全文获取类型
收费全文 | 3694篇 |
免费 | 344篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 147篇 |
妇产科学 | 57篇 |
基础医学 | 420篇 |
口腔科学 | 179篇 |
临床医学 | 443篇 |
内科学 | 664篇 |
皮肤病学 | 34篇 |
神经病学 | 207篇 |
特种医学 | 484篇 |
外科学 | 416篇 |
综合类 | 101篇 |
一般理论 | 2篇 |
预防医学 | 383篇 |
眼科学 | 47篇 |
药学 | 238篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 183篇 |
出版年
2021年 | 33篇 |
2019年 | 27篇 |
2018年 | 46篇 |
2017年 | 31篇 |
2016年 | 42篇 |
2015年 | 46篇 |
2014年 | 82篇 |
2013年 | 104篇 |
2012年 | 111篇 |
2011年 | 109篇 |
2010年 | 79篇 |
2009年 | 101篇 |
2008年 | 115篇 |
2007年 | 128篇 |
2006年 | 138篇 |
2005年 | 149篇 |
2004年 | 147篇 |
2003年 | 123篇 |
2002年 | 103篇 |
2001年 | 76篇 |
2000年 | 68篇 |
1999年 | 72篇 |
1998年 | 114篇 |
1997年 | 102篇 |
1996年 | 107篇 |
1995年 | 82篇 |
1994年 | 60篇 |
1993年 | 81篇 |
1992年 | 55篇 |
1991年 | 62篇 |
1990年 | 65篇 |
1989年 | 107篇 |
1988年 | 94篇 |
1987年 | 96篇 |
1986年 | 96篇 |
1985年 | 114篇 |
1984年 | 69篇 |
1983年 | 69篇 |
1982年 | 56篇 |
1981年 | 52篇 |
1980年 | 54篇 |
1979年 | 38篇 |
1978年 | 53篇 |
1977年 | 46篇 |
1976年 | 53篇 |
1975年 | 39篇 |
1974年 | 40篇 |
1973年 | 35篇 |
1972年 | 29篇 |
1971年 | 28篇 |
排序方式: 共有4043条查询结果,搜索用时 15 毫秒
71.
72.
Arif JM; Gairola CG; Glauert HP; Kelloff GJ; Lubet RA; Gupta RC 《Carcinogenesis》1998,19(8):1515-1517
The present study investigated the effects of dietary oltipraz on cigarette
smoke-related lipophilic DNA adduct formation. Female Sprague- Dawley rats
were exposed daily to sidestream cigarette smoke in a whole- body exposure
chamber 6 h/day for 4 consecutive weeks. One group of rats was maintained
on control diet while another group received the same diet supplemented
with either a low (167 p.p.m.) or high (500 p.p.m.) dose of oltipraz,
starting 1 week prior to initiation of smoke exposure until the end of the
experiment. Analysis of lipophilic DNA adducts by the nuclease P1-mediated
32P-post-labeling showed up to five smoke-related adducts. Adduct no. 5
predominated in both the lung and the heart while adduct nos 3 and 2
predominated in the trachea and bladder, respectively. Quantitative
analysis revealed that the total adduct level was the highest in lungs
(270+/-68 adducts/10(10) nucleotides), followed by trachea (196+/-48
adducts/10(10) nucleotides), heart (141+/-22 adducts/10(10) nucleotides)
and bladder (85+/-16 adducts/10(10) nucleotides). High dose oltipraz
treatment reduced the adduct levels in lungs and bladder by >60%, while
the reduction in lungs in the low-dose group was approximately 35%. In
trachea, the effect of low and high dietary oltipraz on smoke DNA adduction
was equivocal, while smoke-related DNA adducts in the heart were minimally
inhibited by high-dose oltipraz. In a repeat experiment that employed a
3-fold lower dose of cigarette smoke, oltipraz (500 p.p.m.) was found to
inhibit the formation of DNA adducts in rat lungs and trachea by 80 and
65%, respectively. These data clearly demonstrate a high efficacy of
oltipraz in inhibiting the formation of cigarette smoke-induced DNA adducts
in the target tissues.
相似文献
73.
Dejana Selenic Francisco Alvarado-Ramy Mathew Arduino Stacey Holt Fred Cardinali Benjamin Blount Jeff Jarrett Forrest Smith Neil Altman Charlotte Stahl Adelisa Panlilio Michele Pearson Jerome Tokars 《Infection control and hospital epidemiology》2004,25(3):256-261
OBJECTIVE: To determine the cause of acute illness on August 30, 2000, among patients at an outpatient dialysis center (center A). DESIGN: We performed a cohort study of all patients receiving dialysis on August 30, 2000; reviewed dialysis procedures; and analyzed dialysis water samples using microbiologic and chemical assays. SETTING: Dialysis center (center A). PATIENTS: A case-patient was defined as a patient who developed chills within 5 hours after starting hemodialysis at center A on August 30, 2000. RESULTS: Sixteen (36%) of 44 patients at center A met the case definition. All case-patients were hospitalized; 2 died. Besides chills, 15 (94%) of the case-patients experienced nausea; 12 (75%), vomiting; and 4 (25%), fever. Illness was more frequent on the second than the first dialysis shift (16 of 20 vs 0 of 24, P < .001); no other risk factors were identified. The center's water treatment system had received inadequate maintenance and disinfection and a sulfurous odor was noted during sampling of the water from the reverse osmosis (RO) unit. The water had elevated bacterial counts. Volatile sulfur-containing compounds (ie, methanethiol, carbon disulfide, dimethyldisulfide, and sulfur dioxide) were detected by gas chromatography and mass spectrometry in 8 of 12 water samples from the RO unit and in 0 of 28 samples from other areas (P < .001). Results of tests for heavy metals and chloramines were within normal limits. CONCLUSIONS: Parenteral exposure to volatile sulfur-containing compounds, produced under anaerobic conditions in the RO unit, could have caused the outbreak. This investigation demonstrates the importance of appropriate disinfection and maintenance of water treatment systems in hemodialysis centers. 相似文献
74.
