Elements Of X Ray Diffraction

Review on titanium and titanium based alloys as biomaterials for orthopaedic applications.

It is of great importance to develop multifunctional bioactive scaffolds, which combine angiogenesis capacity, osteostimulation, and antibacterial properties for regenerating lost bone tissues. In order to achieve this aim, we prepared copper (Cu)-containing mesoporous bioactive glass (Cu-MBG) scaffolds with interconnective large pores (several hundred micrometer) and well-ordered mesopore channels (around 5 nm). Both Cu-MBG scaffolds and their ionic extracts could stimulate hypoxia-inducible factor (HIF)-1a and vascular endothelial growth factor(VEGF) expression in human bone marrow stromal cells(hBMSCs). In addition, both Cu-MBG scaffolds and their ionic extracts significantly promoted the osteogenic differentiation of hBMSCs by improving their bone-related gene expression (alkaline phosphatase (ALP), osteopontin(OPN) and osteocalcin (OCN)). Furthermore, Cu-MBG scaffolds could maintain a sustained release of ibuprofen and significantly inhibited the viability of bacteria. This study indicates that the incorporation of Cu2þ ions into MBG scaffolds significantly enhances hypoxia-like tissue reaction leading to the coupling of angiogenesis and osteogenesis. Cu2þ ions play an important role to offer the multifunctional properties of MBG scaffold system. This study has demonstrated that it is possible to develop multifunctional scaffolds by combining enhanced angiogenesis potential, osteostimulation, and antibacterial properties for the treatment of large bone defects.

Copper-containing mesoporous bioactive glass scaffolds with multifunctional properties of angiogenesis capacity, osteostimulation and antibacterial activity

Ternary oxide glass system of chemical composition of 80B2O3–(20-x)Na2O–xCdO (where x = 0, 2, 4, 6, 8, 10, 12, 14 mol%) have been prepared by conventional melting and quenching method. The micro structural and morphological investigation of synthesized glass samples were carried out by using XRD, FE-SEM. The supporting physical and composition dependent properties such as experimental and theoretical density, molar volume, oxygen packing density, ionic concentration, interionic distance and polaron radius were determined. Density of glass samples increases, while molar volume decreases with the increasing cadmium oxide concentration from 0 to 14 mol%. X-ray diffraction profiles and FE-SEM images confirmed amorphous nature of investigated glass samples. Elemental analysis and information about the chemical composition of glass matrices have been ascertained by using EDS spectra. The interpretation of functional groups [BO3] and [BO4] units present in the oxide glass was simulated by using deconvoluted Raman spectra and FTIR spectroscopy. B O stretching, metal cation active vibrational modes and bending vibrations of B O B linkage in borate glass network are cross verified by using FTIR and Raman spectroscopy.

Network structure analysis of modifier CdO doped sodium borate glass using FTIR and Raman spectroscopy

Effect of ZrO2 on dielectric, optical and structural properties of yttrium calcium borosilicate glasses

Agricultural waste ashes are used as resource materials to synthesize new glass and glass-ceramics. The as-prepared materials are characterized using various techniques for their structural and dielectric properties to check their suitability in microelectronic applications. Sugarcane leaves ash exhibits higher content of alkali metal oxides than rice husk ash, which reduces the melting point of the components due to eutectic reactions. The addition of sugarcane leaves ash in rice husk ash promotes the glass formation. Additionally, it prevents the cristobalite phase formation. These materials are inherently porous, which is responsible for low dielectric permittivity i.e. 9 to 40. The presence of less ordered augite phase enhances the dielectric permittivity as compared to cristobalite and tridymite phases. The present glass-ceramics exhibit lower losses than similar materials synthesized using conventional minerals. The dielectric permittivity is independent to a wide range of temperature and frequency. The glass-ceramics developed with adequately devitrified phases can be used in microelectronic devices and other dielectric applications.

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Agricultural wastes as a resource of raw materials for developing low-dielectric glass-ceramics.

