全文获取类型
收费全文 | 1449篇 |
免费 | 95篇 |
国内免费 | 10篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 51篇 |
妇产科学 | 34篇 |
基础医学 | 229篇 |
口腔科学 | 82篇 |
临床医学 | 161篇 |
内科学 | 279篇 |
皮肤病学 | 12篇 |
神经病学 | 187篇 |
特种医学 | 23篇 |
外科学 | 88篇 |
综合类 | 5篇 |
预防医学 | 120篇 |
眼科学 | 28篇 |
药学 | 76篇 |
中国医学 | 5篇 |
肿瘤学 | 153篇 |
出版年
2024年 | 2篇 |
2023年 | 24篇 |
2022年 | 43篇 |
2021年 | 74篇 |
2020年 | 29篇 |
2019年 | 41篇 |
2018年 | 48篇 |
2017年 | 37篇 |
2016年 | 53篇 |
2015年 | 47篇 |
2014年 | 62篇 |
2013年 | 87篇 |
2012年 | 146篇 |
2011年 | 137篇 |
2010年 | 72篇 |
2009年 | 50篇 |
2008年 | 84篇 |
2007年 | 78篇 |
2006年 | 84篇 |
2005年 | 88篇 |
2004年 | 76篇 |
2003年 | 69篇 |
2002年 | 53篇 |
2001年 | 6篇 |
2000年 | 1篇 |
1999年 | 7篇 |
1998年 | 9篇 |
1997年 | 2篇 |
1996年 | 9篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1989年 | 1篇 |
1987年 | 1篇 |
1986年 | 3篇 |
1985年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1944年 | 1篇 |
1942年 | 1篇 |
排序方式: 共有1554条查询结果,搜索用时 0 毫秒
1.
Cesar G. Victora Nubia Muoz Nicholas E. Day Lucio B. Barcelos Debora A. Peccin Noris M. Braga 《International journal of cancer. Journal international du cancer》1987,39(6):710-716
There is a cluster of high-incidence areas of oesophageal cancer in south-eastern South America, including Southern Brazil, Uruguay and parts of Argentina. The present case-control study investigated the hypothesis that this may be due to the drinking of maté, a traditional beverage drunk at a very high temperature, and also studied the role of other known risk factors such as alcohol and tobacco. Cases (171) and age- and sex-matched controls (342) were recruited from hospitals in the State of Rio Grande do Sul in Southern Brazil. The crude odds ratio for daily maté drinkers was 1.92 relative to those drinking less frequently than daily (p = 0.006). Other risk factors included the drinking of cachaça (a sugar cane spirit), smoking, rural residence, low fruit consumption and high intake of meats. After adjustment for these variables through conditional logistic regression, the odds ratio associated with daily maté drinking was reduced to 1.47 (90% CI = 0.87 - 2.50). Although the study failed to provide evidence of a strong association between maté and oesophageal cancer, the cluster of high rates could be explained by relative risks of the magnitude observed. This is due to the fact that approximately 70% of adult males and 50% of females are daily drinkers. In addition, this study revealed that alcohol, tobacco smoking and rural residence are the main risk factors for oesophageal cancer in this population and the fruit consumption confers some degree of protection. 相似文献
2.
3.
