity of the enzyme nitric oxide
synthase (NOS), within the uterus. Samples of myometrium, placenta, decidua
and fetal membranes were collected during Caesarean section from 11 women
before and 11 women after the onset of labour at term. Immunocytochemistry
was used to localize each of the three isoforms of NOS (endothelial NOS,
brain NOS, and inducible NOS) in each of these tissues and the intensity of
staining was qualitatively assessed. NOS enzyme activity was determined in
homogenates of frozen myometrium, placenta and fetal membranes (with
attached decidua), by measuring conversion of radio-labelled L-arginine to
L-citrulline. Each of the three isoforms of NOS was localized in each of
the tissues. We found no difference in either the expression or enzyme
activity of NOS in myometrium, placenta or fetal membranes before and
during labour at term. These results suggest that, in contrast to animal
studies, a decrease in NOS enzyme activity may not be involved in the onset
of parturition at term in the human.
相似文献
133.
运用走访调查和工作实践总结的方法,指出高校期刊阅览室服务存在的问题,提出高校期刊阅览室应在服务理念和方式、馆藏结构、馆员整体素质等方面都做出相应的转变,以满足教学模式改革环境下高校教学和科研对情报信息的需求。 相似文献
134.
135.
136.
Use of a questionnaire to identify potential blood donors at risk for infection with Trypanosoma cruzi 总被引:3,自引:0,他引:3
Trypanosoma cruzi is the protozoan parasite that causes American trypanosomiasis (Chagas' disease). Chagas' disease is endemic in Latin America. The infection is usually seen in poor people who live in rural areas in substandard housing, where they are bitten by infected reduviid bugs. Transmission also can occur by blood transfusion. Infected individuals who immigrate to the United States might donate blood if they are asymptomatic and unaware of their infection. This study evaluated the usefulness of a questionnaire for identifying T. cruzi-infected individuals among prospective blood donors who met all American Association of Blood Banks, Food and Drug Administration, and State of California criteria for donor eligibility. Seventy-two of 3492 otherwise eligible donors were disqualified because of their answers on the questionnaire. Forty-five of these 72 agreed to be tested serologically, and 2 were positive for T. cruzi antibodies. One of six autologous blood donors tested also was positive for T. cruzi antibodies. We conclude that the questionnaire selected a subgroup of Latin Americans at high risk for T. cruzi infection. The deferral of these high-risk individuals clearly reduced the risk of transmission of T. cruzi by transfusion, without intolerably decreasing the supply of donated blood. 相似文献
137.
AG Sutcliffe SW D'Souza J Cadman B Richards IA McKinlay B Lieberman 《Archives of disease in childhood》1995,72(4):290-293
A cohort of 91 children from cryopreserved embryos and 83 control children who were conceived normally had their development assessed using the Griffiths's scales of mental development. The controls (81 singletons and two twins) of a similar age, sex, and social class were selected from siblings, cousins, and peers of the cryopreserved embryo group (68 singleton, 20 twins, and three triplets). Children from cryopreserved embryos had a lower mean birth weight and mean gestational age and a higher proportion were born by caesarean section. One child from the cryopreserved embryo group had Down's syndrome, three had squints, and four had conductive hearing loss while in the control children, six had squints, and nine had conductive hearing loss. In both groups, including the child with Down's syndrome, the mean Griffiths's quotient was greater than the standard 100. In the children from cryopreserved embryos, the singleton and multiple birth subgroups had statistically similar assessment results. The mean (SD) Griffiths's quotient was 105.69 (13.55) in children from cryopreserved embryos and 108.18 (9.80) in controls at a chronological age of 25.08 (12.86) and 29.19 (14.65) months respectively. Overall, the development in children from cryopreserved embryos did not cause concern though formal testing had highlighted small differences compared with other children conceived normally and of a similar social class. 相似文献
138.
De novo mutations (GAG deletion) in the DYT1 gene in two non-Jewish patients with early-onset dystonia 总被引:3,自引:0,他引:3
Klein C; Brin MF; de Leon D; Limborska SA; Ivanova-Smolenskaya IA; Bressman SB; Friedman A; Markova ED; Risch NJ; Breakefield XO; Ozelius LJ 《Human molecular genetics》1998,7(7):1133-1136
The DYT1 gene recently has been cloned and shown to contain a three
nucleotide (GAG) deletion responsible for most cases of autosomal dominant
early-onset torsion dystonia. This deletion results in the loss of one of a
pair of glutamic acids in a conserved region of a novel ATP-binding protein
(torsinA). Previous haplotype analysis revealed that this same deletion had
arisen at least two different times in history, suggesting independent
mutational events. This deletion is the only sequence change found thus far
to be associated uniquely with the disease status, regardless of ethnic
origin. Here we describe two patients with typical early-onset torsion
dystonia of Swiss-Mennonite and non-Jewish Russian origin, respectively,
that both carry this same mutation as a de novo GAG deletion. This finding
proves that this 3 bp deletion in the DYT1 gene is indeed a mutation that
causes early-onset torsion dystonia. The DYT1 mutation is one of the rare
examples of the same recurrent mutation causing a dominantly inherited
condition. The sequence surrounding the GAG deletion contains an imperfect
24 bp tandem repeat, suggesting a possible mechanism for the high frequency
of this mutation.
相似文献
139.
140.
Altered expression of Pax-5 gene in human myeloma cells 总被引:6,自引:1,他引:6