Notch Effect on the Fatigue Behavior of a Hot Dip Galvanized Structural Steel

Исследовано влияние гальванического покрытия на усталостную прочность конструкционной стали S355. Несмотря на наличие в литературных источниках экспериментальных данных по гладким образцам из этого материала с покрытием, почти отсутствуют таковые по образцам с концентраторами напряжений. Выполнен сравнительный анализ образцов с центральным отверстием, подвергнутых гальванизации методом горячего погружения, и исходных образцов той же геометрии. Усталостные испытания проводились при двух постоянных значениях асимметрии цикла нагружения. Получено и проанализировано 60 новых экспериментальных данных.Досліджено вплив гальванічного покриття на втомну міцність конструкційної сталі S355. Незважаючи на те, що в літературних джерелах є експериментальні дані щодо гладких зразків із цього матеріалу з покриттям, майже відсуті дані щодо зразків із концентратором напружень. Виконано порівняльний аналіз зразків із центральним отвором, ще зазнали гальванізації методом гарячого занурення, і вихідних зразків такої ж геометрії. Випробування на втому проводились при двох постійних значеннях асиметрії циклу навантаження. Отримано і проаналізовано 60 нових експериментальних даних

Local strain energy density for the fatigue assessment of hot dip galvanized welded joints: some recent outcomes

Since in literature only data about the effect of the hot-dip galvanizing coating on fatigue behavior of unnotched specimens are available, whereas very few for notched components and none for welded joints, the aim of this paper is to partially fill this lack of knowledge comparing fatigue strength of uncoated and hot-dip galvanized fillet welded cruciform joints made of structural steel S355 welded joints, subjected to a load cycle R = 0. 34. The results are shown in terms of stress range ?? and of the averaged strain energy density range DeltaW in a control volume of radius R0 = 0.28 m

Effect of hot dip galvanization on the fatigue strength of steel bolted connections

Hot dip galvanized steel bolted joints has been tested under fatigue loading to evaluate the effect of galvanizing coating on the fatigue strength of S355 structural steel. The experimental results showed that the decrease of the fatigue life of coated specimens in comparison with that of uncoated joints is very limited and the results are in good agreement with Eurocode detail category, without substantial reductions. The procedure for coating and preparation of the bolted joints is described in detail in this paper providing a useful tool for engineers involved in similar practical applications. The experimental results are compared with the previously published data on central hole notched galvanized and not treated specimens characterized by the same geometry

Combined totally mini-invasive approach in necrotizing pancreatitis: A case report and systematic literature review

Background: Currently, both the step-up approach, combining percutaneous drainage (PD) and video-assisted retroperitoneal debridement (VARD), and endoscopic transgastric necrosectomy (ETN) are mini-invasive techniques for infected necrosis in severe acute pancreatitis. A combination of these approaches could maximize the management of necrotizing pancreatitis, conjugating the benefits from both the experiences. However, reporting of this combined strategy is anecdotal. This is the first reported case of severe necrotizing pancreatitis complicated by biliary fistula treated by a combination of ETN, PD, VARD, and endoscopic biliary stenting. Moreover, a systematic literature review of comparative studies on minimally invasive techniques in necrotizing pancreatitis has been provided. Case presentation: A 59-year-old patient was referred to our center for acute necrotizing pancreatitis associated with multi-organ failure. No invasive procedures were attempted in the first month from the onset: enteral feeding by a naso-duodenal tube was started, and antibiotics were administered to control sepsis. After 4 weeks, CT scans showed a central walled-off pancreatic necrosis (WOPN) of pancreatic head communicating bilateral retroperitoneal collections. ETN was performed, and bile leakage was found at the right margin of the WOPN. Endoscopic retrograde cholangiopancreatography confirmed the presence of a choledocal fistula within the WOPN, and a biliary stent was placed. An ultrasound-guided PD was performed on the left retroperitoneal collection. Due to the subsequent repeated onset of septic shocks and the evidence of size increase of the right retroperitoneal collection, a VARD was decided. The CT scans documented the resolution of all the collections, and the patient promptly recovered from sepsis. After 6 months, the patient is in good clinical condition. Conclusions: No mini-invasive technique has demonstrated significantly better outcomes over the others, and each technique has specific indications, advantages, and pitfalls. Indeed, ETN could be suitable for central WOPNs, while VARD or PD could be suggested for lateral collections. A combination of different approaches is feasible and could significantly optimize the clinical management in critically ill patients affected by complicated necrotizing pancreatitis

Foregut caustic injuries: results of the world society of emergency surgery consensus conference

