几种脲酶抑制剂对大豆脲酶和绵羊瘤胃微生物脲酶的抑制作用   总被引：1，自引：0，他引：1  

刘大森  单安山  石宝明  孙金艳 《中国畜牧杂志》2004,40(6):8-10

本文研究了脲酶抑制剂乙酰氧肟酸 (AHA)、邻苯二酚、氢醌 (HQ)和硼砂对大豆脲酶和绵羊瘤胃微生物脲酶的抑制作用。结果表明 ,在浓度为 0 .0 0 0 1,0 .0 0 1,0 .0 1和 0 .1mmol/L时 ,4种脲酶抑制剂对大豆脲酶的抑制率分别为 :AHA为 6 % ,6 .2 % ,9.6 6 %和 2 9.79% ;HQ为 8.4 % ,13.0 3% ,19.79%和 4 4 .75 % ;邻苯二酚为 2 0 .34% ,19.12 % ,83.16 %和 93.78% ;而硼砂为 16 .5 5 % ,17.18% ,18.95 %和 35 .5 0 %。在相同浓度下 ,4种脲酶抑制剂对绵羊瘤胃微生物脲酶的抑制率分别为 :AHA为 9.5 8% ,14 .0 4 % ,4 1.30 %和 72 .73% ;HQ为 12 .2 1% ,39.99% ,6 4 .6 2 %和 78.87% ;邻苯二酚为 6 .0 7% ,9.36 % ,31.2 9%和 5 0 .4 4 % ;而硼砂分别为 4 .97% ,8.6 3% ,2 1.78%和 32 .0 2 %。  相似文献   

Treatment of canine haemangiosarcoma with suberoylanilide hydroxamic acid, a histone deacetylase inhibitor     

L. A. Cohen  B. Powers  S. Amin  D. Desai 《Veterinary and comparative oncology》2004,2(4):243-248

A case report is presented by describing the treatment of a 12‐year‐old dog – diagnosed with haemangiosarcoma (HSA) – with suberoylanilide hydroxamic acid (SAHA), a histone deacetylase (HDAC) inhibitor. The drug was administered orally, on a daily basis, approximately 2 weeks post‐splenectomy at a dose of 3 mg kg^?1. HSA is a lethal malignancy of the endothelium, which is usually disseminated by the time it is diagnosed. Median survival time, usually, is no longer than 80 days. Following treatment with SAHA, no sign of malignant growth could be discerned by means of diagnostic abdominal ultrasound, chest X‐ray or with the help of clinical symptoms, over a period of >1000 days. The precise mechanism by which HDAC inhibitors exert their anti‐cancer effects is uncertain, but evidence suggests that exposure to SAHA generates hyperacetylated chromosomal histones, which, in turn, facilitates the expression of tumour suppressor genes turned off by epigenetic mechanisms during neoplastic transformation of the endothelium.  相似文献   

Effect of benazepril and pimobendan on serum angiotensin‐converting enzyme activity in dogs          下载免费PDF全文

J. N. King  C. Christinaz  G. Strehlau  J. Hornfeld 《Journal of veterinary pharmacology and therapeutics》2018,41(3):485-489

To support their combined use, the objective of the study was to evaluate the effects of benazepril and pimobendan on serum angiotensin‐converting enzyme (ACE) activity in dogs. A total of 48 healthy beagle dogs were randomized into four groups (n = 12 per group) in a parallel‐group design study: A (control, placebo twice daily (BID)); B (0.5–1.0 mg/kg benazepril once daily (SID) in the morning, placebo in the evening); C (0.25–0.5 mg/kg benazepril BID); D (0.25–0.5 mg/kg benazepril and 0.125–0.25 mg/kg pimobendan, both BID). The test items were administered orally for 15 days. Serum ACE activity was measured on days 1 and 15. Groups B, C and D had significantly lower average serum ACE activity compared to baseline and to the control group, on both days 1 and 15. There were no significant differences in average ACE activity between groups B, C and D. Noninferiority of group C to B was demonstrated. In conclusion, 0.25–0.5 mg/kg benazepril administered BID produced noninferior inhibition of serum ACE activity compared to 0.5–1.0 mg/kg benazepril dosed SID. Pimobendan had no significant effect on benazepril's action on serum ACE activity. The results support the use of benazepril BID in dogs and in combination with pimobendan.  相似文献   

