Productizing Nano-Bioactive Glass-Based Bilayer Scaffolds: A Graft for Reconstruction of Mandibular and Femoral Bone Defects

This investigation aimed to construct a bilayer scaffold integrating alginate and gelatin with nanobioactive glass (BG), recognized for their efficacy in tissue regeneration and drug delivery. Scaffolds, namely, alginate/gelatin (AG), alginate-/actonel gelatin (AGD), alginate actenol/gelatin-45S5 BG (4AGD), and alginate-actonel/gelatin-59S BG (5AGD), were assembled using a cost-effective freeze-drying method, followed by detailed structural investigation via powder X-ray diffraction as well as morphological characterization using field emission scanning electron microscopy (FESEM). FESEM revealed a honeycomb-like morphology with distinct pore sizes for nutrient, oxygen, and drug transport. The scaffolds evidently exhibited hemocompatibility, high porosity, good swelling capacity, and biodegradability. In vitro studies demonstrated sustained drug release, particularly for scaffolds containing actonel. In vivo tests showed that the bilayer scaffold promoted new bone formation, surpassing the control group in bone area increase. The interaction of the scaffold with collagen and released ions improved the osteoblastic function and bone volume fraction. The findings suggest that this bilayer scaffold could be beneficial for treating critical-sized bone defects, especially in the mandibular and femoral regions.

Crucial Chemical Revelations in 45S5 Bioactive Glass via Sequential Precursor Integration Order

Among the wet chemical nanoparticle fabrication techniques, the sol-gel process happens through hydrolysis and subsequent polycondensation reactions. The bioactive glass known as the 45S5 SiO2-Na2O-CaO-P2O5 quaternary system has intricate chemistry, yet its advantages benefit the biomedical field on an enormous scale. The order in which the ethanol and TEOS inclusions are exchanged was investigated in this work because it has a direct impact on the early hydrolysis process. Another strategy involves adding phosphate species to the sol before gelation, modifying the network chemistry, and interpreting the findings. Adding phosphate species before gelation in the biomaterial (E-Si-P) resulted in the formation of hydroxyapatite and other calcium silicate phases at 800 °C. Swapping ethanol and TEOS biomaterials (E-Si and Si-E) resulted in the sodium-calcium silicate phase only. Si-E with strong Si-O-Si siloxane rings demonstrated superior mechanical stability, hemocompatibility, and bioactivity. This compact Si-O-Si decreased the surface area of Si-E. XPS spectra revealed that E-Si-P has the lowest Na 1s binding energy (BE) and the highest BE for Si 2p. More Si-O-/Si-OH groups formed by E-Si make the network weak and decrease the surface area and protein adsorption. These differences significantly influenced the morphology, surface properties, mechanical studies, and compatibility test. This study has further unraveled the protocol to design a biomaterial with mechanical stability and load-bearing ability. In addition, the appropriate protocol to yield the desired property-rich biomaterial with preserved bioactivity, mechanical stability, cytocompatibility, as well and surface porosity has been elaborated in detail.

Enhancing Interplanar Spacing in V2O3/V3O7 Heterostructures to Optimize Cathode Efficiency for Zn-Ion Batteries

The improvement of sophisticated cathode materials plays a major role in boosting the efficiency of Zn-ion batteries. These batteries have garnered considerable interest as a result of their excellent energy density and the promise of cost-effective solutions for energy storage. In this work, we present a novel approach to progress the electrochemical investigation of Zn-ion batteries by expanding the interplanar distance of layered hydrated V2O3/V3O7 heterostructure nanosheets. Electrochemical investigations were conducted to assess the effectiveness of the stacked hydrated V2O3/V3O7 heterostructure as a cathode component for Zn-ion batteries. The expanded interplanar space as a result of the introduction of water molecules facilitates the insertion/extraction of Zn ions, leading to significantly enhanced electrochemical characteristics. The layered hydrated V2O3/V3O7 heterostructure exhibited an impressive specific capacity of 330 mAh g-1 at a current density of 0.1 A g-1, maintaining a capacity retention of approximately 92.3% and a coulombic efficiency of 95.8% even after 2000 cycles.

Rapidly derived equimolar Ca: P phasic bioactive glass infused flexible gelatin multi-functional scaffolds - A promising tissue engineering

