bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional reallocation of sensory processing resources caused by long-term neural adaptation to altered optics
Authors: Barbot Antoine , Park Woon Ju , Ng Cherlyn J , Zhang Ru-Yuan , Huxlin Krystel R , Tadin Duje , Yoon Geunyoung
Published: February 2021

The eye’s optics are a major determinant of visual perception. Elucidating how long-term exposure to optical defects affects visual processing is key to understanding the capacity for, and limits of, sensory plasticity. Here, we show evidence of functional reallocation of sensory processing resources following long-term exposure to poor optical quality. Using adaptive optics to bypass all optical defects, we assessed visual processing in neurotypically-developed adults with healthy eyes and with keratoconus – a corneal disease causing severe optical aberrations. Under fully-corrected optical conditions, keratoconus patients showed altered contrast sensitivity, with impaired sensitivity for fine spatial details and better-than-typical sensitivity for coarse spatial details. Both gains and losses in sensitivity were more pronounced in patients experiencing poorer optical quality in their daily life and mediated by changes in signal enhancement mechanisms. These findings show that adult neural processing adapts to better match the changes in sensory inputs caused by long-term exposure to altered optics.
Incomplete removal of extracellular glutamate controls synaptic transmission and integration at a cerebellar synapse
Authors: Balmer Timothy S , Borges-Merjane Carolina , Trussell Laurence O
Published: February 2021

Synapses of glutamatergic mossy fibers (MFs) onto cerebellar unipolar brush cells (UBCs) generate slow excitatory (ON) or inhibitory (OFF) postsynaptic responses dependent on the complement of glutamate receptors expressed on the UBC’s large dendritic brush. Using mouse brain slice recording and computational modeling of synaptic transmission, we found that substantial glutamate is maintained in the UBC synaptic cleft, sufficient to modify spontaneous firing in OFF UBCs and tonically desensitize AMPARs of ON UBCs. The source of this ambient glutamate was spontaneous, spike-independent exocytosis from the MF terminal, and its level was dependent on activity of glutamate transporters EAAT1–2. Increasing levels of ambient glutamate shifted the polarity of evoked synaptic responses in ON UBCs and altered the phase of responses to in vivo-like synaptic activity. Unlike classical fast synapses, receptors at the UBC synapse are virtually always exposed to a significant level of glutamate, which varies in a graded manner during transmission.
Performance analysis of lightweight CNN models to segment infectious lung tissues of COVID-19 cases from tomographic images
Authors: Iyer Tharun J. , Joseph Raj Alex Noel , Ghildiyal Sushil , Nersisson Ruban
Published: February 2021

The pandemic of Coronavirus Disease-19 (COVID-19) has spread around the world, causing an existential health crisis. Automated detection of COVID-19 infections in the lungs from Computed Tomography (CT) images offers huge potential in tackling the problem of slow detection and augments the conventional diagnostic procedures. However, segmenting COVID-19 from CT Scans is problematic, due to high variations in the types of infections and low contrast between healthy and infected tissues. While segmenting Lung CT Scans for COVID-19, fast and accurate results are required and furthermore, due to the pandemic, most of the research community has opted for various cloud based servers such as Google Colab, etc. to develop their algorithms. High accuracy can be achieved using Deep Networks but the prediction time would vary as the resources are shared amongst many thus requiring the need to compare different lightweight segmentation model. To address this issue, we aim to analyze the segmentation of COVID-19 using four Convolutional Neural Networks (CNN). The images in our dataset are preprocessed where the motion artifacts are removed. The four networks are UNet, Segmentation Network (Seg Net), High-Resolution Network (HR Net) and VGG UNet. Trained on our dataset of more than 3,000 images, HR Net was found to be the best performing network achieving an accuracy of 96.24% and a Dice score of 0.9127. The analysis shows that lightweight CNN models perform better than other neural net models when to segment infectious tissue due to COVID-19 from CT slices.
Sensing and processing whisker deflections in rodents
Authors: Burns Thomas F. , Rajan Ramesh
Published: February 2021

The classical view of sensory information mainly flowing into barrel cortex at layer IV, moving up for complex feature processing and lateral interactions in layers II and III, then down to layers V and VI for output and corticothalamic feedback is becoming increasingly undermined by new evidence. We review the neurophysiology of sensing and processing whisker deflections, emphasizing the general processing and organisational principles present along the entire sensory pathway—from the site of physical deflection at the whiskers to the encoding of deflections in the barrel cortex. Many of these principles support the classical view. However, we also highlight the growing number of exceptions to these general principles, which complexify the system and which investigators should be mindful of when interpreting their results. We identify gaps in the literature for experimentalists and theorists to investigate, not just to better understand whisker sensation but also to better understand sensory and cortical processing.
Association between problematic internet use and behavioral/emotional problems among Chinese adolescents: the mediating role of sleep disorders
Authors: Wang Wanxin , Du Xueying , Guo Yangfeng , Li Wenyan , Zhang Sheng , Guo Lan , Lu Ciyong
Published: February 2021

Background

Studies that focus on the relationships of problematic Internet use (PIU), sleep disorders, and behavioral/emotional problems were limited. This study aimed to explore (1) the relationship between PIU and behavioral/emotional problems among Chinese adolescents and (2) whether sleep disorders mediate the relationship between PIU and behavioral/emotional problems.

