NEAR's flyby of 253 mathilde: images of a C asteroid

On 27 June 1997, the Near Earth Asteroid Rendezvous (NEAR) spacecraft flew within 1212 kilometers of asteroid 253 Mathilde. Mathilde is an irregular, heavily cratered body measuring 66 kilometers by 48 kilometers by 46 kilometers. The asteroid's surface is dark (estimated albedo between 0.035 and 0.050) and similar in color to some CM carbonaceous chondrites. No albedo or color variations were detected. The volume derived from the images and the mass from Doppler tracking of the spacecraft yield a mean density of 1.3 +/- 0.2 grams per cubic centimeter, about half that of CM chondrites, indicating a porous interior structure.     

Detection and Characterization of the Cumulene Carbenes H2C5 and H2C6

Two cumulene carbenes, H2C5 and H2C6, were detected in a supersonic molecular beam by Fourier transform microwave spectroscopy. Their rotational and leading centrifugal distortion constants were determined with high accuracy, such that the entire radio spectrum can now be calculated. Like the known carbenes H2C3 and H2C4, both molecules have singlet electronic ground states and linear carbon-chain backbones. They can be produced in sufficiently high concentrations in the laboratory that their electronic spectra, expected to lie in the visible, should be readily detectable by laser spectroscopy. The microwave spectra of other, more exotic isomers may be detectable as well.     

Apple polyphenols and products formed in the gut differently inhibit survival of human cell lines derived from colon adenoma (LT97) and carcinoma (HT29)

Colorectal tumor risks could be reduced by polyphenol-rich diets that inhibit cell growth. Here, apple polyphenols were studied for effects on the survival of colon adenoma (LT97) and carcinoma-derived (HT29) cell lines. Three apple extracts (AEs) from harvest years 2002-2004 were isolated (AE02, AE03, and AE04) and fermented in vitro with human fecal flora. Extracts and fermentation products were analyzed for polyphenols with HPLC. The cells were treated with AEs (0-850 microg/mL) or fermented AEs (F-AEs, 0-9%), and survival was measured by DNA staining. All AEs contained high amounts of polyphenols (311-534 mg/g) and reduced cell survival (in LT97 > HT29). AE03 was most potent, possibly because it contained more quercetin compounds. Fermentation of AEs resulted in an increase of short chain fatty acids, and polyphenols were degraded. The F-AEs were approximately 3-fold less bioactive than the corresponding AEs, pointing to a loss of chemoprotective properties through fermentation.     

由麻疹思考小反刍兽疫的问题

小反刍兽疫(Peste des petits ruminants,PPR)是山羊、绵羊等小反刍兽类的急性接触传染性疾病,国际上将小反刍兽疫归为A类传染病.目前除非洲、中东和南亚次大陆传播外,在我国周边地区的许多国家和地区也频繁出现流行.因此,该病作为一种重大的跨国动物疫病,也在开始危害我国西藏和其他地区的动物生产和卫生安全[1-2].     

Metabolite profiling of colored rice (Oryza sativa L.) grains

HPLC analysis of dehulled red, black and non-colored indica and japonica rice subspecies revealed significant differences in the contents of the anthocyanins cyanidin-3-glucoside and peonidin-3-glucoside. The rice materials were subjected to a comparative capillary gas chromatography-based metabolite profiling approach. The employed extraction and fractionation protocol enables the analysis of a broad spectrum of lipophilic and hydrophilic low molecular weight constituents from different chemical classes. The method covers not only primary metabolites (e.g. sugars, fatty acids) but also nutritionally relevant constituents (e.g. α-tocopherol, γ-aminobutyric acid). Statistical assessment of the data via principal component analysis and agglomerative hierarchical clustering revealed a distinct grouping of the different colored rice subspecies on the basis of their metabolite profiles. Compared to non-colored and red rice, black rice exhibited, in particular, higher levels of fatty acid methyl esters, free fatty acids, organic acids and amino acids.     

Long-term survival of four dogs with disseminated Aspergillus terreus infection treated with itraconazole

SUMMARY Four dogs with disseminated aspergillosis caused by Aspergillus terreus were treated with oral itraconazole for 190 to 1095 days. Infection was eliminated in 1 dog. Two dogs were treated for 1000 and 1095 days but were eventually euthanased 572 and 485 days after treatment was stopped. At necropsy both dogs had widespread aspergillosis. The fourth dog was euthanased for other reasons after 190 days of treatment when it was showing a good clinical response although there was radiographic evidence that the disease was progressing.     

Diurnal Patterns of Ruminal Concentrations and Portal Appearance Rates of Short-chain Fatty Acids in Sheep Fed a Hay or a Concentrate/Straw Diet in Two Meals Daily

Abstract

Three rumen fistulated and catheterized sheep were meal-fed and used to study ruminal and arterial concentrations of short-chain fatty acids (SCFA) as well as portal appearance rates of SCFA and irreversible loss rate (ILR) of acetate in 24 h periods on a hay and a concentrate/straw diet, respectively.

Ruminal and arterial concentrations as well as portal appearance rates of SCFA and ILR of acetate were significantly affected by the intake of feed. Generally, the highest concentrations and appearance rates were obtained 2 h after feeding. The portal recovery of arterial acetate was not affected by feeding or diet. The 24 h means were 0.68 ± 0.01 and 0.67 ± 0.01 on the hay and the concentrate/straw diet, respectively. Partial correlation coefficients corrected for the effects of time, sheep, and diet were calculated for the relationships evaluated. The portal appearance rate of acetate (r = 0.52, P <0.001) and the portal net appearance rate of propionate (r = 0.68, P <0.001) were linearly related to the ruminal concentrations of the two SCFA. The logarithm of the portal net appearance rate of butyrate seemed to be linearly related to the logarithm of the ruminal concentration of undissociated butyric acid (r = 0.70, P <0.001) when the effect of time was omitted from the model. The portal appearance rate of acetate (r = 0.22, P <0.05) and the portal net appearance rate of propionate (r = 0.63, P <0.001) as well as butyrate (r = 0.55, P <0.001) were linearly related to the arterial concentration of the respective SCFA. The results show that within animal and diet the ruminal as well as arterial concentrations are good predictors of SCFA portal appearance rates in sheep fed roughage at maintenance. Ruminal and arterial concentrations of SCFA seem less reliable predictors of portal appearance rates of SCFA between diets and sheep. The portal appearance of SCFA, 5.6 ± 0.5 and 7.0 ± 0.3 mol d^?1, accounted for 44 ± 4 and 43 ± 2% of the calculated metabolizable energy intake on the hay and the concentrate/straw diets, respectively.