全文获取类型
收费全文 | 1015774篇 |
免费 | 79542篇 |
国内免费 | 4686篇 |
专业分类
耳鼻咽喉 | 13218篇 |
儿科学 | 34659篇 |
妇产科学 | 28692篇 |
基础医学 | 146933篇 |
口腔科学 | 28048篇 |
临床医学 | 92905篇 |
内科学 | 195013篇 |
皮肤病学 | 23173篇 |
神经病学 | 80040篇 |
特种医学 | 39395篇 |
外国民族医学 | 312篇 |
外科学 | 151677篇 |
综合类 | 29407篇 |
现状与发展 | 8篇 |
一般理论 | 386篇 |
预防医学 | 79247篇 |
眼科学 | 23119篇 |
药学 | 74650篇 |
22篇 | |
中国医学 | 3627篇 |
肿瘤学 | 55471篇 |
出版年
2019年 | 8187篇 |
2018年 | 11464篇 |
2017年 | 9116篇 |
2016年 | 10149篇 |
2015年 | 11780篇 |
2014年 | 16016篇 |
2013年 | 23536篇 |
2012年 | 31081篇 |
2011年 | 33114篇 |
2010年 | 20215篇 |
2009年 | 18824篇 |
2008年 | 30332篇 |
2007年 | 32016篇 |
2006年 | 32462篇 |
2005年 | 30907篇 |
2004年 | 29889篇 |
2003年 | 28835篇 |
2002年 | 27624篇 |
2001年 | 47514篇 |
2000年 | 48503篇 |
1999年 | 40432篇 |
1998年 | 10858篇 |
1997年 | 9739篇 |
1996年 | 9689篇 |
1995年 | 9855篇 |
1994年 | 9179篇 |
1993年 | 8499篇 |
1992年 | 32252篇 |
1991年 | 31509篇 |
1990年 | 31048篇 |
1989年 | 29906篇 |
1988年 | 27180篇 |
1987年 | 27340篇 |
1986年 | 25427篇 |
1985年 | 24600篇 |
1984年 | 18380篇 |
1983年 | 15463篇 |
1982年 | 9250篇 |
1981年 | 8334篇 |
1979年 | 16822篇 |
1978年 | 12191篇 |
1977年 | 10281篇 |
1976年 | 9718篇 |
1975年 | 10153篇 |
1974年 | 12298篇 |
1973年 | 11827篇 |
1972年 | 10878篇 |
1971年 | 10104篇 |
1970年 | 9370篇 |
1969年 | 8713篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Marike Gabrielson Mattias Hammarström Magnus Bäcklund Jenny Bergqvist Kristina Lång Ann H Rosendahl Signe Borgquist Roxanna Hellgren Kamila Czene Per Hall 《International journal of cancer. Journal international du cancer》2023,152(11):2362-2372
Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to “no dose” (0-1 mg), “low-dose” (2.5-5 mg) or “high-dose” (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen. 相似文献
3.
Kara S. Tanaka MD Veronica R. Andaya BA Steven W. Thorpe MD Kenneth R. Gundle MD James B. Hayden MD Yee-Cheen Duong MD Raffi S. Avedian MD David G. Mohler MD Lee J. Morse MD Melissa N. Zimel MD Richard J. O'Donnell MD Andrew Fang MD Robert Lor Randall MD Tina H. Tran BS Christin New BA Rosanna L. Wustrack MD other members of Study Group FORCE 《Journal of surgical oncology》2023,127(1):148-158
4.
S. Liu A. E. Patanwala J. M. Naylor N. Levy R. Knaggs J. A. Stevens B. Bugeja D. Begley K. E. Khor E. Lau R. Allen S. Adie J. Penm 《Anaesthesia》2023,78(10):1237-1248
Modified-release opioids are often prescribed for the management of moderate to severe acute pain following total hip and knee arthroplasty, despite recommendations against their use due to increasing concerns regarding harm. The primary objective of this multicentre study was to examine the impact of modified-release opioid use on the incidence of opioid-related adverse events compared with immediate-release opioid use, among adult inpatients following total hip or knee arthroplasty. Data for total hip and knee arthroplasty inpatients receiving an opioid analgesic for postoperative analgesia during hospitalisation were collected from electronic medical records of three tertiary metropolitan hospitals in Australia. The primary outcome was the incidence of opioid-related adverse events during hospital admission. Patients who received modified with or without immediate-release opioids were matched to those receiving immediate-release opioids only (1:1) using nearest neighbour propensity score matching with patient and clinical characteristics as covariates. This included total opioid dose received. In the matched cohorts, patients given modified-release opioids (n = 347) experienced a higher incidence of opioid-related adverse events overall, compared with those given immediate-release opioids only (20.5%, 71/347 vs. 12.7%, 44/347; difference in proportions 7.8% [95%CI 2.3–13.3%]). Modified-release opioid use was associated with an increased risk of harm when used for acute pain during hospitalisation after total hip or knee arthroplasty. 相似文献
5.
Jos B. Poell Leon J. Wils Arjen Brink Ralf Dietrich Christine Krieg Eunike Velleuer Ilkay Evren Elisabeth R. Brouns Jan G. de Visscher Elisabeth Bloemena Bauke Ylstra Ruud H. Brakenhoff 《International journal of cancer. Journal international du cancer》2023,152(2):227-238
Oral squamous cell carcinomas (OSCCs) develop in genetically altered epithelium in the mucosal lining, also coined as fields, which are mostly not visible but occasionally present as white oral leukoplakia (OL) lesions. We developed a noninvasive genetic assay using next-generation sequencing (NGS) on brushed cells to detect the presence of genetically altered fields, including those that are not macroscopically visible. The assay demonstrated high accuracy in OL patients when brush samples were compared with biopsies as gold standard. In a cohort of Fanconi anemia patients, detection of mutations in prospectively collected oral brushes predicted oral cancer also when visible abnormalities were absent. We further provide insight in the molecular landscape of OL with frequent changes of TP53, FAT1 and NOTCH1. NGS analysis of noninvasively collected samples offers a highly accurate method to detect genetically altered fields in the oral cavity, and predicts development of OSCC in high-risk individuals. Noninvasive genetic screening can be employed to screen high-risk populations for cancer and precancer, map the extension of OL lesions beyond what is visible, map the oral cavity for precancerous changes even when visible abnormalities are absent, test accuracy of promising imaging modalities, monitor interventions and determine genetic progression as well as the natural history of the disease in the human patient. 相似文献
6.
