bluuebunny/crossref_metadata_2025 huggingface dataset:
A donor design strategy for triazine-carbazole blue thermally activated delayed fluorescence materials
Authors: Li Xin , Li Jiuyan , Liu Di , Li Deli , Dong Ruizhi
Published: May 2020

Enhancing the delayed emission proportion by incorporating bulky substituent at the 1-site of carbazole donors is proved to be effective and practical strategy to improve the EL performance of cyaphenine-carbazole type blue TADF emitters.
The metal centre in salen-acridine dyad N2O2 ligand–metal complexes modulates DNA binding and photocleavage efficiency
Authors: Prasanth Panneerselvam Arun , Nantheeswaran Periyappan , Anbazhagan Veerappan , Senthilnathan Rajendran , Jothi Arunachalam , Bhuvanesh Nattamai S. P. , Sannegowda Lokesh Koodlur , Mariappan Mariappan
Published: May 2020

Metal centre in a coordination complex modulates DNA binding.
Mesoporous carbon host material for stable lithium metal anode
Authors: Jeong Jooyoung , Chun Jinyoung , Lim Won-Gwang , Kim Won Bae , Jo Changshin , Lee Jinwoo
Published: May 2020

Lithium metal is promising anode material for next-generation battery system. Here, mesoporous carbon material is applied as a host material and it extends Li metal's cycle life.
Nanochannels regulating ionic transport for boosting electrochemical energy storage and conversion: a review
Authors: Hao Zhendong , Zhang Qianqian , Xu Xiaolong , Zhao Qing , Wu Congrong , Liu Jingbing , Wang Hao
Published: May 2020

This work reviews the applications of nanochannels regulating ionic transport for boosting electrochemical energy storage and conversion.
Peripheral groups of polyhedral oligomeric silsesquioxane (POSS) core-based dendrimers: a crucial factor for higher-level supra-architecture building
Authors: He Huiwen , Zheng Hao , Ma Meng , Shi Yanqing , Gao Zengliang , Chen Si , Wang Xu
Published: May 2020

Peripheral groups of polyhedral oligomeric silsequioxane based dendrimers act as the crucial factor in unique loofah-like gel superstructures construction via controlling the hierarchical self-assembly in a thermodynamics approach.
Two-dimensional stable Mn based half metal and antiferromagnets promising for spintronics
Authors: Zhang Bingwen , Song Guang , Sun Jie , Leng Jiancai , Zhang Cheng , Wang Jun
Published: May 2020

By phonon band structure calculations and Monte Carlo simulations, we propose that 2D MnSi and MnC0.5Si0.5 monolayers could exhibit mechanical stability and room temperature half-metallic properties.
Rapid access to indole-fused bicyclo[2.2.2]octanones by merging the umpolung strategy and molecular iodine as a green catalyst
Authors: Abe Takumi , Hirao Seiya
Published: May 2020

We have achieved the one-pot construction of otherwise more difficult to access indole-fused bicyclo[2.2.2]octanones by merging the umpolung strategy and molecular iodine catalyst.
A novel reactive phosphonium-containing polyelectrolyte with multiple reactivities: monomer synthesis, RAFT polymerization and post-polymerization modifications
Authors: Sun Jian , Wang Chang , Tan Zhi-Wei , Liu Cheng-Mei
Published: May 2020

A reactive polyelectrolyte can be defined as a kind of functional polymer which possesses not only the basic properties of a polyelectrolyte but also wide post-polymerization modification possibilities, which can be achieved via various reactions.
Synthesis of aromatic polyketones by nonstoichiometric Friedel–Crafts polycondensation using AlCl3
Authors: Matsumoto Kazuya , Fukui Chisa , Shoji Riku , Jikei Mitsutoshi
Published: May 2020

Aromatic polyketones were successfully synthesized by Friedel–Crafts acylation using AlCl3 between aromatic dicarboxylic acid chlorides and 2,2′-dimethoxybiphenyl under both stoichiometric and nonstoichiometric conditions.
Electro-organic synthesis – a 21stcentury technique
Authors: Pollok Dennis , Waldvogel Siegfried R.
Published: May 2020

This perspective provides insight into recent electro-organic methods and general trends in this field, and opens up prospects for future viewpoints.
Correction: Viscoelastic interfaces comprising of cellulose nanocrystals and lauroyl ethyl arginate for enhanced foam stability
Authors: Czakaj Agnieszka , Kannan Aadithya , Wiśniewska Agnieszka , Grześ Gabriela , Krzan Marcel , Warszyński Piotr , Fuller Gerald G.
Published: May 2020

Correction for ‘Viscoelastic interfaces comprising of cellulose nanocrystals and lauroyl ethyl arginate for enhanced foam stability’ by Agnieszka Czakaj et al., Soft Matter, 2020, 16, 3981–3990, DOI: 10.1039/C9SM02392E.
Differences Between School-Age Children With Apraxia of Speech and Other Speech Sound Disorders on Multisyllable Repetition
Authors: Benway Nina R. , Preston Jonathan L.
Published: May 2020

Purpose

The aim of the study was to evaluate whether features of childhood apraxia of speech (CAS) identified in previous literature could be replicated in a sample of school-age children.

