bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Side-Chain-Free Hydrazone-Linked Covalent Organic Frameworks through Supercritical Carbon Dioxide Activation
Authors: Diwakara Shashini D. , McCandless Gregory T. , Alahakoon Sampath B. , Smaldone Ronald A.
Published: April 2021

Supercritical carbon dioxide (scCO2) activation provides milder conditions to process covalent organic frameworks (COFs) without compromising their crystallinity and porosity. To this end, three hydrazone COFs (TFPB-DHz COF, TFPT-DHz COF, Py-DHz COF) were synthesized with a terephthaloyl dihydrazide linker (DHz) which has no substituents. To date, the synthesis of hydrazone COFs without a narrow range of alkoxy linkers has not been possible. The scCO2-activated hydrazone-linked COFs in this study were crystalline and had high surface areas (surface areas of TFPB-DHz COF, TFPT-DHz COF, and Py-DHz COF were 790, 1199, and 932 m2/g, respectively). This study shows the significance of using milder activation methods for making hydrazone-linked COF structures that were previously inaccessible.
Concise Total Synthesis of (+)-Aphanorphine
Authors: Guan Yukun , Wang Cheng
Published: April 2021

A concise total synthesis of (+)-aphanorphine is described. The key features of the strategy include a Pd-catalyzed intermolecular trimethylenemethane [3+2]-cycloaddition to form ring C and a Co-catalyzed radical cyclization through a hydrogen-atom transfer to close ring B. The synthesis was completed in six steps.
Spheno-Orbital Meningioma with Cavernous Sinus Extension
Authors: de Carvalho Rodolfo Figueiredo , de Morais Artur Nóbrega Lima , Olijnyk Leonardo Desessards , Abrao Adriana Azeredo Coutinho , Zanatta Claudia , da Silva Carlos Eduardo
Published: April 2021

We present a case of a 37-year-old female, with progressive left eye proptosis and an extensive ipsilateral en plaque spheno-orbital meningioma, with diffuse involvement of the lateral wall of the cavernous sinus and the orbit.

A cranio-orbital zygomatic approach was performed to reach all extension of the lesion. We made an extradural clinoidectomy and an extensive bone removal of the orbit, exposition of the superior and lateral walls of the cavernous sinus, unroofing of the optic canal, superior orbital fissure, foramen rotundum, and foramen ovale. We performed the peeling of the lateral wall of cavernous sinus with total removal and preservation of the cranial nerves anatomy and function.

In this video, we illustrate the importance of the first time aggressive removal of such tumors. We also demonstrate the concept that secondary invasion of the cavernous sinus are suitable for removal with cranial nerve preservation.

The link to the video can be found at https://youtu.be/GJmkqVa6jSs.
Design and characterization of a velocity-map imaging apparatus for low-energy photo-ion spectroscopy using magneto-optically trapped atoms
Authors: Fang Feng , Zhou Wenchang , Li Yufan , Qian Dongbin , Luo Changjie , Zhao Dongmei , Ma Xinwen , Yang Jie
Published: April 2021

We present a velocity-map imaging (VMI) apparatus coupled with a magneto-optical trap (MOT) of 87Rb atoms designed for low-energy photo-ion spectroscopy. The VMI-electrode geometry uses a three-electrode configuration, and the focusing electric field is optimized based on systematic simulations of relatively low-energy ions. To calibrate the apparatus, we use resonant two-color two-photon ionization of rubidium atoms as Doppler-selected ions. This VMI system provides an accuracy of 0.15 m/s and a resolution of 7.5 m/s for photoions with speeds below 100 m/s. Finally, details of the design, construction, and testing of the VMI–MOT system are presented.
Separating the contributions of electric and magnetic fields in deflecting the probes in proton radiography with multiple proton energies
Authors: Du Bao , Cai Hong-Bo , Zhang Wen-Shuai , Wang Xiao-Fang , Kang Dong-Guo , Deng Luan , Zhang En-Hao , Yao Pei-Lin , Yan Xin-Xin , Zou Shi-Yang , Zhu Shao-Ping
Published: April 2021

In proton radiography, degeneracy of electric and magnetic fields in deflecting the probe protons can prevent full interpretation of proton flux perturbations in the detection plane. In this paper, theoretical analyses and numerical simulations suggest that the contributions of the electric and magnetic fields can be separately obtained by analyzing the difference between the flux distributions of two discriminated proton energies in a single shot of proton radiography. To eliminate the influence of field evolution on the separation, a strategy is proposed in which slow field evolution is assumed or an approximate estimate of field growth is made. This could help achieve a clearer understanding of the radiographic process and allow further quantitative analysis.
Influence of the surface roughness on inner–outer interactions in a turbulent Couette–Poiseuille flow
Authors: Kim Jeong Hyun , Lee Young Mo , Lee Jae Hwa , Kim Jooha
Published: April 2021

