Due to the challenges of maintaining serum levels in a safe therapeutic range (1–3 μM), Clozapine is one of the most promising medications for managing schizophrenia. Recently the barrier to the broader use of clozapine has been recognized to be the measurement of clozapine levels, which is however challenging due to the complexity of serum samples. The determination of clozapine is mainly conducted through a novel, simple, rapid and sensitive air assisted dispersive liquid-liquid microextraction based on solidification of organic droplet method that has been developed and validated by high-performance liquid chromatography with UV detection in human serum. In this method, due to the usage of an organic solvent with a low density and appropriate melting point, no microsyringe or ﬁber is required to support the organic microdrop. Furthermore, the extractant droplet can be collected easily by solidifying it at low temperature. 1-Undecanol was selected as extraction. The optimization of Parameters that inﬂuence extraction efﬁciency, i.e., volumes of extracting solvent, pH, and salt effect, were performed using a factor by factor approach. Enrichment factor for clozapine under optimal conditions was 128. The limit of detection was 1.34 ng/mL in serum sample. The proposed method was successfully applied to the determination of clozapine in serum samples of a person under clozapine therapy.
This study was conducted to apply the Atume’s series in the absolute prediction of melting and freezing points of a wide range of saturated liquid and solid hydrocarbons. The calculated results that were obtained, shows that a range of 92% to 99% accuracy was theoretically achieved when compared to experimental results. Basically, precise interpolations were deployed by equating the energies released by frozen liquid molecules to the energies absorbed by their corresponding boiling molecules; which represents their lower and upper energy fixed points respectively. These two fixed points were also found to vary infinitesimally and inversely to each other. The energies absorbed or released, molar masses, and trigonometric properties formed the basis for this method. In branched chain hydrocarbons, the melting points of their corresponding linear molecules were also used as reference points to determine their melting and freezing points; indicating the mathematical relationships between their fixed points and trigonometric properties.
In this study, a bacterial detection technique utilizing benefits of both positive and negative dielectrophoresis has been simulated with COMSOL Multiphysics. The two dimensional proposed model has six microelectrodes across microfluidic channel. Four of them were positioned on the upper side and the rest were positioned on the bottom side of the microchannel, which serve as a bacteria concentrator using negative dielectrophoresis and as a bacteria detector using positive dielectrophoresis, respectively. In this simulation, the target particle is Escherichia coli that was flowing into the microchannel and repelled under negative dielectrophoretic force exerted by the upper side microelectrodes, and were pushed toward the bottom side microelectrodes situated at the downstream. Finally, concentrated bacteria have been captured and detected by dielectrophoretic impedance measurement method. The numerical simulation proved that negative dielectrophoretic force could increase sensitivity with respect to the absence of the negative dielectrophoretic force and eventually, results represented that 80 percent of releasing E. coli bacteria trapped near bottom side microelectrodes.
A novel method developed for the synthesis of resol based phenol-aniline-formaldehyde (PAF) resins by in situ generation of ammonia using magnesium hydroxide and ammonium chloride as reagents in the presence of phenol, aniline and formaldehyde. The synthesized PAF resol resins were characterized by IR, NMR spectroscopic methods, thermal stability by thermogravimetric analysis (TGA) and thermal properties by differential scanning colorimerty (DSC). Free phenol and free aniline of PAF resins were determined using gas chromatography and also these resins characterized for elemental analysis, inherent viscosity, molecular weight and gel time. DSC results illustrated that the glass transition temperatures of PAF resins exhibited in the range of 72-110 °C, whereas TGA results depicted that the thermal stability of the PAF resins revealed in the range of 516-548 °C. In situ generation of ammonia showed higher thermal stability and lower content of free phenol and free aniline in PAF resin.
The present paper focuses on a unique, optimized process of completely dissolving rhodium that can be employed on a large scale. Dissolution of rhodium has always been a challenging aspect of rhodium metallurgy due to its poor solubility even in mineral acids under ordinary conditions. In this paper, we present a means of achieving complete dissolution of rhodium powder in aqua regia using an experimentally optimized set of process parameters including solvent volume, temperature and heating time. The result is a solution in which the rhodium is completely dissolved which is confirmed by using optical microscopy at 50x magnification. Further, through the outcome of the experiments, it is concluded that it is possible to qualitatively ascertain the extent of rhodium content in the powder by observing the color of the solution. Comparison is also carried out with results obtained from dissolution experiments employing non-optimized process parameters in aqua regia as solvent.
