全文获取类型
收费全文 | 35776篇 |
免费 | 3426篇 |
国内免费 | 2685篇 |
专业分类
耳鼻咽喉 | 237篇 |
儿科学 | 467篇 |
妇产科学 | 264篇 |
基础医学 | 3736篇 |
口腔科学 | 559篇 |
临床医学 | 5035篇 |
内科学 | 4771篇 |
皮肤病学 | 332篇 |
神经病学 | 1534篇 |
特种医学 | 978篇 |
外国民族医学 | 17篇 |
外科学 | 2894篇 |
综合类 | 7793篇 |
现状与发展 | 13篇 |
预防医学 | 2897篇 |
眼科学 | 940篇 |
药学 | 4163篇 |
41篇 | |
中国医学 | 2686篇 |
肿瘤学 | 2530篇 |
出版年
2024年 | 138篇 |
2023年 | 592篇 |
2022年 | 1480篇 |
2021年 | 1848篇 |
2020年 | 1460篇 |
2019年 | 1110篇 |
2018年 | 1132篇 |
2017年 | 1167篇 |
2016年 | 1012篇 |
2015年 | 1651篇 |
2014年 | 2139篇 |
2013年 | 1979篇 |
2012年 | 3043篇 |
2011年 | 3200篇 |
2010年 | 2237篇 |
2009年 | 1878篇 |
2008年 | 2204篇 |
2007年 | 2207篇 |
2006年 | 2001篇 |
2005年 | 1736篇 |
2004年 | 1225篇 |
2003年 | 1118篇 |
2002年 | 912篇 |
2001年 | 799篇 |
2000年 | 678篇 |
1999年 | 631篇 |
1998年 | 353篇 |
1997年 | 361篇 |
1996年 | 276篇 |
1995年 | 236篇 |
1994年 | 230篇 |
1993年 | 134篇 |
1992年 | 126篇 |
1991年 | 146篇 |
1990年 | 113篇 |
1989年 | 92篇 |
1988年 | 67篇 |
1987年 | 57篇 |
1986年 | 44篇 |
1985年 | 25篇 |
1984年 | 13篇 |
1983年 | 13篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 3篇 |
1979年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
黄芪注射液对刀豆蛋白诱导的小鼠肝脏损伤的保护作用 总被引:5,自引:0,他引:5
目的:观察免疫损伤模型组与实验组小鼠外周血中T细胞亚群的变化情况,探讨黄芪注射液对小鼠肝脏损伤的保护作用。方法实验组小鼠每天腹腔注射黄芪注射液400μl,正常组与模型组小鼠每天给予等剂量的生理盐水。第7天在给药1小时后,模型组与实验组小鼠分别经尾静脉注射刀豆蛋白,正常组小鼠则给予等剂量的生理盐水。8小时后检测各组动物外周血中CD4^+T、CD8^+T细胞以及CD4^+/CD25^+T细胞所占比例,检测血浆转氨酶水平,制备肝脏病理标本,进行HE染色。结果尾静脉注射8小时后,实验组小鼠外周血的CD4^+所占T细胞比例较模型组有所升高(P〈0.05),但仍低于正常组水平(P〉0.05):而CD8^+T细胞的比例则无明显变化(P〉0.05)。实验组ALT、AST水平明显低于模型组(P〈0.05)。实验组汇管区淋巴细胞浸润明显减少。结论黄芪注射液对刀豆蛋白诱导的小鼠肝损伤有确切的保护作用。 相似文献
92.
对苄氧基氯苄(p-benzyloxy benzyl chloride,1)是合成抗肿瘤新药的中间体,其纯度直接影响成品的质量.本研究建立了RP-HPLC法测定1纯度[1,2].方法简便、快速,可用于1的质量评定. 相似文献
93.
2-(3-苄基苯基)丙醛和高锰酸钾在相转移催化剂度米芬作用下,以苯为有机相、氢氧化钠水溶液为水相氧化制得酮洛芬,收率69%,纯度99.5%. 相似文献
94.
