64 research outputs found
Aging of dissolved copper and copper-based nanoparticles in five different soils: short-term kinetics vs long-term fate
With the growing availability and use of copper based nanomaterials (Cu-NMs), there is increasing concern regarding their release and potential impact on the environment. In this study, the short term (≤ 5 days) ageing profile and the long term (4 months) speciation of dissolved Cu, copper oxide (CuO-) and copper sulfide nanoparticles (CuS-NPs) were investigated in five different soils using X-ray absorption spectroscopy (XAS). Soil pH was found to strongly influence the short term chemistry of the Cu-NMs added at 100 mg/kg above background. Low pH soils promoted rapid dissolution of CuO-NPs that effectively aligned their behaviour to that of dissolved Cu within 3 days. In higher pH soils, CuO-NPs persisted longer due to slower dissolution in the soil and resulted in contrasting short term speciation compared to dissolved Cu, which formed copper hydroxides and carbonates that were reflective of the soil chemistry. Organic matter appeared to slow the dissolution process but in the long term, the speciation of Cu added as dissolved Cu, CuO-NPs and CuS-NPs were found to be same for each soil. The results imply that in the short term Cu-NMs may exhibit unique behaviour in alkaline soils compared to their conventional forms (e.g. in the event of an adverse leaching event), but in the long term (≥ 4 months), their fates are dictated by the soil properties and are independent of the initial Cu form, and are likely to present minimal risk of nano-specific Cu-NM impact in the soil environment for the concentration studied here
Effect of a prebiotic on performance of partridge
An experiment was conducted to investigate the effect of a prebiotic on performance of partridge. The experiment was carried out with a total of eighty-day-old male Chukar partridge (Alectoris chukar chukar) chicks in a completely randomized design. The dietary treatments consisted of a control and an experimental treatment, and each treatment was replicated four times with 10 chicks per replicate. The experimental period lasted 16 weeks with a starter period (0–8 weeks) and a grower period (9–16 weeks). The control group was fed the basal diet, while the experimental group was fed the basal diet supplemented with 0.18% prebiotic Aspergillus meal in each period. Performance parameters included body weight gain, cumulative feed consumption and cumulative FCR and were recorded at biweekly intervals. Carcass characteristics and blood parameters were measured at the end of the experiment (week 16). Although the results showed that prebiotic had no significant effect on body weight gain and cumulative feed conversion ratio; however, the supplementation of Aspergillus meal significantly (p <0.05) decreased cumulative feed consumption. Also prebiotic significantly increased percentages of breast and gastrointestinal tract, decreased percentage of back-neck, decreased blood triglyceride and total cholesterol content and increased blood calcium content. From this study, it was concluded that dietary supplementation of 0.18% Aspergillus meal might offer beneficial effects on partridge feed consumption, carcass quality and blood cholesterol
The Effect of Cinnamon Extract on Spermatogenesis and
® was more pronounced as compared to natural thyme essential oil. KEY WORDS essential oil, exogenous enzyme, intestinal histomorphology, probiotic, wheat
Effects of Thyme Essential Oil on Performance, Some Blood Parameters and Ileal Microflora of Japanese Quail
The ban on the use of antibiotics as growth promoters has stimulated the search for alternative feed supplements in poultry production. The active principles of thyme essential oil act as a digestibility enhancer, balancing the gut microbial ecosystem and stimulating the secretion of endogenous digestive enzymes and thus improving growth performance in poultry (Lovkova et al., 2001; Williams and Losa, 2001). A study was performed to investigate the effects of thyme essential oil (TEO) on performance, carcass characteristics, some blood parameters and ileal microflora of Japanese quail. This study lasted 35 days of age. One hundred and fifty day-old male Japanese quail chicks in a completely randomized design with two treatments (with or without 1 g/kg TEO) and five replicates of 15 birds each were used. All parameters were measured at the end of the experiment. The supplementation of TEO significantly (
Effects of dietary calcium and microbial phytase on the bioavailability of two sources of zinc in broilers
