Gallbladder Paraganglioma Associated with SDHD Mutation: a Potential Pitfall on 18F-FDOPA PET Imaging

Zahraa Abdul Sater,Abhishek Jha,Adel Mandl,Sheila K. Mangelen,Jorge A. Carrasquillo,Alexander Ling,Melissa K. Gonzales,Osorio Lopes Abath Neto,Markku Miettinen,Karen T. Adams,Pavel Nockel,Mustapha El 대한핵의학회 2019 핵의학 분자영상 Vol.53 No.2

A 36-year-old male patient initially presented with hypertension, tinnitus, bilateral carotid masses, a right jugular foramen, and a periaortic arch mass with an elevated plasma dopamine level but an otherwise normal biochemical profile. On surveillance MRI 4 years after initial presentation, he was found to have a 2.2-cm T2 hyperintense lesion with arterial enhancement adjacent to the gallbladder, which demonstrated avidity on 68Ga-DOTATATE PET/CTand retrospectively on 18F-FDOPA PET/CT but was nonavid on 18F-FDG PET/CT. Biochemical work-up including plasma catecholamines, metanephrines, and chromogranin A levels were found to be within normal limits. This lesion was surgically resected and was confirmed to be a paraganglioma (PGL) originating from the gallbladder wall on histopathology. Pheochromocytoma (PHEO) and PGL are rare tumors of the autonomic nervous system. Succinate dehydrogenase subunit D (SDHD) pathogenic variants of the succinate dehydrogenase complex are usually involved in parasympathetic, extra-adrenal, multifocal head, and neck PGLs.We report an unusual location of PGL in the gallbladder associated with SDHD mutation which could present as a potential pitfall on 18F-FDOPA PET/CT as its normal excretion occurs through biliary system and gallbladder. This case highlights the superiority of 68Ga-DOTATATE in comparison to 18F-FDOPA and 18F-FDG in the detection of SDHD-related parasympathetic PGL.

Pressure leaching of metals from waste printed circuit boards using sulfuric acid

Jha, M. K.,Lee, J. c.,Kumari, A.,Choubey, P. K.,Kumar, V.,Jeong, J. Springer Verlag 2011 JOM Vol.63 No.8

Effects of yttrium substitution on structural and electrical properties of barium zirconate titanate ferroelectric ceramics

Priyanka A. Jha,A.K. Jha 한국물리학회 2013 Current Applied Physics Vol.13 No.7

In the present study, structural, dielectric and ferroelectric properties of Ba1-3x/2Yx Zr0.025Ti0.975O3ferroelectric ceramics have been investigated. The compound was synthesized using solid state reaction technique. The effect of yttrium substitution on structural, dielectric and ferroelectric properties was studied using X-ray diffractometer, scanning electron microscopy (SEM), LCR meter and PeE loops. Phase analysis shows the formation of secondary phase YTi2O6 for Y ≥ 2.5 mol% substitution. The microstructural investigation shows that Y substitution significantly reduces the grain size. An increase in Y content up to 2.5 mol% increases the Curie temperature (Tc) initially but decreases subsequently. The maximum dielectric constant at Tc has been observed for 2 mol% Y substitution and with further increase in Y content the dielectric constant decreases considerably. The solubility limit is found to be 2.5 mol% of Y and after that some of the yttrium atoms enter B-sites and leading to the formation of the secondary phase. The PeE loop studies show that there is an increase in the coercive field with increasing Y content.

Synchronization and Operation of Parallel Inverters using Droop Control

L. K. Sahoo,N. D. Thakur,K. Rai,P Sensarma,R. D. Jha,P. Mohanty,A Sharma 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

To obtain a continuous power supply Distributed Generation (DG) with a Decentralized Power System (DPS), i.e. replacing a single UPS unit with multiple, smaller units in parallel, is emerging as new paradigm. The technically challenging aspect of DPS is the synchronization of inverters and load sharing among the parallel connected inverters. In this paper, a control method is proposed and implemented for synchronization and parallel operation of inverters. Droop control method has been used for equal power sharing, and design of power control loop. The design issues for voltage control loop are analyzed with the discussion of relative stability of the system. A current control loop is designed and analyzed to provide synchronization between the inverters.

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>

MICROBE-MEDIATED NANOTRANSFORMATION: CADMIUM

ANAL K. JHA,K. PRASAD,A. R. KULKARNI 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2007 NANO Vol.2 No.4

An eco-friendly microbe (lactobacillus sp.)-mediated synthesis of cadmium nanoparticles is reported. The synthesis is performed at room temperature. X-ray and transmission electron microscopy analyses are performed to ascertain the formation of Cd nanoparticles. Individual nanoparticles as well as a number of aggregates almost spherical in shape having a size of 40–60 nm are found.

