全文获取类型
收费全文 | 221397篇 |
免费 | 17024篇 |
国内免费 | 7150篇 |
专业分类
耳鼻咽喉 | 1256篇 |
儿科学 | 7660篇 |
妇产科学 | 1550篇 |
基础医学 | 19484篇 |
口腔科学 | 3609篇 |
临床医学 | 23380篇 |
内科学 | 56031篇 |
皮肤病学 | 2717篇 |
神经病学 | 26131篇 |
特种医学 | 6331篇 |
外国民族医学 | 5篇 |
外科学 | 16930篇 |
综合类 | 30155篇 |
现状与发展 | 31篇 |
一般理论 | 9篇 |
预防医学 | 18682篇 |
眼科学 | 2390篇 |
药学 | 15251篇 |
194篇 | |
中国医学 | 10028篇 |
肿瘤学 | 3747篇 |
出版年
2024年 | 656篇 |
2023年 | 4659篇 |
2022年 | 8360篇 |
2021年 | 11844篇 |
2020年 | 11100篇 |
2019年 | 8389篇 |
2018年 | 8330篇 |
2017年 | 8241篇 |
2016年 | 8568篇 |
2015年 | 8258篇 |
2014年 | 15616篇 |
2013年 | 17046篇 |
2012年 | 12753篇 |
2011年 | 13800篇 |
2010年 | 10870篇 |
2009年 | 10452篇 |
2008年 | 10448篇 |
2007年 | 10115篇 |
2006年 | 9025篇 |
2005年 | 7436篇 |
2004年 | 6325篇 |
2003年 | 5439篇 |
2002年 | 4598篇 |
2001年 | 3968篇 |
2000年 | 3318篇 |
1999年 | 2829篇 |
1998年 | 2719篇 |
1997年 | 2401篇 |
1996年 | 2142篇 |
1995年 | 1943篇 |
1994年 | 1789篇 |
1993年 | 1525篇 |
1992年 | 1463篇 |
1991年 | 1290篇 |
1990年 | 1020篇 |
1989年 | 860篇 |
1988年 | 815篇 |
1987年 | 736篇 |
1986年 | 633篇 |
1985年 | 737篇 |
1984年 | 618篇 |
1983年 | 380篇 |
1982年 | 446篇 |
1981年 | 374篇 |
1980年 | 282篇 |
1979年 | 247篇 |
1978年 | 184篇 |
1977年 | 164篇 |
1976年 | 135篇 |
1975年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Leyi Wang Saraswathi Lanka Debbie Cassout Nohra E. Mateus‐Pinilla Ganwu Li William C. Wilson Dongwan Yoo Paul Shelton Richard L. Fredrickson 《Transboundary and Emerging Diseases》2019,66(5):1809-1820
First described in 1955 in New Jersey, epizootic haemorrhagic disease (EHD) causes a severe clinical disease in wild and domestic ruminants worldwide. Epizootic haemorrhagic disease outbreaks occur in deer populations each year from summer to late autumn. The etiological agent is EHD virus (EHDV) which is a double‐stranded segmented icosahedral RNA virus. EHD virus utilizes point mutations and reassortment strategies to maintain viral fitness during infection. In 2018, EHDV serotype 2 was predominantly detected in deer in Illinois. Whole genome sequencing was conducted for two 2018 EHDV2 isolates (IL41747 and IL42218) and the sequence analyses indicated that IL42218 was a reassortant between different serotypes whereas IL41747 was a genetically stable strain. Our data suggest that multiple strains contribute to outbreaks each year. 相似文献
73.
