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Area Values (area + value)
Kinds of Area Values Selected AbstractsEffects of short-term metformin treatment on insulin sensitivity of blood glucose and free fatty acidsDIABETES OBESITY & METABOLISM, Issue 1 2004S. Iannello Aim:, Based on the known effect of metformin (MET) in improving insulin sensitivity in type 2 diabetes, with the scope to focus the effects on glycaemic and free fatty acids (FFA) levels, we studied the effects of a short-term treatment with this drug in obese subjects and obese patients with diabetes or family history of diabetes (FHD). We used a method to allow us to evaluate the possible difference of insulin sensibility with regard to the insulin action on glycaemia and blood FFA, both in the basal state and during oral glucose tolerance test (OGTT). Methods:, Insulin sensitivity was investigated before and after MET treatment (850 mg bid for 10 days) in seven obese subjects with normal glucose tolerance and without FHD and 13 obese patients with diabetes (n = 7) or FHD (n = 6). By using specifically designed formulae, we calculated four insulin-sensitivity indices (ISI) from basal level (b) and area values (a) (during OGTT) of insulinaemia, glycaemia (gly) or FFA (ffa), namely: ISI (gly)-b, ISI (gly)-a, ISI (ffa)-b and ISI (ffa)-a. Results:, In patients with diabetes or FHD, MET improved ISI (gly)-b (0.79 ± 0.06 vs. 0.59 ± 0.07, p < 0.001) and ISI (gly)-a (0.69 ± 0.09 vs. 0.51 ± 0.07, p < 0.05), whereas only minor changes occurred for ISI (ffa)-b and ISI (ffa)-a. In contrast, in simple obese subjects, MET induced further deterioration of both ISI (gly)-a (0.47 ± 0.07 vs. 0.64 ± 0.10, p < 0.01) and ISI (ffa)-a (0.43 ± 0.07 vs. 0.55 ± 0.08, p < 0.05). Fasting level and total area of lactate were high in the obese patients and were not affected by MET. A statistically significant increase (p < 0.01), however, was observed for the ,decremental' area of lactate in obese subjects with diabetes or FHD, which might probably contribute to the reduction of insulin resistance induced by the drug in these patients. Conclusions:, Although the low number of subjects studied precludes absolute conclusions, data would suggest that MET improved ISI towards glucose but not towards FFA, in the diabetic and ,prediabetic' obese patients, whereas worsened it in the obese subjects without FHD. Therefore, the effects of MET would not be secondary to changes of FFA but rather to a primary action of MET on glucose metabolism. Thus, utilization of MET to treat the insulin resistance in obesity is indicated only in the presence of alterations of glucose metabolism or FHD. [source] Impaired nutritional status in common variable immunodeficiency patients correlates with reduced levels of serum IgA and of circulating CD4+ T lymphocytesEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 6 2001M. Muscaritoli Background Common variable immunodeficiency (CVI) is a primary defect of the immune system. Infections, persistent diarrhoea and malabsorption may result in malnutrition, which may in turn contribute to increased morbidity. In this paper, the prevalence of malnutrition in CVI was evaluated. Patients and methods Forty CVI patients (20 male, 20 female, aged 17,75 years) underwent anthropometric measurements from which body mass index, arm fat and muscle area were calculated. Body mass index values <,18·5 and arm fat and muscle area values <,10th percentile were considered indicative of malnutrition. Patients were divided into four groups according to circulating CD4+ T cells (lower or greater than 300 µL,1) and serum immunoglobulin A (IgA) levels (detectable and undetectable). Results Body mass index <,18·5, arm fat and muscle area <,10th percentile were observed in 23%, 58% and 44%, respectively, of patients. Lower values of body mass index, arm fat and muscle area were more frequent in patients with low CD4+ cells and undetectable IgA. Low arm fat values were more frequent in patients with diarrhoea (P = 0·03). Infectious episodes were more frequent in undetectable IgA than in detectable IgA patients (P = 0·04). Conclusions Anthropometric measurements revealed an increased rate of malnutrition in CVI patients, particularly in those with low CD4+ and undetectable IgA, suggesting that selected CVI subjects could be considered for standard or specialized nutritional support. [source] Flammability studies of sodium thiosulphate or metabisulphite impregnated wood using cone calorimeterFIRE AND MATERIALS, Issue 2 2007imkovic Abstract Spruce wood boards impregnated with Na2S2O3 or Na2S2O5 were studied with the cone calorimeter. The presence of Na2S2O3 lowered the average heat release rate in comparison to untreated material. The total amounts of CO and CO2 production were reduced by the treatment and also the specific extinction area and mass loss rate decreased. Washing of the salt from the material with water caused partial loss of the properties. Addition of the second impregnation step using acids (HCOOH, H3BO3 or H3PO4) resulted in the fixation of the sulphur in wood, but gave not the results of single-step modification for thiosulphate. With Na2S2O5 and without acid, the CO and time-to-ignition values were higher and average heat release rate smaller in comparison to unmodified material. Combined one step Na2S2O5/H3BO3 treatment lowered the CO, CO2 and specific extinction area values in comparison to the modification with Na2S2O5, similarly like it was observed for Na2S2O3/H3BO3 two-step-treatment. According to time-to-ignition values, Na2S2O5 