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   58109篇
  免费   4984篇
  国内免费   2072篇
耳鼻咽喉   658篇
儿科学   676篇
妇产科学   1141篇
基础医学   8806篇
口腔科学   1500篇
临床医学   5124篇
内科学   10761篇
皮肤病学   1060篇
神经病学   4116篇
特种医学   1935篇
外国民族医学   14篇
外科学   7901篇
综合类   5117篇
一般理论   5篇
预防医学   3367篇
眼科学   1616篇
药学   5438篇
  1篇
中国医学   1080篇
肿瘤学   4849篇
  2023年   291篇
  2022年   378篇
  2021年   770篇
  2020年   596篇
  2019年   824篇
  2018年   1305篇
  2017年   1066篇
  2016年   1052篇
  2015年   1236篇
  2014年   1660篇
  2013年   1881篇
  2012年   2618篇
  2011年   2603篇
  2010年   1551篇
  2009年   1497篇
  2008年   2155篇
  2007年   2322篇
  2006年   2087篇
  2005年   1805篇
  2004年   1590篇
  2003年   1570篇
  2002年   1471篇
  2001年   4824篇
  2000年   4739篇
  1999年   4096篇
  1998年   1427篇
  1997年   1069篇
  1996年   631篇
  1995年   543篇
  1994年   495篇
  1993年   437篇
  1992年   1971篇
  1991年   1709篇
  1990年   1550篇
  1989年   1524篇
  1988年   1321篇
  1987年   1212篇
  1986年   1081篇
  1985年   914篇
  1984年   595篇
  1983年   472篇
  1982年   252篇
  1981年   184篇
  1980年   141篇
  1979年   283篇
  1978年   82篇
  1974年   82篇
  1973年   102篇
  1972年   82篇
  1970年   74篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的比较飞秒激光制瓣准分子激光原位角膜磨镶术(FS-LASIK)、全飞秒激光小切口角膜基质透镜取出术(SMILE)和有晶状体眼后房型人工晶状体(ICL V4c)植入术三者矫正中低度近视的效果。方法采用回顾性研究。以惠州爱尔眼科医院2019年6月至2020年4月矫正中低度近视120例(120眼)作为研究对象,受术者分为FS-LASIK组、SMILE组及ICL组,每组40例(40眼),各组分别接受相应的手术,术后随访3个月比较其矫正效果。结果术后1个月及3个月,3组间视力及有效性指数对比差异无统计学意义(P>0.05);ICL组安全性指数高于SMILE组及FS-LASIK组(P<0.05)。术后3个月FS-LASIK组的三叶草像差、彗差和球差出现明显变化,而SMILE组的变化较小,ICL组变化最小(P<0.05)。结论对中低度近视FS-LASK、SMILE及ICL植入术三者均有确切疗效,而ICL V4c植入术的安全性最高,患者的视觉质量最好。  相似文献   
2.
Peng  L. Q.  Wu  X. X.  Chen  G.  Cai  H. Z.  Tang  Y. P.  Chen  Q. Y.  Chen  X. Y. 《Bulletin of experimental biology and medicine》2022,173(3):335-340
Bulletin of Experimental Biology and Medicine - This study aimed to explore the effects of Wenyang Zhenshuai granules (WZG) on the morphology of cardiomyocytes, cell viability, and the expression...  相似文献   
3.
Journal of Digital Imaging - Scoliosis is a condition of abnormal lateral spinal curvature affecting an estimated 2 to 3% of the US population, or seven million people. The Cobb angle is the...  相似文献   
4.
兰淑青  毕煜玲  阳钦   《四川医学》2022,43(5):466-471
目的 探讨特发性肺纤维化(IPF)患者慢性肺部感染(CPI)的发生特点及病原学特征。方法 选择我院收治的195例IPF患者为研究对象,将患者分为四组,A组:IPF诊断时CPI阴性且随访期间未出现CPI;B组:IPF诊断为CPI阴性,但在随访期间出现CPI;C组:IPF诊断为CPI阳性,但在随访期间未出现另一种CPI;D组:IPF诊断为CPI阳性,并在随访期间出现另一种CPI。记录患者基线资料及生存状态。结果 在IPF诊断时,31例患者出现CPI(C+D组),在164例诊断IPF时没有CPI的患者(A+B组)中,28例患者(B组)在平均6.1年(0.01~15.00年)的随访期内出现了CPI。在这28例B组患者中,25例(89.29%)只有1种病原体,3例(10.71%)有2种病原体,2例患者发生了二次感染。检出结核分枝杆菌14例(45.16%),禽类分支杆菌复合体10例(32.26%),曲霉属真菌5例(16.13%),诺卡氏菌属1例(3.23%),禽类分支杆菌复合体及曲霉属真菌混合感染1例(3.23%)。多变量COX分析发现,BMI<21 kg/m2、PaO2<70 mmHg、KL-6≥2000 U/ml是影响患者CPI发生的独立性危险因素。Log-rank检验显示,有CPI发展组和无CPI发展组患者的生存率差异无统计学意义(P=0.416)。结论 结核分枝杆菌、非结核分枝杆菌、曲霉菌和诺卡氏菌是CPI患者的最常见病原菌。在IPF随访过程中,尤其是BMI<21 kg/m2、PaO2<70 mmHg、KL-6≥2000 U/ml的患者,临床医生应注意CPI的变化情况。  相似文献   
5.
冯碧  许瑞华 《现代肿瘤医学》2019,(10):1761-1765
目的:探讨三联预康复策略在肝癌腹腔镜肝切除术中的应用价值。方法:选取2015年1月至2018年1月四川大学华西医院胆道外科收治的120例行腹腔镜肝切除术的肝癌患者,按随机数字表法分为观察组及对照组各60例。观察组在门诊收治当日开始三联预康复策略干预,干预时间约2~4周;对照组予以常规肝癌腹腔镜肝切除术术前准备。于干预前、术前1天及术后4周分别记录六分钟步行距离(6MWT)、医院焦虑抑郁量表(HADS)评分、健康调查简表(SF-36)评分及检测血清白蛋白(ALB)、前白蛋白(PA)、转铁蛋白(TRF)水平。结果:术前1天,观察组6MWT、血清ALB、PA、TRF水平高于干预前(P<0.05);对照组6MWT、血清ALB、PA、TRF水平与干预前差异无统计学意义(P>0.05);术后4周,观察组6MWT、血清ALB、PA、TRF水平与干预前差异无统计学意义(P>0.05);对照组6MWT、血清ALB、PA、TRF水平低于干预前(P<0.05);术前1天、术后4周观察组HADS评分低于干预前,SF-36评分高于干预前(P<0.05);对照组HADS、SF-36评分与干预前差异无统计学意义(P>0.05);术前1天、术后4周,观察组6MWT、SF-36评分、血清ALB、PA、TRF水平高于对照组,HADS评分低于对照组(P<0.05)。结论:三联预康复策略应用于肝癌腹腔镜肝切除术可明显改善患者围术期活动能力、心理状态及营养状况,加速患者术后恢复。  相似文献   
