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   42篇
  免费   9篇
林业   3篇
农学   1篇
  8篇
农作物   7篇
水产渔业   16篇
畜牧兽医   13篇
园艺   2篇
植物保护   1篇
  2022年   1篇
  2021年   1篇
  2020年   1篇
  2019年   2篇
  2018年   2篇
  2017年   1篇
  2016年   5篇
  2015年   7篇
  2014年   4篇
  2013年   3篇
  2012年   4篇
  2011年   3篇
  2010年   7篇
  2009年   1篇
  2008年   3篇
  2006年   2篇
  2005年   2篇
  2002年   1篇
  1993年   1篇
排序方式: 共有51条查询结果,搜索用时 31 毫秒
31.
Background: Rheumatoid arthritis (RA) is a chronic inflammatory disease with many genetic factors predisposing to disease susceptibility. The aim of the present study was to investigate the impact of CD226 rs727088 and rs763361 polymorphisms and susceptibility to RA in a sample of the Iranian population. Methods: This case-control study was carried out on 100 patients with RA and 104 healthy subjects. The polymorphisms were determined using tetra amplification refractory mutation system-polymerase chain reaction assay. Results: The rs763361 (Gly307Ser) polymorphism increased the risk of RA in codominant, dominant and recessive-tested inheritance models (odds ratio [OR] = 3.18, 95% confidence intervals [95% CI] = 1.44-7.02, P = 0.004, CC vs. TT, and OR = 1.98, 95% CI = 1.10-3.57, P = 0.023, CC vs. CT-TT, and OR = 2.61, 95% CI = 1.26-5.37, P = 0.010, CC + CT vs. TT, respectively). In addition, the rs763361 T allele increased the risk of RA (OR = 2.06, 95% CI = 1.38-3.08, P<0.001). However, no significant difference was observed among the groups regarding CD226 rs727088 polymorphism (χ2 = 3.20, P = 0.202). Conclusions: Our finding showed that CD226 rs763361, but not rs727088, gene polymorphism increased the risk of RA in a sample of the Iranian population.Key Words: Rheumatoid arthritis (RA), CD226, Polymorphism  相似文献   
32.
Brucella preferentially infects cattle, swine, sheep, and goats. However, some epidemiological surveys have been carried out to investigate nonruminants, such as horses. Horse brucellosis has been found in clinical cases, but there are few epidemiologic patterns. Between May 2008 and April 2009, a total of 120 horses were screened for brucella infections in Mashhad, Iran, by the rose bengal test and the tube agglutination test. Sera from three horses were found positive by rose bengal test and tube agglutination test, and therefore the prevalence rate was 2.5%. In horses, the highest individual seroprevalence was in an animal kept close under the intensive system, with other animals such as cattle, sheep, and goats. The zoonotic aspects of brucellosis from the horse must, therefore, be considered because the disease is important from a public health standpoint. The present study documents the first serological evidence of Brucella spp. infection in horses in Iran.  相似文献   
33.
The virulence properties of Shiga toxin-producing Escherichia coli (STEC) strains isolated from diarrhoeic and non-diarrhoeic calves were compared. The strains were also tested for O157:H7, O111 and O26 serotypes, using PCR and conventional serotyping methods. E coli strains isolated from 297 faecal samples, from 200 diarrhoeic and 97 non-diarrhoeic calves, were screened by multiplex PCR assay for the stx1, stx2, eae and Ehly virulence genes. STECs were recovered from 8 per cent of diarrhoeic calves and 10.3 per cent of non-diarrhoeic calves. The predominant virulence gene profile was stx1/eae/Ehly (47.3 per cent) among isolates from diarrhoeic calves and eae/Ehly (36.8 per cent) among isolates from non-diarrhoeic calves. Among three tested serogroups, the predominant serogroup was O26 (18.4 per cent), and O157:H7 was not detected. Intimin subtyping by restriction fragment length polymorphism analysis revealed only three intimin subtypes (β, γ and ). A significant difference was observed in the distribution of Int- between two groups. Int- was present in 50 per cent of the isolates from diarrhoeic calves and in 11.1 per cent of the isolates from non-diarrhoeic calves; this difference was statistically significant (P=0.01).  相似文献   
34.
