Initial Weight Increase Research Articles

Correlating immediate vapour reactivity with dentin remineralization and tubule occlusion capacity of a bioactive sol-gel borate glass

The use of bioactive glass as a mineralization agent in treating dentin hypersensitivity has been established for almost two decades where the melt-quench-derived silicate glass, 45S5, may be regarded as the gold standard formulation. Compared to silicate glasses, borate glasses are less chemically durable and have the potential to mineralize (i.e., convert to apatite) more rapidly. This study compared the apatite forming capacity of a sol-gel-derived calcium-borate glass, 40CaO–60B2O3 (SGB60), to that of 45S5, on demineralized dentin discs and its ability to occlude tubules on non-demineralized dentin discs, in vitro. Moreover, it investigated the vapour sorption reactivity of the glasses to explore the potential correlation between their immediate aqueous interactions and bioactivity in remineralization solution. Compared to 45S5, SGB60 demonstrated more rapid calcium-phosphate layer formation on demineralized dentin surfaces. On the other hand, after 24 h immersion in remineralization solution, the 45S5-induced calcium-phosphate layer occlusion of tubules in non-demineralized dentin surfaces appeared to be qualitatively greater than that induced by SGB60. Moreover, vapour sorption analysis under either air or nitrogen gas, demonstrated that the reactivity of 45S5 with vapour varied under the different purge gasses, with significant carbonate formation under air. In contrast, SGB60 showed a more rapid rate of initial weight increase with vapour under both purge gasses, and this vapour reactivity may be correlated to its more rapid calcium-phosphate layer formation on demineralized dentin surfaces when immersed in remineralization solution.

Nutritional Characteristics of a Peruvian Anchovy (Engraulis ringens) Protein Concentrate

ABSTRACT The aim of the present study is to present a new anchovy protein concentrate and compare it to other similar fishery products. A 76.4% protein concentrate was prepared from fresh Peruvian anchoveta (Engraulis ringens) (APC) by means of acid treatment with 1% citric acid, solubilization with 1% sodium chloride, and isoelectric precipitation processes. Remaining fat was 5.2%, and 0.51 Aw indicates good stability. When APC was rehydrated for 10 minutes, it had a 3.5 initial weight increase. It provided 17.8% protein of very high nutritional quality, with only histidine content deficient for children 1–2 years old. Fat content in APC offered 33.4% EPA+DHA. No changes in the essential/non-essential amino acids (EAA/non-EAA), polyunsaturated/saturated fatty acids (PUFA/SFA), or w6/w3 ratios were observed as a result of the process in the raw material. Because of the high sodium content, a 25 g portion is recommended to fulfill nutritional FAO recommendations. APC can be considered as an important source of calcium (30% adults and 35% children requirements), phosphorous (30% adults and 52% children requirements), and iron content (approximately 20% adults and children needs). APC is an important high-quality protein, providing w-3 fatty acids, calcium, phosphorous, and iron.

Sorption and Degradation Behaviour of Epoxy Composites Reinforced with Amine-Coated Polyester Triangular Bars in Acid Environment

Sorption and degradation characteristics of epoxy composites reinforced with amine-coated polyester triangular bars in acid environment were studied. The following aspects of amine-coated triangular bars were varied during preparation of epoxy composites: orientation (flat or pointed), alignment (parallel or staggered), spacing (1 or 5 mm), and size (5 or 7 mm). Composites were tested using a one-side acid exposure test in 5 wt% hydrochloric (HCl) acid solution at 40°C for 308 h. Weight change curves of composites with pointed orientation show continuous sorption of acid solution with square root of time, while composites with flat orientation display an initial increase in weight followed by continuous weight loss. This can be attributed to the large interfacial area of triangular bars exposed to diffusing acid in flat orientation. Since the bars are amine-coated, the acid preferentially diffuses in the interfacial region, resulting to early degradation of composite. The following parameters were measured from the weight curves for data analysis: initial sorption rate (% - h-0.5), maximum weight change during sorption (%), and weight loss due to degradation (%). Analysis of variance (ANOVA) shows maximum weight change and weight loss due to degradation of epoxy composites are significantly affected by orientation and spacing.

