微量Bradford法测定提纯禽结核菌素蛋白含量

研究用96孔微量板Bradford法测定提纯禽结核菌素蛋白含量。通过不同浓度的待测禽结核菌素与考马斯亮蓝G-250溶液混合后，在595nm光波下测定各孔样品的OD值。微量Bradford法检测禽结核菌素的线性范围是50—1000μg／mL，相关系数为0．999，最低定量限为50μg／mL。试验用3支禽结核菌素国际参照品，分别配制成125、250、500μg／mL三种不同浓度，每支每种浓度测定4次，计算实际测得的蛋白质浓度。结果显示，批内相对标准偏差为1．6％～4．4％；批间相对标准偏差0．7％-2．2％。研究结果表明微量Bradford法可作为测定禽结核菌素蛋白含量的一种方法。     

Variability in net ecosystem exchange from hourly to inter-annual time scales at adjacent pine and hardwood forests: a wavelet analysis

Orthonormal wavelet transformation (OWT) is a computationally efficient technique for quantifying underlying frequencies in nonstationary and gap-infested time series, such as eddy-covariance-measured net ecosystem exchange of CO2 (NEE). We employed OWT to analyze the frequency characteristics of synchronously measured and modeled NEE at adjacent pine (PP) and hardwood (HW) ecosystems. Wavelet cospectral analysis showed that NEE at PP was more correlated to light and vapor pressure deficit at the daily time scale, and NEE at HW was more correlated to leaf area index (LAI) and temperature, especially soil temperature, at seasonal time scales. Models were required to disentangle the impacts of environmental drivers on the components of NEE, ecosystem carbon assimilation (Ac) and ecosystem respiration (RE). Sensitivity analyses revealed that using air temperature rather than soil temperature in RE models improved the modeled wavelet spectral frequency response on time scales longer than 1 day at both ecosystems. Including LAI improved RE model fit on seasonal time scales at HW, and incorporating parameter variability improved the RE model response at annual time scales at both ecosystems. Resolving variability in canopy conductance, rather than leaf-internal CO2, was more important for modeling Ac at both ecosystems. The PP ecosystem was more sensitive to hydrologic variables that regulate canopy conductance: vapor pressure deficit on weekly time scales and soil moisture on seasonal to interannual time scales. The HW ecosystem was sensitive to water limitation on weekly time scales. A combination of intrinsic drought sensitivity and non-conservative water use at PP was the basis for this response. At both ecosystems, incorporating variability in LAI was required for an accurate spectral representation of modeled NEE. However, nonlinearities imposed by canopy light attenuation were of little importance to spectral fit. The OWT revealed similarities and differences in the scale-wise control of NEE by vegetation with implications for model simplification and improvement.     

Pulmonary cryptococcosis in slaughtered sheep: anatomopathology and culture

Cryptococcosis is considered a zoonosis but is rare in stock animals. In humans it is imputed to be a mortality cause in immunocompromised patients. This case study reports the anatomopathology of respiratory cryptococcosis in ovine and the recuperation and identification of Cryptococcus neoformans var. neoformans from 1-year frozen lung tissue sample. The findings from haematoxylin/eosin staining microscopy and special staining showed the destruction of the columnar respiratory epithelium architecture associated to suppuration, and the growth of spherical yeast buddings sometimes involved by clear halo produced by unstained capsular substance. The agent was identified by miniApi ID32C, while variety neoformans was further identified by culture in CGB agar. The diagnosis in stock animal suggests the involvement of an exogenous source of the agent as an alert to public health and contributes for epidemiological investigations.     

Antioxidant Metabolism during Fruit Development of Different Acerola ( Malpighia emarginata D.C) Clones

The present research work describes the major changes in the antioxidant properties during development of acerola from five different clones. Ripening improved fruit physicochemical quality parameters; however, total vitamin C and total soluble phenols (TSP) contents declined during development, which resulted in a lower total antioxidant activity (TAA). Despite the decline in TSP, at ripening, the anthocyanin and yellow flavonoid content increased and was mainly constituted of cyanidin 3-rhamnoside and quercetin 3-rhamnoside, respectively. The activities of oxygen-scavenging enzymes also decreased with ripening; furthermore, the reduction in vitamin C was inversely correlated to membrane lipid peroxidation, indicating that acerola ripening is characterized by a progressive oxidative stress. Among the studied clones, II47/1, BRS 237, and BRS 236 presented outstanding results for vitamin C, phenols, and antioxidant enzyme activity. If antioxidants were to be used in the food supplement industry, immature green would be the most suitable harvest stage; for the consumer's market, fruit should be eaten ripe.     

