全文获取类型
收费全文 | 881篇 |
免费 | 75篇 |
国内免费 | 12篇 |
专业分类
儿科学 | 43篇 |
妇产科学 | 10篇 |
基础医学 | 80篇 |
口腔科学 | 15篇 |
临床医学 | 99篇 |
内科学 | 229篇 |
皮肤病学 | 5篇 |
神经病学 | 87篇 |
特种医学 | 76篇 |
外科学 | 69篇 |
综合类 | 26篇 |
一般理论 | 4篇 |
预防医学 | 119篇 |
眼科学 | 4篇 |
药学 | 68篇 |
肿瘤学 | 34篇 |
出版年
2021年 | 8篇 |
2020年 | 9篇 |
2019年 | 11篇 |
2018年 | 23篇 |
2017年 | 20篇 |
2016年 | 8篇 |
2015年 | 18篇 |
2014年 | 25篇 |
2013年 | 24篇 |
2012年 | 40篇 |
2011年 | 29篇 |
2010年 | 30篇 |
2009年 | 31篇 |
2008年 | 23篇 |
2007年 | 40篇 |
2006年 | 37篇 |
2005年 | 30篇 |
2004年 | 24篇 |
2003年 | 25篇 |
2002年 | 18篇 |
2001年 | 11篇 |
2000年 | 20篇 |
1999年 | 28篇 |
1998年 | 32篇 |
1997年 | 20篇 |
1996年 | 27篇 |
1995年 | 21篇 |
1994年 | 24篇 |
1993年 | 17篇 |
1992年 | 17篇 |
1991年 | 15篇 |
1990年 | 20篇 |
1989年 | 14篇 |
1988年 | 15篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 12篇 |
1984年 | 7篇 |
1983年 | 8篇 |
1981年 | 7篇 |
1979年 | 9篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1975年 | 10篇 |
1973年 | 9篇 |
1972年 | 11篇 |
1969年 | 11篇 |
1968年 | 11篇 |
1966年 | 7篇 |
1965年 | 6篇 |
排序方式: 共有968条查询结果,搜索用时 125 毫秒
1.
Elizabeth A. Mosley PhD MPH Amy J. Schulz PhD MPH MSW Lisa H. Harris MD PhD Barbara A. Anderson PhD 《Women & health》2020,60(7):806-820
ABSTRACT Abortion is legal in South Africa, but negative abortion attitudes remain common and are poorly understood. We used nationally representative South African Social Attitudes Survey data to analyze abortion attitudes in the case of fetal anomaly and in the case of poverty from 2007 to 2016 (n = 20,711; ages = 16+). We measured correlations between abortion attitudes and these important predictors: religiosity, attitudes about premarital sex, attitudes about preferential hiring and promotion of women, and attitudes toward family gender roles. Abortion acceptability for poverty increased over time (b = 0.05, p < .001), but not for fetal anomaly (b = ?0.008, p = .284). Highly religious South Africans reported lower abortion acceptability in both cases (Odds Ratio (OR)anomaly = 0.85, p = .015; ORpoverty = 0.84, p = .02). Premarital sex acceptability strongly and positively predicted abortion acceptability (ORanomaly = 2.63, p < .001; ORpoverty = 2.46, p < .001). Attitudes about preferential hiring and promotion of women were not associated with abortion attitudes, but favorable attitudes about working mothers were positively associated with abortion acceptability for fetal anomaly ((ORanomaly = 1.09, p = .01; ORpoverty = 1.02, p = .641)). Results suggest negative abortion attitudes remain common in South Africa and are closely tied to religiosity, traditional ideologies about sexuality, and gender role expectations about motherhood. 相似文献
2.
J.W. Mosley 《Vox sanguinis》1994,67(S4):12-15
Hepatitis A virus (HAV) infection occurred after administration of factor VIII concentrate in Europe associated with one manufacturing process. We determined if there was an excess prevalence of anti-HAV among hemophiliacs in the United States, and whether any infections here were potentially concentrate-associated. We observed clotting disorder patients and household members for up to 7 years at 6-month intervals. Selected specimens were titered for anti-HAV-immunoglobulin G content to distinguish whether they were passively or actively acquired. Our results show that anti-HAV prevalence was 20–25%, but males with clotting deficiencies had a 44% rate (p < 0.001). Passive anti-HAV (≥ 30 to < 950 mIU/ml) from intermediate-purity factor VIII may have protected against community HAV exposure. Factor IX concentrates, which contain no anti-HAV, did not protect and a few instances of past transmission are possible. Criteria for present-day concentrate-associated cases were developed; no subject conclusively met these criteria during the period between late 1985 and May 1993. In conclusion, the excess of anti-HAV prevalence in male clotting disorders is attributable to both passive administration in concentrate, and past therapy prior to concentrates. No untoward HAV event related to concentrate was found in our population, but measures to prevent transmission of nonenveloped viruses should be instituted. 相似文献
3.
4.
5.