Methods

A total of 1,976 adolescents were recruited by cluster sampling from ten secondary schools in Guangzhou between January and April 2019, and 1,956 of them provided valid information (response rate: 98.9% ). Among them, 50.8% were males and the mean age was 13.6±1.5 years, ranging from 11 to 18 years. Data on behavioral/emotional problems, sleep disorders, and PIU were collected using a self-reported questionnaire. Linear regression models and mediation analyses were performed.

Results

Of the participants, 14.5% (284/1,956) reported moderate to severe PIU, and their average score for total difficulties was significantly higher than the score for average users (14.9±5.5 Vs 9.8±4.7). After adjusting for controlled variables, PIU was further proven to be positively related to elevated levels of behavioral/emotional problems (unstandardized β = 0.16, p < 0.05). In addition, sleep disorders partially mediated the forgoing associations.

Conclusions

Adolescents with problematic Internet habits were at higher risk of developing behavioral and emotional problems than their normal-use peers, and sleep disorders partially mediated the effect. Close attention and effective guidance for adolescents with PIU and behavioral/emotional problems were recommended for parents and schools.
The click is not the trick: the efficacy of clickers and other reinforcement methods in training naïve dogs to perform new tasks
Authors: Gilchrist Rachel J. , Gunter Lisa M. , Anderson Samantha F. , Wynne Clive D.L.
Published: February 2021

Background

A handheld metal noisemaker known as a “clicker” is widely used to train new behaviors in dogs; however, evidence for their superior efficacy compared to providing solely primary reinforcement or other secondary reinforcers in the acquisition of novel behavior in dogs is largely anecdotal.

Methods

Three experiments were conducted to determine under what circumstances a clicker secondary reinforcer may result in acquisition of a novel behavior more rapidly or to a higher level compared to other readily available reinforcement methods. In Experiment 1, three groups of 30 dogs each were shaped to emit a novel sit and stay behavior of increasing duration with either the delivery of food alone, a verbal stimulus paired with food, or a clicker with food. The group that received only a primary reinforcer reached a significantly higher criterion of training success than the group trained with a verbal secondary reinforcer. Performance of the group experiencing a clicker as a secondary reinforcer was intermediate between the other two groups, but not significantly different from either. In Experiment 2, three groups of 25 dogs each were shaped to emit a nose targeting behavior and then perform that behavior at increasing distances from the experimenter using the same three methods of positive reinforcement as in Experiment 1. No statistically significant differences between the groups were found. In Experiment 3, three groups of 30 dogs each were shaped to emit a nose-targeting behavior upon an array of wooden blocks with task difficulty increasing throughout testing using the same three methods of positive reinforcement as previously tested. No statistically significant differences between the groups were found.

Results

Overall, the findings suggest that both primary reinforcement alone as well as a verbal or clicker secondary reinforcer can be used successfully in training a dog to perform a novel behavior, but that no positive reinforcement method demonstrated significantly greater efficacy than any other.
A multi‐institutional analysis of a general pelvis continuous Hounsfield unit synthetic CT software for radiotherapy
Authors: Yu Victoria Y. , Keyrilainen Jani , Suilamo Sami , Beslimane Ilyes , Dresner Alex , Halkola Aleksi , Van der Heide Uulke A. , Tyagi Neelam
Published: February 2021

Purpose

To validate a synthetic computed tomography (sCT) software with continuous HUs and large field‐of‐view (FOV) coverage for magnetic resonance imaging (MRI)‐only workflow of general pelvis anatomy in radiotherapy (RT).

Methods

An sCT software for general pelvis anatomy (prostate, rectum, and female pelvis) has been developed by Philips Healthcare and includes continuous HUs assignment along with large FOV coverage. General pelvis sCTs were generated using a two‐stack T1‐weighted mDixon fast‐field echo (FFE) sequence with a superior‐inferior coverage of 36 cm. Seventy‐seven prostate, 43 rectum, and 27 gynecological cases were scanned by three different institutions. mDixon image quality and sCTs were evaluated for soft tissue contrast by using a confidence level scale from 1 to 5 for bladder, prostate/rectum interface, mesorectum, and fiducial maker visibility. Dosimetric comparison was performed by recalculating the RT plans on the sCT after rigid registration. For 12 randomly selected cases, the mean absolute error (MAE) between sCT and CT was calculated to evaluate HU similarity, and the Pearson correlation coefficients (PCC) between the CT‐ and sCT‐generated digitally reconstructed radiographs (DRRs) were obtained for quantitative comparison. To examine geometric accuracy of sCT as a reference for cone beam CT (CBCT), the difference between bone‐based alignment of CBCT to CT and CBCT to sCT was obtained for 19 online‐acquired CBCTs from three patients.

Results

Two‐stack mDixon scans with large FOV did not show any image inhomogeneity or fat‐water swap artifact. Fiducials, Foley catheter, and even rectal spacer were visible as dark signal on the sCT. Average visibility confidence level (average ± standard deviation) on the sCT was 5.0 ± 0.0, 4.6 ± 0.5, 3.8 ± 0.4, and 4.0 ± 1.1 for bladder, prostate/rectum interface, mesorectum and fiducial markers. Dosimetric accuracy showed on average < 1% difference with the CT‐based plans for target and normal structures. The MAE of bone and soft tissue between the sCT and CT are 120.9 ± 15.4 HU, 33.4 ± 4.1 HU, respectively. Average PCC of all evaluated DRR pairs was 0.975. The average offset between CT and sCT as reference was (LR, AP, SI) = (0.19 ± 0.35, 0.14 ± 0.60, 0.44 ± 0.54) mm.

