168 research outputs found
Raw milk and the importance of research in proper sanitary and market valuation of dairy products.
No full textEnvironmental risk assessment of antibacterial agents using an in vitro test
No full textAlgal toxicity of antibacterial agents used in intensive farming was investigated. The growth-inhibiting effects of oxytetracycline (OTC), sulphametazine (SMZ) and tylosin (TYL) were investigated by a modified test procedure based on the procedure described in the ISO 8692 (1989) protocol on the freshwater green alga Selenastrum capricornutum. Algal growth was measured as increased chlorophyll concentration. The chlorophyll was extracted with ethanol and fluorometrically determined. Results were quantified in terms of growth rates using Weibull equation to describe the concentration response relationship. The toxicity (EC50 value, mg/l) were: OTC, 4,17; SMZ, 10,7;TYL, 0,949, respectively
Valve-shaped thrombus underneath an aortic bioprosthesis
No full textWe describe massive thrombus formation completely occluding an aortic bioprosthesis in a patient with venoarterial extracorporeal membrane oxygenation and apical venting. The thrombus was surgically removed and the patient recovered with no complications. Timely identification and immediate surgical removal of thrombi may allow patient recovery with no severe complications
In vitro hydroxylation of testosterone in rabbits: influence of age and sex*
No full textIntroduction
Hydroxylated metabolites of testosterone (T) have been proposed as useful markers of specific isoform P450 activity in rats (1). Only few studies have been devoted to characterisation of P450 biotransformation activity in food producing species thus the aim of this study was to define the influence of sex and age in rabbits on the metabolic profile of hydroxylated testosterone (OHT) metabolites using an HPLC method able to separate nine metabolites. The role played by CYP3A was also studied in Rifampicin (RIF) induced rabbits.
Material and methods
Liver microsomes were obtained (2) from rabbits. five male (3±0.4 kg), five female (3±0.2 kg), five young male (1,5±0,3 kg), and two male induced with RIF (50 mg/kg, 4 days, ip). Microsomes (0.2 mg/ml) were incubated for 10 min, at 37°C with 250 μM T. Hydroxylated metabolites were extracted with methylene chloride and separated according to Purdon (3) with HPLC using a C18column and ternary phase gradient elution. Elution times were compared with those of pure standards (Steraloids).
Discussion
Main differences are: the absence in males of 16alfa-OHT; the greater production (*P<0,001) of 6beta-OHT, 11alfa-OHT, 16beta-OHT and 2beta-OHT compared to females; the decreased production (#P<0.001) of 6beta-OHT and 16alfa-OHT in young rabbits versus adult ones. Based on data reported for other species (1, 4) apparently, the isoforms involved in rabbits are CYP3A for 6beta-OHT, and 2beta-OHT; and CYP2B for 16alfa-OHT, and 16beta-OHT. RIF induced microsomes gave a significantly (°P<0,001) greater quantities of 6beta-OHT, 2beta-OHT supporting, also in rabbits, the CYP3A role played in the production of these hydroxyl-derivatives
Studio mediante sistemi in vitro e HPLC delle differenze specie specifiche dei metaboliti idrossilati del Testosterone
No full textSUMMARY - A preliminary study was performed to investigate by HPLC analyses the metabolism of testosterone to various hydroxylated metabolites by using liver microsomal preaparation obtained from different veterinary species. The analytical method was able to identify and quantify the various TST-metabolites produced. Different production of the metabolites was observed among the different veterinary species considered
Dispersione di ossitetraciclina nell'ambiente in seguito a trattamento dei vitelli
No full textDopo aver trattato dei vitelli con 60 mg/kg di ossitetraciclina per cinque giorni, il farmaco e' stato rintracciato nelle feci, nella lettiera e nel letame. Il tempo di cinque mesi necessario per la maturazione del letame consente una degradazione adeguata ed e' sufficiente per minimizzare l'impatto ambientale del farmac
Identificazione dei metaboliti prodotti in vitro di un nuovo beta-agonista mediante cromatografia liquida/spettrometria di massa (LC/MS/MS)
No full textTorsion loads on a ski-touring boot sole during uphill climbing and downhill skiing
No full textIntroduction: Ski-touring is a well settled winter activity in mountain regions. Differently to alpine skiing, the high ground is reached by climbing the mountain using sealskins under the skis and special boots and bindings. This difference introduces higher concerns on the weight of the equipment rather than other skiing disciplines. Nevertheless, to allow a safe and enjoyable skiing the structural properties of the boot must be guaranteed. Past studies aimed to determine loads and stiffness of alpine and cross-country skiboots using in field or laboratory approaches [1,2,3]. The present study aims to provide an estimation of the torsion loads acting on the ski-touring boot sole during walking and skiing phases. Such measure is helpful towards the design of more performant ski-touring boots.
Methods: A ski-touring boot (left side, size: 26.5 MP) was prepared with strain gauge bridges and calibrated using a servohydraulic machine (Fig 1a). First, the outer rubber sole was cut to reach the plastics of the boot shell. Then, two full Wheatstone bridge were placed on the sole in middle length of the boot to measure torsion and flexion loads.
