bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of 2,2′-Bipyridines via Dehydrogenative Dimerization of Pyridines Using Sodium Dispersion
Authors: Ilies Laurean , Takai Kazuhiko , Asako Sobi , De Pinaki Bhusan 
Published: March 2023

Abstract2,2′-Bipyridine derivatives were synthesized by dehydrogenative dimerization of nonactivated pyridines using sodium dispersion. The reaction features operational simplicity, mild conditions, and the use of earth abundant and nontoxic sodium as the sole metal source. Importantly, transition metals are not required, which is beneficial in the fields of materials science and drug synthesis, where the contamination of the transition metals may cause significant problems.
Regioselective anti-Silyllithiation of Propargylic Amines
Authors: Shimokawa Jun , Yorimitsu Hideki , Sato Tomohiko , Karad Somnath N. 
Published: March 2023

AbstractThe regioselective anti-silyllithiation of propargylic amines is developed to facilitate the efficient synthesis of alkenylsilanes. This reaction generates an alkenyllithium intermediate that is stabilized by the formation of a five-membered cyclic structure through intramolecular coordination of the nitrogen functional group. Upon subsequent treatment with an electrophile, the alkenyllithium intermediate is further functionalized to afford tetrasubstituted allylic amines bearing a β-silicon substituent.
Total Synthesis of 4α-Hydroxyallosecurinine and Securingine F, Securinega Alkaloids with a C4-Hydroxy Handle for Biofunctional Derivatizations
Authors: Han Sunkyu , Park Sangbin , Kim Doyoung , Yang Wooil 
Published: March 2023

AbstractWe describe the first total synthesis of the C4-hydroxylated securinega alkaloids 4α-hydroxyallosecurinine and securingine F. The synthetic route features an Ellman’s light-mediated hydrogen-atom-transfer-based epimerization reaction that effectively sets the desired configuration at the C2 position. Simultaneous skeletal rearrangement from neosecurinane to securinane frameworks and stereochemical reversal at the C4 site was achieved under Mitsunobu reaction conditions. The C4-hydroxy group is envisioned to serve as a handle for potential biofunctional derivatizations.
Qi Field Effect of Acupuncture Time-Acupoints-Space in the Treatment of Long Coronavirus Disease and Coronavirus Disease 2019 Vaccine Adverse Reactions
Authors: Zhu Miansheng 
Published: March 2023

AbstractCorona Virus disease 2019 (COVID-19) has become a serious challenge. On the one hand, there is not a single explanation of its pathological mechanism, which directly affects the treatment efficacy. On the other hand, the complicated symptoms of long COVID and COVID-19 vaccine adverse reactions involve multiple systems and the number of affected patients is large, which have attracted great attention. Acupuncture time-acupoints-space (ATAS) is a new acupuncture technique developed on the basis of four methods of day-prescription of acupoints (Na Jia method), hour-prescription of acupoints (Na Zi Method), eightfold methods of the sacred tortoise (Ling Gui Eight Methods), and eight methods of swift puncturing of needles (Fei Teng Eight Methods) in midnight-noon and ebb-flow doctrine (Zi Wu Liu Zhu). The main idea of ATAS is to use the orderly combination of time acupoints and space acupoints to construct a field to regulate qi movement and treat diseases through the qi field effect. In France, although traditional Chinese medicine cannot be directly used to treat COVID-19, hundreds of patients with long COVID and COVID-19 vaccine adverse reactions have been treated using the four methods of ATAS. With reference to the microcirculatory lesions in the pathological mechanism of COVID-19 in Western medicine, hour prescription of acupoints (Na Zi Method) of ATAS showed specific efficacy for long COVID.
Redesigning Care for the Management of Postpartum Hypertension: How Can Ob–Gyns and Primary Care Physicians Partner in Caring for Patients after a Hypertensive Pregnancy?
Authors: Berhie Saba H. , Little Sarah E. , Shulkin Jay , Seely Ellen W. , Nour Nawal M. , Wilkins-Haug Louise 
Published: March 2023

