全文获取类型
收费全文 | 824篇 |
免费 | 53篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 27篇 |
妇产科学 | 26篇 |
基础医学 | 142篇 |
口腔科学 | 23篇 |
临床医学 | 96篇 |
内科学 | 196篇 |
皮肤病学 | 15篇 |
神经病学 | 64篇 |
特种医学 | 20篇 |
外科学 | 78篇 |
综合类 | 12篇 |
预防医学 | 50篇 |
眼科学 | 23篇 |
药学 | 71篇 |
中国医学 | 8篇 |
肿瘤学 | 30篇 |
出版年
2024年 | 1篇 |
2023年 | 14篇 |
2022年 | 27篇 |
2021年 | 76篇 |
2020年 | 34篇 |
2019年 | 42篇 |
2018年 | 53篇 |
2017年 | 46篇 |
2016年 | 41篇 |
2015年 | 32篇 |
2014年 | 40篇 |
2013年 | 49篇 |
2012年 | 77篇 |
2011年 | 68篇 |
2010年 | 39篇 |
2009年 | 43篇 |
2008年 | 35篇 |
2007年 | 44篇 |
2006年 | 33篇 |
2005年 | 19篇 |
2004年 | 19篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 8篇 |
2000年 | 11篇 |
1999年 | 6篇 |
1998年 | 1篇 |
1990年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有884条查询结果,搜索用时 31 毫秒
1.
The finite element model for the propagation of light in scattering media: a direct method for domains with nonscattering regions 总被引:2,自引:0,他引:2
We present a method for handling nonscattering regions within diffusing domains. The method develops from an iterative radiosity-diffusion approach using Green's functions that was computationally slow. Here we present an improved implementation using a finite element method (FEM) that is direct. The fundamental idea is to introduce extra equations into the standard diffusion FEM to represent nondiffusive light propagation across a nonscattering region. By appropriate mesh node ordering the computational time is not much greater than for diffusion alone. We compare results from this method with those from a discrete ordinate transport code, and with Monte Carlo calculations. The agreement is very good, and, in addition, our scheme allows us to easily model time-dependent and frequency domain problems. 相似文献
2.
Amin Sadeghi Dousari Seyed Soheil Hosseininasab Fatemeh Sadeghi Dousari Masoumeh Fuladvandi Naghmeh Satarzadeh 《World Journal of Virology》2023,12(2):91-99
The coronavirus disease 2019 (COVID-19) disease was first detected in December 2019 in Wuhan, China. This disease is currently one of the most important global health problems. The novel coronavirus COVID-19 is a respiratory illness, that has caused a deadly pandemic that is spreading rapidly around the world. It is not only a respiratory system virus that causes severe lung disease, but also a systemic disease agent that can affect all systems. People with COVID-19 disease usually have respiratory signs, however, the liver disorder is not an uncommon presentation. In addition, many studies around the world have revealed that the liver is injured to various degrees in patients with severe acute respiratory syndrome coronavirus 2 disease. This review mainly focuses on the impact of COVID-19 on Liver Injury at various ages. 相似文献
3.
Kiani Zahra Simbar Masoumeh Nazarpour Soheila Rashidi Fakari Farzaneh 《Archives of sexual behavior》2022,51(7):3223-3224
Archives of Sexual Behavior - 相似文献
4.
David P. Bazett-Jones Ren Li Eden Fussner Rosa Nisman Hesam Dehghani 《Chromosome research》2008,16(3):397-412
Electron microscopy has been the ‘gold standard’ of spatial resolution for studying the structure of the cell nucleus. Electron
spectroscopic imaging (ESI) offers advantages over conventional transmission electron microscopy by eliminating the need for
heavy-atom contrast agents. ESI also provides mass-dependent and element-specific information at high resolution, permitting
the distinguishing of structures that are primarily composed of protein, DNA, or RNA. The technique can be applied to understand
the structural consequences of epigenetic modifications, such as modified histones, on chromatin fiber morphology. ESI can
also be applied to elucidate the multifunctional behavior of subnuclear ‘organelles’ such as the nucleolus and promyelocytic
leukemia nuclear bodies.
The authors dedicate this paper to the memory of Ying Ren (1961–2007). We all benefited from knowing her. Our research advanced
through the technical creativity she provided. 相似文献
5.
