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Oxidative Degradation of Thermoplastic Starch Induced by Uv Radiation

Journal of Renewable Materials 2019年第4期7卷 383-391页

作者： Mayte M.Quispe Olivia v.López marcelo A.villar Planta Piloto de Ingeniería Química PLAPIQUI(UNS CONICET)Bahía Blanca(8000)Argentina Departamento de Ingeniería Química Universidad Nacional del Sur(UNS)Bahía Blanca(8000)Argentina

Among biopolymers,thermoplastic starch(TPS)is a good candidate to obtain biomaterials because of its natural origin,biodegradable character,and *** to ultraviolet(Uv)radiation causes significant degradation of starch-based materials,inducing photooxidative reactions which result in breaking of polymer chains,production of free radical,and reduction of molar *** changes produce a deterioration of TPS mechanical properties,leading to useless materials after an unpredictable *** this work,changes induced on TPS by Uv radiation,analyzing structural properties and mechanical behavior,are *** was obtained through thermo-mechanical processing of native corn starch in the presence of water(45%w/w)and glycerol(30%w/w)as *** were obtained by thermocompression and,before testing,specimens were conditioned to reduce material *** process was performed by exposing TPS to 264 h Uv radiation in a weathering test ***’s weight loss was determined *** changes were studied by Fourier Transform Infrared Spectroscopy(FTIR)and morphological modifications were analyzed by Scanning Electron Microscopy(SEM).Reduction of weight average molar mass was measured by Static Light Scattering(SLS).Changes in mechanical properties were studied from tensile *** 96 h exposure,TPS specimens presented a weight reduction of 4-6%,mainly attributed to plasticizers lost by *** observations showed that Uv radiation induced morphological changes on TPS,evidenced by an increment of specimens *** FTIR,it was detected the presence of an additional band located at 1726 cm-1 in samples submitted to Uv radiation,attributed to the formation of-C=O *** average molar mass of native starch was in the order of 107 g *** exposure to Uv radiation decreased significantly its molar mass,confirming molecular degradation of the *** TPS was exposed during 48 h,it

关键词： Thermoplastic starch Uv radiation structural properties mechanical behavior

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On the Performance of the Energy Detector Subject to Impulsive Noise in κ-μ, α-μ, and η-μ Fading Channels

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Tsinghua Science and Technology 2017年第4期22卷 360-367页

作者： Jos v.M.Cardoso Wamberto J.L.Queiroz Hang Liu marcelo S.Alencar Department of Electrical Engineering Federal University of Campina Grande Department of Electrical Engineering and Computer Science The Catholic University of America

This paper presents a unified theoretical analysis of the energy detection of Gaussian and M-PSK signals in κ-μ,α-μ,and η-μ fading channels at the output of an energy detector subject to impulsive noise（Bernoulli-Gaussian model）. As a result, novel, simple, and accurately approximated expressions for the probability of detection are derived. More precisely, the generalized Gauss-Laguerre quadrature is applied to approximate the probability of detection as a simple finite sum. Monte Carlo simulations corroborate the accuracy and precision of the derived approximations. The results are further extended to cooperative energy detection with hard decision combining information.

关键词： spectrum sensing energy detector fading channel impulsive noise

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Atorvastatin and rosuvastatin do not prevent thioacetamide induced liver cirrhosis in rats

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World Journal of Gastroenterology 2013年第2期19卷 241-248页

作者： Haim Shirin Efrat Sharvit Hussein Aeed dov Gavish Rafael Bruck Gastroenterology Institute Assaf Harofeh Medical CenterZerifin 70300Israel Sackler School of Medicine Tel-Aviv University Tel-Aviv 69975Israel Department of Gastroenterology TelAviv Sourasky Medical CenterTelAviv 64239Israel Department of Gastroenterology The E.Wolfson Medical CenterHolon 58100Israel Department of Internal Medicine "A" The E.Wolfson Medical CenterHolon 58100Israel

