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1Endoscopic ultrasonography guided biliary drainage: Summary of consortium meeting, May 7^(th) , 2011, Chicago显示文摘Endoscopic retrograde cholangiopancreatography (ERCP) has become the preferred procedure for biliary or pancreatic drainage in various pancreatico-biliary disorders. With a success rate of more than 90%, ERCP may not achieve biliary or pancreatic drainage in cases with altered anatomy or with tumors obstructing access to the duodenum. In the past those failures were typically managed exclusively by percutaneous approaches by interventional radiologists or surgical intervention. The morbidity associated was significant especially in those patients with advanced malignancy, seeking minimally invasive interventions and improved quality of life. With the advent of biliary drainage via endoscopic ultrasound (EUS) guidance, EUS guided biliary drainage has been used more frequently within the last decade in different countries. As with any novel advanced endoscopic procedure that encompasses various approaches, advanced endoscopists all over the world have innovated and adopted diverse EUS guided biliary and pancreatic drainage techniques. This diversity has resulted in variations and improvements in EUS Guided biliary and pancreatic drainage; and over the years has led to an extensive nomenclature. The diversity of techniques, nomenclature and recent progress in our intrumentation has led to a dedicated meeting on May 7 th , 2011 during Digestive Disease Week 2011. More than 40 advanced endoscopists from United States, Brazil, Mexico, Venezuela, Colombia, Italy, France, Austria, Germany, Spain, Japan, China, South Korea and India attended this pivotal meeting. The meeting covered improved EUS guided biliary access and drainage procedures, terminology, nomenclature, training and credentialing; as well as emerging devices for EUS guided biliary drainage. This paper summarizes the meeting's agenda and the conclusions generated by the creation of this consortium group.Michel Kahaleh Everson LA Artifon Manuel Perez-Miranda Kapil Gupta Takao Itoi Kenneth F Binmoeller California Pacific Medical Center San Francisco CA 94115 United States Marc Giovannini 2013World Journal of Gastroenterology2013,19,9:15
2Epithelial toll-like receptor 9 signaling in colorectal inflammation and cancer: Clinico-pathogenic aspects显示文摘Toll-like receptors (TLRs) recognize specific motifs which are frequently present in bacteria, fungi, prokaryotes and viruses. Amongst TLRs, TLR9 can be activated by such bacterial or viral DNA fragments, immunoglobulin-DNA complexes or synthetic oligonucleotides, which all contain unmethylated cytosineguanine nucleotide sequences (CpGs). Emerging data indicate that TLR9 signaling has a role in, and may influence, colorectal carcinogenesis and colonic inflammation. CpGs are classified into three groups according to their influence on both the antigen-specific humoraland cellular immunity, and the production of type 1 interferons and proinflammatory cytokines. TLR9 activation via CpGs may serve as a new therapeutic target for several cancerous and various inflammatory conditions. Due to its probable anti-cancer effects, the application possibilities of TLR9-signaling modulation may be extremely diverse even in colorectal tumors. In this review we aimed to summarize the current knowledge about TLR-signaling in the pathogenesis and therapy of inflammatory bowel diseases and colorectal cancer. Due to the species-specific differences in TLR9 expression, however, one must be careful in translating the animal model data into the human system, because of the differences between CpG-oligodeoxynucleotide-responsive cells. TLR9 agonist DNA-based immunomodulatory sequences could also represent a promising therapeutic alternative in systemic inflammatory conditions and chronic colonic inflammations as their side effects are not significant.István Fri Ferenc Sipos Tiana M Germann Alexandra Kalmár Zsolt Tulassay Béla Molnár Gyrgyi Mzes 2013World Journal of Gastroenterology2013,19,26:14
