Light transmission and the fine structure of poly(methyl methacrylate) nanofibers and films     

Maryam Mirzaei Sheshkol  Sedigheh Borhani  Mostafa Youssefi 《Fibers and Polymers》2017,18(12):2361-2367

In this paper, the structure and optical properties of poly(methyl methacrylate) (PMMA) nanofibers and films were investigated. Differential scanning calorimetery (DSC) and Wide-Angle X-ray scattering (WAXS) results confirmed the amorphous structure of both nanofibers and films. Low angle X-ray diffraction (LA-XRD) revealed the presence of voids and/or particles with the spacing of 128.4 Å within the nanofibers. From the Porod plots, a three-dimensional surface fractal for the nanofibers and a mass fractal structure for the films were derived. By the interpretation of Small Angle X-ray scattering (SAXS), the shape and size of the particles in the samples were assessed. It was concluded that the particles shape within the nanofibers and the films were globular, with the radius of gyration of 8.5 nm for the nanofibers and 16.5 nm for the films. The nanofiber mat showed less light transparency when compared with the film. This phenomenon could be attributed to the difference in the physical shape, as well as scattering of the light by the voids or particles within the nanofibers.  相似文献   

Effects of nano-fertilizers on physiological and yield characteristics of pinto bean cultivars under water deficit stress     

Maryam Fatollahpour Grangah  Bahram Mirshekari  Ebrahim Khalilvand Behrouzyar  Farhad Farahvash 《Journal of plant nutrition》2020,43(19):2898-2910

Abstract

In order to evaluate the effects of water deficit stress and foliar application of zinc (Zn) and iron (Fe) nanoparticles on physiological characters and seed yield of pinto bean, an experiment was designed as a split factorial design based on randomized complete blocks with three replications in two growing seasons (2016–2017 and 2017–2018). Treatments were included water deficit stress (normal irrigation and water deficit stress in 50% flowering), foliar application of nano-fertilizers (control, nano-Zn (1.5?g L^?1), nano-Fe (2?g L^?1) and combination of nano-Zn and nano-Fe) and four cultivars of pinto bean (Sadri, Coosha, Cos16, and Ghaffar). The results showed that the soluble sugars and proline content was increased under water deficit. Water deficit stress through decreasing chlorophyll and relative water content of leaves as well as the iron and zinc content of seeds, decreased seed yield and quality. The application of nano-fertilizers of zinc and iron enhanced antioxidant enzymes activity, proline and soluble sugars content as well as leaf area. Also applied nano-fertilizers improved seed quality in terms of protein content. According to obtained results the effect of foliar spray of nano-fertilizers on iron and zinc content of seeds regards to bean cultivars was different. It was concluded that the foliar application of iron combined zinc nano-fertilizers can be useful in pinto bean cultivars under water deficit stress. In both normal and water deficit Cos16 cultivar showed the better amount of studied characteristics compared to other cultivars. The results of cluster analysis of these cultivars confirmed the superiority of Cos16 cultivar.  相似文献   

Differences in vitamin D status and calcium metabolism in Saudi Arabian boys and girls aged 6 to 18 years: effects of age, gender, extent of veiling and physical activity with concomitant implications for bone health     

Al-Ghamdi MA  Lanham-New SA  Kahn JA 《Public health nutrition》2012,15(10):1845-1853

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Distribution of the enzyme rhodanese in tissues of the cat (Felis catus)     

Shahbazkia HR  Aminlari M  Tavana M 《Journal of Feline Medicine and Surgery》2009,11(4):305-308

The enzyme rhodanese (EC 2.8.1.1) is an ubiquitous enzyme which is present in all living organisms, from bacteria to man. It is speculated that this enzyme plays a central role in cyanide detoxification. However, its wide tissue distribution suggests this enzyme might perform other functions beside cyanide detoxification. Although the distribution of rhodanese in different tissues of human and domestic animals has been studied, little is known about the pattern of distribution and physiological roles of this enzyme in the cat. The purpose of this investigation was to determine the enzyme levels and compare the distribution of this enzyme in different tissues of the cat. A selection of tissue samples was assayed for rhodanese activity. The protein content of tissue extracts and enzymatic activities were calculated as units per gram tissue and units per milligram protein of the tissue. Results showed that in terms of units per milligram protein of the tissue (specific activity of the enzyme), colon and rectum mucosal layers and testis were the richest sources of the enzyme followed by ovary, mucosal layer of jejunum and liver. With respect to units/gram tissue, liver followed by testis, colon and rectum mucosal layers, ovary and mucosa of jejunum exhibited highest activities. The results of this study will allow one to speculate on the involvement of rhodanese in several biochemical and physiological functions in different tissues and organs of this species.  相似文献   