To calibrate the boot sole close to in-field testing conditions, a silicone dummy foot was fitted inside the boot. Then, the skiboot was mounted on ski-touring bindings surrogates attached to a servohydraulic torsion machine. The torsion channel was calibrated by applying a quasi-static ramp between -5/+5°, reading the applied torque and bridge output synchronously to obtain the bridge sensitivity.
The in-field test took place in Val di Zoldo (BL, Italy), outside temperature was 10 °C, on a slope covered by spring snow. The instrumented boot was connected to a SoMat eDAQ lite data acquisition system (HBM) powered with a 12 V battery, instrumentation was fitted in a small backpack (total weight: 3 kg). Data were acquired at a 500 Hz sampling rate.
Tests were performed by an amateur skier (height: 175 cm, weight: 70 kg, age: 25 yr) who climbed and skied an off-piste route graded BS in Blachère scale. The participant performed a 400 m gain uphill climbing which was divided into straight climb, and left/right side traverses. During the descent the participant was asked to perform narrow and wide slaloms at its own typical speed. Overall length of the test was 45 minutes.
Peak and valleys of data were computed and averaged for each phase to obtain the range of the load. The mean of the signal during each phase was also computed. Internal rotating torques applied to the boot front are positive.
Results and discussion: Calibration trials gave a bridge sensitivity of -12.59 Nm/(mV/V) with an applied torque ranging from -50 to +50 Nm. In field test data (Fig 1b, Table 1) evidenced highest torque ranges during skiing phase; torque mean values showed opposite sign in the two sides of uphill climbing. In both phases the range was well below the torque reached during the calibration trials.
This suggests that ski-touring boot torsion loads should be based on maximal values collected during skiing trials. The analysis and implementation of further measurement channels such as the sole flexion and the ski/walk links will be performed to improve the understanding of climbing and skiing loads. More tests are being conducted to account for subject variability and snow/terrain conditions.
1. Petrone N., Marcolin G., Centofante E., Atzori B. (2010), Analysis of the structural behavior of an innovative reinforced ski boot. Procedia Engineering. 2. 2599-2604. 10.1016/j.proeng.2010.04.038.
2. Petrone N., Marcolin G., Panizzolo F., (2013), The effect of boot stiffness on field and laboratory flexural behavior of alpine ski boots. Sports Engineering. 16. 10.1007/s12283-013-0133-z.
3. Hladnik J. Resman F. Jerman B. (2012), Torsion stiffness of a racing cross-country ski boot. Proceedings of the Institution of Mechanical Engineers Part P Journal of Sports Engineering and Technology
Sicurezza alimentare e sicurezza nutrizionale: un approccio integrato per migliorare i comportamenti dei consumatori.
No full textCrystal structure and chemical composition of Li-, Fe-, and Mn-rich micas
No full textWe present in this paper the crystal chemical characterization of three (Fe, Mn)-rich lithian trioctahedral micas. The samples are from Hirukawa mine (Japan) (unit formula: [iv](Si3.425Al0.575)4.00[vi](Al1.002Ti0.002Cr0.001Fe0.379Mg0.005Mn0.173Li1.438)3.00 [xii](Ca0.002Ba0.001Na0.049K0.948Rb0.002)1.00 O10F2 ; unit-cell dimensions: a = 5.264(1), b = 9.086(2), c = 10.099(3) Å, β = 100.719(5)°, V = 474.6(2) Å3); from Mokrusha mine (Russia) (unit formula: [iv](Si3.304Al0.696)4.00 [vi](Al1.004Ti0.001Fe0.362Mg0.005 Mn0.306Li1.322)3.00 [xii](Ca0.012Ba0.001Na0.042K0.940Rb0.005)1.00 O10F2; unit-cell dimensions: a = 5.297(5), b = 9.133(7), c = 10.168(9) Å, β = 100.78(2)°, V = 483.2(7) Å3); and from Sawtooth Mountains (Boise County, Idaho, U.S.A.) (unit formula: [iv](Si3.105Al0.895)4.00 [vi](Al0.913Ti0.018 Fe0.456Mg0.031 Mn0.521Li1.061)3.00 [xii](Ca0.004Ba0.003Na0.048K0.924Rb0.021)1.00 O10F2; unit-cell dimensions a = 5.2984(3), b = 9.1461(6), c = 10.0966(7) Å, β = 100.818(4)°, V = 480.58(5) Å3). All crystals belong to 1M polytype with layer symmetry C12(1) and show M1 and M3 sites much greater than M2. Moreover mean electron count values are much more variable for M1 and M3 sites than for M2. Unlike sample from Sawtooth Mountains, tetrahedral mean bond lengths appear to be smaller for T1 than for T11 site in Hirukawa mine and in Mokrusha mine.When compared to samples from the zinnwaldite series, crystals under study show similar crystal chemical trends, thus hinting to similar effects produced on layer structure by Fe and Mn cations
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