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High-current discharge is studied between two electrodes where the filling medium is a mixture of methanol and air. Combustion is ignited by a 52 kJ discharge between two T-shaped electrodes. The combustion device consists of a 52 kJ capacitor bank, a discharge and combustion chamber and diagnostic systems. Current disruption has been observed at the moment of a change between the capacitive and inductive discharges. This has been referred to plasma expansion and termination when there is no voltage between the electrodes. The disruption time increases with an increase in the charging voltage. The kinetic pressure of combustion has shown three different behaviours. The first type is similar to partial fuel normal combustion. The second type is complete normal combustion. The third type is fast plasma combustion which results when an exponential pressure decay due to the heat transport process, very low heat losses and the short rise time of the kinetic pressure is obtained. [ABSTRACT FROM AUTHOR]

Background: Given the sparse data on the renin-angiotensin system (RAS) and its biological effector molecules ACE1 and ACE2 in pediatric COVID-19 cases, we investigated whether the ACE1 insertion/deletion (I/D) polymorphism could be a genetic marker for susceptibility to COVID-19 in Egyptian children and adolescents., Methods: This was a case-control study included four hundred sixty patients diagnosed with COVID-19, and 460 well-matched healthy control children and adolescents. The I/D polymorphism (rs1799752) in the ACE1 gene was genotyped by polymerase chain reaction (PCR), meanwhile the ACE serum concentrations were assessed by ELISA., Results: The ACE1 D/D genotype and Deletion allele were significantly more represented in patients with COVID-19 compared to the control group (55% vs. 28%; OR = 2.4; [95% CI: 1.46-3.95]; for the DD genotype; P = 0.002) and (68% vs. 52.5%; OR: 1.93; [95% CI: 1.49-2.5] for the D allele; P = 0.032). The presence of ACE1 D/D genotype was an independent risk factor for severe COVID-19 among studied patients (adjusted OR: 2.6; [95% CI: 1.6-9.7]; P < 0.001., Conclusions: The ACE1 insertion/deletion polymorphism may confer susceptibility to SARS-CoV-2 infection in Egyptian children and adolescents., Impact: Recent studies suggested a crucial role of renin-angiotensin system and its biological effector molecules ACE1 and ACE2 in the pathogenesis and progression of COVID-19. To our knowledge, ours is the first study to investigate the association of ACE1 I/D polymorphism and susceptibility to COVID-19 in Caucasian children and adolescents. The presence of the ACE1 D/D genotype or ACE1 Deletion allele may confer susceptibility to SARS-CoV-2 infection and being associated with higher ACE serum levels; may constitute independent risk factors for severe COVID-19. The ACE1 I/D genotyping help design further clinical trials reconsidering RAS-pathway antagonists to achieve more efficient targeted therapies., (© 2024. The Author(s).)

Cardiovascular disease is the leading cause of mortality and morbidity worldwide. One of the main risk factors for cardiovascular events is hypertension. The use of antihypertensive drugs can protect against these events. It occurs directly through the control of hypertension and indirectly through other cardiovascular effects. This meta-analysis and systematic review aimed to assess the impact of various antihypertensive medications (ACE inhibitors, beta-blockers, calcium channel blockers, diuretics, etc.) on blood pressure and various cardiovascular outcomes. A thorough search was conducted using several online databases and search engines, including PubMed, Google Scholar, ScienceDirect, Medline, Embase, and others. RCTs evaluating the impact of antihypertensive medications on BP and other cardiovascular events like coronary heart disease and stroke were included in this study. Included were studies detailing the use of antihypertensive medication in monotherapy. The meta-analysis was done using RevMan version 5.4 software (Cochrane Collaboration, London, UK). Means and standard deviations were extracted for the continuous variables and events, and the total sample number was extracted for the dichotomous variables. This analysis encompassed a total of 18 RCTs of the elderly population. The data for each variable was extracted independently, and analysis was performed. Overall, systolic blood pressure (SBP) revealed an impact of -11.88, CI=95% (-20.56, -3.19). The diastolic blood pressure (DBP) showed -5.41, CI=95% (-9.62, -1.20), myocardial infarction 0.92, CI=95% (0.82, 1.04), stroke 0.83, CI=95% (0.74, 0.94), and cardiovascular mortality 0.93, CI=95% (0.86, 1.00). Heterogeneity was present due to the variable sample size of the studies and other unidentified biases. In conclusion, there was a significant reduction in the elderly population's risk of stroke, myocardial infarction, and cardiovascular death when antihypertensive medications were taken., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2024, Chaudhry et al.)

