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Background and aims Existing assessments of the time-trends of opioid-related mortality, hospitalization and emergency department visits in Canada have relied mainly on provincial databases, while national assessments generally do not provide information before 2016. We aimed to estimate Canadian national time trends in opioid-related mortality from 2000 to 2017 and opioid-related hospitalization and emergency department visits between 2000 and 2012. Design Retrospective cohort study. Setting and participants Residents of all Canadian provinces and territories for which comparable data were available from 2000 to 2017. Measurements We identified opioid-related mortality, hospitalization and emergency department visits using validated algorithms using ICD codes from administrative databases. We calculated crude rates and sex- and age-adjusted rates per million. For hospitalizations, we calculated case-fatality, 90-day and 365-day all-cause mortality and opioid-related re-hospitalization rates. We used Poisson regression to examine the significance of the time trend. Findings From 2000 to 2017, the adjusted opioid mortality rate in Canada (outside Quebec) increased significantly by 592.9% (from 20.0 opioid deaths per million in 2000 to 118.3 in 2017). The highest year-to-year increases were from 2015 to 2016 (31.8%) and from 2016 to 2017 (52.2%). The adjusted hospitalizations doubled significantly during the study period (an increase of 103.7%, from 159.7 opioid hospitalizations per million Canadians in 2000 to 325.3 in 2012). The adjusted rate of emergency department visits increased significantly by 188.7% (from 280.6 per million in 2000 to 810.1 in 2012). Case-fatality was 2.3% overall and was mainly constant during the study period. Both 90- and 365-day all-cause mortality increased significantly between 2000 and 2011 (from 1.7 to 3.1% and 3.9 to 7.4%, respectively), while re-hospitalization for opioid-related diagnoses was reduced (from 7.8 to 6.4% and 14.2 to 12.9%, respectively). Conclusions Opioid-related mortality, hospitalization and emergency department visits in Canada have been increasing gradually since 2000.

Despite common, serious, costly, and often fatal conditions affecting up to 50 % of older patients, delirium is often unrecognized and overlooked. We examine the accuracy of the 4AT for detecting older patients with delirium.We performed a systematic search of PubMed, Web of Science, PsycINFO, and EMBASE databases from inception to April 2020 and updated to January 2022. Four independently reviewers extracted study data and assessed the methodological quality using the revised quality assessment of diagnostic accuracy studies tool (QUADAS-2). Pooled estimates of sensitivity and specificity were generated using a bivariate random effects model. All statistical analyses were performed with STATA version 15.1 and Meta-DiSc version 1.4 software.Eleven studies with 2789 participants were included. The pooled sensitivity and specificity were 0.87 (95 % CI: 0.81-0.91) and 0.87 (95 % CI: 0.79-0.92), respectively, and the positive and negative likelihood ratios were 6.66 (95 % CI: 4.12-10.74) and 0.15 (95 % CI: 0.10-0.23), respectively. Deeks' test indicated no significant publication bias (t = 0.83, P = 0.43). Univariable meta-regression showed that patient selection and flow and timing significantly influenced the pooled sensitivity (P 0.05), settings significantly influenced the pooled specificity (P 0.05).Our meta-analysis demonstrates that 4AT is a sensitive and specific screening tool for delirium in older patients. Its brevity and simplicity support its use in routine clinical practice, particularly in time-poor settings. Clinicians should come to a conclusion based largely on the 4AT findings in conjunction with clinical judgment.

The near-field electrospinning is considered as one of the most effective techniques to direct-write aligned fibers which can be applied to various high-tech areas, including energy harvester, tissue engineering, and wearable sensors. For large area aligned pattern printing, the multi-nozzle electrohydrodynamic print-ing is an efficient method to enhance productivity. As a branch of electrohydro-dynamic printing technology, the near-field electrospinning is a crucial concern to make an investigation for the formation of aligned nanofibers. Here we fabricated various nanostructures from beaded fibers to aligned fibers and crimped fibers by the double-nozzle near-field electrospinning process. We found three key parameters affecting the process, including the collector speed, the applied voltage, and the electrode-to-collector distance, and the collector speed is the key factor affecting the crimped frequency. This paper provides a reliable experi-mental basis and theoretical guidance for the multi-nozzle near-field electrospin-ning to accurately direct-write microfibers and nanofibers.

