Comparison of Physical and Chemical Properties of Five Different Alloplastic Bone Graft Materials

AIMS AND OBJECTIVES: The present study aims at analysing physicochemical characteristics of 5 different types of alloplastic graft materials used in periodontal regeneration. MATERIALS AND METHODS: The materials used were:- Monophasic Hydroxyapatite – Biograft HA, Tricalcium Phosphate – Biograft TCP, Biphasic Hydroxyapatite – Biograft HT, Bioactive Glass – Perioglas and a combination of Hydroxyapatite and Bioactive Glass – Biograft HABG Active. MATERIAL CHARACTERIZATION: The physicochemical properties of the biomaterials were tested using the following methods: 1. Scanning Electron Microscopy [SEM] - assess the sample`s surface topography & size 2. Thermogravimetry - reflect divergent physical properties and chemical compositions among the specimens resulting from their diverse thermal histories. 3. Fourier Transform Infrared Spectroscopy [FTIR] - to provide information concerning the chemical composition and the major functional groups. 4. X ray diffractometry [XRD] - used to identify phase and composition features and qualitatively evaluate the crystallinity of the materials 5. Dissolution rates - used to evaluate the solubility rate of calcium and silica RESULTS: From the particle size related data it is seen that PG and HA show smaller particles (100 – 300 μm) while TCP, HT and HABG show larger particles (200 – 500 μm). In the present study Biograft HA, Biograft TCP and Biograft HABG showed rough and irregular surface, while Perioglas and Biograft HT showed a smooth surface. The surface of perioglas is said to be smooth with less roughness, Biograft HT shows smooth and sintered surface particles with nano pores visible. All the other materials show rough surface with the presence of micro and nano sized pores ranging from 0.5 – 1 μm. Thermogravimetric analysis is used to determine the content of water, organic material (like collagen) and mineral (CaP). For all of the alloplasts in our study only a minimal weight loss upto 2 % was seen which can be attributed to the presence of moisture or due to oxidation of the samples. As all the test materials were synthetic or alloplastic, there was the absence of lattice water or organic content. All the tested materials were stable upto 10000 C, which renders all test materials to be thermally stable and phase pure and without any impurities. Infra red analysis shows the presence of main functional groups such as phosphates and carbonates. The calcium phosphate class of materials (HA, TCP and HT) and HABG showed almost similar stretching and vibration patterns for both functional groups. Phosphate peak was broad in Perioglas which may be due to the amorphous nature of material. In the Infrared spectra data from the 5 tested materials, hydroxyl peaks had highest intensity in HA, with midway values in HT and almost nil in TCP. HABG does not show a peak corresponding to OH group and PG shows a broadened peak. X ray diffraction patterns of the 5 alloplastic materials indicate their chemical composition (presence of crystalline phases) and lattice parameter information. The XRD peaks of the samples were well defined. Among the 5 alloplastic materials HA, HABG, TCP and HT showed typical crystalline structure whereas PG showed broad peaks indicating the amorphous nature of the material. An increasing order of crystallinity was obtained from XRD data as PG, HABG, TCP, HT and HA. In the dissolution tests done for calcium, all the materials showed positive results. Bioactive glass class of grafts (PG and HABG) had more dissolution when compared to hydroxyapatite class (HA,TCP and HT). The second dissolution test was done for silica, the bioactive glass group of material (PG and HABG) which are silica based were tested. Both PG and HABG showed increased dissolution of silica upto 24 hours, with PG showing constant values and HABG showing decreasing rates after 24 hours. SUMMARY: The main objective of present work was the physicochemical characterization of 5 commercial sample of alloplasts used for bone grafting. The alloplastic biomaterials belonged to 3 main classes calcium phosphate group (HA, TCP and HT), bioactive glass group (PG) and a combination graft (HABG). However even for those with similar chemical characteristics, significant differences were noted with regard to particle size, porosity, surface roughness, presence of functional groups, crystallinity and dissolution properties. Among the materials tested calcium phosphate based ceramics and bioactive glass – ceramic combination showed porous surface architecture parameters conducive to cellular and vascular proliferation. Thermogravimetric analysis revealed that all the materials were phase pure with no impurities. Infra red spectrometry showed presence of functional groups essential for bone integration in all test materials with Perioglas and Biograft HABG showing presence of silica which has a beneficial effect in bone formation. X ray diffractometric analysis revealed that with the exception of Perioglas which was amorphous all the other materials were crystalline in nature. Increased dissolution of calcium and silica were seen in bioactive glass group when compared with calcium phosphate and mixed calcium phosphate grafts

