全文获取类型
收费全文 | 2682428篇 |
免费 | 194498篇 |
国内免费 | 5831篇 |
学科分类
医药卫生 | 2882757篇 |
出版年
2018年 | 27996篇 |
2017年 | 21596篇 |
2016年 | 23956篇 |
2015年 | 27183篇 |
2014年 | 37957篇 |
2013年 | 56525篇 |
2012年 | 76607篇 |
2011年 | 81016篇 |
2010年 | 48121篇 |
2009年 | 45465篇 |
2008年 | 76077篇 |
2007年 | 82025篇 |
2006年 | 82631篇 |
2005年 | 79472篇 |
2004年 | 77063篇 |
2003年 | 73826篇 |
2002年 | 71802篇 |
2001年 | 131534篇 |
2000年 | 134702篇 |
1999年 | 112686篇 |
1998年 | 30491篇 |
1997年 | 27226篇 |
1996年 | 26700篇 |
1995年 | 25498篇 |
1994年 | 23518篇 |
1993年 | 21891篇 |
1992年 | 86353篇 |
1991年 | 84023篇 |
1990年 | 81471篇 |
1989年 | 78827篇 |
1988年 | 72443篇 |
1987年 | 71244篇 |
1986年 | 67620篇 |
1985年 | 64294篇 |
1984年 | 47864篇 |
1983年 | 40732篇 |
1982年 | 23717篇 |
1981年 | 21392篇 |
1979年 | 44340篇 |
1978年 | 31185篇 |
1977年 | 26740篇 |
1976年 | 24543篇 |
1975年 | 27083篇 |
1974年 | 32494篇 |
1973年 | 31542篇 |
1972年 | 29784篇 |
1971年 | 27751篇 |
1970年 | 26039篇 |
1969年 | 24689篇 |
1968年 | 23212篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
41.
Sarina A. Piha-Paul Do-Youn Oh Makoto Ueno David Malka Hyun Cheol Chung Adnan Nagrial Robin K. Kelley Willeke Ros Antoine Italiano Kazuhiko Nakagawa Hope S. Rugo Filippo de Braud Andrea Iolanda Varga Aaron Hansen Hui Wang Suba Krishnan Kevin G. Norwood Toshihiko Doi 《International journal of cancer. Journal international du cancer》2020,147(8):2190-2198
We present data from patients with advanced biliary tract cancer (BTC) receiving pembrolizumab in the KEYNOTE-158 (NCT02628067; phase 2) and KEYNOTE-028 (NCT02054806; phase 1b) studies. Eligible patients aged ≥18 years from both studies had histologically/cytologically confirmed incurable BTC that progressed after standard treatment regimen(s), measurable disease per Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1, Eastern Cooperative Oncology Group performance status 0/1, and no prior immunotherapy. Programmed death ligand 1 (PD-L1)-positive tumors were required for eligibility in KEYNOTE-028 only. Patients received pembrolizumab 200 mg every three weeks (KEYNOTE-158) or 10 mg/kg every two weeks (KEYNOTE-028) for ≤2 years. Primary efficacy endpoint was objective response rate (ORR) by RECIST v1.1. Response assessed by independent central review is reported. KEYNOTE-158 enrolled 104 patients and KEYNOTE-028 enrolled 24 patients. Median (range) follow-up was 7.5 months (0.6-34.3) in KEYNOTE-158 and 5.7 months (0.6-55.4) in KEYNOTE-028. In KEYNOTE-158, ORR was 5.8% (6/104; 95% CI, 2.1%-12.1%); median duration of response (DOR) was not reached (NR) (range, 6.2-26.6+ months). Median (95% CI) OS and PFS were 7.4 (5.5-9.6) and 2.0 (1.9-2.1) months. Among PD-L1-expressers (n = 61) and PD-L1-nonexpressers (n = 34), respectively, ORR was 6.6% (4/61) and 2.9% (1/34). In KEYNOTE-028, ORR was 13.0% (3/23; 95% CI, 2.8%-33.6%); median DOR was NR (range, 21.5-53.2+ months). Median (95% CI) OS and PFS were 5.7 (3.1-9.8) and 1.8 (1.4-3.1) months. Grade 3 to 5 treatment-related adverse events occurred in 13.5% of patients in KEYNOTE-158 (no grade 4; grade 5 renal failure, n = 1) and 16.7% in KEYNOTE-028 (no grade 4/5). In summary, pembrolizumab provides durable antitumor activity in 6% to 13% of patients with advanced BTC, regardless of PD-L1 expression, and has manageable toxicity. 相似文献
42.
43.
