bluuebunny/crossref_metadata_2025 huggingface dataset:
Systematic review of single case design meta‐analyses for school‐age students with autism spectrum disorders: Current trend and future direction
Authors: Zeng Songtian , Zhao Hongxia , Hu Xiaoyi , Pereira Brittany A. , Pan Qichao , Meng Chen , Reyes Arazeliz , Stone‐MacDonald Angela
Published: October 2021

Although numerous meta‐analyses of single‐case design (SCD) research have been published, no systematic review has been conducted to holistically reveal the trends in content focus, and the state‐of‐the‐art practices in conducting SCD meta‐analyses for school‐aged students with autism spectrum disorder (ASD). This study synthesized the intervention/practices and participant characteristics, and identified the trends and limitations in previous SCD meta‐analyses. Systematic review of meta‐analyses can contribute to the summary of current evidence and further identify ways to improve SCD meta‐analyses. We conducted a systematic literature search and identified 30 articles that met the inclusion criteria. Findings suggest that multiple interventions may be employed to improve various outcomes for school‐aged students with ASD. Researchers may use our findings to map out the intervention and targeted outcomes and identify underresearched areas. Meanwhile, findings suggest several measures to improve the quality of future SCD meta‐analysis practices and publication, such as documenting racial/ethnicity information, using a set of potential moderators to conduct heterogenetic analysis, and effects in reducing publication bias. Future research directions are also provided.
Enhancing high schoolers' creative thinking and complex problem‐solving abilities: Examining the effectiveness of spirituality
Authors: Pandya Samta P.
Published: October 2021

High schoolers' creative thinking and complex problem‐solving abilities are important for determining achievement. There is a need to investigate whether spiritual training delivered via a microblogging social networking platform would be effective. This article reports a study that examines the impact of Twitter‐based spiritual posts on high school students' (Npre‐test = 272; Npost‐test = 234) creativity and problem‐solving abilities. Results indicated that spiritual posts were effective as compared with the control condition comprising general creativity‐enhancement posts. Post‐test outcomes were higher for girls, middle class, who had mothers as primary caregivers, whose primary caregivers were highly qualified, living in standard family arrangements, scoring high on conscientiousness, emotional stability, and openness to experience personality characteristics, and whose intervention compliance in terms of reading/liking posts and homework was above threshold (>30). Intervention adherence mediated the association between demographic and personality characteristics and outcomes. Latent class analysis indicated eight clusters/subgroups of participants reporting maximum post‐test gains: female, middle class, with mothers as primary caregivers, whose primary caregivers were higher qualified, who were highly conscientious and open to experience, and whose intervention compliance was above threshold.
Structure of Aedes aegypti carboxypeptidase B1‐inhibitor complex uncover the disparity between mosquito and non‐mosquito insect carboxypeptidase inhibition mechanism
Authors: Gavor Edem , Choong Yeu Khai , Jobichen Chacko , Mok Yu Keung , Kini R. Manjunatha , Sivaraman J.
Published: October 2021

Metallocarboxypeptidases (MCPs) in the mosquito midgut play crucial roles in infection, as well as in mosquito dietary digestion, reproduction, and development. MCPs are also part of the digestive system of plant‐feeding insects, representing key targets for inhibitor development against mosquitoes/mosquito‐borne pathogens or as antifeedant molecules against plant‐feeding insects. Notably, some non‐mosquito insect B‐type MCPs are primarily insensitive to plant protease inhibitors (PPIs) such as the potato carboxypeptidase inhibitor (PCI; MW 4 kDa), an inhibitor explored for cancer treatment and insecticide design. Here, we report the crystal structure of Aedes aegypti carboxypeptidase‐B1 (CPBAe1)‐PCI complex and compared the binding with that of PCI‐insensitive CPBs. We show that PCI accommodation is determined by key differences in the active‐site regions of MCPs. In particular, the loop regions α6‐α7 (Leu242‐Ser250) and β8‐α8 (Pro269‐Pro280) of CPBAe1 are replaced by α‐helices in PCI‐insensitive insect Helicoverpa zea CPBHz. These α‐helices protrude into the active‐site pocket of CPBHz, restricting PCI insertion and rendering the enzyme insensitive. We further compared our structure with the only other PCI complex available, bovine CPA1‐PCI. The potency of PCI against CPBAe1 (Ki = 14.7 nM) is marginally less than that of bovine CPA1 (Ki = 5 nM). Structurally, the above loop regions that accommodate PCI binding in CPBAe1 are similar to that of bovine CPA1, although observed changes in proteases residues that interact with PCI could account for the differences in affinity. Our findings suggest that PCI sensitivity is largely dictated by structural interference, which broadens our understanding of carboxypeptidase inhibition as a mosquito population/parasite control strategy.
Quantitative Evaluation of Thermal Conductivity of Single‐Bent Microwire Using Vanadium Dioxide Temperature Tag
Authors: Huang Runqing , Zhao Yaxuan , Wang Zixu , Gan Yichen , Shen Nan , Amini Abbas , Shi Run , Cheng Chun
Published: October 2021

