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In-Situ Hydrothermal Synthesis of Bi–Bi2O2CO3 Heterojunction Photocatalyst with Enhanced Visible Light Photocatalytic Activity

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Nano-Micro Letters 2017年第2期9卷 58-67页

作者： Prasenjit kar Tuhin Kumar Maji Ramesh Nandi Peter Lemmens Samir Kumar Pal Department of Chemical Biological and Macromolecular Sciences S.N.Bose National Centre for Basic SciencesBlock JDSector ⅢSaltLakeKolkata 700106India Institute for Condensed Matter Physics TU BraunschweigMendelssohnstraße 338106 BrunswickGermany Laboratory for Emerging Nanometrology TU BraunschweigBrunswickGermany

Bismuth containing nanomaterials recently received increasing attention with respect to environmental applications because of their low cost, high stability and nontoxicity. In this work, Bi–Bi_2O_2CO_3 heterojunctions were fabricated by in-situ decoration of Bi nanoparticles on Bi_2O_2CO_3 nanosheets via a simple hydrothermal synthesis approach. X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) and high-resolution TEM(HRTEM) were used to confirm the morphology of the nanosheet-like heterostructure of the Bi–Bi_2O_2CO_3 composite. Detailed ultrafast electronic spectroscopy reveals that the in-situ decoration of Bi nanoparticles on Bi_2O_2CO_3 nanosheets exhibit a dramatically enhanced electron-hole pair separation rate, which results in an extraordinarily high photocatalytic activity for the degradation of a model organic dye, methylene blue(MB) under visible light illumination. Cycling experiments revealed a good photochemical stability of the Bi–Bi_2O_2CO_3 heterojunction under repeated irradiation. Photocurrent measurements further indicated that the heterojunction incredibly enhanced the charge generation and suppressed the charge recombination of photogenerated electron-hole pairs.

关键词： Bi nanoparticles Bi–Bi2O2CO3 nanosheets Heterojunction Hydrothermal method Charge separation Visible light photocatalytic activity

Textural and geochemical characteristics of off shore sediment of North Bay of Bengal:A statistical approach for marine metal pollution

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International Journal of Sediment Research 2015年第3期30卷 208-222页

作者： Sanghamitra Palleyi Sabnam Banoo Rabi Narayan kar Chitta Ranjan Panda Environment & Sustainability Department CSIR-Institute of Minerals and Materials Technology

Metal pollution study on sediments of North Bay of Bengal sediments presented in this paper is based on existing Lithostratigraphy of upstream,mineralogy and geochemical analysis of 42 sediment *** statistical analysis identifies the metal pollution as well as its apparent source in the off shore *** were analyzed for grain size,organic content and heavy metals(Fe,Mn,Cr,Cu,Ni,Pb,Cd,Zn and Co) using the sequential extraction method to evaluate geochemical processes and pollution *** an effort to surmise anthropogenic input,several approaches including classification by quantitative indexes such as enrichment factor,contamination factor,degree of pollution,pollution load index and geo accumulation index,were *** speciation results indicate high%of Cd in exchangeable fraction of Mahanadi transect sediments where as a considerable amount of oxidizable fraction of Cr was detected at *** indexes place North Bay of Bengal under moderately polluted zone due to high level of *** of metals to Fe indicated relatively high enrichment factors for Cd and *** analysis identified seven possible types of geochemical associations where sediment pH plays a major role for the heavy metal *** higher Cd concentration in exchangeable fraction as well as the higher EF for Cd and Cr present in sediment may pose a risk of secondary water pollution under slightest disturbance in the geo-chemistry of *** study with available data of near costal zones and upstream stratigraphy revealed that open cast mining,overburden dumping,mineral based industrial effluents were the major source of pollution for catchment area *** of Bengal is likely to face a serious threat of metal pollution with the present deposition rates unless rigorous pollution control norms are applied.

