Particulate Matter Inhalation Exposure Chambers and Parameters Affecting Their Performance: A Systematic Review Study

Exposure to inhalation aerosols and particulate matter (PM) in different concentrations can increase the risk of respiratory, cardiovascular, and other related diseases. The inhalation exposure studies are implemented to assess the biological effects of these hazardous agents in human or animal models, in whole-body (WB) or nose/head-only conditions. Several factors can affect the performance of the inhalation exposure chambers and if left uncontrolled, the results may not be desirable. The current study reviewed the characteristics, structures, and factors affecting the performance of the WB chambers, especially the ones designed for small animal exposure to the PM. At the primary stage, the criteria and the search strategy were determined and the keywords were searched in the scientific electronic databases. Totally, 1051 articles were extracted in the first stage, and finally seven articles were adopted. The technical and design details, materials, coefficient variations (CVs) of concentration, assessment methods, type and number of laboratory animals, procedure, and animals housing conditions were extracted from the selected articles. Then the most desirable WB inhalation exposure chamber was determined based on the criteria for assessing the presented exposure chambers such as the animal housing and least CVs of the concentration in the respiratory zones of the animals under study. It was concluded that the Kimmel design was the best and the most desirable chamber structurally and geometrically, since the concentration of the particle (NaCl) injected into the chamber varied from 3.5% to 5.2%, under standard conditions. Keywords:Inhalation Chamber; Whole-Body; Inhalation Exposure; Particulate Matter

Model-based Building Retrofit: Experiences at Sharif University of Technology

This paper presents a model-based technique for building retrofit planning. The approach is based on the building energy model. An algorithm has been developed to calibrate building energy model based on hourly data. The calibrated model is used to select candidate retrofit actions and assess the energy saving potential associated with each candidate action. The proposed technique has been applied for retrofit planning in Department of Energy Engineering (DOEE) at the Sharif University of Technology in 2015. An smart reading system has been also developed to capture the hourly gas consumption for DOEE. Building energy model for DOEE has been developed in EnergyPlus and calibrated using the proposed algorithm. A set of retrofit action has been selected and implemented in DOEE based on the proposed technique. The results showed that the average cooling energy use in summers was reduced by 20% compared to the 6-year average summer energy use before retrofit. The results showed that only HVAC control has more than 8% impact on cooling energy use

Experiences of critical care nurses fighting againstCOVID‐19: A qualitative phenomenological study

Aim: This study sought to describe the experiences of critical care nurses caring for patients infected by coronavirus disease 2019 (COVID‐19). Design: A qualitative phenomenological design was used. Methods: We enrolled 15 nurses who provided care for patients infected by COVID‐19 purposively and through snowballing, using a phenomenological approach in critical care units of Iran's public hospitals between May and June 2020. The semi‐structured interviews were carried out either via face‐to‐face or telephone and were analyzed using the 7‐step method of Colaizzi. Results: The experiences of nurses caring for patients infected with COVID‐19 were categorized into four challenges, including psychological (eight subthemes), organizational (six subthemes), social (six subthemes), and professional (five subthemes). In general, based on the current classification, there seems to be a mixture of positive and negative effects on the psychological, social, and professional challenges and the negative effect only on the organizational challenges. Conclusions: Positive and negative emotions and experiences have coexisted for the critical care nurses since the COVID‐19 outbreak. Emotional support and psychological counseling play an important role in maintaining nurses' optimal mental health during the COVID‐19 crisis. Adequate protective equipment, financial and nonfinancial supports, effective communication, training and hiring of staff, and appropriate work shifts are also required to reduce nurses' negative experiences when providing care for the affected individuals

Screening Characteristics of Bedside Ultrasonography in Confirming Endotracheal Tube Placement; a Diagnostic Accuracy Study

