Persistence of pasture feeding volatile biomarkers in lamb fats

Recent studies have evidenced volatile biomarkers in ruminant tissues that distinguish between exclusive pasture and exclusive concentrate diets. As ruminants usually alternate these diets, we set out to monitor the persistence of volatile tracers of pasture diet in perirenal fat and caudal subcutaneous fat in lambs (n = 28) fed on pasture and then fattened at increasing levels with concentrate: Four groups of lambs (n = 7) were stall-finished to achieve a final weight gain of 0, 4, 8, and 12 kg, respectively. Thirty nine pasture diet tracers including terpenes, 2,3-octanedione and toluene were found that distinguish between the four different diets in both tissues. According to their clearance rates monitored in the adipose tissues of lambs fattened with different amounts of concentrate, different types of persistence were evidenced. Most of the compounds exhibited a “short” persistence, e.g. 2,3-octanedione and terpenes, while some displayed a “medium” or “long” persistence. Finally, performing discriminant analysis on ratios of tracers from the two adipose tissues enabled the correct differentiation of the four different diets.     

具有超强耐磨性能和抗化学腐蚀性能的新型辐射固化齐聚物

一、简介 齐聚物能极大地增强UV固化膜的耐磨性能，在许多领域得到了应用。汽车、家具、地板用木材和塑料表面涂层的耐磨性尤为重要，因为它们要在各种苛刻的使用环境中保持其表面的完好与美观。     

SRM 2460/2461 Standard Bullets and Casings Project

The National Institute of Standards and Technology Standard Reference Material (SRM) 2460/2461 standard bullets and casings project will provide support to firearms examiners and to the National Integrated Ballistics Information Network (NIBIN) in the United States. The SRM bullet is designed as both a virtual and a physical bullet profile signature standard. The virtual standard is a set of six digitized bullet profile signatures originally traced from six master bullets fired at the Bureau of Alcohol, Tobacco and Firearms (ATF) and the Federal Bureau of Investigation (FBI). By using the virtual signature standard to control the tool path on a numerically controlled diamond turning machine, 40 SRM bullets were produced. A profile signature measurement system was established for the SRM bullets. The profile signature differences are quantified by the maximum of the cross correlation function and by the signature difference between pairs of compared profile signatures measured on different SRM bullets. Initial measurement results showed high reproducibility for both the measurement system and production process of the SRM bullets. A traceability scheme has been proposed to establish the measurement traceability for nationwide bullet signature measurements to NIST, ATF and FBI. Prototype SRM casings have also been developed.     

Safe and sound

When the ATEX Directives were released in 2003, the only clear point was that ex motors with converter supply had to be safe. Otherwise, the requirements in relevant standards were different for the motors depending on the protection type or voltage, and also, the installation standard was adding new guidelines. In addition, each country had its own history and practices, which confuse the end users and manufacturers. These ATEX Directives are the first attempt to harmonize the rules with respect to the past and the actual installed base.     

Fluorescence quenching effects of nanocrystalline diamond surfaces

Undoped diamond has conductive properties when terminated by hydrogen and exposed to air or aqueous solution. Here, it is shown that nanocrystalline diamond, fabricated with hydrogen termination and deposited on quartz substrates using chemical vapor deposition, significantly quenched the fluorescence of adsorbed, dye-labeled fibrinogen protein in aqueous solutions at near neutral pH. Smaller levels of quenching were observed from oxygen terminated NCD surfaces. We suggest that these near-surface fluorescence quenching effects may arise from surface conductance effects in hydrogen terminated NCD. It is also shown that despite bulk quenching effects, single molecules of fibrinogen could be imaged on nanocrystalline diamond surfaces using epi-fluorescence techniques.     

Diagnosis and surgical management of obstructive ureteral calculi in cats: 11 cases (1993-1996)

OBJECTIVE: To evaluate diagnostic methods, surgical treatment, perioperative management, and renal function of cats with obstructive calcium oxalate ureteroliths. DESIGN: Retrospective case series. ANIMALS: 11 cats that underwent surgery for removal of calcium oxalate ureteroliths. PROCEDURE: Medical records were reviewed, and the following information was recorded: signalment; results of physical examination, clinicopathologic analyses, and abdominal imaging; surgical procedure; postoperative management; and results of ureterolith quantitative analysis. RESULTS: Ureteroliths in the proximal portion of the ureter were removed from 5 cats (pyelotomy, 1 cat; unilateral ureterotomy, 2 cats; bilateral ureterotomies, 2 cats). Calculi in the middle and distal part of the ureter were removed by partial ureterectomy and ureteroneocystostomy (6 cats). Ten cats recovered from surgery and were discharged from the hospital. One cat died from unknown causes 4 months after surgery, and 1 cat had a nephrectomy elsewhere 5 weeks after ureterolith removal. Eight cats were evaluated 12 to 20 months after surgery. Of these, 2 cats that were markedly azotemic before surgery improved after surgery, and 2 cats developed nephroliths after surgery. Also, of 5 cats that had nephroliths that were not removed at the time of surgery, 4 still had visible nephroliths. One cat had recurrent ureteral obstruction from a ureterolith and persistent urinary tract infection. Ureteroliths or ultrasonographic evidence of ureteral obstruction were not detected in other cats. CLINICAL IMPLICATIONS: A combination of microsurgical techniques and intensive postoperative care is necessary to minimize morbidity of cats after removal of a ureterolith. Renal function may improve or stabilize after removal of the ureteral obstruction.     

