624 research outputs found
Aviation Law Comes Home to the Main Street Lawyer
Well controlled in length and highly aligned ZnO nanorods were grown on the gold-coated glass substrate by hydrothermal growth method. ZnO nanorods were functionalised with selective thallium (I) ion ionophore dibenzyldiaza-18-crown-6 (DBzDA18C6). The thallium ion sensor showed wide linear potentiometric response to thallium (I) ion concentrations ( M to  M) with high sensitivity of 36.87 ± 1.49 mV/decade. Moreover, thallium (I) ion demonstrated fast response time of less than 5 s, high selectivity, reproducibility, storage stability, and negligible response to common interferents. The proposed thallium (I) ion-sensor electrode was also used as an indicator electrode in the potentiometric titration, and it has shown good stoichiometric response for the determination of thallium (I) ion
Molecular Aspects of Dopaminergic Neurodegeneration: Gene-Environment Interaction in Parkin Dysfunction
Parkinson’s disease (PD) is a common neurodegenerative movement disorder that is characterized pathologically by a progressive loss of midbrain dopaminergic neurons and by protein inclusions, designated Lewy bodies and Lewy neurites. PD is one of the most common neurodegenerative diseases, affecting almost 1% of the population over 60 years old. Although the symptoms and neuropathology of PD have been well characterized, the underlying mechanisms and causes of the disease are still not clear. Genetic mutations can provide important clues to disease mechanism, but most PD cases are sporadic rather than familial; environmental factors have long been suspected to contribute to the disease. Although more than 90% of PD cases occur sporadically and are thought to be due, in part, to oxidative stress and mitochondrial dysfunction, the study of genetic mutations has provided great insight into the molecular mechanisms of PD. Furthermore, rotenone, a widely used pesticide, and paraquat and maneb cause a syndrome in rats and mice that mimics, both behaviorally and neurologically, the symptoms of PD. In the current review, we will discuss various aspects of gene-environment interaction that lead to progressive dopaminergic neurodegenration, mainly focusing on our current finding based on stress-mediated parkin dysfunction
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Development and characterisation of semi-crystalline composite granules: the effect of particle chemistry and the electrostatic charging
This study investigated the surface of semi-crystalline composite granules produced via a novel mechano-chemical process and assessed the effect of electrostatic charging. Ibuprofen (IBU), a model drug with low solubility and known associated processing challenges was loaded in composite granules to improve its processibility and dissolution rates. Synthetic amorphous mesoporous magnesium alumina metasilicate (MAS) was co-processed with hydrophilic HPMC polymer in the presence of polyethylene glycol 2000 (PEG) and deionised water. The solid state analyses conducted by scanning electron microscopy (SEM), X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) revealed the existence of semi-crystalline IBU in the complex composite structures. Dynamic vapour sorption (DVS) study showed the water sorption and desorption profiles of the manufactured composite granules as well as the effect of water on the solid-state stability of IBU in various formulations. Advanced surface analysis conducted via energy dispersive X-ray (EDS) revealed homogenous distribution of the drug/excipients on the surface of the granules while atomic force microscopy (AFM) complemented the findings. The electrostatic charge analysis showed variable charge property which is affected by the size of the particles/granules. As expected, the in vitro dissolution study showed about 5 fold increase in the release rates of IBU compared to that of the bulk drug. The mechano-chemical processing has been demonstrated as an efficient technique to develop semi-crystalline composite granules with enhanced dissolution rates of water insoluble drugs
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Evaluation of the surface chemistry and drug-polymer interaction of semi-crystalline micro-particles for the development of controlled release formulations
