Protective Effect of Baicalin Against TLR4‐mediated UVA‐induced Skin Inflammation

UVA irradiation is known to cause photoaging via production of reactive oxygen species (ROS) and activation of inflammatory processes. Previously, we have demonstrated that baicalin, a plant‐derived flavonoid possessing both antioxidant and anti‐inflammatory activity, protects mouse keratinocytes against damage from UVB irradiation. However, the role of baicalin in vivo has not been well studied, particularly in the setting of UVA irradiation. To explore the protective effects and mechanisms of baicalin treatment in mice after UVA irradiation, mice were exposed to acute and chronic doses of UVA irradiation with or without baicalin or vehicle. Skin samples were collected for histological staining, RNA isolation, flow cytometry and protein extraction. Our results demonstrate the protective effect of baicalin against UVA‐induced oxidative damage and inflammation in mouse skin. These effects are likely mediated via the TLR4 pathway, which may serve as a target for photochemoprevention against skin inflammation.     

An overview on the recent developments in polyaniline‐based supercapacitors

With the ever‐increasing depletion of nonrenewable fossil fuel reserve, greater attention has been directed towards renewable energy storage devices. One of the most important of such devices is the supercapacitor, which exhibits high specific capacitance. Polyaniline (PAni) is a versatile conducting polymer, which has demonstrated excellent electrochemical properties along with good stability and ease of synthesis. Therefore, PAni has been extensively used in the fabrication of supercapacitors. In the last few decades, researchers have studied the effect of morphology, developed during the synthesis of PAni, on its electrochemical properties. It is known that the electrical conductivity and the electrochemical properties of PAni get influenced by the level and type of dopant used, the method of synthesis adopted, and the surface area and porosity possessed. However, it has been realized that supercapacitors based on PAni suffer from short cycle life. This led to development of PAni composites with carbon‐based materials and transition metal oxides. In this review, focus has been laid on the achieved performance levels of the recently developed PAni‐based supercapacitors. In addition, an attempt has been made to study the fundamental aspects of the conductivity and the electrochemical properties of PAni and their effect on the supercapacitor performance. Moreover, several new interesting applications of PAni‐based supercapacitors have also been included in this review.     

Fabrication of visible light driven nano structured Copper,Boron codoped TiO2 for photocatalytic removal of Lissamine Green B

In the present research work a potentially improved Copper (Cu) and Boron (B) codoped TiO₂ nano materials were synthesized by varying the different dopant concentrations (Copper 0.25, 0.50, 0.75, 1?wt% and Boron 0.25, 0.50, 0.75, 1?wt%) using solgel method for the photocatalytic degradation of Lissamine Green B. In order to investigate the physical, chemical and optical properties of a catalyst, which play a key role in its photocatalytic activity, as prepared samples were characterized by various instrumental techniques. The crystalline phase study performed for all the samples using X-ray powder diffraction (XRD) confirmed the formation of anatase TiO₂. Chemical composition of the prepared catalyst investigated by X-ray photo electron spectroscopy (XPS) affirmed the presence of constituent elements (Ti, O, Cu & B) on the catalyst surface. The surface microstructure studied by field emission scanning electron microscopy (FE-SEM) revealed that the TiO₂ particles having spherical shape with rough surface morphology. The average particle size and surface area of the catalyst determined by high-resolution transmission electron microscopy (HRTEM) and Brunauer-Emmett-Teller (BET) surface area analyser, revealed that the codoped catalyst shows a high percentage of small particles of size 6.8?nm and a high surface area of 135.6?m²/g, respectively. The band edge absorption shift of the samples was determined by diffuse reflectance spectroscopy analysis (DRS) and the results exhibited that among all the codoped samples Copper 0.25?wt% and Boron 1?wt% (CBT1) catalyst shows a reduced band gap energy of 2.73?eV. The characterization results supported the photocatalytic activity of the catalyst for the degradation of Lissamine Green B within 90?min at the optimum reaction parameters such as dopant concentration of Cu at 0.25?wt% & B at 1?wt%, pH?=?3, catalyst dosage 0.075?g/L and dye concentration 10?mg/L under visible light irradiation. The mechanism of enhanced photocatalytic performance of the catalyst was proposed by the results obtained from the PL spectra and main reactive species trapping measurements.     

Phase Time for the Tunneling of Ultracold V-Type Atoms Through a Mazer Cavity

We study the tunneling time of ultracold V-type atoms interacting a high quality microwave cavity. Here atomic coherence is introduced in the system by a strong driving field which couples the two lower states of the three-level atom. It is found that in the presence of coherence, mazer action or the scattering like nature of the interaction may be examined for extended energies of the incident cold atoms. Our results show that position and amplitudes of the peak values of the phase time(traversal time) may be very effectively controlled by the coherent driving field. Further, here we obtained superclassical values of the phase time corresponding to much higher values of the transmission amplitudes of the tunneling atoms which may be advantageous in the possible experimental realization of the superclassical tunneling time of the traversing cold atoms. In addition, we examine a mirror reflection type symmetry in the phase time curve for a judicious choice of the external driving field.     

