Search

Amoxicillin (AMX), one of the most commonly used antibiotic drugs, can cause overwhelming hazards if abused, particularly when it contaminates the environment and affects individuals. As a result, devising an easy and accurate method for estimating AMX content is vital. In this work, we describe a turn off/on detection method for Cr3+ and AMX using a smart pH-switchable ZnO quantum dot (QD) nanoprobe. The ZnO QDs were synthesized using tetraethyl orthosilicate (TEOS) as a capping agent through a simple low-temperature base-hydrolysis reaction. The TEOS-capped ZnO QDs exhibited strong fluorescence with a peak at 520 nm under excitation at 330 nm. Numerous methods, such as energy-dispersive X-ray (EDX), Fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), UV–vis absorption, and UV–vis reflectance, have been used to demonstrate the successful synthesis of TEOS-capped ZnO QDs. The lowest excited state exhibits selective fluorescence quenching and enhancement upon the addition of Cr3+ and AMX, respectively, in the presence of other interferences at pH 7 and pH 1 respectively (both in liquid and solid-state PL). The estimated LOD of 15.94 nM (in case of Cr3+) and 77.86 nM (in case of AMX) was achieved. The recovery of various concentrations of AMX in real samples ranged from 95% to 101.1%, with a relative standard deviation of 0.05–1% (n = 3). This work harnesses the specific and excellent performance of TEOS-capped ZnO QDs, contributing to further progress in the analytical and materials research fields. There is ample scope for using this nanoprobe in the fabrication of both pH sensors (owing to its pH-switching ability) and capacitive sensors (owing to the semiconducting nature of ZnO). [ABSTRACT FROM AUTHOR]

In general, defects are crucial in designing the different properties of two-dimensional materials. Therefore large variations in the electric and optical characteristics of two-dimensional layered molybdenum disulphide might be attributed to defects. This study presents the design of a temperature and nitrogen sensor based on few-layer molybdenum disulfide sheets (FLMS), which was developed from bulk MoS2 (BMS) through an exfoliation approach. The produced sulfur defect, molybdenum defect, line defect, and plane defect were characterized by scanning transmission electron microscopy (STEM), which substantially impacts the sensing characteristics of the resulting FLMS. Our theoretical analysis validates that the sulfur vacancies of the MoS2 lattice improve sensing performance by promoting effective charge transfer and surface interactions with target analytes. The FLMS-based sensor showed a high sensitivity for detecting nitrogen gas with a detection limit (LOD) of ~ 0.18 ppm. Additionally, temperature-detecting capabilities were assessed over various temperatures, showing outstanding stability and repeatability. To the best of our knowledge, this material is the first of its kind, demonstrating visible N2 gas sensing with chromic behaviour. [ABSTRACT FROM AUTHOR]

Graphene has intriguing electrical, mechanical, thermal and biological properties that are being investigated for use in composites, modern electronics, membranes, and in the industry. Also, graphene has huge biological applications. Hydroxypropyl methylcellulose (HPMC) is a widely used bio-polymer effective for various biomedical applications. As a filler in this polymer matrix, graphene oxide (GO), reduced graphene oxide (RGO) and silver (Ag) nanoparticles (NPs) can be used to improve various properties of the matrix. They are also beneficial for bio-applications like drug delivery, the production of reactive oxygen species (ROS) and the antimicrobial properties of nanocomposite films. Here we synthesize a series of polymer nanocomposites taking GO, RGO and Ag NPs as a filler by the solution mixing method and explore the comparative biological application of such composites. We choose Ag NPs as it has the superior potential for multiple drug resistance. X-ray diffraction, Fourier-transform infrared and scanning electron microscope studies are used to describe how nanocomposites are formed. Energy-dispersive X-ray and dynamic mechanical analyzer analyses were also done to check elemental percentage in nanocomposite films and mechanical properties, respectively. To check several fruitful applications, antimicrobial properties, ROS generation and in-vitro drug release study of nanocomposite films with the loading of Ketorolac Tromethamine were also performed. [ABSTRACT FROM AUTHOR]

AC conductivity and dielectric relaxation of MoO3 doped V2O5–ZnO–CuO glass-nanocomposites have been studied in a wide temperature and frequency ranges. Electron microscopic studies reveal that Cu3O8V2 and Cu3Mo2O9 nanophases (for higher MoO3 content) have been developed, which are expected to form various defect states. Owing to formation of such nanophases, different values of maximum barrier height have been developed, which are supposed to play vital roles in the conduction process. Electric modulus formalism has been conceived as it can exclude the electrode polarization effect at low frequency regime and suggest the transition from long-range mobility to short-range mobility assembly of polarons. Correlated barrier hopping model and its modified version have been found to be most appropriate theoretical models to explore the conduction process. It is also noteworthy that relaxation times are found to increase with higher MoO3 content, which may indicate about the slow movement of charge carriers. The nature of variation of Kohlraush Williams Watts parameters can be considered as a tool to reveal the reason for shifting of relaxation process from Debye to Non-Debye type up to a limit with more and more incorporation of MoO3 content into the previous materials. By crossing the limiting value of composition (0.08 mol% of MoO3), it becomes non-Debye type at a very slow rate. Lower values of dielectric constant at high frequencies are expected to be important for their applications in photonics and opto-electronics. Scaling method of electric modulus spectra indicates that the dielectric relaxation process in the present system leads to a common relaxation process at various temperatures, but it is strongly dependent on compositions. [ABSTRACT FROM AUTHOR]

