experimental investigation on the fixed bed of a small size biomass boiler

Abstract During the last decades, the increase of the world energy consumption promoted the renewable resource development and use. Together with wind, solar and hydro energy, biomasses play a key role in the reduction of the industrial environmental impact; moreover, the biomass combustion systems are very attractive for micro-generation purpose. In this paper, experimental tests on a 140kW small size fixed bed biomass boiler were carried out. The main goal was to study the thermal behavior and some chemical products, such as CO, CO2, Methane and Ethylene, from the combusting fixed bed of the system. In fact, despite the wide amount of literature for the laboratory scale systems, the commercial scale boilers have been seldom studied by the experimental point of view. The data were obtained by varying the operational parameters of the boiler, that are the air excess and the secondary to primary air feeding ratio. Furthermore, the collected data were analyzed and the relationship between the thermal-chemical data and the control variables was discussed

biomass early stage combustion in a small size boiler experimental and numerical analysis

Abstract The increment in the world energy consumption and the necessity for a sustainable industrial production, indicate that renewable resources may be key actors for future development. In this scenario, biomass appears fundamental for the smooth transition from fossil fuels to lower carbon footprint technologies, and as a moderator agent within the renewable market. The small size biomass combustion application appears as suitable for smart grid and distributed generation applications, but it is necessary to improve the design tools capabilities and the experimental knowledge of these systems. The present work aims at investigating the thermal behaviour of a 140 kW fixed-bed boiler sited at the Biomass to Energy Research Centre (CRIBE) of the University of Pisa and fed with woodchips. Experimental activities were conducted in order to acquire thermal and chemical data. Moreover, a computational fluid dynamic model was developed and validated. Attention was paid to the fixed bed analysis, and the results showed a good model prediction capability, with respect to the reduced computational demand required

Rituximab in the treatment of patients with systemic sclerosis. Our experience and review of the literature

BACKGROUND: The treatment of systemic sclerosis (SSc) represents a great clinical challenge because of the complex disease pathogenesis including vascular, fibrotic, and immune T- and B-lymphocyte-mediated alterations. Therefore, SSc should be treated by combined or sequential therapies according to prevalent clinico-pathogenetic phenotypes. Some preliminary data suggest that rituximab (RTX) may downregulate the B-cell over expression and correlated immunological abnormalities. METHODS: Here, we describe a series of 10 SSc patients (4M and 6F, mean age 46±13.5SD years, mean disease duration 6.3±2.7SD years; 5 pts had limited and 5 diffuse SSc cutaneous subset) treated with one or more cycles of RTX (4 weekly infusions of 375mg/m(2)). The main indications to RTX were interstitial lung fibrosis, cutaneous, and/or articular manifestations unresponsive to previous therapies; ongoing treatments remained unchanged in all cases. The effects of RTX were evaluated after 6months of the first cycle and at the end of long-term follow-up period (37±21SD months, range 18-72months). An updated review of the world literature was also done. RESULTS: RTX significantly improved the extent of skin sclerosis in patients with diffuse SSc at 6months evaluation (modified Rodnan skin score from 25±4.3 to 17.2±4.6; p=.022). A clinical improvement of other cutaneous manifestations, namely hypermelanosis (7/7), pruritus (6/8), and calcinosis (3/6) was observed. Moreover, arthritis revealed particularly responsive to RTX showing a clear-cut reduction of swollen and tender joints in 7/8 patients; while lung fibrosis detected in 8/10 remained stable in 6/8 and worsened in 2/8 at the end of follow-up. Pro-inflammatory cytokines, namely IL6, IL15, IL17, and IL23, evaluated in 3 patients with diffuse cutaneous SSc, showed a more or less pronounced reduction after the first RTX cycle. These observations are in keeping with the majority of previous studies including 6 single case reports and 10 SSc series (from 5 to 43 pts), which frequently reported the beneficial effects of RTX on some SSc manifestations, particularly cutaneous sclerosis, along with the improvement/stabilization of lung fibrosis. Possible discrepancies among different clinical studies can be related to the etiopathogenetic complexity of SSc and not secondarily to the patients' selection and disease duration at the time of the study. CONCLUSION: The present study and previous clinical trials suggest a possible therapeutical role of RTX in SSc, along with its good safety profile. The specific activity of RTX on B-cell-driven autoimmunity might explain its beneficial effects on some particular SSc clinical symptoms, namely the improvement of skin and articular involvement, and possibly the attenuation of lung fibrosis

Therapeutic approach to bronchiolitis: why pediatricians continue to overprescribe drugs?

