Numerical investigation of heat transfer in a garment convective cooling system

A personal microclimate management system is designed to maintain thermal comfort which allows people to overcome a harsh environment. It consists of several micro-fans placed in the garment side seam to provide cooling air. The computational fluid dynamics method was used to simulate the three-dimensional model and analysis the influence of fan’s number and air gap distance. The obtained results depict that the introduced cool airflow will find its way along paths with flow resistance minimized and exhaust through several separated exit. The body heat flux is taken away at the same time. The convection effect is enhanced by the increase in the fans’ numbers, but the fans’ cooling effect varies a lot because of various air gap distances. When the air gap is small enough, the cooling air impact the body surface directly and causes fierce heat loss. While the air gap distance is large enough, the heat transfer along the skin surface could be enhanced by the eddy flow which is existed in the air gap between body and garment. These phenomena can maintain the body’s thermal comfort in a suitable range.

Patient Specific Numerical Modeling for Renal Blood Monitoring Using Electrical Bio-Impedance

Knowledge of renal blood circulation is considered as an important physiological value, particularly for fast detection of acute allograft rejection as well as the management of critically ill patients with acute renal failure. The electrical impedance signal obtained from kidney with an appropriate electrode system and optimal electrode system position regarding to the kidney projection on skin surface reflects the nature of renal blood circulation and tone of renal blood vessels. This paper proposes a specific numerical modelling based on prior information from MRI-data. The numerical modelling was conducted for electrical impedance change estimation due to renal blood distribution. The proposed model takes into the account the geometrical and electrophysiological parameters of tissues around the kidney as well as the actual blood distribution within the kidney. The numerical modelling had shown that it is possible to register the electrical impedance signal caused by renal blood circulation with an electrode system commensurate with the size of kidney, which makes it possible to reduce the influence of surrounding tissues and organs. Experimental studies were obtained to prove the numerical modelling and the effectiveness of developed electrode systems based on the obtained simulation results. The obtained electrical impedance signal with the appropriate electrode system shows very good agreement with the renal blood change estimated using Doppler ultrasound. For the measured electrical impedance signal, it is possible to obtain the amplitude-time parameters, which reflect the hemodynamic characteristics of the kidneys and used in diagnostics, which is the subject of further research.

Sequential Use of CO2 Laser Prior to Nd:YAG and Dye Laser in the Management of Non-Facial Warts: A Retrospective Study

Background and Objectives: Warts are benign lesions of viral etiology characterized by a hyperkeratotic appearance tending to spread across the skin surface. Various treatments have been proposed to manage this condition, such as acids, imiquimod, photodynamic therapy, cryotherapy, and various lasers. Materials and Methods: In this paper, we describe a combination protocol using CO2 laser prior to Nd:YAG laser for lesions interesting the palmoplantar areas or dye laser for lesions on other skin surfaces in the management of non-facial warts resistant to traditional therapies. In total, 34 patients with 103 warts suffering from wart infection resistant to traditional therapies treated from 1 January 2019 to 1 June 2020 were retrospectively enrolled at the Dermatological Unit of Magna Graecia University (Catanzaro, Italy). Two dermatologists measured clinical results, classifying lesions with complete resolution, partial resolution, or non-responding. Patients at four months follow-up were asked to evaluate their degree of satisfaction with a visual analog scale (VAS). Results: Almost all patients reported the complete resolution of lesions, with no patient reporting scarring. Five patients reported hypopigmentation in the treated areas. The mean satisfaction level was high. Only three patients experienced a relapse of the condition. Conclusions: Using a vascular laser following a CO2 superficial ablation of warts may help reduce the risk of scarring and decrease the incidence of relapses for lesions resistant to traditional therapies. Therefore, more extensive studies will be necessary to confirm the obtained results.

Microneedling Radiofrequency for Acne Vulgaris and Post-Acne Scarring: A Case Report

Background: There are various therapeutic modalities for acne and post acne scarring, but the best option is to have a safe, effective with affordable cost such as monotherapy or combination therapy. One of the recommended combination therapy for acne vulgaris with atrophic acne scars is microneedling radiofrequency which can improve skin structure. Case report: A 25 year old male with moderate comedonal acne vulgaris and severe scarring. The patient came with complaints of uneven skin surface on both cheeks, forehead and chin which had been felt to increase since 3 years ago. The appearance of acne on the face has been felt since 12 years ago. The patient's parents and sister also had acne complaints. On dermatological examination, on the forehead, temples, cheeks, nose and chin found blackheads, whiteheads, papules, hyperpigmented macules, multiple atrophic acne scars. The treatment choice for this patient is microneedling radiofrequency in combination with topical therapy. Discussion: The combination of microneedling with radiofrequency is one of the therapeutic modalities for acne vulgaris and also post-acne scarring with minimal side effects. In the evaluation for 2 weeks after the procedure, this patient did not complaint of any adverse events.