The standard care model in the postpartum period is ripe for disruption and attention. Hypertensive disorders of pregnancy (HDPs) can continue to be a challenge for the postpartum person in the immediate postpartum period and is a harbinger of future health risks. The current care approach is inadequate to address the needs of these women. We propose a model for a multidisciplinary clinic and collaboration between internal medicine specialists and obstetric specialists to shepherd patients through this high-risk time and provide a bridge for lifelong care to mitigate the risks of a HDP.
Key Points
Microbiology in sustainable remediation of contaminated sites
Authors: Lee Matthew , Manefield Mike 
Published: March 2023

The release of chemicals that have negative human or environmental health impacts has been rife around the world for a century. Approaches to contaminated site remediation have evolved over this time to address environmental contamination. Over the past 15 years there has been an increasing focus on sustainability in remediation. Bioremediation has emerged as a remediation technology of choice based on sustainability credentials. Research on pollutant biodegradation, including the discovery and characterisation of microbes responsible, underpins biological remediation applications.
Graviton scattering in self-dual radiative space-times
Authors: Adamo Tim , Mason Lionel , Sharma Atul 
Published: March 2023

Abstract
The construction of amplitudes on curved space-times is a major challenge, particularly when the background has non-constant curvature. We give formulae for all tree-level graviton scattering amplitudes in curved self-dual (SD) radiative space-times; these are chiral, source-free, asymptotically flat spaces determined by free characteristic data at null infinity. Such space-times admit an elegant description in terms of twistor theory, which provides the powerful tools required to exploit their underlying integrability. The tree-level S-matrix is written in terms of an integral over the moduli space of holomorphic maps from the Riemann sphere to twistor space, with the degree of the map corresponding to the helicity configuration of the external gravitons. For the MHV sector, we derive the amplitude directly from the Einstein–Hilbert action of general relativity, while other helicity configurations arise from a natural family of generating functionals and pass several consistency checks. The amplitudes in SD radiative space-times exhibit many novel features that are absent in Minkowski space, including tail effects. There remain residual integrals due to the functional degrees of freedom in the background space-time, but our formulae have many fewer such integrals than would be expected from space-time perturbation theory. In highly symmetric special cases, such as SD plane waves, the number of residual integrals can be further reduced, resulting in much simpler expressions for the scattering amplitudes.
Thickness-dependent catalytic activity of hydrogen evolution based on single atomic catalyst of Pt above MXene
Authors: Shu Zheng , Cai Yongqing 
Published: March 2023

Abstract
Hydrogen as the cleanest energy carrier is a promising alternative renewable resource to fossil fuels. There is an ever-increasing interest in exploring efficient and cost-effective approaches of hydrogen production. Recent experiments have shown that single platinum atom immobilized on the metal vacancies of MXenes allows a high-efficient hydrogen evolution reaction (HER). Here using ab initio calculations, we design a series of substitutional Pt-doped Ti
n

+ 1C
n
T
x
(Ti
n

+ 1C
n
T
x
-PtSA) with different thicknesses and terminations (n = 1, 2 and 3, T
x
= O, F and OH), and investigate the quantum-confinement effect on the HER catalytic performance. Surprisingly, we reveal a strong thickness effect of the MXene layer on the HER performance. Among the various surface-terminated derivatives, Ti2CF2-PtSA and Ti2CH2O2-PtSA are found to be the best HER catalysts with the change of Gibbs free energy ΔG
H* ∼ 0 eV, complying with the thermoneutral condition. The ab initio molecular dynamics simulations reveal that Ti2CF2-PtSA and Ti2CH2O2-PtSA possess a good thermodynamic stability. The present work shows that the HER catalytic activity of the MXene is not solely governed by the local environment of the surface such as Pt single atom. We point out the critical role of thickness control and surface decoration of substrate in achieving a high-performance HER catalytical activity.
Assessment of 2D-based tests for the qualification of simulation software for dXCT
Authors: Borges de Oliveira Fabrício , Reuter Tamara , Plotzki David , Wohlgemuth Florian , Batscher Markus , Bellon Carsten , Kasperl Stefan 
Published: March 2023

