Evaluating humidity sensing response of graphene quantum dots synthesized by hydrothermal treatment of glucose.

Graphene quantum dots (GQDs) were prepared using a single-step hydrothermal treatment of glucose (C6H12O6) powder. X-ray diffraction patterns confirmed the random stacking or amorphous character of GQDs. Additionally, the UV-vis spectra confirmed the formation of GQDs with evident absorption peaks at 237 and 305 nm, which is attributed toπ-π* andn-π* transitions correspondingly. The average size and surface roughness of graphene quantum dots were estimated by atomic force microscopy images and found to be 27.0 ± 1.0 and 2.3 nm, respectively. Afterwards, the effect of increasing relative humidity (RH) from 0%-95%, and frequency, was analyzed using the capacitive and resistive responses of synthesized GQDs. The capacitive output at 0.1 kHz revealed that initially capacitance remains constant (15.0 ± 1.0 pF) up to a humidity level ranging between 0%-50%. Likewise, capacitance also displayed stabilized behavior after frequency levels were increased i.e., 1.0 and 10 kHz, at a humidity ranging from 0%-55%. Moreover, capacitance showed a 115,455, 22,480 and 3,620% improvement from their stable values at each respective frequency level i.e., 0.1, 1.0 and 10 kHz. The capacitive sensitivity decreased to 84.20 and 96.83% at greater frequencies (1.0 and 10 kHz) in comparison to the sensitivity at 0.1 kHz facing similar variations in a humid environment. In contrast, resistance displayed an exponential decline by 99.9900, 99.9796 and 99.9925%, accordingly, when RH increases from 0 to 95% at 0.1, 1.0 and 10 kHz, respectively. However, with the rise in frequency level from 0.1 to 1.0 kHz, resistive sensitivity increased considerably to 69 and 158.5%, respectively, in two prominent humidity ranges i.e., 0 ≤ RH ≤ 25% and 25% ≤ RH ≤ 50%. A further increase in testing frequency to 10 kHz enhances the resistive sensitivity by 598.5 and 178.5% when compared with the lowest sensitivity values at two noticeable humidity levels, 0%-25% and 25%-50%. The response and recovery times of our specimen were better than most of previously fabricated GQDs and other carbon-derived nanomaterials, which makes the nano-GQDs of our study more suitable for RH sensor application.

Oral calcium supplementation reverses the biochemical pattern of parathyroid hormone resistance in underprivileged Indian toddlers.

BACKGROUND: Toddlers in Pune, India, accustomed to low dietary calcium intake but vitamin D replete have low serum ionised calcium and inappropriately raised serum inorganic phosphorus concentrations together with elevated serum parathyroid hormone (PTH) concentrations. We hypothesised that dietary calcium deficiency leads to end organ resistance to PTH, thus resulting in mild hypocalcaemia and hyperphosphataemia, and that this would be reversed by oral calcium supplementation. METHODS: 51 subjects (25 male; mean (SD) age 2.4 (0.8) years) from an urban slum in Pune were randomised to 500 mg of oral calcium supplement or placebo, daily, for 8 weeks. All subjects received 20 mg of oral elemental iron, daily, as 90% had a serum ferritin concentration <12 microg/l. All subjects were examined for clinical stigmata of rickets and had a wrist radiograph performed. Serum concentrations of ionised calcium, phosphorus, PTH and fibroblast growth factor-23 (FGF-23) were measured at the start and end of the trial. RESULTS: No subject had clinical or radiological evidence of rickets. There was a significant increase in mean serum ionised calcium concentration (p<0.001) in the supplemented but not the placebo group (p = 0.32). The decrease in mean serum phosphorus concentration in the supplemented group was greater (p<0.001) than in the placebo group (p = 0.003). Mean serum PTH fell in the calcium supplemented (p = 0.001) but not in the placebo (p = 0.303) group. The mean serum FGF-23 concentration did not change in response to calcium supplementation. CONCLUSIONS: From these data the authors conclude that low dietary calcium intake is associated with resistance to PTH.

Crosssectional growth curves for height, weight and body mass index for affluent Indian children, 2007.