The study aims to design and fabricate an ultra-easier multi-functional biomedical polymeric scaffold loaded with unique equimolar Ca:P phasic bioactive glass material (BG). Gelatin (G) - 45S5 bioactive glass (BG) scaffolds were synthesized via a simple laboratory refrigerator with higher biocompatibility and cytocompatibility. The results proved that BG has enhanced bio-mineralization of the scaffolds and results support that the G: BG (1:2) ratio is the more appropriate composition. Brunauer-Emmett-Teller (BET) study confirms the higher surface area for pure Gelatin and G: BG (1:2). Scanning Electron Microscopic images display the precipitation of hydroxycarbonate apatite layer over the scaffolds on immersing it in simulated body fluid. Alkaline phosphate activity proved that G: BG (1:2) scaffold could induce mitogenesis in MG-63 osteoblast cells, thus helping in hard tissue regeneration. Sirius red collagen deposition showed that higher content bioactive glass incorporated Gelatin polymeric scaffold G: BG (1:2) could induce rapid collagen secretion of NIH 3T3 fibroblast cell line that could help in soft tissue regeneration and earlier wound healing. The scaffolds were also tested for cell viability using NIH 3T3 fibroblast cell lines and MG 63 osteoblastic cell lines through methyl thiazolyl tetrazolium (MTT) assay. Thus, the study shows a scaffold of appropriate composition G: BG (1:2) can be a multifunctional material to regenerate hard and soft tissues.

Lattice distortion-driven band gap engineering and enhanced electrocatalytic activity of Mn-substituted nanostructured SrTiO3 materials: A comprehensive investigation

The lattice distortion and electrocatalytic activity are investigated by the mono-substituent of Mn with different concentrations to generate localized states in the electronic structure of SrTiO3. The sol-gel approach has been employed to fabricate SrTiO3 and SrTi1-xMnxO3 nanostructures (NSs). The structural analysis indicates Mn incorporation into Ti sites of SrTiO3, which shifts the lattice towards a higher diffraction angle with a single-phase cubic structure. The optical absorption spectra exhibit a decrease in band gap from 3.27 to 1.89 eV and reveal the shift in band edge positions towards the visible region. XPS analysis is carried out to confirm the formation of oxygen vacancies and valence band edge position. For SrTi0.88Mn0.12O3, OER and HER have the overpotential of 445 and 157 mV at a current density of 100 and 10 mA cm-2. Hence, the substitution of Mn (x = 0.12) into SrTiO3 lattice results in lattice distortion that enhances the electrochemical performance compared to SrTiO3. The current work manifestly established the optimal Mn composition (x = 0.12) in SrTiO3 lattice as desirable materials with defective valence states for required electrocatalytic redox potential as well as the acceleration of charge transfer kinetics towards water splitting applications.

High-performance EMI shielding effectiveness of Fe3O4-3D rPC nanocomposites: a systematic optimization in the X-band region

In this work, the microwave absorption (MWA) performance of a Fe3O4-3D reduced porous carbon nanocomposite (3D rPC NC) in the X-band region is reported. Three different shields are fabricated by altering the ratio of Fe3O4 nanoparticles (NPs) and 3D rPC and evaluating their microwave (MW) shielding performance with appropriate in-wearing instruments due to their minimum thickness. The chemical interaction between Fe3O4 NPs and 3D rPC is examined from chemical composition analysis of Fe3O4-3D rPC (1 : 2 ratio), which is confirmed by the presence of the Fe-O-C bond in the O 1s spectrum obtained from XPS analysis and subsequent analysis using FESEM images. Furthermore, it is found from N2 adsorption/desorption analysis that 3D rPC possesses a huge surface area of 787.312 m2 g-1 and showcases a type-V isotherm (mesoporous and/or microporous) behavior. The dielectric and magnetic losses of Fe3O4-3D rPC with a 1 : 2 ratio (tan δεr = 1.27 and tan δμr = 5.03) are higher than those of Fe3O4 NPs, 3D rPC and their NCs due to its magnetic and electrical conducting pathways modifying the material's polarization and dipole moment. The lightweight, polymer-free Fe3O4-3D rPC (1 : 2) NCs with minimum thickness on the order of 0.5 mm exhibited a higher total shielding effectiveness (SET = 41.285 dB), and it effectively blocked 99.9963% of the transmittance due to electric and magnetic polarization resulting from the presence of a heterogeneous interface surface.

Layered Structures of Enriched V5+ States of Vanadium Oxide as a Hybrid Cathode Material for Long-Cyclable Aqueous Zinc-Ion Batteries

Recently, aqueous zinc-ion batteries (AZIBs) have garnered much attraction because of their ecofriendly nature, cost effectiveness, and reliability. However, there are still many challenges in developing suitable cathode materials for practical usage in ZIBs. In this work, we have synthesized a layered V⁵⁺-rich vanadium oxide (V₆O₁₃) flaky structure that provided the electrolyte with a large active surface area. In addition to that, the mixed (V^4+/V⁵⁺) valence states of V have significantly improved the ionic diffusion of Zn²⁺, thereby improving the V₆O₁₃ electrical conductivity. Therefore, the AZIBs based on the layered structure V₆O₁₃ cathode with 1 M ZnSO₄ electrolyte exhibited a very high specific capacity of 394 mAh g^-1 @ 0.1 A g^-1 without the addition of any additives or electrode modification. The rate capability and cycle life are investigated at the current density of 2 A g^-1, where the capacity retention was found to be around 94% along with a coulombic efficiency of 96% for over 100 cycles. Such a material with high electrochemical performance can be used for portable electronic devices and electric vehicular applications.