3Metadoxine improves the three- and six-month survival rates in patients with severe alcoholic hepatitis显示文摘AIM:To evaluate the impact of metadoxine(MTD) on the 3- and 6-mo survival of patients with severe alcoholic hepatitis(AH).METHODS:This study was an open-label clinical trial,performed at the'Hospital General de México,Dr.Eduardo Liceaga'.We randomized 135 patients who met the criteria for severe AH into the following groups:35 patients received prednisone(PDN)40 mg/d,35patients received PDN+MTD 500 mg three times daily,33 patients received pentoxifylline(PTX)400 mg three times daily,and 32 patients received PTX+MTD 500 mg three times daily.The duration of the treatment for all of the groups was 30 d.RESULTS:In the groups treated with the MTD,thesurvival rate was higher at 3 mo(PTX+MTD 59.4%vs PTX 33.3%,P=0.04;PDN+MTD 68.6%vs PDN20%,P=0.0001)and at 6 mo(PTX+MTD 50%vs PTX18.2%,P=0.01;PDN+MTD 48.6%vs PDN 20%,P=0.003)than in the groups not treated with MTD.A relapse in alcohol intake was the primary independent factor predicting mortality at 6 mo.The patients receiving MTD maintained greater abstinence than those who did not receive it(74.5%vs 59.4%,P=0.02).CONCLUSION:MTD improves the 3-and 6-mo survival rates in patients with severe AH.Alcohol abstinence is a key factor for survival in these patients.The patients who received the combination therapy with MTD were more likely to maintain abstinence than those who received monotherapy with either PDN or PTX.Fátima Higuera-de la Tijera Alfredo I Servín-Caamano Aurora E Serralde-Zúniga Javier Cruz-Herrera Eduardo Pérez-Torres Juan M Abdo-Francis Francisco Salas-Gordillo JoséL Pérez-Hernández 2015World Journal of Gastroenterology2015,21,16:8
4非诺贝特治疗与2型糖尿病患者长期心血管病风险的关系显示文摘2型糖尿病患者心血管病风险高,部分原因在于高三酰甘油和低高密度脂蛋白胆固醇血症。而在他汀类药物治疗基础上,加强降低三酰甘油治疗,能否降低这种风险尚不清楚。该研究的目的是在使用他汀类药物治疗的2型糖尿病患者中,确定非诺贝特能否降低心血管病风险。刘莉 叶鹏 Elam MB Ginsberg HN Lovato LC Corson M Largay J Leiter LA Lopez C O'Connor PJ Sweeney ME Weiss D Friedewald WT Buse JB Gerstein HC Probstfield J Grimm R Ismail-Beigi F Goff DC Jr Fleg JL Rosenberg Y Byington RP ACCORDION study investigators 2017中华高血压杂志2017,25,6:7
5Embolization of splenorenal shunt associated to portal vein thrombosis and hepatic encephalopathy显示文摘Hepatic encephalopathy(HE)is a cognitive disturbance characterized by neuropsychiatric alterations.It occurs in acute and chronic hepatic disease and also in patients with portosystemic shunts.The presence of these portosystemic shunts allows the passage of nitrogenous substances from the intestines through systemic veins without liver depuration.Therefore,the embolization of these shunts has been performed tocontrol HE manifestations,but the presence of portal vein thrombosis is considered a contraindication.In this presentation we show a cirrhotic patient with severe HE and portal vein thrombosis who was submitted to embolization of a large portosystemic shunt.Case report:a 57 years-old cirrhotic patient who had been hospitalized many times for persistent HE and hepatic coma,even without precipitant factors.She had a wide portosystemic shunt and also portal vein thrombosis.The abdominal angiography confirmed the splenorenal shunt and showed other shunts.The larger shunt was embolized through placement of microcoils,and the patient had