Method

A literature review was conducted to identify candidate speech features that have been previously considered when differentiating CAS from other types of speech sound disorders (SSDs). The candidate features recoverable from blinded transcriptions of multisyllable word repetitions (MSWRs) were applied to a cohort of 61 children aged 7–17 years, previously classified as having CAS (
n
= 21) or non-CAS SSD (
n
= 40).

Results

One hundred and ninety-four features had been explored in previous literature to assess their ability to differentiate CAS from other SSDs. Fifteen perceptual features were selected from this list to be applied to performance on the MSWR. In this sample, children with CAS differed from children with SSD on the prevalence of voicing changes, percentage of structurally correct words, correct lexical stress, and syllable deletions within a speech corpus derived from the MSWR task.

Conclusion

Although previous literature points to numerous features as differentiating CAS from other SSDs, only a portion of those features were replicated in this sample of school-age children. Features of CAS that affect segmental accuracy, prosody, and word structure may be likely to persist into late childhood and early adolescence.
Resilience‐based tri‐level framework for simultaneous transmission and substation expansion planning considering extreme weather‐related events
Authors: Shivaie Mojtaba , Kiani‐Moghaddam Mohammad , Weinsier Philip D.
Published: May 2020

In this study, a new resilience‐based framework is presented for multi‐period simultaneous transmission and substation expansion planning (ST&SEP) considering extreme weather‐related events (EWEs). The formation of the proposed planning framework falls into a tri‐level optimisation problem with the aim of strengthening power network resilience in response to the EWEs. In the lower‐level problem, short‐term remedial corrective strategies of the independent system operator (ISO) after the EWEs are determined by applying network reconfiguration and generation redispatch. In the intermediate‐level problem, an enhanced scenario‐building approach is developed to model and analyse the EWEs, as non‐random uncertain events, and their subsequent detrimental effects using the notion of the fragility curves corresponding to power network components. In the upper‐level problem, however, long‐term remedial preventive strategies of the ISO, as network planner, after the EWEs are obtained through integrated decisions between multi‐period ST&SEP and transmission switching equipment planning. The newly proposed planning framework is formulated as a large‐scale mixed‐integer non‐linear tri‐level optimisation problem and is solved by a powerful symphony orchestra search algorithm in order to obtain the final optimal solution. The proposed planning framework is examined on the real‐world large‐scale Iranian 400‐kV power transmission network and its profitableness is assured by thorough simulation studies.
Research on subway pedestrian detection algorithms based on SSD model
Authors: Yang Jie , He Wen Yu , Zhang Tian Lu , Zhang Chun Lei , Zeng Lu , Nan Bing Fei
Published: May 2020

Accurate target recognition and location is one of the key technologies in the field of smart city application. In order to solve the problem of large pedestriain flow impact in crowded metro stations, a method of in‐depth learning detection based on SSD (single shot multibox detector) is proposed. The algorithm extracts the feature information of the input image, then returns the boundary box of the location on the feature map and classifies the object categories. Using the method of local feature extraction, the features of different positions, different aspect ratios and sizes are obtained, and VGG16 is used as the base network to optimise and improve the network structure. The results of simulation experiments on VOC2007 and data_sub show that the maximum value of mAP is 77% and the highest accuracy is 96.31%. Compared with other mainstream deep learning target detection methods, SSD has higher accuracy, better real‐time and robustness. It can solve the problem of different pedestrian target sizes and better realise pedestrians in subway station environment. Detection provides decision‐making basis for flow statistics.
Mitigating X2‐AP interface cost using quantum teleportation
Authors: Alhumaima Raad S. , Alwan Saib Thiab , Ahmed Riyadh Khlf
Published: May 2020

Many problems in cellular communications cannot be solved classically. Due to its robustness, quantum computing can enrich the classical with other dimensions, security and cryptic‐natured. However, the awareness about how to fully bridge the classical and quantum communications is not fully realised. In other words, the quantum phenomena are not totally utilised within the classical dimension. This work rather discusses directions and evaluations for future quantum solutions to traditional cloud mobile networks. Particularly, using quantum correlation phenomena to enhance the performance of X2 application protocol (X2‐AP) by reducing the signalling overhead regarding the delay and power consumption that classical cloud encounter. Through modelling the latency of both paradigms using ‘MATLAB’, this work promises a delay reduction when adapting quantum method into the cloud. This study also models the power consumption and energy efficiency of traditional and quantum‐based cloud networks. This work also shows, via modelling the power consumption, that installing a quantum‐based paradigm is not a power costly method; rather, it shows identical power and energy efficiency figures with a possibility of improvement.
Power stabilisation scheme design using spatial rotating coil based on magnetic field aggregation
Authors: Tan Linlin , Zhong Ruying , Tang Zongyao , Meng Tao , Huang Xueliang
Published: May 2020

The power fluctuation problem has been a key issue in dynamic wireless power transfer (WPT) systems. In the past research studies, the power fluctuation problem at low‐transmission distance has been solved, but existing solutions often involve complex control strategies and cannot realise power stabilisation for dynamic WPT systems under high‐transmission distance. As a remedy, the spatial rotating coil design scheme is proposed based on magnetic field aggregation to solve the power fluctuation problem without control strategy for high distance dynamic WPT system. Firstly, the crucial parameters affecting power fluctuations are analysed. Then the relative optimisation backgrounds are introduced. Afterwards, the mechanism of power sag is analysed based on magnetic field analysis. Subsequently, the spatial rotating double D (DD) coil design is proposed inspired by omnidirectional WPT coil, and various different DD coil schemes are optimised utilising magnetic field aggregation method to acquire the optimal scheme. Compared with the original coil scheme, the proposed design scheme improves fluctuation of system mutual inductance without complicated control strategies according to simulation results. Finally, a physical coil system consistent with the simulation system is constructed, which verifies the improvement effect of the proposed scheme and effectively confirm feasibility of the optimal scheme.
Efficient implementation and performance improvement of three‐phase EPLL under non‐ideal grid conditions
Authors: Sevilmiş Fehmi , Karaca Hulusi
Published: May 2020

