首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   487篇
  免费   22篇
  国内免费   4篇
  2023年   3篇
  2022年   2篇
  2021年   9篇
  2020年   10篇
  2019年   33篇
  2018年   19篇
  2017年   25篇
  2016年   25篇
  2015年   28篇
  2014年   30篇
  2013年   77篇
  2012年   21篇
  2011年   28篇
  2010年   18篇
  2009年   30篇
  2008年   22篇
  2007年   20篇
  2006年   19篇
  2005年   7篇
  2004年   10篇
  2003年   15篇
  2002年   4篇
  2001年   2篇
  2000年   4篇
  1999年   1篇
  1998年   2篇
  1997年   1篇
  1996年   5篇
  1995年   1篇
  1994年   1篇
  1993年   1篇
  1992年   2篇
  1991年   3篇
  1990年   1篇
  1987年   9篇
  1986年   3篇
  1985年   2篇
  1984年   1篇
  1981年   4篇
  1980年   4篇
  1979年   4篇
  1978年   2篇
  1977年   3篇
  1976年   1篇
  1972年   1篇
排序方式: 共有513条查询结果,搜索用时 31 毫秒
111.
Abstract. Anopheles culicifacies (probably species A) is the main vector of malaria in Baluchistan, southeastern Iran. Adult mosquitoes were collected during 1990-92 by five methods of sampling: knock-down pyrethrum space-spray indoors, human and animal bait (18.00–05.00 hours), pit shelters and CDC light traps, yielding 62%, 3%, 6%, 4% and 25% of specimens, respectively. Whereas spray-catches comprised c. 70% gravid and semi-gravid females, light trap catches were mostly ( c . 60%) unfed females, while females from pit shelters comprised all abdominal stages more equally (13–36%). An. culicifacies populations peaked in April-May and rose again during August-November. Densities of indoor-resting mosquitoes were consistently greater in an unsprayed village than in villages subjected to residual house-spraying with propoxur, malathion or pirimiphos-methyl. Monthly malaria incidence generally followed fluctuations of An. culicifacies density, usually with a peak in May-June.  相似文献   
112.
113.
15 new species are described: Sect.Sclerocalycinae:S. farsistanica, S. stapfii. — Sect.Spergulifoliae:S. paktiensis. — Sect.Auriculatae:S. caroli-henrici, S. daënensis, S. gertraudiae, S. nizvana, S. oligophylla, S. persepolitana, S. pseudaucheriana, S. pseudonurensis, S. renzii, S. salangensis, S. sojakii. — Sect.Brachypodae:S. rasvandica. — All the new species are from Iran with exception ofS. paktiensis andS. parvanica which are from Afghanistan.
Florae Iranicae praecursores 46–60. — Praecursores praecurrentes in Pl. Syst. Evol.142: 239–246 (1983).  相似文献   
114.
In Iran, Plasmodium vivax is responsible for more than 80% of the infected cases of malaria per year. Control interventions for vivax malaria in humans rely mainly on developed diagnostic methods. Recombinant P. vivax apical membrane antigen-1 (rPvAMA-1) has been reported to achieve designing rapid, sensitive, and specific molecular diagnosis. This study aimed to perform isolation and expression of a rPvAMA-1, derived from Iranian patients residing in an endemic area. Then, the diagnostic efficiency of the characterized Iranian PvAMA-1 was assessed using an indirect ELISA method. For this purpose, a partial region of AMA-1 gene was amplified, cloned, and expressed in pET32a plasmid. The recombinant His-tagged protein was purified and used to coat the ELISA plate. Antibody detection was assessed by indirect ELISA using rPvAMA-1. The validity of the ELISA method for detection of anti-P. vivax antibodies in the field was compared to light microscopy on 84 confirmed P. vivax patients and compared to 84 non-P. vivax infected individuals. The ELISA cut-off value was calculated as the mean+2SD of OD values of the people living in malaria endemic areas from a south part of Iran. We found a cut-off point of OD=0.311 that showed the best correlation between the sera confirmed with P. vivax infection and healthy control sera. A sensitivity of 81.0% and specificity of 84.5% were found at this cut off titer. A good degree of statistical agreement was found between ELISA using rPvAMA-1 and light microscopy (0.827) by Kappa analysis.  相似文献   
115.
