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Observations and light curve solutions of the W UMa binaries V796 Cep,V797 Cep,CSS J015341.9+381641 and NSVS 3853195

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Research in Astronomy and Astrophysics 2017年第5期17卷 31-38页

作者： diana petrova kjurkchieva Velimir Angelov Popov Sunay Ibryamov Ibryamov Doroteya Lyubenova Vasileva Nikola Ivanov Petrov Department of Physics Shumen University115 Universitetska Str.9712 ShumenBulgaria IRIDA Observatory Rozhen NAOBulgaria Institute of Astronomy and NAO Bulgarian Academy of Sciences72 Tsarigradsko Shose Blvd.1784 SofiaBulgaria

Photometric observations in Sloan g′and i′bands of four W UMa binaries, V796 Cep,V797 Cep, CSS J015341.9＋381641 and NSVS 3853195, are presented. Our observations showed that CSS J015404.1＋382805 and NSVS 3853195 are the same star. We determined the initial epochs T_0 of all targets and found improved values for the period of NSVS 3853195. The light curve solutions of our data revealed that the components of each target are almost the same in terms of mass, temperature,radius and luminosity. The stellar components are G and K spectral types and undergo partial *** systems have barely-overcontact configurations and can be classified as H subtype W UMa *** established that the relation between the luminosity ratio l_2/l_1 and mass ratio q of our targets is approximately l_2/l_1 = q^（1.5）.

关键词： stars: binaries: eclipsing -- stars: fundamental parameters -- stars: individual (V796 Cep,V797 Cep CSS J015341.9+381641 NSVS 3853195)

Photometric observations and light curve solutions of the W UMa stars NSVS 2244206,NSVS 908513,CSS J004004.7+385531 and VSX J062624.4+570907

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Research in Astronomy and Astrophysics 2016年第9期16卷 15-22页

作者： diana petrova Kiurkchieva Velimir Angelov Popov Doroteya Lyubenova Vasileva Nikola Ivanov Petrov Department of Physics Shumen University115Universitetska Str.1712 ShumenBulgaria IRIDA Observatory 17A Prof.Asen Zlatarov Str.SofiaBulgaria Institute of Astronomy and National Astronomical Observatory Bulgarian Academy of Sciences72Tsarigradsko Shose Blvd.1784 SofiaBulgaria

Photometric observations in Sloan 9＇ and i＇ bands of four W UMa stars, NSVS 2244206, NSVS 908513, CSS J004004.7＋385531 and VSX J062624.4＋570907, are presented. The light curve solutions reveal that all targets have overcontact configurations with fillout factors within 0.15-0.26. Their components are G-K spectral types and are almost in thermal contact. They are also relatively close in size and luminosity： the radius ratios r2/r1 are within 0.75-0.90; the luminosity ratios 12/11 are within 0.53-0.63. The results of the light curve solution of CSS J004004.7＋385531 imply the weak limb-darkening effect of its primary component and possible presence of additional absorbing features in the system.

关键词： methods data analysis -- stars fundamental parameters -- stars binaries eclipsing individ-ual (NSVS 2244206, NSVS 908513, CSS J004004.7+385531, VSX J062624.4+570907)

The influence of composition of asphaltenes of different genesis on the properties of carbon materials manufactured from them by plasma processing

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Petroleum Science 2023年第6期20卷 3830-3840页

作者： Evgeniya Frantsina Yuliya petrova Valentina Arkachenkova Andrey Grin'ko Alexander Pak Pavel Povalyaev Dmitry Zelentsov Kirill Cherednichenko Surgut State University Institute of Natural and Technical Sciencespr.Lenina 1628412SurgutRussian Federation Tomsk Polytechnic University Laboratory of Advanced Materials for the Energy Industrypr.Lenina30643050TomskRussian Federation National University of Oil and Gas Gubkin University Department of Physical and Colloidal Chemistrypr.Lenina65119991MoscowRussian Federation

