bluuebunny/crossref_metadata_2025 huggingface dataset:
Dynamics of pearling instability in polymersomes: The role of shear membrane viscosity and spontaneous curvature
Authors: Lyu J. , Xie K. , Chachanidze R. , Kahli A. , Boëdec G. , Leonetti M.
Published: December 2021

The stability of copolymer tethers is investigated theoretically. Self-assembly of diblock or triblock copolymers can lead to tubular polymersomes, which are known experimentally to undergo shape instability under thermal, chemical, and tension stresses. It leads to a periodic modulation of the radius, which evolves to assembly line pearls connected by tiny tethers. We study the contributions of shear surface viscosity and spontaneous curvature and their interplay to understand the pearling instability. The performed linear analysis of stability of this cylinder-to-pearls transition shows that such systems are unstable if the membrane tension is larger than a finite critical value contrary to the Rayleigh–Plateau instability, an already known result, or if the spontaneous curvature is in a specific range, which depends on membrane tension. For the case of spontaneous curvature-induced shape instability, two dynamical modes are identified. The first one is analog to the tension-induced instability with a marginal mode. Its wavenumber associated with the most unstable mode decreases continuously to zero as membrane viscosity increases. The second one has a finite range of unstable wavenumbers. The wavenumber of the most unstable mode tends to be constant as membrane viscosity increases. In this mode, its growth rate becomes independent of the bulk viscosity in the limit of high membrane viscosity and behaves as a pure viscous surface.
Data-driven splashing threshold model for drop impact on dry smooth surfaces
Authors: Pierzyna Maximilian , Burzynski David A. , Bansmer Stephan E. , Semaan Richard
Published: December 2021

We propose a data-driven threshold model to redefine the boundary between deposition and splashing for drop impact on dry smooth surfaces. The starting point is the collection and digitization of multiple experimental sources with varying impact conditions. The model is based on the theory of Riboux and Gordillo [Riboux and Gordillo, “Experiments of drops impacting a smooth solid surface: A model of the critical impact speed for drop splashing,” Phys. Rev. Lett. 113, 024507 (2014)] and is obtained by an uncertainty quantification analysis coupled with machine learning. The uncertainty quantification analysis elucidates the relevance of the impact condition uncertainties when estimating the splashing parameter. The proposed threshold model is trained using a support vector machine algorithm variant that includes uncertainty as a hyperparameter. This threshold model is generalized by complexity reduction and is eightfold cross-validated on the reference data. The results reveal a dependency of the splashing threshold on the impact velocity, the liquid viscosity, the surface tension, and the gas density. Detailed quantification of the prediction performance and a comparison with state-of-the-art models show that the proposed threshold model is the most accurate model to describe the boundaries between deposition and splashing for a wide range of impact conditions. The simplicity and accuracy of this model make it an alternative to existing approaches.
Multi-fidelity convolutional neural network surrogate model for aerodynamic optimization based on transfer learning
Authors: Liao Peng , Song Wei , Du Peng , Zhao Hang
Published: December 2021

In aerodynamic shape optimization, a high-fidelity (HF) simulation is generally more accurate but more time-consuming than a low-fidelity (LF) simulation. To take advantage of both HF and LF simulations, a multi-fidelity convolutional neural network (CNN) surrogate model with transfer learning (MFCNN-TL) is proposed, which integrates different fidelity information through fine-tuning and adaptively learns their nonlinear mapping. The proposed surrogate model provides a new optimization framework, which maps the relation between shape parameters and aerodynamic performance. In the optimization framework, the HF model with a fine grid and the LF model with a coarse grid is used, respectively. In each optimization iteration, a multi-fidelity infilling strategy is adopted, and HF samples and LF samples are added to update the surrogate model. Finally, it is applied to the aerodynamic shape optimization of NACA0012 airfoil and RAE2822 airfoil. The optimization results show that the proposed MFCNN-TL surrogate model can significantly reduce the calculation cost and improve the optimization efficiency compared with the single-fidelity surrogate model.
Drag reduction of circular cylinder using linear and sawtooth plasma actuators
Authors: Wang Longjun , Alam Md. Mahbub , Zhou Yu
Published: December 2021

The flow around a single circular cylinder modified by the Dielectric Barrier Discharge (DBD) plasma actuator is investigated experimentally at a Reynolds number Re = 5.25 × 103. The main purpose of the present study is to establish a comprehensive understanding of the effects of linear and sawtooth DBD plasma actuators (under steady and unsteady actuation modes, with different applied voltage Va, normalized modulation frequency F+, and duty cycle DC) on the time-averaged drag coefficient CD and flow characteristics of the cylinder. Extensive measurements are performed in the near wake of the cylinder using a load cell, hotwire anemometer, flow visualization, and particle image velocimetry techniques. The maximum drag reductions are 58% and 22.8% under the steady and unsteady actuation modes of the linear actuators, respectively, when a voltage of Va = 11 kV is applied. On the other hand, the maximum drag reductions achieved by the steady and unsteady actuation modes of the sawtooth actuators are 51.8% and 53.0%, respectively. The corresponding power efficiencies are 1.6%, 0.9%, 1.4%, and 2.1%, respectively. A detailed examination of the near wake dynamics unveils that the mechanisms behind the substantial drag reductions are quite different for the two different actuators, which account for the difference in drag reduction and efficiency.
Utilizing reversible solid–liquid phase transition to tune phononic bandgaps
Authors: Ge Xianqiang , Xiang Hongrong , Liu Ying , Shen Jing , Li Yujia , Li Yangbo
Published: December 2021

