Precise Sn-Doping Modulation for Optimizing CdWO4 Nanorod Photoluminescence.

The cadmium tungstate rods have been given much attention due to their potential for usage in numerous luminescent applications. We have prepared single crystalline Sn-doped Cd1-xSnxWO4 (where x = 0, 1, 3, and 5%) nanorods (NRDs) and characterized them using refined X-ray diffraction and TEM analysis, revealing a monoclinic phase and a crystallite size that decreased from 62 to 38 nm as Sn concentration increased. Precise Sn doping modulation in CdWO4 NRDs causes surface recombination of electrons and holes, which causes the PL intensity to decrease as the Sn content rises. The chromaticity diagram shows that an increase in the Sn content caused a change in the emission color from sky blue to light green, which was attributed to the increased defect density. The photoluminescence time decay curve of all samples fit well with double-order exponential decay, and the average decay lifetime was found to be 1.11, 0.93, and 1.16 ns for Cd1-xSnxWO4, x = 0, 1, and 5%, respectively. This work provides an understanding of the behavior of Sn-doped CdWO4 NRDs during electron transitions and the physical nature of emission that could be used in bio-imaging, light sources, displays, and other applications.

One-pot hydrothermal preparation and defect-enhanced photocatalytic activity of Bi-doped CdWO4 nanostructures.

In the field of photocatalysis, the suppression of electron-hole recombination through various defects has been an emerging trend to enhance photocatalytic activity. The separation efficiency of electron-hole recombination of well-explored wolframite structured monoclinic CdWO4, prepared using the one-pot hydrothermal method, was further improved by Bi3+ doping in CdWO4. Studies using the partial density of states illustrated that Bi 6s and 6p orbitals altered the electronic band structure to the extent of lowering the band gap, resulting in more photon absorption. The positron annihilation lifetime studies unveiled the formation of cluster defects such as oxygen (V0o, Vo1+, Vo2+) along with cadmium vacancies () in Bi-doped CdWO4. The coexistence and synergy of more adsorption sites of V0o, Vo1+, Vo2+, VCd for dye and O2 molecules, suitable oxide/redox band potentials, the modified electronic band structure especially owing to W-O1-Bi-O2-W linkages, together with high surface area endowed Bi-doped CdWO4 to form ˙O2- radicals played a predominant role in the methyl orange degradation. All the experimental findings demonstrated conclusively that Bi3+ doping at Cd2+ facilitated CdWO4 to exhibit superior photocatalytic activity.

Assessment of Sea Sickness in Naval Personnel: Incidence and Management.

BACKGROUND: Strategic, operational and tactical superiority of Navy hinges on extremely efficient warships which in turn depend on professionally competent sailors ready to undertake tasks to deliver timely, structured and metered response. Ships and their potentialities are tools to achieve the required strategic advantage which is dependent on the proficiency of sailors. Sailors who are fit ashore may be debilitated on board because of sea sickness. AIMS: To study the incidence and severity of sea sickness among 500 naval personnel from various ships. Setting and design: An observational study conducted from May 2019 to March 2020 among 500 naval personnel from various ships of the fleet. MATERIALS AND METHODS: Motion Sickness Assessment Questionnaire (MSAQ) was used to collect data from personnel of different departments working in different part of ship aged between 20 to 50 years. RESULTS: The majority suffered mild symptoms (78.78%) and did not require any medication. Their symptoms were selflimiting and settled on rest within 24 hours. Moderately severe symptoms were observed among 19.31 % personnel and had to be administered medication and rest for 24 hours. Only 1.91% had severe symptoms and had to be excused from duties along with medication and rest. CONCLUSION: Sea sickness is unpleasant and has an adverse effect on employability of the sailors. It is mild and self limiting in majority of the personnel not requiring active intervention. Some personnel may require desensitisation along with pharmacotherapy.

Room Temperature Magnetic Memory Effect in Cluster-Glassy Fe-doped NiO Nanoparticles.

The Fe-doped NiO nanoparticles that were synthesized using a co-precipitation method are characterized by enhanced room-temperature ferromagnetic property evident from magnetic measurements. Neutron powder diffraction experiments suggested an increment of the magnetic moment of 3d ions in the nanoparticles as a function of Fe-concentration. The temperature, time, and field-dependent magnetization measurements show that the effect of Fe-doping in NiO has enhanced the intraparticle interactions due to formed defect clusters. The intraparticle interactions are proposed to bring additional magnetic anisotropy energy barriers that affect the overall magnetic moment relaxation process and emerging as room temperature magnetic memory. The outcome of this study is attractive for the future development of the room temperature ferromagnetic oxide system to facilitate the integration of spintronic devices and understanding of their fundamental physics.