Metformin, the primary therapy for type 2 diabetes mellitus (T2DM), showed limitations such as varying absorption, rapid system clearance, required large amount, resistance, longstanding side effects. Use of Nano formulations for pharmaceuticals is emerging as a viable technique to reduce negative consequences of drug, while simultaneously attaining precise release and targeted distribution. This study developed a Polyethylene Glycol conjugated Graphene Oxide Quantum dots (GOQD-PEG) nanocomposite for the sustained release of metformin. Herein, we evaluated the effectiveness of metformin-loaded nanoconjugate in in vitro insulin resistance model. Results demonstrated drug loaded nanoconjugate successfully restored glucose uptake and reversed insulin resistance in in vitro conditions at reduced dosage compared to free metformin. [ABSTRACT FROM AUTHOR]

Here, the system of amorphous glassy system, xAgI—(1-x) (0.1CdO—0.3 V2O5—0.4 P2O5—0.2ZnO) with x = 0, 0.05, 0.1, 0.2, 0.3, 0.4 has been developed. The gradual change in the size of various nanocrystallites such as VO2, Zn2V2O7, V6O13, ZnV3O8, and P and the development of new phases of their combinations have been pronounced due to a gradual increase in AgI content. This may lead to possible structural changes of the system under investigation. V–O-V vibration at lower energy may be responsible for weakening the covalent bond, which may be responsible for releasing vanadium ion to contribute more electron/polaron. Correlated barrier hopping (CBH) model has been found to appropriate to predict the hopping conduction paths of charge carriers (or polarons) in pairs via current transfer between localized sites at the Fermi level. By incorporation of more and more AgI content in the composition, more bridging oxygen is expected to be formed in the composition and a strong covalent bonding between Ag+ and O−2 may play dominating role for Ag+ transport over polaron hopping. Double activation energy corresponding to DC conductivity in a wide range of temperature may be considered as the signature of mixed conduction process in the present system. Estimated values of frequency exponent (n) may be highlighted to validate this mixed conduction process. Percolation type of motion of polaron may be predicted from the higher values of n for the as-prepared samples with higher AgI content. Similarly, three-dimensional Ag+ motion may be the dominating charge carriers for the samples with higher AgI content as evidenced from the moderate values of n. A schematic conduction model has been proposed to explain the nature of electrical conductivity in the present system. [ABSTRACT FROM AUTHOR]

Asymmetric scaffolds were developed through electrospinning by utilizing biocompatible materials for effective wound healing applications. First of all, the chitosan surface was modified with decanoyl chloride and crosslinked with collagen to synthesize collagen crosslinked modified-chitosan (CG-cross-CS-g-Dc). Then, the asymmetric scaffolds were fabricated through electrospinning, where the top layer was a monoaxial nanofiber of the PCL/graphene oxide quantum dot (GOQD) nanocomposite and the bottom layer was a coaxial nanofiber having PCL in the core and the CG-cross-CS-g-Dc/GOQD nanocomposite in the shell layer. The formation of monoaxial (∼130 ± 50 nm) and coaxial (∼320 ± 40 nm) nanofibers was confirmed by transmission electron microscopy (TEM). The presence of GOQDs contributed to antioxidant and antimicrobial efficacy. These scaffolds showed substantial antibacterial activity against the common wound pathogens Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). The scaffolds exhibited excellent cytocompatibility (MTT assay) and anti-inflammatory behaviour as analysed via the cytokine assay and biochemical analysis. The in vivo wound healing potential of the nanofibrous scaffolds was assessed with full-thickness excisional wounds in a rat model. The scaffolds accelerated the re-epithelialization as well as the collagen deposition, thereby facilitating the wound healing process in a very short span of time (10 days). Both in vitro and in vivo analyses thus provide a compelling argument for the use of these scaffolds as therapeutic biomaterials and their suitability for application in rapid wound regeneration and repair. [ABSTRACT FROM AUTHOR]

Recently, precise detection of VOCs in particular acetone, ammonia alcohol has attracted huge attention for industrial safety, monitoring of environment and human health. In this article we have reported for a polypyrrole nanotube (PPNT)‐based chemiresistive sensor for the selective detection of trace acetone vapour at room temperature (25 °C). Polypyrrole (PPy) nanoparticles with different morphologies, viz. nanotubes, nanowire, and globular were synthesized using methyl orange (MO), cetyltrimethyl ammonium bromide (CTAB), and pure polypyrrole as the growth template. The as synthesized powders were exploited to fabricate Taguchi‐type thick‐film sensors. The synthesized powders and fabricated sensors were characterized by multiple sophisticated techniques, such as, XRD, FTIR, Raman spectroscopy, SEM, EDS, UV‐VIS spectroscopy, optical non‐contact profilometry, and current‐Voltage (I‐V) measurement. It is observed that the PPNT sensor shows the highest response to trace acetone vapour with a lower detection limit of 500 ppb at room temperature (25 °C) and quick response (∼5.4 sec) and recovery (∼73.94 sec) times. Achieved enhanced sensing behaviour can be attributed to formation of hydrogen bond between acetone and PPy. Combined with room temperature sensing, good stability, repeatability, produce sensor may find application in various sensing fields. [ABSTRACT FROM AUTHOR]

