7 research outputs found
Micro-milling Machinability of DED Additive Titanium Ti-6Al-4V
This work investigates the micro-milling machinability of Ti-6Al-4V alloy produced by a Laser Engineered Net Shaping (LENS) additive manufacturing (AM) process with a specific focus on surface quality, cutting forces and burr formation. The effects of additive deposition parameters are also investigated since the material thermal history during processing can affect porosity and mechanical behavior of the samples, giving different milling performances. The material characterization of samples is done through micrographies, hardness tests and porosity evaluation. The roughness of the machined surfaces shows a statistical distinction between the AM and wrought titanium samples. Similar behavior is seen with the cutting forces, which increase with an increase of hardness of the AM samples. The results also show an increased trend towards burr formation in case of down milling of AM samples compared to wrought titanium samples. The future prospective is to take into account the machinability properties as functional material characteristics to optimize through the deposition process
Characterizing non-tuberculous mycobacteria infection in bronchiectasis
Chronic airway infection is a key aspect of the pathogenesis of bronchiectasis. A growing interest has been raised on non-tuberculous mycobacteria (NTM) infection. We aimed at describing the clinical characteristics, diagnostic process, therapeutic options and outcomes of bronchiectasis patients with pulmonary NTM (pNTM) disease. This was a prospective, observational study enrolling 261 adult bronchiectasis patients during the stable state at the San Gerardo Hospital, Monza, Italy, from 2012 to 2015. Three groups were identified: pNTM disease; chronic P. aeruginosa infection; chronic infection due to bacteria other than P. aeruginosa. NTM were isolated in 32 (12%) patients, and among them, a diagnosis of pNTM disease was reached in 23 cases. When compared to chronic P. aeruginosa infection, patients with pNTM were more likely to have cylindrical bronchiectasis and a “tree-in-bud” pattern, a history of weight loss, a lower disease severity and a lower number of pulmonary exacerbations. Among pNTM patients who started treatment, 68% showed a radiological improvement, and 37% achieved culture conversion without recurrence, while 21% showed NTM isolation recurrence. NTM isolation seems to be a frequent event in bronchiectasis patients, and few parameters might help to suspect NTM infection. Treatment indications and monitoring still remain an important area for future research
Serum cholesterol levels, HMG-CoA reductase inhibitors and the risk of intracerebral haemorrhage. the Multicenter Study on Cerebral Haemorrhage in Italy (MUCH-Italy)
Nontuberculous Mycobacteria in Noncystic Fibrosis Bronchiectasis
During the past decades, a growing interest has been raised in evaluating nontuberculous mycobacteria (NTM) in patients with noncystic fibrosis bronchiectasis (NCFBE). This paper reviews several aspects of the correlations between NTM and NCFBE, including pathogenesis, radiological features, diagnosis, and management. Bronchiectasis and NTM lung disease are connected, but which one comes first is still an unresolved question. The rate of NTM lung disease in NCFBE varies through the studies, from 5% to 30%. The most frequent species isolated is MAC. NCFBE patients affected by NTM infection frequently present coinfections, including both other different NTM species and microorganisms, such as P. aeruginosa. Once a diagnosis of NTM disease has been reached, the initiation of therapy is not always mandatory. NTM species isolated, patients’ conditions, and disease severity and its evolution should be considered. Risk factors for disease progression in NCFBE patients with NTM are low body mass index, cavitary disease, consolidations, and macrolide resistance at presentation
The Role of Lung Ultrasound Monitoring in Early Detection of Ventilator-Associated Pneumonia in COVID-19 Patients: A Retrospective Observational Study
Specific lung ultrasound signs combined with clinical parameters allow for early diagnosis of ventilator-associated pneumonia in the general ICU population. This retrospective cohort study aimed to determine the accuracy of lung ultrasound monitoring for ventilator-associated pneumonia diagnosis in COVID-19 patients. Clinical (i.e., clinical pulmonary infection score) and ultrasound (i.e., presence of consolidation and a dynamic linear–arborescent air bronchogram, lung ultrasound score, ventilator-associated lung ultrasound score) data were collected on the day of the microbiological sample (pneumonia-day) and 48 h before (baseline) on 55 bronchoalveolar lavages of 33 mechanically-ventilated COVID-19 patients who were monitored daily with lung ultrasounds. A total of 26 samples in 23 patients were positive for ventilator-associated pneumonia (pneumonia cases). The onset of a dynamic linear–arborescent air bronchogram was 100% specific for ventilator-associated pneumonia. The ventilator-associated lung ultrasound score was higher in pneumonia-cases (2.5 (IQR 1.0 to 4.0) vs. 1.0 (IQR 1.0 to 1.0); p < 0.001); the lung ultrasound score increased from baseline in pneumonia-cases only (3.5 (IQR 2.0 to 6.0) vs. −1.0 (IQR −2.0 to 1.0); p = 0.0001). The area under the curve for clinical parameters, ventilator-associated pneumonia lung ultrasound score, and lung ultrasound score variations were 0.472, 0.716, and 0.800, respectively. A newly appeared dynamic linear–arborescent air bronchogram is highly specific for ventilator-associated pneumonia in COVID-19 patients. A high ventilator-associated pneumonia lung ultrasound score (or an increase in the lung ultrasound score) orients to ventilator-associated pneumonia
Propensity Score-Based Analysis of Percutaneous Closure Versus Medical Therapy in Patients with Cryptogenic Stroke and Patent Foramen Ovale: The IPSYS Registry (Italian Project on Stroke in Young Adults)
Background-We sought to compare the benefit of percutaneous closure to that of medical therapy alone for the secondary prevention of embolism in patients with patent foramen ovale (PFO) and otherwise unexplained ischemic stroke, in a propensity scored study. Methods and Results-Between 2000 and 2012, we selected consecutive first-ever ischemic stroke patients aged 18 to 45 years with PFO and no other cause of brain ischemia, as part of the IPSYS registry (Italian Project on Stroke in Young Adults), who underwent either percutaneous PFO closure or medical therapy for comparative analysis. Primary end point was a composite of ischemic stroke, transient ischemic attack, or peripheral embolism. Secondary end point was brain ischemia. Five hundred and twenty-one patients qualified for the analysis. The primary end point occurred in 15 patients treated with percutaneous PFO closure (7.3%) versus 33 patients medically treated (10.5%; hazard ratio, 0.72; 95% confidence interval, 0.39-1.32; P=0.285). The rates of the secondary end point brain ischemia were also similar in the 2 treatment groups (6.3% in the PFO closure group versus 10.2% in the medically treated group; hazard ratio, 0.64; 95% confidence interval, 0.33-1.21; P=0.168). Closure provided a benefit in patients aged 18 to 36 years (hazard ratio, 0.19; 95% confidence interval, 0.04-0.81; P=0.026) and in those with a substantial right-to-left shunt size (hazard ratio, 0.19; 95% confidence interval, 0.05-0.68; P=0.011). Conclusions-PFO closure seems as effective as medical therapy for secondary prevention of cryptogenic ischemic stroke. Whether device treatment might be more effective in selected cases, such as in patients younger than 37 years and in those with a substantial right-to-left shunt size, deserves further investigation