318 research outputs found
Identification of a new cocrystal of citric acid and paracetamol of pharmaceutical relevance
Cocrystals have been increasingly recognized as an attractive alternative delivery form for solid drug products. In this work, Raman spectroscopy, X-ray powder diffraction/X-ray crystallography, and differential scanning calorimetry have been used to study the phenomenon of cocrystal formation in stoichiometric mixtures of citric acid with paracetamol. Raman spectroscopy was particularly useful for the characterization of the products and was used to determine the nature of the interactions in the cocrystals. It was observed that little change in the vibrational modes associated with the phenyl groups of the respective reactants took place upon cocrystal formation but changes in intensities of the vibrational modes associated with the amide and the carboxylic acid groups were observed upon cocrystal formation. Several new vibrational bands were identified in the cocrystal which were not manifest in the raw material and could be used as diagnostic features of cocrystal formation. An understanding of the effects of cocrystal formation on the vibrational modes was obtained by the complete assignment of the spectra of the starting materials and of the cocrystal component. The results show that the cocrystals was obtained in a 2:1 molar ratio of paracetamol to citric acid. The asymmetric unit of the crystal contains two paracetamol molecules hydrogen-bonded to the citric acid; one of these acts as a phenolic-OH hydrogen bond donor to the carbonyl of a carboxylic acid arm of citric acid. In contrast, the other phenolic-OH acts as a hydrogen bond acceptor from the quaternary C-OH of citric acid. © 2011 The Royal Society of Chemistry
Effect of SPIO Nanoparticle Concentrations on Temperature Changes for Hyperthermia via MRI
Magnetic nanoparticles (MNPs) are being developed for a wide range of biomedical applications. In particular, hyperthermia involves heating the MNPs through exposure to an alternating magnetic field (AMF). These materials offer the potential for selectively by heating cancer tissue locally and at the cellular level. This may be a successful method if there are enough particles in a tumor possessing sufficiently high specific absorption rate (SAR) to deposit heat quickly while minimizing thermal damage to surrounding tissue. The current research aim is to study the influence of super paramagnetic iron oxides Fe3O4 (SPIO) NPs concentration on the total heat energy dose and the rate of temperature change in AMF to induce hyperthermia in Ehrlich carcinoma cells implanted in female mice. The results demonstrated a linearly increasing trend between these two factors
Assessment of plasma and urinary transforming growth factor beta 1 (TGF-β1) in children with lupus nephritis
Background: Kidney disease is one of the most serious manifestations of systemic lupus erythematosus (SLE). Despite the improvement in the medical care of SLE in the past two decades, the prognosis of lupus nephritis remains unsatisfactory. Transforming growth factor- β1 (TGF-β1) is an immunosuppressive cytokine, as it inhibits T and B cell proliferation and NK cell cytotoxic activity . Objective: The aim of this study was to assess serum and urinary TGF- β1 levels in children with SLE and their possible role in the renal involvement and activity of the disease. Study design: This cross sectional study was conducted in Nephrology Unit of Pediatric Department, plus Outpatient Clinic of Rheumatology Department, Zagazig University Hospital during the year of 2010. Methods: Twenty-five pediatric patients with SLE were randomly selected and classified according to into 2 groups: Group (Ι): included 13 patients presented with urinary abnormalities and/or disturbed renal function(active nephritis): 5 males, 8 females. Their mean age was 9.7±2.53 years and the mean disease duration was 2.46±1.4 years. Group (ΙΙ): included 12 patients presented by lupus without nephritis : 5 males,7 females. Their mean age was 9.9±2.1 years and the mean disease duration was 2.41±0.9 years. Control group(group ΙΙΙ): Twenty healthy children of matched age and sex served as a control group included 8 males ,12 females. Their mean age was 10.0±2.3 years. Results: There was no significant difference among studied patients groups regarding age, sex , disease duration and lupus therapy (p>0.05). There was a significant difference between both groups regarding urinary albumin and serum creatinine (2.76±0.97 and 1.96±0.84 mg/dl respectively), while there was a high significant difference between them regarding C3 (47.3±12.5 and 76.6±6.6 mg/ml respectively) and anti double stranded DNA (anti-dsDNA) (80.7±32.8 and 26.8±4.5 IU/ml respectively). Plasma TGF- β1 showed significantly lower levels in patients with active nephritis relative to other groups, while urinary TGF- β1 levels were significantly high in SLE patients either with active or silent nephritis when compared with the control group. Plasma TGF- β1 showed a highly significant positive correlation with C3 and a highly significant negative correlation with serum creatinine, urinary albumin, anti dsDNA and SLE disease activity index (SLEDAI) score. While, urinary TGF- β1 had a significant negative correlation with C3 and a high significant positive correlation with anti-dsDNA and SLEDAI score. Conclusion: Low plasma TGF β1 level and increased urinary TGF β1 excretion denotes active renal affection in children with SLE.Keywords: SLE , nephritis , TGF- β1Egypt J Pediatr Allergy Immunol 2011;9(1):21-2
Micromechanical Properties of Injection-Molded Starch–Wood Particle Composites
The micromechanical properties of injection molded starch–wood particle composites were investigated as a function of particle content and humidity conditions.