Stress/strain engineering is believed to be an effective way to adjust the thermal conductivity of materials dynamically or as needed. Compared with bulk materials, micro‐/nanoscale structures can withstand greater stress/deformations that lead to evident changes in their thermal conductivity after undergoing stress/strain; this phenomenon has been predicted by theoretical simulations. Nevertheless, measuring the effective thermal conductivity of a single wire of a small size upon controllable bending angles has faced major challenges. Herein, a method using VO2 tag as a temperature indicator is developed to achieve the in situ quantitative measurement of the thermal conductivity of bent silicon microwires (MWs), where thermally insulated spider silk is used to adjust the position of the suspended end of wires for different bending angles. It is found that the thermal conductivity of Si wires increases and then decreases upon subsequent bending; it indicates that the thermal conductivity of MWs can be dynamically tuned by bending. Further studies reveal that the variation of thermal conductivity is reversible with small bending (elastic) and irreversible with large bending (plastic). With this setup, new thermophysical properties of materials are explored at small scales, and possible stress/strain‐gated thermal switches emerge.
Effect of [Ln3+–Si4+] (Ln = Y, La, Gd, Lu) Cosubstitution on the Structure and Luminescence Property of Sr9Mg1.5(PO4)7:Eu2+ Phosphor
Authors: Wang Min , Xie Guangyong , Tang Wanjun
Published: October 2021

Four series of isostructural solid solution phosphors with the composition of Sr8.95−xLnxMg1.5(PO4)7−x(SiO4)x:0.05Eu2+ (Ln = Y, La, Gd, Lu; x = 0−2) are synthesized. The influence of [Ln3+−Si4+] (Ln = Y, La, Gd, Lu) cosubstitution on the structure and luminescence properties of Sr9Mg1.5(PO4)7:Eu2+ phosphor is evaluated. Spectra analysis indicates that the valence state of Eu in Sr9Mg1.5(PO4)7:Eu2+ phosphor can be controlled from Eu3+ to Eu2+ by cosubstituting [Ln3+−Si4+] for [Sr2+−P5+], leading to an obvious enhancement of Eu2+ emission. The mechanism of abnormal reduction of Eu3+ ions in the lattice is discussed. In addition, a blueshift of Eu2+ emission is observed with increasing the [Ln3+−Si4+] content. These findings not only suggest that the as‐prepared Sr9−xLnxMg1.5(PO4)7−x(SiO4)x:Eu2+ phosphors are potential candidates for near‐UV‐based white light‐emitting diodes (LEDs) but also offer a novel way for Eu valence control and spectral tuning in Eu‐doped phosphors with multiple activator sites.
Modeling the Charge State of Monatomic Hydrogen and Other Defects with Arbitrary Concentrations in Crystalline Silicon
Authors: Sun Chang , Yan Di , Macdonald Daniel
Published: October 2021

A rigorous physical‐mathematical model for predicting the charge states of both mono‐ and multivalent defects with arbitrary concentrations in Si in both thermal equilibrium and non‐equilibrium steady‐state conditions is presented. The model avoids the assumption that the defect concentration is much lower than the doping level, which is common in previous approaches. It is shown that the general occupancy ratio given by α = (kn1 + p)/(kn + p1) is still valid under these more general conditions. However, more caution needs to be taken when calculating the equilibrium and excess carrier densities in the presence of larger defect concentrations, because of: a) the non‐negligible contribution to n0 and p0 from defect ionisation, and b) unequal Δn and Δp caused by the change in the occupied states at the defect level from equilibrium to non‐equilibrium. Modeled examples of monatomic H and interstitial Fe in Si are shown and the effects of defect concentration, temperature, and carrier injection are discussed.
Incorporation of organic acids turns classically brittle zein films into flexible antimicrobial packaging materials
Authors: Sözbilen Gözde Seval , Çavdaroğlu Elif , Yemenicioğlu Ahmet
Published: October 2021

This study aimed to turn classically brittle zein films into flexible antimicrobial ones by the use of lactic (LA), malic (MA) and tartaric acids (TA). The most effective plasticizer was LA (400% elongation at break [EB] at 4%), while MA (189% EB at 4.5%) and TA (68% EB at 5%) showed moderate and limited plasticizing effects, respectively. The LA‐ and MA‐loaded films maintained their flexibility during 30‐day storage at 4°C or 25°C. Fourier transform infrared (FTIR) analysis suggested that the plasticization of LA and MA could be related to secondary structural changes in zein such as increased α‐helix and random coils (mainly by MA) and spaced/modified intermolecular (only by LA) and intramolecular (mainly by MA) β‐sheets. Atomic force and scanning electron microscopy showed that LA and MA gave more homogenous and smoother films than TA. Films with LA showed the highest water vapour permeability followed by those of control, MA‐ and TA‐loaded films. Films with 3%–4% LA or MA formed clear zones on Listeria innocua and Klebsiella pneumonia, but only films with LA formed clear zones on Escherichia coli. All OA‐loaded films gave unclear zones on Staphylococcus aureus in disc‐diffusion tests, but this bacterium was inactivated rapidly in antimicrobial tests based on surface inoculation tests. LA is the best OA to develop flexible antimicrobial films from zein, an industrial by‐product that films could not have been utilized as a widespread packaging material due to their brittleness.
Dry and moist atmospheric circulation with uniform sea‐surface temperature
Authors: Suhas D. L. , Sukhatme Jai , Harnik Nili
Published: October 2021

