bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Lifestyle Intervention in the Prevention and Treatment of Gestational Diabetes
Authors: Moholdt Trine , Hayman Melanie , Shorakae Soulmaz , Brown Wendy J. , Harrison Cheryce L.
Published: January 2021

Obesity during pregnancy is associated with the development of adverse outcomes, including gestational diabetes mellitus (GDM). GDM is highly associated with obesity and independently increases the risk of both complications during pregnancy and future impaired glycemic control and risk factors for cardiovascular disease for both the mother and child. Despite extensive research evaluating the effectiveness of lifestyle interventions incorporating diet and/or exercise, there remains a lack of definitive consensus on their overall efficacy alone or in combination for both the prevention and treatment of GDM. Combination of diet and physical activity/exercise interventions for GDM prevention demonstrates limited success, whereas exercise-only interventions report of risk reductions ranging from 3 to 49%. Similarly, combination therapy of diet and exercise is the first-line treatment of GDM, with positive effects on maternal weight gain and the prevalence of infants born large-for-gestational age. Yet, there is inconclusive evidence on the effects of diet or exercise as standalone therapies for GDM treatment. In clinical care, women with GDM should be treated with a multidisciplinary approach, starting with lifestyle modification and escalating to pharmacotherapy if needed. Several key knowledge gaps remain, including how lifestyle interventions can be optimized during pregnancy, and whether intervention during preconception is effective for preventing the rising prevalence of GDM.
Multiple Regression Modeling for Age Estimation by Assessment and Comparison of Spheno-Occipital Synchondrosis Fusion and Cervical Vertebral Maturation Stages
Authors: Belgin Ceren Aktuna , Bayrak Seval , Orhan Kaan , Ankarali Handan
Published: January 2021

Objectives The aim of this study was (1) to evaluate the relationship between spheno-occipital synchondrosis (SOS) fusion stages, cervical vertebral maturation (CVM) stages, and clivus sizes with chronological age on cone-beam computed tomography (CBCT) images, and (2) to compare these methods for accurate age estimation using regression analysis.

Methods The CBCT images of 200 individuals (102 females and 98 males) were included in the study. The SOS fusion stages and CVM stages were evaluated. The width and length of the clivus were measured. The effects of SOS fusion stages, CVM stages, clivus width, and clivus length on age estimation were evaluated by univariate tests and the effects of coexistence with ANCOVA and regression model. Spearman rank correlation analysis was also used to investigate the relationship between the SOS fusion stage, CVM stage, clivus width, and clivus length.

Results The SOS stages, CVM stages, and clivus width were not shown statistically significant differences between the sexes (p-values = 0.205, 0.162, and 0.277, respectively), whereas clivus length was significantly longer in males (42.9 ± 4.26 mm) than in females (41.04 ± 3.74 mm). Multiple regression analysis showed 80% success when all parameters (SOS fusion stages, CVM stages, clivus width, and clivus length) were taken into consideration.

Conclusion In conclusion, with the use of CVM stages and SOS fusion stages together, an accurate and reliable age estimation can be obtained in forensic medicine.
Optic Nerve Gliomas
Authors: Wladis Edward J. , Adamo Matthew A. , Weintraub Lauren
Published: January 2021

Objectives To describe the diagnostic and management features of optic nerve gliomas.

Design Literature review.

Results Optic nerve gliomas are generally benign in the pediatric age group although they are usually malignant and aggressive in adults. As such, the mechanisms by which these lesions are diagnosed, the systemic implications, the goals of intervention, and the nature of therapeutic management all differ between these tumors.

Conclusions This article addresses these lesions and discusses the diagnostic and therapeutic paradigms by which they may be approached.
Molecular Mechanisms of Hepatoblastoma
Authors: Zhang Yi , Solinas Antonio , Cairo Stefano , Evert Matthias , Chen Xin , Calvisi Diego F.
Published: January 2021

Hepatoblastoma (HB) is the predominant primary liver tumor in children. While the prognosis is favorable when the tumor can be resected, the outcome is dismal for patients with progressed HB. Therefore, a better understanding of the molecular mechanisms responsible for HB is imperative for early detection and effective treatment. Sequencing analysis of human HB specimens unraveled the pivotal role of Wnt/β-catenin pathway activation in this disease. Nonetheless, β-catenin activation alone does not suffice to induce HB, implying the need for additional alterations. Perturbations of several pathways, including Hippo, Hedgehog, NRF2/KEAP1, HGF/c-Met, NK-1R/SP, and PI3K/AKT/mTOR cascades and aberrant activation of c-MYC, n-MYC, and EZH2 proto-oncogenes, have been identified in HB, although their role requires additional investigation. Here, we summarize the current knowledge on HB molecular pathogenesis, the relevance of the preclinical findings for the human disease, and the innovative therapeutic strategies that could be beneficial for the treatment of HB patients.
Assessing the Role of Minimal Medial Tissue Release during Navigation-Assisted Varus Total Knee Arthroplasty Based on the Degree of Preoperative Varus Deformity
Authors: Toyooka Seikai , Masuda Hironari , Nishihara Nobuhiro , Miyamoto Wataru , Kobayashi Takashi , Kawano Hirotaka , Nakagawa Takumi
Published: January 2021

