Nanomaterials‐based Electrochemical Sensing of Cardiac Biomarkers for Acute Myocardial Infarction: Recent Progress

The development of the methods for early and accurate diagnosis of acute myocardial infarction are needed to facilitate immediate treatment of patients. One of the ways to achieve that is the detection of cardiac biomarkers for myocardial infarction, such as thrombin, cardiac troponins (I and T), myoglobin, etc. Nanotechnology has played an important role in the development of sensitive and efficient electrochemical sensors for cardiac biomarkers. In this review, we discuss recent progress on nanomaterial‐based electrochemical sensing of various cardiac biomarkers for acute myocardial infarction.     

Contrast source inversion methods in elastodynamics

In this paper a nonlinear inversion method is presented for determining the mass density of an elastic inclusion from the knowledge of how the inclusion scatters known incident elastic waves. The algorithm employed is an extension of the multiplicative regularized contrast source inversion method (MR-CSI) to elasticity. This method involves alternate determination of the mass density contrast and the contrast sources (the product of the contrast and the fields) in each iterative step. The simple updating schemes of the method allow the introduction of an extra regularization term to the cost functional as a multiplicative constraint. This so-called MR-CSI method (MR-CSI) has been proven to be very effective for the acoustic and electromagnetic inverse scattering problems. Numerical examples demonstrate that the MR-CSI method shows excellent edge preserving properties by robustly handling noisy data very well, even for more complicated elastodynamic problems.     

Magnetoelastic vibration of a plate

Summary The propagation of plane harmonic waves in a thin flat homogeneous isotropic plate of finite width and infinite length permeated by a constant magnetic field is examined. The frequency equations corresponding to the symmetric and antisymmetric modes of vibration of the plate are obtained, and some limiting cases of the frequency equations are then discussed.     

The Personality of O.R. Workers—Are They Different?

This paper is a preliminary attempt to compare the personality of O.R. workers with research scientists and other professionals in the management area. It is based on 16PF personality tests carried out on 56 U.K. operational research workers. The results indicate that this group has a personality profile which is significantly different from the published profiles of the professional groupings. It is believed that the results are highly indicative and justify further research.     

Kinetic analysis of dehydroxylation of Ethiopian kaolinite during calcination

Journal of Thermal Analysis and Calorimetry - The calcination process is the dehydroxylation reaction of the kaolinite mineral into the formation of amorphous metakaolinite phase. The...     

Health and ecological hazards due to natural radioactivity in soil from mining areas of Nasarawa State,Nigeria

Nasarawa State is located in north central Nigeria and it is known as Nigeria's home of solid minerals. It is endowed with barite, copper, zinc, tantalite and granite. Continuous releases of mining waste and tailings into the biosphere may result in a build-up of radionuclides in air, water and soil. This work therefore aims to measure the activity concentration levels of primordial radionuclides in the soil/sediment samples collected from selected mines of the mining areas of Nasarawa State. The paper also assesses the radiological and radio ecological impacts of mining activities on the residents of mining areas and their environment. The activity concentrations of primordial radionuclides (²²⁶Ra, ²³²Th and ⁴⁰K) in the surface soils/sediment samples were determined using sodium iodide-thallium gamma spectroscopy. Seven major mines were considered with 21 samples taken from each of the mines for radiochemistry analysis. The human health hazard assessment was conducted using regulatory methodologies set by the United Nations Scientific Committee on the Effects of Atomic Radiation, while the radio ecological impact assessment was conducted using the ERICA tool v. 1.2. The result shows that the activity concentrations of ⁴⁰K in the water ways of the Akiri copper and the Azara barite mines are 60 and 67?% higher than the world average value for ⁴⁰K, respectively. In all mines, the annual effective dose rates (mSv y^?1) were less than unity, and a maximum annual gonadal dose of 0.58 mSv y^?1 is received at the Akiri copper mine, which is almost twice the world average value for gonadal dose. The external hazard indices for all the mines were less than unity. Our results also show that mollusc-gastropod, insect larvae, mollusc-bivalve and zooplankton are the freshwater biotas with the highest dose rates ranging from 5 to 7 µGy h^?1. These higher dose rates could be associated with zinc and copper mining at Abuni and Akiri, respectively. The most exposed terrestrial reference organisms are lichen and bryophytes. In all cases, the radio ecological risks are not likely to be discernible. This paper presents a pioneer data for ecological risk from ionizing contaminants due to mining activity in Nasarawa State, Nigeria. Its methodology could be adopted for future work on radioecology of mining.     

Assignment of E–Z-configurations of spiro-oxirane-oxindoles synthesized by rhodium(II) acetate-catalyzed reaction of ethyl diazoacetate with N-methylisatin

The rhodium(II) acetate [Rh₂(OAc₄)]-catalyzed reaction of ethyl diazoacetate with N-methylisatin leads to the formation of diastereomeric oxiranes spiro-fused to N-methyl-2-oxindole together with 1,3-dioxolane bis-spiro-fused to N-methyl-2-oxindole. The formation of ylide from the reaction of rhodium-carbenoid with C-3 carbonyl group of the N-methylisatin undergoing a 1,3-cyclization, and a [3 + 2]-dipolar cycloaddition with another molecule of N-methylisatin, respectively, explains the formation of products. The application of nuclear overhauser effect spectroscopy to determine the E–Z-configurations of the spiro-oxirane-oxindoles is demonstrated.     