Corrosion behaviour of IN625 in superheated steam at 800°C

Concerns with greenhouse gas emissions and the uncertainty of long-term supply of fossil fuels have resulted in renewed interest in nuclear energy as an essential part of the energy mix for the future. Canada is currently undertaking the design of Generation IV supercritical water-cooled reactor (SCWR) with improved higher thermodynamic efficiency and considerable plant simplification. The identification of appropriate materials for in-core and out-of-core components to contain the SCWR coolant is one of the major challenges for the design of Canadian SCWR. This study is carried out to evaluate the oxidation/corrosion behaviours of Inconel 625 (IN625) under superheated steam (SHS) at a temperature of 800°C (0.1 MPa) for up to 3000 hours. The results show that chromium-based oxide forms on the surface after exposure in SHS for 800, 2000 and 3000 hours. The oxide formation leads to initial weight increase followed by weight loss after extended exposure, likely due to chromium oxide dissolution. No localised oxide spallation was observed on all samples examined. Despite the slight weight reduction, a dense and adhered oxide layer, consisting primarily of Cr2O3 with some spinel (Ni(Cr,Fe)2O4), remained on IN625 after 3000 hours in SHS.

EPA-1389 – Predictive values of appetite and early weight increase for long-term weight variation during psychotropic treatment.

Introduction Atypical antipsychotics and some other psychotropic drugs such as valproate, lithium or mirtazapine are known to induce several metabolic complications. However there is an inter-individual variability in developing metabolic features which may be explained by clinical and genetic factors. Objectives To determine whether weight gain and/or appetite change after one month are predictors for a weight gain after 3 and 12 months of treatment. Methods A longitudinal clinical and pharmacogenetic study is presently ongoing in the Department of Psychiatry-CHUV. Several clinical data have been recorded over one year following the introduction of psychotropic treatment. 406 patients with weight at baseline, after one month and with at least a third weight measure during the first year of treatment were included in the present study. Results Using Receiver Operating Characteristic (ROC) analyses, an initial weight increase of 5% was found to be a good predictor for a consequent weight gain at 3 months (ROC AUC =77) and one year (ROC AUC =68). By using a generalized linear mixed model corrected by several confounders, this weight change of 5% was found to be significantly associated (p-value Conclusion An initial weight gain of 5% during the first month following an introduction of atypical antipsychotics, lithium, valproate and/or mirtazapine is a predictor for further weight gain and should be a warning sign to introduce weight lowering strategies.

Degradation properties and ion release characteristics of Resilon® and phosphate glass/polycaprolactone composites

To (i) characterise the degradation pattern and ion release characteristics of bioactive glass/polycaprolactone (PCL) composites; (ii) compare the degradation behaviour of composites containing phosphate glass to that of Resilon; and (iii) determine the potential to control the degradation of the composites by modifying the iron content of phosphate glasses. The degradation behaviour of the phosphate glass/PCL samples (n = 3) and that of Resilon were determined in two aqueous solutions (buffered distilled water, Hanks Buffered Saline Solution) over a 7-day period using weight change measurement, ion chromatography, light microscopy (LM) and scanning electron microscopy (SEM). An initial increase in weight of the samples was followed by loss. All phosphate glass/PCL composites released various amounts of iron, sodium, calcium and phosphate ions into solution. The Resilon samples released only sodium and calcium ions. The visual methods (LM, SEM) showed distinct precipitate (calcium phosphate) formation on the surface of the phosphate glass/PCL composites but only a faint surface residue on the surface of Resilon. The degradation pattern of the composites containing phosphate glass was different from that of Resilon. The phosphate glass/PCL composites encouraged precipitate formation on the material surface, which may be advantageous in creating a marginal and apical seal.

Oxidation of two three-phase Cu–30Ni–Cr alloys at 700–800 °C in 1 atm of pure oxygen

The oxidation of two ternary Cu–Ni–Cr alloys containing approximately 30 at.% and 40 at.% Cr, but with a similar 30 at.% Ni content, was studied at 700–800 °C in 1 atm of pure oxygen. The two alloys are composed of a mixture of three phases, where the medium gray β phase with an intermediate chromium content forms the matrix and the lightest α phase with the largest copper and lowest chromium content forms large islands and has a rather large volume fraction, while dark γ phase richest in chromium forms isolated particles dispersed in the other two phases, moreover, the γ phase particles for the alloy containing 40 at.% Cr appear to have a precipitation of very small lighter particles. The kinetic curves for the two alloys deviate considerably from the parabolic rate law and are composed of a few of stages, where they show a large initial weight increase after which the rates decrease with time, until they become very small up to 24 h. Generally, the oxidation rates decrease by increasing the Cr content in the alloy under constant temperature and increase with temperature for a constant alloy composition. The alloy containing 30 at.% Cr produced an external scale mainly composed of a rather thick and discontinuous lighter layer of copper oxides. Beneath the external scale there is a dark and continuous layer of irregular chromia in thickness, which at some locations is followed by a thin dark layer of chromia directly in contact with the alloy. On the contrary, at other locations the scale forms deep protrusions into the alloy. The alloy containing 40 at.% Cr formed a lighter thick but discontinuous layer of copper oxides containing some nickel followed by an innermost region composed of a rather thick and continuous dark layer of regular and flat chromia. The formation of an external scale of chromia for the two alloys prevents alloys from being oxidized further.