光质对番茄营养与风味品质的影响     

杨忠武  刘翼  金卓君  徐卫红 《中国农学通报》2020,36(34):134-141

以番茄为试验材料,在田间大棚设施条件下,选用白、蓝、黑、红、绿5种不同颜色的遮阳网,探讨不同光质对番茄营养与风味品质的影响。结果表明,在青熟期,黑色光质促进了总氮、蛋白氮以及非蛋白氮的积累。青熟期到转色期,白色光质的番茄有机酸总量较青熟期增加了4.57倍,蓝色和绿色光质提高了番茄的总糖和还原糖含量。从转色期到成熟期,番茄氨基酸含量大小表现为蓝色>绿色>黑色>红色>白色;黑色光质的番茄有机酸总量较转色期增加了27.8%;红色光质提高了番茄红素含量和Vc含量,降低了硝酸盐含量;白色、红色和绿色光质增加了番茄的总糖和还原糖含量。番茄主要风味物质(>30 μg/kg)为水杨酸甲酯、6-甲基-庚烯-2-酮、柠檬烯、反-2-己烯醛。红光使番茄水杨酸甲酯、6-甲基-庚烯-2-酮和己烯醛含量较白光增加了11.6%、20.2%和17.2%。在大田设施条件下,转色期到成熟期可以采用红色光质提高番茄果实营养品质和风味。  相似文献   

Relevance of Osmotic and Frost Protecting Compounds for the Winter Hardiness of Autumn Sown Sugar Beet          下载免费PDF全文

J. Loel  C. M. Hoffmann 《Journal of Agronomy and Crop Science》2015,201(4):301-311

The cultivation of autumn sown sugar beet (winter beet) is supposed to result in a marked yield increase compared with spring sown sugar beet. Although the importance of the growth stage reached before winter for the survival of autumn sown sugar beet has already been shown, it is not clear to which extent osmotic and potentially frost protecting compounds may contribute to winter hardiness. The study thus aimed to analyse the acclimatization process of sugar beet to low temperatures and to identify compounds which are important for survival of frost. Field trials with autumn sown sugar beet were conducted at eleven environments in Germany from 2009/10 to 2012/13, which were accompanied by greenhouse experiments with controlled temperature regimes. In the field trials, the survival rates after winter varied from 0 % to 99 %, but only in four environments differences between the five genotypes occurred. During acclimatization, betaine, glutamine, proline and raffinose were markedly accumulated and osmolality was enhanced. In particular betaine, amino acids and osmolality showed a positive correlation to the survival rate and were thus identified as potentially frost protecting substances for sugar beet. In contrast, raffinose and proline seem to act rather as stress indicators as they were negatively related to survival. Possible frost protecting substances were identified which can be used in breeding to improve the winter hardiness of sugar beet.  相似文献   

中草药免疫活性物质对鱼类肠道菌群群落的影响研究进展     

林善婷  郑尧  胡庚东  裘丽萍  邴旭文  陈家长 《安徽农业科学》2017,45(32):94-98

对近年来国内外有关中草药免疫活性物质对鱼类肠道菌群群落结构的影响进行了综述,旨在为开发绿色高效、营养全面的饲料提供科学的理论依据。  相似文献   

An improved method for extraction of sorghum polymeric protein complexes     

《Journal of Cereal Science》2020

A method for fractionating sorghum proteins using extraction solvents and techniques designed to obtain polymeric protein structures (especially disulfide linked) was developed. Extraction and separation conditions were optimized in terms of completeness of protein extraction, sample stability, and analytical resolution. After pre-extraction of albumins and globulins, a 3-step sequential procedure involving no reducing agents was applied to ground whole sorghum flour. The three fractions obtained represented proportionally different protein polymer contents and molecular weight distribution as evidenced by comparative size exclusion chromatography. Protein composition also varied among the extracts with differences in kafirin composition and non-kafirin proteins detected in the fractions by RP-HPLC and SDS-PAGE analysis. The ability to quantify and further characterize sorghum polymeric protein complexes will be useful for additional studies linking protein structures with functionality and digestibility and variations for these properties within diverse sorghum germplasm.  相似文献   

Synergistic effects of soil microstructure and bacterial EPS on drying rate in emulated soil micromodels     