The results of experimental studies of carbon materials, which are formed in the plasma of a direct current (DC) arc discharge initiated in open air from the asphaltenes of different origins, extracted from the natural asphaltite and from the oil of the Sredne-Ugutskoye Oilfield, are presented. The influence of the initial asphaltene composition on the composition and properties of the resulting carbon materials is analyzed. The initial asphaltenes and the samples of the carbon materials are characterized by the methods of X-ray diffraction, differential thermal analysis, X-ray fluorescence analysis, IR-Fourier spectroscopy, laser diffraction, transmission and scanning electron microscopy. The changes in the composition and structure of the asphaltenes are determined before and after their plasma treatment and the hypotheses are put forward concerning the chemical processes causing the changes in the molecular structure of the samples. As a result of plasma treatment of asphaltenes (100 A, 30 s), it was shown that graphitization occurs, as well as oxidation, and a decrease in sulfur content. Moreover, nanotubes and nano-onions have been detected using electron microscopy. Petroleum asphaltenes after plasma treatment give a less thermostable carbon material, but with a lower content of heteroatoms, and with a large amount of sulfur in the composition of sulfoxide structural fragments. This method is shown to be a promising technology for processing the petroleum feedstock enriched with heavy asphaltene components for the manufacture of carbon nanomaterials: nanotubes, nano-onions and polyhedral graphite.

关键词： Asphaltenes Natural asphaltite Carbon materials Nanomaterials Plasma treatment Graphite

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World Journal of Clinical Cases 2023年第9期11卷 1918-1929页

作者： Metodija Sekulovski Simona Bogdanova-petrova Monika Peshevska-Sekulovska Tsvetelina Velikova Tsvetoslav Georgiev Department of Anesthesiology and Intensive Care University Hospital LozenetzSofia 1407Bulgaria Medical Faculty Sofia University St.Kliment OhridskiSofia 1407Bulgaria First Department of Internal Medicine Medical University-VarnaVarna 9010Bulgaria Clinic of Rheumatology University Hospital“St.Marina”Varna 9010Bulgaria Department of Gastroenterology University Hospital LozenetzSofia 1407Bulgaria Department of Clinical Immunology University Hospital LozenetzSofia 1407Bulgaria

While severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)quickly spread across the globe,our understanding of its pathogenic mechanisms ***,coronavirus disease 2019(COVID-19)is now considered a syndromic multisystem inflammatory disease involving not only the respiratory system but also the cardiovascular,excretory,nervous,musculoskeletal,and gastrointestinal ***,a membrane-bound form of angiotensin-converting enzyme 2,the entry receptor for SARS-CoV-2,is expressed on the surface of cholangiocytes and hepatocytes,suggesting the potential of COVID-19 to involve the *** the widespread distribution of SARS-CoV-2 throughout the population,infection during pregnancy is no longer a rare occurrence;however,little is known about the course of hepatic injuries and related outcomes in pregnant SARS-CoV-2-positive ***,the understudied topic of COVID-related liver disease during pregnancy poses a great challenge for the consulting gynecologist and *** this review,we aim to describe and summarize potential liver injuries in pregnant women with COVID-19.

关键词： COVID-19 Liver injury Pregnancy SARS-CoV-2 Angiotensin-converting enzyme 2 receptors

Epstein-Barr virus:Silent companion or causative agent of chronic liver disease?

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World Journal of Gastroenterology 2010年第33期16卷 4130-4134页

作者： Mihaela petrova Victor Kamburov Clinic of Gastroenterology Ministry of Interior Gastroenterology Division First Multiprofile Hospital for Active Treatment

The Epstein-Barr virus(EBV)has an important and multifaceted role in liver *** a member of the herpes virus family,EBV establishes a persistent infection in more than 90%of *** acute hepatitis during primary infection,many clinical syndromes of interest for the hepatologist are associated with EBV *** role of EBV in the evolution of chronic hepatitis from hepatotropic viruses is *** EBVassociated hepatitis is suspected in immunocompetent adults with compatible serology,suggestive histology and detection of the viral genome in the liver and/or increase of specific circulating cytotoxic *** is the main cause of post-transplant lymphoproliferative disorders which occur in up to 30%of ***-driven lymphoproliferative diseases are also recognized in non-immunocompromised patients and liver is involved in up to a third of the *** implicated in the pathogenesis of different tumors,EBV has a disputable role in hepatocellular carcinoma *** research is required in order to establish or reject the role of EBV in human liver *** paper attempts to discuss the range of EBV-associated chronic liver diseases in immunocompetent patients,from mild,self-limiting mononuclear hepatitis to liver cancer.

