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   15305篇
  免费   992篇
  国内免费   152篇
耳鼻咽喉   200篇
儿科学   351篇
妇产科学   172篇
基础医学   1905篇
口腔科学   232篇
临床医学   1254篇
内科学   3982篇
皮肤病学   306篇
神经病学   1043篇
特种医学   627篇
外科学   2178篇
综合类   203篇
一般理论   21篇
预防医学   1094篇
眼科学   363篇
药学   918篇
中国医学   60篇
肿瘤学   1540篇
  2023年   96篇
  2022年   198篇
  2021年   344篇
  2020年   236篇
  2019年   332篇
  2018年   376篇
  2017年   353篇
  2016年   396篇
  2015年   441篇
  2014年   556篇
  2013年   693篇
  2012年   1128篇
  2011年   1087篇
  2010年   669篇
  2009年   525篇
  2008年   1011篇
  2007年   1110篇
  2006年   982篇
  2005年   1042篇
  2004年   895篇
  2003年   971篇
  2002年   907篇
  2001年   147篇
  2000年   127篇
  1999年   140篇
  1998年   174篇
  1997年   182篇
  1996年   145篇
  1995年   135篇
  1994年   93篇
  1993年   81篇
  1992年   78篇
  1991年   63篇
  1990年   58篇
  1989年   49篇
  1988年   43篇
  1987年   37篇
  1986年   29篇
  1985年   39篇
  1984年   39篇
  1983年   38篇
  1982年   37篇
  1981年   29篇
  1980年   31篇
  1979年   24篇
  1978年   24篇
  1977年   31篇
  1976年   18篇
  1973年   19篇
  1966年   18篇
排序方式: 共有10000条查询结果,搜索用时 23 毫秒
191.
Aims/IntroductionThe Canagliflozin and Renal Events in Diabetes with Established Nephropathy Clinical Evaluation (CREDENCE) trial has shown the effects of canagliflozin on preventing clinically important kidney outcomes in patients with type 2 diabetes mellitus and chronic kidney disease; however, not many Japanese patients were included in the trial. The present study evaluated the efficacy and safety of canagliflozin in Japanese chronic kidney disease patients with type 2 diabetes mellitus.Materials and MethodsIn this multicenter, randomized, double‐blind, placebo‐controlled, parallel‐group, phase III study, chronic kidney disease patients with type 2 diabetes mellitus were randomly assigned to receive either 100 mg canagliflozin or a matching placebo once daily for 104 weeks. The primary efficacy end‐point was the incidence of a 30% decline in estimated glomerular filtration rate.ResultsOverall, 308 patients were randomized to the canagliflozin (n = 154) and placebo (n = 154) groups. The incidence of a 30% decline in estimated glomerular filtration rate at week 104 was 18.2% and 29.5%, respectively, and the point estimate of the intergroup difference (placebo − canagliflozin) was 11.3% (95% confidence interval 1.2–21.5, P = 0.029), which was significant. The overall incidence of adverse events was similar in the two groups.ConclusionsThis study suggests that canagliflozin safely reduces the risk of end‐stage renal disease in Japanese chronic kidney disease patients with type 2 diabetes mellitus.  相似文献   
192.
193.
194.
195.
