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This study examined spectroscopic, thermal, and other qualities, such as the lasing parameters, of Sm3+-doped glass with the composition 40P2O5–30ZnO–20LiCl–10BaF2. The ellipsometric data were used in a Sellmeier dispersion relation to estimate the refractive index values of the glasses investigated. The measured absorption spectra of the doped glass reveal the presence of various absorption bands assigned to transitions from the 6H5/2 ground state attributed to Sm3+-ion-excited states. We studied the decay of the 4G5/2 level of the Sm3+ ions in the doped glass by analyzing its absorption and emission fluorescence spectra. The Judd–Ofelt hypothesis allowed us to determine that the quantum efficiency of the 4G5/2–6H7/2 transition is high: 96% and 97% for glass doped with 4.05 × 1019 ions/cm−3 and 11 × 1019 ions/cm−3, respectively. Furthermore, this glass exhibits efficient red/orange enhanced spontaneous emission that matches the excitation band of the photosensitizer material used in medical applications. [ABSTRACT FROM AUTHOR]

Designing highly efficient hole-transporting materials (HTMs) has recently become one of the effective approaches to increasing the power conversion efficiencies (PCEs) of perovskite solar cells (PSCs). Herein, twelve novel star-shaped organic small molecules (A1–F2) are simulated by using triphenylamine as the core group, introducing different electron-accepting π-bridges and modulating terminal groups. The equilibrium geometries, electronic structures, optical properties, stabilities, solubilities, hole mobilities and adsorption features on the perovskite surface of the isolated molecules are calculated by using density functional theory (DFT) and time-dependent density functional theory (TDDFT) in combination with the Marcus charge transfer theory. Our theoretical results demonstrate that the electron-withdrawing ability of π-linkers and the molecular planarity have an important influence on the various properties of the studied molecules. Compared with the reference HTMs, the designed molecules with benzothiadiazole-based and benzoxadiazole-based electron-accepting bridges, especially E1, F1, C2, D2, E2 and F2, exhibit more suitable frontier molecular orbital character, good optical properties, larger Stokes shifts, similar or better solubility, good stability and higher hole mobilities, and are expected to be potential HTM candidates to help create more efficient solar cells. [ABSTRACT FROM AUTHOR]

Herein we describe the synthesis and rearrangement of 1,3-diamino-2,7-naphthyridines and 1-amino-3-oxo-2,7-naphthyridines. In the case of 1,3-diamino-2,7-naphthyridines, it was found that the rearrangement reaction was influenced by both the substituent at the 7th position of the 2,7-naphthyridine ring and by the nature of the cyclic amine at the 1st position. The influence was mainly steric. The reaction of 1-amino-3-oxo-2,7-naphthyridines with amines was studied for the first time. It was revealed that for these substrates, the rearrangement occurs faster and without any influence of the alkyl and cyclic amine groups. We also observed the nucleophilic addition of the amine to the carbonyl group of the rearranged product with the formation of a Schiff base. The calculation of the ESP charges on these substrates indicates a considerable increase in the positive charge on the cyano group that suffers the nucleophilic attack during the rearrangement process, possibly explaining its increased tendency to react and to have a higher reaction velocity. [ABSTRACT FROM AUTHOR]

Despite its potential as a clean power source to meet rising electricity demands, nuclear energy generates radioactive waste, including isotopes of iodine, that pose significant environmental and health risks. There is a growing demand to capture radioactive iodine and repurpose it effectively. However, achieving this dual functionality with a single material remains a significant challenge. This study explores phosphorus-based porous organic polymers (P-POPs) as probes for these dual functionalities. By employing 4-formyl(triphenyl)phosphine (BB1) and phenyl-1,4-diacetonitrile (BB2) under the Knoevenagel polycondensation method, P-POPs (PKPOPs) have been synthesized that exhibit a smooth spherical morphology, which efficiently capture and release iodine under ambient conditions, facilitating efficient transportation of molecular iodine. This novel approach aims to potentially transform nuclear waste into valuable organic feedstock via an iodination reaction. The innovative application of PKPOP has also been demonstrated for iodination reactions using ball mills and under continuous flow conditions, showcasing its potential for safer waste management and utilization., (© 2024 Wiley-VCH GmbH.)

The π-conjugated system and the steric configuration of hole transport materials (HTMs) could greatly affect their various properties and the corresponding perovskite solar cells' efficiencies. Here, a molecular engineering strategy of incorporating different amounts of p-methoxyaniline-substituted dibenzofurans as π bridge into HTMs was proposed to develop oligomer HTMs, named mDBF, bDBF, and tDBF. Upon extending the π-conjugation of HTMs, their HOMO energy levels were slightly deepened, significantly increasing the thermal stability and hole mobility. The incorporation of p-methoxyaniline bridges built one or two additional triphenylamine propeller structures, resulting in a denser film. Here, the tDBF-based n-i-p flexible perovskite solar cells createdchampion efficiency, giving a power conversion efficiency of 19.46%. And the simple synthesis and purification process of tDBF contributed to its low manufacturing cost in the laboratory. This work provided a reference for the development of low-cost and efficient HTMs. [ABSTRACT FROM AUTHOR]

In the title benzyl­ideneaniline Schiff base, C18H22N2O, the aromatic rings are inclined to each other by 46.01(6)°, while the Car--N= C--Car torsion angle is 176.9(1)°. In the crystal, the only identifiable directional inter­action is a weak C--H...π hydrogen bond, which generates inversion dimers that stack along the a-axis direction. [ABSTRACT FROM AUTHOR]