Conclusions

The continuous HU sCT software‐generated realistic sCTs and DRRs to enable MRI‐only planning for general pelvis anatomy.
KCNQ2‐DEE: developmental or epileptic encephalopathy?
Authors: Berg Anne T. , Mahida Sonal , Poduri Annapurna
Published: February 2021

Objective

KCNQ2‐associated developmental and epileptic encephalopathies (DEE) present with seizures and developmental impairments. The relation between seizures and functional impairments in affected children and the relation of a specific genetic variant to seizure control remains unknown.

Methods

Parents of children with documented KCNQ2 variants who participated in a structured, online natural history survey provided information about seizure history, functional mobility, hand use, communication function, and feeding independence. Bivariate analyses were performed with nonparametric methods and logistic regression was used for multivariable analyses.

Results

Thirty‐nine children (20, 51% girls, median age 4.5 years, interquartile range (IQR) 1.9—19.3) had a median age of seizure onset of 1 day (IQR 1—3 days). The most common seizure types were bilateral tonic‐clonic (N = 72, 28%) and bilateral tonic (N = 13, 33%). Time since last seizure was <6 months (N = 18, 46%), 6–23 months (N = 11, 28%), and ≥24 months (N = 10 26%). Severe functional impairment was reported for mobility (62%), hand grasp (31%), feeding (59%), and communication (77%). Twenty‐eight (72%) were impaired in ≥2 domains. There were only weak and inconsistent associations between seizure recency and individual impairments or number of impairments after adjustment for other factors. The functional location of the variants within the Kv7.2 protein was not associated with seizure control.

Interpretation

Seizures in KCNQ2‐DEE are often well‐controlled, but children have severe impairments regardless. With the increased potential for precision therapies targeting the Kv7.2 channel or the KCNQ2 gene itself, identifying the most relevant and sensitive clinical endpoints will be critical to ensure successful trials of new therapies.
Angiopoietin‐like protein 4 and clinical outcomes in ischemic stroke patients
Authors: Zheng Xiaowei , Shen Suwen , Wang Aili , Zhu Zhengbao , Peng Yanbo , Peng Hao , Zhong Chongke , Guo Daoxia , Xu Tan , Chen Jing , Ju Zhong , Geng Deqin , Zhang Yonghong , He Jiang
Published: February 2021

Aims

Angiopoietin‐like protein 4 (ANGPTL‐4) had been reported to be associated with the risk of ischemic stroke, but its prognostic value remained unclear. The aim of this study was to investigate the association between plasma ANGPTL‐4 concentrations and prognosis of ischemic stroke.

Methods

Baseline plasma ANGPTL‐4 concentrations were measured in 3379 acute ischemic stroke patients. The primary outcome was a combination of death or major disability (modified Rankin Scale score, ≥3) at 3 months after ischemic stroke.

Results

At 3 months after ischemic stroke, 850 (26.16%) participants experienced major disability or died (750 major disabilities and 100 deaths). After adjusting for important covariates, odds ratios for the highest tertile of plasma ANGPTL‐4 concentrations were 1.59 (1.22–2.06) for primary outcome, 1.53 (1.18–1.97) for major disability, and 2.03 (1.03–4.00) for death when compared with the lowest tertile of plasma ANGPTL‐4 concentrations. For 1‐SD increase in log‐ANGPTL‐4 concentrations (0.44 ng/mL), the adjusted odds ratios were 1.24 (1.11–1.38), 1.14 (1.03–1.27), and 1.72 (1.32–2.23), respectively. Adding ANGPTL‐4 to a model containing conventional risk factors improved risk prediction for composite outcome of death and major disability.

Conclusion

Higher plasma ANGPTL‐4 concentration was associated with poor prognosis in acute ischemic stroke patients, suggesting that ANGPTL‐4 might be a prognostic marker for ischemic stroke.
Supramolecular Peptide Nanofibrils with Optimized Sequences and Molecular Structures for Efficient Retroviral Transduction
Authors: Sieste Stefanie , Mack Thomas , Lump Edina , Hayn Manuel , Schütz Desiree , Röcker Annika , Meier Christoph , Kaygisiz Kübra , Kirchhoff Frank , Knowles Tuomas P. J. , Ruggeri Francesco S. , Synatschke Christopher V. , Münch Jan , Weil Tanja
Published: February 2021

Amyloid‐like peptide nanofibrils (PNFs) are abundant in nature providing rich bioactivities and playing both functional and pathological roles. The structural features responsible for their unique bioactivities are, however, still elusive. Supramolecular nanostructures are notoriously challenging to optimize, as sequence changes affect self‐assembly, fibril morphologies, and biorecognition. Herein, the first sequence optimization of PNFs, derived from the peptide enhancing factor‐C (EF‐C, QCKIKQIINMWQ), for enhanced retroviral gene transduction via a multiparameter and a multiscale approach is reported. Retroviral gene transfer is the method of choice for the stable delivery of genetic information into cells offering great perspectives for the treatment of genetic disorders. Single fibril imaging, zeta potential, vibrational spectroscopy, and quantitative retroviral transduction assays provide the structure parameters responsible for PNF assembly, fibrils morphology, secondary and quaternary structure, and PNF‐virus‐cell interactions. Optimized peptide sequences such as the 7‐mer, CKFKFQF, have been obtained quantitatively forming supramolecular nanofibrils with high intermolecular β‐sheet content that efficiently bind virions and attach to cellular membranes revealing efficient retroviral gene transfer.
The Role of Defects in Metal–Organic Frameworks for Nitrogen Reduction Reaction: When Defects Switch to Features
Authors: Khalil Islam E. , Xue Cong , Liu Wenjing , Li Xiaohan , Shen Yu , Li Sheng , Zhang Weina , Huo Fengwei
Published: February 2021