6.
目的:探讨应用聚乙二醇化重组人粒细胞集落刺激因子(PEG-rhG-CSF)对卵巢癌、宫颈癌化疗患者粒细胞减少的影响,并观察不良反应。方法:选择本院2015年4月至2017年6月卵巢癌、宫颈癌患者136例,随机分为对照组(68例)和研究组(68例),对照组应用rhG-CSF,研究组应用PEG-rhG-CSF,两组均化疗两个周期,评估患者两个周期不同时间血常规绝对中性粒细胞计数值(ANC)水平、ANC不同数量发生率和持续时间以及不良反应。结果:研究组患者第一个化疗周期第5 d、第7 d、第10 d和第14 d 及第二个化疗周期第3 d、第5 d、第7 d、第10 d和第14 d血ANC分别为(3.19±0.32)×109/L、(1.93±0.35)×109/L、(2.08±0.39)×109/L、(2.11±0.36)×109/L和(2.79±0.40)×109/L、(2.44±0.33)×109/L、(1.68±0.34)×109/L、(1.71±0.37)×109/L、(1.92±0.34)×109/L,均高于对照组,差异具有统计学意义(P<0.05)。研究组患者第一个和第二个化疗周期ANC<1.5×109/L、ANC<1.0×109/L和ANC<0.5×109/L发生率分别为23.53%(16/68)、8.82%(6/68)、2.94%(2/68)和29.41%(20/68)、10.29%(7/68)、5.88%(4/68),均低于对照组,差异具有统计学意义(P<0.05)。研究组患者第一个和第二个化疗周期ANC<1.5×109/L、ANC<1.0×109/L和ANC<0.5×109/L持续时间分别为(3.50±0.18)d、(2.17±0.23)d、(2.06±0.29)d和(4.08±0.22)d、(4.62±0.29)d、(4.11±0.24)d,均短于对照组,差异具有统计学意义(P<0.05)。研究组中、重度不良反应总发生率为10.29%(7/68),低于对照组23.53%(16/68),差异有统计学意义(P<0.05)。结论:应用PEG-rhG-CSF能够有效预防卵巢癌、宫颈癌化疗患者粒细胞减少,不良反应显著降低,值得临床推广应用。  相似文献   
7.
AimsAmong all malignancies, the use of radiotherapy incurs the highest survival benefit within cervical cancers. Radiotherapy, however, remains underutilised for cervical cancers within the Brazilian public health system (BPHS). The objective of this study was to estimate the potential health and monetary benefits for universal access to radiotherapy and chemoradiotherapy (CRT) for untreated cervical cancer patients in the BPHS.Materials and methodsUsing 2016 data on Brazilian cervical cancer incidence and availability of radiotherapy/CRT in the BPHS, the number of cancer deaths due to radiotherapy/CRT underutilisation was estimated. The incremental effectiveness was calculated by life-year gain. The indirect costs from mortality-related productivity loss (MRPL) were estimated based on life expectancy, wage and labour force participation rate. MRPL was compared with direct medical costs after being adjusted to 2016 US dollars. This study was conducted from the payer's perspective; both costs and effectiveness were discounted at a rate of 3%. The incremental cost-effectiveness ratio (ICER) was calculated to determine the cost-effectiveness of radiotherapy for cervical cancer in Brazil. One-way sensitivity analyses were carried out to assess the robustness of the model.ResultsThe total number of life-years lost due to lack of universal access to radiotherapy and CRT per year were 27 199 and 31 627, respectively. The annual cost to match the radiotherapy gap was $10.5 million, with an additional cost of $3 million to close the CRT gap. The mean years of potential life lost per death was 20.5. The cost per life saved was $7942 for radiotherapy alone (ICER $388/life-year) and $8774 for CRT (ICER $429/life-year). MRPL due to shortage of radiotherapy and CRT were $59 million and $69 million, respectively.ConclusionProviding universal access to radiotherapy/CRT for cervical cancer patients in the BPHS is highly cost-effective and should be prioritised as an impactful public health initiative.  相似文献   
8.