Patients diagnosed with coronavirus disease (CVD) who experience cardiovascular complications or have pre-existing cardiovascular disease are at an increased risk of death. The primary heart-related consequences associated with COVID-19 encompass venous thromboembolism, shock, heart failure, arrhythmias, myocarditis, acute myocardial infarction, and acute cardiac damage. The coronavirus has the potential to induce cardiovascular complications or exacerbate pre-existing CVD through various mechanisms. These mechanisms include dysregulation of the renin-angiotensin-aldosterone system; direct viral toxicity; damage to endothelial cells; formation of blood clots and subsequent inflammation, a phenomenon known as thromboinflammation; an excessive immune response known as cytokine storm; and an imbalance between the demand and supply of oxygen in the body. In this study, we comprehensively analyze the cardiovascular symptoms, histology, and underlying mechanisms associated with COVID-19. Our aim is to contribute to the identification of future research objectives and aid in the advancement of therapeutic management approaches., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2023, Siddique et al.)

Lower extremity wounds with exposed bone and tendon often need coverage to allow the underlying tissue to regenerate prior to skin graft. The surgeon is limited in his or her choices to augment tissue regeneration in these types of complicated cases; for instance, autologous skin should not be placed on exposed bone or tendon and is at risk for contracture when placed over the joints. Therefore, novel technologies are necessary to provide a scaffolding for tissue to regenerate and allow for a successful graft. One such technology is an esterified hyaluronic acid matrix (eHAM), which can provide a proper scaffold for endothelial cell migration and aid in angiogenesis. The eHAM is made of two layers: a layer of hyaluronic acid covered with a silicone layer. In this retrospective chart review, we describe our usage of eHAM to provide scaffolding for tissue regeneration prior to grafting in 15 cases of complicated lower extremity wounds with exposed bone and tendon. The average patient age was 45.8 years, and all patients had multiple medical comorbidities, such as poorly controlled diabetes mellitus, hypertension, and nicotine addiction. Patient wound types were diverse, including traumatic wounds, chronic diabetic foot ulcers, and thermal or electric burns. Thirteen of the 15 cases were treated successfully with eHAM. In these cases, definitive coverage with split-thickness skin grafting was effective and limb salvage was successful. In the 13 successful cases, the mean time to split-thickness skin graft was 22.9 ± 7.0 days. All patients continue to do well at follow-up (ranging from 6 to 48 weeks), with minimal complications reported. Given the success rate with eHAM in this challenging population, we conclude that eHAM can be a treatment option for similar cases., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Burn Association.)

The keystone perforator flap (KPF) was first introduced in 2003 by Behan et al for use in reconstruction after skin cancer excision. Since its initial description, KPF use has been expanded to complex defects of various etiologies and disorders throughout the body. At its most basic, the KPF is a perforator-type flap designed with a 1:1 flap-to-defect width ratio. Keystone perforator flaps are specifically raised on pedicles arising from musculocutaneous or fasciocutaneous perforator vessels. Major advantages of the KPF derive from the maintenance of perforator vascular territories, perforosomes, permitting increased flap viability. In turn, this allows for more aggressive undermining in sites away from perforators when greater skin mobilization is necessary. Furthermore, the KPF is relatively easy to perform leading to shorter operative times and no postoperative monitoring period. There are basically 4 different types of keystone flaps in order of increasing undermining and disturbance of underlying fascia. These different classifications of KPFs may be used in different anatomical locations over the entire body based on skin laxity and defect size/depth. Numerous advancements and modifications have been documented adapting the KPF to specific conditions, including myelomeningoceles, and scrotal and lower eyelid defects. The purpose of this article is to provide an organized review of the KPF with emphasis on different classifications, applications, and limitations as well as an overview of the surgical technique. We have additionally included a discussion on KPF physiology and review of current literature.

Amniotic band sequence is a complex congenital anomaly in which infants with typically no known genetic mutation have bands of maternal amniotic tissue wrapped around body parts, most commonly the limbs and digits. The authors report a novel variation on this presentation in 3 patients from 2 centers with complex craniofacial clefting and amniotic band sequence. They presented with hypertelorism, different forms of complex craniofacial clefting, and bands connecting ipsilateral hands to facial clefts, with digital-facial translocation in 2 cases. These findings support a model in which complex craniofacial clefts result in areas of exposed, sticky, and temporally and spatially coincident mesenchyme within the embryo that are susceptible to adherence of ipsilateral fetal hands. This strongly supports the intrinsic and adhesion theories of the etiology of amniotic band syndrome.