Introduction: Confirmation of proper endotracheal tube placement is one of the most important and lifesaving issues of tracheal intubation. The present study was aimed to evaluate the accuracy of tracheal ultrasonography by emergency residents in this regard.  Method: This was a prospective, cross sectional study for evaluating the diagnostic accuracy of ultrasonography in endotracheal tube placement confirmation compared to a combination of 4 clinical confirmation methods of chest and epigastric auscultation, direct laryngoscopy, aspiration of the tube, and pulse oximetry (as reference test).Results: 150 patients with the mean age of 58.52 ± 1.73 years were included (56.6% male). Sensitivity, specificity, positive predictive value, negative predictive value, and positive and negative likelihood ratio of tracheal ultrasonography in endotracheal tube confirmation were 96 (95% CI: 92-99), 88 (95% CI: 62-97), 98 (95% CI: 94-99), 78 (95% CI: 53-93), 64 (95% CI: 16-255), and 0.2 (95% CI: 0.1-0.6), respectively.Conclusion: The present study showed that tracheal ultrasonography by trained emergency medicine residents had excellent sensitivity (>90%) and good specificity (80-90) for confirming endotracheal tube placement. Therefore, it seems that ultrasonography is a proper screening tool in determining endotracheal tube placement

A survey of incidental ocular trauma by pencil and pen

AIM: To determine characteristic features of ocular trauma resulted from self-trauma by writing instruments among pediatric population. METHODS: Thirty-six children who suffered from self-inflicted ocular trauma with a writing instrument were included in this prospective cross-sectional study. RESULTS: The mean age was 5.6±2.7y with male: female ratio of 1.77. The right eye was involved two times more than the left eye. The superomedial (55.5%) and inferomedial (30.6%) quadrants were the most common sites of injury. The leading culprit was colored pencils (44.4%). During surgical exploration, no foreign body (FB) was found in 25 (69.4%) patients while an FB was found in 11 (30.5%) patients. Brain injury was present in two patients (5.6%) and only in superomedial quadrant injuries. Zone 1 was the most common site for ocular trauma associated with penetrating injury. The mean ocular trauma score (OTS) in penetrating injuries was 3.8±1.2. The best corrected visual acuity (BCVA) was 0.3±0.6 upon admittance and 0.08±0.21 after one year. The final BCVA was significantly correlated with the entrance site, better final BCVA was found in nasal entrance site (P<0.05). CONCLUSION: The ophthalmologists should keep a high index of suspicion to rule out penetrating eye injuries related to writing instruments in a young uncooperative child. Brain injury is a life-threatening event that should be ruled out by appropriate imaging. Medial canthal area as the most common site needs an especial attention in writing instrument injuries

Evaluating the efficiency of divestiture policy in promoting competitiveness using an analytical method and agent-based computational economics

Choosing a desired policy for divestiture of dominant firms' generation assets has been a challenging task and open question for regulatory authority. To deal with this problem, in this paper, an analytical method and agent-based computational economics (ACE) approach are used for ex-ante analysis of divestiture policy in reducing market power. The analytical method is applied to solve a designed concentration boundary problem, even for situations where the cost data of generators are unknown. The concentration boundary problem is the problem of minimizing or maximizing market concentration subject to operation constraints of the electricity market. It is proved here that the market concentration corresponding to operation condition is certainly viable in an interval calculated by the analytical method. For situations where the cost function of generators is available, the ACE is used to model the electricity market. In ACE, each power producer's profit-maximization problem is solved by the computational approach of Q-learning. The power producer using the Q-learning method learns from past experiences to implicitly identify the market power, and find desired response in competing with the rivals. Both methods are applied in a multi-area power system and effects of different divestiture policies on market behavior are analyzed.Electricity market Divestiture policy Agent-based computational economics

Reliability-Centered Maintenance for Overhead Transmission Lines in Composite Power System

Reliable overhead transmission lines have a vital role in maintaining the reliability of power systems at a desirable level and ensuring the continuity of electrical energy. In this regard, a proper preventive maintenance program can ensure the reliable functioning of transmission lines. Based on the concept of reliability-centered maintenance, this paper proposes a preventive maintenance strategy that can be implemented in real power systems due to the limited data requirements. The priority of each line for preventive maintenance was obtained by two indices revealing the technical condition and importance of each line in the network. The proposed method was applied to a real transmission network in Khorasan province of Iran. In order to extract the condition index of lines, failure statistics during six recent years as well as technical data of lines were investigated. Moreover, this paper presents a two-stage method to determine the importance index of each line by evaluating the consequences of line failures on the network. The presented results show the efficiency of the proposed approach