41 research outputs found

    Dynamic compressive behavior of metallic particulate-reinforced cementitious composites: SHPB experiments and numerical simulations

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    An experimental and numerical evaluation on the dynamic compressive response of mortars containing up to 20% waste iron powder as sand replacement is presented in this paper. The dynamic response is evaluated using split Hopkinson pressure bar (SHPB) apparatus under high strain rates (up to 250/s). The elongated iron particulates present in the iron powder-incorporated mortars warrant significantly improved compressive strength and energy absorption capacity at high strain rates. Multiscale numerical simulations are performed with a view to develop a tool that facilitates microstructure-guided design of these particulate-reinforced mortars for efficient dynamic performance. The dynamic compressive response of particulate-reinforced mortars is simulated adopting a numerical approach that incorporates strain rate-dependent damage in a continuum micromechanics framework. The simulated dynamic compressive strengths and energy absorption capacities for mortars with various iron powder content exhibit good correlation with the experimental observations thereby validating the efficacy of the simulation approach

    The effects of vardenafil and pentoxifylline administration in an animal model of ischemic colitis

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    OBJECTIVES: Vardenafil enhances dilatation of vascular smooth muscle and inhibits platelet aggregation. The purpose of this study was to evaluate the clinical effects of vardenafil and pentoxifylline administration in an experimental model of ischemic colitis. METHODS: Forty female Wistar albino rats weighing 250-300 g were randomized into five experimental groups (each with n = 8) as follows:1) a sham group subjected to a sham surgical procedure and administered only tap water; 2) a control group subjected to a standardized surgical procedure to induce ischemic colitis and administered only tap water; 3) and 4) treatment groups subjected to surgical induction of ischemic colitis followed by the postoperative administration of 5 mg/kg or 10 mg/kg vardenafil, respectively; and 5) a treatment group subjected to surgical induction of ischemic colitis followed by postoperative administration of pentoxifylline at 50 mg/kg/day per day as a single dose for a 3-day period. All animals were sacrificed at 72 h post-surgery and subjected to relaparotomy. We scored the macroscopically visible damage, measured the ischemic area and scored histopathology to determine the severity of ischemia. Tissue malondialdehyde levels were also quantified. RESULTS: The mean Gomella ischemic areas were 63.3 mm2 in the control group; 3.4 and 9.6 mm2 in the vardenafil 5 and vardenafil 10 groups, respectively; and 3.4 mm2 in the pentoxifylline group (p = 0.0001). The mean malondialdehyde values were 63.7 nmol/g in the control group; 25.3 and 25.6 nmol/g in the vardenafil 5 and vardenafil 10 groups, respectively; and 22.8 nmol/g in the pentoxifylline group (p = 0.0001). CONCLUSION: Our findings indicate that vardenafil and pentoxifylline are effective treatment options in an animal model of ischemic colitis. The positive clinical effects produced by these drugs are likely due to their influence on the hemodynamics associated with vascular smooth muscle and platelet functions

    It is time to define an organizational model for the prevention and management of infections along the surgical pathway : a worldwide cross-sectional survey

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    Background The objectives of the study were to investigate the organizational characteristics of acute care facilities worldwide in preventing and managing infections in surgery; assess participants' perception regarding infection prevention and control (IPC) measures, antibiotic prescribing practices, and source control; describe awareness about the global burden of antimicrobial resistance (AMR) and IPC measures; and determine the role of the Coronavirus Disease 2019 pandemic on said awareness. Methods A cross-sectional web-based survey was conducted contacting 1432 health care workers (HCWs) belonging to a mailing list provided by the Global Alliance for Infections in Surgery. The self-administered questionnaire was developed by a multidisciplinary team. The survey was open from May 22, 2021, and June 22, 2021. Three reminders were sent, after 7, 14, and 21 days. Results Three hundred four respondents from 72 countries returned a questionnaire, with an overall response rate of 21.2%. Respectively, 90.4% and 68.8% of participants stated their hospital had a multidisciplinary IPC team or a multidisciplinary antimicrobial stewardship team. Local protocols for antimicrobial therapy of surgical infections and protocols for surgical antibiotic prophylaxis were present in 76.6% and 90.8% of hospitals, respectively. In 23.4% and 24.0% of hospitals no surveillance systems for surgical site infections and no monitoring systems of used antimicrobials were implemented. Patient and family involvement in IPC management was considered to be slightly or not important in their hospital by the majority of respondents (65.1%). Awareness of the global burden of AMR among HCWs was considered very important or important by 54.6% of participants. The COVID-19 pandemic was considered by 80.3% of respondents as a very important or important factor in raising HCWs awareness of the IPC programs in their hospital. Based on the survey results, the authors developed 15 statements for several questions regarding the prevention and management of infections in surgery. The statements may be the starting point for designing future evidence-based recommendations. Conclusion Adequacy of prevention and management of infections in acute care facilities depends on HCWs behaviours and on the organizational characteristics of acute health care facilities to support best practices and promote behavioural change. Patient involvement in the implementation of IPC is still little considered. A debate on how operationalising a fundamental change to IPC, from being solely the HCWs responsibility to one that involves a collaborative relationship between HCWs and patients, should be opened.Peer reviewe

    It is time to define an organizational model for the prevention and management of infections along the surgical pathway: a worldwide cross-sectional survey

