Injection-Limited and Space-Charge-Limited Conduction in Wide Bandgap Semiconductors with Velocity Saturation Effect

Carrier conduction in wide bandgap semiconductors (WBS) often exhibits velocity saturation at the high-electric field regime. How such effect influences the transition between contact-limited and space-charge-limited current in a two-terminal device remains largely unexplored thus far. Here, we develop a generalized carrier transport model that includes contact-limited field-induced carrier injection, space charge, carrier scattering and velocity saturation effect. The model reveals various transitional behaviors in the current-voltage characteristics, encompassing Fowler-Nordheim emission, trap-free Mott-Gurney (MG) SCLC and \emph{velocity-saturated SCLC}. Using GaN, 6H-SiC and 4H-SiC WBS as examples, we show that the velocity-saturated SCLC completely dominates the high-voltage ($10^2 \sim 10^4$ V) transport for typical sub-$\mu$m GaN and SiC diodes, thus unravelling velocity-saturated SCLC as a central transport mechanism in WBG electronics.Comment: 8 pages, 5 figure

Synergy study on charge transport dynamics in hybrid organic solar cell: photocurrent mapping and performance analysis under local spectrum

Charge transport dynamics in ZnO based inverted organic solar cell (IOSC) has been characterized with transient photocurrent spectroscopy and localised photocurrent mapping-atomic force microscopy. The value of maximum exciton generation rate was found to vary from 2.6 × 1027 m−3s−1 (Jsat = 79.7 A m−2) to 2.9 × 1027 m−3s−1 (Jsat = 90.8 A m−2) for devices with power conversion efficiency ranging from 2.03 to 2.51%. These results suggest that nanorods served as an excellent electron transporting layer that provides efficient charge transport and enhances IOSC device performance. The photovoltaic performance of OSCs with various growth times of ZnO nanorods have been analysed for a comparison between AM1.5G spectrum and local solar spectrum. The simulated PCE of all devices operating under local spectrum exhibited extensive improvement with the gain of 13.3–13.7% in which the ZnO nanorods grown at 15 min possess the highest PCE under local solar with the value of 2.82%

Asian Pacific Society of Cardiology Consensus Recommendations on the Use of MitraClip for Mitral Regurgitation

Transcatheter mitral valve repair with the MitraClip, a catheter-based percutaneous edge-to-edge repair technique to correct mitral regurgitation (MR), has been demonstrated in Western studies to be an effective and safe MR treatment strategy. However, randomised clinical trial data on its use in Asian-Pacific patients is limited. Hence, the Asian Pacific Society of Cardiology convened an expert panel to review the available literature on MitraClip and to develop consensus recommendations to guide clinicians in the region. The panel developed statements on the use of MitraClip for the management of degenerative MR, functional MR, and other less common indications, such as acute MR, dynamic MR, hypertrophic obstructive cardiomyopathy, and MR after failed surgical repair. Each statement was voted on by each panel member and consensus was reached when 80% of experts voted ‘agree’ or ‘neutral’. This consensus-building process resulted in 10 consensus recommendations to guide general cardiologists in the evaluation and management of patients in whom MitraClip treatment is being contemplated

The clinical relevance of oliguria in the critically ill patient : Analysis of a large observational database

Funding Information: Marc Leone reports receiving consulting fees from Amomed and Aguettant; lecture fees from MSD, Pfizer, Octapharma, 3 M, Aspen, Orion; travel support from LFB; and grant support from PHRC IR and his institution. JLV is the Editor-in-Chief of Critical Care. The other authors declare that they have no relevant financial interests. Publisher Copyright: © 2020 The Author(s). Copyright: Copyright 2020 Elsevier B.V., All rights reserved.Background: Urine output is widely used as one of the criteria for the diagnosis and staging of acute renal failure, but few studies have specifically assessed the role of oliguria as a marker of acute renal failure or outcomes in general intensive care unit (ICU) patients. Using a large multinational database, we therefore evaluated the occurrence of oliguria (defined as a urine output 16 years) patients in the ICON audit who had a urine output measurement on the day of admission were included. To investigate the association between oliguria and mortality, we used a multilevel analysis. Results: Of the 8292 patients included, 2050 (24.7%) were oliguric during the first 24 h of admission. Patients with oliguria on admission who had at least one additional 24-h urine output recorded during their ICU stay (n = 1349) were divided into three groups: transient - oliguria resolved within 48 h after the admission day (n = 390 [28.9%]), prolonged - oliguria resolved > 48 h after the admission day (n = 141 [10.5%]), and permanent - oliguria persisting for the whole ICU stay or again present at the end of the ICU stay (n = 818 [60.6%]). ICU and hospital mortality rates were higher in patients with oliguria than in those without, except for patients with transient oliguria who had significantly lower mortality rates than non-oliguric patients. In multilevel analysis, the need for RRT was associated with a significantly higher risk of death (OR = 1.51 [95% CI 1.19-1.91], p = 0.001), but the presence of oliguria on admission was not (OR = 1.14 [95% CI 0.97-1.34], p = 0.103). Conclusions: Oliguria is common in ICU patients and may have a relatively benign nature if only transient. The duration of oliguria and need for RRT are associated with worse outcome.publishersversionPeer reviewe