Bocaiuva (Acrocomia aculeata (Jacq.) Lodd) improved Vitamin A status in rats

Carotenoid bioavailability is influenced by various factors including the food matrix. The release of those molecules from the food matrix is the initial and most important step in the absorption process. The relative bioavailability of bocaiuva pulp beta-carotene in relation to pure beta-carotene was assayed by a hepatic retinol store, in vitamin A deficient Wistar rats. After the depletion period, the vitamin A deficient rats were separated into two groups and fed an AIN-93G modified diet, which contained 14 400 microg of pure beta-carotene (beta-carotene diet) or 13 475 microg of beta-carotene from 275 g of bocaiuva pulp (bocaiuva diet) per 1 kg of the diet as a vitamin A source. Both experimental diets resulted in similar body weight gains. The bioavailability, estimated as Retinol Accumulation Factor, was 7.3 and 3.5 for the beta-carotene and the Bocaiuva group, respectively. These results show that in spite of the matrix of the bocaiuva pulp, the beta-carotene bioavailability from this fruit was higher than the pure beta-carotene.     

Design of Nonionic Surfactants for Supercritical Carbon Dioxide

Interfacially active block copolymer amphiphiles have been synthesized and their self-assembly into micelles in supercritical carbon dioxide (CO2) has been demonstrated with small-angle neutron scattering (SANS). These materials establish the design criteria for molecularly engineered surfactants that can stabilize and disperse otherwise insoluble matter into a CO2 continuous phase. Polystyrene-b-poly(1,1-dihydroperfluorooctyl acrylate) copolymers self-assembled into polydisperse core-shell-type micelles as a result of the disparate solubility characteristics of the different block segments in CO2. These nonionic surfactants for CO2 were shown by SANS to be capable of emulsifying up to 20 percent by weight of a CO2-insoluble hydrocarbon into CO2. This result demonstrates the efficacy of surfactant-modified CO2 in reducing the large volumes of organic and halogenated solvent waste streams released into our environment by solvent-intensive manufacturing and process industries.     

High resistance to insect growth disruptors and control failure likelihood in Brazilian populations of the tomato pinworm Tuta absoluta

Phytoparasitica - This study aimed to compare the susceptibility of tomato pinworm, Tuta absoluta, from four Brazilian regions to insect growth disruptor (IGD) insecticides by tomato leaf-dip...     

Unusual ovarian activity in a mare preceding the development of an ovarian granulosa cell tumour

An 8-year-old mare, with a foal at foot, was inseminated on foal heat with frozen semen, with the resultant pregnancy lost between days 34 and 41. The right ovary developed a large anovulatory follicle that was non-responsive to multiple doses of ovulating agents. The follicle eventually appeared to luteinise, although plasma progesterone concentrations did not reflect this. Another follicle developed, responded to GnRH and resulted in a pregnancy from frozen semen that went to term with a healthy foal. When the mare was examined after foaling, the structure on the right ovary appeared to be a granulosa cell tumour; the left ovary was smaller than normal and non-functional. Surgical removal of the right ovary before increasing photoperiod resulted in a return to function of the left ovary and a pregnancy to frozen semen on the second cycle following removal. Figures showing concentrations of inhibin, progesterone, androstenedione, oestradiol and testosterone are presented for this entire period. Unusual ovarian activity in the mare might be a prelude to the development of a granulosa cell tumour.     

Trypanocidal properties of Mikania stipulacea and Mikania hoehnei isolated terpenoids

The in vitro trypanocidal properties of isolated terpenoids from Mikania stipulacea and Mikania hoehnei were investigated in Trypanosoma cruzi Y strain. Both compounds, the diterpene ent-9alpha-hydroxy-15beta-E-cinnamoyloxy-16-kauren-19-oic acid (1) and the sesquiterpene lactone 8beta-hydroxyzaluzanin D (2) were active.