<p>Abstract</p> <p>Background</p> <p>Bronchiolitis guidelines suggest that neither bronchodilators nor corticosteroids, antiviral and antibacterial agents should be routinely used. Although recommendations, many clinicians persistently prescribe drugs for bronchiolitis.</p> <p>Aim of the study</p> <p>To unravel main reasons of pediatricians in prescribing drugs to infants with bronchiolitis, and to possibly correlate therapeutic choices to the severity of clinical presentation. Also possible influence of socially deprived condition on therapeutic choices is analyzed.</p> <p>Methods</p> <p>Patients admitted to Pediatric Division of 2 main Hospitals of Naples because of bronchiolitis in winter season 2008-2009 were prospectively analyzed. An RDAI (Respiratory Distress Assessment Instrument) score was assessed at different times from admission. Enrolment criteria were: age 1-12 months; 1^stlower respiratory infection with cough and rhinitis with/without fever, wheezing, crackles, tachypnea, use of accessory muscles, and/or nasal flaring, low oxygen saturation, cyanosis. Social deprivation status was assessed by evaluating school graduation level of the origin area of the patients. A specific questionnaire was submitted to clinicians to unravel reasons of their therapeutic behavior.</p> <p>Results</p> <p>Eighty-four children were enrolled in the study. Mean age was 3.5 months. Forty-four per cent of patients presented with increased respiratory rate, 70.2% with chest retractions, and 7.1% with low SaO2. Mean starting RDAI score was 8. Lung consolidation was found in 3.5% on chest roentgenogram. Data analysis also unraveled that 64.2% matched clinical admission criteria. Social deprivation status analysis revealed that 72.6% of patients were from areas "at social risk". Evaluation of length of stay vs. social deprivation status evidenced no difference between "at social risk" and "not at social risk" patients. Following therapeutic interventions were prescribed: nasal suction (64.2%), oxygen administration (7.1%), antibiotics (50%), corticosteroids (85.7%), bronchodilators (91.6%). Statistically significant association was not found for any used drug with neither RDAI score nor social deprivation status. The reasons of hospital pediatricians to prescribe drugs were mainly the perception of clinical severity of the disease, the clinical findings at chest examination, and the detection of some improvement after drug administration.</p> <p>Conclusions</p> <p>We strongly confirm the large use of drugs in bronchiolitis management by hospital pediatricians. Main reason of this wrong practice appears to be the fact that pediatricians recognize bronchiolitis as a severe condition, with consequent anxiety in curing so acutely ill children without drugs, and that sometimes they feel forced to prescribe drugs because of personal reassurance or parental pressure. We also found that social "at risk" condition represents a main reason for hospitalization, not correlated to clinical severity of the disease neither to drug prescription. Eventually, we suggest a "step-by-step" strategy to rich a more evidence based approach to bronchiolitis therapy, by adopting specific and shared resident guidelines.</p

Klebsiella pneumoniae infections in COVID-19 patients: a two-month retrospective analysis in an Italian hospital

Italy has experienced one of the harshest and earliest COVID-19 epidemics, with the number of patients infected that followed, from the end of February up to the end of March, an exponential trend [1]. Between the 6 March and the 2 May, 394 patients were confirmed positive for SARS-CoV-2 at the University Hospital of Rome Policlinico Umberto I (PUI) [2]. At the PUI, 5 COVID-19 devoted wards were organized, including two brand new ICUs, counting 32 dedicated to COVID-19 patients: the first was the old general ICU converted into a dedicated COVID-19 ICU, while the second was created in the spaces of four operating rooms (new ICU). In the period of this study, a total of 80 COVID-19-affected patients were hospitalized in the two ICUs at PUI. Among them, 65 patients were screened for carbapenemase producing Enterobacterales (CPE) colonization (Brilliance™ CRE medium plates, Oxoid LTD, Basingstoke, UK): 41 out of 47 SARS-CoV-2 patients hospitalised in the old ICU and 24 out of 33 in the new one. Carbapenemase-producing K. pneumoniae were detected in 14/41 patients (34%) only in the old ICU. No CPE were detected from rectal swabs tested in patients hospitalized in the new ICU. In the same period, 11 CPEs were identified from the 39 rectal swabs out of 48 SARS-CoV-2-negative patients (28%) hospitalized in the non-COVID-ICU of the same hospital. Seven COVID-19 patients developed CPE co-infection (5 bronchoalveolar lavages and 2 blood cultures tested positives for carbapenemase-producing K. pneumoniae), while in the non-COVID-19 ICU 7 bloodstream infections (BSIs) also occurred (Table 1). Symptomatic patients were successfully treated with ceftazidime-avibactam

The role of cross-over bypass graft in the treatment of acute ischaemia of the lower limb

Introduction. The Authors reports their experience with the use of femoro-femoral cross-over bypass graft in the management of acute lower limb ischaemia. Patients and methods. Fourteen femoro-femoral bypass graft were performed for acute lower limb ischaemia due to unilateral thrombosis of iliac and femoral artery in 8 cases, late unilateral occlusion of a branch of previous aortobifemoral bypass in 3 cases, acute thrombosis of abdominal aorta in 2 cases and in the last one for an injury of common iliac artery during urological procedure. In all the cases the operations were carried out under local anaesthesia and a subcutaneous bypass with “C” shape type configuration with 8 mm Dacron prosthesis were performed. The first and second year primary and secondary patency rates and limb salvage rates were evaluated. Results. One and two year patency rate was 83.3 (10/12) and 70% (7/10) respectively. Secondary patency rate and limb salvage rate was 91.6% (11/12) and 80% (8/10) respectively. A tight amputation had to performed in 3 failed reconstruction (3/12, 25%). Two patient died within 30 days after surgery from acute myocardial infarct. In 1 case infection occurred and re-do femorofemoral cross-over bypass with saphenous vein was carried out (8.3%). Conclusions. Cross-over bypass is an attractive technique, especially in case of acute ischemia because of its simplicity, low morbidity and mortality, and good long term results

