bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Access to Functionalized γ-Lactams through Copper-Catalyzed Oxidative Cyclization of Diynes
Authors: Xie Li-Xia , Shen Wen-Bo , Zhang Ting-Ting , Wei Kua-Fei , Ru Guang-Xin , Zhu Xiu-Hong
Published: October 2022

An efficient copper-catalyzed oxidative cyclization of diynes is described. A range of functionalized γ-lactams can be readily constructed by using this protocol. This copper-catalyzed oxidative process proceeds through an alkyne oxidation, carbene/alkyne metathesis, and donor–donor carbene oxidation sequence. The use of readily available substrates, high flexibility, a simple procedure, and mild reaction conditions render the procedure a viable alternative for the preparation of functionalized γ-lactams.
Tf2O-Promoted Morgan–Walls Reaction: From a Flexible Approach to Functionalized Phenanthridines and Quinazolines to the Short and Divergent Total Syntheses of Alkaloids
Authors: Huang Pei-Qiang , Su Xiao-Yu
Published: October 2022

A new protocol for the direct transformation of secondary amides (N-acyl-o-xenylamines) to phenanthridines under mild conditions is reported. The method features trifluoromethanesulfonic anhydride (Tf2O)/2-fluoropyridine as the efficient amide activation system and MeCN or CH2Cl2 as the solvent. For some substrates, MeCN participated in the reaction, which affords a mild access to polysubstituted quinazolines. By employing a Tf2O/2,4,6-tri-tert-butylpyrimidine (TTBP) combination, the method was extended to an N-formyl-o-xenylamine, which represents a recalcitrant amide substrate type for the dehydrative cyclization reaction. More importantly, a one-pot method was established for the direct and divergent synthesis of four types of phenanthridinoids from o-xenylamines, which features both a tert-N-formyl-o-xenylamine and phenanthridinium salt as key and versatile intermediates. The investigation has resulted in one of the shortest and the most efficient total syntheses of the three natural products trisphaeridine, 5,6-dihydrobicolorine, and N-methylcrinasiadine, and in the formal total syntheses of three other ones: 3-hydroxytrisphaeridine, bicolorine, and zephycandidine A.
Perioperative Considerations in a Patient with Kleine–Levin Syndrome Undergoing a Neurosurgical Procedure under General Anesthesia
Authors: Rajaleelan Wesley , Chowdhury Tumul , Moga Rebecca , Todaro Carla , Zadeh Gelareh , Wang Justin , Singh Mandeep
Published: October 2022

Kleine–Levin syndrome (KLS) is a rare central disorder of daytime hypersomnolence and is often characterized by a relapsing and remitting course, recurrent episodes of excessive sleep lasting from 12 to 20 hours a day, and symptoms including hyperphagia, hallucinations, derealization, disorientation, and hypersexuality. There are numerous perioperative considerations in dealing with KLS that include challenges during induction of anesthesia, delayed emergence, postoperative sleep disorders, and delirium. However, due to its rare occurrence, the anesthetic considerations of KLS remain poorly described. This case report outlines the anesthetic considerations and management of a young female patient with KLS who underwent transnasal excision of a trigeminal schwannoma under general anesthesia.
The Association of Teamwork and Adverse Tracheal Intubation–Associated Events in Advanced Airway Management in the PICU
Authors: Jennings John F. , Nett Sholeen , Umoren Rachel , Murray Robert , Kessel Aaron , Napolitano Natalie , Adu-Darko Michelle , Biagas Katherine , Jung Philipp , Spear Debra , Parsons Simon , Breuer Ryan , Meyer Keith , Malone Matthew , Shenoi Asha , Lee Anthony , Mallory Palen , Al-Subu Awni , Tarquinio Keiko , Glater Lily , Toal Megan , Lee Jan Hau , Pinto Matthew , Polikoff Lee , Own Erin , Toedt-Pingel Iris , Kasagi Mioko , Ducharme-Crevier Laurence , Motomura Makoto , Gima Masafumi , Kelly Serena , Panisello Josep , Nuthall Gabrielle , Gladen Kelsey , Shults Justine , Nadkarni Vinay , Nishisaki Akira ,   for the National Emergency Airway Registry for Children (NEAR4KIDS) Investigators Pediatric Acute Lung Injury Sepsis Investigators (PALISI) Network
Published: October 2022

Tracheal intubation (TI) in critically ill children is a life-saving but high-risk procedure that involves multiple team members with diverse clinical skills. We aim to examine the association between the provider-reported teamwork rating and the occurrence of adverse TI-associated events (TIAEs). A retrospective analysis of prospectively collected data from 45 pediatric intensive care units in the National Emergency Airway Registry for Children (NEAR4KIDS) database from January 2013 to March 2018 was performed. A composite teamwork score was generated using the average of each of five (7-point Likert scale) domains in the teamwork assessment tool. Poor teamwork was defined as an average score of 4 or lower. Team provider stress data were also recorded with each intubation. A total of 12,536 TIs were reported from 2013 to 2018. Approximately 4.1% (n = 520) rated a poor teamwork score. TIs indicated for shock were more commonly associated with a poor teamwork score, while those indicated for procedures and those utilizing neuromuscular blockade were less commonly associated with a poor teamwork score. TIs with poor teamwork were associated with a higher occurrence of adverse TIAE (24.4% vs 14.4%, p < 0.001), severe TIAE (13.7% vs 5.9%, p < 0.001), and peri-intubation hypoxemia < 80% (26.4% vs 17.9%, p < 0.001). After adjusting for indication, provider type, and neuromuscular blockade use, poor teamwork was associated with higher odds of adverse TIAEs (odds ratio [OR], 1.77; 95% confidence interval [CI], 1.35–2.34), severe TIAEs (OR, 2.23; 95% CI, 1.47–3.37), and hypoxemia (OR, 1.63; 95% CI, 1.25–2.03). TIs with poor teamwork were independently associated with a higher occurrence of TIAEs, severe TIAEs, and hypoxemia.
Cerebellar Tubers in Tuberous Sclerosis Complex Patients: New Imaging Characteristics and the Relationship with Cerebral Tubers
Authors: Yogi Akira , Hirata Yoko , Linetsky Michael , Ellingson Benjamin M. , Salamon Noriko
Published: October 2022