When rod surface roughness is introduced in a turbulent Couette–Poiseuille flow (CP-flow), it is known that the Reynolds stresses near the centerline decrease due to weakened very-large-scale motions (VLSMs) and roll-cell motions [Lee, Y. M. et al., “Direct numerical simulation of a turbulent Couette–Poiseuille flow with a rod-roughened wall,” Phys. Fluids 30, 105101 (2018)]. In the present study, we examine the origin of the weakened turbulent structures near the centerline in a CP-flow with roughness (CPR-flow) using a dataset from direct numerical simulation. The top–down and bottom–up interactions to organize a CP-flow are very similar to those found in earlier studies in turbulent channel/pipe and boundary layer flows. The circulation of roll-cells in the outer region induces the spanwise congregation of negative streamwise velocity fluctuating structures (u) near the wall, leading to a large-scale ejection into the outer region. This large-scale ejection contributes to the formation of a negative VLSM when two adjacent negative large-scale motions merge, and the VLSM induces the circulation of roll-cell motion due to the pure kinematics. A similar process for the inner–outer interactions is found for a CPR-flow. However, because the impact of the surface roughness suppresses the collective motion of negative u-structures near the surface roughness, strong congregation by roll-cells is observed to occur far from the wall, indicating that relatively few negative u-structures with low strength contribute to the formation of a large-scale ejection for the CPR-flow. The weakened large-scale ejection decreases the strength of the VLSM, resulting in weakened roll-cell motion.
Experimental investigation of bubbly flow by air injection on an inclined hydrofoil
Authors: Nagarathinam David , Kim Kiseong , Ahn Byoung-Kwon , Park Cheolsoo , Kim Gun-Do , Yim Geun-Tae
Published: April 2021

Flow features resulting from air injection through a hole on an inclined hydrofoil in a free stream flow are characterized in this work. The experiments were carried out in a cavitation tunnel at the Chungnam National University. The hydrofoil was oriented at angles of inclination, α=±3.5° and 0°, in the test section with water flowing at the free stream velocity, V∞= 3, 5, and 7 m/s (Froude number, Fn∼ 30–70). The air jet emanating from the hole on the inclined hydrofoil along the streamwise direction [Reynolds number of air, Reair∼O(103)], at various air injection rates, Cq, was characterized by high-speed imaging. Geometric features of the air jet, such as jet width, w, jet angle, β, jet effective diameter, deff, and jet thickness, t, are measured from the high-speed images. A power-law relation is shown to exist between the non-dimensional geometric features of the jet and the non-dimensional parameters, Reair,Fn,Cq. Depending on the Froude number, Fn, and non-dimensional air injection rate, Cq, several jet domains such as unstable jet, cloudy puff, buoyant-bifurcating jet, and stable-buoyant jet domains were observed upon air injection at Reair∼O(103) for various hydrofoil inclinations.
Plasma physics in strong-field regimes: Theories and simulations
Authors: Shi Yuan , Qin Hong , Fisch Nathaniel J.
Published: April 2021

In strong electromagnetic fields, unique plasma phenomena and applications emerge whose description requires recently developed theories and simulations [Y. Shi, Ph.D. thesis, Princeton University (2018)]. In the classical regime, to quantify effects of strong magnetic fields on three-wave interactions, a convenient formula is derived by solving the fluid model to the second order in general geometry. As an application, magnetic resonances are exploited to mediate laser pulse compression, whereby higher intensity pulses can be produced in wider frequency ranges, as confirmed by particle-in-cell simulations. In even stronger fields, relativistic-quantum effects become important, and a plasma model based on scalar quantum electrodynamics (QED) is developed which unveils observable corrections to Faraday rotation and cyclotron absorption in strongly magnetized plasmas. Beyond the perturbative regime, lattice QED is extended as a numerical tool for plasma physics, using which the transition from wakefield acceleration to electron-positron pair production is captured when laser intensity exceeds the Schwinger threshold.
Ultralow thermal conductivity in quaternary compound Ag2BaSnSe4 due to square-cylinder cage-like structure with rattling vibration
Authors: Hong Aijun , Ma Lingling
Published: April 2021

Quaternary compound Ag2BaSnSe4 has ultralow thermal conductivity. However, the physical reasons for it remain ambiguous. By using the first principles calculations combined with the Boltzmann phonon transport equation and inelastic neutron scattering theory, we find that the square-cylinder cage-like structure with rattling vibration is the most important objective reason. The vibrations of rattling Ag atoms cause hybridization and softening of phonon branches and, thus, lead to low specific heat and especially low group velocity, accounting for ultralow lattice thermal conductivity directly. We find that the thermal Grüneisen parameter seriously deviates from acoustic and elastic Grüneisen parameters. We consider that the lattice thermal conductivity is related to the acoustic/elastic Grüneisen parameter rather than the thermal Grüneisen parameter. Our research not only explains the physical origin for ultralow lattice thermal conductivity of compound Ag2BaSnSe4 but also will inspire much research on cage-like structures.
Controlling the rebound on a solid surface by varying impact angles of ellipsoidal drops
Authors: Yun Sungchan
Published: April 2021

Enhancing drop deposition on solid surfaces has received significant attention in various fields. Breaking the circular symmetry in typical impact dynamics has opportunities for altering the mass and momentum distributions significantly and improving the deposition. Here, we study the impact dynamics of ellipsoidal drops on nonwetted solid surfaces to reduce the bounce magnitude as a function of the impact angle and ellipticity. Experimental and numerical studies reveal that the ellipsoidal drop with the impact angle shows a strong reduction in the maximum bounce height, compared with the spherical drops. The oblique drop impact exhibits a remarkable feature of the off-axis aligning process caused by asymmetric retraction dynamics. Axial momentum analyses help us to interpret the underlying principle behind the peculiar retraction dynamics and establish a transition map of the rebound and deposition for varying angles and ellipticities. We believe that a breakup of the symmetry in the dynamics can provide practical implications for the control of drop deposition in diverse applications, such as spraying, coating, and cooling.
Bouncing droplets on an elastic, superhydrophobic cantilever beam
Authors: Upadhyay Gaurav , Kumar Vedant , Bhardwaj Rajneesh
Published: April 2021