This research work explores the surface chemistry and drug-polymer interaction in the manufactured controlled release micro-particles. Isoniazid (INH) was used as a model anti-tubercular drug while Eudragit® S100 (S100), Eudragit® L100-55 based co-processed Acryl EZE (EZE) and Ethylcellulose ECN10 (ECN10) were used as polymeric carriers. INH containing micro-particles were prepared using a mini spray dryer B-290 (Buchi, Switzerland). The drug polymer ratios were optimized at 1:1 and 1:3 to evaluate the effect of polymers on the release of the drug from the micro-particles. Solid state characterization via SEM and particle size analysis of the manufactured micro-particles showed densely aggregated spherical particles with a mean diameter < 10 μm. The advanced surface analysis via EDS revealed a homogenous drug distribution on the spray dried micro-particles. The physico-chemical characterization carried out by using DSC and XRPD showed an increase in the amorphicity of the drug during the spray drying process while the chemical elemental analysis via XPS revealed a strong intermolecular interaction between the amine group of the drug and the carboxyl group of the polymers. As expected, the in vitro dissolution study showed a slow release pattern for the highly water soluble drug INH in acidic media (pH 1.2) for the first 2 h followed by a burst release upon changing the pH to 6.8. It was concluded that emerging spray drying processing can be used as a valuable tool to encapsulate drug for controlled release dosage forms by means of facilitating a possible drug/polymer interaction as outlined by novel XPS analysis
Meperidine and skin surface warming additively reduce the shivering threshold: a volunteer study
INTRODUCTION: Mild therapeutic hypothermia has been shown to improve outcome for patients after cardiac arrest and may be beneficial for ischaemic stroke and myocardial ischaemia patients. However, in the awake patient, even a small decrease of core temperature provokes vigorous autonomic reactions-vasoconstriction and shivering-which both inhibit efficient core cooling. Meperidine and skin warming each linearly lower vasoconstriction and shivering thresholds. We tested whether a combination of skin warming and a medium dose of meperidine additively would reduce the shivering threshold to below 34 degrees C without producing significant sedation or respiratory depression. METHODS: Eight healthy volunteers participated on four study days: (1) control, (2) skin warming (with forced air and warming mattress), (3) meperidine (target plasma level: 0.9 mug/ml), and (4) skin warming plus meperidine (target plasma level: 0.9 mug/ml). Volunteers were cooled with 4 degrees C cold Ringer lactate infused over a central venous catheter (rate asymptotically equal to 2.4 degrees C/hour core temperature drop). Shivering threshold was identified by an increase of oxygen consumption (+20% of baseline). Sedation was assessed with the Observer's Assessment of Alertness/Sedation scale. RESULTS: Control shivering threshold was 35.5 degrees C +/- 0.2 degrees C. Skin warming reduced the shivering threshold to 34.9 degrees C +/- 0.5 degrees C (p = 0.01). Meperidine reduced the shivering threshold to 34.2 degrees C +/- 0.3 degrees C (p < 0.01). The combination of meperidine and skin warming reduced the shivering threshold to 33.8 degrees C +/- 0.2 degrees C (p < 0.01). There were no synergistic or antagonistic effects of meperidine and skin warming (p = 0.59). Only very mild sedation occurred on meperidine days. CONCLUSION: A combination of meperidine and skin surface warming reduced the shivering threshold to 33.8 degrees C +/- 0.2 degrees C via an additive interaction and produced only very mild sedation and no respiratory toxicity
Synthesis, spectral analysis and pharmacological study of N'- substituted-2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazides
A series of molecules bearing multiple functional groups were synthesized to study their antibiotic effect against Gram-positive and Gram-negative bacteria and lipoxygenase activity as well. 2,4-Dimethylcarbolic acid (1) was refluxed with ethyl 2-bromoacetate to synthesize ethyl 2-(2,4-dimethylphenoxy)acetate (2). Compound 2 was converted to the corresponding hydrazide 3, again on refluxing with hydrazine. The compound 5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-thiol (4) was synthesized by the reaction of 3 and CS2 in the presence of KOH. Compound 4 was further converted to the corresponding ester 5 and then 2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazide (6). The final molecules N'-substituted-2-(5-((2,4-dimethylphenoxy)methyl)-1,3,4-oxadiazol-2-ylthio)acetohydrazide, 8a-m, bearing ether, 1,3,4-oxadiazole, thioether, hydrazone and azomethine functional groups were synthesized by stirring the aryl carboxaldehydes 7a-m with 6 in methanol at room temperature. The depicted structures of all synthesized molecules were corroborated by IR, 1H-NMR and EIMS spectral data analysis. 8m and 8i showed substantial antibacterial activity and lipoxygenase inhibitory activity, respectively
A contemplating review on different synthesis methods of 2D-Molybdenum disulfide (MoS2) nanosheets