The steady and transient response of “dynamically” dry and moist atmospheres to uniform sea‐surface temperature (SST) is studied using an aquaplanet general circulation model (GCM). Specifically, the latent heat () of water vapour is varied, so that for small , water substance is essentially a passive tracer from a dynamical point of view. Despite the lack of SST gradients, Hadley and Ferrel cells in the same direction as that on present‐day Earth are observed for relatively stronger moist coupling. Organized convergence by equatorial waves drives tropical overturning, and along with the equatorial deformation radius, the Hadley cell width increases with coupling strength. An abrupt switch to a much shallower tropical cell is noted when the system becomes completely passive. Moist static energy is transported equatorward in the tropics and a larger amount is directed poleward in the midlatitudes. As a whole, there is an almost invariant poleward transport of moist static energy for relatively strong coupling of water substance. Transient extratropical activity is seen in the form of intense warm‐core vortices for strong coupling, and these systems become weaker and smaller as decreases. The drift of these moist vortices results in the observed poleward energy transport in the midlatitudes. In the tropics, intraseasonal variability is dominant and systematically shifts to longer time periods with stronger coupling. In fact, large‐scale, low‐frequency Kelvin waves and MJO‐like modes disappear as water vapour becomes passive in nature. Further, the direction of tropical overturning reverses as decreases due to the off‐equatorial convergence imposed by tropical Rossby waves. Finally, extreme rainfall events associated with cyclonic storms vanish as water vapour becomes dynamically inactive, however, moderate precipitation events increase leading to higher total precipitation for weaker coupling of water substance. Tropospheric heating due to a saturation of the outgoing longwave radiation results in an increase in the stability of the atmosphere for strong coupling, and provides a plausible physical mechanism for interpreting the behaviour of precipitation.
Assimilation of shipborne precipitable water vapour by Global Navigation Satellite Systems for extreme precipitation events
Authors: Ikuta Yasutaka , Seko Hiromu , Shoji Yoshinori
Published: October 2021

Water vapour advection from the sea causes extremely heavy rainfall in Japan. Therefore, accurately describing the water vapour distribution over the sea in a forecast model's initial conditions should improve the prediction accuracy of heavy rainfall events. Thus, we assimilated the shipborne precipitable water vapour (PWV) observed by the Global Navigation Satellite Systems (GNSS) onboard ships to show its impact on a heavy rainfall event in July 2020. We obtained the GNSS observations during a continuous water vapour observation campaign conducted at sea, one of the few in the world. In this study, we applied the shipborne PWV, on the upwind side of the heavy rainfall, to the four‐dimensional variational data assimilation method and conducted assimilation–forecast cycles. Although the shipborne PWV is a point observation, it can be assimilated as observation data covering space and time because the ships conducting the GNSS observation sailed around Japan. In addition, in the assimilation–forecast cycle, the effect of assimilation spread widely over the forecast area. Although the ship motion affects the shipborne observations, we found that the impact on PWV assimilation is negligible for practical use. For the temporal thinning of the data assimilation slot for the shipborne PWV, an interval of 30 min is more effective than an interval of 1 hr. As a result of assimilating this shipborne PWV on the upwind side of the disastrous heavy rainfall of July 2020, the forecast accuracy of rainfall, especially rainfall amount, was improved. We also found that statistical improvements could be obtained from the water vapour profiles and wind velocity field in the lower atmosphere. We demonstrate that the assimilation of shipborne PWV observations can improve the prediction accuracy of heavy rainfall events.
Robotic‐arm assisted bicompartmental knee arthroplasty: Durable results up to 7‐year follow‐up
Authors: Gaudiani Michael A. , Samuel Linsen T. , Diana John N. , DeBattista Jennifer L. , Coon Thomas M. , Moore Ryan E. , Kamath Atul F.
Published: October 2021

Background

The purpose of our study was to investigate the mid‐term clinical and functional outcomes of robotic‐arm assisted Bicompartmental knee arthroplasty (BiKA).

Methods

This study reviewed a single‐centre prospectively maintained cohort of 50 patients (53 knees) who underwent BiKA (patellofemoral and medial compartment) at 5‐ and 7‐year postoperative follow‐up.

Results

Mean follow‐up was 7.1 ± 0.1 years (range, 7.0–7.3). Kaplan‐Meier survivorship rates at 5 and 7 years were 96% and 93%, respectively. At 7‐year follow‐up, patient satisfaction was 76% satisfied, 13% neutral, and 11% not satisfied. Mean KSS‐FS was 80.5 ± 15.8 (range, 30–100) with 82% of patients reporting walking more than 10 blocks, 89% reporting walking without support, and 100% able to go up and down stairs with 61% requiring use of a rail. Three patients (four knees) underwent revision surgery.

Conclusions

Our study reported excellent survivorship and functional outcomes, and good‐excellent satisfaction at mid‐term follow‐up for robotic‐arm assisted BiKA.
Marker‐less augmented reality based on monocular vision for falx meningioma localization
Authors: Yi Zongchao , Deng Zhen , Liu Yuqing , He Bingwei , Huang Shengyue , Hong Wenyao , Shi Jiafeng , Chen Zhongyi
Published: October 2021

Background

The existing augmented reality (AR) based neuronavigation systems typically require markers and additional tracking devices for model registration, which causes excessive preparatory steps.

Methods

For fast and accurate intraoperative navigation, this work proposes a marker‐less AR system that tracks the head features with the monocular camera. After the semi‐automatic initialization process, the feature points between the captured image and the pre‐loaded keyframes are matched for obtaining correspondences. The camera pose is estimated by solving the Perspective‐n‐Point problem.

Results

The localization error of AR visualization on scalp and falx meningioma is 0.417 ± 0.057 and 1.413 ± 0.282 mm, respectively. The maximum localization error is less than 2 mm. The AR system is robust to occlusions and changes in viewpoint and scale.