关键词： North Bay of Bengal Heavy metals Sequential extraction Quantitative index Factor analysis

Fibula pro-tibia vs standard locking plate fixation in an ankle fracture saw bone model

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World Journal of Orthopedics 2021年第8期12卷 548-554页

作者： Tosan Okoro kar Hao Teoh Hiro tanaka Department of Arthroplasty Robert Jones and Agnes Hunt Orthopaedic Hospital NHS Foundation TrustOswestry SY107AGUnited Kingdom Department of Orthopaedic Surgery Princess Alexandra Hospital NHS TrustHarlow CM201QXUnited Kingdom Department of Orthopaedics Royal Gwent HospitalNewport NP202UBUnited Kingdom

BACKGROUND Locking plate fixation in osteoporotic ankle fractures may fail due to cut-out or metalwork *** pro-tibia fixation was a technique prior to the advent of locking plates that was used to enhance stability in ankle fractures by achieving tri or tetra-cortical *** locking plates,the strength of this fixation construct can be further *** is lack of evidence currently on the merits of tibiapro-fibula augmented locking plate fixation of unstable ankle *** To assess if there is increased strength to failure,in an ankle fracture saw bone model,with a fibula pro-tibia construct when compared with standard locking plate *** Ten osteoporotic saw bones with simulated supination external rotation injuries were *** saw bones were fixed with standard locking plates whilst the other 5 saw bones were fixed with locking plates in a fibula pro-tibia *** fibula pro-tibia construct involved fixation with 3 consecutive locking screws applied across 3 cortices proximally from the level of the *** fixations were tested in axial external rotation to failure on an electromagnetic test frame(MTS 858 Mini-Bionix test machine,MTS Corp,Eden Praire,MN,United States).Torque at 30 degrees external rotation,failure torque,and external rotation angle at failure were compared between both groups and statistically *** The fibula pro-tibia construct demonstrated a statistically higher torque at 30 degrees external rotation(4.421±0.796 N/m vs 1.451±0.467 N/m;t-test P=0.000),as well as maximum torque at failure(5.079±0.694N/m vs 2.299±0.931 N/m;t-test P=0.001)compared to the standard locking plate *** fibula pro-tibia construct also had a lower external rotation angle at failure(54.7±14.5 vs 67.7±22.9).CONCLUSION The fibula pro-tibia locking plate construct demonstrates biomechanical superiority to standard locking plates in fixation of unstable ankle fractures in this saw bone ***

关键词： Unstable ankle fractures Pro-tibia fixation Improved stability Simulated biomechanical analysis Osteoporotic fractures Ankle injuries

In silico screening for As/Se-free ovonic threshold switching materials

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npj Computational Materials 2023年第1期9卷 1359-1366页

作者： Sergiu Clima Daisuke Matsubayashi taras Ravsher Daniele Garbin Romain Delhougne Gouri Sankar kar Geoffrey Pourtois imec Kapeldreef 75B-3001 LeuvenBelgium Device Technology Research&Development Center Future Memory Development DepartmentKIOXIA CorporationShin-sugita-cho 8Isogo-kuYokohamaJapan KU Leuven Celestijnenlaan 200DB-3001 LeuvenBelgium

Restricted use of hazardous environmental chemicals is one important challenge that the semiconductor industry needs to face to improve its *** threshold switching(OTS)ternary compound materials used in memory selector devices contain As and *** these elements out of these materials requires significant research *** facilitate this process,we performed systematic material screening for As/Se-free ternary materials,based on ab-initio *** limit the large amount of possible chemical compositions to fewer promising candidates,we used physics-based material parameter filters like material stability,electronic properties,or change in *** OTS gauge concept is introduced as a computed parameter to estimate the probability of a material to show an OTS *** a result,we identified 35 As/Se-free ternary alloy compositions for stand-alone OTS memory applications,as well as 12 compositions for RRAM selector *** work aims seeding the development of As/Se-free OTS materials.