AIM:To examine whether the administration of atorvastatin and rosuvastatin would prevent experimentallyinduced hepatic cirrhosis in ***:Liver cirrhosis was induced by injections of thioacetamide(TAA).Rats were treated concurrently with TAA alone or TAA and either atorvastatin(1,10 and 20 mg/kg) or rosuvastatin(1,2.5,5,10 and 20 mg/kg) given daily by nasogastric ***:Liver fibrosis and hepatic hydroxyproline content,in the TAA-treated group was significantly higher than those of the controls [11.5 ± 3.2 vs 2.6 ± 0.6 mg/g protein(P = 0.02)].There were no differences in serum aminotransferase levels in the TAA controls compared to all the groups treated concomitantly by *** statins used in our study did not prevent liver fibrosis or reduce portal hypertension,and had no effect on hepatic oxidative ***,the hepatic level of malondialdehyde was not lower in those groups treated by TAA + statins compared to TAA *** vitro studies,using the BrdU method have shown that atorvastatin had no effect of hepatic stellate cells ***,statin treatment was not associated with worsening of liver damage,portal hypertension or survival ***:Atorvastatin or rosuvastatin did not inhibit TAA-induced liver cirrhosis or oxidative stress in *** statins may have therapeutic applications in hepatic fibrosis due to other etiologies deserve further investigation.

关键词： Liver cirrhosis Statins Thioacetamide

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Hepatic perivascular epithelioid cell tumors:Benign,malignant,and uncertain malignant potential

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World Journal of Gastroenterology 2024年第18期30卷 2374-2378页

作者： marcelo Fabián Amante División Patología Hospital General de Agudos Cosme ArgerichBuenos Aires C1155AHAArgentina División Patología Hospital Alemán de Buenos AiresBuenos Aires C1155AHAArgentina

In 2013,the World Health Organization defined perivascular epithelioid cell tumor(PEComa)as“a mesenchymal tumor which shows a local association with vessel walls and usually expresses melanocyte and smooth muscle markers.”This generic definition seems to better fit the PEComa family,which includes angiomyolipoma,clear cell sugar tumor of the lung,lymphangioleiomyomatosis,and a group of histologically and immunophenotypically similar tumors that include primary extrapulmonary sugar tumor and clear cell myomelanocytic *** cell tumors with this immunophenotypic pattern have also had their malignant variants *** localizing to the liver,preoperative radiological diagnosis has proven to be very difficult,and most patients have been diagnosed with hepatocellular carcinoma,focal nodular hyperplasia,hemangioma,or hepatic adenoma based on imaging *** of a malignant variant of the liver have been ***,reports of malignant variants of these lesions have increased in recent ***,we support the use of the Folpe criteria,which in 2005 established the criteria for categorizing a PEComa as benign,malignant,or of uncertain malignant *** they are not considered ideal,they currently seem to be the best approach and could be used for the categorization of liver tumors.

关键词： PEComas Liver Pathology Malignant Benign Uncertain malignant potential

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Sequencing of systemic treatment for hepatocellular carcinoma: Second line competitors

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World Journal of Gastroenterology 2020年第16期26卷 1888-1900页

作者： Federico Pinero marcelo Silva Massimo Iavarone Hospital Universitario Austral Facultad de Ciencias BiomédicasUniversidad AustralBuenos Aires B1629HJArgentina Latin American Liver Research Educational and Awareness Network Buenos Aires B1629HJArgentina Division of Gastroenterology and Hepatology CRC“A.M.e A.Migliavacca”Center for the Study of Liver DiseaseUniversity of MilanFondazione IRCCS Ca’Granda Maggiore HospitalMilan 20121Italy

During the last decades,further knowledge of hepatocellular carcinoma(HCC)molecular mechanisms has led to development of effective systemic treatments including tyrosine kinase inhibitors(TKIs)and *** this review,we describe first and second line systemic treatment options for advanced *** trials have evaluated new drugs for the treatment of HCC patients:In first line,lenvatinib resulted non-inferior to sorafenib and it can be used as alternative,even in the lack of evidence for sequential treatment options in second line after ***,atezolizumab plus bevacizumab have shown superiority over sorafenib in ***-regorafenib sequential administration in selected patients has opened a new paradigm of treatment in advanced HCC with a life expectancy exceeding two *** TKIs for second line treatment include cabozantinib and ramucirumab(specifically for patients with Alpha-fetoprotein values≥400 ng/mL).The combination of TKIs with immunotherapy may represent a big step forward for these patients in the near future.