Influence of pH in the synthesis of calcium phosphate based nanostructures with enhanced bioactivity and pro-angiogenic properties

In synthetic fabrication, the process parameters decide the growth nucleation, phase translation, and the evolution of morphological facets of nanostructured materials. This work demonstrates the formation of different crystallographic phases of calcium phosphate by the influence of pH from acidic to alkaline conditions and also investigated their bone regeneration, protein adsorption, and pro-angiogenic properties. Present results illustrate that the alteration of pH is the crucial factor for the synthesis of calcium phosphate (CP) phases. The structural analysis reveals the monetite (CaHPO₄ ) phase with a triclinic crystal system for pH 5, dual-phase of monetite combined with hydroxyapatite at the neutral pH 7, and pure phase of hydroxyapatite (Ca₁₀ [PO₄ ]₆ OH₂ ) with hexagonal structure at pH 10. Microscopic analysis portrays the cubic and rod-like morphologies by changing the pH values. FTIR and RAMAN spectroscopic analyses confirm the stretching, bending, and vibrational modes of dominant phosphate groups of different CP phases. Further, the biocompatibility of the prepared CP phases was examined by hemolysis assay, which showed less than 2% of lysis and enhanced cell viability. Moreover, the bioactivity study revealed rapid mineralization and a higher protein adsorption rate for the monetite CP phase (M-CP). Subsequently, the chick embryo angiogenesis assay elucidated 33% higher neovascularization for M-CP compared with the other two CP phases. The fabricated M-CP nanostructure constitutes a promising candidate for biomedical applications.

Influence of varying thermal treatment on bioactive material with equal Ca/P ratio: A local drug delivery system for bone regeneration

Designing a biomaterial with excellent bioactivity, biocompatibility, mechanical strength, porosity, and osteogenic properties is essential to incorporate therapeutic agents in order to promote efficient bone regeneration. The work intended to prepare bioactive glass with tailor-made equal Ca/P (CP) ratio to obtain clinophosinaite (Cpt) as dominant phase. Clinophosinaite (Na₃ CaPSiO₇ ) is one of the rarest phases of bioactive glass (BG), which is supposed to play key role in bioactivity. The novelty of this work is to track the required sintering temperature to attain equimolar calcium phosphate-containing clinophosinaite phase and its behavior. Further, its consequent physicochemical and biological properties were analyzed. Phase transition from Rhenanite to Cpt, and later the Cpt emerged as dominant phase with increase of calcination temperature from 700 to 1000°C was studied. The quantifying evolution of Cpt with Rhenanite over increasing annealing temperature also results with the major morphological modifications. BET analysis confirmed the surface area and porosity (Type-IV mesoporous) were gradually elevated upto 900°C, which had contrary effect on mechanical strength. Formation of hydroxyl carbonate apatite (HCA) layer confirmed the bioactivity of the prepared samples at varying time intervals. The CP samples demonstrated better hemocompatibility in post-immersion (i.e., less than 1% of lysis) when compared with pre-immersion. Enhanced protein adsorption and cumulative release (85%) of Simvastatin (SIM) drug was attained at 900°C treatment.

High Temperature stabilized Defect Pyrochlore Bi2-xFexWO6 nanostructures and their effect on Photocatalytic Water Remediation and Photo-electrochemical Oxygen Evolution Kinetics

Herein, Fe3+ ions substituted Bi2WO6 nanostructures have been fabricated by a facile co-precipitation technique with Fe concentrations varying from X = 0, 0.2, 0.5, 1.0, and 1.5. X-ray diffraction analysis...

Invigorating chronic wound healing by nanocomposites composed with bioactive materials: a comprehensive review

Wound healing research has revealed a plethora of data regarding various techniques for treating diverse types of wounds. It is well known that chronic wounds heal slowly and are vulnerable to infection. Also, there are numerous factors like destitute blood passage, undetermined inflammation, angiogenesis, neuropathy, and cell multiplication which overhang chronic wound healing. To eliminate the speculative features of chronic wounds, we made a consecutive survey on specific categories of biomaterials like bioglass, bioactive glass, bioceramics, biopolymers, and biocompatible metal oxide nanoparticles. In particular, the bioglass or bioactive glass which is a silica matrix composed of sodium, calcium, phosphorous, etc., is used for bone-bonding ability and easily dissolved in vivo conditions to repair damaged and wounded tissues with their peculiar physiochemical (surface area, porous nature, structural formation, mechanical stability) and biological properties (biocompatible, cytocompatible, osteoinductive, angiogenesis, hemostatic, antibacterial, and anti-inflammation). Furthermore, based on the existing literature studies, we summarized the healing of diabetes wound tendency by bioactive composite materials and offer detailed information on the method, techniques, and future technologies for wound healing.