The purpose of this study was to investigate factors predicting the sensitivity to cabazitaxel therapy in metastatic castration‐resistant prostate cancer (mCRPC) patients with phosphatase and tensin homolog deleted from chromosome 10 (PTEN) alterations. This single‐institution, retrospective study included 12 mCRPC patients with PTEN alterations who had received cabazitaxel therapy. Five patients (41%) responded to cabazitaxel therapy with a prostate‐specific antigen (PSA) level decline of ≥30% from baseline, and all of them had responded to prior docetaxel therapy with a PSA decline of ≥30%. None of the patients with a poor response to prior docetaxel therapy responded well to cabazitaxel therapy. Of the seven patients who did not respond to cabazitaxel and whose PSA declined from baseline was <30%, five (71%) were also refractory to prior docetaxel therapy. The PSA responses to docetaxel and cabazitaxel were significantly correlated (p = 0.027). Kaplan–Meier analysis revealed that progression‐free survival (PFS) for cabazitaxel was significantly shorter for prior docetaxel nonresponders (3.3 versus 9.1 months, p = 0.028). Multivariate analysis revealed that a poor response to prior docetaxel (PSA decline < 30%) (hazard ratio [HR] = 6.382, 95% confidence interval [CI] 1.172–34.750, p = 0.032) and baseline PSA of ≥20 ng/ml (HR = 33.584, 95% CI 2.332–483.671, p = 0.010) were independent prognostic factors for PFS with cabazitaxel therapy. These results demonstrate cross‐resistance between docetaxel and cabazitaxel. The response to prior docetaxel therapy can influence the sensitivity to cabazitaxel therapy in mCRPC patients with PTEN alterations.  相似文献   
196.
Follicular lymphoma (FL) has a high degree of heterogeneity both clinically and molecularly. Early treatment failure (ETF), progression or relapse within 24 months of frontline immunochemotherapy is associated with a poor prognosis in FL. However, the clinical utility of ETF at diagnosis is limited. The maximum standardized uptake value (SUVmax) is a metabolic parameter for positron emission tomography/computed tomography (PET/CT); nevertheless, the relationship between SUVmax and ETF remains unclear. Thus, identifying early biomarkers that incorporate SUVmax and other clinical correlative variables could be helpful in identifying patients at high risk of ETF. A nomogram consisted of three independent variables, including SUVmax ≥ 12, beta-2 microglobulin > 3 mg/L, and Ki67 > 40%, was established to predict ETF in 127 patients with grade 1, 2, or 3a FL from the First Hospital of Jilin University (training cohort) and was validated using data from the Duke University Medical Center (validation cohort, n=95). The nomogram demonstrated prognostic accuracy in predicting ETF (sensitivity 70.8% and specificity 83.5% in the training cohort; sensitivity 84.2% and specificity 68.4% in the validation cohort). The patients were stratified into three groups: low-, intermediate-, and high-risk. In the training cohort, the corresponding 5-year progression-free survival (PFS) rates were 81.7%, 73.4%, and 34.9%, and the 5-year overall survival (OS) rates were 97.4%, 87.4%, and 62.3%, respectively. In the validation cohort, the 5-year PFS rates were 77.7%, 52.9%, and 34.8%, and the 5-year OS rates were 96.4%, 94.1%, and 73.7%, respectively. This was the first study to use a nomogram with SUVmax to predict ETF in FL to identify a subset of patients who might benefit from individualized targeted therapy.  相似文献   
197.
This study focused on everyday furniture and computers used in work from home and aimed to investigate how improper postures increase the risk of musculoskeletal disorders using different combinations of tables, chairs, and computers. Twenty-one healthy participants were asked to perform a visual display terminal task for 30 minutes in a laboratory modeled on the work from home concept. Seven experimental conditions were set up according to the different combinations of desks, chairs, and computers. Three-dimensional body posture was measured using a magnetic tracking device. The results showed that when using a low table, floor chair, and laptop computer, the body posture above the hip was similar to that when using a dining table, chair, and desktop computer. When using a sofa, and tablet computers, or laptop computer, severe neck flexion, which is stressful to the neck, was observed. Moreover, excessive low back flexion was observed when using a floor cushion and laptop computer. We suggest that computer work while sitting on a sofa or floor cushion without a backrest is harmful to the neck and low back.  相似文献   
198.
