Single NUV band pumped PbO-GeO₂-TeO₂:Tb³⁺ yellowish green emitting glass material for tricolor white LEDs

Jayasimhadri, M.,Jha, Kaushal,Ratnam, B.V.,Woo, Hyun-Joo,Jang, Kiwan,Rao, A.S.,Haranath, D. ELSEVIER SCIENCE 2017 JOURNAL OF ALLOYS AND COMPOUNDS Vol.711 No.-

<P><B>Abstract</B></P> <P>In this work, Tb<SUP>3+</SUP> ions doped lead-germanate-tellurite (LGT) glasses were prepared by conventional melt quenching technique with different dopant concentrations ranging from 0.5 to 3.5 mol %. X-ray diffraction (XRD) and FT-IR analysis were carried out to analyze the structural properties of LGT glass. The excitation spectra revealed a single band centered in the NUV region at 380 nm by monitoring emission at 545 nm. The emission spectra consist of four bands, which are attributed to the <SUP>5</SUP>D<SUB>4</SUB>→<SUP>7</SUP>F<SUB>J</SUB> (J = 3–6) transitions. Among these transitions, the strong emission band was observed at 545 nm corresponding to the <SUP>5</SUP>D<SUB>4</SUB>→<SUP>7</SUP>F<SUB>5</SUB> transition and the optimized doping concentration of Tb<SUP>3+</SUP> ions was 2 mol %. The Huang's theory and I-H model indicate the possibility of energy transfer via electric dipole-dipole interaction between Tb<SUP>3+</SUP> ions. The CIE chromaticity coordinates were (<I>x</I> = 0.282 and <I>y</I> = 0.614) and emits intense yellowish green light. The decay curves measured for <SUP>5</SUP>D<SUB>4</SUB> level for the samples with different doping concentrations and the lifetime for the optimized sample was 548 μs. The results indicate that these glasses have potential applications in solid state lighting and display devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Optically transparent Tb<SUP>3+</SUP> doped PbO-GeO<SUB>2</SUB>-TeO<SUB>2</SUB> (LGT) glasses have been prepared. </LI> <LI> Excitation spectrum consists of single band in the NUV region at 380 nm. </LI> <LI> CIE coordinates indicate that Tb<SUP>3+</SUP> doped LGT glass emits yellowish green light. </LI> <LI> Huang's theory applied to reveal the energy transfer process between Tb<SUP>3+</SUP> ions. </LI> <LI> This glass may be potential to use in fabricating GaN based WLEDs. </LI> </UL> </P>

Effect of Tetrahydropalmatine , an Alkaloid on Spore Germination of Some Fungi

(S . Maurya),(J . S . Srivastava),(R . N . Jha),(V . B . Panday),(U . P . Singh) 한국균학회 2001 Mycobiology Vol.29 No.3

N/A N/A

Analysis of the light transmission through nano-apertures on plateau pyramid

S.S. Choi,O.K. Suwal,V.K. Jha,김대욱,M.J. Park 한국물리학회 2009 Current Applied Physics Vol.9 No.11

The nano-size metallic aperture array has been fabricated using conventional semiconductor fabrication techniques and focused ion beam. The micron size patterns were transferred on SOI wafer using photographic patterning process, and the plateau pyramidal structures were fabricated using wet Si etching with alkaline solution followed by thermal oxidation. In order to reveal the plateau type pyramid, the backside Si bulk etching was performed. The metallic Al thin film was deposited and the nano-apertures with the diameters ranging from 190 nm to 380 nm were fabricated using focused ion beam milling method. The skin-depth of the Al thin film at 532 nm wavelength is known to be ~10 nm. The deposited Al thin film is thick enough to become opaque. Circular types of periodic grooves were fabricated around the sub-wavelength size nano-aperture in order to examine the transmittance of the light coupled to circular periodic grooves. The far-field measurements for the optical transmittance through a sub-wavelength size nano-probe have been investigated and found to be up to 103 fold increase, compared to the output intensity of aperture without groove patterns.