Alberto Falchetti Marco Di Stefano Francesca Marini Francesca Del Monte Carmelo Mavilia Debora Strigoli Maria L De Feo Giovan Isaia Laura Masi Antonietta Amedei Federica Cioppi Valentina Ghinoi Susanna Maddali Bongi Giuseppina Di Fede Carmela Sferrazza Giovan B Rini Daniela Melchiorre Marco Matucci-Cerinic Maria L Brandi 《Journal of bone and mineral research》2004,19(6):1013-1017
PDB is genetically heterogeneous. Mutations of the sequestosome1 gene have been reported in sporadic and familial forms of Paget's in patients of French Canadian and British descent. Mutational analyses in different ethnic groups are needed to accurately investigate hereditary diseases. We describe two novel mutations of sequestosome1 in 62 Italian sporadic patients, confirming the role of the encoded protein in this disorder. INTRODUCTION: Paget's disease of bone (PDB) is a relatively common disease of bone metabolism reported to affect up to 3% of whites over 55 years of age. The disorder is genetically heterogeneous, and at present, there is scientific evidence that at least eight different human chromosomal loci are correlated with its pathogenesis. Mutations of the sequestosome1 (SQSTM1) gene were identified as responsible for most of the sporadic and familial forms of Paget in patients of French Canadian and British descent. Such mutations were located at exon 7 and 8 levels, encoding for the ubiquitin protein-binding domain (UBA) and representing a mutational hot spot area. MATERIALS AND METHODS: To verify the involvement of this gene in Italian subjects affected by PDB, we performed mutational analysis in 62 sporadic PDB cases. RESULTS: We described three different mutations at exon 8 level: P392L, already described in the French Canadian population and families predominantly of British descendent, and two novel mutations consisting of the amino acid substitutions M404V and G425R. No significant differences in the clinical history of PDB have been observed in patients with SQSTM1 mutations in respect to those without. CONCLUSIONS: Even though our findings suggest a minor involvement of the SQSTM1 gene in the pathogenesis of sporadic Italian Paget's cases, the identification of different significant mutations within the SQSTM1 gene in unrelated, but clinically similar individuals, offers extremely convincing evidence for a causal relationship between this gene and PDB. Longitudinal studies are needed to assess the penetrance of genotype/phenotype correlations. Our findings confirm the evidence of a clustered mutation area at this level in this disorder. 相似文献
4.
Debora Steiner Tomer Avidor-Reiss Ester Schallmach Daniella Saya Zvi Vogel 《Journal of molecular neuroscience : MN》1996,27(2):195-203
It was shown previously that chronic exposure to opiate agonists increases adenylyl cyclase (AC) activity, a phenomenon termed
AC superactivation (or supersensitization). More recently, we showed that acute Gi/o-coupled receptor activation inhibits the activity of several AC isozymes, including Ca2+/calmodulin-stimulated AC-I and -VIII, whereas chronic receptor activation induces their superactivation. Here, we report
that both acute μ-opioid receptor-induced inhibition and chronic induced superactivation of AC-I and -VIII are pertussis toxin
sensitive. In addition, we show that proteins that interfere with the activity of {ie195-2} subunits ({ie195-3} scavengers)
strongly attenuate the acute inhibition of AC-I and -VIII and the superactivation of AC-I, and abolish the superactivation
of AC-VIII. Based on these results, we suggest that {ie195-4} is involved in the acute inhibition and chronic agonist-induced
superactivation of AC types I and VIII. 相似文献
5.
De Luca A Buccino A Gianni D Mangino M Giustini S Richetta A Divona L Calvieri S Mingarelli R Dallapiccola B 《Human mutation》2003,21(2):171-172
The high mutation rate at the NF1 locus results in a wide range of molecular abnormalities. The majority of these mutations are private and rare, generating elevated allelic diversity with a restricted number of recurrent mutations. In this study, we have assessed the efficacy of denaturing high-performance liquid chromatography (DHPLC), for detecting mutation in the NF1 gene. DHPLC is a fast and highly sensitive technique based on the detection of heteroduplexes in PCR products by ion pair reverse-phase HPLC under partially denaturing conditions. We established theoretical conditions for DHPLC analysis of all coding exons and splice junctions of the NF1 gene using the WAVEmaker software version 4.1.40 and screened for mutations a panel of 40 unrelated NF1 patients (25 sporadic and 15 familial), genetically uncharacterized. Disruptive mutations were identified in 29 individuals with an overall mutation detection rate of 72.5%. The mutations included eight deletions (exons 4b, 7, 10a, 14, 26, and 31), one insertion (exon 8), nine nonsense mutation (exons 10a, 13, 23.1, 27a, 29, 31, and 36), six missense mutations (exons 15, 16, 17, 24, and 31), four splice errors (exons 11, 14, 36, and 40) and a complex rearrangement within exon 16. Eighteen (62%) of the identified disruptive mutations are novel. Seven unclassified and three previously reported polymorphisms were also detected. None of the missense mutations identified in this study were found after screening of 150 controls. Our results suggest that DHPLC provides an accurate method for the rapid identification of NF1 mutations. 相似文献
6.
