首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   6610篇
  免费   506篇
  国内免费   227篇
耳鼻咽喉   19篇
儿科学   114篇
妇产科学   45篇
基础医学   335篇
口腔科学   39篇
临床医学   805篇
内科学   620篇
皮肤病学   68篇
神经病学   116篇
特种医学   393篇
外国民族医学   1篇
外科学   495篇
综合类   1302篇
预防医学   866篇
眼科学   200篇
药学   1381篇
  5篇
中国医学   487篇
肿瘤学   52篇
  2023年   58篇
  2022年   105篇
  2021年   199篇
  2020年   189篇
  2019年   149篇
  2018年   155篇
  2017年   180篇
  2016年   182篇
  2015年   219篇
  2014年   386篇
  2013年   383篇
  2012年   402篇
  2011年   455篇
  2010年   393篇
  2009年   299篇
  2008年   315篇
  2007年   303篇
  2006年   305篇
  2005年   256篇
  2004年   240篇
  2003年   202篇
  2002年   180篇
  2001年   169篇
  2000年   135篇
  1999年   137篇
  1998年   130篇
  1997年   92篇
  1996年   81篇
  1995年   114篇
  1994年   103篇
  1993年   76篇
  1992年   71篇
  1991年   76篇
  1990年   70篇
  1989年   72篇
  1988年   72篇
  1987年   57篇
  1986年   38篇
  1985年   38篇
  1984年   47篇
  1983年   39篇
  1982年   33篇
  1981年   22篇
  1980年   19篇
  1979年   24篇
  1978年   16篇
  1977年   15篇
  1976年   12篇
  1975年   8篇
  1973年   8篇
排序方式: 共有7343条查询结果,搜索用时 78 毫秒
1.
目的分析重症肺炎并呼吸衰竭患儿接受早期持续气道正压通气(CPAP)治疗对血气指标及预后的影响。方法选取2019年2月至2020年6月本院收治的110例重症肺炎并呼吸衰竭患儿,按照组间基本资料具有可比性的原则分为对照组与实验组,各55例。对照组接受常规方案治疗,实验组接受早期持续CPAP治疗,比较两组血气指标改善情况以及患儿预后。结果治疗后,两组PaO2、PaCO2、SaO2均显著改善,且实验组改善程度明显优于对照组(P<0.05)。实验组临床病死率明显低于对照组(P<0.05)。两组并发症发生率比较差异无统计学意义。结论采用早期持续CPAP治疗重症肺炎并呼吸衰竭患儿效果显著,能明显改善血气指标和预后,具有临床推广价值。  相似文献   
2.
3.
4.
Portal venous gas is occasionally encountered in children with intestinal pneumatosis, identified on real‐time ultrasound imaging as hyperechoic foci with quick movement. The origin of the portal venous gas can be identified by following the hyperechoic foci along the branches of the portal vein, providing an estimate of the location of intestinal pneumatosis. This approach may be useful for predicting the patient's prognosis. Our report describes 2 cases of portal venous gas while estimating the area of intestinal pneumatosis, which were evaluated with real‐time ultrasound.  相似文献   
5.
目的:分析鼻塞式同步间歇正压通气(NIPPV)联合布地奈德雾化治疗ARDS(新生儿急性呼吸窘迫综合征)疾病的临床应用效果。方法:纳入病例是2017年5月—2019年11月收治的104例ARDS新生儿,随机平均分为两组。参照组52例采纳CPAP(持续气道正压通气通气)治疗,实验组52例采纳NIPPV+布地奈德雾化治疗,对比两组呼吸机通气时间、用氧时间、住院时间、血气指标以及并发症发生情况。结果:实验组呼吸机通气时间、用氧时间、住院时间均明显短于参照组,差异有统计学意义P<0.05;实验组治疗3 d后PaCO2明显低于参照组,实验组治疗3 d后PH以及PaO2明显高于参照组,差异有统计学意义P<0.05;实验组并发症发生率(3.85%,2/52)明显低于参照组(21.15%,11/52),差异有统计学意义P<0.05。结论:NIPPV+布地奈德雾化可有效缩短ARDS患者机械通气时间,改善血气指标,降低并发症发生率,值得借鉴。  相似文献   
6.
7.
BackgroundOur study was aimed at examining disparate exposure to physically demanding working conditions in France, a key objective being to identify the types of employees/jobs requiring high-priority preventive actions.MethodsWe analyzed the data from the 2017 French nationwide cross-sectional survey (SUMER) on occupational hazards to which French employees in various sectors were subjected. The prevalence of several types of physically demanding working conditions (lifting of heavy loads, awkward body postures, vibrations, noise, and extreme temperatures) was explored. Potential associations of individual and job characteristics with these factors of hardship at work were studied by multivariate logistic regression.ResultsIn total, 48% of employees were exposed to at least one physically demanding working condition and 24.8% were exposed to multiple constraints. While managers and intellectual professionals were exposed relatively infrequently to physical constraints, blue-collar workers experienced the highest frequency of exposure. On the one hand, the role of company size depended on the factor of hardship at work considered; on the other hand, employees in large-scale companies were generally less exposed. As expected, employees in the construction industry were the most exposed to physical constraints; that said, our results also show that some activities in the services sector (e.g., personal care, administrative and support services) were quite significantly affected by a wide array of physically demanding working conditions.ConclusionNotwithstanding the establishment in France of Plans de Santé au travail (preventive workplace health and safety plans), occupational risks were found to be high, and above all, they were unevenly distributed among the various socio-professional categories, and strongly contributed to social inequalities in health. Our results identify the types of publics to be designated as high-priority targets for preventive measures aimed at reducing the adverse impacts of physically demanding working conditions and the incidence of associated musculoskeletal disorders.  相似文献   
8.
目的研究复方鲜竹沥液联合噻托溴铵粉雾剂治疗慢性阻塞性肺疾病急性加重期的临床疗效。方法选取2018年9月—2019年9月在安阳市第六人民医院治疗的100例慢性阻塞性肺疾病急性加重期患者,将所有患者随机分为对照组和治疗组,每组各50例。对照组吸入噻托溴铵粉雾剂,1粒/次,1次/d。治疗组在对照组基础上口服复方鲜竹沥液,20 mL/次,3次/d。两组持续治疗3个月。观察两组的临床疗效,比较血气指标、肺功能指标、血清炎性因子水平。结果治疗后,治疗组总有效率94.00%显著高于对照组82.00%(P0.05)。治疗后,两组二氧化碳分压(pCO_2)显著降低,血氧分压(pO_2)显著升高(P0.05),且治疗组血气指标改善程度较大(P0.05)。治疗后,两组第一秒用力呼气容积(FEV1)占预计值百分比(FEV1%)、每分钟最大通气量(MVV)显著升高,残气量/肺总量(RV/TLC)明显降低(P0.05);且治疗组肺功能指标改善较多(P0.05)。治疗后,两组白细胞介素-17(IL-17)、IL-8、肿瘤坏死因子-α(TNF-α)水平显著降低(P0.05);并且治疗组血清炎性因子水平降低较多(P0.05)。结论复方鲜竹沥液联合噻托溴铵粉雾剂治疗慢性阻塞性肺疾病急性加重期具有较好的临床疗效,可改善血气指标和肺功能指标,降低血清炎性因子水平,值得在临床上推广应用。  相似文献   
9.
10.