In Situ FTIR Spectroscopic Monitoring of the Formation of the Arene Diazonium Salts and its Applications to the Heck-Matsuda Reaction.

This study depicts the use of a fiber-optic coupled Fourier transform infrared spectroscopy-attenuated total reflection (FTIR-ATR) probe for the in-depth study of arene diazonium salt formation and their utilization in the Heck-Matsuda reaction. The combination of these chemical reactions and in situ IR spectroscopy enabled us to recognize the optimum parameters for arene diazonium salt formation and to track the concentrations of reactants, products and intermediates under actual reaction conditions without time consuming HPLC analysis and the necessity of collecting the sample amid the reaction. Overall advantages of the proposed methodology include precise reaction times as well as identification of keto enol tautomerization in allylic alcohols supporting the 'path a' elimination mechanism in the Heck-Matsuda reaction.

Design, synthesis, and antimicrobial screening of novel pyridyl-2-amidrazone incorporated isatin mannich bases.

Isatin is an endogenous compound and reported to possess a wide range of biological activities. Numerous papers have shown that the pyridyl-2-amidrazone nucleus possesses a potent antimicrobial activity. Based on these prior observations, we postulated that a compound containing both isatin and pyridyl-2-amidrazone pharmacophores could be very effective for antimicrobial activity. Unfavorable adsorption, distribution, metabolism, and excretion (ADME) properties can in many cases lead to the clinical trials failure of potentially successful drug candidates. Their evaluation, therefore, at an earlier stage is desired. Here, we also present the predicted ADME properties of our ligands through computation. All the compounds (2a(1-5)) exhibited a better solubility, diffusion, Log P, molecular weight, etc., with no violations making the ligands pharmacodynamically active and better oral absorptive series. Based on the results of computational design, a series of novel pyridyl-2-amidrazone-incorporated isatin Mannich bases were synthesized and screened for their antimicrobial activities. IR, (1)H-NMR, and Mass Spectroscopy data were consistent with the assigned structures. The results exhibited that all of the lead compounds showed good antimicrobial activities; noticeably, the compound 2a(2) showed the best activity against Candida albicans (16 µg/ml) and compound 2a(3) was found to be the most active derivative against Staphylococcus aureus and Escherichia coli at minimal inhibitory concentration values of 4 and 32 µg/ml, respectively.

Achiral bis-imine in combination with CoCl2: A remarkable effect on enantioselectivity of lipase-mediated acetylation of racemic secondary alcohol.

A bis-imine (prepared via a new FeCl3-based method) in combination with CoCl2 facilitated lipase-mediated acetylation of the (R)-isomer of a racemic benzylic secondary alcohol with 91% ee(s). The methodology was used for the preparation of the known drug rivastigmine.

Formulation and evaluation of bioadhesive buccal drug delivery of tizanidine hydrochloride tablets.

The study aim was concerned with formulation and evaluation of bioadhesive buccal drug delivery of tizanidine hydrochloride tablets, which is extensively metabolized by liver. The tablets were prepared by direct compression using bioadhesive polymers such as hydroxylpropyl methylcellulose K4M, sodium carboxymethyl cellulose alone, and a combination of these two polymers. In order to improve the permeation of drug, different permeation enhancers like beta-cyclodextrin (beta-CD), hydroxylpropyl beta-cyclodextrin (HP-beta-CD), and sodium deoxycholate (SDC) were added to the formulations. The beta-CD and HP-beta-CD were taken in 1:1 molar ratio to drug in formulations. Bioadhesion strength, ex vivo residence time, swelling, and in vitro dissolution studies and ex vivo permeation studies were performed. In vitro release of optimized bioadhesive buccal tablet was found to be non-Fickian. SDC was taken in 1%, 2%, and 3% w/w of the total tablet weight. Stability studies in natural saliva indicated that optimized formulation has good stability in human saliva. In vivo mucoadhesive behavior of optimized formulation was performed in five healthy male human volunteers and subjective parameters were evaluated.