Conclusions

We demonstrate that the developed system can successfully display the augmented falx meningioma with enough accuracy and provide guidance for neurosurgeons to locate the tumour in brain.
The prevalence, predictors and outcomes of acute liver injury among patients with COVID‐19: A systematic review and meta‐analysis
Authors: Harapan Harapan , Fajar Jonny Karunia , Supriono Supriono , Soegiarto Gatot , Wulandari Laksmi , Seratin Fiha , Prayudi Nyoman Gede , Dewi Dara Puspita , Monica Elsina Maria Theresia , Atamou Lasarus , Wiranata Sinta , Aprianto Dhito Pemi , Friska Erlin , Sari Firdaus D. Fitria , Alaidin Makdum , Wardhani Firdha Aprillia , Husnah Milda , Hidayati Nurdina Wahyu , Hendriyanti Yeni , Wardani Kristia , Evatta Arde , Manugan Reizal Audi , Pradipto Wiryawan , Rahmawati Ade , Tamara Fredo , Mahendra Aditya Indra , Nainu Firzan , Santoso Budi , Irawan Primasatya Chandra Adi , Tjionganata Nindy , Budiman Hendarto Arif
Published: October 2021

The data on the predictors and prognosis of acute liver injury (ALI) among patients in coronavirus disease 2019 (COVID‐19) patients are limited. The aim of this study was to determine the prevalence, predictors and outcomes of ALI among patients with COVID‐19. A systematic review was conducted up to 10 June 2021. The relevant papers were searched from PubMed, Embase, Cochrane and Web of Science, and the data were analysed using a Z test. A total of 1331 papers were identified and 16 papers consisting of 1254 COVID‐19 with ALI and 4999 COVID‐19 without ALI were analysed. The cumulative prevalence of ALI among patients with COVID‐19 was 22.8%. Male and having low lymphocyte levels were more likely to be associated with ALI compared with female and having higher lymphocyte level, odds ratio (OR): 2.70; 95% confidence interval (CI): 2.03, 3.60 and mean difference (MD) −125; 95% CI: −207, −43, respectively. COVID‐19 patients with ALI had higher risk of developing severe COVID‐19 compared with those without ALI (OR: 3.61; 95% CI: 2.60, 5.02). Our findings may serve as the additional evaluation for the management of ALI in COVID‐19 patients.
Efficient model predictive control for Markovian jump systems with Lur'e nonlinear term: A dual‐mode control scheme
Authors: Zhang Bin , Song Yan
Published: October 2021

In this article, the efficient model predictive control (MPC) problem is investigated for a class of Markovian jump Lur'e systems (MJLSs) subject to parameter uncertainties and input constraints, where each subsystem is described by the combination of a linear part and a nonlinear Lur'e term. The main purpose of the addressed problem is to design a set of dual‐mode feedback controllers in the framework of efficient MPC to make a nice tradeoff among the online computation burden, the initial feasible region, and the control performance. To this aim, the following two tasks need to be fulfilled: 1) for the terminal constraint set, the corresponding fixed feedback gain that is composed of a linear part and a nonlinear part is designed with aid of the Lur'e‐type Lyapunov‐like function related to the modes of subsystems; and 2) a fairly large initial feasible region is obtained off‐line by adjusting the dimension of the control perturbation sequence. Then, an online optimization problem is put forward to design this perturbation sequence with the determined dimension to steer the system state into the terminal constraint set within the pre‐determined steps. Sufficient conditions are presented to guarantee the recursive feasibility of the proposed efficient MPC algorithm and the mean‐square stability of the underlying MJLSs. Finally, a simulation example with regards to the DC motor device system is provided to demonstrate the effectiveness of our proposed MPC strategy.
Optical Imaging in the Second Near Infrared Window for Vascular Bioimaging
Authors: Wang Zi'an , Wang Xuan , Wan Jian‐Bo , Xu Fujian , Zhao Nana , Chen Meiwan
Published: October 2021

Optical imaging in the second near infrared region (NIR‐II, 1000–1700 nm) provides higher resolution and deeper penetration depth for accurate and real‐time vascular anatomy, blood dynamics, and function information, effectively contributing to the early diagnosis and curative effect assessment of vascular anomalies. Currently, NIR‐II optical imaging demonstrates encouraging results including long‐term monitoring of vascular injury and regeneration, real‐time feedback of blood perfusion, tracking of lymphatic metastases, and imaging‐guided surgery. This review summarizes the latest progresses of NIR‐II optical imaging for angiography including fluorescence imaging, photoacoustic (PA) imaging, and optical coherence tomography (OCT). The development of current NIR‐II fluorescence, PA, and OCT probes (i.e., single‐walled carbon nanotubes, quantum dots, rare earth doped nanoparticles, noble metal‐based nanostructures, organic dye‐based probes, and semiconductor polymer nanoparticles), highlighting probe optimization regarding high brightness, longwave emission, and biocompatibility through chemical modification or nanotechnology, is first introduced. The application of NIR‐II probes in angiography based on the classification of peripheral vascular, cerebrovascular, tumor vessel, and cardiovascular, is then reviewed. Major challenges and opportunities in the NIR‐II optical imaging for vascular imaging are finally discussed.
Development of strut‐and‐tie models using topology optimization based on modified optimal criterion
Authors: Zhou Linyun , Wan Shui
Published: October 2021

