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The impact of agglomerates on solid surfaces occurs inevitably during the processing of granular materials. In this work, numerical simulations of the surface impact of wet agglomerates are carried out by introducing liquid bridge interactions into a soft-sphere DEM model, and the instantaneous impact behaviors are discussed quantitatively at the single particle scale. Results indicate that the impact process usually includes four stages, i.e., compression, expansion, fragmentation, and re-agglomeration. The expanding radius is found to follow an exponential-law with time, and the number of fragments follows a power-law with impact velocity. Due to liquid bridge interactions, chain-like structures are observed beyond the impact, similar to those formed during the impact of dense suspension droplets. Moreover, the impact behaviors can be generally classified into four groups with respect to impact velocity, i.e., minor compression without splashing, severe compression with minor splashing, severe splashing with minor fragmentation, and severe fragmentation.

Emerging evidence suggests that the gut microbiota may interact with the host brain and play pivotal roles in the pathogenesis of neuropsychiatric disorders. However, the mechanism underlying reciprocal interactions along the microbiota-gut-brain axis in depression remains unclear. In this study, a murine model of chronic restraint stress (CRS) was established to investigate the metabolic signaling of tryptophan (Trp) neurotransmission at the intestinal and central levels in depression. The results showed that CRS mice displayed depression- and anxiety-like behaviors. Additionally, kynurenine (Kyn) and its metabolites, an important Trp metabolic pathway, were strongly activated in the brain. Intriguingly, the Kyn toxic signaling was exacerbated in the gut, especially in the colon. Indoleamine 2,3-dioxygenase (IDO), a rate-limiting enzyme responsible for Kyn metabolic pathway initiation, was significantly upregulated in the brain and gut in CRS mice compared with control mice, promoting transfer of Trp metabolic pathway to Kyn signaling. Additionally, administration of IDO inhibitor, 1-methyl-tryptophan (1-MT), partially rescued CRS-induced depression- and anxiety-like changes. Moreover, the enhanced intestinal permeability mediated by CRS allowed toxic metabolites to “leak” into the bloodstream. The microbiome profiles of CRS mice displayed obviously altered taxonomic composition and negative correlations were observed between Enterorhabdus, Parabacteroides and Kyn levels in the brain. Reciprocal crosstalk between the brain and gut was further validated by citalopram treatment, IDO inhibitor and microbiota intervention, which counteracted depression-like behavior, Kyn metabolic signaling and microbiota composition in CRS mice. Meanwhile, Parabacteroides treatment affected Trp metabolism in mouse hippocampus, manifesting as elevated concentration of 5-HT as well as ratio of 5-HT to Trp. These results suggest that long-term stress disrupts Kyn metabolism and endocrine function along the gut-brain axis, accompanied by the disrupted homeostasis of certain microbiota, which collectively contribute to the development of depression-like behavior.

MicroRNA-188-5p (miR-188) enhances oncologic progression in various human malignancies. This study aimed to explore its role in colorectal cancer (CRC). Human CRC tissues paired with normal tissues, and several CRC cell lines were utilized. Real-time quantitative PCR was applied to measure the expression of miR-188. Overexpression and knockdown were used to access the function of miR-188 and to investigate whether FOXL1/Wnt signaling mediates such function. The proliferation, migration and invasion of cancer cells were evaluated by CCK8, wound-healing and transwell assays, respectively. Whether FOXL1 acted as a direct target of miR-188 was verified by dual-luciferase reporter assays. Levels of miR-188 were upregulated in CRC tissues than in paired-normal tissues, as well as in various CRC cell lines. High expression of miR-188 was strongly associated with advanced tumor stage, accompanied with significant tumor cell proliferation, invasion and migration. It was confirmed that FOXL1 played positive crosstalk between miR-188 regulation and downstream Wnt/β-catenin signaling activation. All findings indicate that miR-188 promotes CRC cell proliferation and invasion through targeting FOXL1/Wnt signaling and could be served as a potential therapeutic target for human CRC in the future.

Artificial nanostructures, whose spatial symmetry can be arbitrarily designed, play an ever more critical role for the realization of giant chiral optical responses. In order to break the mirror sy...

Water elements pollution has attracted public attention globally. Wuxi is located in East China, and its water source, Taihu Lake, has been severely polluted since 2007. Studies of elemental pollution profiles have yet to be conducted in this area. In this study, 56 water samples were collected in 2018, and 33 elements were determined using inductively coupled plasma-mass spectrometry (ICP-MS). The results showed that the levels of 33 elements ranged from 1.35 × 10

Complex networks have become a center of interdisciplinary research. The robustness and reliability of complex systems can be determined by analyzing the characteristics of networks. The computer numerical control machine tool (CNCMT) is a typical complex system, and reliability is the key factor that affects the processing quality and performance of the CNCMT. The process of quantitatively determining the key functional components of CNCMT and carrying out reliability growth experiments on them remains difficult. A new importance-ranking method for the key functional components of the CNCMT is proposed in this study. First, the real characteristics of the CNCMT are analyzed, and the complex network of the CNCMT is constructed. Then, we study various indicators of the network and determine that the network has small-world characteristics. Finally, a variety of complex network characteristic indicators are fused, the weight of each indicator is determined based on the analytic hierarchy process (AHP), the importance of each node is quantitatively determined, and the fused indicators are compared with a single indicator.