《Soil biology & biochemistry》2015

Microbial extracellular polymeric substances (EPS) have been shown to alter soil moisture retention and to improve seedling survival and plant growth at the bulk scale. The mechanisms of EPS-mediated water retention include reversible swelling of the cross-linked polymer matrix and the promotion of an aggregated soil structure. However, the effects of EPS on water retention have never been directly observed at the pore scale. Here, emulated soil micromodels were developed to directly observe the effects of physical, chemical, and biological factors on pore-scale water retention. In this demonstration, a pseudo-2D pore structure was created to represent physical features of a fine sandy loam. Replicate micromodels were initially saturated with suspensions of different soil bacteria, and pore-scale air infiltration was directly imaged over time. External evaporativity was held constant through the use of a custom constant-humidity environmental chamber. Micromodels filled with suspensions of highly mucoid Sinorhizobium meliloti retained moisture about twice as long as physically identical micromodels filled with suspensions of non-mucoid S. meliloti. Relative drying rates in six replicate experiments ranged from 1.1 to 2.5 times slower for mucoid suspensions. Patterns of air infiltration were similar but not identical across replicates. The results suggest that pore fluid EPS and micromodel geometry act together to limit evaporation at pore throats. Advantages of the micromodel approach include direct observation of pore-scale dynamic process, and the ability to systematically replicate complex physical structures. These abilities will enable users to screen benefits from different structures and from microbial compositions, and build predictive understanding of the overall function of microbe-habitat systems.  相似文献   

柳蛎盾蚧危害与丁香防御蛋白活力的关系   总被引：1，自引：0，他引：1  

程红  严善春 《林业科学》2013,49(8)

在柳蛎盾蚧的未危害期(5月末)、危害盛期(6月末)、危害弱期(7月末)、危害末期(8月末),测定高抗类[什锦丁香等7种(品种)]、中抗类[西南丁香等3种(品种)]、易感类[紫丁香等2种]、高感类(红丁香)13种(品种)丁香叶中的POD,SOD,CAT,PPO,PAL,TI和CI 7种防御蛋白的活性.结果表明:危害时期,丁香种(品种)对丁香防御蛋白活力有极显著影响(P＜0.01).POD活性,在危害盛期,在高抗、中抗类丁香中均显著升高(P＜0.05),而在易感、高感类中应激滞后,即分别在危害弱期和危害末期升高.CAT在易感类和高感类丁香防御上起主导作用,其活性在危害盛期显著升高,而中抗和高抗类未见明显变化.SOD活性,在危害盛期高抗类丁香中无显著变化,而其余3类则显著降低.PPO活性在未危害期的高低与抗性相关,在虫害盛期诱导表达的强弱也与抗性相关;PAL活性未能反映抗性品种间的差异.TI和CI活性,在未危害期的高低与其抗虫性无明显相关性,在危害盛期的升高幅度与抗虫性呈正相关.综上所述,PPO在未危害期的活力可作为筛选丁香抗虫种(品种)的指标,危害盛期POD,PPO,TI和CI活性升高的幅度与丁香抗虫性呈正相关.  相似文献   

外源海藻糖对NaHCO3胁迫下甘草幼苗生长调节及总黄酮含量的影响     

柳福智  张迎芳  陈垣 《草业学报》2021,30(7):148-156

本研究以甘草无菌苗为试验材料,采用植物组织培养的方法,分析50 mmol·L^-1 NaHCO₃ 胁迫下外源海藻糖对甘草幼苗生长量、叶绿素含量、渗透调节物质含量、抗氧化保护酶活性和总黄酮含量的影响。结果表明： 50 mmol·L^-1 NaHCO₃ 胁迫显著降低了甘草幼苗的生长量、叶绿体色素含量、K⁺ 浓度、抗氧化保护酶（SOD、POD、CAT）活性和总黄酮含量,显著提高了丙二醛、脯氨酸和可溶性糖含量以及Na⁺浓度;施加15 mmol·L^-1 海藻糖可显著提高甘草幼苗的生长量,提高叶绿素含量、K⁺ 浓度和总黄酮含量,降低丙二酸含量、脯氨酸含量、可溶性糖含量和Na⁺ 浓度,并且提高抗氧化保护酶活性。因此,NaHCO₃胁迫下施加外源海藻糖对甘草幼苗生长具有良好的调节作用,可以增强甘草的抗碱能力,促进甘草幼苗生长。本研究为外源海藻糖提高甘草耐碱性和揭示其调控机制提供理论依据。  相似文献