Major Hepatectomy for Gall Bladder Cancer with Jaundice - A Formidable Procedure?

( Venkata Vishwanath Reddy Ch ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: Jaundice in gall bladder cancer (GBC) is a sign of advanced disease, inoperability and poor prognosis. Resection with curative intent requires extended right hepatectomy (ERH) after preoperative biliary drainage (PBD) and portal vein embolization (PVE). We report our results of surgical resections in GBC with jaundice. Methods: Retrospective analysis of a prospective database in a tertiary center in India (October 2009 - August 2019). Results: 196 (21%) of 914 patients with GBC had jaundice; 7/196 died in hospital (3 PTBD bleed, 3 cholangitis and 1 aspiration). 74/196 had metastasis and 122/196 had locally advanced disease. 167/196 had biliary drainage (endoscopic 82, PTBD 85; definitive palliative 127, PBD 40). Major complications of biliary drainage were bleed 4, bile leak 2, stent block 3, pancreatitis 1 and perforation 1. 48/122 were operated but only 17/48 underwent resection (extended cholecystectomy + Common bile duct excision 12, ERH 2, central hepatectomy 1, Hepatopancreatoduodenectomy 2) after PBD (no PVE). 33/122 were considered for ERH after PBD and PVE. Out of 33, 8 developed metastasis, 8 developed locally advanced unresectable disease between PBD and PVE and 8 didn’t want to undergo any further management. 9/33 underwent PVE after PBD but none underwent resection - 2 disease progressed, 2 inadequate hypertrophy, 1 procedure abandoned due to cardiac event and 4 metastasis (3 at laparotomy, 1 at laparoscopy). 16/33 were operated but none was resected. Conclusions: The plan of ERH after PBD and PVE in patients with GBC and jaundice could not be executed for various reasons.

Synthesis of CdO/ZnS heterojunction for photodegradation of organic dye molecules

Venkata Reddy, Ch.,Bandaru, Narendra,Shim, Jaesool,Vattikuti, S. V. Prabhakar Springer-Verlag 2017 APPLIED PHYSICS A MATERIALS SCIENCE AND PROCESSING Vol.123 No.6

Synthesis of Cr-doped SnO₂ quantum dots and its enhanced photocatalytic activity

Reddy, Ch.Venkata,Babu, B.,Shim, Jaesool Elsevier Sequoia 2017 Materials Science and Engineering B Vol. No.

<P>Chromium (Cr)-doped SnO2 quantum dots (QDs) with various doping concentration have been successfully synthesized using a simple combustion method. The QDs have been characterized by using various techniques. The X-ray diffraction patterns revealed that the prepared QDs have monophasic tetragonal rutile-type crystallite structure with an average crystallite size of similar to 3 nm. The optical band gap energies of QDs increased with increasing the Cr ion concentration. The XPS spectra reveal the presence of Sn4+, Cr3+, and O respectively. Cr (0.03 mol%)-doped SnO2 QDs are exhibited the greater photocatalytic activity compared with other photocatalysts, which is attributed mainly due to quantum confinement effect and an increase in specific surface area. The existence of a Cr3+ as shown from XPS spectra, act as an electron acceptor and/or hole donor, which enhancing longer survived charge carrier separation in Cr-doped SnO2 QDs as confirmed by PL spectroscopy. (C) 2017 Elsevier B.V. All rights reserved.</P>

Effect of plasmonic Ag nanowires on the photocatalytic activity of Cu doped Fe₂O₃ nanostructures photoanodes for superior photoelectrochemical water splitting applications

Reddy, I. Neelakanta,Reddy, Ch. Venkata,Sreedhar, Adem,Cho, Migyung,Kim, Dongseob,Shim, Jaesool Elsevier 2019 Journal of electroanalytical chemistry Vol.842 No.-