We assessed the impact of a minimal medial soft-tissue release with complete peripheral osteophyte removal on the ability to attain manual preresection deformity correction during navigation-assisted total knee arthroplasty (TKA) for varus osteoarthritis. We included 131 TKAs for 109 patients with medial compartment predominant osteoarthritis. The steps for achieving minimal medial soft-tissue release were performed as follows: (1) elevation of a periosteal sleeve to 5-mm distal to the joint line and (2) complete removal of peripheral osteophytes. The evaluation criteria of this study were as follows: (1) age, (2) height, (3) weight, (4) body mass index (BMI), (5) sex, (6) the preoperative femorotibial mechanical angle in the neutral position before medial release and (7) the mechanical angle in maximum manual valgus stress after the two-step medial-release procedure (measured on the navigation screens). Multiple regression analysis of the criteria was performed to determine the degree of varus deformity that allowed neutral alignment but required extensive medial release. The femorotibial mechanical angle in the neutral position before medial release and sex correlated with the mechanical angle in maximum manual valgus stress on the navigation screen after medial release (r = 0.72, p < 0.001). Based on the regression formula, the maximum degree of preoperative varus deformity that allowed neutral alignment by the minimum medial-release procedure was 5.3 degrees for males and 9.1 degrees for females. The magnitude of deformity which has an impact on the ability to correct varus deformity (by minimal soft-tissue release and complete osteophyte removal) was clarified. If the preoperative degree of varus deformity was within 5.3 degrees for males and 9.1 degrees for females, an extensive medial release was not required to obtain neutral alignment.
Comparison of Scope Classifications for Predicting the Need for Airway Intervention in Acute Supraglottitis
Authors: Nonomura Machi , Yoshizawa Akira , Mizuta Masanobu , Sato Shin-ichi
Published: January 2021

Background Acute supraglottitis (AS) can cause airway obstruction, sometimes necessitating airway intervention. Some scope classifications were developed to predict the need for airway intervention in patients with AS; however, the most suitable classification for predicting the need for airway intervention remains unclear.

Objective This study was performed to validate and compare the usefulness of three scope classifications (Katori's, Tanaka's, and Ovnat-Tamir's classifications) for predicting the need for airway intervention in patients with AS.

Materials and Methods We recruited 75 patients (44 males and 31 females aged 20–94 years) with AS who visited Kurashiki Central Hospital between January 2015 and September 2019. The areas under the receiver operating characteristic curves (AUCs) of the scope classifications for predicting the need for airway intervention were measured.

Results Of the 75 patients, airway intervention was needed in 23 patients. The AUC was 0.818 (95% confidence interval [CI]: 0.715–0.922) for Katori's classification, 0.803 (95% CI: 0.699–0.907) for Tanaka's classification, and 0.814 (95% CI: 0.705–0.922) for Ovnat-Tamir's classification.

Conclusion Although all three classifications appeared to be useful, the AUC tended to be the highest for Katori's classification.
Remote area nursing: best practice or paternalism in action? The importance of consumer perspectives on primary health care nursing practice in remote communities
Authors: McCullough Kylie , Whitehead Lisa , Bayes Sara , Schultz Rebecca
Published: January 2021

This paper reports on a study that aimed to understand how remote area nurses implemented primary health care principles in the Australian remote health care setting. Twenty-four Registered Nurses and Nurse Practitioners who worked in remote health services without inpatient facilities were interviewed using constructivist grounded theory methods. Findings revealed that nurses in this study aimed to practice in a way that was guided by Indigenous empowerment and social justice. However, some nurses questioned elements of their practice such as ‘chasing’ people for appointments or routine screening required by clinical guidelines that may not reflect the values of Indigenous peoples. Nurses expressed concern that they may be reinforcing past colonising practices and their actions may be considered paternalistic rather than empowering. Nurses in this study wanted to develop partnerships and provide nursing care that aligned with the health and wellbeing expectations of communities. However, ways of communicating the needs of communities and the development of partnerships between health providers and communities need to be developed. The present study calls for further research from the perspective of remote community members in order to develop ways of sharing knowledge about health and wellbeing between remote area nurses and communities.
Designing angle-independent structural colors using Monte Carlo simulations of multiple scattering
Authors: Hwang Victoria , Stephenson Anna B. , Barkley Solomon , Brandt Soeren , Xiao Ming , Aizenberg Joanna , Manoharan Vinothan N.
Published: January 2021

Significance

Structural color comes from interference of light scattered from a nanostructure. Disordered nanostructures have structural colors that are independent of viewing angle, similar to dyed materials. Unlike dyes, structural colors resist fading and can be broadly tuned, making them useful for many applications. However, making a nanostructure with a given color is challenging because there are so many tunable parameters. Furthermore, applications such as cosmetics or displays require specific component materials. To solve this design problem, we develop a model that quantitatively predicts the color for given experimental parameters. We then use optimization to determine the parameters required to make a target color under specific constraints. This approach makes it possible to engineer structural color for many different applications.
Creating self-assembled arrays of mono-oxo (MoO
3
)
1
species on TiO
2
(101) via deposition and decomposition of (MoO
3
)
n
oligomers
Authors: Doudin Nassar , Collinge Greg , Gurunathan Pradeep Kumar , Lee Mal-Soon , Glezakou Vassiliki-Alexandra , Rousseau Roger , Dohnálek Zdenek
Published: January 2021