In this study, an advanced phase‐locked‐loop (PLL), which has a simple structure and a low computational burden is proposed. The proposed PLL also improves the dynamic performance and the filtering capability of the conventional three‐phase enhanced‐PLL (3pEPLL) significantly. The conventional 3pEPLL operates three individual EPLL blocks for each phase voltage and a fourth EPLL for estimation of the magnitude, frequency, and phase angle, which considerably increases the structural complexity and computational burden. However, the proposed PLL called enhanced‐3pEPLL (E2 PLL) employs only two single‐phase EPLL modules in its pre‐filtering stage. A moving‐average‐filter (MAF) is also supplemented on the error signal path of these EPLL modules, which allows smoother estimation of the magnitude, frequency, and phase angle, and improves the filtering capability of the EPLLs. Unlike the conventional 3pEPLL, the proposed E2 PLL employs a quasi‐type‐1 PLL (QT1‐PLL) to estimate the magnitude, frequency, and phase information of the fundamental grid voltage. The structure of QT1‐PLL is similar to a type‐1 PLL, which offers a low transient response time. The small‐signal model of the proposed PLL is derived for stability analysis and parameter design procedure. The effectiveness of the E2 PLL is verified owing to experimental results and comparison with the conventional 3pEPLL and QT1‐PLL.
Performance evaluation of the wireless sensor with renewable energy, impatience, and heterogeneous energy requirements
Authors: Chung Shun‐Ping , Liao Mei‐Jun , Yang Li
Published: May 2020

Wireless sensors are utilised to transmit data through the wireless sensor network. The authors consider wireless sensors with a limited energy capacity that needs the energy to complete the transmission service. To extend the lifetime of the wireless sensor, it is assumed that the renewable energy resource, e.g. solar energy, is collected via the energy harvesting method. In order to provide a better bit error rate or data rate, the energy requirement of a packet may be more than one unit of energy. Furthermore, a packet may leave without finishing the service due to impatience if the patient interval is exceeded. They focus on one wireless sensor with one server and two finite queues: one packet queue and one energy queue. In the authors’ system, there are two classes of impatient customers, and each customer has to consume one or two units of energy to finish the service. First, they derive the analytical model for the considered system and find the steady‐state probability distribution and performance measures of interest. Next, the impacts of different system parameters on the performance measures are studied. Last but not least, the analytical results are shown to be in good agreement with the simulation results.
Digital filter based on chaos theory used for removing narrow‐frequency‐band noise in PD signals
Authors: Jiang Tianyan , Wang Baimei , Bi Maoqiang , Chen Xi , Cheng Shouhua , Wang Fan
Published: May 2020

Partial discharge (PD) online monitoring is an effective approach to inspect insulation defects and identify potential faults in high voltage equipment. However, electromagnetic noises such as narrow‐frequency‐band (NFB) noise make it difficult to measure PD signals in the field accurately. This study proposed an approach which can remove the NFB interference in the PD signals by the chaos theory. The basic principles of chaotic oscillator interference filter in suppressing PD signal NFB were researched. The method based on the characteristic that the moving state of chaotic oscillators, and the characteristic was determined by the chaotic phase diagram and Lyapunov exponent. A chaotic oscillator filter has also been proposed to suppress NFB interference in PD detection. The de‐nosing results show that the chaotic oscillator filter de‐noising effect is better than the two order IIR‐rated filter.
Possible evidence of ongoing planet formation in AB Aurigae
Authors: Boccaletti A. , Di Folco E. , Pantin E. , Dutrey A. , Guilloteau S. , Tang Y. W. , Piétu V. , Habart E. , Milli J. , Beck T. L. , Maire A.-L.
Published: May 2020

Context. Planet formation is expected to take place in the first million years of a planetary system through various processes, which remain to be tested through observations.

Aims. With the recent discovery, using ALMA, of two gaseous spiral arms inside the ∼120 au cavity and connected to dusty spirals, the famous protoplanetary disk around AB Aurigae presents a strong incentive for investigating the mechanisms that lead to giant planet formation. A candidate protoplanet located inside a spiral arm has already been claimed in an earlier study based on the same ALMA data.

Methods. We used SPHERE at the Very Large Telescope to perform near-infrared high-contrast imaging of AB Aur in polarized and unpolarized light in order to study the morphology of the disk and search for signs of planet formation.

Results. SPHERE has delivered the deepest images ever obtained for AB Aur in scattered light. Among the many structures that are yet to be understood, we identified not only the inner spiral arms, but we also resolved a feature in the form of a twist in the eastern spiral at a separation of about 30 au. The twist of the spiral is perfectly reproduced with a planet-driven density wave model when projection effects are accounted for. We measured an azimuthal displacement with respect to the counterpart of this feature in the ALMA data, which is consistent with Keplerian motion on a 4 yr baseline. Another point sxce is detected near the edge of the inner ring, which is likely the result of scattering as opposed to the direct emission from a planet photosphere. We tentatively derived mass constraints for these two features.