Type 2 diabetes mellitus (T2DM) predominantly considered a metabolic disease is now being considered an inflammatory disease as well due to the involvement of meta-inflammation. Obesity-induced adipose tissue inflammation (ATI) is one of the earliest phenomena in the case of meta-inflammation, leading to the advent of insulin resistance (IR) and T2DM. The key events of ATI are orchestrated by macrophages, which aggravate the inflammatory state in the tissue upon activation, ultimately leading to systemic chronic low-grade inflammation and Non-Alcoholic Steatohepatitis (NASH) through the involvement of proinflammatory cytokines. The CD44 receptor on macrophages is overexpressed in ATI, NASH, and IR. Therefore, we developed a CD44 targeted Hyaluronic Acid functionalized Graphene Oxide Quantum Dots (GOQD-HA) nanocomposite for tissue-specific delivery of metformin. Metformin-loaded GOQD-HA (GOQD-HA-Met) successfully downregulated the expression of proinflammatory cytokines and restored antioxidant status at lower doses than free metformin in both palmitic acid-induced RAW264.7 cells and diet induced obese mice. Our study revealed that the GOQD-HA nanocarrier enhanced the efficacy of Metformin primarily by acting as a therapeutic agent apart from being a drug delivery platform. The therapeutic properties of GOQD-HA stem from both HA and GOQD having anti-inflammatory and antioxidant properties respectively. This study unravels the function of GOQD-HA as a targeted drug delivery option for metformin in meta-inflammation where the nanocarrier itself acts as a therapeutic agent. [ABSTRACT FROM AUTHOR]

A new sustainable approach for the development of value added devulcanized rubber will augment its application in tire industry and play a significant role toward the product quality, production economy and market completion. The right choice of devulcanizing agent is carried out to keep in mind that the chemical will act as superior devulcanizing agent, easily available, low cost, smoothly penetrate into the crosslinked network in presence of carrier, multifunctional activity and eco‐friendly in nature. Consequently, the current research work is focused on the devulcanization of ground tire rubber (GTR) by way of a multifunctional devulcanizing agent, bis(3‐triethoxysilylpropyl)tetrasulfide. The uniqueness of the chemical agent is that it will devulcanize GTR mechanochemically and subsequently the so‐grown devulcanized rubber can facilitate the homogeneous silica dispersion into the revulcanized rubber compound. The degree of devulcanization and the devulcanized rubber quality is measured by the swelling experiment and Horikx theory. The experimental results clearly specified that the optimal devulcanization time is 40 min to obtain better‐quality of devulcanized rubber and enhanced mechanical and thermal performance of revulcanized rubber. The homogeneous silica dispersion in the rubber matrix is further supported by the scanning electron microscopy images. Ultimately, it was established that the as‐grown technology is suitable for rubber reclaiming, which provides to the advancement in the ecological sustainability. [ABSTRACT FROM AUTHOR]

Trichobezoar are foreign bodies formed from undigested hairs that accumulate in the gastrointestinal tract and cause obstruction. Trichobezoar are usually found in the stomach but when the tail of the bezoar extends into the small intestine it is referred to as Rapunzel syndrome. Patients are usually females and have a history of psychiatric illness. However, in this study, we present two cases of Rapunzel syndrome in adult male patients that were managed with surgery. Trichobezoar should be considered in all patients with a history of psychiatric illness presenting with abdominal symptoms regardless of gender. [ABSTRACT FROM AUTHOR]

In this study, we have designed and assessed a Ketorolac tromethamine (KT) based thermally responsive in situocular gelling system. These gelling systems consist of a thermally responsive in situ gelling polymer, poloxamer 407 (PM) and different molecular weight of poly (vinyl alcohol) (PVA) as release retardant. The formulations were analyzed for sol‐gel transition temperature, gelling aptitude, viscosity and rheological studies, gel morphology study, gel dissolution property and in vitro drug release study. FTIR spectral analysis was performed to explore any polymer‐polymer or drug‐polymer association. In comparison to commercially available drugs, the new formulations present a longer‐lasting drug release profile. [ABSTRACT FROM AUTHOR]

