全文获取类型
收费全文 | 251篇 |
免费 | 23篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 9篇 |
妇产科学 | 3篇 |
基础医学 | 45篇 |
口腔科学 | 1篇 |
临床医学 | 14篇 |
内科学 | 40篇 |
皮肤病学 | 12篇 |
神经病学 | 25篇 |
特种医学 | 4篇 |
外科学 | 25篇 |
综合类 | 8篇 |
预防医学 | 39篇 |
眼科学 | 3篇 |
药学 | 16篇 |
肿瘤学 | 27篇 |
出版年
2023年 | 4篇 |
2022年 | 9篇 |
2021年 | 14篇 |
2020年 | 13篇 |
2019年 | 15篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 10篇 |
2015年 | 11篇 |
2014年 | 17篇 |
2013年 | 13篇 |
2012年 | 15篇 |
2011年 | 22篇 |
2010年 | 12篇 |
2009年 | 5篇 |
2008年 | 15篇 |
2007年 | 15篇 |
2006年 | 10篇 |
2005年 | 16篇 |
2004年 | 17篇 |
2003年 | 9篇 |
2002年 | 7篇 |
2001年 | 2篇 |
1999年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1991年 | 1篇 |
1978年 | 1篇 |
排序方式: 共有275条查询结果,搜索用时 15 毫秒
11.
12.
Rodríguez-Tizcareño MH Barajas L Pérez-Gásque M Gómez S 《Journal of the California Dental Association》2012,40(6):509-517
This report presents a protocol used to transfer the virtual treatment plan data to the surgical and prosthetic reality and its clinical application, bone site augmentation with computer-custom milled bovine bone graft blocks to their ideal architecture form, implant insertion based on image-guided stent fabrication, and the restorative manufacturing process through computed tomography-based software programs and navigation systems and the computer-aided design and manufacturing techniques for the treatment of the edentulous maxilla. 相似文献
13.
Carlos R. Hernandez‐Castillo PhD Sarael Alcauter PhD Victor Galvez MSci Fernando A. Barrios PhD Petra Yescas PhD Adriana Ochoa Msci Lizbeth Garcia MSci Rosalinda Diaz MSci Wei Gao PhD Juan Fernandez‐Ruiz PhD 《Movement disorders》2013,28(12):1708-1716
Spinocerebellar ataxia type 7 (SCA7) is an autosomal‐dominant neurodegenerative disorder characterized by progressive ataxia and retinal dystrophy. It is caused by a CAG trinucleotide expansion in the ataxin7 gene. Anatomical studies have shown severe cerebellar degeneration and region‐specific neocortical atrophy in SCA7 patients. However, the impact of the neurodegeneration on the functional integration of the remaining tissue is still unknown. The aim of this study was to examine functional connectivity abnormalities in areas with significant gray matter atrophy in SCA7 patients and their relationship with number of CAG repeats. Using a combination of voxel‐based morphometry and resting‐state fMRI, we studied 26 genetically confirmed SCA7 patients and aged‐matched healthy controls. In SCA7 patients we found reduced functional interaction between the cerebellum and the middle and superior frontal gyri, disrupted functional connectivity between the visual and motor cortices, and increased functional coordination between atrophied areas of the cerebellum and a range of visual cortical areas compared with healthy controls. The degree of mutation expansion showed a negative effect on both the functional interaction between the right anterior cerebellum and the left superior frontal gyrus and the connectivity between the right anterior cerebellum and left parahippocampal gyrus. We found abnormal functional connectivity patterns, including both hypo‐ and hyperconnectivity, compared with controls. These abnormal patterns show reasonable association with the severity of gene mutation. Our findings suggest that aberrant changes are prevalent in both motor and visual systems, adding significantly to our understanding of the pathophysiology of SCA7. © 2013 International Parkinson and Movement Disorder Society 相似文献
14.