Significance

The design and synthesis of hierarchically ordered oxides remains a critical challenge in material science and catalysis. Here, we demonstrate that well-ordered homotopic arrays of mono-oxo (MoO
3
)
1
can be easily prepared on anatase TiO
2
(101) via the deposition of (MoO
3
)
n
oligomers. As revealed by our combined experiential and theoretical studies, the oligomers spontaneously decompose and self-assemble into chemically identical and thermally stable monomers. The oligomer decomposition is permitted at room temperature due to the dynamic coupling of decomposition steps to the lattice phonons of TiO
2
. We identify transient mobility of the oligomers as key to the self-assembly of the complete overlayer. The ease of preparation and thermal stability of this atomically precise system makes it highly suitable for a broad range of applications.
Efficacy of Two-Way Prayer Meditation in Improving the Psychospiritual Well-Being of People with Substance use Disorders: A Pilot Randomized Controlled Trial
Authors: Hai Audrey Hang , Wigmore Bill , Franklin Cynthia , Shorkey Clayton , von Sternberg Kirk , Cole Allan Hugh , DiNitto Diana M.
Published: January 2021

Background

The study goal was to conduct a preliminary evaluation of a spiritual intervention called Two Way Prayer Meditation's (TWPM) effectiveness on the psychological distress, self-esteem, and spiritual well-being of people with substance use disorders.

Methods

This study employed a randomized controlled trial design with pretest and posttest. In total, 134 adults in four residential recovery programs participated in the study and were randomly assigned to either the TWPM group or the treatment as usual group. Primary and sensitivity analyses were conducted using linear mixed modeling. Hedges's g was used to estimate treatment effect sizes.

Results

Both primary and sensitivity analyses found significant treatment effects on daily spiritual experiences (Hedges's g = 0.62), reliance on God ( g = 0.49), private religious practice ( g = 0.36), and positive religious/spiritual coping ( g = 0.68). Treatment effects on psychological distress ( g = 0.33), self-esteem ( g = 0.41), and overall spirituality self-ranking ( g = 0.32) reached significance in the primary analysis but not in the sensitivity analysis.

Conclusions

This study found evidence of TWPM's effectiveness in improving some aspects of the spiritual well-being of adults with substance use disorders. TWPM was also found to be promising in decreasing psychological distress and increasing self-esteem.
On the thermodynamics of the Hayward black hole
Authors: Molina Martín , Villanueva J R
Published: January 2021

In light of the growing interest in the Hayward black hole solution, a detailed study on the corresponding lapse function and its roots is presented. The lapse function is expressed in terms of the classical Schwarzschild radius r
s and the Hayward’s parameter l. Both of these quantities are used as thermodynamic variables to find related thermodynamic quantities. In this context, the variable l is associated with a canonical conjugate variable

F

H

, and a free energy Ξ. Moreover, a second order phase transition is found to appears at l ≈ 0.333r
s.
Quantum black hole spectroscopy: probing the quantum nature of the black hole area using LIGO–Virgo ringdown detections
Authors: Laghi Danny , Carullo Gregorio , Veitch John , Del Pozzo Walter
Published: January 2021

We present a thorough observational investigation of the heuristic quantised ringdown model presented by Foit and Kleban (2019 Class. Quantum Grav.
36 035006). This model is based on the Bekenstein–Mukhanov conjecture, stating that the area of a black hole (BH) horizon is an integer multiple of the Planck area

l

P

2

multiplied by a phenomenological constant, α, which can be viewed as an additional BH intrinsic parameter. Our approach is based on a time-domain analysis of the gravitational wave (GW) signals produced by the ringdown phase of binary BH mergers detected by the LIGO and Virgo collaboration. Employing a full Bayesian formalism and taking into account the complete correlation structure among the BH parameters, we show that the value of α cannot be constrained using only GW150914, in contrast to what was suggested by Foit and Kleban (2019 Class. Quantum Grav.
36 035006). We proceed to repeat the same analysis on the new GW events detected by the LIGO and Virgo Collaboration up to 1 October 2019, obtaining a combined-event measure equal to

α
=
15
.

6

−
13.3

+
20.5

and a combined log odds ratio of 0.1 ± 0.6, implying that current data are not informative enough to favor or discard this model against general relativity. We then show that using a population of

O

(

20

)

GW150914-like simulated events—detected by the current infrastructure of ground-based detectors at their design sensitivity—it is possible to confidently falsify the quantised model or prove its validity, in which case probing α at the few % level. Finally we classify the stealth biases that may show up in a population study.
Ultrabroadband compact lens antenna with high performance based on a transmission gradient index medium
Authors: Chen Jin , Chu Hongchen , Huang Yixing , Lai Yun , Liu Zhanwei , Chen Mingji , Fang Daining
Published: January 2021