目的:比较两种鼻黏膜切口在鼻内镜下鼻腔泪囊吻合术中出血情况和术后治疗效果。
方法:回顾性研究。收集2016-06/2018-05在我院眼科确诊为慢性泪囊炎并接受鼻内镜下鼻腔泪囊吻合手术治疗的患者63例66眼。根据鼻黏膜瓣基底部位的不同分组,A组以中鼻甲腋为基底的鼻腔黏膜切口行泪囊鼻腔吻合术,B组以上颌骨线为基底的鼻腔黏膜切口行泪囊鼻腔吻合术。随访至术后6mo,比较两组患者术中出血和术后疗效。
结果:两组患者术中出血情况有差异(χ2=11.803,P<0.05),术后有效率比较无差异(82% vs 73%,P>0.05)。
结论:以中鼻甲腋为基底部的鼻腔黏膜切口,术中并发出血较多; 而以上颌骨线为基底的鼻腔黏膜切口,术中出血较少。两组患者术后疗效无差异。 相似文献
95.
目的 通过测定机械通气对急性呼吸窘迫综合征(Acute Respiratory Distress Syndrome,ARDS)患者支气管肺泡灌洗液(BronchoAlveolar Lavage Fluid,BALF)与血清中肺损伤标记物的变化,明确气道压力释放通气(Airway Pressure Release Ventilation,APRV)与小潮气量保护性通气(Low Tidal Volume Protective Ventilation,LTV)对ARDS患者呼吸机相关性肺损伤(Ventilator-Induced Lung Injury,VILI)的影响。方法 收集深圳大学总医院及海南省人民医院2018-01至2019-05内ARDS住院患者40例,以随机数字法分为两组:A组21例,B组19例,A组先予APRV通气24 h,随后转为LTV 24 h;B组先予LTV 24 h,再转为APRV 24 h,比较干预治疗0 h、24 h、48 h两组患者氧合指数、呼吸力学、BALF及血清中肺泡表面活性蛋白(Pulmonary Surfactant Protein D,SP-D)、重组... 相似文献
96.
Liposarcoma is a rare malignant tumor type and surgical resection is the gold standard treatment. The present study reported on the case of a 51-year-old woman who presented with a mass in the left upper abdomen. Computed tomography revealed a 32-cm giant retroperitoneal liposarcoma. Complete tumor resection was performed without the removal of other organs. Postoperative pathological examination indicated retroperitoneal well-differentiated liposarcoma and immunohistochemistry revealed S-100(−), MDM2(+), vimentin(+), CDK4(+), p16(+) and STAT6(+) results. The patient recovered well after the surgery. Complete tumor resection during the first surgery is key to cure liposarcoma. The present case report will be helpful for clinical oncologists to fully understand giant retroperitoneal liposarcoma and treat it accordingly. 相似文献
97.
Hydration of fat-free mass (FFM), defined as the ratio of total body water (TBW) to FFM (TBW/FFM), is stable at 0.739 in adult mammals. However, an increase in the TBW/FFM ratio is common in hemodialysis (HD) patients. This study aimed to evaluate the determinants of TBW/FFM and investigate its predictive value for the prognosis of all-cause mortality in HD patients.We enrolled patients undergoing maintenance HD between July 2020 and May 2021. All patients were prospectively followed until death, HD dropout, or until the end of the study (November 1, 2021). A forward stepwise multivariable linear regression analyses was performed to test the independent relationship between TBW/FMM and other clinical variables. Receiver operating characteristic (ROC) analysis was used to discriminate the TBW/FFM with respect to 180-day mortality.Of the 106 patients, 42 had elevated TBW/FFM levels. Multiple linear regression analysis revealed that the TBW/FFM ratio was significantly associated with extracellular water (ECW)/TBW (standardized regression coefficient [β = 1.131, P < .001], phase angle (PhA) [β = 0.453, P < .001], and sex (β = 0.440, P < .001). We calculated the ROC curve (AUC) of TBW/FFM, ECW, ECW/TBW, and intracellular water (ICW) to compare the discriminatory capacities of these parameters in predicting 180-day mortality. The AUC for TBW/FFM (AUC = 0.849; 95% CI, 0.745–0.953) exhibited better discriminatory potential than ECW (AUC = 0.562; 0.410–0.714), although it had a similar predictive potential as the ECW/TBW ratio (AUC = 0.831; 0.731–0.932). High TBW/FFM can be used as a valuable prognostic index for predicting all-cause mortality in patients on HD. 相似文献
98.