Objective The imaging characteristics, evolution, and clinical features of cerebellar tubers in tuberous sclerosis complex (TSC) patients have not been well described. The purpose of this study is to investigate the imaging characteristics of cerebellar tubers, including their dynamic changes, and to evaluate the relationship with cerebral tubers in TSC patients.

Materials and Methods Two observers retrospectively reviewed 75 consecutive TSC patients to identify cerebellar tubers and to evaluate their imaging characteristics, including location, presence of retraction change, calcification, contrast enhancement, and the presence of an associated vascular anomaly, as well as dynamic changes in these characteristics. The number of cerebral tubers was compared between TSC patients with and without cerebellar tubers.

Results Twenty-five TSC patients with 28 cerebellar tubers were identified. All cerebellar tubers occurred within the lateral portions of the cerebellar hemispheres. Thirteen cerebellar tubers demonstrated calcification. Ten cerebellar tubers showed contrast enhancement, half of which demonstrated a zebra-like appearance. A vascular anomaly was associated with 12 tubers, one of which subsequently developed parenchymal hemorrhage. Fifteen cerebellar tubers demonstrated complex dynamic changes in size and contrast enhancement. Patients with cerebellar tubers had more cerebral tubers (p = 0.001).

Conclusion Cerebellar tubers demonstrate a specific distribution, suggesting a possible influence on higher brain function. The presence of an associated vascular anomaly may be an important imaging characteristic. Cerebellar tubers may be associated with a more severe manifestation of TSC, given their association with increased numbers of cerebral tubers. These findings may provide insights into the pathogenesis and clinical manifestations of cerebellar tubers in TSC patients.
Mitochondrial Leukoencephalopathy in a One and Half-Year-old Boy
Authors: Ainapure Anish , Kulkarni Shilpa , Gala Foram , Shah Payal , Gavali Vrushabh
Published: October 2022

A one and half-year-old baby boy presented with subacute regression of milestones in all domains. On examination, he had spastic dystonic quadriparesis. Reflexes were brisk. Magnetic resonance imaging of the brain showed diffuse cavitating leukodystrophy involving bilateral periventricular white matter, centrum semiovale, and corona radiata. Magnetic resonance spectroscopy revealed a lactate peak and serum lactate levels were also elevated. Genetic studies revealed compound heterozygous autosomal recessive mutations in IBA57 gene. This case illustrates a rare mitochondrial encephalopathy called multiple mitochondrial dysfunction syndrome-3 caused by a novel IBA57 gene mutation.
Pituitary Stalk Hemangioblastoma: Complete Resection through Orbitozygomatic Approach with Extradural Anterior Clinoidectomy
Authors: Messina Raffaella , Cirrottola Giovanni , Tacconi Leonello , Guyotat Jacques , Signorelli Francesco
Published: October 2022

Background Pituitary stalk hemangioblastomas (PSHBLs) are rare vascular tumors and their surgical removal is challenging due to the proximity with several fundamental anatomic structures including the pituitary stalk, third ventricle, hypothalamus, and optic pathways. To date, only few descriptions of transcranial and transsphenoidal approaches for PSHBLs have been reported in the literature and none in video, with suboptimal outcomes in terms of pituitary function preservation. Here, we describe the use of orbitozygomatic (OZ) craniotomy with extradural anterior clinoidectomy (EAC) for the removal of a PSHBL with preservation of the pituitary stalk.

Case Description A 60-year-old woman with a sporadic symptomatic HBL of the pituitary stalk, with the typical features of avid contrast enhancement on T1- and flow voids on T2-weighted magnetic resonance imaging (MRI) images, underwent a right OZ craniotomy with EAC. The choice of the approach was guided by the necessity of exposing the floor of the 3rd ventricle and infundibulum, where the origin of the pituitary stalk is better appreciated and preserved, without brain retraction. EAC was deemed important due to the necessity of widening the right carotico-oculomotor and opticocarotid triangles and gaining access to the ophthalmic segment of the internal carotid artery, origin of the superior hypophyseal artery, and the tumor supply. The postoperative MRI confirmed gross tumor removal with preservation of the pituitary stalk and no tumor recurrence after 2 years of follow-up.

Conclusion OZ craniotomy coupled with EAC facilitates surgical removal of PSHBLs thus augmenting the chances of pituitary function preservation.

