Phase equilibrium studies of or anometallic chelates for analytical application

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VALIDATION OF A BIOANALYTICAL REVERSE-PHASE HIGH-PERFORMANCE LIQUID CHROMATOGRAPHIC METHOD FOR THE QUANTITATION OF NYSTATIN IN AN ANIMAL MODEL AFTER INTRANASAL IN SITU GEL ADMINISTRATION

Objective: The aim of the study was to develop and validate a bioanalytical reverse-phase high-performance liquid chromatographic (HPLC) method for the estimation of nystatin in rat plasma after intranasal administration. Methods: The reversed-phase HPLC system was equipped with a Luna C18 column, the mobile system comprised of methanol, water, and dimethylformamide (55:30:15) and the flow rate was set at 0.9 ml/min. Results: The elution time for nystatin was 4.096±0.025 min. The calibration curves constructed in rat plasma were linear from 0.25 to 50 μg/ml. The lower limit of quantification (LOQ) was found to be 0.25 μg/ml. The standards for accuracy and precision of the intra- and inter-day variation studies were in the acceptable ranges as per the FDA guidelines. Conclusion: The LOQ value determined by the proposed method was noted to be satisfactory for inspecting the plasma pharmacokinetics of nystatin in rats’ post-administration of a nasal in situ gelling liquid crystalline precursor formulation in an in vivo study

Quantum Cyber-Attack on Blockchain-based VANET

Blockchain-based Vehicular Ad-hoc Network (VANET) is widely considered as secure communication architecture for a connected transportation system. With the advent of quantum computing, there are concerns regarding the vulnerability of this architecture against cyber-attacks. In this study, a potential threat is investigated in a blockchain-based VANET, and a corresponding quantum cyber-attack is developed. Specifically, a quantum impersonation attack using Quantum-Shor algorithm is developed to break the Rivest-Shamir-Adleman (RSA) encrypted digital signatures of VANET and thus create a threat for the trust-based blockchain scheme of VANET. A blockchain-based VANET, vehicle-to-everything (V2X) communication, and vehicular mobility are simulated using OMNET++, the extended INET library, and vehicles-in-network simulation (VEINS) along with simulation of urban mobility (SUMO), respectively. A small key RSA based message encryption is implemented using IBM Qiskit, which is an open-source quantum software development kit. The findings reveal that the quantum cyber-attack, example, impersonation attack is able to successfully break the trust chain of a blockchain-based VANET. This highlights the need for a quantum secured blockchain.Comment: This paper consists of 10 pages with 7 figures. It has been submitted to IEEE Internet of Things Journa

“MEMORY STRESS”: physical and mathematical modelling of the influence of water-working on sediment entrainment and transport

Recent research has indicated that variability of antecedent flows is a fundamental control on the entrainment and transport of sediment in river systems. Specifically, the low flows between successive floods appear to have a far greater influence on the stability of a river bed than previously assumed. Increased durations of low flows increase sand-gravel bed stability so as to delay entrainment and significantly reduce transport. Although a degree of quantification of “memory stress” effects has been attempted by previous researchers, their applied methodology precludes development of appropriate mathematical relationships implicit to correcting existing sediment transport equations. The overall aim of this thesis is therefore to address this deficiency via robust physical and mathematical modelling. In total, 84 flume experiments were carried out in a flume. Two poorly sorted (g ≥1.6) sand-gravel mixtures of unimodal and bimodal distribution were compared and contrasted for sensitivity of modality to memory effects upon bedload and entrainment threshold. Five memory timescales (10, 30, 60, 120 and 240 minutes) were tested and contrasted with baseline data obtained for runs performed without any memory. Experiments employed a stepped discharge hydrograph covering sub-threshold to fully mobile conditions. A reference transport based approach was employed to determine entrainment threshold, and to develop mathematical descriptors of memory effects. Results show that increasing memory timescales up to 240 minutes increases entrainment thresholds ( ) by up to 49% whilst subsequent transport decreases by up to 97%. The memory effect prevails non-linearly for the range of low flows of non-dimensional transport between 10-6 to 10-1. Using these flume data, novel mathematical functions for bedload are developed to account for the influence of memory timescales. Here, memory is described via rising exponents of the function to quantify degree of non-linearity of transport to shear stress, and changes in the structure of the bed due to memory are represented within a lumped coefficient. Trends in the suite of exponents and coefficients indicate that changes in bed structure are of greater importance than the shift in non-linearity of bedload. Hence, the first framework for correcting existing graded sediment formulae for memory stress has been effectively developed using a scaling of the granular scale roughness parameter, An. Predicted results are calibrated and validated against available memory stress datasets from both field and laboratory based studies. Results show that without memory correction, over 80% of estimates fail to predict measured bedload effectively; once An based correction is applied, 100% of data are predicted effectively