Aim: The functionalization and characterization of antibacterial nanoceria with folic acid (FA) and elucidation of their in vivo wound-healing application. Materials & methods: Functionalization of nanoceria were done with FA using a chemical method and their antibacterial activity, cellular biocompatibility and in vivo wound-healing application were evaluated. Results: The functionalization of nanoceria with FA was done with 10–20 nm size and -20.1 mV zeta potential. The nanoformulation showed a bacteriostatic effect along with biocompatibility to different cell lines; 0.1% w/v spray of FA-nanoceria demonstrated excellent wound-healing capacity within 14 days in a Wister rat model. Conclusion: The antioxidant and reactive oxygen species scavenging activity of the FA-nanoceria make it a promising therapeutic agent as a unique spray formulation in wound-healing applications. The emergence of chronic wounds is a main reason for mortality in patients with diabetes and other severe pathological complications. Advances in the use of nanotechnology have resulted in beneficial technology for tailoring of pharmacokinetic properties of different drug-delivery vehicles for different biomedical applications. In this study, folic acid (FA) functionalized nanoceria (FA-nanoceria) were formulated and their potential efficacy in the wound-healing process was explored. The nanoformulation showed a remarkable bacteriostatic effect on both Gram-negative and Gram-positive bacteria. In vitro cell line studies showed satisfactory biocompatibility in three different types of cell lines. In addition, a 0.1% w/v spray of FA-nanoceria was applied to full-thickness wounds in an in vivo mice model where it demonstrated excellent wound-healing capacity within 14 days. The combined antioxidant and reactive oxygen species scavenging activity of both the FA and nanoceria makes FA-nanoceria a promising therapeutic agent as a unique spray formulation in wound-healing applications. [ABSTRACT FROM AUTHOR]

Diethyl chlorophosphate (DCP) has similar reactivity to sarin, which is widely known as a nerve agent that is often used in terrorist attacks. As DCP lacks high toxicity, it can be used as a model compound for sarin detection. Besides their use as chemical warfare agents (CWAs), organophosphorus compounds (OPs) also have greater implications for human health. To maintain the balance in global security the first and most in demand work is to establish efficient detection methods for monitoring CWAs. The work presented here reports a benzothiazole-based fluorescent chemodosimeter (BZ-DAM) for the fluorogenic detection of DCP via the ESIPT assisted ICT mechanism. The benzothiazole unit serves as a fluorophore, whereas the phenolic and imine groups act as a recognition unit for DCP. In this mechanistic path, the phenol group in BZ-DAM is phosphoesterified by DCP, which leads to a significant fluorescence change and assists the hydrolysis of the aldemine of BZ-DAM. The detection limit was found to be 0.43 μM by the fluorescence method. BZ-DAM is also stable in biological mediums and a physiological pH range and can be successfully used to detect intracellular DCP in living cells. Scanning electron microscopy (SEM) studies of a polycaprolactone (PCL)-BZ-DAM composite also revealed partial deformation of the surface of the nanomaterials upon the adsorption of DCP, indicating a DCP-mediated chemical transformation. [ABSTRACT FROM AUTHOR]

Physico‐mechanical and dynamic mechanical properties of typical solution grade styrene‐butadiene rubber (S‐SBR) and polybutadiene rubber (PBR) based tire‐tread compound were investigated by partially replacing highly dispersible (HD) silica with naturally occurring α‐cellulose. Fourier transform infrared spectrum detected abundance of hydroxyl group in α‐cellulose, which has created keenness to investigate its reinforcement characteristics in an S‐SBR and PBR based compound. Scanning electron microscope and transmission electron microscope were employed to investigate the microstructure and dispersion of α‐cellulose at higher magnification. Thermo‐gravimetric analysis was performed to understand the degradation behavior of α‐cellulose. Differential scanning calorimeter was engaged to detect phase transition and degree of purity of α‐cellulose. An increase in cure rate was observed with partial replacement of HD silica by α‐cellulose. The cure rate index was increased by 13% over control one at 10% replacement of silica with α‐cellulose. It was noticed that at an optimum level of replacement (10%), α‐cellulose containing compounds exhibited lower viscoelastic energy dissipation (both loss modulus [E″] and loss tangent [tan δ]) at the slight expense of tensile moduli. Beside these, substitution of silica with α‐cellulose found to have no effect on wet grip property of the compounds. [ABSTRACT FROM AUTHOR]

Here, development of some Ag2S mixed chalcogenide glassy systems has been discussed in the light of DC conductivity model and variable range hopping model. X-ray diffraction (XRD) pattern has been collected to explore microstructure of them. Various nanophases such as Ag2Se and GeSe2 have been pointed out from XRD studies. Defects have been identified in the form of dislocation, and their roles in the electrical transport properties have been established. FE-SEM micrographs exhibit their amorphous nature with distributed sharper crystal-like structure. Optical phonon frequency may cause to enhance the structural vibrations by means of increasing DC electrical conductivity. Significant enhancement of density of states near Fermi level at low and high temperatures have been explained. Present glassy structure is expected to expand to reduce the scattering cross-section for getting higher values of N(EF) at higher temperature up to a great extent. [ABSTRACT FROM AUTHOR]