The link to the video can be found at https://youtu.be/hH65W937RGY.
Narratives in Kailash Satyarthi’s Nobel Peace Prize lecture: an analysis of rhetorical agency
Authors: Ghimire Som Nath , Neupane Smirti
Published: October 2022

In 2014, the Nobel Peace Prize was jointly awarded to Indian-born Kailash Satyarthi and Pakistani-born Malala Yousafzai in recognition of their struggle against the suppression of children. They accepted the prize on behalf of the world’s children who were facing injustices such as poverty, poor labor conditions, forced servitude, and terrorism. Since the Nobel Foundation statutes require the Nobel Laureates to give a lecture at the Nobel Prize Ceremony, Kailash Satyarthi—whose speech is the focus of this study—delivered a Nobel Peace Prize lecture on December 10th, 2014, at Oslo City Hall, Norway. In his lecture, he raised the plight of millions of children on the global stage. This paper offers new insights into the narrative rhetoric concerning each child’s freedom in his Nobel Peace Prize lecture, which demonstrates his life-long mission to help children to enjoy their childhood. Adopting an overarching theoretical lens of narrative rhetoric and agency perspective, the paper analyses the speaker’s agency in his narrative of the plight of children in the face of injustices prevalent across societies and cultures. In doing so, the paper highlights Satyarthi’s employment of narrative rhetoric coupled with his rescuer agency, which appeals to the global citizens to create peaceful, humane, and just societies for children. We argue that his narrative serves as a powerful rhetorical device for arguments, which reinforces his ethos as a life-long champion of children’s rights.
The essence of generating vortex-within-a-vortex structures behind forked caudal fins
Authors: Xiong Zhongying
Published: October 2022

This work focuses on vortex-within-a-vortex (VV) structures behind three different shapes of forked caudal fin with a heaving-pitching motion. The results show that the synchronization of trailing-edge vortex separation and the shedding of the leading-edge vortex contributes to the generation of the VV structure. The VV structures of caudal fins with different chord lengths can be observed almost simultaneously. The Strouhal number not only determines the number of shedding vortices in the wake but also reflects the activation time and the superimposed effect of the leading-edge vortex and trailing-edge vortex on propulsion performance. This study provides an important theoretical reference for the design and control of fork propellers for use in underwater vehicles.
Temperature dependence of the complex permittivity in microwave range of some industrial polymers
Authors: Porteanu Horia-Eugen , Kaempf Rudolf , Flisgen Thomas , Heinrich Wolfgang
Published: October 2022

The microwave properties of a number of polymers common in industry are investigated. A cylindrical resonator in the TM012 mode is used. The cavity perturbation method and detailed COMSOL simulations are applied for extracting the complex permittivity as a function of temperature. The results are useful for the design of plastic processing tools by heating with electromagnetic fields. The intrinsic parameters of absorption are derived based on two exponential decays: polarization and Arrhenius dependence of the decay times on temperature.
Fabrication of 3D microstructures for flexible pressure sensors based on direct-writing printing
Authors: Shen Xiaoqiang , Yu Zhiheng , Huang Fengli , Gu Jinmei , Zhang Hui
Published: October 2022

Microstructure plays an important role in improving the performance of flexible sensors. Changing the shape of the dielectric layer microstructure is an effective countermeasure to promote the sensitivity of capacitive sensors. Nevertheless, traditional microstructure fabrication methods have high manufacturing costs, cumbersome manufacturing processes, and single structure manufacturing, which restrict the development of flexible sensors. In this work, electro-hydro-dynamic (EHD) printing method and aerosol jet (AJ) printing method were applied to fabricate 3D microstructures, in a manner of printing the same pattern in multiple layers. The height and morphology of 3D microstructures, under different printing parameters, were compared by changing the number of printing layers and printing speed. Additionally, the printing effects of the two printing methods were compared. The results demonstrated that various shapes and highly controllable 3D microstructures could be fabricated by both methods. The EHD printing method had higher manufacturing precision, whereas the AJ printing method had higher stacking efficiency. The height and morphology of 3D microstructures could be effectively controlled by changing the number of printed layers and the printing speed of the microstructures. It is indicated that the EHD printing method and the AJ printing method both have great potential in the fabrication of 3D microstructures and that both methods had their own advantages.
Process engineering of GaN power devices via selective-area p-type doping with ion implantation and ultra-high-pressure annealing
Authors: Kachi Tetsu , Narita Tetsuo , Sakurai Hideki , Matys Maciej , Kataoka Keita , Hirukawa Kazufumi , Sumida Kensuke , Horita Masahiro , Ikarashi Nobuyuki , Sierakowski Kacper , Bockowski Michal , Suda Jun
Published: October 2022