The electrochemical nitrogen reduction reaction (NRR), a contributor for producing ammonia under mild conditions sustainably, has recently attracted global research attention. Thus far, the design of highly efficient electrocatalysts to enhance NRR efficiency is a specific focus of the research. Among them, defect engineering of electrocatalysts is considered a significant way to improve electrocatalytic efficiency by regulating the electronic state and providing more active sites that can give electrocatalysts better physicochemical properties. Recently, metal–organic frameworks (MOFs), along with their derivatives, have captured immense interest in electrocatalytic reactions owing to not only their large surface area and high porosity but also the ability to create rich defects in their structures. Hence, they can provide plenty of exposed active sites for electron transfer, NN cleavage, and N2 adsorption to enhance NRR performance. Herein, the concept, the in situ characterizations techniques for defects, and the most common ways to create defects into MOFs have been summarized. Furthermore, the recent advances of MOF‐based electrocatalysts towards NRR have been recapitulated. Ultimately, the major challenges and outlook of defects in MOFs for NRR are proposed. This paper is anticipated to provide critical guidelines for optimizing NRR electrocatalysts.
Controlled Assembly of MXene Nanosheets as an Electrode and Active Layer for High‐Performance Electronic Skin
Authors: Fu Xiyao , Wang Lili , Zhao Lianjia , Yuan Zeyu , Zhang Yupu , Wang Dongyi , Wang Depeng , Li Junzhi , Li Dongdong , Shulga Valerii , Shen Guozhen , Han Wei
Published: February 2021

MXenes are an emerging class of 2D transition metal carbides and nitrides. They have been widely used in flexible electronics owing to their excellent conductivity, mechanical flexibility, and water dispersibility. In this study, the electrode and active layer applications of MXene materials in electronic skins are realized. By utilizing vacuum filtration technology, few‐layer MXene electrodes are integrated onto the top and bottom surfaces of the 3D polyacrylonitrile (PAN) network to form a stable electronic skin. The fabricated flexible device with Ti3C2Tx MXene electrodes outperforms those with other electrodes and exhibits excellent device performance, with a high sensitivity of 104.0 kPa−1, fast response/recovery time of 30/20 ms, and a low detection limit of 1.5 Pa. Furthermore, the electrode and the constructed MXene/PAN‐based flexible pressure sensor exhibit robust mechanical stability and can survive 240 bending cycles. Such a robust, flexible device can be enlarged or folded like a jigsaw puzzle or origami and transformed from 2D to 3D structures; moreover, it can detect tiny movements of human muscles, such as movements corresponding to sound production and intense movements during bending of fingers.
Actuation of Three‐Dimensional‐Printed Nanocolloidal Hydrogel with Structural Anisotropy
Authors: Gevorkian Albert , Morozova Sofia M. , Kheiri Sina , Khuu Nancy , Chen Heyu , Young Edmond , Yan Ning , Kumacheva Eugenia
Published: February 2021

Polymer hydrogels exhibit actuation properties that result in reversible shape transformations and have promising applications in soft robotics, drug delivery systems, sensors, and microfluidic devices. Actuation occurs due to differential hydrogel swelling and is generally achieved by modulating hydrogel composition. Here a different approach to hydrogel actuation that originates solely from its structural anisotropy is reported. For 3D‐printed single‐layer hydrogels formed by cellulose nanocrystals (CNCs) and gelatin methacryloyl it is shown that shear‐induced orientation of CNCs results in anisotropic mechanical and swelling properties of the hydrogel. Upon swelling in water, planar hydrogels acquire multiple complex 3D shapes that are achieved by i) varying CNC orientation with respect to the shape on the hydrogel sheet and ii) patterning the hydrogel with the regions of shear‐mediated and random CNC orientation. This study shows the capability to generate multiple shapes from the same hydrogel actuator based on the degree of its structural anisotropy. In addition, it introduces a biocompatible nanocolloidal ink with shear‐thinning and self‐healing properties for additive manufacturing of hydrogel actuators.
Chemically Controllable Magnetic Transition Temperature and Magneto‐Elastic Coupling in MnZnSb Compounds
Authors: Murgatroyd Philip A. E. , Routledge Kieran , Durdy Samantha , Gaultois Michael W. , Surta T. Wesley , Dyer Matthew S. , Claridge John B. , Savvin Stanislav N. , Pelloquin Denis , Hébert Sylvie , Alaria Jonathan
Published: February 2021