Pillar[5]arene‐Stabilized Silver Nanoclusters: Extraordinary Stability and Luminescence Enhancement Induced by Host–Guest Interactions

Herein, we report the synthesis of a new class of functional silver nanoclusters (AgNCs) capped with pillar[5]arene (P5)‐based host ligands. These NCs are readily prepared through direct synthesis or ligand exchange synthesis and are stable at room temperature for over 4 months. The pillar[5]arene‐stabilized NCs (Ag₂₉(LA‐P5)₁₂(TPP)₂) endorse reversible host–guest interactions with neutral alkylamines and cationic quaternary ammonium guests. This results in the formation of spherical assemblies with unparalleled changes in their optical properties including an astonishing circa 2000‐fold luminescence enhancement. This is the highest luminescence enhancement ratio reported so far for such atomically precise NCs. Our synthetic protocol paves the way for the preparation of a new generation of metal nanoclusters protected by macrocyclic ligands with molecular recognition and selectivity toward specific guests.     

Phosphite‐Catalyzed C−H Allylation of Azaarenes via an Enantioselective [2,3]‐Aza‐Wittig Rearrangement

A phosphite‐mediated [2,3]‐aza‐Wittig rearrangement has been developed for the regio‐ and enantioselective allylic alkylation of six‐membered heteroaromatic compounds (azaarenes). The nucleophilic phosphite adducts of N‐allyl salts undergo a stereoselective base‐mediated aza‐Wittig rearrangement and dissociation of the chiral phosphite for overall C?H functionalization of azaarenes. This method provides efficient access to tertiary and quaternary chiral centers in isoquinoline, quinoline, and pyridine systems, tolerating a broad variety of substituents on both the allyl part and azaarenes. Catalysis with chiral phosphites is also demonstrated with synthetically useful yields and enantioselectivities.     

Synthesis,in vitro urease inhibitory activity and molecular docking of 3,5‐disubstituted thiadiazine‐2‐thiones

A series of 3,5‐disubstituted‐tetrahydro‐thiadiazine‐2‐thione ( 1 ‐ 16 ) have been synthesized, characterized by elemental analysis, infrared (IR), UV‐visible, ¹H NMR, ¹³C NMR, and MS spectroscopic techniques, and screened against jack bean urease. Among 16 compounds, compounds ( 1 ), ( 2 ), ( 3 ), ( 4 ), ( 6 ), ( 7 ), and ( 9 ) demonstrated excellent urease inhibitory activity with IC₅₀ values (9.8 ± 0.5, 11.0 ± 0.6, 16.0 ± 1.5, 17.2 ± 0.5, 15.4 ± 0.5, 19.7 ± 0.4, and 15.8 ± 0.2μM), respectively, even better than the standard thiourea (IC₅₀ = 21 ± 0.01μM). However, compound ( 8 ) shows an almost same level of inhibition (IC₅₀ = 22.9 ± 0.3μM), as like standard. In this work, we reported for the first time urease inhibitory activity of thiadiazine thiones and its molecular docking studies.     

Microwave-assisted catalytic oxidative desulfurization of gasoil fuel using synthesized CuO-ZnO nanocomposites

Recently,organosulfur removal from liquid petroleum fuels is very significant aspect of environment protecting and fuel cell requests.Therefore,improved approaches to remove sulfur are still essential.In the present work,a simple catalytic oxidative desulfurization(CODS)system for Iraqi gasoil fraction has been successfully developed using CuO-ZnO nanocomposites as catalysts,and H_2O_2 as oxidant under microwave irradiation.The main reaction parameters influencing sulfur conversion including microwave power,irradiation time,catalyst dosage and H_2O_2 to gasoil volume ratio have been investigated.The CuO-ZnO nanocomposites was synthesized with different weight ratios and characterized by XRD,FE-SEM,AFM and BET surface area methods.The results reveal that,high sulfur conversion(93%)has been achieved under suitable conditions of microwave CODS as follows:microwave power of 540 W,irradiation time of 15 min,catalyst dosage of 8 g/L(0.4 g),and H_2O_2:gasoil volume ratio of 0.3.The catalyst reusability shows that the synthesized catalyst can be reused five times without an important loss in its activity.     

Carbofuran: analytical methods and its determination in natural water samples by flow injection DPA(III)–H2SO4 chemiluminescence

This study proposes, a simple, rapid and sensitive chemiluminescent (CL) method for determination of carbofuran based on diperiodatoargentate(III) (DPA)-sulfuric acid (H₂SO₄) reaction coupled with flow injection (FI) methodology. Under optimum conditions, a linear standard curve is achieved in the range of 0.001–8.0 mg L^–1 (R²= 0.9994 (n = 11) with relative standard deviation (RSD) of 1.4–3.7% (n = 4)), a limit of detection (LOD) 5.0 × 10^–4 mg L^–1 (S/N = 3) and injection throughput 180 h^–1. The proposed method was applied satisfactorily for the analysis of carbofuran in freshwater samples using solid phase extraction (SPE) technique with the recoveries of 94–110% (% RSD = 1.7–3.8, n = 4). A possible CL reaction mechanism has also been discussed briefly.     

Effect of polar aprotic solvents on hydroxyethyl cellulose-based gel polymer electrolyte

Quasi-solid bioelectrolytes based on hydroxyethyl cellulose (HEC) and sodium iodide (NaI) in three different polar aprotic solvent systems, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), and dimethylacetamide (DMA), were fabricated and characterized. FTIR studies revealed active solvent-ion interactions in DMF-based electrolytes in comparison to DMA and DMSO. The effect of the solvent system on the crystallinity of HEC gel electrolytes was more significant at low NaI concentration. In each solvent system, the highest ionic conductivity was achieved at 70 wt% NaI and generally DMF-based electrolytes showed higher conductivity than the other solvents. The availability of multiple complexation sites present in DMF is ascribed to improvement in ion mobility and hence conductivity. Rheological analysis was carried out to elucidate the mechanical properties of the gels. Generally, the mechanical strength of the polymer gels was unaffected by the type of solvent.