P-type doping in selected areas of gallium nitride (GaN) using magnesium (Mg)-ion implantation and subsequent ultra-high-pressure annealing (UHPA) are investigated to improve the performance of vertical GaN power devices. UHPA allows a high-temperature process without decomposition of the GaN surface and virtually complete activation of the implanted Mg ions in GaN. In the present paper, we provide an overview of recent challenges in making UHPA more realistic as an industrial process. Instead of UHPA at more than 1400 °C for a short duration, prolonged UHPA at 1300 °C demonstrates a comparable acceptor activation of Mg-ion-implanted GaN. This can reduce the annealing pressure to approximately 300 MPa and enlarge the processable wafer diameter. The second challenge is controlling the doping profiles in the lateral and vertical directions. We demonstrate fine patterning of the p-type regions, which indicates the limited lateral diffusion of Mg through UHPA. However, controlling the vertical doping profile is challenging. The nitrogen vacancies formed by ion implantation reduce the effective acceptor concentration near the surface, which can be compensated for by sequential nitrogen ion implantation. Defect-assisted Mg diffusion to the deeper region causes a redistribution of the Mg atoms and should be considered in the design of a device. Such anisotropic diffusion of Mg to the c-axis has potential applications in the fabrication of unique vertical device structures such as super junctions.
Spin-dependent polaron transport in helical molecules
Authors: Barroso M. , Balduque J. , Domínguez-Adame F. , Díaz E.
Published: October 2022

We study thermal effects on spin transport along a deformable helical molecule in the presence of chiral-induced spin–orbit coupling. The carrier–lattice interaction is modeled by the well-established Peyrard–Bishop–Holstein model within the Langevin approach to include temperature as a stochastic noise. The carrier–lattice interaction causes the occurrence of polaron states in the molecule. We demonstrate the existence of two well-differentiated spin-dependent polaron transport regimes as a function of temperature. In the low-temperature regime, the spatial separation of the two spin-dependent polaron wave-packets results in a nonzero spin current. On the contrary, the spin current becomes negligible if the temperature of the system is high enough. Finally, we characterize this transition and estimate the critical temperature at which it takes place.
Dense disordered jammed packings of hard very elongate particles: A new derivation of the random contact equation
Authors: Cinacchi Giorgio
Published: October 2022

This work describes a derivation of the random contact equation that predicts the packing fraction ϕMRJ hr of a dense disordered (maximally random) jammed state of hard, very elongate particles. This derivation is based on (i) the compressibility equation connecting the compressibility of a uniform system with its pair-correlation function: it is assumed equal to zero at jamming; (ii) the pair-correlation function of the interparticle distance scaled with respect to the orientationally dependent contact distance: it is assumed equal to the sum of a delta function and a unit-step function at jamming, where the former function accounts for the interparticle contacts, while the latter function accounts for the background. On assuming that the hard, very elongate particles are cylindrically symmetric with a length L and a diameter D and isostaticity occurs at jamming, the prediction, in particular that, in the limit of L/D → +∞, ϕMRJ hr L/D = (10 + 1)/2, is compared to the available experimental data.
Direct determination of the piezoelectric field using the quantum-confined Stark effect in a strained [111]-oriented zinc-blende MQW-SOA
Authors: Soto-Ortiz Horacio , Torres-Miranda Gerson
Published: October 2022

Here, we present a method, based on Stark shifts induced by the quantum-confined Stark effect, to directly determine the piezoelectric field in strained zinc-blende quantum wells (QWs) grown along the 111 direction and embedded in the p–i–n diode structure (p-iMQW-n) of a semiconductor optical amplifier. Under short-circuit and open-circuit conditions and resonant optical excitation, we experimentally determine the energy of the 1s e-hh excitonic resonance and the potential difference across the p-iMQW-n junction. Using these parameters in an analytical expression derived in this work, we directly determined a piezoelectric field of −108.71 ± 8.51 kV/cm acting on each of the eight 12-Å-wide strained [111]-oriented In0.687Ga0.313As /In0.807Ga0.193As0.304P0.696 QWs of a semiconductor optical amplifier (SOA). The theoretical prediction of −112.24 kV/cm was in very good agreement, within the experimental error, with the value of the piezoelectric field extracted through the proposed procedure, which was also indirectly validated by comparing the experimental value of the 1s e-hh excitonic resonance Stark shift with the extracted one. Even though the implemented technique was specially designed to experimentally determine the piezoelectric field acting on each of the QWs of a multiple quantum well SOA, it can be applied to any p–i–n structure with electrodes and strained [111]-oriented zinc-blende QWs embedded in its intrinsic region. Remarkably, the method proposed here allows direct experimental determination of the piezoelectric field through an analytical expression, with which it is also possible to estimate, with high reliability, the precision of the result and how it is affected by the accuracy of each measuring instrument intervening in the procedure.
Simulation of electrospray emission processes for low to moderate conductivity liquids
Authors: Huh Henry , Wirz Richard E.
Published: October 2022

The leaky-dielectric model is incorporated in the Finite Volume Method (FVM) code, OpenFOAM, to investigate the electrospray emission behavior of low to moderate conductivity liquids. This work extends FVM modeling to moderate conductivities by employing a new interface interpolation scheme that is devised in the volume of fluid method to ensure charge conservation for accurate reproduction of charge accumulation and resulting meniscus shape in the cone-to-jet region and jet breakup. The model results agree well with experiments and scaling laws for droplet diameter and total current for low and moderate conductivity fluids, i.e., heptane and tributyl phosphate, respectively. The droplet diameter is shown to increase as the dimensionless flow rate increases or the electric Reynolds number decreases. The results are also consistent with a parametric investigation of the meniscus shape and the maximum charge density for key operating conditions (flow rate and extraction potential) and liquid properties (conductivity, surface tension, viscosity, and relative permittivity). These results show that the new interface interpolation scheme provides accurate results for a wide range of conductivities, fluid properties, and operating conditions. The results also provide valuable physical insight for varying liquid conductivity in the electrospray emission process. In particular, low dimensionless flow rate or high electric Reynolds number leads to the emergence of convex-outward menisci associated with a high charge density in the cone-to-jet region, resulting in high jetting velocity and high specific charge droplets.
Dissolution characteristics of solutes with different shapes using the moving particle semi-implicit method
Authors: Zhang Kai , Zhou Zi-Qi , Han Pei-Dong , Sun Zhong-Guo , Xi Guang
Published: October 2022