Lizbeth López-Carrillo Raúl Ulises Hernández-Ramírez A. Jay Gandolfi José Manuel Ornelas-Aguirre Luisa Torres-Sánchez Mariano E. Cebrian 《Toxicology and applied pharmacology》2014
Exposure to environmental contaminants, dietary factors and lifestyles may explain worldwide different breast cancer (BC) incidence. Inorganic arsenic (iAs) in the drinking water is a concern in many regions, such as northern Mexico. Studies in several countries have associated the proportion of urinary monomethylarsenic (%MMA) with increased risks for many As-related diseases, including cancer. To investigate the potential relationships between the risk of BC and the capacity to methylate iAs, a hospital-based case–control study (1016 cases/1028 controls) was performed in northern Mexico. Women were directly interviewed about their reproductive histories. The profile of As metabolites in urine was determined by HPLC-ICP-MS and methylation capacity was assessed by metabolite percentages and indexes. Total urinary As, excluding arsenobetaine (TAs-AsB), ranged from 0.26 to 303.29 μg/L. Most women (86%) had TAs-AsB levels below As biological exposure index (35 μg/L). Women with higher %MMA and/or primary methylation index (PMI) had an increased BC risk (%MMA ORQ5vs.Q1 = 2.63; 95%CI 1.89,3.66; p for trend < 0.001; PMI ORQ5vs.Q1 = 1.90; 95%CI 1.39,2.59, p for trend < 0.001). In contrast, women with higher proportion of urinary dimethylarsenic (%DMA) and/or secondary methylation index (SMI) had a reduced BC risk (%DMA ORQ5vs.Q1 = 0.63; 95%CI 0.45,0.87, p for trend 0.006; SMI ORQ5vsQ1 = 0.42, 95%CI 0.31,0.59, p for trend < 0.001). Neither %iAs nor total methylation index was associated to BC risk. Inter-individual variations in iAs metabolism may play a role in BC carcinogenesis. Women with higher capacity to methylate iAs to MMA and/or a lower capacity to further methylate MMA to DMA were at higher BC risk. 相似文献
15.
Striepen B Pruijssers AJ Huang J Li C Gubbels MJ Umejiego NN Hedstrom L Kissinger JC 《Proceedings of the National Academy of Sciences of the United States of America》2004,101(9):3154-3159
Nucleotide metabolic pathways provide numerous successful targets for antiparasitic chemotherapy, but the human pathogen Cryptosporidium parvum thus far has proved extraordinarily refractory to classical treatments. Given the importance of this protist as an opportunistic pathogen afflicting immunosuppressed individuals, effective treatments are urgently needed. The genome sequence of C. parvum is approaching completion, and we have used this resource to critically assess nucleotide biosynthesis as a target in C. parvum. Genomic analysis indicates that this parasite is entirely dependent on salvage from the host for its purines and pyrimidines. Metabolic pathway reconstruction and experimental validation in the laboratory further suggest that the loss of pyrimidine de novo synthesis is compensated for by possession of three salvage enzymes. Two of these, uridine kinase-uracil phosphoribosyltransferase and thymidine kinase, are unique to C. parvum within the phylum Apicomplexa. Phylogenetic analysis suggests horizontal gene transfer of thymidine kinase from a proteobacterium. We further show that the purine metabolism in C. parvum follows a highly streamlined pathway. Salvage of adenosine provides C. parvum's sole source of purines. This renders the parasite susceptible to inhibition of inosine monophosphate dehydrogenase, the rate-limiting enzyme in the multistep conversion of AMP to GMP. The inosine 5' monophosphate dehydrogenase inhibitors ribavirin and mycophenolic acid, which are already in clinical use, show pronounced anticryptosporidial activity. Taken together, these data help to explain why widely used drugs fail in the treatment of cryptosporidiosis and suggest more promising targets. 相似文献
16.
Jessica Roberts Williams PhD MPH RN Stephen J. Tregear DPhil Tracy Dusablon PhD Lizbeth E. Caceda-Castro MEd Kristin J. Miller MSW Gary Hill PhD Kevin D. Hennessy PhD 《The journal of behavioral health services & research》2014,41(3):258-275
Increased efforts in comparative effectiveness research (CER) (comparing various health care intervention and treatment options) are being used to inform health care delivery. While CER research itself is an important step in developing best practices in health care, it is not enough to ensure success. The knowledge must also be successfully disseminated to increase adoption and implementation of practices. To ensure the greatest benefits of successful interventions, it is essential to understand which dissemination strategies are effective and under what conditions. This article provides the background and methodology used in a large-scale, 2-year study aimed at determining how knowledge gained from CER research may be most effectively disseminated to those responsible for delivering behavioral health services. The study takes an important step toward addressing the gaps in dissemination and translation of CER. 相似文献
17.