Phononic crystals (PCs) are periodic synthetic materials that can manipulate the propagation of elastic waves and acoustic waves. However, for traditional phononic crystals, once the structure is identified, only a certain bandgap frequency can exist. Here, a supersaturated sodium acetate solution (SSAS) is introduced to realize a reversible liquid–solid phase transition by heating/cooling, which is utilized to tune the low-frequency bandgaps of elastic waves. Based on local resonance, we designed a one-dimensional (1D) PC, which consists of a 1D assembly of a series of goblets filled with the SSAS and heater pasted on the wall of the goblet. Low-amplitude transmission testing was conducted in both the liquid and solid states of the SSAS. An analytical model was proposed to calculate the first bandgap of the PC and to verify the testing results. In addition, numerical simulations were conducted to explore more bandgap zones. The results indicate that the phase transition induces tunable bandgaps of elastic waves. The underlying mechanism is that the phase transition leads to a unit cell stiffness and local heterogeneity. The bandgap from the solid to the liquid state is broadened by 20%. The findings reported here provide a new routine for designing architected metamaterial systems with broad and wide bandgaps for a wide range of potential applications in seismic, vibration, and acoustic wave control and guiding.
Trophic ecology of Humboldt squid (
Authors: Hu Guan Yu , Li Jian Hua , Liu Bi Lin , Liu Na , Chen Xin Jun
Published: December 2021

The sclerotised beaks of cephalopods have emerged as useful material to track their habitat and trophic ecology by using stable isotope analysis, because beaks grow continuously throughout their life without replacement. Here, stable isotopes of δ13C and δ15N in five continuous sections along the crest were measured to investigate the potential ontogenetic habitat shift and foraging-ecology change of Dosidicus gigas from the oceanic waters off Ecuador. In total, 90 sections from 18 upper beaks were examined with δ13C values of −18.99 to −17.49‰ and δ15N values of 0.69 to 7.09‰. Kruskal–Wallis test showed that there were significant differences in both isotopes between sections. The result of generalised additive models showed a significant overall decrease in both δ13C and δ15N values across the beak crest. The corrected standard ellipse area (SEAc) of the beak sections was 0.48 to 0.93‰2, with no high overlap between the two sections, with values ranging from 0.00 to 0.57. High individual variation of δ15N values in most beak sections indicated that D. gigas in our study area appears to have a generalist food spectrum in most of its life history, except for the stage just before being captured.
A 6-year survey of plastic ingestion by aquatic birds in southern Portugal
Authors: Rao Silvia , Nicastro Katy R. , Casero María , McQuaid Christopher D. , Zardi Gerardo I.
Published: December 2021

Anthropogenic litter in the environment is pervasive globally. Of particular concern are plastics because of their ubiquity, longevity in the environment and lethal effects. Plastics affect organisms at most levels of biological organisation but, even in well studied animals like birds, we have limited insight into species-specific vulnerability or temporal trends of ingestion. We examined stomach contents of four aquatic bird species over more than 6 years in southern Portugal. Of the 462 individuals analysed, 22.7% had ingested anthropogenic litter, predominantly plastics, most of which were clear or white in colour. The white stork (Ciconia ciconia) exhibited the highest frequency of occurrence of anthropogenic litter (61.1%) and of plastics specifically (55.6%), whereas the yellow-legged gull (Larus michahellis) had the lowest (13.4% for both anthropogenic litter and plastics). Similar frequencies of occurrence were found for the northern gannet (Morus bassanus) (22 and 20.3%) and the lesser black-backed gull (Larus fuscus) (21.4 and 20.8%). The composition of the plastic ingested varied throughout the study period for each species, but with no clear temporal pattern. Our results revealed the ubiquity and frequency of occurrence of plastic ingestion as well as clear differences among species, providing a basis for long-term monitoring of litter ingestion.
Enhanced SCC resistance of 7056 aluminium alloy by Y and Si additions
Authors: Zhou Liang , Sheng Zhiyong , Liu Qiang , Xin Ligang , Chen Kanghua , Chen Songyi
Published: December 2021

The effect of Y and Si additions on the microstructure and stress corrosion cracking (SCC) of the high Zn-containing 7056 aluminium alloy has been investigated. The morphology and composition of dispersions were analysed by transmission electron microscope equipped with super-X energy disperse spectroscopy. The SCC resistance was measured by a double-cantilever beam experiment. Results indicated that the SCC resistance was significantly improved by the mixed Y and Si additions, which can mainly be attributed to the reduction in the recrystallisation fraction and the increase in the sub-grain boundaries fraction caused by the high coherent (Al,Si)3(Zr,Y) dispersions and another important reason was the formation of the Y–Si-containing oxide film with the higher compactness and electrochemical impedance.
CRISPR screens for lipid regulators reveal a role for ER-bound SNX13 in lysosomal cholesterol export
Authors: Lu Albert , Hsieh Frank , Sharma Bikal R. , Vaughn Sydney R. , Enrich Carlos , Pfeffer Suzanne R.
Published: December 2021