no recurrence of overt HE.There was a little increase of esophageal and gastric varices,but no endoscopic treatment was needed.Since portosystemic shunts are frequent causes of recurrent HE in cirrhotic patients,portal vein thrombosis should be considered a relative contraindication to perform a shunt embolization.However,in particular cases with many shunts and severe HE,we found that one of these shunts can be safely embolized and this procedure can be sufficient to obtain a good HE recovery.In conclusion,we reported a case of persistent HE due to a wide portosystemic shunt associated with portal vein thrombosis.As the patient had other shunts,she was successfully treated by embolization of the larger shunt.Letícia de Campos Franzoni Fábio Cardoso de Carvalho Rafael Gomes de Almeida Garzon Fábio da Silva Yamashiro Laís Augusti Lívia Alves Amaral Santos Mariana de Souza Dorna Júlio Pinheiro Baima Talles Bazeia Lima Carlos Antonio Caramori Giovanni Faria Silva Fernando Gomes Romeiro 2014World Journal of Gastroenterology2014,20,42:6
6Potential of soluble CD26 as a serum marker for colorectal cancer detection显示文摘Colorectal cancer is characterized by a low survival rate even though the basis for colon cancer development,which involves the evolution of adenomas to carcinoma,is known.Moreover,the mortality rates continue to rise in economically transitioning countries although there is the opportunity to intervene in the natural history of the adenoma–cancer sequence through risk factors,screening,and treatment.Screening in particular accounted for most of the decline in colorectal cancer mortality achieved in the USA during the period 1975-2000.Patients show a better prognosis when the neoplasm is diagnosed early.Among the variety of screening strategies,the methods range from invasive and costly procedures such as colonoscopy to more low-cost and non-invasive tests such as the fecal occult blood test(guaiac and immunochemical).As a non-invasive biological serum marker would be of great benefit because of the performance of the test,several biomarkers,including cytologic assays,DNA and mRNA,and soluble proteins,have been studied.We found that the soluble CD26(sCD26)concentration is diminished in serum of colorectal cancer patients compared to healthy donors,suggesting the potential utility of a sCD26 immunochemical detection test for early diagnosis.sCD26 originates from plasma membrane CD26 lacking its transmembrane and cytoplasmic domains.Some 90%–95%of sCD26 has been associated with serum dipeptidyl peptidase IV(DPPIV)activity.DPP-IV,assigned to the CD26 cluster,is a pleiotropic enzyme expressed mainly on epithelial cells and lymphocytes.Our studies intended to validate this test for population screening to detect colorectal cancer and advanced adenomas are reviewed here.Oscar J Cordero Monica Imbernon Loretta De Chiara Vicenta S Martinez-Zorzano Daniel Ayude Maria Paez de la Cadena F Javier Rodriguez-Berrocal 2011World Journal of Clinical Oncology2011,2,6:5
7Mechanisms of autophagy activation in endothelial cell and their targeting during normothermic machine liver perfusion显示文摘Ischaemia-reperfusion injury(IRI) is the leading cause of injury seen in the liver following transplantation. IRI also causes injury following liver surgery and haemodynamic shock. The first cells within the liver to be injured by IRI are the liver sinusoidal endothelial cells(LSEC). Recent evidence suggests that LSEC coordinate and regulates the livers response to a variety of injuries. It is becoming increasingly apparent that the cyto-protective cellular process of autophagy is a key regulator of IRI. In particular LSEC autophagy may be an essential