Antonio C. Buzaid David S. Alberts Janine Eispahr Kurt Mosley Yei-Mei Peng Kendra Tutsch Collin P. Spears Harinder S. Garewal 《Cancer chemotherapy and pharmacology》1989,25(2):124-130
Summary Dipyridamole (DP) has previously been studied both in vitro and in vivo in combination with various antimetabolites, including methotrexate and 5-fluorouracil (5FU). We evaluated in vitro and clinically the effects of adding DP to fluorodeoxyuridine (FUDR) in colorectal cancer. Using a human colony-forming assay, we observed that 0.05 M DP increased the cytotoxicity of FUDR by a median of 33.5-fold vs 1.5-fold for 5FU against human colon-cancer cell lines. The mechanism of the DP-enhanced antitumor activity of FUDR is not completely understood but appears to be related to a profound inhibition by DP of thymidine accumulation in and FUDR efflux from colon-cancer cell lines. On the basis of these in vitro results, 28 patients with metastatic colon cancer were entered in a clinical trial of monthly courses of 0.1 mg/kg FUDR daily for 14 days and 75 mg oral DP 5 times daily for 14 days starting on the 3rd day of continuous i.v. FUDR infusion. The pharmacokinetics of DP was studied in three patients; the results showed that 98% of total serum DP was protein-bound and that free DP levels were significantly lower than the concentrations necessary for the expected in vitro DP/FUDR modulation. Treatment was well tolerated, with only 12 patients developing mild to moderate toxicity. Of 27 evaluable patients, 4 achieved a partial response that lasted 2, 3, 5, and 6+ months. This relatively low response rate (15%), which is similar to that achieved with FUDR alone, may be explained by the low steady-state plasma concentrations of free DP achieved in our patients. Other means of DP administration, such as i.v., i.a., and i.p. injection, may be required to achieve free DP concentrations necessary for successful biochemical modulation of FUDR in patients.Supported in part by grants CA17094, CA23074, and CA39629 from the National Institutes of Health, Bethesda, Md 20205, and a grant from the Arizona Chronic Disease Commission. HSG is a recipient of an American Cancer Society Career Development Award 相似文献
6.
Evaluation of three substitutes for Percoll in sperm isolation by density gradient centrifugation 总被引:9,自引:4,他引:9
Silane-coated silica particle solutions (ISolate(TM) and PureSperm)TM)) and
iodixanol (OptiPrep(TM)) were compared to polyvinylpyrrolidone (PVP)-coated
silica particles (Percoll(TM)) in their efficacy to recover spermatozoa by
gradient centrifugation for use in assisted reproductive procedures.
Efficacy was assessed in terms of percentages of sperm recovery, sperm
vitality and motility, normal sperm morphology and normal sperm chromatin
condensation. No significant difference was found in the recovery of
spermatozoa for men with both normal sperm counts and oligozoospermia,
between PVP-coated and silane-coated particle solutions. Iodixanol had
significantly lower sperm recovery compared to the other products. Sperm
vitality, progressive motility, normal morphology and normal chromatin
condensation did not differ significantly between any of the sperm
isolation products.
相似文献
7.
Screening of selected male blood donors for p24 antigen of human immunodeficiency virus type 1. The Transfusion Safety Study Group 总被引:1,自引:0,他引:1
M P Busch P E Taylor B A Lenes S H Kleinman M Stuart C E Stevens P A Tomasulo J P Allain C G Hollingsworth J W Mosley 《The New England journal of medicine》1990,323(19):1308-1312
BACKGROUND. The p24 antigen of human immunodeficiency virus type 1 (HIV-1) is sometimes detected before antibody (anti-HIV-1) is detectable in the serum of recently infected persons. This has led to the consideration of p24-antigen testing for routine screening of blood donors. METHODS. To estimate how many HIV-infected seronegative donors would be identified if p24-antigen screening was introduced, we tested selected donations from a repository of 200,000 serum samples from voluntary donors that was established in late 1984 and early 1985. The 8597 serum samples selected for p24-antigen screening were chosen because their donors had demographic characteristics known to be associated with a high prevalence of seropositivity. RESULTS. The prevalence of anti-HIV-1 antibodies in the 1984-1985 serum samples selected for p24-antigen screening was 1.54 percent--more than 100 times the 0.012 percent prevalence in present-day donations in the United States. The antigen was detected in 15 of 132 serum samples (11.4 percent) from donors who had already been confirmed as seropositive. No instance of confirmed positivity for p24 antigen was found among the 8465 seronegative serum samples. CONCLUSIONS. These data indicate that the yield of screening for p24 antigen in volunteer donors to identify HIV-1 carriers would be negligible. We therefore recommend against routine screening with currently available p24-antigen assays. 相似文献
8.
D M Surgenor T C Chalmers M E Conrad W T Friedewald G F Grady M Hamilton J W Mosley A M Prince J M Stengle 《The New England journal of medicine》1975,293(21):1060-1062
Plasma from persons with high titers of hepatitis B antibody (anti-HBs) was used to manufacture one lot of hepatitis B "immune" globulin sufficient for four interlocking clinical trials of prevention or modification of hepatitis B infections. The trials were carried out in renal dialysis units, in medical personnel with accidental exposures to hepatitis B, in transfused patients, and in patients with fulminant hepatitis. A single policy board developed protocols that allowed comparisons among the four studies while respecting the unique requirements of each. 相似文献
9.