75.
RA D. Wüstenberg 《Der Gyn?kologe》2006,39(10):824-828
Some of the girls who live in Germany and have Muslim parents are threatened by female genital mutilation. This report describes the kinds and medical consequences of female genital mutilation as well as the criminal judgement. Female genital mutilation is considered as dangerous bodily harm, not as grievous bodily harm. Consent does not justify the infringement of rights. The argument that Islam justifies the infringement of rights is irrelevant by law. The human right of bodily intactness has priority over the right of religious freedom. Finally the legal regulations about dealing with personal data are presented. A legal compulsory registration still does not exist. 相似文献
76.
Donna L Forrest Donna E Hogge Thomas J Nevill Stephen H Nantel Michael J Barnett John D Shepherd Heather J Sutherland Cynthia L Toze Clayton A Smith Julye C Lavoie Kevin W Song Nicholas J Voss Randy D Gascoyne Joseph M Connors 《Journal of clinical oncology》2005,23(31):7994-8002
PURPOSE: To determine the incidence of second malignancies among patients with Hodgkin's lymphoma (HL) treated with autologous hematopoietic stem cell transplantation (AHSCT) compared with patients receiving conventional therapy alone and to identify potential risk factors for their occurrence. PATIENTS AND METHODS: We analyzed data on 1,732 consecutive patients with HL treated at the British Columbia Cancer Agency from 1976 to 2001, including 202 patients undergoing AHSCT. The median follow-up duration was 9.8 years for the whole cohort, 9.7 years for those patients treated with conventional therapy, and 7.8 years from AHSCT. RESULTS: The cumulative incidence of developing any second malignancy 15 years after therapy for HL was 9% (risk ratio = 3.5; P < .001); however, the incidence did not differ between those patients receiving conventional therapy alone compared with those undergoing AHSCT (10% and 8%, respectively; P = .48). In multivariate analysis, the only factor significantly associated with an increased risk of developing any second neoplasm or solid tumor was age > or = 35 years (P < .0001). An increased risk of therapy-induced acute myeloid leukemia and therapy-induced myelodysplastic syndrome was seen for patients aged > or = 35 years (P = .03) and stage III/IV (P = .04). CONCLUSION: Patients with HL are at increased risk of developing a second neoplasm. However, those patients undergoing AHSCT do not seem to be at greater risk compared with those patients receiving conventional therapy alone, at least during the first decade after therapy. 相似文献
77.
McCaffery K Forrest S Waller J Desai M Szarewski A Wardle J 《British journal of cancer》2003,88(1):42-46
This study examined attitudes to human papillomavirus (HPV) testing among a purposively selected sample of women from four ethnic groups: white British, African Caribbean, Pakistani and Indian. The design was qualitative, using focus group discussion to elicit women's attitudes towards HPV testing in the context of cervical cancer prevention. The findings indicate that although some women welcomed the possible introduction of HPV testing, they were not fully aware of the sexually transmitted nature of cervical cancer and expressed anxiety, confusion and stigma about HPV as a sexually transmitted infection. The term 'wart virus', often used by medical professionals to describe high-risk HPV to women, appeared to exacerbate stigma and confusion. Testing positive for HPV raised concerns about women's sexual relationships in terms of trust, fidelity, blame and protection, particularly for women in long-term monogamous relationships. Participation in HPV testing also had the potential to communicate messages of distrust, infidelity and promiscuity to women's partners, family and community. Concern about the current lack of available information about HPV was clearly expressed and public education about HPV was seen as necessary for the whole community, not only women. The management of HPV within cervical screening raises important questions about informed participation. Our findings suggest that HPV testing has the potential to cause psychosocial harm to women and their partners and families. 相似文献
78.
79.
80.
This study examines the relative importance of fitness versus fatness in predicting mortality in elderly populations aged 70 years and over, and whether fitness may account for the ‘paradoxical’ relationship between better survival and increasing weight. Four thousand community-living Chinese men and women aged 65 years or over were recruited and stratified so that approximately 33% were in each of the age groups: 65–69, 70–74, and 75 or above. Medical history, height, weight, waist–hip ratio, body composition using DEXA, and walking speed were obtained. They were followed up for a mean of 7.0 years to ascertain death. Compared with the high fitness category, those in the moderate and low categories have a 43% and 68% increased risk of mortality at 7 years adjusting for multiple confounders. When mortality risk according to various fatness indicators was examined, only the lowest quartile of BMI, BFI, and FLMR conferred statistically significant increased risk. Fitness categories were significantly associated with all fatness indicators. The finding of fewer people in the high fitness category among the highest quartiles of other fatness indicators suggests that fitness is not the underlying mechanism for the obesity paradox. Within each quartile of fatness indicator, there was a significant trend towards reduced mortality with increasing fitness. In conclusion, the study confirms the beneficial effects of cardiorespiratory fitness on mortality but does not explain the ‘obesity paradox’. The findings underscore the importance of maintaining physical fitness through exercise and re-confirm the importance of weight maintenance in reducing mortality risk. 相似文献