The impact dynamics of a water droplet on a flexible substrate is useful for designing pesticide sprays and understanding insects flying in rainfall. We experimentally analyze the impact dynamics of a microliter water droplet on a superhydrophobic cantilever beam for Weber number in the range of 30–76. A thin copper sheet was coated with a commercial coating to render it superhydrophobic and high-speed imaging was used for visualization. During the impact, the spreading droplet converts its inertial energy into surface energy and elastic energy of the substrate. While retraction of the contact line, the latter energies convert to the kinetic energy of the droplet, and the droplet could bounce off the deforming cantilever beam. The characteristics timescales of droplet and cantilever beams are varied by changing the droplet diameter and impact velocity, and beam length, respectively. We show that the overall system dynamics, i.e., bouncing of the droplet and oscillations of the cantilever, is dependent on the interplay of these two timescales. A spring-mass system has been used to model this coupling and to explain the experimental observations. These findings can help to design systems to achieve desirable contact time, droplet rebound kinetic energy, energy transfer to the cantilever beam, and the droplet spreading diameter.
Effect of dielectric barrier discharge plasma actuator on the dynamic moment behavior of pitching airfoil at low Reynolds number
Authors: Huang Guangjing , Dai Yuting , Yang Chao , Wu You , Xia Yingjie
Published: April 2021

The purpose of this paper is to investigate the feasibility of using dielectric barrier discharge plasma actuation for the pitch stability control of a National Advisory Committee for Aeronautics 0012 pitch oscillating airfoil at low Reynolds number. The effects of the plasma actuator on the flow are incorporated into Navier–Stokes equations as a body force source term. The plasma body force is modeled by a phenomenological approach. Solutions are obtained by two-dimensional numerical simulations using the γ−Reθ transition model. The flow control effects of plasma actuator locations, strengths, force directions, and laminar separation flutter (LSF) conditions are investigated. The energy extracted by the airfoil from the flow over one oscillation cycle is defined to evaluate the control performance. The LSF analysis based on energy maps is also implemented. The control effect of co-flow plasma configuration on pitch instability is better than the counterflow configuration. The co-flow plasma actuator located at 0.6c reaches the best control performance and the energy extracted by the airfoil from the flow over one oscillation cycle reduces by 726% relative to the baseline case. The flow feature inducing the pitch instability and the flow control mechanism of co-flow and counterflow plasma actuator is analyzed in terms of the flow structure and pressure distribution, respectively. The results show that the plasma flow control is effective to mitigate the pitch instability across a wide range of Reynolds numbers at which laminar separation flutter occurs without control.
Leading health reform: a critical review of ‘leadership’ within allied health competency standards
Authors: Dalton Lisa , Butler-Henderson Kerryn , Newstead Toby , Quinn Wendy
Published: April 2021

Objective The study examined if, when and how select allied health professional standards currently articulate the Health LEADS Australia themes. Methods Eighteen allied health professional standards were searched to locate references to leadership. Data were extracted and analysed inductively, deductively and thematically as a meta-synthesis. Frequencies were counted, with subanalysis by professional area, classification level, competency type and level of cognition. Results There were 953 direct and indirect leadership statements. Only two leadership definitions were located, for pharmacists and dentists. The principal theme ‘Leadership’ only appeared in 18 (2%) statements from the total dataset that made direct references to leadership, which were mostly vague and unclear. The remaining indirect references to leadership are reported as four overarching themes: Self-leadership (n = 289 statements; 30%); Leadership With and of Others (n = 263; 28%); Improvement and Change Leadership (n = 223; 23%); and Health Reform Leadership (n = 139; 15%). Conclusion Health leadership was not easily recognisable in the allied health practice standards examined. With some refinement and alignment with a contemporary leadership framework, professional standards could play a critical role in preparing allied health graduates to support the ongoing health system reform required to improve health and well-being outcomes in the future. What is known about the topic? Leadership is essential at all health system levels, and leadership frameworks can usefully guide leadership development. However, little is known about allied health leadership compared with other clinical groups, and their contributions to directional changes in health system reform may be overlooked. What does this paper add? This paper presents results of an analysis of where and how 18 allied health disciplines align with the Australian Health LEADS framework, and where greater clarity or alignment is needed. What are implications for practitioners? Reinstatement of a national health leadership framework, such as the Australian Health LEADS framework, to articulate the need for and capabilities of leadership to enable innovation and support reform across all professional groups working in health care, including medical, nursing and allied health is required. A recognised national leadership framework could guide the revisions to allied health practice standards and coupled with a co-design process involving practitioners and professional associations, further development and incorporation of leadership competencies in a consistent manner would be enabled. Furthermore, alignment of allied health education and professional development with a national health leadership framework may strengthen allied health leadership graduate outcomes.
Ground pearls (Hemiptera: Margarodidae) in crops and pastures: biology and options for management
Authors: Thomson Melody B. , Campbell Shane D. , Young Anthony J.
Published: April 2021