Behrooz Nikahval Seifollah Dehghani Nazhvani Mohammad Hadi Bagheri Nader Tanideh Mehrangiz Keramati Hamid Reza Gheisari 《Comparative clinical pathology》2012,21(6):1451-1456
The objectives of the present study were to describe radiographic and magnetic resonance imaging (MRI) findings of early osteoarthritis and their relationships at the same time. A total number of ten rabbits were used and randomly divided into two equal groups. In one group, cranial cruciate ligament (CCL) of the left knee was transected to produce experimental osteoarthritis and in the other group, only the articular capsule was entered as sham operation (arthrotomy group). All of the left knees were examined by MRI and radiography before operation to exclude preexisting abnormalities and serve as control. One month postoperation, two conventional radiographic views and MR imaging were performed under general anesthesia. Statistical analysis of the MRI results revealed that there was a significant difference between the CCL-transected group with arthrotomy and control groups. There was no significant difference in the radiographic findings between the operated, arthrotomy and control groups. It was concluded that osteoarthritic changes of the joints can be detectable 1?month postinjury by MRI. Meniscal degeneration and subchondral bone irregularity are detectable diagnostic signs. 相似文献
6.
Ilnaz Sahragard Yahya Tahamtan Majid Valadan Masoumeh Hyati Farid Moazeni Zahra Shirazi 《Comparative clinical pathology》2012,21(6):1333-1336
Toxigenicity, species, and type species of Pasteurella multocida isolates cannot be differentiated by morphology or standard biochemical reactions. A more rapid method is needed for P. multocida detection from clinical cases. These findings provide rapid insights into the characteristics of P. multocida isolates and suggest that this method can identify toxigenic and specific capsular type P. multocida. A PCR assay has been developed for rapid detection of P. multocida and differentiation of capsular types A and D. In this rapid method, kmt1, capA and capD, and toxA genes were amplified and a reliable multiplex PCR method for the detection of P. multocida in sheep and goats in the south of Iran was designed. Twenty isolates were obtained, which evinced characteristic morphological and cultural properties. Ten samples were identified simultaneously through the presence of the kmt1 gene as P. multocida species, the hydD–hydC gene as type A capsule, and the toxA gene as dermonecrotic toxin by mPCR, but none of them belonged to type D. 相似文献
7.
8.
High rate of A2142G point mutation associated with clarithromycin resistance among Iranian Helicobacter pylori clinical isolates 下载免费PDF全文
Reza Khashei Mahintaj Dara Abdollah Bazargani Kamran Bagheri Lankarani Alireza Taghavi Maryam Moeini Behzad Dehghani Maryam Sohrabi 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2016,124(9):787-793
This study aimed to investigate the clarithromycin resistance and its associated molecular mechanisms among Helicobacter pylori isolates from dyspeptic patients in Shiraz, Iran. From January to May 2014, 100 H. pylori strains were isolated from patients with gastroduodenal disorders. The resistance to clarithromycin was quantitatively evaluated, using Epsilometer (E‐test) method. Polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) was performed on all the isolates to detect A2143G and A2142G mutations in 23S rRNA gene. The H. pylori isolation rate was found to be 31.4%. E‐test showed that 20% of isolates were resistant to clarithromycin (MIC ≥ 1 mg/L). MIC of clarithromycin ranged between 0.016 and 24 mg/L. Findings of PCR‐RFLP showed that the A2142G was the most (90%) frequently point mutation, followed by the A2143G (10%). No statistically significant difference was found between H. pylori clarithromycin resistance point mutations and patients’ gender or age. To the best of our knowledge, this is the first report of high frequency of A2142G point mutation in Iran and probably in other regions of the world. Considering the increasing trend of H. pylori resistance to clarithromycin due to these mutations, it is crucial to investigate the new therapeutic approaches against H. pylori infection. 相似文献
9.
10.
The association between obesity and migraine in a population of Iranian adults: a case-control study
Ali Miri Morteza Nasiri Sahar Zonoori Fatemeh Yarahmad Arasb Dabbagh-Moghadam Gholamreza Askari Omid Sadeghi Masoumeh Asadi 《Diabetes & Metabolic Syndrome: Clinical Research & Reviews》2018,12(5):733-736