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H Values (h + value)
Selected AbstractsFractal Analysis of Radiographic Trabecular Bone Texture and Bone Mineral Density: Two Complementary Parameters Related to Osteoporotic FracturesJOURNAL OF BONE AND MINERAL RESEARCH, Issue 4 2001C. L. Benhamou Abstract Trabecular bone microarchitecture and bone mineral density (BMD) are two main factors related to osteoporotic fractures. Currently, however, microarchitecture is not evaluated. We have developed and validated a trabecular bone texture analysis from radiographic images. The objective was to determine if the fractal analysis of texture was able to distinguish osteoporotic fracture groups from control groups, either in vertebrae, hip, or wrist fractures, and to determine if this indicator and BMD were independent and complementary. In this cross-sectional unicenter case-control population study in postmenopausal women, 107 fracture cases were enrolled and age-matched with 197 control cases. This population comprised 40 vertebral fractures (with 70 controls), 30 hip fractures (55 controls), and 37 wrist fractures (62 controls). Hip and lumbar spine BMD were measured by double-energy X-ray absorptiometry. Fractal analysis of texture was performed on calcaneus radiographs and the result was expressed as the H parameter (H = 2-fractal dimension). The H parameter showed a lower value (0.679 ± 0.053 SD) in fracture cases versus control cases (0.696 ± 0.030; p = 0.007), the statistical significance persisting after adjustment for age and for lumbar spine (LS) or hip BMD. This result was confirmed in vertebral fractures (p = 0.0001) and hip fractures (p = 0.003) but not wrist fractures (p = 0.07). We determined the threshold between high and low H values and then the odds ratios (OR) of fracture for low H for BMD , ,2.5 SD in T score and for the combinations of both parameters. The OR of fracture for low H was 1.6 (95% CI, 1.1,2.6). For LS BMD , ,2.5 SD the OR of 6.1 (3.4,10.8) shifted to 9.0 (4.0,20.4) when we added low H and for hip BMD it shifted from 5.6 (3.3,9.4) to 8.1 (4.0,16.8). In vertebral, hip, and wrist fracture cases the results were also significant. These data have shown that the fractal analysis of texture on calcaneus radiographs can distinguish osteoporotic fracture groups from control groups. This analysis and BMD provide independent and complementary information. These data suggest that we can improve the fracture risk evaluation by adding information related to microarchitecture, derived from analysis of conventional radiographic images. [source] Effect of Slaughter Method on Postmortem Changes of Grass Carp (Ctenopharyngodon idella) Stored in IcestiJOURNAL OF FOOD SCIENCE, Issue 5 2005Rodrigo Scherer ABSTRACT: The effect of 2 slaughter methods (immersion in ice-water slurry and electrical stunning followed by ice slurry asphyxiation) on the quality of grass carp (Ctenopharyngodon idella) stored in ice for 20 d was evaluated using sensory and chemical analysis. Electricity immediately stunned the fish and did not induce blood spots in the flesh. Fish killed by electricity showed a faster initial rate of ATP degradation and entered into rigor mortis earlier, but did not show significant differences in the sensory score when compared with fish killed by immersion in ice-water slurry. Thus, no differences were observed in the shelf life of carps between the 2 slaughter methods evaluated. The limit for acceptability of grass carp stored in ice was around 13 to 16 d. Grass carp accumulated more inosine than hypoxanthine. K, Ki, P, Fr, and H values were highly correlated with storage time and with the TFRU sensory scores in both groups; these could be used to assess the freshness quality of grass carp. [source] A NUMERICAL APPROACH WITH VARIABLE TEMPERATURE BOUNDARY CONDITIONS TO DETERMINE THE EFFECTIVE HEAT TRANSFER COEFFICIENT VALUES DURING BAKING OF COOKIESJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2006EREN DEMIRKOL ABSTRACT The increasing trade of ready-to-eat foods such as cookies highlights an interest in quality defects during baking. Heat (h and thermal diffusivity) and mass (mass transfer and diffusion coefficients) transfer parameters are significant parameters affecting the quality changes. Therefore, it is important to determine these parameters for modeling and process optimization studies. Among these, the h is important, revealing the relationship between the heating medium and product surface. As baking involves a simultaneous heat and mass transfer involving moisture diffusion and heat conduction inside and convective heat and mass transfer outside, a lumped system