Strut‐and‐tie models (STMs) have been widely used to design disturbed regions in structural concrete members. Recently, topology optimization methods, based on the principle of minimum strain energy directly and indirectly, have been adopted to generate STMs in reinforced concrete structures. Unfortunately, current topology optimization methods do not work in many typical disturbed regions. The optimization history of the rectangular anchorage zones shows that the principle of minimum strain energy is a necessary condition for STM, not a sufficient condition. Because, it fails to capture the load transfer path properly in structural concrete tensile regions. To address this issue, a modified optimality criterion is proposed to illustrate the load path in tensile regions. And the desired STM is the one with the maximum overall stiffness and minimum strain energy of the tie. The STM of the rectangular anchorage zones and dapped beams have been developed successfully, and verified by the current ACI 318‐08 code recommendations and experimental evidence.
Recent advances in electrocatalysts, mechanism, and cell architecture for direct formic acid fuel cells
Authors: Bhaskaran Rashmi , Abraham Bincy George , Chetty Raghuram
Published: October 2021

Direct formic acid fuel cells (DFAFCs) are potential candidates as power sources for various applications, especially in portable electronics and medical diagnostic devices. Though they have been the subject of considerable research, commercial prototypes of DFAFCs are rudimentary compared to other liquid fuel cells, particularly the widespread methanol‐based direct methanol fuel cells. Various strategies for rationally engineering the electrocatalysts for enhancing DFAFC performance have been explored in the last few years, such as alloying noble metals with earth‐abundant transition metals, designing specific morphological and structural arrangements, decorating the surface with corrosion‐tolerant cocatalysts, and providing better catalyst support for effective catalyst dispersion. An overall approach may be necessary and should include (i) understanding the underlying mechanism, which will guide the direction of catalyst engineering, (ii) employing morphological, compositional, and structural control of the electrocatalysts to improve catalyst utilization and enhance the intrinsic activity for real‐world applications, and (iii) integrating these in a proficiently designed cell architecture suitable for targeted applications. In this review, we focus on the recent advances in electrocatalysts, formic acid electrooxidation mechanisms, and DFAFC cell architectures, which could help address the opportunities and challenges of commercializing DFAFC as a prospective alternative power source for portable applications.

This article is categorized under:

Fuel Cells and Hydrogen > Science and Materials

Energy Research & Innovation > Science and Materials
The crucial role of model systems in understanding the complexity of cell signaling in human neurocristopathies
Authors: Cerrizuela Santiago , Vega‐Lopez Guillermo A. , Méndez‐Maldonado Karla , Velasco Iván , Aybar Manuel J.
Published: October 2021

Animal models are useful to study the molecular, cellular, and morphogenetic mechanisms underlying normal and pathological development. Cell‐based study models have emerged as an alternative approach to study many aspects of human embryonic development and disease. The neural crest (NC) is a transient, multipotent, and migratory embryonic cell population that generates a diverse group of cell types that arises during vertebrate development. The abnormal formation or development of the NC results in neurocristopathies (NCPs), which are characterized by a broad spectrum of functional and morphological alterations. The impaired molecular mechanisms that give rise to these multiphenotypic diseases are not entirely clear yet. This fact, added to the high incidence of these disorders in the newborn population, has led to the development of systematic approaches for their understanding. In this article, we have systematically reviewed the ways in which experimentation with different animal and cell model systems has improved our knowledge of NCPs, and how these advances might contribute to the development of better diagnostic and therapeutic tools for the treatment of these pathologies.

This article is categorized under:

Congenital Diseases > Genetics/Genomics/Epigenetics

Congenital Diseases > Stem Cells and Development

Congenital Diseases > Molecular and Cellular Physiology

Neurological Diseases > Genetics/Genomics/Epigenetics
Filtered asymmetric dark matter during the Peccei-Quinn phase transition
Authors: Ahmadvand M.
Published: October 2021

Abstract

In this paper, we propose a bubble filtering-out mechanism for an asymmetric dark matter scenario during the Peccei-Quinn (PQ) phase transition. Based on a QCD axion model, extended by extra chiral neutrinos, we show that the PQ phase transition can be first order in the parameter space of the model and regarding the PQ symmetry breaking scale, the mechanism can generate PeV-scale heavy neutrinos as a dark matter candidate. Considering a CP-violating source, during the phase transition, discriminating between the neutrino and antineutrino number density, we find the observed dark matter relic abundance, such that the setup can be applied to the first order phase transition with different strengths. We then calculate effective couplings of the QCD axion addressing the strong CP problem within the model. We also study the energy density spectrum of gravitational waves generated from the first order phase transition and show that the signals can be detected by future ground-based detectors such as Einstein Telescope. In particular, for a visible heavy axion case of the model, it is shown that gravitational waves can be probed by DECIGO and BBO interferometers. Furthermore, we discuss the dark matter-standard model neutrino annihilation process as a source for the creation of PeV-scale neutrinos.
Risking your NEC
Authors: Hoyos Carlos , Jokela Niko , Penín José Manuel , Ramallo Alfonso V. , Tarrío Javier
Published: October 2021

