Multi-phase simulation of infected respiratory cloud transmission in air

In the face of the increasing death toll of the COVID-19 global pandemic, countries around the world have instituted restrictive measures to mitigate the serious effects of the pandemic. Human-to-human transmission of COVID-19 occurs primarily through large droplets that are expelled with sufficient momentum to come in direct contact with the recipients' mouth. Therefore, the physics of flow is central to transmission of COVID-19. Respiratory infections increase the frequency of violent expiration, including coughing and sneezing that are particularly effective in dispersing virus-carrying droplets. Moreover, the high viral load in droplets of asymptomatic hosts that are expelled during respiratory activities is contributing to the rapid growth of the COVID-19 global pandemic. The present study uses 2D smoothed-particle-hydrodynamics multi-phase simulations of the fluid dynamics of violent expiratory events in order to obtain a deeper understanding of the multi-phase nature of respiratory clouds, which can help determine separation distances from an infected person needed to minimize respiratory transmission. Our results indicate that there are three phases of jet cloud flow: the first is dominated by no-buoyancy jet-like dynamics characterized by a high speed, the second is dominated by negative buoyancy, and the third is dominated by gravity that deflects the cloud downward. Moreover, two modes of jet behavior that differ in dilution have been identified to be a function of distance from the human mouth. This work is of direct relevance to studies on the spread of COVID-19 and similar outbreaks in the future

Percutaneous collagen induction: An effective and safe treatment for post-acne scarring in different skin phototypes

Background: Atrophic scars can complicate moderate and severe acne. There are, at present, several modalities of treatment with different results. Percutaneous collagen induction (PCI) has recently been proposed as a simple and effective therapeutic option for the management of atrophic scars. Objective:The aim of our study was to analyze the efficacy and safety of percutaneous collagen induction for the treatment of acne scarring in different skin phototypes. Methods & materials: A total of 60 patients of skin types phototype I to VI were included in the study. They were divided into three groups before beginning treatment: Group A (phototypes I to II), Group B (phototypes III to V), and Group C (phototypes VI). Each patient had three treatments at monthly intervals. The aesthetic improvement was evaluated by using a Global Aesthetic Improvement Scale (GAIS), and analyzed statistically by computerized image analysis of the patients' photographs. The differences in the GAIS scores in the different time-points of each group were found using the Wilcoxon's test for nonparametric-dependent continuous variables. Computerized image analysis of silicone replicas was used to quantify the irregularity of the surface micro-relief with Fast Fourier Transformation (FFT); average values of gray were obtained along the x- and y-axes. The calculated indexes were the integrals of areas arising from the distribution of pixels along the axes. Results:All patients completed the study. The Wilcoxon's test for nonparametric-dependent continuous variables showed a statistically significant (p < 0.05) reduction in severity grade of acne scars at T5 compared to baseline (T1). The analysis of the surface micro-relief performed on skin replicas showed a decrease in the degree of irregularity of skin texture in all three groups of patients, with an average reduction of 31% in both axes after three sessions. No short- or long-term dyschromia was observed. Conclusion: PCI offers a simple and safe modality to improve the appearance of acne scars without risk of dyspigmentation in patient of all skin types. © 2014 Informa Healthcare USA on behalf of Informa UK Ltd

Workers’ Aging Management—Human Fatigue at Work: An Experimental Offices Study

The aging issue in the work context is becoming a significant element of the future sustainability of service and industrial companies. It is well known that with increasing worker age the problem of maintaining the performance and the safety level when fatigue increases is a crucial point, and fatigue increases with the age. Due to social and political developments, especially in Western countries, the retirement age is increasing and companies operate with a higher workforce mean age. Therefore, the problem of recognizing and measuring fatigue has become a key aspect in the management of aging. Note that in the scientific engineering field, the problem of fatigue evaluation when a worker is performing his/her work activities is an important issue in the industrial and service world and especially in the context of the researchers that are investigating the human reliability assessment. As it is clear from the literature, the industrial operations management are suffering from some misleading concepts that only the medicine scientific context can clarify. Therefore, the aim of this paper is to define what are the open issues and the misleading concepts present in the classical fatigue evaluation methods, and second to define two experimental curves of fatigue that will help the decision makers to minimize the impact of fatigue on the workers, thus maximizing the sustainability of the working tasks assigned. This aim is achieved by examining the medical literature about the measurement of a particular kind of fatigue related to the circadian cycle, i.e., the cognitive one; after that, a survey about the possible technologies for measurements is performed. On the basis of technology selection, an experiment on real work activities is performed and some remarkable results about the fatigue in the workers observed and the technology use and its limitations are defined

A dietary supplement to reduce side effects of oral isotretinoin therapy in acne patients.

AIM: The purpose of the study was to analyze the potential capacity of a dietary supplement, based on gamma linolenic acid, vitamin E, vitamin C, beta-carotene, coenzyme Q10 and Vitis Vitifera, to reduce side effects, in particular the dry skin, erythema and desquamation, due to treatment with oral isotretinoin, and evaluate the ability of the product to increase adherence to therapy in patients with acne. METHODS: Forty-eight patients with nodular acne (32 females and 16 males) were randomly divided into 2 groups: 24 receveid isotretinoin therapy (20-30 mg/day) for 6 months associated to dietary supplement (twice a day), while the other 24 patients received only isotretinoin (20-30 mg/day) for 6 months. For all patients the degree of acne severity, through GAGS (Global Acne Grading System), the sebum production by Sebutape, the hydration by Corneometer and the erythema by Mexameter, were measured. We have also evaluated the adherence to treatment, asking to patients how many days a week they follow the therapy. RERSULTS: Patients treated with dietary supplement had lower side effects, with a less degree of erythema and dryness, and greater degree of hydration; a greater adherence to therapy was also reported. CONCLUSION: Thanks to antioxidant and moisturizing properties, the dietary supplement containing gamma linolenic acid, vitamin E, vitamin C, betacarotene, coenzyme Q10 and Vitis Vitifera, can be considered a useful supplement in the treatment and prevention of dry skin associated with the use of oral isotretinoin