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81.
A pot experiment was conducted to appraise the inhibitory effects of salt stress on biochemical attributes in the three mungbean cultivars (NCM-209, NCM-89 and NM-92). Salt stress caused a significant decrease in plant height, shoot relative water contents, photosynthetic pigments, endogenous levels of K+ and K+/Na+ ratios and increase in cellular levels of H2O2, MDA, Na+ and Cl?. However, cv. NCM-209 was found to be tolerant in terms of lower salt-induced decline in K+, K+/Na+ ratio and photosynthetic pigments. The endogenous levels of H2O2 and MDA were also lower in cv. NCM-209. Salt stress markedly also affected different yield attributes in all mungbean cultivars. Again cultivar NCM-209 exhibited less inhibitory effects of salt stress on different growth attributes. Salt stress resulted in a marked increase in the activities of antioxidant enzymes (superoxide dismutase, peroxidase, catalase and ascorbate peroxidase) in mungbean cultivars. Activity of peroxidase was maximal in cv. NCM-209 and catalase activity was maximal in cv. NCM-89, whereas cvs. NCM-89 and NM-92 showed higher activities of superoxide dismutase. Similarly activity of ascorbate peroxidase was higher in cv. NM-92. It could be inferred from data of antioxidant enzymes that mungbean cultivars cannot be categorized as salt tolerant or sensitive on the basis of a single antioxidant enzyme.  相似文献   
82.
Poly(ethylene terephthalate) (PET) fibers were grafted with glycidyl methacrylate (GMA) using benzoyl peroxide as initiator. 1,6-diaminohexane (HMDA) was then covalently attached to this GMA grafted PET fibers. Variations of time, temperature, initiator and monomer concentrations were investigated. HMDA-GMA-g-PET fibers were used as a new sorbent for removal of Cr(VI) ions from aqueous solutions through batch adsorption method. Effects of various parameters such as pH, treatment time, and initial ions concentration on the adsorption amount of ions onto reactive fibers were investigated. The adsorption rates of Cr(VI) ions were much higher on the HMDA-GMA-g-PET fiber than on GMA-g-PET and ungrafted PET fiber. Within 60 min, at pH 3, Cr(VI) was removed by 98 % while the initial concentration of ions was at 25 mg/l and by 94 % at 400 mg/l. The Cr(VI) ions adsorbed were easily desorbed by treating with 1M KOH within 10 min.  相似文献   
83.
The aim of this study were to detect the gyrA, parC and marR mutations and qnr genes (qnrA, qnrB and qnrS) in 120 strains of Escherichia coli isolated from animals. European Committee on Antimicrobial Susceptibility Testing and Clinical Laboratory Standards Institute disc diffusion and minimum inhibitory concentration (MIC) tests, respectively, were used to determine fluoroquinolone (FQ) resistance, and molecular methods were used to detect the mutations and the genes. E coli isolates with an MIC of ≥8 mg/l had mutation at Ser-80 in parC in addition to mutations at Ser-83, Asp-87 or both in gyrA. The nucleotide change was detected in marR (Ser-3?→?Asn, Ala-53?→?Glu, Gly-103?→?Ser, Tyr-137?→?His). Only four E coli isolates (3.3 per cent) contained qnrA and qnrS, and qnrB was not detected. Two E coli isolates from healthy calves also contained qnrA and qnrS. The MICs of enrofloxacin and danofloxacin for qnr-containing E coli isolates ranged from 32 mg/l to 256 mg/l. The results of this study indicated that the FQ-resistant E coli isolates presented an alteration in gyrA (Ser-83?→?Leu, Asp-87?→?Asn) and parC (Ser-80?→?Ile) with high MICs (8-256 mg/l), and there was a low prevalence of qnr genes among E coli isolated from animals.  相似文献   
84.
基于离散元法的旋耕过程土壤运动行为分析   总被引:22,自引:0,他引:22  
土壤与耕作部件间的相互作用规律是设计和选用土壤耕作部件的基础。研究土壤和耕作部件间的相互作用规律就是要研究耕作部件对土壤产生的作用和它们之间的作用力,首先必须探讨耕作部件工作时土壤运动规律和施加于土壤的作用力。为此本文建立基于离散元方法的旋耕工作模型;对比分析实验与仿真的土壤位移:在土槽实验中采用示踪块方法测量土壤位移,仿真中通过追踪表层土壤颗粒的运动获得仿真位移;利用实验和仿真数据对土壤位移和运动机理进行分析。结果表明:土壤水平和侧向位移都随着转速增加呈现增加的趋势;土壤的水平运动位移总是大于同转速下的侧向位移。浅层土壤颗粒的运动位移最大,中层土壤次之,深层土壤最小。较深位置的土壤,距离旋转中心越近的土壤颗粒水平位移和侧向位移越大。在旋耕刀切土范围内的土壤,有向相反方向运动趋势的浅、中、深层颗粒比例分别为26.2%、72.1%、48.4%。在水平力作用下,大部分土壤颗粒随着旋耕刀切土有向后运动的行为;土壤在开始时刻的侧向受力和侧向运动方向,由颗粒的侧向位置是否偏离侧切刃轴线决定,位于侧切刃轴线左侧的颗粒,则其侧向力向左,反之亦然;土壤在垂直方向先随着刀具入土向下运动,然后滑出刀刃边界被抛起。本文建立的仿真模型得到的土壤水平位移和侧向位移与相应实验值的误差为24.9%和15.3%。本文运用离散元法进行旋耕过程中土壤宏观和细观运动行为的分析,有助于理解旋耕刀与土壤的相互作用机理,为旋耕机械的设计与优化提供理论依据。  相似文献   
85.