背景:儿童新型冠状(新冠)病毒Omicron变异株流行期间,免疫抑制状态儿童新冠病毒清除时间定量分析研究较少。
目的:探讨新冠病毒Omicron株感染后免疫抑制和非免疫抑制儿童病毒清除的时间差别,为公共卫生政策制定和精准疫情防控措施提供临床数据。
设计:回顾性队列研究。
方法:以新冠病毒Omicron变异株感染住院患儿为队列人群,分为免疫抑制组和非免疫抑制组,免疫抑制分为绝对免疫抑制、相对免疫抑制和实施免疫抑制疗法,以免疫抑制组病例的性别、年龄和新冠病毒感染的分型与非免疫抑制组行1∶3匹配。以鼻咽拭子新冠病毒PCR检测拷贝数阈(Ct)值≥35为队列终点。
主要结局指标:新冠病毒清除时间。
结果:2022年4月12日至2022年5月12日在上海市新冠病毒感染定点收治医院符合本文共同纳入和排除标准的连续病例728例。免疫抑制组33例,其中绝对免疫抑制8例,相对免疫抑制23例,接受免疫抑制疗法2例(不包括绝对和相对免疫抑制患儿)。非免疫抑制组匹配后99例。2组临床症状、新冠病毒感染治疗和疫苗接种次数差异均无统计学意义。免疫抑制组和非免疫抑制组新冠病毒清除时间分别为(16.5±6.8)和(10.3±4.4)d,差异有统计学意义。免疫抑制组和非免疫抑制组新冠病毒感染轻型病例病毒清除时间分别为(14.0 ± 8.3)和(9.7 ± 3.1)d,普通型病例病毒清除时间分别为(18.3 ± 4.9)和(11.2 ± 5.9)d,差异均有统计学意义。2组单日病毒清除率在第9~14天时差异有统计学意义(P为0.005~0.039)。2组普通型病例单日病毒清除率在第10~15天时差异有统计学意义。免疫抑制组新冠病毒感染2周后核酸检测再次呈阳性3例(9%),临床分型均较前轻,3例均未接种新冠疫苗。
结论:Omicron株感染的免疫抑制患儿病毒清除时间较非免疫抑制患儿显著延长,主要反映在第9~14天,免疫抑制患儿病毒复阳风险高,提示需要更长的隔离时间和转阴后严格的病毒监测。 相似文献
7.
Boffa Joseph W. Tock Jamie L. Morabito Danielle M. Schmidt Norman B. 《Cognitive therapy and research》2022,46(5):1016-1029
Cognitive Therapy and Research - Despite interest in psychological inflexibility as a marker of suicide risk, no measure of psychological inflexibility specific to SI exists. The present study... 相似文献
8.
9.
10.
Keith B. Diamond Ivan J. Golub Asad M. Ashraf Samuel J. Swiggett Paul V. Romeo Jack Choueka 《Seminars in Arthroplasty》2022,32(1):15-22
BackgroundWhile studies have demonstrated favorable outcomes in utilization of primary total shoulder arthroplasty (TSA) for the treatment of glenohumeral osteoarthritis (OA), adverse events such as infections can still occur. Periprosthetic joint infections (PJIs) are associated with worse outcomes and patient morbidity. The purpose of this study was to: (1) compare patient demographics amongst TSA patients with and without PJIs following primary TSA; and (2) identify patient-related risk factors for PJIs following primary TSA.MethodsPatients undergoing primary TSA for the treatment of glenohumeral OA were identified using the Mariner administrative claims database by CPT code 23,472. Laterality modifiers were utilized to ensure PJIs were developing in the correct laterality as those patients undergoing primary TSA. Inclusion for the study group consisted of patients who developed PJIs within 2-years after the index procedure, whereas patients who did not develop PJIs served as the comparison cohort. Primary outcomes analyzed included patient demographics and patient-related risk factors for PJIs following primary TSA. A stepwise backwards elimination multivariate binomial logistic regression analyses was performed to determine the odds (OR) of PJIs in patients undergoing primary TSA. A P value less than .05 was considered statistically significant.ResultsThe query yielded 15,396 patients who underwent primary TSA for glenohumeral OA, of which 191 patients developed PJIs and 15,205 did not develop PJIs. The study found statistically significant differences amongst patients who did and did not develop PJIs following primary TSA with respect to age, sex, and presence of comorbid conditions. Risk factors associated with developing PJIs following primary TSA included: pathologic weight loss (OR: 2.06, P < .0001), obesity (OR: 1.56, P = .0001), male sex (OR: 1.52, P = .007), and peripheral vascular disease (OR: 1.46, P = .022).ConclusionAs the number of primary TSAs for the treatment of glenohumeral OA increase worldwide, identifying modifiable risk-factors to reduce the incidence of infection is critical. The study found various modifiable and non-modifiable risk factors associated with developing PJIs following primary TSA. This study is valuable to orthopedists in order to identify and risk-stratify patients with regard to PJI in the setting of primary TSA for OA.Level of EvidenceLevel III; Case-Control Study 相似文献