Co-RGO nanocomposites are known to show interesting properties suitable for various applications. However, its use in the vital field of plasmonic nanocomposites is restricted as Co nanoparticles have high damping and dielectric loss. In this work, we have demonstrated a simple synthetic way to produce water-dispersible shape variant Co-reduced graphene oxide (RGO) hybrid nanocomposites, which can overcome those barriers and delineate two plasmonic peaks. Prepared multifunctional optical materials show both UV and visible range of plasmonic responses of Co NPs. While the single domain Co NPs show spin-up channel based sharp plasmonic peak in the UV range, the larger particles introduce shape-dependent enhancement of the excitation independent blue photoluminescence of graphene oxide (GO). Usually, due to their different size regime, it is not possible to see both UV and visible range plasmonic responses of Co NPs simultaneously. The variation of the Co particle size was deliberate to achieve multifunctionality. Shape-induced enhancement in the PL spectrum and decoration of plasmonic metal NPs are achieved. TEM micrographs of hybrids confirm the decoration of different shapes of Co nanoparticles on RGO sheets. The size distribution of the nanoparticles in the composites was quantified using two complementary techniques; SAXS/SANS and TEM. Scattering revealed the alteration of RGO agglomeration with the incorporation of differently shaped nanoparticles. Prepared hybrid nanocomposite having both the responses could be promising in magnetoplasmonics, GMR- and doping-based optoelectronics. [ABSTRACT FROM AUTHOR]

Herein, the potential impact of tamarind seed polysaccharide (TSP) on the gelation nature and in vitro release of a particular drug, pilocarpine hydrochloride, from different poloxamer 407-based ophthalmic formulations were evaluated. The combination of TSP (0.5–1.5 wt%) and 18 wt% poloxamer (PM) solutions resulted in a significant improvement in gel elasticity under physiological conditions. The introduction of TSP to PM not only enhanced the viscosity of the gel, but also stimulated the gelation procedure. Due to the inclusion of TSP, the gel dissolution rate of the PM-based formulation was greatly reduced. The FTIR spectral analysis revealed the interaction between –OH groups of both polymers, resulting in a decline in the gelation temperature of the PM–TSP-based formulations. It was also detected in the cryo-SEM analysis that the pore size of the PM gel decreased and the depth of its pores increased with the inclusion of TSP. Furthermore, the in vitro release analysis indicated that the retention capacity of PM–TSP-based formulations was superior to that of the only PM-based formulation. The SEM study and the cell viability data demonstrated the biocompatibility and non-toxicity of TSP. Therefore, the designed formulation is fairly promising to be utilized as an in situ ophthalmic drug carrier. [ABSTRACT FROM AUTHOR]

Coal being the most abundant natural resource is used worldwide and shows graphite-like clusters. Here, for the first time, we report an innovative and cost-effective oxidative functionalization approach, followed by an acid-free and oxone oxidant-assisted solvothermal synthesis of graphene quantum dots from coal. This method involving the oxidative functionalization of coal was performed through the heat treatment of nitric acid, followed by an acid recovery process. Indeed, the solvothermal method used was entirely free from the utilization of strong acids, and involved a simple, eco-friendly, and salt-free purification process with a high production yield (∼45%). Due to the synergistic synthesis technique, our developed GQDs were found to exhibit a strong blue photoluminescence (PL) characteristic with a significantly high quantum yield (∼14.42%). High-resolution transmission electron microscopy (HRTEM) images indicated that the nanocrystalline GQDs had a uniform and narrow particle-size distribution in the range of 2.5–5 nm. The anticancer efficacy of the as-synthesized GQD nanomaterial was validated through cellular morphological pattern analysis and DAPI-staining images of neuroblastoma cells and breast cancer cells. In addition, the alteration of the mitochondrial membrane potential was scrutinized using JC-1 micrographs. Interestingly, the RITC-tagged GQDs showed cellular internalization within breast cancer cells. The robust functionality, luminescence stability, nanosecond lifetime, biocompatibility, and low toxicity of our developed GQDs suggest they could be promising probes for cancer therapeutic applications. This study unveils new opportunities for the sustainable production of GQDs with novel attributing features due to the easily availability of the raw materials, their cost-effective production, and fascinating photoluminescence property. [ABSTRACT FROM AUTHOR]

Nanoclay-based drug delivery vehicle has acquired immense recognition owing to its unique physico-chemical properties. In this study, tetracycline hydrochloride (TCH) drug was intercalated into the interlayer gallery of montmorillonite (Mt) clay by a cation exchange process. The intercalated nanocomposites were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive X-ray and thermogravimetric study. It was evident from the characterization that TCH drug was successfully intercalated into the interlayer gallery of Mt clay. These clay-based formulations exhibited antibacterial activity against both Gram-positive and Gram-negative bacteria on analyses via zone inhibition methods. An in-vitro drug release study was performed in phosphate buffer at physiological temperature and interestingly it exhibited sustained and controlled release of TCH from the nanocomposites, after an initial burst-out effect. Overall, this study showed that these nanocomposite materials have immense potential for use in controlled drug delivery strategies for antibacterial treatment. [ABSTRACT FROM AUTHOR]

This article investigates the possibility of using electrical impedance spectroscopy (EIS) technique for detection and quantification of metanil yellow (MY) in turmeric powder. The observation is supported by ultraviolet–visible (UV–Vis) absorption spectroscopy and Fourier transform mid infrared (FT-MIR) spectroscopy. Variation of electrical parameters like capacitance, impedance, conductance, and current–voltage (I–V) characteristics for pure as well as adulterated turmeric are analyzed. System capacitance, conductance, and current are observed to increase, whereas the impedance values have been found to decrease with increase in MY content. Also, UV–Vis and FT-MIR spectroscopic measurements suggest the increase of absorbance with gradual increment of MY in the solution. Electrical and optical results have been physically corroborated with respect to the system internal energy. This study sought to provide a deterministic approach towards developing an EIS-based adulterant sensor for simple, rapid, economical, and precise quantification of controlled percentage weights of MY in pure turmeric powder. [ABSTRACT FROM AUTHOR]