We report here two genome-wide CRISPR screens performed to identify genes that, when knocked out, alter levels of lysosomal cholesterol or bis(monoacylglycero)phosphate. In addition, these screens were also performed under conditions of NPC1 inhibition to identify modifiers of NPC1 function in lysosomal cholesterol export. The screens confirm tight coregulation of cholesterol and bis(monoacylglycero)phosphate in cells and reveal an unexpected role for the ER-localized SNX13 protein as a negative regulator of lysosomal cholesterol export and contributor to ER–lysosome membrane contact sites. In the absence of NPC1 function, SNX13 knockdown redistributes lysosomal cholesterol and is accompanied by triacylglycerol-rich lipid droplet accumulation and increased lysosomal bis(monoacylglycero)phosphate. These experiments provide unexpected insight into the regulation of lysosomal lipids and modification of these processes by novel gene products.
TCR signal strength defines distinct mechanisms of T cell dysfunction and cancer evasion
Authors: Shakiba Mojdeh , Zumbo Paul , Espinosa-Carrasco Gabriel , Menocal Laura , Dündar Friederike , Carson Sandra E. , Bruno Emmanuel M. , Sanchez-Rivera Francisco J. , Lowe Scott W. , Camara Steven , Koche Richard P. , Reuter Vincent P. , Socci Nicholas D. , Whitlock Benjamin , Tamzalit Fella , Huse Morgan , Hellmann Matthew D. , Wells Daniel K. , Defranoux Nadine A. , Betel Doron , Philip Mary , Schietinger Andrea
Published: December 2021

T cell receptor (TCR) signal strength is a key determinant of T cell responses. We developed a cancer mouse model in which tumor-specific CD8 T cells (TST cells) encounter tumor antigens with varying TCR signal strength. High-signal-strength interactions caused TST cells to up-regulate inhibitory receptors (IRs), lose effector function, and establish a dysfunction-associated molecular program. TST cells undergoing low-signal-strength interactions also up-regulated IRs, including PD1, but retained a cell-intrinsic functional state. Surprisingly, neither high- nor low-signal-strength interactions led to tumor control in vivo, revealing two distinct mechanisms by which PD1hi TST cells permit tumor escape; high signal strength drives dysfunction, while low signal strength results in functional inertness, where the signal strength is too low to mediate effective cancer cell killing by functional TST cells. CRISPR-Cas9–mediated fine-tuning of signal strength to an intermediate range improved anti-tumor activity in vivo. Our study defines the role of TCR signal strength in TST cell function, with important implications for T cell–based cancer immunotherapies.
Electrokinetic energy conversion through cylindrical microannulus with periodic heterogeneous wall potentials
Authors: Chu Xin , Jian Yongjun
Published: December 2021

In microfluidic electrokinetic flows, heterogeneous wall potentials are often required to fulfill some functions, such as increasing dispersion and mixing efficiency. In this paper, we study the pressure-driven electrokinetic flow through microannulus with heterogeneous wall potentials in circumferential direction. The streaming potential induced by the ions accumulating in downstream of the microannulus is considered and the electrokinetic energy conversion (EKEC) efficiency is further investigated. Interestingly, based on the method of Fourier expansion, the analytical solutions of fluid velocity, streaming potential and energy conversion efficiency are derived for arbitrary peripheral distribution of the small wall potential for the first time. Four specific patterned modes of the heterogeneous wall potential, i.e. constant, step, sinusoid with period 2π and sinusoid with period π/2 are represented. The distributions of the electric potential and the velocity for four different modes are depicted graphically. Furthermore, the variations of the streaming potential and the EKEC conversion efficiency with related parameters are also discussed. Results show that when these integral values from −π to π associated with the wall potentials are identical, the streaming potential and the EKEC efficiency corresponding to different modes are the same. Additionally, the amplitude of fluid velocity peripherally reduces with the increase of the wavenumber of wall potential distribution in θ-direction.
Highly sensitive voltammetric determination of NADH based on N-CQDs decorated SnO2/ionic liquid/carbon paste electrode
Authors: Moshirian-Farahi Sareh Sadat , Zamani Hassan Ali , Abedi Mohammad Reza
Published: December 2021

A highly sensitive and selective modified electrode was successfully developed for the monitoring of nicotinamide adenine dinucleotide (NADH) in the presence of folic acid. In this regard, a carbon paste electrode (CPE) was functionalized by the nitrogen-doped carbon quantum dots/tin oxide (N-CQDs/SnO2) nanocomposite and 1-butyl-2,3-dimethyl imidazolium hexafluorophosphate ([C4DMIM][PF6]) ionic liquid (IL). The structure and surface morphology of the nanocomposite were characterized by various methods, including field emission scanning electron microscopy, energy dispersive spectroscopy (EDS), high-resolution transmission electron microscopy (HR-TEM), and x-ray diffraction (XRD). The modified electrode displayed powerful and long-lasting electron mediating activity, with well-separated NADH and folic acid oxidation peaks. The sensing response of the developed [C4DMIM][PF6]/N-CQDs/SnO2/CPE platform was evaluated by determining NADH via the voltammetric technique under the optimized operating conditions. The current peaks of the square wave voltammograms of NADH and folic acid increased linearly with enhancing its concentrations within the ranges of 0.003–275μM NADH and 0.4–380μM folic acid. The detection limits for NADH and folic acid were obtained at 0.8 nM and 0.1μM, respectively. Interference species such as glucose, urea, tryptophan, glycine, methionine, and vitamin B12had no influence on the ability of the fabricated modified electrode to detect the target species. The low detection limit, high sensitivity, excellent selectivity, superior stability, and cost-effectiveness made it suitable for the quantification of NADH in the real biological samples with the recovery percent values in the range of 97.5%–103%.
Investigation of transport mechanisms induced by filament-coupling bridges-network in Bi-2212 wires
Authors: Angrisani Armenio A , Leveratto A , de Marzi G , Traverso A , Bernini C , Celentano G , Malagoli A
Published: December 2021

