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Exceptional rate capability from carbon-encapsulated polyaniline supercapacitor electrodes

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Energy & Environmental Materials 2020年第3期3卷 389-397页

作者： Ash Stott Mehmet O.Tas Elaine Y.Matsubara Mateus G.Masteghin Jose M.Rosolen radu a.sporea S.Ravi P.Silva Advanced Technology Institute Guildford Surrey GU27XHUK Departamento de Química Faculdade de FilosofiaCiên-cias e Letras de Ribeirão Preto1-Universidade de São PauloAvenida Bandeirantes 390014040-901Ribeirão Preto SP Brazil

A high-rate capability carbon-encapsulated polyaniline(PANI)composite is fabricated by a novel electrodeposition method of polyaniline on a carbon nanotube(CNT)forest,grown on carbon *** is followed by coating of an amorphous carbon layer via hydrothermal carbonization(HTC)of glucose,forming a three-layer *** demonstrate that a slow scan rate,voltage-restricted electrodeposition process can be used to produce a uniform PANI coating on individual CNTs throughout the *** CNT forest structure offers excellent electronic and structural connection for the PANI nanofiber network,while the coating of amorphous carbon reduces electrode resistance,promoting enhanced electrochemical performance and reinforced structural stability during charging and *** as-prepared CNT/PANI/HTC composite exhibited a high specific capacitance of 571 F g-1 at 1 A g-1,and 557 F g-1 at 100 A g-1,whilst demonstrating a record rate capability of 98%capacitance retention,when the current density is increased *** advanced rate performance indicates that a slow electrodeposition process produces an electrochemically stable three-layer composite with enhanced diffusion ***,the method developed in this work establishes further control on the electrochemical deposition of energy storage materials,for high-rate capability.

关键词： CNT electrodeposition high rate polyaniline supercapacitor

Fermion scattering by a class of Bardeen black holes

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Chinese Physics C 2019年第3期43卷 107-116页

作者： Ciprian a.sporea West University of Timisoara

In this study, the scattering of fermions by a class of Bardeen black holes is investigated. After obtaining the scattering modes by solving the Dirac equation in this geometry, we use the partial wave method to derive an analytical expression for the phase shifts that enter into the definitions of partial amplitudes that define the scattering cross sections and induced polarization. It is shown that, similar to Schwarzschild and Reissner-Nordstrom black holes, the phenomena of glory and spiral scattering are present.

关键词： Bardeen black hole fermion scattering partial wave method

Scattering of massless fermions by Schwarzschild and Reissner-Nordstrm black holes

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Chinese Physics C 2017年第12期41卷 4-10页

作者： Ciprian a.sporea West University of Timisoara V. Parvan Ave. 4 RO-300223 Timisoara Romania

We study the scattering of massless Dirac fermions by Schwarzschild and Reissner-Nordstrm black holes. This is done by applying partial wave analysis to the scattering modes obtained after solving the massless Dirac equation in the asymptotic regions of the two black hole geometries. We successfully obtain analytic phase shifts, with the help of which the scattering cross section is computed. The glory and spiral scattering phenomena are shown to be present, as in the case of massive fermion scattering by black holes.

关键词： black holes scattering massless fermions

Multiparametric ultrasound as a new concept of assessment of liver tissue damage

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World Journal of Gastroenterology 2024年第12期30卷 1663-1669页

作者： Angela Peltec Ioan sporea Department of Internal Medicine Discipline of GastroenterologyState University of Medicine and Pharmacy"Nicolae Testemitanu"Chishinev 2019Moldova Department of Gastroenterology and Hepatology "Victor Babes"University of Medicine and PharmacyTimisoara 300736Romania