Ethoxy functionalized devulcanize natural rubber (DeVulcNR) is used as compatibilizer for silica/graphene oxide (SiO2@GO) hybrid fillers in the styrene butadiene rubber (SBR) to fabricate SBR composites. The dispersion behavior of SiO2@GO hybrid filler was investigated through scanning electron microscopy (SEM) analysis of the tensile fracture surface along with the broken rubber surface developed by plunging into liquid nitrogen. The rubber–filler interfacial interactions were evaluated through the measurement of equilibrium swelling experiment, fraction of immobilized polymer chain by DSC study, FTIR analysis, and molecular dynamics simulation. The results reveal that in the presence of DeVulcNR, the rubber–filler interaction is enhanced compared with that of the control formulations containing only SBR. SiO2@GO hybrid‐filler shows synergistic effect on the mechanical properties of the composites in the presence of DeVulcNR. The improved mechanical properties of the SiO2@GO hybrid filler rubber composites may be due to chemical interaction among the functional groups of SiO2 and GO with the DeVulcNR. Further, XRD study indicates that there is no significant layer‐by‐layer restack of GO in the SBR/DeVulcNR composites. The higher storage modulus and lower tan δ of the SiO2@GO hybrid filler rubber composites show superior interfacial interaction between rubber and filler compared with that of the control formulations. POLYM. COMPOS., 40:E1559–E1572, 2019. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

A 61-year-old man presented with non-specific abdominal symptoms, including left groin pain and change in bowel habits. Investigations revealed a cystic lesion, containing numerous irregular calcifications, with the primary differential being a dermoid cyst containing teeth-like calcifications. At laparoscopy it was found to be a Meckel’s diverticulum, containing a large number of enteroliths. This case revealed the importance of considering enteroliths in patients with imaging showing intra-abdominal calcifications, and laparoscopy for diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Background: Bacteria endogenously residing within the plant tissues have attracted significant attention for production of biopolyester, polyhydroxyalkanoates (PHAs). Bacillus cereus RCL 02 (MCC 3436), a leaf endophyte of oleaginous plant Ricinus communis L. accumulates 81% poly(3-hydroxybutyrate) [P(3HB)] of its cell dry biomass when grown in mineral salts (MS) medium.Methods: The copolymer production efficiency of B. cereus RCL 02 was evaluated in valeric acid supplemented MS medium under biphasic cultivation condition. The copolymer so produced has been compared with the P(3HB) isolated from RCL 02 in terms of thermal, mechanical and chemical properties.Results: Valeric acid supplementation as co-substrate in the medium has led to the production of copolymer of 3-hydroxybutyrate (3HB) and 3-hydroxyvalerate (3HV) [P(3HB-co-3HV)] with 14.6 mol% 3HV. The identity of the polymers has been confirmed by X-ray diffraction (XRD) analysis, Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic studies. Thermogravimetric analysis (TGA) revealed that P(3HB) and P(3HB-co-3HV) films degraded at 278.66°C and 273.49°C, respectively. The P(3HB-co-3HV) showed lower melting temperature (165.03°C) compared to P (3HB) (170.74°C) according to differential scanning calorimetry (DSC). Incorporation of 3HV monomers decreased the tensile strength (21.52 MPa), tensile modulus (0.93 GPa), storage modulus (E′) (0.99 GPa) and increased % elongation at break (12.2%) of the copolyester. However, P(3HB) showed better barrier properties with lower water vapor transmission rate (WVTR) of 0.55 g-mil/100 in2/24 h.Conclusion: These findings emphasized exploration of endophytic bacterial strain (RCL 02) to produce biodegradable polyesters which might have significant potential for industrial application. [ABSTRACT FROM AUTHOR]

Cellulose nanofibrils (CNFs) have attracted attention as a promising material in the biomedical field because of their outstanding properties such as hydrophilicity, biocompatibility, biodegradability, and high surface area. In this work, we have prepared cellulose nanofibrils from jute fibres (JF), to develop a CNF/chitosan transdermal film for the delivery of ketorolec tromethamine (KT) where the CNFs act as an elegant nanometric carrier. The KT-loaded CNF/chitosan transdermal film matrices have been characterized by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Fourier transform infrared spectroscopy (FTIR) reveals the successful KT loading into the CNF/chitosan transdermal film. Scanning electron microscopy (SEM) study shows the different morphological features of the CNF/chitosan transdermal films. The crystalline nature of the CNF/chitosan transdermal films has been analyzed by X-ray diffraction study. Release profiles from the CNF/chitosan matrices indicate that the drug release rate is sustained with the incorporation of CNFs. We believe that this new nanocarrier may be a potential choice for transdermal drug delivery systems. [ABSTRACT FROM AUTHOR]

