全文获取类型
收费全文 | 7317篇 |
免费 | 455篇 |
国内免费 | 91篇 |
专业分类
耳鼻咽喉 | 80篇 |
儿科学 | 102篇 |
妇产科学 | 131篇 |
基础医学 | 1158篇 |
口腔科学 | 187篇 |
临床医学 | 502篇 |
内科学 | 1342篇 |
皮肤病学 | 202篇 |
神经病学 | 472篇 |
特种医学 | 488篇 |
外科学 | 922篇 |
综合类 | 43篇 |
预防医学 | 229篇 |
眼科学 | 93篇 |
药学 | 982篇 |
中国医学 | 159篇 |
肿瘤学 | 771篇 |
出版年
2023年 | 33篇 |
2022年 | 24篇 |
2021年 | 217篇 |
2020年 | 125篇 |
2019年 | 152篇 |
2018年 | 236篇 |
2017年 | 164篇 |
2016年 | 273篇 |
2015年 | 422篇 |
2014年 | 422篇 |
2013年 | 503篇 |
2012年 | 820篇 |
2011年 | 714篇 |
2010年 | 429篇 |
2009年 | 354篇 |
2008年 | 449篇 |
2007年 | 361篇 |
2006年 | 350篇 |
2005年 | 372篇 |
2004年 | 310篇 |
2003年 | 235篇 |
2002年 | 176篇 |
2001年 | 110篇 |
2000年 | 108篇 |
1999年 | 83篇 |
1998年 | 54篇 |
1997年 | 49篇 |
1996年 | 40篇 |
1995年 | 31篇 |
1994年 | 32篇 |
1993年 | 21篇 |
1992年 | 19篇 |
1991年 | 27篇 |
1990年 | 19篇 |
1989年 | 18篇 |
1988年 | 18篇 |
1987年 | 16篇 |
1986年 | 16篇 |
1985年 | 12篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1981年 | 8篇 |
1980年 | 2篇 |
1979年 | 6篇 |
1977年 | 3篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1967年 | 1篇 |
1966年 | 2篇 |
排序方式: 共有7863条查询结果,搜索用时 250 毫秒
1.
2.
3.
4.
Yu-Syuan Wang Tsai-Wei Hung Eun-Kyung Bae Kuo-Jen Wu Wei Hsieh Seong-Jin Yu 《CNS Neuroscience & Therapeutics》2021,27(7):831-841
AimsNaltrexone is a mu opioid receptor (MOR) antagonist used to treat drug dependence in patients. Previous reports indicated that MOR antagonists reduced neurodegeneration and inflammation after brain injury. The purpose of this study was to evaluate the neuroprotective effect of naltrexone in cell culture and a mouse model of traumatic brain injury (TBI).MethodsThe neuroprotective effect of naltrexone was examined in primary cortical neurons co‐cultured with BV2 microglia. Controlled cortical impact (CCI) was delivered to the left cerebral cortex of adult male MOR wild‐type (WT) and knockout (KO) mice. Naltrexone was given daily for 4 days, starting from day 2 after lesioning. Locomotor activity was evaluated on day 5 after the CCI. Brain tissues were collected for immunostaining, Western, and qPCR analysis.ResultsGlutamate reduced MAP2 immunoreactivity (‐ir), while increased IBA1‐ir in neuron/BV2 co‐culture; both responses were antagonized by naltrexone. TBI significantly reduced locomotor activity and increased the expression of IBA1, iNOS, and CD4 in the lesioned cortex. Naltrexone significantly and equally antagonized the motor deficits and expression of IBA1 and iNOS in WT and KO mice. TBI‐mediated CD4 protein production was attenuated by naltrexone in WT mice, but not in KO mice.ConclusionNaltrexone reduced TBI‐mediated neurodegeneration and inflammation in MOR WT and KO mice. The protective effect of naltrexone involves non‐MOR and MOR mechanisms. 相似文献
5.
Su Yeon Jang Jeong-Yeon Seon Baik-Lin Eun Seong-Beom Koh Jin-Hong Yoo Woo Yong Lee Ho-Kee Yum Seok-Jun Yoon In-Hwan Oh Sang-Cheol Bae Sung-Goo Chang 《Journal of Korean medical science》2021,36(18)
BackgroundCoronavirus disease 2019 (COVID-19) has spread around the globe, and it is important to determine the risk factors of death in the general population. Our study aimed to determine the risk factors of death and severe illness requiring supplemental oxygen therapy based on the demographic and clinical characteristics of COVID-19 patients in Korea.MethodsIn this study, we used data provided by the Korea Disease Control and Prevention Agency (KDCA) and analyzed a total of 5,068 patients with COVID-19, excluding 19 pregnant women and 544 individuals with missing data. We performed logistic regression analysis to determine the impact of early symptoms on survival and severe disease. Logistic regression models included sex, age, number of comorbidities, symptoms on admission, blood pressure, heart rate, and body temperature as explanatory variables, and death and oxygen therapy as outcome variables.ResultsLogistic regression analyses revealed that the male sex, older age (≥ 60 years), higher number of comorbidities, presence of symptoms on admission, heart rate ≥ 120 bpm, and body temperature ≥ 37.5°C presented with higher risk of in-hospital death and oxygen therapy requirement. Conversely, rhinorrhea and headache were associated with a low risk of death and oxygen therapy requirement. The findings showed that cough, sputum, and fever were the most common symptoms on admission, while 25.3% of patients with COVID-19 were asymptomatic.ConclusionCOVID-19 patients with high-risk early symptoms on admission, such as dyspnea and altered mental status, and those without low-risk symptoms of rhinorrhea and headache should be included in priority treatment groups. 相似文献
6.