Conclusions. The twist and its apparent orbital motion could well be the first direct evidence of a connection between a protoplanet candidate and its manifestation as a spiral imprinted in the gas and dust distributions.
Different types of uncertainty in nuclear emergency management
Authors: French S. , Haywood S. , Oughton D.H. , Turcanu C.
Published: May 2020

The objective of the CONFIDENCE project has been to identify, assess and communicate the uncertainties that arise in managing and recovering from a nuclear accident. To do that, it is important to be clear on what uncertainty means, how it arises and how we might analyse it. In fact, there are many forms of uncertainty, some of which we can assess with current tools, but some of which are more nebulous and difficult to deal with. Nonetheless, all need to be communicated to the emergency managers. Starting with a review of different categories of uncertainties, and using examples from the CONFIDENCE project, this paper discusses how the various uncertainties are manifested in nuclear emergency management. It concludes with a simple framework for categorising and analysing them. The overall intention is that such a framework could contribute to a broader discussion on identifying and handling uncertainties with nuclear emergency management actors
An ils-based heuristic applied to the car renter salesman problem
Authors: Dias Sávio S. , Simonetti Luidi G. , Ochi Luiz Satoru
Published: May 2020

The present paper tackles the Car Renter Salesman Problem (CaRS), which is a Traveling Salesman Problem variant. In CaRS, the goal is to travel through a set of cities using rented vehicles at minimum cost. The main aim of the current problem is to establish an optimal route using rented vehicles of different types to each trip. Since CaRS is N P-Hard, we herein present a heuristic approach to tackle it. The approach is based on a Multi-Start Iterated Local Search metaheuristic, where the local search step is based on the Random Variable Neighborhood Descent methodology. An Integer Linear Programming Formulation based on a Quadratic Formulation from literature is also proposed in the current study. Computational results for the proposed heuristic method in euclidean instances outperform current state-of-the-art results. The proposed formulation also has stronger bounds and relaxation when compared to others from literature.
Multi-objective permutation and non-permutation flow shop scheduling problems with no-wait: a systematic literature review
Authors: Singh Harpreet , Oberoi Jaspreet Singh , Singh Doordarshi
Published: May 2020

Flow shop scheduling is a type of scheduling where sequence follows for each job on a set of machines for processing. In practice, jobs in flow shops can arrive at irregular times, and the no-wait constraint allows the changes in the job order to flexibly manage such irregularity. The flexible flow shop scheduling problems with no-wait have mainly addressed for flow optimization on the shop floor in manufacturing, processing, and allied industries. The scope of this paper is to identify the literature available on permutation and non-permutation flow shop scheduling with no-wait constraint. This paper organizes scheduling problems based on performance measures of variability and shop environments. The extended summary of two/three-machine and m-machine problems has been compiled, including their objectives, algorithms, parametric considerations, and their findings. A systematic appearance of both conceptual and analytical results summarizes various advances of the no-wait constraint. The paper includes independently investigated problems and suggestions for future research directions.
Rezidivprophylaxe bei okulärer Toxoplasmose
Authors: Pleyer Uwe , Ness Thomas , Garweg Justus
Published: May 2020

Hintergrund Die okulare Toxoplasmose (OT) führt bei einem hohen Anteil der Patienten zu bleibenden Sehstörungen. Eine Kombination von Antibiotika und Kortikosteroiden verringert möglicherweise das Risiko einer dauerhaften Sehbehinderung und kann ein erneutes Auftreten verzögern. In dieser Übersicht fassen wir den aktuellen Kenntnisstand zur Rezidivprophylaxe der OT zusammen.

Methode Grundlage dieser auf Expertenbewertung basierten Übersichtsarbeit bildet eine Literatursuche in PubMed mit den Schlüsselwörtern (MeSH terms) „human ocular toxoplasmosis“ oder „retinochoroiditis“ und „recurrence“ und „prophylaxis“ oder „prevention“. Unter den resultierenden Publikationen wurden Fallserien mit mehr als 20 Patienten, prospektive klinische Studien sowie Metaanalysen berücksichtigt, die innerhalb der letzten 25 Jahre publiziert wurden, außerdem darin erwähnte weitere Publikationen, und basierend auf der Erfahrung der Autoren bewertet.

Ergebnisse Die Häufigkeit von Rezidiven unterscheidet sich nicht zwischen Lateinamerika, Nordamerika und Europa, liegt in den ersten beiden Jahren bei etwa 12 – 15% und nimmt danach ab, wobei Rezidive bis 49 Jahre nach einer aktiven Affektion beobachtet wurden. Nach 2 placebokontrollierten Doppelblindstudien aus Brasilien, wo besonders schwerwiegende Rezidive auftreten, kann eine Antibiotikaprophylaxe mit Trimethoprim 160 mg kombiniert mit Sulfamethoxazol 800 mg (Cotrim forte) 3-mal pro Woche über 12 Monate das Auftreten von Rezidiven über bis zu 3 Jahre von 22 auf 3% senken. Danach ist die Rezidivwahrscheinlichkeit so hoch wie bei Patienten, die keine Prophylaxe erhalten haben.

