Optical bandgap tuning in nanocrystalline ZnO:Y films <i>via</i> forming defect-induced localized bands

Kaur, Narinder,Lee, Youngmin,Kim, Deuk Young,Lee, Sejoon Elsevier 2018 Materials & Design Vol.148 No.-

<P><B>Abstract</B></P> <P>Understanding of optical bandgap-tuning in terms of defect natures and their distribution in the nanocrystalline material proposes a fertile ground for the emergent optoelectronic device applications. In this contribution, nanocrystalline Y-doped ZnO (ZnO:Y) thin films with various thicknesses (50–300nm) were prepared on quartz substrates by spin-coating techniques, and their morphological, structural, and optical properties were thoroughly investigated. The surfaces of the films, consisting of uniformly-distributed nanograins, showed an improved crystallinity as the thickness of the nanocrystalline film was increased. With increasing film thickness, the optical bandgap of the nanocrystalline ZnO:Y thin film was decreased from 3.25 to 3.09eV because of the formation of the localized energy band, which arises from the charged defects at the boundaries of nano-grains. The correlations between the optical bandgap tunability and the distribution of charged defects are systematically examined, and the mechanisms of optical bandgap-tuning in nanocrystalline ZnO:Y thin films are discussed on the basis of the defect-induced localized band model.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nanocrystalline ZnO:Y films with various thicknesses were synthesized by using sol-gel and subsequent annealing processes. </LI> <LI> Thickness-dependent optical bandgap tuning was attributed to the charged defects at the boundaries of the ZnO:Y nanograins. </LI> <LI> Optical bandgap tuning in nanocrystalline ZnO:Yfilms could be explained through the defect-induced localized band model. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A facile route to ionic liquids-functionalized ZnO nanorods for the fluorometric sensing of thiabendazole drug

Kaur, Narinder,Raj, Pushap,Singh, Amanpreet,Singh, Narinder,Kim, Deuk Young Elsevier 2018 Journal of molecular liquids Vol.261 No.-

<P>In this report, we introduce a simple and cost-effective hydrothermal method for the functionalization of ZnO nanorods with three different ionic liquids (ILs (1-3)) to check their sensing response with various drugs including thiabendazole, phenylbutazone, chloramphenicol, neomycin, and theophylline through fluorescence spectroscopy. The rod like-microstructure and hexagonal wurtzite structure of synthesized ZnO nanorods were examined with SEM-EDS and XRD techniques. On the other hand, ionic liquids-functionalized ZnO nanorods (ILs (1-3)/ZnO) exhibited various self-organized (layered-sheet similar to IL1, distorted nanorods similar to IL2, peanut beaded surface similar to IL3/ZnO) structures due to the intercalation of ILs on the surface of ZnO nanorods. Compared to ZnO nanorods, similar to ILs (1-3)/ZnO nanorods showed a blue shift in UV-absorption band which resulted to the variation in optical bandgap values. Ionic liquids-functionalized nanorods samples (ILs (1-3)/ZnO) have been selected for their recognition behaviour with available drug molecules using fluorescence spectroscopic technique. Interestingly, with the addition of thiabendazole drug molecules to two samples (ILs (1,3)/ZnO), a significant response corresponding to the peaks at similar to 350 nm and similar to 357 nm was observed, which led to the development of fluorescent sensors with a detection limit of 12 and 304 nM, respectively. (C) 2018 Elsevier B.V. All rights reserved.</P>

ZnO decorated with organic nanoparticles based sensor for the ratiometric selective determination of mercury ions

Kaur, Narinder,Singh, Jasminder,Raj, Pushap,Singh, Narinder,Singh, Harpreet,Sharma, Sanjeev K.,Kim, Deuk Young,Kaur, Navneet The Royal Society of Chemistry 2016 New journal of chemistry Vol.40 No.2

<P>ZnO nanoparticles decorated with organic receptor 1 (R1) have been prepared and the resultant compound (N1) was investigated for its metal recognition ability. N1 was found to be selective for mercury ions (Hg2+) in a DMSO/water mixture in a ratio of 7 : 3 and possessed no interference from any of the potential interferent metal ions. The crystal size and morphology of ZnO is characterized using various spectroscopic and diffraction techniques like scanning electron microscopy, X-ray diffraction (XRD), dynamic light scattering (DLS), etc. Surface decoration of the ZnO with receptor 1 is confirmed using NMR spectroscopy. On successive additions of Hg2+ ions, the fluoresence intensity of the compound was quenched at 427 nm with enhancement of the peak at 482 nm, which led to ratiometric sensor development for the recognition of mercury ions having a detection limit of 0.19 nM. The prepared receptor was also tested for real sample application by preparing a known concentration of Hg2+ solution and it was found to respond well with an accuracy more than 90%.</P>

