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   102285篇
  免费   6901篇
  国内免费   3661篇
耳鼻咽喉   415篇
儿科学   2072篇
妇产科学   525篇
基础医学   9974篇
口腔科学   1507篇
临床医学   14311篇
内科学   20688篇
皮肤病学   529篇
神经病学   12900篇
特种医学   4835篇
外国民族医学   8篇
外科学   6836篇
综合类   17901篇
现状与发展   14篇
一般理论   2篇
预防医学   2768篇
眼科学   919篇
药学   8640篇
  78篇
中国医学   3276篇
肿瘤学   4649篇
  2024年   100篇
  2023年   1060篇
  2022年   1831篇
  2021年   3149篇
  2020年   3128篇
  2019年   2650篇
  2018年   2849篇
  2017年   3151篇
  2016年   3544篇
  2015年   3652篇
  2014年   7378篇
  2013年   7711篇
  2012年   6497篇
  2011年   7326篇
  2010年   6180篇
  2009年   5714篇
  2008年   5745篇
  2007年   5708篇
  2006年   5377篇
  2005年   4608篇
  2004年   3600篇
  2003年   3024篇
  2002年   2409篇
  2001年   2203篇
  2000年   1850篇
  1999年   1518篇
  1998年   1243篇
  1997年   1191篇
  1996年   934篇
  1995年   837篇
  1994年   770篇
  1993年   603篇
  1992年   559篇
  1991年   490篇
  1990年   442篇
  1989年   345篇
  1988年   335篇
  1987年   362篇
  1986年   297篇
  1985年   355篇
  1984年   309篇
  1983年   200篇
  1982年   240篇
  1981年   200篇
  1980年   203篇
  1979年   174篇
  1978年   142篇
  1977年   137篇
  1976年   121篇
  1973年   89篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
目的:观察非霍奇金淋巴瘤(non-Hodgkin's lymphoma,NHL)患者自体造血干细胞移植(autologous hematopoietic stem cell transplantation,ASCT)术后应用重组人α-2b干扰素(α-2b IFN)进行早期干预治疗的临床疗效。方法:选取18例行ASCT的NHL患者为研究对象,移植前疾病评估均未达到完全缓解(complete remission,CR),试验组血象恢复后给予IFN 3 000 000 U次/隔日干预治疗,3个月后停用;对照组未行干扰素干预治疗,分析总体疗效及两组对比的生存情况。结果:随访中位时间为34(10~50)个月,患者中位生存时间为37(31~45)个月,3年总体无进展生存(progressive free survival,PFS)、总生存(overall survivial,OS)分别为54.7%、66.8%。ASCT后试验组1年内无疾病复发,2年内复发率为12.5%;对照组1年内复发率为20%,2年内复发率为30%。结论:NHL患者在ASCT后给予重组人α-2b IFN早期干预治疗,患者耐受性好,可能降低移植后早期复发率。  相似文献   
12.
目的探讨CT与MRI在脑梗死后出血性转变(HT)中的诊断价值。方法对2011-01—2014-04我院收治的45例HT患者的临床资料进行回顾性分析,对CT与MRI的检查结果进行对比。结果45例患者中,脑内血肿34例(75.6%),脑梗死病灶内片状、斑点状或条状出血11例(24.4%)。其中大面积脑梗死继发出血24例(53.3%),中等面积继发出血15例(33.3%),小面积脑梗死继发出血6例(13.3%);CT检出HT 10例(22.2%),MRI检出45例(100%),差异有统计学意义(P0.05);在对不同部位的HT检查中,CT检出幕上出血9例(20.0%),幕下出血1例(2.2%);MRI检出幕上出血39例(86.7%),幕下出血6例(13.3%)。MRI对幕上及幕下出血的检出率均优于CT(P0.05)。结论在HT的诊断中,MRI比CT更加准确和敏感,在判断出血时间、指导临床治疗以及预后判断中具有重要意义。  相似文献   
13.
14.
《Journal of endodontics》2020,46(10):1455-1464
IntroductionThe aim of this study was to investigate whether mineral trioxide aggregate (MTA) can be modified with caffeic acid (CA) to form caffeic acid/mineral trioxide aggregate (CAMTA) cement and to evaluate its physicochemical and biological properties as well as its capability in immune suppression and angiogenesis.MethodsMTA was immersed in trishydroxymethyl aminomethane buffer with CA to allow coating onto MTA powders. X-ray diffractometry and tensile stress-strain tests were conducted to assess for physical characteristics of CAMTA and to evaluate for successful modification of MTA. Then, the CAMTA cement was immersed in simulated body fluid to evaluate its hydroxyapatite formation capabilities and Si release profiles. In addition, RAW 264.7 cells and human dental pulp stem cells were used to evaluate CAMTA’s immunosuppressive capabilities and cell responses, respectively. hDPSCs were also used to assess CAMTA’s angiogenic capabilities.ResultsThe X-ray diffractometry results showed that CA can be successfully coated onto MTA without disrupting or losing MTA’s original structural properties, thus allowing us to retain the initial advantages of MTA. CAMTA was shown to have higher mechanical properties compared with MTA and had rougher pitted surfaces, which were hypothesized to lead to enhanced adhesion, proliferation, and secretion of angiogenic- and odontogenic-related proteins. In addition, it was found that CAMTA was able to enhance hydroxyapatite formation and immunosuppressive capabilities compared with MTA.ConclusionsCAMTA cements were found to have improved physicochemical and biological characteristics compared with their counterpart. In addition, CAMTA cements had enhanced odontogenic, angiogenic, and immunosuppressive properties compared with MTA. All of the results of this study proved that CAMTA cements could be a biomaterial for future clinical applications and tissue engineering use.  相似文献   
15.
In this article, we draw on recent scholarly work in the poststructuralist analysis of policy to consider how policy itself functions as a key site in the constitution of alcohol ‘problems’, and the political implications of these problematisations. We do this by examining Australian alcohol policy as it relates to young adults (18–24 years old). Our critical analysis focuses on three national alcohol policies (1990, 2001 and 2006) and two Victorian state alcohol policies (2008 and 2013), which together span a 25-year period. We argue that Australian alcohol policies have conspicuously ignored young adult men, despite their ongoing over-representation in the statistical ‘evidence base’ on alcohol-related harm, while increasingly problematising alcohol consumption amongst other population subgroups. We also identify the development of a new problem representation in Australian alcohol policy, that of ‘intoxication’ as the leading cause of alcohol-related harm and rising hospital admissions, and argue that changes in the classification and diagnosis of intoxication may have contributed to its prioritisation and problematisation in alcohol policy at the expense of other forms of harm. Finally, we draw attention to how preliminary and inconclusive research on the purported association between binge drinking and brain development in those under 25 years old has been mobilised prematurely to support calls to increase the legal purchasing age from 18 to 21 years. Our critical analysis of the treatment of these three issues – gender, intoxication, and brain development – is intended to highlight the ways in which policy functions as a key site in the constitution of alcohol ‘problems’.  相似文献   
16.
目的:系统评价丹红注射液对急性心肌梗死(AMI)经皮冠状动脉介入治疗(PCI)围手术期心功能和心肌梗塞溶栓治疗(TIMI)血流分级的影响。方法:计算机检索CNKI,万方数据库,维普数据库,Pub Med,CBM,Web of Science,The Cochrane Library共7个数据库,全面采集在PCI围手术期应用丹红注射液治疗急性心梗的临床试验,采用Cochrane风险评价表进行文献质量评价,运用Revman 5.3软件进行Meta分析。结果:共纳入12个临床试验,包含1131例患者,其中丹红治疗组569例,对照组562例,结果显示在常规治疗的基础上加入丹红注射液治疗,患者的左室射血分数明显增高[均数差(MD)=6.62,95%可信区间(CI)(4.91,8.34),P<0.00001],TIMI分级3级患者明显增多[相对危险度(RR)=0.22,95%CI(0.12,0.41),P<0.00001],脑利钠肽水平明显降低[MD=-151.86,95%CI(-247.00,-56.72),P=0.002]。结论:丹红注射液可以提高急性心梗PCI围手术期心功能和增加TIMI血流的分级。  相似文献   
17.
18.