<P><B>Abstract</B></P> <P>The Present study focuses on the synthesis and analysis of Cu doped hematite (α-Fe<SUB>2</SUB>O<SUB>3</SUB>) nanostructures for effectively enhancing the optical properties as well as their implementation as photoelectrodes for energy-harvesting applications. In addition to this, the influence of noble metal plasmonic layer of Ag nanowires as a bottom layer for undoped and doped Fe<SUB>2</SUB>O<SUB>3</SUB> photoanodes has been investigated. Herein, we studied the influence of dopant on morphology, structural, and optical properties of Fe<SUB>2</SUB>O<SUB>3</SUB>. X-ray diffraction technique and X-ray photoelectron spectroscopy analysis were confirmed Cu ion substitution into host Fe<SUB>2</SUB>O<SUB>3</SUB> nanostructures. The optical band gap decreases from ~ 1.95eV to ~ 1.38eV with increasing of Cu dopant concentration. Impedance analysis reveals that the Cu dopant works as an electron donor and improves the Fe<SUB>2</SUB>O<SUB>3</SUB> charge carrier density. The photoelectrochemical water splitting studies reveals that the photoanodes without plasmonic layer was shown improved photocurrents compare to the undoped sample, thus improving the absorption of the incident light. Significantly, the optimized 0.2mol% Cu-doped α-Fe<SUB>2</SUB>O<SUB>3</SUB> photoelectrodes without Ag layer reached the maximum photocurrent density of ~0.31mA/cm<SUP>2</SUP>, ~ 28-fold that of pure Fe<SUB>2</SUB>O<SUB>3</SUB> (0.011mA/cm<SUP>2</SUP>). Further, the same photoanode with plasmonic Ag nanowires showed a significantly improved photocurrent density of 1.48mA/cm<SUP>2</SUP>, which is ~ 135-fold that of pure Fe<SUB>2</SUB>O<SUB>3</SUB> and ~ 5-folds that of 0.2mol% Cu doped α-Fe<SUB>2</SUB>O<SUB>3</SUB> photoelectrodes without plasmonic nanowire layer. The superior photocurrent is ascribed to the enhanced electron donor density and reduced charge recombination rate, as an outcome of optimized Cu doping and Ag nanowires.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cu-doped Fe<SUB>2</SUB>O<SUB>3</SUB> and Ag plasmonic nanostructures were synthesized by hydrothermal and polyol methods. </LI> <LI> Optimal 0.2mol% Cu doped Fe<SUB>2</SUB>O<SUB>3</SUB> photoanode showed the highest photocurrent density of 1.48mA/cm<SUP>2</SUP>. </LI> <LI> Photoanode with Ag plasmonic increases the photocurrents of 135-fold that of pure Fe<SUB>2</SUB>O<SUB>3</SUB>. </LI> <LI> Excellent photoelectrochemical water splitting activity was achieved. </LI> </UL> </P>

Influence of calcination temperature on Cd_0.3Co_0.7Fe₂O₄ nanoparticles: Structural, thermal and magnetic properties

Reddy, Ch.Venkata,PrabhakarVattikuti, S.V.,Ravikumar, R.V.S.S.N.,Moon, Sang Jun,Shim, Jaesool Elsevier 2015 Journal of magnetism and magnetic materials Vol.394 No.-

<P><B>Abstract</B></P> <P>Cadmium substituted cobalt ferrite nanoparticles are synthesis using the chemical method. The as-prepared ferrite nanoparticles are calcinated at 300°C and 600°C respectively. The samples are studied using; Powder XRD, SEM with EDX, TEM, FT-IR, TG-DTA and vibrating sample magnetometer (VSM) in order to study the calcination temperature effect on structural, morphological and magnetic properties. The magnetic properties, like saturation magnetization and coercivity increases with increasing the calcination temperature. This enhancement is attributed to the transition from amulti-domain to a single-domain nature. The absorption bands observed at 588cm<SUP>−1</SUP> (<I>ν</I> <SUB>1</SUB>) and 440cm<SUP>−1</SUP> (<I>ν</I> <SUB>2</SUB>) are attributed to the vibrations of tetrahedral and octahedral complexes. The TG-DTA curves reveal the thermal stability of the prepared ferrite nanoparticles. The calcination temperature influences the magnetic properties, surface morphology and crystalline size.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cd<SUB>0.3</SUB>Co<SUB>0.7</SUB>Fe<SUB>2</SUB>O<SUB>4</SUB> nanoparticles synthesized using the chemical co-precipitation. </LI> <LI> The magnetization, coercivity values increases with increasing the calcination temperature. </LI> <LI> The calcination temperature influences the magnetic properties and crystallite size. </LI> <LI> The FTIR spectra results confirmed the vibrations of tetrahedral and octahedral complexes. </LI> </UL> </P>