Ground pearls (Hemiptera: Margarodidae), so called for their shiny spherical cyst stage, are important root-feeding pests of a broad range of plants predominantly belonging to the family Poaceae. In the tropical and subtropical regions of eastern Australia, ground pearl species cause significant damage on sugarcane and turf grasses and have been identified at multiple sites of pasture dieback in Queensland. The potential impact of ground pearls on pasture production in Australia and elsewhere is largely unknown. This paper reviews Australian and international literature on the biology and management of this poorly understood group of pests. Ground pearls have several features that make control difficult, including a resilient cyst which provides resistance to drought and excessive moisture, a relative impermeability to insecticides, and ease of dispersal through movement of soil. Ground pearls can also modulate the period of encystment to survive adverse environmental conditions, with some species capable of surviving for years while disassociated from a host. No insecticide effectively controls ground pearl cysts. Biological control agents have been identified for some species; however, these pathogens are relatively ineffective on subterranean ground pearl cysts. Cultural control methods such as cultivation and fallowing have helped to reduce ground pearl populations in sugarcane. In turf, practices that maintain plant health such as adequate irrigation and nutrition can mask signs of ground pearl infestation. The paucity of research conducted on the biology and impact of ground pearls represents a constraint to improving management of this pest.
Barley stripe mosaic virus (stripe mosaic of barley).
Authors: Jezewska Malgorzata
Published: April 2021

In the USA, BSMV has been economically significant only in Montana and North Dakota (Carroll, 1983). Between 1953 and 1970 the total loss in barley caused by this virus was calculated at more than US$ 30 million. In 1964 the virus caused damage estimated at over US$ 3.1 million (Carroll, 1980). Yield reductions in barley were 24-46% when BSMV was inoculated mechanically (Chiko and Barker, 1978; Carroll, 1980). In most states of the USA and also in most other countries where it occurs, the economic significance of BSMV has decreased (Carroll, 1983). For further information, see Carroll (1986). The impact of mild strains of BSMV on barley yield is substantially lower (Jezewska, 2006).
Colubrina asiatica (latherleaf).
Authors: Rojas-Sandoval Julissa , Acevedo-Rodríguez Pedro
Published: April 2021

A datasheet on Colubrina asiatica covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.
Indigofera suffruticosa (Anil indigo).
Authors: Parker Chris
Published: April 2021

A datasheet on Indigofera suffruticosa covering, as an economically important tree, its taxonomy, importance, silviculture, distribution, biology and ecology, uses, products and pests.
Hemolysis-associated phosphatidylserine exposure promotes polyclonal plasmablast differentiation
Authors: Vijay Rahul , Guthmiller Jenna J. , Sturtz Alexandria J. , Crooks Sequoia , Johnson Jordan T. , Li Lei , Lan Linda Yu-Ling , Pope Rosemary L. , Chen Yani , Rogers Kai J. , Dutta Nirmal , Toombs Jason E. , Wilson Mary E. , Wilson Patrick C. , Maury Wendy , Brekken Rolf A. , Butler Noah S.
Published: April 2021

Antimalarial antibody responses are essential for mediating the clearance of Plasmodium parasite–infected RBCs from infected hosts. However, the rapid appearance of large numbers of plasmablasts in Plasmodium-infected hosts can suppress the development and function of durable humoral immunity. Here, we identify that the formation of plasmablast populations in Plasmodium-infected mice is mechanistically linked to both hemolysis-induced exposure of phosphatidylserine on damaged RBCs and inflammatory cues. We also show that virus and Trypanosoma infections known to trigger hemolytic anemia and high-grade inflammation also induce exuberant plasmablast responses. The induction of hemolysis or administration of RBC membrane ghosts increases plasmablast differentiation. The phosphatidylserine receptor Axl is critical for optimal plasmablast formation, and blocking phosphatidylserine limits plasmablast expansions and reduces Plasmodium parasite burden in vivo. Our findings support that strategies aimed at modulating polyclonal B cell activation and phosphatidylserine exposure may improve immune responses against Plasmodium parasites and potentially other infectious diseases that are associated with anemia.
Broad and potent neutralizing human antibodies to tick-borne flaviviruses protect mice from disease
Authors: Agudelo Marianna , Palus Martin , Keeffe Jennifer R. , Bianchini Filippo , Svoboda Pavel , Salát Jiří , Peace Avery , Gazumyan Anna , Cipolla Melissa , Kapoor Tania , Guidetti Francesca , Yao Kai-Hui , Elsterová Jana , Teislerová Dana , Chrdle Aleš , Hönig Václav , Oliveira Thiago , West Anthony P. , Lee Yu E. , Rice Charles M. , MacDonald Margaret R. , Bjorkman Pamela J. , Růžek Daniel , Robbiani Davide F. , Nussenzweig Michel C.
Published: April 2021

