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   111875篇
  免费   11130篇
  国内免费   7503篇
耳鼻咽喉   950篇
儿科学   1384篇
妇产科学   1514篇
基础医学   12308篇
口腔科学   1954篇
临床医学   13299篇
内科学   16467篇
皮肤病学   1241篇
神经病学   5200篇
特种医学   4356篇
外国民族医学   54篇
外科学   12309篇
综合类   20146篇
现状与发展   23篇
一般理论   18篇
预防医学   8347篇
眼科学   2736篇
药学   12129篇
  93篇
中国医学   7019篇
肿瘤学   8961篇
  2024年   385篇
  2023年   1613篇
  2022年   4127篇
  2021年   5343篇
  2020年   4095篇
  2019年   3589篇
  2018年   3733篇
  2017年   3495篇
  2016年   3411篇
  2015年   4898篇
  2014年   5959篇
  2013年   5900篇
  2012年   7892篇
  2011年   8479篇
  2010年   5722篇
  2009年   4555篇
  2008年   5700篇
  2007年   6145篇
  2006年   5760篇
  2005年   5191篇
  2004年   4885篇
  2003年   5257篇
  2002年   4713篇
  2001年   3848篇
  2000年   3010篇
  1999年   2417篇
  1998年   1401篇
  1997年   1359篇
  1996年   1017篇
  1995年   885篇
  1994年   770篇
  1993年   494篇
  1992年   707篇
  1991年   586篇
  1990年   541篇
  1989年   484篇
  1988年   375篇
  1987年   353篇
  1986年   273篇
  1985年   225篇
  1984年   142篇
  1983年   105篇
  1982年   70篇
  1981年   89篇
  1980年   49篇
  1979年   77篇
  1978年   37篇
  1974年   36篇
  1973年   33篇
  1972年   41篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
The first universal hepatitis B vaccination program for newborns in the world was launched in Taiwan in July 1984. Most studies on the effectiveness of hepatitis B vaccination focused on the seroprevalence of HBs Ag among children under 14 years old. Only few studies focused on the seropositivity of anti-HBs among adolescents aged 15–18 years old. The present study aimed to evaluate the impact of the nationwide hepatitis B vaccination program on the immunity to HBV infection and the necessity of boost among adolescents. In this study including eight annual seroprevalence surveys from 2000 to 2007, 2342 college entrants (1589 15-year-olds in group I and 753 18-year-olds in group II) and 1851 university freshmen (18-year-olds in group III) participated. Subjects identified anti-HBs, HBs Ag and anti-HBc negative were given boost three doses of HBV vaccine. The HBs Ag seroprevalence was 11.6%, 3.5% and 1.0% for participants who were born before 1984, 1984–1986 and after 1986. The anti-HBs-seropositive rates were significantly higher in group II (83.1%) than in group I (53.0%) and group III (53.5%). All 572 participants who were seronegative for anti-HBs, HBs Ag and anti-HBc became anti-HBs-seropositive after catch-up vaccination. It is concluded that the anti-HBs-seropositive rate decreased to 50% in 15 years after vaccination, and boost vaccination was 100% effective. The necessity and age for boost among anti-HBs negative adolescents and the timing of the first immunization should be further evaluated.  相似文献   
82.
目的探讨暴发性急性胰腺炎并发腹腔室隔综合征的治疗方案。方法回顾性分析1998年1月至2007年3月共收治FAP并发腹腔室隔综合征31例的诊治经验,对收治的31例暴发性急性胰腺炎并发腹腔室隔综合征患者根据腹腔内压力、腹腔室隔综合征分型,以及早期(发病后3d内)手术治疗与非手术治疗结果进行总结。结果31例暴发性急性胰腺炎并发腹腔室隔综合征患者13例行非手术治疗,其中轻度腹腔室隔综合征者5例(死亡1例),中、重度8例(死亡4例);3d内早期手术治疗18例,其中轻度腹腔室隔综合征者5例(死亡2例),中、重度13例(死亡4例)。当腹腔内压力〉21mmHg时,早期手术治疗组死亡人数明显低于早期非手术治疗组(P〈0.05)。根据ACS分型,Ⅰ型非手术治疗5例(死亡2例),Ⅱ型非手术治疗4例(死亡2例),Ⅲ型非手术治疗4例(死亡2例);Ⅰ型手术治疗9例(死亡2例),Ⅱ型4例(死亡2例),Ⅲ型5例(死亡2例)。Ⅰ型手术治疗组死亡人数明显低于非手术治疗组(P〈0.05),Ⅱ、Ⅲ型两组手术治疗组与非手术治疗组比较,死亡人数差异无统计学意义(P〉0.05)。结论当腹腔内压力〉21mmHg,且CT提示为Ⅰ型ACS的FAP患者,宜尽早行有效的腹腔减压引流;而对于腹腔内压力〉21mmHg,CT提示为Ⅱ、Ⅲ型ACS的FAP患者,早期手术减压效果有待进一步观察。  相似文献   
83.
Background The incidence rate of incisional hernias after open surgery has been reported to be higher than that of port site hernias after laparoscopic surgery. No studies have compared the costs for the health care system in treating those two types of hernia. Methods A systematic review was conducted to obtain the baseline data, and a decision analysis model was created to simulate the occurrence and recurrence of incisional and port site hernias. Results The overall risk of having incisional hernias was eight-times higher than that of having port site hernias (7.4% vs 0.9%). A cost savings of £93 per patient can be generated for the health care system in the UK. Similar results were obtained for Germany, Italy and France. Conclusions The additional treatment costs for incisional hernia should be taken into account when the costs of a surgery performed by open approach are compared with by laparoscopy.  相似文献   
84.