gatekeeper to the development of IRI. The recent availability of liver perfusion devices has allowed for the therapeutic targeting of autophagy to reduce IRI. In particular normothermic machine liver perfusion(NMP-L) allow the delivery of pharmacological agents to donor livers whilst maintaining physiological temperature and hepatic flow rates. In this review we summarise the current understanding of endothelial autophagy and how this may be manipulated during NMP-L to reduce liver IRI.Yuri L Boteon Richard Laing Hynek Mergental Gary M Reynolds Darius F Mirza Simon C Afford Ricky H Bhogal 2017World Journal of Gastroenterology2017,23,48:4
8Enzymatic hydrolysis of proteins from yellowfin tuna ( Thunnus albacares ) wastes using Alcalase显示文摘F Guérard L Dufossé D De La Broise A Binet 2001Journal of Molecular Catalysis B Enzymatic2001,,4:3
9Malnutrition negatively impacts the quality of life of patients with cirrhosis: An observational study显示文摘AIM To verify how malnutrition is related to health-related quality of life(HRQL) impairment in patients with cirrhosis.METHODS Data was retrospectively abstracted from medical records and obtained by direct interview. We included patients with cirrhosis from any etiology, evaluated at the Liver Clinic from Gastroenterology Department in a tertiary healthcare center, from June 2014 to June 2016. Child-Pugh score, data about complications, and demographic, clinical and anthropometric characteristics of patients were obtained. Nutritional status was evaluated by the Subjective Global Assessment(SGA). HRQL was evaluated through the Chronic Liver Disease Questionnaire. Patients were requested to assess their global HRQL with the following code: 0 = impairment of HRQL, when it was compared with other healthy subjects; 1 = good HRQL, if it was similar to the quality of life of other healthy subjects. To compare the primary outcome between malnourished and well-nourished groups, the χ~2 test, Fisher's exact test or Student's t-test were used, based on the variable type. Associations between predictor variables and deterioration of HRQL were determined by calculating the hazard ratio and 95% confidence interval using Cox proportional hazards regression. RESULTS A total of 127 patients with cirrhosis were included, and the mean age was 54.1 ± 12.3 years-old. According to Child-Pugh scoring, 25(19.7%) were classified as A(compensated), 76(59.8%) as B, and 26(20.5%) as C(B/C = decompensated). According to SGA, 58(45.7%) patients were classified as well-nourished. Sixty-nine patients identified HRQL as good, and 76 patients(59.8%) perceived impairment of their HRQL. Multivariate analysis to determine associations between predictor variables and self-perception of an impairment of HRQL found strong association with malnutrition(P < 0.0001). The most important impaired characteristics in malnourished patients were: Presence of body pain, dyspnea on exertion with daily activities, decreased appetite, generalized weakness, trouble lifting or carrying heavy objects, and decreased level of energy(P < 0.0001).CONCLUSION Malnutrition is a key factor related to impairment of HRQL in patients with cirrhosis.Gabriela Rojas-Loureiro Alfredo Servín-Caamano Elizabeth Pérez-Reyes Luis Servín-Abad Fátima Higuerade la Tijera 2017World Journal of Hepatology2017,9,5:3