Bioactive glasses and glass-ceramics are well-proven potential biomaterials for bone-tissue engineering applications because of their compositional flexibility. Many research groups have been focused to explore the utility of bioactive glass–ceramics beyond bone engineering to hyperthermia treatment of cancer. Hyperthermia refers to raising the temperature of tumor close to 44°C at which malignant cells perish with negligible harm to normal cells. Hyperthermia can be employed by many means such as by ultrasonic waves, electromagnetic waves, infrared radiations, alternating magnetic fields, etc. Magnetic bioactive glass–ceramics are advantageous over other potential candidates for thermoseeds such as nanofluids, superparamagnetic nanoparticles because they can bond not only to the natural bone but also with soft tissues in few cases, which helps regenerating the affected part due to its bioactive nature. Strict restrictions on clinical settings ( H × f 5 × 10 9 ) force the research activities to be more focused on material characteristics to raise the implant temperature to required ranges. Lots of efforts have been made in past years to tackle these challenges and design best-suited glass–ceramics for hyperthermia treatment. This review aims to provide essential information on the concept of hyperthermia treatment of cancer and recent developments in the field of bioactive glass–ceramics for cancer treatment. The advantages and disadvantages of magnetic glass–ceramics over other potential thermoseed materials are highlighted. In this field, the major challenges are to develop magnetic glasses, which have fast and bulk crystallization with optimized magnetic phases with lower Curie and Neel temperatures.

Bioactive glasses and glass-ceramics for hyperthermia treatment of cancer: state-of-art, challenges, and future perspectives.

In the present study, the effect of variable vanadium oxidation states on the structural, optical, and dielectric properties of vanadium oxide containing lithium borate glasses has been investigated. Electron paramagnetic resonance studies indicate that vanadium in these glasses is mostly in the V4+ state, having a tetragonal symmetry. As the glass composition of V2O5 increases, tetragonality also increases at the cost of octahedral symmetry. The photoluminescence (PL) spectra of these glasses are dominated by zinc oxide transition, whereas the peaks pertaining to the vanadyl group are not visible in the PL spectra. The optical absorption spectra show a single wide absorption band, which is attributed to V4+ ions in these glasses. The ac conductivity of the glasses increases with an increase in vanadium content. The highest electrical conductivity observed is ∼10–5 S cm–1 at 250 °C for the glass with 2.5 mol % V2O5. Electrical conductivity is dominated by electron conduction, as indicated by the activatio...

Effect of Variable Oxidation States of Vanadium on the Structural, Optical, and Dielectric Properties of B2O3–Li2O–ZnO–V2O5 Glasses

Glasses with composition B2O3–Li2O–ZnO–TiO2–V2O5 were prepared with a melt and quench technique with variable concentration of TiO2 and V2O5. Structural aspects of the as-prepared sample were explored with the help of electron paramagnetic resonance spectroscopy (EPR). Conductivity and dielectric properties of the glasses and nanocrystalline glass ceramic were investigated using impedance spectroscopy. Vanadium was present in these glasses in the V4+ state, however, in initial composition, it was in the V5+ state. The maximum quantity of TiO2 contained glasses formed a nanocrystalline rutile phase, which dominated the electronic conduction at lower temperatures with decreased activation energy, i.e. 0.21 eV. Moreover, the presence of a nanocrystalline TiO2 phase reduced the dielectric constant ∼3 at room temperature and 1 MHz with excellent stability over a wide temperature and frequency range. The present nanocrystalline glass ceramic and glasses can be used in fast communication devices.

Satwinder Singh Danewalia

Papers

Agricultural wastes as a resource of raw materials for developing low-dielectric glass-ceramics.

Bioactive glasses and glass-ceramics for hyperthermia treatment of cancer: state-of-art, challenges, and future perspectives.

Effect of Variable Oxidation States of Vanadium on the Structural, Optical, and Dielectric Properties of B2O3–Li2O–ZnO–V2O5 Glasses

Frequency independent low-k lithium borate nanocrystalline glass ceramic and glasses for microelectronic applications

Antimicrobial and bioactive phosphate-free glass-ceramics for bone tissue engineering applications.