Abstract
The interest in using computer simulations of dimensional x-ray computed tomography (dXCT) for various metrological purposes—such as measurement planning, performance prediction, performance optimisation and, finally, measurement uncertainty estimation—is increasing along with the ever-growing demand for more reliable measurements with dXCT. However, before a piece of simulation software can be used for tasks related to coordinate metrology, it has to be ensured that it is able to simulate physical laws, characteristic effects and basic CT system functionalities correctly and with sufficient accuracy. In short, the software must be qualified for dimensional metrology tasks. As one part of such a qualification process, a method is presented here for determining conformity intervals of 2D tests (projection-based tests) based on 3D tests (testing based on dimensional evaluations in a reconstructed volume) for the assessment of dXCT simulation software. The method consists of varying relevant parameter values in order to verify their influence on 3D measurement results. The results of the 3D tests with varied parameter values are then transferred to the quantities tested in the 2D tests and used as the basis for determining conformity intervals. Two approaches are applied for determining whether or not a variation of a parameter value is significant: (a) statistical and (b) heuristic. Two examples are presented, each based on simulated images, which show the application of the two different approaches for determining conformity intervals for the results of the 2D tests.
Meta-autoencoder-based zero-shot learning for insulation defect diagnosis in gas-insulated switchgear
Authors: Wang Yanxin , Yan Jing , Yang Zhou , Wang Zhanbei , Wang Jianhua , Geng Yingsan 
Published: March 2023

Abstract
Data-driven methods are the primary methods of training models for the diagnosis of insulation defects in gas-insulated switchgear (GIS). Due to complicated operating environments, target samples are not available for training sometimes, leading to insufficient feature learning. Therefore, a meta-autoencoder-based zero-shot learning (MAZL) method is proposed for the diagnosis of GIS insulation defects. First, the visual features of insulation defects’ signals are extracted by a convolutional neural network. Next, the mapping between visual and semantic spaces is learned by semantic autoencoder (SAE). For SAE, the triplet loss is adapted to align semantic information, and unknown class semantic constraints are used to alleviate the domain offset. Finally, a nearest-neighbor algorithm is used to achieve zero-sample diagnosis. In model training, episode training is introduced to make the MAZL model learn a more discriminative semantic prototype, which alleviates classification deviations. The MAZL achieved a diagnostic accuracy for single and multi-source GIS insulation defects of 96.215% and 90.41% without using test classes for training, respectively. This finding provides ideas for the diagnosis of new GIS insulation defects.
Vortex merging in ion phase-space induced by two-ion decay instability
Authors: Liu D J , Wang Qing , Yang T , Cheng R J , Li X M , Li X X , Zhang S T , Lv S Y , Huang Z M , Wang Qiang , Liu Z J , Cao L H , Zheng C Y 
Published: March 2023

Abstract
We theoretically and numerically study the merger phenomenon of the ion-phase vortex structure in hydrogen plasma. The results indicate that the merging of vortex structures during the nonlinear evolution of ion-acoustic waves (IAW) is mainly due to two-ion decay (TID) instability. When the daughter IAWs of the TID grow to be comparable to the fundamental mode, vortex merging will occur. Furthermore, the vortex merging can abruptly convert the significant energy of the fundamental mode into subharmonic energy, resulting in saturation for the TID of the fundamental mode. After several vortex-merging processes, the system eventually evolves into a turbulent state. In particular, the TID growth rate has been improved by considering two additional second-order coupling terms in this paper, which agree much better with the simulation results. Finally, the importance of the electron kinetic effects in the TID process is also presented by comparing hybrid-Vlasov and full-Vlasov simulations.
Photon energy-resolved velocity map imaging from spectral domain ghost imaging
Authors: Wang Jun , Driver Taran , Allum Felix , Papadopoulou Christina C , Passow Christopher , Brenner Günter , Li Siqi , Düsterer Stefan , Tul Noor Atia , Kumar Sonu , Bucksbaum Philip H , Erk Benjamin , Forbes Ruaridh , Cryan James P 
Published: March 2023

Abstract
We present an approach that combines photon spectrum correlation analysis with the reconstruction of three-dimensional momentum distribution from velocity map images in an efficient, single-step procedure. We demonstrate its efficacy with the results from the photoionization of the 2 p-shell of argon using the Free-electron LASer in Hamburg free-electron laser (FEL). Distinct spectral features due to the spin-orbit splitting of Ar

