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Clinical trials play an important role in improvement of quality on healthcare practice. Good clinical practice is a backbone of conductance of trials. A lack of knowledge may translate to a negative perception towards clinical trials. The study aims to evaluate the awareness of clinical trials among undergraduate dental students in a private dental institute. We have quantified the knowledge and perception of clinical trials by a structured validated questionnaire. The questionnaire was administered to dental students from first year undergraduate to third year Postgraduate. The percentage of questions answered were calculated and tabulated in the excel sheet. Data were analysed using SPSS statistical software and the chi-square test was done. P valve was set as 0.05 as a level of significance. From statistical analysis, postgraduate students (59.2%) had better knowledge than undergraduate students (40.8%). Around (46.7%) had been involved in clinical trial training. Within the limitations of current study, students pursuing postgraduate had a better knowledge of clinical trial methodology than compared to undergraduate students.

Nanocrystalline nickel oxide (NiO) was successfully synthesised as a phase-pure product from an inorganic precursor through a “single-pot”, gas-phase synthesis method, nebulised spray pyrolysis (NSP). Functional properties such as magnetic behaviour, luminescence and band gap were studied and compared with the properties of NiO powder synthesised by a conventional reverse co-precipitation process (RCP) which also needed an additional calcination step. Although NiO crystallised in the cubic (rocksalt) form, Rietveld analysis of X-ray diffraction data revealed the synthesised nanopowders to be in a distorted cubic (rocksalt) or monoclinic form. This distortion resulted from the antiferromagnetic exchange interaction energy and increased magnetic surface anisotropy, as seen from the bond lengths determined from Fourier transform infra-red (FTIR) studies. Raman spectroscopy also confirmed the distortion in the structure indicated by the presence of a first order phonon peak. The band gap decreased in case of both the powders and was attributed to the shallow donor or acceptor levels created due to the presence of defect states as determined from photoluminescence studies. The NSP powders also exhibited a dependence on the excitation wavelength during emission luminescence. A mixed antiferromagnetic and ferromagnetic behaviour was observed in the NSP powders and the susceptibility of each was deconvoluted through low and high field magnetometry studies. Further, the nanopowders from both the processes showed “core-shell” magnetism, with paramagnetic behaviour in the shell and antiferromagnetism in the core. The thicknesses of the core and shell were also determined.

A nanocrystalline high entropy oxide with near-equimolar composition consisting of 5 transition metal cations and one alkali cation (Co,Cu,Mg,Na,Ni,Zn)O was synthesised by a reverse co-precipitation (RCP) process and characterised by standard methods of X-ray diffraction (for crystallite size and phases), electron microscopy (for particle morphology and size distribution) and Fourier transform infra-red spectroscopy (for bond identification and bond lengths). Charge compensation in the lattice by the formation of Co3+ and/or Ni3+ (in order to offset the +1 oxidation state of Na) and the creation of oxygen vacancies was quantified from X-ray photoelectron spectroscopy and Raman spectroscopy and further studied using vibrating sample magnetometry (VSM). The influence of different transition metals in being able to accommodate the larger and aliovalent sodium ion in a single phase-pure rocksalt lattice was investigated and the criteria for element selection in such multicomponent systems for single-phase formation examined. Presence of multivalency/non-stoichiometry to accommodate a different-sized cation and maintaining electroneutrality were identified as the critical criteria for single-phase formation in multicomponent systems and further confirmed through synthesis of various lower combination systems (by systematic removal of one transition metal cation) and by addition of bivalent Ca as well as cations of higher valencies. These criteria would aid in designing the compositions of high entropy oxides with aliovalent substitutions.