This research delves into the influence of red lead content on the red and NIR emission characteristics of Pr3+ ions within a nonconventional antimony silicate glass system. The glasses were synthesized across a composition spectrum of (40 − x) Pb3O4‒49Sb2O3‒(10 + x)SiO2:1Pr2O3, where x ranged from 0 to 35 mol%. Characterization was carried out using XRD, DSC, XPS, and IR spectroscopy. These analyses unveiled the presence of antimony ions in both Sb3+ and Sb5+ states and lead ions in Pb4+ and Pb2+ states within these glass compositions. Optical absorption and emission spectra (at λexc = 445 nm) were recorded within the wavelength range of 400‒1800 nm. Luminescence decay profiles of two pivotal transitions, namely, 3P0 → 3F2 (red emission) and 1G4 → 3H5 (1.3 µm NIR emission), were also recorded. Various radiative parameters from these spectra were extracted using the J–O theory. The findings indicated that, as the Pb3O4 content declined from 40 to 10 mol%, the covalent nature of the samples diminished, resulting in a remarkable amplification in the intensity of both the red and NIR emission bands of Pr3+ ions. The glass containing 10 mol% of Pb3O4 exhibited the most elevated radiative parameters and quantum efficiency. This augmentation was attributed to the reduction of Pb4+ and Sb5+ ions within the glass network or the augmentation of Pb2+ ions, serving as modifiers that mitigated phonon losses. Consequently, glasses with 10 mol% Pb3O4 demonstrate great potential for telecommunications applications, owing to their significant enhancement in PL emission for the 3P0 → 3F2 and 1G4 → 3H5 transitions. [ABSTRACT FROM AUTHOR]

The thermal properties and alignment of crystallinity of materials in thin films play crucial roles in the performance and reliability of various devices, especially in the fields of electronics, materials science, and engineering. The slight variations in the molecular packing of the active layer can make considerable differences in the optical and thermal properties. Herein, we aim to investigate the tuning of the physical properties of a blended thin film of n-type small organic molecules of perylene-3,4,9,10-tetracarboxylic acid (PTCA-SMs) with the mixing of the p-type polymer poly(3-hexylthiophene) (P3HT). The resulting thin films exhibit an enhanced surface crystallinity compared to the pristine material, leading to the formation of long crystallites, and these crystallites are thermally stable in the solid state, as confirmed by X-ray diffraction (XRD), atomic force microscopy (AFM), and thermal analysis using variable-temperature spectroscopic ellipsometry (VTSE) and differential scanning calorimetry (DSC). We believe that the crystalline structure of the obtained P3HT/PTCA-SMs blends is a combination of edge-on and face-on orientations, which enable the potential use of this material as an active layer in organic electronics. [ABSTRACT FROM AUTHOR]

π-Conjugated azomethine ligands differing in the naphthalene or phenylmethane-centered core structure and their divalent cobalt, nickel, copper, and zinc metal complexes were prepared and well-characterized by spectral analyses in solid state. Magnetic natures of the complexes were determined by magnetic susceptibility measurements in solid-state. Their remarkable photophysical characteristics were recorded by Uv-vis and Fluorescence spectroscopic techniques. At their excitation wavelenght of 265 nm, all molecules exhibited triple fluorescence emission bands with promising intensities above 673 nm in near infra-red region. Antibacterial and antibiofilm activities of the π-conjugated azomethines are promising for potential applications in medical and healthcare settings. Hence, the antibacterial/antibiofilm activity of the π-conjugated azomethine ligands and their metal complexes against some clinically important bacteria namely Staphylococcus aureus (MSSA), Methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus epidermidis, Escherichia coli, Pseudomonas aeruginosa and Proteus mirabilis was investigated, and the obtained results have shown that the ligands and complexes had a remarkable antibacterial effect, especially on Proteus mirabilis. Metal complexes have been found to have a significant inhibitory effect on biofilm formation by MRSA, MSSA, and P. mirabilis compared to ligands. The copper (II) complex of ligand-2 showed the highest inhibition percentage, significantly reducing biofilm formation for MRSA and MSSA. Furthermore, cobalt (II) complexes of the ligands selectively inhibited the growth of the opportunistic pathogen P. mirabilis biofilms, indicating that metal complexes might be a good choice for future antibiofilm studies., (© 2024. The Author(s).)

Photovoltaics has become one of the emerging alternatives to progressively supply/replace conventional energy sources, considering the potential exploitation of solar energy. Depending on the nature of the light harvester to influence on its light-absorption capability and the facility to produce electricity, different generations of solar devices have been fabricated. Early studies of organic molecules (dye sensitizers) with good absorption coefficients, going through metal chalcogenides and, lastly, the timely emergence of halide perovskites, have promoted the development of novel and low-cost solar cells with promising photoconversion efficiency (PCE), close to the well-established Si-based devices. However, main drawbacks such as the degradation/photocorrosion of the active layer, the existence of intrinsic defect sites, and the inherent toxicity of the material due to the presence of some harmful elements have blocked the future commercialization of the above kind of solar cells. In this review, we highlight the current progress in achieving efficient photomaterials for organic, chalcogenides and halide perovskites-based solar cells with the purpose of achieving high PCE values, some of which are breakthroughs in this research topic, and the diverse approaches used to extend the stability of the active layer and improve the performance of the solar devices. [ABSTRACT FROM AUTHOR]