One of the features unique in Bi-2212/Ag wires is the network of bridges between the filaments formed by grains grown through the Ag matrix during the partial-melt heat treatment process. Although these interconnections favor a redistribution of the current among the filaments allowing high critical current density, they represent a strong electrical coupling between the filaments themselves. Such a coupling increases the AC losses, present also in the case of the charge and discharge of DC magnets, and principal applications of this kind of superconductor. In this work, through transport and magnetic measurements and their comparison, we study the behavior of these bridges as a function of applied magnetic field and temperature and the implications they have on the electrical coupling. The experiment has been performed on two multifilamentary wires prepared by Groove-Die-Groove Powder In Tube process starting from two commercial Bi-2212 precursor powders: Nexans and Engi-Mat. The reported results show that the effective length scale on which the filaments are coupled is dependent on the field and temperature, passing from the filaments-bundle diameter at low field and temperature to single filament diameter at high field and temperature. Although the two samples have different Jc values, such filaments coupling behavior is common to both. We believe that these findings are very useful in magnet design.
Temperature-field-angle dependent critical current estimation of commercial second generation high temperature superconducting conductor using double hidden layer Bayesian regularized neural network
Authors: Liu Quanyue , Kim Seokho
Published: December 2021

We estimated the critical current of the second generation (2G) high-temperature superconducting (HTS) conductor using neural network fitting methods. The critical current of 2G HTS conductors depends on magnetic field strength and angle as well as on temperature, Ic(T, B, θ). Moreover, the critical current values vary for 2G HTS conductors from different manufacturers. In this study, we addressed three challenging issues in critical current assessment by neural network fitting methods, namely 90° asymmetry, a wide range of temperature-field-angle dependence, and different manufacturer conductor differences. Prediction models for three commercial HTS conductors were trained and evaluated by convergence, accuracy, and robustness. The linear regression correlation coefficient R was approximately equal to 1 for the three models. The critical current estimation obtained from the proposed method was compared with the critical current estimation from the interpolation method at different fixed temperatures using a multi-width no-insulation magnet. The model computation speed was also discussed. The proposed model needed only 2.7 s to compute 10 million data sets. Therefore, the convergence, accuracy, reliability, and speed of the proposed method prove that it can be used in a wide range of industrial applications and academic fields.
Compact itinerant microwave photonics with superconducting high-kinetic inductance microstrips
Authors: Goldstein Samuel , Pardo Guy , Kirsh Naftali , Gaiser Niklas , Padurariu Ciprian , Kubala Björn , Ankerhold Joachim , Katz Nadav
Published: December 2021

Microwave photonics is a remarkably powerful system for quantum simulation and technologies, but its integration in superconducting circuits, superior in many aspects, is constrained by the long wavelengths and impedance mismatches in this platform. We introduce a solution to these difficulties via compact networks of high-kinetic inductance microstrip waveguides and coupling wires with strongly reduced phase velocities. We demonstrate broadband capabilities for superconducting microwave photonics in terms of routing, emulation and generalized linear and nonlinear networks.
Spatial phase retrieval of vortex beam using convolutional neural network
Authors: Ding Ge , Xiong Wenjie , Wang Peipei , Huang Zebin , He Yanliang , Liu Junmin , Li Ying , Fan Dianyuan , Chen Shuqing
Published: December 2021

Vortex beam (VB) possessing spatially helical phase–front has attracted widespread attention in free-space optical communication, etc. However, the spiral phase of VB is susceptible to atmospheric turbulence, and effective retrieval of the distorted conjugate phase is crucial for its practical applications. Herein, a convolutional neural network (CNN) approach to retrieve the phase distribution of VB is experimentally demonstrated. We adopt a spherical wave to interfere with VB for converting its phase information into intensity changes, and construct a CNN model with excellent image processing capabilities to directly extract phase–front features from the interferogram. Since the interference intensity is correlated with the phase–front, the CNN model can effectively reconstruct the wavefront of conjugate VB carrying different initial phases from a single interferogram. The results show that the CNN-based phase retrieval method has a loss of 0.1418 in the simulation and a loss of 0.2344 for the experimental data, and remains robust even in turbulence environments. This approach can improve the information acquisition capability for recovering the distorted wavefront and reducing the reliance on traditional inverse retrieval algorithms, which may provide a promising tool to retrieve the spatial phase distributions of VBs.
Effect of low temperature rolling on mechanical properties and corrosion resistance of CrCoNi medium entropy alloy
Authors: Chen Jinliang , Feng Zhongxue , Yi Jianhong , Yang Jun
Published: December 2021

For the casted CrCoNi medium entropy alloy melted by magnetic levitation, the deformation was carried out in 4 passes under the condition of liquid nitrogen temperature (−196 °C), the total reduction was 50%, The microstructure and properties were analyzed after liquid nitrogen low temperature rolled. The experimental data showed that the phase structure of the alloy was not changed under the low-temperature rolling. The grains, crushed and refined, were elongated along the rolling direction. With the increasing of passes and reduction, the tensile strength increased from 585 MPa to 1359 MPa, while the elongation decreased from 37.8% to 5.9%. work With the increasing of work hardening, the tensile strength of the CrCoNi medium entropy alloy gradually increased, while the plasticity dramatic decreased. At the same time, the corrosion resistance of the CrCoNi medium entropy alloy was improved by low temperature cold rolled. The corrosion resistance of as-cast and rolled CrCoNi was much better than 304 stainless steel.
Supersolidity enters second dimension
Authors: Wogan Tim
Published: December 2021

