全文获取类型
收费全文 | 13769篇 |
免费 | 1399篇 |
国内免费 | 325篇 |
专业分类
耳鼻咽喉 | 38篇 |
儿科学 | 92篇 |
妇产科学 | 75篇 |
基础医学 | 761篇 |
口腔科学 | 392篇 |
临床医学 | 2355篇 |
内科学 | 1672篇 |
皮肤病学 | 159篇 |
神经病学 | 461篇 |
特种医学 | 2997篇 |
外国民族医学 | 2篇 |
外科学 | 688篇 |
综合类 | 1611篇 |
预防医学 | 624篇 |
眼科学 | 687篇 |
药学 | 2006篇 |
7篇 | |
中国医学 | 286篇 |
肿瘤学 | 580篇 |
出版年
2024年 | 9篇 |
2023年 | 137篇 |
2022年 | 179篇 |
2021年 | 375篇 |
2020年 | 405篇 |
2019年 | 437篇 |
2018年 | 398篇 |
2017年 | 493篇 |
2016年 | 451篇 |
2015年 | 530篇 |
2014年 | 853篇 |
2013年 | 969篇 |
2012年 | 847篇 |
2011年 | 813篇 |
2010年 | 639篇 |
2009年 | 702篇 |
2008年 | 696篇 |
2007年 | 775篇 |
2006年 | 755篇 |
2005年 | 540篇 |
2004年 | 506篇 |
2003年 | 515篇 |
2002年 | 449篇 |
2001年 | 380篇 |
2000年 | 237篇 |
1999年 | 257篇 |
1998年 | 256篇 |
1997年 | 273篇 |
1996年 | 168篇 |
1995年 | 161篇 |
1994年 | 173篇 |
1993年 | 142篇 |
1992年 | 118篇 |
1991年 | 98篇 |
1990年 | 86篇 |
1989年 | 81篇 |
1988年 | 76篇 |
1987年 | 73篇 |
1986年 | 51篇 |
1985年 | 79篇 |
1984年 | 63篇 |
1983年 | 36篇 |
1982年 | 51篇 |
1981年 | 30篇 |
1980年 | 26篇 |
1979年 | 15篇 |
1978年 | 27篇 |
1977年 | 24篇 |
1976年 | 20篇 |
1973年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
《Journal of vascular and interventional radiology : JVIR》2022,33(9):1073-1082.e2
PurposeTo create a nonsurgical animal model of osteoarthritis (OA) to evaluate the effects of embolotherapy during geniculate artery embolization (GAE).Materials and MethodsFluoroscopy-guided injections of 700 mg of sodium monoiodoacetate were performed into the left stifle in 6 rams. Kinematic data were collected before and after induction. At 10 weeks after induction, Subjects 1 and 4–6 underwent magnetic resonance (MR) imaging with dynamic contrast enhancement (DCE) and Subjects 1, 3, and 4–6 underwent angiography with angiographic scoring to identify regions with greatest disease severity for superselective embolization (75–250-μm microspheres). Target vessel size was measured. At 24 weeks after angiography, DCE-MR imaging, angiography, and euthanasia were performed, and bilateral stifles were harvested. Medial/lateral tibial and femoral condylar, patellar, and synovial samples were cut, preserved, decalcified, and scored using the Osteoarthritis Research Society International criteria. The stifle and synovium Whole-Organ Magnetic Resonance Imaging Score and Multicenter Osteoarthritis Study score were determined. The volume transfer constant (Ktrans) and extracellular volume fraction (ve) were calculated from DCE-MR imaging along the lateral synovial regions of interest.ResultsThe mean gross and microscopic pathological scores were elevated at 38 and 61, respectively. Mean synovitis score was elevated at 9.2. Mean pre-embolization and postembolization angiographic scores were 5 and 3.8, respectively. Mean superior, transverse, and inferior geniculate artery diameters were 3.1 mm ± 1.21, 2.0 mm ± 0.50, and 1.6 mm ± 0.41 mm, respectively. Mean pre-embolization and postembolization cartilage and synovitis scores were elevated at 35.13 and 73.3 and 5.5 and 9.2, respectively. The Ktrans/ve values of Subjects 4, 5, and 6 were elevated at 0.049/0.38, 0.074/0.53, and 0.065/0.51, respectively. Altered gait of the hind limb was observed in all subjects after induction, with reduced joint mobility. No skin necrosis or osteonecrosis was observed.ConclusionsA nonsurgical ovine animal knee OA model was created, which allowed the collection of angiographic, histopathological, MR imaging, and kinematic data to study the effects of GAE. 相似文献
2.