Weight change with atypical antipsychotics in the treatment of schizophrenia

Weight gain is a common complication of antipsychotic treatment. Its consequences include decreased self-esteem, reduced quality of life, reduced adherence with medication and increased morbidity and mortality. Most studies that assess weight change are short term. Among the atypicals mean weight gain is greatest with olanzapine and clozapine and least with aripiprazole and ziprasidone. Mean weight change obscures the marked individual variation in weight change that occurs during antipsychotic treatment i.e. irrespective of the antipsychotic, some subjects lose weight, some maintain their weight and some gain weight. In several long-term naturalistic studies (>6 months) mean weight gain is less marked than in randomised controlled trials of a shorter or comparable duration. This may reflect selective prescribing, the effect of weight management interventions and differences in the statistical analysis employed. With most antipsychotics weight stabilizes in the short to medium term but with clozapine it may continue beyond the first year. With some drugs clinical improvement is associated with short-term weight gain. Predictors of long-term weight gain include lower body mass index, increased appetite and rapid initial weight increase. Weight gain is greater in first onset patients due to the lack of prior antipsychotic exposure and associated weight gain. The potential for weight gain should be discussed with patients before starting antipsychotic treatment and weight monitored regularly during treatment. It may be possible to predict weight gain before an antipsychotic is started or early on in treatment enabling high-risk patients to receive more intensive strategies to reduce weight gain.

AN EVALUATION OF THE TOXIC EFFECTS OF <i>HYPTIS SUAVEOLENS</i> IN RATS

The effects of prolonged administration of graded doses of Hyptis suaveolens (Linn.) Piot Labiatae leaf extract on the changes in the body weight, haematological, toxicological and histological indices in rats were evaluated. There was an initial increase in weight which later significantly (p0.05) in white blood cell (WBC) count were observed. No fatality was recorded in acute toxicity tests in which the animals were given 100mg/Kg to1600mg/Kg body weight of the aqueous extract, although the rats given higher doses (800mg to 1600mg/Kg body weight ) exhibited some behavioral changes such as aggressive scratching of the body and head, drowsiness and sleep depressed pulse, loss of vigor, and apparent loss of weight. Quantitative phytochemical constituents present in the extract were found to include saponin, tannin and flavonoids. Histopathological examination of the liver revealed fatty changes and congestion of the central vein as the major indicator of hepatic damage. Key Words: Hyptis suaveolens; Labiatae; rats; toxicity Nigerian Journal of Natural Products and Medicine Vol.7 2003: 49-52

Thermal Optima for the Culture of Juvenile Summer Flounder, Paralichthys dentatus

Summer flounder, Paralichthys dentatus, aquaculture has shown promise over the recent past and a considerable body of knowledge is amassing for this species of flatfish. Even with the amassing data, basic information on environmental parameter ranges to maintain in indoor culture systems is still lacking. Therefore, the current study was undertaken to elucidate a temperature range that may be best suited for juvenile summer flounder production in indoor recirculating aquaculture. A 10-week study was designed to address 19, 24 and 29°C as potential temperatures for the culture of summer flounder. Fish averaging 9.5 g initial weight were stocked into triplicate 20-L aquaria per treatment after conditioning to their respective temperatures for 1 week. Fish were fed to apparent satiation twice daily a 50% crude protein fingerling diet and weighed every 2 weeks to assess growth rates. Juvenile summer flounder grew better at 24 and 29°C (167 and 197% increase initial weight, respectively) than at 19°C (97% increase in initial weight) with increased individual fish variation within a treatment as temperature increased above 19°C. Feed efficiency was greatest at 24 and 29°C (0.65 and 0.57, respectively), but survival decreased at temperatures above 19°C (93, 60 and 57% for 19, 24 and 29°C, respectively). There was no effect of temperature on the hepatosomatic index or interior muscle ratio, but the finray muscle ratio was slightly elevated when flounder were cultured at 29°C. The lipid content of the finray muscle and liver also increased at 29°C. Therefore, 24°C appears to be the best culture temperature for summer flounder with respect to growth rates and efficiency, but survival and homogeneity of flounder may be lowered at temperatures above 19°C.