Background: Delirium is a common type of acute brain dysfunction among emergency department (ED) patients. The prevalence of delirium in the ED is up to 40%. Although screening instruments used to identify delirium have been developed, it is unclear which tool is the most accurate in the ED. To address this challenging, we systematically examine the accuracy of delirium screening tools used to assess the ED patients. Methods: This study has been registered at the International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY), and the registration number is INPLASY202110041. We will search the PubMed, EMBASE, PsycINFO, and the Cochrane Library. Studies involving patients which compared diagnostic instruments with the criteria in Diagnostic and Statistical Manual of Mental Disorders (DSM) as a reference standard will be included. We will use STATA 15.1 and MetaDiSC to make careful analysis of the results. The quality of included studies will be assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 scale. Results: In this study, the accuracy of different screening methods among ED patients is assessed by a high-quality synthesis. The number of tools available for screening delirium in the ED, the information of studies including the countries, the study design, the sample size and the characteristic of studies, the quality of the studies and the results of meta-analysis. The systematic review and meta-analysis will be published in a peer-reviewed journal. Conclusion: According to the conclusion of the systematic review, evidence will be provided to judge which screening method is the best for the ED patients. The results will bring better understanding of screening methods in the ED and highlight gaps for future research.

Background. Cigarette smoking and Th2-inflammation are both crucial in the pathogenesis of asthma. However, it is unknown whether smoking can affect the association between Th2-inflammation and small airway obstruction in adults with asthma. Methods. Adults diagnosed with asthma by a pulmonologist according to Global Initiative for Asthma guidelines were recruited from September 2016 to April 2018 to participate in this study. Participants were divided into two groups, the small airway obstruction group (those with FEF25–75% predicted value ≤ 65%) and the normal small airway function group (those with FEF25–75% predicted value > 65%). Final data analysis included 385 and 93 people in the Obstructive Group and the Normal Group, respectively. Total serum IgE level and blood eosinophil count were used as biomarkers of the Th2 phenotype. Results. The Obstructive Group had a larger fraction of smokers, higher blood eosinophil count, and lower lung function than the Normal Group. Current-smoking status was associated with an increased risk of small airway obstruction (adjusted odds ratio = 4.677, 95% confidence interval [1.593–13.730]); and log-IgE level was associated with a decreased risk of small airway obstruction (0.403 [0.216–0.754]). Smoking status stratified analysis showed an association between log-IgE level and a decreased risk of small airway obstruction only in never-smoker asthmatics (0.487 [0.249–0.954]). Conclusions. Current-smoking status and total serum IgE are, respectively, associated with small airway obstruction. Smoking status modifies the relationship between Th2 biomarkers and small airway function. These findings contribute to the understanding of risk factors associated with asthma endotyping.

Background: Delirium is a complex syndrome characterized by a disturbance in attention and awareness, with a prevalence of 10-20% in patients admitted to the Emergency Department (ED). Screening tools have been developed to identify delirium in the ED, but their accuracy of screening remains unclear. To address this challenge, we conducted a comprehensive meta-analysis to systematically review the accuracy of delirium screening tools currently being used to assess ED patients.Methods: PubMed, PsycINFO, EMBASE, and the Cochrane Library were searched. Studies involving ED inpatients which compared diagnostic tools with the Diagnostic and Statistical Manual of Mental Disorders (DSM) criteria as a reference standard were included. Two reviewers independently screened the studies, extracted data, and assessed the quality of studies using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 scale. We conducted a conventional meta-analysis for each screening tool. Then we used network meta-analysis method to calculate the relative sensitivity and specificity among the diagnostic tests. The diagnostic accuracies were then ranked through the superiority index.Results: Thirteen studies included six screening tools. The pooled sensitivity and specificity for the Confusion Assessment Method (CAM) were 0.71 and 0.98, and for 4AT (Arousal, Attention, Abbreviated Mental Test 4, Acute change) were 0.83 and 0.93, respectively. The other four tools used were only reported in one or two studies. Their sensitivity ranged from 0.70 to 1.00, and their specificity ranged from 0.64 to 0.99. Moreover, network meta-analysis indicated that the CAM and 4AT had a greater superiority index and a higher diagnostic accuracy.Conclusions: The available data suggested that both the CAM and 4AT can be used as efficient screening tools for the ED patients.

