全文获取类型
收费全文 | 1684篇 |
免费 | 371篇 |
国内免费 | 29篇 |
专业分类
耳鼻咽喉 | 8篇 |
儿科学 | 53篇 |
妇产科学 | 50篇 |
基础医学 | 151篇 |
口腔科学 | 50篇 |
临床医学 | 246篇 |
内科学 | 380篇 |
皮肤病学 | 10篇 |
神经病学 | 53篇 |
特种医学 | 16篇 |
外科学 | 118篇 |
综合类 | 58篇 |
预防医学 | 369篇 |
眼科学 | 45篇 |
药学 | 90篇 |
中国医学 | 6篇 |
肿瘤学 | 381篇 |
出版年
2024年 | 1篇 |
2023年 | 16篇 |
2022年 | 37篇 |
2021年 | 55篇 |
2020年 | 64篇 |
2019年 | 216篇 |
2018年 | 152篇 |
2017年 | 102篇 |
2016年 | 92篇 |
2015年 | 135篇 |
2014年 | 225篇 |
2013年 | 240篇 |
2012年 | 149篇 |
2011年 | 105篇 |
2010年 | 89篇 |
2009年 | 90篇 |
2008年 | 72篇 |
2007年 | 59篇 |
2006年 | 49篇 |
2005年 | 37篇 |
2004年 | 25篇 |
2003年 | 11篇 |
2002年 | 13篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 1篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1994年 | 2篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1989年 | 2篇 |
1988年 | 1篇 |
1985年 | 1篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1980年 | 1篇 |
1979年 | 6篇 |
1978年 | 4篇 |
1977年 | 2篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1974年 | 1篇 |
排序方式: 共有2084条查询结果,搜索用时 0 毫秒
41.
Mona Seyed Attaran Zohreh Sharifi Seyed Masoud Hosseini Shahram Samei Zahrah Ataee 《APMIS : acta pathologica, microbiologica, et immunologica Scandinavica》2014,122(3):243-247
Hepatitis delta virus (HDV) is a satellite virus that needs hepatitis B virus (HBV) surface antigen for amplification and transition. HDV appears in HBsAg carriers as acute coinfection and superinfection in patients with chronic hepatitis B. This coinfection leads to chronic hepatitis, cirrhosis, and liver carcinoma. The aim of this study was to detect the prevalence of coinfection and superinfection of HBVs and HDVs in blood donor individuals in Iran. Sera from 854 asymptomatic blood donors from the Bank of positive samples storage at the National Blood Transfusion Organization of Iran that were positive for hepatitis B surface antigen were analysed. The presence of antibody against HDV in blood donors was detected using ELISA followed by conventional PCR, seminested PCR and real‐time PCR to determine coinfection and/or superinfection. Restriction fragment length polymorphism was used for HDV genotyping. All 854 samples were HBsAg and anti‐HBc positive whereas only 18 (2%) of them were positive for anti‐HDV. Of the 854 samples, 154 (18%) were HBV‐DNA positive. HDV‐RNA was detected in 0.6% of the total samples by seminested PCR and real‐time PCR and the two PCR methods produced similar results. Moreover, 16.6% and 83.4% of anti‐HDV‐positive samples exhibited coinfection and superinfection with HBV, respectively. Genotype I of HDV was determined in positive samples. 相似文献
42.
43.
