A novel hybrid radiative and ventilative cooling system integrated with latent heat storage for buildings in hot-arid climates

The use of phase change material (PCM) as potential energy storage for cooling of buildings using night low-temperature air is one of the promising sustainable strategies referred to as “the free cooling of buildings”. Application of this strategy in hot climates is not exploited, and most of the published work has been carried out in moderate and continental climates. Moreover, the free cooling potential is insufficient under extreme summer conditions, owing to the small temperature difference between the PCM and the ambient air in addition to the limited available charging time. Therefore, with the aim of sustaining and enhancing the free cooling potential in such disadvantageous conditions, an innovative hybrid nocturnal radiative and ventilative cooling system using latent heat storage (NRV-LHS) has been proposed in this study. Such a combined system has not been adduced in previous studies. In this research, the nocturnal radiative and free cooling potential in hot-arid regions is assessed. According to the local climate and thermal comfort conditions of the case study, a paraffin-based RT28HC PCM of a transition temperature range of 27-29 °C was considered. Thermal energy storage (TES) system comprising a number of PCM panels has been proposed and assessed using transient computational fluid dynamics modelling to optimise the geometrical configuration under various inlet air conditions. The proposed PCM storage system has been investigated experimentally to evaluate the charging and discharging behaviour of the PCM for a range of PCM modules arrangements. The operational performance of the hybrid NRV-LHS system has been evaluated experimentally under hot and moderate summer conditions of hot-arid climate for various scenarios of free and radiative cooling operation modes. The parametric study results have shown that a compact TES system design made of thin PCM modules and narrow air flow channels is more effective in accelerating the PCM charging process. The difference between the PCM transition temperature and the inlet air temperature, along with the air flow rate play a significant role in the heat transfer rate during both transformation phases. The findings have indicated that the proposed NRV-LHS system has a great potential to operate satisfactorily under the severe summer conditions in hot-arid regions. The system can improve the thermal performance of the free cooling systems by extending the charging period beyond the free cooling range. The system also enhances the heat transfer rate and minimises the effect of PCM supercooling, which contributes positively to the charging effectiveness. For the summer period (May-October), the system could fulfil up to 57% of the cooling load. The estimated COP of the system varied between 5.82 and 9.01. This performance could allow the system to maintain the thermal comfort, leading to substantial energy savings up to 76% compared to conventional air conditioning systems. The outcomes of this research would be beneficial to introduce an appropriate design of PCM-air heat exchangers combined with an air-based nocturnal radiative cooling system, applicable for real implementation in buildings, especially in hot-arid regions

Green roof and louvers shading for sustainable mosque buildings in Riyadh, Saudi Arabia

The number of mosque buildings is continuously increasing with the Muslim population, which is in fast growth around the world. In particular, the demand of new mosque buildings is high in the urban areas, due to increasing urban population growth in many parts of Muslims countries, as a result of economic growth and political instabilities in some parts of the Muslims world. Mosques are becoming more overcrowded and as a result a number of researches have been conducted to address the issue of thermal comfort of mosque users. Additionally, mosque building is unique because of its intermittent operation and various users, which require a unique heating or cooling strategies. On the other hand due to environmental pressure to suppress global warming, more energy efficient and sustainable buildings design is one of the current issues in building industries. This research aims to explore the sustainable techniques for mosque buildings in different climate zones. This research assesses a number of mosques buildings in different parts of the world with different climate; and investigates the strategies employed to cool or heat these buildings depending on the climate and season. The effectiveness of the building features in relation to each climate are carefully analysed, and possibility of potential replication of these features elsewhere are examined. This paper examined two techniques, green roof and louver shading in hot arid climate. The eventual objectives are establishing a guideline for architects and mosques building designer at any climate in order to achieve sustainable mosque building. The study concludes that there is a potential saving of up to 10% in cooling loads when green roof and louvers shading are applied on simulated mosque building in Riyadh, thus achieving the environmental feasibility in addition to economic and social benefits