Abstract

Energy conditions, especially the null energy condition (NEC), are generically imposed on solutions to retain a physically sensible classical field theory and they also play an important role in the AdS/CFT duality. Using this duality, we study non-trivially deformed strongly coupled quantum field theories at large-Nc. The corresponding dual classical gravity constructions entail the use of radially non-monotonic D-brane distributions. The distributions are phenomenological in the sense that they do not correspond to the smearing of known probe D-brane embeddings. The gravity backgrounds are supersymmetric and hence perturbatively stable, and do not possess curvature singularities. There are no short-cuts through the bulk spacetime for signal propagation which assures that the field theory duals are causal. Nevertheless, some of our solutions violate the NEC in the gravity dual. In these cases the non-monotonicity of the D-brane distributions is reflected in the properties of the renormalization group flow: none of the c-functions proposed in the literature are monotonic. This further suggests that the non-monotonic behavior of the c-functions within previously known anisotropic backgrounds does not originate from the breaking of Lorentz invariance. We surmise that NEC violations induced by quantum corrections also need to be considered in holographic duals, but can be studied already at the classical level.
On deformations and extensions of Diff(S2)
Authors: Rojo Martín Enríquez , Procházka Tomáš , Sachs Ivo
Published: October 2021

Abstract

We investigate the algebra of vector fields on the sphere. First, we find that linear deformations of this algebra are obstructed under reasonable conditions. In particular, we show thaths[λ], the one-parameter deformation of the algebra of area-preserving vector fields, does not extend to the entire algebra. Next, we study some non-central extensions through the embedding of$$ \mathfrak{vect} $$vect(S2) into$$ \mathfrak{vect} $$vect(ℂ*). For the latter, we discuss a three parameter family of non-central extensions which contains the symmetry algebra of asymptotically flat and asymptotically Friedmann spacetimes at future null infinity, admitting a simple free field realization.
Monotonicity Properties for Ratios and Products of Modified Bessel Functions and Sharp Trigonometric Bounds
Authors: Segura J.
Published: October 2021

Let $$I_{\nu }(x)$$

I
ν

(
x
)

and $$K_{\nu }(x)$$

K
ν

(
x
)

be the first and second kind modified Bessel functions. It is shown that the nullclines of the Riccati equation satisfied by $$x^{\alpha } \Phi _{i,\nu }(x)$$

x
α

Φ

i
,
ν

(
x
)

, $$i=1,2$$

i
=
1
,
2

, with $$\Phi _{1,\nu }=I_{\nu -1}(x)/I_{\nu }(x)$$

Φ

1
,
ν

=

I

ν
-
1

(
x
)

/

I
ν

(
x
)

and $$\Phi _{2,\nu }(x)=-K_{\nu -1}(x)/K_{\nu }(x)$$

Φ

2
,
ν

(
x
)

=
-

K

ν
-
1

(
x
)

/

K
ν

(
x
)

, are bounds for $$x^{\alpha } \Phi _{i,\nu }(x)$$

x
α

Φ

i
,
ν

(
x
)

, which are solutions with unique monotonicity properties; these bounds hold at least for $$\pm \alpha \notin (0,1)$$

±
α
∉
(
0
,
1
)

and $$\nu \ge 1/2$$

ν
≥
1
/
2

. Properties for the product $$P_{\nu }(x)=I_{\nu }(x)K_{\nu }(x)$$

P
ν

(
x
)

=

I
ν

(
x
)

K
ν

(
x
)

can be obtained as a consequence; for instance, it is shown that $$P_{\nu }(x)$$

P
ν

(
x
)

is decreasing if $$\nu \ge -1$$

ν
≥
-
1

(extending the known range of this result) and that $$xP_{\nu }(x)$$

x

P
ν

(
x
)

is increasing for $$\nu \ge 1/2$$

ν
≥
1
/
2

. We also show that the double ratios $$W_{i,\nu }(x)=\Phi _{i,\nu +1}(x)/\Phi _{i,\nu }(x)$$

W

i
,
ν

(
x
)

=

Φ

i
,
ν
+
1

(
x
)

/

Φ

i
,
ν

(
x
)

are monotonic and that these monotonicity properties are exclusive of the first and second kind modified Bessel functions. Sharp trigonometric bounds can be extracted from the monotonicity of the double ratios. The trigonometric bounds for the ratios and the product are very accurate as $$x\rightarrow 0^+$$

x
→

0
+

, $$x\rightarrow +\infty $$

x
→
+
∞

and $$\nu \rightarrow +\infty $$

ν
→
+
∞

in the sense that the first two terms in the power series expansions in these limits are exact.
A monitoring framework based on exergetic analysis for sustainability assessment of direct laser metal deposition process
Authors: Selicati Valeria , Mazzarisi Marco , Lovecchio Francesco Saverio , Guerra Maria Grazia , Campanelli Sabina Luisa , Dassisti Michele
Published: October 2021

With the constant increase of energy costs and environmental impacts, improving the process efficiency is considered a priority issue for the manufacturing field. A wide knowledge about materials, energy, machinery, and auxiliary equipment is required in order to optimize the overall performance of manufacturing processes. Sustainability needs to be assessed in order to find an optimal compromise between technical quality of products and environmental compatibility of processes. In this new Industry 4.0 era, innovative manufacturing technologies, as the additive manufacturing, are taking a predominant role. The aim of this work is to give an insight into how thermodynamic laws contribute at the same time to improve energy efficiency of manufacturing resources and to provide a methodological support to move towards a smart and sustainable additive process. In this context, a fundamental step is the proper design of a sensing and real-time monitoring framework of an additive manufacturing process. This framework should be based on an accurate modelling of the physical phenomena and technological aspects of the considered process, taking into account all the sustainability requirements. To this end, a thermodynamic model for the direct laser metal deposition (DLMD) process was proposed as a test case. Finally, an exergetic analysis was conducted on a prototype DLMD system to validate the effectiveness of an ad-hoc monitoring system and highlight the limitations of this process. What emerged is that the proposed framework provided significant advantages, since it represents a valuable approach for finding suitable process management strategies to identify sustainable solutions for innovative manufacturing procedures.
Energy landscapes of perfect and defective solids: from structure prediction to ion conduction
Authors: Allan Neil L. , Conejeros Sergio , Hart Judy N. , Mohn Chris E.
Published: October 2021