alone at 5% addition is a better flame retardant than Na2S2O3 at 7%, but the effect is diminished at 10% amount or presence of acids. The total smoke release curves showed decrease due to modification in both phases of the process. Introduction of water washing as well as the acid treatment further lowered the values. The best results were achieved with 15% Na2S2O3,2% H3PO4,H2O system. According to the total smoke release curve the specimen produced more than five times smaller amount of smoke than untreated material in the first phase of the process. It seams that the concentration of Na2S2O5 is less affecting the properties than the synergistic effect of the Na2S2O3 or Na2S2O5/H3BO3 system. Although the level of smoke is low, the presence of elemental sulphur causes smaller times-to-ignition than on starting material. Copyright © 2006 John Wiley & Sons, Ltd. [source] Measuring masticatory performance using a new device and ,-carotene in test gummy jellyJOURNAL OF ORAL REHABILITATION, Issue 11 2010T. NOKUBI Summary, Objective methods for evaluating masticatory performance are invaluable for quantitative comparisons between various dental treatments as well as diagnosing masticatory disorder. The purpose of this study was to develop an accurate method for automatically measuring masticatory performance using a new measuring device consisting of light-emitting diodes and a photodiode and test gummy jelly. First, the relationship between six known ,-carotene concentrations in aqueous solution and the voltage values exhibited on a photodiode was investigated. Mean voltage obtained by red light incident on the photodiode indicated a significantly high correlation (r = 0·999 in a cubic function, P < 0·01) with ,-carotene concentration in the aqueous solution. Second, to establish the optimal measuring conditions for evaluating masticatory performance, factors influencing mean voltage were investigated, such as water temperature and times for rinsing the gummy jelly and dissolving ,-carotene from the jelly. A stable mean voltage was obtained by measuring under the following conditions: rinsing water temperature, 35 °C; rinsing time, 30 s; water dissolving temperature, 35 °C; dissolving time, 10 s. Finally, the relationship between seven surface area values of divided gummy jelly and ,-carotene concentrations dissolved from the divided jellies was investigated. The increase in surface area of divided test gummy jelly particles was accurately calculated (r = 0·992, P < 0·001) from mean voltage on the photodiode to change with ,-carotene concentration dissolved from the jelly surface. This new method using test gummy jelly and an automatic measuring device appears useful for precisely evaluating masticatory performance. [source] Measuring the surface area of aluminum hydroxide adjuvantJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 7 2002Cliff T. Johnston Abstract The traditional method of determining surface area, nitrogen gas sorption, requires complete drying of the sample prior to analysis. This technique is not suitable for aluminum hydroxide adjuvant because it is composed of submicron, fibrous particles that agglomerate irreversibly upon complete removal of water. In this study, the surface area of a commercial aluminum hydroxide adjuvant was determined by a gravimetric/FTIR method that measures the water adsorption capacity. This technique does not require complete drying of the adjuvant. Five replicate determinations gave a mean surface area of 514 m2/g and a 95% confidence interval of 36 m2/g for a commercial aluminum hydroxide adjuvant. The X-ray diffraction pattern and the Scherrer equation were used to calculate the dimensions of the primary crystallites. The average calculated dimensions were 4.5,×,2.2,×,10 nm. Based on these dimensions, the mean calculated surface area of the commercial aluminum hydroxide adjuvant was 509 m2/g, and the 95% confidential interval was 30 m2/g. The close agreement between the two surface area values indicates that either method may be used to determine the surface area of aluminum hydroxide adjuvant. The high surface area, which was determined by two methods, is an important property of aluminum hydroxide adjuvants, and is the basis for the intrinsically high protein adsorption capacity. © 2002 Wiley-Liss Inc. and the American Pharmaceutical Association J Pharm Sci 91:1702,1706, 2002 [source] Triboelectrification of Spray-dried Lactose Prepared from Different Feedstock ConcentrationsJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 1 2000ORLA E. CASSIDY Powder systems may acquire electrostatic charge during various pharmaceutical processing operations and may give rise to difficulties in handling and powder flow, mainly due to adhesion/cohesion effects. We have investigated the electrostatic charging of spray-dried lactose prepared from different feedstock concentrations using a laboratory spray-dryer. Triboelectrification of the spray-dried lactose samples was effected through contact with the stainless steel surface of either a mixing vessel or a cyclone separator. Results from both techniques showed differences in charge accumulation and particle-steel adhesion between the spray-dried lactose samples. As the feedstock concentration used to produce the spray-dried lactose was increased in the range 10,50% w/v, the mean charge on the lactose decreased from ,20.8 to ,1.3 nC g,1 and ,54.9 to ,4.1 nC g,1 for the mixing vessel and cyclone separator, respectively, with a corresponding decrease in adhesion. In addition, as the feedstock