Magneto‐caloric materials offer the possibility to design environmentally friendlier thermal management devices compared to the widely used gas‐based systems. The challenges to develop this solid‐state based technology lie in the difficulty of finding materials presenting a large magneto‐caloric effect over a broad temperature span together with suitable secondary application parameters such as low heat capacity and high thermal conductivity. A series of compounds derived from the PbFCl structure is investigated using a combination of computational and experimental methods focusing on the change of cell volume in magnetic and non‐magnetic ground states. Scaling analysis of the magnetic properties determines that they are second order phase transition ferromagnets and that the magnetic entropy change is driven by the coupling of magneto‐elastic strain in the square‐net through the magnetic transition determined from neutron and synchrotron X‐ray diffraction. The primary and secondary application related properties are measured experimentally, and the c/a parameter is identified as an accurate proxy to control the magnetic transition. Chemical substitution on the square‐net affords tuning of the Curie temperature over a broad temperature span between 252 and 322 K. A predictive machine learning model for the c/a parameter is developed to guide future exploratory synthesis.
Surface and Interface Engineering of Nanoarrays toward Advanced Electrodes and Electrochemical Energy Storage Devices
Authors: Li Linpo , Liu Wenyi , Dong Haoyang , Gui Qiuyue , Hu Zuoqi , Li Yuanyuan , Liu Jinping
Published: February 2021

The overall performance of electrochemical energy storage devices (EESDs) is intrinsically correlated with surfaces and interfaces. As a promising electrode architecture, 3D nanoarrays (3D‐NAs) possess relatively ordered, continuous, and fully exposed active surfaces of individual nanostructures, facilitating mass and electron transport within the electrode and charge transfer across interfaces and providing an ideal platform for engineering. Herein, a critical overview of the surface and interface engineering of 3D‐NAs, from electrode and interface designs to device integration, is presented. The general merits of 3D‐NAs and surface/interface engineering principles of 3D‐NA hybrid electrodes are highlighted. The focus is on the use of 3D‐NAs as a superior platform to regulate the interface nature and unveiling new mechanism/materials without the interference of binders. The engineering and utilization of the surface of 3D‐NAs to develop flexible/solid‐state EESDs with 3D integrated electrode/electrolyte interfaces, or 3D triphase interfaces involving other active species, which are characteristic of (quasi‐)solid‐state electrolyte infiltration into the entire device, are also considered. Finally, the challenges and future directions of surface/interface engineering of 3D‐NAs are outlined. In particular, potential strategies to obtain electrode charge balance, optimize the multiphase solid‐state interface, and attain 3D solid electrolyte infiltration are proposed.
2D Material Based Thin‐Film Nanocomposite Membranes for Water Treatment
Authors: Yang Jindi , Li Zhikao , Wang Zhuyuan , Yuan Shi , Li Yang , Zhao Wang , Zhang Xiwang
Published: February 2021

Membrane‐based separation technologies are essential in the fields of desalination and wastewater treatment. 2D material based thin‐film nanocomposite (2D‐M‐TFN) membranes are emerging technology that combines 2D nanomaterials and conventional thin‐film composite membranes. It has great potential to further improve the efficiency of the membrane separation process. Although extensive studies are reported, 2D‐M‐TFN membranes for water treatment are not systemically reviewed. This work gives an intensive summary of this emerging technology. The function, mechanisms, and common characteristics of various 2D materials in the 2D‐M‐TFN membrane are first summarized and compared. An in‐depth discussion of different types of 2D‐M‐TFN membranes is then conducted, followed by the discussions on the challenges and opportunities.
VCSELs with On‐Facet Metasurfaces for Polarization State Generation and Detection
Authors: Wen Dandan , Meng Jiajun , Cadusch Jasper J. , Crozier Kenneth B.
Published: February 2021

Polarization plays a critical role in optical systems that range from optical communications to imaging, lithography, metrology, and data storage. Thus, in systems that need to generate a certain polarization state, a light source (e.g., laser) is combined with polarization control elements such as polarizers, polarizing beam splitters, and waveplates. Similarly, in systems requiring polarization state detection, such elements are combined with photodetectors. There is currently a trend toward miniaturized optical systems. This motivates the question of how to achieve what may be argued as an ultimate level of miniaturization: a single chip that can both generate light with a prescribed polarization state and detect the polarization state of light impinging upon it. This paper demonstrates this via vertical cavity surface emitting lasers (VCSELs) with on‐facet metasurfaces. Two classes of devices are demonstrated. The first class uses high‐index dielectric metasurfaces (amorphous silicon nanofins), whereas the second class uses plasmonic metasurfaces (aluminum bilayer gratings). Each can operate as a laser (to generate) and as a photodetector (to detect) circularly or linearly polarized light.
Organic Permeable Base Transistors – Insights and Perspectives
Authors: Guo Erjuan , Dollinger Felix , Amaya Baltasar , Fischer Axel , Kleemann Hans
Published: February 2021

Vertical organic transistors have emerged as a new device concept holding great promise to overcome the limitations of lateral organic transistors. In this regard, the organic permeable base transistor (OPBT), a special kind of vertical transistor, stands out due to excellent performance figures such as low‐voltage operation and high transition frequency measured in a pulse‐biasing mode. On the occasion of Prof. Karl Leo's 60th birthday, his contributions to the development of high‐performance OPBTs are honored and a perspective for the future of OPBT development is provided. The current state of the art of OPBTs is reviewed and the principles of the device operation are summarized. New insights into the formation of the permeable base layer, which is vital to the function of OPBTs, are discussed. Additionally, a full yield analysis on a batch of 144 equivalent OPBTs is reported and the device yield and temporal evolution of device parameters are statistically analyzed. This analysis proves a device yield of >90% for these short‐channel transistors, rendering the possibility for circuit integration. Finally, the scaling laws of OPBTs are derived and strategies for new materials and device layouts to push the performance to the gigahertz regime are concluded.
Ultrafast All‐Optical Polarization Switching Based on Composite Metasurfaces with Gratings and an Epsilon‐Near‐Zero Film
Authors: Niu Xinxiang , Hu Xiaoyong , Xu Yi , Yang Hong , Gong Qihuang
Published: February 2021