Schlussfolgerung Rezidive können wirkungsvoll unterdrückt werden, wenn dies medizinisch indiziert ist, insbesondere bei zentraler Lage der Läsionen, unzureichender Immunkompetenz und häufigen Rezidiven. Die Prophylaxe sollte für mindestens 12 Monate durchgeführt werden, da das Rezidivrisiko in den ersten beiden Jahren am höchsten ist.
Efficient Heterogeneous Palladium-Catalyzed Transfer Hydrogenolysis of Benzylic Alcohols by Formic Acid
Authors: Afewerki Samson , Córdova Armando , Palo-Nieto Carlos
Published: May 2020

An efficient heterogeneous palladium-catalyzed transfer hydrogenolysis­ of primary, secondary, and tertiary benzylic alcohols using formic acid as hydrogen source has been developed. The resulting hydrocarbon products were obtained in excellent yields. Moreover, the system exhibits high chemoselectivity, reacting only with the hydroxy groups in the presence of other functional groups, and excellent re­cyclability.
Teaching Glasgow Coma Scale Assessment by Videos: A Prospective Interventional Study among Surgical Residents
Authors: Bajaj Jitin , Rathore Sanjay , Parihar Vijay , Agarwal Pawan , Yadav Yad Ram , Sharma Dhananjaya
Published: May 2020

Objective Glasgow Coma Scale (GCS) assessment is vital for the management of various neurological, neurosurgical, and critical care disorders. Learning GCS scoring needs good training and practice. Due to limitation of teachers, the new entrants of the clinical team find it difficult to learn and use it correctly. Training through videos is being increasingly utilized in the medical field. This study aimed to evaluate the efficiency of video teaching of GCS scoring among general surgery residents.

Materials and Methods A prospective study was done utilizing the freely available video at glasgowcomascale.org. The participants (general surgery residents, 1st–3rd year) were asked to assess and record their responses related to GCS both before and after watching the video. A blinded neurosurgeon recorded the correct responses separately.

Statistical Analysis The difference between correct responses of the residents before and after watching the video was calculated using the “chi-square test.” p-Value ≤ 0.05 was taken as significant.

Results There was a significant improvement in GCS scoring by residents after watching the videos (p < 0.05). On estimating the responses separately, all the three responses (eye, verbal, and motor) improved significantly for 1st-year residents while only the motor response improved significantly for 2nd- and 3rd-year residents. The mode subjective improvement for the 1st-, 2nd-, and 3rd-year residents was 5, 4, and 3, respectively.

Conclusion Training GCS scoring through videos is an effective way of teaching the surgery residents with maximum benefit to the junior-most ones.
Patellar Resurfacing Does Not Improve Clinical Outcome in Patients with Symptomatic Tricompartmental Knee Osteoarthritis. An RCT Study of 40 Patients Receiving Primary Cruciate Retaining Total Knee Arthroplasty
Authors: Raaij Tom M. van , Meij Evelien van der , Vries Astrid J. de , Raay Jos J.A.M. van
Published: May 2020

There is some evidence that patellofemoral (PF) joint osteoarthritis (OA) causes anterior knee pain (AKP) after total knee arthroplasty (TKA). We hypothesized that patellar resurfacing in primary TKA for patients with symptomatic tricompartmental knee OA yields better clinical results after 2 years than non-resurfacing. A single center randomized controlled clinical trial comparing 40 patients receiving 42 cruciate retaining TKAs with (n = 21) or without patellar resurfacing (n = 21) was conducted. Primary outcome was the specific PF joint score HSS Baldini and secondary outcomes were the Knee Society Score (KSS) and the Knee Osteoarthritis Outcome Scale (KOOS). After 2 years no significant differences between both groups and between the groups in time for HSS Baldini, KSS, and KOOS were found. HSS Baldini score improved significantly after 6 weeks in both groups (p < 0.001) and did not improve in time afterward. At final follow-up the HSS Baldini mean score improved from a preoperative mean of 39 to 88 (difference of 49 points; p < 0.001)) for without patellar resurfacing group, and from a preoperative mean of 37 to 81 for patellar resurfacing group (difference of 47 points; p < 0.001). One patient in the patellar resurfacing group underwent a soft tissue re-alignment procedure because of patellar subluxation. Two patients in without patellar resurfacing group received secondary patellar button placement. Patellar resurfacing in primary TKA for patients with symptomatic tricompartmental OA has no beneficial effect over non-resurfacing and seems unnecessary. A special PF joint outcome measurement tool (HSS Baldini) and common knee scores showed no better knee function or AKP outcomes for with patellar resurfacing over without patellar resurfacing group in time and after 2 years of follow-up.
Giant Cell Tumor of the Capitate and Hamate: Case Report and of Literature Review
Authors: Abdusamad V. , Singh Vivek , Jain Rohit , Singh Divya
Published: May 2020

Background In the hand, giant cell tumors (GCTs) of the bones account for 2 to 5% of all hand tumors; they are often seen in the metacarpals and phalanges, seldom in the carpal bones. In the carpal bones, GCT usually occurs as a single lesion, with multifocal involvement being extremely rare. On analysis of recent English literature, we could find out only two reports having simultaneous involvement of multiple carpal bones.