BackgroundThe strength, assistance in walking, rising from a chair, climbing stairs, and falls questionnaire (SARC-F) is widely used for screening sarcopenia. We aimed to examine the association of SARC-F scores with the measurements of quality of life and activity in patients with idiopathic pulmonary fibrosis (IPF).MethodsThis cross-sectional pilot study prospectively enrolled 54 patients with IPF who completed pulmonary function tests, the 6-min walk test, the chronic obstructive pulmonary disease assessment test (CAT), St. George’s Respiratory Questionnaire (SGRQ), the Hospital Anxiety and Depression Scale, and a daily step count. The daily step count was measured continuously for 7 consecutive days using a tri-axis accelerometer device.ResultsThe mean age was 73.6±7.9 years and the mean percent predicted forced vital capacity was 80.4%±15.6%. The median [interquartile range] SARC-F score, SGRQ total scores, and CAT scores were 2 [1–3.25], 28.8 [14.4–46.9], and 13 [7–22], respectively. SARC-F scores were correlated with the percent predicted forced vital capacity (r=−0.51, P<0.001), CAT score (r=0.57, P<0.001), SGRQ total score (r=0.77, P<0.001), Hospital Anxiety and Depression Scale anxiety score (r=0.31, P=0.025), and Hospital Anxiety and Depression Scale depression score (r=0.28, P=0.041). Linear regression analyses revealed that the 6-minute walk test (6MWT) (standardized β=0.33, P=0.011) and SARC-F score (standardized β=−0.39, P=0.005), but not the CAT score and SGRQ total score, were significant predictors for daily step count.ConclusionsSARC-F scores were correlated with health status and daily activity in patients with IPF. Further studies are warranted to validate the utility of the SARC-F in patients with IPF.  相似文献   
199.
Study ObjectivesWe investigated associations between inflammatory profiles/clusters and sleep measures in people living with HIV and demographically-/lifestyle-similar HIV-negative controls in the Pharmacokinetic and clinical Observations in PeoPle over fiftY (POPPY)-Sleep substudy.MethodsPrimary outcome was insomnia (Insomnia Severity Index [ISI]>15). Secondary sleep outcomes included 7-day actigraphy (e.g. mean/standard deviation of sleep duration/efficiency), overnight oximetry (e.g. oxygen desaturation index [ODI]) and patient-reported measures (Patient-Reported Outcomes Measurement Information System (PROMIS) sleep questionnaires). Participants were grouped using Principal Component Analysis of 31 biomarkers across several inflammatory pathways followed by cluster analysis. Between-cluster differences in baseline characteristics and sleep outcomes were assessed using Kruskal–Wallis/logistic regression/Chi-squared/Fisher’s exact tests.ResultsOf the 465 participants included (74% people with HIV, median [interquartile range] age 54 [50–60] years), only 18% had insomnia and secondary sleep outcomes suggested generally good sleep (e.g. ODI 3.1/hr [1.5–6.4]). Three clusters with distinct inflammatory profiles were identified: “gut/immune activation” (n = 47), “neurovascular” (n = 209), and “reference” (relatively lower inflammation; n = 209). The “neurovascular” cluster included higher proportions of people with HIV, obesity (BMI>30 kg/m2), and previous cardiovascular disease, mental health disorder, and arthritis of knee/hip relative to the other two clusters. No clinically relevant between-cluster differences were observed in proportions with insomnia (17%, 18%, 20%) before (p = .76) or after (p = .75) adjustment for potential confounders. Few associations were observed among actigraphy, oximetry, and PROMIS measures.ConclusionsAlthough associations could exist with other sleep measures or biomarker types not assessed, our findings do not support a strong association between sleep and inflammation in people with HIV.  相似文献   
200.
Due to low imaging contrast, a widely-used cone-beam computed tomography-guided small animal irradiator is less adept at localizing in vivo soft tissue targets. Bioluminescence tomography (BLT), which combines a model of light propagation through tissue with an optimization algorithm, can recover a spatially resolved tomographic volume for an internal bioluminescent source. We built a novel mobile BLT system for a small animal irradiator to localize soft tissue targets for radiation guidance. In this study, we elaborate its configuration and features that are indispensable for accurate image guidance. Phantom and in vivo validations show the BLT system can localize targets with accuracy within 1 mm. With the optimal choice of threshold and margin for target volume, BLT can provide a distinctive opportunity for investigators to perform conformal biology-guided irradiation to malignancy.  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