method may not be an accurate choice to determine the h value. Changes in the product volume and contact heating from bottom of the product also bring extra challenges to the determination of h. Therefore, the objective of this study was to use realistic approaches including simultaneous heat and mass transfer to determine the changes in h. The heffvalues for the bottom and top surface of the cookies were then determined, applying a numerical procedure where the surface temperature changes were the boundary conditions with evaporation on the surface. The hband ht values increased with baking temperature and varied with baking time. The results of this study showed that evaporative mass flux for the top surface, heat flux for the bottom surface and the product's volume changes were significant in the variation of h values. [source] Subacute toxicities and toxicokinetics of a new erectogenic, DA-8159, after single and 4-week repeated oral administration in dogsBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 3 2001Hyun J. Shim Abstract The subacute toxicities and toxicokinetics of a new erectogenic, DA-8159, were evaluated after single (at the 1st day) and 4-week (at the 28th day) oral administration of the drug, in doses of 0 (to serve as a control), 12.5, 50 and 200 mg/kg/day, to male and female dogs (n=3 for male and female dogs for each dose). DA-8159 had an effect on the immune-related organs (or tissues), circulatory systems, liver, adrenal glands, ovaries and pancreas. The toxic dose was 200 mg/kg and no observed adverse effect level was less than 50 mg/kg for male and female dogs. There were no significant gender differences in the pharmacokinetic parameters of DA-8159 for each dose after both single and 4-week oral administration. The pharmacokinetic parameters of DA-8159 were dose-independent after single oral administration; the time to reach a peak plasma concentration (Tmax) and the dose-normalized area under the plasma concentration,time curve from time zero to 24 h in plasma (AUC0,24 h) were not significantly different among three doses. However, accumulation of DA-8159 after 4-week oral administration was considerable at toxic dose, 200 mg/kg/day. For example, after 4-week administration, the dose-normalized AUC0,24 h value at 200 mg/kg/day (4.71 and 15.3 ,g h/ml) was significantly greater than that at 12.5 mg/kg/day. After 4-week oral administration, the dose-normalized Cmax and AUC0,24 h at 200 mg/kg/day were significantly higher and greater, respectively, than those after a single oral administration. Copyright © 2001 John Wiley & Sons, Ltd. [source] Acute and chronic toxicity of mercury to early life stages of the rainbow mussel, Villosa iris (Bivalvia: Unionidae)ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2005Theodore W. Valenti Abstract Mercury (Hg) contamination is receiving increased attention globally because of human health and environmental concerns. Few laboratory studies have examined the toxicity of Hg on early life stages of freshwater mussels, despite evidence that glochidia and juvenile life stages are more sensitive to contaminants than adults. Three bioassays (72-h acute glochidia, 96-h acute juvenile, and 21-d chronic juvenile toxicity tests) were conducted by exposing Villosa iris to mercuric chloride salt (HgCl2). Glochidia were more sensitive to acute exposure than were juvenile mussels, as 24-, 48-, and 72-h median lethal concentration values (LC50) for glochidia were >107, 39, and 14 ,g Hg/L, respectively. The 24-, 48-, 72-, and 96-h values for juveniles were 162, 135, 114, and 99 ,g Hg/L, respectively. In the chronic test, juveniles exposed to Hg treatments ,8 ,g/L grew significantly less than did control organisms. The substantial difference in juvenile test endpoints emphasizes the importance of assessing chronic exposure and sublethal effects. Overall, our study supports the use of glochidia as a surrogate life stage for juveniles in acute toxicity tests. However, as glochidia may be used only in short-term tests, it is imperative that an integrated approach be taken when assessing risk to freshwater mussels, as their unique life history is atypical of standard test organisms. Therefore, we strongly advocate the use of both glochidia and juvenile life stages for risk assessment. [source] A NUMERICAL APPROACH WITH VARIABLE TEMPERATURE BOUNDARY CONDITIONS TO DETERMINE THE EFFECTIVE HEAT TRANSFER COEFFICIENT VALUES DURING BAKING OF COOKIESJOURNAL OF FOOD PROCESS ENGINEERING, Issue 5 2006EREN DEMIRKOL ABSTRACT The increasing trade of ready-to-eat foods such as cookies highlights an interest in quality defects during baking. Heat (h and thermal