The present study examines the effect of four semi‐purified diets (casein–gelatin based) where the source of fatty acids was free (esterified) oleic acid and linoleic acid (LA) (LOA diet), linseed and olive oil (predominantly LA and linolenic acid) (LO diet), cod liver oil (rich in highly unsaturated fatty acids) (CLO diet), and soybean lecithin (phospholipids; mostly LA) (LE diet) on the growth of juvenile South American catfish (surubim, Pseudoplatystoma fasciatum, Pimelodidae) (0.98 ± 0.04 g individual weight). Fish were fed at a restricted–readjusted feeding rate for 8 wk. At the end of the experiment, LE‐diet‐fed fish grew significantly larger than those of the other three groups (P < 0.05). Considerable cannibalism was observed in all the treatments. It is suggested that the quantitative growth performance may possibly change under other conditions, with less or no cannibalism. Survival did not differ significantly among the fish fed four different diets. Muscle and liver lipid contents did not vary among dietary treatments (P > 0.05), but whole‐body lipid concentrations were affected by dietary treatments. Fish fed LE diet contained significantly lower lipid level than those fed three other diets (P < 0.05). Muscle and liver fatty acid profiles reflected dietary fatty acid composition. Arachidonic acid level was significantly higher in muscle and liver of fish fed LOA and LE diets than in those fed LO and CLO diets. The results suggest that the efficiency of elongation and desaturation of 18C fatty acids depends on the dietary lipid source, and South American catfish has considerable capacity to transform linoleate to arachidonate.  相似文献   
86.
87.
Coccidia were detected in the faeces of 556 out of 592 sheep (93.9%) in sheep in Kars province. The prevalence of coccidiosis was significantly higher (p>0.01) in young (97.9%) and immature sheep (96.6%) than in adult sheep (90.2%). Mixed infections were widespread (71.5%). Ten species of Eimeria were recognized. These species (and their prevalences) were: Eimeria ovinoidalis (47.7%), E. bakuensis (E. ovina) (46.6%), E. parva (37.1%), E. granulosa (27.7%), E. ahsata (23.4%), E. pallida (23.2%), E. faurei (15.1%), E. intricata (13.9%), E. crandallis (13.7%) and E. punctata (2.3%). Eimeria punctata is reported in sheep from Turkey for the first time. The mean oocyst count from infected animals was 3451±409 opg (range 50–117 600). The mean was higher (9529±502) in young sheep. Differences in the counts from young, immature and adult sheep were statistically significant (p>0.01). However, no clinical cases of coccidiosis were encountered.  相似文献   
88.
This work deals with the evaluation of in vitro antioxidant, DNA preventing and antiamoebic activities of the water extracts of Teucrium polium and Stachys iberica. In all systems, T. polium extract exhibited excellent activity potential than that of S. iberica. The amount of total phenolics and flavonoids were high in this extract. In the presence of 40 mg/ml T. polium extract, a significant protection was observed for native super coiled DNA of pBR322 plasmid DNA. In the presence of 32 mg/ml of T. polium extract, no trophozoite was after the 24th hour.  相似文献   
89.
Arslan I  Celik A  Chol JH 《Fitoterapia》2012,83(4):699-703
A cytotoxic triterpenoid saponin was isolated from the under-ground parts of Gypsophila pilulifera Boiss.& Heldr. (Caryophyllaceae) naturally grow in the southwestern region of the Turkey. The structures of saponin was elucidated as 3-O-β-D-galactopyranosyl-(1→2)-[β-D-xylopyranosyl-(1→3)]-β-D-glucuronopyranosyl quillaic acid 28-O-β-D-glucopyranosyl-(1→3)-[β-d-xylopyranosyl-(1→4]-α-l-rhamnopyranosyl-(1→2)-β-D-fucopyranosyl ester on the basis of extensive spectral analysis and chemical evidence. The separated triterpenoid saponin was isolated from Gypsophila pilulifera for the first time. The saponin compound displayed significant cytotoxicity against A549 cell line with IC(50) values >16μM.  相似文献   
90.
This study was carried out to determine the prevalence of Cryptosporidium species in diarrhoeic lambs and investigate some risk factors in Kars province (Northeastern region of Anatolia) in Turkey. Four hundred faecal samples were taken from the rectums of clinically diarrhoeic and aged to 1-month-old lambs from 34 sheep farms in 20 villages in March-April 2007 and examined by using the modified acid-fast staining technique. The prevalence of Cryptosporidium species was found as 38.8% (155/400). Cryptosporidium oocysts were detected in 90.0% (18/20) of villages and in 76.5% (26/34) of the sheep farms. Infection rates were detected as: 44.4% (67/151) in 1-week-old lambs, 37.5% (39/104) in 2-week-old lambs, 40.0% (38/95) in 3-week-old lambs, and 22.0% (11/50) in 4-week-old lambs. Farms classified according to their zoohygienic conditions and fine, average and bad conditioned farms were contaminated with Cryptosporidium with the percentages of 14.7%, 20.6% and 41.2%, respectively. Clinical cryptosporidiosis was determined in 35.0% of the villages (7/20) and in 29.4% of the sheep farms (10/34), Cryptosporidium oocysts were found in 81.3% of the lambs (91/112) in these farms. Cryptosporidiosis may be a major epidemiological significance in lambs in Kars province, and suggests that naturally infected lambs may be reservoirs of Cryptosporidiosis infections for calves even for humans too.  相似文献   
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