Tick-borne encephalitis virus (TBEV) is an emerging human pathogen that causes potentially fatal disease with no specific treatment. Mouse monoclonal antibodies are protective against TBEV, but little is known about the human antibody response to infection. Here, we report on the human neutralizing antibody response to TBEV in a cohort of infected and vaccinated individuals. Expanded clones of memory B cells expressed closely related anti-envelope domain III (EDIII) antibodies in both groups of volunteers. However, the most potent neutralizing antibodies, with IC50s below 1 ng/ml, were found only in individuals who recovered from natural infection. These antibodies also neutralized other tick-borne flaviviruses, including Langat, louping ill, Omsk hemorrhagic fever, Kyasanur forest disease, and Powassan viruses. Structural analysis revealed a conserved epitope near the lateral ridge of EDIII adjoining the EDI–EDIII hinge region. Prophylactic or early therapeutic antibody administration was effective at low doses in mice that were lethally infected with TBEV.
Investigation and suppression of asymmetric modes competition in Cerenkov device by conductivity anisotropic material loading
Authors: Fan Zhiqiang , Cao Yibing , Wu Ping , Song Zhimin , Tan Nongchao , Sun Jun
Published: April 2021

Efficient and stable operation of Cerenkov devices relies on effective mode control, which means efficient generation of the operation mode and effective suppression of the competition modes. This paper explores the feasibility of suppressing asymmetric modes by loading a conductivity anisotropic material in Cerenkov devices. We theoretically study the dispersion characteristics of a slow-wave structure (SWS) loaded with a conductivity anisotropic material. The theoretical analyses indicate that asymmetric modes such as the HE11 mode have a low net temporal growth rate in a SWS coaxially loaded with the anisotropic material, of which the azimuthal conductivity is in the transition region from good to poor conductor. Accordingly, an anisotropic material with suitable azimuthal conductivity effectively suppresses asymmetric mode competition while maintaining the original characteristics of the symmetric TM modes. Furthermore, we numerically investigate the effectiveness of asymmetric mode suppression by anisotropic material loading using a 3D particle-in-cell CHIPIC code. A coaxially loaded conductivity anisotropic material effectively suppresses the asymmetric HE11 mode in a Ku-band Cerenkov device, and a pure quasi-TEM mode is obtained in the output waveguide. The output power of the generator is 2.9 GW, and the efficiency is 44%. This study provides a feasible method to eliminate asymmetric modes in Cerenkov devices, which may lead to a wide range of applications.
L-shaped electrode design for high-density spin–orbit torque magnetic random access memory with perpendicular shape anisotropy
Authors: Chi Kequn , Shi Yinuo , Li Zhou , Zhang Wenbiao , Xing Yun , Feng Xiang , Ma Yungui , Meng Hao , Liu Bo
Published: April 2021

Magnetic tunneling junctions with strong perpendicular shape anisotropy attract attention due to their high-density magnetic random access memory. As thermal stability increases, the power consumption also increases. To solve this problem, devices are made to be driven by spin–orbit torque (SOT) instead of spin-transfer torque. However, the assisting field needed for deterministic switching is a major obstacle for SOT devices. In this work, we demonstrate an L-shaped electrode structure attached to the magnetic recording layer to induce a composite SOT, achieving high-speed and field-free magnetization switching. Meanwhile, a comparative study between L-shaped and sidewall electrode structure demonstrates that the L-shaped structure leads to fast and low-power switching. Finally, the switching characteristic at various current densities and spin Hall angles is studied and it turns out that to achieve high-speed reversal, the current density and the spin Hall angle need to be optimized, which might be attributed to strong in-plane effective field component disturbance. The novel L-shaped structure is feasible for high-speed, low-power and deterministic switching and has great potential in spintronic applications.
Enhanced crystallization of solution-processed perovskite using urea as an additive for large-grain MAPbI3 perovskite solar cells
Authors: Wen Xiaoning , Cai Qingbing , Shen Guibin , Xu Xiangning , Dong Pei , Du Yaxin , Dong Hongye , Mu Cheng
Published: April 2021

Perovskite crystal quality plays an important role in perovskite solar cells, given that multiple grain boundaries and trap states in the perovskite films hamper further enhancement of solar cell efficiency. Using the solution method to prepare perovskite films with large grains and high coverage requires further improvements. Herein, we introduce Lewis base urea as an additive into the precursor of perovskite to control the crystallization dynamics, allowing for large-grain crystal growth. As a result, MAPbI3 films with urea as an additive are well crystallized with large crystal grains of sizes >3 μm. The large-grain perovskite is found to simultaneously improve the power-conversion efficiency (PCE) and device stability. With an optimal urea additive of 20 mol%, the PCE is significantly increased from 15.47% for the reference MAPbI3 solar cell to 18.53% for the device with MAPbI3 with urea as an additive. Finally, the optimized device demonstrates excellent stability and maintains 80% of the initial PCE after 60 days.
Stable and scalable SERS tags conjugated with neutravidin for the detection of fibroblast activation protein (FAP) in primary fibroblasts
Authors: Talamona Federica , Truffi Marta , Caldarone Alessandro Aldo , Ricciardi Alessandra , Corsi Fabio , Pellegrini Giovanni , Morasso Carlo , Taglietti Angelo
Published: April 2021