Dissolution characteristics of solutes with different shapes are studied. To simulate the process of dissolution, a diffusion and dissolution model based on the moving particle semi-implicit (MPS) method is proposed. First, the diffusion equation is introduced to the MPS method. Compared with the analytical solution, concentration diffusion can be accurately simulated with the model. Then, a coupling relationship between concentration, density, and viscosity is established. The relationship deals with the changes in physical parameters of the fluids caused by the diffusion, affecting the fluid flow. As the density change cannot be ignored in the mass conservation equation, the equation is re-deduced in this paper. In addition, the dissolution model is introduced to the MPS method. The dissolution model is verified by the dissolution simulation of sessile droplets in water. Finally, the dissolution of solutes with different shapes in water is simulated using the proposed method. Five cases with different solute shapes are set to simulate five different drugs. Five cases with different solute shapes are set to simulate five different drugs. The solid solute shapes used are rectangle, capsule, heart-shaped, and circle, and the liquid solute is a rectangle shape. The dissolution of the solute is comprehensively affected by the contact between the solute and water, the concentration difference, and the intensity of convection. The small concentration difference and the low convective velocity cause the existence of insoluble points in the heart-shaped case, which decreases the dissolution rate. Dimensional analysis is carried out to address the relative importance of diffusion to convection. In the dissolution of solutes with different shapes, the effect of convective cannot be ignored when the non-dimensional number is lower than 2.5 × 10−5.
Radiation-induced transformation of the C2H2⋯NH3 complex in cryogenic media: Identification of C2H2⋯NH2∙ complex and evidence of cold synthetic routes
Authors: Volosatova Anastasia D. , Zasimov Pavel V. , Feldman Vladimir I.
Published: October 2022

Acetylene and ammonia are important constituents of the interstellar medium, and their coupled chemistry induced by high-energy radiation may be responsible for the formation of a variety of prebiotically important organic–nitrogen compounds. In this work, we first comprehensively characterized the vibrational spectrum of the 1:1 C2H2⋯NH3 complex obtained by deposition of the C2H2/NH3/Ng (Ng = Ar, Kr, or Xe) gaseous mixtures at 5 K using Fourier transform infrared spectroscopy and ab initio calculations at the CCSD(T)/L2a_3 level of theory and examined its radiation-induced transformations. The parent complex adopts a C3v symmetric top molecular structure with C2H2 acting as a proton donor. The x-ray-induced transformations of this complex result in the formation of the C2H2⋯NH2∙ complex and various CN-containing species (CH2CNH, CH3NC, CH2NCH, CH2NC∙, CCN∙, and CNC∙). The radical–molecule complex was identified based on comparison of experimental data with the results of the UCCSD(T)/L2a_3 computations. It is characterized by distinct features in the region of acetylene CHasym str mode, red-shifted from the corresponding absorptions of non-complexed acetylene by −72.9, −70.4, and −60.6 cm−1 for Ar, Kr, and Xe, respectively. Additionally, in krypton and xenon matrices, the blue-shifted features in the CHasym bend region of acetylene were observed, which can be also tentatively attributed to the C2H2⋯NH2∙ complex. The extrapolated to the complete basis set limit unrestricted coupled cluster method with single and double, and perturbative triple excitations binding energy of the C2H2⋯NH2∙ complex (including zero-point vibration energy correction) is lower than that of the C2H2⋯NH3 complex (1.90 and 2.51 kcal mol−1, respectively). We believe that the C2H2⋯NH2∙ complex may be an important intermediate in cold synthetic astrochemistry.
Feasibility of hydrodynamically activated valves for salp-like propulsion
Authors: Bi Xiaobo , Tang Hui , Zhu Qiang
Published: October 2022

Using valves to control the direction of internal flow for effective swimming, the jet-propulsion method of sea salp (a barrel-shaped marine invertebrate) provides a promising locomotion mechanism for bio-inspired robots. In this study, we numerically investigate this problem via an axisymmetric fluid–structure interaction model within the immersed-boundary framework. Specifically, we prove that in these systems, it is feasible to use fully passive valves whose opening and closing actions are driven solely by the hydrodynamic load. This finding is going to greatly reduce the complexity of locomotion devices based on this design. Furthermore, we have examined the effect of the design parameters, i.e., the stiffness and inertia, of the valves upon the swimming performance. In general, it is found that stiff and heavy valves increase the swimming speed, whereas soft and light valves decrease the cost of transport.
Water, economic systems, and mental health: A review of theorized relationships
Authors: Choudhary Neetu , Brewis Alexandra , Beresford Melissa , Workman Cassandra , Wutich Amber
Published: October 2022

