bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spider‐Inspired Electrohydraulic Actuators for Fast, Soft‐Actuated Joints
Authors: Kellaris Nicholas , Rothemund Philipp , Zeng Yi , Mitchell Shane K. , Smith Garrett M. , Jayaram Kaushik , Keplinger Christoph 
Published: June 2021

AbstractThe impressive locomotion and manipulation capabilities of spiders have led to a host of bioinspired robotic designs aiming to reproduce their functionalities; however, current actuation mechanisms are deficient in either speed, force output, displacement, or efficiency. Here—using inspiration from the hydraulic mechanism used in spider legs—soft‐actuated joints are developed that use electrostatic forces to locally pressurize a hydraulic fluid, and cause flexion of a segmented structure. The result is a lightweight, low‐profile articulating mechanism capable of fast operation, high forces, and large displacement; these devices are termed spider‐inspired electrohydraulic soft‐actuated (SES) joints. SES joints with rotation angles up to 70°, blocked torques up to 70 mN m, and specific torques up to 21 N m kg−1 are demonstrated. SES joints demonstrate high speed operation, with measured roll‐off frequencies up to 24 Hz and specific power as high as 230 W kg−1—similar to human muscle. The versatility of these devices is illustrated by combining SES joints to create a bidirectional joint, an artificial limb with independently addressable joints, and a compliant gripper. The lightweight, low‐profile design, and high performance of these devices, makes them well‐suited toward the development of articulating robotic systems that can rapidly maneuver.
Facile Fabrication of Multivalent VOx/Graphene Nanocomposite Electrodes for High‐Energy‐Density Symmetric Supercapacitors
Authors: Huang Ailun , El‐Kady Maher F. , Chang Xueying , Anderson Mackenzie , Lin Cheng‐Wei , Turner Christopher L. , Kaner Richard B. 
Published: June 2021

AbstractSupercapacitors have emerged as one of the leading energy‐storage technologies due to their short charge/discharge time and exceptional cycling stability; however, the state‐of‐the‐art energy density is relatively low. Hybrid electrodes based on transition metal oxides and carbon‐based materials are considered to be promising candidates to overcome this limitation. Herein, a rational design of graphene/VOx electrodes is proposed that incorporates vanadium oxides with multiple oxidation states onto highly conductive graphene scaffolds synthesized via a facile laser‐scribing process. The graphene/VOx electrodes exhibit a large potential window with a high three‐electrode specific capacitance of 1110 F g–1. The aqueous graphene/VOx symmetric supercapacitors (SSCs) can reach a high energy density of 54 Wh kg–1 with virtually no capacitance loss after 20 000 cycles. Moreover, the flexible quasi‐solid‐state graphene/VOx SSCs can reach a very high energy density of 72 Wh kg–1, or 7.7 mWh cm–3, outperforming many commercial devices. With Rct < 0.02 Ω and Coulombic efficiency close to 100%, these gel graphene/VOx SSCs can retain 92% of their capacitance after 20 000 cycles. The process enables the direct fabrication of redox‐active electrodes that can be integrated with essentially any substrate including silicon wafers and flexible substrates, showing great promise for next‐generation large‐area flexible displays and wearable electronic devices.
The pandemic of workplace violence: the gendered experience of emergency medicine trainees
Authors: Snavely Cheyenne , Romeo Michelle , Ciardiello Amber , Mojica Michael 
Published: June 2021

AbstractObjectivesMany health care providers experience physical and verbal abuse from patients and their visitors. This abuse is a form of workplace violence and likely has negative implications for the providers well‐being. The objective of our study was to determine the rates of nonphysical workplace violence against emergency medicine (EM) trainees with a focus on prevalence by provider gender.MethodsThis was a single‐center prospective cohort study using tally counters to track occurrences of nonphysical workplace violence perpetrated by patients and their visitors against EM trainees in the adult emergency department.ResultsThere were a total of 39 completed responses submitted by 22 respondents. Of the 22 respondents, 14 identified as women and eight identified as men. On average, both men and women experienced near daily occurrences of nonphysical workplace violence. However, women experienced higher rates compared to their colleagues who are men with a mean of three occurrences per day versus 0.9, respectively.ConclusionWe found that women trainees were more likely to experience nonphysical workplace violence from patients and their visitors.
Virtual multispecialty point‐of‐care ultrasound rotation for fourth‐year medical students during COVID‐19: Innovative teaching techniques improve ultrasound knowledge and image interpretation
Authors: Zavitz Joshua , Sarwal Aarti , Schoeneck Jacob , Glass Casey , Hays Brandon , Shen E. , Bryant Casey , Gupta Karisma 
Published: June 2021