A gradient refractive index design strategy is proposed for a flat lens, which can transform a wavefront by rectifying the local transmission phase. The designed lens is composed of two types of low-loss dielectrics with subwavelength gradient periodic structure and manufactured by 3D printing and computer controlled machining. The measured results of the near and far field agree well with those of theoretical predictions and numerical simulations. It is demonstrated that this light-weight, low cost, compact lens antenna is highly directive (side lobes below −10 dB) and the incident plane waves are focused well with high focusing efficiency (above 80%) over an ultrabroadband frequency range with a bandwidth ratio of 138% (4–22 GHz). The demonstrated flat lens provides an alternative strategy for microwave communication, detection, and imaging applications.
Electronic properties of donor:acceptor complexes in all-polymer solar cells based on density functional theory
Authors: Shen Pengchao , Wang Haiyan , Liao Peishan , Wang Lilong
Published: January 2021

The electronic properties at the donor (D):acceptor (A) interface are a crucial factor in determining the efficiency of organic photovoltaic devices. Here, based on first-principles calculations, the electronic properties of ten configuration complexes composed of D polymer PDPPTPT and A polymer PNDI2OD-TVT were simulated. Results show that the bandgap values of the homo-/heterojunctions decrease with the increase of the number of molecular layers, and that of AAA is close to zero. This indicates that the homogeneous stacking is favorable for charge transport; furthermore, the bandgap of the complexes is affected by the molecular arrangement. Through the differential charge density and Bader charge analysis method, it was found that charge transfer will occur intermolecularly, which promotes the formation of a dipole moment at the D:A interface, and the dipole electric field then helps the dissociation of excitons in the active layer. The amount of charge transfer at the D:A interface in the DDA, DAA and DDAA configurations is about twice that in the DA configuration alone, demonstrating that homogeneous accumulation in complexes can enhance the interface dipole interaction. The comprehensive analysis suggests that homogeneous accumulation is conducive to charge transport, that heterogeneous stacking helps to promote exciton dissociation, and that there should be an optimal ratio. Furthermore, the dipole electric fields formed at the D:A interface exhibit the characteristics of local and non-uniform distribution.
An evidence of triple kinetic freezeout scenario observed in all centrality intervals in Cu–Cu, Au–Au and Pb–Pb collisions at high energies
Authors: Waqas M , Peng G X , Liu Fu-Hu
Published: January 2021

Transverse momentum spectra of π
+, K
+, p,

K

S

0

, Λ, Ξ or

Ξ

̄

+

and Ω or

Ω

̄

+

or

Ω
+

Ω

̄

in copper–copper (Cu–Cu), gold–gold (Au–Au) and lead–lead (Pb–Pb) collisions at 200 GeV, 62.4 GeV and 2.76 TeV respectively, are analyzed in different centrality bins by the blast wave model with Tsallis statistics. The model results are approximately in agreement with the experimental data measured by BRAHMS, STAR and ALICE Collaborations in special transverse momentum ranges. Kinetic freeze out temperature, transverse flow velocity and kinetic freezeout volume are extracted from the transverse momentum spectra of the particles. It is observed that

Ξ

̄

+

and Ω or

Ω

̄

+

or

Ω
+

Ω

̄

have larger kinetic freezeout temperature followed by K
+,

K

S

0

and Λ than π
+ and p due to smaller reaction cross-sections of multi-strange and strange particles than non-strange particles. The present work reveals the scenario of triple kinetic freezeout in collisions at BRAHMS, STAR and ALICE Collaborations, however the transverse flow velocity and kinetic freezeout volume are mass dependent and they decrease with the increasing rest mass of the particle. In addition, the kinetic freezeout temperature, transverse flow velocity and kinetic freezeout volume are decreasing from central to peripheral collisions while the parameter q increase from central to peripheral collisions, indicating the approach of quick equilibrium in the central collisions. Besides, the kinetic freezeout temperature and kinetic freezeout volume are observed to be larger in larger collision system which shows its dependence on the size of the interacting system, while transverse flow velocity increase with increasing energy.
Rotational bands beyond the Elliott model
Authors: Zbikowski Ryan , Johnson Calvin W , McCoy Anna E , Caprio Mark A , Fasano Patrick J
Published: January 2021

Rotational bands are commonplace in the spectra of atomic nuclei. Inspired by early descriptions of these bands by quadrupole deformations of a liquid drop, Elliott constructed discrete nucleon representations of SU(3) from fermionic creation and annihilation operators. Ever since, Elliott’s model has been foundational to descriptions of rotation in nuclei. Later work, however, suggested the symplectic extension Sp(3, R) provides a more unified picture. We decompose no-core shell-model nuclear wave functions into symmetry-defined subspaces for several beryllium isotopes, as well as 20Ne, using the quadratic Casimirs of both Elliott’s SU(3) and Sp(3, R). The band structure, delineated by strong B(E2) values, has a more consistent description in Sp(3, R) rather than SU(3). In particular, we confirm previous work finding in some nuclides strongly connected upper and lower bands with the same underlying symplectic structure.
Excitations of atomic vibrations in amorphous solids
Authors: Wan Li
Published: January 2021