In this study, the processes led to the production of gasoline and reactions resulting in increasing the octane number in the catalytic conversion unit with continuous resuscitation has been described first then simulated with Petrochem software. Considering all the research and investigations, the best recommended values of operational variables for producing high quality gasoline at nominal capacity has been achieved to account for temperature 525 degrees centigrade in the reactors input, flow rate of 22 tons per hour with 93% hydrogen purity, pressure 5.5 relative bar of the circulating gas compressor output, concentration of 0.9 percent weight of catalyst chloride, Naphtha hydrogen purification unit which resulted in the production of 25630 gasoline barrels per day and 0.37 volume percent benzene that the mass efficiency of the catalytic converter.
Bangladesh is a riverine country where arsenic bearing silt and sediments coming from Himalayas via different rivers (the Padma, Jamuna and Meghna) gets deposited in the groundwater aquifers at different locations of Bangladesh. Groundwater is the most dependent form of sources for drinking in this area, unfortunately arsenic is of extensive amount (more than 50 ppb) found in this groundwater. Fourteen water samples from different depth of tube well, 8 soil samples from topsoil (15 cm) and subsurface (30 cm) and 7 different types of food materials were collected from Alampur Village, Amjhupi Union at Megerpur district. Water samples are preserved by HNO3 for maintaining pH (2-3).Food and food materials were digested with HNO3- H2SO4 in order to determine the arsenic by Ag-DDTC, UV-visible method. The arsenic of tubewell water was beyond the Bangladesh acceptable limit and arsenic in food materials were with the limit of Australian food hygiene limit (1 mg /kg). Concentration of arsenic in topsoil (15 cm) was higher than arsenic in the subsurface (30 cm). The values of arsenic in food materials was lower, which indicated that arsenic from tubewell water is adsorbed in soil but not to propagate food materials. It might be due to the type of soil.
Biological application of nanoparticles (NPs) is a rapidly developing area of nanotechnology, providing new possibilities in the diagnosis and treatment of human diseases. Nowadays, NPs have shown abilities to be used as alternative treatment for difficult diseases. Therefore, it is important to understand NP chemistry, preparation, interaction and possible mechanisms involved in its interaction with cancer cells and bacterial membranes. This study reports comparison between Au, Ag and ZnO NPs, and discusses their toxicity and physicochemical properties. In addition, this work aims to review different strategies of surface modification and functionalization of colloidal nanoparticles.
Rice is a major diet and staple food in Iran. The most common organophosphorus pesticide used in rice paddies of this area is diazinon. The objective of this research is to determine the concentration of diazinon in soil and rice grains and specify health risk assessment of diazinon in rice when marketed. 30 mixed samples were collected from paddies. High Performance Liquid Chromatography was used to distinguish diazinon pesticide in soil and rice. The results show that diazinon was detected in 96.66 percent of the total samples. The average level of this diazinon in rice was 0.4±0.43 (mg/kg-1) three months after harvesting. There was a significant correlation between diazinon concentration of rice grains in all samples (P0.05). Also, the average level of diazinon in soil was 0.132±0.092 (mg/kg-1). There was no significant difference between the average diazinon concentration in the soil of five zones (P0.05). The result indicates that this amount is higher than the MRLs allowed by the European Union and Iran. Target Hazard Quotient was applied to assess human health risk for adults, women and children. Although estimated THQ for all target population is less than 1 that can be a slight non-carcinogen health risk for human.
Crops, soil and fish from irrigation farms were investigated in the Upper East Region of Ghana. Questionnaire was administered to collect pesticide use information from farmers, and tomatoes, okro, pepper and garden eggs as well as fish and soil samples were collected and analysed using Gas Chromatography-Electron Capture Detector (GC-ECD). The results were compared with standard acceptable Maximum Residue Limits (MRLs). The results indicated that up to 35.9% of 50 respondent farmers frequently cultivated tomatoes. 50% of the farmers have been using agrochemicals for the past 5 years, with glyphosphate as the most commonly used (42%). 65 % of the farmers indicated that information on proper use or handling of agrochemicals was obtained from colleague farmers. High levels of organochlorine residues (2.232-5.112 ng/g) were found in okro and garden eggs from the Tono site, and also pepper and tomatoes from Pungu site. 6 pesticides residues were found in 5 varieties of tomatoes samples analysed with Lindane and Aldrin having the highest concentration of 0.00069 and 0.027 μg/g respectively. 4 soil samples contained detectable levels of β-HCH and α-Endosulfan (organochlorines), while all 6 samples had one or more traces of 10 organophosphate pesticides. Chlorpyrifos was widely available and in quite high levels. 21 organochlorine residues were detected in tilapia and mud fishes, 17 in fishes from the Precast yard water. Residual concentration of Aldrin and Cis-heptachlor (1069.7 ng/g and 780.7 ng/g respectively) in tilapia from the Tono dam was noted to be above the acceptable limits.