Atoms in a Bose–Einstein condensate (BEC) can exist in a mysterious “supersolid” state in two dimensions.
Solar polarization paradox resolved at last
Authors: Wogan Tim
Published: December 2021

Careful numerical modelling shows that the discrepancy between solar observations and atomic theory vanishes after complex, previously neglected interactions are considered.
‘Significant step’ towards break-even target
Authors: Banks Michael
Published: December 2021

Scientists at the Lawrence Livermore National Laboratory in California say they have come closer to realizing “ignition”, at which fusion reactions generate at least as much energy as its lasers put in.
Review planned for Fukushima waste-water release
Authors: Banks Michael
Published: December 2021

The International Atomic Energy Agency (IAEA) is to conduct a safety review of the planned discharge of millions of tonnes of treated waste water from the Fukushima nuclear reactor into the ocean.
Scientists with children suffer ‘parenting penalty’
Authors: Allen Michael
Published: December 2021

Academics with children become less productive and do work of lower impact as their childcare responsibilities increase, finds a worldwide survey.
A life in China
Authors: Xin Ling
Published: December 2021

Italian astrophysicist Roberto Soria talks to Ling Xin about the opportunities and challenges of living in China and how that changed when the pandemic hit.
Afghan scientists fear for the future
Authors: Boerkamp Martijn
Published: December 2021

Many Afghan scientists fear they are at risk of retaliation from the Taliban, who have said their values do not lie with scientific advancement.
The challenge of change
Authors: McKenzie James
Published: December 2021

James McKenzie believes the climate crisis offers opportunities to business – but warns that solutions will only be found with the help of governments and financial markets.
Why ‘net zero’ needs nuclear
Authors: Preston Henry , Thomas Saralyn
Published: December 2021

Henry Preston and Saralyn Thomas say that nuclear energy must be part of the conversation during the COP26 climate talks in Glasgow next month.
Towards proton arc therapy
Authors: Freeman Tami
Published: December 2021

Do we need proton arc therapy, and can we deliver it? At the recent European Society for Radiotherapy and Oncology (ESTRO) 2021 congress, Tami Freeman heard from researchers describing the latest developments with the technique and its potential to improve cancer treatments.
Frames of reference and objectivity
Authors: Adewumi Immanuel
Published: December 2021

Immanuel Adewumi reviews The Disordered Cosmos: a Journey into Dark Matter, Spacetime, and Dreams Deferred by Chanda Prescod-Weinstein.
Meddling to mend the planet
Authors: Dacey James
Published: December 2021

James Dacey reviews Under a White Sky: the Nature of the Future by Elizabeth Kolbert.
Climate realism
Authors: Dacey James
Published: December 2021

James Dacey reviews How to Avoid a Climate Disaster: the Solutions We Have and the Breakthroughs We Need by Bill Gates.
Climate in a nutshell
Authors: Hiscott Laura
Published: December 2021

Laura Hiscott reviews Small Gases, Big Effect: This is Climate Change by David Nelles and Christian Serrer.
Magic smartphone trees
Authors: Hiscott Laura
Published: December 2021

Laura Hiscott reviews Brave Green World: How Science Can Save Our Planet by Chris Forman and Claire Asher.
Green jobs for physics graduates
Authors: Hiscott Laura
Published: December 2021

With their mix of technical knowledge and problem-solving skills, physics graduates are ideally placed to tackle the world’s environmental challenges. Laura Hiscott speaks to a range of physicists who are doing their bit to build a greener, more sustainable future.
Neutrons put limit on ‘fifth force’
Authors: Cartlidge Edwin
Published: December 2021

Researchers have devised an improved search method for a potential fifth force of nature, through observations of neutron interactions in silicon.
Inkjet prints structural colours from a single transparent ink
Authors: Allen Michael
Published: December 2021

Scientists in China have developed a technique for printing structural colours using a commercial inkjet printer.
Observational test found for Planet Nine hypothesis
Authors: Gater Will
Published: December 2021

Computer simulations by astronomers in the US have presented a new clue in the hunt for a hypothesized planet hiding in the far reaches of the solar system.
UK announces five potential sites for prototype energy plant
Authors: Banks Michael
Published: December 2021

Five sites have been shortlisted as a potential home of the UK’s prototype fusion energy plant.
Research by women shared less than research by men
Authors: Allen Michael
Published: December 2021

Female academics are less successful than men at disseminating their research online according to an analysis of the activity of over half a million scientists.
Why workplace interactions boost women in science
Authors: Allen Michael
Published: December 2021

A survey of more than 1200 STEM professionals suggests that organizations should encourage positive male–female workplace relationships to help increase the number of women in science.
Learning from your mistakes
Authors: Duffy Caitlin
Published: December 2021

Caitlin Duffy says that physicists must recognize that failure is part and parcel of science.
Below the surface
Authors: Budden John , Allen John , Read Frank
Published: December 2021

A response to Philip G Judge’s feature article “The enduring mystery of the solar corona” in which he explores the question of why the solar corona is so much hotter than the surface of the Sun.
The Geiger counter and the chair
Authors: Merlin Roberto
Published: December 2021

An awkward question from an amateur science buff makes the author realise they do not fully understand what defines a quantum measuring device.
Physicists unveil secret of glacier table formation
Authors: Dumé Isabelle
Published: December 2021

