全文获取类型
收费全文 | 5452篇 |
免费 | 406篇 |
国内免费 | 20篇 |
专业分类
耳鼻咽喉 | 43篇 |
儿科学 | 176篇 |
妇产科学 | 142篇 |
基础医学 | 810篇 |
口腔科学 | 110篇 |
临床医学 | 607篇 |
内科学 | 1119篇 |
皮肤病学 | 113篇 |
神经病学 | 438篇 |
特种医学 | 112篇 |
外国民族医学 | 3篇 |
外科学 | 531篇 |
综合类 | 52篇 |
一般理论 | 1篇 |
预防医学 | 388篇 |
眼科学 | 102篇 |
药学 | 375篇 |
中国医学 | 16篇 |
肿瘤学 | 740篇 |
出版年
2023年 | 39篇 |
2022年 | 76篇 |
2021年 | 179篇 |
2020年 | 93篇 |
2019年 | 147篇 |
2018年 | 162篇 |
2017年 | 112篇 |
2016年 | 105篇 |
2015年 | 132篇 |
2014年 | 182篇 |
2013年 | 248篇 |
2012年 | 403篇 |
2011年 | 369篇 |
2010年 | 221篇 |
2009年 | 178篇 |
2008年 | 317篇 |
2007年 | 342篇 |
2006年 | 308篇 |
2005年 | 296篇 |
2004年 | 299篇 |
2003年 | 248篇 |
2002年 | 246篇 |
2001年 | 137篇 |
2000年 | 99篇 |
1999年 | 118篇 |
1998年 | 40篇 |
1997年 | 55篇 |
1996年 | 31篇 |
1995年 | 32篇 |
1994年 | 35篇 |
1993年 | 27篇 |
1992年 | 55篇 |
1991年 | 57篇 |
1990年 | 44篇 |
1989年 | 35篇 |
1988年 | 44篇 |
1987年 | 29篇 |
1986年 | 44篇 |
1985年 | 25篇 |
1984年 | 22篇 |
1983年 | 25篇 |
1982年 | 27篇 |
1980年 | 10篇 |
1979年 | 25篇 |
1977年 | 9篇 |
1976年 | 12篇 |
1975年 | 10篇 |
1974年 | 12篇 |
1972年 | 17篇 |
1967年 | 10篇 |
排序方式: 共有5878条查询结果,搜索用时 15 毫秒
1.
Kinase alterations are increasingly recognised as oncogenic drivers in mesenchymal tumours. Infantile fibrosarcoma and the related renal tumour, congenital mesoblastic nephroma, were among the first solid tumours shown to harbour recurrent tyrosine kinase fusions, with the canonical ETV6::NTRK3 fusion identified more than 20 years ago. Although targeted testing has long been used in diagnosis, the advent of more robust sequencing techniques has driven the discovery of kinase alterations in an array of mesenchymal tumours. As our ability to identify these genetic alterations has improved, as has our recognition and understanding of the tumours that harbour these alterations. Specifically, this study will focus upon mesenchymal tumours harbouring NTRK or other kinase alterations, including tumours with an infantile fibrosarcoma-like appearance, spindle cell tumours resembling lipofibromatosis or peripheral nerve sheath tumours and those occurring in adults with a fibrosarcoma-like appearance. As publications describing the histology of these tumours increase so, too, do the variety kinase alterations reported, now including NTRK1/2/3, RET, MET, RAF1, BRAF, ALK, EGFR and ABL1 fusions or alterations. To date, these tumours appear locally aggressive and rarely metastatic, without a clear link between traditional features used in histological grading (e.g. mitotic activity, necrosis) and outcome. However, most of these tumours are amenable to new targeted therapies, making their recognition of both diagnostic and therapeutic import. The goal of this study is to review the clinicopathological features of tumours with NTRK and other tyrosine kinase alterations, discuss the most common differential diagnoses and provide recommendations for molecular confirmation with associated treatment implications. 相似文献
2.
Borrelli Enrico Grosso Domenico Vella Giovanna Sacconi Riccardo Battista Marco Querques Lea Zucchiatti Ilaria Prascina Francesco Bandello Francesco Querques Giuseppe 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2020,258(12):2621-2628
Graefe's Archive for Clinical and Experimental Ophthalmology - To estimate the impact of delayed care during the coronavirus disease 2019 (COVID-19) pandemic on the outcomes of patients with... 相似文献
3.
4.
5.
