全文获取类型
收费全文 | 254880篇 |
免费 | 60402篇 |
国内免费 | 14241篇 |
专业分类
耳鼻咽喉 | 2873篇 |
儿科学 | 5857篇 |
妇产科学 | 2237篇 |
基础医学 | 35979篇 |
口腔科学 | 8208篇 |
临床医学 | 36470篇 |
内科学 | 48478篇 |
皮肤病学 | 9081篇 |
神经病学 | 21899篇 |
特种医学 | 8850篇 |
外国民族医学 | 119篇 |
外科学 | 31413篇 |
综合类 | 35136篇 |
现状与发展 | 57篇 |
一般理论 | 29篇 |
预防医学 | 16973篇 |
眼科学 | 6454篇 |
药学 | 25146篇 |
142篇 | |
中国医学 | 12490篇 |
肿瘤学 | 21632篇 |
出版年
2024年 | 679篇 |
2023年 | 3056篇 |
2022年 | 7624篇 |
2021年 | 10868篇 |
2020年 | 12099篇 |
2019年 | 16405篇 |
2018年 | 16184篇 |
2017年 | 16850篇 |
2016年 | 17169篇 |
2015年 | 19935篇 |
2014年 | 21823篇 |
2013年 | 21043篇 |
2012年 | 17233篇 |
2011年 | 18490篇 |
2010年 | 17991篇 |
2009年 | 12608篇 |
2008年 | 11483篇 |
2007年 | 10405篇 |
2006年 | 10251篇 |
2005年 | 9820篇 |
2004年 | 7272篇 |
2003年 | 7196篇 |
2002年 | 6469篇 |
2001年 | 5704篇 |
2000年 | 5316篇 |
1999年 | 4798篇 |
1998年 | 3012篇 |
1997年 | 2962篇 |
1996年 | 2252篇 |
1995年 | 2131篇 |
1994年 | 1852篇 |
1993年 | 1132篇 |
1992年 | 1423篇 |
1991年 | 1130篇 |
1990年 | 980篇 |
1989年 | 870篇 |
1988年 | 749篇 |
1987年 | 628篇 |
1986年 | 556篇 |
1985年 | 404篇 |
1984年 | 180篇 |
1983年 | 154篇 |
1982年 | 88篇 |
1981年 | 90篇 |
1980年 | 62篇 |
1979年 | 70篇 |
1977年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1935年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
1.
2.
目的 探讨右美托咪定联合综合体温保护对腔镜手术治疗老年恶性肿瘤患者苏醒期质量及免疫功能的影响。方法 选择择期行腔镜手术治疗的老年恶性肿瘤患者90例,随机均分为3组:对照组(C组)、体温保护组(T组)和体温保护联合右美托咪定组(T-D组),每组30例。C组常规体温保护,T组和T-D组综合体温保护;T-D组麻醉诱导前10 min泵注右美托咪定0.5 μg/kg。记录3组患者麻醉诱导开始时(T0)、手术开始30 min(T1)、60 min(T2)、90 min(T3)、120 min(T4)以及手术结束时(T5)的鼻咽温度;于T0、术后2 h(T6)、24 h(T7)和48 h(T8)时抽取静脉血标本,测定T淋巴细胞亚群(CD3+、CD4+和CD8+)和自然杀伤细胞(NK cell)水平;记录患者术中麻醉药物用量及苏醒期质量指标。结果 与T0比较,C组T2~T5时点鼻咽温度均明显降低(P < 0.05);与C组比较,T组和T-D组T2~T5时点鼻咽温度明显升高(P < 0.05)。与T0时点比较,C组、T组和T-D组T6、T7和T8时点CD3+和NK cell活性均明显降低(P < 0.05);C组在T6、T7和T8时点,T组和T-D组在T6和T7时点,CD4+活性均明显降低(P < 0.05)。与C组比较,T组和T-D组T6和T7时点CD3+细胞活性均明显升高(P < 0.05);T组在T7时点,T-D组在T6和T7时点,CD4+细胞活性均明显升高(P < 0.05);T组在T7时点,T-D组在T6、T7和T8时点,NK cell活性均明显升高(P < 0.05)。结论 采用体温保护措施联合右美托咪定能够维持老年恶性肿瘤患者的体温稳定,减少围手术期意外低体温(IPH)的发生,并有效提高患者苏醒期质量,减轻免疫抑制程度,加速患者早期恢复。 相似文献
3.