Probing long-range correlations in the Berezinskii-Kosterlitz-Thouless fluctuation regime of ultra-thin NbN superconducting films using transport noise measurements

We probe the presence of long-range correlations in phase fluctuations by analyzing the higher-order spectrum of resistance fluctuations in ultra-thin NbN superconducting films. The non-Gaussian component of resistance fluctuations is found to be sensitive to film thickness close to the transition, which allows us to distinguish between mean field and Berezinskii-Kosterlitz-Thouless (BKT) type superconducting transitions. The extent of non-Gaussianity was found to be bounded by the BKT and mean field transition temperatures and depend strongly on the roughness and structural inhomogeneity of the superconducting films. Our experiment outlines a novel fluctuation-based kinetic probe in detecting the nature of superconductivity in disordered low-dimensional materials.Comment: submitted to PR

Fast Moving Consumer Goods Industry in Rural Market of India: A Case of Mutual Reinvigoration

The present study has been undertaken to make an assessment of the growing eminence of FMCG industry in the era of enriching rural market in India. The Indian Fast Moving Consumer Goods (FMCG) industry began to take shape during the past five decades. The FMCG sector is a keystone of the Indian economy as it touches every aspect of human life. The FMCG sector, which offers tremendous growth prospects, are food and beverage sector, health care and personal care. Presently, rural India accounts for 34% of total FMCG consumption, but it accounts for more than 40% consumption in major FMCG categories like as personal care, hot beverages, and fabric care. Moreover, 80% of FMCG categories are growing faster in rural India as against urban India (Nielson, 2011). There is a huge growth potential for all the FMCG companies as the per capita consumption of almost all products in the country is amongst the lowest in the world. In recent years, rural markets have acquired significance in countries like China and India, as the overall growth of the economy has resulted in substantial increase in the purchasing power of the rural communities. On account of the green revolution in India, the rural areas are consuming a large quantity of industrial and urban manufactured products.&nbsp

EFFECT OF PESTICIDES ON MICROBIAL TRANSFORMATION OF SULPHUR IN SOIL

to investigate the effect of pesticides, on the microbial transformation of sulphur (S) in soil. Insecticide (Endosulfan), fungicide (Dithane M-45), herbicide (2,4-D) were added to the soil at their recommended doses, respectively and their effect on the proliferation and potentiality of thiosulphate oxiding bacteria, aryl sulphatase, available and total sulphur were investigated in soil. The results of the present investigation revealed that insecticide, endosulfan effectuated a significant detrimental effect on some microbiological, biochemical and chemical properties in soil whereas fungicide, dithane M-45 caused a significant detrimental influence during the later stages in spite of stimulating influence at early stages incubation period. However, herbicide, 2,4-D, brought about a beneficial influence on the microbiological, biochemical and chemical properties in soil. Among the pesticides used in the study, the performance of the herbicide was favorable in all respect

Phase diagram of a strongly disordered s-wave superconductor, NbN, close to the metal-insulator transition

We present a phase diagram as a function of disorder in three-dimensional NbN thin films, as the system enters the critical disorder for the destruction of the superconducting state. The superconducting state is investigated using a combination of magnetotransport and tunneling spectroscopy measurements. Our studies reveal 3 different disorder regimes. At low disorder the (k_{F}l~10-4), the system follows the mean field Bardeen-Cooper-Schrieffer behavior where the superconducting energy gap vanishes at the temperature where electrical resistance appears. For stronger disorder (k_{F}l<4) a "pseudogap" state emerges where a gap in the electronic spectrum persists up to temperatures much higher than Tc, suggesting that Cooper pairs continue to exist in the system even after the zero resistance state is destroyed. Finally, very strongly disordered samples (k_{F}l<1) exhibit a pronounced magnetoresistance peak at low temperatures, suggesting that localized Cooper pairs continue to survive in the system even after the global superconducting ground state is completely destroyed.Comment: pdf file with figures (Modified Version

Phase diagram and upper critical field of homogenously disordered epitaxial 3-dimensional NbN films

We report the evolution of superconducting properties with disorder, in 3-dimensional homogeneously disordered epitaxial NbN thin films. The effective disorder in NbN is controlled from moderately clean limit down to Anderson metal-insulator transition by changing the deposition conditions. We propose a phase diagram for NbN in temperature-disorder plane. With increasing disorder we observe that as kFl-->1 the superconducting transition temperature (Tc) and minimum conductivity (sigma_0) go to zero. The phase diagram shows that in homogeneously disordered 3-D NbN films, the metal-insulator transition and the superconductor-insulator transition occur at a single quantum critical point at kFl~1.Comment: To appear in Journal of Superconductivity and Novel Magnetism (ICSM2010 proceedings

