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   10203篇
  免费   621篇
  国内免费   282篇
耳鼻咽喉   52篇
儿科学   225篇
妇产科学   179篇
基础医学   791篇
口腔科学   58篇
临床医学   1012篇
内科学   1496篇
皮肤病学   103篇
神经病学   430篇
特种医学   174篇
外科学   629篇
综合类   2388篇
预防医学   1213篇
眼科学   32篇
药学   1387篇
  5篇
中国医学   493篇
肿瘤学   439篇
  2023年   102篇
  2022年   238篇
  2021年   341篇
  2020年   353篇
  2019年   230篇
  2018年   246篇
  2017年   283篇
  2016年   328篇
  2015年   347篇
  2014年   792篇
  2013年   680篇
  2012年   682篇
  2011年   749篇
  2010年   601篇
  2009年   487篇
  2008年   489篇
  2007年   477篇
  2006年   434篇
  2005年   369篇
  2004年   321篇
  2003年   279篇
  2002年   216篇
  2001年   197篇
  2000年   185篇
  1999年   151篇
  1998年   129篇
  1997年   122篇
  1996年   93篇
  1995年   106篇
  1994年   90篇
  1993年   80篇
  1992年   72篇
  1991年   60篇
  1990年   73篇
  1989年   56篇
  1988年   74篇
  1987年   52篇
  1986年   52篇
  1985年   51篇
  1984年   65篇
  1983年   37篇
  1982年   40篇
  1981年   37篇
  1980年   31篇
  1979年   25篇
  1978年   29篇
  1977年   20篇
  1976年   23篇
  1973年   20篇
  1972年   19篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 通过分析特发性肺纤维化急性加重期(AE-IPF)患者证候与血清生物标志物的关系,为中医辨证治疗提供参考。方法 采用观察性研究设计,收集2019年3月至2019年11月三个中心的AE-IPF患者76例,其中痰热壅肺证26例、痰浊阻肺证50例,并纳入健康志愿者10例作为对照。采用ELISA测定患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平,分析与中医证候的相关性。结果 AE-IPF患者血清CCL18、HMGB1、KL-6、MMP-7、SP-A和SP-D水平均显著高于健康对照组。血清CCL18、HMGB1、KL-6、MMP-7和SP-D水平在痰热壅肺证和痰浊阻肺证患者间无显著性差异(P>0.05),而血清SP-A水平存在显著性差异(P<0.05)。结论 血清SP-A与AE-IPF证候存在一定的相关性,血清SP-A的浓度升高,与痰热壅肺证关系越密切,反之,血清SP-A浓度降低,则与痰浊阻肺证关系越密切。AE-IPF痰热壅肺证患者的预后可能较痰浊阻肺证患者更差。  相似文献   
2.
3.
BackgroundContrast associated-acute kidney injury (CA-AKI) has been associated with adverse outcomes after ST-segment elevation myocardial infarction (STEMI). However, early markers of CA-AKI are still needed to improve risk stratification. We investigated the association between elevated serum uric acid (eSUA) and CA-AKI in patients with STEMI treated with primary percutaneous coronary intervention (pPCI).Methods and resultsSerum creatinine (Scr) was measured at admission and 24, 48 and 72 h after pPCI. CA-AKI was defined as an increase of 25% (CA-AKI 25%) or 0.5 mg/dl (CA-AKI 0.5) of Scr level above the baseline after 48 h following contrast administration. Multivariable analyses to investigate CA-AKI predictors were performed by binary logistic regression and multivariable backward logistic regression model.In the 3023 patients considered, CA-AKI was more frequent among patients with eSUA as compared with patients with normal SUA levels, considering both CA-AKI definitions (CA-AKI25%: 20.8% vs 16.2%, p < 0.012; CA-AKI 0.5: 10.1% vs 5.8%, p < 0.001). The association between eSUA and CA-AKI was confirmed at multivariable analyses (CA-AKI 25%: odd ratio 1.32, 95% CI 1.03–1.69, p = 0.027; CA-AKI 0.5: odd ratio 1.76, 95% CI 1.11–2.79, p = 0.016).ConclusionElevated serum uric acid is associated with CA-AKI after reperfusion in patients with STEMI treated with pPCI.  相似文献   
4.