DON\u27T BLAME THE VACCINE

Background: The mRNA COVID vaccine is a rare cause of myocarditis in young patients. We describe a case of cardiogenic shock with extensive workup ruling out COVID vaccine induced myocarditis. Case: 42-year-old female who drinks 5 Monster energy drinks and 3-4 cups of coffee daily presented to the hospital with palpitations two weeks following her mRNA COVID vaccine. EKG showed atrial tachycardia with heart rates of 160 beats per minute. Adenosine and Lopressor were administered resulting in hemodynamic instability requiring norepinephrine. An echocardiogram showed dilated cardiomyopathy with ejection fraction of 15%. Right heart catheterization was performed, and the cardiac index was 1.22 L/min/m², systemic vascular resistance was 1918 dynes*sec*cm-5 and wedge pressure was 31 mm Hg. The patient was started on nitroprusside, furosemide, and milrinone drips and she began to improve. The patient was adamant the vaccine is what triggered her heart failure and extensive testing was performed to rule out COVID vaccine induced myocarditis. Workup showed normal coronary arteries and no evidence of infiltrative disease or myocarditis on cardiac MRI. The etiology was from tachycardia induced cardiomyopathy triggered by excessive stimulants and the patient had successful atrial tachycardia ablation of the right superior pulmonary vein. She was discharged on medical therapy for heart failure and advised to stop drinking energy drinks. Decision-making: Once the patient did not respond to the rate controlling agents an echocardiogram showed reduced ejection fraction. Right heart catheterization confirmed cardiogenic shock and nitroprusside and milrinone were started to help reduce afterload and improve contractility. Workup to exclude COVID induced myocarditis lead to the diagnosis of tachycardia induced cardiomyopathy and atrial tachycardia ablation was performed. Conclusion: We report a case of cardiogenic shock with workup diagnosing tachycardia induced cardiomyopathy induced from a combination of excessive monster energy drinks and coffee. She was treated successfully with afterload reduction, inotrope support, and atrial tachycardia ablation

Miniforceps EBUS-guided lymph node biopsy: impact on diagnostic yield

Introduction: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is the standard diagnostic method for sampling mediastinal and hilar lymph nodes. Non-diagnostic samples have led some pulmonologists to add a miniforceps biopsy (EBUS-TBFB) in order to increase diagnostic yield. Our study aims to analyze the impact of adding EBUS-TBFB to the EBUS-TBNA in cases where Rapid On-site Evaluation (ROSE) was negative for malignancy or was non-diagnostic.Material and methods: This retrospective chart review included 91 patients who were aged 18–90 years old and underwent EBUS with both TBNA and TBFB between January 1, 2013 and July 1, 2018.Results: There was no significant statistical difference in the diagnostic yield of TBNA vs TBFB with a McNemar value of 0.167, and this conclusion was the same when stratified by race, age and lymph node size. Using TBNA as a gold standard, the sensitivity and specificity of TBFB was 87% and 69%, respectively. Out of the non-diagnostic TBNA samples on ROSE and cell-block, subsequent TBFB resulted in additional pathologic diagnoses in 16% of cases, of which 67% were non-caseating granulomas. Furthermore, two additional malignant cases were identified by TBFB consisting of small cell carcinoma and non-Hodgkin’s lymphoma.Conclusion: In conclusion, TBFB is a useful adjunctive tool in the diagnosis of non-malignant conditions (i.e. granulomatous diseases) with the potential to spare the patient from more invasive surgical biopsies. Training of future fellows in performing TBFB in addition to TBNA should be strongly encouraged

A Review of the Impella Devices

The use of mechanical circulatory support (MCS) to provide acute haemodynamic support for cardiogenic shock or to support high-risk percutaneous coronary intervention (HRPCI) has grown over the past decade. There is currently no consensus on best practice regarding its use in these two distinct indications. Impella heart pumps (Abiomed) are intravascular microaxial blood pumps that provide temporary MCS during HRPCI or in the treatment of cardiogenic shock. The authors outline technical specifications of the individual Impella heart pumps and their accompanying technology, the Automated Impella Controller and SmartAssist, their indications for use and patient selection, implantation techniques, device weaning and escalation, closure strategies, anticoagulation regimens, complications, future directions and upcoming trials

Association of Operator and Hospital Experience With Procedural Success Rates and Outcomes in Patients Undergoing Percutaneous Coronary Interventions for Chronic Total Occlusions: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium

BACKGROUND: An inverse relationship has been described between procedural success and outcomes of all major cardiovascular procedures. However, this relationship has not been studied for percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). METHODS: We analyzed the data on patients enrolled in Blue Cross Blue Shield of Michigan Cardiovascular Consortium registry in Michigan (January 1, 2010 to March 31, 2018) to evaluate the association of operator and hospital experience with procedural success and outcomes of patients undergoing CTO-PCI. CTO-PCI was defined as intervention of a 100% occluded coronary artery presumed to be ≥3 months old. RESULTS: Among 210 172 patients enrolled in the registry, 7389 (3.5%) CTO-PCIs were attempted with a success rate of 53%. CTO-PCI success increased with operator experience (45% and 65% in the lowest and highest experience tertiles) and was the highest for highly experienced operators at higher experience centers and the lowest for inexperienced operators at low experience hospitals. Multivariable logistic regression models (with spline transformed prior operator and institutional experience) demonstrated a positive relationship between prior operator and site experience and procedural success rates (likelihood ratio test=141.12, df=15, P\u3c0.001) but no relationship between operator and site experience and major adverse cardiac event (likelihood ratio test=19.12, df=15, P=0.208). CONCLUSIONS: Operator and hospital CTO-PCI experiences were directly related to procedural success but were not related to major adverse cardiac event among patients undergoing CTO-PCIs. Inexperienced operators at high experience centers had significantly higher success but not major adverse cardiac event rates compared with inexperienced operators at low experience centers. These data suggested that CTO-PCI safety and success could potentially be improved by selective referral of these procedures to experienced operators working at highly experienced centers

Incidence and clinical outcomes of nosocomial infections in patients presenting with STEMI complicated by cardiogenic shock in the United States

OBJECTIVES: This study addresses the incidence, trends, and impact of nosocomial infections (NI) on the outcomes of patients admitted with ST-segment elevation myocardial infarction (STEMI) and cardiogenic shock (STEMI-CS) using the United States National Inpatient Sample (NIS) database. METHODS: We analyzed data from 105,184 STEMI-CS patients using the NIS database from the years 2005-2014. NI was defined as infections of more than or equal to three days, comprising of central line-associated bloodstream infection (CLABSI), urinary tract infection (UTI), hospital-acquired pneumonia (HAP), Clostridium difficile infection (CDI), bacteremia, and skin related infections. Outcomes of the impact of NI on STEMI-CS included in-hospital mortality, length of hospital stay (LOS) and costs. Significant associations of NI in patients admitted with STEMI-CS were also identified. RESULTS: Overall, 19.1% (20,137) of patients admitted with STEMI-CS developed NI. Trends of NI have decreased from 2005-2014. The most common NI were UTI (9.2%), followed by HAP (6.8%), CLABSI (1.5%), bacteremia (1.5%), skin related infections (1.5%), and CDI (1.3%). The strongest association of developing a NI was increasing LOS (7-9 days; OR: 1.99; 95% CI: 1.75-2.26; \u3e9 days; OR: 4.51; 95% CI: 4.04-5.04 compared to 4-6 days as reference). Increased mortality risk among patients with NI was significant, especially those with sepsis-associated NI compared to those without sepsis (OR: 2.95; 95% CI: 2.72-3.20). Patients with NI were found to be associated with significantly longer LOS and higher costs, irrespective of percutaneous mechanical circulatory support placement. CONCLUSIONS: NI were common among patients with STEMI-CS. Those who developed NI were at a greater risk of in-hospital mortality, increased LOS and costs

Health-related quality of life of relapsing or remitting multiple sclerosis patients: A case-control study

Background: Patients with multiple sclerosis (MS) report lower health-related quality of life (HRQoL) than other chronic disease populations. This study aims to identify risk factors of relapsing or remitting multiple sclerosis (RRMS) and assess its impact on HRQoL in Lebanese MS patients. Patients and methods: A thre-month case-control study was performed among 75 RRMS case patients recruited from two clinics in Beirut and 225 controls from the general population. Results: Heavy cigarette smoking, moderate and heavy waterpipe smoking, vitamin D deficiency, cardiovascular disease, and psychological disorders were significantly associated with RRMS. Linear regression showed that the multiple sclerosis international quality of life global index significantly decreased with the number of relapses, the incomplete recovery between relapses, and the psychological disorder. Higher-income and physical activity had a positive effect on QoL. Conclusions: Findings of this study highlighted the risk factors of RRMS, which can be used for informed decision-making and targeted awareness campaigns. Other factors affecting the HRQoL of MS patients should be considered to improve their experience throughout and after treatment