Unscrambling the Influence of Sodium Cation on the Structure, Bioactivity, and Erythrocyte Compatibility of 45S5 Bioactive Glass

The 45S5 bioglass uttering Class A bioactivity promotes both osteoconduction as well as osteoinduction. Though one of the higher reactive bioactive materials known with structural and physiological influence upon ionic modulation, poor mechanical properties are perceived. The possible solution to overcome the weak stability is to choose material's composition that provides retained bioactivity and improved mechanical stability. Meanwhile, primary burst out of Na⁺ ions increases the local pH, harms cell life, and acts as a well-known disruptive modifying species that weakens the bioactive glass network, decreasing network connectivity, showing faster degradation and lowering mechanical stability. Therefore, in this study, more detailed systematic exploration on structural influence of sodium monovalent cation and its behavior on physiological environment was genuinely studied and reported that bioactivity of the bioactive glass can be highly achieved even without Na⁺ ions. The result exhibits benefits of sodium free bioactive glass (denoted as No Na⁺ BG) over Na⁺ BG and exhibits improved mechanical stability and also possible degradability, having in-built apatite phase even before immersion in simulated body fluid (SBF). Also, sodium free bioglass proved as a superior candidate for erythrocyte compatibility with rapid clotting tendency on interaction with blood and a promising replacement for 45S5 bioglass in all aspects especially in mechanical stability view, which can withstand more than 5 months in phosphate buffer saline (PBS).

Pulsed laser deposition of nanostructured bioactive glass and hydroxyapatite coatings: Microstructural and electrochemical characterization

Bioactive coatings on metallic implants promote osseointegration between bone and implant interfaces. A suitable coating enhances the life span of the implant and reduces the requirement of revision surgery. The coating process needs to be optimized such that it does not alter the bioactivity of the material. To understand this, the biocompatibility of nanostructured bioactive glass and hydroxyapatite-coated Titanium substrate by pulsed laser deposition method is evaluated. Raman and IR spectroscopic techniques based on silica and phosphate functional groups mapping have confirmed homogeneity in coatings by pulse laser deposition method. Comparative studies on nanostructured bioactive glass and hydroxyapatite on titanium surface elaborated the significance of bioactivity, hemocompatibility, and cytocompatibility of the coated surface. Notably, both hydroxyapatite and bioactive glass show good hemocompatibility in powder form. Hemocompatibility and cytocompatibility results validate the enhanced sustenance for hydroxyapatite coating. These results signify the importance of the choice of coating methodology of bioceramics towards implant applications.

New Insights for Consummate Diagnosis and Management of Oral Submucous Fibrosis Using Reactive and Reparative Fibrotic Parameter Derived Algorithm

Objective

Reproducibility of qualitative changes in histopathological diagnosis involving narrow variation is often challenging. This study aims to characterize the histological fibrotic events in detail so as to derive an in-depth multiparametric algorithm with individually quantified histological parameters for effective monitoring of the. disease process in oral submucous fibrosis and for potential therapeutic targets for early intervention.

Methods

Formalin fixed paraffin embedded (FFPE) blocks of oral submucous fibrosis (OSMF), were taken and sections were stained with Hematoxylin & Eosin stain and Masson Trichrome stain. Photomicrographs were assessed for various morphometric parameters with Image J software version 1.8. Linear Regression was used to model the relationship using Inflammatory Cell Count, Extent of Inflammation collagen stained area, Epithelial thickness integrated density of collagen, MVPA, Area, Perimeter, were taken as variables.

Result

Inflammatory cell count and the extent of inflammation also decreased with increasing grades of OSMF. Collagen proportionate area, integrated collagen density and epithelial thickness were compared among different grades of OSMF. Grade IV OSMF had greatest mean collagen proportionate area , highest integrated collagen density and lowest epithelial thickness when compared to other grades of OSMF. Linear regression model revealed smaller variation between Grade I to Grade II. Whereas Grade II to Grade IV exhibited larger variation suggestive of increased growth rate and all the coefficients were found to lie within 95% confidence limits.

Conclusion

Diagnostic algorithm with multiparametric regression model were derived and combinatorial therapeutic approaches have been suggested for more effective management of oral submucous fibrosis.