Assessment of health hazard due to natural radioactivity in Kluang District,Johor, Malaysia

The radiation survey of the ambient environment was conducted using two gamma detectors, and the measurement results were used in the computation of the mean external radiation dose rate, mean-weighted dose rate and annual effective dose, which are 144 nGy h^?1, 0.891 mSv y^?1 and 178 μSv, respectively. A high-purity germanium detector was used to determine the activity concentrations of ²³²Th, ²²⁶Ra and ⁴⁰K in soil samples. The results of the gamma spectrometry of the soil samples show radioactivity concentration ranges from 19±1 to 405±13 Bq kg^?1 with a mean value of 137±5 Bq kg^?1 for ²³²Th, from 21±2 to 268±9 Bq kg^?1with a mean value of 78±3 Bq kg^?1 for ²²⁶Ra and from 23±9 to 1268±58 Bq kg^?1 with a mean value of 207±13 Bq kg^?1 for ⁴⁰K. Radium equivalent activity (Ra_eq) and external hazard index (H_ex) were 290 Bq kg^?1 and 0.784, respectively, which were safe for the population. The mean lifetime dose and lifetime cancer risk for each person living in the area with average lifetime (70 y) were 12.46 mSv and 7.25×10^?4 Sv year, respectively. The results were compared with values given in United Nations Scientific Committee on the Effects of Atomic Radiation 2000.     

Ginger Essential Oils-Loaded Nanoemulsions: Potential Strategy to Manage Bacterial Leaf Blight Disease and Enhanced Rice Yield

The bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is one of the most serious rice diseases, causing huge yield losses worldwide. Several technologies and approaches have been opted to reduce the damage; however, these have had limited success. Recently, scientists have been focusing their efforts on developing efficient and environmentally friendly nanobactericides for controlling bacterial diseases in rice fields. In the present study, a scanning electron microscope (SEM), transmission electron microscope (TEM), and a confocal laser scanning microscope (CLSM) were utilized to investigate the mode of actions of ginger EOs on the cell structure of Xoo. The ginger EOs caused the cells to grow abnormally, resulting in an irregular form with hollow layers, whereas the dimethylsulfoxide (DMSO) treatment showed a typical rod shape for the Xoo cell. Ginger EOs restricted the growth and production of biofilms by reducing the number of biofilms generated as indicated by CLSM. Due to the instability, poor solubility, and durability of ginger EOs, a nanoemulsions approach was used, and a glasshouse trial was performed to assess their efficacy on BLB disease control. The in vitro antibacterial activity of the developed nanobactericides was promising at different concentration (50–125 µL/mL) tested. The efficacy was concentration-dependent. There was significant antibacterial activity recorded at higher concentrations. A glasshouse trial revealed that developed nanobactericides managed to suppress BLB disease severity effectively. Treatment at a concentration of 125 μL/mL was the best based on the suppression of disease severity index, AUDPC value, disease reduction (DR), and protection index (PI). Furthermore, findings on plant growth, physiological features, and yield parameters were significantly enhanced compared to the positive control treatment. In conclusion, the results indicated that ginger essential oils loaded-nanoemulsions are a promising alternative to synthetic antibiotics in suppressing Xoo growth, regulating the BLB disease, and enhancing rice yield under a glasshouse trial.     

Counterflow ignition and extinction of FACE gasoline fuels

The demand for petroleum-derived gasoline in the transportation sector is on the rise. For better knowledge of gasoline combustion in practical combustion systems, this study presents experimental measurements and numerical prediction of autoignition temperatures and extinction limits of six FACE (fuels for advanced combustion engines) gasoline fuels in counterflow flames. Extinction limits were measured at atmospheric pressures while the experiments for autoignition temperatures were carried out at atmospheric and high pressures. For atmospheric pressure experiment, the fuel stream consists of the pre-vaporized fuel diluted with nitrogen, while a condensed fuel configuration is used for ignition experiment at higher chamber pressures. The oxidizer stream is pure air. Autoignition temperatures of the tested fuels are nearly the same at atmospheric pressure, while a huge difference is observed as the pressure is increased. Unlike the ignition temperatures at atmospheric pressures, minor difference exists in the extinction limits of the tested fuels. Simulations were carried out using a recently developed gasoline surrogate model. Both multi-component and n-heptane/isooctane mixtures were used as surrogates for the simulations. Overall, the n-heptane/isooctane surrogate mixtures are consistently more reactive as compared the multi-component surrogate mixtures. Transport weighted enthalpy and radical index analysis was used to explain the differences in extinction strain rates for the various fuels.