Density of Yang-Lee zeros for the Ising ferromagnet

The densities of Yang-Lee zeros for the Ising ferromagnet on the $L\times L$ square lattice are evaluated from the exact grand partition functions ($L=3\sim16$). The properties of the density of Yang-Lee zeros are discussed as a function of temperature $T$ and system size $L$. The three different classes of phase transitions for the Ising ferromagnet, first-order phase transition, second-order phase transition, and Yang-Lee edge singularity, are clearly distinguished by estimating the magnetic scaling exponent $y_h$ from the densities of zeros for finite-size systems. The divergence of the density of zeros at Yang-Lee edge in high temperatures (Yang-Lee edge singularity), which has been detected only by the series expansion until now for the square-lattice Ising ferromagnet, is obtained from the finite-size data. The identification of the orders of phase transitions in small systems is also discussed using the density of Yang-Lee zeros.Comment: to appear in Physical Review

Underwater adhesive using solid–liquid polymer mixes

Instantaneous adhesion between different materials is a requirement for several applications ranging from electronics to biomedicine. Approaches such as surface patterning, chemical cross-linking, surface modification, and chemical synthesis have been adopted to generate temporary adhesion between various materials and surfaces. Because of the lack of curing times, temporary adhesives are instantaneous, a useful property for specific applications that need quick bonding. However, to this day, temporary adhesives have been mainly demonstrated under dry conditions and do not work well in submerged or humid environments. Furthermore, most rely on chemical bonds resulting from strong interactions with the substrate such as acrylate based. This work demonstrates the synthesis of a universal amphibious adhesive solely by combining solid polytetrafluoroethylene (PTFE) and liquid polydimethylsiloxane (PDMS) polymers. While the dipole-dipole interactions are induced by a large electronegativity difference between fluorine atoms in PTFE and hydrogen atoms in PDMS, strong surface wetting allows the proposed adhesive to fully coat both substrates and PTFE particles, thereby maximizing the interfacial chemistry. The two-phase solid–liquid polymer system displays adhesive characteristics applicable both in air and water, and enables joining of a wide range of similar and dissimilar materials (glasses, metals, ceramics, papers, and biomaterials). The adhesive exhibits excellent mechanical properties for the joints between various surfaces as observed in lap shear testing, T-peel testing, and tensile testing. The proposed biocompatible adhesive can also be reused multiple times in different dry and wet environments. Additionally, we have developed a new reactive force field parameterization and used it in our molecular dynamics simulations to validate the adhesive nature of the mixed polymer system with different surfaces. This simple amphibious adhesive could meet the need for a universal glue that performs well with a number of materials for a wide range of conditions

Primordial Neutrinos, Cosmological Perturbations in Interacting Dark-Energy Model: CMB and LSS

We present cosmological perturbation theory in neutrinos probe interacting dark-energy models, and calculate cosmic microwave background anisotropies and matter power spectrum. In these models, the evolution of the mass of neutrinos is determined by the quintessence scalar field, which is responsible for the cosmic acceleration today. We consider several types of scalar field potentials and put constraints on the coupling parameter between neutrinos and dark energy. Assuming the flatness of the universe, the constraint we can derive from the current observation is $\sum m_{\nu} < 0.87 eV$ at the 95 % confidence level for the sum over three species of neutrinos. We also discuss on the stability issue of the our model and on the impact of the scattering term in Boltzmann equation from the mass-varying neutrinos.Comment: 26 pages Revtex, 11 figures, Add new contents and reference

Deformation behavior and strengthening effects of an eutectic AlCoCrFeNi2.1 high entropy alloy probed by in-situ synchrotron X-ray diffraction and post-mortem EBSD

