全文获取类型
收费全文 | 9231篇 |
免费 | 638篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 130篇 |
儿科学 | 309篇 |
妇产科学 | 310篇 |
基础医学 | 1308篇 |
口腔科学 | 461篇 |
临床医学 | 1053篇 |
内科学 | 1748篇 |
皮肤病学 | 163篇 |
神经病学 | 765篇 |
特种医学 | 195篇 |
外科学 | 808篇 |
综合类 | 65篇 |
一般理论 | 3篇 |
预防医学 | 1206篇 |
眼科学 | 98篇 |
药学 | 661篇 |
中国医学 | 32篇 |
肿瘤学 | 586篇 |
出版年
2023年 | 91篇 |
2022年 | 76篇 |
2021年 | 231篇 |
2020年 | 250篇 |
2019年 | 281篇 |
2018年 | 351篇 |
2017年 | 275篇 |
2016年 | 254篇 |
2015年 | 326篇 |
2014年 | 366篇 |
2013年 | 517篇 |
2012年 | 797篇 |
2011年 | 818篇 |
2010年 | 431篇 |
2009年 | 389篇 |
2008年 | 669篇 |
2007年 | 639篇 |
2006年 | 563篇 |
2005年 | 546篇 |
2004年 | 496篇 |
2003年 | 452篇 |
2002年 | 400篇 |
2001年 | 49篇 |
2000年 | 29篇 |
1999年 | 45篇 |
1998年 | 49篇 |
1997年 | 46篇 |
1996年 | 24篇 |
1995年 | 48篇 |
1994年 | 42篇 |
1993年 | 45篇 |
1992年 | 21篇 |
1991年 | 21篇 |
1990年 | 17篇 |
1989年 | 9篇 |
1988年 | 15篇 |
1987年 | 14篇 |
1986年 | 17篇 |
1985年 | 25篇 |
1984年 | 18篇 |
1983年 | 16篇 |
1982年 | 8篇 |
1981年 | 11篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1978年 | 11篇 |
1976年 | 6篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1971年 | 7篇 |
排序方式: 共有9901条查询结果,搜索用时 62 毫秒
1.
Suyen Karki Eila Laukkanen Helena Länsimies Tomi-Pekka Tuomainen Anna-Maija Pietilä 《Journal of substance use》2019,24(3):300-308
Background: Research has demonstrated that problem behavior has been associated with substance use, but knowledge is lacking on such associations in a low-income country like Nepal. Aims: This study aimed to find associations between emotional and behavioral problems and substance use among Nepalese adolescents. Method: A cross-sectional study was conducted at the end of 2011, with participants from three schools in the Province 4 of Nepal. We selected 408 adolescents aged 12 to 18 (mean 15.2 years, 54% boys) at one urban and two rural schools. The data were collected using the Youth Self-Report and Adolescents’ Substance Use Measurement. Results: Higher scores on withdrawn/depressed symptoms, thought problems, attention problems, delinquent or aggressive behavior or internalizing or externalizing problems were associated with the use of tobacco, alcohol or other substances. In the broadband scales, only internalizing problems predicted the use of intoxicants. Higher scores for attention problems predicted the use of tobacco, any intoxicants, and high-risk user. Conclusion: Our findings indicated that problem behavior among Nepalese adolescents was associated with substance use. Future studies should explore the association between problem behavior and substance use, including causal factors, so that risky behavior among Nepalese adolescents can be prevented. 相似文献
2.
3.
Miku Mislav Benco Nikolina Matak Luka Planini Pavao ori Mario Lovri Helena Radoevi Velena Puevski Tomislav Bajt Mirna Vuji Goran 《Archives of gynecology and obstetrics》2020,301(5):1227-1233
Archives of Gynecology and Obstetrics - To describe a case series of patients with malignant ovarian germ cell tumors (MOGCT) treated exclusively with fertility-sparing surgery (FSS) with or... 相似文献
4.