International audienc
Effect of feed supplementation with a thymol plus carvacrol mixture, in combination or not with an NSP-degrading enzyme, on productive and physiological parameters of broilers fed on wheat-based diets
The current study was conducted to evaluate the effect of feed supplementation with a phytogenic product (equal mixture of thymol plus carvacrol; T+C) on performance, nutrient retention, volatile fatty acid (VFA) profiles, cecum microbial ecosystem, serum parameters and characteristics of gastrointestinal tract of broilers fed on wheat-based diets with or without an NSP-degrading enzyme product (xylanase plus β-glucanase; E) from d 0 to 42. Six dietary treatments were arranged according to a factorial design with three levels of T+C (0, 100 and 200. mg/kg of diet) and two levels of E (0 and 0.5 g/kg of diet). Each treatment was replicated five times with 12 chicks per replicate. There was no interaction effect between E and T+C on any of the measured parameters. Compared with the control group, birds fed diets containing E or T+C had a higher ( P<0.01) final body weight, average daily gain and feed efficiency at d 42. Digesta viscosity was reduced ( P<0.05) in treatments with E addition in all parts of the small intestine. In treatments with T+C inclusion digesta viscosity was reduced in jejunum and ileum at d 24. E or T+C treated birds showed an increased ( P<0.05) retention of DM, protein and energy. Dietary supplementation with E and T+C increased ( P<0.01) total VFA and acetate levels at d 24 and 42, whereas the level of butyrate decreased ( P<0.01). Escherichia coli and Clostridium perfringens counts were lower ( P<0.01) than controls, and Lactobacilli counts were higher ( P<0.01), in birds fed on diets supplemented with enzyme or T+C at the rate of 200. mg/kg. E supplementation increased ( P<0.05) serum triglyceride, total cholesterol, total protein (TP), albumin and globulin concentrations, while T+C supplementation decreased ( P<0.05) total cholesterol, TP and albumin at d 40. E supplementation decreased ( P<0.01) the relative length of duodenum, jejunum and ileum of broilers. Moreover, carcass, liver and pancreas relative weights decreased ( P<0.05) with E supplementation at d 42. T+C dietary supplementation only affected carcass relative weight and jejunum and ileum relative lengths. The present study showed that thymol + carvacrol, in combination or not with an NSP-degrading enzyme, improved growth performance, enhanced nutrients retention, increased total VFA, reduced cholesterol and modulated intestinal microbial counts in broilers fed on a wheat-based diet.</p
In vitro antifungal susceptibility of oral candida species from Iranian HIV infected patients
Background: Oropharyngeal candidiasis and antifungal drug resistance are major problems in HIV positive patients. The increased reports of antifungal resistance and expanding therapeutic options prompted the determination of antifungal susceptibility profile of Candida species isolates in Iranian patients living with HIV/AIDS (PLWHA) in the present study.
Methods: One hundred fifty oral samples from Iranian HIV positive patients were obtained and cultured on CHROMagar and Sabouraud's dextrose agar. All isolates were identified according to assimilation profile, germ tube, colony color and other conventional methods. Disk diffusion testing and Broth Microdilution of six antifungal agents were performed according to the methods described in CLSI.
Results: Candida albicans (50.2%) was the most frequent isolated yeast, followed by C. glabrata (22%). Non-Candida albicans species were isolated from 71 (61%) positive cultures. 25.7% of Candida albicans isolates were resistant to fluconazole (MIC≥64 µg/ml) as were 21.9% and 16.4% to ketoconazole and clotrimazole (MIC>0.125 µg/ml), respectively. Resistance to polyene antifungals including amphotericin B and nystatin, and caspofungin were scarce. 57.7% of candida glabrata isolates were resistant to fluconazole, 31% to ketoconazole and 35% to clotrimazole.
Conclusion: Screening for antifungal resistant candida isolates by disk diffusion or broth dilution methods in clinical laboratories is an ideal surveillance measure in the management of oral thrush in patients with HIV/AIDS. Although nystatin is widely used in clinical practice for HIV positive patients, there was no evidence of enhanced resistance to it. Regarding no resistance to caspofungin, its administration is suggested
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