3.
《Clinical Lymphoma, Myeloma & Leukemia》2022,22(9):e853-e866
Introduction/BackgroundTherapy with infused or injected hypomethylating agents (HMAs) may lead to higher treatment administration burden (ie, local reaction, visit frequency and duration) vs. oral HMAs. ObjectivesTo reveal preferences of US and Canadian patients with myelodysplastic syndromes (MDS) for HMAs’ benefits, risks, and administration burden through an online discrete-choice experiment (DCE).Materials and MethodsChoice of DCE attributes and survey development were informed by literature review and interviews with clinicians, MDS patients, and caregivers serving as patient proxies, and patient advocacy groups (PAGs) representatives, including from AAMAC, AAMDS, and MDSF. DCE choice tasks were analyzed using random parameter logit models. Survey patients were recruited by the PAGs via their networks. To understand key preference drivers and how much patients were willing to trade between attributes, we calculated each attribute's relative attribute importance (RAI) and marginal rates of substitution.ResultsOne hundred eighty-four respondents (including 158 patients; mean age, 67.2 years; male, 50.5%; White, 50.5%; US residents, 88%) completed the survey. MDS risk was low (34.8%), high (30.9%), or unknown (34.2%). RAI (in decreasing order) was as follows: risk of AML (40%), fatigue level (33%), number of visits (12%), mode of administration (6%), visit duration (5%), and administration frequency (4%). Assuming the same risk of AML transformation or level of fatigue, most respondents (76.6%) were predicted to switch to an oral pill if it were available to them.ConclusionGiven equivalent effectiveness across HMAs, patients’ preferences for HMA administration method should be considered in treatment decision-making to minimize burden and facilitate adherence. 相似文献
4.
《Journal of the American College of Radiology》2022,19(5):655-662
PurposeTo improve the efficiency and accuracy of clinicians documenting acute clinical events related to contrast agent administration using a web browser–based semistructured documentation support tool.MethodsA new tool called Contrast Incident Support and Reporting (CISaR) was developed to enable radiologists responding to contrast reactions to document inciting contrast class, type of event, severity of contrast reaction, and recommendation for future contrast use. Retrospective analysis was conducted of all CT and MRI examinations performed between February 2018 and December 2019 across our hospital system with associated contrast reaction documentation. Time periods were defined as before tool deployment, early adoption, and steady-state deployment. The primary outcome measure was the presence of event documentation by a radiologist. The secondary outcome measure was completeness of the documentation parameters.ResultsA total of 431 CT and MRI studies with reactions were included in the study, and 50% of studies had radiologist documentation during the pre-CISaR period. This increased to 66% during the early adoption period and 89% in the post-CISaR period. It took approximately 9 months from the introduction of CISaR to reach full adoption and become the main method for adverse contrast reaction documentation. The percentage of radiologist documentation that detailed provoking contrast agent class, severity of reaction, reaction type, and future contrast agent recommendation all significantly increased (P < .0001), with greater than 95% inclusion of each element.ConclusionThe implementation of a semistructured electronic application for adverse contrast reaction reporting significantly increased radiologist documentation rate and completeness of the documentation. 相似文献
5.
《Saudi Dental Journal》2022,34(8):699-707
Uncontrolled bleeding is linked to higher treatment costs, risk of post-surgical infection and increased disease and death. Hemostatic agents are used to treat excessive bleeding. A good hemostatic agent controls bleeding effectively, reduces the need for blood transfusion, removes the need for systemic drugs to control bleeding, results in shorter surgery time, and reduces the cost and length of hospital stay of the patient. Gelatin-based hemostatic agents have been widely used in medical and dental procedures, owing to their biodegradability and biocompatibility, as well as availability and low cost of raw materials. In this narrative literature review, we discuss the background and different types of gelatin-based hemostatic agents in medical and dental procedures, the comparison of gelatin-based and non-gelatin-based hemostatic agents, and the usage and development of enhanced or novel gelatin-based hemostatic agents. Gelatin-based hemostatic agents are effective and important part of bleeding control, as evidenced by its wide application in medicine and dentistry. The development of novel combination gelatin-based hemostatic agents has much potential for effective control of excessive bleeding. 相似文献
6.
