全文获取类型
收费全文 | 13497篇 |
免费 | 1020篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 183篇 |
儿科学 | 356篇 |
妇产科学 | 363篇 |
基础医学 | 1689篇 |
口腔科学 | 230篇 |
临床医学 | 1456篇 |
内科学 | 2700篇 |
皮肤病学 | 97篇 |
神经病学 | 1065篇 |
特种医学 | 474篇 |
外科学 | 2183篇 |
综合类 | 175篇 |
一般理论 | 13篇 |
预防医学 | 1209篇 |
眼科学 | 850篇 |
药学 | 666篇 |
中国医学 | 9篇 |
肿瘤学 | 836篇 |
出版年
2023年 | 71篇 |
2022年 | 145篇 |
2021年 | 309篇 |
2020年 | 159篇 |
2019年 | 230篇 |
2018年 | 331篇 |
2017年 | 241篇 |
2016年 | 237篇 |
2015年 | 342篇 |
2014年 | 444篇 |
2013年 | 633篇 |
2012年 | 942篇 |
2011年 | 995篇 |
2010年 | 555篇 |
2009年 | 487篇 |
2008年 | 884篇 |
2007年 | 883篇 |
2006年 | 909篇 |
2005年 | 885篇 |
2004年 | 841篇 |
2003年 | 777篇 |
2002年 | 751篇 |
2001年 | 132篇 |
2000年 | 97篇 |
1999年 | 150篇 |
1998年 | 146篇 |
1997年 | 132篇 |
1996年 | 101篇 |
1995年 | 107篇 |
1994年 | 105篇 |
1993年 | 84篇 |
1992年 | 86篇 |
1991年 | 67篇 |
1990年 | 73篇 |
1989年 | 67篇 |
1988年 | 64篇 |
1987年 | 72篇 |
1986年 | 57篇 |
1985年 | 77篇 |
1984年 | 92篇 |
1983年 | 72篇 |
1982年 | 88篇 |
1981年 | 104篇 |
1980年 | 84篇 |
1979年 | 51篇 |
1978年 | 48篇 |
1977年 | 32篇 |
1976年 | 35篇 |
1975年 | 29篇 |
1974年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Dongbing Lai Emma C. Johnson Sarah Colbert Gayathri Pandey Grace Chan Lance Bauer Meredith W. Francis Victor Hesselbrock Chella Kamarajan John Kramer Weipeng Kuang Sally Kuo Samuel Kuperman Yunlong Liu Vivia McCutcheon Zhiping Pang Martin H. Plawecki Marc Schuckit Jay Tischfield Leah Wetherill Yong Zang Howard J. Edenberg Bernice Porjesz Arpana Agrawal Tatiana Foroud 《Alcoholism, clinical and experimental research》2022,46(3):374-383
2.
3.
4.
5.
6.
Benjamin R. Griffin J. Pedro Teixeira Sophia Ambruso Michael Bronsert Jay D. Pal Joseph C. Cleveland T. Brett Reece David A. Fullerton Sarah Faubel Muhammad Aftab 《The Journal of thoracic and cardiovascular surgery》2021,161(4):1346-1355.e3
ObjectivesSevere acute kidney injury (AKI) is a known risk factor for infection and mortality. However, whether stage 1 AKI is a risk factor for infection has not been evaluated in adults. We hypothesized that stage 1 AKI following cardiac surgery would independently associate with infection and mortality.MethodsIn this retrospective propensity score–matched study, we evaluated 1620 adult patients who underwent nonemergent cardiac surgery at the University of Colorado Hospital from 2011 to 2017. Patients who developed stage 1 AKI by Kidney Disease Improving Global Outcomes creatinine criteria within 72 hours of surgery were matched to patients who did not develop AKI. The primary outcome was an infection, defined as a new surgical-site infection, positive blood or urine culture, or development of pneumonia. Secondary outcomes included in-hospital mortality, stroke, and intensive care unit (ICU) and hospital length of stay (LOS).ResultsStage 1 AKI occurred in 293 patients (18.3%). Infection occurred in 20.9% of patients with stage 1 AKI compared with 8.1% in the no-AKI group (P < .001). In propensity-score matched analysis, stage 1 AKI independently associated with increased infection (odds ratio [OR]; 2.24, 95% confidence interval [CI], 1.37-3.17), ICU LOS (OR, 2.38; 95% CI, 1.71–3.31), and hospital LOS (OR, 1.30; 95% CI, 1.17-1.45).ConclusionsStage 1 AKI is independently associated with postoperative infection, ICU LOS, and hospital LOS. Treatment strategies focused on prevention, early recognition, and optimal medical management of AKI may decrease significant postoperative morbidity. 相似文献
7.
