排序方式: 共有69条查询结果,搜索用时 62 毫秒
1.
Hamed Abdollahpour Bahram Falahatkar Iraj Efatpanah Bahman Meknatkhah 《Aquaculture Research》2020,51(4):1372-1380
Thyroid hormones (THs) play important roles in regulating growth, development and physiological functions in vertebrates. To study the role of short‐term effects of thyroxine (T4) on metabolism and growth in female Sterlet sturgeon, thirty fish with a weight of 707.97 ± 37.15 g were divided into six tanks. Fish were injected intraperitoneal with (a) coconut oil alone (control), (b) 1 mg T4 kg per BW in coconut oil (T1) and (c) 10 mg T4 kg per BW in coconut oil (T10). Blood samples were collected at 0, 4, 7, 14, 28 and 60 days for plasma biochemical analysis, and body length and mass were determined at day 60. Based on results, higher growth was indicated in T10 group. The highest T4 levels were observed on day 4 in the T1 and T10 treatments and gradually declined during the trial. Plasma T3 levels were highest on days 4 and 7 in the T1 and T10 groups, respectively. Plasma triglyceride levels were significantly elevated on day 28 in the T1 group and on day 60 in the T10 group. Plasma glucose concentrations were significantly elevated on days 7 and 14 in T10 group. Overall, the present results suggest that a single injection of T4 can improve growth via changes in the metabolic profile of Sterlet sturgeon. 相似文献
2.
Davoud Amini Erfan Oliaei Mehdi Rajabi-Hamane Hossein Mahdavi 《Fibers and Polymers》2017,18(8):1561-1567
Polyvinylidene fluoride (PVdF) membranes in spite of having many critical properties necessary for lithium-ion batteries, do not have satisfying thermal and mechanical resistance. The goal of this study was to combine the good mechanical and thermal properties of PP nonwoven fabric with the excellent electrochemical properties of PVdF nanofibers to exploit a high-performance membrane for lithium-ion batteries. This work reports the preparation of PVdF nanofiber membranes using electrospinning on a polypropylene (PP) spunbonded nonwoven fabric and an aluminum foil followed by a hot-pressing treatment. The morphology and size of the membranes were studied by the scanning electron microscopy. The tensile strength of the membrane with the PP support was superior to the PVdF membrane. Thermal stability of the prepared membranes was determined using the TGA method and the dimensional stability was investigated by measuring the shrinkage ratio at 105 °C. The results have shown that the PVdF/PP membrane was thermally more stable than the PVdF and the commercial Celgard 2325 membranes. The batteries using PVdF/PP membrane exhibited higher electrochemical oxidation limit, better cycling performance and less discharge capacity fading during 100 cycles compared to PVdF and Celgard membranes. The results of this study showed that PVdF/PP membrane is a promising advanced membrane in lithium-ion batteries. 相似文献
3.
A study was conducted to investigate the effects of skid trail slope and traffic levels on soil disturbances at two soil depths
(0–10 and 10–20 cm). The treatments were set at four traffic levels (2, 7, 12 and 20), two slope classes (<20% and >20%) and
two soil depths (0–10 and 10–20 cm). Results show that skidder traffic, longitudinal slope and soil depth have significant
effect on soil bulk density in skid trail. Comparison of average soil bulk density in different traffic levels shows that
there are significant differences in average bulk density between different traffic levels and control (p<0.05). The average bulk densities in different slopes and soil depths are significantly increased with increase in traffic
levels, maximized at 12 passes (p<0.05), but there are no significant differences between 12 and 20 passes. The interaction effects between traffic and soil
depth are significant (F
0.05,3=0.109, p<0.001). For all traffic treatments, there are significant differences in soil moisture content between the two slope classes
and the two depths (p<0.001). However, the interaction effects between traffic levels and slope classes are not significant (p >0.05), although skidder traffic and slope affected soil moisture content. 相似文献
4.
