Design, Fabrication and Testing of Hybrid Parabolic Dish Concentrator, Stirling Engine & PCM-Storage in Oman

This work outlines the conceptualization, design, fabrication and parameters that influence the operation of direct hybridization of solar parabolic dishes with the thermal energy storage in phase change material (PCM) and hybrid Stirling engine. This mathematical method consists of two different sizes of parabolic dishes, PCM-storage and hybrid Stirling engine. The hybrid Stirling engine was used reflective heat to electrical energy in direct and indirect ways. The direct way involved using the sunrays directly from the parabolic dishes into the engine to generate energy. This was done simultaneously while charging the PCM-storage system for later use. For the indirect way, stored heat energy in the PCM-storage was used to supply heat energy to the Stirling engine for applications at night. Tests were carried out to ensure the system performs optimally based on the design. Each part of prototype model was first tested alone and then later on as part of the complete system of the prototype model. This was carried out continuously over a period of 24hover a number of days. The result from the experiments showed the system was designed to work for 24h,which depends on efficiency of parabolic concentrator, Stirling engine, heat transfer, and storage. The system combines the solar parabolic concentrator and solar energy storage connected in one system. The design, fabrication and testing of each part as well as the complete system were presented. Result presented hybrid Stirling engine proved promising, it was working, as it showed the ability to increase energy production from morning until midday and decreases as the sunset approaches. Also, PCM- storage system proved was working, as it showed the ability to store heat production from morning until sunset approaches and the ability to supply hybrid Stirling engine at night. This project has shown positive steps towards the future of solar thermal technology; one major finding and benefit from this design is that energy generated during the day can be stored for applications during the night when there is no solar radiation. The design also offers the flexibility of adjusting storage area for more space. Moreover, the entire system is affordable, less cumbersome, and with greater ease of movement

Isolation and preservation of multipotent mesenchymal stem cells from bone marrow of Arabian leopard (Panthera pradus nimr)

The Arabian leopard (Panthera pardus nimr) is critically endangered by the International Union for Conservation of Nature, with an effective population of 150-250 across its entire range in the Arabian Peninsula. Isolation and preservation of multipotent mesenchymal stem cells is beneficial both for medical and research purposes. The optimal protocol for collection, handling, culturing and preserving the Arabian leopard mesenchymal stem cells acquired from bone marrow was established. Anesthesia with combination of medetomidine and tiletamine-zozalepam is the safest option even for old animals with concurrent disease including chronic kidney disease

Accuracy of Platelet Counting by Optical and Impedance Methods in Patients with Thrombocytopaenia and Microcytosis

Objectives: Obtaining accurate platelet counts in microcytic blood samples is challenging, even with the most reliable automated haematology analysers. The CELL-DYN™ Sapphire (Abbott Laboratories, Chicago, Illinois, USA) analyser uses both optical density and electronic impedance methods for platelet counting. This study aimed to evaluate the accuracy of optical density and electrical impedance methods in determining true platelet counts in thrombocytopaenic samples with microcytosis as defined by low mean corpuscular volume (MCV) of red blood cells. Additionally, the impact of microcytosis on platelet count accuracy was evaluated. Methods: This study was carried out between February and December 2014 at the Haematology Laboratory of the Sultan Qaboos University Hospital in Muscat, Oman. Blood samples were collected and analysed from 189 patients with thrombocytopaenia and MCV values of <76 femtolitres. Platelet counts were tested using both optical and impedance methods. Stained peripheral blood films for each sample were then reviewed as a reference method to confirm platelet counts. Results: The platelet counts estimated by the impedance method were on average 30% higher than those estimated by the optical method (P <0.001). The estimated intraclass correlation coefficient was 0.52 (95% confidence interval: 0.41–0.62), indicating moderate reliability between the methods. The degree of agreement between methods ranged from -85.5 to 24.3 with an estimated bias of -30, suggesting that these methods generate different platelet results. Conclusion: The impedance method significantly overestimated platelet counts in microcytic and thrombocytopaenic blood samples. Further attention is therefore needed to improve the accuracy of platelet counts, particularly for patients with conditions associated with microcytosis

