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Design and simulation of optoelectronic oscillator with micro ring resonator and radio frequency amplifier modelling at 110 GHz

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Optoelectronics Letters 2021年第8期17卷 482-489页

作者： Anil kurian P Ugra mohan Roy Department of Electronics and Communication Engineering Ramaiah University of Applied SciencesBangalore 560034India

There is an increasing need for high performance oscillators as the faster transmission networks demand for high frequency ***-electronic oscillators(OEO)enable us to make better oscillators in terms of size,weight and *** this paper,photonic integration is proposed for realizing the OEO with micro ring resonator(mRR)and radio-frequency(RF)amplifiers of monolithic microwave integrated circuit(mmIC),which can be used for generating 110 GHz sine *** OEO architecture is proposed and block diagram developed considering Silicon based mRR and three-stage RF amplifier based on Ga N high-electron-mobility transistor(HEmT).A simulation model is developed according to the Klein model of mRR and is validated against the calculated performance *** dimensions are calculated as with silicon on insulator(SOI)technology and a radius 5.27μm for the device is *** spectral range(FSR)of 48.52 nm and filter rejection ratio of 16.79 d B are obtained for this *** proposed RF amplifier is modelled with Ga N parameters derived from high frequency pinch-off model and with power amplifier *** gain for this amplifier is obtained as 10.6 d *** OEO design is developed in this project in such a way that the system can be manufactured with the existing methods.

关键词： amplifier resonator optoelectronic

Geochemistry of core sediments from the southeastern Bay of Bengal:Inferences on weathering and early diagenetic changes

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Geoscience Frontiers 2021年第2期12卷 495-504页

作者： A.Prajith Abhishek Tyagi P.John kurian National Centre for Polar and Ocean Research(NCPOR) Ministry of Earth Sciences(MoES)Headland SadaVasco-da-Gama403804GoaIndia

A sediment core(ABP24/05),collected at a water depth of 3520 m from the southeastern Bay of Bengal was studied to determine the change in chemical weathering during the last glacial to deglacial periods and the factors of sedimentary environment which controlled earliest diagenetic changes in the sediment after its *** ratios of K/Rb,Ti/Al and Zr/Rb during~45 to~18 cal kyr *** the core sediments may be attributed to the stronger physical erosion and turbidity currents activity during this *** might have brought a higher quantity of unaltered minerals to the study *** ratios of K/Rb,Zr/Rb,and Ti/Al and increase of SiO_(2)/TiO_(2),Rb/Al and Cs/Al from~18 cal kyr *** present may be indicating an increase in the rate of chemical weathering during this *** time of increased chemical weathering in the study area is consistent with deglaciation warming in the tropical Indian Ocean and strengthening of river runoff into the Andaman *** change during the interglacial period by increased solar insolation thereby strengthened the summer monsoon which might have led to intensified chemical weathering in the source region since~18 cal kyr *** low organic carbon(OC),high mn/Al,Fe/Al and the mn-oxides minerals precipitation indicate prevailing of oxic conditions during~11 cal kyr *** the core sediments,which is contradictory to suboxic conditions developed in the deep ocean sediments in the western Bay of Bengal and the equatorial Indian *** low terrigenous influx and export of less OC to the bottom sediments might have created a favorable condition for the formation of mn-oxides in the study area during Holocene.

关键词： Bay of Bengal Trace elements Chemical weathering Summer monsoon mn-oxides

Differential effect of aqueous Desmodium gangeticum root extract mediated TiO2 nanoparticles on isolated mitochondria, cells and Wistar rats

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Asian Pacific Journal of Tropical Biomedicine 2017年第11期7卷 1031-1035页

作者： mahalakshmi Ansari Gino A.kurian School of Chemical and Biotechnology SASTRA UniversityThanjavur613401Tamil NaduIndia