We study excitations of atomic vibrations in the reciprocal space for amorphous solids. There are two kinds of excitations we obtained, collective excitation and local excitation. The collective excitation is the collective vibration of atoms in the amorphous solids while the local excitation is stimulated locally by a single atom vibrating in the solids. We introduce a continuous wave vector for the study and transform the equations of atomic vibrations from the real space to the reciprocal space. We take the amorphous silicon as an example and calculate the structures of the excitations in the reciprocal space. Results show that an excitation is a wave packet composed of a collection of plane waves. We also find a periodical structure in the reciprocal space for the collective excitation with longitudinal vibrations, which is originated from the local order of the structure in the real space of the amorphous solid. For the local excitation, the wave vector is complex. The imaginary part of the wave vector is inversed to evaluate the decaying length of the local excitation. It is found that the decaying length is larger for the local excitation with a higher vibration frequency.
First-principles studies of the strain-induced band-gap tuning in black phosphorene
Authors: Galicia Hernandez Jose Mario , Sanchez Jonathan Guerrero , Fernandez Escamilla Hector Noe , Cocoletzi Gregorio Hernandez , Takeuchi Noboru
Published: January 2021

Using first-principles calculations, we have studied the band-gap modulation as function of applied strain in black phosphorene (BP). Dynamical stability has been assessed as well. Three cases have been considered, in the first and second, the strain was applied uniaxially, in the x- and y-axis, separately. In the third, an isotropic in-plane strain was analyzed. Different strain percentages have been considered, ranging from 4% to 20%. The evolution of the band-gap is studied by using standard DFT and the G0W0 approach. The band-gap increases for small strains but then decreases for higher strains. A change in electronic behavior also takes place: the strained systems change from direct to indirect band-gap semiconductor, which is explained in terms of the s and p-orbitals overlap. Our study shows that BP is a system with a broad range of applications: in band-gap engineering, or as part of van der Waals heterostructures with materials of larger lattice parameters. Its stability, and direct band-gap behavior are not affected for less than 16% of uniaxial and biaxial strain. Our findings show that phosphorene could be deposited in a large number of substrates without losing its semiconductor behavior.
One-dimensional spin–orbit coupled Dirac system with extended s-wave superconductivity: Majorana modes and Josephson effects
Authors: Udupa Adithi , Banerjee Abhishek , Sengupta K , Sen Diptiman
Published: January 2021

Motivated by the spin–momentum locking of electrons at the boundaries of certain topological insulators, we study a one-dimensional system of spin–orbit coupled massless Dirac electrons with s-wave superconducting pairing. As a result of the spin–orbit coupling, our model has only two kinds of linearly dispersing modes, and we take these to be right-moving spin-up and left-moving spin-down. Both lattice and continuum models are studied. In the lattice model, we find that a single Majorana zero energy mode appears at each end of a finite system provided that the s-wave pairing has an extended form, with the nearest-neighbor pairing being larger than the on-site pairing. We confirm this both numerically and analytically by calculating the winding number. We find that the continuum model also has zero energy end modes. Next we study a lattice version of a model with both Schrödinger and Dirac-like terms and find that the model hosts a topological transition between topologically trivial and non-trivial phases depending on the relative strength of the Schrödinger and Dirac terms. We then study a continuum system consisting of two s-wave superconductors with different phases of the pairing, with a δ-function potential barrier lying at the junction of the two superconductors. Remarkably, we find that the system has a single Andreev bound state (ABS) which is localized at the junction. When the pairing phase difference crosses a multiple of 2π, an ABS touches the top of the superconducting gap and disappears, and a different state appears from the bottom of the gap. We also study the AC Josephson effect in such a junction with a voltage bias that has both a constant V
0 and a term which oscillates with a frequency ω. We find that, in contrast to standard Josephson junctions, Shapiro plateaus appear when the Josephson frequency ω
J = 2eV
0/ℏ is a rational fraction of ω. We discuss experiments which can realize such junctions.
Evolution of Griffiths phase and critical behaviour of La1-xPbxMnO3±ysolid solutions
Authors: Ghorai Sagar , Ivanov Sergey A , Skini Ridha , Svedlindh Peter
Published: January 2021

Polycrystalline La1-xPbxMnO3±y(x= 0.3, 0.35, 0.4) solid solutions were prepared by solid state reaction method and their magnetic properties have been investigated. Rietveld refinement of x-ray powder diffraction patterns showed that all samples are single phase and crystallized with the rhombohedral structure in theR-3cspace group. A second order paramagnetic to ferromagnetic (FM) phase transition was observed for all materials. The Griffiths phase (GP), identified from the temperature dependence of the inverse susceptibility, was suppressed by increasing magnetic field and showed a significant dependence on A-site chemical substitution. The critical behaviour of the compounds was investigated near to their Curie temperatures, using intrinsic magnetic field data. The critical exponents (β,γandδ) are close to the mean-field approximation values for all three compounds. The observed mean-field like behaviour is a consequence of the GP and the formation of FM clusters. Long-range FM order is established as the result of long-range interactions between FM clusters. The magnetocaloric effect was studied in terms of the isothermal entropy change. Our study shows that the material with the lowest chemical substitution (x= 0.3) has the highest potential (among the three compounds) as magnetic refrigerant, owing to its higher relative cooling power (258 J kg−1at 5 T field) and a magnetic phase transition near room temperature.
On-line angle self-correction strategy based on a cobweb-structured grating scale
Authors: Zhao Guobo , Ye Guoyong , Wu Zeze , Xing Hongwen , Liu Siren , Fan Xiaojun , Li Yingjiang , Wei Pingping , Liu Hongzhong
Published: January 2021