BACKGROUND: The assessment of growth is crucial in child care and reference data are central to growth monitoring. As the pattern of growth of a population changes with time it is recommended that references be updated regularly. OBJECTIVE: To produce contemporary growth curves for Indian children from 5-18 years for height, weight and BMI. DESIGN: Cross-sectional. SETTING: Multicentric, School based. PARTICIPANTS: 19834 children were measured from 10 affluent schools from five major geographical regions of India. Data were analyzed on 18666 children (10496 boys and 8170 girls) using the LMS method and smoothed percentiles 2007 were produced. RESULTS: Compared to the 1989 data, median height at 18 years was 0.6 cm greater for boys but unchanged for girls, while the 97th height percentile had increased by 1.7 cm for boys and 2 cm for girls. Boys and girls were heavier and taller at almost all ages. The study also showed that boys and girls were taller at a younger age. CONCLUSIONS: Contemporary cross sectional reference percentile curves for height, weight and body mass index for the assessment of physical growth of present day Indian children are presented.

Body fat measurement in Indian men: comparison of three methods based on a two-compartment model.

UNLABELLED: Obesity is a major risk factor for diabetes and related disorders. The current classification of obesity is based on body mass index (BMI, kg/m(2)), which is a surrogate for the total body fat. Since the relationship between BMI and body fat varies in different populations, an independent validation of the BMI-body fat relationship in the population of interest is desirable. OBJECTIVES: (1) To study the validity of field methods of measuring body fat (multiple skinfolds and bioimpedance) against a criterion method (deuterium dilution) and (2) To compare the prevalence of obesity (WHO 2000 criteria for BMI) with adiposity (body fat >25%) in middle-aged Indian men in rural and urban Pune. DESIGN: Community-based multistage stratified random sampling of middle-aged men from rural and urban Pune for study of body composition and cardiovascular risk. A third of these men, selected to represent wide BMI distribution, were studied for body fat measurements by specific methods. SUBJECTS: A total of 141 healthy men, approximately similar number from rural, urban slums and middle class from Pune. They were 39.3 (+/-6.2) y old and had a BMI of 21.9 (+/-3.7) kg/m(2). MEASUREMENTS: Anthropometry (height, weight and multiple skinfold thicknesses) by trained observers using standardised technique to calculate body fat by Durnin and Womersley's equation. Total body water and body fat by bioelectrical impedance analysis (BIA) and deuterium oxide dilution (D(2)O). RESULTS: Mean total body fat was 14.3 kg (23.0%) by anthropometry, 16.5 kg (26.0%) by BIA and 15.3 kg (24.6%) by D(2)O method. Although there was a good correlation between fat estimation by three methods (r= approximately 0.9, P<0.001 all), compared to D(2)O method anthropometry underestimated body fat by 1.0 kg and BIA overestimated fat by 1.2 kg (P<0.001 both). Using the standard cut-point of 25% body fat for 'adiposity' 29.5% rural, 46.0% slum and 75.0% middle class men were adipose. These proportions were considerably higher than the number of men who were 'preobese' (BMI> or =25-29.9 kg/m(2), 9.0% rural, 22.0% urban slums and 27.0% urban middle class) and 'obese' (BMI >30 kg/m(2), 4.0% urban slums, none in rural and urban middle class). CONCLUSION: We recommend that future studies assessing risk for chronic diseases in Indians should measure adiposity by anthropometry (multiple skinfolds) or BIA (calibrated for Indians) rather than relying only on BMI cut-points.

Complications of surgery of the foot and ankle in hereditary neurologic disorders.

The hereditary motor and sensory neuropathies are one of a group of hereditary neurologic disorders. Patients with these disorders initially may present with a deformity of the feet and toes. Complications in the treatment of these deformities can be minimized by a proper diagnosis, identifying the components of the deformity, and selecting the appropriate procedure(s). Correcting the muscle imbalance and the deformity will be necessary in most patients and most patients will require a combination of surgical procedures.

Hyperhomocysteinemia and elevated methylmalonic acid indicate a high prevalence of cobalamin deficiency in Asian Indians.