Objective: To study the renal toxic effect of titanium dioxide nanoparticles(TiNPs)prepared by chemical and green ***: TiNPs were prepared by chemical(sol gel technique) and green route(using aqueous extract of Desmodium gangeticum root by using titanium tetraisopropoxide as precursor). Thus prepared TiNPs were characterized using UV–visible spectrophotometry, X-ray diffractometry and evaluated its renal toxic impact in different experimental models viz., Wistar rats(100 mg/kg ***.; oral), LLC-PK1 cells(100 mg/m L) and isolated renal mitochondria(0.25, 0.5 and 1 mg/m L).Results: Compared to the chemically synthesized TiNPs, Desmodium gangeticum synthesized nanoparticles showed less nephrotoxicity, determined by elevated serum renal markers like urea(62%), creatinine(35%), aspartate aminotransferase(61%) and alanine transaminase(37%) and the result was in agreement with cellular toxicity(measured by mTT assay and lactate dehydrogenase activity). Further toxicity evaluation at the level of mitochondria showed not much significant difference in TiNPs effect between two synthetic ***: The biochemical findings in renal tissue and epithelial cell(LLC-PK1)supported by histopathology examination and isolated mitochondrial activity showed minor toxicity with TiNPs prepared by green route(Ti NP DG) than TiNP Chem.

关键词： Titanium dioxide nanoparticles mitochondria Renal toxicity LLC PK1 cell line

Anti-proliferative potential of sodium thiosulfate against HT 29 human colon cancer cells with augmented effect in the presence of mitochondrial electron transport chain inhibitors

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Asian Pacific Journal of Tropical Biomedicine 2020年第7期10卷 333-340页

作者： Bhavana Sivakumar Sri Rahavi Boovarahan Gino A kurian Vascular Biology Lab School of Chemical and BiotechnologySASTRA Deemed UniversityThanjavurIndia

Objective:To compare the anti-proliferative effect of sodium thiosulfate on human colorectal cancer cells(HT-29)and normal small intestine cells(IEC6).methods:Cells(HT-29 and IEC6)were treated with different concentrations of sodium thiosulfate ranging from 0.5 m m to 80 m m for 24 *** viability was measured via crystal violet and mTT ***-29 cells were further treated in the presence and absence of mitochondrial electron transport chain(ETC)inhibitors,KATP channel opener and closer and H2S inhibitors for 24 h followed by sodium thiosulfate in order to study their respective roles in the anti-proliferative activity of sodium ***:The IC50 values of sodium thiosulfate on HT-29 cells were 40.93 m m and 42.45 m m by crystal violet and mTT assay whereas,in the case of IEC6 cells,the values were 45.17 m m and 47.22 m *** inhibition of endogenous H2S enzymes and KATP channel induced no change in the anti-proliferative capacity of sodium ***,the anti-proliferative activity of sodium thiosulfate was enhanced in the presence of mitochondrial ETC ***:HT-29 cell growth is effectively attenuated by sodium thiosulfate and the anti-proliferative activity of sodium thiosulfate is enhanced in the presence of mitochondrial ETC inhibitors.

关键词： Colorectal cancer Sodium thiosulfate HT-29 IEC6 mitochondria Rotenone Clonogenic assay

Surgical outcomes and strategy of hypertrophic obstructive cardiomyopathy

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第2期7卷 148-153页

作者：朱亚彬 RAJAN S. kurian V.m. 刘志勇 Department of Thoracic and Cardiovascular Surgery Affiliated Su Bei Hospital Yangzhou University Yangzhou 225001 China Department of Thoracic and Cardiovascular Surgery Madras Medical Mission Moggapair East Chennai 600037 India Department of Thoracic and Cardiovascular Surgery Affiliated Zhong Da Hospital Southeast University Nanjing 210009 China

Objective： To evaluate the surgical clinical results of hypertrophic obstructive cardiomyopathy. methods： We retrospectively collected data on 24 patients who underwent surgical management in the past ten years in two hospitals in China and madras medical mission in India. myomectomy was carried out on all patients. Among them 3 patients underwent mitral valve replacement; 2 patients underwent mitral valve repair （anterior mitral leaflet plication）; 2 patients underwent aortic valve replacement; 1 patient underwent aortic valve repair; 2 patients underwent aortic root replacement; 1 patient underwent Bentall＇s procedure and 1 patient underwent coronary artery bypass grafting because of a breached muscle bridge, Results： One patient died of post-operative heart failure. The mean follow-up time was 4.3 years, There was significant improvement in the symptomatic status. Sixteen patients were asymptomatic with good effort tolerance and only four patients had New York heart association （NYHA） Classes Ⅰ-Ⅱ due to associated valvular lesions, Conclusion： Our experience proved that symptomatic hypertrophic obstructive cardiomyopathy or non-symptomatic hypertrophic obstructive cardiomyopathy with combined heart disease is indication for surgery as surgical intervention could get better clinical results in this kind of patients compared with other non-surgical method because it beneficially reduces the systolic anterior motion （SAm） of the mitral valve leaflet, which could not be avoided by other non-surgical treatment.

