全文获取类型
收费全文 | 40499篇 |
免费 | 2827篇 |
国内免费 | 822篇 |
专业分类
耳鼻咽喉 | 294篇 |
儿科学 | 1425篇 |
妇产科学 | 1121篇 |
基础医学 | 2788篇 |
口腔科学 | 360篇 |
临床医学 | 5771篇 |
内科学 | 9559篇 |
皮肤病学 | 475篇 |
神经病学 | 1867篇 |
特种医学 | 905篇 |
外科学 | 3561篇 |
综合类 | 5554篇 |
一般理论 | 1篇 |
预防医学 | 2998篇 |
眼科学 | 249篇 |
药学 | 2928篇 |
12篇 | |
中国医学 | 2851篇 |
肿瘤学 | 1429篇 |
出版年
2023年 | 582篇 |
2022年 | 1226篇 |
2021年 | 1518篇 |
2020年 | 1281篇 |
2019年 | 1414篇 |
2018年 | 1343篇 |
2017年 | 1284篇 |
2016年 | 1349篇 |
2015年 | 1339篇 |
2014年 | 2811篇 |
2013年 | 2736篇 |
2012年 | 2687篇 |
2011年 | 3099篇 |
2010年 | 2381篇 |
2009年 | 2493篇 |
2008年 | 2380篇 |
2007年 | 2262篇 |
2006年 | 1768篇 |
2005年 | 1544篇 |
2004年 | 1286篇 |
2003年 | 1073篇 |
2002年 | 706篇 |
2001年 | 681篇 |
2000年 | 531篇 |
1999年 | 480篇 |
1998年 | 369篇 |
1997年 | 301篇 |
1996年 | 299篇 |
1995年 | 254篇 |
1994年 | 224篇 |
1993年 | 178篇 |
1992年 | 161篇 |
1991年 | 171篇 |
1990年 | 126篇 |
1989年 | 130篇 |
1988年 | 152篇 |
1987年 | 123篇 |
1986年 | 103篇 |
1985年 | 159篇 |
1984年 | 146篇 |
1983年 | 91篇 |
1982年 | 97篇 |
1981年 | 101篇 |
1980年 | 104篇 |
1979年 | 89篇 |
1978年 | 72篇 |
1977年 | 61篇 |
1976年 | 52篇 |
1975年 | 55篇 |
1973年 | 45篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
《Journal of infection and chemotherapy》2022,28(4):548-553
IntroductionCOVID-19 patients have been reported to have digestive symptoms with poor outcome. Ivermectin, an antiparasitic drug, has been used in COVID-19 patients. The objective of this study was to evaluate whether ivermectin has effects on gastrointestinal complications and ventilator-free days in ventilated patients with COVID-19.MethodsCOVID-19 patients who were mechanically ventilated in the ICU were included in this study. The ventilated patients who received ivermectin within 3 days after admission were assigned to the Ivermectin group, and the others were assigned to the Control group. Patients in the Ivermectin group received ivermectin 200 μg/kg via nasal tube. The incidence of gastrointestinal complications and ventilator-free days within 4 weeks from admission were evaluated as clinical outcomes using a propensity score with the inverse probability weighting method.ResultsWe included 88 patients in this study, of whom 39 patients were classified into the Ivermectin group, and 49 patients were classified into the Control group. The hazard ratio for gastrointestinal complications in the Ivermectin group as compared with the Control group was 0.221 (95% confidence interval [CI], 0.057 to 0.855; p = 0.029) in a Cox proportional-hazard regression model. The odds ratio for ventilator-free days as compared with the Control group was 1.920 (95% CI, 1.076 to 3.425; p = 0.027) in a proportional odds logistic regression model.ConclusionsIvermectin improved gastrointestinal complications and the number of ventilator-free days in severe COVID-19 patients undergoing mechanical ventilation. Prevention of gastrointestinal symptoms by SARS-Cov-2 might be associated with COVID-19 outcome. 相似文献
4.
5.
6.