The objective of this research was improvement of apple hot water treatment efficiency by using acetic acid. The apples (cultivar Red Delicious) were treated using hot acetic acid solutions (1, 2 and 3%) at 50 °C for 1, 2 and 3 min. The results of in vitro study showed that treatment with acetic acid at 50 °C can significantly reduce the growth of Penicillium expansum spores. The treatment of apples with 50 °C acetic acid solutions, in particular 2% acetic acid solution for 3 min or 3% acetic acid solution for 2 min, had significant impacts in reducing the extent of decay of the fruit during the short time storage experiment, while this effect was not significant in the long-time storage.  相似文献   
35.
One of the most important periods in artificial breeding of sturgeon is incubation. In general, little is known about ontogeny of the stress response in early developmental stages of sturgeon. In this study, cortisol content was measured by radioimmunoassay for the first time in eggs of Persian sturgeon Acipenser persicus to elicit at which times during early developmental stages, that they were particularly sensitive to stressful events. In this study, fertilized eggs of mature Persian sturgeons were placed in special boxes (as replicates) that were put in incubation units of Yushchenko. To assess pre-stress samples (resting cortisol levels), 5 eggs were selected randomly from each box in 7 important stages of incubation (2-cell division, blastula, end of blastula, mid of gastrula, neurula, eyed stage and heart beaten). In another experiment, eggs were exposed to an acute stress (10 min out of water) in 7 developmental stages. For determination of post-stress cortisol, eggs were collected 2 and 6 h after the stress. The results indicated significant difference in various stages of incubation but cortisol levels revealed no differences in whole-body levels between stressed samples (2 and 6 h post-stress) and unstressed samples (P > 0.05). The highest percentage of hatching rate for post-stressed eggs was recorded in 2-cell division stage while this percentage declined steadily in the heart beaten stage when a statistically significant difference was revealed with regard to other stages (P = 0.000). These findings suggested that sturgeon eggs were not so much sensitive in their early developmental stages and relatively resistant to stress. However, significant decrease in survival rate in heart beaten stage showed a sensitivity of this stage to stress. Lack of an increase in cortisol after acute stress indicated that hypothalamus-pituitary-interrenal (HPI) axis for cortisol synthesis was not yet functional. However, further studies seem necessary to clarify when HPI axis is activated in this species.  相似文献   
36.
Long‐day photoperiods are considered as an effective managerial tool in manipulating of reproduction and somatic growth in a number of fish species. In this study, the effects of three different artificial photoperiods on the gonadal development and somatic growth of rainbow trout (Oncorhynchus mykiss L.) were investigated. Two years‐old immature female rainbow trout (279.94 ±2.25 g) were exposed to three artificial photoperiod regimes of 24L:0D, 18L:6D and 6L:18D and natural light (NL) regime for 5 months. The highest gonadosomatic indices were recorded in NL and 6L:18D groups while the rates were significantly lower in fish maintained under 18L:6D and 24L:0D photoperiods (< 0.05). Mean oocyte diameters in fish exposed to 24L:0D and also to 18L:6D were significantly lower than the 6L:18D and NL groups. Photoperiods with 24L:0D and 18L:6D regimes resulted in significantly higher mean final weights and specific growth rates (SGR) than NL regime. The highest mean final weight (635.45 ± 16.19 g) and SGR (1.03 ± 0.04% day?1) were obtained under 24L:0D photoperiod. Fish exposed to 24L:0D and 18L:6D showed the highest condition factor as 1.44 ± 0.01 and 1.44 ± 0.02 respectively, when compared with the NL (1.27 ± 0.01) and 6L:18D (1.34 ± 0.02) groups. Basically, the results suggested that continuous artificial lightning can be used as an influential factor in delaying gonadal development and enhancing somatic growth in rainbow trout during gonadal growth phase.  相似文献   
37.
The present study evaluated various sodium and potassium concentrations in hatchery water to determine which proportions would be optimal for Macrobrachium rosenbergii larviculture. Using a closed RAS system (60‐L), experiments were conducted in two stages. In the first stage, larval quality parameters were compared among triplicate treatments of sodium (2000, 3000, 4000 and 5000 mg L?1) and potassium (100, 150, 200 and 250 mg L?1). During the second stage, these same parameters were compared from interactions of the two best concentrations determined in the first stage. Initial larval density was fixed at 100 larvae L?1 and larval quality parameters such as larval stage index (LSI), larval condition index (LCI), larvae dry weight, survival (%), LC50‐24 h for formalin stress and time of the first postlarvae (PL) appearance were measured. Results showed that during the early larval period time LSI, LCI and survival parameters were affected only by potassium and the interaction with sodium was not significant. At a later period of the larval development, interactions between both sodium and potassium were measurable for LSI (< 0.05) while the interactions on LCI and survival were not significant. Measurable differences among the combined treatments 4000 mg L?1 sodium and 150 mg L?1 potassium resulted in the best performance for M. rosenbergii larviculture. This concentration also provided the highest final survival to PL metamorphosis (40.6 ± 2.5%) which was at least 10% higher than the other treatments.  相似文献   
38.
