全文获取类型
收费全文 | 2830篇 |
免费 | 120篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 152篇 |
妇产科学 | 79篇 |
基础医学 | 186篇 |
口腔科学 | 155篇 |
临床医学 | 271篇 |
内科学 | 501篇 |
皮肤病学 | 15篇 |
神经病学 | 137篇 |
特种医学 | 209篇 |
外科学 | 675篇 |
综合类 | 54篇 |
预防医学 | 92篇 |
眼科学 | 53篇 |
药学 | 99篇 |
中国医学 | 6篇 |
肿瘤学 | 160篇 |
出版年
2023年 | 27篇 |
2022年 | 39篇 |
2021年 | 87篇 |
2020年 | 53篇 |
2019年 | 53篇 |
2018年 | 95篇 |
2017年 | 61篇 |
2016年 | 94篇 |
2015年 | 102篇 |
2014年 | 146篇 |
2013年 | 153篇 |
2012年 | 192篇 |
2011年 | 164篇 |
2010年 | 82篇 |
2009年 | 82篇 |
2008年 | 173篇 |
2007年 | 204篇 |
2006年 | 177篇 |
2005年 | 173篇 |
2004年 | 174篇 |
2003年 | 139篇 |
2002年 | 112篇 |
2001年 | 77篇 |
2000年 | 60篇 |
1999年 | 61篇 |
1998年 | 24篇 |
1997年 | 10篇 |
1996年 | 12篇 |
1995年 | 8篇 |
1994年 | 5篇 |
1993年 | 6篇 |
1992年 | 12篇 |
1991年 | 16篇 |
1990年 | 10篇 |
1989年 | 7篇 |
1988年 | 10篇 |
1987年 | 5篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1981年 | 3篇 |
1980年 | 2篇 |
1979年 | 5篇 |
1978年 | 3篇 |
1972年 | 4篇 |
1970年 | 2篇 |
1969年 | 4篇 |
1968年 | 2篇 |
1967年 | 2篇 |
1966年 | 6篇 |
1955年 | 2篇 |
排序方式: 共有2964条查询结果,搜索用时 31 毫秒
151.
Aspirin and Epithelial Ovarian Cancer 总被引:6,自引:0,他引:6
Arslan Akhmedkhanov M.D. Paolo Toniolo M.D. MSPH Anne Zeleniuch-Jacquotte M.D. M.S. Ikuko Kato M.D. Ph.D. Karen L. Koenig Ph.D. Roy E. Shore Ph.D. Dr.P.H. 《Preventive medicine》2001,33(6):682-687
BACKGROUND: Epidemiological evidence suggests that chronic inflammation may influence ovarian carcinogenesis. The study objective was to examine the association between the commonly used anti-inflammatory drug aspirin and epithelial ovarian cancer. METHODS: The authors conducted a case-control study based in the New York University Women's Health Study cohort enrolled between 1985 and 1991 in New York City. After a median follow-up period of 12 years, 68 incident cases of epithelial ovarian cancer were identified. Data about regular aspirin use were collected during the 1994-1996 follow-up questionnaire. Using a case-control study design, 10 controls per case were randomly selected among study participants who matched the case by age and menopausal status. Conditional logistic regression analysis was used to study the relationships between aspirin and epithelial ovarian cancer by generating odds ratios (ORs) and 95% confidence intervals (CIs). RESULTS: Relative to no aspirin use, the OR for epithelial ovarian cancer among women who reported aspirin use three or more times per week for a period of at least 6 months was 0.60 (95% CI 0.26, 1.38), after adjustment for age at menarche, parity, oral contraceptive use, and first-degree family history of breast cancer before age 50. Among recent, within the previous 5 years, users of aspirin, the adjusted OR was 0.36 (95% CI 0.11, 1.18). CONCLUSION: Although confidence intervals included unity, the observed risk estimates seem to be compatible with previous studies suggesting that regular aspirin use could be inversely associated with risk of epithelial ovarian cancer. 相似文献
152.
153.