Active control of light polarization is necessary for the development of laser physics, optical communications, and also the molecular dynamics. Conventional polarization control methods suffer from low speed, and the existing all‐optical switching based on nonlinear materials solely has a lot of conducting restrictions, impeding its practical utilizations. Herein, an all‐optical polarization switching in the near‐IR range, composed of the plasmonic gratings deposited on an indium tin oxide (ITO) film with epsilon‐near‐zero response, is realized. A sub‐1 ps response speed and the 19° rotation of the polarization ellipse are determined with the excitation power of 1.37 GW cm−2. The device is demonstrated to output the varied signal with tuning the incident polarization and intensity in a spectral range from 1200 to 1500 nm. The ultrafast processing speed, broadband, and diverse tunability ensure the designed device a promising and necessary element for practically integrating into the next‐generation signal‐processing systems with high performance and large capacity.
Dual‐Sensitivity Terahertz Metasensor Based on Lattice–Toroidal‐Coupled Resonance
Authors: Lou Jing , Yang Ruisheng , Liang Jiangang , Yu Ying , Zhang Lei , Zhang Chiben , Li Tangjing , Fan Yuancheng , Zhang Fuli , Wang Guangming , Wang Jun , Cai Tong
Published: February 2021

High quality factor resonance with extremely narrow line‐width offers an important platform for terahertz (THz) sensing technology as it enables strong light‐matter interaction between THz waves and analyte materials. Lattice mode arising from the collective Rayleigh scattering of metamaterial periodic structures has the ability to strongly confine the electromagnetic waves on the surface that fails to radiate to the far‐field. Herein, for the first time, a strategy is experimentally demonstrated to design THz metasensors, which exhibit dual‐sensitivity of frequency and resonance intensity by coupling the first‐order lattice mode to the toroidal resonance. The frequency sensitivity mainly results from the localized field confinement, whereas the sensitivity of resonance intensity depends on the matching degree between toroidal resonance and lattice mode. It is found that both the frequency shift and resonance intensity show exponential growth with the increase in the analyte thickness. In addition, the sensing performance between toroidal and toroidal–lattice modes is compared to verify the superiority of the dual‐sensitivity property. This work would greatly improve the practical applications of THz sensing technology and open up new opportunities for the realization of slow light devices, multiband narrow filters, and nonlinear systems.
Recent Progress of Nanogenerators Acting as Self‐Powered Drug Delivery Devices
Authors: Zhao Chaochao , Cui Xi , Wu Yuxiang , Li Zhou
Published: February 2021

Self‐powered technology based on nanogenerators (NGs) has developed rapidly since the invention of NGs. This technology can transform mechanical energy into electrical energy and be applied to self‐powered healthcare systems. Meanwhile, after the development of five generations, drug dosage forms have entered the era of pulsed drug delivery system (DDS), which promotes the application of NGs in self‐powered DDS. This review first reviews the type, working principle, materials, and structure strategy of NGs. Next, frontier applications of NGs as drug delivery devices (DDDs), in combination with membrane, microneedle, electrochemistry, microfluidics, and electroporation techniques, are introduced. Then the challenges of NG technology applied for clinical treatment and research are discussed. In the future, NG may become the key technology for drug controlled release, which can realize precise drug delivery and clinical disease therapy.
Mechanistic Insight into Charge and Energy Transfers of Luminescent Metal–Organic Frameworks Based Sensors for Toxic Chemicals
Authors: Mohan Brij , Kumar Sandeep , Ma Shixuan , You Hengzhi , Ren Peng
Published: February 2021

Mechanistic studies of materials able to detect hazardous and toxic chemicals, such as common organic solvents, pesticides, and nitroaromatic compounds (NACs), are critically important owing to the threat they pose to humans and the environment. Recently, porous luminescent metal–organic frameworks (MOFs) with multifunctional sites, high surface areas, and structural tunability have emerged as sensory devices for the detection of hazardous and toxic chemicals. Herein, recent progress regarding the mechanistic behavior of MOF sensors in the detection of common organic solvents, pesticides, and NACs using luminescence signal changes is presented. This review focuses on the origins of charge and charge‐energy transfer in different MOFs, ligands and metal centers, modes of interaction, common mechanisms, and limits of detection of MOF sensors for toxic analyte detection. These studies indicate the remaining challenges and directions for future research.
Nb2O5‐Based Photocatalysts
Authors: Su Kaiyi , Liu Huifang , Gao Zhuyan , Fornasiero Paolo , Wang Feng
Published: February 2021

Photocatalysis is one potential solution to the energy and environmental crisis and greatly relies on the development of the catalysts. Niobium pentoxide (Nb2O5), a typically nontoxic metal oxide, is eco‐friendly and exhibits strong oxidation ability, and has attracted considerable attention from researchers. Furthermore, unique Lewis acid sites (LASs) and Brønsted acid sites (BASs) are observed on Nb2O5 prepared by different methods. Herein, the recent advances in the synthesis and application of Nb2O5‐based photocatalysts, including the pure Nb2O5, doped Nb2O5, metal species supported on Nb2O5, and other composited Nb2O5 catalysts, are summarized. An overview is provided for the role of size and crystalline phase, unsaturated Nb sites and oxygen vacancies, LASs and BASs, dopants and surface metal species, and heterojunction structure on the Nb2O5‐based catalysts in photocatalysis. Finally, the challenges are also presented, which are possibly overcome by integrating the synthetic methodology, developing novel photoelectric characterization techniques, and a profound understanding of the local structure of Nb2O5.
Interface Design for Stretchable Electronic Devices
Authors: Kim Dong Wook , Kong Minsik , Jeong Unyong
Published: February 2021