Role of bioglass in enamel remineralization: Existing strategies and future prospects-A narrative review

Enamel, once formed, loses the ability to regenerate due to the loss of the formative ameloblasts. It is subjected to constant damaging events due to exposure to external agents and oral microbiomes. An enamel remineralization process targets to replenish the lost ionic component of the enamel through a multitude of methods. Enamel remineralization is highly challenging as it has a complex organized hierarchical microstructure. Hydroxyapatite nanocrystals of the enamel vary in size and orientation along alignment planes inside the enamel rod. The inability of the enamel to remodel unlike other mineralized tissues is another substantial deterrent. One of the well-known biomaterials, bioglass (BG) induces apatite formation on the external surface of the enamel in the presence of saliva or other physiological fluids. Calcium, sodium, phosphate, and silicate ions in BG become responsive in the presence of body fluids, leading to the precipitation of calcium phosphate. Studies have also demonstrated the bactericidal potential of BG against Streptococcus mutans biofilms. The anticariogenicity and antibacterial activity were found to be enhanced when BG was doped with inorganic ions such as F, Ag, Mg, Sr, and Zn. Due to the versatility of BG, it has been combined with a variety of agents such as chitosan, triclosan, and amelogenin to biomimic remineralization process. Key strategies that can aid in the development of contemporary enamel remineralization agents are also included in this review.

Biological performance of metal metalloid (TiCuZrPd:B) TFMG fabricated by pulsed laser deposition

The aim of our study is to investigate the effect of boron with different ratios in Ti-Cu-Pd-Zr metallic glass (MG) matrix (Ti-Cu-Pd-Zr:B) fabricated by Pulsed Laser Deposition (PLD) for biomedical implants. The Ti based Thin Film Metallic Glasses (TFMGs) in combination with boron (in different atomic %) was assessed in attaining the combined properties, like outstanding corrosion resistant properties and good biocompatibility in this work. The disordered structure and amorphous nature of the Ti-Cu-Pd-Zr:B thin films systems were achieved by the PLD process and affirmed by XRD and transmission electron microscopy. The boron incorporation in the TFMG has been elucidated by XPS analysis. The boron containing films displays distribution of boron protuberances interleaved in the amorphous matrix was stated from SEM analysis. It is found that increase in atomic percentage of boron contents in TFMG results in the improvement in glass transition temperatures. The electrochemical parameters suggest better corrosion resistance and capabilities of passivity when boron percentage was increased in the film thereby preventing adverse biological reactions. TFMGs exhibited excellent hemocompatibility by preventing the platelet activation. MTT assay manifests increase in cell concentration with culture period on the TFMGs for the MC3T3-E1 preosteoblasts cells. Cell morphology was also studied which confirmed the viable state of the cells on the TFMG surfaces. The combination of such distinctive properties marks these TFMG systems as prospective aspirants for biomedical implants.

Respiratory health status is associated with treatment outcomes in pulmonary tuberculosis

<sec id="st1"> <title>BACKGROUND</title> The association between respiratory impairment and tuberculosis (TB) treatment outcomes is not clear. </sec> <sec id="st2"> <title>METHODS</title> We prospectively evaluated respiratory health status, measured using the Saint George's Respiratory Questionnaire (SGRQ), in a cohort of new adult pulmonary TB cases during and up to 18 months following treatment in India. Associations between total SGRQ scores and poor treatment outcomes of failure, recurrence and all-cause death were measured using multivariable Poisson regression. </sec> <sec id="st3"> <title>RESULTS</title> We enrolled 455 participants contributing 619 person-years at risk; 39 failed treatment, 23 had recurrence and 16 died. The median age was 38 years (interquartile range 26-49); 147 (32%) ever smoked. SGRQ scores at treatment initiation were predictive of death during treatment (14% higher risk per 4-point increase in baseline SGRQ scores, 95%CI 2-28, P = 0.01). Improvement in SGRQ scores during treatment was associated with a lower risk of failure (1% lower risk for every per cent improvement during treatment, 95%CI 1-2, P = 0.05). Clinically relevant worsening in SGRQ scores following successful treatment was associated with a higher risk of recurrence (15% higher risk per 4-point increase scores, 95%CI 4-27, P = 0.004). </sec> <sec id="st4"> <title>CONCLUSION</title> Impaired respiratory health status was associated with poor TB treatment outcomes. The SGRQ may be used to monitor treatment response and predict the risk of death in pulmonary TB. </sec>.

Electrochemical Performance of Nitrogen-Doped TiO2 Nanotubes as Electrode Material for Supercapacitor and Li-Ion Battery

Electrochemical anodized titanium dioxide (TiO2) nanotubes are of immense significance as electrochemical energy storage devices owing to their fast electron transfer by reducing the diffusion path and paving way to fabricating binder-free and carbon-free electrodes. Besides these advantages, when nitrogen is doped into its lattice, doubles its electrochemical activity due to enhanced charge transfer induced by oxygen vacancy. Herein, we synthesized nitrogen-doped TiO2 (N-TiO2) and studied its electrochemical performances in supercapacitor and as anode for a lithium-ion battery (LIB). Nitrogen doping into TiO2 was confirmed by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS) techniques. The electrochemical performance of N-TiO2 nanotubes was outstanding with a specific capacitance of 835 µF cm-2 at 100 mV s-1 scan rate as a supercapacitor electrode, and it delivered an areal discharge capacity of 975 µA h cm-2 as an anode material for LIB which is far superior to bare TiO2 nanotubes (505 µF cm-2 and 86 µA h cm-2, respectively). This tailor-made nitrogen-doped nanostructured electrode offers great promise as next-generation energy storage electrode material.