关键词： alloy ternary free

An EOQ model with backordering for perishable items under multiple advanced and delayed payments policies

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Journal of Management Analytics 2022年第3期9卷 403-434页

作者： Prasanta Kumar Ghosh Amalesh Kumar Manna Jayanta Kumar Dey Samarjit kar Department of Mathematics National Institute of Technology DurgapurDurgapurIndia Department of Mathematics The University of BurdwanBurdwanIndia Department of Mathematics Mahishadal Raj CollegePurba MedinipurIndia Department of Mathematics Y.S.Palpara MahavidyalayaPurba MedinipurIndia

This study investigated an economic order quantity (EOQ) model with completebackorder for fixed lifetime perishable items under multiple advance and delayedpayments policies. Here, a new type of business policy is consideredwhere supplieroffers the retailer to pay a fraction of the purchasing cost before the order deliverybymultiple equal installments starting from the ordering time and the rest amountafter the delivery by multiple equal installments. Here, some theoretical results areillustrated to determine the conditions of existence and uniqueness of the optimalsolutions. A closed form solution is determined to solve the proposed model underapproximation. Some numerical examples are provided to examine the validity ofthe proposed model. Finally, sensitivity analyses are presented to obtain the effectof optimal policy and provide some managerial insights of the model.

关键词： inventory perishable item expiry date advance payment delayed payment

Gallbladder polyp as a manifestation of hemobilia caused by arterial-portal fistula after percutaneous liver biopsy: A case report

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World Journal of Gastroenterology 2005年第2期11卷 305-307页

作者： Chih-Lang Lin Tsung-Shih Lee kar-Wai Lui Cho-Li Yen Division of Gastroenterology Department of Internal MedicineChang-Gung Memorial Hospital and UniversityKeelungTaiwanChina

Outpatient percutaneous liver biopsy is a common practice in the differential diagnosis and treatment of chronic liver disease. The major complication and mortality rate were about 2-4% and 0.01-0.33% respectively. Arterio-portal fistula as a complication of percutaneous liver biopsy was infrequently seen and normally asymptomatic. Hemobilia, which accounted for about 3% of overall major percutaneous liver biopsy complications, resulted rarely from arterio-portal fistula We report a hemobilia case of 68 years old woman who was admitted for abdominal pain after liver biopsy. The initial ultrasonography revealed a gallbladder polypoid tumor and common bile duct (CBD) dilatation. Blood clot was extracted as endoscopic retrograde cholangiopancreatography (ERCP) showed hemobilia. The patient was shortly readmitted because of recurrence of symptoms. A celiac angiography showed an intrahepatic arterio-portal fistula. After superselective embolization of the feeding artery, the patient was discharged uneventfully. Most cases of hemobilia caused by percutaneous liver biopsy resolved spontaneously. Selective angiography embolization or surgical intervention is reserved for patients who failed to respond to conservative treatment.

关键词： Gallbladder polyp Hemobilia Arterial-portal fistula Percutaneous liver biopsy

Superinfection of hepatitis E Virus as a cause of decompensation in liver cirrhosis due to hepatitis B virus

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Asian Pacific Journal of Tropical Medicine 2009年第2期2卷 54-57页

作者： Manisha Jain Anita Chakravarti P kar Mbbs Md Department of Microbiology Maulana Azad Medical College Department of Medicine Lok Nayak and Associated HospitalsNew Delhi-110019India

Objevtive:Super infection with hepatitis A virus(HAV ) and hepatitis E virus(HEV ) in the presence of underlying hepatocellular injury can cause severe *** endemic areas such as India,however most patients already have been exposed to HAV but could still be susceptible to HEV *** our study we determined the seroprevalence of anti-HAV IgM and anti-HEV IgM to assess the incidence of superinfection with these viruses in cirrhotic patients with the goal of defining the need for protection against these viruses and further correlate the presence of these viruses with the clinical ***:We studied 53 patients of cirrhosis as a result of Hepatitis B *** causes of decompensation were ruled out before their inclusion in the study *** sample from these patients was tested for HBsAg,anti HBc IgG,anti HEV IgM and anti HAV IgG and IgM by commercially available ELISA *** function test was done on all the patients and correlated with various serological ***:anti HBc IgG was present in all the cases of cirrhosis. Hepatitis B surface antigen was present in 20 out of 53 cases of *** of the patients demonstrated anti-HAV IgM,however one patient had anti-HEV ***:Superinfection with HAV in adult patient is uncommon in *** of acute HEV infection in decompensated cirrhosis is low in the present study but presence of HEV superinfection in one patient corroborates the apprehension of liver function deterioration following superinfection with HEV virus.

