全文获取类型
收费全文 | 471434篇 |
免费 | 39497篇 |
国内免费 | 15673篇 |
专业分类
耳鼻咽喉 | 4490篇 |
儿科学 | 13328篇 |
妇产科学 | 6532篇 |
基础医学 | 65218篇 |
口腔科学 | 9952篇 |
临床医学 | 43187篇 |
内科学 | 79164篇 |
皮肤病学 | 7562篇 |
神经病学 | 33227篇 |
特种医学 | 18119篇 |
外国民族医学 | 104篇 |
外科学 | 52329篇 |
综合类 | 52223篇 |
现状与发展 | 68篇 |
一般理论 | 2篇 |
预防医学 | 25653篇 |
眼科学 | 7335篇 |
药学 | 56257篇 |
132篇 | |
中国医学 | 13910篇 |
肿瘤学 | 37812篇 |
出版年
2023年 | 5950篇 |
2022年 | 8933篇 |
2021年 | 18732篇 |
2020年 | 14840篇 |
2019年 | 20621篇 |
2018年 | 15889篇 |
2017年 | 15347篇 |
2016年 | 16897篇 |
2015年 | 20619篇 |
2014年 | 33081篇 |
2013年 | 32571篇 |
2012年 | 33800篇 |
2011年 | 33747篇 |
2010年 | 29803篇 |
2009年 | 29113篇 |
2008年 | 26964篇 |
2007年 | 25494篇 |
2006年 | 22156篇 |
2005年 | 16980篇 |
2004年 | 12051篇 |
2003年 | 10352篇 |
2002年 | 8090篇 |
2001年 | 6938篇 |
2000年 | 5943篇 |
1999年 | 4740篇 |
1998年 | 4098篇 |
1997年 | 3894篇 |
1996年 | 3426篇 |
1995年 | 3590篇 |
1994年 | 3306篇 |
1993年 | 2767篇 |
1992年 | 2624篇 |
1991年 | 2381篇 |
1990年 | 2165篇 |
1989年 | 1972篇 |
1988年 | 1796篇 |
1987年 | 1594篇 |
1986年 | 1506篇 |
1985年 | 2862篇 |
1984年 | 2965篇 |
1983年 | 2145篇 |
1982年 | 2350篇 |
1981年 | 2105篇 |
1980年 | 1801篇 |
1979年 | 1559篇 |
1978年 | 1163篇 |
1977年 | 1103篇 |
1976年 | 975篇 |
1975年 | 647篇 |
1974年 | 629篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
101.
《Journal of Clinical Orthopaedics and Trauma》2021,12(6):976-982
ObjectiveMultiple treatment options for acetabular fractures in geriatric patients exist. However, no large-scale studies have reported the outcomes of acute total hip arthroplasty (THA) in this patient population. We systematically evaluated all available evidence to characterize clinical outcomes, complications, and revisions of acute THA for acetabular fractures in geriatric patients.MethodsMeta-analysis of 21 studies of 430 acetabular fractures with mean follow-up of 44 months (range, 17−97 months). Two independent researchers searched and evaluated the databases of Ovid, Embase, and United States National Library of Medicine using a Boolean search string up to December 2019. Population demographics and complications, including presence of heterotopic ossification (HO), dislocation, infection, revision rate, neurological deficits, and venous thromboembolic event (VTE), were recorded and analyzed.ResultsWeighted mean Harris Hip Score was 83.3 points, and 20% of the patients had reported complications. The most common complication was HO, with a rate of 19.5%. Brooker grade III and IV HO rates were lower at 6.8%. Hip dislocation occurred at a rate of 6.1%, 4.1% of patients developed VTE, deep infection occurred in 3.8%, and neurological complications occurred in 1.9%. Although the revision rate was described in most studies, we were unable to perform a survival analysis because the time to each revision was described in only a few studies. The revision rate was 4.3%.ConclusionsAcute THA is a viable option for treatment of acetabular fracture and can result in acceptable clinical outcomes and survivorship rates in older patients but with an associated complication rate of approximately 20%. Considering the limited treatment options, THA might be a viable alternative for appropriately selected patients. 相似文献
102.