Background:The findings on the effectiveness of platelet-rich plasma, ozone, and hyaluronic acid in the treatment of osteoarthritis of the knee are controversial, and the existing original studies and meta-analyses are mostly comparisons of a single joint cavity injection method, lacking direct and indirect comparisons of different drugs in the joint cavity. The lack of direct and indirect comparisons of different drugs in the joint cavity makes it difficult to have a clearer and more comprehensive understanding of joint cavity injection methods. In this study, the efficacy of platelet-rich, ozone, sodium hyaluronate, and combined knee cavity injections were compared directly or indirectly using a reticulated meta-analysis in this field, and the efficacy of treatment measures was ranked to provide more comprehensive and reliable evidence-based clinical evidence for the selection of knee cavity injections in osteoarthritis of the knee.Objective:To compare the effects of platelet-rich plasma, ozone, and sodium glassate injection interventions on the efficacy of osteoarthritis of the knee through reticulated Meta-analysis, and to comprehensively compare the clinical effectiveness of platelet-rich plasma, ozone, and sodium glassate injection joint cavity injection for the treatment of osteoarthritis of the knee.Methods:The PubMed, CBM, CNKI, VIP, and Wan-Fang databases were searched for information on the effectiveness of platelet-rich plasma, ozone, and sodium vitrate injection for the comparative treatment of osteoarthritis of the knee, with a search time frame of each database from the date of creation to July 20, 2021. Two investigators independently screened the literature, extracted data according to inclusion and exclusion criteria, and evaluated the quality of the literature in parallel. Statistical analysis was performed using Stata 16.0 software to compare the differences in the efficacy of each treatment measure using the ratio and 95% confidence interval as effect indicators and to rank the efficacy.Results:Thirty-three RCTs with 7003 patients with osteoarthritis of the knee were included, involving 5 therapeutic measures. Meta-analysis showed that the efficacy of platelet-rich plasma injection was superior to both ozone and hyaluronic acid therapies. Hyaluronic acid+ozone and platelet-rich plasma+hyaluronic acid were both superior to ozone and hyaluronic acid monotherapy. The differences in efficacy between hyaluronic acid and ozone compared with platelet-rich plasma were statistically significant, and the differences in efficacy between the 2 combination therapies (platelet-rich plasma+hyaluronic acid, hyaluronic acid+ozone) and the 3 monotherapies (platelet-rich plasma, ozone, hyaluronic acid) were statistically significant. Platelet-rich plasma+hyaluronic acid, hyaluronic acid+ozone compared with 3 monotherapies (platelet-rich plasma, ozone, hyaluronic acid) were statistically significant, except for the difference in efficacy with platelet-rich plasma, which was not statistically significant, indicating that this platelet-rich plasma+hyaluronic acid and Hyaluronic acid+ozone combination therapy was superior to monotherapy. Also, the efficacy of platelet-rich plasma was better than hyaluronic acid and ozone and the difference was statistically significant, indicating that platelet-rich plasma was more effective than ozone and sodium glass in the treatment of osteoarthritis of the knee in monotherapy.Conclusion:It is believed that in the course of clinical practice, hyaluronic acid+ozone or platelet-rich plasma+hyaluronic acid combination therapy or platelet-rich plasma therapy can be preferred for patients with osteoarthritis of the knee. 相似文献
99.