AbstractObjectivesPoint‐of‐care ultrasound (PoCUS) has been integrated into undergraduate medical education. The COVID‐19 pandemic forced medical schools to evolve clinical rotations to minimize interruption through implementation of novel remote learning courses. To address the students’ need for remote clinical education, we created a virtual PoCUS course for our fourth‐year class. We present details of the course's development, implementation, quality improvement processes, achievements, and limitations.MethodsA virtual PoCUS course was created for 141 fourth‐year medical students. The learning objectives included ultrasound physics, performing and interpreting ultrasound applications, and incorporating PoCUS into clinical decisions and procedural guidance. Students completed a 30‐question pre‐ and posttest focused on ultrasound and knowledge of clinical concepts. PoCUS educators from 10 different specialties delivered the course over 10 days using video‐conferencing software. Students watched live scanning demonstrations and practiced ultrasound probe maneuvers using a cellular telephone to simulate ultrasound probe. Students completed daily course evaluations that were used as a continuous needs assessment to make improvements.ResultsA total of 141 students participated in the course; all received a passing grade. The mean pre‐ and posttest scores improved from 58% to 88% (p < 0.001) through the course duration. Daily evaluations revealed the percentage of students who rated the course's live scanning sessions and didactic components as “very well” increased from 32.7% on day 1 to 69.7% on day 10. The end‐of‐course evaluation revealed that 91% of students agreed they received effective teaching.ConclusionsIn response to the COVID‐19 pandemic, our multispecialty faculty expeditiously developed a virtual PoCUS curriculum for the entire fourth‐year class. This innovative course improved students’ ultrasound knowledge, image interpretation, and clinical application while utilizing novel techniques to teach a hands‐on skill virtually. As the demand for PoCUS instruction continues to increase, the accessibility of virtual training and blended learning will be beneficial.
Proximal variants in CCND2 associated with microcephaly, short stature, and developmental delay: A case series and review of inverse brain growth phenotypes
Authors: Pirozzi Filomena , Lee Benson , Horsley Nicole , Burkardt Deepika D. , Dobyns William B. , Graham John M. , Dentici Maria L. , Cesario Claudia , Schallner Jens , Porrmann Joseph , Di Donato Nataliya , Sanchez‐Lara Pedro A. , Mirzaa Ghayda M. 
Published: June 2021

AbstractCyclin D2 (CCND2) is a critical cell cycle regulator and key member of the cyclin D2‐CDK4 (DC) complex. De novo variants of CCND2 clustering in the distal part of the protein have been identified as pathogenic causes of brain overgrowth (megalencephaly, MEG) and severe cortical malformations in children including the megalencephaly‐polymicrogyria‐polydactyly‐hydrocephalus (MPPH) syndrome. Megalencephaly‐associated CCND2 variants are localized to the terminal exon and result in accumulation of degradation‐resistant protein. We identified five individuals from three unrelated families with novel variants in the proximal region of CCND2 associated with microcephaly, mildly simplified cortical gyral pattern, symmetric short stature, and mild developmental delay. Identified variants include de novo frameshift variants and a dominantly inherited stop‐gain variant segregating with the phenotype. This is the first reported association between proximal CCND2 variants and microcephaly, to our knowledge. This series expands the phenotypic spectrum of CCND2‐related disorders and suggests that distinct classes of CCND2 variants are associated with reciprocal effects on human brain growth (microcephaly and megalencephaly due to possible loss or gain of protein function, respectively), adding to the growing paradigm of inverse phenotypes due to dysregulation of key brain growth genes.
Atypical, severe hypertrophic cardiomyopathy in a newborn presenting Noonan syndrome harboring a recurrent heterozygous MRAS variant
Authors: Pires Lucas Vieira Lacerda , Bordim Renata de Almeida , Maciel Maria Beatriz Rabelo , Tanaka Ana Cristina Sayuri , Yamamoto Guilherme Lopes , Honjo Rachel Sayuri , Kim Chong Ae , Bertola Debora Romeo 
Published: June 2021