Inertial deposition of wet microparticles on a fiber is numerically investigated by means of discrete element method, taking the effects of impact velocity and initial spin into consideration. Results indicate that the overall, normal and tangential coefficients of restitution remain zero as the impact velocity is lower than a critical value, beyond which these restitution coefficients will increase nonlinearly with increasing the impact velocity. As the impact angle increases, the normal critical impact velocity will show a parabolic decrease and the tangential critical impact velocity will increase linearly, different from dry collisions where the critical impact velocities almost keep constant. As the impact velocity increases, the capture efficiency of wet microparticles by the fiber decreases exponentially, meanwhile the deposit microstructures tend to be denser. It becomes much more complex if clockwise or anti-clockwise initial spins are encountered. The rotational coefficient of restitution will first decrease with increasing the rotational rate until reaching a minimum value, beyond which the rotational restitution coefficient will increase as the rotational rate increases further. However, the overall restitution coefficient changes slightly if the rotational rate is less than about 105 rad/s. The effect of clockwise spin on capture efficiency is found to be distinctly different from that of anti-clockwise spin, and it can be reasonably interpreted by their effects on the overall coefficient of restitution.

Perfect absorbers with high quality factors (Q-factors) are of great practical significance for optical filtering and sensing. Moreover, tunable multiwavelength absorbers provide a multitude of possibilities for realizing multispectral light intensity manipulation and optical switches. In this study, we demonstrate the use of vanadium dioxide (VO

Coherence, like amplitude, polarization and phase, is a fundamental characteristic of the light fields and is dominated by the statistical optical property. Generally, accurate coherence manipulation is challenging since coherence as a statistical quantity requires the combination of various bulky optical components and fast tuning of optical media. Spatial coherence as another pivotal optical dimension still has not been significantly manipulated on the photonic platform. Here, we theoretically and experimentally realize accurate manipulation of the spatial coherence of light fields by loading a temporal random phase distribution onto the wave-front on the statistical photonic platform. By quantitatively manipulating the statistical photonic properties, we can successfully achieve the partially coherent light with the pre-defined degree of coherence and continuously modulate it from fully coherent to incoherent. This design strategy can also be easily extended to manipulate the spatial coherence of other special beams such as partially coherent vortex beam generations. Our approach provides straightforward rules to manipulate the coherence of the light fields and paves the way for applications of partially coherent beams in information encryption, ghost imaging, and information transmission in turbulent media.

Aims To investigate the level of implicit care rationing and its association with training needs in nursing homes in Shanghai, China. Background Nursing homes in Shanghai are confronted with a lack of care resources. Implicit care rationing can emerge due to inadequate training of care workers. Methods A cross-sectional survey was conducted between 10 September and 17 November 2020. A total of 374 care workers from 16 randomly were selected nursing homes from each of the administrative districts participated the surveys. The Basel Extent of Rationing of Nursing Care-Nursing Home instrument and the training needs analysis were adopted to measure implicit care rationing and training needs, respectively. Multiple regression techniques were used to explore the factors associated with implicit care rationing. Results Activities related to social care, documentation and activation/rehabilitation (mean rating = 2.8, 1.89 and 1.93 respectively) were mostly likely to be rationed. Training needs of activities of daily living (ADL), activation/rehabilitation and documentation were significantly related to their implicit rationing (β = 0.864, 0.21 and 0.166, respectively, p Conclusion Training needs are crucial determinants of implicit care rationing. Implications for nursing management Quality control systems are needed to ensure care comprehensiveness. The current training system should be re-designed according to results of training needs analysis.

Bound states in the continuum (BICs) enabling resonances with high quality ($Q$) factor allow for high-efficiency light-matter interactions and boost various research fields such as nonlinear photonics and optical detecting. However, further improvement of the $Q$ factor of the resonances is challenging since the accurate fabrication of the tiny symmetry defects of meta-atoms is limited by the nanofabrication technology, which is critical for transition from BICs to quasi-BICs in previous works. Here we propose a different approach to trigger the transition of quasi-BICs that does not need to change the space group symmetry of nanostructures. By modulating the periods of the nanostructures, our approach enlarges the unit cell and enriches the ideal BICs eigenstates, achieving multiband quasi-BICs in metasurfaces. By tuning the asymmetry parameters, the selective excitation of multiband quasi-BICs is demonstrated. Thanks to the multi-narrow-band resonances obtained by the unit cell perturbation, a multivariable sensing method is proposed to simultaneously obtain the birefringence property and thickness of a nanoscale layer. The proposed approach exciting multiband quasi-BICs offers a possible solution for ultra-high-$Q$ devices without complex fabrication techniques and may found realistic application in many fields such as harmonic generation, optical detecting, and compact low-threshold lasers.