10Quality of life, work productivity impairment and healthcare resources in inflammatory bowel diseases in Brazil显示文摘BACKGROUND Inflammatory bowel diseases(IBD)have been associated with a low quality of life(QoL)and a negative impact on work productivity compared to the general population.Information about disease control,patient-reported outcomes(PROs),treatment patterns and use of healthcare resources is relevant to optimizing IBD management.AIM To describe QoL and work productivity and activity impairment(WPAI),treatment patterns and use of healthcare resources among IBD patients in Brazil.METHODS A multicenter cross-sectional study included adult outpatients who were previously diagnosed with moderate to severe Crohn’s disease(CD)or ulcerative colitis(UC).At enrolment,active CD and UC were defined as having a Harvey Bradshaw Index≥8 or a CD Activity Index≥220 or calprotectin>200μg/g or previous colonoscopy results suggestive of inadequate control(per investigator criteria)and a 9-point partial Mayo score≥5,respectively.The PRO assessment included the QoL questionnaires SF-36 and EQ-5D-5L,the Inflammatory Bowel Disease Questionnaire(IBDQ),and the WPAI questionnaire.Information about healthcare resources and treatment during the previous 3 years was collected from medical records.Chi-square,Fisher’s exact and Student’s t-/Mann-Whitney U tests were used to compare PROs,treatment patterns and the use of healthcare resources by disease activity(α=0.05).RESULTS Of the 407 patients in this study(CD/UC:64.9%/35.1%,mean age 42.9/45.9 years,54.2%/56.6%female,38.3%/37.1%employed),44.7%/25.2%presented moderate-to-severe CD/UC activity,respectively,at baseline.Expressed in median values for CD/UC,respectively,the SF-36 physical component was 46.6/44.7 and the mental component was 45.2/44.2,the EQ-visual analog scale score was 80.0/70.0,and the IBDQ overall score was 164.0/165.0.Moderate to severe activity,female gender,being unemployed,a lower educational level and lower income were associated with lower QoL(P<0.05).Median work productivity impairment was 20%and 5%for CD and UC patients,respectively,and activity impairment was 30%,the latter being higher among patients with moderate to severe disease activity compared to patients with mild or no disease activity(75.0%vs 10.0%,P<0.001).For CD/UC patients,respectively,25.4%/2.8%had at least one surgery,38.3%/19.6%were hospitalized,and 70.7%/77.6%changed IBD treatment at least once during the last 3 years.The most common treatments at baseline were biologics(75.3%)and immunosuppressants(70.9%)for CD patients and 5-ASA compounds(77.5%)for UC patients.CONCLUSION Moderate to severe IBD activity,especially among CD patients,is associated with a substantial impact on QoL,work productivity impairment and an increased number of IBD surgeries and hospitalizations in Brazil.Rogerio Serafim Parra Julio MF Chebli Heda MBS Amarante Cristina Flores Jose ML Parente Odery Ramos Milene Fernandes Jose JR Rocha Marley R Feitosa Omar Feres Antonio S Scotton Rodrigo B Nones Murilo M Lima Cyrla Zaltman Carolina D Goncalves Isabella M Guimaraes Genoile O Santana Ligia Y Sassaki Rogerio S Hossne Mauro Bafutto Roberto LK Junior Mikaell AG Faria Sender J Miszputen Tarcia NF Gomes Wilson R Catapani Anderson A Faria Stella CS Souza Rosana F Caratin Juliana T Senra Maria LA Ferrari 2019World Journal of Gastroenterology2019,25,38:2
11高血压患者肾素血管紧张素系统阻断的血浆分子标志:肾损害与初发蛋白尿的新预测指标显示文摘蛋白尿是一个与心血管病密切相关的危险因素,也是一般人群的首位死亡原因。虽然已经明确肾素血管紧张素系统(renin-angiotensin system,RAS)阻断剂能延缓高血压患者初发蛋白尿进展、减少蛋白尿排出,但仍不能忽视高血压患者发生初发蛋白尿的比例。Baldan-Martin M Mourino-Alvarez L Gonzalez-Calero L Moreno-Luna R Sastre-Oliva T Ruiz-Hurtado G Segura J Lopez JA Vazquez J Vivanco F Alvarez-Llamas G Ruilope LM de la Cuesta F Barderas MG 赵狄 练桂丽 2016中华高血压杂志2016,24,6:2
12含有菊粉但不含羽扇豆的饲粮有助预防实验诱导的猪痢疾显示文摘猪痢疾是一种传染性黏膜出血的腹泻疾病,由定植于肠道的猪痢疾短螺旋体引起,能够诱发盲肠和结肠发炎。据报道饲料中添加菊苣根和甜羽扇豆可预防猪痢疾。本试验旨在验证是菊苣根中的菊粉而不是羽扇豆中的半乳糖起到保护作用的假设。Hansen C F Phillips N D La T.(等) 闫轶洁(译) 2010养猪2010,,6:2
