48 research outputs found
Enhanced Solar Energy Conversion Through Optimized Multijunction Photovoltaic Cells
As technology advances, the demand for energy sources continues to grow. In response to this demand, renewable energy has emerged as a key solution, leveraging environmentally friendly methods such as photovoltaic technology. However, existing solar cells exhibit low efficiency and power conversion rates. This study aims to identify the optimal materials and number of junctions necessary to enhance solar cell efficiency through the multijunction concept, which has been modelled using Matlab Simulink. The research employed various equations to design solar cells, including calculations for energy bandgap, reverse leakage, short circuit current, open circuit voltage, and power output. The findings revealed that a quadruple junction utilizing specific semiconductor materials achieved an impressive efficiency of 58.84%, a notable improvement compared to the 11.03% efficiency of single-junction solar cells
Enhanced Solar Energy Conversion Through Optimized Multijunction Photovoltaic Cells
As technology advances, the demand for energy sources continues to grow. In response to this demand, renewable energy has emerged as a key solution, leveraging environmentally friendly methods such as photovoltaic technology. However, existing solar cells exhibit low efficiency and power conversion rates. This study aims to identify the optimal materials and number of junctions necessary to enhance solar cell efficiency through the multijunction concept, which has been modelled using Matlab Simulink. The research employed various equations to design solar cells, including calculations for energy bandgap, reverse leakage, short circuit current, open circuit voltage, and power output. The findings revealed that a quadruple junction utilizing specific semiconductor materials achieved an impressive efficiency of 58.84%, a notable improvement compared to the 11.03% efficiency of single-junction solar cells
Using Virtual Reality to teach ultrasound-guided needling skills for regional anaesthesia:A randomised controlled trial
STUDY OBJECTIVE: We previously designed and validated a virtual reality-based simulator to help train novices in ultrasound-guided needling skills necessary for safe and competent ultrasound-guided regional anaesthesia. This study was designed to compare the performance and error rates of novices trained by a human faculty aided with the assistance of this virtual reality simulator (virtual reality-assisted training), versus novices trained wholly by humans (conventional training).DESIGN, SETTING, AND PARTICIPANTS: In this single centre, randomised controlled study, we used a standardised teaching protocol, rigorous blinding, iterative training of assessors, and validated global rating scale and composite error score checklists to assess skills learning of novice participants.MAIN RESULTS: We recruited 45 novices and scored 270 assessments of performance and error rates. Inter-rater correlation coefficient of reliability of scoring between assessors for the global rating scale was 0.84 (95%CI 0.68-0.92) and for the composite error score checklist was 0.87 (95%CI 0.73-0.93). After adjustment for age, sex, Depression, Anxiety and Stress-21, and baseline score, there was no statistical difference for virtual reality-assisted training compared to conventional training in final global rating score (average treatment effect -3.30 (95%CI-13.07-6.48), p = 0.51) or in the final composite error score (average treatment effect 1.14 (95%CI -0.60-2.88), p = 0.20). Realism in the virtual reality simulator was similar to real-life when measured by the Presence Questionnaire, all components p > 0.79; and task workload assessed by the NASA-Task Load Index was not statistically different between groups, average treatment effect 5.02 (95%CI -3.51-13.54), p = 0.25. Results were achieved in the virtual reality-assisted group with half the human faculty involvement.CONCLUSION: Novices trained using a hybrid, virtual reality-assisted teaching program showed no superiority to novices trained using a conventional teaching program, but with less burden on teaching resources.</p
Incidence, trends and demographics of Staphylococcus aureus infections in Auckland, New Zealand, 2001–2011
BACKGROUND: New Zealand has a higher incidence of Staphylococcus aureus disease than other developed countries, with significant sociodemographic variation in incidence rates. In contrast to North America, the majority of disease is due to methicillin-susceptible S. aureus (MSSA), although relatively little is known about the comparative demographics of MSSA and methicillin-resistant S. aureus (MRSA) infections in New Zealand. METHODS: Our objectives were to describe the trends, incidence and patient demographics of all S. aureus infections in patients presenting to our institution between 2001 and 2011, and compare the epidemiology of MSSA and MRSA infections. We identified all patients with S. aureus infections over the study period. A unique S. aureus infection was defined as the first positive S. aureus culture taken from the same patient within a thirty-day period. Standard definitions were used to classify episodes into community- or healthcare-associated S. aureus infection. RESULTS: There were 16,249 S. aureus infections over the study period. The incidence increased significantly over the study period from 360 to 412 per 100,000 population (P < 0.001), largely driven by an increase in community-associated non-invasive MSSA infections. When compared with MSSA infections, patients with non-multiresistant MRSA infections were more likely to be older, have hospital-onset infections and be Māori or Pacific Peoples. CONCLUSIONS: Our work provides valuable baseline data on the epidemiology and trends of S. aureus infections in New Zealand. The significant increase in community-associated S. aureus infections is of public health importance. Future studies should investigate the reasons underlying this concerning trend