关键词： HEV HAV Superinfection Liver cirrhosis

Environmental application of three-dimensional graphene materials as adsorbents for dyes and heavy metals: Review on ice-templating method and adsorption mechanisms

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Journal of Environmental Sciences 2019年第5期31卷 174-199页

作者： kar Chiew Lai Lai Yee Lee Billie Yan Zhang Hiew Suchithra Thangalazhy-Gopakumar Suyin Gan Department of Chemical and Environmental Engineering University of Nottingham Malaysia Campus

The remediation of wastewater requires treatment technologies which are robust, efficient,simple to operate and affordable such as adsorption. Lately, three-dimensional(3D)graphene based materials have attracted significant attention as effective adsorbents for wastewater treatment. The intrinsic properties of 3D graphene structure such as large surface area and interconnected porous structure can facilitate the transport of pollutants into the 3D network and provide abundant active sites for trapping the pollutants. For the synthesis of 3D graphene structure, ice-templating is commonly practiced due to its facile steps, cost effectiveness and high scalability potential. This review covers the icetemplating fabrication technique for 3D graphene based materials and their application as adsorbents in eliminating dyes and heavy metals from aqueous media. The assembly mechanisms of the ice-templating fsynthesis are comprehensively discussed. Further discussion on the fundamental principles, critical process parameters and characteristics of ice-templated 3D graphene structures is also included. A thorough review on the mechanisms for batch adsorption of dyes and heavy metals is presented based on the structures and properties of the 3D graphene materials. The review further evaluates the dynamic adsorption in packed columns and the regeneration of 3D graphene based materials.

关键词： Ice-templating 3D graphene based structure Adsorption mechanism Dyes Heavy metals

Immunogenicity and reactogenicity of a recombinant hepatitis B vaccine in subjects over age of forty years and response of a booster dose among nonresponders

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World Journal of Gastroenterology 2003年第5期9卷 1132-1134页

作者： Kunal Das R.K.Gupta V.Kumar P.kar Department of Medicine Maulana Azad Medical College & L.N.HospitalNew Delhi.Medical AdvisorPanacea Biotec Co.New Delhi

AIM:The study was initiated to evaluate the reactogenicity and immunogenicity of a recombinant hepatitis B vaccine in age group >40 years and to study the response of a single booster dose in primary non-responders to the hepatitis B vaccination. METHODS:A total of 102 volunteers without markers of hepatitis B infection (negative for HBsAg,anti-HBc antibody, HBeAg and anti-HBs antibody) received 20μg of recombinant HB vaccine intramuscularly at 0,1,and 6 *** HBs titers were evaluated by a quantitative Elisa kit at 90 and 210 days.A booster dose of 20μg HB vaccine was given after 6 months of the 3^(rd) vaccine dose to the 15 non- responders and anti-HBs titers were measured after i month. RESULTS:Seroprotection (anti-HBs GMT^3 10 IU/L) was achieved in 85.3 % (87/102) *** mean GMT titers of the vaccine responders was 136.1 IU/*** the seroprotected individuals,there were 32.4% (33/102) hyporesponders (anti- HBs titers 100 IU/L).All the non-responders (15/15) responded to a single dose of the booster dose of recombinant HB vaccine and their mean anti-HBs antibody titers were more than 100.5 mIU/ml after the booster dose. CONCLUSION:Recombinant hepatitis B vaccine offers good seroprotection in the age group >40 years and has a good safety profile.A single booster dose after 6 months in primary non-responders leads to good seroprotective anti-HBs antibody ***,larger population based studies are needed to evaluate the role of a booster dose in selected group of non-responders and whether such an approach will be cost effective.

关键词： Adult Age Factors Aged Female Hepatitis B Antibodies Hepatitis B Vaccines dosage Humans Immunization, Secondary Male Middle Aged Safety Vaccines, Synthetic