Cytocompatibility assessment of Ti-Nb-Zr-Si thin film metallic glasses with enhanced osteoblast differentiation for biomedical applications

Biologically safe Ti-based quaternary Ti-Nb-Zr-Si thin film metallic glass (TFMG) was fabricated by sputtering on Titanium alloy (Ti6Al4V or Ti alloy) substrates. A preliminary assessment regarding glass forming ability, thermal stability and corrosion behavior was performed. The amorphous nature of the film is evidenced from the X-ray Diffraction (XRD) and Transmission Electron Microscope (TEM) and Selected Area Electron Diffraction (SAED) patterns. Ion scattering spectroscopy (ISS) and X-ray Photoelectron Spectroscopy (XPS) were used to analyse the chemical composition of surface which indicated oxygen on the top surface of the film and confirms the presence of Ti, Nb, Si, Zr without any other impurities. The surface morphology of the film showed a smooth surface as observed from scanning electron microscope (SEM) and atomic force microscope (AFM) analysis. It is found that the TFMG can sustain in the body-fluid, exhibiting superior corrosion resistance and electrochemical stability than the bare titanium. The cytotoxicity studies with L929 fibroblast cells showed that coatings were graded as zero and non-cytotoxic in nature. No hemolysis was observed on the coated surface indicating a better hemocompatibility. Assay using SaOS-2 bone cells showed good growth on the coated surfaces. The calcium assay showed that the SaOS-2 cells grown and differentiated on the control (Tissue Culture Polystyrene) TCPS surface had the highest mineral level. Higher alkaline phosphatase activity is obtained in SaOS-2 osteoblast cell cultures on TFMG than the control.

Effect of Ablation Rate on the Microstructure and Electrochromic Properties of Pulsed-Laser-Deposited Molybdenum Oxide Thin Films

Molybdenum trioxide (MoO₃) is a well-known electrochromic material. In the present work, n-type α-MoO₃ thin films with both direct and indirect band gaps were fabricated by varying the laser repetition (ablation) rate in a pulsed laser deposition (PLD) system at a constant reactive O₂ pressure. The electrochromic properties of the films are compared and correlated to the microstructure and molecular-level coordination. Mixed amorphous and textured crystallites evolve at the microstructural level. At the molecular level, using NMR and EPR, we show that the change in the repetition rate results in a variation of the molybdenum coordination with oxygen: at low repetition rates (2 Hz), the larger the octahedral coordination, and greater the texture, whereas at 10 Hz, tetrahedral coordination is significant. The anion vacancies also introduce a large density of defect states into the band gap, as evidenced by XPS studies of the valence band and supported by DFT calculations. The electrochromic contrast improved remarkably by almost 100% at higher repetition rates whereas the switching speed decreased by almost 6-fold. Although the electrochromic contrast and coloration efficiency were better at higher repetition rates, the switching speed, reversibility, and stability were better at low repetition rates. This difference in the electrochromic properties of the two MoO₃ films is attributed to the variation in the defect and molecular coordination states of the Mo cation.

Chromatographic, NMR and vibrational spectroscopic investigations of astaxanthin esters: application to "Astaxanthin-rich shrimp oil" obtained from processing of Nordic shrimps

Astaxanthin (ASTX) is a keto carotenoid, which possesses a non-polar linear central conjugated chain and polar β-ionone rings with ketone and hydroxyl groups at the extreme ends. It is well known as a super anti-oxidant, and recent clinical studies have established its nutritional benefits. Although it occurs in several forms, including free molecule, crystalline, aggregates and various geometrical isomers, in nature it exists primarily in the form of esters. Marine animals accumulate ASTX from primary sources such as algae. Nordic shrimps (P. borealis), which are harvested widely in the Atlantic Ocean, form a major source of astaxanthin esters. "Astaxanthin-rich shrimp oil" was developed as a novel product in a shrimp processing plant in Eastern Canada. A compositional analysis of the shrimp oil was performed, with a view to possibly use it as a nutraceutical product for humans and animals. Astaxanthin-rich shrimp oil contains 50% MUFAs and 22% PUFAs, of which 20% are omega-3. In addition, the shrimp oil contains interesting amounts of EPA and DHA, with 10%/w and 8%/w, respectively. Astaxanthin concentrations varied between 400 and 1000 ppm, depending on the harvesting season of the shrimp. Astaxanthin and its esters were isolated from the oil and analysed by NMR, FTIR and Micro-Raman spectroscopy. Astaxanthin mono- and diesters were synthesized and used as standards for the analysis of astaxanthin-rich shrimp oil. NMR and vibrational spectroscopy techniques were successfully used for the rapid characterization of monoesters and diesters of astaxanthin. Raman spectroscopy provided important intermolecular interactions present in the esterified forms of astaxanthin molecules. Also discussed in this paper is the use of NMR, FTIR and Micro-Raman spectroscopy for the detection of astaxanthin esters in shrimp oil.