《Saudi Dental Journal》2022,34(8):730-737
BackgroundDentures with antimicrobial properties are desirable for preventing Candida albicans adhesion. This study was to assess the effectiveness of bioactive glass (BAG) on C. albicans adhesion, surface roughness, and hardness of denture base materials.MethodsHeat-polymerized (HP) and autopolymerized (AP) acrylic resins were used to fabricate 240 disk specimens (120/material, 60/C. albicans, 60/surface roughness and hardness). Specimens were divided into five groups (n = 10) based on the BAG concentration: 0.5, 1.5, 3, 5, and 7.5 wt% of the acrylic powder, with a control group comprised of unmodified specimens. Direct culture method was used to assess C. albicans adhesion. A profilometer and Vickers hardness test were used to measure surface roughness and hardness respectively. Analysis of variance (ANOVA) and post hoc Tukey’s test were used for data analysis (α = 0.05).ResultsBAG addition significantly decreased the C. albicans count when compared with the control group (P < 0.001) for both HP and AP. Regarding surface roughness, there was no change in the HP acrylic resins (P > 0.05), while the AP acrylic resins exhibited significantly higher surface roughness with BAG addition (P < 0.001). The hardness of the HP and AP acrylic resins were significantly higher with the addition of BAG (P < 0.001).ConclusionsThe addition of BAG to HP and AP acrylic resins effectively decreases C. albicans adhesion. The roughness of AP acrylic resins increases with the addition of BAG, while the hardness of both HP and AP acrylic resins increase with the addition of BAG. 相似文献
7.
8.
9.
目的 采用Meta分析对比四维子宫输卵管超声造影(4D-HyCoSy)与子宫输卵管造影(HSG)评估输卵管通畅性的效能。方法 系统搜索PubMed、Cochrane Library、Embase、Web of Science、中国生物医学文献数据库、中国知网、万方医学网及维普数据库中建库至今有关4D-HyCoSy和/或HSG评估输卵管通畅性的文献。由2名研究人员依据纳入标准和排除标准筛选文献并提取信息;分别计算4D-HyCoSy和HSG评估输卵管通畅性的合并敏感度(SEN)、特异度(SPE)及诊断比值比(DOR),绘制综合受试者工作特征(SROC)曲线,获得曲线下面积(AUC),并以Medcalc 19.1.1统计软件比较AUC。结果 最终纳入19篇文献、1 358例疑似输卵管因素导致不孕患者,其中4篇同时采用4D-HyCoSy及HSG评估输卵管通畅性,10篇仅以4D-HyCoSy评估,5篇仅以HSG评估。Meta分析结果显示,4D-HyCoSy评估输卵管通畅性的合并SEN、SPE及DOR分别为0.92[95%CI(0.91,0.94)]、0.91[95%CI(0.89,0.93)]及115.06[95%CI(54.23,224.10)];HSG评估输卵管通畅性的合并SEN、SPE及DOR分别为0.84[95%CI(0.81,0.87)]、0.80[95%CI(0.76,0.83)]及28.64[95%CI(10.08,81.35)]。4D-HyCoSy评估输卵管通畅性的AUC为0.98[95%CI(0.96,0.99)],HSG为0.93[95%CI(0.90,0.95)],差异有统计学意义(Z=6.97,P<0.01)。结论 4D-HyCoSy评估输卵管通畅性的效能高于HSG。 相似文献
10.
《Zeitschrift für medizinische Physik》2022,32(2):209-217
This work describes a measurement method for assessing dose-related image-quality of CT scans based on the difference detail curve (DDC) method, and showcases its use in a low contrast setting. The method is based on a phantom consisting of elliptical slices of different sizes into which contrast object modules can be inserted. These modules contain contrast objects based on (synthetic) resin mixtures with sucrose (native) or sodium iodine (contrast medium). Mixing ratios are provided to achieve a range of clinically relevant CT-numbers with these materials. The phantom is characterized in terms of contrast accuracy, energy dependency and long-term drift with satisfying results. Contrast accuracy and energy dependency are similar to that of water or soft tissue. Image quality of 655 scans of the phantom acquired at 30 different clinical institutions and with 16 different CT scanner models from 4 manufacturers was assessed by calculating a difference detail curve (DDC) from evaluation of up to 5 human observers using a custom-made software (RadiVates) described in this work. Based on these measurements, inter-observer variability was quantified using a bootstrap method and was shown to be a large contributor to the overall variability. This work demonstrates that assessment of CT image quality is feasible with the aforementioned phantom and DDC method. 相似文献