Stress relaxation and transitions in optical bandgap of yttrium doped zinc oxide (YZO) thin films

Narinder Kaur,Sanjeev K. Sharma,Deuk Young Kim 한국물리학회 2016 Current Applied Physics Vol.16 No.3

The stress relaxation and its effect on the bandgap of Y-doped ZnO (YZO) thin films were investigated by thermal annealing. YZO thin films were prepared on quartz glass by spin coating and subsequent annealed in vacuum. All the annealed YZO films showed a preferred (002) orientation. Photoluminescence (PL) provides the direct evidence of shifting the bandgap owing to stress release phenomena. The shifting in bandgap by increasing the annealing temperature can be attributed to the stress relaxation of YZO thin films. The bandgap of annealed films was initially decreased due to increase in magnitude of compressive stress and then increased as the tensile stress induced in the films. Therefore, these results may suggest the way to tune the band gap of YZO thin films by varying the residual stress through annealing.

SARS-CoV-2 IgG Antibody Seroprevalence in Children from the Amritsar District of Punjab

Amandeep Kaur,Narinder Singh,Kanwardeep Singh,Shailpreet Kaur Sidhu,Harleen Kaur,Poonam Jain,Manmeet Kaur,Mohan Jairath 대한임상검사과학회 2022 대한임상검사과학회지(KJCLS) Vol.54 No.3

The majority of the children experience milder coronavirus disease 2019 (COVID-19) symptoms. Children represent a significant source of community transmission. Children under 18 years of age account for an estimated 4.8% of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections globally. However, no conclusive statements pertaining to the multi-fold aspects of the virus in children could be drawn due to the lower prevalence of pediatric cases. The present study was conducted to identify the indirect impact of SARS-CoV-2 infections on developing herd immunity among children in the age group 3 to 18 years by investigating their antibody levels. In the study, 240 children aged 3∼18 years were recruited by the Department of Pediatrics, Government Medical College and Hospital, Amritsar, India, and quantification of the antibodies was performed at the Viral Research and Diagnostic Laboratory (VRDL), Government Medical College (GMC), Amritsar, India. Out of the 240 serum samples, 197 (82.08%) showed seropositivity, while 43 (17.92%) were seronegative. When stratified, it was observed that in the age group 3∼6 years, 22.33% of children were found to have anti-SARS-CoV-2 antibodies while in the age groups 7∼10 years, 11∼14 years, and 15∼18 years, respectively, 37.06%, 30.46%, and 10.15% were seropositive. Although there was seroconversion among children which was useful for predicting the next wave, no differences in seropositivity were observed between adults and children.

Rapid sonochemical synthesis of spherical silica nanoparticles derived from brown rice husk

Sankar, S.,Kaur, Narinder,Lee, Sejoon,Kim, Deuk Young Elsevier 2018 CERAMICS INTERNATIONAL Vol.44 No.7

<P><B>Abstract</B></P> <P>The nanoparticles of silica (SiO<SUB>2</SUB>) were synthesized from brown rice husk <I>via</I> the sonochemical process, during which the sonication time was varied from 0 to 50 min so as to modulate the material properties of the nanoparticles. The synthesized SiO<SUB>2</SUB> nanoparticles were confirmed to have amorphous natures in their structural characteristics. The mean particle sizes of the nanoparticles were increased from 5 to 40 nm with increasing sonication time from 0 to 50 min, respectively. The SiO<SUB>2</SUB> nanoparticles synthesized with the sonication time of 50 min showed to possess the highest porosity among our samples. Accordingly, the sample exhibited a higher effective surface area of 271.22 m<SUP>2</SUP>g<SUP>−1</SUP>. In addition, the bandgap of the SiO<SUB>2</SUB> nanoparticles was decreased from 5.77 to 5.68 eV with increasing sonication time (<I>i.e.</I>, 0 → 50 min). The results suggest that the SiO<SUB>2</SUB> nanoparticles synthesized with an appropriate control of the sonication time (<I>e.g.</I>, 50 min) hold promise for future nano-ecosystem applications such as nano-biosensors and energy storage nano-devices.</P>

Protective effect of Prunus amygdalus nut extract on chronic unpredictable stress (CUS) induced memory deficits and biochemical alterations in rats

Nitish Bhatia,Abhitinder Kumar,Parminder Kaur,Benu George,Narinder Kaur,Masih Uzaaman Khan,Ravi Kumar Dhawan 경희대학교 융합한의과학연구소 2022 Oriental Pharmacy and Experimental Medicine Vol.22 No.2

