One year of surgical mask testing at the University of Bologna labs: Lessons learned from data analysis.

The outbreak of SARS-CoV-2 pandemic highlighted the worldwide lack of surgical masks and personal protective equipment, which represent the main defense available against respiratory diseases as COVID-19. At the time, masks shortage was dramatic in Italy, the first European country seriously hit by the pandemic: aiming to address the emergency and to support the Italian industrial reconversion to the production of surgical masks, a multidisciplinary team of the University of Bologna organized a laboratory to test surgical masks according to European regulations. The group, driven by the expertise of chemical engineers, microbiologists, and occupational physicians, set-up the test lines to perform all the functional tests required. The laboratory started its activity on late March 2020, and as of the end of December of the same year 435 surgical mask prototypes were tested, with only 42 masks compliant to the European standard. From the analysis of the materials used, as well as of the production methods, it was found that a compliant surgical mask is most likely composed of three layers, a central meltblown filtration layer and two external spunbond comfort layers. An increase in the material thickness (grammage), or in the number of layers, does not improve the filtration efficiency, but leads to poor breathability, indicating that filtration depends not only on pure size exclusion, but other mechanisms are taking place (driven by electrostatic charge). The study critically reviewed the European standard procedures, identifying the weak aspects; among the others, the control of aerosol droplet size during the bacterial filtration test results to be crucial, since it can change the classification of a mask when its performance lies near to the limiting values of 95 or 98%.

Biomimetic graphene for enhanced interaction with the external membrane of astrocytes.

Graphene and graphene substrates display huge potential as material interfaces for devices and biomedical tools targeting the modulation or recovery of brain functionality. However, to be considered reliable neural interfaces, graphene-derived substrates should properly interact with astrocytes, favoring their growth and avoiding adverse gliotic reactions. Indeed, astrocytes are the most abundant cells in the human brain and they have a crucial physiological role to maintain its homeostasis and modulate synaptic transmission. In this work, we describe a new strategy based on the chemical modification of graphene oxide (GO) with a synthetic phospholipid (PL) to improve interaction of GO with brain astroglial cells. The PL moieties were grafted on GO sheets through polymeric brushes obtained by atom-transfer radical-polymerization (ATRP) between acryloyl-modified PL and GO nanosheets modified with a bromide initiator. The adhesion of primary rat cortical astrocytes on GO-PL substrates increased by about three times with respect to that on glass substrates coated with standard adhesion agents (i.e. poly-d-lysine, PDL) as well as with respect to that on non-functionalized GO. Moreover, we show that astrocytes seeded on GO-PL did not display significant gliotic reactivity, indicating that the material interface did not cause a detrimental inflammatory reaction when interacting with astroglial cells. Our results indicate that the reported biomimetic approach could be applied to neural prosthesis to improve cell colonization and avoid glial scar formation in brain implants. Additionally, improved adhesion could be extremely relevant in devices targeting neural cell sensing/modulation of physiological activity.

Prospective validation of a new priority allocation model for liver transplant candidates: an interim analysis.

BACKGROUND: The system that controls the waiting list (WL) and organ allocation for liver transplantation (OLT) seeks to achieve 3 main goals: objectivity, low dropout risks and good post-OLT results. We sought to prospectively validate a priority allocation model that is believed to achieve objectivity without penalizing dropout risk and post-OLT results. METHODS: We evaluated a study group of 272 patients enrolled in 2006-2007. WL candidates were divided into 2 categories: cirrhotic patients classified according to Model for End-Stage Liver Disease (MELD) score (MELD list and patients with hepatocellular carcinoma (HCC) organized according to a specific score (non-MELD list). The allocation algorithm for donor-recipient match assigned an optimal graft to the first MELD candidate with a MELD score of >or=20; a suboptimal graft, to the first non-MELD patient. A respective control group of 327 patients transplanted from 2003-2006 was characterized by a unique WL with a free allocation policy. We performed an interim analysis of this prospectively controlled study. RESULTS: Although the study group showed a lower percentage of OLT (P < .05) than the control group (37% vs 45%), it selected patients for OLT based on a higher MELD score (P < .05), thus obtaining similar dropout, post-OLT survivals, and intention-to-treat (ITT) survival probabilities as the controls. Among MELD patients, we observed a significantly reduced dropout and better ITT survival profiles than those of the control group (P = .02), whereas the similar results were delivered among non-MELD patients (P > .05). Among patients with a MELD score of >or=20, the prevalences of suboptimal grafts (0% vs 48%) and of early graft losses (0% vs 21%) were lower in the study than in the control group (P < .05). CONCLUSIONS: We prospectively validated a priority allocation model based on objective criteria that achieved high ITT survival rates.

Validation of the BCLC prognostic system in surgical hepatocellular cancer patients.