Mette Nissen Tiina‐Mari Ikheimo Jukka Huttunen Ville Leinonen Henna‐Kaisa Jyrkknen Mikael von und zu Fraunberg 《Neuromodulation》2021,24(1):102-111
ObjectiveSpinal cord stimulation (SCS) is an effective treatment in failed back surgery syndrome (FBSS). We studied the effect of preimplantation opioid use on SCS outcome and the effect of SCS on opioid use during a two-year follow-up period.Materials and methodsThe study cohort included 211 consecutive FBSS patients who underwent an SCS trial from January 1997 to March 2014. Participants were divided into groups, which were as follows: 1) SCS trial only (n = 47), 2) successful SCS (implanted and in use throughout the two-year follow-up period, n = 131), and 3) unsuccessful SCS (implanted but later explanted or revised due to inadequate pain relief, n = 29). Patients who underwent explantation for other reasons (n = 4) were excluded. Opioid purchase data from January 1995 to March 2016 were retrieved from national registries.ResultsHigher preimplantation opioid doses associated with unsuccessful SCS (ROC: AUC = 0.66, p = 0.009), with 35 morphine milligram equivalents (MME)/day as the optimal cutoff value. All opioids were discontinued in 23% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.004). Strong opioids were discontinued in 39% of patients with successful SCS, but in none of the patients with unsuccessful SCS (p = 0.04). Mean opioid dose escalated from 18 ± 4 MME/day to 36 ± 6 MME/day with successful SCS and from 22 ± 8 MME/day to 82 ± 21 MME/day with unsuccessful SCS (p < 0.001).ConclusionsHigher preimplantation opioid doses were associated with SCS failure, suggesting the need for opioid tapering before implantation. With continuous SCS therapy and no explantation or revision due to inadequate pain relief, 39% of FBSS patients discontinued strong opioids, and 23% discontinued all opioids. This indicates that SCS should be considered before detrimental dose escalation. 相似文献
4.
5.
Qing-Yang Que Lin-Cheng Zhang Jia-Qi Bao Sun-Bin Ling Xiao Xu 《World journal of gastrointestinal surgery》2022,14(5):397-408
Over the last 40 years, the incidence and prevalence of gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) have continued to increase. Compared to other epithelial neoplasms in the same organ, GEP-NENs exhibit indolent biological behavior, resulting in more chances to undergo surgery. However, the role of surgery in high-grade or advanced GEP-NENs is still controversial. Surgery is associated with survival improvement of well-differentiated high-grade GEP-NENs, whereas poorly differentiated GEP-NENs that may benefit from resection require careful selection based on Ki67 and other tissue bio markers. Additionally, surgery also plays an important role in locally advanced and metastatic disease. For locally advanced GEP-NENs, isolated major vascular involvement is no longer an absolute contraindication. In the setting of metastatic GEP-NENs, radical intended surgery is recommended for patients with low-grade and resectable metastases. For unresectable metastatic disease, a variety of surgical approaches, including cytoreduction of liver metastasis, liver transplantation, and surgery after neoadjuvant treatment, show survival benefits. Primary tumor resection in GEP-NENs with unresectable metastatic disease is associated with symptom control, prolonged survival, and improved sensitivity toward systemic therapies. Although there is no established neoadjuvant or adjuvant strategy, increasing attention has been given to this emerging research area. Some studies have reported that neoadjuvant therapy effectively reduces tumor burden, improves the effectiveness of subsequent surgery, and decreases surgical complications. 相似文献
6.
Qiangsheng He Chongfei Huang Xiwen Qin Yuanyuan Yu Di Tang Junjie Huang Zi Chong Kuo Yuyao Ling Deli Mao Bin Xia Wenjing Li Kuiqing Lu Man Yang Yulong He Wenbo Meng Jinqiu Yuan Yihang Pan 《International journal of cancer. Journal international du cancer》2023,153(5):942-949
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes. 相似文献
8.
目的 探讨低危单胎的足月妊娠自然临产后,潜伏期脑胎盘率(CPR)对预测新生儿不良结局的价值。方法 选取2018年1月至2021年3月我院住院临产分娩的673例孕妇为研究对象,测量胎儿大脑中动脉、脐动脉血流参数,获得分娩结局及新生儿结局。参考既往研究得出的不同孕周CPR正常参考值百分位作为分组指标(CPR≤10%参考值定为低CPR)。比较低CPR组(72例)与正常CPR组(601例)两组妊娠结局、新生儿不良结局。结果 低CPR组与正常CPR组在孕妇年龄、孕龄、产次、孕期体质量增长、总产程、新生儿体质量的构成上差异均无统计学意义(P>0.05)。低CPR组因胎儿窘迫行剖宫产或助产发生率、新生儿任一不良结局发生率、新生儿不良结局率均高于正常CPR组,差异均有统计学意义(P<0.05)。低CPR预测新生儿不良结局的准确率为89.5%(602/673),敏感度为51.7%(15/29),特异度为91.1%(587/644)。结论 本研究数据显示,对于无并发症及合并症、低风险的单胎足月妊娠,潜伏期低CPR与新生儿不良结局相关。 相似文献
9.
Janitz Amanda E. Schraw Jeremy M. Xu Chao Lupo Philip J. 《Cancer causes & control : CCC》2022,33(3):483-488
Cancer Causes & Control - Congenital malformations are strong risk factors for childhood cancer. Our objective was to determine whether cancer survival differs by birth defect status among... 相似文献
10.
Major depressive disorder is a serious and common neuropsychiatric disorder that affects more than 350 million people worldwide. Electroconvulsive therapy is the oldest and most effective treatment available for the treatment of severe major depressive disorder. Electroconvulsive therapy modifies structural network changes in patients with major depressive disorder and schizophrenia. And it can also affect neuroinflammatory responses and may have neuroprotective effects. Electroconvulsive therapy plays an irreplaceable role in the treatment of major depressive disorder. 相似文献