Genome-based retrospective analysis of a Providencia stuartii outbreak in Rome, Italy. Broad spectrum IncC plasmids spread the NDM carbapenemase within the hospital

Providencia stuartii is a member of the Morganellaceae family, notorious for its intrinsic resistance to several antibiotics, including last-resort drugs such as colistin and tigecycline. Between February and March 2022, a four-patient outbreak sustained by P. stuartii occurred in a hospital in Rome. Phenotypic analyses defined these strains as eXtensively Drug-Resistant (XDR). Wholegenome sequencing was performed on the representative P. stuartii strains and resulted in fully closed genomes and plasmids. The genomes were highly related phylogenetically and encoded various virulence factors, including fimbrial clusters. The XDR phenotype was primarily driven by the presence of the (NDM)-N-bla- 1 metallo- beta-lactamase alongside the rmtC 16S rRNA methyltransferase, conferring resistance to most beta-lactams and every aminoglycoside, respectively. These genes were found on an IncC plasmid that was highly related to an NDM-IncC plasmid retrieved from a ST15 Klebsiella pneumoniae strain circulating in the same hospital two years earlier. Given its ability to acquire resistance plasmids and its intrinsic resistance mechanisms, P. stuartii is a formidable pathogen. The emergence of XDR P. stuartii strains poses a significant public health threat. It is essential to monitor the spread of these strains and develop new strategies for their control and treatment

The prevalence of hyper- and hypothyroidism in patients with ulcerative colitis

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Differential Toll like receptor expression in cystic fibrosis patients' airways during rhinovirus infection

Objectives: Since an inappropriate and sustained activation of TLRs may contribute to a chronic inflammatory response resulting in detrimental effects in cystic fibrosis (CF) patients, we sought to examine whether HRV infection might alter the respiratory expression of TLRs according to the microbiological status of CF patients. Methods: Respiratory samples were collected from the respiratory tract of CF patients (n = 294) over a period of 12 months. In addition to the usual microbiological investigation, HRV-RNA detection and typing were performed by RT-PCR and sequencing. HRV viral load and TLRs levels were measured by RT-Real Time PCR. Results: HRV-RNA was detected in 80 out of 515 respiratory samples (15.5%) with a similar rate in all age groups (0–10 years, 11–24 years, ≥ 25 years). Patients infected with different HRV A, B and C species exhibited higher levels of TLR2, TLR4 and TLR8 as compared to HRV negative patients. Moreover, the expression level of TLR2, TLR4 and TLR8 correlated with high level of HRV viral load. HRV positive patients co-colonized by Staphylococcus aureus or Pseudomonas aeruginosa showed also enhanced amounts of TLR2 and TLR2/4-mRNAs expression respectively. In the case of presence of both bacteria, TLR2, TLR4, TLR8 and TLR9 levels are elevated in positive HRV patients. Conclusions: TLRs, especially TLR2 and TLR4, increased in HRV positive CF individuals and varies according to the presence of S. aureus, P. aeruginosa and both bacteria

SARS-CoV-2 pre-exposure prophylaxis with tixagevimab/cilgavimab (AZD7442) provides protection in inborn errors of immunity with antibody defects: a real-world experience

Background: Preventive strategies against severe COVID-19 in Inborn Errors of Immunity (IEI) include bivalent vaccines, treatment with SARS-CoV-2 monoclonal antibodies (mAbs), early antiviral therapies, and pre-exposure prophylaxis (PrEP). Objective: To assess the effectiveness of the PrEP with tixagevimab/cilgavimab (AZD7442) in IEI with primary antibody defects during the COVID-19 Omicron wave. Methods: A six-month prospective study evaluated the SARS-CoV-2 infection rate and the COVID-19 severity in the AZD7442 group, in the no-AZD7442 group, and in a group of patients with a recent SARS-CoV-2 infection (&lt; three months). Spike-specific IgG levels were measured at regular intervals. Results: Six out of thirty-three patients (18%) and 54/170 patients (32%) became infected in the AZD7442 group and in the no-AZD7442 group, respectively. Within 90 days post-administration, the AZD7442 group was 85% less likely to be infected and 82% less likely to have a symptomatic disease than the no-AZD7442 group. This effect was lost thereafter. In the entire cohort, no mortality/hospitalisation was observed. The control group of 35 recently infected patients was 88% and 92% less likely to be infected than the AZD7442 and no-AZD7442 groups. Serum anti-Spike IgG reached the highest peak seven days post-AZD7442 PrEP then decreased, remaining over 1000 BAU/mL 180 days thereafter. Conclusion: In patients with IEI and antibody defects, AZD7442 prophylaxis had a transient protective effect, possibly lost possibly because of the appearance of new variants. However, PrEP with newer mAbs might still represent a feasible preventive strategy in the future in this population