Water insecurity—the lack of access to sufficient, safe water to meet all household needs—is an escalating challenge in all world regions. It is also associated with unfavorable mental health outcomes, like anxiety and depression. Often situated in the context of drought or general water scarcity, connections between water and mental health often manifest out of the unique characteristics of water—as an important economic and household resource, and one managed primarily by women. This article identifies recognized and theorized pathways between water insecurity and common mental health conditions, as mediated by broader socioeconomic systems in which households are embedded. To this end, we synthesize and connect different literature sets, including limited economic studies in a resource insecurity framework and a small but authoritative body of ethnographic literature. Our review identifies multiple proximate candidate pathways connecting water insecurity with mental health outcomes including community conflicts and/or perceived injustice around water sharing and upkeep, agricultural decline and unemployment, food insecurity or distress migration, decreased water intake, non-exposure to blue spaces, and stress around water management. The gendered role of water management is an overlapping theme across pathways, exposing women disproportionately to forms of conflict, violence, and injustice associated with the risk of common mental illness. In general, there are varied forms of marginalization that people experience within water-insecure contexts. Greater engagement between economics and other disciplines can lend additional theoretical pathways to empirically test the water and mental health connections, associated with people’s water insecurity experiences.
Noise resilience in path-polarization hyperentangled probe states
Authors: Sairam Akshay Kannan , Chandrashekar C M
Published: October 2022

Most quantum systems that are used for generating entanglement and for practical applications are not isolated from the environment, and are hence susceptible to noise. Entanglement in more than one degree of freedom between two systems, known as hyperentanglement, is known to have certain advantages, including robustness against noise over conventional entangled states. Quantum illumination, imaging and communication schemes that involve sending one photon from a pair of entangled photons and retaining the other photon usually involve exposing only the signal photon to environmental noise. The disruptive nature of noise degrades entanglement and other correlations which are crucial for many of these applications. In this paper, we study the advantages of using photon pairs in certain path-polarization hyperentangled states in a noisy interaction where photons in only one of the paths are affected by noise. We model such noise and study the effect of noise on the correlations present in the hyperentangled photons. Three different methods, entanglement negativity, entanglement witnesses and Bell nonlocality are used to show the resilience of path-polarization hyperentangled probe state against noise.
Strong-field ionization of N2 and CO molecules using two-color laser field
Authors: P Madhusudhan , Das Rituparna , Bhardwaj Pranav , K M Muhammed Shameem , Nimma Vinitha , Soumyashree Swetapuspa , Kushawaha Rajesh K
Published: October 2022

Two-color strong-field photoionization of two diatomic molecules (N2, CO) is studied using a velocity map imaging (VMI) spectrometer. The fundamental frequency, along with the second harmonic (800 + 400 nm) at different phases, with the two different polarization schemes viz, orthogonal and parallel, is employed for measuring the ion yields and photoelectron momentum distributions. The yield of the parent ion and its charged fragments as a function of the phase difference between the two-color field has been studied thoroughly, and the results are presented here. The correlation trends of the parent ion with their fragments as a function of the relative phase are discussed. It is observed that the ionized CO and its fragments have different correlation trends at different polarization schemes. Additionally, the photoelectron momentum distribution of N2 and CO due to orthogonal two-color (OTC) and parallel two-color (PTC) is performed in order to understand the modulation of electron dynamics as a function of phase between 800 nm and 400 nm. Further, the asymmetry parameter as a function of electron momenta due to the two-color fields has been estimated and discussed.
Numerical investigation of the spark discharge process in a crossflow
Authors: Kim Joohan , Scarcelli Riccardo , Karpatne Anand , Subramaniam Vivek , Breden Douglas , Raja Laxminarayan L , Zhai Jiachen , Lee Seong-Young
Published: October 2022

The present study numerically investigates the spark discharge process under crossflow conditions using a thermal equilibrium plasma solver that fully couples the electromagnetic physics and fluid dynamics in a computational framework. Numerical results are validated by the comparison with experimental data. The spark discharge experiment is performed in a constant volume vessel using an inductive coil ignition system for automotive applications, and the evolution of the spark channel is measured using high-speed imaging. The crossflow in the gap between the spark-plug electrodes is generated by a rotating fan with two different fan speeds, and the flow velocity across the gap is characterized by particle image velocimetry (PIV) measurement. A computational fluid dynamics (CFD) solver is employed to simulate the crossflow and provide the flow field variables (velocity, pressure, temperature) to the plasma solver. The crossflow velocity predicted in the flow simulation agrees well with the PIV data in that the non-uniform velocity profiles at monitoring points are reproduced by the CFD code. With the crossflow initialization in the plasma solver, the simulated spark discharge process from the breakdown to spark discharge matches the experimental data, including the voltage and circuit waveforms and the high-speed images of the spark channel evolution. The stretch of spark channel captured by plasma simulations agrees with the measured data. The plasma simulation reveals that the mean temperature of the spark channel is maintained at 5000 K during the discharge phase, and the temperature varies along the spark channel so that the highest value is obtained at the spark root on the center electrode. Overall, the results presented in this paper are meant to provide valuable information about the properties of the plasma generated by the spark discharge.
Shubnikov–de Haas oscillations and nontrivial topological states in Weyl semimetal candidate SmAlSi
Authors: Xu Longmeng , Niu Haoyu , Bai Yuming , Zhu Haipeng , Yuan Songliu , He Xiong , Han Yibo , Zhao Lingxiao , Yang Yang , Xia Zhengcai , Liang Qifeng , Tian Zhaoming
Published: October 2022