无线网络技术在医学仪器中的应用   总被引:1,自引:0,他引:1  
简要介绍无线网络技术的原理、特点及其在医学仪器中的应用.  相似文献   
85.
BACKGROUND: There are limited studies of large cohorts of patients with specific polysaccharide antibody deficiency (SPAD) syndrome. OBJECTIVE: To study the clinical and laboratory characteristics of patients with specific polysaccharide antibody deficiency syndrome. METHODS: We retrospectively studied 75 patients with total IgG levels of at least 500 mg/dL and fewer than 9 of 12 responses to vaccination with pneumococcal vaccine polyvalent. Exclusion criteria included an IgG level less than 500 mg/dL, established immunodeficiency syndrome, and secondary immunodeficiency. RESULTS: The most common clinical presentation was frequent infections (n = 69; 92%), including sinusitis (n = 53; 77%), pneumonia (n = 29; 42%), ear infections (n = 18; 26%), and bronchitis (n = 19; 28%). Other presentations were systemic infections (n = 5; 7%), autoimmune or rheumatic diseases (n = 6; 8%), and chronic diarrhea (n = 4; 5%). The median IgG2 level of patients with no response to pneumococcal vaccine polyvalent tended to be lower than that of patients with at least 1 response (150 vs 193 mg/dL, respectively; P = .06). There was no association between total IgG level (categorized as 500-600 or > or = 600 mg/dL) and frequency of infection (P = .43). Patients with fewer responses to pneumococcal vaccine polyvalent and a higher frequency of infections were more likely to receive intravenous immunoglobulin (IVIG) therapy (P = .01 and .003, respectively). Treatment with IVIG significantly reduced the number of infections (P < .001). CONCLUSION: Patients with no response to pneumococcal vaccine polyvalent tended to have lower IgG2 levels; those with fewer responses were more likely to receive IVIG therapy.  相似文献   
86.
目的 研究利福昔明对比环丙沙星治疗急性肠炎的有效性和安全性。 方法 采用随机对照方法 ,共治疗 5 1例急性肠炎。利福昔明治疗 2 5例 ,环丙沙星 2 6例 ,用药时间方法相同。观察治疗前后临床症状、大便性状、大便次数、便常规、血常规、尿常规及肝肾功能 ,以了解其疗效及不良反应情况。 结果 利福昔明组 (治疗组 )与环丙沙星组 (对照组 )相比 ,显效率分别为 92 .0 %和 80 .8% ,总有效率分别为 92 .0 %和 96 .2 % ,止泻时间治疗组 2 8.6 7± 15 .92h ,对照组 36 .12± 2 0 .70h ,均未见明显毒副作用。以上各项指标及两组在治疗过程中大便次数变化、大便常规复常率经统计学处理均无显著性差异 (P >0 0 5 )。 结论 利福昔明可用于治疗急性肠炎 ,与环丙沙星比较 ,疗效相仿 ,但耐受性好 ,口服不吸收 ,故值得推广  相似文献   
87.
全同非典进行特死斗争过程中,医护人员表现出一种临危不惧、挺身而出、全力救治、不怕牺牲、恪尽职守、患者至上、竭诚服务、科学防治的“抗非典精神”值得宣传,学习和效法。  相似文献   
88.
Tissue engineering is an application for gene therapy that is in its infancy. We show that simple liposomal-mediated gene transfer could result in a potentially useful biological effect in the field of wound healing. cDNA encoding the 165 amino acid form of vascular endothelial growth factor complexed to commercially available liposomes was injected into rat skin 1 week before raising a random pattern 3 x 10 cm flap. The flap survival was enhanced by 14 percent, and was accomplished without accessing the arterial inflow of the territory. These results were statistically significant (p<0.002) and reproducible. No adverse effects were seen. Histological analysis of the angiogenesis localized much of the new vessel formation to the area around the hair follicles. Polymerase chain reaction amplification of extracted flap tissue confirmed the presence of the transgene.  相似文献   
89.
The levels and temporal variations of surface ozone at a coastal site in East China during summer and autumn were analyzed and the influences of meteorological parameters on ozone were investigated. An inland city was chosen as a comparison site. The main results and conclusions of this study are: (1) ozone pollution, with a maximum 1 h concentration of 150.98 ppbv, was severe during summer and autumn at the coastal site; (2) the ozone level was obviously higher at the coastal site than that at the inland site in September; (3) besides temperature and solar radiation, sea-land breeze circulation is an important factor influencing the ozone level at the coastal site, and sea breeze often induce high ozone levels (the average ozone concentration for sea breeze was about 13 ppbv higher than that for land breeze).  相似文献   
90.
目的 探究注意缺陷多动障碍儿童初始沙盘游戏特征.方法 对29名注意缺陷多动障碍儿童和29名正常儿童进行沙盘游戏干预,对照分析两组儿童初始沙盘游戏主题及沙具使用情况.结果 注意缺陷多动障碍儿童沙盘游戏主题较正常儿童混乱无序,两组比较差异有统计学意义(χ2=22.58,P<0.00);两组儿童在沙具使用方面比较差异无统计学意义(均P>0.05).结论 注意缺陷多动障碍儿童沙盘游戏具有独特特征以及一定的临床诊断筛查价值.  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