Relationship Between Keloid Pathogenesis and Endothelial Progenitor Cells: A Review Study

Context: Keloid scars are disfiguring lesions (ie, reddish-brown bulges on the skin surface) formed after a minor injury or surgical invasion. They lead to severe itching or pain, thereby causing physical and psychological distress in patients. Evidence Acquisition: Scholarly databases, including Web of Science, PubMed, and Google Scholar, were searched for relevant articles using keywords such as “keloids,” “endothelial progenitor cells” (EPCs), and “CD34-positive cells.” Results: Keloid scars are classified as an intractable disease; their cause is unknown, and there is no specific therapy. Their pathogenic effects on inflammation around wounds and fibroblasts have been extensively studied. However, details regarding their onset mechanism and definitive factors that contribute to their formation have not yet been elucidated. Adult stem cell therapy, especially regenerative therapy aimed at recovering tissue structure and function, has been extensively studied globally. In our recently published study, we identified an association between keloid scar development and EPCs. However, there is still no systematic review in this regard. Conclusions: This paper provides information on preventing keloids and further understanding the cause of this disease by reviewing previous studies on the association between keloids and EPCs.

Superficial Peroneal Neuromodulation of Nonobstructive Urinary Retention Induced by Prolonged Pudendal Afferent Activity in Cats

The purpose of this study is to determine if superficial peroneal nerve stimulation (SPNS) can improve nonobstructive urinary retention (NOUR) induced by prolonged pudendal nerve stimulation (PNS). In this exploratory acute study using 8 cats under anesthesia, PNS and SPNS were applied by nerve cuff electrodes. Skin surface electrodes were also used for SPNS. A double lumen catheter was inserted via the bladder dome for bladder infusion and pressure measurement and to allow voiding without a physical urethral outlet obstruction. The voided and postvoid residual (PVR) volumes were also recorded. NOUR induced by repetitive (4-13 times) application of 30-min PNS significantly (p<0.05) reduced voiding efficiency by 49.5±16.8% of control (78.3±7.9%) with a large PVR volume at 208.2±82.6% of control bladder capacity. SPNS (1 Hz, 0.2 ms) at 1.5 to 2 times threshold intensity (T) for inducing posterior thigh muscle contractions was applied either continuously (SPNSc) or intermittently (SPNSi) during cystometrograms to improve the PNS-induced NOUR. SPNSc and SPNSi applied by nerve cuff electrodes significantly (p<0.05) increased voiding efficiency to 74.5±18.9% and 67.0±15.3%, respectively, and reduced PVR volume to 54.5±39.0% and 88.3±56.0%, respectively. SPNSc and SPNSi applied non-invasively by skin surface electrodes also improved NOUR similar to the stimulation applied by a cuff electrode. This study indicates that abnormal pudendal afferent activity could be a pathophysiological cause for the NOUR occurring in Fowler's syndrome and a noninvasive superficial peroneal neuromodulation therapy might be developed to treat NOUR in patients with Fowler's syndrome.

Estimating the Postmortem Interval of Carcasses in the Water Using the Carrion Insect, Brain Tissue RNA, Bacterial Biofilm, and Algae

The accurate estimation of postmortem interval (PMI) is crucial in the investigation of homicide cases. Unlike carcasses on land, various biological and abiotic factors affect the decomposition of carcasses in water. In addition, the insect evidence (e.g., blow flies) that is commonly used to estimate the PMI are unavailable before the carcasses float on water. Therefore, it is difficult to estimate the PMI of a carcass in water. This study aimed to explore an effective way of estimating the PMI of a carcass in water. Carrion insects, brain tissue RNA, bacterial biofilm on the skin surface, and algae in water with PMI were studied using 45 rat carcasses in a small river. The results showed that carrion insects might not be suitable for the estimation of PMI of a carcass in water since they do not have a regular succession pattern as a carcass on land, and the flies only colonized six of the carcasses. The target genes (β-actin, GAPDH, and 18S) in the brain tissue were associated with the PMI in a time-dependent manner within 1 week after death. A polynomial regression analysis was used to assess the relationship between the gene expression profiles and PMI. The correlation coefficient R2 of each regression equation was ≥ 0.924. A third-generation sequencing analysis showed that the bacteria on the skin surface of the carcass and the algae in the water samples around the carcass had a regular succession pattern, where Cryptomonas and Placoneis incased and decreased, respectively, within first 9 days. The results of this study provide a promising way to use the brain tissue RNA, bacterial biofilm, and algae to estimate the PMI of a carcass in water.