100 research outputs found

    Inherent Metal Elements in Biomass Pyrolysis: A Review

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    One of the main drawbacks of using biomass as pyrolysis feedstock consists of the huge variability of the different biomass resources which undermines the viability of downstream processes. Inherent inorganic elements greatly contribute to enhance the compositional variability issues due to their catalytic effect (especially alkali and alkaline earth metals (AAEMs)) and the technical problems arising due to their presence. Due to the different pretreatments adopted in the experimental investigations as well as the different reactor configurations and experimental conditions, some mechanisms involving interactions between these elements and the biomass organic fraction during pyrolysis are still debated. This is the reason why predicting the results of these interactions by adapting the existing kinetic models of pyrolysis is still challenging. In this work, the most prominent experimental works of the last 10 years dealing with the catalytic effects of biomass inherent metals on the pyrolysis process are reviewed. Reaction pathways, products distributions and characteristics, and impacts on the products utilization are discussed with a focus on AAEMs and on potential toxic metallic elements in hyperaccumulator plants. The literature findings are discussed in relation to the applied laboratory procedures controlling the concentration of inherent inorganic elements, their capability of preserving the chemical integrity of the main organic components, and the ability of resembling the inherent inorganic elements in the raw biomass. The goal is to reveal possible experimental inconsistencies and to provide a clear scheme of the reaction pathways altered by the presence of inherent inorganics. This analysis paves the way for the examination of the proposed modifications of the existing models aiming at capturing the effect of inorganics on pyrolysis kinetics. Finally, the most relevant shortcomings and bottlenecks in existing experimental and modeling approaches are analyzed and directions for further studies are suggested

    A retrospective whole-genome sequencing analysis of carbapenem and colistin-resistant klebsiella pneumoniae nosocomial strains isolated during an MDR surveillance program

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    Multidrug-resistant Klebsiella pneumoniae (MDR Kp), in particular carbapenem-resistant Kp (CR-Kp), has become endemic in Italy, where alarming data have been reported on the spread of colistin-resistant CR-Kp (CRCR-Kp). During the period 2013–2014, 27 CRCR-Kp nosocomial strains were isolated within the Modena University Hospital Policlinico (MUHP) multidrug resistance surveillance program. We retrospectively investigated these isolates by whole-genome sequencing (WGS) analysis of the resistome, virulome, plasmid content, and core single nucleotide polymorphisms (cSNPs) in order to gain insights into their molecular epidemiology. The in silico WGS analysis of the resistome revealed the presence of genes, such as blaKPC, related to the phenotypically detected resistances to carbapenems. Concerning colistin resistance, the plasmidic genes mcr 1–9 were not detected, while known and new genetic variations in mgrB, phoQ, and pmrB were found. The virulome profile revealed the presence of type-3 fimbriae, capsular polysaccharide, and iron acquisition system genes. The detected plasmid replicons were classified as IncFIB(pQil), IncFIB(K), ColRNAI, IncX3, and IncFII(K) types. The cSNPs genotyping was consistent with the multi locus sequence typing (MLST) and with the distribution of mutations related to colistin resistance genes. In a nosocomial drug resistance surveillance program, WGS proved to be a useful tool for elucidating the spread dynamics of CRCR-Kp nosocomial strains and could help to limit their diffusion

    Hormonal therapy with megestrol in inoperable hepatocellular carcinoma characterized by variant oestrogen receptors

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    Variant liver oestrogen receptor transcripts in hepatocellular carcinoma are associated with aggressive clinical course and unresponsiveness to tamoxifen. To evaluate the impact on survival and on tumour growth of megestrol (progestin drug acting at post-receptorial level) we enrolled 45 patients with HCC characterized by variant liver oestrogen receptors in a prospective, randomized study with megestrol vs. placebo. Presence of variant oestrogen receptors was determined by RT/PCR. 24 patients were randomized to no treatment and 21 to therapy with megestrol 160 mg day−1. Results were analysed by Kaplan-Meier and Cox methods. Survival of hepatocellular carcinoma characterized by variant oestrogen receptors was extremely poor (median survival 7 months); megestrol significantly improved survival (18 months) (P = 0.0090). Tumour growth at one year was significantly slowed down in megestrol-treated patients (P = 0.0212). Bilirubin levels, presence of portal thrombosis, HBV aetiology and treatment were identified at univariate analysis as factors significantly associated with survival; at multivariate analysis, only megestrol therapy (P = 0.0003), presence of HBV infection (P = 0.0009) and presence of portal vein thrombosis (P = 0.0051) were factors independently related with survival. (1) Megestrol slows down the aggressive tumour growth of patients with hepatocellular carcinoma characterized by variant estrogen receptors and (2) is also able to favourably influence the course of disease, more than doubling median survival. © 2001 Cancer Research Campaignhttp://www.bjcancer.co