diffusivity) and mass (mass transfer and diffusion coefficients) transfer parameters are significant parameters affecting the quality changes. Therefore, it is important to determine these parameters for modeling and process optimization studies. Among these, the h is important, revealing the relationship between the heating medium and product surface. As baking involves a simultaneous heat and mass transfer involving moisture diffusion and heat conduction inside and convective heat and mass transfer outside, a lumped system method may not be an accurate choice to determine the h value. Changes in the product volume and contact heating from bottom of the product also bring extra challenges to the determination of h. Therefore, the objective of this study was to use realistic approaches including simultaneous heat and mass transfer to determine the changes in h. The heffvalues for the bottom and top surface of the cookies were then determined, applying a numerical procedure where the surface temperature changes were the boundary conditions with evaporation on the surface. The hband ht values increased with baking temperature and varied with baking time. The results of this study showed that evaporative mass flux for the top surface, heat flux for the bottom surface and the product's volume changes were significant in the variation of h values. [source] Pharmacokinetics and pharmacokinetic/pharmacodynamic integration of marbofloxacin in calf serum, exudate and transudateJOURNAL OF VETERINARY PHARMACOLOGY & THERAPEUTICS, Issue 3 2002F. SHOJAEE ALIABADI Aliabadi, F. S., Lees, P. Pharmacokinetics and pharmacokinetic/pharmacodynamic integration of marbofloxacin in calf serum, exudate and transudate. J. vet. Pharmacol. Therap.25, 161,174. Marbofloxacin is a fluoroquinolone antimicrobial drug used in cattle for the treatment of respiratory infections. In this investigation the pharmacokinetics (PK) of marbofloxacin were determined after intravenous and intramuscular dosing at a dosage of 2 mg/kg. In addition the ex vivo pharmacodynamics (PD) of the drug were determined in serum and three types of tissue cage fluid (transudate, inflammatory exudate generated by carrageenan and exudate generated by lipopolysaccharide). Marbofloxacin PK was characterized by a high volume of distribution after dosing by both routes (1.28 L/kg intravenous and 1.25 L/kg intramuscular). Corresponding area under the concentration,time curve (AUC) and elimination half-life (t½el) values were 9.99 and 10.11 ,g h/mL and 4.23 and 4.33 h, respectively. Values of AUC for carrageenan-induced exudate, lipopolysaccharide-induced exudate and transudate were, respectively, 8.28, 7.83 and 7.75 ,g h/mL after intravenous and 8.84, 8.53 and 8.52 ,g h/mL after intramuscular dosing. Maximum concentration (Cmax) values were similar for the three tissue cage fluids after intravenous and intramuscular dosing. For in vivo PK data values of AUC: minimum inhibitory concentration (MIC) (AUIC) ratio for serum were 250 and 253, respectively, after intravenous and intramuscular dosing of marbofloxacin against a pathogenic strain of Mannheimia haemolytica (MIC=0.04 ,g/mL). For all tissue cage fluids AUIC values were >194 and >213 after intravenous and intramuscular dosing, and Cmax/MIC ratios were 9 or greater, indicating a likely high level of effectiveness in clinical infections caused by M. haemolytica of MIC 0.04 ,g/mL or less. This was confirmed by both in vitro (serum) and ex vivo (serum, exudate and transudate) measurements, which demonstrated a concentration-dependent killing profile for marbofloxacin against M. haemolytica. Ex vivo, after 24-h incubation, virtually all bacteria were killed (<10 cfu/mL) in all samples collected up to 9 h (serum), 24 h (carrageenan-induced exudate and transudate) and 36 h (lipopolysaccharide-induced exudate). Application of the sigmoid Emax equation to the ex vivo antibacterial data provided, for serum, AUIC24 h values of 37.1 for bacteriostasis, 46.3 for bactericidal activity and 119.6 for elimination of bacteria. These data may be used as a rational basis for setting dosing schedules which optimize clinical efficacy and minimize the opportunities for emergence of resistant organisms. [source] Pharmacokinetics of lovastatin extended-release dosage form (Lovastatin XL) in healthy volunteersBIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 4 2002Michael Lamson Abstract The purpose of this study was to evaluate pharmacokinetics and dose proportionality of lovastatin extended-release dosage form (ER-lovastatin) in the dosage levels of 10, 20 and 40 mg in 9 healthy male subjects. Each subject was randomized to receive a