Characterization Studies of a GC based SAW Sensor System for Potential Detection and Identification of Toxic Environmental Gases/Vapors

The characterization of a custom-designed GC-based SAW e-Nose sensor system is presented here to study the sensing ability of the sensor system to detect and identify low medium and high toxic vapors. A semi-automated multi-vapor generator generates vapors of chemical compounds that are then exposed to the sensing system to examine its performance under various concentrations. Time-domain verses frequency response of GC-SAW Sensor is noted for repeated cycles against different chemical compounds like xylene, 1,2 dibromoethane, dimethyl sulfate, triethyl phosphate, nitrobenzene, phosphorous trichloride being tested. The generated data is examined using a principle component analysis (PCA) technique to detect a unique response for an individual chemical compound. Experimental results are reported.

Color Stability, Chemico-Physical and Optical Features of the Most Common PETG and PU Based Orthodontic Aligners for Clear Aligner Therapy

It is difficult to find research papers collecting comparative results about characterization studies of clear aligners. Therefore, the aim of this paper is to provide the first comparative analysis of most commercial clear aligners, in terms of their stability towards intra-oral staining agents, their physicochemical and optical properties, as well as their water absorption behavior. Five types of aligners, characterized by different techniques, are considered: Erkodur, Essix Plastic, Ghost Aligner, Zendura, and Invisalign. The obtained results show that clear aligners are made up of PETG, semi rigid PU, and a mixture of PU and PETG, with different degrees of crystallinity which affect the transparency of each aligner. In particular, the PETG-based materials reveal the highest value of short-range order and the highest properties in terms of transparency in the visible range. After 14 days of immersion into red wine and coffee, PETG and PU-based aligners reveal a perceivable change in color (NBS values from 1.5 to 3), corresponding to a loss of transparency due to the deposition of impurities on the surface. These results are particularly marked for Invisalign, showing changes towards other colors (NBS up to 35), probably due to the thermoforming process which led to the formation of a wrinkled surface entrapping the impurities.

Morphometric and morphological characterization of chicken resources adapted to pastoral and agropastoral areas of southern Ethiopia

Thirteen qualitative and six quantitative variables taken from 303 adult chickens (95 cocks and 208 hens) from three locations/districts were used to phenotypically characterize the indigenous chicken populations in pastoral areas of South Omo Zone, Ethiopia. The studied traits were influenced by the effect of location and sex, where chicken populations from Hamer district and females of all districts were the smallest and lightest. Qualitative characteristics of the studied chicken populations such as normal feather morphology and distribution, plain plumage pattern, flat head shape, triangular body shape, and dominant red eye, earlobe and plumage colour suggest that they constitute previously undescribed populations. Chest circumference, wingspan and body length were the three most important morphometric traits used in discriminating the studied chicken populations. On average, 61% of the sampled populations were classified correctly into their respective locations. The multivariate analysis results discriminate the chicken populations into two groups: the Hamer group and the Omo group (chickens from Bena Tsemay and Male districts). However, such grouping should be confirmed and advanced to ecotype level using further genetic characterization studies as the observed phenotypic differences might be due to genetic or environmental variations. Such confirmation is important to design breeding programmes (for sustainable utilization) specific to each ecotype.

PREPARATION, CHARACTERIZATION AND DISSOLUTION STUDY OF SPRAY DRIED SOLID DISPERSIONS OF SIMVASTATIN WITH PVP K25 AND AEROSIL 200

BCS class II is well-known for the drugs, having poor aqueous solubility and high permeability. Simvastatin is also categorized as BCS class II, suffering from poor aqueous solubility, affecting its bioavailability. In an attempt to resolve this problem, solid dispersions of simvastatin were prepared by spray-drying method. Solid dispersions of simvastatin with PVP K25 and aerosol in ratio (1:1:1 to 1:5:1) and without aerosil 200 (1:1 to 1:5) were prepared by spray drying method. The dissolution test showed the enhancement of dissolution as compared to the pure drug and nearly equal to marketed formulation “SIMVOTIN 20mg” in both types of formulation, but formulations with aerosil 200 showed faster drug release as compared to the simple formulations without aerosil. The formulation containing the 1:3:1 (simvastatin: PVP K25: Aerosil 200) showed the faster drug release as compared to other formulation that do not contain the Aerosil 200. Other characterization studies were also performed such as FTIR, differential scanning colorimetry and powdered X-ray crystallographic studies. These studies showed the increased amorphous nature of the drug in the formulation, which explain the enhanced dissolution rate of the drug for these formulations.