Kidney graft failure and presensitization against HLA class I and class II antigens 总被引:10,自引:0,他引:10
BACKGROUND: It is well known that kidney transplant recipients with preformed lymphocytotoxic antibodies against HLA antigens have an increased graft rejection rate. However, the individual contribution of anti-HLA class I and class II antibodies to this phenomenon is poorly understood. We investigated the clinical relevance of preformed anti-HLA class I and class II antibodies on graft outcome in more than 4000 kidney recipients. METHODS: Pretransplant sera of 4136 cadaver kidney recipients from 28 transplant centers were tested in ELISA for IgG-anti-HLA class I and IgG-anti-HLA class II antibodies. The influence of antibody reactivity on graft survival was analyzed. RESULTS: Four hundred eighty of the anti-HLA class I antibody-positive recipients had a graft survival rate at 2 years of 77+/-2%, compared with an 84+/-1% rate in 3656 anti-HLA class I antibody-negative recipients (P<0.0001), and 770 anti-HLA class II-positive recipients had a graft survival rate of 79+/-2%, compared with an 84+/-1% rate in 3366 anti-HLA class II-negative patients (P<0.0001). Importantly, good 2-year graft survival rates of 85+/-3% and 84+/-2%, respectively, were observed in 206 anti-HLA class I-positive/class II-negative and 496 anti-HLA, class I-negative/class II-positive recipients. In contrast, the 274 recipients positive for both types of antibodies showed a poor graft survival rate of 71+/-3% (P<0.0001). Among 853 patients who received a well-matched kidney (0 or 1 HLA-A+B+DR mismatch), sensitization against either class I or class II, or both, had no deleterious effect. However, in 113 class I and class II antibody-positive patients who received a kidney with > or =3 HLA-A+B+DR mismatches, the 2-year graft survival rate was only 60+/-5%. CONCLUSION: Presensitization of first kidney transplant recipients against either HLA class I or class II is of no clinical consequence, whereas sensitization against both HLA class I and class II results in increased rejection of HLA mismatched grafts. 相似文献
154.
Long-term survival with heterotopic liver transplantation 总被引:1,自引:0,他引:1
Haberal M Emiroğlu R Arslan G Karakayali H Moray G Bilgin N 《Transplantation proceedings》2002,34(6):2468-2471
155.
Body mass index in relation to ovarian cancer: a multi-centre nested case-control study 总被引:2,自引:0,他引:2
Lukanova A Toniolo P Lundin E Micheli A Akhmedkhanov A Muti P Zeleniuch-Jacquotte A Biessy C Lenner P Krogh V Berrino F Hallmans G Riboli E Kaaks R 《International journal of cancer. Journal international du cancer》2002,99(4):603-608
The incidence of ovarian cancer is up to 10 times higher in Western countries than in rural Asia and Africa. One common consequence of a Western lifestyle is the development of excessive body weight and obesity. A multi‐centre prospective study was conducted to investigate the association between body mass index (BMI) and ovarian cancer risk. A case‐control study was nested within 3 prospective cohorts in New York (USA), Umeå (Sweden) and Milan (Italy). Information on anthropometry, demographic characteristics, medical history and lifestyle was obtained at the time of subjects' recruitment in each cohort. Women diagnosed with primary, invasive epithelial ovarian cancer from the 3 cohorts (n = 122) diagnosed 12 months or later after recruitment into the respective cohort served as case subjects. For each case subject, 2 control subjects that matched the case subject on cohort, menopausal status, age and date of recruitment were randomly identified. Data were analyzed by conditional logistic regression. There was an inverse association between BMI and ovarian cancer risk. For increasing quartiles of BMI above the lowest, the ORs were 0.62 (0.32–1.21), 0.59 (0.30–1.17) and 0.46 (0.23–0.92), p = 0.03. Analyses limited to women diagnosed 3 or more years after recruitment into the cohorts did not alter these findings. When obese women (BMI > 30) were compared to lean women (BMI ≤ 23), the inverse association became stronger, with an OR of 0.38 (0.17–0.85), p < 0.02. There was some evidence of direct association of ovarian cancer with height, which was limited to cancers diagnosed before age 55. Our data suggest that increasing body weight may confer a protection against ovarian cancer. © 2002 Wiley‐Liss, Inc. 相似文献
156.