Periodontal disease is a set of inflammatory conditions affecting the tissues surrounding the teeth, which can be fairly preventable. In this research, antibacterial polymeric nanofibers were prepared for the management of periodontal disease treatment. New hybrid organic/inorganic nanofibers of chitosan/polyethylene oxide (CS/PEO) contains doxycycline hyclate (DOXH) (as an antibacterial drug) and silver/hydroxyapatite/silica (Ag/HA/Si) nanocomposite (CS/PEO-DOXH-Ag/HA/Si) fabricated by electrospinning technique. The nanofibers were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), field emission scanning electron microscope (FE-SEM), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). In vitro release profile, degradation (DE) test, swelling (SW) test, antimicrobial activity and cell viability were also obtained. The DOXH release profile was measured by ultraviolet visible (UV–Vis) spectrophotometer in artificial saliva (pH 6.8) at 37 °C. The application of Ag/HA/Si increased the morphological integrity during the degradation process and decreased the rate of drug delivery. The electrospun nanofibers showed an enhanced antibacterial activity against Escherichia coli (E. coli), Staphylococcus aureus (S. aureus), and Streptococcus mutans (S. mutans) bacterium strains with the lowest DOXH amount, which can reduce the high dosage of antibiotics and side effects. Cell viability assays revealed that the prepared nanofibers had no cytotoxicity against the human gingival fibroblast 2 (HGF-2) cell line. The results suggest that the prepared organic/inorganic hybrid nanofibers with drug delivery properties could be a promising candidate for the treatment of periodontal diseases. [ABSTRACT FROM AUTHOR]

Latanoprost (LTP) is a prostaglandin F2α analog used to lower intraocular pressure in glaucoma treatment administered daily as eye drops. In this study, a universal model based on poly(l-lactide-co-glycolide-co-trimethylene carbonate) with shape memory was proposed for the development of a solid biodegradable formulation with prolonged release administered intraconjunctivally, intravitreally, subconjunctivally, and subcutaneously. Solution casting and electron beam (EB) irradiation were applied to the matrix formulation. The properties of the native matrix and matrices degraded in a PBS buffer (pH 7.4) were monitored by NMR, DSC, GPC, and SEM. Water uptake (WU) and weight loss (WL) were also analyzed. LTP was released over 113 days in a tri-phasic and sigmoidal pattern without a burst effect and with a relatively long second release phase, in which changes were observed in the glass transition temperature, molecular weight (Mn), WU, and WL. EB irradiation decreased the initial Mn, increased WU, and accelerated LTP release with a shortened lag phase. This provides the opportunity to partially eliminate the use of drops at the start of treatment. SEM observations indicated that surface erosion is the prevalent degradation mechanism. The proposed model is an interesting solution during a preliminary study to develop final medicinal products that provide high adherence. [ABSTRACT FROM AUTHOR]

The current study introduces a two-terminal (2T) thin-film tandem solar cell (TSC) comprised of a polymer-based top sub cell and a thin crystalline silicon (c-Si) bottom sub cell. The photoactive layer of the top sub cell is a blend of PDTBTBz-2F as a polymer donor and PC71BM as a fullerene acceptor. Initially, a calibration of the two sub cells is carried out against experimental studies, providing a power conversion efficiency (PCE) of 9.88% for the top sub cell and 14.26% for the bottom sub cell. Upon incorporating both sub cells in a polymer/Si TSC, the resulting cell shows a PCE of 20.45% and a short circuit current density (Jsc) of 13.40 mA/cm2. Then, we optimize the tandem performance by controlling the valence band offset (VBO) of the polymer top cell. Furthermore, we investigate the impact of varying the top absorber defect density and the thicknesses of both absorber layers in an attempt to obtain the maximum obtainable PCE. After optimizing the tandem cell and at the designed current matching condition, the Jsc and PCE of the tandem cell are improved to 16.43 mA/cm2 and 28.41%, respectively. Based on this TCAD simulation study, a tandem configuration established from an all thin-film model may be feasible for wearable electronics applications. All simulations utilize the Silvaco Atlas package where the cells are subjected to standard one Sun (AM1.5G, 1000 W/m2) spectrum illumination. [ABSTRACT FROM AUTHOR]

The aim of this study was to develop an innovative, dual-stimuli-responsive smart hydrogel local drug delivery system (LDDS), potentially useful as an injectable simultaneous chemotherapy and magnetic hyperthermia (MHT) antitumor treatment device. The hydrogels were based on a biocompatible and biodegradable poly(ε-caprolactone-co-rac-lactide)-b-poly(ethylene glycol)-b-poly(ε-caprolactone-co-rac-lactide) (PCLA-PEG-PCLA, PCLA) triblock copolymer, synthesized via ring-opening polymerization (ROP) in the presence of a zirconium(IV) acetylacetonate (Zr(acac)4) catalyst. The PCLA copolymers were successfully synthesized and characterized using NMR and GPC techniques. Furthermore, the gel-forming and rheological properties of the resulting hydrogels were thoroughly investigated, and the optimal synthesis conditions were determined. The coprecipitation method was applied to create magnetic iron oxide nanoparticles (MIONs) with a low diameter and a narrow size distribution. The magnetic properties of the MIONs were close to superparamagnetic upon TEM, DLS, and VSM analysis. The particle suspension placed in an alternating magnetic field (AMF) of the appropriate parameters showed a rapid increase in temperature to the values desired for hyperthermia. The MIONs/hydrogel matrices were evaluated for paclitaxel (PTX) release in vitro. The release was prolonged and well controlled, displaying close to zero-order kinetics; the drug release mechanism was found to be anomalous. Furthermore, it was found that the simulated hyperthermia conditions had no effect on the release kinetics. As a result, the synthesized smart hydrogels were discovered to be a promising antitumor LDDS, allowing simultaneous chemotherapy and hyperthermia treatment. [ABSTRACT FROM AUTHOR]

This work reports a new method to synthesize polyphenylmethanimine (polyPMI) as a linear or a hyperbranched, conjugated polymer using an aldehyde‐imine metathesis reaction. This work details the reaction mechanisms of this polymerization by characterizing a red‐shift in its absorption spectrum as polymer conjugation length increases and verifies that this optical shift results from extended π‐condensation using density functional theory. This new synthetic approach provides a polymer that can potentially be depolymerized for facile recyclability and is compatible with air‐ and water‐sensitive chemistries. As an example of the utility of this new approach, this work demonstrates that this polymer can be directly grown on silicon nanoparticles to create silicon anodes for lithium‐ion batteries with a high degree of electrochemical interfacial passivation. These silicon anodes exhibit Coulombic efficiencies above 99.9% and can accommodate silicon nanoparticle expansion and contraction during lithiation and delithiation as demonstrated by stable reversible capacities for 500 cycles. Finally, this work demonstrates that polyPMI facilitates the formation of a lithium fluoride rich solid electrolyte interphase that remains chemically and mechanically stable after long term cycling. [ABSTRACT FROM AUTHOR]

