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排序方式: 共有219条查询结果,搜索用时 20 毫秒
181.
This study examined the effects of exposing the eggs of the purple sea urchin (Arbacia punctulata) to two commercial polychlorinated biphenyl mixtures (PCB's), Aroclors 1254 and 1016, on fertilization through pluteus (larva) development. Eggs were exposed to various concentrations of the PCB's (0.5, 1.0, 5.0, and 10.0 mg L?1) beginning 25 min prior to insemination, with continuous exposure post-insemination for the 72 hr observation period employed in this study. The PCB's were administered as a component of a filtered sea water (FSW) medium. A FSW control and a FSW-acetone conditioned control where used since acetone was utilized in a 49 : 1, acetone: PCB ratio, to emulsify the PCB's. Since Arbacia eggs cleave synchronously following insemination, the percentage of the eggs cleaving at 1.75 hr post-insemination was used to determine the fertilization efficiency. Pluteus development and morphology was assayed at 24 hr intervals. The results of the fertilization efficiency studies were tested using Chi square and Pearson's-Product-Moment-Correlation Coefficient (r) at a 95% level of confidence. The morphology data were treated with a two-tailed t-test (99% confidence level) and (r). Both PCB's affected fertilization efficiency with the Aroclor 1016 being an order of magnitude more toxic than the Aroclor 1254. Likewise, both Aroclors were toxic to the pluteus development process with Aroclor 1016 being the more toxic of the two mixtures. At the highest PCB level employed, Aroclor 1254 proved more lethally toxic than Aroclor 1016 although both treatment-groups exhibited more than 90% toxicity to the morphogenic process. 相似文献
182.
Calucci L Pinzino C Zandomeneghi M Capocchi A Ghiringhelli S Saviozzi F Tozzi S Galleschi L 《Journal of agricultural and food chemistry》2003,51(4):927-934
Nine spice and aromatic herb samples (i.e., basil, bird pepper, black pepper, cinnamon, nutmeg, oregano, parsley, rosemary, and sage) were gamma-irradiated at a dose of 10 kGy according to commercial practices. The effects of the disinfection treatment on the content of organic radicals and some nutrients (namely, vitamin C and carotenoids) in the samples were investigated by chromatographic and spectroscopic techniques. Irradiation resulted in a general increase of quinone radical content in all of the investigated samples, as revealed by electron paramagnetic resonance spectroscopy. The fate of these radicals after storage for 3 months was also investigated. The cellulose radical was clearly observed in a few samples. Significant losses of total ascorbate were found for black pepper, cinnamon, nutmeg, oregano, and sage, whereas a significant decrease of carotenoids content was observed for cinnamon, oregano, parsley, rosemary, bird pepper, and sage. 相似文献
183.
184.
Joseph C. Parambeth Sara D. Lawhon Joanne Mansell Jing Wu Sabrina D. Clark Deanna Sutton Connie Gibas Nathan P. Wiederhold Alexandra N. Myers Mark C. Johnson Gwendolyn J. Levine Samantha Schlemmer Catherine Ruoff Anitha Isaiah Kate E. Creevy 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2019,48(1):83-88
A 2‐year‐old female spayed Boxer dog was presented for a 1‐month history of progressive hemorrhagic diarrhea with tenesmus and weight loss despite trial courses of antibiotics and diet change. Abdominal ultrasound revealed severe, focal thickening, and loss of normal architecture of the colonic wall with abdominal lymphadenomegaly. Dry‐mount fecal cytology, performed on several consecutive days, consistently revealed numerous, round, 16‐20 μm structures with basophilic, granular content, and a thin cell wall. Transmission electron microscopy identified these structures as fungi. Culture, polymerase chain reaction (PCR), and sequencing of the internal transcribed spacer, D1/D2 regions, and DNA‐directed RNA polymerase II core subunit (RPB2) confirmed the presence of Basidiobolus microsporus in the feces. Biopsies collected via ileocolonoscopy revealed marked, multifocal, chronic, neutrophilic, and eosinophilic ileitis and colitis with ulceration, granulation tissue, and intralesional hyphae (identified with Gomori methenamine silver stain). A Pythium enzyme‐linked immunosorbent assay and Pythium‐specific PCR performed on the formalin‐fixed paraffin‐embedded biopsy specimens were positive while Basidiobolus‐specific PCR was negative, thus confirming a diagnosis of pythiosis. This report describes a fatal case of colonic and intestinal pythiosis with the presence of fecal Basidiobolus sp. spores, suggestive of concurrent gastrointestinal basidiobolomycosis. 相似文献
185.