《Journal de Mycologie Médicale》2020,30(1):100917
ObjectiveLimited data are available on the epidemiology and etiology of cryptococcal infections in the Middle East. We aimed to conduct the systematic review and meta-analysis to summarize the epidemiological data on prevalence of Cryptococcus species complexes in trees and their surroundings, bird guano and secretions, animals, and highlight the reported episodes of cryptococcosis in Iran.Materials and methodsTwelve databases, including PubMed, Science Direct, Scopus, Proquest, Google Scholar, Embase, and the ISI Web of Science, as well as the national databases, from January 1969 to October 2019 were searched. Furthermore, gray literature (e.g., thesis, congress abstracts) was evaluated using Iran Doc and www.thesis.research.ac.ir. Search process was accomplished on English or Persian language articles using the following keywords: “Cryptococcus”, “Cryptococcosis”, “invasive fungal infection”, “Humans”, “Birds”, “Pigeon”, “Animals”, “Tree”, “Eucalyptus”, and “Iran”, both alone and in combination.ResultsOverall 36 studies were eligible regarding Cryptococcus and cryptococcosis in Iran. The total prevalence rates of Cryptococcus species in the tree was 4.7% (95% CI: 2.3–7.8), and in bird guano was 20.4% (95% CI: 10.7–32.2). Cryptococcosis in animal, and human were 1.7% (95% CI: 0.01–5.1), and 2.8% (95% CI: 0.7v6.1), respectively. The highest prevalence of Cryptococcus in the trees (14.6%), and bird guano (89.4%) in Khorasan, animals (8.9%) in Chaharmahal and Bakhtiari, and human (4.4%) in Mazandaran provinces were reported.ConclusionsGiven the significant risk of Cryptococcus species for susceptible humans, mainly HIV-infected patients, it seems quite necessary to adopt concrete preventive strategies to pinpoint the environmental habitats of this yeast. 相似文献
44.
Epidemiology of children with acquired immune deficiency syndrome (stage 3): A referral hospital‐based study in Iran 下载免费PDF全文
45.
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
46.
Amini-Bavil-Olyaee S Sarrami-Forooshani R Mahboudi F Sabahi F Adeli A Noorinayer B Azizi M Reza Zali M 《Journal of medical virology》2005,75(2):227-234
Hepatitis B virus (HBV) is one of the major causative agents of acute and chronic liver disease worldwide and is believed to be responsible for a million deaths annually. Eight genotypes of HBV, A to H, have been described on the basis of similarity of the complete genomes sequence. Although, it is reported that the predominant HBV genotype in the Mediterranean area and the middle east is genotype D, there are no reports on HBV genotypes prevalent in Iran. In this study, the C and S regions of HBV from 26 chronic hepatitis B Iranian patients were amplified and sequenced. Phylogenetic analysis revealed that all Iranian HBV isolates sequences were classified into genotype D with bootstrap values of 100%, 73%, and 100% (1,000 replicates each) for S, C, and preS2 regions, respectively. The mean percent intra-distance of S and C regions were 0.8% and 2.3%, respectively. The mean percent inter-distance of S and C regions between Iranians and genotype D isolates were 1.7% and 3.0%, respectively, and the range of mean percent nucleotide distance of S and C regions between Iranians and the other reference isolates were 7.9%-17.5% and 4.8%-14.7%, respectively. Thirteen out of 23 HBV C region sequences showed nucleotide "A" at position 1896 (precore mutant) in C region. Nucleotide 1858 showed presence of "T" in all isolates. No insertion or deletion was found in both regions. SimPlot and BootScanning analyses did not show any recombination between Iranian isolates and other genotypes in both regions. 相似文献
47.
Ebrahim Faghihloo Vahid Salimi Farhad Rezaei Maryam Naseri Setare Mamishi Mahmood Mahmoodi Talat Mokhtari-Azad 《Iranian journal of pediatrics.》2011,21(1):58-64
Objective
Acute respiratory infection (ARI) is the major cause of morbidity and mortality in children worldwide. Human respiratory syncytial virus (HRSV) is main viral agent of ARI in infants and young children in terms of effect and prevalence. The aim of this study was to investigate HRSV genotypes during one season in Iran.Methods
In this cross-sectional study, 107 throat swabs were collected from children less than 5 years of age with acute respiratory infection from October to December 2009. The respiratory samples were obtained from several provinces: Tehran, Isfahan, Hamadan, Zanjan, Kordestan, Lorestan and West Azarbayjan, and were tested for G protein gene of HRSV by RT-PCR.Findings
Of the 107 respiratory samples, 24 (22.42%) were positive for HRSV, of which 16 (66.6%) belonged to subgroup A and 8 (33.4%) to subgroup B. Phylogenetic analysis revealed that subgroup A strains fell in two genotypes GA1 and GA2, whereas subgroup B strains clustered in genotype BA.Conclusion
This study revealed that multiple genotypes of HRSV cocirculated during the season 2009 in Iran. Also subgroup A strains were more prevalent than subgroup B strains, and genotype GA1 was predominant during the season. 相似文献48.