Recently transdermal drug delivery systems (TDDS) based on polymeric nanocomposites have been widely researched by polymer and biomedical scientists for the remedy of various diseases. Thus to develop an efficient patch, we have synthesized guar gum-g-polyacrylamide by free radical polymerization using potassium persulphate as an initiator. The transdermal membranes were fabricated via solution casting, by incorporating different wt% of nanosilica and diltiazem hydrochloride to the synthesized copolymer. The resulting copolymer and the nanocomposite membranes were characterized using solid state 13C nuclear magnetic resonance, Fourier transform infrared spectra, thermo-gravimetric analysis, electron microscopy and viscometry. A hydro-swelling study and surface contact angle measurement showed that the membrane containing 1 wt% nanosilica was the most hydrophobic. The in vitro drug release patterns of all the transdermal membranes showed that the nanocomposite containing 1 wt% nanosilica provides the best result with 8.58 and 24.76% drug release after 5 and 20 h, respectively. Furthermore, the nanocomposite formulation exhibited good cyto-compatibility and non-irritant behaviour, which are primary requirements for an efficient transdermal drug delivery system. [ABSTRACT FROM AUTHOR]

In recent times, biosynthetic approaches toward the synthesis of nanoparticles have been shown to have several advantages over physical and chemical methods. Here, we report the extracellular mycosynthesis of γ-FeO nanoparticles by Alternaria alternata. The fungal biomass when exposed to aqueous iron(III) chloride solution led to the formation of highly stable γ-FeO nanoparticles extracellularly. The influence of these biosynthesized γ-FeO nanoparticles on the properties of hydroxyl propyl methyl cellulose was also investigated. Characterization of the biosynthesized γ-FeO nanoparticles and HPMC-γ-FeO nanocomposite films were done by the different types of spectral and electron microscopic analysis. The size of the γ-FeO nanoparticles ranges from 75 to 650 nm. The mechanical effect of the agglomerated γ-FeO nanoparticles into the HPMC polymer matrix was also investigated. [ABSTRACT FROM AUTHOR]

Chemical reduction of graphene oxide (GO) to graphene employs the use of toxic and environmentally harmful reducing agents, hindering mass production of graphene which is of tremendous technological importance. In this study we report a green approach to the synthesis of graphene, bio-reduced by crude polysaccharide. The polysaccharide reduces exfoliated GO to graphene at room temperature in an aqueous medium. Transmission electron microscopy image provides clear evidence for the formation of few layer graphene. Characterization of the resulting polysaccharide reduced GO by Raman spectroscopy, Fourier transform infrared spectroscopy and Energy dispersive X-ray analysis confirms reduction of GO to graphene. We also investigated the degree of biosafety of the reduced GO and found it to be safe under 100 μg/ml. [ABSTRACT FROM AUTHOR]

Lac, a natural resin, is used to synthesize gold nanoparticles (AuNPs). This biodegradable natural fluorophore contains different laccaic acids, which consist of mainly the derivatives of red anthraquinone dye. For the first time, we report an in situ green synthesis of fluorophore stabilized AuNPs. The synthesis of AuNPs is monitored using both excitation and emission spectrophotometry, which gives us an idea about the progress of the reaction during nanoparticles synthesis. The size of the synthesized nanoparticles is visualised by TEM. The TEM data of the AuNPs are also correlated using DLS measurements, and the zeta potential values establish the stability of the nanoparticles. The FTIR spectra indicate the different groups present in lac and also their probable interactions during the reducing-cum-stabilizing process with the nanoparticles. The AuNPs are crystalline in nature, which is established by XRD analysis. The lac extract also binds with calf thymus DNA and forms a ground state complex, which is established spectrophotometrically by UV-Vis, as well as fluorimetrically. The antimicrobial tests against bacteria and the antitoxicity study have revealed that the lac stabilized AuNPs are safe and non-toxic, having the potential for clinical applications in the medical field. [ABSTRACT FROM AUTHOR]

Graphene and its related materials are important areas of research in recent years owing to their unique properties. The wide-range industrial application of graphene-related compounds has led to the development of novel and simple methods for the synthesis of graphene. In this paper, an environmentally friendly green synthesis for the partial reduction of graphene oxide (GO) to reduced GO (RGO) in a cost-effective single-step mechanism was reported. The method completely avoids the use of toxic and environmentally harmful reducing agents commonly used in the chemical reduction of GO to obtain RGO. The reduction of GO was carried out using aqueous leaf extracts of Paederia foetide L. The prepared GO and green RGO were characterized by ultraviolet-visible, Raman and Fourier transform infra-red spectroscopic analysis which showed a clear indication of the partial removal of oxygen-containing groups from the GO and the formation of RGO. The morphology of the green RGO was characterized by transmission electron and scanning electron microscopy. Dynamic light scattering was used for zeta potential measurement and correlated with the morphology of the sheets. Electrical conductivity was also measured to check the extent of reduction of GO to RGO. [ABSTRACT FROM AUTHOR]