Mutation spectrum and genotype-phenotype analyses in Cowden disease and Bannayan-Zonana syndrome, two hamartoma syndromes with germline PTEN mutation 总被引:22,自引:1,他引:22
Marsh DJ; Coulon V; Lunetta KL; Rocca-Serra P; Dahia PL; Zheng Z; Liaw D; Caron S; Duboue B; Lin AY; Richardson AL; Bonnetblanc JM; Bressieux JM; Cabarrot-Moreau A; Chompret A; Demange L; Eeles RA; Yahanda AM; Fearon ER; Fricker JP; Gorlin RJ; Hodgson SV; Huson S; Lacombe D; Eng C 《Human molecular genetics》1998,7(3):507-515
The tumour suppressor gene PTEN , which maps to 10q23.3 and encodes a 403
amino acid dual specificity phosphatase (protein tyrosine phosphatase;
PTPase), was shown recently to play a broad role in human malignancy.
Somatic PTEN deletions and mutations were observed in sporadic breast,
brain, prostate and kidney cancer cell lines and in several primary tumours
such as endometrial carcinomas, malignant melanoma and thyroid tumours. In
addition, PTEN was identified as the susceptibility gene for two hamartoma
syndromes: Cowden disease (CD; MIM 158350) and Bannayan-Zonana (BZS) or
Ruvalcaba-Riley-Smith syndrome (MIM 153480). Constitutive DNA from 37 CD
families and seven BZS families was screened for germline PTEN mutations.
PTEN mutations were identified in 30 of 37 (81%) CD families, including
missense and nonsense point mutations, deletions, insertions, a
deletion/insertion and splice site mutations. These mutations were
scattered over the entire length of PTEN , with the exception of the first,
fourth and last exons. A 'hot spot' for PTEN mutation in CD was identified
in exon 5 that contains the PTPase core motif, with 13 of 30 (43%) CD
mutations identified in this exon. Seven of 30 (23%) were within the core
motif, the majority (five of seven) of which were missense mutations,
possibly pointing to the functional significance of this region. Germline
PTEN mutations were identified in four of seven (57%) BZS families studied.
Interestingly, none of these mutations was observed in the PTPase core
motif. It is also worthy of note that a single nonsense point mutation,
R233X, was observed in the germline DNA from two unrelated CD families and
one BZS family. Genotype-phenotype studies were not performed on this small
group of BZS families. However, genotype-phenotype analysis inthe group of
CD families revealed two possible associations worthy of follow-up in
independent analyses. The first was an association noted in the group of CD
families with breast disease. A correlation was observed between the
presence/absence of a PTEN mutation and the type of breast involvement
(unaffected versus benign versus malignant). Specifically and more
directly, an association was also observed between the presence of a PTEN
mutation and malignant breast disease. Secondly, there appeared to be an
interdependent association between mutations upstream and within the PTPase
core motif, the core motif containing the majority of missense mutations,
and the involvement of all major organ systems (central nervous system,
thyroid, breast, skin and gastrointestinal tract). However, these
observations would need to be confirmed by studying a larger number of CD
families.
相似文献
10.
A. G. Torrance J. R. Mosley R. F. L. Suswillo L. E. Lanyon 《Calcified tissue international》1994,54(3):241-247
Adaptive changes in bone modeling in response to noninvasive, cyclic axial loading of the rat ulna were compared with those using 4-point bending of the tibia. Twenty cycles daily of 4-point bending for 10 days were applied to rat tibiae through loading points 23 and 11 mm apart. Control bones received nonbending loads through loading points 11 mm apart. As woven bone was produced in both situations, any strain-related response was confounded by the response to direct periosteal pressure. Four-point bending is not, therefore, an ideal mode of loading for the investigation of strain-related adaptive modeling. The ulna's adaptive response to daily axial loading over 9 days was investigated in 30 rats. Groups 1–3 were loaded for 1200 cycles: Group 1 at 10 Hz and 20 N, Group 2 at 10 Hz and 15 N, and Group 3 at 20 Hz and 15 N. Groups 4 and 5 received 12,000 cycles of 20 N and 15 N at 10 Hz. Groups 1 and 4 showed a similar amount of new bone formation. Group 4 showed the same pattern of response but in reduced amount. The responses in Groups 2 and 3 were either small or absent. Strains were measured with single-element, miniature strain gauges bonded around the circumference of dissected bones. The 20 N loading induced peak strains of 3500–4500 strain. The width of the periosteal new bone response was proportional to the longitudinal strain at each point around the bone's circumference. It appears that when a bone is loaded in a normal strain distribution, an osteogenic response occurs when peak physiological strains are exceeded. In this situation the amount of new bone formed at each location is proportional to the local surface strain. Cycle numbers between 1200 and 12,000, and cycle frequencies between 10 and 20 Hz have no effect on the bone's adaptive response. 相似文献