Ameliorative effect of selenium on tomato plants grown under salinity stress     

Maryam Mozafariyan  Mohammad Mojtaba Kamelmanesh  Barbara Hawrylak-Nowak 《Archives of Agronomy and Soil Science》2016,62(10):1368-1380

The ability of selenium (Se) to counteract salt inhibitory effects in crop plants, especially in tomato, is still poorly documented. In order to examine the impact of Se addition on the growth, some biochemical parameters related to osmotic adjustment and antioxidant defense of salt-stressed tomato, a two-factorial experiment was conducted in a greenhouse. The plants were supplied with NaCl (0, 25, or 50 mM) and Se (0, 5, or 10 μM), individually or simultaneously. The results showed that salinity had a deleterious impact on plant biomass and physiological parameters studied. The application of Se alleviated this adverse effect by improving the integrity of cell membranes and by increasing leaf relative water content under stress conditions. Moreover, the application of 10 μM Se significantly increased the photosynthetic pigments concentration under salt stress. Salt stress also caused an inhibition of catalase activity, but its activity was restored in the presence of Se. The free radical scavenging activity significantly increased in plants subjected to 25 mM NaCl and supplied with 5 µM Se, compared to NaCl-alone treatment. Both physiological and biochemical results indicate that 10 µM Se treatment can increase plant performance under salt stress, especially under high NaCl concentration.

Abbreviations: CAT: catalase; Chl: chlorophyll; DPPH: 2,2-diphenyl-1-picrylhydrazyl; DW: dry weight; FW: fresh weight; POD: peroxidase; REL: relative electrolyte leakage; RWC: relative water content; free radical scavenging activity (FRSA); TW: turgid weight  相似文献   

Importance of brucellosis control programs of livestock on the improvement of one health     

Maryam Dadar  Ruchi Tiwari  Khan Sharun  Kuldeep Dhama 《The Veterinary quarterly》2021,41(1):137

Brucellosis not only represents an important health restraint on livestock but also causes high economic losses in many developing countries worldwide. Despite considerable efforts made for the control of brucellosis, the disease is still spreading in many regions (such as the Middle East) where it represents one of the most important health hazards impacting both animals and humans. The present review aims to investigate the efficacy of veterinary control programs regarding brucellosis, with a special focus on current prevention, control, and eradication approaches. The reasons for unsuccessful control programs such as the absence of highly effective vaccines and non-certified bulls are also debated, to understand why the prevalence of brucellosis in livestock is not decreasing in many areas despite considerable efforts taken to date. The importance of governmental and regional investment in brucellosis control remains one of the main limiting factors owing to the limited budget allocated to tackle this disease. In this context, one health concept has generated novel comprehensive approaches with multiple economic implications across the livestock industry and public health. However, the implementation of such global preventive strategies appears to be a key issue for many endemic and low-income countries. According to the collected data, epidemiological contexts including management and trade systems along with well-defined agro-ecological zones should be evaluated in brucellosis endemic countries to improve milk production and to enhance the sustainability of the livestock sector at both national and regional levels.  相似文献   

Yellow mealworm,Tenebrio molitor (Col: Tenebrionidae), larvae powder as dietary protein sources for broiler chickens: Effects on growth performance,carcass traits,selected intestinal microbiota and blood parameters     

Shadi Sedgh-Gooya  Mehran Torki  Maryam Darbemamieh  Hassan Khamisabadi  Mohammad Amir Karimi Torshizi  Alireza Abdolmohamadi 《Journal of animal physiology and animal nutrition》2021,105(1):119-128

This study was conducted to evaluate the effects of dietary Tenebrio molitor larvae meal (TM meal) inclusion on the performance, carcass traits, caecum microbiota and blood parameters of broiler chickens. A total of 180-day-old chickens were allocated to three dietary groups with five replicate pens (12 birds/pen). Experimental diets were included a corn-soybean basal diet, and two diets with 2.5% and 5% TM. TM-included diets have been administered for periods of starter (1–10 days) and grower (11–25 days). A regular finisher diet was given to all groups during the 26–42 days of age. Diets containing TM meal did not influence feed intake and mortality percentage. Feed conversion ratio was lower with the 2.5% TM meal diet compared with the control group at starter period (p < .05). Besides, broiler chickens fed TM meal included diet had a higher body weight gain than the control group during 1–10 days of age (p < .05). The carcass characteristics and length and weight of different parts of small and large intestines were not influenced by diets. TM meal inclusion decreased the albumin-to-globulin ratio compared with the control group (p < .05). Additionally, lower total count of aerobic and Escherichia coli bacteria was observed in response to diet inclusion of 5% TM meal. Overall, the inclusion of TM meal in broilers' diet improved body weight gain and feed conversion ratio in the starting period, decreased albumin-to-globulin ratio and E. coli bacteria content.  相似文献   