SERS tags are a class of nanoparticles with great potential in advanced imaging experiments. The preparation of SERS tags however is complex, as they suffer from the high variability of the SERS signals observed even at the slightest sign of aggregation. Here, we developed a method for the preparation of SERS tags based on the use of gold nanostars conjugated with neutravidin. The SERS tags here obtained are extremely stable in all biological buffers commonly employed and can be prepared at a relatively large scale in very mild conditions. The obtained SERS tags have been used to monitor the expression of fibroblast activation protein alpha (FAP) on the membrane of primary fibroblasts obtained from patients affected by Crohn’s disease. The SERS tags allowed the unambiguous identification of FAP on the surface of cells thus suggesting the feasibility of semi-quantitative analysis of the target protein. Moreover, the use of the neutravidin–biotin system allows to apply the SERS tags for any other marker detection, for example, different cancer cell types, simply by changing the biotinylated antibody chosen in the analysis.
Flexible and highly responsive photodetectors based on heterostructures of MoS2 and all-carbon transistors
Authors: Li Li , Shang Yuanyuan , Lv Suye , Li Yunxing , Fang Ying , Li Hongbian
Published: April 2021

Heterostructures of graphene and transition-metal dichalcogenides (TMDCs) are promising candidates for high-performance flexible photodetectors because of their high photoresponsivity and detectivity. However, the mechanical stability of current flexible photodetectors is limited, due to a mechanical mismatch between their two-dimensional channel materials and metallic contacts. Herein, we develop a type of mechanically stable, highly responsive, and flexible photodetector by integrating MoS2 and all-carbon transistors. By combining the high mobility of graphene with the strong light–matter interactions of MoS2, our heterostructure photodetector exhibits a greatly improved photoresponse performance, compared with individual graphene or MoS2 photodetectors. In addition, the mechanical properties of the all-carbon electrodes are a good match for those of the active two-dimensional channels, resulting in greatly improved electrical stability of the heterostructure photodetector under mechanical deformation. These capabilities make our heterostructure photodetector a promising candidate for flexible photodetection and photoimaging applications.
Neutron microtomography to investigate the bone-implant interface—comparison with histological analysis
Authors: Guillaume Florian , Le Cann Sophie , Tengattini Alessandro , Törnquist Elin , Falentin-Daudre Céline , Albini Lomami Hugues , Petit Yvan , Isaksson Hanna , Haïat Guillaume
Published: April 2021

Bone properties and especially its microstructure around implants are crucial to evaluate the osseointegration of prostheses in orthopaedic, maxillofacial and dental surgeries. Given the intrinsic heterogeneous nature of the bone microstructure, an ideal probing tool to understand and quantify bone formation must be spatially resolved. X-ray imaging has often been employed, but is limited in the presence of metallic implants, where severe artifacts generally arise from the high attenuation of metals to x-rays. Neutron tomography has recently been proposed as a promising technique to study bone-implant interfaces, thanks to its lower interaction with metals. The aim of this study is to assess the potential of neutron tomography for the characterisation of bone tissue in the vicinity of a metallic implant. A standardised implant with a bone chamber was implanted in rabbit bone. Four specimens were imaged with neutron tomography and subsequently compared to non-decalcified histology to stain soft and mineralised bone tissues, used here as a ground-truth reference. An intensity-based image registration procedure was performed to place the 12 histological slices within the corresponding 3D neutron volume. Significant correlations (p < 0.01) were obtained between the two modalities for the bone-implant contact (BIC) ratio (R = 0.77) and the bone content inside the chamber (R = 0.89). The results indicate that mineralised bone tissue can be reliably detected by neutron tomography. However, the BIC ratio and bone content were found to be overestimated with neutron imaging, which may be explained by its sensitivity to non-mineralised soft tissues, as revealed by histological staining. This study highlights the suitability of neutron tomography for the analysis of the bone-implant interface. Future work will focus on further distinguishing soft tissues from bone tissue, which could be aided by the adoption of contrast agents.
Dirac equation from the extended uncertainty principle
Authors: Chemisana Daniel , Giné Jaume , Madrid Jaime
Published: April 2021

The existence of a minimal momentum modifies the Heisenberg’s uncertainty principle, which implies modifications of the Dirac equation. In this work, we study the influence of this minimal uncertainty in the particle’s momentum to deduce a generalized Dirac equation and solve its eigenvalue problem for a free particle and a particle within a gravitational field.
Probing oscillons of ultra-light axion-like particle by 21 cm forest
Authors: Kawasaki Masahiro , Nakano Wakutaka , Nakatsuka Hiromasa , Sonomoto Eisuke
Published: April 2021

Ultra-Light Axion-like Particle (ULAP) is motivated as one
of the solutions to the small scale problems in astrophysics. When
such a scalar particle oscillates with an 𝒪(1) amplitude
in a potential shallower than quadratic, it can form a localized
dense object, oscillon. Because of its longevity due to the
approximate conservation of the adiabatic invariant, it can survive
up to the recent universe as redshift z ∼𝒪(10). The
scale affected by these oscillons is determined by the ULAP mass m
and detectable by observations of 21 cm line. In this paper, we
examine the possibility to detect ULAP by 21 cm line and find that
the oscillon can enhance the signals of 21 cm line observations when
m ≲ 10-19 eV and the fraction of ULAP to dark
matter is much larger than 10-2 depending on the form of the
potential.
Cross section measurements for (n,2n), (n,α), and (n,p) reactions on rhenium isotopes around 14 MeV neutrons and their theoretical calculations of excitation functions*
Authors: Zhou Fengqun , Song Yueli , Chang Xinyi , Li Yong , Yuan Shuqing , Ji Pengfei , Tian Mingli
Published: April 2021