Krishna S. Iyer 《Platelets》2020,31(4):474-482
Abstract Platelets are small, anucleated effector cells that play an important role in linking the hemostatic and inflammatory processes in the body. Platelet function is known to be altered under various inflammatory conditions including aging. A gain in platelet function during aging can increase the risk of thrombotic events, such as stroke and acute myocardial infarction. Anti-platelet therapy is designed to reduce risk of serious cerebrovascular and cardiovascular events, but the adverse consequences of therapy, such as risk for bleeding increases with aging as well. Age-associated comorbidities such as obesity, diabetes, and hyperlipidemia also contribute to increased platelet activity and thus can enhance the risk of thrombosis. Therefore, identification of unique mechanisms of platelet dysfunction in aging and in age-associated comorbidities is warranted to design novel antiplatelet drugs. This review outlines some of the current areas of research on aging-related mechanisms of platelet hyperactivity and addresses the clinical urgency for designing anti-platelet therapies toward novel molecular targets in the aging population. 相似文献
44.
45.
46.
Mohid S Khan Thomas Walter Amy Buchanan-Hughes Emma Worthington Lucie Keeber Marion Feuilly Enrique Grande 《World journal of gastroenterology : WJG》2020,26(30):4537-4556
BACKGROUND Approximately 20% of patients with neuroendocrine tumours(NETs) develop carcinoid syndrome(CS),characterised by flushing and diarrhoea.Somatostatin analogues or telotristat can be used to control symptoms of CS through inhibition of serotonin secretion.Although CS is often the cause of diarrhoea among patients with gastroenteropancreatic NETs(GEP-NETs),other causes to consider include pancreatic enzyme insufficiency(PEI),bile acid malabsorption and small intestinal bacterial overgrowth.If other causes of diarrhoea unrelated to serotonin secretion are mistaken for CS diarrhoea,these treatments may be ineffective against the diarrhoea,risking detrimental effects to patient quality of life.AIM To identify and synthesise qualitative and quantitative evidence relating to the differential diagnosis of diarrhoea in patients with GEP-NETs.METHODS Electronic databases(MEDLINE,Embase and the Cochrane Library) were searched from inception to September 12,2018 using terms for NETs and diarrhoea.Congresses,systematic literature review bibliographies and included articles were also hand-searched.Any study designs and publication types were eligible for inclusion if relevant data on a cause(s) of diarrhoea in patients with GEP-NETs were reported.Studies were screened by two independent reviewers at abstract and full-text stages.Framework synthesis was adapted to synthesise quantitative and qualitative data.The definition of qualitative data was expanded to include all textual data in any section of relevant publications.RESULTS Forty-seven publications(44 studies) were included,comprising a variety of publication types,including observational studies,reviews,guidelines,case reports,interventional studies,and opinion pieces.Most reported on PEI on/after treatment with somatostatin analogs;9.5%-84% of patients with GEP-NETs had experienced steatorrhoea or confirmed PEI.Where reported,14.3%–50.7% of patients received pancreatic enzyme replacement therapy.Other causes of diarrhoea reported in patients with GEP-NETs included bile acid malabsorption(80%),small intestinal bacterial overgrowth(23.6%-62%),colitis(20%) and infection(7.1%).Diagnostic approaches included faecal elastase,breath tests,tauroselcholic(selenium-75) acid(Se HCAT) scan and stool culture,although evidence on the effectiveness or diagnostic accuracy of these approaches was limited.Assessment of patient history or diarrhoea characteristics was also reported as initial approaches for investigation.From the identified evidence,if diarrhoea is assumed to be CS diarrhoea,consequences include uncontrolled diarrhoea,malnutrition,and perceived ineffectiveness of CS treatment.Approaches for facilitating differential diagnosis of diarrhoea include improving patient and clinician awareness of non-CS causes and involvement of a multidisciplinary clinical team,including gastroenterologists.CONCLUSION Diarrhoea in GEP-NETs can be multifactorial with misdiagnosis leading to delayed patient recovery and inefficient resource use.This systematic literature review highlights gaps for further research on prevalence of non-CS diarrhoea and suitability of diagnostic approaches,to determine an effective algorithm for differential diagnosis of GEP-NET diarrhoea. 相似文献
47.
Stepanova E. S. Makarenkova L. M. Chistyakov V. V. Rybakov Yu. L. Gukasov V. M. Fedotcheva T. A. Parshin V. A. Votyakov V. A. Shimanovskii N. L. 《Pharmaceutical Chemistry Journal》2019,52(12):1016-1020
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was... 相似文献
48.
M.F. Werner A. López-Rueda F.X. Zarco J. Blasco L. San Román S. Amaro E. Carrero R. Valero L. Oleaga J.M. Macho N. Bargalló 《Radiologia》2019,61(2):143-152
Purpose
Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy.Methods
Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24 hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.< 8) and PMI (≥3vs.< 3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate.Results
CTASI pc-ASPECTS, dichotomized at < 8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived.Conclusion
PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO. 相似文献49.
50.
Kenny P. Pang FRCSEd FRCSI Claudio Vicini MD Filippo Montevecchi MD Ottavio Piccin MD MSc Sudipta Chandra MBBS MS Hyung C. Yang MD PhD Vikas Agrawal MS DLO Joseph C. K. Chung FRCS Yiong H. Chan BSc PhD Scott B. Pang Kathleen A. Pang Edward B. Pang Brian Rotenberg MD MPH FRCSC 《The Laryngoscope》2020,130(9):2281-2284