•Successful synthesis of chitosan functionalized LaF3:Yb,Er upconverting nanotransducers (UCNTs).•Chitosan/LaF3:Yb,Er nanocrystals show visible green emission under low energy IR excitation.•First ...report on in-vitro cell viability of LaF3:Yb,Er nanocrystals in human breast cancer cells (MCF-7).•Excellent cell viability in MCF-7 cells was achieved by chitosan capping.•The developed UCNTs can be used in photodynamic therapy (PDT) for deep tissue cancers.
In this study, chitosan functionalized LaF3:Yb,Er upconverting nanotransducers (UCNTs) with controlled size and shape have been successfully synthesized by a facile one pot precipitation method. The chitosan encapsulated UCNTs show bright upconversion fluorescence upon excitation with 974nm NIR region. The average crystallite size of UCNTs about 7.6nm was achieved using chitosan mediated synthesis. The FTIR result confirms the chitosan coating over the LaF3:Yb,Er nanoparticles. Due to the surface modification using natural biopolymer chitosan, the as-prepared nanocrystals show excellent biocompatibility even at high dose at 200μg/ml. To the best of our knowledge the presented work is the first report on in vitro analysis of chitosan conjugated LaF3:Yb,Er upconverting nanocrystals in human breast (MCF-7) cancer cells. These nanotransducers can be used as luminescent probes for bioimaging and deep tissue cancer therapeutic applications.
To derive macronutrient recommendations for remission and prevention of type 2 diabetes (T2D) in Asian Indians using a data-driven optimization approach.
Dietary, behavioral, and demographic ...assessments were performed on 18,090 adults participating in the nationally representative, population-based Indian Council of Medical Research-India Diabetes (ICMR-INDIAB) study. Fasting and 2-h postglucose challenge capillary blood glucose and glycosylated hemoglobin (HbA1c) were estimated. With HbA1c as the outcome, a linear regression model was first obtained for various glycemic categories: newly diagnosed diabetes (NDD), prediabetes (PD), and normal glucose tolerance (NGT). Macronutrient recommendations were formulated as a constrained quadratic programming problem (QPP) to compute optimal macronutrient compositions that would reduce the sum of the difference between the estimated HbA1c from the linear regression model and the targets for remission (6.4% for NDD and 5.6% for PD) and prevention of progression in T2D in PD and NGT groups.
Four macronutrient recommendations (%E- Energy) emerged for 1) diabetes remission in NDD: carbohydrate, 49-54%; protein, 19-20%; and fat, 21-26%; 2) PD remission to NGT: carbohydrate, 50-56%; protein,18-20%; fat, 21-27%; 3 and 4) prevention of progression to T2D in PD and NGT: carbohydrate, 54-57% and 56-60%; protein, 16-20% and 14-17%, respectively; and fat 20-24% for PD and NGT.
We recommend reduction in carbohydrates (%E) and an increase in protein (%E) for both T2D remission and for prevention of progression to T2D in PD and NGT groups. Our results underline the need for new dietary guidelines that recommend appropriate changes in macronutrient composition for reducing the burden due to diabetes in South Asia.