Camilo Brando-de-Resende Helena Hollanda Santos Angel Alessio Rojas Lagos Camila Munayert Lara Jacqueline Souza Dutra Arruda Ana Paula Maia Peixoto Marino Lis Ribeiro do Valle Antonelli Ricardo Tostes Gazzinelli Ricardo Wagner de Almeida Vitor Daniel Vitor Vasconcelos-Santos 《Emerging infectious diseases》2020,26(12):2922
In 2015, an outbreak of presumed waterborne toxoplasmosis occurred in Gouveia, Brazil. We conducted a 3-year prospective study on a cohort of 52 patients from this outbreak, collected clinical and multimodal imaging findings, and determined risk factors for ocular involvement. At baseline examination, 12 (23%) patients had retinochoroiditis; 4 patients had bilateral and 2 had macular lesions. Multimodal imaging revealed 2 distinct retinochoroiditis patterns: necrotizing focal retinochoroiditis and punctate retinochoroiditis. Older age, worse visual acuity, self-reported recent reduction of visual acuity, and presence of floaters were associated with retinochoroiditis. Among patients, persons >40 years of age had 5 times the risk for ocular involvement. Five patients had recurrences during follow-up, a rate of 22% per person-year. Recurrences were associated with binocular involvement. Two patients had late ocular involvement that occurred >34 months after initial diagnosis. Patients with acquired toxoplasmosis should have long-term ophthalmic follow-up, regardless of initial ocular involvement. 相似文献
5.
Bo Freyschuss Maria K. Svensson Thomas Cars Lars Lindhagen Helena Johansson Andreas Kindmark 《Journal of bone and mineral research》2022,37(4):649-659
Results from real-world evidence (RWE) from the largest healthcare region in Sweden show low uptake of antiresorptive (AR) treatment, but beneficial effect in those receiving treatment, especially for the composite outcome of hip fracture or death. For RWE studies, Sweden is unique, with virtually complete coverage of electronic medical records (EMRs) and both regional and national registries, in a universal publicly funded healthcare system. To our knowledge, there is no previous RWE study evaluating the efficacy of AR treatment compared to no AR treatment after fragility fracture, including data on parenteral treatments administered in hospital settings. The Stockholm Real World Management (STORM) study cohort was established in the healthcare region of Stockholm to retrospectively assess the effectiveness of AR treatment after first fragility fracture using the regional EMR system for both hospital and primary care. Between 2012 and 2018, we identified 69,577 fragility fracture episodes among 59,078 patients, men and women, 50 years and older. Of those, 21,141 patients met inclusion and exclusion criteria (eligible cohort). From these, the final matched study cohort comprised 9840 fragility fractures (cases receiving AR treatment [n = 1640] and controls not receiving AR treatment [n = 8200]). Propensity scores were estimated using logistic regression models with AR treatment as outcome and confounders as independent variables followed by analysis using Cox proportional hazard models. Real world evidence from Sweden's largest healthcare region, comprising a quarter of the Swedish population, show that only 10% of patients receive AR treatment within 1 year after a fragility fracture. Factors associated with not receiving treatment include having a diagnosis of cardiovascular disease. In those treated, AR have positive effects particularly on the composite of fracture and death (any fracture/death and hip fracture/death) in individuals matched for all major confounders. © 2022 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR). 相似文献
6.
Glutathione S-transferase Polymorphisms in Head and Neck Squamous Cell Carcinoma Treated with Chemotherapy and/or Radiotherapy 下载免费PDF全文
Mauricio Pereira ManigliaAnelise RussoPatrícia Matos Biselli-ChicoteJuliana Garcia de Oliveira-CucoloGabriela Helena Rodrigues-Flemingjosé Victor -ManigliaÉrika Cristina PavarinoEny Maria Goloni-Bertollo 《Asian Pacific journal of cancer prevention》2020,21(6):1637-1644
Background/Aim: The Glutathione S-transferases (GSTs) are important carcinogen-metabolizing enzymes. Polymorphisms involved in these enzymes can modulate the development and treatment of head and neck cancer. To investigate the association of GSTs polymorphisms with head and neck cancer and risk factors, clinical-pathological features, and survival time of the patients treated with chemotherapy and/or radiotherapy. Methods: The GST gene polymorphisms were evaluated in 197 cases and 514 controls by PCR-RFLP-Polymerase Chain Reaction Restriction Fragment Length Polymorphism. Results: The GSTP-313 was associated with a decreased risk for HNSCC (p=0.050). The GSTP1 haplotype analysis revealed a higher frequency of the AC and AT haplotypes in the case group than in the control group (p=0.013 and p=0.019, respectively), and the opposite for G-C haplotype (p = 0.015). Yet, the different combinations between the genotypes were associated with an increased risk of cancer. The study showed no association between the polymorphisms and primary tumor site, clinical-pathological characteristics, treatment (chemotherapy and/or radiotherapy) and survival time of the patients. Conclusion: The GST polymorphisms combination showed an increased risk for carcinogenesis, and studies with larger casuistry can contribute to the clarification of the role in individual patient differences for the response to chemotherapy and/or radiotherapy and identify biomarkers of susceptibility. 相似文献
7.