Bile salts carry out a vital bioactive responsibility among the various physiologically important molecules. The use of bile acids and their conjugates in nanoscience is a novel idea, which opens up fascinating prospects and gives rise to various versatile properties. Sodium cholate, a biosurfactant which is environmentally safe, has been used to reduce and stabilize silver nitrate solution. The silver nanostructures thus produced are crystalline and anisotropic in nature and show different types of particle shapes and sizes depending on the reaction conditions including star and wire shapes which have not been reported earlier, by simply varying the reaction conditions. The silver precursor concentration and the ratio of sodium cholate to silver precursor were the key factors which controlled the morphosynthesis. The formation of the silver NPs was monitored using UV-vis spectrophotometry. The transmission electron microscopy (TEM) technique was used to study the morphology of the synthesized NPs. Fourier transform infrared (FT-IR) spectroscopy was used to identify the interaction of sodium cholate with the synthesized NP. The possible mechanistic role of sodium cholate in the reduction and stabilization of silver nanoparticles (Ag NPs) has also been discussed. The obtained Ag NPs exhibit antibacterial and anticancerous activities. The present study also explores the cytotoxic role of Ag NPs in KG-1A (human acute myeloid leukemia) and K562 (human chronic myeloid leukemia) cell lines. [ABSTRACT FROM AUTHOR]

Alkyne-terminated poly( d,l-lactide-co-glycolide) (PLGA) has been synthesized via ROP at room temperature. Amphiphilic PLGA- b-poly( N-vinylpyrrolidone) (PNVP) block copolymers have been synthesized via alkyne-azide click reaction of it with azide-terminated PNVPs prepared by RAFT polymerization of NVP using an azide-terminated RAFT agent. H NMR and gel permeation chromatography (GPC) confirmed the formation of block copolymers. Self-assembly of these block copolymers was confirmed by fluorescence study using pyrene as a probe and supported by H NMR, DLS and TEM studies. Hydrophobic drug doxorubicin was successfully encapsulated at the micellar core of PLGA- b-PNVP with drug-loading content (DLC) and drug-loading efficiency (DLE) of 10.8 and 43.2 %, respectively. Sustained drug release of these drug-loaded micelles was observed at both pH of 6.4 and 7.4. Faster drug release was observed at pH 6.4. Such PLGA- b-PNVP amphiphilic block copolymer may find extensive application in sustained drug delivery, specifically in antitumor drug delivery. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Food Science (John Wiley & Sons, Inc.) is the property of John Wiley & Sons, Inc. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The impedance, capacitance and conductance of deionized waterglucose polar solution is measured by employing impedance spectroscopy and a quasi-oscillatory nature of variation with glucose content in the solution is observed. Such quasi-oscillatory nature is attributed to the randomly distributed water-water, waterglucose and glucose-glucose dipole interactions at the molecular level in the solution. A relevant analytical model is developed on the basis of such random distribution of the molecular dipoles and the experimental data agree well with those obtained from the theoretical model. The electrical parameters are measured in the frequency range of 100Hz to 4MHz for the volume fractions of glucose with respect to water in the range of 0.1 to 0.5. The impedance, capacitance and conductance are obtained to be in the range of 1.03 kΩ - 112 kΩ, 34.9 pF - 1.66 nF, and 8.95 μS - 52.9 μS respectively for the glucose volume fraction range considered. [ABSTRACT FROM AUTHOR]

A rapid polymerization technique was successfully employed to synthesize interconnected polyaniline ( PANI) nanofibers using chemical oxidative polymerization inside a soft template. The thermoreversible hydrogels of Lutrol F 127 and gelatin were used as templates where the interstices present in the hydrogel were responsible for the formation of PANI nanofibers with a diameter in the range ca 70−75 nm and ca 50−55 nm respectively and several micrometers in length. The doped emeraldine salt of PANI was confirmed by Fourier transform infrared spectroscopy and ultraviolet-visible spectroscopy. The crystallinity of as-synthesized PANI nanofibers for both cases was verified by an X-ray diffraction study while thermogravimetric analysis was performed to compare the relative stability of the synthesized PANI nanofibers. The electrical conductivities of polymerized PANI are of the order of 10−3 S cm−1 and are compared with those of template fabricated PANI. The Lutrol F 127 gel guided PANI nanofibers showed a rectifying property while the gelatin gel guided PANI provided a simple ohmic nature. © 2013 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Poly(butylene adipate- co-terephthalate) (PBAT) nanocomposites films are prepared by a solution intercalation process using natural montmorillonite (MMT) and cetyltrimethylammonium bromide (CTAB)-modified montmorillonite (CMMT). Cation exchange technique has been used for modification of MMT by CTAB and characterized by Fourier transform infrared analysis, thermo-gravimetric analysis, and X-ray diffraction (XRD) studies. CMMT gives better dispersion in the PBAT matrix than MMT and is confirmed by XRD and transmission electron microscopy. Because of better compatibility of CMMT, water vapor transmission rate of PBAT decreases more in the presence of CMMT than MMT. The biodegradability of PBAT and its nanocomposite films are studied in compost and from the morphological analysis it is apparent that the PBAT/CMMT shows a lower biodegradation rate in comparison to the PBAT/MMT. The antimicrobial activity of PBAT and its nanocomposite films is tested by an inhibition zone method. Because of the presence of the quaternary ammonium group of CTAB-modified MMT, PBAT/CMMT nanocomposites show adequate antimicrobial activity. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40079. [ABSTRACT FROM AUTHOR]