The composite materials were characterized by scanning electron microscopy and X-ray diffraction methods. The microhardness
of the composites was shown to increase notably with the concentration of the wood particles. In addition,creep behavior under the indenter and temperature dependence
were evaluated in terms of the independent contribution of the starch matrix and the wood microparticles to the hardness value. The influence of drying time on the density
and weight uptake of the injection-molded composites was highlighted. The results revealed the role of the mechanism of water evaporation, showing that the dependence of water uptake and temperature was greater for the starch–wood composites than for the pure starch sample. Experiments performed during the drying process at 70°C indicated that
the wood in the starch composites did not prevent water loss from the samples.Peer reviewe
Associations between Birth Weight and Adult Sleep Characteristics: A Cross-Sectional Analysis from the UAEHFS
Abnormal birth weight, particularly low birth weight (LBW), is known to have long-term adverse health consequences in adulthood, with disrupted sleep being suggested as a mediator or modifier of this link. We thus aimed to assess the associations between birth weight and self-reported adult sleep characteristics: sleep duration, difficulty waking up in the morning, daily nap frequency, sleep problems at night, snoring, daytime tiredness or sleepiness, and ever-stop breathing during sleep. This cross-sectional analysis used the United Arab Emirates Healthy Future Study data collected from February 2016 to March 2023 involving 2124 Emiratis aged 18–61 years. We performed a Poisson regression under unadjusted and age-sex-and-BMI-adjusted models to obtain the risk ratio and its 95% confidence interval for our analysis of the association between birth weight and each adult sleep characteristics, compared to individuals with normal birth weight (≥2.5 kg). Those with LBW had significantly a 17% increased risk of difficulty waking up in the morning, compared to those with normal birth weight. In addition, females with LBW history were also at an increased risk of reporting difficulty waking up in the morning. Studies with objective sleep assessments that include measurements of more confounding factors are recommended to confirm these risks
Influence of Methomyl (Copter 90%) on certain biochemical activities and histological structures of land snails Monacha cartusiana
This manuscript was conducted to spotlight the toxic effect of two sub-lethal concentrations of Methomyl (Copter) LC20 (0.075 g/L) and LC40 (0.180 g/L) on some biochemical parameters and histological alterations for land snail Monacha Cartusiana (Muller, 1774). Land snails belong to the class Gastropoda and Phylum Mollusca. This study cleared that both the used concentrations (of Copter) caused a significant increase for activities of three enzymes: alkaline phosphatase (ALP), alanine amino transaminase (ALT), and Aspartate amino transaminase (AST) after 24, 48, and 72 h from exposure starting. In contrast, a total protein (TP) activity decreased at exposure for two concentrations at all lethality periods. Both concentrations of Copter (0.0.75 g/L and 0.180 g/L) have shown histological changes for land snail tissues after 96 h of exposure; digestive gland, hermaphrodite gland, foot, and mantle. Degeneration, rupture, and vacuolization for digestive cells have been shown; furthermore, hemolytic infiltration in connective tissue will be recognized for the digestive gland. The Oocyte and sperm show degenerated with deformation in the connective tissue of the hermaphrodite gland. Likewise, deformation in the muscle fiber layer of the foot in the land snail distorts the epidermis and mucus gland suffering from necrosis. Moreover, mantle shows rapture in epidermis layer, deformed in muscle fiber layer, and vacuolization and necrosis take place in mucus gland. © 2021 The Author(s
An International Investigation of Molar Incisor Hypomineralisation (iMIH) and Its Association with Dental Anomalies: Development of a Protocol
Background: Molar incisor hypomineralisation (MIH) is a common disorder of tooth development, which has recently been found to be associated with a higher prevalence of hypodontia. The aim of this international multicentre study is to determine the association between MIH and other developmental anomalies in different populations. Methods: Investigators were trained and calibrated for the assessment of MIH and dental anomalies and ethical approvals obtained in each participating country. The study aimed to recruit 584 children with MIH and 584 children without MIH. Patients aged 7–16 years who attend specialist clinics will be invited to participate. Children will undergo a clinical examination to determine the presence and severity of MIH, using an established index. The presence of any other anomalies, affecting tooth number, morphology, or position, will be documented. Panoramic radiographs will be assessed for dental anomalies and the presence of third permanent molars. Statistical analysis, using a chi squared test and regression analysis, will be performed to determine any differences in dental anomaly prevalence between the MIH and non-MIH group and to determine any association between dental anomalies and patient characteristics. Conclusion: This large-scale study has the potential to improve understanding about MIH with benefits for patient management
The solar noise barrier project: 3. The effects of seasonal spectral variation, cloud cover and heat distribution on the performance of full-scale luminescent solar concentrator panels
We report on the relative performances of two large-scale luminescent solar concentrator (LSC) noise barriers placed in an outdoor environment monitored for over a year. Comparisons are made for the performances of a number of attached photovoltaic cells with changing spectral illumination, cloud cover conditions and other seasonal variations, and the temperatures of the cells. Differences in performance are attributed to the positioning of the panels, whether facing North/South or East/West. In general, the panels facing East/West run cooler than those facing North/South. The LSCs in both orientations appear to perform more efficiently under lower light conditions: one factor contributing to this increased performance is better spectral matching of the solar spectrum under cloudy conditions to the absorption spectrum of the embedded fluorescent dye. This work is a step forward in the characterization of a large scale LSC device, and suggests predictions of performance of devices could be made for any location given sufficient knowledge of the illumination conditions, and provides an important step towards the commercialization of these alternative solar energy generators for the urban setting
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