Conan MacDougall Theora Canonica Chris Keh Binh An P. Phan Janice Louie 《Pharmacotherapy》2022,42(4):343-361
Rifamycins (rifampin, rifabutin, and rifapentine) play an essential role in the treatment of mycobacterial and some nonmycobacterial infections. They also induce the activity of various drug transporting and metabolizing enzymes, which can impact the concentrations and efficacy of substrates. Many anticoagulant and antiplatelet (AC/AP) agents are substrates of these enzymes and have narrow therapeutic indices, leading to risks of thrombosis or bleeding when coadministered with rifamycins. The objective of this systematic review was to evaluate the effects on AC/AP pharmacokinetics, laboratory markers, and clinical safety and efficacy of combined use with rifamycins. A systematic review following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidance was performed. The PubMed, Embase, and Web of Science databases were queried for English-language reports on combination use of rifamycins and AC/AP agents from database inception through August 2021. The 29 studies identified examined warfarin (n = 17), direct oral anticoagulants (DOACs) (n = 8), and antiplatelet agents (n = 4) combined with rifampin (n = 28) or rifabutin (n = 1). Eleven studies were case reports or small case series; 14 reported on pharmacokinetic or laboratory markers in healthy volunteers. Rifampin-warfarin combinations led to reductions in warfarin area under the curve (AUC) of 15%–74%, with variability by warfarin isomer and study. Warfarin dose increases of up to 3–5 times prerifampin doses were required to maintain coagulation parameters in the therapeutic range. DOAC AUCs were decreased by 20%–67%, with variability by individual agent and with rifampin versus rifabutin. The active metabolite of clopidogrel increased substantially with rifampin coadministration, whereas prasugrel was largely unaffected and ticagrelor saw decreases. Our review suggests most combinations of AC/AP agents and rifampin are problematic. Further studies are required to determine whether rifabutin or rifapentine could be safe alternatives for coadministration with AC/AP drugs. 相似文献
74.
目的 研究血清窖蛋白-1 (Cav-1) 在慢性阻塞性肺疾病 (COPD) 相关肺动脉高压 (PAH) 患者中的表达及其意义。方法 选取稳定期COPD患者65例, 根据是否合并PAH分成COPD组 [肺动脉收缩压 (PASP) <40 mmHg, 35例] 及COPD-PAH组 (PASP ≥40 mmHg, 30例)。另选取在本院健康体检的志愿者30例作为对照组。对比各组基线资料、 动脉血气分析、 肺功能指标, 以及血清Cav-1、 白细胞介素 (IL) -6和肿瘤坏死因子-α (TNF-α) 的表达水平。绘制受试者工作特征 (ROC) 曲线, 评价Cav-1对COPD合并PAH的诊断价值。结果 COPD-PAH组与COPD组第一秒用力呼吸容积 (FEV1) /用力肺活量 (FVC)、 FEV1占预计值百分比 (FEV1%) 及氧分压 [p (O2 )] 低于对照组, 而二氧化碳分压 [p (CO2 )]、 PASP均高于对照组 (P<0.01)。COPD-PAH组p (O2 ) 低于COPD组, p (CO2 )、 PASP均高于COPD 组 (P<0.01)。对照组、 COPD组及COPD-PAH组Cav-1表达水平呈逐渐降低趋势, 而IL-6、 TNF-α表达水平呈逐渐升高趋势 (P<0.01)。血清Cav-1诊断COPD合并PAH的ROC曲线下面积为0.902 (0.821~0.955), 最佳截断值为 6.66 μg/L, 此时诊断敏感度为76.7%, 特异度为85.7%, 与多普勒超声诊断仪测量PASP结果比较一致性较好 (Kappa 值=0.627)。结论 血清Cav-1在COPD相关PAH患者表达明显下调, 可以作为预测COPD相关PAH的新型血清标志物。 相似文献
75.
BackgroundPercutaneous endoscopic gastrostomy (PEG) is required for Levodopa/Carbidopa Intestinal Gel (LCIG) delivery in patients with advanced Parkinson's disease (PD) as well as for enteral feeding in a variety of neurological disorders. Buried Bumper Syndrome (BBS) is a serious complication of PEG. The frequency of BBS in patients receiving LCIG treatment has never been reported.ObjectivesTo compare the frequency of BBS in patients on LCIG treatment or on enteral feeding over the past 12 years and identify possible risk factors.MethodsWe reviewed prospectively recorded data from 2009 to 2020 on two case-series: LCIG-treated PD patients and non-PD patients on enteral nutrition. We identified all BBS incidences. Patients’ characteristics, clinical manifestations, BBS management, possible risk factors and outcomes were analyzed.ResultsDuring the 12 years, 35 PD patients underwent PEG insertion for LCIG infusion, and 123 non-PD patients for nutritional support. There were eight cases of BBS in six PD patients (17.1%). Six of them were effectively managed without treatment discontinuation. Of the enteral feeding patients, only one developed BBS (0.8%) (p < 0.001). We identified inappropriate PEG site aftercare, weight gain, early onset PD, longer survival, treatment duration, dementia and PEG system design as potential risk factors for BBS development.ConclusionsBBS occurs more frequently in LCIG patients than in patients receiving enteral feeding. If detected early, it can be successfully managed, and serious sequalae or treatment discontinuation can be avoided. Regular endoscopic follow-up visits of LCIG-treated patients and increased awareness in patients and clinicians are recommended. 相似文献
76.