The energy landscape concept is increasingly valuable in understanding and unifying the structural, thermodynamic and dynamic properties of inorganic solids. We present a range of examples which include (i) structure prediction of new bulk phases including carbon nitrides, phosphorus carbides, LiMgF3 and low-density, ultra-flexible polymorphs of B2O3, (ii) prediction of graphene and related forms of ZnO, ZnS and other compounds which crystallise in the bulk with the wurtzite structure, (iii) solid solutions, (iv) understanding grossly non-stoichiometric oxides including the superionic phases of δ-Bi2O3 and BIMEVOX and the consequences for the mechanisms of ion transport in these fast ion conductors. In general, examination of the energy landscapes of disordered materials highlights the importance of local structural environments, rather than sole consideration of the average structure.
Identification and quantification of immune infiltration landscape on therapy and prognosis in left- and right-sided colon cancer
Authors: Guo Jun-Nan , Chen Du , Deng Shen-Hui , Huang Jia-Rong , Song Jin-Xuan , Li Xiang-Yu , Cui Bin-Bin , Liu Yan-Long
Published: October 2021

Background

The left-sided and right-sided colon cancer (LCCs and RCCs, respectively) have unique molecular features and clinical heterogeneity. This study aimed to identify the characteristics of immune cell infiltration (ICI) subtypes for evaluating prognosis and therapeutic benefits.

Methods

The independent gene datasets, corresponding somatic mutation and clinical information were collected from The Cancer Genome Atlas and Gene Expression Omnibus. The ICI contents were evaluated by “ESTIMATE” and “CIBERSORT.” We performed two computational algorithms to identify the ICI landscape related to prognosis and found the unique infiltration characteristics. Next, principal component analysis was conducted to construct ICI score based on three ICI patterns. We analyzed the correlation between ICI score and tumor mutation burden (TMB), and stratified patients into prognostic-related high- and low- ICI score groups (HSG and LSG, respectively). The role of ICI scores in the prediction of therapeutic benefits was investigated by "pRRophetic" and verified by Immunophenoscores (IPS) (TCIA database) and an independent immunotherapy cohort (IMvigor210). The key genes were preliminary screened by weighted gene co-expression network analysis based on ICI scores. And they were further identified at various levels, including single cell, protein and immunotherapy response. The predictive ability of ICI score for prognosis was also verified in IMvigor210 cohort.

Results

The ICI features with a better prognosis were marked by high plasma cells, dendritic cells and mast cells, low memory CD4+ T cells, M0 macrophages, M1 macrophages, as well as M2 macrophages. A high ICI score was characterized by an increased TMB and genomic instability related signaling pathways. The prognosis, sensitivities of targeted inhibitors and immunotherapy, IPS and expression of immune checkpoints were significantly different in HSG and LSG. The genes identified by ICI scores and various levels included CA2 and TSPAN1.

Conclusion

The identification of ICI subtypes and ICI scores will help gain insights into the heterogeneity in LCC and RCC, and identify patients probably benefiting from treatments. ICI scores and the key genes could serve as an effective biomarker to predict prognosis and the sensitivity of immunotherapy.
Molecular characteristics of Bombus (Alpinobombus) polaris from North Greenland with comments on its general biology and phylogeography
Authors: Namin Saeed Mohamadzade , Park Tae-Yoon , Jung Chuleui , Meyer-Rochow Victor Benno
Published: October 2021

The bumble bee Bombus polaris (Curtis 1835) is known from the northernmost region of Greenland. But how it can survive there, where in terms of geographic origin it came from, and which species in addition to B. pyrrhopygus (Friese 1902) genetically it is most closely related to are insufficiently answered questions that have motivated us to carry out this study. On the basis of a molecular analysis of the cytochrome oxidase I gene of a B. (Alpinobombus) polaris from North Greenland (82° 48′ N; 42° 14′ W), we conclude that the female specimen we analysed was most closely related to the Canadian populations of B. polaris. Geographic proximity, occurrence of B. polaris on Ellesmere Island and wind direction are likely factors that have aided B. polaris to establish itself in northern and eastern Greenland. The presence of five haplotypes in the studied sequences from Greenland indicates a moderately high level of genetic diversity of B. polaris in Greenland, reflecting the successful adaptation of B. polaris populations. In the broader context of entomological life in the high Arctic, our results on B. polaris allow us to conclude that the survival of pollinating species in the high Arctic under the changing climate scenario depends not only on the weather but also on an individual’s opportunity to continue to locate suitable food sources, i.e. pollen and nectar in the case of B. polaris. This aspect, briefly touched upon in this study, is of relevance not just to B. polaris, but the Arctic entomofauna generally.
Development and validation of a preoperative CT-based radiomic nomogram to predict pathology invasiveness in patients with a solitary pulmonary nodule: a machine learning approach, multicenter, diagnostic study
Authors: Huang Luyu , Lin Weihuan , Xie Daipeng , Yu Yunfang , Cao Hanbo , Liao Guoqing , Wu Shaowei , Yao Lintong , Wang Zhaoyu , Wang Mei , Wang Siyun , Wang Guangyi , Zhang Dongkun , Yao Su , He Zifan , Cho William Chi-Shing , Chen Duo , Zhang Zhengjie , Li Wanshan , Qiao Guibin , Chan Lawrence Wing-Chi , Zhou Haiyu
Published: October 2021

Objectives

To develop and validate a preoperative CT-based nomogram combined with radiomic and clinical–radiological signatures to distinguish preinvasive lesions from pulmonary invasive lesions.