Structural, optical, and improved photocatalytic properties of CdS/SnO₂ hybrid photocatalyst nanostructure

Venkata Reddy, Ch.,Ravikumar, R.V.S.S.N.,Srinivas, G.,Shim, J.,Cho, M. Elsevier 2017 Materials science and engineering B. Advanced Func Vol.221 No.-

<P>CdS, SnO2 and CdS/SnO2 hybrid photocatalyst nanostructure were synthesized using a two-step (co-pre cipitation/hydrothermal) method. The as-prepared materials were characterized by powder X-ray diffraction, transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), surface analysis (BET), photoluminescence spectra (PL), UV-Vis diffusion reflectance spectroscopy (DRS), fourier transform infrared spectroscopy (FT-IR), and photocatalytic activity. The band gap energies calculated from the DRS results are 3.30, 2.15, and 2.99 eV for pristine SnO2, CdS, and the CdS/SnO2 hybrid photocatalyst, respectively. The CdS/SnO2 hybrid photocatalyst showed more efficient charge carrier separation and improved photocatalytic degradation of methyl orange (MO). The highest degradation rate constant was achieved for the CdS/SnO2 hybrid photocatalyst (0.02434 min(-1)) compared to CdS (0.01381 min(-1)) and SnO2 (0.00878 min(-1)). The present study provides insights for improving the photocatalytic activity and photo-stability of CdS/SnO2 hybrid photocatalyst. (C) 2017 Elsevier B.V. All rights reserved.</P>

Systematic studies of Bi₂O₃ hierarchical nanostructural and plasmonic effect on photoelectrochemical activity under visible light irradiation

Reddy, I. Neelakanta,Reddy, Ch. Venkata,Sreedhar, Adem,Cho, Migyung,Kim, Dongseob,Shim, Jaesool Elsevier 2019 CERAMICS INTERNATIONAL Vol.45 No.14

<P><B>Abstract</B></P> <P>The effect of Ag plasmonic nanowire layers on the hierarchical nanostructure of Bi<SUB>2</SUB>O<SUB>3</SUB> photoelectrodes for water splitting under visible light irradiation was studied for the first time. In addition, the impact of various Bi<SUB>2</SUB>O<SUB>3</SUB> nanostructures on light harvesting and generation of relative photocurrent have been investigated. The cubic structure of Bi<SUB>2</SUB>O<SUB>3</SUB> was confirmed using X-ray diffraction analysis. Optical bandgaps of 2.14 and 2.30 eV have been achieved for the Bi<SUB>2</SUB>O<SUB>3</SUB> nanoparticles and nanoflowers photoelectrodes (BP and BF), respectively. The photocurrent density (J) of the BP featuring Ag plasmonic layer photoelectrode (Ag/BP) was 6.47 mA cm<SUP>−2</SUP>, and was higher than that of the BF featuring Ag plasmonic layer photoelectrode (Ag/BF), which was 4.33 mA cm<SUP>−2</SUP>. These values were approximately 647 and 2165 times higher than those of BP and BF, respectively. However, the J value of BP was 2.13 mA cm<SUP>−2</SUP> higher than that of BF. The superior J values of Ag/BP and Ag/BF were attributed to the increased light absorption and reduced electron-hole recombination rate at the time scale beyond a few 10<SUP>−12</SUP> s, owing to the Ag nanowires. In addition, the plasmonic field was able to reduce the charge recombination rate of the nanostructured electrodes in reactor cells.</P>

Effect of ball milling on optical properties and visible photocatalytic activity of Fe doped ZnO nanoparticles

Reddy, I. Neelakanta,Reddy, Ch. Venkata,Sreedhar, M.,Shim, Jaesool,Cho, Migyung,Kim, Dongseob Elsevier 2019 Materials science and engineering B. Advanced Func Vol.240 No.-