Lizbeth E. García-Velázquez Samuel Canizales-Quinteros Sandra Romero-Hidalgo Adriana Ochoa-Morales Leticia Martínez-Ruano Carla Márquez-Luna Víctor Acuña-Alonzo M. Teresa Villarreal-Molina M. Elisa Alonso-Vilatela Petra Yescas-Gómez 《Neurogenetics》2014,15(1):13-17
Spinocerebellar ataxia type 7 (SCA7) is an autosomal dominant disease characterized by progressive cerebellar ataxia and macular degeneration causing progressive blindness. It accounts for 1 to 11.6 % of spinocerebellar ataxias (SCAs) cases worldwide and for 7.4 % of SCA7 cases in Mexico. We identified a cluster of SCA7 families who resided in a circumscribed area of Veracruz and investigated whether the high incidence of the disease in this region was due to a founder effect. A total of 181 individuals from 20 families were studied. Four microsatellite markers and one SNP flanking the ATNX7 gene were genotyped and the ancestral origin and local ancestry analysis of the SCA7 mutation were evaluated. Ninety individuals from 19 families had the SCA7 mutation; all were found to share a common haplotype, suggesting that the mutation in these families originated from a common ancestor. Ancestral origin and local ancestry analysis of SCA7 showed that the chromosomal segment containing the mutation was of European origin. We here present evidence strongly suggesting that the high frequency of SCA7 in Veracruz is due to a founder effect and that the mutation is most likely of European origin with greatest resemblance to the Finnish population. 相似文献
18.
Esteban Arrieta-Bolaños J. Alejandro Madrigal Steven G.E. Marsh Bronwen E. Shaw Lizbeth Salazar-Sánchez 《Human immunology》2014
HLA-B∗57:01 is a well-known and cost-effective pharmacogenetic marker for abacavir hypersensitivity. As with other HLA alleles, there is widespread variation in its frequency across populations. The Costa Rica Central Valley Population (CCVP) is the major population in this country. The frequency of HLA-B∗57:01 in this population has not been described yet. Thus, our aim was to determine the frequency of this allele in the CCVP. 200 unrelated healthy volunteer donors born in the CCVP were typed. HLA-B∗57-positive samples identified by HLA intermediate resolution typing methods were further typed by SBT to high resolution. An HLA-B∗57:01 carrier frequency of 5.00% was determined in this sample. This frequency is relatively high in comparison to reports from other populations in Latin America. These results suggest that there is a considerable frequency of HLA-B∗57:01 in the CCVP and that pharmacogenetic testing for HIV+ patients who are going to receive abacavir-based treatment should be considered in this country. 相似文献
19.
20.
Lady D Ladino Lizbeth Hernández‐Ronquillo José F. Téllez‐Zenteno 《Epileptic Disord》2014,16(3):343-353
Aim. Previous studies support the concept that obesity is a common comorbid condition in patients with epilepsy (PWE). In this study, we present the body mass index (BMI) and data from a survey to assess physical activity in a sample of PWE from an epilepsy clinic. Methods. Between June of 2011 and January of 2013, 100 PWE from an adult epilepsy clinic were included. We obtained BMI, waist circumference, and information regarding physical activity using a standardised questionnaire. Clinical, demographic, electrographic, and imaging parameters were collected from charts. Results. Mean age of patients was 40±14 (18–77) years. The BMI distribution was as follows: 2 patients (2%) underweight, 26 (26%) normal weight, 34 (34%) overweight, 25 (25%) obese, and 13 (13%) with morbid obesity. In our study, obesity was defined as having a BMI ≥30. We found 38 (38%) patients in this range. There was no difference in the rate of drug‐resistant epilepsy between obese and non‐obese patients (55 vs. 55%; p=0.05). Leisure time habit was reported in 82% of obese patients and 79% of patients without obesity. Overall, the most frequent activity was walking (70%). Factors associated with obesity were generalised epilepsy (OR: 2.7, 1.1–6.6; p=0.012), idiopathic syndrome (OR: 2.7, 1.04–7; p=0.018), and family history of epilepsy (OR: 6.1, 1.5–24.2; p=0.002). Conclusion. Our study suggests an association between obesity, idiopathic generalised epilepsy, and family history of epilepsy. Our study shows that PWE are physically active and there is no clear relation between exercise and obesity. We could not identify any association between drug‐resistant epilepsy and obesity. Absence of direct comparison with a control non‐epileptic population; a cross‐sectional design not allowing evaluation of a causal association among variables; and reliance on self‐reported physical activity are to be considered as limitations of the present study. 相似文献