Funding Information: JS, JGL, and JPO acknowledge Fundação para a Ciência e a Tecnologia (FCT - MCTES) for its financial support via the project UID/00667/2020 (UNIDEMI). JS acknowledges the China Scholarship Council for funding the Ph.D. grant (CSC NO. 201808320394). JGL acknowledges FCT – MCTES for funding the Ph.D. grant 2020.07350.BD. JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia, I.P. in the scope of the projects LA/P/0037/2020, UIDP/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication – i3N. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beamtime was allocated for proposal I-20210899 EC. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872from the EU Framework Programme for Research and Innovation HORIZON 2020. HSK acknowledges the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (NRF-2021R1A2C3006662, NRF-2022R1A5A1030054). Yeon Taek Choi was supported by the Basic Science Research Program “Fostering the Next Generation of Researcher” through the NRF funded by the Ministry of Education [grant number 2022R1A6A3A13073824]. The raw/processed data required to reproduce the above findings cannot be shared at this time as the data also forms part of an ongoing study. Funding Information: JS, JGL, and JPO acknowledge Fundação para a Ciência e a Tecnologia (FCT - MCTES) for its financial support via the project UID/00667/2020 (UNIDEMI). JS acknowledges the China Scholarship Council for funding the Ph.D. grant (CSC NO. 201808320394 ). JGL acknowledges FCT – MCTES for funding the Ph.D. grant 2020.07350.BD . JPO acknowledges funding by national funds from FCT - Fundação para a Ciência e a Tecnologia , I.P., in the scope of the projects LA/P/0037/2020 , UIDP/50025/2020 and UIDB/50025/2020 of the Associate Laboratory Institute of Nanostructures, Nanomodelling and Nanofabrication – i3N. The authors acknowledge DESY (Hamburg, Germany), a member of the Helmholtz Association HGF, for the provision of experimental facilities. Beamtime was allocated for proposal I-20210899 EC. The research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020 . HSK acknowledges the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) ( NRF-2021R1A2C3006662 , NRF-2022R1A5A1030054 ). Yeon Taek Choi was supported by the Basic Science Research Program “Fostering the Next Generation of Researcher” through the NRF funded by the Ministry of Education [grant number 2022R1A6A3A13073824 ]. Publisher Copyright: © 2023 The AuthorsIn this work, high energy synchrotron X-ray diffraction was used during tensile testing of an as-cast eutectic AlCoCrFeNi2.1 high entropy alloy. Aside, from determining for the first time the volume fractions of existing phases, we further detail their role on the alloy deformation behavior. The two major phases, a soft disordered FCC and a hard ordered B2 BCC, were observed to exhibit a stress partitioning effect which can be used to modulate the mechanical response of the material based on the relative volume fraction of each phase. Dislocation density analysis revealed that the soft FCC phase had a significantly higher dislocation density right after the onset of plastic deformation. This is attributed to the existence of strain gradients across the lamellar structure, where the hard B2 BCC prevents free deformation of the FCC phase. Nonetheless, despite the increase of the dislocation density in the soft FCC phase, calculations of the strengthening effects induced by generation of dislocations are more significant in the hard B2 BCC phases, as this phase is primarily responsible for the strength increase in the alloy. Besides, the evolutions in dislocation density of the soft FCC and hard B2 BCC phases during tensile deformation obtained from synchrotron X-ray diffraction data are consistent with the evolution of KAM determined by EBSD characterization. Also, lattice strain analysis across two principal directions (parallel and perpendicular to the loading axis) reveals that for these specific orientations there is a preferential deformation of the hard FCC planes which can be related to the deformation response of specific lattice planes at distinct orientations, as well as to the phase partitioning stress behavior.publishersversionpublishe

Antiphospholipid antibodies: Paradigm in transition

OBJECTIVES: This is a critical review of anti-phospholipid antibodies (aPL). Most prior reviews focus on the aPL syndrome (APS), a thrombotic condition often marked by neurological disturbance. We bring to attention recent evidence that aPL may be equally relevant to non-thrombotic autoimmune conditions, notably, multiple sclerosis and ITP. ORGANIZATION: After a brief history, the recent proliferation of aPL target antigens is reviewed. The implication is that many more exist. Theories of aPL in thrombosis are then reviewed, concluding that all have merit but that aPL may have more diverse pathological consequences than now recognized. Next, conflicting results are explained by methodological differences. The lupus anticoagulant (LA) is then discussed. LA is the best predictor of thrombosis, but why this is true is not settled. Finally, aPL in non-thrombotic disorders is reviewed. CONCLUSION: The current paradigm of aPL holds that they are important in thrombosis, but they may have much wider clinical significance, possibly of special interest in neurology