The RAlX (R = Light rare earth; X = Ge, Si) compounds, as a family of magnetic Weyl semimetal, have recently attracted growing attention due to the tunability of Weyl nodes and its interactions with diverse magnetism by rare-earth atoms. Here, we report the magnetotransport evidence and electronic structure calculations on nontrivial band topology of SmAlSi, a new member of this family. At low temperatures, SmAlSi exhibits large non-saturated magnetoresistance (MR) (as large as ∼5500% at 2 K and 48 T) and distinct Shubnikov–de Haas (SdH) oscillations. The field dependent MRs at 2 K deviate from the semiclassical (μ
0
H)2 variation but follow the power-law relation MR

∝

(μ
0
H)
m
with a crossover from m ∼ 1.52 at low fields (μ
0
H< 15 T) to m ∼ 1 under high fields (μ
0
H> 18 T), which is attributed to the existence of Weyl points and electron–hole compensated characteristics with high mobility. From the analysis of SdH oscillations, two fundamental frequencies originating from the Fermi surface pockets with non-trivial π Berry phases and small cyclotron mass can be identified, this feature is supported by the calculated electronic band structures with two Weyl pockets near the Fermi level. Our study establishes SmAlSi as a paradigm for researching the novel topological states of RAlX family.
Void fraction measurement of lubricant air-oil two-phase flow using a near infrared optical-fiber spectrometer associated with partial least squares regression models
Authors: Zhou Yan , Cui Hongshuai
Published: October 2022

Motivated by recent research on two-phase flow void fraction measurement, this paper presents a study on void fraction measurements of a lubricant air-oil two-phase flow using a near infrared (NIR) optical-fiber spectrometer associated with partial least squares (PLS) regression models. To overcome the measurement inaccuracy due to interface scattering, this study used PLS regression models to analyse the spectrum of air-oil two-phase flow. First, an NIR optical-fiber spectrometer experimental system was developed. Second, a flow regime analysis was conducted for the bubble flow transition inside the experimental system. Finally, the PLS regression model validations, the void fraction measurement accuracies, and the uncertainties of the experimental system were evaluated and discussed, and the different PLS regression models were compared in detail. The results indicate that the NIR optical-fiber spectrometer combined with the PLS regression model can achieve void fraction measurements of lubricants in air-oil two-phase flow, with a maximum squared correlation coefficient (R
2) of 0.981, a minimum Type A uncertainty of 0.039% and a minimum expanded uncertainty of 0.077%.
First-principles investigation of a-line Shockley partial dislocations in wurtzite GaN: core reconstruction and electronic structure
Authors: Belabbas I , Dimitrakopulos G P , Kioseoglou J , Chen J , Smalc-Koziorοwska J
Published: October 2022

Αtomistic simulations based on density functional theory were performed to investigate Shockley partial dislocations, parallel to the <11–20> direction, in wurtzite gallium nitride. The cores of both 30° and 90° Shockley partial dislocations, their possible reconstructions and their electronic structures were analyzed and compared systematically. Shockley partial dislocations were found to have a variety of core structures while exhibiting different bonding states like: deformed Ga–N bonds, Ga–Ga and N–N homo-nuclear bonds, as well as Ga– and N–dangling bonds. We have demonstrated that the core reconstruction of these dislocations is not always energetically favourable in wurtzite GaN, as it is the case in elemental semiconductors. It results from interplay between the energy gain from eliminating dangling and forming homo-nuclear bonds and the energy excess from the induced strain of hetero-nuclear Ga–N bonds within the core. Depending on their core configurations, Shockley partial dislocations are expected to have different electronic behaviours in wurtzite GaN, as they can act either as sources of parasitic luminescence or non-radiative recombination centres, or give pathways to leakage currents. We have demonstrated that deep states associated with dislocations are not due to the dangling bonds, as generally believed, but rather to Ga–Ga bonds in their cores, and that N–N bonds do not lead to any gap states. These results are of high relevance as guidelines in defect engineering strategies aiming at producing dislocations with a particular electronic behaviour in wurtzite GaN.
3D in vivo dose verification in prostate proton therapy with deep learning-based proton-acoustic imaging
Authors: Jiang Zhuoran , Sun Leshan , Yao Weiguang , Wu Q Jackie , Xiang Liangzhong , Ren Lei
Published: October 2022

