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41.
本文对采用纯苎麻纱作经纱及沟槽异形涤纶纤维混纺纱(交捻纱和sirofil纺纱)和其它纱线作为纬纱的不同织物试样的性能进行了测试和对比,分析了沟槽纤维混纺对织物吸湿排湿及其它性能的影响及其机理。  相似文献   
42.
Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.  相似文献   
43.
Summary

This study addresses the effects of air temperature and plant growth regulators on anthocyanin synthesis, sugar content and phenylalanine ammonia-lyase (PAL) activity in chicory (Cichorium intybus L.). Anthocyanin in chicory was synthesised at the highest level under 15°/10°C (day/night) temperatures, followed by 20°/15°C, and 25°/20°C; while synthesis was inhibited > 90% at 30°/25°C, resulting in an almost green colour. Sugar contents paralleled anthocyanin development under the same temperatures. The plant growth regulators, abscisic acid (ABA), ethephon and uniconazole all stimulated anthocyanin synthesis, with uniconazole treatment showing the greatest effect. Gibberellic acid (GA3) inhibited anthocyanin development, while GA3 in combination with uniconazole alleviated this inhibition.

PAL activity was higher at 15°/10°C or 20°/15°C (day/night) temperatures when plants were treated with ABA, ethephon or GA3, than at 25°/20°C and 30°/25°C (day/night) temperatures. These results suggest that, under lower temperatures, plant growth regulators may play an important role in anthocyanin synthesis and PAL activity in chicory.  相似文献   
44.
用鸡胚感染柔嫩艾美耳球虫子孢子作为抗球虫药活性峰期测定的模型。每一鸡胚在接种5000个子孢子后,分别于感染的当天、第2天、第3天和第4天注入测试药物,以不同注药时间对鸡胚卵囊所产生的抑制率的差异,判定药物的活性峰期。结果表明,氯甲吡啶酚和丁氧喹啉的活性峰期是球虫生活史的第1天,卵囊抑制率分别为100%和98%;莫能菌素、盐霉素、球R和加福的作用峰期是第2天,卵囊抑制率均为100%;氨丙啉的峰期是第3天,卵囊抑制率为100%;尼卡巴嗪的峰期是第4天,卵囊抑制率为100%;速丹则在球虫生活史的整个无性阶段均呈现活性作用。加福+氨丙体+乙氧乙胺苯甲酯、球R+氨丙啉+乙氧乙胺苯甲酯、加福+速丹、加福+尼卡巴嗪及加福+乙氧乙胺苯甲酯等合剂亦在球虫生活史的整个无性阶段发挥高峰作用,其印囊的抑制率均为100%;尼卡巴嗪+氨丙啉合剂则在球虫生活史的第2~4天发挥最大作用,卵囊抑制率为100%。作者认为,本方法具有操作简单,结果可信及成本低廉的特点,可作为抗球虫药的筛选方法。  相似文献   
45.
Barnyardgrass (Echinochloa crus-galli) seed samples were collected in rice fields in different locations at Mekong delta in Vietnam for herbicide resistance tests. The ALS-resistant and synthetic auxin-resistant E. crus-galli were confirmed at several locations in the Mekong Delta. The average LD90 value of bispyribac, penoxsulam and quinclorac for assessed weed populations was 33.1, 15.1 and 550.2 g a.i.ha?1 respectively. There were cross resistant barnyardgrass populations to bispyribac and penoxsulam, the LD90 value of the two ALS inhibitors for E. crus-galli was positively correlated at R2=0.39, the cross resistant population was 33.3% of total sample. The correlation analysis was not useful to evaluate the multiple resistance between quinclorac and the two ALS inhibitors, the R2 value was lower than 0.05, however, the percentage of multiple resistance weed was 36.2% of population. There was no cross resistance or multiple resistance among the 3 tested herbicides and the new synthetic auxin herbicide Rinskor?. All tested weed samples, including quinclorac-resistant populations, were effectively controlled by Rinskor?. There was no difference between control from Rinskor? in the different herbicide resistant populations. Average LD90 value of Rinskor? in all tested barnyardgrass was 17.1 g a.i ha?1.  相似文献   
46.