Stretchable electronics has emerged over the past decade and is now expected to bring form factor‐free innovation in the next‐generation electronic devices. Stretchable devices have evolved with the synthesis of new soft materials and new device architectures that require significant deformability while maintaining the high device performance of the conventional rigid devices. As the mismatch in the mechanical stiffness between materials, layers, and device units is the major challenge for stretchable electronics, interface control in varying scales determines the device characteristics and the level of stretchability. This article reviews the recent advances in interface control for stretchable electronic devices. It summarizes the design principles and covers the representative approaches for solving the technological issues related to interfaces at different scales: i) nano‐ and microscale interfaces between materials, ii) mesoscale interfaces between layers or microstructures, and iii) macroscale interfaces between unit devices, substrates, or electrical connections. The last section discusses the current issues and future challenges of the interfaces for stretchable devices.
15.3% Efficiency All‐Small‐Molecule Organic Solar Cells Achieved by a Locally Asymmetric F, Cl Disubstitution Strategy
Authors: Hu Dingqin , Yang Qianguang , Zheng Yujie , Tang Hua , Chung Sein , Singh Ranbir , Lv Jie , Fu Jiehao , Kan Zhipeng , Qin Bo , Chen Qianqian , Liao Zhihui , Chen Haiyan , Xiao Zeyun , Sun Kuan , Lu Shirong
Published: February 2021

Single junction binary all‐small‐molecule (ASM) organic solar cells (OSCs) with power conversion efficiency (PCE) beyond 14% are achieved by using non‐fullerene acceptor Y6 as the electron acceptor, but still lag behind that of polymer OSCs. Herein, an asymmetric Y6‐like acceptor, BTP‐FCl‐FCl, is designed and synthesized to match the recently reported high performance small molecule donor BTR‐Cl, and a record efficiency of 15.3% for single‐junction binary ASM OSCs is achieved. BTP‐FCl‐FCl features a F,Cl disubstitution on the same end group affording locally asymmetric structures, and so has a lower total dipole moment, larger average electronic static potential, and lower distribution disorder than those of the globally asymmetric isomer BTP‐2F‐2Cl, resulting in improved charge generation and extraction. In addition, BTP‐FCl‐FCl based active layer presents more favorable domain size and finer phase separation contributing to the faster charge extraction, longer charge carrier lifetime, and much lower recombination rate. Therefore, compared with BTP‐2F‐2Cl, BTP‐FCl‐FCl based devices provide better performance with FF enhanced from 71.41% to 75.36% and Jsc increased from 22.35 to 24.58 mA cm−2, leading to a higher PCE of 15.3%. The locally asymmetric F, Cl disubstitution on the same end group is a new strategy to achieve high performance ASM OSCs.
2D Materials Bridging Experiments and Computations for Electro/Photocatalysis
Authors: Zhang Xu , Chen An , Chen Letian , Zhou Zhen
Published: February 2021

The exploration of catalysts for energy conversion lies at the center of sustainable development. The combination of experimental and computational approaches can provide insights into the inner laws between the catalytic performance and the structural and electronic properties of catalysts. Owing to the inherent advantages of 2D materials over their 3D counterparts, including high specific surface area and abundant surface defects that could provide sufficient active sites, 2D materials are promising candidates and have attracted wide interest in catalysis. Importantly, 2D materials are the most widely computationally investigated models with which to relate computational prediction with experimental confirmation conveniently. Recently, more 2D catalysts have been prepared in experiments while more accurate computational methods have been used to disclose catalytic performance, and explore the mechanism at an atomic level. In this review, recent advances are summarized related to the development and design of 2D electro/photocatalysts. The main emphasis is put on the unique properties of 2D catalysts investigated by the combination of experiments and computations. Computational methods closer to experimental environments are introduced with particular attention to bridge the gap between experiments and computations. In addition, the challenges of computations and experiments are also discussed for 2D catalysts.
Initial return to work and long‐term employment patterns: Associations with work‐related permanent impairment and with participation in workers' compensation‐based return‐to‐work programs
Authors: Sears Jeanne M. , Fulton‐Kehoe Deborah , Hogg‐Johnson Sheilah
Published: February 2021

Background

Roughly 10% of injured workers experience work injuries that result in permanent impairment and a permanent partial disability (PPD) award. This study aimed to characterize and quantify long‐term employment outcomes for injured workers, by the degree of whole body impairment (WBI) and by participation in several workers' compensation (WC)‐based return‐to‐work (RTW) programs.

Methods

A retrospective cohort of 43,968 Washington State workers were followed for up to 10 years after WC claim closure (2009–2017). Degree of impairment was classified as: (1) no PPD award, (2) PPD award with WBI < 10%, or (3) PPD award with WBI ≥ 10%. State wage files were used to construct employment outcomes for regression, modeling: (1) time to first RTW, (2) time to first RTW interruption, (3) RTW volatility, and (4) employment gaps.