Perovskite oxides are well-known for their dielectric and ferroelectric properties. In this work, the dielectric properties of calcium lead strontium titanate synthesized by reverse co-precipitation process with two different solvent concentrations were studied. Formation of single phase was confirmed by X-ray diffraction and tetragonality present in the lattice was analysed through Rietveld refinement. The grain size, morphology and composition were studied using scanning electron microscope and energy dispersive spectroscopy. The influence of frequency in the range of 1 ​Hz–107 ​Hz and temperature range -100 ​°C to 300 ​°C on dielectric response were studied. Curie-Weiss fits showed both the systems to be relaxor ferroelectrics. The dielectric relaxation mechanism and activation energy were determined from the electric modulus. The relaxation time and the dissipation factors were obtained from Cole-Cole analysis. The ferroelectric properties were assessed using a polarization-electric field loop tracer and efficiencies of memory storage were analysed.

Keratocystic odontogenic tumour is eccentric among the cyst of the maxillofacial region. In spite of generous research, the universally accepted treatment is still debated. We report a case of Keratocystic odontogenic tumour in a 35-year old male who had a recurrence within three and a half years of conservative treatment. Hence during the second time, the aggressive treatment protocol was carried out. There was no recurrence noted after 17 years follow-up

For the first time, this study shows that distortion in a crystal structure due to magnetic effect is possible in a lattice with extreme chemical disorder. The multicomponent equimolar transition metal oxide (ME TMO), (Co,Cu,Mg,Ni,Zn)O, which is a high entropy oxide, has been attracting a lot of attention due to its unique application potential in many fields including electrochemical energy storage. In the present investigation, nanocrystalline ME TMO was synthesised by three bottom up methods. The presence of distortion in the rocksalt crystal structure, revealed by X ray diffraction and Raman spectroscopy, and correlated with magnetic measurements from SQUID and EPR studies could be attributed to the additive effects of exchange striction (from the magnetic constituents) and magnetic anisotropy (from the decreased crystallite size). For the first time, iron has been doped into ME TMO, to show that a higher amount of magnetic constituent increases the distortion in the lattice. Nanocrystalline ME TMO also showed a core shell magnetic behavior below the bifurcation temperature arising from the uncompensated or canted spin at the surface. Neel temperature of the nanocrystalline ME TMO is reported for first time to be as high as 700 K. This study helps unravel the structure and magnetic properties of such high entropy materials, and augurs a definite scope for better understanding of the factors influencing the crystal structure in high entropy oxides., Comment: 11 pages, 10 figures

High entropy oxides (HEOs) with 5 or more cations in a single sublattice have recently emerged as a novel class of ceramic materials with interesting properties in the fields of energy and electronics. On the other hand, Ti-based oxides are well-known for their applications in the field of energy harvesting. In this study, Ti was added to a transition metal high entropy oxide, TM-HEO (Co,Cu,Mg,Ni,Zn)O and, a phase-pure orthotitanate inverse spinel structure (tetragonal lattice – P4122 space group) was obtained as (Co,Cu,Mg,Ni,Zn)2TiO4 and confirmed by X-ray diffraction (XRD) studies. The presence of tetragonal distortion was confirmed from Fourier transform infra-red (FTIR) spectroscopy and attributed to the smaller ionic radii of Ti. The degree of inversion in the spinel structure was studied by Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The stoichiometry, distribution of cations and the defect states in the compound were also quantified from XPS. The effect of the individual cations in the phase formation was analysed through the systematic elimination of each cation from the (Co,Cu,Mg,Ni,Zn)2TiO4 system, which revealed that formation of a phase-pure spinel structure was achieved when a 1:2 ratio of cations occupying the tetrahedral to octahedral sites was maintained. The band gap energies of the (Co,Cu,Mg,Ni,Zn)2TiO4 system as well as those of the phase-pure lower combination spinels were found to be in the infrared range of 1.02–1.54 eV which varied with the composition and the fact that it was lower than any of the individual oxides could be attributed to the band alignment of the individual cations. Band diagram for (Co,Cu,Mg,Ni,Zn)2TiO4 was constructed from the valence band spectrum obtained from the XPS studies. (Co,Cu,Mg,Ni,Zn)2TiO4 could, therefore, be a potential material for light harvesting applications as the band gap lies in the infrared regime.