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121.
In this study, we developed new method to prepare one-pot current collector/electrode plate to be utilized in the fuel cell technology. In situ preparation of zero-valent N-doped Co carbon nanofibers (Co/N-CNFs) as an immobilized thin film onto graphite disc was achieved by electrospinning technique, followed by calcination at 1100 oC in argon atmosphere. This catalyst was used for methanol electrooxidation in alkaline media. The effects of nitrogen doping and immobilization on the activity and stability of the prepared catalysts were studied using cyclic voltammetry and chronoamperometry, respectively. SEM, TEM, EDX, XRD, and TGA were used to characterize the morphology and composition of Co/N-CNFs catalysts. The results showed that the electrocatalytic activity as well as the stability of Co/N-CNFs towards methanol electrooxidation in alkaline media were significantly affected by both nitrogen doping and immobilization of the catalyst on the graphite disc. Moreover, the methanol concentration has also affected the electrocatalytic activity of Co/N-CNFs-supported immobilized onto graphite disc and Co/N-CNFs-unsupported graphite disc.  相似文献   
122.
A study was conducted to determine the effect of pollen source on fruit, aril, and seed characteristics in pomegranate. The cultivar Malas Yazdi was pollinated with three pollen sources including: Rabab Neyriz (a commercial cultivar), Malas Pishva Varamin (selected superior local cultivar), and Poost Sefid Dezful (non-commercial cultivar). The results showed that the rate of fruit set from different pollen sources varied from 13% to 46%. Pollen source also had significant effects on other fruit properties, such as fruit weight, fruit shape, fruit length and diameter, fruit peel color, fruit peel thickness, and edible portion of the fruit. Aril characteristics including number of arils per fruit, aril length and diameter, aril weight, and aril color were also significantly affected by pollen source as well as seed physical properties, including seed weight, seed length and diameter, seed hardness, and seed toughness. However ‘Malas Pishva Varamin’ as a pollinizer showed the lowest rate of fruit set, but performed better in terms of fruit quality and seed characteristic than ‘Rabab Neyriz’ and ‘Poost Sefid Dezful’. This is the first observation of xenia effect in pomegranate breeding and could serve as a new area of research for pomegranate production. These findings suggest that selection of suitable pollinizer could be a new area of research for pomegranate production.  相似文献   
123.
RN Zare 《Science (New York, N.Y.)》1998,279(5358):1875-1879
Experiments show how product pathways can be controlled by irradiation with one or more laser beams during individual bimolecular collisions or during unimolecular decompositions. For bimolecular collisions, control has been achieved by selective excitation of reagent vibrational modes, by control of reagent approach geometry, and by control of orbital alignment. For unimolecular reactions, control has been achieved by quantum interference between different reaction pathways connecting the same initial and final states and by adjusting the temporal shape and spectral content of ultrashort, chirped pulses of radiation. These collision-control experiments deeply enrich the understanding of how chemical reactions occur.  相似文献   
124.

Background:

Hyperprolactinemia is a common side effect of antipsychotic drugs that requires further investigation. The current study was designed to evaluate dose-dependent effect of chlorpromazine (CPZ) on hormonal changes and uterine horn histological structure in rats. Moreover, the mammary glands were analyzed to show hyperprolactinemia-induced histological changes.

Methods:

Albino Wistar rats (n = 32) were divided into four groups. The first group was set as a control. In the three drug-treated groups (eight rats in each group), CPZ was administered by a gavage at doses of 3, 10, and 30 mg/kg/day for 28 days. One day after the last administration of the drug, the animals were sacrificed. Histopathological and histomorphometrical analyses of the uterine horns and mammary glands were carried out to evaluate dose-dependent effect of CPZ on histological structure. Serum levels of prolactin (PRL), estradiol, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were also evaluated.

Results:

Remarkable (P < 0.05) elevation was observed in CPZ-administrated animals'' uterine horn endometrium, myometrium, and perimetrium thicknesses, and the mammary glands were observed with galactorrhea features. The serum level of progesterone and PRL significantly (P < 0.05) increased, while the serum concentration of LH, FSH, and estradiol was notably (P < 0.05) decreased depending on administrated CPZ dose. No histological and biological changes were occurred in the control animals.

Conclusion:

The present findings suggest that CPZ-induced disturbances not only depend on PRL level and increased PRL level largely depends on administrated doses of the CPZ. Key Words: Hyperprolactinemia, Uterus, Rats  相似文献   
125.
Journal of Plant Diseases and Protection - Crown and root rot of wheat caused by Fusarium pseudograminearum is one of the most important wheat diseases in Iran. In this study, the genetic structure...  相似文献   
126.
Over the past decade, several natural and synthetic cationic polymers have been utilized for gene delivery into cells. Among them, polyethylenimine (PEI) was used for gene therapy successfully. The present study investigated the effect of PEI and ultrasound waves on ssDNA delivery into saffron cells. Gel retardation, dynamic light scattering (DLS) and scanning electron microscopy (SEM) assays were employed to determine the physicochemical properties of PEI/f-DNA polyplex (complex of PEI and fluorescently labeled DNA). Moreover, the cytotoxicity of PEI, PEI/f-DNA polyplex and ultrasound were investigated on saffron cells at different concentrations. The gel retardation results indicated that the formation and neutralization of the PEI/f-DNA polyplex were completed at N/P=5. The particle size distribution of the polyplexes was from 50 to 122 nm. The experimental results revealed that the cytotoxicity of the PEI/f-DNA polyplex was lower than that of PEI alone, hence the cells showed both dose- and exposure duration-dependent responses. Furthermore, the viability of saffron cells declined extremely after 5 and 10 min sonication but this reduction was not significant at 2 min exposure duration. The results also indicated that the combined utilization of ultrasound and PEI nanoparticles increased the transfection efficiency of saffron cells up to two times higher than those obtained by PEI or ultrasound separately.  相似文献   
127.
不同立地条件下哈密大枣果园营养特征及果实品质的研究   总被引:1,自引:0,他引:1  
[目的]研究不同土壤类型(沙土、沙壤土和粘土)下,不同树龄(初果期和盛果期)哈密大枣在花芽分化期、开花盛期和果实膨大期的土壤和叶片,主要营养成分及其果实品质之间的差异性.[方法]以哈密大枣作为试材,主要测定土壤有机质、碱解氮、速效磷和速效钾含量,叶片的氮、磷、钾含量,以及果实VC、可滴定酸、可溶性糖和可溶性固形物含量.[结果]不同土壤类型不同树龄下哈密大枣果园在各物候期内0~20 cm 土层的有机质、碱解氮、速效钾和速效磷含量均明显高于20~80 cm土层;初果期三种土壤类型的哈密大枣果园在0~20 cm土层中开花盛期的有机质、碱解氮、速效磷和速效钾含量比花芽分化期和果实膨大期较高.不同树龄不同土壤类型哈密大枣果园在不同物候期间相比,除了初果期粘土枣园开花盛期的叶片氮和钾含量均高于花芽分化期和果实膨大期以外,叶片氮和钾含量在果实膨大期均最高,而叶片磷含量在花芽分化期均最高.初果期哈密大枣果实品质在土壤类型之间比较而言,沙壤土枣园的果实VC、可滴定酸和可溶性糖含量最高,而粘土枣园的果实可溶性固形物含量较高;盛果期而言,沙土枣园的果实VC和可滴定酸含量最高,沙壤土的可溶性糖和固形物含量最高.[结论]在哈密大枣生产中,根据土壤营养情况花芽分化期要适当加大磷肥的施用比例,而果实膨大期要增加氮肥和钾肥的施用量.  相似文献   
128.
ABSTRACT

The need for salinity resistance in turfgrass is increasing because of the enhanced use of effluent and other low-quality water for turfgrass irrigation. Although most turfgrasses form an arbuscular mycorrhizal fungus (AMF) symbiosis, there is little information on the mycorrhization of turfgrass species. Therefore, the aim of this study was to determine the effects of three AMF species, Glomus intraradices Schenck & Smith, Glomus etunicatum Becker & Gerdemann, and Glomus deserticola Trappe & John, and a mixture thereof on the growth, productivity, and nutrient uptake of two species of cool-season turfgrasses, Challenger Kentucky bluegrass (Poa pratensis L.) and Arid tall fescue (Festuca arundinacea Schreb.), and to relate the effects to colonization of the roots by mycorrhiza to assess the dependency of the plants (mycorrhizal dependency [MD]). Following the experimental period (4 months) and measurements, the mycorrhizal inoculated plants had significantly greater biomass production compared to that of non-inoculated plants. MD and shoot mineral contents (particularly P) differed among turfgrass hosting AMF, and the highest value (13%) occurred for P. pratensis and F. arundinacea seedlings colonized with G. intraradices and G. deserticola, respectively. The P content was highest for the F. arundinacea/mixed AMF combination compared to other treatments. We confirmed that mycorrhizal inoculation (P. pratensis/G. intraradices and F. arundinacea/mixed AMF combinations) enhanced plant productivity and nutrient uptake (especially P) even under non-optimum conditions.  相似文献   
129.
Non-woody biomass species have high-energy potentials, which could be used for bioenergy production. Invasive species are species spreading into areas, where they are not native, consequently causing environmental and economic problems. Therefore, the present study evaluated the proximate, ultimate, chemical, and fuel characteristics of wood and charcoal of three invasive non-forest tree species in Saudi Arabia: Calotropis procera, Rhazya stricta, and Phragmites australis, which were compared with the wood of Acacia tortilis, a preferable local fuelwood. All these data were discussed to investigate the possibility of using the invasive plants for energy production. The thermal behavior of wood was analyzed using thermo-gravimetric and derivative thermo-gravimetric methods. Overall, compared with the wood of A. tortilis, the woods of R. stricta and P. australis are suitable for energy production. The charcoal produced from P. australis emitted less nitrogen (N) oxide than that of R. stricta.  相似文献   
130.
One hundred compost samples were examined for the presence of nematophagous fungi on the sheep farms of Mazanderan, province, Iran. Arthrobotrys cladodes var. macroides (IRAN 677C = CBS 143565) was isolated from 3% of the samples examined. Nematophagous activity of this fungus which was shown for the first time in this study, revealed the addition of 1000, 8000, 20 000 and 100 000 conidia per gram of feces of sheep reduced significantly (P < 0.001) the number of Haemonchus contortus infective larvae in the feces by 41.71%, 63, 27%, 73.49% and 94.96%, respectively. These results show that A. cladodes var. macroides is a promising candidate for biological control of H. contortus.  相似文献   
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