Ménégoz F Little J Colonna M Arslan A Preston-Martin S Schlehofer B Blettner M Howe GR Ryan P Giles GG Rodvall Y Choi WN 《European journal of cancer (Oxford, England : 1990)》2002,38(5):696-704
While numerous studies have addressed the possible role of farming and related exposures as risk factors for brain tumours in adults, few of them have examined the potential effect of exposure to farm animals or pets. In an international multicentre case-control study, we investigated whether residence on a farm, contact with animals, or working in occupations with a high degree of potential contact with animals or humans were associated with brain tumours. Using a common questionnaire, 1177 cases of glioma, 330 with meningioma and 2478 controls from eight centres were interviewed about the exposures and, in particular, about their contacts with nine species of animals: dairy cattle, beef cattle, pigs, horses, sheep, goats, poultry, dogs and cats. Living or working on a farm was not a risk factor, for either glioma or meningioma. Except in some centres, there was no relationship between having contacts with farm animals or pets and the risk of brain tumour, for either type of tumour or either sex. In relation to seven industrial groups involving frequent human and/or animal contacts, no association was apparent for either glioma or meningioma. In relation to 25 occupational groups with potential frequent contact with humans and/or animals, for glioma there was a reduced risk for biological technicians (Odds Ratio (OR)/=0, P=0.01), and general farm workers (OR=0.66, 95% Confidence Interval (CI): 0.5-0.9). For meningioma, there was an increased risk for cooks (OR=2.0; CI: 1.2-3.4). With some exceptions, these results indicate no association between either the type of brain tumour and contacts with animals, or with occupations that include a high level of contact with animals or a high level of contact with humans. 相似文献
157.
158.
Systemic lupus erythematosus (SLE) is characterized by the presence of various autoantibodies and the deposition of immune complex, which is cleared by Fcgamma receptors. Genotype analysis was done to investigate whether the FcgammaRIIIA-176F/V polymorphism is a risk factor for SLE in Koreans. We genotyped 145 Korean SLE patients and 75 control subjects for FcgammaRIIIA-176F/ V. After amplifying a 1.7-kb fragment containing the Fcgamma/RIIIA-176F/V polymorphic site using two FcgammaRIIIA gene-specific primers, we performed a nested polymerase chain reaction (PCR) for allele-specific genotyping at position 559 in FcgammaRIIIA. FcgammaRIIIA genotype or allele distribution was not significantly different between lupus patients and controls, and also between lupus nephritis patients and healthy controls. Neither creatinine clearance, 24 h urine proteinuria, number of American College of Rheumatology (ACR) criteria, nor the Systemic Lupus International Collaborating Clinics (SLICC)/ACR damage index was different according to the genotype. In conclusion, FcgammaRIIIA-176F/V polymorphism is not associated with SLE in Koreans. 相似文献
159.
Demir H Berk F Memisoglu K Arslan A Muezzinoglu B Erdincler RO Isgoren S Sarlak A Aktolun C 《Annals of nuclear medicine》2002,16(2):151-155
The authors report a case of alveolar soft-part sarcoma with lung metastases demonstrated by "double imaging" with Tc-99m HDP and Tc-99m MIBI. The tumor originated in the soft tissue with direct invasion to the right scapula, which was hypoactive on bone scan and hyperactive on Tc-99m MIBI images. A focus of dense accumulation of Tc-99m MIBI in the lungs, suggesting metastasis was also demonstrated. 相似文献
160.
M Arslan O Pata T U K Dilek A Aktas M Aban S Dilek 《International journal of gynaecology and obstetrics》2005,89(2):163-166
OBJECTIVE: Pregnancy in previous cesarean scar is the rarest form of ectopic pregnancy. All reported cases in the literature that were treated with uterine curettage either become unsuccessful or complicated. We aimed to present a case of cesarean scar ectopic pregnancy that was successfully treated with suction curettage without any additional therapy. CASE: A 32-year-old asymptomatic woman, gravida 2, para 1 was referred to our hospital with the possible diagnosis of cervical ectopic pregnancy. Transvaginal and transabdominal sonographic examination revealed the diagnosis of viable ectopic pregnancy in a previous cesarean scar. Suction curettage with carman canulles was performed under transabdominal ultrasonographic guidance. beta-hCG decreased progressively postoperatively. CONCLUSION: Suction curettage under ultrasonography guidance can be used in termination of selected cases (early diagnosed, without symptoms that necessitates emergency intervention) of cesarean scar pregnancy. 相似文献