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61.
Antifungal bioactivity-guided fractionation of the organic extract of the sponge Polymastia boletiformis, collected from the west coast of Ireland, led to the isolation of two new sulfated steroid-amino acid conjugates (1 and 2). Extensive 1D and 2D NMR analyses in combination with quantum mechanical calculations of the electronic circular dichroism (ECD) spectra, optical rotation, and 13C chemical shifts were used to establish the chemical structures of 1 and 2. Both compounds exhibited moderate antifungal activity against Cladosporium cucumerinum, while compound 2 was also active against Candida albicans. Marine natural products containing steroidal and amino acid constituents are extremely rare in nature.  相似文献   
62.
In this study, 32 Salmonella strains isolated from 400 chicken carcasses were serotyped, and antibiotic resistance profiles were detected against 12 selected antimicrobial agents using disc diffusion method. Thirty-two isolates were identified as follows; 22 (68.7%) Salmonella Enteritidis, five (15.6%) Salmonella Virchow, three (9.3%) Salmonella Typhimurium and two (6.2%) Salmonella Hadar. In all Salmonella isolates, antibiotic resistance were detected. Out of 32 Salmonella strains, 22 (68.75%) displayed multi-drug resistance. Thirty-two (100.0%) of the isolates were found to be resistant to penicillin G, 20 (62.5%) to nalidixic acid, four (12.5%) to cephalothin, two (6.2%) to streptomycin and two (6.2%) to tetracycline. Fifteen (68.1%) Salmonella Enteritidis, one (33.3%) Salmonella Typhimurium, two (100.0%) Salmonella Hadar and two (40.0%) Salmonella Virchow were shown to be resistant to nalidixic acid. Cephalothin resistance was detected in 9.0%, 33.3%, and 20.0% for Salmonella Enteritidis, Salmonella Typhimurium and Salmonella Virchow, respectively. The results indicate that Salmonella recovered from chicken carcasses were resistant to multiple antimicrobials and that resistance among these isolates varies by serotype. Also, this emerged as a significant public health problem.  相似文献   
63.
仔猪球虫病不只引起腹泻   总被引:1,自引:1,他引:0  
<正>等孢球虫病,也称为仔猪球虫病,是一种感染8~15日龄仔猪的寄生虫病。其最主要的临床特征是感染仔猪发生乳白色水样腹泻和断奶时体重过轻。该病也可以表现为亚临床感染。病原体是猪等孢球虫,具有很强的繁殖  相似文献   
64.
Carbonic anhydrase enzymes have been shown to play an important role in ion transport and pH regulation in several organisms including fish. Despite this information and the wealth of knowledge regarding the significance of CA enzymes in fish, few studies have reported the hazardous effects of chemicals on fish CA. Using rainbow trout (Oncorhynchus mykiss) as a model, this study aimed to determine the risk of pesticides and fungicides on fish carbonic anhydrase enzymes. For this purpose, screening of rainbow trout carbonic anhydrase activities was carried out in the presence of some pesticides and fungicides. Carbonic anhydrase enzymes were initially purified from rainbow trout liver, muscle, kidney and brain, and exposed to pesticides and fungicides, including mancozeb, cypermethrin, deltamethrin and dinocap. Pesticides and fungicides dose-dependently decreased in vitro CA activity at micromolar concentrations. Since deltamethrin was the most powerful inhibitor for all tissues in in vitro experiments, it was chosen for in vivo analysis as well. rtCAs were significantly inhibited by the three concentrations of deltamethrin (0.25, 1.0 and 2.5 μg/L) at 24th and 48th hours. Our findings indicate that deltamethrin, dinocap, mancozeb and cypermethrin are potent inhibitors for fish CA enzymes, and might cause undesirable results by disrupting acid-base regulation as well as salt transport in freshwater or seawater adapted fish.  相似文献   
65.
In this paper, the aims were (a) to test the usefulness of using genomic and phenotypic information from public databases (open access) to predict genetic values for tropical maize inbred lines regarding plant and ear height; (b) to identify how the population structure, the use of optimized training sets (OTSs) and the amount of information originating from public databases affect the predictive ability. Thus, 29 training sets (TSs) were defined considering three diversity panels: the University of São Paulo (USP—validation set (VS)) and the ASSO and USDA North Central Regional Plant Introduction Station (NCRPIS) (external public panels—predictors), which were divided into four scenarios with different TS configurations. We showed that it is possible to use public datasets as a primary TS and that population structure can modify the predictive abilities of GS. In the four scenarios proposed, very large or very small sets did not provide predictive abilities over 0.53 for GS. However, OTSs composed of 250 individuals were sufficient to achieve predictive abilities over this limit.  相似文献   
66.
