Heart rate variability (HRV) contains important information about the modulation of the cardiovascular system. Various methods of nonlinear dynamics (e.g., estimating Lyapunov exponents) and ...complexity measures (e.g., correlation dimension or entropies) have been applied to HRV analysis. Permutation entropy, which was proposed recently, has been widely used in many fields due to its conceptual and computational simplicity. It maps a time series onto a symbolic sequence of permutation ranks. The original permutation entropy assumes the time series under study has a continuous distribution, thus equal values are rare and can be ignored by ranking them according to their order of emergence, or broken by adding small random perturbations to ensure every symbol in a sequence is different. However, when the observed time series is digitized with lower resolution leading to a greater number of equal values, or the equalities represent certain characteristic sequential patterns of the system, it may not be rational to simply ignore or break them. In the present paper, a modified permutation entropy is proposed that, by mapping the equal value onto the same symbol (rank), allows for a more accurate characterization of system states. The application of the modified permutation entropy to the analysis of HRV is investigated using clinically collected data. Results show that modified permutation entropy can greatly improve the ability to distinguish the HRV signals under different physiological and pathological conditions. It can characterize the complexity of HRV more effectively than the original permutation entropy.
Recently developed explicitly correlated local coupled‐cluster methods PNO‐LCCSD(T)‐F12 are reviewed. Extensive benchmarks for reaction energies and intermolecular interaction energies are presented, ...in which the convergence of the results with respect to all local approximations is studied. The explicit correlation treatment (F12) is shown to be essential to minimize basis set incompleteness errors, as well as errors caused by domain approximations. Generally, the errors of relative energies due to local approximations can be reduced to below 1 kcal/mol. The methods are well parallelized, and using small computer clusters with 100–200 computing cores, calculations for systems with 100–200 atoms using augmented triple‐ζ basis sets can be carried out within a few hours of elapsed time. Recommendations are made on how such calculations should be carried out, how the accuracy can be tested, and which computational resources are required.
This article is categorized under:
Electronic Structure Theory> Ab Initio Electronic Structure Methods
Software> Quantum Chemistry
Speedup for the PNO‐LCCSD(T)‐F12 calculation of the shown molecule relative to 60 CPU cores.
Due to its advantages of label-free and highly sensitive, the resistive pulse sensing with a nanopore has recently become even more potent for the discrimination of analytes in single molecule level. ...Generally, a transient interruption of ion current originated from the captured molecule passing through a nanopore will provide the rich information on the structure, charge and translocation dynamics of the analytes. Therefore, nanopore sensors have been widely used in the fields of DNA sequencing, protein recognition, and the portable detection of varied macromolecules and particles. However, the conventional nanopore devices are still lack of sufficient selectivity and sensitivity to distinguish more metabolic molecules involving ATP, glucose, amino acids and small molecular drugs because it is hard to receive a large number of identifiable signals with the fabricated pores comparable in size to small molecules for nanopore sensing. For all this, a series of innovative strategies developed in the past decades have been summarized in this review, including host-guest recognition, engineering alteration of protein channel, the introduction of nucleic acid aptamers and various delivery carriers integrating signal amplification sections based on the biological and solid nanopore platforms, to achieve the high resolution for the small molecules sensing in micro-nano environment. These works have greatly enhanced the powerful sensing capabilities and extended the potential application of nanopore sensors.
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•A topical review covering advances of small molecule detection in nanopore sensing.•Detection of small molecules are critical for bioanalysis.•New ways enhance nanopore sensing capabilities for small molecule detection.•Recent advances offer more opportunities for nanopore sensing.