Objectives

Short successive periods of skeletal muscle disuse have been suggested to substantially contribute to the observed loss of skeletal muscle mass over the life span. Hospitalization of older individuals due to acute illness, injury, or major surgery generally results in a mean hospital stay of 5 to 7 days, during which the level of physical activity is strongly reduced. We hypothesized that hospitalization following elective total hip arthroplasty is accompanied by substantial leg muscle atrophy in older men and women.

Design and participants

Twenty-six older patients (75 ± 1 years) undergoing elective total hip arthroplasty participated in this observational study.

Measurements

On hospital admission and on the day of discharge, computed tomographic (CT) scans were performed to assess muscle cross-sectional area (CSA) of both legs. During surgery and on the day of hospital discharge, a skeletal muscle biopsy was taken from the m. vastus lateralis of the operated leg to assess muscle fiber type–specific CSA.

Results

An average of 5.6 ± 0.3 days of hospitalization resulted in a significant decline in quadriceps (?3.4% ± 1.0%) and thigh muscle CSA (?4.2% ± 1.1%) in the nonoperated leg (P < .05). Edema resulted in a 10.3% ± 1.7% increase in leg CSA in the operated leg (P < .05). At hospital admission, muscle fiber CSA was smaller in the type II vs type I fibers (3326 ± 253 μm2 vs 4075 ± 279 μm2, respectively; P < .05). During hospitalization, type I and II muscle fiber CSA tended to increase, likely due to edema in the operated leg (P = .10).

Conclusions

Six days of hospitalization following elective total hip arthroplasty leads to substantial leg muscle atrophy in older patients. Effective intervention strategies are warranted to prevent the loss of muscle mass induced by short periods of muscle disuse during hospitalization.  相似文献   
9.
10.
As inherited genetic alterations are important etiological factors causing endometrial cancer (EC), our study aimed to outline the ethnic-related prevalence and the associated clinical and biological characteristics of germline mutations in cancer predisposition genes in Chinese EC patients. One hundred ninety-eight Chinese EC patients were screened for germline mutations in a panel of cancer susceptibility genes using next-generation sequencing combined with multiplex ligation-dependent probe amplification. First, we found that among patients under 50 years of age, 26% (18/69) carried germline genetic mutations, all involving mismatch repair (MMR) genes except for one mutation affecting BRCA1. Second, when we focused on Lynch syndrome (LS) with additional selected patients, 45 were identified to carry pathogenic mutations in MMR genes, with a higher frequency found in MSH2 and MSH6. We found that age at onset, personal and familial history together with immunohistochemical assay results were the most useful criteria for the diagnosis of LS although limitations in routine practice and the sensitivity and specificity of each parameter should be taken into account. One pathogenic mutation in the PALB2 gene was detected in a patient with no breast cancer in her family. Interestingly, we identified a family carrying pathogenic variant in both PMS2 and BRCA1 genes with distinct clinical phenotypes. Multigene panel testing should be recommended to patients based on their clinical information and tumor phenotype. Our study also showed the genetic complexity in EC, which requires further investigations.  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