Case Description We report a case of a 29-year-old female with simultaneous involvement of two carpal bones: capitate and hamate. After confirming the diagnosis by histopathological examination, the affected carpals were resected, and the defect was filled with autologous bone graft. Follow-up at 18 months demonstrated no evidence of local recurrence or metastatic disease, and the patient is now having a reasonable hand function.

Literature Review We analyzed nine case reports on GCTs in carpal bones in the past 25 years. Seven out of nine cases that we could analyze showed single carpal bone involvement (three capitate, two scaphoid, one hamate, one triquetrum). In these, four patients had undergone resection, and five patients had undergone curettage, of whom one patient came back 5 months later with recurrence. Only two cases were there with simultaneous involvement of multiple carpal bones. Both the cases were managed with resection and reconstruction with autologous graft iliac graft.

Clinical Relevance GCTs of the carpal bones are relatively rare, and simultaneous involvement of two bones is rarer. Every attempt should be made to preserve useful wrist range of motion by excision and limited carpal fusion.
Effects of electric and magnetic fields on the resistive switching operation of iPCM
Authors: Mitrofanov K. V. , Saito Y. , Miyata N. , Fons P. , Kolobov A. V. , Tominaga J.
Published: May 2020

Interfacial phase change memory devices based on chalcogenide superlattices show a remarkable performance improvement over traditional phase change memory devices. Here, we report on the effects of the resistive switching of Ge–Te/Sb–Te superlattices in the presence of an external magnetic field at elevated temperature. In addition to the unique thermal dependence of the switching behavior, a new resistance level was found. This resistance level, once initiated, could be then obtained without a magnetic field. The observed phenomena are associated with the structural reconfiguration of domains at the superlattice interfaces and grain boundaries. It has been proposed that these effects may be caused by the localization of spin-polarized electrons generated by a combination of electric and magnetic fields in the ferroelectric phase of the superlattice.
Pair-distribution function of active Brownian spheres in two spatial dimensions: Simulation results and analytic representation
Authors: Jeggle Julian , Stenhammar Joakim , Wittkowski Raphael
Published: May 2020

We investigate the full pair-distribution function of a homogeneous suspension of spherical active Brownian particles interacting by a Weeks–Chandler–Andersen potential in two spatial dimensions. The full pair-distribution function depends on three coordinates describing the relative positions and orientations of two particles, the Péclet number specifying the activity of the particles, and their mean packing density. This five-dimensional function is obtained from Brownian dynamics simulations. We discuss its structure taking into account all of its degrees of freedom. In addition, we present an approximate analytic expression for the product of the full pair-distribution function and the interparticle force. We find that the analytic expression, which is typically needed when deriving analytic models for the collective dynamics of active Brownian particles, is in good agreement with the simulation results. The results of this work can thus be expected to be helpful for the further theoretical investigation of active Brownian particles as well as nonequilibrium statistical physics in general.
A temperature-controlled cryogen free cryostat integrated with transceiver-mode superconducting coil for high-resolution magnetic resonance imaging
Authors: Saniour Isabelle , Authelet Gilles , Baudouy Bertrand , Dubuisson Rose-Marie , Jourdain Laurène , Willoquet Georges , Darrasse Luc , Ginefri Jean-Christophe , Poirier-Quinot Marie
Published: May 2020

Small-sized High Temperature Superconducting (HTS) radiofrequency coils are used in a number of micro-magnetic resonance imaging applications and demonstrate a high detection sensitivity that improves the signal-to-noise ratio. However, the use of HTS coils could be limited by the rarity of cryostats that are suitable for the MR environment. This study presents a magnetic resonance (MR)-compatible and easily operated cryogen-free cryostat based on the pulse tube cryocooler technology for the cooling and monitoring of HTS coils below the temperature of liquid nitrogen. This cryostat features a real-time temperature control function that allows the precise frequency adjustment of the HTS coil. The influence of the temperature on the electrical properties, resonance frequency (f0), and quality factor (Q) of the HTS coil was investigated. Temperature control is obtained with an accuracy of over 0.55 K from 60 K to 86 K, and the sensitivity of the system, extracted from the frequency measurement from 60 K to 75 K, is of about 2 kHz/K, allowing a fine retuning (within few Hz, compared to 10 kHz bandwidth) in good agreement with experimental requirements. We demonstrated that the cryostat, which is mainly composed of non-magnetic materials, does not perturb the electromagnetic field in any way. MR images of a 10 × 10 × 15 mm3 liquid phantom were acquired using the HTS coil as a transceiver with a spatial resolution of 100 × 100 × 300 µm3 in less than 20 min under experimental conditions at 1.5 T.
An entropy scaling demarcation of gas- and liquid-like fluid behaviors
Authors: Bell Ian H. , Galliero Guillaume , Delage-Santacreu Stéphanie , Costigliola Lorenzo
Published: May 2020