+

(
2

p

−
1

)

are resolved, despite the large average bandwidth of the ionizing pulses from the FEL. This demonstrates a clear advantage over the conventional analysis method, and it will be broadly beneficial for velocity map imaging experiments with FEL sources. The retrieved linewidth of the binding energy spectrum approaches the resolution limitation prescribed by the spectrometers used to collect the data. Our approach presents a path to extend spectral-domain ghost imaging to the case where the photoproduct observable is high-dimensional.
Research on the design of phononic crystal shaft bandgaps based on lumped mass method
Authors: Shi Xiaona , Liu Hongyi , Wang Xuerui , Zhao Lei , Mou Di , He Qiang , Lv Chenghao , Wang Kelong , Wang Xuejing 
Published: March 2023

Abstract
Phononic crystals tend to mature in the research of forward problems due to their unique bandgap characteristics, but it is difficult to realize reasonable parameter design at specific bandgap frequencies in practical engineering applications. Thus, based on the lumped mass method, a research method for the inverse problem of phononic crystal shaft bandgaps is proposed in this paper. On the basis of the discretization model, the relationship between polynomials and the characteristic of bandgaps is discussed through derivation of the dispersive polynomial, and the feasible regions of the corresponding parameters are solved according to the bandgap existence criterion established by the characteristic rules for analytical verification. The results show that the bandgap existence criterion for frequency points and frequency bands can accurately and effectively invert the relevant parameters that meet the requirements, and the method is of great practical significance for promoting the development of phononic crystal shaft parameter design under the target bandgap in engineering applications.
Probing Lorentz-violating electrodynamics with CMB polarization
Authors: Caloni L. , Giardiello S. , Lembo M. , Gerbino M. , Gubitosi G. , Lattanzi M. , Pagano L. 
Published: March 2023

Abstract
We perform a comprehensive study of the signatures of Lorentz violation in electrodynamics
on the Cosmic Microwave Background (CMB) anisotropies. In the framework of the minimal Standard
Model Extension (SME), we consider effects generated by renormalizable operators, both CPT-odd and
CPT-even. These operators are responsible for sourcing, respectively, cosmic birefringence and
circular polarization. We propagate jointly the effects of all the relevant Lorentz-violating
parameters to CMB observables and provide constraints with the most recent CMB datasets. We bound
the CPT-even coefficient to kF,E+B
< 2.31 × 10-31 at 95% CL. This improves previous
CMB bounds by one order of magnitude. The limits we obtain on the CPT-odd coefficients,
i.e. |k
(3)
(V)00| < 1.54 × 10-44 GeV and |kAF
| < 0.74 ×
10-44 GeV at 95% CL, are respectively one and two orders of magnitude stronger than
previous CMB-based limits, superseding also bounds from non-CMB searches. This analysis provides
the strongest constraints to date on CPT-violating coefficients in the minimal SME from
CMB searches.
Cosmological imprints of SUSY breaking in models of sgoldstinoless non-oscillatory inflation
Authors: Heurtier L. , Moursy A. , Wacquez L. 
Published: March 2023

Abstract
In supergravity, the dynamics of the sgoldstino – superpartner of the goldstino superfield associated with the breaking of supersymmetry at low energy – can substantially modify the dynamics of inflation in the primordial Universe. So-called sgoldstinoless models assume the existence of a nilpotency constraint S
2 = 0 that effectively removes the sgoldstino from the theory. Such models were proposed to realise non-oscillatory inflation scenarios with a single scalar field, which feature a long period of kination at the end of inflation, and therefore a non-standard post-inflationary cosmology. Using effective operators, we propose models in which the sgoldstino is stabilized close to the origin to reproduce the nilpotent constraint. We show that small sgoldstino fluctuations may lead to a sizeable back-reaction on the cosmological history. We study the effect of this back-reaction on the inflation observables measured in the cosmic microwave background and confront the model to a series of constraints including limits on ΔN
eff. We show that the peculiar form of the potential in the large supersymmetry breaking scale limit can generate peaks in the scalar power spectrum produced from inflation. We study how certain perturbation modes may re-enter the horizon during or after kination and show that a large supersymmetry breaking scale may lead to the formation of primordial black holes with various masses in the early Universe.
Velocity analysis of supersonic jet flow in double-cone ignition scheme
Authors: Zhu 朱 Zhong-Yuan 仲源 , Zhang 张 Cheng-Long 成龙 , Li 李 Ying-Jun 英骏 
Published: March 2023

