全文获取类型
收费全文 | 187522篇 |
免费 | 34472篇 |
国内免费 | 1336篇 |
专业分类
耳鼻咽喉 | 3059篇 |
儿科学 | 4888篇 |
妇产科学 | 3750篇 |
基础医学 | 15048篇 |
口腔科学 | 6729篇 |
临床医学 | 35198篇 |
内科学 | 43598篇 |
皮肤病学 | 4430篇 |
神经病学 | 20446篇 |
特种医学 | 6384篇 |
外国民族医学 | 1篇 |
外科学 | 30965篇 |
综合类 | 1237篇 |
现状与发展 | 41篇 |
一般理论 | 97篇 |
预防医学 | 20804篇 |
眼科学 | 4139篇 |
药学 | 7400篇 |
1篇 | |
中国医学 | 129篇 |
肿瘤学 | 14986篇 |
出版年
2024年 | 790篇 |
2023年 | 5475篇 |
2022年 | 1963篇 |
2021年 | 4849篇 |
2020年 | 6418篇 |
2019年 | 3951篇 |
2018年 | 9117篇 |
2017年 | 8930篇 |
2016年 | 9597篇 |
2015年 | 9970篇 |
2014年 | 13351篇 |
2013年 | 16037篇 |
2012年 | 10477篇 |
2011年 | 10402篇 |
2010年 | 10502篇 |
2009年 | 12228篇 |
2008年 | 9445篇 |
2007年 | 8860篇 |
2006年 | 9801篇 |
2005年 | 8085篇 |
2004年 | 7234篇 |
2003年 | 6418篇 |
2002年 | 6219篇 |
2001年 | 2481篇 |
2000年 | 1617篇 |
1999年 | 2453篇 |
1998年 | 3131篇 |
1997年 | 2791篇 |
1996年 | 2672篇 |
1995年 | 2372篇 |
1994年 | 1678篇 |
1993年 | 1466篇 |
1992年 | 1169篇 |
1991年 | 977篇 |
1990年 | 832篇 |
1989年 | 804篇 |
1988年 | 818篇 |
1987年 | 664篇 |
1986年 | 639篇 |
1985年 | 585篇 |
1984年 | 641篇 |
1983年 | 692篇 |
1982年 | 686篇 |
1981年 | 632篇 |
1980年 | 539篇 |
1979年 | 302篇 |
1978年 | 411篇 |
1977年 | 344篇 |
1976年 | 249篇 |
1974年 | 209篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
82.
Prevalence of Potentially Inappropriate Prescribing Among Hong Kong Older Adults: A Comparison of the Beers 2003, Beers 2012, and Screening Tool of Older Person's Prescriptions and Screening Tool to Alert doctors to Right Treatment Criteria 下载免费PDF全文
83.
Anand Dayama Nikolaos Tsilimparis Stephen Kolakowski Nathaniel M. Matolo Misty D. Humphries 《Journal of vascular surgery》2019,69(1):156-163.e1
Background
Chronic limb-threatening ischemia (CLTI), defined as ischemic rest pain or tissue loss secondary to arterial insufficiency, is caused by multilevel arterial disease with frequent, severe infrageniculate disease. The rise in CLTI is in part the result of increasing worldwide prevalence of diabetes, renal insufficiency, and advanced aging of the population. The aim of this study was to compare a bypass-first with an endovascular-first revascularization strategy in patients with CLTI due to infrageniculate arterial disease.Methods
We reviewed the American College of Surgeons National Surgical Quality Improvement Program targeted lower extremity revascularization database from 2012 to 2015 to identify patients with CLTI and isolated infrageniculate arterial disease who underwent primary infrageniculate bypass or endovascular intervention. We excluded patients with a history of ipsilateral revascularization and proximal interventions. The end points were major adverse limb event (MALE), major adverse cardiovascular event (MACE), amputation at 30 days, reintervention, patency, and mortality. Multivariable logistic regression was used to determine the association of a bypass-first or an endovascular-first intervention with outcomes.Results
There were 1355 CLTI patients undergoing first-time revascularization to the infrageniculate arteries (821 endovascular-first revascularizations and 534 bypass-first revascularizations) identified. There was no significant difference in adjusted rate of 30-day MALE in the bypass-first vs endovascular-first revascularization cohort (9% vs 11.2%; odds ratio [OR], 0.73; 95% confidence interval [CI], 0.50-1.08). However, the incidence of transtibial or proximal amputation was lower in the bypass-first cohort (4.3% vs 7.4%; OR, 0.60; CI, 0.36-0.98). Patients with bypass-first revascularization had higher wound complication rates (9.7% vs 3.7%; OR, 2.75; CI, 1.71-4.42) compared with patients in the endovascular-first cohort. Compared with the endovascular-first cohort, the incidence of 30-day MACE was significantly higher in bypass-first patients (6.9% vs 2.6%; adjusted OR, 3.88; CI, 2.18-6.88), and 30-day mortality rates were 3.23% vs 1.8% (adjusted OR, 2.77; CI, 1.26-6.11). There was no difference in 30-day untreated loss of patency, reintervention of treated arterial segment, readmissions, and reoperations between the two cohorts. In subgroup analysis after exclusion of dialysis patients, there was also no significant difference in MALE or amputation between the bypass-first and endovascular-first cohorts.Conclusions
CLTI patients with isolated infrageniculate arterial disease treated by a bypass-first approach have a significantly lower 30-day amputation. However, this benefit was not observed when dialysis patients were excluded. The bypass-first cohort had a higher incidence of MACE compared with an endovascular-first strategy. These results reaffirm the need for randomized controlled trials, such as the Bypass versus Angioplasty in Severe Ischaemia of the Leg (BASIL-2) trial and Best Endovascular vs Best Surgical Therapy in Patients with Critical Limb Ischemia (BEST-CLI), to provide level 1 evidence for the role of endovascular-first vs bypass-first revascularization strategies in the treatment of this population of challenging patients. 相似文献84.