Charge Storage and Solar Rechargeable Battery Devices Based on Electrodes Electrochemically Modified with Conducting Polymer Nanowires

In this work, the use of nanostructured conducting polymer deposits on energy-storing devices is described. The cathode and the anode are electrochemically modified with nanowires of polypyrrole and poly(3,4-ethylenedioxythiophene), respectively, prepared after the use of a mesoporous silica template. The effect of aqueous or ionic liquid medium is assayed during battery characterization studies. The nanostructured device greatly surpasses the performance of the bulk configuration in terms of specific capacity, energy, and power. Moreover, compared with devices found in the literature with similar designs, the nanostructured device prepared here shows better battery characteristics, including cyclability. Finally, considering the semi-conducting properties of the components, the device was adapted to the design of a solar-rechargeable device by the inclusion of a titanium oxide layer and cis-bis(isothiocyanate)-bis(2,2′-bipyridyl-4,4′-dicarboxylate) ruthenium (II) dye. The device proved that the nanostructured design is also appropriate for the implementation of solar-rechargeable battery, although its performance still requires further optimization.

Rutin-Loaded Nanovesicles for Improved Stability and Enhanced Topical Efficacy of Natural Compound

Rutin is a natural compound with several pharmacological effects. Among these, antioxidant activity is one of the best known. Despite its numerous benefits, its topical application is severely limited by its physicochemical properties. For this reason, the use of suitable systems could be necessary to improve its delivery through skin, thus enhancing its pharmacological effects. In this regard, the aim of this work is to optimize the ethosomal dispersion modifying both lipid and ethanol concentrations and encapsulating different amounts of rutin. Characterization studies performed on the realized systems highlighted their great stability properties. Studies of encapsulation efficiency and loading degree allowed us to identify a better formulation (EE% 67.5 ± 5.2%, DL% 27 ± 1.7%), which was used for further analyses. The data recorded from in vitro studies showed that the encapsulation into these nanosystems allowed us to overcome the photosensitivity limitation of rutin. Indeed, a markable photostability of the loaded formulation was recorded, compared with that reported from the free rutin solution. The efficacy of the nanosystems was finally evaluated both in vitro on keratinocyte cells and in vivo on human healthy volunteers. The results confirmed the potentiality of rutin-loaded nanosystems for skin disease, mainly related to their anti-inflammatory and antioxidant effects.

Formulation and Evaluation of Metoprolol Controlled Release Formulations

Aim: The main perspective of the present research work was to prepare Metoprolol floating controlled release formulations. Methodology: After performing the characterization studies, Metoprolol tablets were prepared using various concentrations of poly ethylene oxide (PEO) WSR 303 (5% to 30%) by direct compression method. Formulations MP1 and MP6 were formulated using PEO WSR 303. Various pre and post compression parameters were evaluated. Dissolution studies were performed for the prepared tablets using dissolution medium of 0.1N hydrochloric acid. Results: Characterization studies like Fourier Transform Infra Red (FTIR) and Scanning Electron Microscopy (SEM) for Metoprolol, Polyethylene oxide WSR 303 and their combination were carried out, which revealed that there is no interaction between drug and polymer. The dissolution studies showed the controlled release pattern of Metoprolol up to 24h. The formulation MP5 prepared using 25% w/w of PEO WSR 303 showed maximum drug release of 98.22% at 24h. Similar drug release profile was observed for MP6 which was formulated using 30%w/w PEO WSR 303. These two formulations were further added with various concentrations of sodium bicarbonate (5% to 15%) and citric acid (2.5% to 10%) which enhanced floating of drug. Formulation MP8 containing 10% of sodium bicarbonate with 25% PEO WSR 303 showed less buoyancy lag time and prolonged drug release. Formulation MP15 showed very less buoyancy lag time of 4sec. Conclusion: Thus the prepared Metoprolol floating tablets showed prolonged drug release which could be a promising formulation for anti-hypertensive patients.

Synthesis, Characterization, and Application of Co-Al-Zn Layered Double Hydroxide/Hydrochar Composite for Simultaneous Removal of Cationic and Anionic Dyes

Decontamination of organic dyes from wastewater requires efficient and compatible materials that must be able to remove dyes with different charges at the same time. In this study, composites of layered double hydroxide (LDH) and hydrochar (HC) were prepared and tested for use as general-purpose sorbents for the simultaneous removal of cationic and anionic dyes (i.e., methylene blue (MB), methyl orange (MO), and reactive yellow (RY)). Characterization studies reveal that the surface functional groups on composites are –OH, NO3, M–O bonds. It was observed that crystallinity of LDH decreased with an increasing amount of HC. Preliminary experiments showed that the dyes (i.e., MB, MO, and RY) were well removed simultaneously onto the composite with HC (2.0 g HC/prepared composite). This composite was selected for more experiments, and the adsorption efficiency was optimized by the multivariate technique using the response surface methodology (RSM). Removal efficiency of 100% was obtained for all three dyes with an adsorption capacity of 243, 5.3, and 16.3 µmol g−1 for MB, MO, and RY, respectively. Elovich’s initial intake rates (α) were 4,272, 441, and 99.5 mg g−1 min−1 for RY, MB, and MO, respectively. Data fitted in various models suggested second-order multiplex kinetics, where the surface heterogeneity response was sorbate dependent.