Stefania Astolfi Sabrina Zuchi Stefano Cesco Zeno Varanini Roberto Pinton 《Soil Science and Plant Nutrition》2013,59(7):1079-1083
Abstract Recent research has evidenced a relationship between Fe nutrition and S nutrition. Aim of the present work was to investigate the effect of Fe deficiency on the capacity of maize roots to take up and metabolize S. Maize (Zea mays L. cv. Cecilia) plants were grown for 10 d in nutrient solution (NS) with (+S) or without (?S) sulphate and Fe was added as FeIII-EDTA at 80 μm. After removing the extraplasmatic Fe pool, half of the plants of each treatment (+S and ?S) were transferred to a new Fe-free NS. Roots were collected 4 and 24 h from the beginning of Fe deprivation. Fe deprivation slightly increased root thiols content in both nutritive conditions (+S and ?S). ATP sulphurylase activity was enhanced by sulphur deprivation, but greatly depressed when Fe and S were both omitted from the nutrient solution. O-Acetylserine sulphydrylase activity was also enhanced by S deprivation; this activity was increased by Fe starvation in +S plants, while it was unaffected by Fe nutrition in ?S plants. S deprivation greatly increased uptake rates of 35SO4 2? (1.9 ± 0.1 vs. 5.2 ± 0.2 μmol g?1 root d.w. h?1); furthermore, Fe deficiency increased 35SO4 2? uptake rates by 11 and 55% in +S and ?S plants, respectively. Data show that Fe-deficiency in maize results in a higher ability to take up sulphate, while limiting the first step of S assimilation in S deprived plants. 相似文献
186.
Rafael de Paula Xavier de Andrade Marcelo de Andrade Ferreira Stela Antas Urbano Marcílio de Azevedo Sabrina Carla Rodrigues Félix Michelle Christina Bernardo de Siqueira Felipe José Lins Alves Juana Catarina Cariri Chagas 《Tropical animal health and production》2013,45(5):1191-1196
The objective of this study was to evaluate the effect of replacing Tifton 85 hay (0, 33, 66, or 100 %) with by castor bean hulls on the intake and nutrient digestibility and performance of 28 noncastrated lambs, averaging 7 months in age, 19.5?±?2.0 kg average live weight, fed on diets based on forage cactus. The animals were housed in individual pens for 100 days. The digestibility trial occurred 40 days after the start of the performance using LIPE® as an external indicator for estimating fecal dry matter production. The replacement of hay with Castor beans hulls linearly decreased the intakes of dry matter, neutral detergent fiber, organic matter, and crude protein and reduced the digestibility coefficients of the dry matter, neutral detergent fiber, organic matter content, crude protein, and total digestible nutrient content. The hot carcass and true carcass yields were not influenced by the treatments and the feed conversion increased linearly. The empty body weight, live weight at slaughter, hot and cold carcass weights, total gain, and average daily gain decreased linearly with the replacement. The replacement of Tifton 85 hay with castor bean hulls reduced the intake of dry matter, crude protein and energy, consequently reducing the performance of the animals. However, as the regression coefficients were of low magnitude, data were subjected to analysis of variance and means were compared using the Dunnett test with diet without castor bean hulls set as the control treatment. The Tifton 85 hay can be replaced up to 66 % by castor bean hulls in finishing diets for lambs. 相似文献
187.
Luiz A. F. Silva Maria I. de Moura Carlos E. Dambros Sabrina L. R. Freitas Luiz A. Souza Morgana P. Abreu 《Tropical animal health and production》2013,45(5):1177-1181
Hoof care, lesion curettage, and application of 5 % Stryphnodendron adstringens bark extract (S. adstringens (Mart.) Coville) or 3 % copper sulfate on surgical wounds of cattle were carried out in this research. A total of 180 cattle with digital dermatitis were used. They were distributed into six groups of 30 animals each (GI, GII, GIII, GIV, GV, and GVI). In GI and GII, only the sick digit was trimmed; in GIII and GIV, both sick and healthy digits of the lesioned limb were trimmed; and in GV and GVI, all digits were trimmed. During the postoperative period, 5 % S. adstringens extract was applied in GI, GIII, and GV, and 3 % copper sulfate solution was applied in GII, GIV, and GVI. After 60 days of evaluation, the data were analyzed using the Chi-squared test (p?≤?0.05). Both therapeutic protocols utilizing surgical curettage of the lesions were efficient for treating digital dermatitis. However, when the procedure is followed by the trimming of sick and healthy digits, the healing is optimized and a greater number of animals are rehabilitated. 相似文献
188.
Maxwell C. Wilson Xiao-Yong Chen Richard T. Corlett Raphael K. Didham Ping Ding Robert D. Holt Marcel Holyoak Guang Hu Alice C. Hughes Lin Jiang William F. Laurance Jiajia Liu Stuart L. Pimm Scott K. Robinson Sabrina E. Russo Xingfeng Si David S. Wilcove Jianguo Wu Mingjian Yu 《Landscape Ecology》2016,31(2):219-227
189.
Maxwell C. Wilson Xiao-Yong Chen Richard T. Corlett Raphael K. Didham Ping Ding Robert D. Holt Marcel Holyoak Guang Hu Alice C. Hughes Lin Jiang William F. Laurance Jiajia Liu Stuart L. Pimm Scott K. Robinson Sabrina E. Russo Xingfeng Si David S. Wilcove Jianguo Wu Mingjian Yu 《Landscape Ecology》2016,31(2):229-230
190.