7.
Go Eun Bae Arom Choi Jin Ho Beom Min Joung Kim Hyun Soo Chung In Kyung Min Sung Phil Chung Ji Hoon Kim 《Medicine》2021,100(16)
Background:The American Heart Association guidelines recommend switching chest compression providers at least every 2 min depending on their fatigue during cardiopulmonary resuscitation (CPR). Although the provider''s heart rate is widely used as an objective indicator for detecting fatigue, the accuracy of this measure is debatable.Objectives:This study was designed to determine whether real-time heart rate is a measure of fatigue in compression providers.Study design:A simulation-based prospective interventional study including 110 participants.Methods:Participants performed chest compressions in pairs for four cycles using advanced cardiovascular life support simulation. Each participant''s heart rate was measured using wearable healthcare devices, and qualitative variables regarding individual compressions were obtained from computerized devices. The primary outcome was correct depth of chest compressions. The main exposure was the change in heart rate, defined as the difference between the participant''s heart rate during individual compressions and that before the simulation was initiated.Results:With a constant compression duration for one cycle, the overall accuracy of compression depth significantly decreased with increasing heart rate. Female participants displayed significantly decreased accuracy of compression depth with increasing heart rate (odds ratio [OR]: 0.97; 95% confidence interval [CI]: 0.95–0.98; P < .001). Conversely, male participants displayed significantly improved accuracy with increasing heart rate (OR: 1.03; 95% CI: 1.02–1.04; P < .001).Conclusion:Increasing heart rate could reflect fatigue in providers performing chest compressions with a constant duration for one cycle. Thus, provider rotation should be considered according to objectively measured fatigue during CPR. 相似文献
8.
9.
Ji-Hyun Lee Jung-il Bae Young-Eun Jang Eun-Hee Kim Hee-Soo Kim Jin-Tae Kim 《British journal of anaesthesia》2019,122(5):692-701
Background
Perioperative ventilatory strategies for lung protection in children are underexplored. This study evaluated the effects of lung protective ventilation (LPV) on postoperative clinical outcomes in children requiring one-lung ventilation (OLV) for pulmonary resection.Methods
Children age ≤5 yr scheduled for video-assisted thoracoscopic lung lobectomy or segmentectomy were randomly assigned to LPV or control ventilation. For LPV, tidal volume (VT) was 6 ml kg?1 during two-lung ventilation (TLV(VT)), 4 ml kg?1 during OLV, with 6 cm H2O PEEP maintained throughout. In the control group, TLV(VT) was 10 ml kg?1, 8 ml kg?1 during OLV, but without PEEP. The primary outcome was the incidence of pulmonary complications within 72 h after operation. Secondary outcomes included intraoperative desaturation, arterial oxygen partial pressure/inspiratory fraction of oxygen (P/F) ratio >40 kPa, and development of consolidation and B-lines (assessed by lung ultrasound at the end of surgery, by an investigator masked to group allocation). Odds ratio (OR) with 95% confidence intervals are reported.Results
Overall, 19/110 (17.3%) children sustained pulmonary complications after surgery. LPV reduced pulmonary complications (5/55; 9.1%), compared with 14/55 (25.5%) children sustaining complications in the control group (OR=0.29 [0.10–0.88]; P=0.02). Masked ultrasound assessment showed less consolidation, and fewer B-lines, after LPV (P<0.001). Intraoperative desaturation was more common in control mode (eight/55; 14.5%), compared with 1/55 (1.8%) after LPV (OR=9.2 [1.1–76]; P=0.015). LPV maintained (P/F) ratio >40 more frequently (53/55; 96.4%) than control-mode (45/55; 81.8%) ventilation (OR=5.9 [1.2–28.3%]; P<0.01).Conclusions
Lung protective ventilation decreased postoperative pulmonary complications compared with conventional ventilation in children requiring one-lung ventilation for pulmonary resection.Clinical trial registration
NCT02680925. 相似文献10.
Serum Folate Levels and Lung Cancer Risk: A Meta- Epidemiological Study of Population-based Case-Control Studies 下载免费PDF全文
Jong-Myon Bae 《Asian Pacific journal of cancer prevention》2020,21(6):1829-1833
Objective: While it has been claimed that lung cancer occurs due to epigenetic mechanisms, four systematic reviews were reported to investigate the association between serum folate levels and lung cancer risk. Considering some methodological problems founded in the systematic review, a meta-epidemiological study was conducted. Methods: The selection criteria of this study were defined that a case-control study was conducted to determine the risk of lung cancer occurrence according to the concentration of serum folate and its results showed odds ratio and its 95% confidence interval. Additional paper was explored from cited lists of 4 papers selected by previous systematic reviews. Random effect model was applied if I-squared value was over 50%. Results: For 5 case-control studies selected, the summary odds ratios (and their 95% confidence intervals) were 0.82 (0.74-0.90) in men, 0.70 (0.62-0.79) in former smokers, and 0.86 (0.75-1.00) in non-smokers. Conclusion: Higher foliate levels can decrease lung cancer risk in men and former smokers. Especially, the protective effect was highest in former smokers compared in non-smokers and current smokers. Based on these facts, folate fortification programs to reduce lung cancer risk would be focused on former smokers in men. And some epidemiological studies are needed to provide a hypothesis to explain the sex differences in the association between folate and lung cancer risk. 相似文献