Spatial and Temporal Variability of the 365‐nm Albedo of Venus Observed by the Camera on Board Venus Express

We mapped the distribution of the 365‐nm albedo of the Venus atmosphere over the years 2006–2014, using images acquired by the Venus Monitoring Camera (VMC) on board Venus Express. We selected all images with a global view of Venus to investigate how the albedo depends on longitude. Bertaux et al. (2016, https://doi.org/10.1002/2015JE004958) reported a peak in albedo around 100° longitude and speculated on an association with the Aphrodite Terra mountains. We show that this peak is most likely an artifact, resulting from long‐term albedo variations coupled with considerable temporal gaps in data sampling over longitude. We also used a subset of images to investigate how the albedo depends on local time, selecting only south pole viewing images of the dayside (local times 7–17 hr). Akatsuki observed mountain‐induced waves in the late afternoon at 283 nm and 10 μm (Fukuhara et al., 2017, https://doi.org/10.1038/ngeo2873). We expect that the presence of such waves may introduce 365‐nm albedo variations with a periodicity of one solar day (116.75 Earth days). We searched for such a periodicity peak at 15:30–16:00 local time and low latitudes but did not find it. In conclusion, we find that temporal albedo variations, both short and long term, dominate any systematic variations with longitude and local time. The nature of VMC dayside observations limits regular data sampling along longitudes, so longitudinal variations, if they exist, are difficult to extract. We conclude that any influence by the Venus surface on 365‐nm albedo is negligible within this data set.TU Berlin, Open-Access-Mittel – 2020EC/H2020/841432/EU/Cloud Worlds: from Venus to Exoplanet/CLOUDWORLD

Radioluminescent nanoparticles for radiation-controlled release of drugs

The present work demonstrates a novel concept for intratumoral chemo-radio combination therapy for locally advanced solid tumors. For some locally advanced tumors, chemoradiation is currently standard of care. This combination treatment can cause acute and long term toxicity that can limit its use in older patients or those with multiple medical comorbidities. Intratumoral chemotherapy has the potential to address the problem of systemic toxicity that conventional chemotherapy suffers, and may, in our view, be a better strategy for treating certain locally advanced tumors. The present study proposes how intratumoral chemoradiation can be best implemented. The enabling concept is the use of a new chemotherapeutic formulation in which chemotherapy drugs (e.g., paclitaxel (PTX)) are co-encapsulated with radioluminecsnt nanoparticles (e.g., CaWO4 (CWO) nanoparticles (NPs)) within protective capsules formed by biocompatible/biodegradable polymers (e.g., poly(ethylene glycol)-poly(lactic acid) or PEG-PLA). This drug-loaded polymer-encapsulated radioluminescent nanoparticle system can be locally injected in solution form into the patient's tumor before the patient receives normal radiotherapy (e.g., 30–40 fractions of 2–3 Gy daily X-ray dose delivered over several weeks for locally advanced head and neck tumors). Under X-ray irradiation, the radioluminescent nanoparticles produce UV-A light that has a radio-sensitizing effect. These co-encapsulated radioluminescent nanoparticles also enable radiation-triggered release of chemo drugs from the polymer coating layer. The non-toxic nature (absence of dark toxicity) of this drug-loaded polymer-encapsulated radioluminescent nanoparticle (“PEG-PLA/CWO/PTX”) formulation was confirmed by the MTT assay in cancer cell cultures. A clonogenic cell survival assay confirmed that these drug-loaded polymer-encapsulated radioluminescent nanoparticles significantly enhance the cancer cell killing effect of radiation therapy. In vivo study validated the efficacy of PEG-PLA/CWO/PTX-based intratumoral chemo-radio therapy in mouse tumor xenografts (in terms of tumor response and mouse survival). Results of a small-scale NP biodistribution (BD) study demonstrate that PEG-PLA/CWO/PTX NPs remained at the tumor sites for a long period of time (> 1 month) following direct intratumoral administration. A multi-compartmental pharmacokinetic model (with rate constants estimated from in vitro experiments) predicts that this radiation-controlled drug release technology enables significant improvements in the level and duration of drug availability within the tumor (throughout the typical length of radiation treatment, i.e., > 1 month) over conventional delivery systems (e.g., PEG-PLA micelles with no co-encapsulated CaWO4, or an organic liquid, e.g., a 50:50 mixture of Cremophor EL and ethanol, as in Taxol), while it is capable of maintaining the systemic level of the chemo drug far below the toxic threshold limit over the entire treatment period. This technology thus has the potential to offer a new therapeutic option that has not previously been available for patients excluded from conventional chemoradiation protocols