Cross-section data of the 185Re(n,2n)184mRe, 185Re(n,2n)184gRe, 185Re(n,α)182m1+m2+gTa, 187Re(n, 2n)186g,(m)Re, 187Re(n,α)184Ta, and 187Re(n,p)187W reactions were measured at four neutron energies, namely 13.5, 14.1, 14.4, and 14.8 MeV, by means of the activation technique, relative to the reference cross-section values of the 93Nb(n,2n)92mNb reaction. The neutrons were generated from the T(d,n)4He reaction at the K-400 Neutron Generator at China Academy of Engineering Physics. The induced γ activities were measured using a high-resolution γ-ray spectrometer equipped with a coaxial high-purity germanium detector. The excitation functions of the six above-mentioned nuclear reactions at neutron energies from the threshold to 20 MeV were calculated by adopting the nuclear theoretical model program system Talys-1.9 with the relevant parameters properly adjusted. The measured cross sections were analyzed and compared with previous experiments conducted by other researchers, and with the evaluated data of BROND-3.1, ENDF/B-VIII.0, JEFF-3.3, and the theoretical values based on Talys-1.9. The new measured results agree with those of previous experiments and the theoretical excitation curve at the corresponding energies. The theoretical excitation curves based on Talys-1.9 generally match most of experimental data well.
Dimensional scaling of thin-film stimulation electrode systems in translational research
Authors: Schiavone Giuseppe , Vachicouras Nicolas , Vyza Yashwanth , Lacour Stéphanie P
Published: April 2021

Objective. Electrical stimulation of biological tissue is an established technique in research and clinical practice that uses implanted electrodes to deliver electrical pulses for a variety of therapies. Significant research currently explores new electrode system technologies and stimulation protocols in preclinical models, aiming at both improving the electrode performance and confirming therapeutic efficacy. Assessing the scalability of newly proposed electrode technology and their use for tissue stimulation remains, however, an open question. Approach. We propose a simplified electrical model that formalizes the dimensional scaling of stimulation electrode systems. We use established equations describing the electrode impedance, and apply them to the case of stimulation electrodes driven by a voltage-capped pulse generator. Main results. We find a hard, intrinsic upward scalability limit to the electrode radius that largely depends on the conductor technology. We finally provide a simple analytical formula predicting the maximum size of a stimulation electrode as a function of the stimulation parameters and conductor resistance. Significance. Our results highlight the importance of careful geometrical and electrical designs of electrode systems based on novel thin-film technologies and that become particularly relevant for their translational implementation with electrode geometries approaching clinical human size electrodes and interfacing with voltage-capped neurostimulation systems.
Segmentation and Features Extraction of Malaysian Herbs Leaves
Authors: Halim Suhaila Abd , Hadi Normi Abdul , Lazim Nur Syafiqah Mat
Published: April 2021

In modern medical practice, herbs play a very important role as the source of bio-technology. Therefore, providing a database containing information of these herbs is significant to assist the medicinal practitioners and users. Image recognition, a process that includes image segmentation, features extraction and classification, is one of the methods to develop the database for herbs. This paper focuses on image segmentation and features extraction of 125 images with 1616×1080 pixels of Malaysian Herb Leaves including Sirih, Mexican Mint, Rerama, Belalai Gajah and Senduduk. The images were first segmented using Sobel operator to get the boundary points. Then, 7 geometrical features and 7 textural features were extracted for each image including area, perimeter, major axis length, minor axis length, roundness, smoothness and flatness. The experimental results were obtained using MATLAB R2018a. The results show that Sobel can successfully segment the images and calculates the features of the herb leaves.
Identification of Phishing Urls Using Machine Learning
Authors: Vineeth Krishna C , Narayana Swamy C , Viji Amutha Mary A , Selvan Mercy Paul
Published: April 2021

Phishing is a typical assault on unsuspecting individuals by making them to reveal their one-of-a-kind data utilizing fake sites. The target of phishing site URLs is to purloin the individual data like client name, passwords and web based financial exchanges. Phishers utilize the sites which are outwardly and semantically like those genuine sites. As innovation keeps on developing, phishing strategies began to advance quickly and this should be forestalled by utilizing against phishing systems to recognize phishing. AI is a useful asset used to endeavor against phishing assaults. We as a whole know bunches of assaults are happening continuously situation in light of phishing URLS. There is no programmed procedure has been set up so far Multiple assaults of phishing URLs has not yet coordinated. In the proposed framework finding the phishing assaults/URLs, the System will identify various phishing assaults in equal succession and caution the ordinary clients with respect to phishing URLs.
E-Voting System Using Homomorphic Encryption Technique
Authors: Sheela A.C. Santha , Franklin Ramya. G.
Published: April 2021

The main objective of this project is to develop a safe Electronic voting System Software using Fingerprint Authentication method. i.e., e-voting system. Initially, fingerprints are collected and stored in a large database which will be created by the admins. During the elections, a valid authentication can be done through finger vein sensing. This authentication system is highly reliable and will facilitate casting of votes by the voters. In many democratic countries, elections have become a huge matter of concern. An election is seen as a system that basically creates the formal structure of a nation. It is an opportunity to elect the right leader and contribute towards the development of the nation. In addition, security and authenticity of these elections have become a major concern for the authorities. Although we use advanced electronic voting machines, the problem of rigging often arises. This e-voting software provides solution to rigging and also facilitates high authenticity and reliability. Depending on the particular implementation, e-voting may use standalone electronic voting machines (also called EVM) or computers connected to the Internet. It may encompass a range of Internet services, from basic transmission of tabulated results to full-function online voting through common connectable household devices. The data collected from the election will directly be transferred to the nearest database centers on real time basis using Zigbee systems and applications of cryptography.
Prosthetic Hand Using Emg
Authors: Selvan Mercy Paul , Raj Rishi , Gowtham Sai R , Jancy S. , Mary Viji Amutha
Published: April 2021

