Oral smokeless tobacco consumption pattern among rural Indian cancer patients: A prospective survey.

BACKGROUND: Oral tobacco consumption predisposes to cancer. The pattern of its use in rural Indian cancer patients is unknown. AIM: The aim of this study is to estimate the prevalence of oral tobacco consumption in cancer patients. OBJECTIVES: To identify oral tobacco consumption pattern with respect to demographic variables and clinical profiles in adult Indian rural cancer patients. MATERIALS AND METHODS: All consecutive individual adult (age >18 years) patients diagnosed with any cancer and registered in the Medical Oncology Outpatient department were enrolled for questionnaire-based survey on oral tobacco consumption between July 2017 and October 2017. Demographic variables were also recorded, including income, education, and occupation. Frequency distribution and cross-tabulation were used for statistical analysis using SPSS version 17. RESULTS: Of 517 cancer patients enrolled, 456 (88%) were rural. 230/517 (44%) consumed several forms of oral tobacco. Out of 230, 179 (78%) of them had dried tobacco leaves, whereas 23 (10%) and 26 (11%) had Gutkha and pan (betel leaves) alone, respectively. 63 (27%) consumed tobacco leaves and gutkha both. 163 (91%) of tobacco chewers were male, whereas 65% of pan chewers were male and 35% of females. About 48% of tobacco chewers were addicted since >20 years, whereas 13% started in the past 5 years. 47/179 (26%) of tobacco chewers were illiterate, whereas 13/179 (7.2%) were graduates. 106 (59%) had monthly income of between Rs. 5000-10,000. 57 (32%) and 40 (22%) were farmers and laborers, respectively. 25/215 (12%) housewives were addicted. 41/58 (70%) of the head-and-neck cancer patients consumed tobacco products, where 29/41 (70%) used dried tobacco leaves to chew. CONCLUSION: More than 40% of adult Indian rural cancer patients consume oral smokeless tobacco products. Dried tobacco leaves are the most common form of smokeless tobacco consumed.

Pediatric cancers in Bihar: A retrospective tertiary cancer center study.

BACKGROUND: There is lack of information regarding pattern of distribution of pediatric cancers in Bihar. Aim: The aim of this study is to identify the pattern of distribution of pediatric cancers. OBJECTIVES: To analyze demographic data, type, and pattern of pediatric cancers in Bihar by retrospective clinical audit. MATERIALS AND METHODS: All individual consecutive patients between ages 0 and 18 years registered in the Department of Medical and Pediatric Oncology from January 1, 2018 till December 31, 2018, were enrolled in this study. Data pertaining to age, sex, and type of cancer were retrieved from clinical database by retrospective audit and stratified into hematolymphoid and solid pediatric cancer cohorts. Frequency distribution and descriptive statistics were used to analyze the data using SPSS version 17.0. RESULTS: A total of 247 pediatric cancers were registered, of which 142/247 (57%) and 15/247 (43%) were pediatric hematolymphoid and solid cancers, respectively. The median age was 9 years, while male-to-female ratio was 2.26. Acute lymphoblastic leukemia (ALL), 76/247 (31%) was the most common pediatric cancer overall. Hodgkin's lymphoma, 27/142 (19%) was the second most common hematolymphoid malignancy, after ALL was 76/142 (54%). Among solid tumors, Wilms' tumor was the most common, 28/105 (27%) followed by Ewing's sarcoma, 16/105 (15%), and germ cell tumor, 15/105 (14%). Central nervous system malignancies were among the least common solid tumor cancers, 3/105 (3%). CONCLUSION: ALL and Hodgkin's lymphoma are the most common pediatric cancers. Among solid malignancies, Wilms tumor, Ewing's sarcoma, and Germ cell tumor are predominant.

Using Mosaicity to Tune Thermal Transport in Polycrystalline Aluminum Nitride Thin Films.

The effect of controlling the c-axis alignment (mosaicity) to the cross-plane thermal transport in textured polycrystalline aluminum nitride (AlN) thin films is experimentally and theoretically investigated. We show that by controlling the sputtering conditions we are able to deposit AlN thin films with varying c-axis grain tilt (mosaicity) from 10° to 0°. Microstructural characterization shows that the films are nearly identical in thickness and grain size, and the difference in mosaicity alters the grain interface quality. This has a significant effect to thermal transport where a thermal conductivity of 4.22 vs 8.09 W/mK are measured for samples with tilt angles of 10° versus 0° respectively. The modified Callaway model was used to fit the theoretical curves to the experimental results using various phonon scattering mechanisms at the grain interface. It was found that using a non-gray model gives an overview of the phonon scattering at the grain boundaries, whereas treating the grain boundary as an array of dislocation lines with varying angle relative to the heat flow, best describes the mechanism of the thermal transport. Lastly, our results show that controlling the quality of the grain interface provides a tuning knob to control thermal transport in polycrystalline materials.

Observation of a low temperature n-p transition in individual titania nanotubes.

Manipulating the transport properties of titania nanotubes (NTs) is paramount in guaranteeing the material's successful implementation in various solid state applications. Here we present the unique semiconducting properties of individual titania NTs as revealed from thermoelectric and structural studies performed on the same individual NTs. The NTs were in the anatase phase fabricated by anodic oxidation and doped with intrinsic defects created by reducing the lattice thermally. Despite their polycrystalline nature and nanoscale walls, the doped NTs were found to be 4-5 orders of magnitude more electrically conducting than TiO2 nanowires and thin films, with values approaching the bulk single crystal conductivity. The reason for the high conductivity was found to be the high carrier concentration on the order of 1022 cm-3, which counteracted the low mobility values ∼0.006 cm2 V-1 s-1. Furthermore, this high level of carrier concentration transitioned the NTs to a degenerate state, which is the first such example in thermally doped titania NTs. More importantly, our study showed the creation of acceptor states along with donor states in individual nanotubes upon lattice reduction. These acceptor levels were found to be active at low temperatures when donor states were not ionized, shifting the Fermi level (Ef) from the conduction band to the valence band.

In-Plane Thermal Conductivity of Radial and Planar Si/SiOx Hybrid Nanomembrane Superlattices.

Silicon, although widely used in modern electronic devices, has not yet been implemented in thermoelectric applications mainly due to its high thermal conductivity, κ, which leads to an extremely low thermoelectric energy conversion efficiency (figure of merit). Here, we present an approach to manage κ of Si thin-film-based nanoarchitectures through the formation of radial and planar Si/SiOx hybrid nanomembrane superlattices (HNMSLs). For the radial Si/SiOx HNMSLs with various numbers of windings (1, 2, and 5 windings), we observe a continuous reduction in κ with increasing number of windings. Meanwhile, the planar Si/SiOx HNMSL, which is fabricated by mechanically compressing a five-windings rolled-up microtube, shows the smallest in-plane thermal conductivity among all the reported values for Si-based superlattices. A theoretical model proposed within the framework of the Born-von Karman lattice dynamics to quantitatively interpret the experimental data indicates that the thermal conductivity of Si/SiOx HNMSLs is to a great extent determined by the phonon processes in the SiOx layers.