Paola Origone Carlo Bellini Debora Sambarino Barbara Banelli Guido Morcaldi Carmen La Rosa Franco Stanzial Claudio Castellan Domenico A. Coviello Cecilia Garrè Eugenio Bonioli 《Human mutation》2003,22(4):341-341
In the original version of this article, the title was incorrect. Please find the correct title given here. The publisher deeply regrets this error. The original article to which this Erratum refers was published in Human Mutation 22:179–180 Human Mutation(2003) 22(2) 179–180 相似文献
7.
Dobrovolny R Dvorakova L Ledvinova J Magage S Bultas J Lubanda JC Elleder M Karetova D Pavlikova M Hrebicek M 《Journal of molecular medicine (Berlin, Germany)》2005,83(8):647-654
We have identified 21 different -galactosidase A gene (GLA) mutations in 22 unrelated Czech and Slovak families with Fabry disease. Eleven of these mutations were novel (point mutations D93N, A135V, D155H, G171R, Q280K, G360S, Q330X, splicing errors c.194ins14, c.801ins36 and deletions c.674_732del59, g.3405_6021del2617). Genotyping of family members for family-specific mutations revealed 55 heterozygotes that manifested clinical symptoms of different severity. To examine the contribution of X-inactivation skewing to disease manifestation in Fabry heterozygotes, we have adopted the Mainz severity scoring scheme and compared the score values with the X-inactivation status in 39 carriers in an age-dependent manner. The age-score trendline of Fabry females who had a predominantly inactivated X-chromosome bearing a wild-type GLA allele (10 of 38 females) was markedly steeper than in the rest of the cohort. One female carrier with an inactivated mutated allele had a low score value when compared to the other heterozygotes of the same age. These data suggest that X-inactivation is indeed a major factor determining the severity of clinical involvement in Fabry heterozygotes. There was a statistically significant difference between the severity score values of heterozygotes with random and non-random X-chromosome inactivation at the 5% level of significance. Further studies will show if the degree of the wildtype allele inactivation will be useful as a predictive marker of severity of phenotype in Fabry heterozygotes. Although the correlation between X-inactivation skewing and presentation of the disease in Fabry heterozygotes has previously been suggested in the literature, this report is among the first attempts to examine this relationship systematically. 相似文献
8.
Davide Serrano Chiara Pozzi Silvia Guglietta Bruno Fosso Mariano Suppa Patrizia Gnagnarella Federica Corso Federica Bellerba Debora Macis Valentina Aristarco Paolo Manghi Nicola Segata Cristina Trovato Maria Giulia Zampino Marinella Marzano Bernardo Bonanni Maria Rescigno Sara Gandini 《Nutrients》2021,13(2)
Obesity and diet are associated with colorectal cancer (CRC) risk, and microbiome could mediate this risk factor. To investigate this interaction, we performed a case–control study (34 CRC cases and 32 controls) and analyzed fecal microbiota composition using 16S rRNA metabarcoding and sub-sequential shotgun analyses of genomic bacterial DNA to evaluate the role of microbiome and diet in CRC etiology, taking into account vitamin D and other risk biomarkers. Dietary habits were evaluated using a short questionnaire. Multivariate methods for data integration and mediation analysis models were used to investigate causal relationships. CRC cases were significantly more often deficient in vitamin D than controls (p = 0.04); FokI and CYP24A1 polymorphism frequency were different between cases and controls (p = 0.03 and p = 0.02, respectively). A diet poor in fatty fish and rich in carbohydrates was found to be significantly associated with CRC risk (p = 0.011). The mediation analysis confirmed the significant role of the microbiome in mediating CRC risk—increasing levels of Bifidobacteria/Escherichia genera ratio, an indicator of “healthy” intestinal microbiome, can overcome the effect of diet on CRC risk (p = 0.03). This study suggests that microbiome mediates the diet effect on CRC risk, and that vitamin D, markers of inflammation, and adipokines are other factors to consider in order to achieve a better knowledge of the whole carcinogenic process. 相似文献
9.