Rainbow trout egg quality determination by the relative weight increase during hardening: a practical standardization

The relative weight of fish eggs increases during water hardening; this increase is significantly correlated with egg viability in rainbow trout when determined after 120 min, providing an assay test for egg quality control. In the present paper, additional investigations on egg water uptake at different time intervals during the hardening process were performed to correlate these with egg viability and to improve the sensitivity of the assay while also reducing the handling time. Eggs of high quality had a significantly higher rate of water uptake than low quality eggs, with the highest rate occurring during the first 30 min of hardening. Bivariate correlation coefficients and regression models revealed that in addition to egg weight increase after 120 min of water hardening, the increases in weight after 30 min and 60 min were also significantly related to egg viability (P < 0.001). In contrast, the initial weight increase after 15 min of hardening revealed a lower correlation (P < 0.006) with egg viability. These results indicate the initial velocity of water uptake is not a valid criterion, but that the total amount of water imbibed during hardening provides the most reliable information on egg quality. The present study confirms the previously reported sensitivity of the assay, and also shows that a shorter incubation time of 30 min is adequate for reliable results. The shorter handling time is an improvement for testing large numbers of egg batches.

Increased Sinusoidal Pressure Is Associated with Early Liver Weight Gain in Ischemia–Reperfusion Injury in Isolated Perfused Rat Liver

Background. Hepatic ischemia–reperfusion (I/R) is accompanied by liver weight gain and ascites formation. This could be caused by an increase in sinusoidal pressure, a determinant of hepatic transvascular fluid movement. We determined the role of sinusoidal pressure, assessed by triple vascular occlusion pressure (Pto), in the I/R injury in isolated rat livers perfused with leukocyte-free diluted blood bivascularly via the portal vein and hepatic artery.Materials and methods. Ischemia was induced at room temperature by occlusion of either the inflow lines of the hepatic artery and portal vein (the open outflow group, n = 10) or both the inflow and the outflow (hepatic venous) lines (the closed outflow group, n = 10) for 1 h, followed by 1-h reperfusion in a recirculating manner.Results. Liver weight in both groups increased biphasically after reperfusion; the initial peak occurred at 3 min and the second peak at 60 min. Immediately after reperfusion, Pto peaked, followed by a gradual decline. The initial weight increase in groups combined was significantly and positively correlated with an increase in Pto (r = 0.716, P = 0.0002), but the second peak was independent of Pto. Liver injury, assessed by perfusate levels of hepatic enzymes and reduced bile flow rate, was observed at 60 min after reperfusion in both groups.Conclusions. These findings suggest that increased sinusoidal pressure contributes to only the early liver weight gain after reperfusion in isolated perfused rat livers. The late weight gain may be presumably due to liver injury.

Water absorption and leaching effects in cellulose diacetate

Degradation of polymers caused by water ingress is a recognised problem for the long term strength of structural materials but may be considered too slow for some packaging materials! Following an earlier study of water degradation in an epoxy resin, we here consider effects in cellulose diacetate—a biodegradable material. As before, initial weight increase following exposure to water is followed by weight decrease such that, at sufficiently long times, there is a net weight loss. The overall behaviour has been wholly or partially observed at six temperatures ranging from 10°C to 90°C. A model based conceptually on the initial attachment of water to the polymeric structure (causing weight increase) followed by chain segment separation and subsequent leaching (leading to weight decrease) was developed and explains satisfactorily the overall behaviour.

Long-term function of experimental substitutes of the ileocecal valve.

The bacteriological barrier function of the ileocecal valve (ICV) can be replaced according to the principle of the nipple-valve anastomosis. Since late complications due to technical measures for stabilizing the ileal nipple have been hitherto unknown, 12 adult beagle dogs were operated on by three technical modifications of a nipple-valve anastomosis and were followed up for 1 year: In three cases the ileal nipple was stabilized by longitudinal staples (NVA), in three cases an intestinal neosphincter (INS) was produced by healing of the muscular layers between the ileal nipple and colon, and in six cases an oral zone of stabilization, preserving an aboral valve zone (S-NVA) was constructed. Measures for valve function at the end of the study period were the weight course of the animals and the intestinal bacterial profile, considering morphological complications of the substituted valves. As reference the respective bacterial counts in ICV and end-to-end anastomosis (EEA) were used, which had been determined in the same animals in earlier experiments. Following an initial increase in weight the 3 animals with NVA and the three animals with INS continuously lost weight from the 4th postoperative month onward. The 6 animals with S-NVA, however, showed from the 4th postoperative month onward a significantly higher weight level (p < 0.05), which remained constant up to the end of the 1-year observation period. Because of a morphologically intact structure of the substituted valve a significantly (p < 0.05) better bacteriological clearance of the ileum was confirmed in these animals after 12 months when compared with the EEA group. In contrast, in the NVA and INS animals a severe bacterial overgrowth of the entire small intestine was observed. This was caused by an intestinal stagnation due to partial prolapse of the nipple in NVA and due to fibrotic stenosis in INS. The results of our study suggest that technical measures to relieve the tendency to devaginate are only successful, if they do not lead to obstruction of the orthograde intestinal passage in the long term. Thus, only the clinical introduction of the S-NVA model may be justified.