Installation eccentricity of the grating scale is the main source of error for rotary optical encoders in practical applications. In this paper, an on-line angle self-correction strategy for rotary optical encoders is proposed. Firstly, the eccentricity error model is described, which explains the numerical relationship between the eccentricity error and the eccentric parameters including eccentric distance and eccentric angle. Then, a bioinspired cobweb-structured grating scale is adopted as the measurement standard of the rotary optical encoder. This grating scale allows the rotary optical encoder to sense the rotary angle and the radial displacement simultaneously. The eccentric parameters can be determined in real time from the rotary angle and the radial displacement information. Thus, the measured rotary angle can be on-line corrected by applying the eccentric parameters to the eccentricity error model. The feasibility and effectiveness of the proposed strategy have been confirmed from the experimental results.
Tire defect classification using a deep convolutional sparse-coding network
Authors: Zheng Zhouzhou , Shen Jinyue , Shao Yuyi , Zhang Jie , Tian Chengliang , Yu Bin , Zhang Yan
Published: January 2021

Automatic quality control has garnered great interest from academia and industry in recent decades. Tire defect detection and classification are critical research topics for driving safety and improving yields. In this work, a novel deep convolutional sparse-coding network (DCScNet) is built for tire defect classification. In DCScNet, sparse coding is utilized to replace the convolution kernel of a convolutional neural network (CNN) for the extraction of features. Compared with CNN, it requires unsupervised training, reduces the subjectivity of artificially defined labels, and achieves higher classification accuracy. The experimental results validate its superior classification performance, compared with state-of-the-art classification algorithms. The classification accuracy reaches 96.8%, which meets industrial requirements.
Analysis of strain sensitivity under flexural load of 3D printed carbon nanotube-doped epoxy circuits
Authors: Manzano-Santamaría J , Sánchez M , Sánchez-Romate X F , Rams J , Ureña A
Published: January 2021

A 3D printing system able to print circuits of conductive epoxy resin doped with carbon nanotubes (CNTs) is proposed. Different simple circuits, more specifically lines and strain gauge patterns, made of resins reinforced with 0.3, 0.5, 0.8 and 1 wt% of CNTs were printed on the surface of glass fiber laminates. It was observed that increasing the CNT content reduced the wettability of the printed circuits on the glass fiber substrate. In every case the contact angle was far below 90°. Furthermore, the strain sensing capabilities were analyzed under a flexural load. The results showed that the sensitivity increased with CNT content (with gauge factor values from 1.5 to 2.5) as a result of the prevalent effect of well-dispersed areas due to a reduction in the tunneling distance. On the other hand, the strain gauges showed a lower sensitivity (around 20%–40% less, depending on the condition) compared with line circuits due to localized compressive effects. Furthermore, good repeatability of the strain sensors was proved during cycling tests, with similar baseline and peak values for the electrical resistance in each cycle. Therefore, the proposed materials have a high potential for applications in structural health monitoring.
Epitope recognition of magnetic peptide-imprinted chitosan composite nanoparticles for the extraction of CRISPR/dCas9a proteins from transfected cells
Authors: Lee Mei-Hwa , Lin Cheng-Chih , Thomas James L , Chan Chih-Kai , Lin Hung-Yin
Published: January 2021

The clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein (Cas9) technology is a powerful method for genetic modification (and regulation) that is of great current interest. The development of new, economical methods of detecting and extracting Cas9 (and/or dCas9) from transfected cells is thus an important advance. In this work, we employed molecular imprinting, using two peptides from the Cas9 protein, to make magnetic peptide-imprinted chitosan nanoparticles. dCas9 was encoded in a plasmid which was then transfected into human embryonic kidney (HEK293T) cells. The expression of dCas9 protein was measured by using total protein kits. Finally, the imprinted nanoparticles were used to extract dCas9 from transfected cell homogenates.
Reversible engineering of topological insulator surface state conductivity through optical excitation
Authors: Xie Faji , Lian Zhen , Zhang Shuai , Wang Tianmeng , Miao Shengnan , Song Zhiyong , Ying Zhe , Pan Xing-Chen , Long Mingsheng , Zhang Minhao , Fei Fucong , Hu Weida , Yu Geliang , Song Fengqi , Kang Ting-Ting , Shi Su-Fei
Published: January 2021