Population-based incidence and comparative demographics of community-associated and healthcare-associated Escherichia coli bloodstream infection in Auckland, New Zealand, 2005 – 2011
The Political Consequences of Outsider Labour Market Status in the United States: A Micro-level Study
This paper contributes to recent research that seeks to understand the political consequences of ‘outsider’ labour market status. There is an emerging consensus that labour market outsiders have systematically different policy preferences and display systematically different political behavior to securely employed ‘insiders’ in Europe. Yet the political consequences of outsider status in the United States are less clear. They may be expected to differ from those that have been documented in the European context, because 1) the US is characterized by low employment protection of insiders, and 2) there is evidence that Americans are more reluctant than Europeans to hold governments responsible for personal economic hardship. We therefore use the General Social Survey to examine how outsider labour market status is related to voting behavior and to social policy preferences in the United States. We find that the concept of ‘labour market outsider’ - as conventionally operationalized - holds little explanatory power in the American context. Disaggregating the outsider category, our results suggest that the political consequences of outsider labour market status may be contingent on individual beliefs about government responsibility
Hot flashes are not predictive for serum concentrations of tamoxifen and its metabolites
Recommendations for effective documentation in regional anesthesia: an expert panel Delphi consensus project
Background and objectives: Documentation is important for quality improvement, education, and research. There is currently a lack of recommendations regarding key aspects of documentation in regional anesthesia. The aim of this study was to establish recommendations for documentation in regional anesthesia.
Methods: Following the formation of the executive committee and a directed literature review, a long list of potential documentation components was created. A modified Delphi process was then employed to achieve consensus amongst a group of international experts in regional anesthesia. This consisted of 2 rounds of anonymous electronic voting and a final virtual round table discussion with live polling on items not yet excluded or accepted from previous rounds. Progression or exclusion of potential components through the rounds was based on the achievement of strong consensus. Strong consensus was defined as ≥75% agreement and weak consensus as 50%-74% agreement.
Results: Seventy-seven collaborators participated in both rounds 1 and 2, while 50 collaborators took part in round 3. In total, experts voted on 83 items and achieved a strong consensus on 51 items, weak consensus on 3 and rejected 29.
Conclusion: By means of a modified Delphi process, we have established expert consensus on documentation in regional anesthesia
Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers
https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd
Elective surgery system strengthening: development, measurement, and validation of the surgical preparedness index across 1632 hospitals in 119 countries
Background:
The 2015 Lancet Commission on global surgery identified surgery and anaesthesia as indispensable parts of holistic health-care systems. However, COVID-19 exposed the fragility of planned surgical services around the world, which have also been neglected in pandemic recovery planning. This study aimed to develop and validate a novel index to support local elective surgical system strengthening and address growing backlogs.
Methods:
First, we performed an international consultation through a four-stage consensus process to develop a multidomain index for hospital-level assessment (surgical preparedness index; SPI). Second, we measured surgical preparedness across a global network of hospitals in high-income countries (HICs), middle-income countries (MICs), and low-income countries (LICs) to explore the distribution of the SPI at national, subnational, and hospital levels. Finally, using COVID-19 as an example of an external system shock, we compared hospitals' SPI to their planned surgical volume ratio (SVR; ie, operations for which the decision for surgery was made before hospital admission), calculated as the ratio of the observed surgical volume over a 1-month assessment period between June 6 and Aug 5, 2021, against the expected surgical volume based on hospital administrative data from the same period in 2019 (ie, a pre-pandemic baseline). A linear mixed-effects regression model was used to determine the effect of increasing SPI score.