<P><B>Abstract</B></P> <P>The Fe doped ZnO nanoparticles were prepared using high-energy ball milling technique. The X-ray diffraction was utilized to study the effect of ball milling time on the crystalline structure. Field emission scanning electron microscopy was used to analyze the morphology of Fe doped ZnO. The intensity of the peaks decreases with the ball milling time and also no evidence was found the appearance of Fe<SUB>3</SUB>O<SUB>4</SUB> peaks at above 30 h, indicates a decrement in crystallinity owing to the incorporation of Fe into ZnO sites and it confirmed through peak shift in phase analysis. The electron structure was studied by X-ray photoelectron spectroscopy. It was observed that the both Zn and Fe are in 2+ oxidation state. The effect of milling time on optical properties and photocatalytic activity of Fe doped ZnO was determined using UV–visible spectrophotometry. Photocatalytic efficiency of the prepared samples was estimated by degradation of methylene orange dye in aqueous solution under sunlight irradiation. Maximum degradation of ∼98.7% for MO was achieved using 40 h ball milled Fe doped ZnO nanoparticles.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Fe doped ZnO nanoparticle was successfully grown by ball milling. </LI> <LI> The lowest bandgap of 2.55 eV was achieved for 40 h milled Fe doped ZnO sample. </LI> <LI> Fe doped ZnO nanoparticles exhibited high the visible light absorption properties. </LI> <LI> Maximum degradation of ∼98.7% for MO was observed under solar light irradiation. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Structural, optical, and XPS studies of doped yttria for superior water splitting under visible light illumination

Reddy, I. Neelakanta,Reddy, Ch. Venkata,Cho, Migyung,Kim, Dongseob,Shim, Jaesool Elsevier 2019 Journal of electroanalytical chemistry Vol.848 No.-

<P><B>Abstract</B></P> <P>Recently, there has been much research on developing highly efficient semiconductor photoelectrodes for photoelectrochemical (PEC) water splitting applications. In this study, we synthesized and investigated Cu-doped Y<SUB>2</SUB>O<SUB>3</SUB> photoelectrodes for this application using the hydrothermal method. The effects of Cu (0.0, 0.1, 0.3, and 0.5 mol) concentration on the crystal structure, morphology, and optical properties and their impact as photoelectrodes for energy-harvesting applications have been systematically explored. XPS analysis confirmed the incorporation of Cu ions into the host Y<SUB>2</SUB>O<SUB>3</SUB> photoelectrodes. The optical band gap of Y<SUB>2</SUB>O<SUB>3</SUB> photoelectrodes considerably decreases from ~4.35 eV to ~2.67 eV as a function of the Cu concentration, and the lowest bandgap was obtained for 0.3 mol% Cu-doped Y<SUB>2</SUB>O<SUB>3</SUB> electrodes. Electrochemical impedance spectroscopy analysis confirmed that the Cu dopant enhanced the charge carrier density of Y<SUB>2</SUB>O<SUB>3</SUB> and that it acts as an electron donor. PEC studies of Y<SUB>2</SUB>O<SUB>3</SUB> revealed that the photoanodes with 0.3 mol% of Cu dopant exhibited the highest photocurrent density of ~7.5 × 10<SUP>−5</SUP> A/cm<SUP>2</SUP>, which is ~15-fold that of pure Y<SUB>2</SUB>O<SUB>3</SUB> (5.0 × 10<SUP>−6</SUP> A/cm<SUP>2</SUP>). The superior photocurrent density is attributed to the improved electron donor density, the significantly reduced particle size, and the electron–hole recombination rate, which improved because of the Cu doping.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Doped Yttria photoelectrodes synthesis via hydrothermal method. </LI> <LI> Superior reduction of bandgap was achieved through Cu doping. </LI> <LI> Enhanced photocurrent density was attained at 0.3 mol% Cu doped Yttria. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Synthesis, structural and optical properties of CdS nanoparticles with enhanced photocatalytic activities by photodegradation of organic dye molecules

Venkata Reddy, Ch.,Prabhakar Vattikuti, S. V.,Shim, Jaesool Chapman and Hall 2016 Journal of materials science Materials in electron Vol.27 No.8