Hygroscopic Expansion of Polyester Films

The hygroscopic expansion of polyethylene terephthalate (PET) and polyethylene 2,6-naphthalate (PEN) films was measured by use of a thermomechanical analyzer at 30, 40 or 50°C. Their initial weight increase was proportional to the square root of time after exposure to moisture, obeying Fick's law; the hygroscopic expansion with time showed the same relationship. The equilibrium moisture content was 1.0×10-5/% RH for both films; the hygroscopic expansion at equilibrium was also about the same for these films. However, the diffusion constant for moisture in PEN films was 1·6×10-9 cm2/s at 30°C in comparison with 4·8×10-8 for PET, although the activation energies were 45 kJ/mol for PET and 41 for PEN.

Endothelial pump function in rabbit corneas kept under eye bank conditions

Endothelial pump activity of rabbit corneas kept under eye bank conditions was examined. Different swelling rates for medium with and without ouabain were used for the calculation of endothelial pump rate. After an initial weight increase during 24 h, the control corneas kept approximately constant weight for 1 week. The ouabain-treated corneas increased continually, and during the time interval 24-48 h the increase was 41% of start weight. This corresponds to a pump activity of 2.3% of the weight of the normal corneal stroma per h, or to 9 microns of the corneal thickness per h. Each endothelial cell pumped fluid corresponding to 200-300% of the cell volume per h between day 1 (24 h) and day 8. The pump activity was gradually reduced after 8 days. The average weight was the same in both groups after 7 weeks.

Oxidation of Nickel Sulfides in Oxygen at 700°C

The kinetics of oxidation of containing ∼38, 39, 40, 41.4, and 42 atom percent (a/o) S and were studied at in oxygen at 1 atm. The oxidation of was strongly dependent on its composition. All compositions showed an initial increase followed by a slow decrease in weight. For compositions with 41.4 and 42 a/o S, however, the initial increase in weight was extremely small. Oxidation products of all the compositions were identified by x‐ray diffraction as . Oxidation of showed a sharp initial decrease, followed by a slow increase in weight. The oxidation products were identified as and only. The morphology of the oxidized samples was studied using SEM. EDAX was used to identify phases. The possible mechanisms of oxidation are discussed.

The performance of beef animals on a permanent pasture*

AbstractBetween 1967 and 1975, 416 beef animals were grazed rotationally on an indigenous pasture (11.65 ha) containing Festuca rubra, Holcus lanatus, Poa trivialis and Agrostis spp. and dicotyledonous plants, but little Lolium perenne or Trifolium repens. Part of the land received fertilizer nitrogen at rates varying between 120 and 200 kg h−1 each year and part did not; some of the land was grazed only and some was cut and then grazed.The winter gains of the animals (approx. 45 kg) were more variable and less than the summer gains (approx. 155 kg). Summer gain was inversely correlated with winter gain. An increase in initial weight of animals purchased from 1973 onwards did not increase either winter or summer gain. Friesians gained more than Hereford‐cross animals during the winter, but there was no difference in summer gain.During 9 years the average animal weight per grazed ha in April was increased from 1260 to 2122 kg. The mean total gain on 1165 ha of grass was 6486 kg per annum in the first 3 years and 7266 kg per annum in the last 3 years. The average annual production was 590 kg live‐weight gain and 1.01 t hay or 2.33 t silage per ha. The output of fertilized grass in 1975 was calculated as 842 Livestock Unit Grazing Days (LUGD) per ha and that from unfertilized grass as 360 LUGD per ha. The overall output of utilized metabolizable energy in 1975 was 59–7 GJ h−1, with 69.3 GJ h−1 from fertilized grass and 29.8 GJ h−1 from unfertilized grass.