H-densities: a new concept for hydrated molecules

It is common to represent molecules by "ball-and-stick" models that represent static positions of atoms. However, the vibrational states of water molecules involved in hydrogen bonding have wide amplitudes, even in their ground states. Here we introduce a new representation of this wide-amplitude vibrational motion: H-density plots. These plots represent the delocalized zero-point vibrational motion of terminal hydrogen atoms of water molecules weakly bound to other molecules. They are a vibrational analogy to electron densities. Calculations of the H-densities for complexes of water with water, benzene, phenol, and DNA bases are presented. These are obtained using the quantum diffusion Monte Carlo method. Comparisons of measured and calculated rotational constants provide experimental evidence of the new concept.     

Arsenic speciation in plankton organisms from contaminated lakes: transformations at the base of the freshwater food chain

The two complementary techniques high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) and X-ray absorption near edge structure (XANES) analysis were used to assess arsenic speciation in freshwater phytoplankton and zooplankton collected from arsenic-contaminated lakes in Yellowknife (Northwest Territories, Canada). Arsenic concentrations in lake water ranged from 7 μg L(-1) in a noncontaminated lake to 250 μg L(-1) in mine-contaminated lakes, which resulted in arsenic concentrations ranging from 7 to 340 mg kg(-1) d.w. in zooplankton organisms (Cyclops sp.) and from 154 to 894 mg kg(-1) d.w. in phytoplankton. The main arsenic compounds identified by HPLC-ICP-MS in all plankton were inorganic arsenic (from 38% to 98% of total arsenic). No other arsenic compounds were found in phytoplankton, but zooplankton organisms showed the presence of organoarsenic compounds, the most common being the sulfate arsenosugar, up to 47% of total arsenic, with traces of phosphate sugar, glycerol sugar, methylarsonate (MMA), and dimethylarsinate (DMA). In the uncontaminated Grace Lake, zooplankton also contained arsenobetaine (AB). XANES characterization of arsenic in the whole plankton samples showed As(V)-O as the only arsenic compound in phytoplankton, and As(III)-S and As(V)-O compounds as the two major inorganic arsenic species in zooplankton. The proportion of organoarsenicals and inorganic arsenic in zooplankton depends upon the arsenic concentration in lakes and shows the impact of arsenic contamination: zooplankton from uncontaminated lake has higher proportions of organoarsenic compounds and contains arsenobetaine, while zooplankton from contaminated area contains mostly inorganic arsenic.     

Superhydrophobic/highly oleophobic surfaces based on poly(3,4-propylenedioxythiophene) surface <Emphasis Type="Italic">post</Emphasis>-functionalization

Here, we report for the first time the use of poly(3,4-propylenedioxythiophene) as platform for surface post-functionalization using the Staudinger-Vilarrasa reaction in order to covalently link perfluorinated chains and obtain various hydrophobic/oleophobic properties. 3,4-propylenedioxythiophene with one or two azido groups are prepared, in order to determine the impact of the number of functional groups on the surface morphology and wettability. Here, we show the possibility to prepare parahydrophobic (high water adhesion) or superhydrophobic (low water adhesion) surfaces with highly oleophilic to highly oleophobic properties.     

Instability zones for isotropic and anisotropic multibladed rotor configurations

Helicopter ground resonance is an unstable dynamic phenomenon which can lead to the total destruction of the aircraft during take-off or landing phases. The earliest research in this domain was carried out by Coleman and Feingold during the decade of 60s. The instability was predicted by using classical procedures once the rotor was considered as isotropic, consequently, the periodic equations of motion could be simplified to a system with constant coefficients by introducing a change of variables, known as the Coleman Variable Transformation. The goal of the present work is to further comprehend the phenomenon and the influence of the anisotropic properties of rotors by analyzing the periodic set of equations of motion. For this, Floquet's Theory (Floquet's Method — FM) is used. The analysis for predicting the ground resonance phenomenon in isotropic and anisotropic rotor configurations is explored. The conclusions lead to verify the appearance of bifurcation points depending on the anisotropic characteristic present in the rotor. The temporal response analysis in the motion of helicopter with one asymmetric blade at unstable regions highlighted the presence of non symmetric rotor deformation shapes.