Researchers in France have confirmed the conditions under which “glacier tables” – large rocks perched atop thin columns of ice – form within retreating glaciers.
Major physics labs join forces to tackle climate change
Authors: Banks Michael
Published: December 2021

Leading physics facilities including CERN, the European Space Agency, Fermilab and the Los Alamos National Laboratory plan to step up scientific collaboration on carbon-neutral energy and climate change.
Futile finance
Authors: Short Tim
Published: December 2021

A response to James McKenzie’s Transactions article “The challenge of change” in which he argues that financial markets can enable the transition to a green economy.
Audience participation
Authors: Giblin Stephen
Published: December 2021

A response to Philip Moriarty’s book review “Flights of fancy, feet on the ground” which discusses the notion that physics needs more bold “out-of-the-box” thinking, akin to that of experimental artists and musicians.
Technologies that changed us
Authors: Gardner Kate
Published: December 2021

Kate Gardner reviews The Alchemy of Us: How Humans and Matter by Ainissa Ramirez.
The shape of things
Authors: Banks Michael
Published: December 2021

Michael Banks reviews Shape: the Hidden Geometry of Information, Biology, Strategy, Democracy, and Everything Else by Jordan Ellenberg.
How to get ahead in quantum tech
Authors: Hiscott Laura
Published: December 2021

The quantum industry is blossoming and has lots of new and exciting jobs that physicists are well placed to fill. Laura Hiscott talks to experts who have studied the quantum-tech jobs market about what’s on offer and what skills you’ll need to forge a successful career in this area.
Flexible, scalable, and efficient thermoelectric touch detector based on PDMS and graphite flakes
Authors: Figueira Joana , Loureiro Joana , Vieira Eliana , Fortunato Elvira , Martins Rodrigo , Pereira Luís
Published: December 2021

This paper presents freestanding thermoelectric touch detectors consisting of graphite conductive flakes into a polydimethylsiloxane matrix. An optimal concentration of graphite flakes (45 wt%) lead to robust and homogeneous detectors that exhibited signal-noise ratio values up to 170 with rise and falling times below 1 s and 7 s, respectively. The detectors performance was stable over continuous operation and did not reveal significant degradation while bended under different curvature radii (45, 25 and 15 mm) and consecutive bending cycles. Moreover, the twist of the thermal gradient direction between the electrodes of the detector enables a Yes or No response which opens new usage possibilities. Therefore, this work provides an efficient way to develop robust, low-cost, and scalable thermal detectors with potential use in wearable technologies.
Explicit interval estimates for prime numbers
Authors: Cully-Hugill Michaela , Lee Ethan
Published: December 2021

Using a smoothing function and recent knowledge on the zeros of the Riemann zeta-function, we compute pairs of

(
Δ
,

x
0

)

(\Delta ,x_0)

such that for all

x
≥

x
0

x \geq x_0

there exists at least one prime in the interval

(
x
(
1
−

Δ

−
1

)
,
x
]

(x(1-\Delta ^{-1}),x]

.
Renorming AM-spaces
Authors: Oikhberg T. , Tursi M.
Published: December 2021

We prove that any separable AM-space

X
X

has an equivalent lattice norm for which no non-trivial surjective lattice isometries exist. Moreover, if

X
X

has no more than one atom, then this new norm may be an AM-norm. As our main tool, we introduce and investigate the class of so called regular AM-spaces, which “approximate” general AM-spaces.
An upper bound for the Menchov-Rademacher operator for right triangles
Authors: Vagharshakyan Armen
Published: December 2021

The Menchov-Rademacher inequality is an inequality in harmonic analysis that bounds the

L
2

L_2

norm of a certain maximal operator. It was first established in order to prove almost everywhere convergence of a one-parameter series of orthogonal functions. When two-parameter series of orthogonal functions is considered, the exact way the series is grouped becomes essential. We will consider grouping of a two-parameter series, generated by a sequence of right triangles with a vertex at the origin, who might be non-equilateral, and prove almost everywhere convergence when the eccentricity of those triangles is bounded. In order to carry out the proof, we will derive an analogue of the Menchov-Rademacher inequality for right triangles.
Logarithmic concavity of Schur and related polynomials
Authors: Huh June , Matherne Jacob , Mészáros Karola , St. Dizier Avery
Published: December 2021

We show that normalized Schur polynomials are strongly log-concave. As a consequence, we obtain Okounkov’s log-concavity conjecture for Littlewood–Richardson coefficients in the special case of Kostka numbers.
Counting the zeros of an elephant random walk
Authors: Bertoin Jean
Published: December 2021

We study how memory impacts passages at the origin for a so-called elephant random walk in the diffusive regime. We observe that the number of zeros always grows asymptotically like the square root of the time, despite the fact that, depending on the memory parameter, first return times to

0
0

may have a finite expectation or a fat tail with exponent less than

1

/

2

1/2

. We resolve this apparent paradox by recasting the questions in the framework of scaling limits for Markov chains and self-similar Markov processes.
Association of Metformin Use With Risk of Venous Thromboembolism in Adults With Type 2 Diabetes: A General-Population–Based Cohort Study
Authors: Sha Tingting , Zhang Yuqing , Li Changjun , Lei Guanghua , Wu Jing , Li Xiaoxiao , Yang Zidan , Zeng Chao , Wei Jie
Published: December 2021