关键词： Hypertrophic obstructive cardiomyopathy Systolic anterior motion myomectomy

Genotype phenotype correlation in Wilson's disease within families-a report on four south Indian families

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World Journal of Gastroenterology 2008年第29期14卷 4672-4676页

作者： S Santhosh RV Shaji CE Eapen V Jayanthi S malathi P Finny N Thomas m Chandy G kurian Gm Chandy Department of GI Sciences Christian Medical CollegeVellore Tamil Nadu India Department of Haematology Christian Medical CollegeVellore Tamil Nadu India Department of medical Gastroenterology Stanley Medical College Chennai Tamil Nadu India Department of Pediatrics Institute of Child HealthChennai Tamil Nadu India Department of Endocrinology Christian Medical CollegeVellore Tamil Nadu India

AIm: To study the genotype phenotype correlation in Wilson's disease (WD) patients within families. mETHODS: We report four unrelated families from South India with nine members affected with WD. Phenotype was classified as per international consensus phenotypic classifi cation of WD. DNA was extracted from peripheral blood and 21 exons of ATP7B gene and flanking introns were amplified by polymerase chain reaction (PCR). The PCR products were screened for mutations and the aberrant products noted on screening were sequenced. RESULTS: Four separate ATP7B mutations were found in the four families. ATP7B mutations were identical amongst affected members within each family. Three families had homozygous mutations of ATP7B gene while one family had compound heterozygous mutation, of which only one mutation was identifi ed. We noted concordance between ATP7B gene mutation and Wilson's disease phenotype amongst members within each family. The age of onset of symptoms or of detection of asymptomatic disease, baseline serum ceruloplasmin and baseline urinary copper levels were also similar in affected members of each family. minor differences in phenotype and baseline serum ceruloplasmin level were noted in one ***: We report concordance between ATP7B mutation and WD phenotype within each family with > 1 member affected with WD. Homozygous ATP7B mutation was present in 3 of the 4 families studied. Our report supports allelic dominance as a determinant of WD phenotype. However, in one family with compound heterozygous mutation, there was a similar WD phenotype which suggests that there may be other factors determining the phenotype.

关键词： Wilson's disease Genotype phenotypecorrelation

Sedimentary sources and processes in the eastern Arabian Sea:Insights from environmental magnetism,geochemistry and clay mineralogy

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Geoscience Frontiers 2016年第2期7卷 253-264页

作者： Kumar Avinash P.John kurian Anish Kumar Warrier R.Shankar T.C.Vineesh Rasik Ravindra Earth System Science Organization National Centre for Antarctic and Ocean Research(ESSO-NCAOR)Ministry of Earth Sciences(MoES) Department of marine Geology Mangalore University Earth System Science Organization Ministry of Earth Sciences(MoES)

The spatial distribution patterns of surficial sediment samples from different sedimentary domains （shallow to deep-sea regions） of the eastern Arabian Sea were studied using sediment proxies viz. environmental magnetism, geochemistry, particle size and clay mineralogy. Higher concentrations of magnetic minerals （high Xlf） were recorded in the deep-water sediments when compared with the shallow water sediments. The magnetic mineralogy of one of the shallow water samples is influenced by the presence of bacterial magnetite as evidenced from the XARm/Xlf VS. XARm/Xfd biplot. However, the other samples are catchment-derived. The high correlation documented for Xlf, anhysteretic remanent mag- netisation （XARm） and isothermal remanent magnetisation （IRm） with Al indicates that the deep-sea surflcial sediments are influenced by terrigenous fluxes which have been probably derived from the southern Indian rivers, the Sindhu （the Indus） and the Narmada-Tapti rivers. A lower mn concentration is recorded in the upper slope sediments from the oxygen minimum zone （OmZ） but a higher mn/AI ratio is documented in the lower slope and deep-sea sediments. Clay minerals such as illite （24-48.5%）, chlorite （14.1-34.9%）, smectite （10.6-28.7%） and kaolinite （11.9-27.5%） dominate the sediments of shallow and deep-sea regions and may have been derived from different sources and transported by fluvial and aeolian agents. Organic carbon （OC） data indicate a low concentration in the shallow/shelf region （well oxygenated water conditions） and deeper basins （increased bottom-water oxygen concentration and low sedimentation rate）. High OC concentrations were documented in the OmZ （very low bottom-water oxygen concentration with high sedimentation rate）. The calcium carbonate concentration of the surface sediments from the continental shelf and slope regions （〈 1800 m） up to the Chagos-Laccadive Ridge show higher concentrations （average - 58%） when compared to deep basin sediments （average - 44%）.