13Progress and challenges in the comprehensive management of chronic viral hepatitis: Key ways to achieve the elimination显示文摘Chronic viral hepatitis is a significant health problem throughout the world,which already represents high annual mortality.By 2040,chronic viral hepatitis due to virus B and virus C and their complications cirrhosis and hepatocellular carcinoma will be more deadly than malaria,vitellogenesis-inhibiting hormone,and tuberculosis altogether.In this review,we analyze the global impact of chronic viral hepatitis with a focus on the most vulnerable groups,the goals set by the World Health Organization for the year 2030,and the key points to achieve them,such as timely access to antiviral treatment of direct-acting antiviral,which represents the key to achieving hepatitis C virus elimination.Likewise,we review the strategies to prevent transmission and achieve control of hepatitis B virus.Finally,we address the impact that the coronavirus disease 2019 pandemic has had on implementing elimination strategies and the advantages of implementing telemedicine programs.Fátima Higuera-de la Tijera Alfredo Servín-Caamaño Luis Servín-Abad 2021World Journal of Gastroenterology2021,27,26:2
142013年美国心脏病学会/美国心脏协会胆固醇管理指南在美国心脏病学实践中的应用显示文摘2013年美国心脏病学会/美国心脏协会(American College of Cardiology/American Heart Association,ACC/AHA)胆固醇管理指南建议在符合治疗标准的患者中采用中等强度至高强度他汀类药物治疗。该研究的目的在于审查2013年ACC/AHA指南在美国心脏病学实践中的应用情况。刘莉 叶鹏 Pokharel Y Tang F Jones PG Nambi V Bittner VA Hira RS Nasir K Chan PS Maddox TM Oetgen WJ Heidenreich PA Borden WB Spertus JA Petersen LA Ballantyne CM Virani SS 2017中华高血压杂志2017,25,6:2
15Current trends of liver cirrhosis in Mexico: Similitudes and differences with other world regions显示文摘AIM To investigate the main current etiologies of cirrhosis in Mexico.METHODS We performed a cross-sectional retrospective multicenter study that included eight hospitals in different areas of Mexico. These hospitals provide health care to people of diverse social classes. The inclusion criteria were a histological, clinical, biochemical, endoscopic, or imaging diagnosis of liver cirrhosis. Data were obtained during a 5-year period(January 2012-December 2017). RESULTS A total of 1210 patients were included. The mean age was 62.5 years(SD = 12.1), and the percentages of men and women were similar(52.0% vs 48.0%). The most frequent causes of liver cirrhosis were hepatitis C virus(HCV)(36.2%), alcoholic liver disease(ALD)(31.2%), and nonalcoholic steatohepatitis(23.2%), and the least frequent were hepatitis B virus(1.1%), autoimmune disorders(7.3%), and other conditions(1.0%).CONCLUSION HCV and ALD are the most frequent causes of cirrhosis in Mexico. However, we note that non-alcoholic fatty liver disease(NAFLD) as an etiology of cirrhosis increased by 100% compared with the rate noted previously. We conclude that NAFLD will soon become one of the most frequent etiologies of liver cirrhosis in Mexico.Nahum Méndez-Sánchez Felipe Zamarripa-Dorsey Arturo Panduro Emma Purón-González Edgar Ulises Coronado-Alejandro Carlos Alejandro Cortez-Hernández Fátima Higuera de la Tijera José Luis Pérez-Hernández Eira Cerda-Reyes Heriberto Rodríguez-Hernández Vania César Cruz-Ramón Oscar Lenin Ramírez-Pérez Nancy Edith Aguilar-Olivos Olga Fabiola Rodríguez-Martínez Samantha Cabrera-Palma Guillermo Cabrera-álvarez 2018World Journal of Clinical Cases2018,6,15:2
16高血压患者同型半胱氨酸水平升高与代谢综合征和心血管事件相关显示文摘高同型半胱氨酸(homocysteine,Hcy)血症和代谢综合征(metabolic syndrome,MS)是明确的心血管危险因素,常与高血压相关。然而血浆Hcy与MS、胰岛素抵抗相关性存在争议,且在高血压患者中的研究较少。该研究探讨高血压患者Hcy与MS和心脑血管事件的相关性。Catena C Colussi G Nait F Capobianco F Sechi LA 陈云 叶鹏 2016中华高血压杂志2016,24,1:2