Comparison of floral ontogeny in wild-type and double-flowered phenotypes of Syringa vulgaris L. (Oleaceae)     

Mohammad Reza Dadpour  Somayeh Naghiloo  Seyed Hadi Peighambardoust  Sima Panahirad  Maryam Aliakbari  Ali Movafeghi 《Scientia Horticulturae》2011

A comparative study of floral ontogeny in normal and double-flowered phenotype of Syringa vulgaris was conducted using the epi-illumination light microscopy. In the wild phenotype, floral differentiation starts with calyx inception and the formation of four sepals in orthogonal positions (two median and two lateral). The corolla emerges as a continuous ring-like structure leading to the appearance of four petal lobes alternating with the sepals. Androecium was formed by initiation of two stamen primordia in transverse plane and finally the bicarpellate gynoecium emerges in median position. In the case of the double-flowered lilac, there are supernumerary petals in an additional whorl. In double-flowered phenotype, a ring meristem is formed acropetally after the first petal whorl initiates. Stamens and carpels initiated similarly in double-flowered as well as in wild-type plants. However, position of stamens deviates from the typical transverse situation. It seems that the appearing of an extra petal whorl did not exhibit any adverse effect on the initiation of other whorls, in terms of organ identity. Therefore, it would be suggested that the double-flowered phenotype of Syringa represents a case of neoheterotopy, with formation of an extra petal whorl, rather than a case of homoheterotopy with transformation of an ancestral androecium whorl into petals.  相似文献   

The response of drought-tolerant sugar beet to salinity stress under field and controlled environmental conditions     

Zahra Abbasi  Maryam Golabadi  Samar Khayamim  Mohammad Pessarakli 《Journal of plant nutrition》2013,36(20):2660-2672

Abstract

Thirty-four sugar beet drought-tolerant half-sib families were screened in greenhouse experiment under saline (16?dSm^?1) and normal conditions, and a subset of 10 tolerant genotypes were selected for evaluating of yield-related traits, Na⁺, K⁺, and α-amino-N nitrogen contents under saline field condition (12?dSm^?1). Drought-tolerant genotypes showed a different tolerance level under salt stress. Significant correlation was observed between EP2_s and STIEP2 in greenhouse with root yield (RY) in saline field condition. It should be possible that a simple measurement at 16?dSm^?1 in the greenhouse can be used as main part of sugar beet salt-tolerant breeding program. In total, genotypes SBSI-DR I-HSF14-P.23 (# 16) and 436B-HSF9-P.27 (# 26) were recognized as salt- and drought-tolerant genotypes with low Na⁺ and K⁺ contents in root and high white sugar content (WSC) and RY in field. A larger panel of genotypes to validate this kind of association is necessary.  相似文献   

Influence of applied zinc and organic matter on zinc desorption kinetics in calcareous soils     

Maryam Zahedifar  Najafali Karimian  Jafar Yasrebi 《Archives of Agronomy and Soil Science》2013,59(2):169-178

Zinc (Zn) desorption from an exchange complex to solution, the release of Zn from organic matter (OM), crystalline minerals and other precipitates into the solution phase, is the process that controls Zn mobility in soils. An experiment was conducted to determine the pattern of Zn desorption and the soil characteristics affecting it. Desorption of Zn in 15 calcareous soils from southern Iran, treated with 10 mg Zn kg soil^?1 as zinc sulfate (ZnSO₄?7H₂O) and 10 g organic matter (OM) kg^?1 as feedlot cattle manure, equilibrated and extracted with diethylenetriamine pentaacetic acid (DTPA), was studied. Eight kinetic models were evaluated to describe the rate of Zn desorption of soil extracted with DTPA. There was a rapid rate of desorption during the first 4 h followed by a slower rate during the next 12 h. Two-constant rate and simple Elovich models were determined as the best models describing Zn desorption kinetics. Zinc desorption increased as Zn was applied, whereas it decreased with applied OM. The constants of the simple Elovich (β_s) and two-constant rate equations (a and b) were closely correlated with cation-exchange capacity (CEC), OM and pH, which affect Zn solubility, sorption–desorption and diffusion in soils.  相似文献