关键词： Epstein-Barr virus Chronic hepatitis Liver disease Chronic active Epstein-Barr virus Post-transplant lymphoproliferative disorder Infectious mononucleosis

Breastfeeding and chronic HBV infection: Clinical and social implications

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World Journal of Gastroenterology 2010年第40期16卷 5042-5046页

作者： Mihaela petrova Victor Kamburov Clinic of Gastroenterology Ministry of Interior Department of Gastroenterology First Multi Profile Hospital for Active Treatment

Mother-to-child transmission of hepatitis B virus (HBV) is among the most important causes of chronic HBV infection and is the commonest mode of transmission worldwide. Currently, the presence of HBsAg, HBeAg and HBV DNA in breast milk is confirmed. Several studies have reported that breastfeeding carries no additional risk that might lead to vertical transmission. Beyond some limitations, the surveys have not demonstrated any differences in HBV transmission rate regarding feeding practices in early childhood. Promotion of breastfeeding is substantial, especially for low-income individuals and regions with uncertain, unfeasible, and unsafe water supplies. Lactoferrin, minimal inflammation or activation within the infant gut during exclusive breastfeeding, and nonspecific biological molecules in the milk are identified as major factors of breast-milk defense. This review discusses preemptive antiviral therapy during pregnancy and lactation. Long-term follow up of breast-milk HBV concentrations and correlation with serum viral load; nucleos(t)ide analogue concentrations in breast milk in HBV-positive mothers in the setting of chronic HBV infection; safety of antiviral therapy during pregnancy and lactation; and the difference in viral load in the milk in exclusive or non-exclusive breastfeeding are still open questions. The paper reviews the current data and outlines the course of further investigation into this often underestimated issue.

关键词： Breastfeeding Lamivudine Tenofovir Hepatitis B virus Chronic hepatitis B

活动期糖尿病夏科神经性骨关节病诊疗指南——《国际糖尿病足工作组:糖尿病相关的足病预防与管理指南(2023)》的一部分

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感染、炎症、修复 2024年第1期25卷 52-71页

作者： Dane K.Wukich Nicolaas C.Schaper Catherine Gooday Arun Bal Robert Bem Avneesh Chhabra Mary Hastings Crystal Holmes Nina L.petrova Maria Gala Santini Araujo Eric Senneville Katherine M.Raspovic on behalf of the International Working Group on the Diabetic Foot 赵宏谋徐俊(译) 张明珠(审校) Department of Orthopaedic Surgery University of Texas Southwestern Medical CenterDallasTexasUSA Division of Endocrinology MUMC+CARIM and CAPHRI InstituteMaastrichtthe Netherlands Elsie Bertram Diabetes Centre Norfolk&Norwich University Hospitals NHS Foundation TrustNorfolkUK Secretary International Association of Diabetic Foot SurgeonsMumbaiIndia Diabetes Centre Institute for Clinical and Experimental MedicinePrague Department of Radiology UT Southwestern Medical CenterDallasTexasUSA Program in Physical Therapy Washington University School of MedicineSt.LouisMissouriUSA The Division of Metabolism Endocrinology and DiabetesThe University of Michigan Medical SchoolAnn ArborMichiganUSA Department of Diabetes Diabetic Foot ClinicKing’s College Hospital NHS Foundation TrustLondonUK Italian Hospital of Buenos Aires Buenos AiresArgentina Department of Infectious Diseases Gustave Dron HospitalTourcoingFrance 不详西安交通大学医学院附属红会医院陕西西安710054 天津医科大学朱宪彝纪念医院天津300314 首都医科大学附属同仁医院北京100730

国际糖尿病足工作组(IWGDF)自1999年以来发布了糖尿病足病预防和治疗的循证指南。这是IWGDF发布的第一部关于糖尿病患者活动期夏科神经性骨关节病诊断和治疗的指南。我们遵循GRADE方法,以人群-评估-比较-结局(PACO)和人群-干预-比较-结... 详细信息

国际糖尿病足工作组(IWGDF)自1999年以来发布了糖尿病足病预防和治疗的循证指南。这是IWGDF发布的第一部关于糖尿病患者活动期夏科神经性骨关节病诊断和治疗的指南。我们遵循GRADE方法,以人群-评估-比较-结局(PACO)和人群-干预-比较-结局(PICO)的格式设计临床问题,系统检索医学文献,并提出有依据的推荐。这些推荐是基于我们系统综述的证据,如无证据则参考专家意见,并考虑到与干预相关的受益和危害、患者偏好、可行性和适用性以及成本的权衡。我们在本章节介绍了2023年糖尿病患者活动期夏科神经性骨关节病的诊断和治疗指南,并提出了未来的关键研究方向。