In this work, we propose a generic and simple definition of a line separating gas-like and liquid-like fluid behaviors from the standpoint of shear viscosity. This definition is valid even for fluids such as the hard sphere and the inverse power law that exhibit a unique fluid phase. We argue that this line is defined by the location of the minimum of the macroscopically scaled viscosity when plotted as a function of the excess entropy, which differs from the popular Widom lines. For hard sphere, Lennard-Jones, and inverse-power-law fluids, such a line is located at an excess entropy approximately equal to −2/3 times Boltzmann’s constant and corresponds to points in the thermodynamic phase diagram for which the kinetic contribution to viscosity is approximately half of the total viscosity. For flexible Lennard-Jones chains, the excess entropy at the minimum is a linear function of the chain length. This definition opens a straightforward route to classify the dynamical behavior of fluids from a single thermodynamic quantity obtainable from high-accuracy thermodynamic models.
Study of vertical hole transport in InAs/InAsSb type-II superlattices by steady-state and time-resolved photoluminescence spectroscopy
Authors: Tsai Cheng-Ying , Zhang Yang , Ju Zheng , Zhang Yong-Hang
Published: May 2020

It is known that the vertical hole mobility in superlattice structures, such as InAs/InAs1−xSbx type-II superlattices, is low and limits their photodetector performance. This paper reports the determination of vertical hole mobility in these superlattices with bandgaps in the mid-wave infrared range by using two methods based on steady-state and time-resolved photoluminescence measurements at 12 K–210 K. An ambipolar diffusion model is adopted to extract the hole mobility. The results show that the hole mobility first increases from 0.2 cm2/V s at 12 K and then levels off at ∼50 cm2/V s as the temperature exceeds ∼60 K.
Suppression of vortex–antivortex structures by anti-trimer point defects in hexagonal manganites
Authors: Lin H. L. , Yang K. L. , Chen P. Z. , Zhou G. Z. , Li C. F. , Zheng S. H. , Lin L. , Yan Z. B. , Jiang X. P. , Liu J.-M.
Published: May 2020

The topologically protected vortex–antivortex (V–AV) domain structure in ferroelectric hexagonal manganites has been highly concerned recently, but its stability against intrinsic defects remains to be understood, given the claim that a topological structure would be robust against defects and other perturbations. In fact, it is also known that the V–AV structure is sensitive to the sample quality, and such a well-developed structure is hardly observed in thin films and defective single crystals. In this work, we investigate the influence of anti-trimer point defects on the stability of the V–AV domain structure by employing the phase-field simulation based on the Landau–Devonshire phenomenological theory. It is revealed that the characteristic V–AV structure essentially relies on the anti-trimer point defects under consideration. These defects lower the trimerization transition temperature on one hand and produce pinning effect on the vortex cores/walls on the other hand. However, the V–AV structure does remain robust if the anti-trimer magnitude of these defects is relatively weak but will be eventually destroyed if the anti-trimer magnitude is strong.
Origins of irreversible capacity loss in hard carbon negative electrodes for potassium-ion batteries
Authors: Katorova Natalia S. , Luchkin Sergey Yu. , Rupasov Dmitry P. , Abakumov Artem M. , Stevenson Keith J.
Published: May 2020

Hard carbon (HC) is considered as a negative electrode material for potassium-ion batteries, but it suffers from significant irreversible capacity loss at the first discharge cycle. Here, we investigated the possible reasons of this capacity loss with a combination of in situ AFM and various ex situ TEM techniques (high resolution TEM and high angle annular dark field scanning TEM imaging, and STEM-EELS and STEM-EDX spectroscopic mapping) targeting the electrode/electrolyte interphase formation process in the carbonate-based electrolyte with and without vinylene carbonate (VC) as an additive. The studied HC consists of curved graphitic layers arranged into short packets and round cages, the latter acting as traps for K+ ions causing low Coulombic efficiency between cycling. Our comparative study of solid electrolyte interphase (SEI) formation in the carbonate-based electrolyte with and without the VC additive revealed that in the pristine electrolyte, the SEI consists mostly of inorganic components, whereas adding VC introduces a polymeric organic component to the SEI, increasing its elasticity and stability against fracturing upon HC expansion/contraction during electrochemical cycling. Additionally, significant K+ loss occurs due to Na+ for K+ exchange in Na-carboxymethyl cellulose used as a binder. These findings reflect the cumulative impact of the internal HC structure, SEI properties, and binder nature into the electrochemical functional properties of the HC-based anodes for K-ion batteries.
Negative differential thermal resistance effect in a macroscopic homojunction
Authors: Yang Yu , Ma Dengke , Zhao Yunshan , Zhang Lifa
Published: May 2020

The negative differential thermal resistance (NDTR) effect is an important mechanism to realize a thermal transistor that is of great significance to realize thermal control. We find that with accompanying an interface thermal resistance (ITR), which has a certain temperature-dependence, the macroscopic homojunction can present a NDTR. The temperature-dependent ITR to achieve NDTR can be realized by using materials with negative thermal expansion. As an example, a NDTR in the silicon homojunction was found at low temperature. The discovery of macro-NDTR will pave the way to design a macroscopic thermal transistor and also help us manipulate thermal flow more freely and effectively.
Flow topology and its transformation inside droplets traveling in rectangular microchannels
Authors: Li Mengqi , Liu Zhaomiao , Pang Yan , Yan Chengjin , Wang Ju , Zhao Siyu , Zhou Qiang
Published: May 2020