In this study, viral pathogens associated with nine outbreaks of naturally occurring dairy calf pneumonia in Mashhad area of Khorasan Razavi province from September 2008 to May 2009 were assessed. Five diseased calves from each farm were chosen for examination. Acute and convalescent serum samples were taken from calves with signs of respiratory disease. Sera were analyzed for antibodies to bovine viral diarrhea virus (BVDV), bovine herpesvirus type 1 (BHV-1), bovine respiratory syncytial virus (BRSV), parainfluenza virus type 3 (PI-3V), and bovine adenovirus-3 (BAV-3) by indirect ELISA kits. Among 42 serum samples collected at sample 1, seroprevalence values for viruses BHV-1, BVDV, BRSV, PI-3V, and BAV-3 were 61.9% (26), 57.1% (24), 64.2% (27), 90% (38), and 61.9% (26), respectively. Seroconversion to BVDV, BRSV, PI-3V, and BAV-3 occurred in 11.9% (5), 16.6% (7), 26.1% (11), and 21.4% (9) of animals, and 52.3% (22) had generated antibodies against one or more viral infections at sample 2. In addition, no significant relationship between seroprevalence of BHV-1, BVDV, BRSV, PI-3V, and BAV-3 and dairy herd size was observed (P > 0.05). According to serological findings, BHV-1, BVDV, BRSV, PI-3V, and BAV-3 are common pathogens of the dairy calf pneumonia in dairy herds in Mashhad area of Khorasan Razavi province, Iran.  相似文献   
39.
Humic acid (HA) might benefit plant growth by improving nutrient uptake and hormonal effects. The effect of HA on growth, macro—and micronutrient contents, and postharvest life of gerbera (Gerbera jamesonii L.) cv. ‘Malibu’ were examined. Different levels of humic acid (0, 100, 500, and 1000 mg/L) were applied to nutrient solution.

Root growth increased at 1000 mg/L HA incorporated into the solution. Macro- and micronutrient contents of leaves and scapes including nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), and zinc (Zn) were significantly enhanced by HA. However, high levels of HA decreased some nutrient contents.

Five-hundred mg/L HA increased the number of harvested flowers per plant (52%). Higher HA levels extended the vase life of harvested flowers by 2—3.66 days and could prevent and delay bent neck incidence. These postharvest responses were most probably due to Ca accumulation in scapes and hormone-like activity of HA.  相似文献   
40.
Introduction: Autosomal dominant polycystic kidney disease (ADPKD) is one of the most common genetic kidney disorders with the incidence of 1 in 1,000 births. ADPKD is genetically heterogeneous with two genes identified: PKD1 (16p13.3, 46 exons) and PKD2 (4q21, 15 exons). Eighty five percent of the patients with ADPKD have at least one mutation in the PKD1 gene. Genetic studies have demonstrated an important allelic variability among patients, but very few data are known about the genetic variation among Iranian populations. Methods: In this study, exon direct sequencing of PKD1 was performed in a seven-year old boy with ADPKD and in his parents. The patient’s father was ADPKD who was affected without any kidney dysfunction, and the patient’s mother was congenitally missing one kidney. Results: Molecular genetic testing found a mutation in all three members of this family. It was a missense mutation GTG>ATG at position 3057 in exon 25 of PKD1. On the other hand, two novel missense mutations were reported just in the 7-year-old boy: ACA>GCA found in exon 15 at codon 2241 and CAC>AAC found in exon 38 at codon 3710. For checking the pathogenicity of these mutations, exons 15, 25, and 38 of 50 unrelated normal cases were sequenced. Conclusion: our findings suggested that GTG>ATG is a polymorphism with high frequency (60%) as well as ACA>GCA and CAC>AAC are polymorphisms with frequencies of 14% and 22%, respectively in the population of Southwest Iran. Key Words: Autosomal dominant polycystic kidney disease (ADPKD), Polycystic kidney diseases (PKD), PKD1 gene, Iran  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