The prosthetic hand is a device used for the amputee to make them capable of doing daily life stuff. Losing upper limbs is not just a physical loss it also affects the way that person sees their life, they start feeling disabled all the time. This event grows and make them disabled mentally or by god if they can handle it even though people will remind them time to time about their disabilities which may lead to suicide or even worse. To join hand to hand and to makes more abled than disabled, we are introducing prosthetic hand at the cheapest price. It’s not that this event is the only device in the market but I could say this event is the cheapest one with these many qualities. It could not be very good looking but it could be better than a decent one. Disability does not differentiate by the salary of a person or capability of someone, so this should be affordable to most of them. In the west, we have some country who can make prosthetic at an affordable price but their money and employment are stronger than us. So, a project like this can make a difference. The concept partially fulfilled the goals and targets set at the outset of the project. The initiative originally had four primary goals. The first goal is to create a tool like a prosthetic hand that can help an amputee with hand loss accomplish simple everyday tasks. Because of all the EMG signal calculation of various hand movements performed on a person who does not lose his her hand the system can only partially accomplish this goal.
Stagnation Point Flow in Copper Nanofluid over Slippery Cylinder with Viscous Dissipation
Authors: Ghazali Nur Miza Syaheera , Aziz Ahmad Sukri Abd , Soid Siti Khuzaimah , Ilias Mohd Rijal , Ali Zaileha Md
Published: April 2021

This study investigates the heat transfer dissipation on stagnation point flow over a slippery stretching/shrinking cylinder in a copper nanofluid by considering the effect of viscous dissipation. A system of nonlinear partial differential equations is modelled and transformed into ordinary differential equations using similarity transformations. The governing equations with the corresponding boundary conditions are analysed numerically using a bvp4c solver in MATLAB. The solutions are found to be dependent on the Eckert number and slip parameters. The results are represented by the velocity and temperature profiles as well as the skin friction coefficient and the Nusselt number. Dual solutions are observed for the shrinking cylinder in the presence of Eckert number. Velocity profile and skin friction coefficient consistently increase while temperature profile increases initially and then decreases with the increase of slip parameter for both first and second solutions. Moreover, the presence of copper nanoparticles reduces the thermal boundary layer thickness. This research can be enhanced by using hybrid nanofluids to further improve the heat transfer.
MHD Boundary Layer Flow in Double Stratification Medium
Authors: Aznidar Ismail Nur Suhaida , Abd Aziz Ahmad Sukri , Ilias Mohd Rijal , Soid Siti Khuzaimah
Published: April 2021

Magnetohydrodynamic (MHD) fluid flow over an exponentially permeable stretching sheet in a thermally and chemically stratified porous medium with heat source is investigated. The partial differential equations are reduced to ordinary differential equations using suitable similarity transformation, which are then solved numerically with MAPLE software. The effect of the pertinent parameters on the flow, heat and mass transfer characteristics are examined graphically. The results indicated that the velocity profile decreases with increasing value of porosity, magnetic, and suction parameters. The temperature increases with porosity, magnetic and heat source parameters. The concentration profile increases with the increase in porosity and magnetic parameters. Thermal stratification reduces the temperature while chemical stratification reduces the concentration of the fluid.
Soret Effects of Mass Transfer and Radiation with Heat Source on MHD Oscillatory Viscoelastic Fluid in a Channel With Porous Medium
Authors: Lawanya T. , Vidhya M. , Govindarajan A.
Published: April 2021

Soret and radiative heat transmission impacts are considered with an unstable stream, directing viscoelastic liquid past channel with permeable medium, non-uniform walls warmth inspected. The liquid has trivial electromagnetic strength created is lesser. The impact of the mass transfer, radiation and the magnetic field constraints for speed, temperature, mass diffusion profiles for values of viscoelastic constraints discussed.
Novel Fuzzy Assignment Problem Using Hexagonal Fuzzy Numbers
Authors: Thiruppathi A. , Kirubhashankar C. K.
Published: April 2021

In this paper, a hexagonal fuzzy assignment problem employing a fuzzy new ranking technique is applied. This method requires less number of iterations to succeed in an optimality solution compared to the prevailing methods. Numerical examples show the effectiveness of the proposed fuzzy hexagonal assignment problem.
Cover pebbling number of Comb, Friendship and Helm graphs
Authors: Prabha R. , Sandhiya B.
Published: April 2021

For a connected graph G with a distribution of p pebbles on it, a pebbling move involves the removal of two pebbles from a vertex and an addition of one pebble to an adjacent vertex. The cover pebbling number γ(G) is the minimum number of pebbles required to place one pebble on each vertex of the graph G after a sequence of pebbling moves, regardless of the initial configuration of the pebbles. It is known that the problem of computing the cover pebbling number is NP-complete [7]. In this paper we compute the cover pebbling number of Comb, Friendship and Helm graphs.