Sami S Zoghbi H Umesha Shetty Masanori Ichise Masahiro Fujita Masao Imaizumi Jeih-San Liow Jay Shah John L Musachio Victor W Pike Robert B Innis 《Journal of nuclear medicine》2006,47(3):520-527
18F-2beta-Carbomethoxy-3beta-(4-chlorophenyl)-8-(2-fluoroethyl)nortropane (18F-FECNT), a PET radioligand for the dopamine transporter (DAT), generates a radiometabolite that enters the rat brain. The aims of this study were to characterize this radiometabolite and to determine whether a similar phenomenon occurs in human and nonhuman primate brains by examining the stability of the apparent distribution volume in DAT-rich (striatum) and DAT-poor (cerebellum) regions of the brain. METHODS: Two rats were infused with 18F-FECNT and sacrificed at 60 min. Extracts of brain and plasma were analyzed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometric (LC-MS) techniques. Two human participants and 3 rhesus monkeys were injected with 18F-FECNT and scanned kinetically, with serial arterial blood analysis. RESULTS: At 60 min after the injection of rats, 18F-FECNT accumulated to levels about 7 times higher in the striatum than in the cortex and cerebellum. The radiometabolite was distributed at equal concentrations in all brain regions. The LC-MS techniques identified N-dealkylated FECNT as a major metabolite in the rat brain, and reverse-phase HPLC detected an equivalent amount of radiometabolite eluting with the void volume. The radiometabolite likely was 18F-fluoroacetaldehyde, the product expected from the N-dealkylation of 18F-FECNT, or its oxidation product, 18F-fluoroacetic acid. The distribution volume in the cerebellum increased up to 1.7-fold in humans between 60 and 300 min after injection and 2.0 +/- 0.1-fold (mean +/- SD; n = 3) in nonhuman primates between 60 and 240 min after injection. CONCLUSION: An 18F-fluoroalkyl metabolite of 18F-FECNT originating in the periphery confounded the measurements of DAT in the rat brain with a reference tissue model. Its uniform distribution across brain regions suggests that it has negligible affinity for DAT (i.e., it is an inactive radiometabolite). Consistent with the rodent data, the apparent distribution volume in the cerebellum of both humans and nonhuman primates showed a continual increase at late times after injection, a result that may be attributed to entry of the radiometabolite into the brain. Thus, reference tissue modeling of 18F-FECNT will be prone to more errors than analysis with a measured arterial input function. 相似文献
8.
This review discusses treatment options for men with premature ejaculation (PE), a common sexual dysfunction characterized
by short ejaculatory latency, decreased sexual satisfaction, and distress. For a number of reasons, including embarrassment
and the belief that PE is a normal part of aging, that it has no effective treatment, or that it will resolve itself, few
men with PE seek treatment. Although several treatment options exist (eg, behavioral, cognitive, and sex therapy methods;
desensitizing drugs; off-label use of antidepressants, phosphodiesterase type 5 inhibitors, or à-blockers), the majority of
men with PE are not satisfied with their results. New pharmacologic drugs develped specifically for the treatment of PE are
undergoing evaluation in clinical trials. For example, recent clinical research studies have revealed on-demand administration
of one such drug, dapoxetine, which achieved significant improvements in ejaculatory latency, control over ejaculation, and
satisfaction with sexual intercourse. In addition, partners of men who received dapoxetine likewise reported improved satisfaction
with sexual intercourse. Future studies may reveal that integration of pharmacologic drugs with psychologic and/or behavioral
therapy techniques may be the optimal approach to the management of PE. PE is a treatable condition, and new drugs in development
may provide benefits over those available. 相似文献
9.
Jay N Cohn 《Journal of the American College of Cardiology》2006,48(3):430-433
Mortality and morbid events are insensitive guides to the efficacy and safety of interventions in chronic cardiovascular disease (CVD). To enhance the ability to find new and effective long-term treatments, especially for the early stages of CVD, a revised strategy for clinical trials should emphasize efficacy on disease progression while monitoring symptoms and quality of life as guides to clinical benefit. Mortality, which is uncommon except in acute or advanced disease, provides at best a crude guide to net efficacy and safety. It must be monitored to support demonstrated efficacy on disease progression without adverse safety effects. This revised approach, made possible by our enhanced ability to monitor the progression of disease, should make it possible to study earlier disease and to improve cardiovascular health while reducing health care costs. 相似文献
10.
Jay Nicholson Peter Mirtschin Frank Madaras Michael Venning Michael Kokkinn 《Toxicon》2006,48(4):422-428
The digestive properties of Australian elapid snake venoms have not been studied to any great extent. To address this, the in vitro digestive properties of Oxyuranus scutellatus (Australian Coastal Taipan) venom were investigated in a simulation of the in vivo conditions using the parameters reported for the stomach of snakes and representative prey for this species. The amount of soluble protein released was measured over time using a bicinchoninic acid (BCA) assay. Dismembered mouse hindlegs were injected intramuscularly with 0.1 ml O. scutellatus venom (concentration 10 mg/ml) and maintained in a micro-anaerobic, acidic environment (pH approximately 1.2-1.7) at 25 degrees C. The bathing liquid was sampled every 24 h for 7 days, and assayed for soluble protein. Statistical analysis revealed that O. scutellatus venom increased the rate at which proteins were released when compared to a negative control suggesting the potential importance of envenomation in the digestion of whole prey. 相似文献