Results

Wage patterns and employment outcomes differed significantly by the degree of impairment. Compared to other workers, workers with WBI ≥ 10% had delayed RTW, shorter average times to first RTW interruption, and higher rates of both RTW interruptions and quarters without wages. Time to first RTW averaged over a year, increasing with the degree of impairment. About 9% overall—and 27% of workers with ≥10% WBI—had no observed wages after claim closure. In adjusted models, workers with WBI ≥ 10% had significantly poorer employment outcomes, compared to workers with no PPD award (p < 0.001).

Conclusions

State wage files provide an efficient approach to identifying RTW patterns. Workers with permanent impairment were at substantially higher risk of poor employment outcomes. WC‐based RTW programs may promote better employment outcomes.
Workers' compensation costs for healthcare caregivers: Home healthcare, long‐term care, and hospital nurses and nursing aides
Authors: Davis Kermit G. , Freeman Andrew M. , Ying Jun , Huth Jeffrey R.
Published: February 2021

Background: Healthcare workers (nurses and nursing aides) often have different exposures and injury risk factors depending on their occupational subsector and location (hospital, long‐term care, or home health care).

Methods: A total of 5234 compensation claims for nurses and nursing aides who suffered injuries to their lower back, knee, and/or shoulder over a 5‐year period were obtained from the Ohio Bureau of Workers' Compensation and analyzed. Injury causation data was also collected for each claim. The outcome variables included indemnity costs, medical costs, total costs, and the number of lost work days. The highest prescribed morphine equivalent dose for opioid medications was also calculated for each claim.

Results: Home healthcare nurses and nursing aides had the highest average total costs per claim. Hospital nurses and nursing aides had the highest total claim costs, of $5 million/year. Shoulder injuries for home healthcare nursing aides (HHNAs) had the highest average total claim costs ($20,600/injury) for all occupation, setting, and body area combinations. Opioids were most frequently prescribed for home healthcare nurses (HHNs) and nursing aides (18.9% and 17.7% having been prescribed opioids, respectively). Overexertion was the most common cause for HHN and nursing aide claims.

Conclusions: With the rapidly expanding workforce in the home healthcare sector, there is a potential health crisis from the continued expansion of home healthcare worker injuries and their associated costs. In addition, the potential for opioid drug usage places these workers at risk for future dependence, overdose, and prolonged disability. Future research is needed to investigate the specific and ideally reversible causes of injury in claims categorized as caused by overexertion.
Clinical phenotype and management of individuals with mosaic monosomy X with Y chromosome material stratified by genital phenotype
Authors: Guzewicz Lindsey , Howell Susan , Crerand Canice E. , Umbaugh Hailey , Nokoff Natalie J. , Barker Jennifer , Davis Shanlee M.
Published: February 2021

Individuals mosaic for monosomy X and a cell line with Y chromosome material can have genitalia that appear phenotypical female, male, or ambiguous. Those with this karyotype and typical female genitalia are diagnosed with Turner syndrome; however, this definition specifically excludes those with genitalia other than typical female. There is limited information on whether medical and neurodevelopmental risks are similar among individuals with monosomy X and Y chromosome material across genital phenotypes. This multicenter retrospective study compared comorbidities and clinical management in individuals with monosomy X and Y material and male/ambiguous genitalia to those with typical female genitalia. Electronic medical records for all patients with monosomy X and Y material (n = 76) at two large U.S. pediatric centers were abstracted for predetermined data and outcomes. Logistic regression was used to compare the two phenotypic groups adjusting for site and duration of follow‐up. The male/ambiguous genitalia group was just as likely to have congenital heart disease (RR 1.0, 95%CI [0.5–1.9]), autoimmune disease (RR 0.6 [0.2–1.3]), and neurodevelopmental disorders (RR 1.4 [0.8–1.2]) as those with female genitalia. Despite similar risks, they were less likely to receive screening and counseling. In conclusion, individuals with monosomy X and Y chromosome material have similar medical and neurodevelopmental risks relative to individuals with Turner syndrome regardless of genitalia, but there are notable differences in clinical management.
Nachweis des Lewis‐amphoteren Charakters von Tris(pentafluorethyl)silanid, [Si(C2F5)3]−
Authors: Tiessen Natalia , Keßler Mira , Neumann Beate , Stammler Hans‐Georg , Hoge Berthold
Published: February 2021

Bei Betrachtung der geometrischen und elektronischen Struktur des Tris(pentafluorethyl)silanids erscheint das Anion auf den ersten Blick als Lewis‐Base. Quantenmechanischen Rechnungen zufolge liegen die HOMO‐ und LUMO‐Energien von Perfluoralkylsilaniden deutlich niedriger als die nicht fluorierter Derivate. Dies hat eine geringere Lewis‐Basizität und zugleich eine erhöhte Lewis‐Acidität des [Si(C2F5)3]−‐Ions zur Folge. Mit diesen Erkenntnissen und einer der N‐heterocyclischen Silylenen (NHSis) ähnlichen HOMO‐LUMO‐Lücke von 4.80 eV sind Perfluoralkylsilanide dazu prädestiniert, Lewis‐amphoteres Verhalten ähnlich dem der Silylene aufzuweisen. Die Deprotonierung von Si(C2F5)3H mit sterisch anspruchsvollen Phosphazenbasen liefert thermisch stabile Phosphazenium‐Salze des [Si(C2F5)3]−‐Anions, welche in unterschiedlicher Weise an Benzaldehyd, Benzophenon, CS2 und CO2 addieren. Dieses Verhalten spiegelt die Reaktivität von Silylenen gegenüber Ketonen sowie Heterocumulenen wider und wird durch die Lewis‐Amphoterie des Silanids begründet.