As the most desirable hydrogen production device, the highly efficient acidic proton exchange membrane water electrolyzers (PEMWE) are severely limited by the sluggish kinetics of oxygen evolution ...reaction (OER) at the anode. Rutile IrO2 is a commercial acid‐stable OER catalyst with poor activity and high cost, which has motivated the development of alternatives. However, hitherto most of the designed acidic OER catalysts have disadvantages of low activity or stability, which cannot meet the requirement of industrial applications. Thus, exploring suitable strategies to enhance the activity and stability of cost‐effective acidic OER catalysts is crucial for developing the PEMWE technique. In this review, the main OER mechanisms, different types of catalysts, and their activity and stability characteristics are summarized and discussed, and then possible strategies to improve activity and stability are proposed. Finally, the problems and prospects of such catalysts are generalized to shed some light on the future research of advanced catalysts for acidic OER.
The highly efficient conversion process of acidic proton exchange membrane water electrolyzes, as the most desirable hydrogen production device, is limited by poor activity and stability of acid oxygen evolution reaction (OER) catalysts. Thus, this review is devoted to systematically analyzing and summarizing the reaction mechanism, the classification, the strategy for promoting activity and stability, and the challenges for acidic OER catalysts.
Cancer phototheranostics, composed of optical diagnosis and phototherapy (including photodynamic therapy and photothermal therapy), is a promising strategy for precise tumor treatment. Due to the ...unique properties of near-infrared absorption/emission, high reactive oxygen species generation, and photothermal conversion efficiency, aza-boron-dipyrromethene (aza-BODIPY), as an emerging organic photosensitizer, has shown great potential for tumor phototheranostics. By encapsulating aza-BODIPY photosensitizers within functional amphiphilic polymers, we can afford hydrophilic nanomedicines that selectively target tumor sites via an enhanced permeability and retention effect, thereby efficiently improving diagnosis and therapeutic efficacy. Herein, in this spotlight article, we attempt to highlight our recent contributions in the development of aza-BODIPY-based nanomedicines, which comprises three main sections: (1) to elucidate the design strategy of aza-BODIPY photosensitizers and corresponding nanomedicines; (2) to overview their photophysical properties and biomedical applications in phototheranostics, including fluorescence imaging, photoacoustic imaging, photodynamic therapy, photothermal therapy, and synergistic therapy; and (3) to depict the challenges and future perspectives of aza-BODIPY nanomedicines. It is believed that this Spotlight on Applications article would illuminate the way of developing new aza-BODIPY nanomedicines as well as other organic photosensitizer-based nanomedicines for future clinical translation.
Scaling laws characterize diverse complex systems in a broad range of fields, including physics, biology, finance, and social science. The human language is another example of a complex system of ...words organization. Studies on written texts have shown that scaling laws characterize the occurrence frequency of words, words rank, and the growth of distinct words with increasing text length. However, these studies have mainly concentrated on the western linguistic systems, and the laws that govern the lexical organization, structure and dynamics of the Chinese language remain not well understood. Here we study a database of Chinese and English language books. We report that three distinct scaling laws characterize words organization in the Chinese language. We find that these scaling laws have different exponents and crossover behaviors compared to English texts, indicating different words organization and dynamics of words in the process of text growth. We propose a stochastic feedback model of words organization and text growth, which successfully accounts for the empirically observed scaling laws with their corresponding scaling exponents and characteristic crossover regimes. Further, by varying key model parameters, we reproduce differences in the organization and scaling laws of words between the Chinese and English language. We also identify functional relationships between model parameters and the empirically observed scaling exponents, thus providing new insights into the words organization and growth dynamics in the Chinese and English language.
A new type of flexible Janus nanoribbons array with anisotropic electrical conductivity, magnetism, and photoluminescence has been successfully fabricated by electrospinning technology using a ...specially designed parallel spinneret. Every single Janus nanoribbon in the array consists of a half side of Fe3O4 nanoparticles/polyaniline/polymethylmethacrylate (PMMA) conductive‐magnetic bifunctionality and the other half side of Tb(BA)3phen/PMMA insulative‐photoluminescent characteristics, and all the Janus nanoribbons are aligned to form array. Owing to the unique nanostructure, the conductance along with the length direction of nanoribbons reaches up to eight orders of magnitude higher than that along with perpendicular direction, which is by far the most excellent conductive anisotropy for anisotropic conductive materials. The Janus nanoribbons array is also simultaneously endowed with magnetic and photoluminescent characteristics. The obtained Janus nanoribbons array will have important applications in the future subminiature electronic equipments owing to its high electrical anisotropy and multifunctionality. Furthermore, the design concept and fabrication technique for the flexible Janus nanoribbons array provide a new and facile approach for the preparation of anisotropic conductive films with multifunctionality.