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    Background The objectives of the study were to investigate the organizational characteristics of acute care facilities worldwide in preventing and managing infections in surgery; assess participants' perception regarding infection prevention and control (IPC) measures, antibiotic prescribing practices, and source control; describe awareness about the global burden of antimicrobial resistance (AMR) and IPC measures; and determine the role of the Coronavirus Disease 2019 pandemic on said awareness. Methods A cross-sectional web-based survey was conducted contacting 1432 health care workers (HCWs) belonging to a mailing list provided by the Global Alliance for Infections in Surgery. The self-administered questionnaire was developed by a multidisciplinary team. The survey was open from May 22, 2021, and June 22, 2021. Three reminders were sent, after 7, 14, and 21 days. Results Three hundred four respondents from 72 countries returned a questionnaire, with an overall response rate of 21.2%. Respectively, 90.4% and 68.8% of participants stated their hospital had a multidisciplinary IPC team or a multidisciplinary antimicrobial stewardship team. Local protocols for antimicrobial therapy of surgical infections and protocols for surgical antibiotic prophylaxis were present in 76.6% and 90.8% of hospitals, respectively. In 23.4% and 24.0% of hospitals no surveillance systems for surgical site infections and no monitoring systems of used antimicrobials were implemented. Patient and family involvement in IPC management was considered to be slightly or not important in their hospital by the majority of respondents (65.1%). Awareness of the global burden of AMR among HCWs was considered very important or important by 54.6% of participants. The COVID-19 pandemic was considered by 80.3% of respondents as a very important or important factor in raising HCWs awareness of the IPC programs in their hospital. Based on the survey results, the authors developed 15 statements for several questions regarding the prevention and management of infections in surgery. The statements may be the starting point for designing future evidence-based recommendations. Conclusion Adequacy of prevention and management of infections in acute care facilities depends on HCWs behaviours and on the organizational characteristics of acute health care facilities to support best practices and promote behavioural change. Patient involvement in the implementation of IPC is still little considered. A debate on how operationalising a fundamental change to IPC, from being solely the HCWs responsibility to one that involves a collaborative relationship between HCWs and patients, should be opened

    Diversity and ethics in trauma and acute care surgery teams: results from an international survey

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    Background Investigating the context of trauma and acute care surgery, the article aims at understanding the factors that can enhance some ethical aspects, namely the importance of patient consent, the perceptiveness of the ethical role of the trauma leader, and the perceived importance of ethics as an educational subject. Methods The article employs an international questionnaire promoted by the World Society of Emergency Surgery. Results Through the analysis of 402 fully filled questionnaires by surgeons from 72 different countries, the three main ethical topics are investigated through the lens of gender, membership of an academic or non-academic institution, an official trauma team, and a diverse group. In general terms, results highlight greater attention paid by surgeons belonging to academic institutions, official trauma teams, and diverse groups. Conclusions Our results underline that some organizational factors (e.g., the fact that the team belongs to a university context or is more diverse) might lead to the development of a higher sensibility on ethical matters. Embracing cultural diversity forces trauma teams to deal with different mindsets. Organizations should, therefore, consider those elements in defining their organizational procedures. Level of evidence Trauma and acute care teams work under tremendous pressure and complex circumstances, with their members needing to make ethical decisions quickly. The international survey allowed to shed light on how team assembly decisions might represent an opportunity to coordinate team member actions and increase performance

    Infected pancreatic necrosis: outcomes and clinical predictors of mortality. A post hoc analysis of the MANCTRA-1 international study

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    : The identification of high-risk patients in the early stages of infected pancreatic necrosis (IPN) is critical, because it could help the clinicians to adopt more effective management strategies. We conducted a post hoc analysis of the MANCTRA-1 international study to assess the association between clinical risk factors and mortality among adult patients with IPN. Univariable and multivariable logistic regression models were used to identify prognostic factors of mortality. We identified 247 consecutive patients with IPN hospitalised between January 2019 and December 2020. History of uncontrolled arterial hypertension (p = 0.032; 95% CI 1.135-15.882; aOR 4.245), qSOFA (p = 0.005; 95% CI 1.359-5.879; aOR 2.828), renal failure (p = 0.022; 95% CI 1.138-5.442; aOR 2.489), and haemodynamic failure (p = 0.018; 95% CI 1.184-5.978; aOR 2.661), were identified as independent predictors of mortality in IPN patients. Cholangitis (p = 0.003; 95% CI 1.598-9.930; aOR 3.983), abdominal compartment syndrome (p = 0.032; 95% CI 1.090-6.967; aOR 2.735), and gastrointestinal/intra-abdominal bleeding (p = 0.009; 95% CI 1.286-5.712; aOR 2.710) were independently associated with the risk of mortality. Upfront open surgical necrosectomy was strongly associated with the risk of mortality (p < 0.001; 95% CI 1.912-7.442; aOR 3.772), whereas endoscopic drainage of pancreatic necrosis (p = 0.018; 95% CI 0.138-0.834; aOR 0.339) and enteral nutrition (p = 0.003; 95% CI 0.143-0.716; aOR 0.320) were found as protective factors. Organ failure, acute cholangitis, and upfront open surgical necrosectomy were the most significant predictors of mortality. Our study confirmed that, even in a subgroup of particularly ill patients such as those with IPN, upfront open surgery should be avoided as much as possible. Study protocol registered in ClinicalTrials.Gov (I.D. Number NCT04747990)

    Complicated intra-abdominal infections in a worldwide context: an observational prospective study (CIAOW Study)

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