This article explores the ways in which timelessness affected prisoners in Nazi concentration camps and how some prisoners attempted to track time. By depriving prisoners of timekeeping methods, the Schutzstaffel (SS) sought to deprive them of a sense of future and therefore hope. Going against the idea that the SS achieved absolute power, however, is the evidence that some prisoners managed to keep track of time, albeit in unconventional ways. This research looks at the material records of timekeeping from the camps, from graffiti writing to recovered personal possessions, in conjunction with survivor testimony to understand exactly how prisoners were able to track time. The ability to keep time was of material and emotional benefit to many prisoners, allowing them to intercept food parcels, avoid beatings, mentally sustain themselves during difficult hours and days, connect through religion, and plan for the future. By opening a window into how prisoners were able to track time, this research contributes to the literature on daily life in the camps and demonstrates the value of integrated studies of prisoner life, showing how prisoner groups communicated and how their communication affected prisoner hierarchies, power, and survival. [ABSTRACT FROM AUTHOR]

The experimental and theoretical study of influence of the conformational state and association on the chirality of the stereochemically nonrigid biologically active bis-camphorolidenpropylenediamine (CPDA) and its ability to induce the helical mesophase of alkoxycyanobiphenyls liquid–crystalline binary mixture was carried out. On the basis of quantum-chemical simulation of the CPDA structure, four relatively stable conformers were detected. A comparison of the calculated and experimental electronic circular dichroism (ECD) and 1H, 13C, 15N NMR spectra, as well as specific optical rotation and dipole moments, allowed to establish the most probable trans-gauche conformational state (tg) of dicamphorodiimine and CPDA dimer with a predominantly mutually parallel arrangement of molecular dipoles. The induction of helical phases in LC mixtures based on cyanobiphenyls and bis-camphorolidenpropylenediamine was studied by polarization microscopy. The clearance temperatures and the helix pitch of the mesophases were measured. The helical twisting power (HTP) was calculated. The decrease in HTP with increasing dopant concentration was shown to be connected with the CPDA association process in the LC phase. The effect of camphor-containing chiral dopants of various structures on nematic LCs was compared. The values of the permittivity and birefringence components of the CPDA solutions in CB-2 were measured experimentally. A strong effect of this dopant on the anisotropic physical properties of the induced chiral nematic was established. A significant decrease in the dielectric anisotropy was associated with the 3D compensation of the LC dipoles during the formation of the helix. [ABSTRACT FROM AUTHOR]

The efficiency of solar cell and the corresponding output power is mainly affected by the rise in the film temperature, and in such cases, the stability in thermal conductivity value is required to ensure adequate rate of heat loss. This study investigates the effect of temperature rise on the overall thermal conductivity of the perovskite cell including the response of polymeric additives that have been used recently to enhance the interaction between different grains in perovskite films. The polymers under study are: polyethylene oxide (PEO), polyacetylene (PA), polythiophene (PT), polystyrene (PS) and polymethyl methacrylate (PMMA). The work assumes mathematical procedure that links the variation of temperature to the degree of polymer’s crystallinity and then converting this impact in terms of thermal conductivity. The calculations assumed three different concentrations of the polymer as: 1, 3 and 5%. Each polymer has served with two degrees of crystallinity. In general, the results show that the effect of added polymers on the final value of the thermal conductivity of the film may be positive or negative depending on three main factors: k-value of the perovskite-based material, k-value of the polymer and concentration of the polymer. The effect of the polymer appears more when it is used with the low k-value perovskite material (0.2 W/m∙K) rather than with high k-value perovskite material (0.8 W/m∙K). The addition of PEO to the perovskite-based materials makes the overall k-value of the film reaches to 3.7 W/m∙K and even higher when the temperature rises up. Hence, this polymer is useful in high operation temperature. In the case of using polymers (PA and PT), the overall k-value of the film was less sensitive. The use of amorphous polymers (PS and PMMA) has not witnessed any significant contribution in the overall k-value of the film. [ABSTRACT FROM AUTHOR]

In the present work, we have studied the interaction behaviour of various metal phthalocyanines (MPcs); functionalized copper and nickel Phthalocyanines (CuPcS and NiPcS) and Aluminium Phthalocyanine hydroxide (AlPcOH) and their combinations dispersed in sol–gel glass towards organic vapors. Addition of AlPcOH in MPcs combinations has enabled faster response-recovery times with better stability of MPcs composites under ambient conditions. The concept of primary and secondary charge transfer mechanism coupled with steric hindrance effect explains the varied sensing responses of MPcs. Amendment in the sensing responses towards organic vapors has been observed after combining MPcs. Significant shifts in Q bands of MPcs after DEA exposure and distortions observed in central metal ion coordinated vibration bands confirm the primary participation of MPcs during charge transfer with organic vapors. Consistencies of the optical and spectroscopic results with electrical sensing results confirm better sensitivity of MPcs towards DEA vapors as compared to methanol under ambient conditions. [ABSTRACT FROM AUTHOR]