Cadmium sulfide nanowires were successfully obtained via a poly (ethylene glycol)-assisted solvothermal route. In this procedure, cadmium nitrate and thiourea were used as Cd and S sources, respectively, and polyethylene glycol 400 was used as an inducing soft template to control the one-dimensional growth of CdS nanostructures. The effects of different growth parameters in the solvothermal process such as type of the solvents, reaction time, and temperature on the morphology, structural and optical properties of the products were investigated. The provided structures were characterized by X-ray diffractometery, scanning electron microscopy, and UV-visible absorption spectroscopy. The results show that the as-prepared samples have hexagonal phase and grow into long nanowire shape with increasing the reaction time, temperature and volume ratios of ethylenediamine (en) to H2O. Uniform sized nanowires with the average diameter of 75 nm and the average length of 2.5 µm were obtained using ethylenediamine solvent at 170 °C for 3 days. 相似文献
5.
This study is focussed on evaluation of temperature effectduring frozen storage on movement of trace elements in differenttissues (exoskeleton, carapace and abdominal muscle) of twocommercially important shrimp species (Penaeusmerguiensis and Metapenaues affinis). Moreoverrelationships between total length and sex of specimens with concentration of trace elements in selected tissues were assessed. Concentrations of Cd, Cr, Cu, Fe, Mn, Ni and Znin samples were determined by ICP-AES. Only in the case of Niand Zn sex related differences could be observed. With theexception of Cu, the trace metals distributed significantlydifferent between the tissues. The only significant differencesbetween species were found in bioaccumulation of Mn. Sizedependent relationship was observed only for Ni. Associationsbetween Mn and Fe were positively and highly significant in allthe cases. The levels of all the metals in muscle of the shrimpsfrom the studied region were comparable to other world areas. MeanCu and Zn levels in edible parts of M. affinis stored at–10 °C exceeded some existing guidelines, while the concentrations at –30 °C were somewhat lower than them. 相似文献
6.
Maraisa Crestani Solange Ferreira da Silveira Silveira Elisane Weber Tessmann Itamara Mezzalira Henrique de Souza Luche José Antonio Gonzalez da Silva Luiz Carlos Gutkoski Fernando Irajá Félix de Carvalho Antonio Costa de Oliveira 《Euphytica》2012,185(1):139-156
There has been a strong demand for oat genotypes that contain caryopsis with high chemical quality which can suit the different market niches. Therefore, the objectives of this study were to assess the general (GCA) and specific combining ability (SCA) of white oat cultivars through diallelic crosses providing information about the genetic effects on expression of grain chemical quality components. Also, it was aimed to estimate the heterosis on F1 and F2 generations and the vigor loss due to inbreeding. During 2008, 21 hybrid populations F1 and F2 were obtained from artificial crossing among seven Brazilian white oat cultivars, following the complete diallel design, without considering the reciprocals. These populations and their parents were evaluated in the 2009 season in the experimental field in Capão do Leão, RS, Brazil. The higher values of mean squares associated to GCA indicates a strong contribution of additive genetic effects to the expression of grain chemical components. The parents tested showed a tendency to develop progeny with negative heterosis regarding protein, lipid, β-glucan and soluble dietary fiber in the grain, and positive for the content of nitrogen-free extract, total and insoluble dietary fiber. IAC 7 features a potential parent for obtaining grains with high protein and dietary fiber content, and low caloric content, fit to human diet. Meanwhile, UPF 15 and FAPA Louise can represent donors of alleles to increase lipid contents, while FAPA Louise and URS Guapa can be used to raise the grain nitrogen-free extract contents of lines intended for animal feeding. 相似文献
7.
Amin Bigham-Sadegh Iraj Karimi Mahsa Alebouye Zahra Shafie-Sarvestani Ahmad Oryan 《Journal of veterinary science (Suw?n-si, Korea)》2013,14(3):337-343
The present study was conducted to compare the effects of xenogenic bovine fetal demineralized bone matrix (DBM), commercial DBM, omentum, omentum-calf fetal DBM, cortical autograft and xenogenic cartilage powder on the healing of tibial defects in a dog model to determine the best material for bone healing. Seven male adult mongrel dogs, weighing 26.2 ± 2.5 kg, were used in this study. Seven holes with a diameter of 4-mm were created and then filled with several biomaterials. Radiographs were taken postoperatively on day 1 and weeks 2, 4, 6, 8. The operated tibias were removed on the 56th postoperative day and histopathologically evaluated. On postoperative days 14, 42 and 56, the lesions of the control group were significantly inferior to those in the other group (p < 0.05). On the 28th postoperative day, the autograft group was significantly superior to the control and omentum groups (p < 0.05). Moreover, calf fetal DBM was significantly superior to the control group. There was no significant difference between the histopathological sections of all groups. Overall, the omentum and omentum-DBM groups were superior to the control group, but inferior to the autograft, commercial-DBM, calf fetal DBM and calf fetal cartilage groups. 相似文献
8.