The flow topology inside a droplet acts directly on the cells or substances enclosed therein and is, therefore, of great significance in controlling the living environment of cells and the biochemical reaction process. In this paper, the flow characteristics inside droplets moving in rectangular microchannels are studied experimentally by particle image velocimetry for capillary numbers ranging from 10−5 to 10−2. In order to decouple the effects of total flow, droplet spacing, viscosity ratio, droplet size, and the depth-to-width ratio of the channel on the flow field, the droplet trains with a designed initial state are first produced by controlling the two-phase flow rate and setting up an auxiliary inlet, which is used to adjust the droplet size and spacing, and then run at a set flow rate. As the total flow increases, the flow topologies inside the plunger droplet gradually change from four eddies to two at relatively high viscosity ratios, whereas the opposite transition direction is observed in the low-viscosity-ratio system. The flow topology inside spherical droplets is unaffected by the total flow or capillary number, invariably producing double vortices. The effect of the channel wall on the droplet boundary decreases as the droplet spacing increases or the droplet size decreases. Assuming the continuity of the fluid mass, the competition between the gutter-flow driving stress and the oil-film resistance determines the boundary velocity of the droplet. The oil-film resistance dominates the motion of the droplet boundary in high-aspect-ratio channels, resulting in the negative rotation of the boundary velocity vectors and six vortices in the interior of the droplet. The results are conducive to the further development of microfluidic flow cytometry, particle concentration control, and droplet micromixers.
Numerical study on transition structures of oblique detonations with expansion wave from finite-length cowl
Authors: Xiang G. X. , Gao X. , Tang W. J. , Jie X. Z. , Huang X.
Published: May 2020

The oblique detonation wave (ODW) triggered by a semi-infinite cowl or wedge has been widely studied, but the effects of finite-length cowls require further clarification to enhance their applicability. Based on two-dimensional inviscid Euler equations and a two-step induction–reaction model, two structures with smooth and abrupt transitions are simulated, and their interactions with the cowl-induced expansion wave are investigated. The expansion waves located downstream and far away from the initiation zone do not affect the macroscopic structures of the ODW. However, when the expansion waves move upstream, the structures evolve into a decoupled shock and a reactive front. Alongside findings from previous studies, these results indicate that the initiation mechanism, rather than the transition type, determines the near-quenching evolution of the structure. Moreover, given the same parameter settings for the chemical and inflow gas dynamics, these numerical results show that the abrupt transition evolves into a smooth transition under an expansion wave disturbance. This demonstrates that the local wave interaction plays a key role in the ODW structures.
Operando Raman spectroscopy tracks oxidation-state changes in an amorphous Co oxide material for electrocatalysis of the oxygen evolution reaction
Authors: Pasquini Chiara , D’Amario Luca , Zaharieva Ivelina , Dau Holger
Published: May 2020

Transition metal oxides are of high interest in both energy storage (batteries) and production of non-fossil fuels by (photo)electrocatalysis. Their functionally crucial charge (oxidation state) changes and electrocatalytic properties are best investigated under electrochemical operation conditions. We established operando Raman spectroscopy for investigation of the atomic structure and oxidation state of a non-crystalline, hydrated, and phosphate-containing Co oxide material (CoCat), which is an electrocatalyst for the oxygen evolution reaction (OER) at neutral pH and is structurally similar to LiCoO2 of batteries. Raman spectra were collected at various sub-catalytic and catalytic electric potentials. 2H labeling suggests Co oxidation coupled to Co—OH deprotonation at catalytic potentials. 18O labeling supports O—O bond formation starting from terminally coordinated oxygen species. Two broad bands around 877 cm−1 and 1077 cm−1 are assigned to CoCat-internal H2PO4-. Raman peaks corresponding to terminal oxide (Co=O) or reactive oxygen species were not detectable; 1000–1200 cm−1 bands were instead assigned to two-phonon Raman scattering. At an increasingly positive potential, the intensity of the Raman bands decreased, which is unexpected and explained by self-absorption relating to CoCat electrochromism. A red-shift of the Co—O Raman bands with increasing potentials was described by four Gaussian bands of potential-dependent amplitudes. By linear combination of Raman band amplitudes, we can follow individually the Co(2+/3+) and Co(3+/4+) redox transitions, whereas previously published x-ray absorption spectroscopy analysis could determine only the averaged Co oxidation state. Our results show how electrochemical operando Raman spectroscopy can be employed as a potent analytical tool in mechanistic investigations on OER catalysis.
Estimation of mean turbulent kinetic energy and temperature variance dissipation rates using a spectral chart method
Authors: Lemay Jean , Djenidi Lyazid , Antonia Robert
Published: May 2020

A method aimed at estimating εk and εθ, respectively, the mean dissipation rates of turbulent kinetic energy k and half the temperature variance θ2/2, is developed for slightly heated turbulent flows of air. It is limited to a Prandtl number near unity and applicable to flows where temperature can be treated as a passive scalar. A significant advantage of the method is that εk and εθ can both be estimated from the measurement of a temperature frequency spectrum, Gθθ(f). The method relies on the collapse in the dissipative range of one-dimensional temperature spectra, ϕθ(k1η), when normalized with εθ, εk, and ν. This collapse ensues from a similarity analysis of scale-by-scale budgets of the second-order structure function for the temperature. A generic spectrum ϕθG(k1η), defined in the wavenumber range 0.07 ≤ k1η ≤ 0.7, is used to construct a spectral chart. The method has been tested in several flows and found to be reliable. In particular, it is tested on the axis of a slightly heated round jet, where εk and εθ can be estimated accurately via the budgets of k and θ2/2, and the agreement between these estimates and the spectral chart results is almost perfect.