Liver disease accounts for approximately 2 million deaths per year *** chronic liver diseases(CLDs),whether of toxic,genetic,autoimmune,or infectious origin,undergo typical histological changes in the structure of the *** changes may include the accumulation of extracellular matrix material,fats,triglycerides,or tissue *** methods for diagnosing CLD,such as conventional B-mode ultrasound(US),play a significant role in *** US,when coupled with B-mode US,can be helpful in evaluating the hemodynamics of hepatic vessels and detecting US findings associated with hepatic *** elastography can assess liver stiffness,serving as a surrogate marker for liver *** is important to note that interpreting these values should not rely solely on a histological ***-enhanced US(CEUS)provides valuable information on tissue perfusion and enables excellent differentiation between benign and malignant focal liver *** evaluation,the etiology of liver disease,and the patient current comorbidities all influence the interpretation of liver stiffness *** measurements are most clinically relevant when interpreted as a probability of compensated advanced CLD.B-mode US offers a subjective estimation of fatty infiltration and has limited sensitivity for mild *** controlled attenuation parameter requires a dedicated device,and cutoff values are not clearly ***-titative US parameters for liver fat estimation include the attenuation coefficient,backscatter coefficient,and speed of *** parameters offer the advantage of providing fat quantification alongside B-mode evaluation and other US *** US(MPUS)of the liver introduces a new concept for complete noninvasive *** encourages examiners to utilize the latest features of an US machine,including conventional B-mode,liver stiffness evaluation,fat quantification,dispersion imaging,

关键词： Multiparametric ultrasound Ultrasound-based elastography Liver stiffness Noninvasive diagnostic test for chronic liver disease Liver steatosis assessment Portal hypertension evaluation

Ultrasound-based elastography for the diagnosis of portal hypertension in cirrhotics

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World Journal of Gastroenterology 2015年第41期21卷 11542-11551页

作者： Roxana Sirli Ioan sporea Alina Popescu Mirela Danila Department of Gastroenterology and Hepatology "Victor Babes" University of Medicine and Pharmacy

Progressive fibrosis is encountered in almost all chronicliver diseases. Its clinical signs are diagnostic in advanced cirrhosis, but compensated liver cirrhosis is harder to diagnose. Liver biopsy is still considered the reference method for staging the severity of fibrosis, but due to its drawbacks(inter and intra-observer variability, sampling errors, unequal distribution of fibrosis in the liver, and risk of complications and even death), non-invasive methods were developed to assess fibrosis(serologic and elastographic). Elastographic methods can be ultrasound-based or magnetic resonance imaging-based. All ultrasoundbased elastographic methods are valuable for the early diagnosis of cirrhosis, especially transient elastography(TE) and acoustic radiation force impulse(ARFI) elastography, which have similar sensitivities and specificities, although ARFI has better feasibility. TE is a promising method for predicting portal hypertension in cirrhotic patients, but it cannot replace upper digestive endoscopy. The diagnostic accuracy of using ARFI in the liver to predict portal hypertension in cirrhotic patients is debatable, with controversial results in published studies. The accuracy of ARFI elastography may be significantly increased if spleen stiffness is assessed, either alone or in combination with liver stiffness and other parameters. Two-dimensional shearwave elastography, the Elast PQ technique and strain elastography all need to be evaluated as predictors of portal hypertension.

关键词： Portal hypertension Transient elastography Acoustic radiation force impulse elastography Two-dimensional shear-wave elastography

Is it better to use two elastographic methods for liver fibrosis assessment?

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World Journal of Gastroenterology 2011年第33期17卷 3824-3829页

作者： Ioan sporea Roxana Sirli Alina Popescu Simona Bota radu Badea Monica Lupsor Mircea Focsa Mirela Danila Department of Gastroenterology and Hepatology University of Medicine and Pharmacy Timisoara10 Iosif Bulbuca Bv.300736 TimisoaraRomania Department of Medical Imaging 3rd Medical ClinicUniversity of Medicine and PharmacyClujNapoca2123 Croitorilor str.400162 ClujNapocaRomania Department of Biophysics and Medical Informatics University of Medicine and Pharmacy Timisoara14 Tudor Vladimirescu str.300173 TimisoaraRomania