The pivotal role played by lipocalin-2 in chronic inflammatory pain

Jha, M.K.,Jeon, S.,Jin, M.,Ock, J.,Kim, J.H.,Lee, W.H.,Suk, K. Academic Press 2014 Experimental neurology Vol.254 No.-

Lipocalin-2 (LCN2) is an acute phase protein induced in response to injury, infection or other inflammatory stimuli. Based on the previously reported involvement of LCN2 in chemokine induction and in the recruitment of neutrophils at the sites of infection or tissue injury, we investigated the role of LCN2 in the pathogenesis of chronic/persistent inflammatory pain hypersensitivity. In the complete Freund's adjuvant (CFA)-induced chronic inflammatory pain model, LCN2 expression was strongly induced in the ipsilateral hindpaws, peaking at 12h after CFA injection and then gradually subsiding. In CFA-injected hindpaw tissues, LCN2 and its receptor 24p3R were mainly expressed in infiltrating neutrophils and macrophages. CFA-induced thermal hyperalgesia and mechanical allodynia were significantly diminished in Lcn2-deficient mice compared to wild-type animals. Furthermore, neutrophil infiltration, myeloperoxidase activity, expression of TNF-α, IL-1β and MIP-2 in CFA-injected hindpaws, and spinal glial activation were markedly reduced by Lcn2 deficiency. An intraplantar injection of recombinant LCN2 protein induced thermal and mechanical hypersensitivities in naive mice, and this was accompanied by neutrophil and macrophage infiltration into the hindpaws and glial activation in the dorsal horn of the spinal cord. Taken together, our results show that inflammatory cell-derived LCN2 at the sites of inflammation plays important roles in central sensitization and the subsequent nociceptive behavior in the rodent model of chronic inflammatory pain.

Development of PCR Microchip for Early Cancer Risk Prediction

Jha, S. K.,Gi-Sung Joo,Gyu-Sik Ra,Hyun Ho Lee,Yong-Sang Kim IEEE 2011 IEEE SENSORS JOURNAL Vol.11 No.9

<P>An integrated continuous-flow microfluidic chip was fabricated on glass substrate with polydimethylsiloxane (PDMS)-based microchannels, cell lysis and Polymerase chain reaction (PCR) modules on the same chip. While gold-microelectrode was used for electrochemical cell lysis, indium-tin-oxide (ITO) microheater was used for thermal cycling during PCR reaction. The fabricated device was used for PCR amplification of pancreatic cancer DNA marker (SMAD4) from non-tumorigenic MCF10a human cell lines. The PCR product (193 bp) was verified for MCF10a cells by agarose gel electrophoresis after 20 cycles of reaction on the microchip, whereas no product was detected in case of tumorigenic MCF7 cells. The total time required for the entire reaction was less than 45 min. Therefore, the proposed microchip can be helpful in predicting the risk of metastatic cancer by analysis of genetic tumor markers from human samples and can also be used for other genetic analysis involving PCR reaction.</P>

Analysis of the light transmission through nano-apertures on plateau pyramid

Choi, S.S.,Suwal, O.K.,Jha, V.K.,Kim, D.W.,Park, M.J. Elsevier 2009 Current Applied Physics Vol.9 No.1

The nano-size metallic aperture array has been fabricated using conventional semiconductor fabrication techniques and focused ion beam. The micron size patterns were transferred on SOI wafer using photographic patterning process, and the plateau pyramidal structures were fabricated using wet Si etching with alkaline solution followed by thermal oxidation. In order to reveal the plateau type pyramid, the backside Si bulk etching was performed. The metallic Al thin film was deposited and the nano-apertures with the diameters ranging from 190nm to 380nm were fabricated using focused ion beam milling method. The skin-depth of the Al thin film at 532nm wavelength is known to be ∼10nm. The deposited Al thin film is thick enough to become opaque. Circular types of periodic grooves were fabricated around the sub-wavelength size nano-aperture in order to examine the transmittance of the light coupled to circular periodic grooves. The far-field measurements for the optical transmittance through a sub-wavelength size nano-probe have been investigated and found to be up to 10<SUP>3</SUP> fold increase, compared to the output intensity of aperture without groove patterns.

A capillary electrophoresis microchip for amperometric detection of DNA

Joo, G.S.,Jha, S.K.,Kim, Y.S. Elsevier 2009 CURRENT APPLIED PHYSICS Vol.9 No.4

Capillary electrophoresis amperometric detection (CE-AD) microchip was fabricated for separation and detection of DNA fragments. The chip was fabricated on glass substrate and microchannels were laid in PDMS mold. The capillary was filled with 5% polyacrylamide gel and separation of DNA fragments of different molecular weight was achieved by application of 100V DC potential across sample and waste reservoirs made at the capillary ends. The amperometric detection (AD) system involved in-channel gold microelectrodes to analyze oxidation peak for adenine residues in DNA chain. This technique was used in resolving single as well as double stranded DNA fragments.