AbstractNoonan syndrome (NS) is a Mendelian phenotype, member of a group of disorders sharing neurocardiofaciocutaneous involvement, known as RASopathies, caused by germline variants in genes coding for components of the RAS/MAPK signaling pathway. Recently, a novel gene of the RAS family (MRAS) was reported to be associated with NS in five children, all of them presenting, among the cardinal features of NS, the same cardiac finding, hypertrophic cardiomyopathy (HCM). We report on a 2‐month‐old infant boy also presenting this cardiac anomaly that evolved to a fatal outcome after a surgical myectomy. In addition, a thick walled left ventricle apical aneurysm, rarely described in NS, was also disclosed. Next‐generation sequencing revealed a missense, previously reported variant in MRAS (p.Thr68Ile). This report reinforces the high frequency of HCM among individuals harboring MRAS variants, contrasting to the 20% overall prevalence of this cardiac anomaly in NS. Thus, these preliminary data suggest that variants in MRAS per se are high risk factors for the development of an early, severe HCM, mostly of them with left ventricle outflow tract obstruction, with poor prognosis. Because of the severity of the cardiac involvement, other clinical findings could not be addressed in detail. Therefore, long‐term follow‐up of these individuals and further descriptions are required to fully understand the complete phenotypic spectrum of NS associated with MRAS germline variants, including if these individuals present an increased risk for cancer.
Facile Synthesis of Oleanane‐type Pentacyclic Triterpenoids Bearing Hydroxy Groups on D/E Rings
Authors: Mu Tong , Xu Peng , Yu Biao 
Published: June 2021

AbstractPentacyclic triterpenoids (PTs) comprise one of the largest class of natural products; many bear higher oxidation state on the D/E rings and exhibit a wide range of biological activities. Here, we report the chemical synthesis of a series of oleanane‐type PTs bearing hydroxy groups on D/E rings from the largely available oleanolic acid by transformations following site‐selective C−H hydroxylation.
Acute systemic inflammation exacerbates neuroinflammation in Alzheimer's disease: IL‐1β drives amplified responses in primed astrocytes and neuronal network dysfunction
Authors: Lopez‐Rodriguez Ana Belen , Hennessy Edel , Murray Carol L. , Nazmi Arshed , Delaney Hugh J. , Healy Dáire , Fagan Steven G. , Rooney Michael , Stewart Erika , Lewis Anouchka , de Barra Niamh , Scarry Philip , Riggs‐Miller Louise , Boche Delphine , Cunningham Mark O. , Cunningham Colm 
Published: June 2021

AbstractNeuroinflammation contributes to Alzheimer's disease (AD) progression. Secondary inflammatory insults trigger delirium and can accelerate cognitive decline. Individual cellular contributors to this vulnerability require elucidation. Using APP/PS1 mice and AD brain, we studied secondary inflammatory insults to investigate hypersensitive responses in microglia, astrocytes, neurons, and human brain tissue. The NLRP3 inflammasome was assembled surrounding amyloid beta, and microglia were primed, facilitating exaggerated interleukin‐1β (IL‐1β) responses to subsequent LPS stimulation. Astrocytes were primed to produce exaggerated chemokine responses to intrahippocampal IL‐1β. Systemic LPS triggered microglial IL‐1β, astrocytic chemokines, IL‐6, and acute cognitive dysfunction, whereas IL‐1β disrupted hippocampal gamma rhythm, all selectively in APP/PS1 mice. Brains from AD patients with infection showed elevated IL‐1β and IL‐6 levels. Therefore, amyloid leaves the brain vulnerable to secondary inflammation at microglial, astrocytic, neuronal, and cognitive levels, and infection amplifies neuroinflammatory cytokine synthesis in humans. Exacerbation of neuroinflammation to produce deleterious outcomes like delirium and accelerated disease progression merits careful investigation in humans.
A Trapezoidal Octacyanoquinoid Acceptor Forms Solution and Surface Products by Antiparallel Shape Fitting with Conformational Dipole Momentum Switch
Authors: Medina Rivero Samara , Urieta‐Mora Javier , Molina‐Ontoria Agustín , Martín‐Fuentes Cristina , Urgel José I. , Zubiria‐Ulacia Maria , Lloveras Vega , Casanova David , Martínez José I. , Veciana Jaume , Écija David , Martín Nazario , Casado Juan 
Published: June 2021