8.
Diego Dias da Silva Ana Helena da Rosa Paz Ciro Paz Portinho Elizabeth Obino Cirne Lima Lúcia Maria Kliemann Marcus Vinicius Martins Collares 《Acta cirúrgica brasileira / Sociedade Brasileira para Desenvolvimento Pesquisa em Cirurgia》2020,35(12)
Purpose:This study assessed the regeneration potential of mesenchymal stem cells (MSC) from adipose tissue associated with platelet-rich plasma (PRP) in bone regeneration.Methods:Thirty Wistar rats (Rattus norvegicus albinos) were divided into five groups (according to the grafting material and time to euthanasia): (1) autograft - 14 days (control), (2) autograft - 28 days (control), (3) MSC + PRP - 14 days, (4) MSC + PRP + papaverine - 14 days and (5) MSC + PRP + papaverine - 28 days. After euthanasia, the graft was removed and histological slides were prepared. They were assessed by a blinded pathologist using a previously published histological scale as parameter.Results:There was some degree of neoformed bone trabeculae (NBT) in 93.3% of the samples, as well as osteoblastic activity (OA). The autograft groups (14 and 28 days) had higher levels in the formation of bone trabeculae. Nonparametric data were analyzed using the Wilcoxon-Mann-Whitney test and proved not to be statistically significant at p < 0.05.Conclusions:Experimental parietal bone reconstruction, combining MSC, PRP and papaverine presented regeneration in all groups with no significant difference among them.Key words: Bone Regeneration, Platelet-Rich Plasma, Tissue Engineering, Rats 相似文献
9.
Jack Cuzick Rachael Adcock Francesca Carozzi Anna Gillio-Tos Laura De Marco Annarosa Del Mistro Helena Frayle Salvatore Girlando Cristina Sani Massimo Confortini Manuel Zorzi Paolo Giorgi-Rossi Raffaella Rizzolo Guglielmo Ronco the New Technologies for Cervical Cancer Screening Working Group 《International journal of cancer. Journal international du cancer》2020,147(7):1864-1873
Human papillomavirus (HPV) testing is very sensitive for primary cervical screening but has low specificity. Triage tests that improve specificity but maintain high sensitivity are needed. Women enrolled in the experimental arm of Phase 2 of the New Technologies for Cervical Cancer randomized controlled cervical screening trial were tested for high-risk HPV (hrHPV) and referred to colposcopy if positive. hrHPV-positive women also had HPV genotyping (by polymerase chain reaction with GP5+/GP6+ primers and reverse line blotting), immunostaining for p16 overexpression and cytology. We computed sensitivity, specificity and positive predictive value (PPV) for different combinations of tests and determined potential hierarchical ordering of triage tests. A number of 1,091 HPV-positive women had valid tests for cytology, p16 and genotyping. Ninety-two of them had cervical intraepithelial neoplasia grade 2+ (CIN2+) histology and 40 of them had CIN grade 3+ (CIN3+) histology. The PPV for CIN2+ was >10% in hrHPV-positive women with positive high-grade squamous intraepithelial lesion (61.3%), positive low-grade squamous intraepithelial lesion (LSIL+) (18.3%) and positive atypical squamous cells of undetermined significance (14.8%) cytology, p16 positive (16.7%) and, hierarchically, for infections by HPV33, 16, 35, 59, 31 and 52 (in decreasing order). Referral of women positive for either p16 or LSIL+ cytology had 97.8% sensitivity for CIN2+ and women negative for both of these had a 3-year CIN3+ risk of 0.2%. Similar results were seen for women being either p16 or HPV16/33 positive. hrHPV-positive women who were negative for p16 and cytology (LSIL threshold) had a very low CIN3+ rate in the following 3 years. Recalling them after that interval and referring those positive for either test to immediate colposcopy seem to be an efficient triage strategy. The same applies to p16 and HPV16. 相似文献
10.