AIM:To find out if by combining 2 ultrasound based elastographic methods:acoustic radiation force impulse(ARFI)elastography and transient elastography(TE),we can improve the prediction of fibrosis in patients with chronic hepatitis ***:Our study included 197 patients with chronic hepatitis *** each patient,we performed,in the same session,liver stiffness(LS)measurements by means of TE and ARFI,respectively,and liver biopsy(LB),assessed according to the Metavir score.10 LS measurements were performed both by TE and ARFI;median values were calculated and expressed in kilopascals(kPa)and meters/second(m/s),*** TE and ARFI measurements with IQR<30%andSR≥60%were considered ***:On LB 13(6.6%)patients had F0,32(16.2%) had F1,52(26.4%)had F2,47(23.9%)had F3,and 53(26.9%)had F4.A direct,strong correlation was found between TE measurements and fibrosis(r=0.741),between ARFI and fibrosis(r=0.730)and also between TE and ARFI(r=0.675).For predicting significant fibrosis(F≥2),for a cutoff of 6.7 kPa,TE had 77.5% sensitivity(Se)and 86.5%specificity(Sp)[area under the receiver operating characteristic curve(AUROC)0.87] and for a cutoff of 1.2 m/s,ARFI had 76.9%Se and 86.7%Sp(AUROC 0.84).For predicting cirrhosis(F=4),for a cutoff of 12.2 kPa,TE had 96.2%Se and 89.6% Sp(AUROC 0.97)and for a cutoff of 1.8 m/s,ARFI had 90.4%Se and 85.6%Sp(AUROC 0.91).When both elastographic methods were taken into consideration,for predicting significant fibrosis(F≥2),(TE≥6.7 kPa and ARFI≥1.2 m/s)we obtained 60.5%Se,93.3% Sp,96.8%positive predictive value(PPV),41.4%negative predictive value(NPV)and 68%accuracy,while for predicting cirrhosis(TE≥12.2 kPa and ARFI≥1.8 m/s) we obtained 84.9%Se,94.4%Sp,84.9%PPV,94.4% NPV and 91.8%***:TE used in combination with ARFI is highly specific for predicting significant fibrosis;therefore when the two methods are concordant,liver biopsy can be avoided.

关键词： Transient elastography Acoustic radiation force impulse elastography Liver stiffness Combined methods

Why,who and how should perform liver biopsy in chronic liver diseases

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World Journal of Gastroenterology 2008年第21期14卷 3396-3402页

作者： Ioan sporea Alina Popescu Roxana Sirli Department of Gastroenterology University of Medicine and PharmacyTimisoara 700736Romania

Chronic viral hepatitis is a common disease in the general *** chronic hepatitis,the prognosis and clinical management are highly dependent on the extent of liver *** fibrosis evaluation can be performed by FibroTest(using serological markers),by Elastography or FibroScan(a noninvasive percutaneous technique using the elastic properties of the hepatic tissue) and by liver biopsy(LB),considered to be the "gold standard".Currently,there are three techniques for performing LB:percutaneous,transjugular and *** percutaneous LB can be performed blind,ultrasound(US) guided or US *** are two main categories of specialists who perform LB:gastroenterologists(hepatologists) and radiologists,and the specialty of the individual who performs the LB determines if the LB is performed under ultrasound guidance or *** are two types of biopsy needles used for LB:cutting needles(Tru-Cut,Vim-Silverman) and suction needles(Menghini,Klatzkin,Jamshidi).The rate of major complications after percutaneous LB ranges from 0.09% to 2.3%,but the echo-guided percutaneous liver biopsy is a safe method for the diagnosis of chronic diffuse hepatitis(cost-effective as compared to blind biopsy) and the rate of complications seems to be related to the experience of the physician and the type of the needle used(Menghini type needle seems to be safer).Maybe,in a few years we will use non-invasive markers of fibrosis,but at this time,most authorities in the field consider that the LB is useful and necessary for the evaluation of chronic hepatopathies,despite the fact that it is not a perfect test.

关键词： Chronic hepatitis Liver biopsy Fibrosis Ultrasound guidance

Is ARFI elastography reliable for predicting fibrosis severity in chronic HCV hepatitis?