Elevated serum uric acid (SUA) levels have been associated with several cardiovascular risk factors and the progression of coronary artery disease. In the setting of acute myocardial infarction, increasing evidence suggests that high SUA levels could be related to adverse outcomes. Interestingly elevated SUA levels have been linked to endothelial dysfunction, inflammation and oxidative stress. The aim of this review is to discuss the potential negative effects of SUA in patients with ST-segment elevation myocardial infarction undergoing primary percutaneous coronary intervention, analyzing the possible underlying pathophysiological mechanisms.  相似文献   
5.
IntroductionSeptic arthritis is a serious orthopaedic emergency that must be diagnosed and managed early to prevent devastating complications. The current gold standard for diagnosing septic arthritis is synovial fluid culture, but results are delayed by 48–72 h, and the sensitivity of the test is very low. Differentiating Septic from non-septic arthritis is vital to prevent unnecessary use of antibiotics and prevent complications. Serum Procalcitonin (PCT) is a useful marker in differentiating septic from non-septic arthritis but there are very few studies that have studied the role of synovial PCT for the same.AimTo determine the role of serum and synovial PCT in differentiating acute Septic from non-septic arthritis.Materials and methodsProspective clinical study in which 60 patients presenting with acute inflammatory arthritis (<2 weeks duration) were enrolled from May 2018 to May 2020. Serum and synovial fluid samples were drawn at presentation and routine blood investigations, synovial fluid culture sensitivity, and Procalcitonin levels were measured. Patients were divided into 3 groups, with group-1 having confirmed pyogenic, group-2 having presumed pyogenic, and group-3 having non –pyogenic patients, respectively. All data was tabulated and statistically analysed using appropriate tests.ResultsMean serum PCT values in groups 1, 2 and 3 were 1.06 ± 1.11, 0.85 ± 0.74, and 0.11 ± 0.24, respectively. Patients in the Pyogenic group (group1 and group 2) had significantly higher mean serum PCT as compared to group3 (p < 0.0001). Group 1 had higher serum PCT as compared to group 2, but the difference was not significant (p = 0.58). Mean synovial PCT in group 1, 2 and 3 were 2.42 ± 1.98, 1.89 ± 1.18, and 0.22 ± 0.40, respectively. Patients in the Pyogenic group (Group1 and Group2) had significantly higher mean synovial PCT as compared to Group 3 (p < 0.0001). Group 1 had higher mean synovial PCT as compared to group 2, but the difference was not significant (p = 0.54). The area under the ROC curve of the serum levels of PCT was 0.0.895, and the area under the ROC curve of the synovial fluid levels of PCT was 0.914, which was higher than the serum PCT level.ConclusionSerum and synovial Procalcitonin may be used as a diagnostic marker in differentiating septic from inflammatory arthritis and can help in reducing unnecessary use of antibiotics and early diagnosis and management of septic arthritis, thereby preventing complications.  相似文献   
6.

