Partial versus Full Sternotomy for Aortic Valve Replacement

Background: Minimal invasive approaches are used more frequently for aortic valve replacement (AVR). This study aimed to compare the outcomes of both minimally invasive upper mini-sternotomy and full sternotomy for AVR. Methods: 100 patients with isolated aortic valve disease were enrolled in this prospective observational study. We grouped the patients according to the technique, group A (n=40) underwent upper J-shaped mini-sternotomy, and group B (n=60) underwent full sternotomy. Study endpoints were operative times and pain score. Results: The mean age of the patients was 46.4±10.1 years. There was no difference in preoperative data between both groups. There was a significant difference in aortic cross-clamp time (87.2± 8.6 vs. 59.2± 6.6  min in group A and B, respectively, p= 0.001), and total bypass time (115.1± 9.2 vs. 75.3± 4.3 min in group A and B, respectively, p= 0.001) between both groups. The total operative time was 341±11.7 and 196.1±18.4 min in groups A and B, respectively (p= 0.001). The ICU stay was 29.4±8.2 hours in group A and 41.2±13.3 hours in group B (p= 0.001). Patients who had mini-sternotomy had lower pain (p= 0.001) and better patient satisfaction score (p< 0.001). Conclusion: J-shaped upper mini-sternotomy is a safe and effective strategy for aortic valve replacement. The procedure may be associated with decreased pain and comparable morbidity to the conventional approach

Application of the ANOVA method in the optimization of a thermoelectric cooler-based dehumidification system

© 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).In recent studies, Thermo-Electric Coolers (TEC) have been utilized for dehumidification purposes, which is mainly based on the extraction of moisture from humid atmospheric air. The reviewed literature showed that the rate of water collection from the TEC-based system can be affected by various parameters such as the module’s input voltage, the heat sink orientation, and tilt angles. In this research, the analysis of variance (ANOVA) was used to examine the significance of these factors and their interaction within the system on the TEC-based dehumidification system. Four levels were investigated for both, the Peltier’s input voltage and the rotation angle, and three levels for the tilt angle. This study indicated the significance of the studied factors and their interactions within the dehumidification system along with performing an overall numerical optimization. The experiments were conducted under the same working conditions in an enclosed environment to minimize errors. According to the overall numerical optimization, which was validated experimentally, the optimum system performance was predicted to be obtained at approximately 6.8V Peltier input volt, 65° rotation angle, and 90° tilt angles, with predicted optimum productivities of 0.32278 L/kWh and 13.03 mL/hr. For the same set of parameters, the variation between the experiment and the numerical optimization was less than 4%. The experiments show that when optimizing water collection rates for thermoelectric cooling heat sinks​ under high humidity conditions, the orientation of the heat sink should be considered.Peer reviewe

Thermohydraulic analysis of covalent and noncovalent functionalized graphene nanoplatelets in circular tube fitted with turbulators

© The Author(s) 2022. This article is licensed under a Creative Commons Attribution 4.0 International. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.Covalent and non-covalent nanofluids were tested inside a circular tube fitted with twisted tape inserts with 45° and 90° helix angles. Reynolds number was 7000 ≤ Re ≤ 17,000, and thermophysical properties were assessed at 308 K. The physical model was solved numerically via a two-equation eddy-viscosity model (SST k-omega turbulence). GNPs-SDBS@DW and GNPs-COOH@DW nanofluids with concentrations (0.025 wt.%, 0.05 wt.% and 0.1 wt.%) were considered in this study. The twisted pipes' walls were heated under a constant temperature of 330 K. The current study considered six parameters: outlet temperature, heat transfer coefficient, average Nusselt number, friction factor, pressure loss, and performance evaluation criterion. In both cases (45° and 90° helix angles), GNPs-SDBS@DW nanofluids presented higher thermohydraulic performance than GNPs-COOH@DW and increased by increasing the mass fractions such as 1.17 for 0.025 wt.%, 1.19 for 0.05 wt.% and 1.26 for 0.1 wt.%. Meanwhile, in both cases (45° and 90° helix angles), the value of thermohydraulic performance using GNPs-COOH@DW was 1.02 for 0.025 wt.%, 1.05 for 0.05 wt.% and 1.02 for 0.1 wt.%.Peer reviewe

First Covid-19 maternal mortality in the UK associated with thrombotic complications.