Retinoic acid receptor α as a novel contributor to adrenal cortex structure and function through interactions with Wnt and Vegfa signalling

International audiencePrimary aldosteronism (PA) is the most frequent form of secondary arterial hypertension. Mutations in different genes increase aldosterone production in PA, but additional mechanisms may contribute to increased cell proliferation and aldosterone producing adenoma (APA) development. We performed transcriptome analysis in APA and identified retinoic acid receptor alpha (RARα) signaling as a central molecular network involved in nodule formation. To understand how RARα modulates adrenal structure and function, we explored the adrenal phenotype of male and female Rarα knockout mice. inactivation of Rarα in mice led to significant structural disorganization of the adrenal cortex in both sexes, with increased adrenal cortex size in female mice and increased cell proliferation in males. Abnormalities of vessel architecture and extracellular matrix were due to decreased Vegfa expression and modifications in extracellular matrix components. On the molecular level, Rarα inactivation leads to inhibition of non-canonical Wnt signaling, without affecting the canonical Wnt pathway nor PKA signaling. Our study suggests that Rarα contributes to the maintenance of normal adrenal cortex structure and cell proliferation, by modulating Wnt signaling. Dysregulation of this interaction may contribute to abnormal cell proliferation, creating a propitious environment for the emergence of specific driver mutations in PA. Primary aldosteronism (PA) is the most common and curable form of secondary arterial hypertension, with prevalence estimations of up to 10% of cases in referred hypertensive patients, 4% of patients in primary care 1,2 and 20% of patients with resistant hypertension 3,4. Rapid diagnosis and treatment are important to prevent severe cardiovas-cular consequences of long term aldosterone exposure, which are independent of blood pressure levels and are du

A novel hybrid radiative and ventilative cooling system integrated with latent heat storage for buildings in hot-arid climates

The use of phase change material (PCM) as potential energy storage for cooling of buildings using night low-temperature air is one of the promising sustainable strategies referred to as “the free cooling of buildings”. Application of this strategy in hot climates is not exploited, and most of the published work has been carried out in moderate and continental climates. Moreover, the free cooling potential is insufficient under extreme summer conditions, owing to the small temperature difference between the PCM and the ambient air in addition to the limited available charging time. Therefore, with the aim of sustaining and enhancing the free cooling potential in such disadvantageous conditions, an innovative hybrid nocturnal radiative and ventilative cooling system using latent heat storage (NRV-LHS) has been proposed in this study. Such a combined system has not been adduced in previous studies. In this research, the nocturnal radiative and free cooling potential in hot-arid regions is assessed. According to the local climate and thermal comfort conditions of the case study, a paraffin-based RT28HC PCM of a transition temperature range of 27-29 °C was considered. Thermal energy storage (TES) system comprising a number of PCM panels has been proposed and assessed using transient computational fluid dynamics modelling to optimise the geometrical configuration under various inlet air conditions. The proposed PCM storage system has been investigated experimentally to evaluate the charging and discharging behaviour of the PCM for a range of PCM modules arrangements. The operational performance of the hybrid NRV-LHS system has been evaluated experimentally under hot and moderate summer conditions of hot-arid climate for various scenarios of free and radiative cooling operation modes. The parametric study results have shown that a compact TES system design made of thin PCM modules and narrow air flow channels is more effective in accelerating the PCM charging process. The difference between the PCM transition temperature and the inlet air temperature, along with the air flow rate play a significant role in the heat transfer rate during both transformation phases. The findings have indicated that the proposed NRV-LHS system has a great potential to operate satisfactorily under the severe summer conditions in hot-arid regions. The system can improve the thermal performance of the free cooling systems by extending the charging period beyond the free cooling range. The system also enhances the heat transfer rate and minimises the effect of PCM supercooling, which contributes positively to the charging effectiveness. For the summer period (May-October), the system could fulfil up to 57% of the cooling load. The estimated COP of the system varied between 5.82 and 9.01. This performance could allow the system to maintain the thermal comfort, leading to substantial energy savings up to 76% compared to conventional air conditioning systems. The outcomes of this research would be beneficial to introduce an appropriate design of PCM-air heat exchangers combined with an air-based nocturnal radiative cooling system, applicable for real implementation in buildings, especially in hot-arid regions