Meng-Luen Lee Lon-Yen Tsao Wun-Tsong Chaou Albert D Yang Kun-Tu Yeh Jou-Kou Wang Mei-Hwan Wu Hung-Chi Lue Ing-Sh Chiu Chung-I Chang 《Pediatric pulmonology》2002,33(1):1-11
We propose a haphazard branching theory to support the concept of bronchopulmonary malinosculations, and we apply this theory to classify congenital bronchopulmonary vascular malformation (BPVM) based on the anatomical results we have found. Between January 1990 and December 1997, a total of 22 pediatric patients (10 male and 12 female), aged 2 days to 14 years (median, 19.6 months), with congenital BPVM were enrolled in this retrospective study. Study modalities include the clinical features and plain chest films (n = 22) plus at least two of the following: echocardiography (n = 13), barium esophagraphy (n = 2), bronchoscopy (n = 4), contrast bronchography (n = 8), high-resolution direct coronal CT (n = 1) and electron beam or ultrafast CT (n = 1) of the chest, MRI (n = 10), MRA (n = 1), contrast cineangiocardiography (n = 9), surgery (n = 11), or autopsy (n = 2). The salient clinical features were recurrent lung infections in 14 patients, acute respiratory distress in 13, associated cardiovascular malformations in 8, dextroversion in 7, congestive heart failure in 7, dextrocardia in 4, and complex congenital heart diseases in 4. There were abnormal openings (malinosculations) of the pulmonary airway in 20 patients: to an artery in 12, to a vein in 8, and to the lung parenchyma in 9. These 22 patients with congenital BPVM can be classified into bronchial malinosculation (10 cases), arterial malinosculation (2 cases), and bronchoarterial malinosculation (10 cases). Congenital BPVM can be classified in terms of bronchopulmonary malinosculation based upon a haphazard branching theory, in which abnormal communications between two independent systems (primitive foregut system and aortic-pulmonary arch system) occurred coincidentally rather than causally. 相似文献
6.
7.
Carrier diagnosis of Duchenne muscular dystrophy using restriction fragment length polymorphisms 总被引:6,自引:0,他引:6
Molecular probes that are tightly linked to and flank the Duchenne muscular dystrophy (DMD) locus, have been used to characterize DMD mutations and diagnose female carriers. Deletions within the Xp21 region were identified for 8 of 71 families studied. Using both DNA and CK studies, accurate (96 to 98%) carrier or noncarrier diagnoses were made for 51 of 75 females at risk in 24 families with a single affected male. DNA studies resulted in an alteration of predicted risk in 40% of the cases. Recombinant diagnostic methods are useful for carrier detection in families with one or more affected males. 相似文献
8.
Jing‐Long Huang Liang‐Shiou Ou Ching‐Hsiung Tsao Li‐Chen Chen Ming‐Ling Kuo 《Pediatric allergy and immunology》2002,13(6):426-433
T lymphocytes play a fundamental role in the initiation and regulation of chronic inflammatory responses in patients with asthma. CD69 is an early marker of T‐cell activation. The levels of intercellular adhesion molecule‐1 (ICAM‐1, CD54) and L ‐selectin have been reported to increase in patients with allergic diseases and asthma. The present study was therefore undertaken to investigate the expression of CD69, CD54, and L ‐selectin by T lymphocytes of children with asthma, before and after immunotherapy. Eighteen children newly diagnosed with asthma, 11 good and nine poor responders to immunotherapy, and 16 normal subjects, were enrolled in this study. The percentages of CD69+, CD54+, and CD62L+ cells in T lymphocytes were measured by using flow cytometry. The levels of CD69, CD54, and CD62L in serum and culture supernatants were determined by using enzyme‐linked immunosorbent assay (ELISA). The expression of CD69 and CD54 on CD3+ T lymphocytes was significantly higher in children with asthma than in control patients. All the patient groups expressed (spontaneously and following stimulation with phorbol myristate acetate and ionomycin together with mite‐extract proteins) greater amounts of CD69 and CD54 than did control subjects. With long‐term immunotherapy, the percentages of CD69+ and CD54+ T lymphocytes were significantly lower in patients with a good response to immunotherapy. Our results also showed significantly lower serum L ‐selectin levels following immunotherapy. In conclusion, successful immunotherapy resulted in decreased expression and production of CD69 and CD54. These results may explain, in part, the clinical efficacy of immunotherapy. 相似文献
9.
10.
Activated neutrophils aggravate endothelial dysfunction after reperfusion of the ischemic feline myocardium. 总被引:3,自引:0,他引:3
Endothelial dysfunction, as evidenced by decreased stimulated release of endothelium-derived relaxing factor (EDRF), occurs after reperfusion of the ischemic myocardium. To better understand this endothelial dysfunction, isolated cat hearts were perfused under constant flow by the Langendorff procedure with Krebs-Henseleit solution devoid of blood cells. Following global ischemia (90 minutes) and reperfusion (20 minutes), coronary vasorelaxation to the endothelium-dependent vasodilator acetylcholine (ACh) was 70 +/- 3% of initial values (p less than 0.01) compared with 90 +/- 4% in nonischemic control perfused hearts. No decrement occurred in response to the endothelium-independent vasodilator nitroglycerin (NTG). Coronary artery rings isolated from the ischemic left circumflex coronary artery showed a similar degree of endothelial dysfunction to ACh, with normal relaxation in response to NaNO2. Autologous cat neutrophils (100 million cells), activated with 100 nmol/L f-met-leu-phe infused into the heart directly before and throughout reperfusion, resulted in a further decrement in ACh-induced vasodilation, to 55 +/- 5% of initial response, with no effect on NTG-induced vasodilation. Similar results were obtained with coronary artery rings isolated from perfused cat hearts and exposed to neutrophils. This neutrophil-enhanced endothelial dysfunction was inhibited by human superoxide dismutase as well as by an antibody to the adherence glycoprotein complex CD-18 (i.e., MAbR 15.7). Therefore endothelial dysfunction occurs initially upon reperfusion of the previously ischemic heart and is aggravated by superoxide radicals produced by activated neutrophils. 相似文献