In this study, we present some design suggestions for all-polymer solar cells by utilizing device simulation. The polymer solar cell under investigation is formed by a photoactive film of a blend comprising PBDB-T as a polymer donor and PZT as a polymerized small molecule acceptor. The initial cell is based on a fabricated cell whose structure is ITO/PEDOT:PSS/PBDB-T:PZT/PFN-Br/Ag, which has a power conversion efficiency (PCE) of about 14.9%. A calibration procedure is then performed by comparing the simulation results with experimental data to confirm the simulation models, and the material parameters, implemented in the SCAPS (Solar Cell Capacitance Simulator) simulator. To boost the open circuit voltage, we investigate a group of hole transport layer (HTL) materials. An HTL of CuI or P3HT, that may replace the PEDOT:PSS, results in a PCE of higher than 20%. However, this enhanced efficiency results in a minor S-shape curve in the current density-voltage (J-V) characteristic. So, to suppress the possibility of the appearance of an S-curve, we propose a double HTL structure, for which the simulation shows a higher PCE with a suppressed kink phenomenon due to the proper band alignment. Moreover, the designed cell is investigated when subjected to a low light intensity, and the cell shows a good performance, signifying the cell's suitability for indoor applications. The results of this simulation study can add to the potential development of highly efficient all-polymer solar cells. [ABSTRACT FROM AUTHOR]

Evolving technology has posed a constantly increasing need for materials that can work well under harsh conditions such as elevated temperatures. Aromatic polyimides have a great potential for this purpose, having excellent thermal, mechanical, dielectric, and optical properties, along with good chemical resistance and high dimensional stability. In spite of their general difficulty in processing and high cost, polyimides are intensively studied for applications in many areas due to their high-end value. This article reviews the progress made on polyimide materials in the "Petru Poni" Institute of Macromolecular Chemistry (ICMPP) of the Romanian Academy during the last decade, with focus on their performance as films, matrices for nanocomposites, coatings for microelectronics and opto-electronic devices, or dielectrics for thin film capacitors. [ABSTRACT FROM AUTHOR]

Vanadium-doped nano zinc sulfide (ZnS/V) was formed using solid state reaction method at low temperature. Polyvinyl alcohol (PVA)/carboxymethyl cellulose (CMC)/polyethylene glycol (PEG) films composed with different content of ZnS/V nanoparticles (0, 1, 3, 5, 10 wt%) were produced using casting technique. The structural feature of ZnS/V nanoparticles was examined using Rietveld method. The structure and optical characteristics of the filled PVA/CMC/PEG blended polymers were investigated applying X-ray diffraction, Fourier transform infrared, fluorescence, energy dispersive X-ray analysis, scanning electron microscope and diffused reflectance techniques. The investigated results indicated that the optical parameters including the refractive index and nonlinear optics of the blended polymer exhibited a considerable improvement by loading nano ZnS/V. The direct and indirect optical bandgaps could be tailored between (5.63, 5.28) eV for the pure blend and (3.64, 2.77) eV for blended polymer doped with10% ZnS/V. Broad FL spectra were obtained for all blended polymers with FL intensity greatly affected with ZnS/V nanoparticles while the FL peaks are shifted a little. These results indicate the possibility of applying the samples under the study in several potential optoelectronic applications. [ABSTRACT FROM AUTHOR]

In order to reduce the infrared emissivity to meet the requirements of modern warfare for infrared stealth materials, we prepared the polymers containing Schiff base moieties using polyetheramine and 2,6-pyridinedicarboxaldehyde by solution polycondensation and coordinated with Ni2+, Cu2+, and Sm3+ ions to prepare organic coatings. The structure and the thermal and mechanical properties of the coatings were studied in detail. Meanwhile, the effect of the conductivity change of coordination polymers on infrared emissivity was studied systematically. The results showed the polymer coordinated with Sm3+ ions had the lowest energy band gap, which was 2.99 eV, and the best electrical conductivity of 3.54 × 10−4 S/cm compared with Ni2+ and Cu2+ coordination polymers. The infrared emissivity was the lowest in the 2–22 μm infrared waveband range, which reached 0.58, suggesting the polymers containing Schiff base moieties and their coordination polymers may have a great potential to be applied as infrared stealth materials in military applications. [ABSTRACT FROM AUTHOR]

Three new azomethines based on triphenylamine with two or three substituents were obtained. Chemical structure and purity were confirmed by 1H NMR, FTIR elemental analysis and mass spectroscopy. The investigations were focused on the relationship between chemical structure and properties important for optoelectronic materials. Thus, the studies of thermal, optical and electrochemical properties were carried out based on differential scanning calorimetry, thermogravimetric analysis, electronic absorption, photoluminescence and cyclic voltammetry measurements. The ongoing consideration of experimental results was complemented by theoretical calculations using the density functional theory method. The donor activity of obtained compounds was tested in bulk-heterojuntion photovoltaic cells with structure ITO/PEDOT:PSS/imine:PCBM/Al and ITO/PEDOT:PSS/imine:P3HT:PCBM/Al). The effect of the presence of the amino-thiophene-3,4-dicarboxylic acid diethyl ester groups and various number of hexyloxyphenyl units on imines properties was demonstrated. [ABSTRACT FROM AUTHOR]

The performance of photovoltaics with superstrate configuration is limited by the rigidity and low refractivity of a classical glass cover. In this work, two polyimides (PIs) and two copolyimides combined in the main chain cycloaliphatic moieties, aromatic sequences, chalcogen atoms, and having/lacking fluorine atoms, are proposed as shielding covers for solar cells. The samples containing small cycloaliphatic moieties displayed high transmittance above 80% at 550 nm. The refractive index values under changeable wavelengths and temperatures were shown to influence the magnitude of the reflection losses. At the sample interface with the transparent electrode, optical losses were reduced (~0.26%) in comparison to the classical glass (~0.97%). The samples with the best optical features were further subjected to a surface treatment to render the self-cleaning ability. For this, a new approach was used residing in irradiation with the diffuse coplanar surface barrier discharge (DCSBD), followed by spraying with a commercial substance. Scanning electron microscopy and atomic force microscopy scans show that the surface characteristics were changed after surface treatment, as indicated by the variations in root mean square roughness, surface area ratio, and surface bearing index values. The proposed PI covers diminish the optical losses caused by total internal reflection and soiling, owing to their adapted refractivity and superhydrophobic surfaces (contact angles > 150°), and open up new perspectives for modern photovoltaic technologies. [ABSTRACT FROM AUTHOR]