Translating and Testing the Validation of the Arabic Peer Mental Health Stigmatization Scale

Objective: Attitudes toward mental difficulties are influenced by culture, and different cultural backgrounds have different effects on people's behavior. This study aimed to prepare the Arabic version of the Peer Mental Health Stigmatization Scale (PMHSS) and validate it among Omani adolescents. Method: The study was conducted from October 2020 to the end of February 2021. The 24-items PMHSS was translated into Arabic and tested in a sample of 369 adolescents from different governmental schools in Oman. Both exploratory factor analysis (a principal component analysis (PCA) technique with Varimax rotation) and confirmatory factor analysis were performed to examine the construct validity of the PMHSS. Results: Confirmatory factor analysis was performed to examine the construct validity of the PMHSS. Cronbach’s α was 0.86 for the total scale and 0.84 and 0.81 for awareness and agreement, respectively. Therefore, the goodness-of fit-indicators support the two-correlated factor 16-item model to measure stigma (χ2 / df = 2.64 (p > 0.001), GFI = 0.92, AGFI = 0.89, CFI = 0.90, IFI = 0.90, RMSEA = 0.067). Conclusion: The Arabic version of the Peer Mental Health Stigmatization Scale (PMHSS) could assess adolescents’ stigmatizing attitudes toward various types of mental health problems within the Arabic context, and it can be utilized by researchers in Arab countries to screen for stigmatizing attitudes and to suggest suitable, effective, and outcome-focused interventions based on its results

Busulphan-Cyclophosphamide Cause Endothelial Injury, Remodeling of Resistance Arteries and Enhanced Expression of Endothelial Nitric Oxide Synthase

Stem cell transplantation (SCT) is a curative treatment for malignant and non malignant diseases. However, transplantation-related complications including cardiovascular disease deteriorate the clinical outcome and quality of life. We have investigated the acute effects of conditioning regimen on the pharmacology, physiology and structure of large elastic arteries and small resistance-sized arteries in a SCT mouse model. Mesenteric resistance arteries and aorta were dissected from Balb/c mice conditioned with busulphan (Bu) and cyclophosphamide (Cy). In vitro isometric force development and pharmacology, in combination with RT-PCR, Western blotting and electron microscopy were used to study vascular properties. Compared with controls, mesenteric resistance arteries from the Bu-Cy group had larger internal circumference, showed enhanced endothelium mediated relaxation and increased expression of endothelial nitric oxide synthase (eNOS). Bu-Cy treated animals had lower mean blood pressure and signs of endothelial injury. Aortas of treated animals had a higher reactivity to noradrenaline. We conclude that short-term consequences of Bu-Cy treatment divergently affect large and small arteries of the cardiovascular system. The increased noradrenaline reactivity of large elastic arteries was not associated with increased blood pressure at rest. Instead, Bu-Cy treatment lowered blood pressure via augmented microvascular endothelial dependent relaxation, increased expression of vascular eNOS and remodeling toward a larger lumen. The changes in the properties of resistance arteries can be associated with direct effects of the compounds on vascular wall or possibly indirectly induced via altered translational activity associated with the reduced hematocrit and shear stress. This study contributes to understanding the mechanisms that underlie the early effects of conditioning regimen on resistance arteries and may help in designing further investigations to understand the late effects on vascular system

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Correction to: Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

The original version of this article unfortunately contained a mistake

Prevalence, associated factors and outcomes of pressure injuries in adult intensive care unit patients: the DecubICUs study