116.
doi: 10.1111/j.1741‐2358.2011.00588.x
Prevalence of oral mucosal lesions in institutionalized elderly people in Mashhad, Northeast Iran Objective: The aim of this study was to determine the prevalence of oral mucosal lesions in institutionalized elderly people in Mashhad, northeast of Iran. Background: This study was conducted to assess the prevalence of oral lesions in the institutionalized elderly. Methods: In this survey, we studied all of the nursing homes in Mashhad; a total of five encompassing 237 residents. The subjects were examined and lesions recorded in a designed checklist. T‐test, chi‐square and Fisher’s exact tests were used for the analysis. Results: The mean age of the patients was 79.59 ± 8.88. Ninety‐eight per cent of cases had at least one oral mucosal lesion. The most common lesions were fissured tongue (66.5%), atrophic glossitis (48.8%), sublingual varicosity (42%) and xerostomia (38%). There was no significant difference in the prevalence of denture‐related lesions (DRLs) between men and women (p > 0.05). Xerostomia was more prevalent in 70–79‐year‐old than in 60–69‐year‐old subjects. No case of oral malignant lesion was detected. Discussion: These findings revealed a higher prevalence of oral mucosal lesions in Mashhad city compared with other studies conducted in other major cities in Iran and abroad. The results emphasise the necessity of national programmes towards oral health promotion.  相似文献   
117.
Summary Three strains of Dunaliella salina (I, G and A) were cultivated under the climatic conditions of Iran, in open ponds to compare the β-carotene production and the specific rate of growth. The experiments were accomplished in two separate stages. In the first stage, the cells were grown in ponds on nutrient-rich medium containing 2 M NaCl to obtain the necessary biomass. In the second stage, cells were stressed on nutrient-poor medium containing 2.5 M NaCl for β-carotene induction. The results showed that the specific growth rate of strain I was the highest during the first stage, whereas during the second stage, the growth rates of three strains were approximately the same. The overall results indicated that strain G had the highest potential for β-carotene accumulation of the strains tested and hence it was concluded that this strain is more suitable for outdoor cultivation under the climatic conditions of Iran than the other two.  相似文献   
118.
Cochlosoma sp. infection was identified in a single case among 60 stunted diarrheic native turkey poults, Meleagris galopavo. A large number of the flagellated parasites was found free or within the intervillous spaces of the jejunum, ileum and cecum. Moderate enteritis was associated with the parasites. In TEM studies of the parasagittal sections of the parasite, a prominent ventral sucker like disc and flagella emerging from an opening on the ventrodorsal surface of the pyriform uninuclear parasite were found. The morphological characteristics of this protozoan match with those described for Cochlosoma anatis. The parasite could be considered as an intestinal pathogenic protozoan causing stunting and diarrhea in turkeys in Iran.  相似文献   
119.
Karaj is an area with large influx of refugee people in Iran. To increase knowledge about parasitic infections, we carried out this research during 2006-2008. We recorded the stool examination results and some of their personal characteristics. A total of 13,915 human stools were examined, and 649 (4.7%) were positive for intestinal parasites. Among them, 13 (0.09%) had worm and 636 (4.6%) had protozoan infections. Maximum infections belonged to Giardia intestinalis, and 534 (3.8%) samples had this infection. Other parasitic infections included Entamoeba coli (0.39%), Entamoeba histolytica (0.021%), Blastocystis hominis (0.08%), Trichomonas hominis (0.1%), Iodamoeba butschlii (0.06%), Chilomastix mesnili (0.007%), Endolimax nana (0.05%), Enterobius spp. eggs (0.028%), Taenia proglottids (0.028%), and Strongyloides stercoralis larvae (0.03%). The maximum numbers of referred people to laboratories were in July and the maximum percentage of infections was in August. There is a point that all 5 Strongyloides stercoralis infections were pertained to 2008. With attention to the rate of parasitic infections (4.7%), it seems that we should take additional educational information to wide spectrum of people living in this city.  相似文献   
120.
A total of 370 specimens of Paracobitis malapterura in the Zarrin-Gol River (east of the Elburz Mts, Iran) were caught by regular monthly collection throughout one year from November 2006 to October 2007. The specimens were then examined for age and growth, reproduction and feeding attributes. Based on otolith readings the maximum ages of the population observed were 3+ years for males and 4+ years for females. The specimens ranged in size from 38 to 130 mm total length, weighing from 0.68 to 30.55 g total weight. Length-weight relationship was estimated as W = 0.020L 2.62 for males, W = 0.002L 3.81 for females and W = 0.008L 3.08 for the population. Sex ratio was 1: 1.27 in favor of females. The Gonadosomatic index indicated that reproduction of the loach in the river occurred around April–May, with the highest average value of 1.48 for males and of 5.36 for females in May. The absolute fecundity ranged between 92–1180 eggs with a mean of 456.31 eggs. Diameter of oocytes ranged from 0.11 to 2.80 mm with a mean value of 0.95 mm. The absolute fecundity and oocyte diameter to fish size (length and weight) and age were not significantly correlated. Plecoptera and Trichoptera dominated the diet contents composing 72.43% and 20.80% of total frequency of food items, respectively.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号