17益生菌抑制自发性高血压大鼠的菌群失调和血压升高:短链脂肪酸的作用显示文摘该研究旨在评估益生菌短双歧杆菌CECT7263(BFM)及发酵乳酸杆菌CECT5716(LC40)、短链脂肪酸丁酸盐及醋酸盐对自发性高血压大鼠(spontaneously hypertensive rat,SHR)心血管的作用。方法和结果:5周龄的Wistar Kyoto大鼠(WKY)10只和周龄匹配的SHR 50只随机分为6组:对照WKY、对照SHR、BFM干预的SHR、LC40干预的SHR、丁酸盐干预的SHR和醋酸盐干预的SHR。袁源(译) 练桂丽(审校) Robles-Vera I Toral M de la Visitación N Sánchez M Gómez-Guzmán M Romero M Yang T Izquierdo-Garcia JL Jiménez R Ruiz-Cabello J Guerra-Hernández E Raizada MK Pérez-Vizcaíno F Duarte J 2020中华高血压杂志2020,28,9:2
18Introducing problem-based learning in a medical school with traditional/conventional curriculum显示文摘Baig LA Asad F 2003J-CollPhysicians-Surg-Pak2003,13,7:2
19脊髓损伤后残存自主神经功能载录国际标准显示文摘近年来,脊髓损伤神经学分类园际标准(International Stand- ards for the Neurological Classification of Spinal Cord Injury, ISNCSCI)被用来记载脊髓损伤后运动和感觉功能的损害,目前该标准已是第六版。1992年第一份国际认可的标准出版时,曾进行了较大的修订,修订内容包括完全性损伤与不完全性损伤的定义,MS Alexander AB Jackson W Donovan DE Graves SL Elliott A Krassioukov AW Sheel I Estoresl B Green A Gousse NL Braekett D Cardenas M Kennelly A-K Karlason F Biering-Sorensen K Krogh T Linsenmeyer R Marino J Ditunno CJ Mathias I Perkash G Creasey G Schilero J Wecht B Schurch V Dietz J Sonksen S Stiens D Bodner LA Wuermser J-J Wyndaele 周谋望 刘楠 S Charlifue 2010中华物理医学与康复杂志2010,32,4:2
20Competition between fusion-evaporation and multifragmentation in central collisions in ^(58)Ni+^(48)Ca at 25A MeV显示文摘The experimental data concerning the58Ni+48Ca reaction at Elab(Ni)=25A MeV,collected by using the CHIMERA 4π device,have been analyzed in order to investigate the competition among different reaction mechanisms for central collisions in the Fermi energy domain.As a main criterion for centrality selection we have chosen the flow angle(flow) method,making an event-by-event analysis that considers the shape of events,as it is determined by the eigenvectors of the experimental kinetic-energy tensor.For the selected central events(flow >60°) some global variables,good to characterize the pattern of central collisions have been constructed.The main features of the reaction products were explored by using different constraints on some of the relevant observables,like mass and velocity distributions and their correlations.Much emphasis was devoted,for central collisions,to the competition between fusion-evaporation processes with subsequent identification of a heavy residue and a possible multifragmentation mechanism of a well defined(if any) transient nuclear system.Dynamical evolution of the system and pre-equilibrium emission were taken into account by simulating the reactions in the framework of transport theories.Different approaches have been envisaged(dynamical stochastic BNV calculations + sequential SIMON code,QMD,CoMD,etc.).Preliminary comparison of the experimental data with BNV calculations shows reasonable agreement with the assumption of sequential multifragmentation emission in the mass region of IMFs close to the heavy residues.Possible deviations from sequential processes were found for those IMFs in the region of masses intermediate between the mass of heavy residues and the mass of light IMFs.Further simulations are in progress.The experimental analysis will be enriched also by information obtained inspecting the IMF-IMF correlation function,in order to elucidated the nature of space-time decay property of the emitting source associated with events having the largest IMF multiplicity.FRANCALANZA L ABBONDANNO U AMORINI F BARLINI S BINI M BOUGAULT R BRUNO M CARDELLA G CASINI G AGOSTINO M D' De FILIPPO V De SANCTIS J GERACI E GIUSSANI A GRAMEGNA F GUIOT B KRAVCHUK V La GUIDARA E LANZALONE G Le NEINDRE N MAIOLINO C MARINI P MORELLI L OLMI A PAGANO A PAPA M PIANTELLI S PIRRONE S POLITI G POGGI G PORTO F RUSSOTTO P RIZZO F VANNINI G VANNUCCI L 2013Nuclear Science and Techniques2013,24,5:2
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