关键词： Hepatocellular carcinoma Systemic Options Sequencing Advanced Future

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Extreme liver resections with preservation of segment 4 only

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World Journal of Gastroenterology 2017年第26期23卷 4815-4822页

作者： Silvio Marcio Pegoraro Balzan vinícius Grando Gava marcelo Arbo Magalhaes marcelo Luiz Dotto Department of Pharmacy and Biology University of Santa Cruz do Sul Department of Surgery Hospital Moinhos de Vento

To evaluate safety and outcomes of a new technique for extreme hepatic resections with preservation of segment 4 only. METHODSThe new method of extreme liver resection consists of a two-stage hepatectomy. The first stage involves a right hepatectomy with middle hepatic vein preservation and induction of left lobe congestion; the second stage involves a left lobectomy. Thus, the remnant liver is represented by the segment 4 only (with or without segment 1, ± S1). Five patients underwent the new two-stage hepatectomy (congestion group). Data from volumetric assessment made before the second stage was compared with that of 10 matched patients (comparison group) that underwent a single-stage right hepatectomy with middle hepatic vein preservation. RESULTSThe two stages of the procedure were successfully carried out on all 5 patients. For the congestion group, the overall volume of the left hemiliver had increased 103% (mean increase from 438 mL to 890 mL) at 4 wk after the first stage of the procedure. Hypertrophy of the future liver remnant (i.e., segment 4 ± S1) was higher than that of segments 2 and 3 (144% vs 54%, respectively, P ver volume-to-body weight ratio was 0.3 (range, 0.28-0.40) before the first stage and 0.8 (range, 0.45-0.97) before the second stage. For the comparison group, the rate of hypertrophy of the left liver after right hepatectomy with middle hepatic vein preservation was 116% ± 34%. Hypertrophy rates of segments 2 and 3 (123% ± 47%) and of segment 4 (108% ± 60%, P > 0.05) were proportional. The mean preoperative volume of segments 2 and 3 was 256 ± 64 cc and increased to 572 ± 257 cc after right hepatectomy. Mean preoperative volume of segment 4 increased from 211 ± 75 cc to 439 ± 180 cc after surgery. CONCLUSIONThe proposed method for extreme hepatectomy with preservation of segment 4 only represents a technique that could allow complete resection of multiple bilateral liver metastases.

关键词： Hepatectomy Colorectal liver metastases Hepatic congestion Liver regeneration Liver resection Liver failure

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Periodontal and inflammatory bowel diseases: Is there evidence of complex pathogenic interactions?

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World Journal of Gastroenterology 2016年第35期22卷 7963-7972页

作者： Ronaldo Lira-Junior Carlos marcelo Figueredo Department of Periodontology Faculty of Odontology Rio de Janeiro State University Rio de Janeiro RJ 20551-030 Brazil

Periodontal disease and inflammatory bowel disease(IBD) are both chronic inflammatory diseases. Their pathogenesis is mediated by a complex interplay between a dysbiotic microbiota and the host immuneinflammatory response, and both are influenced by genetic and environmental factors. This review aimed to provide an overview of the evidence dealing with a possible pathogenic interaction between periodontal disease and IBD. There seems to be an increased prevalence of periodontal disease in patients with IBD when compared to healthy controls, probably due to changes in the oral microbiota and a higher inflammatory response. Moreover, the induction of periodontitis seems to result in gut dysbiosis and altered gut epithelial cell barrier function, which might contribute to the pathogenesis of IBD. Considering the complexity of both periodontal disease and IBD, it is very challenging to understand the possible pathways involved in their coexistence. In conclusion, this review points to a complex pathogenic interaction between periodontal disease and IBD, in which one disease might alter the composition of the microbiota and increase the inflammatory response related to the other. However, we still need more data derived from human studies to confirm results from murine models. Thus, mechanistic studies are definitely warranted to clarify this possible bidirectional association.

关键词： Periodontal disease Inflammatory bowel disease Crohn’s disease Ulcerative colitis Inflammation

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Posterior partially edentulous jaws, planning a rehabilitation with dental implants

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World Journal of Clinical Cases 2015年第1期3卷 65-76页

作者： Douglas R Monteiro Emily v F Silva Eduardo P Pellizzer Osvaldo Magro Filho marcelo C Goiato Department of Dental Materials and Prosthodontics Araçatuba Dental SchoolUniv Estadual Paulista(UNESP)São Paulo 16015-050Brazil