Background: Delirium is a frequent form of acute brain dysfunction in mechanically ventilated patients. Screening tools have been developed to identify delirium, but it is unclear which tool is the most accurate. Therefore, we provide a protocol of systematic evaluation to assess the accuracy of delirium screening tools in mechanically ventilated patients. Methods: PubMed, PsycINFO, EMBASE, and the Cochrane Library will be searched. Studies involving mechanically ventilated patients which compared diagnostic tools with the Diagnostic and Statistical Manual of Mental Disorders criteria as a reference standard will be included. We will use MetaDiSC and STATA 15.1 to analyze carefully when a network meta-analysis is allowed. Results: This study will provide a high-quality synthesis to assess the accuracy of different screening methods in mechanically ventilated patients. Conclusion: The conclusion of our systematic review will provide evidence to judge which screening method is the best for mechanically ventilated patients.

BACKGROUND: The threshold of the lower limit of the normal range of lung function has been suggested to be more accurate than the 0.7 fixed ratio (FEV1/FVC METHODS: Subjects with COPD diagnosed by a pulmonologist according to guidelines of the Global Initiative for Chronic Obstructive Lung Disease were recruited from October 2016 to April 2018. Overdiagnosed COPD was defined as FEV1/FVC that meets the criterion of the 0.7 fixed ratio but not the the lower limit of the normal range criterion. Spirometry and questionnaires were performed by eligible subjects. RESULTS: Of the 513 subjects included in the final analysis, 20 (3.9%) were overdiagnosed when using the lower limit of the normal range as the diagnostic reference. The subjects who were overdiagnosed were older, weighed more, had better lung function, lower modified Medical British Research Council scores, and higher St. George9s Respiratory Questionnaire and 36-item Short Form Survey scores than the subjects who were correctly diagnosed. Older age, heavier weight, exposure to cooking oil fumes, or a new-built or newly renovated home were associated with an increased risk of overdiagnosis of COPD (age adjusted odds ratio (OR) 1.17, 95% CI 1.09–1.26; weight adjusted OR 1.08, 95% CI 1.03–1.13; exposure to cooking oil fumes adjusted OR 3.00, 95% CI, 1.04–8.68; exposure to new-built or newly renovated home adjusted OR 10.88, 95% CI 1.46–80.87. CONCLUSIONS: The subjects with overdiagnosed COPD had a better health status and lung function than the subjects who were correctly diagnosed. Older age, heavier weight, and exposure to cooking oil fumes or a new-built or newly renovated home were factors associated with the overdiagnosis of COPD. These findings may help reduce overdiagnosis of COPD.

Inkjet printable and highly conductive PEDOT: PSS films on hydrophobic silicon surface were successfully developed in this work. Contact angle measurements were used to validate the substrate surface treatments for enhanced ink wetting characteristics. The improved wettability of the Si surface promotes easy spreading of the PEDOT:PSS solution, allowing a uniform coverage of the surfaces. Several inkjet printing parameters, including droplet spacing, substrate temperature and number of layers, were explored to study the impact they have on the film thickness and roughness. With an optimized printing setting, the number of surface defects and shunting problems in PEDOT:PSS films were drastically reduced. Lastly, the inkjet printed PEDOT:PSS thin film was implemented into a solar cell structure and proven to be an effective hole transport layer.