Natural sawdust of Calabrian pine was explored as low-cost industrial by-product for a hetero-bireactive dye removal from aqueous solution in this study. Batch experiments were carried out to investigate the effects of contact time and dye concentration on biosorption efficiency. Maximum biosorption amounts were achieved almost in the 20-30 min of contact for the studied dye range (50-200 mg l -1). An increase in the dye concentration resulted in decrease in the percent dye removal and increase in the biosorption capacity of biosorbent. Different kinetic and isotherm models were used to examine the biosorption experimental data for elucidating the dye removal mechanism. The equilibrium data were best represented by Freundlich isotherm model confirming multilayer coverage. The kinetics of dye biosorption best obeyed the pseudo-secondorder equation. The negative value of standard Gibbs free energy change (-3.61 kJ mol-1) indicated that physical forces were involved in the spontaneous dye biosorption. Thus, the sawdust as a possible non-conventional biosorbent presented an interesting option for bioremediation of contaminated environments by such unsafe dyes.  相似文献   
67.
In this study, residual shell biomass of Corylus avellana L. was used as potential biosorbent for biosorption of a model industrial hetero-bireactive dye. The biosorbent was characterized by FTIR and SEM. The batch biosorption studies were performed as a function of dye concentration and contact time. The biosorption of dye was found to be very quick. Various kinetic and isotherm models were used to evaluate the obtained experimental data. The biosorption kinetic was best represented by the pseudo-second-order model while the biosorption equilibrium was best described by Langmuir model. The maximum dye biosorption capacity of biosorbent based on Langmuir isotherm was obtained as 74.527 mg g-1. These results showed that the use of such plant waste biomass in biosorption system could be a feasible method for the removal of such recalcitrant dye from industrial effluents to reduce operating costs.  相似文献   
68.
In this study, the influence of commercial probiotic, Lactobacillus spp., supplementation was investigated on growth parameters and digestive enzyme activities in gilthead sea bream, Sparus aurata, during larval development. All experiments were triplicated and designed in three different administrations of probiotic from 3 days after hatching (DAH) concurrently with starting of exogenous feeding. In the first group, probiotic was added to live food (rotifer and Artemia). In the second group, probiotic was supplemented directly to both live food and water. In the third group, probiotic was added directly to water. Also, no probiotic treatment was maintained in control group. Total bacterial counts among probiotic probiotic-supplemented groups were significantly different from total bacterial counts in controls in water and digestive tract of larvae (p < 0.05). The mean of total bacterial counts in control was approximately 4 × 104-fold increased from the experimental groups in the sea water (p < 0.05). Besides, mean digestive enzyme activities of all probiotics treatment groups were significantly different (p < 0.05) with that of the control. Except probiotic water supplementation group, in all treatments, the specific activities of pancreatic and intestinal enzymes were significantly higher (p < 0.05) in larvae to which probiotic had been supplemented by live food and live food with water. Also, S. aurata larvae that had probiotic administered by live food with water demonstrated significant (p < 0.05) increases in both survival (13–105% higher) and specific growth rate (2–9% higher) as compared to controls. As a result, supplementation of probiotic to directly tank water could not significantly increase growth parameters and digestive enzyme activities and therefore, administration of probiotics by this method would not be effective in terms of husbandry parameters and nutritional condition.  相似文献   
69.
Summary The antinutritional factors found in soybean, lectin (SBL) and Kunitz trypsin inhibitor (SKTI), are usually inactivated by heat treatment. However, residual activity of these factors can be found in several types of soy-derived products. Heat treatment does not completely eliminate these factors, and in addition it may considerably decrease protein solubility. The genetic elimination of these antinutritional factors could be an alternative to the heat treatment. This study aimed to develop soybean lines devoid of SKTI and SBL in their seeds. The population under study was obtained by crossing the normal cv. Monarca with a soybean line lacking SKTI and SBL. Specific DNA primers were designed for the identification of the recessive alleles that condition the absence of SKTI and SBL. F2 seeds presenting the DNA markers that identify the recessive alleles were selected and the corresponding F2 plants were backcrossed with the recurrent parent (‘Monarca’), producing the BC1F1 generation. The F2 generation was analyzed by SDS-PAGE in order to confirm the genotypes of the F2 selected. The segregation tests confirmed that these traits are governed by two genes that segregate independently.  相似文献   
70.
Summary We studied the genetic basis of isoflavone content inheritance in soybean seeds. The progenitors BARC-8 (low isoflavone content), IAC-100 (high isoflavone content), the F1 and F2 populations derived from reciprocal crosses, and backcross populations were analyzed for isoflavone content and composition. Six isoflavones were detected: daidzin (DZ), genistin (GT), glycitin (GC), malonyldaidzin (MDZ), malonylgenistin (MGT) and malonylglycitin (MGC). DZ, GT, MDZ and MGT contents were influenced by the cytoplasm and the nuclear genes of the maternal parent. For this reason, a genetic model was considered that included the cytoplasmic effect and epistasis between nuclear and cytoplasmic genes. Except for GT, the additive effect was the most important one. For GT content the cytoplasmic effect was the most important. Except for MDZ, the epistatic effects were significant for all the isoflavone forms. Our data indicate that genetic improvement for these traits should explore the additive genetic variances in superior lines or the cytoplasmic effect and the epistatic interactions between cytoplasmic and nuclear genes to obtain the largest selection gains.  相似文献   
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