全文获取类型
收费全文 | 18736篇 |
免费 | 1542篇 |
国内免费 | 30篇 |
专业分类
耳鼻咽喉 | 238篇 |
儿科学 | 665篇 |
妇产科学 | 458篇 |
基础医学 | 2370篇 |
口腔科学 | 221篇 |
临床医学 | 1934篇 |
内科学 | 3537篇 |
皮肤病学 | 316篇 |
神经病学 | 2250篇 |
特种医学 | 436篇 |
外科学 | 2118篇 |
综合类 | 146篇 |
一般理论 | 20篇 |
预防医学 | 2623篇 |
眼科学 | 486篇 |
药学 | 1152篇 |
1篇 | |
中国医学 | 23篇 |
肿瘤学 | 1314篇 |
出版年
2024年 | 49篇 |
2023年 | 338篇 |
2022年 | 511篇 |
2021年 | 993篇 |
2020年 | 596篇 |
2019年 | 869篇 |
2018年 | 944篇 |
2017年 | 638篇 |
2016年 | 672篇 |
2015年 | 662篇 |
2014年 | 824篇 |
2013年 | 1037篇 |
2012年 | 1498篇 |
2011年 | 1441篇 |
2010年 | 718篇 |
2009年 | 596篇 |
2008年 | 1011篇 |
2007年 | 936篇 |
2006年 | 786篇 |
2005年 | 735篇 |
2004年 | 622篇 |
2003年 | 536篇 |
2002年 | 439篇 |
2001年 | 219篇 |
2000年 | 194篇 |
1999年 | 162篇 |
1998年 | 104篇 |
1997年 | 77篇 |
1996年 | 63篇 |
1995年 | 70篇 |
1994年 | 76篇 |
1993年 | 72篇 |
1992年 | 125篇 |
1991年 | 106篇 |
1990年 | 97篇 |
1989年 | 109篇 |
1988年 | 81篇 |
1987年 | 93篇 |
1986年 | 99篇 |
1985年 | 85篇 |
1984年 | 67篇 |
1983年 | 77篇 |
1982年 | 66篇 |
1981年 | 53篇 |
1979年 | 75篇 |
1978年 | 53篇 |
1976年 | 58篇 |
1974年 | 50篇 |
1973年 | 45篇 |
1972年 | 44篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Madan M. Rehani Emily R. Melick Raza M. Alvi Ruhani Doda Khera Salma Batool-Anwar Tomas G. Neilan Michael Bettmann 《European radiology》2020,30(4):1839-1846
To determine percent of patients without malignancy and ≤ 40 years of age with high cumulative radiation doses through recurrent CT exams and assess imaging appropriateness. From the cohort of patients who received cumulative effective dose (CED) of ≥ 100 mSv over a 5-year period, a sub-set was identified with non-malignant disease. The top 50 clinical indications leading to multiple CTs were determined. Clinical decision support (CDS) system scores were analyzed using a widely adopted standard of 1–3 (red) as “not usually appropriate,” 4–6 (yellow) “may or may not be appropriate,” and 7–9 (green) “usually appropriate.” Clinicians reviewed patient records to assess compliance with appropriate use criteria (AUC). 9.6% of patients in our series were with non-malignant conditions and 1.4% with age ≤ 40 years. CDS scores (rounded) were 2% red, 38% yellow, 27% green, and 33% unscored CTs. Clinical society guidelines for CT exams, wherever available, were followed in 87.5 to 100% of cases. AUCs were not available for several clinical indications as also referral guidelines for serial CT imaging. More than half of CT exams were unrelated to follow-up of a primary chronic disease. We are faced with a situation wherein patients in age ≤ 40 years require or are thought to require many CT exams over the course of a few years but the radiation risk creates concern. There is a fair number of conditions for which AUC are not available. Suggested solutions include development of CT scanners with lesser radiation dose and further development of appropriateness criteria. 相似文献
3.
Selwyn Arlington Headley Nayara Emily Viana Mariana de Mello Zanim Michelazzo Ana Aparecida Correa Xavier Cícero Júlio Silva Costa Felipe Hideki Ogo de Pinho Marcelo Diniz dos Santos 《Transboundary and Emerging Diseases》2020,67(Z2):49-59
Neorickettsia helminthoeca (NH), the agent of salmon poisoning disease or canine neorickettiosis (CN), is a bacterial endosymbiont of the nematode Nanophyetus salmincola, and infections are spreading among specific fish‐eating mammalians. This article describes the pathologic and immunohistochemical findings associated with spontaneous NH‐induced infections in dogs from Southern Brazil. The principal pathologic findings were hypertrophy of Peyer patches and lymphadenopathy with lymphocytic proliferation, chronic interstitial pneumonia, and chronic enteritis associated with positive intralesional immunoreactivity to antigens of NH within macrophages and histiocytes. Positive immunoreactivity against canine parvovirus‐2 (CPV‐2) or/and canine distemper virus was not detected in the evaluated intestinal segments or in the samples from the cerebellum and lungs, respectively, from the dogs evaluated. These findings demonstrated that NH was involved in the enteric, pulmonary, and lymphoid lesions herein described, and provide additional information to confirm the occurrence of this bacterial endosymbiont within this geographical location. It is proposed that chronic pneumonia should be considered as a pathologic manifestation of NH‐induced infections. Additionally, our results show that the occurrences of CN seem to be underdiagnosed in Southern Brazil due to the confusion with the incidence of CPV‐2. 相似文献
4.
