全文获取类型
收费全文 | 18578篇 |
免费 | 1556篇 |
国内免费 | 574篇 |
专业分类
耳鼻咽喉 | 115篇 |
儿科学 | 382篇 |
妇产科学 | 288篇 |
基础医学 | 1886篇 |
口腔科学 | 607篇 |
临床医学 | 2501篇 |
内科学 | 3430篇 |
皮肤病学 | 320篇 |
神经病学 | 877篇 |
特种医学 | 357篇 |
外国民族医学 | 1篇 |
外科学 | 1851篇 |
综合类 | 2174篇 |
现状与发展 | 3篇 |
预防医学 | 788篇 |
眼科学 | 139篇 |
药学 | 3766篇 |
6篇 | |
中国医学 | 626篇 |
肿瘤学 | 591篇 |
出版年
2023年 | 347篇 |
2022年 | 629篇 |
2021年 | 928篇 |
2020年 | 728篇 |
2019年 | 655篇 |
2018年 | 598篇 |
2017年 | 604篇 |
2016年 | 556篇 |
2015年 | 635篇 |
2014年 | 958篇 |
2013年 | 1254篇 |
2012年 | 908篇 |
2011年 | 1041篇 |
2010年 | 792篇 |
2009年 | 670篇 |
2008年 | 715篇 |
2007年 | 758篇 |
2006年 | 620篇 |
2005年 | 555篇 |
2004年 | 550篇 |
2003年 | 467篇 |
2002年 | 384篇 |
2001年 | 350篇 |
2000年 | 330篇 |
1999年 | 279篇 |
1998年 | 279篇 |
1997年 | 269篇 |
1996年 | 245篇 |
1995年 | 244篇 |
1994年 | 226篇 |
1993年 | 221篇 |
1992年 | 187篇 |
1991年 | 201篇 |
1990年 | 208篇 |
1989年 | 185篇 |
1988年 | 162篇 |
1987年 | 155篇 |
1986年 | 165篇 |
1985年 | 211篇 |
1984年 | 199篇 |
1983年 | 140篇 |
1982年 | 209篇 |
1981年 | 136篇 |
1980年 | 144篇 |
1979年 | 103篇 |
1978年 | 78篇 |
1977年 | 93篇 |
1976年 | 71篇 |
1975年 | 63篇 |
1974年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
《Transfusion and apheresis science》2022,61(4):103487
When the COVID-19 pandemic hit, blood transfusion services worldwide started collection of convalescent plasma as early as possible, as exemplified by the response in Norway. There were challenges related to donor selection, donor safety, testing for relevant antibodies and indications for and dosing of the convalescent plasma. As more knowledge became available, the product quality was more standardised. Multiple case reports, observational studies and some randomized studies were published during the pandemic, as well as laboratory studies reporting different approaches to antibody testing. The results were conflicting and the importance of convalescent plasma was disputed.Even though there has been strong international collaboration with involvement of many key organisations, we may better prepare for the next pandemic. An even stronger, more formalised collaboration between these organisations could provide more clear evidence of the importance of convalescent plasma, based on the principles of passive immunisation. 相似文献
2.
A Coupled FEM-BEM Approach for the Solution of the Free-Boundary Axi-Symmetric Plasma Equilibrium Problem
下载免费PDF全文
![点击此处可从《Communications In Computational Physics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
M. Bonotto D. Abate P. Bettini & F. Villone 《Communications In Computational Physics》2022,31(1):27-59
In this paper we present a coupled Finite Element Method – Boundary Element Method (FEM-BEM) approach for the solution of the free-boundary axi-symmetric
plasma equilibrium problem. The proposed method, obtained from an improvement
of the Hagenow-Lackner coupling method, allows to efficiently model the equilibrium
problem in unbounded domains by discretizing only the plasma region; the external
conductors can be modelled either as 2D or 3D models, according to the problem of interest. The paper explores different iterative methods for the solution of the nonlinear
Grad-Shafranov equation, such as Picard, Newton-Raphson and Newton-Krylov, in order to provide a robust and reliable tool, able to handle large-scale problems (e.g. high
resolution equilibria). This method has been implemented in the FRIDA code (FRee-boundary Integro-Differential Axisimmetric – https://github.
om/matteobonotto/
FRIDA), together with a suitable Adaptive Integration Technique (AIT) for the computation of the source term. FRIDA has been successfully tested and validated against
experimental data from RFX-mod device, and numerical equilibria of an ITER-like device. 相似文献
3.
Noreen M. Walsh Heinz Kutzner Luis Requena Lorenzo Cerroni 《Journal of cutaneous pathology》2019,46(9):698-708
We review the spectrum of cutaneous disorders associated with inflammatory and neoplastic plasmacytic pathology. Because plasma cells are derived from B‐lymphocytes our overview includes discussion of certain lymphoplasmacytic proliferations. It is structured along histopathological lines, addressing conditions characterized by (a) cutaneous plasma cell infiltrates, (b) deposits of plasma cell products or their derivatives in the skin and (c) miscellaneous, poorly understood cutaneous complications of plasmacytic disorders. Lesions arising primarily in the skin and those due to cutaneous involvement by multisystem disorders are addressed. The range includes a spectrum of tumefactive and circulatory manifestations. We highlight key clinical and pathological features of the different conditions and outline recent advances in our understanding of these entities. By emphasizing the dermatopathological characteristics of this spectrum of disorders we hope to hone the diagnostic accuracy of practitioners in the field. 相似文献
4.