Dose delivery uncertainty is a major concern in proton therapy, adversely affecting the treatment precision and outcome. Recently, a promising technique, proton-acoustic (PA) imaging, has been developed to provide real-time in vivo 3D dose verification. However, its dosimetry accuracy is limited due to the limited-angle view of the ultrasound transducer. In this study, we developed a deep learning-based method to address the limited-view issue in the PA reconstruction. A deep cascaded convolutional neural network (DC-CNN) was proposed to reconstruct 3D high-quality radiation-induced pressures using PA signals detected by a matrix array, and then derive precise 3D dosimetry from pressures for dose verification in proton therapy. To validate its performance, we collected 81 prostate cancer patients’ proton therapy treatment plans. Dose was calculated using the commercial software RayStation and was normalized to the maximum dose. The PA simulation was performed using the open-source k-wave package. A matrix ultrasound array with 64 × 64 sensors and 500 kHz central frequency was simulated near the perineum to acquire radiofrequency (RF) signals during dose delivery. For realistic acoustic simulations, tissue heterogeneity and attenuation were considered, and Gaussian white noise was added to the acquired RF signals. The proposed DC-CNN was trained on 204 samples from 69 patients and tested on 26 samples from 12 other patients. Predicted 3D pressures and dose maps were compared against the ground truth qualitatively and quantitatively using root-mean-squared-error (RMSE), gamma-index (GI), and dice coefficient of isodose lines. Results demonstrated that the proposed method considerably improved the limited-view PA image quality, reconstructing pressures with clear and accurate structures and deriving doses with a high agreement with the ground truth. Quantitatively, the pressure accuracy achieved an RMSE of 0.061, and the dose accuracy achieved an RMSE of 0.044, GI (3%/3 mm) of 93.71%, and 90%-isodose line dice of 0.922. The proposed method demonstrates the feasibility of achieving high-quality quantitative 3D dosimetry in PA imaging using a matrix array, which potentially enables the online 3D dose verification for prostate proton therapy.
Input feature design and its impact on the performance of deep learning models for predicting fluence maps in intensity-modulated radiation therapy
Authors: Li Xinyi , Ge Yaorong , Wu Qiuwen , Wang Chunhao , Sheng Yang , Wang Wentao , Stephens Hunter , Yin Fang-Fang , Wu Q. Jackie
Published: October 2022

Objective. Deep learning (DL) models for fluence map prediction (FMP) have great potential to reduce treatment planning time in intensity-modulated radiation therapy (IMRT) by avoiding the lengthy inverse optimization process. This study aims to improve the rigor of input feature design in a DL-FMP model by examining how different designs of input features influence model prediction performance. Approach. This study included 231 head-and-neck intensity-modulated radiation therapy patients. Three input feature designs were investigated. The first design (D1) assumed that information of all critical structures from all beam angles should be combined to predict fluence maps. The second design (D2) assumed that local anatomical information was sufficient for predicting radiation intensity of a beamlet at a respective beam angle. The third design (D3) assumed the need for both local anatomical information and inter-beam modulation to predict radiation intensity values of the beamlets that intersect at a voxel. For each input design, we tailored the DL model accordingly. All models were trained using the same set of ground truth plans (GT plans). The plans generated by DL models (DL plans) were analyzed using key dose-volume metrics. One-way ANOVA with multiple comparisons correction (Bonferroni method) was performed (significance level = 0.05). Main results. For PTV-related metrics, all DL plans had significantly higher maximum dose (p < 0.001), conformity index (p < 0.001), and heterogeneity index (p < 0.001) compared to GT plans, with D2 being the worst performer. Meanwhile, except for cord+5 mm (p < 0.001), DL plans of all designs resulted in OAR dose metrics that are comparable to those of GT plans. Significance. Local anatomical information contains most of the information that DL models need to predict fluence maps for clinically acceptable OAR sparing. Input features from beam angles are needed to achieve the best PTV coverage. These results provide valuable insights for further improvement of DL-FMP models and DL models in general.
Study on the series resistance of betavoltaic batteries
Authors: Zhang Jiachen , Han Yuncheng , Ren Lei , Wang Xiaoyu , He Houjun , Chen Chunhua , Li Taosheng
Published: October 2022

Series resistance (Rs
) is an essential factor that affects the performance of betavoltaic batteries. However, the Rs
value of betavoltaic batteries tends to be anomaly high when it is extracted from the IV characteristic curve. To explore the reasons for this phenomenon, different injection conditions and their impacts on Rs
of betavoltaic and photovoltaic cells were compared and analyzed, since photovoltaic cells have been studied in-depth in respect of Rs
and have similar principles to betavoltaic batteries. The results show that Rs
will be significantly affected by the injection conditions, and the high resistance of the depletion region under low-level radiation injection of betavoltaic batteries is the main reason for their high Rs
. The effect of high Rs
on betavoltaic battery performance was further explored, and the results show that the IV characteristic curve will be distorted obviously when Rs
is close to or higher than the shunt resistance. This thus leads to a significant decrease in the battery’s fill factor and energy conversion efficiency. The effect of the input power on Rs
should be considered in the future analysis of betavoltaic batteries. This work provides theoretical support for the parameter analysis of betavoltaic batteries.
Predicting the structural, optoelectronic, dynamical stability and transport properties of Boron-doped CaTiO3: DFT based study
Authors: Attou Loubaba , Al-Shami Ahmed , Boujemaâ Jaber , Mounkachi Omar , Ez-Zahraouy Hamid
Published: October 2022

Undoped and B-doped CaTiO3 Semiconductor Perovskite is investigated by the Density Functional Theory (DFT) and Boltzman transport theory (BoltzTraP) using full potential linearized augmented plane wave (FP-LAPW) method with GGA-PBE approximation. By incorporating B into CaTiO3, the electrical band gap is effectively reduced, and adjusting the substitution atom type may regulate the degree of band gap reduction. As a result, the visible light absorption ability is increased. Our results indicate that all doped structures are highly absorbent and productive, with optical transition energy of between 2 and 4 eV. Temperature-dependent transport characteristics are also determined, which favors undoped CaTiO3 at room temperature and B-doped CaTiO3 at elevated ones.