Electron-Electron Interactions based Metal-Insulator Transition in Ga Doped ZnO Thin Films

R V Muniswami Naidu,A Subrahmanyam,A Verger,M K Jain,S V N Bhaskara Rao,S N Jha,D M Phase 대한금속·재료학회 2012 ELECTRONIC MATERIALS LETTERS Vol.8 No.4

We report on the charge carrier transport mechanisms of undoped and Ga doped (2 wt. % and 4 wt. %)ZnO thin films grown by pulsed dc magnetron sputtering technique. Temperature dependent resistivity measurements showed typical semiconducting behaviour for undoped ZnO thin films where as Ga doped ZnO thin films showed metallic nature at higher temperatures and insulating nature with a metal to insulator transition at lower temperatures. The observed transition temperatures are 91 K and 140 K for 2 wt. % and 4 wt. %Ga doped ZnO films respectively. The observed metal insulator transition is attributed to the electron-electron interactions at low temperatures. The variations in the transition temperatures are explained based on the disorderness induced in the system due to the doping effect. ZnO doped with 4 wt. % Ga showed the lowest resistivity of 5.7 × 10−4Ω cm with a carrier concentration of 1.2 × 1021/cm3. Undoped and doped ZnO thin films are about 90% transparent in the visible region. Blue shift is observed in the absorption edge with the effect of doping and it is explained based on B-M shift. The Fermi level measured from valance band spectroscopy showed a shift of +0.6 eV for 2 wt. % Ga doped ZnO thin film and +0.7 eV for 4 wt. %Ga doped ZnO thin film compared to the Fermi edge of undoped ZnO thin films. This ascertains the movement of Fermi level in to the conduction band with the effect of doping.

Optimization of Cobalt Loading in Co–CeO2 Catalyst for the High Temperature Water–Gas Shift Reaction

Lee, Y. L.,Jha, A.,Jang, W. J.,Shim, J. O.,Jeon, K. W.,Na, H. S.,Kim, H. M.,Lee, D. W.,Yoo, S. Y.,Jeon, B. H. Springer Science + Business Media 2017 Topics in catalysis Vol.60 No.9

<P>We varied the cobalt loading (10, 15, 25, 35 wt%) to determine the optimum loading in a Co-CeO2 catalytic system used for the high temperature water-gas shift (WGS) reaction. Severe reaction conditions were used to compare the catalytic performances including a very high gas hourly space velocity (142,663 h(-1)) and a high CO concentration (similar to 38%). Among the prepared catalysts, 15% Co-CeO2 exhibited excellent catalytic activity in the temperature range of 350-550 degrees C without promoting the methanation reaction. In addition, this catalyst showed relatively stable activity for 50 h at 400 degrees C. The outstanding performance of 15% Co-CeO2 catalyst is mainly due to the highest amount of dispersed cobalt atoms on the catalyst surface. Additionally, the WGS activity was affected by the oxygen vacancy concentration.</P>

Corrosion and Nanomechanical Behaviors of 16.3Cr-0.22N-0.43C-1.73Mo Martensitic Stainless Steel

( Rahul Ghosh ),( S. Chenna Krishna ),( A. Venugopal ),( P. Ramesh Narayanan ),( Abhay K. Jha ),( P. Ramkumar ),( P. V. Venkitakrishnan ) 한국부식방식학회(구 한국부식학회) 2016 Corrosion Science and Technology Vol.15 No.6

The effect of nitrogen on the electrochemical corrosion and nanomechanical behaviors of martensitic stainless steel was examined using potentiodynamic polarization and nanoindentation test methods. The results indicate that partial replacement of carbon with nitrogen effectively improved the passivation and pitting corrosion resistance of conventional high-carbon and high- chromium martensitic steels. Post-test observation of the samples after a potentiodynamic test revealed a severe pitting attacks in conventional martensitic steel compared with nitrogen- containing martensitic stainless steel. This was shown to be due to (i) microstructural refinement results in retaining a high-chromium content in the matrix, and (ii) the presence of reversed austenite formed during the tempering process. Since nitrogen addition also resulted in the formation of a Cr₂N phase as a process of secondary hardening, the hardness of the nitrogen- containing steel is slightly higher than the conventional martensitic stainless steel under tempered conditions, even though the carbon content is lowered. The added nitrogen also improved the wear resistance of the steel as the critical load (Lc2) is less, along with a lower scratch friction coefficient (SFC) when compared to conventional martensitic stainless steel such as AISI 440C.

An enhanced numerical procedure for modelling fully grouted bolts intersected by rock joint

Kamal C. Das,Debasis Deb,A.K. Jha 한국자원공학회 2013 Geosystem engineering Vol.16 No.1

The stability of underground structure made especially in jointed rock mass is of the utmost important to designer, engineers and operators. Rock bolting is generally being practised to reinforced excavation walls and roofs by minimizing the movement of rock joints. In this study, a numerical procedure has been developed in extended finite element framework (XFEM) to analyze the behaviour of grouted bolt intersected by a joint. A solid finite element intersected by a bolt and a joint along any arbitrary direction is termed as ‘doubly enriched’ element. Nodes of an doubly enriched element have additional degrees of freedom for determining displacements, stresses developed in the bolt rod as well as the displacements jump and traction along the joint. The paper also provides verifications of this procedure by solving two known examples (i) direct shear test performed on a bolted joint sample-experimental verification and (ii) reinforcement of a joint located in the vicinity of a circular tunnel-analytical verification.