Stress intervenes in the brain’s capability to encode and regain information from a person, it alters the biochemical parameters in specific regions of the brain can cause long-term damage to various parts of brain. The present investigations aid in understanding the effect of the Prunus amygdalus nut extract on CUS induced memory deficits in rats. The methanolic extract with an antioxidant potential (~ 60%) and was selected for in vivo analysis. CUS was induced in rats using different stress paradigms for 10 days. On day 11 and 12, acquisition trials for memory evaluation were performed using Morris Water Maze. On day 13 and 10 days later on, i.e. day 23, short-term and long-term memory retrievals trials were evaluated, respectively. Treatment groups were given test methanolic extract an hour before the subjection of CUS. Biochemical estimations and histopathological studies were carried out using brain tissue homogenate and brain tissue section, respectively. CUS altered the Transfer Latency time in both acquisition and retrieval trials, indicating memory impairment, which was reduced significantly in extract-treated groups. Administration of P. amygdalus nut methanolic extract protected the rat brains against CUS-induced neuroinflammatory changes. The observed beneficial effects could be attributed to the antioxidant potential of P. amygdalus.

Graft tunnel integration occurs early in the tibial tunnel compared with the femoral tunnel after anterior cruciate ligament reconstruction with preserved insertion hamstring tendon graft

( Ravi Gupta ),( Sandeep Singh ),( Anil Kapoor ),( Ashwani Soni ),( Ravinder Kaur ),( Narinder Kaur ) 대한슬관절학회 2021 대한슬관절학회지 Vol.33 No.-

Background: Preservation of hamstring tendon insertion at the time of anterior cruciate ligament (ACL) reconstruction is a well-known technique; however, its effect on graft integration is not well studied. The present study was conducted to study the graft integration inside the tibial and femoral tunnels, respectively, after ACL reconstruction using hamstring tendon graft with preserved insertion. Methods: Twenty-five professional athletes who underwent ACL reconstruction using hamstring tendon graft with preserved tibia insertion were enrolled in the study. Functional outcomes were checked at final follow-up using Lysholm score and Tegner activity scale. Magnetic resonance imaging (MRI) was done at 8 months and 14 months follow-up to study the graft tunnel integration of the ACL graft at both tibial and femoral tunnels. Results: The mean Fibrous interzone (FI) score (tibial tunnel) decreased from 2.61 (1-5) at 8 months to 2.04 (1-4) at 14 months follow-up (p = 0.02). The mean FI score (femoral side) decreased from 3.04 (2-5) at 8 months to 2.57 (2-4) at 14 months (p = 0.02). Conclusions: Graft integration occurs early in the tibial tunnel as compared with the femur tunnel with preserved insertion hamstring tendon autograft. Trial registration CTRI/2019/07/020320 [registered on 22/07/2019]; http:// www. ctri. nic. in/ Clini caltr ials/ pdf_ gener ate. php? trial id= 33884 & EncHid= & modid= & compi d=% 27,% 27338 84det% 27

Extruded black gram flour: Partial substitute for improving quality characteristics of Indian traditional snack

Laxmi Ananthanarayan,Yogesh Gat,Vikas Kumar,Anil Panghal,Narinder Kaur 한국식품연구원 2018 Journal of Ethnic Foods Vol.5 No.1

Background During extrusion of black gram flour, formation of amylose-lipid complexes lowers down the gelatinization enthalpy of extrudates, and the partially gelatinized black gram starch leads to lowering down the water-holding capacity and alters functional properties resulting in changing quality attributes of the end product on frying/microwaving/roasting. Methods Attempts have been made to improve the quality of an Indian traditional snack (e.g., papad) by incorporating extruded black gram flour as partial substitute for raw (unextruded) black gram flour. In present work, overall quality improvement was achieved by analyzing prefrying and postfrying characteristics (diameter, moisture content, expansion ratio, oil uptake, texture, and color) of papad and physical properties (color and viscosity) of fried oil. Results Four different papad samples were prepared (control papads without addition of papadkhar, papads with use of 3% papadkhar, papads with incorporation of extruded black gram flour at 25% concentration, papads with incorporation of extruded black gram flour at 50% concentration along with 1% papadkhar) and analyzed along standard market sample. Incorporation of extruded black gram flour in papad resulted in greater expansion with less oil uptake in fried papad. Further addition of extruded black gram flour permitted the use of lower concentration of papadkhar. After frying, the quality of oil was characterized after numerous frying cycles. Conclusion Oil used for frying of papads containing highest concentration of papadkhar was effective only up to two frying cycles, after which color and viscosity increased significantly, adversely affecting the quality of fried oil.