BACKGROUND/AIM: Prognosis assessment in surgical patients with hepatocellular carcinoma (HCC) remains controversial. The most widely used HCC prognostic tool is the Barcelona Clinic Liver Cancer (BCLC) classification, but its prognostic ability in surgical patients has not been yet validated. The aim of this study was to investigate the value of known prognostic systems in 400 Italian HCC patients treated with radical surgical therapies. METHODS: We analyzed a prospective database collection (400 surgical, 315 nonsurgical patients) observed at a single institution from 2000 and 2007. By using survival times as the only outcome measure (Kaplan-Meier method and Cox regression), the performance of the BCLC classification was compared with that of Okuda, Cancer of the Liver Italian Program, United Network for Organ sharing TNM, and Japan Integrated Staging Score staging systems. RESULTS: Two hundred twenty-five patients underwent laparotomy resection; 55, laparoscopic procedures (ablation and/or resection); and 120, liver transplantations. In the surgical group, BCLC proved the best HCC prognostic system. Three-year survival rates of patients in BCLC Stages A, B, and C were 81%, 56%, and 44% respectively, (P < .01); whereas all other tested staging systems did not show significant stratification ability. When all 715 HCC patients were considered, surgery proved to be a significant survival predictor in each BCLC stage (A, B, and C). CONCLUSIONS: BCLC staging showed the best interpretation of the survival distribution in a surgical HCC population. The BCLC treatment algorithm should consider the role of surgery also for intermediate-advanced stages of liver disease.

Effect of alcohol consumption versus abstinence on 24-h blood pressure profile in normotensive alcoholic patients.

The aim of this study was to evaluate 24-h ambulatory blood pressure monitoring in 15 male alcoholic normotensive subjects during alcohol consumption and following an abstinence phase and the effects of alcohol consumption compared with a period of 1 week of abstinence. The average 24-h BP was not different, but the diurnal pattern showed a fall in systolic BP early (06:00 to noon; P < .005) and late (18:00 to 22:00; P < .002) in the day during abstinence. BP variability was increased during the alcohol phase (P < .05). This study showed that 1 week of abstinence does not influence 24-h BP levels in normotensive subjects, but alters the diurnal pattern, characterized by a fall in systolic BP and increased BP variability.

Physical exercise and hypertension. New insights and clinical implications.

In the last few years, the role of habitual physical activity in blood pressure regulation and in the prevention and treatment of mild hypertension has stimulated general interest. Both experimental and observational studies seem to show that physical exercise has a lowering effect on blood pressure. Some longitudinal training studies supplied data regarding the possibility of using physical training in the treatment of hypertensive patients. The mechanisms responsible for lower blood pressure induced by physical training are still unknown; however, the benefits from physical training last only as long as individuals continue to engage in regular physical activity.

Blood pressure and isometric exercise. Correlation with anthropometric data and electrolyte urinary excretion in two groups of trained and untrained young men.

Blood pressure (BP) and heart rate (HR) at rest and at the third minute of hand grip exercise (HG), body weight (W), height (H), body index (BI), triceps skinfold (TS), arm circumference (AC), and 24-hour excretion of Na, K, and creatinine were measured in two groups of 50 males 18 to 21 years of age. The subjects were divided in two groups depending on their physical activity. Group 1 included 50 trained subjects who had been regularly engaging in dynamic exercise for at least one month (four one-hour sessions a week); Group 2 included 50 untrained subjects. In Group 1 there was no significant correlation among systolic blood pressure (SBP) and anthropometric data at rest, but it was significantly correlated during HG with W, H, BI, and AC. In Group 2, SBP was significantly correlated only with W and BI at rest, with W, H, BI, and AC during HG. Diastolic blood pressure (DBP) was well correlated, both at rest and during HG, with anthropometric data in both groups studied. No correlation was found between BP and urinary excretion of electrolytes. The BP values appeared to be slightly lower in Group 1 than the ones in Group 2, both at rest and during HG (P less than .05). No significant difference was found in any of the other parameters considered. Our data seem to confirm that regular physical exercise may have a moderate lowering effect on BP both at rest and during exercise; this is independent of any concomitant weight loss.(ABSTRACT TRUNCATED AT 250 WORDS)

Anthropometric data, urinary sodium excretion, and isometric exercise in epidemiological study of arterial hypertension.

Relationships between cardiovascular response to isometric exercise, anthropometric data, and urinary sodium excretion were examined a group of 80 young males aged 19.7 +/- 1.3 years. Diastolic blood pressure (DBP) was well correlated with the anthropometric data both at rest and during hand grip (HG). During hand grip even the systolic blood pressure (SBP) was correlated with height, arm circumference, body weight, and body index. There was no significant correlation between urinary excretion of sodium and BP. The correlation between SBP and some anthropometric measures found during hand grip but not at rest suggests that the sympathetic nervous system may play a role in determining a relationship between excessive body weight and blood pressure increase.

Anthropometric data, urinary electrolytes excretion, and blood pressure in adolescents.

Relationships between arterial pressure, age, sex, anthropometric measurements, body fat, and urinary excretion of electrolytes were examined in a group of 120 adolescents from 11 to 14 years of age. Body weight and triceps skinfold thickness are two variables that have the highest correlation with arterial pressure levels, especially among girls. Only a slight correlation was found between urinary excretion of sodium and arterial hypertension. The apparent contradiction between positive correlation of fat percent and arterial pressure and the negative correlation between urinary excretion of sodium and arterial pressure can possibly be explained by the low sodium content of the diet of the subjects studied. Their typical Mediterranean diet was abundant in fresh food, mainly based on carbohydrates (macaroni, bread, vegetables), rather than conserved foods in which salt plays an important role in the conservation process (butter, bacon, salad, etc.), typical of the continental diet.