Variability and molecular diversity of wild sugarcane germplasm collected from low temperature regions Lohit and Changlang of Arunachal Pradesh

159-168Saccharum spontaneum L. is a perennial grass representing the most genetically diversified species in Saccharum genus. It has the potential to withstand severe biotic/abiotic stresses and frequently used as donor of stress tolerant genes in sugarcane improvement program through gene introgression. In this study, the phenotypic variation and molecular diversity of forty nine S. spontaneum accessions collected from Lohit and Changlang regions of Arunachal Pradesh, North Eastern India were investigated for morphometric traits and polymorphic STMS marker. The phenotypic coefficient of variation showed ample variability for the traits viz., plant height (27.19%), stalk diameter (28.21%), single cane weight (48.97%), internode number (22.60%) and internode length (29.15%). Further, twenty nine sequence-tagged microsatellite site (STMS) markers generated 495 bands with an average of 14.06 polymorphic bands. The accessions specific bands in respect to specific marker combinations were identified. The Jaccard&rsquo;s similarity coefficients among these accessions ranged from 0.42 to 0.78 with an average of 0.58 and clustering using unweighted pair group method of arithmetic-average (UPGMA) showed two major clusters with subclusters. Similarly polulation structure analysis based Bayesian approach grouped the individuals into two subpopulations, with alpha value of 0.112. The study shows that S. spontaneum accessions collected from Arunachal Pradesh is highly diverse, most of them will be harbouring the genes for cold tolerance and biomass. The set of markers which produced specific bands for the specific accessions identified in the study will help in identification of the particular accessions. The accessions studied are potential source for cold tolerance and high biomass, the results obtained in the present study will definitely help in planning and utilising them in sugarcane improvement programme

Diagnostic and therapeutic medical devices for safer blood management in cardiac surgery : systematic reviews, observational studies and randomised controlled trials

Funding: This project was funded by the National Institute for Health Research (NIHR) Programme Grants for Applied Research programme and will be published in full in Programme Grants for Applied Research; Vol. 5, No. 17. See the NIHR Journals Library website for further project information.Peer reviewedPublisher PD

Combined searches for the production of supersymmetric top quark partners in proton-proton collisions at root s=13 TeV

A combination of searches for top squark pair production using proton-proton collision data at a center-of-mass energy of 13 TeV at the CERN LHC, corresponding to an integrated luminosity of 137 fb(-1) collected by the CMS experiment, is presented. Signatures with at least 2 jets and large missing transverse momentum are categorized into events with 0, 1, or 2 leptons. New results for regions of parameter space where the kinematical properties of top squark pair production and top quark pair production are very similar are presented. Depending on themodel, the combined result excludes a top squarkmass up to 1325 GeV for amassless neutralino, and a neutralinomass up to 700 GeV for a top squarkmass of 1150 GeV. Top squarks with masses from 145 to 295 GeV, for neutralino masses from 0 to 100 GeV, with a mass difference between the top squark and the neutralino in a window of 30 GeV around the mass of the top quark, are excluded for the first time with CMS data. The results of theses searches are also interpreted in an alternative signal model of dark matter production via a spin-0 mediator in association with a top quark pair. Upper limits are set on the cross section for mediator particle masses of up to 420 GeV

Search for new particles in events with energetic jets and large missing transverse momentum in proton-proton collisions at root s=13 TeV

A search is presented for new particles produced at the LHC in proton-proton collisions at root s = 13 TeV, using events with energetic jets and large missing transverse momentum. The analysis is based on a data sample corresponding to an integrated luminosity of 101 fb(-1), collected in 2017-2018 with the CMS detector. Machine learning techniques are used to define separate categories for events with narrow jets from initial-state radiation and events with large-radius jets consistent with a hadronic decay of a W or Z boson. A statistical combination is made with an earlier search based on a data sample of 36 fb(-1), collected in 2016. No significant excess of events is observed with respect to the standard model background expectation determined from control samples in data. The results are interpreted in terms of limits on the branching fraction of an invisible decay of the Higgs boson, as well as constraints on simplified models of dark matter, on first-generation scalar leptoquarks decaying to quarks and neutrinos, and on models with large extra dimensions. Several of the new limits, specifically for spin-1 dark matter mediators, pseudoscalar mediators, colored mediators, and leptoquarks, are the most restrictive to date.Peer reviewe