Funder: European Society of Intensive Care Medicine; doi: http://dx.doi.org/10.13039/501100013347Funder: Flemish Society for Critical Care NursesAbstract: Purpose: Intensive care unit (ICU) patients are particularly susceptible to developing pressure injuries. Epidemiologic data is however unavailable. We aimed to provide an international picture of the extent of pressure injuries and factors associated with ICU-acquired pressure injuries in adult ICU patients. Methods: International 1-day point-prevalence study; follow-up for outcome assessment until hospital discharge (maximum 12 weeks). Factors associated with ICU-acquired pressure injury and hospital mortality were assessed by generalised linear mixed-effects regression analysis. Results: Data from 13,254 patients in 1117 ICUs (90 countries) revealed 6747 pressure injuries; 3997 (59.2%) were ICU-acquired. Overall prevalence was 26.6% (95% confidence interval [CI] 25.9–27.3). ICU-acquired prevalence was 16.2% (95% CI 15.6–16.8). Sacrum (37%) and heels (19.5%) were most affected. Factors independently associated with ICU-acquired pressure injuries were older age, male sex, being underweight, emergency surgery, higher Simplified Acute Physiology Score II, Braden score 3 days, comorbidities (chronic obstructive pulmonary disease, immunodeficiency), organ support (renal replacement, mechanical ventilation on ICU admission), and being in a low or lower-middle income-economy. Gradually increasing associations with mortality were identified for increasing severity of pressure injury: stage I (odds ratio [OR] 1.5; 95% CI 1.2–1.8), stage II (OR 1.6; 95% CI 1.4–1.9), and stage III or worse (OR 2.8; 95% CI 2.3–3.3). Conclusion: Pressure injuries are common in adult ICU patients. ICU-acquired pressure injuries are associated with mainly intrinsic factors and mortality. Optimal care standards, increased awareness, appropriate resource allocation, and further research into optimal prevention are pivotal to tackle this important patient safety threat

Comparative analysis of four methods for enumeration of platelet counts in thrombocytopenic patients

Background: Even with the most reliable automated blood cell analyzers, obtaining an accurate platelet count in patients with thrombocytopenia is still challenging especially when making decisions for platelet transfusions. The Cell-Dyn Sapphire offers three methods for platelet counting including the optical, impedance, and immunological techniques. Aim: A comparative analysis evaluating the performance of these three methods, along with the manual technique, was performed in thrombocytopenic patients. Materials and Methods: A total of 32 blood samples from patients without a history of chemotherapy and a platelet count <50 ×- 109/l were tested in parallel by four different methods. Results: Compared to other techniques, impedance method provided an overestimation of platelet count (P = 0.0008) and failed to show a result in 15% of cases with low platelet counts (<15 ×- 109/l). Good to excellent correlations and reliability values were evidenced among study methods, but a poor reliability was noticed between the impedance and immunological methods with an intraclass correlation coefficient of 0.49 (confidence interval: 0.15–0.73; P = 0.003). In the bias analysis, the impedance method showed the highest levels of disagreement with other techniques. Summary/Conclusion: Collectively, these results provide evidence that the optical or immunological technique appear to be superior to the impedance method in estimating low platelet counts with the automated analyzer Cell-Dyn Sapphire. As such, the healthcare staff and the physicians must be aware of this limitation, especially in the presence of severe thrombocytopenia, when a decision of platelet transfusion has to be made

Complete utilization of date seeds for biofuel production

The utilization of agricultural waste to produce energy is considered a promising solution that combines waste minimization with energy diversification. This study investigated the full utilization of date seeds (DSs) for the combined production of biodiesel, bioethanol, and bio-oil. To optimize this process, the efficacy of oil extraction as a pretreatment method to enhance enzymatic hydrolysis was explored. Oil extraction was not only proved to be a good pretreatment method, it was also shown that it is superior to the conventional alkaline-pretreated under optimum operating conditions. Using post oil extraction samples, with 7% oil yield, the total sugars production by enzymatic hydrolysis increased by an impressive 75%, as compared to alkaline pretreatment, with 30% lignin removal. Subjecting the leftover DSs, after oil extraction and enzymatic hydrolysis, to pyrolysis at a temperature, heating rate, and residence time of 500 °C, 10 °C/min, and 10 min, respectively, resulted in bio-oil yield of 33.3%. This work demonstrated the potential of fully utilizing DSs for producing various biofuels, by providing a promising alternative for managing agricultural waste