Background

Degenerative biomechanical factors and immunologic processes with effect on collagen and corneal reparative process are known as the main cause of ocular surface dysfunction in mustard gas keratopathy (MGK) and may cause changes in the corneal biomechanical values. Therefore, we evaluate corneal biomechanical properties of these patients.

Methods and materials

This case-control study includes 61 chemical warfare victims with MGK. After omission according to our exclusion criteria, 88 eyes of patients with MGK were enrolled as the case group and also a group of 88 normal eyes, which were matched regarding their age and sex in the control group, were enrolled. Measurements of corneal biomechanical properties which reported by ORA and Corvis ST (CST) devices were compared. The SPSS software version 23.0 was used in the statistical analysis. For comparisons between groups, if the data had a normal distribution, were analyzed by Student’s t-test and ANOVA, and if the data didn’t have a normal distribution, Mann–Whitney U test, and Kruskal-Wallis were used. Furthermore, to identify a relationship between two groups of data Spearman's rank Correlation test was used. P value?<?0.05 were considered statistically significant.

Results

In the MGK group, A1 length (A1L), A1 velocity (A1V), A2 velocity (A2V), deformation amplitude (DA) and peak distance (PD) were higher than the control group (P?<?0.001). However, the corneal hysteresis (CH) (P?=?0.003), corneal resistant factor (CRF), non-corrected IOP (IOPnct), corrected IOP based on corneal thickness (IOPpachy), and central corneal thickness (CCT) were lower than the control group (P?<?0.001). The visual acuity according to the LogMAR scale and severity of MGK was positively associated with IOPpachy and negatively associated with CH, CRF, CCT and highest concavity radius (Radius).

Conclusion

Measurement of corneal biomechanical properties may be, have a useful role in the classification, monitoring or diagnosis of MGK.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号