Interaction between zinc, cadmium, and lead in scalp hair samples of Pakistani and Irish smokers rheumatoid arthritis subjects in relation to controls

The incidence of rheumatoid arthritis (RA) has been associated with cigarette smoking. The aim of our study was to assess the trace essential and toxic metals, cadmium (Cd), lead (Pb), and zinc (Zn), in scalp hair samples of 32 Irish and 46 Pakistani smokers and non-smokers RA male patients with age range 42-56 years. For comparison purpose, the scalp hair samples of 27 Irish and 55 Pakistani non-RA male subjects of the same age group were collected. The concentrations of trace and toxic elements were measured by inductive coupled plasma atomic emission spectrophotometer and atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using certified reference materials and using conventional wet acid digestion method on the same certified reference materials (CRMs). The recovery of all studied elements was found to be in the range of 97.5-99.7% of certified reference values of CRMs. The results of this study showed that the mean values of Cd and Pb were significantly higher in scalp hair samples of both smoker and non-smoker RA patients than in referents (P < 0.001), whereas the concentration of Zn was lower in the scalp hair samples of smokers and non-smokers rheumatoid arthritis patients. The deficiency of Zn and the high exposure of Cd and Pb as a result of cigarette smoking may be synergistic risk factors associated with rheumatoid arthritis

Comparative metal distribution in scalp hair of Pakistani and Irish referents and diabetes mellitus patients

Background: The essential metals, chromium (Cr), magnesium (Mg), manganese (Mn) and zinc (Zn), are necessary for many metabolic processes and their homeostasis is crucial for life. The toxic metals, cadmium (Cd) and lead (Pb), have no beneficial role in human metabolism. The aim of this study was to investigate the levels of Cd, Cr, Mg, Mn, Pb, and Zn in scalp hair samples of type 2 diabetes mellitus patients of both genders, ages ranging from 30 to 50 y, and belong to urban areas of Ireland and Pakistan. For comparison purposes, age matched non-diabetic subjects of both countries were selected as referents. Methods: The concentrations of metals in scalp hair samples were measured by inductively coupled plasma atomic emission spectrophotometer and atomic absorption spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked by conventional wet-acid-digestion method and using certified reference materials. Results: The mean values of Cd and Pb were significantly higher in scalp hair samples of both Pakistani and Irish diabetic patients as compared to referents of both countries (P<0.001). In contrast, lower Cr, Mg, Mn, and Zn (P<0.01) concentrations were detected in scalp hair derived from patients with type 2 diabetes versus healthy subjects of both countries. Conclusion: This study showed that, increased toxic elements and decreased essential elements are associated with diabetes mellitus. Therefore, these elements may play a role in the development and pathogenesis of diabetes mellitus

Interaction between essential trace and toxic elements in the scalp hair samples of smokers and alcohol user diabetics

In the present study, trace and toxic elements were determined in the Scalp Hair (SH) samples of patients diagnosed with diabetes mellitus (DM) who were smokers and habitual alcohol drinkers living in Dublin, Ireland. The concentrations of elements were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology was checked using Certified Reference Material (CRM) (NCS ZC 81002b) and by the conventional wet acid digestion method on the same CRM. The results of this study showed that the mean values of cadmium, copper, iron, nickel and lead were significantly higher (P<0.001), in scalp hair samples of diabetic patients as compared to referents of both gender. While the smokers and alcohol drinker referents and DM patients have two to three time higher values of these elements than those subjects who were not smokers and teetotallers. The concentrations of zinc, chromium and manganese were lower in the scalp hair samples of diabetic patients as compared to referents. The deficiency of zinc, chromium and manganese, while the high exposure of cadmium, lead and nickel, as a result of cigarette smoking and alcohol consumption, may be synergistic with risk factors associated with diabetes

Evaluation of essential trace and toxic elements in scalp hair samples of smokers and alcohol user hypertensive patients

The incidence of hypertension has been associated to cigarette smoking and consumption of alcohol. In the present study, trace and toxic elements were determined in scalp hair of patients diagnosed with hypertension who are smokers and habitual alcohol drinkers living in Dublin, Ireland. These results were compared with age- and sex-matched healthy, nonsmokers, nondrinking controls. The concentrations of trace and toxic elements were measured by inductively coupled plasma atomic emission spectrophotometer after microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference material (NCS ZC 81002b) and by the conventional wet acid digestion method on the same certified reference material and on real samples. The recovery of all the studied elements was found to be in the range of 97.5%–99.7% in certified reference material. The results of this study showed that the mean values of cadmium, copper, iron, nickel and lead were significantly higher in scalp hair samples of both smoker and nonsmoker hypertensive patients than referents (P < 0.001); whereas, the concentration of zinc was lower in the scalp hair samples of hypertensive patients of both genders. The deficiency of zinc and the high exposure of trace and toxic metals as a result of cigarette smoking and alcohol consumption may be synergistic with risk factors associated with hypertension