AIM: To discuss important characteristics of the useof dental implants in posterior quadrants and the rehabilitation planning. METHODS: An electronic search of English articles was conducted on MEDLINE(PubM ed) from 1990 up to the period of March 2014. The key terms were dental implants and posterior jaws, dental implants/treatment planning and posterior maxilla, and dental implants/treatment planning and posterior mandible. No exclusion criteria were used for the initial search. Clinical trials, randomized and non randomized studies, classical and comparative studies, multicenter studies, in vitro and in vivo studies, case reports, longitudinal studies and reviews of the literature were included in this review. RESULTS: One hundred and fifty-two articles met the inclusion criteria of treatment planning of dental implants in posterior jaw and were read in their entirety. The selected articles were categorized with respect to their context on space for restoration, anatomic considerations(bone quantity and density), radiographic techniques, implant selection(number, position, diameter and surface), tilted and pterygoid implants, short implants, occlusal considerations, and success rates of implants placed in the posterior region. The results derived from the review process were described under several different topic headings to give readers a clear overview of the literature. In general, it was observed that the use of dental implants in posterior region requires a careful treatment plan. It is important that the practitioner has knowledge about the theme to evaluate the treatment parameters. CONCLUSION: The use of implants to restore the posterior arch presents many challenges and requires a detailed treatment planning.

关键词： Dental implants Mandible Maxilla Edentulous jaw Treatment

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Acute pancreatitis:The stress factor

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World Journal of Gastroenterology 2014年第19期20卷 5801-5807页

作者： marcelo G Binker Laura I Cosen-Binker CBRHC Research Center 1053 Ciudad Autónoma de Buenos AiresBuenos Aires 1426Argentina Department of Molecular and Cell Biology Henry M Goldman School of Dental MedicineBoston UniversityBostonMA 02118United States

Acute pancreatitis is an inflammatory disorder of the pancreas that may cause life-threatening *** of pancreatitis vary,with gallstones accounting for the majority of all cases,followed by *** causes of pancreatitis include trauma,ischemia,mechanical obstruction,infections,autoimmune,hereditary,and *** main events occurring in the pancreatic acinar cell that initiate and propagate acute pancreatitis include inhibition of secretion,intracellular activation of proteases,and generation of inflammatory *** cytokines known as chemokines are released from damaged pancreatic cells and attract inflammatory cells,whose systemic action ultimately determined the severity of the ***,severe forms of pancreatitis may result in systemic inflammatory response syndrome and multiorgan dysfunction syndrome,characterized by a progressive physiologic failure of several interdependent organ *** occurs when homeostasis is threatened,and stressors can include physical or mental forces,or combinations of *** on the timing and duration,stress can result in beneficial or harmful *** it is well established that a previous acute-short-term stress decreases the severity of experimentally-induced pancreatitis,the worsening effects of chronic stress on the exocrine pancreas have received relatively little *** review will focus on the influence of both prior acute-short-term and chronic stress in acute pancreatitis.

关键词： Pancreatitis Acute stress Chronic stress Heat shock proteins Tumor necrosis factor alpha

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Hepatitis B virus lineages in mammalian hosts:Potential for bidirectional cross-species transmission

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World Journal of Gastroenterology 2014年第24期20卷 7665-7674页

作者： Cibele R Bonvicino Miguel A Moreira marcelo A Soares Genetics Division Instituto Nacional de CancerRio de JaneiroRJ 20231-050Brazil Laboratório de Biologia e Parasitologia de Mamíferos Reservatórios Silvestres IOCFIOCRUZRio de JaneiroRJ 21045-900Brazil Genetics Department Universidade Federal do Rio de JaneiroRio de JaneiroRJ 21949-570Brazil

The hepatitis B virus(HBv)is a cosmopolitan infectious agent currently affecting over 350 million people worldwide,presently accounting for more than two billion *** addition to man,other hepatitis virus strains infect species of several mammalian families of the Primates,Rodentia and Chiroptera orders,in addition to *** mounting evidence of HBv infection in African,Asian and neotropical primates draws attention to the potential crossspecies,zoonotic transmission of these viruses to ***,recent evidence also suggests the humans may also function as a source of viral infection to other mammals,particularly to domestic animals like poultry and *** this review,we list all evidence of HBv and HBvlike infection of nonhuman mammals and discuss their potential roles as donors or recipients of these viruses to humans and to other closely-related species.

关键词： Hepatitis B Hepatitis B virus nonhuman host Cross-species transmission Hepatitis B virus

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