Background

Refractory acute myeloid leukemia (AML) includes AML includes failure of disease to respond to standard induction chemotherapy, relapse within 6 months after first CR, and 2 or more relapses. The outcome of these patients is usually very poor; only a small proportion can be rescued by allogenic hematopoietic stem-cell transplantation (allo-HSCT). The aim of this study was to evaluate the efficacy and feasibility of allo-HSCT in patients with refractory AML.

Patients and Methods

We retrospectively analyzed the clinical outcome of 91 patients who were diagnosed with treatment-refractory AML at Hacettepe University Hospital between January 2002 and June 2018. Patients' disease status included refractory AML, defined as failure to respond to standard induction chemotherapy and relapse within 6 months after first complete remission.

Results

The median follow-up was 12 months (range, 0.5-184 months) for the entire group. Kaplan-Meier estimates of the 3-year overall survival for patients who underwent allo-HSCT and patients who received only salvage chemotherapy were 67% and 12%, respectively. Additionally, the Kaplan-Meier estimates of 5-year overall survival for patients who underwent allo-HSCT and patients who received only salvage chemotherapy were 44% and 4%, respectively (P < .001). Complete remission was obtained in 25 patients (83.3%) who underwent allo-HSCT; however, the disease of only 3 patients (3.8%) exhibited complete response after salvage chemotherapy.

Conclusion

Allo-HSCT is still the best-known treatment option with curative potential in patients with treatment-refractory AML. Therefore, all efforts should be made in an attempt to find a suitable matched donor in order to perform allo-HSCT.  相似文献   
19.
The progress of modern medicine would be impossible without the use of general anesthetics (GAs). Despite advancements in refining anesthesia approaches, the effects of GAs are not fully reversible upon GA withdrawal. Neurocognitive deficiencies attributed to GA exposure may persist in neonates or endure for weeks to years in the elderly. Human studies on the mechanisms of the long-term adverse effects of GAs are needed to improve the safety of general anesthesia but they are hampered not only by ethical limitations specific to human research, but also by a lack of specific biological markers that can be used in human studies to safely and objectively study such effects. The latter can primarily be attributed to an insufficient understanding of the full range of the biological effects induced by GAs and the molecular mechanisms mediating such effects even in rodents, which are far more extensively studied than any other species. Our most recent experimental findings in rodents suggest that GAs may adversely affect many more people than is currently anticipated. Specifically, we have shown that anesthesia with the commonly used GA sevoflurane induces in exposed animals not only neuroendocrine abnormalities (somatic effects), but also epigenetic reprogramming of germ cells (germ cell effects). The latter may pass the neurobehavioral effects of parental sevoflurane exposure to the offspring, who may be affected even at levels of anesthesia that are not harmful to the exposed parents. The large number of patients who require general anesthesia, the even larger number of their future unexposed offspring whose health may be affected, and a growing number of neurodevelopmental disorders of unknown etiology underscore the translational importance of investigating the intergenerational effects of GAs. In this mini review, we discuss emerging experimental findings on neuroendocrine, epigenetic, and intergenerational effects of GAs.  相似文献   
20.
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