Charles Varnell Jr Lyndsay A. Harshman Laurie Smith Chunyan Liu Shiran Chen Samhar Al-Akash Gina-Marie Barletta Craig Belsha Paul Brakeman Abanti Chaudhuri Paul Fadakar Rouba Garro Caroline Gluck Jens Goebel David Kershaw Debora Matossian Corina Nailescu Hiren P. Patel Cozumel Pruette Saritha Ranabothu Nancy Rodig Jodi Smith Judith Sebestyen VanSickle Patricia Weng Lara Danziger-Isakov David K. Hooper Michael Seifert 《American journal of transplantation》2021,21(8):2740-2748
There are limited data on the impact of COVID-19 in children with a kidney transplant (KT). We conducted a prospective cohort study through the Improving Renal Outcomes Collaborative (IROC) to collect clinical outcome data about COVID-19 in pediatric KT patients. Twenty-two IROC centers that care for 2732 patients submitted testing and outcomes data for 281 patients tested for SARS-CoV-2 by PCR. Testing indications included symptoms and/or potential exposures to COVID-19 (N = 134, 47.7%) and/or testing per hospital policy (N = 154, 54.8%). Overall, 24 (8.5%) patients tested positive, of which 15 (63%) were symptomatic. Of the COVID-19-positive patients, 16 were managed as outpatients, six received non-ICU inpatient care and two were admitted to the ICU. There were no episodes of respiratory failure, allograft loss, or death associated with COVID-19. To estimate incidence, subanalysis was performed for 13 centers that care for 1686 patients that submitted all negative and positive COVID-19 results. Of the 229 tested patients at these 13 centers, 10 (5 asymptomatic) patients tested positive, yielding an overall incidence of 0.6% and an incidence among tested patients of 4.4%. Pediatric KT patients in the United States had a low estimated incidence of COVID-19 disease and excellent short-term outcomes. 相似文献
10.
Luciana Tornquist Debora Tornquist Letícia B. Schneiders Silvia I. R. Franke Jane D. P. Renner Czane P. Reuter 《Arquivos brasileiros de cardiologia》2022,119(2):236
BackgroundCardiometabolic risk has been shown to be inversely associated with cardiorespiratory fitness (CRF) and positively associated with body mass index (BMI).ObjectiveOur objective was to analyze the association of cardiometabolic risk factors with combined BMI and CRF in schoolchildren from a city in southern Brazil.MethodsCross-sectional study with a sample of 1252 schoolchildren aged seven to 17 years. Total cholesterol (TC), HDL-c, LDL-c, triglycerides (TG), systolic (SBP) and diastolic blood pressure (DBP) were evaluated. CRF and BMI were grouped into one variable and the schoolchildren were classified as eutrophic/fit, eutrophic/unfit, overweight-obese/fit, and overweight-obese/unfit. Crude and adjusted analyzes were performed using Poisson Regression and an alpha of 0.05 was adopted.ResultsOverweight-obese and fit schoolchildren showed a prevalence ratio (PR) of 1.50 (1.04 – 2.16) for altered TG, 3.05 (2.05 – 4.54) for elevated SBP, and 2.70 (1.87 – 3.88) for elevated DBP. Overweight-obese and unfit schoolchildren showed a PR for high TC of 1.24 (1.11 – 1.39) and 1.51(1.11 – 2.04) for low HDL levels. In addition, they had a risk of 2.07 (1.60 – 2.69) for altered TG, 3.36 (2.31 – 4.60) for elevated SBP and 2.42 (1.76 – 3.32) for altered DBP.ConclusionBMI played a central role in the association with risk and CRF was shown to attenuate the association between risk factors and obesity. Overweight-obese children and adolescents had a higher cardiometabolic risk, but the effect size was larger among the unfit. 相似文献