Introduction: Lesions of the upper digestive tract due to ingestion of caustic agents still represent a major medical and surgical emergency worldwide. The work-up of these patients is poorly defined and no clear therapeutic guidelines are available. Purpose of the study: The aim of this study was to provide an evidence-based international consensus on primary and secondary prevention, diagnosis, staging, and treatment of this life-threatening and potentially disabling condition. Methods: An extensive literature search was performed by an international panel of experts under the auspices of the World Society of Emergency Surgery (WSES). The level of evidence of the screened publications was graded using the Oxford 2011 criteria. The level of evidence of the literature and the main topics regarding foregut caustic injuries were discussed during a dedicated meeting in Milan, Italy (April 2015), and during the 3rd Annual Congress of the World Society of Emergency Surgery in Jerusalem, Israel (July 2015). Results: One-hundred-forty-seven full papers which addressed the relevant clinical questions of the research were admitted to the consensus conference. There was an unanimous consensus on the fact that the current literature on foregut caustic injuries lacks homogeneous classification systems and prospective methodology. Moreover, the non-standardized definition of technical and clinical success precludes any accurate comparison of therapeutic modalities. Key recommendations and algorithms based on expert opinions, retrospective studies and literature reviews were proposed and approved during the final consensus conference. The clinical practice guidelines resulting from the consensus conference were approved by the WSES council. Conclusions: The recommendations emerging from this consensus conference, although based on a low level of evidence, have important clinical implications. A world registry of foregut caustic injuries could be useful to collect a homogeneous data-base for prospective clinical studies that may help improving the current clinical practice guidelines.Lesions of the upper digestive tract due to ingestion of caustic agents still represent a major medical and surgical emergency worldwide. The work-up of these patients is poorly defined and no clear therapeutic guidelines are available. Purpose of the stu1044110sem informaçãosem informaçã

Endo-therapies for biliary duct-to-duct anastomotic stricture after liver transplantation: outcomes of a nationwide survey

BACKGROUND: The most appropriate endo-therapeutic approach to biliary anastomotic strictures is yet to be defined. AIM: To retrospectively report on the endo-therapy of duct-to-duct anastomotic strictures during 2013 in Italy. METHODS: Data were collected from 16 Endoscopy Units at the Italian Liver Transplantation Centers (BASALT study group). RESULTS: Complete endo-therapy and follow-up data are available for 181 patients: 101 treated with plastic multistenting, 26 with fully covered self-expandable metal stenting (SEMS) and 54 with single stenting. Radiological success was achieved for 145 patients (80%), i.e. 88% of plastic multistenting, 88% of SEMS and 61% of single stenting (p<0.001 vs plastic multistenting; p<0.05 vs SEMS)]. After first-line endo-therapy failure, the patients underwent a second-line endo-therapy with plastic multistenting for 25%, fully covered SEMS for 53% and single stenting for 22% of cases, and radiological success was achieved for 84%, i.e. 100%, 85%, and 63% with plastic multistenting, SEMS and single stenting (p<0.05 vs plastic multistenting or SEMS), respectively. Procedure-related complications occurred in 7.8% of ERCP. Overall clinical success was achieved in 87% of patients after a median follow-up of 25 months. CONCLUSION: Plastic multistenting is confirmed as the preferred first-line treatment, while fully covered SEMS as rescue option for biliary anastomotic strictures. Single stenting has sub-optimal results and should be abandoned. This article is protected by copyright. All rights reserved

Foregut caustic injuries: Results of the world society of emergency surgery consensus conference

Introduction: Lesions of the upper digestive tract due to ingestion of caustic agents still represent a major medical and surgical emergency worldwide. The work-up of these patients is poorly defined and no clear therapeutic guidelines are available. Purpose of the study: The aim of this study was to provide an evidence-based international consensus on primary and secondary prevention, diagnosis, staging, and treatment of this life-threatening and potentially disabling condition. Methods: An extensive literature search was performed by an international panel of experts under the auspices of the World Society of Emergency Surgery (WSES). The level of evidence of the screened publications was graded using the Oxford 2011 criteria. The level of evidence of the literature and the main topics regarding foregut caustic injuries were discussed during a dedicated meeting in Milan, Italy (April 2015), and during the 3rd Annual Congress of the World Society of Emergency Surgery in Jerusalem, Israel (July 2015). Results: One-hundred-forty-seven full papers which addressed the relevant clinical questions of the research were admitted to the consensus conference. There was an unanimous consensus on the fact that the current literature on foregut caustic injuries lacks homogeneous classification systems and prospective methodology. Moreover, the non-standardized definition of technical and clinical success precludes any accurate comparison of therapeutic modalities. Key recommendations and algorithms based on expert opinions, retrospective studies and literature reviews were proposed and approved during the final consensus conference. The clinical practice guidelines resulting from the consensus conference were approved by the WSES council. Conclusions: The recommendations emerging from this consensus conference, although based on a low level of evidence, have important clinical implications. A world registry of foregut caustic injuries could be useful to collect a homogeneous data-base for prospective clinical studies that may help improving the current clinical practice guidelines