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World Journal of Radiology 2011年第7期3卷 188-193页

作者： Ioan sporea Roxana Sirli Simona Bota Carmen Fierbinteanu-Braticevici Alina Popescu radu Badea Monica Lupsor Ana Petrisor Mirela Dnil Department of Gastroenterology and Hepatology University of Medicine and Pharmacy Timi oara10 Iosif Bulbuca Bv.300736 TimisoaraRomania IInd Medical Clinic and Gastroenterology University Hospital169 Independen ei AvenueSector 5050098 BucharestRomania Department of Medical Imaging 3rd Medical ClinicUniversity of Medicine and PharmacyClujNapoca21-23 Croitorilor Str.400162Cluj-NapocaRomania

AIM:To determine whether acoustic radiation force impulse(ARFI) elastography is a reliable method for predicting fibrosis severity in patients with chronic hepatitis C virus(HCV) ***:We performed a multicenter study including 274 subjects with HCV chronic hepatitis in which we compared ARFI with liver biopsy(LB).In each patient we performed LB(evaluated according to the Metavir score) and ARFI measurements(using a Siemens Acuson S2000TM ultrasound system:10 valid measurements were performed and median values were calculated and expressed in meters/second(m/s).RESULTS:A direct,strong,correlation(Spearman r = 0.707) was found between ARFI measurements and fibrosis(P < 0.0001).For predicting the presence of fibrosis(F ≥ 1 Metavir),significant fibrosis(F ≥ 2),severe fibrosis(F ≥ 3) and cirrhosis(F = 4),the cutoff values of 1.19,1.21,1.58 and 1.82 m/s were determined,respectively,liver stiffness measurements had 73%,84%,84% and 91% Se respectively;93%,91%,94%,90% Sp,respectively;with AUROCs of 0.880,0.893,0.908 and 0.937,***:ARFI measurement is a reliable method for predicting the severity of fibrosis in HCV

关键词： Acoustic radiation force impulse elastography Chronic HCV hepatitis Cirrhosis Liver fibrosis Liver stiffness

Severe adverse events during antiviral therapy in hepatitis C virus cirrhotic patients: A systematic review

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World Journal of Hepatology 2013年第3期5卷 120-126页

作者： Simona Bota Ioan sporea Roxana Sirli Alina Popescu Adriana Maria Neghinǎ Mirela Dǎnilǎ Mihnea Strǎin Department of Gastroenterology and Hepatology University of Medicine and Pharmacy Department of Biochemistry and Pharmacology University of Medicine and Pharmacy

AIM: To identify severe adverse events (SAEs) leading to treatment discontinuation that occur during antiviral therapy in hepatitis C virus (HCV)-infected cirrhotic patients. METHODS: We identified all the articles published prior to December 2011 in the PubMed, Medline, Lilacs, Scopus, Ovid, EMBASE, Cochrane and Medscape databases that presented these data in cirrhotic patients. These studies evaluated the rate of SAEs leading to discontinuation of standard care treatment: Pegylated interferon (PegIFN) alpha 2a (135-180 μg/wk) or PegIFN alpha 2b (1 or 1.5 μg/kg per week) and ribavirin (800-1200 mg/d). Patients with genotype 1 + 4 underwent treatment for 48 wk, whereas those with genotypes 2 + 3 were treated for 24 ***: We included 17 papers in this review, comprising of 1133 patients. Treatment was discontinued due to SAEs in 14.5% of the patients. The most common SAEs were: severe thrombocytopenia and/or neutropenia (23.2%), psychiatric disorders (15.5%), decompensation of liver cirrhosis (12.1%) and severe anemia (11.2%). The proportion of patients who needed to discontinue their therapy due to SAEs was significantly higher in patients with Child-Pugh class B and Cvs those with Child-Pugh class A: 22%vs 11.4% (P = 0.003). A similar discontinuation rate was found in cirrhotic patients treated with PegIFN alpha 2a and those treated with PegIFN alpha 2b, in combination with ribavirin: 14.2%vs 13.7% (P = 0.96). The overall sustained virological response rate in cirrhotic patients was 37% (95%CI: 33.5-43.1) but was significantly lower in patients with genotype 1 + 4 than in those with genotype 2 + 3: 20.5% (95%CI: 17.9-24.8) vs 56.5% (95%CI: 51.5-63.2), (P < 0.0001). CONCLUSION: Fourteen point five percent of HCV cirrhotic patients treated with PegIFN and ribavirin needed early discontinuation of therapy due to SAEs, the most common cause being hematological disorders.

关键词： Liver cirrhosis Hepatitis C virus Adverse events Sustained virological response