Kaivan Karimi Asadollah Babai Ahari Mahdi Arzanlou Jahanshir Amini Ilaria Pertot Omar Rota-Stabelli 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(2):375-387
Anthracnose caused by Colletotrichum spp. is one of main strawberry diseases worldwide. The disease recently arrived in Iran and become epidemic in the Kurdistan province. A combination of morphological, molecular and pathogen-host interaction approaches (referred to the consolidated species concept) were applied to isolates from symptomatic strawberry tissues collected in Iran. Multi-gene phylogenetic analysis based on ITS-rDNA, beta-tubulin (TUB2) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) identified the species as the S5 clade of Colletotrichum nymphaeae. No significant intraspecies variation was observed in terms of morphology and pathogenicity. No significant genetic variation was observed among the isolates using inter simple sequence repeat analysis (ISSR) and primer pair combination of ERIC1/BOX and ERIC2/BOX fingerprinting markers. Based on the results of this study, it can be postulated that the C. nymphaeae population in Iran established itself from a single origin due to a founder effect. More generally, molecular dating based on relaxed clocks indicates co-radiation of C. nymphaeae S5 and strawberry plants and suggests high reciprocal specificity between the host and pathogen. 相似文献
9.
Mohammad Golbashy Iraj Allahdadi Hossein Nazokdast Morteza Hosseini 《Archives of Agronomy and Soil Science》2017,63(1):84-95
The present study describes the preparation and characterization of montmorillonite-urea nanocomposites (Mt-Ur) using aqueous suspension technique at various stirring times and different ratio of montmorillonite to urea (Mt/Ur) via an impure and domestic montmorillonite (Mt), without the application of any chemical reagents and high-energy-demand process (environmentally friendly). The intercalation of urea into Mt interlayer was clearly demonstrated by a significant expansion of d001 spacing (interlayer space of Mt) from 1.23 to 1.71 nm which has not yet been reported by aqueous suspension technique. Analyses performed by Fourier transform-infrared spectroscopy (FT-IR), Thermogravimetric analysis (TGA) and X-ray diffraction (XRD) also confirmed the effectiveness of this simple process to intercalate the urea into clay lamella. The release pattern demonstrated that the nanocomposite had a slow-release behaviour for urea dissolution. The results also suggested that the Mt type applied in the current study, in a 1:20 Mt/Ur ratio and stirred for 1 h, possessed desirable ecological and economic efficiency in the production of slow-release urea fertilizer due to the application of the impure and domestic clay which is of very low-cost and eco-friendly. Nevertheless, urea was fully intercalated into the interlayer of clay by a simple technique and with a good slow-release behaviour. 相似文献
10.
Mahin Karami Manouchehr Amini Majid Afyuni Amir Hossin Khoshgoftarmanesh Armin Keller Ali Abdi 《Archives of Agronomy and Soil Science》2013,59(3):437-456
Mass flux assessment can provide information that is essential for a sustainable management of elements in agricultural soils. In this article, we present an assessment of regional-scale averages of zinc (Zn) fluxes into agricultural soils and crops of central Iran for the period 1997–2011, using available databases such as regional agricultural statistics. The basic units of the balances were 15 townships of the provinces Qom, Isfahan and Fars. Averaged over the entire study region, the net Zn input into arable soil resulting from all fertilizer inputs – Zn removal with harvested crops was 1515 g ha?1 yr?1 across the entire region, with a range of 438–3009 g ha?1 yr?1 among townships. Estimated average Zn inputs with manure, mineral fertilizers, sewage sludge and compost were 1254, 531, 19 and 7 g ha?1 yr?1, respectively. The input-to-output ratio of these fluxes ranged from 1.8 to 12.9 among townships and averaged 6.1 for the entire study area. Considering that outputs other than with crop harvests are minor, Zn stocks are rapidly building up in the soils of the study region. Uncertainties in the manure and crop removal data were the main sources of estimation uncertainty in this study. 相似文献