Effect of Temperature, Solvent and Precursor Concentration on Anti-Aggregation of ZnO Nanoparticles Prepared by Polyol Method

We have investigated the formation mechanism of ZnO microspheres in polyol medium. The synthesis conditions have been varied with respect to temperature, medium and Zn-precursor concentration. The X-ray diffraction (XRD) and Raman spectroscopy result shows that the prepared ZnO nanoparticles are hexagonal wurtzite crystal structure and quite crystalline in nature. High resolution transmission electron microscopy (HRTEM) image indicates that the microsphere consists of aggregated nanoparticles in the range of 6 nm to 15 nm. The samples prepared in ethylene glycol medium shows a characteristic ether bond vibration mode in FTIR and it is additionally confirmed by NMR analysis. Initially, the nanoparticles are self-assembled into loosely packed microsphere and then the particles are densely packed by ether bonds formed between the glycol molecules adsorbed on adjacent particles which then grow as perfect microspheres. The sample prepared in EG medium at 150 °C did not show much aggregation. This study proposes the possible mechanism for the formation of ZnO microsphere.

Enhancement of bioactivity of titanium carbonitride nanocomposite thin films on steels with biosynthesized hydroxyapatite

Thin films of titanium carbonitride (TiCN) were fabricated by DC magnetron sputtering on medical grade steel. The biocompatibility of the coating was further enhanced by growing hydroxyapatite crystals over the TiCN-coated substrates using biologically activated ammonia from synthetic urine. The coatings were characterized using X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscopy (SEM)-energy dispersive spectroscopy, and Raman spectroscopy. The electrochemical behavior of the coatings was determined in simulated body fluid. In addition, hemocompatibility was assessed by monitoring the attachment of platelets on the coating using SEM. The wettability of the coatings was measured in order to correlate with biocompatibility results. Formation of a coating with granular morphology and the preferred orientation was confirmed by SEM and X-ray diffraction results. The hydroxyapatite coating led to a decrease in thrombogenicity, resulting in controlled blood clot formation, hence demonstrating the hemocompatibility of the coating.

Nanostructured Bi(1−x)Gd(x)FeO3 – a multiferroic photocatalyst on its sunlight driven photocatalytic activity

We report the manifestation of sunlight driven photocatalytic activity in the nanostructured Gd substituted bismuth ferrite (BiFeO₃) multiferroic photocatalyst.

Nanocrystallization in magnetron sputtered Zr–Cu–Al–Ag thin film metallic glasses

Zr-based thin film metallic glasses (TFMG) were fabricated from a polycrystalline Zr₄₈Cu₃₆Al₈Ag₈ (at.%) target by DC magnetron sputtering. A series of characterization techniques were employed to study the structure, composition and thermal stability of the glassy coating. Annealing studies show nanocrystallites of CuZr₂ in an amorphous matrix.

Enhancement of biocompatibility of metal implants by nanoscale tiN/NbN multilayer coatings

Titanium nitride (TiN)/niobium nitride (NbN) nanostructured multilayer coatings were prepared by DC reactive magnetron sputtering method using the combination of a titanium and niobium target and an Ar-N2 mixture discharge gas on to 316L stainless steel substrates. The coatings showed a polycrystalline structure with (111) for TiN and (101) for NbN preferential growth. Raman spectroscopy measurements on the multilayer films exhibited the characteristic peaks at 212, 303, 458 and 578 cm-1. A higher hardness of 38 GPa was observed for TiN/NbN coatings. Electrochemical polarization tests were performed in simulated biological fluid solutions at 37 degreesC in order to determine and compare the corrosion behavior of the coated and uncoated 316L SS substrates. The TiN/NbN multilayer coatings could improve the corrosion resistance of 316L SS substrate. The bacterial culture experiments were performed and the bacteria treated samples were examined by epi fluorescence microscope measurements.

Surface modification of 316L stainless steel with magnetron sputtered TiN/VN nanoscale multilayers for bio implant applications

Nanoscale multilayered TiN/VN coatings were developed by reactive dc magnetron sputtering on 316L stainless steel substrates. The coatings showed a polycrystalline cubic structure with (111) preferential growth. XPS analysis indicated the presence of peaks corresponding to Ti2p, V2p, N1s, O1s, and C1s. Raman spectra exhibited the characteristic peaks in the acoustic range of 160-320 cm(-1) and in the optic range between 480 and 695 cm(-1). Columnar structure of the coatings was observed from TEM analysis. The number of adherent platelets on the surface of the TiN/VN multilayer, VN, TiN single layer coating exhibit fewer aggregation and pseudopodium than on substrates. The wear resistance of the multilayer coatings increases obviously as a result of their high hardness. Tafel plots in simulated bodily fluid showed lower corrosion rate for the TiN/VN nanoscale multilayer coatings compared to single layer and bare 316L SS substrate.

