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71.
72.
AIM: To study the regulatory effect of nitric oxide on the lymphatic stomata and probe into the mechanism of ultrafiltration failure during long-term peritoneal dialysis(PD). METHODS: ①Sodium nitroprusside(SNP) and NG-monomethyl-L-arginine(L-NMMA)(inhibitor of nitric oxide synthase(NOS)) were injected into the peritoneal cavity of the mouse model of PD. ②NO concentration was measured in serum. ③The lymphatic stomata was studied with SEM and computer image processing.RESULTS: During PD, a lot of macrophages wandered out of the lymphatic stomata to form milky spots on the peritoneal mesothelium, and the diameter and density of the stomata were increased with NO concentration raised. After PD cessation, the stomata was normal gradually and numbers of milky spots reduced with NO concentration fall. The diameter and density of the stomata were increased with a rise in NO concentration as SNP was used, oppositely those were decreased with the increase in NO concentration as L-NMMA was injected intraperitoneally. CONCLUSIONS: The lymphatic stomata might be regulated through increasing the endogenous NO concentration. During PD, NO is increased gradually and the ultrafiltration failure would occur when re-absorption of the stomata was increased from the peritoneal cavity. 相似文献
73.
Influence of porcine intestinal pH and gastric digestion on antigenicity of F4 fimbriae for oral immunisation 总被引:1,自引:0,他引:1
Newly weaned piglets can be orally immunised against F4+ enterotoxigenic Escherichia coli (ETEC) infection with F4 fimbriae. However, to efficiently develop a vaccine against ETEC induced postweaning diarrhoea, knowledge of the stability of the F4 fimbriae to different pH and gastric digestion is needed. The gastrointestinal pH in suckling and recently weaned piglets was measured and the stability of F4 fimbriae to different pH and to pepsin was assessed in vitro. In the stomach the lowest pH was found in the fundus gland region. Gastric pH values below 2.5 were not found in suckling piglets or at the day of weaning, in contrast to piglets 1 and 2 weeks postweaning. Along the first half of the small intestine and in the caecum, a negative correlation was found between pH and age. The F4 fimbriae were stable to pH 1.5 and 2 for 2 h, whereas longer incubation periods resulted in conversion of the multimeric forms into monomers. The F4 fimbriae were partially degraded by incubation for 15-30 min in simulated gastric fluid at pH 1.5 and 2, and completely digested from 3 h onwards. At pH 3, the fimbriae maintained their antigenicity for at least 4h. The results demonstrate that gastric digestion will only have a limited impact on oral immunisation since liquid passes through the stomach relatively quickly (50% within 2 h). However, we previously demonstrated that the transit times are prolonged shortly after weaning. Shortly after weaning it could be necessary to protect the F4 fimbriae against gastric digestion to obtain efficient oral immunisation of the piglets. 相似文献
74.
David J. Simbo Sebastiaan De Smedt Nina Van den Bilcke Bruno De Meulenaer John Van Camp Veronique Uytterhoeven Filip Tack Roeland Samson 《Agroforestry Systems》2013,87(3):493-505
Among the priority species identified for domestication in the Sahel region of Sub-Sahara Africa is the baobab (Adansonia digitata L.) tree. The quantification of the variation in nutrient content and fruit morphological traits of trees is one of the most important steps in identifying superior planting material for domestication. Ten provenances in Mali covering all the different agro-ecological zones were selected and the fruit morphological traits, vitamin C, calcium, iron and colour were studied. Mean pulp content was 2,149 ± 1,117 , 2,406 ± 776 and 25 ± 17 mg kg?1 for vitamin C, calcium and iron, respectively. Fruit pulp colour varied from white, creamy to pink and a significant correlation between pulp vitamin C content and reflectance in the green and blue bands was observed. Significant negative correlations were found between rainfall and pulp vitamin C content and between mean annual temperature and fruit and pulp weight and pulp fraction, suggesting that these traits are influenced by the environment. Pulp iron content correlated positively with topsoil sodicity and base saturation. Similarly, pulp vitamin C content correlated positively with topsoil sand fraction. Pulp reflectance in the blue and green bands correlated negatively with topsoil pH water and base saturation, respectively. The variation in nutritive and morphological traits offers the opportunity for selecting plus trees with a combination of desired traits for domestication. 相似文献
75.
Robert J Brosnan Bruno H Pypendop Chalon R Majewski‐Tiedeken Yael Shilo‐Benjamini Jan E Ilkiw 《Veterinary anaesthesia and analgesia》2013,40(2):225-228
ObjectiveTo test whether naltrexone, an opioid receptor antagonist, affects the minimum alveolar concentration (MAC) of isoflurane in cats, a species that is relatively resistant to the general anesthetic sparing effects of most opioids.Study designRandomized, crossover, placebo-controlled, blinded experimental design.AnimalsSix healthy adult cats weighing 4.9 ± 0.7 kg.MethodsThe cats were studied twice. In the first study, baseline isoflurane MAC was measured in duplicate. The drug (saline control or 0.6 mg kg?1 naltrexone) was administered IV every 40–60 minutes, and isoflurane MAC was re-measured. In the second study, cats received the second drug treatment using identical methods 2 weeks later.ResultsIsoflurane MAC was 2.03 ± 0.12% and was unchanged from baseline following saline or naltrexone administration.Conclusion and clinical relevanceMinimum alveolar concentration was unaffected by naltrexone. Because MAC in cats is unaffected by at least some mu-opioid agonists and antagonists, spinal neurons that are directly modulated by mu-opioid receptors in this species cannot be the neuroanatomic sites responsible for immobility from inhaled anesthetics. 相似文献
76.