We report a comprehensive investigation of the third-order nonlinear interaction of femtosecond laser pulses with nanostructured anatase TiO2 doped with varying concentrations of gadolinium ...impurities. The samples were synthesized using a facile sol‒gel method. The physicochemical characteristics of the prepared samples were investigated using various analytical techniques, including XRD, SEM, TEM, SAED, UV‒Vis, PL and XPS. The average crystallite sizes of the pristine TiO2- and Gd (1, 2, and 3%)-doped TiO2 nanoparticles were calculated to be 10.9, 9.2, 10.2 and 8.9 nm, respectively. The W-H plots also revealed average crystallite sizes in the range of 13.9, 16.6, 13.9 and 10.4 for pristine and Gd (1, 2, 3%)-doped TiO2 nanoparticles. The lattice strain values for pristine and Gd (1, 2, and 3%) doped TiO2 nanoparticles were computed as 0.00203, 0.00667, 0.0036 and 0.00262, respectively, from the W‒H plots. The average crystallite size was calculated to 9.2 nm from the TEM images using ImageJ software. The optical band gap values of pristine TiO2 and Gd (1, 2, and 3%)-doped TiO2 nanoparticles were calculated to be 3.3, 3.23, 3.21 and 3.20 eV from the Kubelka–Munk function plot. The emission peaks of pristine and Gd(1,2,3%) doped TiO2 nanoparticles were calculated as 3.2, 3.23, 3.26 and 3.32 eV from the photoluminescence spectra recorded at 330 nm photo excitation. The binding energies of the O1s, Ti2P and Gd4d peaks present in the survey scan of TiO2 nanoparticles doped with one weight percentage of Gd impurity were 528.79, 531.53, 457.53, 463.25 and 149.6 eV, respectively. The third-order nonlinear characteristics of the TiO2:Gd samples were probed using the ultrafast laser Z-scan technique. We observed that the density of bound excitons can be regulated by controlling the dopant concentration. The strong oscillatory interactions between photogenerated bound excitons, which act as dipole oscillators with large oscillating frequencies, were recorded using a single-beam femtosecond z-scan. The third-order nonlinear susceptibility χ(3) for pristine and Gd(1,2,3%)-doped TiO2 nanoparticles were calculated as 7.258 × 10-18, 9.4 × 10-18, 11 × 10-18 and 13 × 10-18 cm2/V2, respectively. The obtained results suggest that the thermal lensing phenomenon in nanostructured anatase TiO2 can be generated and effectively controlled using a band gap engineering technique. We determined that the small pump power in nonlinear media with controllable band fluctuations can produce large phase distortions in TiO2:Gd nanosystems. Our findings reveal that Gd doping induces controlled modification of the electronic structure of TiO2, leading to a tailored energy landscape for exciton formation and binding. These findings provide a novel approach for engineering systems of TiO2-based nanostructures for energy-efficient optical-limiting nanophotonic systems and optoelectronic-switching devices.
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In this work, we described one pot hydrothermal synthesis of surface modified water soluble YF3: Yb, Er upconverting nanofluorophores (UCNFs) using natural biopolymer chitosan. The obtained ...nanocrystals have undergone X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), high resolution transmission electron microscopy (HRTEM) and photoluminescence (PL) studies. The nanoparticles possess uniform particle size distribution with average size about 27 nm. The cytotoxicity results revealed that the chitosan capped nanoparticles exhibit excellent biocompatibility in human breast cancer cells. In conclusion, the water soluble chitosan capped YF3: Yb, Er nanoparticles could be used as a potential candidate in bio-imaging and therapeutic applications.
Call Centers have always played a highly significant role in the service industry, from retail to technical support. Government of India (GOI) has launched Kisan Call Centers (KCC) across the country ...to deliver extension services to the farming community for resolving their diverse problems. Every time a farmer makes a call, the query asked by the farmer is recorded manually and the number of calls generated in a day will be many and that leads to Big Data. As the questions asked by farmers are recorded manually, the same question asked by different farmers can be framed differently in terms of the words used for the query. The idea of this paper is to analyze the large KCC datasets using Hadoop based MapReduce algorithms to draw interesting insights such as the hour during which highest number of calls are made, the crop which has been questioned a lot by farmers and use Natural Language Processing (NLP) techniques to group the similar queries to know which queries are frequently asked by farmers, project these findings graphically.
ZnO nano particles are synthesized at different percentages of Ag dopant by facile precipitation method. Two photon absorption (2PA) cross-section and nonlinear refractive index of ZnO nano particles ...are studied with 130 femto-second laser pulses at a repletion rate of 1 kHz with central wavelength of 532 nm by z-scan technique. The 2PA cross-section of ZnO nano particles are obtained by theoretical calculations, using rate equation approach. Both absorption cross-section and nonlinear refractive index increased with increasing the Ag dopant percentage. We have observed an increase of order of 104 in the nonlinear refractive index in the presence of femto-second laser excitation with reference to nano-second laser excitation.
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