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   24307篇
  免费   1748篇
  国内免费   405篇
耳鼻咽喉   91篇
儿科学   2248篇
妇产科学   1236篇
基础医学   2273篇
口腔科学   233篇
临床医学   2266篇
内科学   3303篇
皮肤病学   106篇
神经病学   1460篇
特种医学   577篇
外科学   2024篇
综合类   2400篇
一般理论   2篇
预防医学   4722篇
眼科学   142篇
药学   2086篇
  9篇
中国医学   631篇
肿瘤学   651篇
  2023年   436篇
  2022年   678篇
  2021年   1061篇
  2020年   959篇
  2019年   1036篇
  2018年   961篇
  2017年   899篇
  2016年   841篇
  2015年   829篇
  2014年   1648篇
  2013年   1956篇
  2012年   1293篇
  2011年   1547篇
  2010年   1241篇
  2009年   1230篇
  2008年   1289篇
  2007年   1190篇
  2006年   937篇
  2005年   858篇
  2004年   681篇
  2003年   599篇
  2002年   461篇
  2001年   411篇
  2000年   353篇
  1999年   257篇
  1998年   222篇
  1997年   177篇
  1996年   168篇
  1995年   146篇
  1994年   173篇
  1993年   145篇
  1992年   135篇
  1991年   121篇
  1990年   111篇
  1989年   78篇
  1988年   90篇
  1987年   84篇
  1986年   83篇
  1985年   150篇
  1984年   129篇
  1983年   102篇
  1982年   92篇
  1981年   90篇
  1980年   87篇
  1979年   76篇
  1978年   65篇
  1977年   39篇
  1976年   50篇
  1975年   30篇
  1973年   43篇
排序方式: 共有10000条查询结果,搜索用时 41 毫秒
31.
目的探讨低分子肝素钙预防腰椎退行性疾病术后深静脉血栓形成(DVT)的有效性和安全性。方法回顾性分析广安市广安区人民医院68例腰椎退行性疾病患者的临床资料,术后均采用抗凝预防血栓形成,按照术后预防DVT所采用方式的不同分为对照组和低分子肝素钙组。分析比较2组患者术后引流量、切口愈合情况、DVT发生率、皮下瘀斑情况、血小板数值、凝血功能、D-二聚体。结果术后2组患者引流量、切口愈合情况、皮下瘀斑情况、凝血功能相关指标比较,差异无统计学意义(P>0.05)。术前和术后1、10 d 2组患者血小板数量的变化差异无统计学意义(P>0.05)。DVT发生率2组患者比较差异有统计学意义(P<0.05)。术前及术后1 d 2组患者D-二聚体比较,差异无统计学意义(P>0.05);术后10 d,对照组患者D-二聚体显著增加,2组比较差异有统计学意义(P<0.05)。结论腰椎退行性疾病术后使用低分子肝素钙进行抗凝,可以显著降低DVT的发生率,具有良好的安全性。  相似文献   
32.
目的 了解深圳市龙华区代谢综合征发病情况及相关因素。方法 采取横断面研究,经过多阶段随机抽样,最终确定1 015名调查对象。调查内容包括问卷调查、身体测量和实验室检测。结果 龙华区代谢综合征的患病率为15.57%, 11种组分组合中,有4个组分组合的比例为28.49%,有5个组分组合的比例为5.06%。膳食调查中,水果分别在代谢综合征和非代谢综合征被调查者中的摄入有统计学差异(Z = - 2.47, P = 0.0135)。logistic回归分析结果显示在控制了年龄、性别、婚姻和户籍所在地后,不吸烟者与吸烟≥20支/天者相比,患代谢综合征的可能性可降低58%。性别分别与年龄和BMI的交互效应结果显示,女性在55~65岁,或女性肥胖,患代谢综合征的可能性分别是男性的40.56倍和32.82倍。结论 龙华区代谢性综合征患病情况不容乐观,因代谢性综合征诱导的心血管疾病风险较大,应针对其风险因素采取措施,以控制代谢性综合征的发生,并控制其进行性发展。  相似文献   
33.
Casting is being utilized as a therapeutic strategy in some mild to moderate cases obviating surgical intervention for management of early-onset scoliosis (EOS). Bracing, another conservative modality, applies comparable correcting forces on chest wall and axial skeleton. But cast application carries additional advantage of sustained restorative force which bypasses issue of compliance seen with brace wear. There is no specific blanket treatment, conservative or surgical, for the early-onset spinal deformities. Serial cast application provides near total correction of less severe curves (less than 500 to 600) if treatment is initiated before age of 2 yrs. In this review article, we will assess the evolution of plaster cast application in management of EOS and also describe technique of EDF (Elongation- Derotation- Flexion) casting.  相似文献   
34.
BackgroundSurface topography can be used for the evaluation of spinal deformities without any radiation. However, so far this technique is limited to posterior trunk measurements due to the use of a single posterior camera.Research questionPurpose of this study was to introduce a new multi camera surface topography system and to test its reliability and validity.MethodsThe surface topograph uses a two-camera system for imaging and evaluating the subjects front and back simultaneously. Inter- and intra-rater reliability was tested on 40 human subjects by two observers. For validation human, subjects were scanned by MRI and surface-topography. For additional validation we used a phantom with an anthropomorphic body which was scanned by CT and surface topography.ResultsInter- (0.97−0.99) and intra-rater reliability (0.81−0.98) testing revealed good and excellent results in the detection of the body surface structures and measurement of areas and volumes. CT based validation revealed good correspondence between systems in the imaging and evaluation of the phantom model (0.61–10.52 %). Results on validation of human subjects revealed good to moderate results in the detection and measurements of almost all body surface structures (1.36–13.34 %). Only measurements using jugular notch as a reference showed moderate results in validity (0.62–27.5%) testing.SignificanceWe have introduced a novel and innovative surface topography system that allows for simultaneous anterior and posterior trunk measurements. The results of our reliability and validity tests are satisfactory. However, in particular around the jugular notch region further improvements in the surface topography reconstruction are needed.  相似文献   
35.