85.
Stephen Hanessian 《ACS medicinal chemistry letters》2016,7(1):6-9
Current major advances in drug discovery
can be traced back to
pioneering contributions originating from academics over a century
ago. Living in a symbiotic yet noninvasive coexistence, the academic
community and the pharmaceutical industry have strived, each in their
own way, to develop the modern medicines that benefit humankind today.
The subject is presented from a historical and personal perspective. 相似文献
86.
Uwe Schneider PhD Antony Lomax Peter Pemler Jürgen Besserer Dieter Ross Norbert Lombriser Barbara Kaser-Hotz 《Strahlentherapie und Onkologie》2006,182(11):647-652
BACKGROUND AND PURPOSE: There is concern about the increase of radiation-induced malignancies with the application of modern radiation treatment techniques such as intensity-modulated radiotherapy (IMRT) and proton radiotherapy. Therefore, X-ray scatter and neutron radiation as well as the impact of the primary dose distribution on secondary cancer incidence are analyzed. MATERIAL AND METHODS: The organ equivalent dose (OED) concept with a linear-exponential and a plateau dose-response curve was applied to dose distributions of 30 patients who received radiation therapy of prostate cancer. Three-dimensional conformal radiotherapy was used in eleven patients, another eleven patients received IMRT with 6-MV photons, and eight patients were treated with spot-scanned protons. The treatment plans were recalculated with 15-MV and 18-MV photons. Secondary cancer risk was estimated based on the OED for the different treatment techniques. RESULTS: A modest increase of 15% radiation-induced cancer results from IMRT using low energies (6 MV), compared to conventional four-field planning with 15-MV photons (plateau dose-response: 1%). The probability to develop a secondary cancer increases with IMRT of higher energies by 20% and 60% for 15 MV and 18 MV, respectively (plateau dose-response: 2% and 30%). The use of spot-scanned protons can reduce secondary cancer incidence as much as 50% (independent of dose-response). CONCLUSION: By including the primary dose distribution into the analysis of radiation-induced cancer incidence, the resulting increase in risk for secondary cancer using modern treatment techniques such as IMRT is not as dramatic as expected from earlier studies. By using 6-MV photons, only a moderate risk increase is expected. Spot-scanned protons are the treatment of choice in regard to secondary cancer incidence. 相似文献
87.
88.
89.
Although psychoanalysis was the first-choice treatment for premature ejaculation (PE) between 1920 and 1960, hardly any reports on its efficacy have been published. Moreover, a scientific debate about its findings has never been fully developed. The recent progress that has been made in the classification of three different PE syndromes creates a new opportunity for psychoanalytic investigations of men with complaints of PE, distinguished by the actual duration of their intravaginal ejaculation latency time (IELT). The term premature-like ejaculatory dysfunction has been introduced to distinguish men with self-perceived PE at normal and long IELT durations from those men with lifelong, acquired and normal variable PE. Psychoanalytic research may contribute to a better understanding of the consequences of objective early ejaculations on the unconscious mental life of men with the four forms of PE. By integrating neurobiological, clinical and epidemiological data of ejaculatory performance, a revival of psychoanalytic research of PE in the four distinct, classified PE groups, will probably contribute to a deeper insight in to the unconscious mental life of men affected by PE. 相似文献
90.