目的 肝纤维化是一种由于反复肝损伤而导致肝组织细胞外基质过多沉积导致的疾病。缺氧损伤为肝损伤的一部分,缺氧诱导因子-1α(HIF-1α)是响应缺氧应激的关键转录因子,在肝纤维化组织和活化的肝星状细胞(HSC)表达显著增加。目前,通过对大量HIF-1α依赖性基因和信号通路的研究,确认这些基因及其通路的变化参与肝纤维化发展过程,并可能在肝纤维化发生发展过程中起关键作用。本文综述了HIF-1α相关的信号通路参与肝纤维化发展的相关机制,并对上游影响HIF-1α合成和降解的相关信号通路进行了阐述,为其作为新型治疗靶点的可能潜力提供依据。 相似文献
103.
目的研究小细胞肺癌(SCLC)患者外周血中辅助性T细胞1(Th1)、Th2、Th17及调节性T淋巴细胞(Treg)的表达情况,探讨其在SCLC进展中的作用。方法选择2016年1月至2018年4月本院收治的44例住院的SCLC患者(SCLC组)及24名健康者(对照组)作为研究对象。采用流式细胞法检测两组研究对象外周血中Th1、Th2、Th17及Treg细胞的表达情况,应用微量样本多指标流式蛋白定量技术(CBA)检测血清中的细胞因子IFN-γ、IL-17及IL-10的表达情况。结果SCLC组患者的外周血中Th1细胞、Th1/Th2、IFN-γ表达水平显著低于对照组,差异具有统计学意义(P<0.01)。SCLC组患者的外周血中Th2、Treg、Th17、Treg/Th17、IL-17、IL-10表达水平显著高于对照组,差异具有统计学意义(P<0.01)。结论SCLC患者外周血中Th1/Th2的降低、Treg/Th17的升高可能与SCLC的致病机理及预后密切相关,该结论将为SCLC的治疗提供新的思路。 相似文献
104.
Tetsuji Terazawa Takeshi Kato Masahiro Goto Katsuya Ohta Shingo Noura Hironaga Satake Yoshinori Kagawa Hisato Kawakami Hiroko Hasegawa Kazuhiro Yanagihara Tatsushi Shingai Ken Nakata Masahito Kotaka Masayuki Hiraki Ken Konishi Shiro Nakae Daisuke Sakai Yukinori Kurokawa Toshio Shimokawa Taroh Satoh 《The oncologist》2021,26(1):17-e47
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.
105.
106.
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
107.
《Clinical neurophysiology》2021,132(2):315-322
ObjectivePrevious studies have demonstrated voluntary movement alterations as well as motor cortex excitability and plasticity changes in patients with mild cognitive impairment (MCI). To investigate the pathophysiology of movement abnormalities in MCI, we tested possible relationships between movement abnormalities and primary motor cortex alterations in patients.MethodsFourteen amnestic MCI (aMCI) patients and 16 healthy controls were studied. Cognitive assessment was performed using clinical scales. Finger tapping was recorded by a motion analysis system. Transcranial magnetic stimulation was used to test the input/output curve of motor evoked potentials, intracortical inhibition, and short-latency afferent inhibition. Primary motor cortex plasticity was probed by theta burst stimulation. We investigated correlations between movement abnormalities, clinical scores, and cortical neurophysiological parameters.ResultsMCI patients showed less rhythmic movement but no other movement abnormalities. Cortical excitability measures were normal in patients, whereas plasticity was reduced. Movement rhythm abnormalities correlated with frontal dysfunction scores.ConclusionOur study in MCI patients demonstrated abnormal voluntary movement and plasticity changes, with no correlation between the two. Altered rhythm correlated with frontal dysfunction.SignificanceOur results contribute to the understanding of pathophysiological mechanisms of motor impairment in MCI. 相似文献
108.
《Diagnostic and interventional imaging》2021,102(10):629-639
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
109.
Kazuko Sakai Takayuki Takahama Mototsugu Shimokawa Koichi Azuma Masayuki Takeda Terufumi Kato Haruko Daga Isamu Okamoto Hiroaki Akamatsu Shunsuke Teraoka Akira Ono Tatsuo Ohira Toshihide Yokoyama Nobuyuki Yamamoto Kazuhiko Nakagawa Kazuto Nishio 《Molecular oncology》2021,15(1):126
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
110.
Syed S. Razi Joy A. Stephens-McDonnough Safi Haq Michael Fabbro Aliercy Nunez Sanchez Richard H. Epstein Nestor R. Villamizar Dao M. Nguyen 《The Journal of thoracic and cardiovascular surgery》2021,161(5):1689-1701
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