Negative regulation of signal transducer and activator of transcription-3 signalling cascade by lupeol inhibits growth and induces apoptosis in hepatocellular carcinoma cells

Siveen, K S,Nguyen, A H,Lee, J H,Li, F,Singh, S S,Kumar, A P,Low, G,Jha, S,Tergaonkar, V,Ahn, K S,Sethi, G Nature Publishing Group 2014 The British journal of cancer Vol.111 No.7

<P><B>Background:</B></P><P>Constitutive activation of signal transducer and activator of transcription signalling 3 (STAT3) has been linked with survival, proliferation and angiogenesis in a wide variety of malignancies including hepatocellular carcinoma (HCC).</P><P><B>Methods:</B></P><P>We evaluated the effect of lupeol on STAT3 signalling cascade and its regulated functional responses in HCC cells.</P><P><B>Results:</B></P><P>Lupeol suppressed constitutive activation of STAT3 phosphorylation at tyrosine 705 residue effectively in a dose- and time-dependent manner. The phosphorylation of Janus-activated kinases (JAKs) 1 and 2 and Src was also suppressed by lupeol. Pervanadate treatment reversed the downregulation of phospho-STAT3 induced by lupeol, thereby indicating the involvement of a phosphatase. Indeed, we observed that treatment with lupeol increased the protein and mRNA levels of SHP-2, and silencing of SHP-2 abolished the inhibitory effects of lupeol on STAT3 activation. Treatment with lupeol also downregulated the expression of diverse STAT3-regulated genes and decreased the binding of STAT3 to VEGF promoter. Moreover, the proliferation of various HCC cells was significantly suppressed by lupeol, being associated with substantial induction of apoptosis. Depletion of SHP-2 reversed the observed antiproliferative and pro-apoptotic effects of lupeol.</P><P><B>Conclusions:</B></P><P>Lupeol exhibited its potential anticancer effects in HCC through the downregulation of STAT3-induced pro-survival signalling cascade.</P>

Operational performance model for Indian container terminals using qualitative comparative analysis

Nanyam V.P.S. Nihar,Jha Kumar Neeraj 한국해운물류학회 2022 The Asian journal of shipping and Logistics Vol.38 No.4

Trend forecasting shows that Indian container terminals will handle 25 million twenty-foot equivalent units (TEUs) by 2025. However, improving operational performance is the best strategy to achieve this target. Many factors have adversely affected the Indian container terminal's operational performance despite the fact that the Indian government has undertaken several initiatives. This study identifies factors and interactive effects of the factors influencing the operational performance of Indian container terminals. A conceptual model is developed using fuzzy qualitative comparative analysis (QCA) encompassing the successful factors. The conceptual model developed through QCA includes the physical characteristics, driving factors, and challenges. This study reveals the combined and individual effects of the identified factors. The results show that the most common factors are the quay infrastructure, yard infrastructure, infrastructure up-gradation, system initiatives, reefer systems, and logistics advantage. This study adds to the existing literature regarding the Indian container terminals' performance and supports the decisionmakers in improving the operational performance of container terminals. © 2022 The Authors. Production and hosting by Elsevier B.V. on behalf of The Korean Association of Shipping and Logistics, Inc. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Miniaturisation of a capillary electrophoresis microchip for the sensing of endocrine disruptors

Ha, K,Joo, G.-S,Jha, S K,Yeon, I.-J,Kim, Y.-S IET 2010 IET nanobiotechnology Vol.4 No.4

<P>Although capillary electrophoresis amperometric detector (CE-AD) involving double-T microchannel configuration is a powerful analytical tool in terms of sensitivity and selectivity, its long microchannel configuration hinders further miniaturisation. Therefore a twisted CE microchannel configuration was used in the present study to fabricate CE-AD devices for detection of endocrine disruptors. The analyte separation time varied slightly for the twisted microchannel structure, whereas the detector sensitivities were similar for the two configurations. The conventional indium tin oxide amperometric detector in the device with twisted microchannel configuration was later modified with Prussian blue to enhance the sensitivity of detection.</P>