关键词：糖尿病夏科神经性骨关节病,活动期诊断治疗国际糖尿病足工作组指南

Detection of Malignant and Benign Breast Cancer Using the ANOVA-BOOTSTRAP-SVM

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Journal of Data and Information Science 2020年第2期5卷 62-75页

作者： Borislava petrova Vrigazova Department of Statistics and Econometric Faculty of Economics and Business AdministrationSofia UniversityBulgaria

Purpose:The aim of this research is to propose a modification of the ANOVA-SVM method that can increase accuracy when detecting benign and malignant breast ***:We proposed a new method *** involves applying the analysis of variance(ANOVA)to support vector machines(SVM)but we use the bootstrap instead of cross validation as a train/test splitting *** have tuned the kernel and the C parameter and tested our algorithm on a set of breast cancer ***:By using the new method proposed,we succeeded in improving accuracy ranging from 4.5 percentage points to 8 percentage points depending on the *** limitations:The algorithm is sensitive to the type of kernel and value of the optimization parameter *** implications:We believe that the ANOVA-BOOTSTRAP-SVM can be used not only to recognize the type of breast cancer but also for broader research in all types of ***/value:Our findings are important as the algorithm can detect various types of cancer with higher accuracy compared to standard versions of the Support Vector Machines.

关键词： Breast cancer detection ANOVA Bootstrap Support vector machines

Telbivudine vs tenofovir in hepatitis B e antigen-negative chronic hepatitis B patients: OPTIMA roadmap study

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World Journal of Hepatology 2016年第32期8卷 1402-1413页

作者： Zahari Krastev diana petrova Iskren Kotzev Mustafa Kemal Celen Meryl Mendelson Richa Chandra Priti Pandey Kamal Hamed Clinic of Gastroenterology St.Ivan Rilsky University HospitalMedical University Department of Gastroenterology University Hospital Alexandrovska Clinic of Hepatogastroenterology University Hospital St Marina Infectious Disease Clinic Dicle University Novartis Pharmaceuticals Corporation East Hanover Novartis Healthcare Pvt. Ltd.

AIM To make efficacy and safety comparison of telbivudineraodmap and tenofovir-roadmap in hepatitis B e antigen(HBe Ag)-negative chronic hepatitis B(CHB) *** This was the first prospective, randomised, two-arm, open-label, non-inferiority study in HBe Ag-negative CHB patients that compared telbivudine and tenofovir administered as per roadmap concept. Patients were treated up to 24 wk and, depending on virologic response, continued the same therapy or received addon therapy up to 104 wk. Eligible patients received an additional 52 wk of treatment in the extension period(i.e., up to 156 wk). Patients who developed virologic breakthrough(VB) while on monotherapy also received add-on therapy. The primary efficacy endpoint was the rate of patients achieving hepatitis B virus(HBV) DNA < 300 copies/m L at week 52. Secondary efficacy endpoints included the rates of HBV DNA < 300 and < 169 copies/m L, HBV DNA change from baseline, alanine aminotransferase normalisation, hepatitis B surface antigen(HBs Ag) loss, HBs Ag seroconversion, VB, and emergence of resistance at various timepoints throughout the study. Safety and estimated glomerular filtration rate(e GFR) were also *** A total of 241 patients were randomised. Non-inferiority of telbivudine arm to tenofovir arm was demonstrated at week 52(± 7 d window), with over 91% of patients in each treatment arm achieving HBV DNA level < 300 copies/m L. Both arms were similar in terms of key secondary efficacy variables at weeks 104 and 156. The percentage of patients achieving HBV DNA < 300 copies/m L remained high and was similar in the telbivudine and tenofovir arms at both weeks 104 and 156. Over 82% of patients in both arms achieved alanine aminotransferase normalisation at week 52, and this percentage remained high at weeks 104 and 156. Telbivudine treatment progressively reduced serum HBs Ag levels from baseline while no change was reported in quantitative HBs Ag during therapy with tenofovir. Bot

关键词：长期的肝炎 B Glomerular 过滤率 Telbivudine Tenofovir 路线图概念