Osric A. Forrest Daniel M. Chopyk Yael Gernez Milton R. Brown Carol K. Conrad Richard B. Moss Vin Tangpricha Limin Peng Rabindra Tirouvanziam 《Journal of cystic fibrosis》2019,18(1):64-70
Background
Resistin is an immunometabolic mediator that is elevated in several inflammatory disorders. A ligand for Toll-like receptor 4, resistin modulates the recruitment and activation of myeloid cells, notably neutrophils. Neutrophils are major drivers of cystic fibrosis (CF) lung disease, in part due to the release of human neutrophil elastase- and myeloperoxidase-rich primary granules, leading to tissue damage. Here we assessed the relationship of resistin to CF lung disease.Methods
Resistin levels were measured in plasma and sputum from three retrospective CF cohorts spanning a wide range of disease. We also assessed the ability of neutrophils to secrete resistin upon activation in vitro. Finally, we constructed a multivariate model assessing the relationship between resistin levels and lung function.Results
Plasma resistin levels were only marginally higher in CF than in healthy control subjects. By contrast, sputum resistin levels were very high in CF, reaching 50–100 fold higher levels than in plasma. Among CF patients, higher plasma resistin levels were associated with allergic bronchopulmonary aspergillosis, and higher sputum resistin levels were associated with CF-related diabetes. Mechanistically, in vitro release of neutrophil primary granules was concomitant with resistin secretion. Overall, sputum resistin levels were negatively correlated with CF lung function, independently of other variables (age, sex, and genotype).Conclusions
Our data establish relationships between resistin levels in the plasma and sputum of CF patients that correlate with disease status, and identify resistin as a novel mechanistic link between neutrophilic inflammation and lung disease in CF. 相似文献5.
目的 探究高糖饮食对小鼠真菌性角膜炎的影响。方法 选取健康无眼疾的雄性C57BL/6J小鼠78只,随机分为高糖饮食组和模型对照组,每组36只,模型对照组给予正常饮用水,高糖饮食组给予含体积分数10%果糖溶液,每2 d测量两组小鼠体质量及血糖,10 d后建立真菌性角膜炎模型。造模后24 h、36 h、48 h、72 h、96 h、120 h、168 h裂隙灯显微镜下对角膜进行临床评分并拍照。处死小鼠后,取角膜组织进行HE染色和PAS染色;测定角膜内中性粒细胞和巨噬细胞浸润体积。利用酶联免疫吸附实验对小鼠角膜内的白细胞介素-1β含量进行测定。结果 造模后 0~14 d,两组小鼠体质量与血糖差异均无统计学意义(均为P>0.05)。造模后24 h、36 h、48 h、120 h、168 h,高糖饮食组小鼠角膜临床评分均明显高于模型对照组,差异均有统计学意义(均为P<0.05)。高糖饮食组小鼠角膜穿孔率79.5%,高于模型对照组的40.9%,差异有统计学意义(P=0.000)。造模后各时间点,高糖饮食组中性粒细胞浸润体积均高于模型对照组,差异均有统计学意义(均为P=0.000)。造模后72 h、96 h、120 h、168 h,高糖饮食组巨噬细胞浸润体积均高于模型对照组(均为P=0.000)。角膜组织病理学检查结果示,高糖饮食组炎症反应更重,角膜组织破坏更早且更为严重。造模后24 h、48 h高糖饮食组白细胞介素-1β含量均明显高于模型对照组(均为P<0.05)。结论 高糖饮食加重了真菌性角膜炎感染的严重程度,增强了中性粒细胞、巨噬细胞的趋化,促进了IL-1β的分泌。 相似文献
6.
7.
Pierre Tiberghien Xavier de Lamballerie Pascal Morel Pierre Gallian Karine Lacombe Yazdan Yazdanpanah 《Vox sanguinis》2020,115(6):488-494
Plasma provided by COVID-19 convalescent patients may provide therapeutic relief as the number of COVID-19 cases escalates steeply worldwide. Prior findings in various viral respiratory diseases including SARS-CoV-related pneumonia suggest that convalescent plasma can reduce mortality, although formal proof of efficacy is still lacking. By reducing viral spread early on, such an approach may possibly downplay subsequent immunopathology. Identifying, collecting, qualifying and preparing plasma from convalescent patients with adequate SARS-CoV-2-neutralizing Ab titres in an acute crisis setting may be challenging, although well within the remit of most blood establishments. Careful clinical evaluation should allow to quickly establish whether such passive immunotherapy, administered at early phases of the disease in patients at high risk of deleterious evolution, may reduce the frequency of patient deterioration, and thereby COVID-19 mortality. 相似文献
8.
9.
10.