Asma Delshad Mehrzad Saraei Safar Ali Alizadeh Soheila Rahimi Niaraki Mahmood Alipour Bahram Hosseinbigi Arezoo Bozorgomid Elham Hajialilo 《African health sciences》2020,20(3):1179
IntroductionBlastocystis is a common intestinal parasite of human and animal hosts. The parasite has 17 subtypes, and among those at least nine subtypes (ST1-ST9) are found in human hosts.ObjectiveThe aim of the present study was to investigate the presence of different subtypes of Blastocystis spp. among the patients referred to Velayat hospital of Qazvin province, Iran.MethodsOverall, 864 stool samples were examined by using formalin-ethyl acetate concentration method and Trichrome staining. All specimens were cultured in clotted fetal bovine medium. Later, DNA extraction and PCR amplification of 18S ribosomal RNA gene region was conducted and phylogenetic tree constructed.ResultsThe results revealed 7.9% (68/864) of the study population were infected with Blastocystis. Intestinal symptoms were observed in 61% (36/59) of individuals positive for Blastocystis, with abdominal pain in 58% (21/36) of cases which was more frequent than other intestinal signs. No significant relationship was observed among the study variables. By molecular and phylogenetic analysis, three subtypes ST1 (45%), ST2 (30%) and ST3 (23%) of parasite were identified.ConclusionThis study showed ST1 subtype was the predominant subtype among the positive specimens, meanwhile the highest haplotype and nucleotide diversity were clarified in ST3 subtype. 相似文献
49.
Jalilvand S Tornesello ML Buonaguro FM Buonaguro L Naraghi ZS Shoja Z Ziaee AA Hamkar R Shahmahmoodi S Nategh R Mokhtari-Azad T 《Virus research》2012,163(2):644-649
Kaposi's sarcoma (KS) is a rare cancer in Iran and there is no epidemiological and molecular information about HHV-8 variants circulating among the Iranian population. In this study HHV-8 sequences have been analyzed in 43 cutaneous KS biopsies from Iranian patients mainly affected by classic KS. DNA samples were subjected to PCR amplification of HHV-8 ORF26, T0.7 and K1 followed by direct nucleotide sequencing and phylogenetic analysis. The analysis of ORF26 showed that 30 (69.8%) and 13 (30.2%) samples belonged to subtypes A/C and K, respectively. In general, the clustering of HHV-8 T0.7 variants paralleled that of ORF26. Genotyping of K1 sequences showed that the majority of samples (39 out of 41) fall into the large C clade with only 2 belonging to the A clade. In conclusion, HHV-8 variants identified among classic Iranian KS are largely related to Eurasian genotypes previously identified in KS from Mediterranean, Middle East, and East Asian regions. 相似文献
50.
Background: Cystic fibrosis is a monogenic recessive disorder found predominantly in Caucasian population. This disease arises from mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. In this study we consider poly T polymorphism c.1210-12T[5], c.1210-12T[7], c.1210-12T[9] (T5, T7, T9) in the intron 8 of CFTR gene in normal individuals and cystic fibrosis patients in the north of Iran.
Material and methods: 40 CF patients and 40 normal individuals were screened for poly T polymorphism in intron 8 of CFTR gene using Reverse Dot Blot method which was also used to detect p.Phe508del among CF patients.
Results: T7 allele is the most prevalent in both normal and CF patients. Its abundance is approximately 75%. T9 and T5 represent approximately 20% and 5% of alleles respectively. T7/ T7 genotype is the most present in both normal and CF patients with 72.5% and 60% prevalence respectively. p.Phe508del was present in 13 CFTR alleles belonging to 7 patients with either homozygote T9/ T9, T7/ T7 or compound heterozygote T7/ T9 genotypes.
Conclusion: Contrary to the Caucasians, T7 allele is more frequent in Northern Iranian CF patients. The presence of p.Phe508del and T7 allele in the same framework is reported for the first time in this part of the world. Further investigations of other populations will help to understand whether p.Phe508del arose by selection pressure in this part of the world or was imported from European countries. The abundance of T5, T7, T9 alleles indicates that this polymorphism can be used as one of the informative markers for detection of normal and mutant alleles in prenatal diagnosis or carrier assessment in families with previous history of the disease in regions with high degree of CFTR mutation heterogeneity. 相似文献