The surface passivation of p-benzoquinone (BQ) and hydroquinone (HQ) when dissolved in methanol (ME) has been examined through effective lifetime testing of crystalline silicon (c-Si) wafers treated with the aforementioned solutions. Changes in the availability of both photons and protons in the solutions were demonstrated to affect the level of passivation achieved. The requirement of both excess protons and ambient light exposure to maintain high effective lifetimes supports the presence of a free radical species that drives the surface passivation. Surface analysis suggests a 1:1 ratio of HQ-like bonds to methoxy bonds on the c-Si surface after treatment with a BQ/ME solution.

Organic-inorganic hybrid induced junction solar cells were fabricated with radical-driven benzoquinone (BQ) passivation and conductive and transparent polymer poly (3, 4ethylenedioxythiophene)-poly (styrenesulfonate) (PEDOT:PSS) as hole-selective contact. A monolayer of benzoquinone not just passivates the surface of silicon but is responsible for band bending. Implementing a back surface field in these cells reduces rear recombination losses to a great extent. Thickness, conductivity and uniformity of the hole-selective PEDOT:PSS layer are crucial to the properties of these carrier selective solar cells. Devices fabricated with BQ passivation and PEDOT:PSS on n-type silicon have demonstrated 11% power conversion efficiency. In the end, degradation mechanism in these cells is discussed. Future work on optimizing these solar cells and other alternatives will be discussed.

The electrical passivation mechanism of benzoquinone-methanol solutions on silicon has been examined through the study of the silicon surface electronic structure. Surface photovoltage (SPV) measurements using both X-ray photoelectron spectroscopy (XPS) and scanning Kelvin probe microscopy (SKPM) indicate a downward band bending of H-Si and benzoquinone (BQ) and methanol (ME) treated samples. This suggests the creation of an accumulation layer of majority carriers near the surface, with a significant field-effect contribution to the observed surface passivation. The highest SPV values recorded for the ME-Si and BQ-Si samples of about −220 mV are approaching the Fermi level—conduction band crossover. Density functional theory (DFT) calculations show that a dipole is formed upon bonding of BQ radicals on the surface, decreasing the surface electron affinity and work function. Considering the 0.07 eV shift due to the dipole and the 0.17 eV downward band bending, the work function of BQ-Si is found to be 4.08 eV. Both the dipole and downward band bending contribute to the formation of surface electron accumulation, and decrease the minority carrier density of n-Si passivated by BQ.

Semiconductor surfaces are inherently unstable, both chemically and electrically. The dangling bonds formed on cleavage lead to chemical reactivity. These same dangling bonds also act as electrical defects, and may hold charge or act as recombination centers for excited minority carriers. In this article, the difference between chemical and electrical passivation of semiconductor surfaces is discussed. Chemical passivation is provided by stoichiometric reaction with the chemical bonds. Electrical passivation may simply result from chemical reaction of the dangling bonds, or, often is provided by the presence of interfacial charge, which Coulombically repels minority carriers, thereby limiting recombination. Both organic and inorganic methods of passivating semiconductor surfaces are discussed.

Devices were demonstrated making use of benzoquinone passivation of silicon surfaces in a PEDOT:PSS-Silicon hybrid device structure. It is shown that the insertion of the benzoquinone layer does not provide an impediment to current flow across the PEDOT:PSS-Silicon interface and device efficiencies of 9.6% can be obtained. Devices using this passivation exhibited exceptionally high external quantum efficiencies in the low wavelength region, indicative of a high-quality front surface. Multiple rear contact schemes were evaluated, with Al giving the best results. Front-side texturing is shown to boost the short-circuit current of the devices by 20%, yielding significant gains to device fill factors.