BACKGROUND: In India, most people adhere to a vegetarian diet, which may lead to cobalamin deficiency. OBJECTIVE: The objective was to examine indicators of cobalamin status in Asian Indians. DESIGN: The study population included 204 men and women aged 27-55 y from Pune, Maharashtra, India, categorized into 4 groups: patients with cardiovascular disease (CVD) and diabetes, patients with CVD but no diabetes, patients with diabetes but no CVD, and healthy subjects. Data on medical history, lifestyle, and diet were obtained by interviews and questionnaires. Blood samples were collected for measurement of serum or plasma total cobalamin, holotranscobalamin (holoTC), methylmalonic acid (MMA), and total homocysteine (tHcy) and hemetologic indexes. RESULTS: MMA, tHcy, total cobalamin, and holoTC did not differ significantly among the 4 groups; therefore, the data were pooled. Total cobalamin showed a strong inverse correlation with tHcy (r = -0.59) and MMA (r = -0.54). Forty-seven percent of the subjects had cobalamin deficiency (total cobalamin <150 pmol/L), 73% had low holoTC (<35 pmol/L), 77% had hyperhomocysteinemia (tHcy >15 micromol/L), and 73% had elevated serum MMA (>0.26 micromol/L). These indicators of impaired cobalamin status were observed in both vegetarians and nonvegetarians. Folate deficiency was rare and only 2.5% of the subjects were homozygous for the MTHFR 677C-->T polymorphism. CONCLUSIONS: About 75% of the subjects had metabolic signs of cobalamin deficiency, which was only partly explained by the vegetarian diet. If impaired cobalamin status is confirmed in other parts of India, it may have important health implications.

Prevention of surface encrustation of urological implants by coating with inhibitors.

The encrustation of materials used for urological implants is as yet an unresolved problem. The crystallisation-inhibiting effect of the glycosaminoglycan heparin was used to reduce encrustation. Heparin was covalently bound to the surface of slotted-tube stents of tantalum and stainless steel using a spacer molecule. To verify the inhibition of crystallisation processes, reproducible in vitro tests and in vivo tests using the rat as animal model were carried out. The in vitro and in vivo experiments showed that the heparin coating has a significant influence on the encrustation of the surface. After 7 days in vitro and 120 days in vivo, heparin coated stents were free of encrustation, whereas the uncoated reference stents were extensively covered.

Intra-abdominal pressure as a quantitative measure for spinal stresses.

The purpose of this study was to measure the effects of lifting, placing, and removing different magnitudes of loads on the spinal stress. Eight male volunteers were measured for spinal stress utilizing intra-abdominal pressure (IAP). The loads used in the lifting tasks to different vertical and horizontal levels, varied from 5 kg up to 15 kg and were placed in a random order. The ANOVA analysis revealed significant individual variation (p < 0.001) both when placing and removing the loads. The effect of increase in load magnitude on the mean peak IAP values was highly significant (p < 0.001) when both placing and removing the loads. It is suggested that the area of activity falls within the limits of low truncal stress. The low truncal stress limits are large enough for most loading or unloading activities. Such requirements should also apply to physical therapists using passive movements and transfer activities allowing the therapist to carry out the required treatment or transfer within the safe limits of low truncal stress. J Orthop Sports Phys Ther 1987;9(2):70-76.

Comparison of roentgenography and moiré topography for quantifying spinal curvature.

The purpose of this study was to compare roentgenography and moiré topography for identification, treatment, and prevention of scoliosis at an early age. Moiré topography was used as an assessment tool for the quantitative examination of 12 children with mild-to-moderate scoliosis receiving physical therapy during a three-month period. Each child's roentgenogram also was analyzed independently by orthopedic physicians and radiologists using the Cobb method of measuring spinal curvature. Rho correlations of Cobb angles and the spinal curvature angles based on moiré photographs taken at weeks 4, 8, and 12 were found to be +.94, +.96, and +.93, respectively. The moiré method, thus, may be used as an available, inexpensive, and easily interpreted diagnostic and treatment tool in physical therapy.