全文获取类型
收费全文 | 343744篇 |
免费 | 17190篇 |
国内免费 | 5973篇 |
专业分类
耳鼻咽喉 | 3052篇 |
儿科学 | 8830篇 |
妇产科学 | 5769篇 |
基础医学 | 43695篇 |
口腔科学 | 7747篇 |
临床医学 | 23812篇 |
内科学 | 54200篇 |
皮肤病学 | 5096篇 |
神经病学 | 22234篇 |
特种医学 | 11288篇 |
外国民族医学 | 3篇 |
外科学 | 40316篇 |
综合类 | 33778篇 |
现状与发展 | 24篇 |
一般理论 | 12篇 |
预防医学 | 24101篇 |
眼科学 | 5519篇 |
药学 | 41998篇 |
64篇 | |
中国医学 | 17751篇 |
肿瘤学 | 17618篇 |
出版年
2023年 | 2703篇 |
2022年 | 4099篇 |
2021年 | 9991篇 |
2020年 | 7267篇 |
2019年 | 17960篇 |
2018年 | 17724篇 |
2017年 | 11909篇 |
2016年 | 7995篇 |
2015年 | 7636篇 |
2014年 | 9937篇 |
2013年 | 15643篇 |
2012年 | 11677篇 |
2011年 | 13689篇 |
2010年 | 9338篇 |
2009年 | 9483篇 |
2008年 | 11376篇 |
2007年 | 13388篇 |
2006年 | 13112篇 |
2005年 | 12355篇 |
2004年 | 10234篇 |
2003年 | 9864篇 |
2002年 | 8464篇 |
2001年 | 8017篇 |
2000年 | 7240篇 |
1999年 | 6312篇 |
1998年 | 5731篇 |
1997年 | 5182篇 |
1996年 | 4711篇 |
1995年 | 4673篇 |
1994年 | 4418篇 |
1993年 | 3623篇 |
1992年 | 3074篇 |
1991年 | 2952篇 |
1990年 | 2492篇 |
1989年 | 2029篇 |
1988年 | 2002篇 |
1987年 | 1878篇 |
1985年 | 6486篇 |
1984年 | 8074篇 |
1983年 | 6409篇 |
1982年 | 6888篇 |
1981年 | 6201篇 |
1980年 | 5387篇 |
1979年 | 5363篇 |
1978年 | 4314篇 |
1977年 | 3269篇 |
1976年 | 3703篇 |
1975年 | 2867篇 |
1974年 | 2612篇 |
1973年 | 2309篇 |
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
81.
82.
目的探讨输尿管支架管结壳患者尿液菌群的分布特点。方法选取2018年10月至2019年3月在山东省立第三医院、山东大学齐鲁医院、济南市中心医院和济南市济钢医院就诊的35例输尿管支架管置入术后患者。纳入标准:年龄18~65岁;输尿管镜碎石术后留置内支架管4周。排除标准:尿液细菌培养阳性;严重肉眼血尿;近期口服抗生素;存在明显残石患者。本研究采用横断面研究方法(临床研究注册号为ChiCTR1800020025),根据有无支架管结壳将患者分为结壳组23例和无结壳组12例。收集拔管当日患者尿液行细菌16s DNA检测。使用UPARSE、UCHIME和RDP calssifier等软件分析两组患者尿液菌群分布特点,明确两组患者尿液中细菌种类总数、细菌丰度,以及丰度占比较大的细菌类别,比较两组患者尿液细菌种类、数量及细菌丰度的差异,明确结壳组患者尿液中丰度占比较大的细菌菌属。结果两组患者的年龄、性别、体质指数、置管侧别、内支架管型号及结石成分差异均无统计学意义(P>0.05)。16s DNA检测结果显示,结壳组丰度占比>1%的菌属数量为11个,丰度占比>0.01%的菌属数量为74个;无结壳组丰度占比>1%的菌属数量为7个,丰度占比>0.01%的菌属数量为11个,两组丰度占比>1%的菌属数量比较差异有统计学意义(t=5.12,P=0.000)。结壳组中菌属丰度占比前3位分别为乳杆菌属(23.1%)、拟杆菌属(18.8%)和未分级拟杆菌属(17.1%),非结壳组中菌属丰度占比前3位分别是为埃希菌-志贺菌属(32.2%)、肠球菌属(24.9%)和假单胞菌属(18.2%)。两组间差异最大的3种细菌是乳杆菌属(P=0.010),拟杆菌属(P=0.004)和未分级拟杆菌属(P=0.004)。结论支架管结壳患者尿液中细菌种类和数量都明显多于非支架管结壳患者。拟杆菌属细菌在支架管结壳患者尿液中的细菌种类丰度较大。 相似文献
83.
《Clinical neurophysiology》2021,132(12):3104-3115
ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials. 相似文献
84.
Pancreatic ductal adenocarcinoma (PDAC) is predicted to become the second leading cause of cancer-related mortality within the next decade, with limited effective treatment options and a dismal long-term prognosis for patients. Genomic profiling has not yet manifested clinical benefits for diagnosis, treatment or prognosis in PDAC, due to the lack of available tissues for sequencing and the confounding effects of low tumour cellularity in many biopsy specimens. Increasing focus is now turning to the use of minimally invasive liquid biopsies to enhance the characterisation of actionable PDAC tumour genomes. Circulating tumour DNA (ctDNA) is the most comprehensively studied liquid biopsy analyte in blood and can provide insight into the molecular profile and biological characteristics of individual PDAC tumours, in real-time and in advance of traditional imaging modalities. This can pave the way for identification of new therapeutic targets, novel risk variants and markers of tumour response, to supplement diagnostic screening and provide enhanced scrutiny in treatment stratification. In the roadmap towards the application of precision medicine for clinical management in PDAC, ctDNA analyses may serve a leading role in streamlining candidate biomarkers for clinical integration. In this review, we highlight recent developments in the use of ctDNA-based liquid biopsies for PDAC and provide new insights into the technical, analytical and biological challenges that must be overcome for this potential to be realised. 相似文献
85.
Rohi Shah Nomaan Sheikh Jitendra Mangwani Nicolette Morgan Hamidreza Khairandish 《Journal of Clinical Orthopaedics and Trauma》2021,12(1):138
Demographic projections for hip fragility fractures indicate a rising annual incidence by virtue of a multimorbid, ageing population with more noncommunicable diseases (NCDs). NCDs are characterised by slow progression and long duration ranging from ischaemic cardiovascular disease, cerebrovascular disease, diabetes, chronic obstructive pulmonary disease to various cancers. Management of this disease burden often involves commencing patients on oral anticoagulants to reduce the risk of thromboembolic events. The use of direct oral anticoagulants (DOACs) in clinical practice has increased due to their rapid onset of action, short half-life and predictable anticoagulant effects, without the need for routine monitoring. Safe and timely surgical intervention relies on reversal of anticoagulants. However, the lack of specific evidence-based guidelines for the perioperative management of patients on DOACs with hip fractures has proved challenging; in particular, the accessibility of DOAC-specific assays, justification of the cost-benefit ratio of targeted reversal agents and indications for neuraxial anaesthesia. This has led to potentially avoidable delays in surgical intervention. Following a literature review of the pharmacokinetic and pharmacodynamics of commonly used DOACs in our region including the role of surrogate markers, we propose a systematic, evidence-based guideline to the perioperative management of hip fractures DOACs. We believe this standardised protocol can be easily replicated between hospitals. We recommend that if patients are deemed suitable for a general anaesthesia, with satisfactory renal function, optimal surgical time should be 24 h following the last ingested dose of DOAC. 相似文献
86.
87.
88.
89.