SiOC thin films have been successfully deposited using carbosilane compounds with ultra-low-temperature ALD (ULT-ALD) around 50°C to 70°C. This plasma-free ULT-ALD eliminates the damage to the silicon surfaces due to plasma and high temperature. Silicon substrates with native oxide, as well as hydroxyl terminated silicon, without a pre-cleaning, can be passivated by this method, which greatly shortens the processing time in fabrication. Lifetime tests show that the SiOC film deposited by precursors R#2 (Air Liquide proprietary) and a BTCSM precursor can passivate the p-Si substrates giving a lifetime of up to $349\ \mu \mathbf{s}$. XPS and FTIR analysis shows that the film is approximately 10%C, 40%O and 50%Si with trace amounts of N and Cl. Most of the films' lifetime performances follow an exponential decay with time when exposed to air. Some of the relatively thinner samples do have good stability in that they can maintain 80% passivation performance for two days. Moreover, an increase in lifetime is observed when samples are heated to 100°C, which might be related to hydrogen migration in the film.

This work provides an analysis of the thin crystalline silicon PV module for a Lightweight PV (LPV) system. We first examine the advantages of the LPV system and then discuss the technical and economic challenges of the thin crystalline silicon PV module in assisting LPV system development for future market penetration. A critical analysis is conducted on the efficiency and yield challenge, and the system weight and costs reduction of thin crystalline silicon PV for the future development of the LPV system. It has shown that the key in speeding up thin silicon LPV market diffusion lies in developing cost-effective passivation and light trapping methods, as well as high-yield thin silicon fabrication technologies.

© 2019 Institute of Physics Publishing. All rights reserved. Question generation is an important task in the field of natural language processing and intelligent tutoring system. Previous work on Chinese question generation focused on the rule-based approach, which requires a large amount of human resource to develop the question generation rules. With the recent success of deep neural network in natural language processing, especially the encoder-decoder neural network framework in machine translation, this study explored the effectiveness of the encoder-decoder network in Chinese question generation, where a triple from the knowledge base as an input is encoded and a question as the output is decoded. More importantly, the traditional encoder-decoder network is extended to have multiple encoders that can capture more diverse features to represent the triple. The study results showed that the model with multiple encoders outperformed the traditional encoder-decoder neural network by 1.78 BLEU points.

Etching of transition metals is one of the major challenges in magnetic random-access memory fabrication. In this work, atomic layer etching of iron surfaces with halogen and an organic molecule was studied. The authors successfully etched Fe thin films by forming volatile metal complexes at low temperature with cyclic reactions of Cl2 and acetylacetone (acac). The mechanism of acac reacting on Cl-modified Fe surface was investigated: the surface was first activated with Cl2 gas, and then the top layer of metal was removed by acac reaction. The extent of Cl2 reaction determined the etching rate. At substrate temperatures lower than 135 °C, acac could not remove chlorine. In situ x-ray photoelectron spectroscopy and density functional theory simulation show that the reaction of acac on Cl-dosed Fe surface is likely following a complex pathway instead of simple acac substitution for Cl2. Acac decomposition may play an important role in the process.Etching of transition metals is one of the major challenges in magnetic random-access memory fabrication. In this work, atomic layer etching of iron surfaces with halogen and an organic molecule was studied. The authors successfully etched Fe thin films by forming volatile metal complexes at low temperature with cyclic reactions of Cl2 and acetylacetone (acac). The mechanism of acac reacting on Cl-modified Fe surface was investigated: the surface was first activated with Cl2 gas, and then the top layer of metal was removed by acac reaction. The extent of Cl2 reaction determined the etching rate. At substrate temperatures lower than 135 °C, acac could not remove chlorine. In situ x-ray photoelectron spectroscopy and density functional theory simulation show that the reaction of acac on Cl-dosed Fe surface is likely following a complex pathway instead of simple acac substitution for Cl2. Acac decomposition may play an important role in the process.

The measurement of minority carrier lifetime of silicon in chemical passivation studies is often taken with the wafer in solution. We show that variations in the optical constant and inductive coupling to the wafer, as well as the presence of the liquid solution, will lead to discrepancies in the measured lifetime of the wafers. Continued deterioration of lifetime is observed when wafers are in the passivation solution and is presumably due to oxygen in the bag. N-type silicon (100) wafers appear to have a limit of ten trials repeated use, after which carrier lifetime decreases, likely caused by surface degradation.