A novel lab-scale batch foaming equipment: The mini-batch

In this paper, we report the design of a new experimental apparatus for the study of the foaming process of thermoplastic polymers with physical blowing agents. The novel lab-scale batch foaming equipment is capable of achieving accurate control of the processing variables, namely, the temperature, the saturation pressure and the pressure drop rate and, furthermore, of allowing the achievement of very high pressure drop rates, the observation of the sample while foaming and the very fast extraction of the foamed sample. By recalling the considerations discussed by Muratani et al. ( J Cell Plast 2005; 24: 15), the design converged into a simple, cheap, and very small pressure vessel, thereby denoted as mini-batch. We herein describe the overall design path of the mini-batch, its characteristics, configurations, together with some examples of use with polystyrene and CO2 as the blowing agent.

Serum resistin levels in children with primary snoring

Primary Snoring (PS) has been positioned at the milder end of the Sleep-Disordered Breathing severity continuum characterized by snoring and it is usually underestimated. PS is defined as snoring without apnea, frequent arousals, or gas exchange abnormalities and recent studies demonstrated that children with PS have increased blood pressure and reduced arterial distensibility. The association between adipokines and SDB has been recently investigated, though most of the studies were focused on OSAS where intermittent hypoxia characterizing the disease may lead to an inflammatory cascade and to the release of several adipokines, contributing to oxidative stress. Resistin, initially described s an adipokine increasing insulin resistance, has been recently identified as a novel important member of the cytokine family involved in the regulation of inflammation. The aim of our study was to investigate circulating resistin levels in normal weight children with PS. Sixty-five children of normal weight aged between 4 and 14 years of age were selected for habitual snoring. Children with positive polysomnography were excluded from the study. Serum resistin levels were detected in all children with PS. Thirty-three healthy non-snorer children with similar age, sex and BMI were selected as a control group. A significantly higher level of resistin was observed in patients with PS compared to the control group (4.67±1.91 ng/ml vs 3.98±1.58 ng/ml; p<0.01). Patients with inconclusive pulse oximetry showed significantly higher resistin levels than those with negative recordings recordings (5.29±1.91 ng/ml vs 4.20±1.93 ng/ml; p<0.008). Moreover, there was a significant increasing trend between sieric adipokine level and the frequency of snoring (p<0.006). Our results suggest that systemic inflammation and oxidative stress may also play a significant role in the pathophysiology of PS.

The role of rhinomanometry after nasal decongestant test in the assessment of adenoid hypertrophy in children

INTRODUCTION

Nasal respiratory obstruction is a very common otolaryngologic problem, often caused by adenoid hypertrophy (AH). Nasal fiberoptic endoscopy (NFE) represents the gold standard method to diagnose AH. Rhinomanometry represents a valid diagnostic support.

OBJECTIVE

The aim of our study was to analyze the diagnostic value of rhinomanometry after nasal decongestant (ND) test for the evaluation of adenoid hypertrophy in children.

MATERIALS AND METHODS

Seventy-one of 97 collaborative children, aged 6-12 years, affected by upper airways obstructive symptoms and diagnosed as 'chronic oral breathers' by a standardized questionnaire were included in the study. The first evaluation included a complete physical examination, anterior rhinoscopy and anterior active rhinomanometry. Patients with a positive rhinomanometry underwent a second rhinomanometry after the administration of the nasal decongestant (ND) xylometazoline. All children were evaluated using nasal fiberoptic endoscopy (NFE).

RESULTS

At rhinomanometry a normal nasal airflow was found in 19 (26.8%) of children while nasal obstruction was underlined in 52 (73.2%). These patients were tested also with rhinomanometry after ND which confirmed the presence of nasal obstruction in 29 (55.7%) of patients. All patients included in the study underwent a NFE: 34 (47.8%) of them presented severe AH with an occlusion >75% of the choanal opening (grade ≥ 3) and 37 (52.2%) presented no or a mild form of AH (grade < 3). When compared to NFE, rhinomanometry test after ND had 82.7% sensitivity and 82.6% specificity. Positive predictive value and negative predictive value were 85.7% and 79.2%, respectively. Two receiver operating characteristic (ROC) curves were derived using data related to rhinomanometry vs NFE, and to rhinomanometry after ND vs NFE.

CONCLUSIONS

Rhinomanometry after ND, compared to rhinomanometry, is more specific and useful to evaluate nasal obstruction due to AH in children, and it may be helpful to avoid unnecessary surgical procedures in children with temporary nasal obstruction.