Metformin is hypothesized to protect against the risk of venous thromboembolism (VTE); however, there is a paucity of data supporting this hypothesis. Among individuals aged 40–90 years with a diagnosis of type 2 diabetes in the Health Improvement Network database (2000–2019), we compared the risks of incident VTE, pulmonary embolism, and deep vein thrombosis among metformin initiators with those among sulfonylurea initiators. Individuals were followed from their first prescription refill to an incident VTE, drug discontinuation, switching or augmenting, plan disenrollment, or the end of the study, whichever occurred first. Hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated using the Cox model, adjusting for confounders using inverse probability of treatment weighting. Among 117,472 initiators of metformin and 13,835 initiators of sulfonylureas, 555 (1.3/1,000 person-years) and 75 (2.1/1,000 person-years) VTE cases occurred in each group, respectively. The multivariable-adjusted HR was 0.65 (95% CI: 0.51, 0.84). The corresponding risks for pulmonary embolism (adjusted HR = 0.71, 95% CI: 0.50, 1.01) and deep vein thrombosis (adjusted HR = 0.64, 95% CI: 0.48, 0.87) were also lower in metformin initiators than in sulfonylurea initiators. Our study provided empirical evidence to support a lower risk of VTE after initiation of metformin as compared with sulfonylureas among patients with type 2 diabetes.
MAINE: a web tool for multi-omics feature selection and rule-based data exploration
Authors: Gruca Aleksandra , Henzel Joanna , Kostorz Iwona , Stęclik Tomasz , Wróbel Łukasz , Sikora Marek
Published: December 2021

Patient multi-omics datasets are often characterized by a high dimensionality; however, usually only a small fraction of the features is informative, that is change in their value is directly related to the disease outcome or patient survival. In medical sciences, in addition to a robust feature selection procedure, the ability to discover human-readable patterns in the analyzed data is also desirable. To address this need, we created MAINE—Multi-omics Analysis and Exploration. The unique functionality of MAINE is the ability to discover multidimensional dependencies between the selected multi-omics features and event outcome prediction as well as patient survival probability. Learned patterns are visualized in the form of interpretable decision/survival trees and rules.

Availability and implementation

MAINE is freely available at maine.ibemag.pl as an online web application.

Supplementary information

Supplementary data are available at Bioinformatics online.
Methylation-reprogrammed CHRM3 results in vascular dysfunction in the human umbilical vein following IVF-ET
Authors: Shi Yajun , Liu Jingliu , Zhu Dan , Lu Likui , Zhang Mengshu , Li Weisheng , Zeng Hongtao , Yu Xi , Guo Jun , Zhang Yingying , Zhou Xiuwen , Gao Qinqin , Xia Fei , Chen Youguo , Li Min , Sun Miao
Published: December 2021

Assisted reproductive technology (ART) has been used globally among infertile couples. However, many epidemiological investigations have indicated that ART is associated with a range of long-term adverse health outcomes in offspring, including cardiovascular disease, obesity, and increased plasma lipid levels. Until now, direct evidence has been limited regarding the pathological changes in vascular function in fetuses with ART. In this study, human umbilical cords were collected from healthy normal pregnancies and in vitro fertilization and embryo transfer (IVF-ET) pregnancies. Vascular functional studies involving acetylcholine (ACh), antagonists of its specific receptors, and L-type calcium channel/PKC-MLC20 phosphorylation pathway specific inhibitors were conducted. Quantitative real-time PCR, Western blotting, and methylation analyses were performed on umbilical vein samples. We found that the umbilical vein constriction induced by ACh in the IVF-ET group was significantly attenuated compared with that in the healthy normal pregnancy group, which was not only associated with the hypermethylation of ACh muscarinic receptor subtype 3 (CHRM3) and decreased expression of CHRM3, PKCβ, and CaV1.2, but was also related to the reduced phosphorylation of MLC20. This study revealed that the hypermethylation of CHRM3, leading to a reduction in CHRM3 expression and downregulation of the CaV1.2/PKC-MLC20 phosphorylation pathway, was responsible for the decreased sensitivity to ACh observed in the umbilical vein under IVF-ET conditions. The hypermethylation of CHRM3 caused by IVF-ET might play an important role in altered vasoconstriction and impact cardiovascular systems in the long run.
Trimming the fat: is there a health economic case for the use of new lipid-lowering drugs in chronic kidney disease? A scoping review
Authors: Gallagher Alexandra , Agresta Blaise , Smyth Brendan , Jardine Meg , Ferro Charles , Morton Rachael L
Published: December 2021

Background

Individuals with chronic kidney disease (CKD) are at a very high risk for atherosclerotic cardiovascular disease (ASCVD). New lipid-lowering agents offer hope of improved outcomes where traditional agents have been less efficacious, yet the cost of these agents needs consideration in this population before their widespread application.

Objective

We sought to evaluate the cost-effectiveness of novel lipid-lowering therapies for a CKD population.

Methods

We searched four electronic databases, one government registry and the reference lists of included literature to identify cost-effectiveness analyses of novel lipid-lowering agents in CKD. Costs were converted to a single currency to allow cross-country comparisons. Completeness of reporting was analysed using the Consolidated Health Economic Evaluation Reporting Standards checklist. Results were synthesized in narrative form with graphical representation of cost-effectiveness ratios.

Results

Of the 1041 identified studies, 4 met the inclusion criteria. None were specific to a CKD-only population. All examined the impact of proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9is) in the secondary prevention of ASCVD. Incremental cost-effectiveness ratios of new agents compared with standard care were between €7288 and €112 530 per quality-adjusted life year gained. Cost-effectiveness was sensitive to the degree of cardiovascular risk of the underlying populations.