Background: The concept of utilizing drug repurposing/repositioning in the development of hybrid molecules is an important strategy in drug discovery. Fluoroquinolones, a class of antibiotics, have been reported to exhibit anticancer activities. Although anticancer drug development is achieving some positive outcomes, there is still a need to develop new and effective anticancer drugs. Some limitations associated with most of the available anticancer drugs are drug resistance and toxicity, poor bio-distribution, poor solubility, and lack of specificity, thereby reducing their therapeutic outcomes., Objectives: Fluoroquinolones, a known class of antibiotics, have been explored by hybridizing them with other pharmacophores and evaluating their anticancer activity in silico and in vitro . Hence, this review provides an update on new anticancer drugs containing fluoroquinolones moiety, Ciprofloxacin and Norfloxacin between 2020 and 2023, their structural relationship activity, and the future strategies to develop potent chemotherapeutic agents., Methods: Fluoroquinolones were mostly hybridized via the N-4 of the piperazine ring on position C-7 with known pharmacophores characterized, followed by biological studies to evaluate their anticancer activity., Results: The hybrid molecules displayed promising and interesting anticancer activities. Factors such as the nature of the linker, the presence of electron-withdrawing groups, nature, and position of the substituents influenced the anticancer activity of the synthesized compounds., Conclusion: The hybrids were selective towards some cancer cells. However, further in vivo studies are needed to fully understand their mode of action., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

Polyazomethines containing electron-donor triphenylamine (TPA) or carbazole (Cbz) and electron-acceptor naphthyl(di)imide were synthesized and investigated with regard to thermal, optical and electronic features, with a focus on their modulation by molecular design. The polycondesation of an imido-based diamine with a Cbz- or TPA-based dialdehyde led to donor-acceptor polymers with good thermostability, up to 318 °C. These displayed good solubility in organic solvents, which enabled easy polymer processability in thin films with different molecular assemblies. The molecular order improved the charge carrier's mobility, with a direct impact on the bandgap energy. The optical properties studied by UV–Vis absorption and fluorescence experiments showed solvent-dependence, characteristic for donor-acceptor systems. The structural parameters exerted a strong influence on the light-emissive behavior, with the prevalence of intrinsic or intramolecular charge transfer fluorescence contingent on the donor-acceptor strength and polymer geometry. All polymers showed good electroactivity, supporting both electrons and holes transport. The exchange of Cbz with TPA proved to be an efficient tool with which to decrease the bandgap energy, while that of naphthyl(di)imide with bis(naphthylimide) was beneficial for fluorescence enhancement. This study may contribute to a deeper understanding of the physico-chemistry of electronic materials so as to make them more competitive in the newest energy-related or other optoelectronic devices. [ABSTRACT FROM AUTHOR]

In this study, a poly(azomethine) compound (SBP) containing sulfur and oxygen bridge was obtained from 4,4'-[thiobis(4,1-phenyleneoxy)]dibenzaldehyde (DBA) and 4,4'diamino-2,2'-biphenyl sulfonic acid from condensation reaction. Structural, optical, electrochemical and morphological analyzes of the obtained polymeric material were performed. Structural characterizations were performed from 1H-NMR and FT-IR spectra. Optical properties were determined in the UV-Vis spectrum and the optical band gap was calculated as 3.63 eV. Electrochemical properties were investigated by cyclic voltammetry (CV) and HOMO-LUMO and electrochemical band gap values were calculated. In addition, with the help of Gel Permeation Chromatography (GPC), the average molecular mass was found 5050 Da. Thermogravimetric analysis (TGA) results showed that the thermal degradation of SBP occurred in four steps and the maximum mass loss was at 391 °C. The surface analysis of the obtained polymeric material was investigated with scanning electron microscope (SEM) and it was determined that the surface was rough. [ABSTRACT FROM AUTHOR]

The first‐line therapy against locally advanced prostate cancer is radical prostatectomy as well as radiation therapy which might contribute to the swelling of the prostate. To prevent this, prostatic urethral stents might be used and they are mostly made of metal alloys. However, biodegradable prostatic stents are constantly explored. The aim of the study was 3D printing of tubular biodegradable scaffolds intended as a model prostatic stent since 3D printing allows obtaining devices with controlled geometric shape and function. Additional docetaxel‐loaded layers on bioresorbable scaffolds were obtained for local chemotherapeutic delivery. Scaffolds were characterized before and during incubation in artificial urine for 6 weeks. Changes in the chain microstructure of the scaffolding polymer during this period were stable. Weight loss of the scaffolds was very low contrary to molecular weight changes. During incubation, slow release of the docetaxel was observed. After 6 weeks, 20% of the drug was released from the coating. The stable release of the cytostatic drug during chemotherapy is advantageous. Contrary to systemic administration of docetaxel used nowadays as a standard treatment in castration‐resistant prostatic cancer, local administration is proposed instead, with the aim to downstage the disease before radical therapy and thus to minimize the risk of recurrence. [ABSTRACT FROM AUTHOR]