Purpose

Mild traumatic brain injury (TBI) is common but accurate diagnosis and its clinical consequences have been a problem. Maxillofacial trauma does have an association with TBI. Neuron-specific enolase (NSE) has been developed to evaluate neuronal damage. The objective of this study was to investigate the accuracy of NSE serum levels to detect mild brain injury of patients with sustained maxillofacial fractures during motor vehicle accidents.

Methods

Blood samples were drawn from 40 healthy people (control group) and 48 trauma patients who had sustained isolated maxillofacial fractures and mild brain injury in motor vehicle accidents. Brain injuries were graded by Glasgow Coma Scale. In the trauma group, correlations between the NSE serum value and different facial fracture sites were also assessed.

Results

The NSE serum level (mean ± SD, ng/ml) in the 48 patients with maxillofacial fractures and mild TBI was 13.12 ± 9.68, significantly higher than that measured in the healthy control group (7.72 ± 1.82, p < 0.001). The mean NSE serum level (ng/ml) in the lower part of the facial skeleton (15.44 with SD 15.34) was higher than that in the upper facial part (12.42 with SD 7.68); and the mean NSE level (ng/ml) in the middle-and lower part (11.97 with SD 5.63) was higher than in the middle part (7.88 with SD 2.64).

Conclusion

An increase in NSE serum levels can be observed in patients sustained maxillofacial fractures and mild brain injury.  相似文献   
7.
《Vaccine》2019,37(47):6987-6995
Vero cells are nowadays widely used in the production of human vaccines. They are considered as one of the most productive and flexible continuous cell lines available for vaccine manufacturing. However, these cells are anchorage dependent, which greatly complicates upstream processing and process scale-up. Moreover, there is a recognized need to reduce the costs of vaccine manufacturing to develop vaccines that are affordable worldwide. The use of cell lines adapted to suspension growth contributes to reach this objective.The current work describes the adaptation of Vero cells to suspension culture in different serum free media according to multiple protocols based on subsequent passages. The best one that relies on cell adaption to IPT-AFM an in-house developed animal component free medium was then chosen for further studies. Besides, as aggregates have been observed, the improvement of IPT-AFM composition and mechanical dissociation were also investigated.In addition to IPT-AFM, three chemically defined media (CD293, Hycell CHO and CD-U5) and two serum free media (293SFMII and SFM4CHO) were tested to set up a serum free culture of the suspension-adapted Vero cells (VeroS) in shake flasks. Cell density levels higher than 2 × 106 cells/mL were obtained in the assessed conditions. The results were comparable to those obtained in spinner culture of adherent Vero cells grown on Cytodex 1 microcarriers.Cell infection with LP-2061 rabies virus strain at an MOI (Multiplicity of Infection) of 0.1 and a cell density of 8 ± 0.5 × 105 cells/mL resulted in a virus titer higher than 107 FFU/mL in all media tested. Nevertheless, the highest titer equal to 5.2 ± 0.5 × 107 FFU/mL, was achieved in IPT-AFM containing a reduced amount of Ca++ and Mg++. Our results demonstrate the suitability of the obtained VeroS cells to produce rabies virus at a high titer, and pave the way to develop VeroS cells bioreactor process for rabies vaccine production.  相似文献   
8.
9.
目的:探讨评价消风散合黄连解毒汤治疗湿疹效果及价值。方法:选择2017年5—12月治疗湿疹的患者54例作为对象,随机数字表分为对照组(27例)和观察组(27例)。对照组给予常规盐酸西替利嗪片治疗的方法,观察组采用消风散合黄连解毒汤治疗,15 d后对两组治疗方法的患者血清白细胞介素(Interleukin,IL)-4、γ-干扰素(γ-Interferon,IFN-γ)水平和临床治疗效果进行评估,比较两组湿疹患者体内的血清IL-4、IFN-γ含量以及患者治愈、显效、好转、无效以及总有效率的情况。结果:治疗前后两组患者IL-4、IFN-γ差异无统计学意义(P>0.05)。经15 d治疗后,观察组血清IL-4、IFN-γ水平相较于对照组有明显改善,差异有统计学意义(P<0.05),观察组患者总有效率高于对照组,临床治疗效果显著优于对照组(P<0.05)。结论:将消风散合黄连解毒汤治疗用于湿疹,相较于盐酸西替利嗪片治疗,患者血清水平更佳,临床疗效更好,值得推广应用。  相似文献   
10.
目的探讨支气管镜灌注术(BP)联合抗生素治疗肺癌术后感染的效果及对血清肿瘤坏死因子α(TNF-α)、白细胞介素-8(IL-8)、超敏C反应蛋白(hs-CRP)和降钙素原(PCT)水平的影响。方法选取2017年5月至2018年9月间西安市北方医院收治的80例肺癌术后感染患者,采用随机数表法分为观察组和对照组,每组40例。对照组患者采用常规抗感染治疗,观察组患者在常规治疗基础上应用BP联合局部灌注抗生素治疗,比较两组患者临床疗效、呼吸力学指标、血清TNF-α、IL-8、hs-CRP、PCT及不良反应情况。结果观察组患者临床治疗总有效率为92.5%,高于对照组患者的75.0%,差异有统计学意义(P<0.05)。治疗前,两组患者的气道峰压(PIP)、动态顺应性(Cdyn)、呼吸做功(WOB)和气道阻力(Raw)指标比较,差异无统计学意义(P>0.05)。治疗后,两组患者的PIP、WOB和Raw指标均下降,且观察组均低于对照组,两组患者Cdyn指标均上升,且观察组高于对照组,差异均有统计学意义(均P<0.05)。治疗前,两组患者TNF-α、IL-8、hs-CRP和PCT指标比较,差异无统计学意义(P>0.05)。治疗后,两组患者TNF-α、IL-8、hs-CRP和PCT指标均下降,且观察组上述指标均低于对照组,差异均有统计学意义(均P<0.05)。治疗期间,对照组患者出现呛咳1例,低氧血症1例,发绀1例;观察组患者出现低氧血症1例,对症治疗后,两组患者症状均消失。两组患者不良反应情况比较,差异无统计学意义(P>0.05)。结论采用BP联合抗生素治疗肺癌术后感染患者疗效确切,可有效减轻炎症反应,提升呼吸功能。  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