ELECTROCHEMICAL AND PHYSICAL PROPERTIES OF ACTINIDES AND LANTHANIDES IN HIGH TEMPERATURE MOLTEN SALTS

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP)

Canonical quantization of so-called non-Lagrangian systems

We present an approach to the canonical quantization of systems with equations of motion that are historically called non-Lagrangian equations. Our viewpoint of this problem is the following: despite the fact that a set of differential equations cannot be directly identified with a set of Euler-Lagrange equations, one can reformulate such a set in an equivalent first-order form which can always be treated as the Euler-Lagrange equations of a certain action. We construct such an action explicitly. It turns out that in the general case the hamiltonization and canonical quantization of such an action are non-trivial problems, since the theory involves time-dependent constraints. We adopt the general approach of hamiltonization and canonical quantization for such theories (Gitman, Tyutin, 1990) to the case under consideration. There exists an ambiguity (not reduced to a total time derivative) in associating a Lagrange function with a given set of equations. We present a complete description of this ambiguity. The proposed scheme is applied to the quantization of a general quadratic theory. In addition, we consider the quantization of a damped oscillator and of a radiating point-like charge.Comment: 13 page

Catalytic Enantioselective [2,3]-Rearrangements of Allylic Ammonium Ylides: A Mechanistic and Computational Study

The research leading to these results (T. H. W., J. E. T., G. C. L.-J. and A.D.S) has received funding from the ERC under the European Union's Seventh Framework Programme (FP7/2007-2013) / E.R.C. grant agreements n° 279850 and n° 340163. A.D.S. thanks the Royal Society for a Wolfson Research Merit Award. P.H.-Y.C. is the Bert and Emelyn Christensen Professor and gratefully acknowledges financial support from the Stone Family of OSU. Financial support from the National Science Foundation (NSF) (CHE-1352663) is acknowledged. D.M.W. acknowledges the Bruce Graham and Johnson Fellowships of OSU. A.C.B. acknowledges the Johnson Fellowship of OSU. D.M.W., A.C.B., and R.C.J. and P.H.-Y.C. also acknowledge computing infrastructure in part provided by the NSF Phase2 CCI, Center for Sustainable Materials Chemistry (CHE1102637).A mechanistic study of the isothiourea-catalyzed enantioselective [2,3]-rearrangement of allylic ammonium ylides is described. Reaction kinetic analyses using 19F NMR and density functional theory computations have elucidated a reaction profile and allowed identification of the catalyst resting state and turnover-rate limiting step. A catalytically-relevant catalyst-substrate adduct has been observed, and its constitution elucidated unambiguously by 13C and 15N isotopic labeling. Isotopic entrainment has shown the observed catalyst-substrate adduct to be a genuine intermediate on the productive cycle towards catalysis. The influence of HOBt as an additive upon the reaction, catalyst resting state, and turnover-rate limiting step has been examined. Crossover experiments have probed the reversibility of each of the proposed steps of the catalytic cycle. Computations were also used to elucidate the origins of stereocontrol, with a 1,5-S•••O interaction and the catalyst stereodirecting group providing transition structure rigidification and enantioselectivity, while preference for cation-π interactions over C-H•••π is responsible for diastereoselectivity.Publisher PDFPeer reviewe