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   229363篇
  免费   12184篇
  国内免费   6455篇
耳鼻咽喉   2746篇
儿科学   8438篇
妇产科学   3720篇
基础医学   16434篇
口腔科学   4165篇
临床医学   27045篇
内科学   39372篇
皮肤病学   3059篇
神经病学   10798篇
特种医学   12194篇
外国民族医学   22篇
外科学   40014篇
综合类   20639篇
现状与发展   25篇
预防医学   14863篇
眼科学   4397篇
药学   24237篇
  86篇
中国医学   4487篇
肿瘤学   11261篇
  2023年   1909篇
  2022年   3798篇
  2021年   9125篇
  2020年   5362篇
  2019年   11290篇
  2018年   5938篇
  2017年   5197篇
  2016年   7154篇
  2015年   9969篇
  2014年   18750篇
  2013年   16129篇
  2012年   19662篇
  2011年   16474篇
  2010年   15160篇
  2009年   14709篇
  2008年   13307篇
  2007年   13276篇
  2006年   11198篇
  2005年   7458篇
  2004年   3810篇
  2003年   3274篇
  2002年   2567篇
  2001年   2081篇
  2000年   1825篇
  1999年   1176篇
  1998年   1566篇
  1997年   1410篇
  1996年   1173篇
  1995年   1244篇
  1994年   1193篇
  1993年   901篇
  1992年   1109篇
  1991年   987篇
  1990年   1032篇
  1989年   1004篇
  1988年   929篇
  1987年   820篇
  1986年   668篇
  1985年   1579篇
  1984年   1736篇
  1983年   1252篇
  1982年   1338篇
  1981年   1323篇
  1980年   1142篇
  1979年   981篇
  1978年   755篇
  1977年   759篇
  1976年   660篇
  1974年   454篇
  1973年   432篇
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
51.
Lessons Learned
  • Panitumumab monotherapy showed favorable efficacy and feasibility in the treatment of frail or elderly patients with RAS wild‐type unresectable colorectal cancer.
  • It is especially effective for left‐sided tumors; therefore, panitumumab as first‐line treatment could be an additional therapeutic option for frail elderly patients, particularly in those who are unsuitable for upfront oxaliplatin‐based or irinotecan‐based combination regimens.
BackgroundFirst‐line panitumumab monotherapy is expected to be well tolerated and improve survival in patients ineligible for intensive chemotherapy. However, its safety and efficacy in chemotherapy‐naïve frail or elderly patients with unresectable RAS wild‐type (WT) colorectal cancer (CRC) have not been studied. The aim of this phase II trial was to evaluate the efficacy and safety of panitumumab as first‐line treatment.MethodsWe conducted a multicenter phase II study on patients aged ≥76 years or ≥65 years considered unsuitable for intensive chemotherapy. Panitumumab 6 mg/kg of intravenous infusion was administered every 2 weeks. The primary endpoint was disease control rate (DCR). Secondary endpoints included progression‐free survival (PFS), overall survival (OS), response rate (RR), time to treatment failure (TTF), and incidence of grade 3 or 4 toxicities.ResultsThirty‐six patients (median age: 81 [range, 67–88] years) were enrolled between February 2017 and August 2018. Two patients were excluded from the analysis of efficacy: one from lack of image examination at baseline and the other from lack of a measurable lesion. Thirty‐three (91.6%) patients had a performance status (PS) of 0 or 1, whereas two (5.6%) patients and one (2.8%) patient had a PS of 2 and 3, respectively. Twenty‐eight patients (77.8%) had left‐sided CRC, whereas eight (22.2%) had right‐sided CRC. The RR was 50.0% (95% confidence interval [CI], 32.4–67.6), including three patients (8.8%) who had complete responses. A total of 26.5% had stable diseases, resulting in a DCR of 76.5% (90% CI, 61.5–87.7). The RR of patients with left‐ and right‐sided tumors was 65.4% (95% CI, 44.3–82.8) and 0.0% (95% CI, 0.0–36.9), respectively. Major grade 3 or 4 nonhematologic toxicities were rash (n = 6, 16.7%), hypomagnesemia (n = 4, 11.1%), fatigue (n = 3, 8.3%), paronychia (n = 2, 5.6%), and hyponatremia (n = 2, 5.6%). The only grade 3 hematologic toxicity was neutropenia (n = 1, 2.8%).ConclusionPanitumumab monotherapy showed favorable efficacy and feasibility in frail or elderly patients with RAS WT unresectable CRC. Survival analysis including OS, PFS, and TTF is currently in progress.  相似文献   
52.
53.