Whitney S. Brandt Wanpu Yan Jian Zhou Kay See Tan Joseph Montecalvo Bernard J. Park Prasad S. Adusumilli James Huang Matthew J. Bott Valerie W. Rusch Daniela Molena William D. Travis Mark G. Kris Jamie E. Chaft David R. Jones 《The Journal of thoracic and cardiovascular surgery》2019,157(2):743-753.e3
Objective
Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.Methods
Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.Results
In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.Conclusions
Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection. 相似文献5.
6.
Can EGFR mutation status be reliably determined in pre‐operative needle biopsies from adenocarcinomas of the lung?
下载免费PDF全文
![点击此处可从《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Kim Hein Lindahl Flemming Brandt Sørensen Søren Peter Jonstrup Karen Ege Olsen Siegfried Loeschke 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2015,123(4):289-297
The identification of EGFR mutations in non‐small‐cell lung cancer is important for selecting patients, who may benefit from treatment with EGFR tyrosine kinase inhibitors. The analysis is usually performed on cytological aspirates and/or histological needle biopsies, representing a small fraction of the tumour volume. The aim of the present investigation was to evaluate the diagnostic performance of this molecular test. We retrospectively included 201 patients with primary adenocarcinoma of the lung. EGFR mutation status (exon 19 deletions and exon 21 L858R point mutation) was evaluated on both pre‐operative biopsies (131 histological and 70 cytological) and on the surgical specimens, using PCR. Samples with low tumour cell fraction were assigned to laser micro‐dissection (LMD). We found nine (4.5%) patients with EGFR mutation in the lung tumour resections, but failed to identify mutation in one of the corresponding pre‐operative, cytological specimens. Several (18.4%) analyses of the pre‐operative biopsies were inconclusive, especially in case of biopsies undergoing LMD and regarding exon 21 analysis. Discrepancy of mutation status in one patient may reflect intra‐tumoural heterogeneity or technical issues. Moreover, several inconclusive results in the diagnostic biopsies reveal that attention must be paid on the suitability of pre‐operative biopsies for EGFR mutation analysis. 相似文献
7.
8.
Marta Rozanski Valentin Neuhaus Emily Thornton Stéphanie J. E. Becker James P. Rathmell David Ring 《Journal of hand and microsurgery》2015,7(1):30-35
This study used the National Survey of Ambulatory Surgery (NSAS) database to measure the incidence of and risk factors for symptoms in the ambulatory surgery center and problems within 24 h after isolated carpal tunnel release (CTR). The NSAS contained records on 400,000 adult patients with carpal tunnel syndrome who were treated with CTR in 2006, based on ICD-9 codes. The type of anesthesia used and factors associated with symptoms and problems were sought in bivariate and multivariable statistical analyses. The mean duration of the procedure was 16 ± 8.8 min. Only 5 % were performed under local anesthesia without sedation, 45 % with IV sedation, 28 % regional anesthesia, and 19 % general anesthesia. Symptoms in the ambulatory surgery center or a problem within 24 h after discharge were recorded in 10 % of patients, all of them minor and transient, including difficulties with pain and its treatment. The strongest risk factors were male sex, age of 45 years and older, and participation of an anesthesiologist. Local anesthesia and regional anesthesia were associated with more perioperative symptoms and postoperative problems. Most CTR are performed with some sedation in the United States. CTR is a safe procedure: one in 10 patients will experience a minor issue in the perioperative or immediate postoperative period. 相似文献
9.
Richard Kim Elaine Tan Emily Wang Amit Mahipal Dung-Tsa Chen Biwei Cao Fadzai Masawi Cindy Machado James Yu Dae Won Kim 《The oncologist》2020,25(12):e1893-e1899
Lessons Learned
- The combination of trametinib and sorafenib has an acceptable safety profile, albeit at doses lower than approved for monotherapy.
- Maximum tolerated dose is trametinib 1.5 mg daily and sorafenib 200 mg twice daily.
- The limited anticancer activity observed in this unselected patient population does not support further exploration of trametinib plus sorafenib in patients with hepatocellular carcinoma.
10.
Yasmine Yousef Etienne St-Louis Robert Baird Emily R. Smith Elena Guadagno Dickens St-Vil Dan Poenaru 《Journal of pediatric surgery》2019,54(4):831-837