Triphenylamine (TPA)‐based polyimides (PIs) have excellent discoloration characteristics and widely used as functional films. However, these PIs usually exhibit lower mechanical and thermal properties, and TPA units as the electron donor also weaken the optical transmittance of PIs. Utilized blending with diaminodiphenyl ether (ODA)‐based PIs, we successfully prepared the blend polyimide (BPI) films containing ODA/TPA units, to realize complementary advantages of excellent mechanical, thermal, optical, and electrochemical properties. Among them, the tensile strength of BPI‐53 film (mole ratio of TPA/ODA = 5:3) is reached up to 105.5 MPa, which is 641.9% much higher than 14.22 MPa of TPA‐PI film. Moreover, the thermal stability of BPI‐53 film is also significantly improved. T5 (temperature of 5% weight loss) can be increased to 548.26°C for BPI‐53 film, and the weight residual rate at 800°C in N2 atmosphere is increased by an addition of 4%. Besides, BPI‐53 film also has good transmittance property in district of 400–700 nm, and the variation range of transmittance under 1.0 V positive bias voltage is of 36.61%. For the electrochromics, the discoloration properties of blend polyamide acid (BPAA) dry film can be well maintained. [ABSTRACT FROM AUTHOR]

The fabrication of anion‐coordinated assemblies into functional soft materials remains a major challenge. To this end, four C2‐symmetric anion‐binding ligands equipped with ortho‐phenylene‐bridged bis(urea) and amine or amide ends were designed, which generated A2L3 triple helical architectures upon self‐assembly with phosphate ions. Hierarchical intermolecular hydrogen bonds among the terminal amine/amide groups and urea moieties resulted in the formation of functional gels. The obtained gels were further applied for conductive adhesion between different surfaces, displaying excellent flexibility and selective wettability. The viscoelastic gels constructed from anion‐coordinated assemblies described in this work represent the first example of a new class of anion‐coordination‐driven smart materials. [ABSTRACT FROM AUTHOR]

Heavy metal-based oxide glasses with composition 30Li2O·20PbO·xBi2O3·(50 − x)SiO2 (where, x = 0 to 50 mol%) were prepared by standard melt-quench procedure at temperature 1150 °C for 30 min. The amorphous nature of the prepared samples was confirmed by the low-intensity broad hump in XRD analysis. Fourier transform infrared spectroscopy predicts the role of Bi2O3 as network former as well as modifier due to the existence of BiO3 and BiO6 structural units. The Archimedes principle was used to compute the density of samples, which was found to increase with the bismuth concentration. The optical properties of synthesized samples were measured using UV–VIS–NIR spectroscopy. With increasing bismuth content, optical parameters such as cut-off wavelength, theoretical optical basicity, oxide ion polarizability, and molar refractivity increase, whereas the optical energy bandgap decreases. The large values of refractive index and smaller metallization criterion for all the samples (ranges from 0.310 to 0.395) suggest that studied glasses can be explored for non-linear optical applications. [ABSTRACT FROM AUTHOR]

Vancomycin hydrochloride (HCl) is a glycopeptide antibiotic used to treat serious or life-threatening infections, and it reduces plaque scores and gingivitis in periodontal patients. In this study, vancomycin HCl was incorporated into rosin in situ forming gel (ISG) and rosin in situ forming microparticles (ISM) to generate a local drug delivery system to treat periodontal disease. The physical properties of the ISG and ISM were measured, including pH, viscosity, injectability, adhesion properties, in-vitro transformation, and drug release. Moreover, the effectiveness of antimicrobial activity was tested using the agar-cup diffusion method against Staphylococcus aureus, Streptococcus mutans, Porphyromonas gingivalis, and Escherichia coli. Vancomycin HCl-loaded rosin-based ISG and ISM had a pH value in the range of 5.02–6.48 and exhibited the ease of injection with an injection force of less than 20 N. Additionally, the lubricity effect of the external oil phase of ISM promoted less work of injection than ISG and 40–60% rosin-based ISM showed good emulsion stability. The droplet size of emulsions containing 40%, 50%, and 60% rosin was 98.48 ± 16.11, 125.55 ± 4.75, and 137.80 ± 16.8 µm, respectively. Their obtained microparticles were significantly smaller in diameter, 78.63 ± 12.97, 93.81 ± 10.53, and 118.32 ± 15.61 µm, respectively, because the particles shrank due to the solvent loss from solvent exchange. Moreover, increasing the concentration of rosin increased the size of microparticles. After phase transformation, all formulations had better plasticity properties than elasticity; therefore, they could easily adapt to the specific shape of a patient's gum cavity. Both developed ISG and ISM presented inhibition zones against S. mutans and P. gingivalis, with ISG presenting significantly more effectively against these two microbes (p < 0.05). The vancomycin HCl-loaded rosin ISG and ISM delayed drug release for 7 days with efficient antimicrobial activities; thus, they exhibit potential as the drug delivery systems for periodontitis treatment. [ABSTRACT FROM AUTHOR]

Cyclic and linear conjugated molecules featuring 9,10-dithienylanthracene linked with vinylene were synthesized by McMurry coupling, ring-opening metathesis polymerization (ROMP), and dehydration. The cyclic and linear dimers displayed strained ring and planar structures by single-crystal X-ray crystallography, respectively. UV-Vis and photoluminescence (PL) spectra of the cyclic dimer in benzene solution exhibited reversible changes in absorbance and PL intensity by UV irradiation and reversion by heating. The reversion followed the first-order equation, giving a kinetic constant of 0.75 min−1 at 35 °C and an activation energy of 70.9 kJ mol−1. Computational studies based on density functional theory supported the explanation of the experimental results. These spectral changes were attributed to unique conformational changes, particularly the flipping of the alkylated thienyl group. Furthermore, a single crystal of the cyclic dimer showed photoinduced bending. Contrarily, a free-standing film of polyvinylene synthesized via ROMP and polyimine synthesized via dehydration exhibited photoinduced elongation and bending, respectively. [ABSTRACT FROM AUTHOR]

Shape-memory characteristics shed light on materials science and open horizons for accessing to unconventional functions in material categories subsuming metals, polymers, and ceramics. Biomedical fields manifest great interest in adopting shape-memory materials for unconventional properties, specifications, and well-defined mechanical properties. In spite of the mentioned advantages, their biocompatibility for long-term and permanent applications has not yet been comprehensively distinguished. This article summarizes the most common clinical applications of shape memory alloys and polymers, e.g., tissue engineering, drug delivery, hydrogels, orthodontic wires/distracters, artificial discs, orthopedic staples, atrial septal occlusion devices, neurosurgical stents, etc., and also addresses their critical biocompatibility issues. [ABSTRACT FROM AUTHOR]