Novel Janus nanoribbons arrays with excellent electrically conductive anisotropy, magnetism, and photoluminescence are prepared via electrospinning technology. Based on the unique nanostructure, conductance in the direction parallel to the Janus nanoribbons is almost eight orders of magnitude higher than that in the perpendicular direction, which is by far the most excellent conductive anisotropy for anisotropic conductive materials.
Al-contaminated Ta-substituted Li7La3Zr2O12 (LLZ:Ta), synthesized via solid-state reaction, and Al-free Ta-substituted Li7La3Zr2O12, fabricated by hot-press sintering (HP-LLZ:Ta), have relative ...densities of 92.7% and 99.0%, respectively. Impedance spectra show the total conductivity of LLZ:Ta to be 0.71 mS cm–1 at 30 °C and that of HP-LLZ:Ta to be 1.18 mS cm–1. The lower total conductivity for LLZ:Ta than HP-LLZ:Ta was attributed to the higher grain boundary resistance and lower relative density of LLZ:Ta, as confirmed by their microstructures. Constant direct current measurements of HP-LLZ:Ta with a current density of 0.5 mA cm–2 suggest that the short circuit formation was neither due to the low relative density of the samples nor the reduction of Li–Al glassy phase at grain boundaries. TEM, EELS, and MAS NMR were used to prove that the short circuit was from Li dendrite formation inside HP-LLZ:Ta, which took place along the grain boundaries. The Li dendrite formation was found to be mostly due to the inhomogeneous contact between LLZ solid electrolyte and Li electrodes. By flatting the surface of the LLZ:Ta pellets and using thin layers of Au buffer to improve the contact between LLZ:Ta and Li electrodes, the interface resistance could be dramatically reduced, which results in short-circuit-free cells when running a current density of 0.5 mA cm–2 through the pellets. Temperature-dependent stepped current density galvanostatic cyclings were also carried out to determine the critical current densities for the short circuit formation. The short circuit that still occurred at higher current density is due to the inhomogeneous dissolution and deposition of metallic Li at the interfaces of Li electrodes and LLZ solid electrolyte when cycling the cell at large current densities.
The Molpro quantum chemistry package
Journal of chemical physics online/The Journal of chemical physics/Journal of chemical physics,
04/2020
Journal Article
Learning to Dress 3D People in Generative Clothing Ma, Qianli; Yang, Jinlong; Ranjan, Anurag ...
2020 IEEE/CVF Conference on Computer Vision and Pattern Recognition (CVPR),
01/2020
Conference Proceeding
Odprti dostop
Three-dimensional human body models are widely used in the analysis of human pose and motion. Existing models, however, are learned from minimally-clothed 3D scans and thus do not generalize to the ...complexity of dressed people in common images and videos. Additionally, current models lack the expressive power needed to represent the complex non-linear geometry of pose-dependent clothing shapes. To address this, we learn a generative 3D mesh model of clothed people from 3D scans with varying pose and clothing. Specifically, we train a conditional Mesh-VAE-GAN to learn the clothing deformation from the SMPL body model, making clothing an additional term in SMPL. Our model is conditioned on both pose and clothing type, giving the ability to draw samples of clothing to dress different body shapes in a variety of styles and poses. To preserve wrinkle detail, our Mesh-VAE-GAN extends patchwise discriminators to 3D meshes. Our model, named CAPE, represents global shape and fine local structure, effectively extending the SMPL body model to clothing. To our knowledge, this is the first generative model that directly dresses 3D human body meshes and generalizes to different poses. The model, code and data are available for research purposes at https://cape.is.tue.mpg.de.
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