    Severe acute respiratory syndrome coronavirus 2 infection in patients with hematological malignancies in the Omicron era: Respiratory failure, need for mechanical ventilation and mortality in seronegative and seropositive patients

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    Background: Patients with hematological malignancies (HM) have a high risk of severe coronavirus disease 2019 (COVID-19), also in the Omicron period.Material and methods: Retrospective single-center study including HM patients with severe acute respiratory syndrome Coronavirus 2 (SARS-CoV2) infection from January 2022 to March 2023. Study outcomes were respiratory failure (RF), mechanical ventilation (MV), and COVID-related mortality, comparing patients according to SARS-CoV2 serology.Results: Note that, 112 patients were included: 39% had negative SARS-CoV2 serology. Seronegative were older (71.5 vs. 65.0 years, p = 0.04), had more often a lymphoid neoplasm (88.6% vs. 69.1%, p = 0.02), underwent anti-CD20 therapy (50.0% vs. 30.9% p = 0.04) and had more frequently a severe disease (23.0% vs. 3.0%, p = 0.02) than seropositive.Kaplan-Meier showed a higher risk for seronegative patients for RF (p = 0.014), MV (p = 0.044), and COVID-related mortality (p = 0.021). Negative SARS-CoV2 serostatus resulted in a risk factor for RF (hazards ratio [HR] 2.19, 95% confidence interval [CI] 1.03-4.67, p = 0.04), MV (HR 3.37, 95% CI 1.06-10.68, p = 0.04), and COVID-related mortality (HR 4.26, 95% CI 1.09-16.71, p = 0.04).Conclusions: HM patients with negative SARS-CoV2 serology, despite vaccinations and previous infections, have worse clinical outcomes compared to seropositive patients in the Omicron era. The use of serology for SARS-CoV2 diagnosis could be an easy tool to identify patients prone to developing complications

    Severe pneumonia caused by Legionella pneumophila serogroup 11, Italy.

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    Legionella pneumophila serogroups (SGs) 1–16 cause pneumonia in humans. Although SG 1 is the serogroup most commonly associated with disease, we report a case of community-acquired legionellosis caused by SG 11

    Viral Resistance in Hepatitis B: Prevalence and Management

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    Hepatitis B is a DNA virus affecting hundreds of millions of individuals worldwide. As the clinical sequelae of cirrhosis and hepatocellular cancer are increasingly recognized to be related to viral levels, the impetus increases to offer treatment to those previously not treated. With the development of more robust antivirals with reasonable safety profiles, long-term treatment is becoming more common. The oral nucleos(t)ide analogs have become the preferred first-line therapies for most genotypes of hepatitis B. Five are now available, all with different potencies and resistance profiles. Long-term data spanning several years are now available for most compounds in this arena. This article focuses on the common natural variants and those secondary to nucleos(t)ide therapy, as well as diagnostic methods to detect resistance

    Large Fragment Pre-S Deletion and High Viral Load Independently Predict Hepatitis B Relapse after Liver Transplantation

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    Hepatitis B virus (HBV) associated end-stage liver diseases are the leading causes of liver transplantation (LT) in Taiwan. Relapse of hepatitis B occurs after LT, raising the risk of graft failure and reducing patient survival. Although several oral antiviral agents have been approved for anti-HBV treatment, lamivudine (LAM) remained to be the most widely used preventive regimen in Taiwan. While several clinical predictors have been identified for hepatitis B relapse, the predictive roles of the histopathological characteristics in liver explants as well as the genotypic features of the viruses in pre-LT serum samples have not been assessed. Between September 2002 and August 2009, 150 consecutive hepatitis B surface antigen (HBsAg) positive patients undergoing LT were included for outcome analysis following assessment of the clinicopathological and virological factors prior to LT. Kaplan-Meier analyses discovered that pre-operative LAM treatment ≤3 months; membranous distribution and higher expression of tissue HBsAg in liver explants; preoperative viral load ≧106 copies/ml; and presence of large fragment (>100 base pairs) pre-S deletion (LFpreSDel) correlated significantly with hepatitis B relapse. Multivariate Cox regression analysis showed that the presence of LFpreSDel (P = 0.001) and viral load ≧106 copies/mL (P = 0.023) were independent predictors for hepatitis B relapse. In conclusion, besides high viral load, LFpreSDel mutation is an important independent predictor for hepatitis B relapse after LT. More aggressive preventive strategies should be applied for patients carrying these risk factors