Unlabelled: Aim of the study was to present the best methods for reconstruction of extensive defects after removal of the head and neck cancer., Introduction: Key to success of reconstrucive surgery is choosing an appropriate option that aim at single stage replacement of lost tissue and provide the integrity, function and aesthetic outcome in a perfect balance., Patients: This descriptive study was carried out between march 2009. And march 2013. at the Clinic of Maxillofacial surgery, Clinical center of University of Sarajevo, Bosnia and Herzegovina. A total number of 483 patients with extensive defects were included., Results: Most of the patients 421 (87%) were males. The diagnosis of squamous cell carcinoma was present in 355 (73.5%) cases wich was statistically significant. Pectoralis major myocutaneous flap was the most common reconstruction method, in 267 (55.3%) cases. Second common method used were local flap 147 (30.4%), then temporal flap 36 (7.5%). Infrahyoid flap, latissimus dorsi, radial forearm free flap and free fibula graft were also used. The prevalence ofpectoralis major myocutaneous flap was statistically significant. The most comon complication among donor and recipient side was hematoma. Total flap necrosis occured in 9 (1.9%) patients. Comparing donor and recipient side in common complications there were no statistical significant difference., Conclusion: Wich technique for closure to choose depends on the complexity of defect. The pectoralis major myocutaneous flap continues to be the most universal flap in head and neck reconstruction.

Introduction: Understanding technique of flap surgery allow uncompromising tumor resection and operation of tumors previously considered inoperable. Infrahyoid neuro-myocutaneous flap (IHNMCF) is pedicled flap harvested from the anterior part of the neck. IHNMCF is a good solution for the moderated sized defects of the head and neck below the zygomatic arch. The objective of this article was to describe modified infrahyoid neuromyocutaneous flap used for reconstruction of tongue and mouth floor defects, immediate after removing neoplasm., Case Report: A 63 year old patient were hospitalized with pathohistologically confirmed-squamocellular carcinoma. The tumor were in the region of the ventral part of the mouth. Magnetic resonance imaging (MRI) and ultrasound investigation of the head and neck showed detectable nodes in the right side of the neck and suspicious nodes in the left side of the neck. Through the transmandibular approach it was performed a wide local excision of the tumor. IHNMCF was harvested from the right side. It was performed meticulous microvascular procedure venous end-to-end anastomosis of the right superior thyroid vein to the left superior thyroid vein. Patient is during procedure subjected to the supraomohyoid neck dissection on the left side and radical neck dissection on the right side., Discussion and Conclusion: Disadvantage of this modified infrahyoid flap is the extremely limited arc of rotation. This seriously limits its applications to specific situations, where defects are located very close to the flap. Othervise, advantage of this modified flap is that radical neck dissection is not contraindication anymore. In this case flap was successful, without flap necrosis or complications in the donor side. Speech and swallow were without significant decrease. After radiation therapy flap remained sufficiently soft, trophic and mobile.

Introduction: Pedicled temporalis muscle flap presenting a good flap for closing large craniofacial defects. Careful surgeons usually do not mobilize temporalis muscle flap enough to make appropriate use, fully closure, especially if defect exceeds the median line., Patients and Methods: Temporalis flap was used in 16 patients, ages ranged between 12 and 76. In all cases defect reconstruction was done by useing new method of extending standard temporal muscle flap. During surgical procedure it is very important to keep periosteal elevator in close contact with the bone. Then, there is no risk for pedicle injury. After vascular pedicle is identified elevating temporal muscle has to be continued by releasing the muscle insertion from the coronoid process. By this way, flap length and arc of rotation is increased., Results: The flap remained viable in all instances. Most of the patients experienced no perioperative complications. There was no major complications or mortality as a result of performed procedures., Conclusion: With this division, flap length was increased at least 2 cm wich is enough for covering defects crossing the midline. Instead of using bilateral temporalis muscle flaps for defect closure, unilateral is sufficient. With this extension of the pedicle length now rotation point is not at the level of the zygomatic arch but lower part mandibular neck.