Findings:
In the first phase, from a longlist of 103 candidate indicators, 23 were prioritised as core indicators of elective surgical system preparedness by 69 clinicians (23 [33%] women; 46 [67%] men; 41 from HICs, 22 from MICs, and six from LICs) from 32 countries. The multidomain SPI included 11 indicators on facilities and consumables, two on staffing, two on prioritisation, and eight on systems. Hospitals were scored from 23 (least prepared) to 115 points (most prepared). In the second phase, surgical preparedness was measured in 1632 hospitals by 4714 clinicians from 119 countries. 745 (45·6%) of 1632 hospitals were in MICs or LICs. The mean SPI score was 84·5 (95% CI 84·1–84·9), which varied between HIC (88·5 [89·0–88·0]), MIC (81·8 [82·5–81·1]), and LIC (66·8 [64·9–68·7]) settings. In the third phase, 1217 (74·6%) hospitals did not maintain their expected SVR during the COVID-19 pandemic, of which 625 (51·4%) were from HIC, 538 (44·2%) from MIC, and 54 (4·4%) from LIC settings. In the mixed-effects model, a 10-point increase in SPI corresponded to a 3·6% (95% CI 3·0–4·1; p<0·0001) increase in SVR. This was consistent in HIC (4·8% [4·1–5·5]; p<0·0001), MIC (2·8 [2·0–3·7]; p<0·0001), and LIC (3·8 [1·3–6·7%]; p<0·0001) settings.
InterpBackground
The 2015 Lancet Commission on global surgery identified surgery and anaesthesia as indispensable parts of holistic health-care systems. However, COVID-19 exposed the fragility of planned surgical services around the world, which have also been neglected in pandemic recovery planning. This study aimed to develop and validate a novel index to support local elective surgical system strengthening and address growing backlogs.
Methods:
First, we performed an international consultation through a four-stage consensus process to develop a multidomain index for hospital-level assessment (surgical preparedness index; SPI). Second, we measured surgical preparedness across a global network of hospitals in high-income countries (HICs), middle-income countries (MICs), and low-income countries (LICs) to explore the distribution of the SPI at national, subnational, and hospital levels. Finally, using COVID-19 as an example of an external system shock, we compared hospitals' SPI to their planned surgical volume ratio (SVR; ie, operations for which the decision for surgery was made before hospital admission), calculated as the ratio of the observed surgical volume over a 1-month assessment period between June 6 and Aug 5, 2021, against the expected surgical volume based on hospital administrative data from the same period in 2019 (ie, a pre-pandemic baseline). A linear mixed-effects regression model was used to determine the effect of increasing SPI score.
Findings:
In the first phase, from a longlist of 103 candidate indicators, 23 were prioritised as core indicators of elective surgical system preparedness by 69 clinicians (23 [33%] women; 46 [67%] men; 41 from HICs, 22 from MICs, and six from LICs) from 32 countries. The multidomain SPI included 11 indicators on facilities and consumables, two on staffing, two on prioritisation, and eight on systems. Hospitals were scored from 23 (least prepared) to 115 points (most prepared). In the second phase, surgical preparedness was measured in 1632 hospitals by 4714 clinicians from 119 countries. 745 (45·6%) of 1632 hospitals were in MICs or LICs. The mean SPI score was 84·5 (95% CI 84·1–84·9), which varied between HIC (88·5 [89·0–88·0]), MIC (81·8 [82·5–81·1]), and LIC (66·8 [64·9–68·7]) settings. In the third phase, 1217 (74·6%) hospitals did not maintain their expected SVR during the COVID-19 pandemic, of which 625 (51·4%) were from HIC, 538 (44·2%) from MIC, and 54 (4·4%) from LIC settings. In the mixed-effects model, a 10-point increase in SPI corresponded to a 3·6% (95% CI 3·0–4·1; p<0·0001) increase in SVR. This was consistent in HIC (4·8% [4·1–5·5]; p<0·0001), MIC (2·8 [2·0–3·7]; p<0·0001), and LIC (3·8 [1·3–6·7%]; p<0·0001) settings.
Interpretation:
The SPI contains 23 indicators that are globally applicable, relevant across different system stressors, vary at a subnational level, and are collectable by front-line teams. In the case study of COVID-19, a higher SPI was associated with an increased planned surgical volume ratio independent of country income status, COVID-19 burden, and hospital type. Hospitals should perform annual self-assessment of their surgical preparedness to identify areas that can be improved, create resilience in local surgical systems, and upscale capacity to address elective surgery backlogs.retation
The SPI contains 23 indicators that are globally applicable, relevant across different system stressors, vary at a subnational level, and are collectable by front-line teams. In the case study of COVID-19, a higher SPI was associated with an increased planned surgical volume ratio independent of country income status, COVID-19 burden, and hospital type. Hospitals should perform annual self-assessment of their surgical preparedness to identify areas that can be improved, create resilience in local surgical systems, and upscale capacity to address elective surgery backlogs