Conclusion

This review found PCSK9is were moderately cost-effective in populations with high cardiovascular risk. People with CKD were included as an undifferentiated subpopulation in the primary studies, but application of these findings to CKD-specific populations should be interpreted with caution. There is insufficient evidence for a health economic case to support novel lipid-lowering therapies for advanced CKD.
Comparison of antibody response to SARS-CoV-2 after two doses of inactivated virus and BNT162b2 mRNA vaccines in kidney transplant
Authors: Seija Mariana , Rammauro Florencia , Santiago José , Orihuela Natalia , Zulberti Catherine , Machado Danilo , Recalde Cecilia , Noboa Javier , Frantchez Victoria , Astesiano Rossana , Yandián Federico , Guerisoli Ana , Morra Álvaro , Cassinelli Daniela , Coelho Cecilia , de Aramburu Belén , González-Severgnini Paulina , Moreno Romina , Pippolo Aldana , López Gabriela , Lemos Mónica , Somariva Lorena , López Eliana , Fumero Soledad , Orihuela Carla , Rodríguez Rosalía , Acuña Gonzalo , Rabaza Victoria , Perg Nancy , Cordero Rossana , Reisfeld Cristina , Olivera Paula , Montero Paola , Nogueira Cecilia , Nalerio Catheryn , Orihuela Sergio , Curi Lilián , Burgstaller Ema , Noboa Oscar , Pritsch Otto , Nin Marcelo , Bianchi Sergio
Published: December 2021

Background

Antibody response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) after mRNA or adenoviral vector-based vaccines is weak in kidney transplant (KT) patients. However, few studies have focused on humoral response after inactivated virus-based vaccines in KT. Here, we compare antibody response following vaccination with inactivated virus (CoronaVac®) and BNT162b2 mRNA.

Methods

A national multicentre cross-sectional study was conducted. The study group was composed of patients from all KT centres in Uruguay, vaccinated between 1 and 31 May 2021 (CoronaVac®, n = 245 and BNT162b2, n = 39). The control group was constituted of 82 healthy individuals. Participants had no prior confirmed coronavirus disease 2019 (COVID-19) test. Blood samples were collected between 30 and 40 days after the second dose. Serum-specific immunoglobulin G (IgG) antibodies against the receptor-binding domain (RBD) of SARS-CoV-2 Spike protein were determined using the COVID-19 IgG QUANT ELISA Kit.

Results

Only 29% of KT recipients showed seroconversion (36.5% BNT162b2, 27.8% inactivated virus, P = 0.248) in comparison with 100% in healthy control with either vaccine. Antibody levels against RBD were higher with BNT162b mRNA than with inactivated virus [median (interquartile range) 173 (73–554) and 29 (11–70) binding antibody units (BAU)/mL, P < 0.034] in KT and 10 times lower than healthy control [inactivated virus: 308 (209–335) and BNT162b2: 2638 (2608–3808) BAU/mL, P < 0.034]. In multivariate analysis, variables associated with negative humoral response were age, triple immunosuppression, estimated glomerular filtration rate and time post-KT.

Conclusion

Seroconversion was low in KT patients after vaccination with both platforms. Antibody levels against SARS-CoV-2 were lower with inactivated virus than BNT162b mRNA. These findings support the need for strategies to improve immunogenicity in KT recipients after two doses of either vaccine.
Epidemiology and outcomes of pulmonary hypertension in the cardiac intensive care unit
Authors: Jentzer Jacob C , Wiley Brandon M , Reddy Yogesh N V , Barnett Christopher , Borlaug Barry A , Solomon Michael A
Published: December 2021

Aims

Pulmonary hypertension (PH) has been consistently associated with adverse outcomes in hospitalized patients. Limited epidemiologic data exist regarding PH in the cardiac intensive care unit (CICU) population. Here, we describe the prevalence, aetiology, and outcomes of PH in the CICU.

Methods and results

Cardiac intensive care unit patients admitted from 2007 to 2018 who had right ventricular systolic pressure (RVSP) measured via transthoracic echocardiography near CICU admission were included. PH was defined as RVSP >35 mmHg, and moderate-to-severe PH as RVSP ≥50 mmHg. Predictors of in-hospital mortality were determined using multivariable logistic regression. Among 5042 patients (mean age 69.4 ± 14.8 years; 41% females), PH was present in 3085 (61%). The majority (68%) of patients with PH had left heart failure, and 29% had lung disease. In-hospital mortality occurred in 8.3% and was more frequent in patients with PH [10.9% vs. 4.2%, adjusted odds ratio (OR) 1.40, 95% confidence interval (CI) 1.03–1.92, P = 0.03], particularly patients with moderate-to-severe PH (14.4% vs. 6.2%, adjusted OR 1.65, 95% CI 1.27–2.14, P < 0.001). In-hospital mortality increased incrementally as a function of higher RVSP (adjusted 1.18 per 10 mmHg increase, 95% CI 1.09–1.28, P < 0.001). Patients with higher RVSP or moderate-to-severe PH had increased in-hospital mortality across admission diagnoses (all P < 0.05).

Conclusions

Pulmonary hypertension is very common in the CICU population and appears to be independently associated with a higher risk of death during hospitalization, although the strength of this association varies according to the underlying admission diagnosis. These data highlight the importance of PH in patients with cardiac critical illness.