The white spot syndrome virus (WSSV) is a pathogen of great concern to the worldwide shrimp culture. In comparative studies on the WSSV genome, regions such as the open reading frame (ORF) 14–15 and ORF 23–24, prone to deletions and recombination, had been useful to study the evolutive relationships among viral strains. When looking for the WSSV strains infecting Litopenaeus vannamei (Boone) in northwest Mexico, we found evidence of a genetic similarity in ORF 14–15 to a strain from India and a recombination involving ORFs 78, 79 and 80. Two genotypes were found involving the insertion of a 265 base‐pair segment of ORF 108 into ORF 78 with inversions and deletions within ORFs 78, 79 and 80. The WSSV has an Asian origin and the mutations found could be an adaptation strategy to infect L. vannamei and other crustacean species of the American continent.  相似文献   
47.
We analyzed the expression level and cellular localization of pro- and anti-inflammatory cytokines and histopathologically characterized canine traumatic brain injury (TBI). Canine TBI brains revealed subarachnoid and cerebral cortical hemorrhage, neutrophilic infiltration, neuronal necrosis, astrocytosis, and vasogenic edema. Immunohistochemical evaluations suggested that both pro-inflammatory cytokines [interleukin (IL)-1β, IL-6, and tumor necrosis factor-α] and anti-inflammatory cytokines [IL-10 and transforming growth factor-beta (TGF-β)] were highly expressed in neurons and neutrophils. In particular, the highest magnitude of expression was identified for IL-1β and TGF-β. This data helps describe the pathologic characteristics of canine TBI, and may help in the design of potential therapeutic approaches to control secondary damage by inflammatory cytokines.  相似文献   
48.
White spot syndrome virus (WSSV) has caused substantial global economic impact on aquaculture, and it has been determined that strains can vary in virulence. In this study, the effect of viral load was evaluated by infecting Litopenaeus vannamei with 10‐fold serial dilution of tissue infected with strain WSSV Mx‐H, and the virulence of four WSSV strains from north‐western Mexico was assessed along with their variable number of tandem repeat (VNTR) genotypes in ORF75, ORF94 and ORF125. The LD50 of the Mx‐H strain was a dilution dose of 10?7.5; the mortality titre was 109.2 LD50 per gram. In shrimp injected with 102.5 to 106.5 LD50, no significant virulence differences were evident. Using mortality data, the four WSSV strains grouped into three virulence levels. The Mx‐F strain (intermediate virulence) and the Mx‐C strain (high virulence) showed more genetic differences than those observed between the Mx‐G (low‐virulence) and Mx‐H (high‐virulence) strains, in ORF94 and ORF125. The application of high‐viral‐load inocula proved useful in determining the different virulence phenotypes of the WSSV strains from the Eastern Pacific.  相似文献   
49.
50.
The aim of this investigation was to study the antioxidant and anticancer activities of young sprouts of some traditional Korean salad plants. Total phenolics, antioxidant and anticancer activities of the methanol extracts from young sprouts of 11 salad plants were determined. The highest amount of phenolics was found in methanol extracts of Euonymus alatus (235.7 mg kg−1), followed by Hypericum ascyron (197.1 mg kg−1), Zanthoxylum piperitum (194.1 mg kg−1) and Zanthoxylum schinifolium (142.5 mg kg−1). Methanol extracts of E. alatus, H. ascyron, and Z. piperitum at 63 mg kg−1 exhibited the highest dose-depend DPPH radical scavenging activity by 91.2, 91.2 and 83.9%, respectively. According to the MTT results, the methanol extracts from Stellaria aquatica, Eleutherococcus sessilifolrus and Z. schinifolium showed the highest anticancer activities against Calu-6 (IC50 < 25.0 μgml−1) and from S. aquatica—the highest anticancer activities against SNU-601 (153.3 μgml−1), following by E. sessilifolrus (196.7 μg ml−1) and Amaranthus mangostanus (303.1 μgml−1). Total phenolics were highly correlated with the DPPH, suggesting that they contribute to the antioxidant properties of the studied plants. In conclusion: young sprouts of Korean salad possess antioxidant and anticancer properties and could be used as a supplement to proper drugs.  相似文献   
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