single oral dose of ER-lovastatin either 10, 20 or 40 mg in a three-way crossover design with a washout period of 7 days between the treatments. Subjects were served dinner at approximately 5:30 PM followed by dosing at approximately 10:00 PM in each study period. Serial plasma samples were collected up to 48 h after dosing and assayed for lovastatin and its active metabolite lovastatin acid using an LC/MS/MS method. The plasma concentration,time profiles of lovastatin and its active metabolite lovastatin acid exhibited delayed- and extended-release characteristics at each dose. Mean (±) values for the Cmax of lovastatin were 1.04±0.43, 2.03±0.65 and 4.03±3.02 ng/ml for the 10, 20 and 40 mg dosage, respectively. The corresponding values for the AUC0,48 h of lovastatin were 14.6±7.8, 34.1 ±13.7, and 53.9±35.6 ng h/ml. The same tendency was also found for Cmax and AUC0,48 h values of lovastatin acid. Results from this study demonstrated as the dose of ER-lovastatin increased from 10 to 40 mg, the Cmax and AUC0,48 h values of lovastatin as well as lovastatin acid appeared to increase linearly. Copyright © 2002 John Wiley & Sons, Ltd. [source] Solvent-dependent conformation of amylose tris(phenylcarbamate) as deduced from scattering and viscosity dataBIOPOLYMERS, Issue 9 2009Taichi Fujii Abstract The z -average mean-square radius of gyration ,S2,z, the particle scattering function P(k), the second virial coefficient, and the intrinsic viscosity [,] have been determined for amylose tris(phenylcarbamate) (ATPC) in methyl acetate (MEA) at 25°C, in ethyl acetate (EA) at 33°C, and in 4-methyl-2-pentanone (MIBK) at 25°C by light and small-angle X-ray scattering and viscometry as functions of the weight-average molecular weight in a range from 2 × 104 to 3 × 106. The first two solvents attain the theta state, whereas the last one is a good solvent for the amylose derivative. Analysis of the ,S2,z, P(k), and [,] data based on the wormlike chain yields h (the contour length or helix pitch per repeating unit) = 0.37 ± 0.02 and ,,1 (the Kuhn segment length) = 15 ± 2 nm in MEA, h = 0.39 ± 0.02 and ,,1 = 17 ± 2 nm in EA, and h = 0.42 ± 0.02 nm and ,,1 = 24 ± 2 nm in MIBK. These h values, comparable with the helix pitches (0.37,0.40 nm) per residue of amylose triesters in the crystalline state, are somewhat larger than the previously determined h of 0.33 ± 0.02 nm for ATPC in 1,4-dioxane and 2-ethoxyethanol, in which intramolecular hydrogen bonds are formed between the CO and NH groups of the neighbor repeating units. The slightly extended helices of ATPC in the ketone and ester solvents are most likely due to the replacement of those hydrogen bonds by intermolecular hydrogen bonds between the NH groups of the polymer and the carbonyl groups of the solvent. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 729,736, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] Solvent effects on coupling yields during rapid solid-phase synthesis of CGRP(8-37) employing in situ neutralization,CHEMICAL BIOLOGY & DRUG DESIGN, Issue 1 2005C.K. Taylor Abstract:, The success of solid-phase peptide synthesis is often dependent upon solvation of the resin and the growing resin-bound peptide chain. We investigated the relationship between solvent properties and solvation of the resin and peptide-resin in order to obtain satisfactory coupling yields for the rapid solid-phase peptide synthesis, using butyloxycarbonyl-(Boc)-amino acid derivatives, of human-,-calcitonin gene-related peptide(8-37) (CGRP(8-37)). Solvation of (p -methylbenzhydrylamine)copoly(styrene,1% divinylbenzene (DVB) (resin) and resin covalently bound to the fully protected amino acid sequence of CGRP(8-37) (peptide,resin) was correlated to solvent Hildebrand solubility (,) and hydrogen-bonding (,h) parameters. Contour solvation plots of ,h vs. , revealed maximum solvation regions of resin and peptide,resin. Maximum resin solvation occurred with N-methylpyrrolidinone (NMP), NMP : dimethylsulfoxide (DMSO) (8 : 2) and DMSO. Inefficient solvation of the peptide,resin occurred with these solvents and resulted in poor syntheses with average coupling yields of 78.1, 88.9 and 91.8%, respectively. Superior peptide,resin solvation was obtained using dimethylacetamide (DMA) and dimethylformamide (DMF), resulting in significantly higher average coupling yields of 98.0 and 99.5%, respectively. Thus, the region of maximum peptide,resin solvation shifts to solvents with higher ,h values. DMF provided the most effective peptide,resin solvation and was the only solvent from which CGRP(8-37) was obtained as a single major product in the crude cleaved material. [source] | ||||||||||||||||