目的:探讨养老机构老年人衰弱对生活质量影响的作用路径。方法:采用便利抽样法选取四川省成都市8所养老机构中符合纳入与排除标准的436名老年人作为调查对象,于2019年8月—12月应用一般资料调查表、衰弱表型(FP)、微型营养评定量表简表(MNA-SF)、日常生活活动能力量表(ADL)、社会支持评估量表(SSRS)、中文版健康调查量表(SF-36)对老年人进行调查。结果:养老机构436名老年人衰弱发生率为58.0%。非衰弱、衰弱老年人MNA-SF得分、ADL总分及各维度、SSRS总分及对支持的利用度维度、SF-36各维度得分比较差异均有统计学意义(P<0.05)。结构方程模型分析显示:老年人衰弱对生活质量的总效应为-10.326(P<0.001),直接效应为-4.215(P<0.001),通过营养状态、日常生活活动能力、社会支持对生活质量的间接效应为-6.111(P<0.001),间接效应占总效应的59.2%。结论:养老机构老年人衰弱的发生率高,衰弱既可直接影响老年人生活质量,亦可通过营养状态、日常生活活动能力、社会支持间接作用于生活质量。应重视对养老机构老年人衰弱... 相似文献
100.
Wei Zhang Ming Lei Qianwen Wen Dunke Zhang Guangcheng Qin Jiying Zhou Lixue Chen 《The journal of headache and pain》2022,23(1)
BackgroundThe pathogenesis of chronic migraine remains unresolved. Recent studies have affirmed the contribution of GLUA1-containing AMPA receptors to chronic migraine. The dopamine D2 receptor, a member of G protein-coupled receptor superfamily, has been proven to have an analgesic effect on pathological headaches. The present work investigated the exact role of the dopamine D2 receptor in chronic migraine and its effect on GLUA1-containing AMPA receptor trafficking.MethodsA chronic migraine model was established by repeated inflammatory soup stimulation. Mechanical, periorbital, and thermal pain thresholds were assessed by the application of von Frey filaments and radiant heat. The mRNA and protein expression levels of the dopamine D2 receptor were analyzed by qRT‒PCR and western blotting. Colocalization of the dopamine D2 receptor and the GLUA1-containing AMPAR was observed by immunofluorescence. A dopamine D2 receptor agonist (quinpirole) and antagonist (sulpiride), a PI3K inhibitor (LY294002), a PI3K pathway agonist (740YP), and a GLUA1-containing AMPAR antagonist (NASPM) were administered to confirm the effects of the dopamine D2 receptor, the PI3K pathway and GULA1 on central sensitization and the GLUA1-containing AMPAR trafficking. Transmission electron microscopy and Golgi-Cox staining were applied to assess the impact of the dopamine D2 receptor and PI3K pathway on synaptic morphology. Fluo-4-AM was used to clarify the role of the dopamine D2 receptor and PI3K signaling on neuronal calcium influx. The Src family kinase (SFK) inhibitor PP2 was used to explore the effect of Src kinase on GLUA1-containing AMPAR trafficking and the PI3K signaling pathway.ResultsInflammatory soup stimulation significantly reduced pain thresholds in rats, accompanied by an increase in PI3K-P110β subunit expression, loss of dopamine receptor D2 expression, and enhanced GLUA1-containing AMPA receptor trafficking in the trigeminal nucleus caudalis (TNC). The dopamine D2 receptor colocalized with the GLUA1-containing AMPA receptor in the TNC; quinpirole, LY294002, and NASPM alleviated pain hypersensitivity and reduced GLUA1-containing AMPA receptor trafficking in chronic migraine rats. Sulpiride aggravated pain hypersensitivity and enhanced GLUA1 trafficking in CM rats. Importantly, the anti-injury and central sensitization-mitigating effects of quinpirole were reversed by 740YP. Both quinpirole and LY294002 inhibited calcium influx to neurons and modulated the synaptic morphology in the TNC. Additional results suggested that DRD2 may regulate PI3K signaling through Src family kinases.ConclusionModulation of GLUA1-containing AMPA receptor trafficking and central sensitization by the dopamine D2 receptor via the PI3K signaling pathway may contribute to the pathogenesis of chronic migraine in rats, and the dopamine D2 receptor could be a valuable candidate for chronic migraine treatment.Supplementary InformationThe online version contains supplementary material available at 10.1186/s10194-022-01469-x. 相似文献