Despite the broadband response, limited optical absorption at a particular wavelength hinders the development of optoelectronics based on Dirac fermions. Heterostructures of graphene and various semiconductors have been explored for this purpose, while non-ideal interfaces often limit the performance. The topological insulator (TI) is a natural hybrid system, with the surface states hosting high-mobility Dirac fermions and the small-bandgap semiconducting bulk state strongly absorbing light. In this work, we show a large photocurrent response from a field effect transistor device based on intrinsic TI Sn–Bi1.1Sb0.9Te2S (Sn-BSTS). The photocurrent response is non-volatile and sensitively depends on the initial Fermi energy of the surface state, and it can be erased by controlling the gate voltage. Our observations can be explained with a remote photo-doping mechanism, in which the light excites the defects in the bulk and frees the localized carriers to the surface state. This photodoping modulates the surface state conductivity without compromising the mobility, and it also significantly modify the quantum Hall effect of the surface state. Our work thus illustrates a route to reversibly manipulate the surface states through optical excitation, shedding light into utilizing topological surface states for quantum optoelectronics.
Kupffer cell-targeting strategy for the protection of hepatic ischemia/reperfusion injury
Authors: Dai Qingqing , Jiang Wei , Liu Hu , Qing Xin , Wang Guobin , Huang Fan , Yang Zhilai , Wang Chunhui , Gu Erwei , Zhao Hongchuan , Zhang Jiqian , Liu Xuesheng
Published: January 2021

The aim of this study is to evaluate the effect of rare earth upconversion nanoparticles (UCNs) on hepatic ischemia reperfusion injury (IRI) and explore its possible mechanism. Hepatic IRI seriously affects the prognosis of patients undergoing liver surgery. Liver-resident Kupffer cells have been reported to promote IRI. Nanomedicines are known to be effective in the treatment of liver diseases, however, Kupffer cell-targeting nanomedicines for the treatment of IRI are yet to be developed. As potential bioimaging nanomaterials, UCNs have been found to specifically deplete Kupffer cells, but the underlying mechanism is unknown. In this study, we found that UCNs specifically depleted Kupffer cells by pyroptosis, while the co-administration of the caspase-1 inhibitor VX-765 rescued the UCN-induced Kupffer cell pyroptosis in mice. Furthermore, the pre-depletion of Kupffer cells by the UCNs significantly suppressed the release of inflammatory cytokines and effectively improved hepatic IRI. The rescue of the pyroptosis of the Kupffer cells by VX-765 abrogated the protective effect of UCNs on the liver. These results suggest that UCNs are highly promising for the development of Kupffer cell-targeting nanomedicines for intraoperative liver protection.
Vertical bounce of a spinning ball
Authors: Cross Rod
Published: January 2021

An experiment is described where three different spinning balls were dropped vertically on a horizontal surface, and the bounce was filmed with a video camera. The change in spin and horizontal speed of each ball was estimated theoretically, using equations familiar to physics students. The experiment provides an extension of the usual student exercise where a non-spinning ball is dropped vertically on a surface to measure the coefficient of restitution.
Characterization of surface roughness by speckle pattern—an experimental approach
Authors: Souza P V S , Rodrigues D P , Silva L da , Huguenin J A O , Balthazar W F
Published: January 2021

Although it originates from the ancient Greeks, optics still arouses a lot of scientific interest, mainly due to the technological innovation associated with it. One of its most interesting applications is related to optical metrology and the characterization of materials through optical techniques. While some of these processes can be explained in a simplified way using a few of the fundamental principles of physics, there are hardly any proposals whose objective is to discuss this topic at a basic level. Accordingly, we present a low-cost experiment that allows the characterization of surface roughness using the fractal dimension of the speckle pattern associated with the light scattered by a surface. For simplicity, the entire activity is adaptable to the most diverse school situations. Moreover, it allows the discussion of many fundamental physics concepts and provides students with an experience similar to that experienced by scientists.
Rotating ring on a vertical rod
Authors: Cross Rod
Published: January 2021

If a ring is spun around a vertical rod then the ring remains at the same height for several seconds before it starts to fall. The effect is counter-intuitive. Experimental results are presented to show that if the ring is spinning fast enough then static friction will be sufficient to prevent the ring falling.
Probabilistic dose prediction using mixture density networks for automated radiation therapy treatment planning
Authors: Nilsson Viktor , Gruselius Hanna , Zhang Tianfang , De Kerf Geert , Claessens Michaël
Published: January 2021

We demonstrate the application of mixture density networks (MDNs) in the context of automated radiation therapy treatment planning. It is shown that an MDN can produce good predictions of dose distributions as well as reflect uncertain decision making associated with inherently conflicting clinical tradeoffs, in contrast to deterministic methods previously investigated in the literature. A two-component Gaussian MDN is trained on a set of treatment plans for postoperative prostate patients with varying extents to which rectum dose sparing was prioritized over target coverage. Examination on a test set of patients shows that the predicted modes follow their respective ground truths well, both spatially and in terms of their dose–volume histograms. A special dose mimicking method based on the MDN output is used to produce deliverable plans and thereby showcase the usability of voxel-wise predictive densities. Thus, this type of MDN may serve to support clinicians in managing clinical tradeoffs and has the potential to improve the quality of plans produced by an automated treatment planning pipeline.
Coupled plasma transport and electromagnetic wave simulation of an ECR thruster
Authors: Sánchez-Villar Álvaro , Zhou Jiewei , Ahedo Eduardo , Merino Mario
Published: January 2021

