Investigation of carrier confinement in direct bandgap GeSn/SiGeSn 2D and 0D heterostructures

Since the first demonstration of lasing in direct bandgap GeSn semiconductors, the research efforts for the realization of electrically pumped group IV lasers monolithically integrated on Si have significantly intensified. This led to epitaxial studies of GeSn/SiGeSn hetero- and nanostructures, where charge carrier confinement strongly improves the radiative emission properties. Based on recent experimental literature data, in this report we discuss the advantages of GeSn/SiGeSn multi quantum well and quantum dot structures, aiming to propose a roadmap for group IV epitaxy. Calculations based on 8-band k∙p and effective mass method have been performed to determine band discontinuities, the energy difference between Γ- and L-valley conduction band edges, and optical properties such as material gain and optical cross section. The effects of these parameters are systematically analyzed for an experimentally achievable range of Sn (10 to 20 at.%) and Si (1 to 10 at.%) contents, as well as strain values (−1 to 1%). We show that charge carriers can be efficiently confined in the active region of optical devices for experimentally acceptable Sn contents in both multi quantum well and quantum dot configurations

Shortening Door-to-Balloon Time: The Use of Ambulance versus Private Vehicle for Patients with ST-Segment Elevation Acute Myocardial Infarction

Abdulrhman Saleh Alghamdi,1,2 Abdullah Alshibani,1,2 Meshary Binhotan,1,2 Meshal Alharbi,1,2 Saleh S Algarni,2,3 Mohammed Musaed Alzahrani,1,2 Abdulmalik Nasser Asiri,1,2 Faisal Faleh Alsulami,1,2 Kamal Ayoub,2,4 Abdullah Alabdali1,2 1Department of Emergency Medical Services, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia; 2King Abdullah International Medical Research Center, Riyadh, Saudi Arabia; 3Department of Respiratory Therapy, College of Applied Medical Sciences, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, 11481, Saudi Arabia; 4Ministry of the National Guard - Health Affairs, Riyadh, Saudi ArabiaCorrespondence: Abdulrhman Saleh Alghamdi, Emergency Medical Services, College of Applied Medical Sciences, Ext. 95186, Mail Code 3129, P.O. Box 3660, Riyadh, 11481, Saudi Arabia, Tel +96611 429 9999, Email [email protected]: Time is critical when dealing with acute myocardial infarction (AMI) patients in the Emergency Department (ED), as 90 min is crucial for overall health. Using non-EMS transportation for critical patients, such as patients with acute myocardial infarction, to a hospital might delay the rapid identification of the underlying medical disease and initiating definitive treatment. We aim to evaluate the association between the mode of transportation and the D2B time in patients presenting at the ED with AMI.Patients and Methods: We conducted a retrospective cohort study with patients who presented at ED with AMI and underwent percutaneous coronary intervention (PCI). The participants were patients with confirmed AMI at the ED of King Abdullah Medical City (KAMC) from January 2019 to December 2019.Results: In total, 162 AMI patients were enrolled in the study and divided based on the method of transportation. Less than half (n=65, 40.1%) were transported with an ambulance and 97 (59.9%) patients with a private car. The door-to-balloon (D2B) time for the ambulance group was 93.6± 38.31 minutes, and the private car group was 93.8± 30.88 minutes.Conclusion: There was no statistical significance when comparing the D2B time between the private car group and the ambulance group (P = 0.1870). Finally, ambulance transport significantly shortened the time to first ED physician contact. However, it was not associated with shortened D2B time when compared to private vehicle transport.Keywords: chest pain, acute myocardial infarction, ambulance, door to balloon, emergency departmen

COVID-19: Factors associated with psychological distress, fear, and coping strategies among community members across 17 countries

Abstract Background The current pandemic of COVID-19 impacted the psychological wellbeing of populations globally. Objectives We aimed to examine the extent and identify factors associated with psychological distress, fear of COVID-19 and coping. Methods We conducted a cross-sectional study across 17 countries during Jun-2020 to Jan-2021. Levels of psychological distress (Kessler Psychological Distress Scale), fear of COVID-19 (Fear of COVID-19 Scale), and coping (Brief Resilient Coping Scale) were assessed. Results A total of 8,559 people participated; mean age (&plusmn;SD) was 33(&plusmn;13) years, 64% were females and 40% self-identified as frontline workers. More than two-thirds (69%) experienced moderate-to-very high levels of psychological distress, which was 46% in Thailand and 91% in Egypt. A quarter (24%) had high levels of fear of COVID-19, which was as low as 9% in Libya and as high as 38% in Bangladesh. More than half (57%) exhibited medium to high resilient coping; the lowest prevalence (3%) was reported in Australia and the highest (72%) in Syria. Being female (AOR 1.31 [95% CIs 1.09-1.57]), perceived distress due to change of employment status (1.56 [1.29-1.90]), comorbidity with mental health conditions (3.02 [1.20-7.60]) were associated with higher levels of psychological distress and fear. Doctors had higher psychological distress (1.43 [1.04-1.97]), but low levels of fear of COVID-19 (0.55 [0.41-0.76]); nurses had medium to high resilient coping (1.30 [1.03-1.65]). Conclusions The extent of psychological distress, fear of COVID-19 and coping varied by country; however, we identified few higher risk groups who were more vulnerable than others. There is an urgent need to prioritise health and well-being of those people through well-designed intervention that may need to be tailored to meet country specific requirements. </jats:sec

Pharmacotherapies for cannabis use disorders: Clinical challenges and promising therapeutic agents

This chapter reviews pharmacotherapies that have been trialled for cannabis dependence, identifying those that warrant further research and those of little or uncertain value. A diverse range of medicines have been tested, representing a broad range of pharmacological strategies. These include tetrahydrocannabinol preparations, various types of antidepressant, anxiolytics, a glutamatergic modulator and the neuropeptide oxytocin. Cannabinoid agonists warrant further research. For the FAAH inhibitor PF-04457845, oxytocin, varenicline and gabapentin, although there is a signal to indicate further research is warranted, these medications do not yet have sufficient evidence to support clinical use, and larger, longer-term trials are needed in representative treatment-seeking populations. Special populations that warrant consideration are those with cannabis dependence and concurrent mental health conditions and those that develop dependence through therapeutic use.Suzanne Nielsen, Pamela Sabioni, Linda Gowing, and Bernard Le Fol