    Effects of cytokine blocking agents on hospital mortality in patients admitted to ICU with acute respiratory distress syndrome by SARS-CoV-2 infection: Retrospective cohort study

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    Background: The use of cytokine-blocking agents has been proposed to modulate the inflammatory response in patients with COVID-19. Tocilizumab and anakinra were included in the local protocol as an optional treatment in critically ill patients with acute respiratory distress syndrome (ARDS) by SARS-CoV-2 infection. This cohort study evaluated the effects of therapy with cytokine blocking agents on in-hospital mortality in COVID-19 patients requiring mechanical ventilation and admitted to intensive care unit. Methods: The association between therapy with tocilizumab or anakinra and in-hospital mortality was assessed in consecutive adult COVID-19 patients admitted to our ICU with moderate to severe ARDS. The association was evaluated by comparing patients who received to those who did not receive tocilizumab or anakinra and by using different multivariable Cox models adjusted for variables related to poor outcome, for the propensity to be treated with tocilizumab or anakinra and after patient matching. Results: Sixty-six patients who received immunotherapy (49 tocilizumab, 17 anakinra) and 28 patients who did not receive immunotherapy were included. The in-hospital crude mortality was 30,3% in treated patients and 50% in non-treated (OR 0.77, 95% CI 0.56-1.05, p=0.069). The adjusted Cox model showed an association between therapy with immunotherapy and in-hospital mortality (HR 0.40, 95% CI 0.19-0.83, p=0.015). This protective effect was further confirmed in the analysis adjusted for propensity score, in the propensity-matched cohort and in the cohort of patients with invasive mechanical ventilation within 2 hours after ICU admission. Conclusions: Although important limitations, our study showed that cytokine-blocking agents seem to be safe and to improve survival in COVID-19 patients admitted to ICU with ARDS and the need for mechanical ventilation

    Evaluating the risk for Usutu virus circulation in Europe : comparison of environmental niche models and epidemiological models

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    Abstract Background Usutu virus (USUV) is a mosquito-borne flavivirus, reported in many countries of Africa and Europe, with an increasing spatial distribution and host range. Recent outbreaks leading to regional declines of European common blackbird (Turdus merula) populations and a rising number of human cases emphasize the need for increased awareness and spatial risk assessment. Methods Modelling approaches in ecology and epidemiology differ substantially in their algorithms, potentially resulting in diverging model outputs. Therefore, we implemented a parallel approach incorporating two commonly applied modelling techniques: (1) Maxent, a correlation-based environmental niche model and (2) a mechanistic epidemiological susceptible-exposed-infected-removed (SEIR) model. Across Europe, surveillance data of USUV-positive birds from 2003 to 2016 was acquired to train the environmental niche model and to serve as test cases for the SEIR model. The SEIR model is mainly driven by daily mean temperature and calculates the basic reproduction number R0. The environmental niche model was run with long-term bio-climatic variables derived from the same source in order to estimate climatic suitability. Results Large areas across Europe are currently suitable for USUV transmission. Both models show patterns of high risk for USUV in parts of France, in the Pannonian Basin as well as northern Italy. The environmental niche model depicts the current situation better, but with USUV still being in an invasive stage there is a chance for under-estimation of risk. Areas where transmission occurred are mostly predicted correctly by the SEIR model, but it mostly fails to resolve the temporal dynamics of USUV events. High R0 values predicted by the SEIR model in areas without evidence for real-life transmission suggest that it may tend towards over-estimation of risk. Conclusions The results from our parallel-model approach highlight that relying on a single model for assessing vector-borne disease risk may lead to incomplete conclusions. Utilizing different modelling approaches is thus crucial for risk-assessment of under-studied emerging pathogens like USUV
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