The current challenges arising from the rapid development in science and technology attracted researchers to focus on the development of new advanced materials like two-dimensional (2D) nanomaterials, which offer exceptional features that can be used to resolve different industrial problems, which include enhancing energy storage and conversion systems, improving electronic and optoelectronic devices, advancing catalysis and sensing applications, enabling flexible and transparent electronics, advancing healthcare technologies, and addressing environmental concerns such as pollution monitoring and remediation. There are many different layered-structure materials on earth. To get the desired form of these materials, various scientific approaches are applied in laboratories and processing industries. As a result, different methods have been developed for the synthesis of 2D materials. Among various 2D materials, molybdenum disulfide (MoS2) is one of the emerging and promising transition metal dichalcogenides (TMDs) materials that has remarkable electrical, magnetic, optical, and mechanical characteristics. Furthermore, MoS2 nanosheets, when incorporated in different materials, produce promising results, such as better catalytic activities, improved hydrogen production, a super-capacitive feature, and enhanced battery performances, etc. Therefore, in this review, we have focused on significant and practical techniques for synthesizing 2D-MoS2 nanosheets developed by different researchers over the years. We comprehensively discuss their applications, characteristics, as well as provide a brief introduction to the physical and chemical properties of 2D MoS2 nanosheets. Furthermore, we address the current challenges associated with the synthesis of these nanosheets. These discussions highlights that the choice of synthesis method mainly relies on factors such as material type, resources, complexity, environmental impact, scalability, cost, and desired properties of 2D MoS2 nanosheets. Additionally, this literature review also outlines future research directions aimed at overcoming these challenges and advancing synthesis processes to enable the economically feasible scaled-up production of 2D MoS2 nanosheets
Machine learning model demonstrates stunting at birth and systemic inflammatory biomarkers as predictors of subsequent infant growth - A four-year prospective study
Background: Stunting affects up to one-third of the children in low-to-middle income countries (LMICs) and has been correlated with decline in cognitive capacity and vaccine immunogenicity. Early identification of infants at risk is critical for early intervention and prevention of morbidity. The aim of this study was to investigate patterns of growth in infants up through 48 months of age to assess whether the growth of infants with stunting eventually improved as well as the potential predictors of growth.Methods: Height-for-age z-scores (HAZ) of children from Matiari (rural site, Pakistan) at birth, 18 months, and 48 months were obtained. Results of serum-based biomarkers collected at 6 and 9 months were recorded. A descriptive analysis of the population was followed by assessment of growth predictors via traditional machine learning random forest models.Results: Of the 107 children who were followed up till 48 months of age, 51% were stunted (HAZ \u3c - 2) at birth which increased to 54% by 48 months of age. Stunting status for the majority of children at 48 months was found to be the same as at 18 months. Most children with large gains started off stunted or severely stunted, while all of those with notably large losses were not stunted at birth. Random forest models identified HAZ at birth as the most important feature in predicting HAZ at 18 months. Of the biomarkers, AGP (Alpha- 1-acid Glycoprotein), CRP (C-Reactive Protein), and IL1 (interleukin-1) were identified as strong subsequent growth predictors across both the classification and regressor models.Conclusion: We demonstrated that children most children with stunting at birth remained stunted at 48 months of age. Value was added for predicting growth outcomes with the use of traditional machine learning random forest models. HAZ at birth was found to be a strong predictor of subsequent growth in infants up through 48 months of age. Biomarkers of systemic inflammation, AGP, CRP, IL1, were also strong predictors of growth outcomes. These findings provide support for continued focus on interventions prenatally, at birth, and early infancy in children at risk for stunting who live in resource-constrained regions of the world
The performance of robust multivariate Ewma control charts
Multivariate Exponential Weighted Moving Average (MEWMA) control chart is a popular statistical tool for monitoring multivariate process over time. However, this chart is sensitive to the presence of outliers arising from the use of classical mean vector and covariance matrix in estimating the MEWMA statistic. These classical
estimators are known to be sensitive to the outliers. To address this problem, robust MEWMA control charts based on modified one-step M-estimator (MOM) and Winsorized modified one-step M-estimator (WM) are proposed. Their performance is then compared with the standard MEWMA control chart in various situations. The findings
revealed that the proposed robust MEWMA control charts are more effective in controlling false alarm rates especially for large sample sizes and high percentage of outlier
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