An electron-cyclotron resonance thruster (ECRT) prototype is simulated numerically, using two coupled models: a hybrid particle-in-cell/fluid model for the integration of the plasma transport and a frequency-domain full-wave finite-element model for the computation of the fast electromagnetic (EM) fields. The quasi-stationary plasma response, fast EM fields, power deposition, particle and energy fluxes to the walls, and thruster performance figures at the nominal operating point are discussed, showing good agreement with the available experimental data. The ECRT plasma discharge contains multiple EM field propagation/evanescence regimes that depend on the plasma density and applied magnetic field that determine the flow and absorption of power in the device. The power absorption is found to be mainly driven by radial fast electric fields at the electron-cyclotron resonance region, and specifically close to the inner rod. Large cross-field electron temperature gradients are observed, with maxima close to the inner rod. This, in turn, results in large localized particle and energy fluxes to this component.
Particle-in-cell simulations of the alpha and gamma modes in collisional nitrogen capacitive discharges
Authors: Kawamura E , Lieberman M A , Lichtenberg A J , Chabert P
Published: January 2021

We perform one-dimensional (1D) particle-in-cell (PIC) simulations to study the α and γ modes in an intermediate pressure 1.6 Torr, 2.5 cm gap capacitive nitrogen discharge driven at 13.56 MHz with current density amplitudes J
0 = 7 to 150 A m−2. In the α-mode, ion-induced secondary electron emission has minimal effects on the discharge equilibrium, while in the γ-mode, it is essential for sustaining the discharge. As in a previous study of a comparable argon discharge, [Kawamura et al 2020, J. Vac. Sci. Technol. A
38, 023003], the nitrogen discharge in the α-mode can be described by a ‘passive bulk’ model in which the ionization is negligible in the central bulk region and is due solely to electron sheath heating. The nitrogen discharge undergoes an α to γ transition in the applied J
0 range, characterized by an increase in density and a decrease in electron temperature, sheath widths and sheath voltages. For the γ-mode, we calculate the scalings of the maximum sheath width s
m and the rf sheath voltage amplitude V
1 with J
0. We compare the PIC results in the α-mode to the passive bulk model (modified for nitrogen), and, in the γ-mode with the expected J
0-V
1 and s
m-V
1 curves. We find good agreement with the simulations in both the α and γ regimes, and the α to γ transition is well predicted by the models.
Correlation between frequency and location on the wafer for terahertz quantum-cascade lasers
Authors: Lü Xiang , Röben Benjamin , Schrottke Lutz , Biermann Klaus , Grahn Holger T
Published: January 2021

We have investigated the emission frequency of terahertz (THz) quantum-cascade lasers (QCLs) as a function of the location on the wafer. The frequency varies due to an inhomogeneous growth rate across the wafer. For three wafers based on GaAs/AlAs heterostructures for lasers with target frequencies of 3.36 and 3.92 THz, we observed a blue shift of the emission frequency from the center to the edge of the wafer. This blue shift is attributed to a decrease of the period length of the QCLs, which can be determined with spectroscopic techniques. The location-dependent period length is used to calculate a position-dependent frequency of the gain maximum for the active region. The correlation of the calculated frequencies with the emission frequencies of lasers fabricated from different locations on the wafer allows us to establish an effective method for the fabrication of THz QCLs emitting at a particular target frequency.
Development of spacer warp knitted thermoelectric generators
Authors: Dallmann Anke , Franz Christian , Hoffmann Gerald , Cherif Chokri
Published: January 2021

The research presented in this paper was aimed at developing spacer warp knitted thermoelectric generators (TEGs), which can generate electrical current from waste heat. Hence, this paper introduces a structural design approach and a calculation model in addition to describing the manufacturing of prototypes and analyses on their basic functionality regarding thermoelectric power generation. Wires as well as wire strands of iron and constantan can be used for knitting on a double bar raschel machine. Wires can be connected to a thermocouple (TC) by means of various spacer warp knitting patterns while using the feed system of the spacer yarn for the wires. The friction locking electrical contacting of several TC, thus forming an applicable TEG, was achieved by sewing together silver plated copper wire strands. A large wire cross section, clear separation of iron and con-stantan wires in the knitted fabric, and consistently high temperature difference between the TEG surfaces produce a constant thermoelectric voltage. The maximum voltage depends on the number of TC, the material properties, and the temperature difference. By reducing the internal resistance of the TEG, electric power can be increased.
Simultaneous double ionization of C60 molecules in single-cycle pulses
Authors: Schubert I , Bart G , Brabec T
Published: January 2021

We theoretically investigate simultaneous double ionization of C60 Buckminsterfullerene clusters within the strong field approximation, taking into account two-body effects like Coulomb blocking. Our analysis suggests that for infrared single-cycle pulses, simultaneous double ionization becomes comparable in magnitude to sequential double ionization. Additionally, estimates show that Coulomb blocking weakens with increasing cluster size and field strength.
Floquet topological phase transition in two-dimensional quadratic band crossing system*
Authors: Zhu Guo-Bao , Yang Hui-Min
Published: January 2021

We investigate the Hall effects of quadratic band crossing (QBC) fermions in a square optical lattice with spin–orbit coupling and orbital Zeeman term. We find that the orbital Zeeman term and shaking play critical roles in the systems, which can drive a topological transition from spin Hall phases to anomalous Hall phase with nonvanishing (spin) Chern numbers. Due to the interplay among the orbital Zeeman term, spin–orbit coupling, and the shaking, the phase diagram of the system exhibits rich phases, which are characterized by Chern number.