concentration was increased from 10 to 50% w/v, decreases were obtained in surface area values (1.06 to 0.56 m2 g,1), pore diameter (198.7 to 83.5 ,m) and pore volume (1.09 to 0.75 cm3 g,1), and together with differences in crystal form correlated with the charge and adhesion results. The results suggested that the feedstock concentration could have a considerable influence on the charging and adhesional properties of spray-dried lactose. This may have relevance during pharmaceutical processing and manufacturing operations. [source] Surface Enthalpy, Enthalpy of Water Adsorption, and Phase Stability in Nanocrystalline Monoclinic ZirconiaJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 1 2009A. V. Radha A fundamental issue that remains to be solved when approaching the nanoscale is how the size induces transformation among different polymorphic structures. Understanding the size-induced transformation among the different polymorphic structures is essential for widespread use of nanostructured materials in technological applications. Herein, we report water adsorption and high-temperature solution calorimetry experiments on a set of samples of single-phase monoclinic zirconia with different surface areas. Essential to the success of the study has been the use of a new ternary water-in-oil/water liquid solvothermal method that allows the preparation of monoclinic zirconia nanoparticles with a broad range of (BET) Brunauer,Emmett,Teller surface area values. Thus, the surface enthalpy for anhydrous monoclinic zirconia is reported for the first time, while that for the hydrous surface is a significant improvement over the previously reported value. Combining these data with previously published surface enthalpy for nanocrystalline tetragonal zirconia, we have calculated the stability crossovers between monoclinic and tetragonal phases to take place at a particle size of 28 ± 6 nm for hydrous zirconia and 34 ± 5 nm for anhydrous zirconia. Below these particle sizes, tetragonal hydrous and anhydrous phases of zirconia become thermodynamically stable. These results are within the margin of the theoretical estimation and confirm the importance of the presence of water vapor on the transformation of nanostructured materials. [source] Synthesis, Characterization, and In Vitro Bioactivity of Sol-Gel-Derived Zn, Mg, and Zn-Mg Co-Doped Bioactive GlassesCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 7 2010M. Erol Abstract Bioactive glasses in the systems CaO-SiO2 -P2O5 -ZnO, CaO-SiO2 -P2O5 -MgO, and CaO-SiO2 -P2O5 -MgO-ZnO were prepared and characterized. Bioactive glass powders were produced by the sol-gel method. The prepared bioactive glass powders were immersed in a simulated body fluid (SBF) for periods of up to 28,days at 310,K to investigate the bioactivity of the produced samples. Inductively coupled plasma (ICP) and ultraviolet (UV) spectroscopic techniques were used to detect changes in the SBF composition. X-Ray diffraction (XRD) was utilized to recognize and confirm the formation of a hydroxyapatite (HA) layer on the bioactive glass powders. Microstructural characterizations of the bioactive glass samples were investigated by scanning electron microscopy (SEM) techniques. Density, porosity, and surface area values of bioactive glass powders were also determined in order to characterize the textural properties of the samples. The results revealed the growth of an HA layer on the surface of the bioactive glass samples. MgO in the glass sample increases the rate of formation of an HA layer while ZnO in the glass slows it down. [source] Could the coefficient of variation (COV) of the corneal endothelium be overestimated when a centre-dot method is used?CLINICAL AND EXPERIMENTAL OPTOMETRY, Issue 1 2008Michael J Doughty PhD Background:, Little has been published on the reliability of estimates of the coefficient of variation (COV) in cell area for human corneal endothelia. The present study compares two methods. Methods:, A non-contact specular micrograph (Topcon SP-2000P) was obtained from the central region of the corneal endothelium of 20 healthy myopic white European subjects, aged from 32 to 53 years, half of whom were successful long-term soft contact lens wearers. The captured image file was either assessed using a machine-based algorithm, in which 25 cells in the middle of the image were marked and their areas reported (designated as ,centre-dot' method) or by a manual method, by which all the cells in the image were outlined on very high magnification prints of the endothelia and the cell areas measured by a manual digitiser in stream mode. The average cell area was used to calculate the endothelial cell density (ECD), while the COV was calculated from the standard deviation (SD) of the cell area measures. Results:, Identical mean cell area values were found (392 µm2) with the two methods, a marginally higher ECD estimate (2,594 versus 2,569) with the centre-dot method (p = NS) but a much higher COV with the centre-dot method (43.8 versus 29.0 per cent). This highly statistically significant difference in COV (p < 0.001) was seen in both contact lens wearers and non-contact lens wearers. A Bland-Altman analysis reveals a bias in the centre-dot method, especially for the COV estimates, that appears to be linked to erroneous definition of a single large cell domain on any individual image. Conclusions:, A centre-dot method can be reliably used to generate useful data on cell area and ECD but it should be used cautiously for estimates of polymegethism (COV). [source] | |||||||||||||