关键词： magnetic minerals major elements Organic carbon Calcium carbonate Terrigenous fluxes Eastern Arabian Sea

Early vs late oral nutrition in patients with diabetic ketoacidosis admitted to a medical intensive care unit

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World Journal of Diabetes 2019年第1期10卷 57-62页

作者： Kirill Lipatov Kevin K kurian Courtney Shaver Heath D White Shekhar GhamANDe AlejANDro C Arroliga Salim Surani Department of Internal medicine Division of Pulmonary Critical Care and Sleep MedicineBaylor Scott and White Health Department of Biostatistics Baylor Scott and White Health Department of medicine Texas A and M University

BACKGROUND Diabetic ketoacidosis(DKA) has an associated mortality of 1% to 5%. Upon admission, patients require insulin infusion and close monitoring of electrolyte and blood sugar levels with subsequent transitioning to subcutaneous insulin and oral nutrition. No recommendations exist regarding the appropriate timing for initiation of oral *** To assess short-term outcomes of oral nutrition initiated within 24 h of patients being admitted to a medical intensive care unit(mICU) for *** A retrospective observational cohort study was conducted at a single academic medical center. The patient population consisted of adults admitted to the mICU with the diagnosis of DKA. Baseline characteristics and outcomes were compared between patients receiving oral nutrition within(early nutrition group) and after(late nutrition group) the first 24 h of admission. The primary outcome was 28-d mortality. Secondary outcomes included 90-d mortality, mICU and hospital lengths of stay(LOS), and time to resolution of *** There were 128 unique admissions to the mICU for DKA with 67 patientsreceiving early nutrition and 61 receiving late nutrition. The APACHE(Acute Physiology and Chronic Health Evaluation) IV mortality and LOS scores and DKA severity were similar between the groups. No difference in 28-or 90-d mortality was found. Early nutrition was associated with decreased hospital and mICU LOS but not with prolonged DKA resolution, anion gap closure, or greater rate of DKA *** In patients with DKA, early nutrition was associated with a shorter mICU and hospital LOS without increasing the rate of DKA complications.

关键词： Diabetes mellitus Diabetic ketoacidosis Diabetic complications Acidosis Ketosis Critical care

Floating production storage and offloading systems＇ cost and motion performance： A systems thinking application

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Frontiers of Engineering management 2018年第3期5卷 357-368页

作者： Rini NISHANTH Andrew WHYTE V.John kurian Civil & Environmental Engineering University Tech. PETRONASBandar Seri Iskandar Malaysia Civil Engineering Curtin University Perth Australia

Floating production storage and offloading （FPSO） units increasingly represent a practical and economic means for deep-water oil extraction and production. Systems thinking gives a unique opporamity to seek a balance between FPSO technical performance（s）, with whole-cost; stakeholder decision-making is charged to align different fit-for-use design specification options＇ that address technical-motion（s）, with respective life-cycle cost analyses （LCCA）. Soft system methodology allows situation based analyses over set periods-of-time by diagnosing the problem-at-hand; namely, assessing the antecedents of life-cycle cost relative to FPSO sub- component design alternatives. Alternative mooring- component comparisons for either new-build hulls or refurbished hulls represent an initial necessary considera- tion to facilitate extraction, production and storage of deep- water oil reserves. Coupled dynamic analysis has been performed to generate FPSO motion in six degrees of freedom using SESAm DeepC, while life-cycle cost analysis （LCAA） studies give net-present-value comparsons reflective of market conditions. A parametric study has been conducted by varying wave heights from 4 - 8 m to understand FPSO motion behavior in the presence of wind and current, as well as comparing the motions of turreted versus spread mooring design alternatives. LCCA data has been generated to compare the cost of such different mooring options/hull conditions over 10 and 25- year periods. Systems thinking has been used to explain the interaction of problem variables; resultantly this paper is able to identify explicit factors affecting the choice of FPSO configurations in terms of motion and whole-cost, toward assisting significantly with the front-end engineering design （FEED） phase of fit-for-purpose configured FPSOs, in waters off malaysia and Australia.

关键词： FPSO LCCA spread/turret-mooring DeepC cost motion soft-systems