目的 分析内囊预警综合征(capsular warning syndrome,CWS)的临床特点、影像学特征及治疗预后,
以提高对此病的认识。
方法 回顾性分析战略支援部队特色医学中心神经内科2013年1月-2018年12月收住院治疗的CWS的
临床资料、影像学特征及治疗预后情况。
结果 共12例患者,男性8例(66.67%),中位年龄为60岁。高脂血症9例(75.0%),高血压8例
(66.67%),糖尿病4例(33.33%),肿瘤病史3例(25.0%)。纯运动性卒中4例(33.33%),运动伴有构
音障碍者4例(33.33%),运动及感觉性障碍3例(25.00%),纯感觉障碍1例(8.33%)。影像学示豆纹
动脉供血区新发脑梗死6例(50%)。所有患者给予口服双联抗血小板治疗,其中3例症状复发患者又
给予静脉溶栓和静脉抗血小板治疗。3个月随访,所有患者均未再出现症状发作,10例mRS评分为0
分,2例mRS评分分别为4分及3分。
结论 CWS主要表现为运动障碍,发作刻板,常见原因为动脉粥样硬化性。在本组病例中发现双重
抗血小板治疗有效,静脉溶栓效果不肯定。  相似文献   
54.
PurposeTo investigate the reproducibility of diffusion-weighted (DW) MRI and 18F-Fluorodeoxyglucose (18F-FDG)-Positron emission tomography/CT (PET/CT) in monitoring response to neoadjuvant chemotherapy in epithelial ovarian cancer.Materials and methodsTen women (median age, 67 years; range: 41.8–77.3 years) with stage IIIC-IV epithelial ovarian cancers were included in this prospective trial (NCT02792959) between 2014 and 2016. All underwent initial laparoscopic staging, four cycles of carboplatine-paclitaxel-based chemotherapy and interval debulking surgery. PET/CT and DW-MRI were performed at baseline (C0), after one cycle (C1) and before surgery (C4). Two nuclear physicians and two radiologists assessed five anatomic sites for the presence of ≥ 1 lesion. Target lesions in each site were defined and their apparent diffusion coefficient (ADC), maximal standardized uptake value (SUV-max), SUV-mean, SUL-peak, metabolic tumor volume (MTV) and total lesion glycolysis (TLG) were monitored (i.e., 10 patients × 5 sites × 3 time-points). Their relative early and late changes were calculated. Intra/inter-observer reproducibilities of qualitative and quantitative analysis were estimated with Kappa and intra-class correlation coefficients (ICCs).ResultsFor both modalities, inter- and intra-observer agreement percentages were excellent for initial staging but declined later for DW-MRI, leading to lower Kappa values for inter- and intra-observer variability (0.949 and 1 at C0, vs. 0.633 and 0.643 at C4, respectively) while Kappa values remained > 0.8 for PET/CT. Inter- and intra-observer ICCs were > 0.75 for SUV-max, SUL-peak, SUV-mean and their change regardless the time-point. ADC showed lower ICCs (range: 0.013–0.811). ANOVA found significant influences of the evaluation time, the measurement used (ADC, SUV-max, SUV-mean, SUV-max, SUL-peak, MTV or TLG) and their interaction on ICC values (P = 0.0023, P< 0.0001 and P =0.0028, respectively).ConclusionWhile both modalities demonstrated high reproducibility at baseline, only SUV-max, SUL-peak, SUV-mean and their changes maintained high reproducibility during chemotherapy.  相似文献   
55.
The WJOG8815L phase II clinical study involves patients with non‐small cell lung cancer (NSCLC) that harbored the EGFR T790M mutation, which confers resistance to EGFR tyrosine kinase inhibitors (TKIs). The purpose of this study was to assess the predictive value of monitoring EGFR genomic alterations in circulating tumor DNA (ctDNA) from patients with NSCLC that undergo treatment with the third‐generation EGFR‐TKI osimertinib. Plasma samples of 52 patients harboring the EGFR T790M mutation were obtained pretreatment (Pre), on day 1 of treatment cycle 4 (C4) or cycle 9 (C9), and at diagnosis of disease progression or treatment discontinuation (PD/stop). CtDNA was screened for EGFR‐TKI‐sensitizing mutations, the EGFR T790M mutation, and other genomic alterations using the cobas EGFR Mutation Test v2 (cobas), droplet digital PCR (ddPCR), and targeted deep sequencing. Analysis of the sensitizing—and T790M—EGFR mutant fractions (MFs) was used to determine tumor mutational burden. Both MFs were found to decrease during treatment, whereas rebound of the sensitizing EGFR MF was observed at PD/stop, suggesting that osimertinib targeted both T790M mutation‐positive tumors and tumors with sensitizing EGFR mutations. Significant differences in the response rates and progression‐free survival were observed between the sensitizing EGFR MF‐high and sensitizing EGFR MF‐low groups (cutoff: median) at C4. In conclusion, ctDNA monitoring for sensitizing EGFR mutations at C4 is suitable for predicting the treatment outcomes in NSCLC patients receiving osimertinib (Clinical Trial Registration No.: UMIN000022076).

Abbreviations

CIs
confidence intervals
ctDNA
circulating tumor DNA
ddPCR
droplet digital PCR
EGFR
epidermal growth factor receptor
MFs
mutant fractions
NGS
next‐generation sequencing
NSCLC
non‐small cell lung cancer
ORR
overall response rate
OS
overall survival
PD
progressive disease
PFS
progression‐free survival
PR
partial response
SD
stable disease
TKI
tyrosine kinase inhibitor
  相似文献   
56.