Large expert-curated database for benchmarking document similarity detection in biomedical literature search

Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe

Morphological Characterization of Higher-Order Thalamic Inputs from the POm and Cortico-cortical Inputs from M1 in the superficial L1 of the Murine Somatosensory Cortex

Our ability to repeatedly image identified neuronal processes such as axons and dendrites in vivo over time have allowed for the documentation of structural changes related to plasticity. These microarchitectural changes have profound impact, both qualitatively and quantitatively, on neuronal functions. In this thesis, we examined dendritic and axonal structural features through high-resolution imaging by means of correlative light and electron microscopy (CLEM). Chapter I will introduce readers to the general concept of somatosensation (in mice) through the following topics: i) inputs and outputs of the Thalamus involved in somatosensation; ii) thalamocortical (TC) and cortico-cortical (CC) inputs to the primary somatosensory cortex (S1), part of this will direct readers to a book chapter: Thalamocortical Synapses in the upcoming book: “The Cerebral Cortex and Thalamus” ; and iii) how they fit into the general landscape in the superficial layer (L) 1 of S1. I will also cover a non-exhaustive list of techniques that have been essential in examining the players involved in synaptic transmission. Finally, I round off Chapter I by specifying the various aims of this thesis. Chapter II presents a proof-of-concept CLEM workflow that was crucial in the characterization of a subtype of vaso-intestinal peptide positive (VIP+) interneurons (INs) with spiny dendrites. Here, we describe a subpopulation of VIP+ INs with dendrites of high spine densities extending to the superficial L1. This work led to a published manuscript (Georgiou et al., 2022). Chapter III represents the core of my thesis. Here, I characterize both the TC input arising from the posterior medial complex (POm) of the thalamus as well as the CC inputs from the primary motor cortex (M1) that arborizes in the layer 1 of S1. First, we describe and compare the axonal varicosities of both populations as observed in LM. I meticulously traced axons and attributed detected varicosities with bouton probabilities. With the bouton probabilities, I was also able to describe the structural plasticity (e.g., bouton addition, elimination, potentiation, and depression) over subsequent imaging sessions. This structural index will allow future studies to investigate bouton turnover on targeted axonal population. Further, with the ultrastructural data, we describe the difference between the two axonal population both qualitatively and quantitatively. In Chapter IV, we investigated the elusive serotonergic (SERT) fibers also known to arborise in the superficial L1. We found that SERT fibers have an unusually high degree of tortuosity and do not form “traditional” synapses. I also highlighted work from other collaborators to allow for meaningful comparisons with other neuromodulatory afferents, as well as TC and CC axons presented in the previous chapter. In Chapter V, we round up the thesis and summarise the findings from Chapter II – IV. Here, we discussed how the work and findings from my thesis contribute towards the general understanding of the insofar inscrutable superficial L1 of the murine somatosensory cortex, and shed light on the interchange of axonal and dendritic morphology, axon targeting strategies and non-conventional neurotransmission.</p

The voluntary disclosure of environmental information : a study of listed companies in Singapore

106 p.This project examines the perceptions of listed companies in Singapore concerning the disclosure of environmental information. It is argued that companies will be more willing to disclose positive environmental information than negative information. However, the perception of whether an item of information is positive or negative will depend on whether the company has established an environmental policy. Further, it is hypothesised that Singapore companies with principal market outside Singapore are more willing to disclose environmental information than companies with principal market in Singapore. Companies' perceived importance of an audit opinion on environmental disclosure is also tested.ACCOUNTANC