Periodontal diseases (gingivitis and periodontitis) are characterized by inflammatory processes which arise as a result of disruption of the balance in the oral ecosystem. According to the current S3 level clinical practice guidelines, therapy of patients with periodontitis involves a stepwise approach that includes the control of the patient's risk factors and the debridement of supra and subgingival biofilm. This debridement can be performed with or without the use of some adjuvant therapies, including physical or chemical agents, host modulating agents, subgingivally locally delivered antimicrobials, or systemic antimicrobials. Therefore, the main aim of this article is to review in a narrative manner the existing literature regarding the adjuvant application of local agents, either subgingivally delivered antibiotics and antiseptics or supragingivally applied rinses and dentifrices, during the different steps in periodontal therapy performed in Europe., (© 2023 The Authors. Periodontology 2000 published by John Wiley & Sons Ltd.)

The fabrication of anion-coordinated assemblies into functional soft materials remains a major challenge. To this end, four C 2 -symmetric anion-binding ligands equipped with ortho-phenylene-bridged bis(urea) and amine or amide ends were designed, which generated A 2 L 3 triple helical architectures upon self-assembly with phosphate ions. Hierarchical intermolecular hydrogen bonds among the terminal amine/amide groups and urea moieties resulted in the formation of functional gels. The obtained gels were further applied for conductive adhesion between different surfaces, displaying excellent flexibility and selective wettability. The viscoelastic gels constructed from anion-coordinated assemblies described in this work represent the first example of a new class of anion-coordination-driven smart materials., (© 2022 Wiley-VCH GmbH.)

Optical and structural properties of a blend thin film of (1:1 wt.) of poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) doped with iodine (I2) and then exposed to a stepwise heating were reported and compared with the properties of doped P3HT films. The UV-Vis(T) absorption measurements were performed in situ during annealing runs, at the precisely defined temperatures, in a range of 20–210 °C. It was demonstrated that this new method allows one to observe the changes of absorption spectra, connected with the iodine release and other structural processes upon annealing. In addition, the thermally-induced changes of the exciton bandwidth (W) and the absorption edge parameters, i.e., the energy gap (EG) and the Urbach energy (EU) were discussed in the context of different length of conjugation and the structural disorder in polymers and blends films. During annealing, several stages were distinguished and related to the following processes as: the iodine escape and an increase in P3HT crystallinity, the orderly stacking of polymer chains, the thermally inducted structural defects and the phase separation caused by an aggregation of PCBM in the polymer matrix. Moreover, the detailed X-ray diffraction studies, performed for P3HT and P3HT:PCBM films, before and after doping and then after their thermal treatment, allowed us to consider the structural changes of polymer and blend films. The effect of iodine content and the annealing process on the bulk heterojunction (BHJ) solar cells parameters was checked, by the impedance spectroscopy (IS) measurements and the J-V characteristics registration. All of the investigated P3HT:PCBM blend films showed the photovoltaic effect; the increase in power conversion efficiency (PCE) upon iodine doping was demonstrated. [ABSTRACT FROM AUTHOR]

The results presented in this communication concern visible and near-IR emission of Pr3+ ions in selected inorganic glasses, i.e., borate-based glass with Ga2O3 and BaO, lead-phosphate glass with Ga2O3, gallo-germanate glass modified by BaO/BaF2, and multicomponent fluoride glass based on InF3. Glasses present several emission bands at blue, reddish orange, and near-infrared spectral ranges, which correspond to 4f–4f electronic transitions of Pr3+. The profiles of emission bands and their relative intensity ratios depend strongly on glass-host. Visible emission of Pr3+ ions is tuned from red/orange for borate-based glass to nearly white light for multicomponent fluoride glass based on InF3. The positions and spectral linewidths for near-infrared luminescence bands at the optical telecommunication window corresponding to the 1G4 → 3H5, 1D2 → 1G4, and 3H4 → 3F3,3F4 transitions of Pr3+ are dependent on glass-host matrices and excitation wavelengths. Low-phonon fluoride glasses based on InF3 and gallo-germanate glasses with BaO/BaF2 are excellent candidates for broadband near-infrared optical amplifiers. Spectroscopic properties of Pr3+-doped glasses are compared and discussed in relation to potential optical applications. [ABSTRACT FROM AUTHOR]

The aim of this work was to obtain pH-dependent nanofibers with an electrospinning technique as a novel controlled release system for the treatment of periodontal disease (PD). Cellulose acetate phthalate (CAP) was selected as a pH-sensitive and antimicrobial polymer. The NF was optimized according to polymeric dispersion variables, polymer, and drug concentration, and characterized considering morphology, diameter, entrapment efficiency (EE), process efficiency (PE), thermal properties, and release profiles. Two solvent mixtures were tested, and CHX-CAP-NF prepared with acetone/ethanol at 12% w/v of the polymer showed a diameter size of 934 nm, a uniform morphology with 42% of EE, and 55% of PE. Meanwhile, CHX-CAP-NF prepared with acetone/methanol at 11% w/v of polymer had a diameter of 257 nm, discontinuous nanofiber morphology with 32% of EE, and 40% of PE. EE and PE were dependent on the polymer concentration and the drug used in the formulation. Studies of differential scanning calorimetry (DSC) showed that the drug was dispersed in the NF matrix. The release profiles of CHX from CHX-CAP-NF followed Fickian diffusion dependent on time (t0.43−0.45), suggesting a diffusion–erosion process and a matrix behavior. The NF developed could be employed as a novel drug delivery system in PD. [ABSTRACT FROM AUTHOR]