36.
37.
Abscopal effect is an interesting phenomenon in radiobiology that causes activation of immune system against cancer cells. Traditionally, this phenomenon was known as a suppressor of non-irradiated tumors or metastasis. However, it can be used as a stimulator of the immune system against primary tumor during radiotherapy. Immunotherapy, a novel tumor therapy modality, also triggers immune system against cancer. To date, some immunotherapy types have been developed. However, immune checkpoint blockade is a more common modality and some drugs have been approved by the FDA. Studies have shown that radiotherapy or immunotherapy administered alone have low efficiency for tumor control. However, their combination has a more potent anti-tumor immunity. For this aim, it is important to induce abscopal effect in primary tumors, and also use appropriate drugs to target the mechanisms involved in the exhaustion of cytotoxic CD8+T lymphocytes (CTLs) and natural killer (NK) cells. Among the different radiotherapy techniques, stereotactic body radiation therapy (SBRT) with some few fractionations is the best choice for inducing abscopal effect. On the other hand, programmed cell death 1 (PD-1) is known as one of the best targets for triggering anti-tumor immunity. This combination is known as the best choice among various strategies for radioimmunotherapy. However, there is the need for other strategies to improve the duration of immune system’s activity within tumor microenvironment (TME). In this review, we explain the cellular and molecular mechanisms behind abscopal effect by radiotherapy and evaluate the molecular targets which induce potent anti-tumor immunity.  相似文献   
38.
Outpatient therapeutic feeding protocols for the treatment of uncomplicated severe acute malnutrition in children were initially based on weight gain data from inpatient settings and expert knowledge of the physiological requirements during recovery. However, weight gain and energy requirements from historic inpatient settings may differ from modern outpatient settings and therefore may not be appropriate to guide current therapeutic feeding protocols. We calculated the weight gain and average estimated total daily energy requirement of children successfully treated for uncomplicated severe acute malnutrition as outpatients in Niger (n = 790). Mean energy provided by six therapeutic feeding protocols was calculated and compared with average estimated energy requirements in the study population. Overall weight gain was 5.5 g·kg?1·day?1 among recovered children. Average energy requirements ranged from 92 to 110 kcal·kg?1·day?1 depending on the estimation approach. Two current therapeutic feeding protocols were found to provide an excess of energy after the first week of treatment in our study population, whereas four research protocols tended to provide less energy than the estimated requirement after the first week of treatment. Alternative feeding protocols have the potential to simplify and lead to important savings for programmes but should be evaluated to show adequacy to meet the energy needs of children under treatment, as well as feasibility and cost efficiency. Our findings rely on theoretical calculations based on several assumptions and should be confirmed in field studies.  相似文献   
39.
《Science & Sports》2022,37(7):564-571
ObjectiveObesity is the most common childhood illness in developed countries and its prevalence continues to increase. The objective was to analyze the influence of obesity on the motor coordination of children between 6 and 9 years old.Equipment and methodsA number of 52 pupils of both genders participated for evaluation of the prevalence of obesity using the measurement of the abdominal perimeter and the Body Mass Index (BMI) categorized as Normal-Weighted, Excess Weight and Obesity. The assessment of motor coordination was performed by the KTK test. SPSS (version 19.0) was used for statistical purposes.ResultsGirls had lower levels of performance rather than boys, and the pupils presented worse levels of motor performance as the age progressed. Regarding the prevalence of obesity, the two-gender obtained high mean values for the Normal-weighted category, whereas 25% is overweight. Regarding the level of motor coordination, 57.7% of the pupils had Normal Coordination and 40.4% had coordinative difficulties. Pupils with higher values of BMI and abdominal perimeter obtains lower results of motor coordination.  相似文献   
40.
Background/objectivesThis study aimed to examine the variations of circadian activity rhythm of children according to objective body mass index (BMI) values, using a novel statistical framework (ie, Functional Linear Modeling, FLM), separately for school- and weekend days.MethodsA total of 107 participants (60 females; mean age: 10.25 ± 0.48 years) wore an actigraph for seven days during a regular school-week. While valid actigraphic data during school days were available for each of these children, this number decreased to 53 (31 females; mean age: 10.28 ± 0.51 years) during weekend days.ResultsExamining the school days, significantly higher motor activity in participants with higher BMI was observed from around 4:00 a.m. to 6:00 a.m., with a peak about 5:00 a.m. On the contrary, applying the FLM to the weekend days actigraphic data, no significantly different variation of circadian activity rhythm was observed, according to BMI.ConclusionsIn this specific sample of children, during school days, higher BMI is associated with higher activity level in a specific time window in the second half of nocturnal sleep. The lack of significant findings during weekend days could be explained because of higher variability of get-up time and/or the reduced sample size. Future longitudinal studies could explore if the higher motor activity in that specific time window qualifies as a predictive marker of the development of overweight and obesity. If so, early preventive strategies directed towards those at higher risk could be effectively implemented.  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