AbstractA new compound (1) formed by two antiparallelly disposed tetracyano thienoquinoidal units has been synthesized and studied by electrochemistry, UV/Vis‐NIR, IR, EPR, and transient spectroscopy. Self‐assembly of1on a Au(111) surface has been investigated by scanning tunneling microscopy. Experiments have been rationalized by quantum chemical calculations.1exhibits a unique charge distribution in its anionic form, with a gradient of charge yielding a neat molecular in‐plane electric dipole momentum, which transforms out‐of‐plane after surface deposition due to twisted→folded conformational change and to partial charge transfer from Au(111). Intermolecular van der Waals interactions and antiparallel trapezoidal shape fitting lead to the formation of an optimal dense on Au(111) two‐dimensional assembly of1.
Precisely Engineered Supported Gold Clusters as a Stable Catalyst for Propylene Epoxidation
Authors: Kapil Nidhi , Weissenberger Tobias , Cardinale Fabio , Trogadas Panagiotis , Nijhuis T. Alexander , Nigra Michael M. , Coppens Marc‐Olivier 
Published: June 2021

AbstractDesigning a stable and selective catalyst with high H2 utilisation is of pivotal importance for the direct gas‐phase epoxidation of propylene. This work describes a facile one‐pot methodology to synthesise ligand‐stabilised sub‐nanometre gold clusters immobilised onto a zeolitic support (TS‐1) to engineer a stable Au/TS‐1 catalyst. A non‐thermal O2 plasma technique is used for the quick removal of ligands with limited increase in particle size. Compared to untreated Au/TS‐1 catalysts prepared using the deposition precipitation method, the synthesised catalyst exhibits improved catalytic performance, including 10 times longer lifetime (>20 days), increased PO selectivity and hydrogen efficiency in direct gas phase epoxidation. The structure‐stability relationship of the catalyst is illustrated using multiple characterisation techniques, such as XPS, 31P MAS NMR, DR‐UV/VIS, HRTEM and TGA. It is hypothesised that the ligands play a guardian role in stabilising the Au particle size, which is vital in this reaction. This strategy is a promising approach towards designing a more stable heterogeneous catalyst.
Introducing Intermolecular Cation‐π Interactions for Water‐Stable Low Dimensional Hybrid Lead Halide Perovskites
Authors: Sheikh Tariq , Maqbool Shabnum , Mandal Pankaj , Nag Angshuman 
Published: June 2021

AbstractOptoelectronically active hybrid lead halide perovskites dissociate in water. To prevent this dissociation, here, we introduce long‐range intermolecular cation‐π interactions between A‐site cations of hybrid perovskites. An aromatic diamine like 4,4′‐trimethylenedipyridine, if protonated, can show a long‐range cation‐π stacking, and therefore, serves as our A‐site cation. Consequently, 4,4′‐trimethylenedipyridinium lead bromide [(4,4′‐TMDP)Pb2Br6], a one‐dimensional hybrid perovskite, remains completely stable after continuous water treatment for six months. Mechanistic insights about the cation‐π interactions are obtained by single‐crystal X‐ray diffraction and nuclear magnetic resonance spectroscopy. The concept of long‐range cation‐π interaction is further extended to another A‐site cation 4,4′‐ethylenedipyridinium ion (4,4′‐EDP), forming water‐stable (4,4′‐EDP)Pb2Br6 perovskite. These water‐stable perovskites are then used to fabricate white light‐emitting diode and for light up‐conversion through tunable third‐harmonic generation. Note that the achieved water stability is the intrinsic stability of perovskite composition, unlike the prior approach of encapsulating the unstable perovskite material (or device) by water‐resistant materials. The introduced cation‐π interactions can be a breakthrough strategy in designing many more compositions of water‐stable low‐dimensional hybrid perovskites.
Origin of the α‐Effect in SN2 Reactions
Authors: Hansen Thomas , Vermeeren Pascal , Bickelhaupt F. Matthias , Hamlin Trevor A. 
Published: June 2021

AbstractThe α‐effect is a term used to explain the dramatically enhanced reactivity of α‐nucleophiles (R−Y−X:−) compared to their parent normal nucleophile (R−X:−) by deviating from the classical Brønsted‐type reactivity‐basicity relationship. The exact origin of this effect is, however, still heavily under debate. In this work, we have quantum chemically analyzed the α‐effect of a set of anionic nucleophiles, including O‐, N‐ and S‐based normal and α‐nucleophiles, participating in an SN2 reaction with ethyl chloride using relativistic density functional theory at ZORA‐OLYP/QZ4P. Our activation strain and Kohn–Sham molecular orbital analyses identified two criteria an α‐nucleophile needs to fulfill in order to show α‐effect: (i) a small HOMO lobe on the nucleophilic center, pointing towards the substrate, to reduce the repulsive occupied–occupied orbital overlap and hence (steric) Pauli repulsion with the substrate; and (ii) a sufficiently high energy HOMO to overcome the loss of favorable HOMO–LUMO orbital overlap with the substrate, as a consequence of the first criterion, by reducing the HOMO–LUMO orbital energy gap. If one of these two criteria is not fulfilled, one can expect no α‐effect or inverse α‐effect.
Two‐Photon Ionization Induced Stable White Organic Long Persistent Luminescence
Authors: Liang Xiao , Zheng You‐Xuan , Zuo Jing‐Lin 
Published: June 2021