Abstract
In the double-cone ignition schemes (DCIS), the deuterium–tritium target shell is ablated and compressed by a high-power nanosecond laser in Au-cones to generate plasmas. Under the actions of spherically symmetric compression and acceleration along the Au cone, they will be ejected out of the cone mouth and collide with each other. The plasmas experience conversion from kinetic energy to internal energy at the vertex of the geometric center of two Au cones that are symmetric to each other, because of which high-density fusion plasmas are preheated. This key physical process has undergone experimental verification on the Shenguang-II upgraded facility in China. Apparently, the improvement and optimization of the velocity of plasmas in hypersonic jet flow at the cone mouth are crucial for the success of the DCIS. In the DCIR7 experiment of the Shenguang-II upgraded facility, a velocity yield of approximately 130–260 km/s was achieved for the plasmas at the cone mouth, with a result of nearly 300 km/s based on numerical simulation. In this paper, theoretical analysis is performed as regards the process, in which target shells are ablated and compressed by laser to generate high-velocity plasmas ejected through jet flow. Based on this analysis, the formula for the velocity of plasmas in supersonic jet flow at the cone mouth is proposed. This study also provides measures that are more effective for improving the kinetic energy of plasmas and optimizing energy conversion efficiency, which can serve as theoretical references for the adjustment and optimization of processes in subsequent experiments.
Gravastar in the framework of symmetric teleparallel gravity*
Authors: Pradhan Sneha , Mandal Sanjay , Sahoo P.K. 
Published: March 2023

Abstract
We present a novel gravastar model based on the Mazur-Mottola (2004) method with an isotropic matter distribution in

gravity. The gravastar, which is a hypothesized substitute for a black hole, is built using the Mazur-Mottola mechanism. This approach allows us to define the gravastar as having three stages. The first one is an inner region with negative pressure; the next region is a thin shell that is made up of ultrarelativistic stiff fluid, and we studied the proper length, energy, entropy, and surface energy density for this region. Additionally, we demonstrated the possible stability of our suggested thin shell gravastar model through the graphical study of the surface redshift. The exterior Schwarzschild geometry describes the outer region of the gravastar. In the context of

gravity, we discovered analytical solutions for the interior of gravastars that are free of any type of singularity and the event horizon.
Effect of radiation exposure on function human body by CBC parameter for workers in nuclear medicine field
Authors: Lafta H A , Allawi R A , Mahmood M A , Hammudi R A , Al Hasani M H , Sharhan S I , Abbas I M 
Published: March 2023

Abstract
In this study, eight cases of workers in gamma camera scans and Positron Emission Tomography (PET/CT scan) fields (employed for various medical diagnoses) had their complete blood counts (CBCs) assessed. From the first hour of work until the last, the investigation of radiation’s impact on hematology was ongoing. By using a personal dose meter (Geiger Badge), the radiation exposure reading for a whole workday is directly recorded in (μSv). The study concluded that while the number of WBC count increased for all workers after radiation exposure, the number of RBC count decreased after exposure, suggesting that RBC amount may be a reliable indicator of exposure degree.
Measuring radioactive content and the effective radiation doses of natural origin in most consumed foodstuffs in the city of Kut – Iraq
Authors: Aleqaby Mohammed Wasfi T , Dwaich Zal-Attabi Hadi 
Published: March 2023

Abstract
Natural radioactive materials known by the term (NORM) are among the most important sources of radiation that can be transmitted to humans through eating foodstuffs. Therefore, researchers took care to study the levels of this type of radiation. In the current study, the levels of radioactivity were determined for the three most important natural radioactive elements, uranium (U-238), thorium (Th-232), and potassium (K-40) in (29) of the most consumed food samples collected from Wasit Governorate Markets. A gamma-ray spectroscopy system consisting of a sodium iodide activated thallium detector (NaI)Tl with dimensions of “3×3” and electronic units attached to it was used in this study. The results obtained from the studied samples showed the concentrations of (U-238, Th-232, and K-40), the value of the annual effective dose, the equivalent concentration of radium Raeq-226, and external and internal risk factors indicated that all concentrations of the radioactive elements targeted in the study were within the permissible limits despite the discrepancy in the values of the concentrations of these elements according to the samples.