Type 2 diabetes: postprandial hyperglycemia and increased cardiovascular risk

Hyperglycemia is a major risk factor for both the microvascular and macrovascular complications in patients with type 2 diabetes. This review summarizes the cardiovascular results of large outcomes trials in diabetes and presents new evidence on the role of hyperglycemia, with particular emphasis on postprandial hyperglycemia, in adverse cardiovascular outcomes in patients with type 2 diabetes. Treatment options, including the new dipeptidyl peptidase-4 inhibitors and glucagon-like peptide-1 mimetics that primarily target postprandial hyperglycemia, are also discussed. Hyperglycemia increases cardiovascular mortality, and reducing hyperglycemia lowers cardiovascular risk parameters. Control of both fasting and postprandial hyperglycemia is necessary to achieve optimal glycated hemoglobin control. Therefore, anti-hyperglycemic agents that preferentially target postprandial hyperglycemia, along with those that preferentially target fasting hyperglycemia, are strongly suggested to optimize individual diabetes treatment strategies and reduce complications

Designer peptides to understand the mineralization of calcium salts

Recently, we reported the extraction, purification and amino acid sequence of ansocalcin, the major goose eggshell matrix protein. In vitro studies showed that ansocalcin induces spherical calcite crystal aggregates. We designed two peptides using the unique features of the sequence of ansocalcin and the role of these peptides in CaCO₃ crystallization was investigated. The peptides showed similar activities as compared to ansocalcin, but at a higher concentration. The full characterization of the peptides and a rational for the observed morphology for the calcite crystals are discussed in detail.Singapore-MIT Alliance (SMA

Eggshell Matrix Protein Mimetics: Elucidation of Molecular Mechanism of Goose Eggshell Calcification using Designed Peptides

Model peptides were designed, synthesized and conducted a detailed structure-property study to unravel the molecular mechanism of goose eggshell calcification. The peptides were designed based on the primary structural features of the eggshell matrix proteins ansocalcin and OC-17. In vitro CaCO₃ crystal growth experiments in presence of these peptides showed calcite crystal aggregation as observed in the case of the parent protein ansocalcin. The structure of these peptides in solution was established using intrinsic tryptophan fluorescence studies and quasi-elastic light scattering experiments. The structural features are correlated with observed results of the in vitro crystallization studies.Singapore-MIT Alliance (SMA

Studies on tuning surface electronic properties of hydrogenated diamond by oxygen functionalization

Ultra-wide bandgap and the absence of shallow dopants are the major challenges in realizing diamond based electronics. However, the surface functionalization offers an excellent alternative to tune electronic structure of diamonds. Herein, we report on tuning the surface electronic properties of hydrogenated polycrystalline diamond films through oxygen functionalization. The hydrogenated diamond (HD) surface transforms from hydrophobic to hydrophilic nature and the sheet resistance increases from ~ 8 kohms/sq. to over 10 Gohms/sq. with progressive ozonation. The conductive atomic force microscopic (c-AFM) studies reveal preferential higher current conduction on selective grain interiors (GIs) than that of grain boundaries confirming the surface charge transfer doping on these HDs. In addition, the local current conduction is also found to be much higher on (111) planes as compared to (100) planes on pristine and marginally O-terminated HD. However, there is no current flow on the fully O-terminated diamond (OD) surface. Further, X-ray photoelectron spectroscopic (XPS) studies reveal a redshift in binding energy (BE) of C1s on pristine and marginally O-terminated HD surfaces indicating surface band bending whilst the BE shifts to higher energy for OD. Moreover, XPS analysis also corroborate c-AFM study for the possible charge transfer doping mechanism on the diamond films which results in high current conduction on GIs of pristine and partially O-terminated HDs.Comment: 24 pages, 6 figures, 1 tabl

Thermogravimetry-evolved gas analysis-mass spectrometry system for materials research

Thermal analysis is a widely used analytical technique for materials research. However, thermal analysis with simultaneous evolved gas analysis describes the thermal event more precisely and completely. Among various gas analytical techniques, mass spectrometry has many advantages. Hence, an ultra high vacuum (UHV) compatible mass spectrometry based evolved gas analysis (EGA-MS) system has been developed. This system consists of a measurement chamber housing a mass spectrometer, spinning rotor gauge and vacuum gauges coupled to a high vacuum, high temperature reaction chamber. A commercial thermogravimetric analyser (TGA: TG + DTA) is interfaced to it. Additional mass flow based gas/vapour delivery system and calibration gas inlets have been added to make it a versatile TGA-EGA-MS facility. This system which gives complete information on weight change, heat change, nature and content of evolved gases is being used for (i) temperature programmed decomposition (TPD), (ii) synthesis of nanocrystalline materials, (iii) gas-solid interactions and (iv) analysis of gas mixtures. The TPD of various inorganic oxyanion solids are studied and reaction intermediates/products are analysed off-line. The dynamic operating conditions are found to yield nanocrystalline products in many cases. This paper essentially describes design features involved in coupling the existing EGA-MS system to TGA, associated fluid handling systems, the system calibration procedures and results on temperature programmed decomposition. In addition, synthesis of a few nanocrystalline oxides by vacuum thermal decomposition, gas analysis and potential use of this facility as controlled atmosphere exposure facility for studying gas-solid interactions are also described

Protein Microarray: "Theory" to "Real Practice"

Fueled by ever-growing genomic information and rapid developments of proteomics–the large scale analysis of proteins and mapping its functional role has become one of the most important disciplines for characterizing complex cell function. For building functional linkages between the biomolecules, and for providing insight into the mechanisms of biological processes, last decade witnessed the exploration of combinatorial and chip technology for the detection of bimolecules in a high throughput and spatially addressable fashion. Among the various techniques developed, the protein chip technology has been rapid. Recently we demonstrated a new platform called “Spacially addressable protein array” (SAPA) to profile the ligand receptor interactions. To optimize the platform, the present study investigated various parameters such as the surface chemistry and role of additives for achieving high density and high-throughput detection with minimal nonspecific protein adsorption. In summary the present poster will address some of the critical challenges in protein micro array technology and the process of fine tuning to achieve the optimum system for solving real biological problems.Singapore-MIT Alliance (SMA