Psychopathology, traumatic life events, and coping skills among patients attending a primary-care adolescent clinic

OBJECTIVE

To compare the type of life events experienced and coping styles used by adolescents with and without psychopathology, attending a primary-care adolescent clinic.

METHODS

One hundred adolescents with and without psychopathology attending a drop-in adolescent clinic in a tertiary-care teaching hospital were recruited. Face-to-face interview used Child Behaviour Checklist, Life Event Scale, Coddington's life event scale, Impact of Event Scale and Modified Jalowiec coping scale as measures after getting written, informed consent from the primary care-giver and verbal assent from the adolescents. Bivariate and multivariate comparisons were done between the groups appropriately.

RESULTS

Adolescents with psychopathology had experienced more parental fights, increased arguments with parents, increased arguments between parents, serious illness requiring hospitalization of the adolescent. The intrusive symptoms of PTSD were noted more than avoidant symptoms among those adolescents with life events. Confrontative, emotive and optimistic coping styles were most often used in adolescent with psychopathology.

CONCLUSIONS

In India, adolescents with psychopathology attending a primary care clinic have significant life events and different coping styles. Therefore, adolescents with psychopathology in this setting should be screened for life events as well as dysfunctional coping styles and given appropriate intervention.

Regeneration of three-way automobile catalysts using biodegradable metal chelating agent--S, S-ethylenediamine disuccinic acid (S, S-EDDS)

Regeneration of the activity of three-way catalytic converters (TWCs) was tested for the first time using a biodegradable metal chelating agent (S, S-ethylenediamine disuccinic acid (S, S-EDDS). The efficiency of this novel environmentally friendly solvent in removing various contaminants such as P, Zn, Pb, Cu and S from commercial aged three-way catalysts, and improving their catalytic performance towards CO and NO pollutants removal has been investigated. Four samples of catalysts from the front and rear inlets of two different TWCs with different mileages and aged under completely different driving conditions were investigated. The catalysts were characterized using various techniques, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) surface area measurements (N(2) adsorption at 77 K). Quantitative ICP-MS analyses and SEM-EDS studies show the removal of Zn, P and Pb. SEM-EDS images obtained at low magnification (50 μm) showed considerable differences in the surface morphology and composition after washing with S, S-EDDS. However, XRD studies indicated neither little to no removal of major contaminant compound phases nor major structural changes due to washing. Correspondingly, little or no enhancement in BET surface area was observed between the used and washed samples. Light-off curves show that the regeneration procedure employed can effectively improve the catalytic performance towards NO pollutant.

Eimeria maxima recombinant Gam82 gametocyte antigen vaccine protects against coccidiosis and augments humoral and cell-mediated immunity (46.19)

Intestinal infection with Eimeria, the etiologic agent of avian coccidiosis, stimulates protective immunity to subsequent colonization by the homologous parasite, whilst cross-protection against heterologous species is poor. This study was designed to assess a purified recombinant protein from E. maxima gametocytes (Gam82) in stimulating immunity against experimental infection with live parasites. Following Gam82 intramuscular immunization and oral parasite challenge, body weight gain, fecal oocyst output, gut lesions, serum antibody response, cytokine production, and lymphoproliferation were assessed to evaluate vaccination efficacy. Animals vaccinated with Gam82 and challenged with E. maxima showed lower oocyst shedding and reduced intestinal pathology compared with non-vaccinated and parasite-challenged animals. Gam82 vaccination also stimulated the production of antigen-specific serum antibodies, induced greater levels of IL-2 and IL-15 mRNAs, and increased splenic lymphoproliferation compared with non-vaccinated controls. These results demonstrate that the Gam82 recombinant protein protects against coccidiosis and augments humoral and cell-mediated immunity.

An experimental study on using a diagnostic computed radiography system as a quality assurance tool in radiotherapy

The advent of improved digital imaging modalities in diagnostic and therapy is fast making conventional films a nonexistent entity. However, several radiotherapy centers still persist with film for performing quality assurance (QA) tests. This paper investigates the feasibility of using a diagnostic computed radiography (CR) system as a QA tool in radiotherapy. QA tests such as light field congruence, field size verification, determination of radiation isocentre size, multileaf collimator (MLC) check and determination of isocentric shift for stereotactic radiosurgery (SRS) were performed and compared with film. The maximum variation observed between CR and film was 0.4 mm for field size verification, -0.13 mm for the radiation isocentre size check, 0.77 for MLC check and -0.1 mm for isocentric shift using the Winston Lutz test tool for SRS QA. From these results obtained with the CR it is concluded that a diagnostic CR system can be an excellent cost-effective digital alternative to therapy film as a tool for QA in radiotherapy.