《Nefrología : publicación oficial de la Sociedad Espa?ola Nefrologia》2022,42(6):714-721
SARS-CoV-2 pandemic has changed across the last 2 years. The development and approval of SARS-CoV-2 vaccines and the emergence of new variants has opened up a new scenario. On this regard, Spanish Society of Nephrology (S.E.N.) Council considers that an update of the previous recommendations should be performed. In the present statement, and taking into account the current epidemiological situation, are included updated recommendations of protection and isolation for patients on dialysis programs. 相似文献
77.
78.
目的 分析HBV患者YKL-40、CA19-9、GP73水平差异及与患者病情轻重程度的相关性,探讨HBV患者病情的判定指标。方法 选取2015年5月—2018年5月收治的100例HBV患者,其中慢性HBV感染组40例、慢性乙型肝炎组36例、HBV相关肝硬化组24例,同期选择我院健康体检的健康者50例作为健康对照组;检测患者血中YKL-40、CA19-9、GP73水平;分析HBV感染患者血清YKL-40、CA19-9、GP73水平与病情轻重程度的相关性。结果 慢性HBV感染、慢性乙型肝炎及HBV相关肝硬化患者血中YKL-40水平分别为(36.38±4.19)ng/mL 、(49.02±4.32)ng/mL、(65.14±5.21)ng/mL ,CA19-9分别为(12.03±1.03)KU/L、(13.84±0.98)KU/L、(16.94±0.81)KU/L,GP73分别为(47.22±5.38)ng/mL 、(98.53±10.24)ng/mL 、(229.85±12.19)ng/mL,均明显高于对照组的(28.19±3.27)ng/mL 、(7.34±0.92)KU/L 、(30.93±3.89)ng/mL,均P=0.000 0。随着慢性HBV感染者、慢性乙型肝炎患者和不同HBV相关肝硬化患者肝脏炎症及纤维化程度加重,患者血中YKL-40、CA19-9和GP73也随之显著增加,均P=0.000 0;YKL-40、CA19-9和GP73均是影响HBV感染患者体内炎症坏死及肝脏纤维化的独立性影响因素,差异有统计学意义(P<0.05)。结论 HBV感染患者血清中YKL-40、CA19-9、GP73水平是HBV感染患者病情轻重程度的独立性影响因素。 相似文献
79.
《Journal of the American Medical Directors Association》2022,23(1):161-164
ObjectivesAs more countries are implementing measures to address Alzheimer’s disease (AD), it is essential to update the available knowledge on the relationship between economic status and mortality in patients with AD. This study examined the influence of economic status on mortality in Japanese individuals with AD using a medical claims dataset.DesignThis was a retrospective cohort study.Setting and ParticipantsMedical claims data from April 2014 to March 2019 were obtained from 13 local cities participating in the Longevity Improvement and Fair Evidence study. The inclusion criteria were patients aged 65 years and older who were newly diagnosed with AD during the study period.MethodsThe outcome was death during the follow-up period. We assessed economic status by household income (middle to high income and low income); data were obtained from the use of the Medical Expenditure Ceiling Application and Standard Copayment Reduction Card (fee reduction card) when receiving an AD diagnosis, as an indicator of low-income status. We performed multivariate Cox proportional hazards analyses to examine the relationship between economic status and mortality; the model was adjusted for age, sex, the Charlson comorbidity index, and antidementia drug use.ResultsWe identified 39,081 newly diagnosed patients with AD from the Longevity Improvement and Fair Evidence study database (mean age, 83.6 years; female, 67.1%). Of these, 3189 individuals were identified as having a low-income status. After adjusting for possible confounders, low-income status was associated with mortality (hazard ratio, 1.95; 95% confidence interval, 1.84–2.07).Conclusions and ImplicationsLow-income status was associated with substantially poorer prognoses in new AD cases, indicating a need for a thorough examination of medical and nursing care services utilized by low-income individuals with AD and to explore improvement strategies. 相似文献
80.