ObjectiveTo evaluate differences in postoperative pain control and opioids requirement in thoracic surgical patients following implementation of an Enhanced Recovery after Thoracic Surgery protocol with a comprehensive postoperative pain management strategy.Material and MethodsA retrospective analysis of a prospectively maintained database of patients undergoing pulmonary resections by robotic thoracoscopy or thoracotomy from January 1, 2017, to January 31, 2019, was conducted. Multimodal pain management strategy (opioid-sparing analgesics, infiltration of liposomal bupivacaine to intercostal spaces and surgical sites, and elimination of thoracic epidural analgesia use in thoracotomy patients) was implemented as part of Enhanced Recovery after Thoracic Surgery on February 1, 2018. Outcome metrics including patient-reported pain levels, in-hospital and postdischarge opioids use, postoperative complications, and length of stay were compared before and after protocol implementation.ResultsIn total, 310 robotic thoracoscopy and 62 thoracotomy patients met the inclusion criteria. This pain management strategy was associated with significant reduction of postoperative pain in both groups with an overall reduction of postoperative opioids requirement. Median in-hospital opioids use (morphine milligram equivalent per day) was reduced from 30 to 18.36 (P = .009) for the robotic thoracoscopy group and slightly increased from 15.48 to 21.0 (P = .27) in the thoracotomy group. More importantly, median postdischarge opioids prescribed (total morphine milligram equivalent) was significantly reduced from 480.0 to 150.0 (P < .001) and 887.5 to 150.0 (P < .001) for the thoracoscopy and thoracotomy groups, respectively. Similar short-term perioperative outcomes were observed in both groups before and following protocol implementation.ConclusionsImplementation of Enhanced Recovery after Thoracic Surgery allows safe elimination of epidural use, better pain control, and less postoperative opioids use, especially a drastic reduction of postdischarge opioid need, without adversely affecting outcomes.  相似文献   
57.
目的:探讨盆腔腹膜关闭技术在腹腔镜低位直肠癌根治术应用的疗效。方法:回顾性分析2012年1月至2016年5月我院54例腹腔镜低位直肠癌根治术中行盆底腹膜关闭患者和57例未行盆底腹膜关闭患者的临床资料。结果:盆腔腹膜关闭组与盆腔腹膜未关闭组在手术时间、术中出血量、肛门排气时间、术后进食时间以及盆腔引流管拔除时间等方面差异均无统计学意义(P>0.05)。盆腔腹膜关闭组中8例患者发生短期并发症;6例患者发生中期并发症;14例患者发生远期并发症,均为肠梗阻。盆腔腹膜未关闭组中31例患者发生短期并发症,28例患者发生中期并发症,36例患者发生远期并发症。所有患者均治疗好转。Coxs回归模型分析提示,盆腔腹膜是否关闭是腹腔镜低位直肠癌根治术患者术后生存的独立指标。结论:腹腔镜Miles术中行盆底腹膜关闭安全可行,具有临床实用价值。  相似文献   
58.
59.
目的:基于原发肿瘤及淋巴结CT特征建立评分模型预测食管鳞癌患者喉返神经旁淋巴结(RLN-LN)转移风险。方法:回顾性收集2014年1月至2019年12月于北京大学肿瘤医院行食管癌根治术并清扫RLN-LN的92例食管鳞癌患者。根据术后淋巴结病理结果分为RLN-LN转移组(n=37)和非转移组(n=55)。评估术前CT图像,记录食管癌患者年龄、性别、分化程度、肿瘤位置、肿瘤大小(肿瘤长度、肿瘤厚度、厚度/长度)、RLN-LN大小(淋巴结短径、长径、短径/多平面重建(MPR)最长径]。采用多元logistic回归筛选独立预测因子并建立评分模型,采用ROC曲线评估评分模型及独立预测因子诊断RLN-LN转移的效能,采用Z检验比较曲线下面积(AUC)的差异。应用Hosmer-Lemeshow检验和校准曲线评估模型拟合度。结果:肿瘤位置、肿瘤长度、RLN-LN短径、短径/MPR最长径是RLN-LN转移的独立预测因子,其诊断RLN-LN转移的AUC分别为0.586、0.705、0.831、0.777。基于以上4个CT特征建立评分模型,评分模型诊断RLN-LN转移的AUC为0.903(95%CI 0.846~0.959),优于各单一CT特征(Z=5.812,P<0.001;Z=2.161,P=0.030;Z=2.929,P=0.003;Z=4.052,P<0.001)。拟合优度Hosmer-Lemeshow检验结果显示P=0.555,校准曲线提示评分模型预测RLN-LN转移风险与实际转移风险之间具有良好的一致性。结论:基于CT图像的评分模型有助于食管鳞癌RLN-LN转移状态危险分层。  相似文献   
60.
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