AbstractOrganic long persistent luminescence (OLPL) materials with afterglow duration in the scale of minutes or even hours are still rare. Most OLPL systems are based on exciplexes, which require complicated multi‐component system in order to realize white afterglow but with slightly compromised duration and color stability. In this work, OLPLs lasting from 20 to 40 minutes are realized in a simple binary system based on two‐photon ionization mechanism, which can simultaneously harvest excitons from both singlet and triplet excited states, making it potentially one of the most promising candidates to achieve stable white OLPL. Through modulation and optimization of dopant molecules in dibenzo[b,d]thiophen‐2‐yldiphenyl phosphine oxide host, the emission profiles of afterglow can be readily tuned from cyan (0.19, 0.22), cold white (0.31, 0.35), standard white (0.33, 0.33) to warm white (0.31, 0.46), with excellent color consistency.
Talc reinforcement of polylactide and biodegradable polyester blends via injection‐molding and pilot‐scale film extrusion
Authors: Helanto Karoliina , Talja Riku , Rojas Orlando J. 
Published: June 2021

AbstractAs a renewable and biodegradable polymer, polylactide (PLA) has taken a foothold in the packaging industry. However, the thermomechanical and barrier properties of PLA‐based films need to be improved to facilitate a wider adoption. To address this challenge, we examined the effect of talc reinforcement in composites based on PLA and a biodegradable polyester. Masterbatches of the polymers and talc were produced by melt compounding and processed by either injection‐molding or film extrusion in a pilot‐scale unit operating at 60–80 m/min. The effect of talc was investigated in relation to the morphological, thermal, mechanical, and barrier properties of the composites. Based on SEM‐imaging, talc was found to increase the miscibility of PLA and the polyester while acting as a nucleating agent that improved PLA crystallinity. While this effect did not track with an increased mechanical strength, the composites with 3–4 wt% talc displayed a significantly higher barrier to water vapor. Compared to the neat polymer films, a reduction of water vapor transmission rate, by ~34–37%, was observed at 23°C/50% RH. Meanwhile, the systems loaded with 1 wt% talc showed a reduction in oxygen transmission rates, by up to 34%. Our results highlight the challenges and prospects of commercial PLA‐based blends filled with talc from films extruded in pilot‐scale units.
Tunable fluorescent and antimicrobial properties of poly(vinyl amine) affected by the acidic or basic hydrolysis of poly(N‐vinylformamide)
Authors: Sütekin S. Duygu , Demirci Sahin , Kurt Saliha B. , Güven Olgun , Sahiner Nurettin 
Published: June 2021

AbstractSynthesis of poly(N‐vinylformamide) (PNVF) and its subsequent hydrolysis to convert it to poly(vinyl amine) (PVAm) were performed. Kinetics of acidic and basic hydrolysis of poly(N‐vinylformamide) (PNVF), and products of hydrolysis were investigated by using Fourier transform infrared, size exclusion chromatography,1H NMR, and13C NMR spectroscopies, and thermogravimetric analysis. It was observed that amide groups did not completely transform into amine groups by acidic hydrolysis of PNVF while the conversion of amides into amine groups via basic hydrolysis of PNVF was complete in 12 h, as confirmed by spectroscopic measurements. Results of extensive characterization revealed significant structural and conformational differences between acidic and basic hydrolysis products. Fluorescence spectroscopy was used for the first time to follow the conversion of amide groups into amine groups. The fluorescence intensity of PVAm obtained from basic hydrolysis of PVNF showed significant increase with amide/amine conversion. Finally, PVAm obtained from acidic hydrolysis of PNVF demonstrated potent antimicrobial activity, 10–20 times more, against common pathogens for example,C. albicans asfungal strain andE. coli,S. aureus,B. subtilis,andP. aeruginosaas bacterial strains as compared to PVAm obtained from basic hydrolysis.