Methods

This was a retrospective, diagnostic study conducted from August 1, 2018, to May 1, 2020, at three centers. Patients with a solitary pulmonary nodule were enrolled in the GDPH center and were divided into two groups (7:3) randomly: development (n = 149) and internal validation (n = 54). The SYSMH center and the ZSLC Center formed an external validation cohort of 170 patients. The least absolute shrinkage and selection operator (LASSO) algorithm and logistic regression analysis were used to feature signatures and transform them into models.

Results

The study comprised 373 individuals from three independent centers (female: 225/373, 60.3%; median [IQR] age, 57.0 [48.0–65.0] years). The AUCs for the combined radiomic signature selected from the nodular area and the perinodular area were 0.93, 0.91, and 0.90 in the three cohorts. The nomogram combining the clinical and combined radiomic signatures could accurately predict interstitial invasion in patients with a solitary pulmonary nodule (AUC, 0.94, 0.90, 0.92) in the three cohorts, respectively. The radiomic nomogram outperformed any clinical or radiomic signature in terms of clinical predictive abilities, according to a decision curve analysis and the Akaike information criteria.

Conclusions

This study demonstrated that a nomogram constructed by identified clinical–radiological signatures and combined radiomic signatures has the potential to precisely predict pathology invasiveness.

Key Points

• The radiomic signature from the perinodular area has the potential to predict pathology invasiveness of the solitary pulmonary nodule.

• The new radiomic nomogram was useful in clinical decision-making associated with personalized surgical intervention and therapeutic regimen selection in patients with early-stage non-small-cell lung cancer.
Unilateral axillary adenopathy induced by COVID-19 vaccine: US follow-up evaluation
Authors: Igual-Rouilleault Alba Cristina , Soriano Ignacio , Quan Paola Leonor , Fernández-Montero Alejandro , Elizalde Arlette , Pina Luis
Published: October 2021

Objectives

This study was conducted in order to investigate COVID-19 vaccine influence on unilateral axillary lymph nodes, comparing nodal basal features with their characteristics after the first and second vaccination dose.

Methods

Ninety-one volunteer employees from our center who participated in the BNT162b2 (Pfizer-BioNTech) vaccination campaign were prospectively recruited. A total of three axillary ultrasound evaluations of the ipsilateral vaccinated arm were performed: before vaccination, the week after the first dose and the week after the second dose. The following findings were recorded: the total number of visible nodes, the maximum measurements of the diameter and cortex, Bedi’s classification, and color Doppler evaluation. The collected data were compared using paired-sample Student’s t-test for quantitative continuous variables and Wilcoxon rank-sum test for ordinal variables. Additional analyses were performed after classifying patients according to the previous history of COVID-19 disease. Differences among both groups were evaluated with the Mann–Whitney U test. Variables with a p value < 0.05 were considered statistically significant.

Results

Comparative analyses between the three US examinations showed a statistically significant augmentation of total visible nodes, maximum diameter, cortical thickness, grade of Bedi’s classification, and Doppler signal (p < 0.001). Analyses between patients with and without previous COVID-19 infection showed a higher lymph node response in naïve patients compared to those who were previously infected.

Conclusions

According to our results, both doses of COVID-19 vaccine induced an increase of all axillary lymph node parameters with statistically significant differences, especially in coronavirus-naïve patients.

Key Points

• Pfizer COVID-19 vaccine induces a high incidence of ipsilateral axillary lymphadenopathy.

• US scan identified an increase of all lymph nodes parameters, especially in coronavirus-naïve patients.
Superhydrophobic drag reduction in turbulent flows: a critical review
Authors: Park Hyungmin , Choi Chang-Hwan , Kim Chang-Jin
Published: October 2021

Superhydrophobic (SHPo) surfaces have been investigated vigorously since around 2000 due in large part to their unique potential for hydrodynamic frictional drag reduction without any energy or material input. The mechanisms and key factors affecting SHPo drag reduction have become relatively well understood for laminar flows by around 2010, as has been reviewed before [Lee et al. Exp Fluids 57:176 (2016)], but the progress for turbulent flows has been rather tortuous. While improved flow tests made positive SHPo drag reduction in fully turbulent flows more regular since around 2010, such a success in a natural, open water environment was reported only in 2020 [Xu et al. Phys Rev Appl 13:034056 (2020b)]. In this article, we review studies from the literature about turbulent flows over SHPo surfaces, with a focus on experimental studies. We summarize the key knowledge obtained, including the drag-reduction mechanism in the turbulent regime, the effect of the surface roughness morphology, and the fate and role of the plastron. This review is aimed to help guide the design and application of SHPo surfaces for drag reduction in the large-scale turbulent flows of field conditions.

Graphic abstract