We report the first maternal death of a 29-year woman of Pakistani origin at Birmingham Heartlands Hospital (BHH), UK on the 8 April 2020. She had a body mass index (BMI) of 35, type 2 diabetes mellitus (T2DM) on metformin and insulin, renal tubular acidosis, asthma and vitamin D deficiency. In her first pregnancy, she had a stillborn baby. At her first antenatal (booking) visit, her glycated haemoglobin (HbA1c) was 9.7%. She also had a high albumin creatinine ratio but with normal kidney function

Severe pre-eclampsia complicated by acute fatty liver disease of pregnancy, HELLP syndrome and acute kidney injury following SARS-CoV-2 infection.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has presented many diagnostic challenges and uncertainties. Little is known about common pathologies complicating pregnancy and how their behaviour is modified by the presence of SARS-CoV-2. Pregnancy itself can alter the body's response to viral infection, which can cause more severe symptoms. We report the first case of a patient affected with sudden-onset severe pre-eclampsia complicated by acute fatty liver disease of pregnancy, HELLP (haemolysis, elevated liver enzymes and low platelet) syndrome and acute kidney injury following SARS-CoV-2 infection. Although an initial diagnostic dilemma, a multidisciplinary team approach was required to ensure a favourable outcome for both the mother and the baby. Our case report highlights the need for health professionals caring for pregnant women to be aware of the complex interplay between SARS-CoV-2 infection and hypertensive disorders of pregnancy

SARS-CoV-2: Do corticosteroids for fetal lung maturation worsen maternal or fetal outcomes?

Immune system changes during pregnancy could make pregnant women more susceptible to SARS-Cov-2 infection.The use of corticosteroids within obstetrics has been shown to reduce the risks of respiratory distress syndrome, intraventricular haemorrhage, necrotizing enterocolitis and neonatal death in the baby associated with premature delivery. During the COVID-19 pandemic, corticosteroids have been trialled as a treatment to dampen the 'cytokine storm' and associated inflammatory processes. Corticosteroids have long been known to have immunosuppressive effects that could hinder the body's ability to mount a defence against COVID-19 and thereby delaying viral clearance. In this clinical case studies, antenatal steroids for fetal lung maturation appear to be of benefit and did not result in a deterioration of maternal disease. Our clinical case studies support the current recommendations from the Royal College of Obstetricians and Gynaecologists ie corticosteroids for fetal lung maturation is appropriate in patients who are suspected or have confirmed SARSCoV-2 infection

Study of the LMNA 1908 C/T gene polymorphism in type 2 diabetic Egyptians with vascular complications

Aims/introduction Vascular complications are the main cause of morbidity and mortality in type 2 diabetic patients. Genetic susceptibility is associated with the evolution of diabetic complications. One such gene is the lamin A and C gene located on chromosome 1q21, a susceptibility locus for type 2 diabetes mellitus, and encodes nuclear lamins A and C. The LMNA 1908 C/T polymorphism has been reported to be associated with dyslipidemia, metabolic syndrome, and obesity, suggesting that this polymorphism increases the risk of atherosclerosis and vascular disease. The present study aims to elucidate the association between the LMNA 1908 C/T single nucleotide polymorphism and the prevalence of vascular complications in a sample of type 2 diabetic Egyptian patients. Materials and methods Genomic DNA from 47 type 2 diabetic patients with vascular complications and 20 control participants was analyzed for the LMNA 1908 C/T polymorphism using PCR-RFLP. Results Carriers of the LMNA 1908 T-allele showed a significantly higher prevalence in patients with diabetic nephropathy than carriers of the C-allele (P < 0.05). Multiple regression analysis showed that the LMNA 1908 T-allele tended to be independent risk factor for diabetic nephropathy (P = 0.012, odds ratio = 5.460). Conclusion The findings of this study suggest that the LMNA 1908 C/T single nucleotide polymorphism is associated with the development of diabetic nephropathy in Egyptian type 2 diabetic patients

Deep clustering of cooperative multi-agent reinforcement learning to optimize multi chiller HVAC systems for smart buildings energy management

© 2022 Elsevier Ltd. All rights reserved. All rights reserved. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.1016/j.jobe.2022.105689Chillers are responsible for almost half of the total energy demand in buildings. Hence, the obligation of control systems of multi-chiller due to changes indoor environments is one of the most significant parts of a smart building. Such a controller is described as a nonlinear and multi-objective algorithm, and its fabrication is crucial to achieving the optimal balance between indoor thermal comfort and running a minimum number of chillers. This work proposes deep clustering of cooperative multi-agent reinforcement learning (DCCMARL) as well-suited to such system control, which supports centralized control by learning of agents. In MARL, since the learning of agents is based on discrete sets of actions and stats, this drawback significantly affects the model of agents for representing their actions with efficient performance. This drawback becomes considerably worse when increasing the number of agents, due to the increased complexity of solving MARL, which makes modeling policy very challenging. Therefore, the DCCMARL of multi-objective reinforcement learning is leveraging powerful frameworks of a hybrid clustering algorithm to deal with complexity and uncertainty, which is a critical factor that influences to the achievement of high levels of a performance action. The results showed that the ability of agents to manipulate the behavior of the smart building could improve indoor thermal conditions, as well as save energy up to 44.5% compared to conventional methods. It seems reasonable to conclude that agents' performance is influenced by what type of model structure.Peer reviewe