Gut bacteria and gut barrier plays important roles in body homeostasis. Ciprofloxacin (CPFX) is widely used to treat bacterial infections. However, whether high dosage of CPFX has side effects on gut barrier integrity is still unclear. Our results indicated that the High CPFX treatment (1 mg/ml) caused weight loss, nervousness, anorexia, and increased apoptosis cells in gut, but less influence was observed in the Low CPFX group (0.2 mg/ml). Meanwhile, the High CPFX treatment impaired tight junction molecules Ocln/ZO-1 level and down-regulated antibacterial genes expression (reg3γ, pla2g2α and defb1). Further, the High CPFX treatment increased pro-inflammatory cytokine IL-1β in intestinal tract, decreased IL-17A of duodenum but increased IL-17A of colon at day 37. In addition, the gut bacterial diversity and richness behaved significantly loss regarding CPFX treatment, especially in the High CPFX group during the experiment. Indole exhibited sharply decline in both Low and High CPFX groups at day 7, and the High CPFX mice needed longer time on restoring indole level. Meanwhile, CPFX treatment strongly decreased the concentrations of butyric acid and valeric acid at day 1. Correlation analysis indicated that the linked patterns between the key bacteria (families Bacteroidales_S247, Ruminococcaceae and Desulfovibrionaceae) and metabolites (indole and butyric acid) were disturbed via the CPFX treatment. In conclusion, the High CPFX treatment impaired the gut barrier with the evidence of reduced expression of tight junction proteins, increased apoptosis cells and inflammatory cells, decreased the bacterial diversity and composition, which suggesting a proper antibiotic-dosage use should be carefully considered in disease treatment. 相似文献
7.
Ehsan Zarei Elmira Madarshahian Adeleh Nikkhah Soheila Khodakarim 《Journal of tissue viability》2019,28(2):70-74
Background and objective
Pressure ulcer (PU) is one of the important and frequent complications of hospitalization, associated with high treatment costs. The present study was conducted to determine the incidence of PU and its direct treatment costs for patients in intensive care unit (ICU) in Iran.Material and methods
In this retrospective study, medical records of 643 discharged patients from ICU of two selected hospitals were examined. The demographic and clinical data of all patients and data of resources and services usage for patients with PU were extracted through their records. Data analysis was done using logistic regression tests in SPSS 22 software. The cost of PU treatment was calculated for each grade of ulcer.Results
The findings showed that 8.9% of patients developed PU during their stay in ICU. Muscular paralysis (OR?=?5.1), length of stay in ICU (OR?=?4.0), diabetes (OR?=?3.5) age (OR?=?2.9), smoking (OR?=?2.1) and trauma (OR?=?1.4) were the most important risk factors of PU. The average cost of PU treatment varied from USD 12 for grade I PU to USD 66?834 for grade IV PUs. The total treatment costs for all studied patients with PU was estimated at USD 519?991.Conclusion
The cost of PU treatment is significant. Since the preventive measures are more cost-effective than therapeutic measures, therefore, effective preventive interventions are recommended. 相似文献8.
Interprofessional collaboration and communication in nursing homes: a qualitative exploration of problems in medical care for nursing home residents – study protocol
下载免费PDF全文
![点击此处可从《Journal of advanced nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
9.
《Respiratory investigation》2022,60(1):137-145
BackgroundSome chronic obstructive pulmonary disease (COPD) patients develop hypoxemia with disease progression, with some even requiring long-term oxygen therapy (LTOT). Lung function, especially diffusing capacity, and the annual decline in PaO2, are reported to be predictive factors of chronic respiratory failure. However, the association between lung morphometry evaluated using computed tomography (CT) images and LTOT initiation is unknown.MethodsWe retrospectively evaluated the relationship between clinical indices, including pulmonary function, body mass index (BMI), and CT parameters, at baseline and LTOT initiation in two prospective COPD cohorts. In the Nara Medical University cohort (n = 76), the low attenuation area (LAA) and its fractal dimension (fractal D) were adapted as the indices for parenchymal destruction in CT images. The association between these CT measurements and LTOT initiation was replicated in the Kyoto University cohort (n = 130).ResultsIn the Nara Medical University cohort, lower BMI (hazard ratio [HR]:0.70, p = 0.006), lower % diffusing capacity (%DLCO) (HR: 0.92, p = 0.006), lower %DLCO/VA (HR, 0.90, p = 0.008), higher RV/TLC (HR, 1.26, p = 0.012), higher LAA% (HR: 1.18, p = 0.001), and lower fractal D (HR: 3.27 × 10?8, p < 0.001) were associated with LTOT initiation. Multivariate analysis in the Kyoto University cohort confirmed that lower %DLCO and lower fractal D were independently associated with LTOT initiation, whereas LAA% was not.ConclusionFractal D, which is the index for morphometric complexity of LAA in CT analysis, is predictive of LTOT initiation in COPD patients. 相似文献
10.