Tuneable luminescence properties of EDTA-assisted ZnS:Mn nanocrystals from a yellow-orange to a red emission band.

Luminescence technology has been improved with the help of semiconductor nanoparticles that possess novel optical and electrical properties compared with their bulk counterpart. The aim of this study was to design semiconductor nanocrystals in their pure (ZnS) or doped form (ZnS:Mn) with different concentrations of Mn2+ ions by a wet chemical route stabilized by ethylenediamine tetra-acetic acid (EDTA) and to evaluate their luminescence properties. The nanocrystals were characterized by physicochemical techniques such as X-ray diffraction (XRD), High-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SEAD), EDS, and ultraviolet (UV)-visible light and photoluminescence (PL) studies. These results showed the presence of cubic phase and spherically shaped nanocrystals. A blue shift with respect to their bulk counterpart was observed. PL emission spectra were observed with a fixed blue peak and the yellow-orange bands were red shifted towards the red region under the same excitation wavelength. The orange-red bands were attributed to the radiation transition of electrons in 3d5 unfilled shells of Mn2+ ions [4 T1 (4 G)-6 A1 (6 S)]; the ZnS matrix varied with Mn2+ concentration. Shift and increase in the intensity of the PL and absorption bands were observed with increase in Mn content. The study showed that Mn2+ -doped ZnS nanocrystal emission bands can be tuned from the yellow-orange to the red regions under a controlled synthesis process and could be used as promising luminescent emitters in the biology field upon functionalization with suitable materials. Further studies on construction with various other materials will be useful for practical applications.

Association of IL-1ß +3953 C and HLA-DRB1*15 with Coronary Artery and Rheumatic Heart Diseases in South India.

Among the various candidate genes predisposing for cardiovascular diseases, HLA-DRB1* and IL-1ß +3953C/T alleles have been implicated repeatedly. To test these in South India, we carried out a case control study of 323 Coronary Artery Disease (CAD) patients, 56 Rheumatic Heart Disease (RHD) patients and 254 endemic controls. The polymorphisms were studied by PCR - SSP and ARMS-PCR methods and results analyzed for various clinical and demographic parameters. In CAD, HLA-DRB1*14 allele showed significant predisposition (OR: 2.19; 95% CI: 1.04-4.58; p value=0.023), particularly in male patients (OR: 4.07; 95% CI: 1.20-13.81; p value=0.01) and further in males with Triple Vessel Disease (OR: 5.49; 95% CI: 1.45-20.60; p value=0.007). On the other hand, HLA-DRB1*15 predisposed for RHD (OR: 3.56; 95% CI: 1.87-6.78; p value=0.001) in both the genders. Population stratification showed this higher risk association in Vanniyar caste (OR: 5.00; 95% CI: 1.27-19.59; p value=0.022). Among the IL1-ß +3953C/T polymorphism, the ancestral allele 'C' showed a significant high risk association with CAD (OR: 1.83; 95% CI: 1.24-2.70; p value=0.001), particularly in Mudaliar (OR: 6.07; 95% CI: 1.77-20.74; p value=0.003; AF=0.7) and Vanniyar castes (OR: 3.67; 95% CI: 0.92-14.57; p value=0.05; AF=0.660). Two different cardiac ailments studied, RHD & CAD thus showed varied associations in this South Indian cohorts. RHD having an infectious aetiology shared a HLA-DRB1*15 high risk association, while HLA-DRB1*14 and IL-1ß +3953C predisposed for CAD, an inflammatory disorder, reiterating the diverse genetic predisposition of the two cardiac ailments studied.

A novel design of a transitional complete denture in full arch fixed implant restoration.

The transitional denture given in a full arch fixed implant restoration should not disturb the healing and osseointegration process. This is made possible by lining the denture with a uniform thickness of soft liner. The article describes a method of achieving uniform thickness of soft liner and minimizing the load transmitted to the area where implants were placed.

Three dimensional finite element analysis of stress distribution around implant with straight and angled abutments in different bone qualities.

The aim of the study was to compare the stress distribution around implant in different bone qualities of D1, D2, D3, and D4 with straight and angled abutments using three dimensional finite element analysis. A three dimensional finite element model of the premaxilla region, and two solid 4.3 × 10 mm implant, one with a straight abutment and the other with an angled abutment was done. Four distinctly different bone qualities of D1, D2, D3, and D4 were made. A static load of 178 N was applied at the centre of incisal edge along the long axis of each abutment. The maximum equivalent von Misses stress values around the implants were recorded. The distribution of stresses changed considerably with abutment angulation. As angulation increased from 0° to 15° the concentration of Von Misses stresses shifted to the cortical layer of bone on the facial side of the fixture. Although Von Misses stress increased in straight abutment as the bone quality changed from D1 to D4, it was more noticeable under the loading side of the angulated abutments. The high stresses induced through angled abutments at the cervical zone of the implant due to forces and moments could be a dominant factor that may aggravate the peri-implant bone loss or changes the existing peri-implantitis direction.

Incidence of dengue in a tertiary care centre--Kasturba Hospital, Manipal.

Dengue is the most important Arbovirus in the world in terms of occurrence and impact. It has been responsible for some devastating outbreaks and accounts for nearly 50-100 million cases of dengue fever and 2-5 lac cases of the dengue hemorrhagic fever worldwide. Dengue is caused by an arbovirus, which belongs to the Flaviviridae and is maintained in nature principally through biological transmission between susceptible vertebrate hosts by hematophagous arthropods. The incidence and global distribution of dengue has greatly increased in recent years and affects almost every country between the topics of Capricorn and Cancer. Although outbreaks of dengue fever has been occurring with regularity all over the country, and there have been 2 reported outbreaks in the neighboring district Mangalore in 1993 and 1996, there has been no reported outbreak in Manipal, which is what is responsible for the present study. In the study, out of the 100 clinically suspected cases of dengue, 44% tested positive for dengue IgM antibody, thus proving current dengue infection. Twenty six cases were from Shimoga district, which indicates increased dengue virus activity in this area and the possible endemicity in the region.