Davide Viglietti Margherita Maggioni Enrico Bruno Ermanno Zanini Michele Freppaz 《林业研究》2013,24(4):633-642
The presence of a thick snowpack could interfere with forest stability, especially on steep slopes with potential damages for young and old stands. The study of snow gliding in forests is rather comple... 相似文献
77.
Anne Praud Olivier Gimenez Gina Zanella Nathalie Pozzi Valérie Antras Laurence Meyer Bruno Garin-Bastuji 《Tropical animal health and production》2013,45(4):931-933
Porcine brucellosis due to Brucella suis biovar 1 raises important issues for pig breeders in French Polynesia. In this region, the disease is enzootic, spreads silently and engenders economic losses in infected farms as well as sporadic human cases. While serological tests are essential in surveillance and control programmes of animal diseases, to date none of the available tests have been shown to be reliable enough to be used as a gold standard in routine individual diagnosis of porcine brucellosis. Few studies about the estimation of the sensitivity and the specificity of porcine brucellosis screening tests have been published, none of them dealing with French Polynesia. The studied population included 1,595 pigs from French Polynesia. Five tests were evaluated: Rose Bengal test, fluorescence polarisation assay, indirect ELISA, and two competitive ELISAs (C-ELISA). The sensitivity and the specificity of each test were estimated. C-ELISA2 was the most sensitive test (Se C-ELISA2?=?0.954 [0.889; 0.992] 95 % credibility interval (CrI)) while both C-ELISA and Rose Bengal test (RBT) were the most specific ones (Sp C-ELISA1?=?0.856 [0.806; 0.915] 95 % CrI; Sp C-ELISA2?=?0.849 [0.817; 0.879] 95 % CrI; Sp RBT?=?0.853 [0.812; 0.898] 95 % CrI). 相似文献
78.
Schossler Thiago Rodrigo Mantovanelli Bruno Campos de Almeida Brivaldo Gomes Freire Fernando José da Silva Manassés Mesquita de Almeida Ceres Duarte Guedes Cabral Freire Maria Betânia Galvão dos Santos 《Precision Agriculture》2019,20(6):1274-1291
Precision Agriculture - Sugarcane productivity is highly variable across space, and knowledge about the spatial distribution of soil physical attributes is important to guide management practices... 相似文献
79.
Christoph Steiner Bruno Glaser Wenceslau Geraldes Teixeira Johannes Lehmann Winfried E.H. Blum Wolfgang Zech 《植物养料与土壤学杂志》2008,171(6):893-899
Leaching losses of N are a major limitation of crop production on permeable soils and under heavy rainfalls as in the humid tropics. We established a field trial in the central Amazon (near Manaus, Brazil) in order to study the influence of charcoal and compost on the retention of N. Fifteen months after organic‐matter admixing (0–0.1 m soil depth), we added 15N‐labeled (NH4)2SO4 (27.5 kg N ha–1 at 10 atom% excess). The tracer was measured in top soil (0–0.1 m) and plant samples taken at two successive sorghum (Sorghum bicolor L. Moench) harvests. The N recovery in biomass was significantly higher when the soil contained compost (14.7% of applied N) in comparison to only mineral‐fertilized plots (5.7%) due to significantly higher crop production during the first growth period. After the second harvest, the retention in soil was significantly higher in the charcoal‐amended plots (15.6%) in comparison to only mineral‐fertilized plots (9.7%) due to higher retention in soil. The total N recovery in soil, crop residues, and grains was significantly (p < 0.05) higher on compost (16.5%), charcoal (18.1%), and charcoal‐plus‐compost treatments (17.4%) in comparison to only mineral‐fertilized plots (10.9%). Organic amendments increased the retention of applied fertilizer N. One process in this retention was found to be the recycling of N taken up by the crop. The relevance of immobilization, reduced N leaching, and gaseous losses as well as other potential processes for increasing N retention should be unraveled in future studies. 相似文献
80.
Berli F D'Angelo J Cavagnaro B Bottini R Wuilloud R Silva MF 《Journal of agricultural and food chemistry》2008,56(9):2892-2898
The responses of Vitis vinifera L. cv. Malbec to different solar ultraviolet-B radiation (UV-B) levels were assessed in two contrasting situations, under sunlight with full UV-B (+UV-B) and filtered UV-B (-UV-B), in three different locations at 500, 1000, and 1500 m above sea level (asl). To evaluate the effects of radiation, a simple, accurate, and rapid method for the separation and simultaneous determination of representative phenolic compounds in grape berry skins by capillary zone electrophoresis was developed. Separation was carried out in less than 20 min with 20 mM sodium tetraborate buffer containing 30% methanol, pH 9.00. The procedure is fast and reliable, and extracted grape berry skins can be directly analyzed without prior sample cleanup procedure. Berry skins from the +UV-B treatment at 1500 m asl showed the highest levels of total polyphenols anthocyanins, and resveratrol, compared with the -UV-B treatment at this altitude. 相似文献