Realizing full-dimensional arbitrary manipulation of optical waves, which is known to be important for the implementation of optical devices with ondemand functionalities, still remains a challenge. Recently, Metasurfaces have shown unprecedented capabilities for the manipulation of optical waves at the subwavelength scale. Here, we demonstrated the use of chiral mirrors for the implementation of spin-selective multidimensional manipulation of optical waves. we validated that the three dimensions (amplitude, phase and operation wavelength) of optical waves is directly related to the three main structure variables of the designed chiral mirror. By simply and orderly changing the three structural variables of the designed chiral mirror, the spin-selective full and near independent manipulation of amplitude and phase of optical waves with a large and continuous wavelength agility can be implemented

Optical chirality plays a key role in optical biosensing and spin-selective optical field manipulation. However, the maximum optical intrinsic chirality, which is represented by near-unity circular dichroism (CD), is yet to be achieved in a wide bandwidth range based on nanostructures. Here, we utilize dielectric bilayer polyatomic metasurfaces to realize the maximum optical intrinsic chirality over a wide bandwidth range. The CD efficiency of the two designed metasurfaces with opposite chirality is 99.9% at 1350 nm and over 98% from 1340 nm to 1361 nm. Our work provides a straightforward and powerful method for the realization of maximum optical intrinsic chirality, which has great potential in spin-selective optical wave manipulation.

We propose an approach to realize a multi-band on-chip photonic spin Hall effect and selective excitation of whispering gallery modes (WGMs) by integrating metasurfaces with microcavities. Free-space circularly polarized light with opposite spin angular momentum can effectively excite WGMs with opposite propagation directions at fixed wavelengths. Moreover, the different WGMs with different propagation directions and polarizations can be selectively excited by manipulating the number of antennas. We demonstrate that the optical properties (i.e., coupling efficiency, peak positions, and peak widths) of the proposed metasurface-integrated microcavities can be easily tailored by adjusting different geometric parameters. This study enables the realization of chiral microcavities with exciting novel functionalities, which may provide a further step in the development of photonic integrated circuits, optical sensing, and chiral optics.

Inertial migration of a nonneutrally buoyant disk particle in a linear shear flow under thermal convection (TC) is studied numerically. Particle dynamics and equilibrium position depend on competition between the inertial lift force, the gravitational force (buoyancy), and the TC lift force. When the particle is heavier than the fluid, inertial lift-off is observed and a modified phase diagram is established in terms of the channel Reynolds number Re and density ratio \ensuremath{\sigma}. When the particle is lighter than the fluid, TC induced re-suspension and sedimentation are observed, where the normalized critical Grashof number, Gr${}_{\mathrm{crit}}$/\ensuremath{\sigma}, depends linearly on Re for all particle densities studied.

Colors with high saturation are of prime significance for display and imaging devices. So far, structural colors arising from all-dielectric metasurfaces, particularly amorphous silicon and titanium oxide, have exceeded the gamut of standard RGB (sRGB) space. However, the excitation of higher-order modes for dielectric materials hinders the further increase of saturation. Here, to address the challenge, we propose a new design strategy of multipolar-modulated metasurfaces with multi-dielectric stacked layers to realize the deep modulation of multipolar modes. Index matching between layers can suppress the multipolar modes at nonresonant wavelength, resulting in the dramatic enhancement in the monochromaticity of reflection spectra. Ultrahigh-saturation colors ranging from 70% to 90% with full hue have been theoretically and experimentally obtained. The huge gamut space can be realized in an unprecedented way, taking up 171% sRGB space, 127% Adobe RGB space, and 57% CIE space. More interestingly, the coverage for Recommendation 2020 (Rec. 2020) space, which almost has not been successfully realized so far, can reach 90%. We anticipate that the proposed multipolar-modulated metasurfaces are promising for the enlargement of the color range for high-end and advanced display applications.

This paper takes advantage of fractal method to research some soil characteristics through case analysis. The multifractal spectrum and random Sierpinski carpet are used to describe the spatial variability and thermal conductivity of soil quantitatively. On the basis of predecessors, the scatter plots of various types of data have been used to supplement the multifractal results in a more detailed way. It turns out that the content of clay, silt, and coarse sand could reflect the degree of spatial variability of soil. Then based on this case, the effect of porosity on soil thermal conductivity is discussed by using random Sierpinski carpet. The result shows that the effective thermal conductivity of the clay, silt and coarse sand decreases linearly with the increase of porosity, but the degree of reduction is different. Moreover, when the porosity is definite, the effective thermal conductivity of the coarse sand is the largest, that of the clay with the highest thermal conductivity is second, and that of the silt is the smallest.

Two kinds of liquid chromatography coupled with tandem mass spectrometry (LC–MS/MS) techniques with high resolution and good sensitivity characteristics respectively are used to analyze the chemicals and rat metabolites of Biqi capsule with different exposure level. On the one hand, 23 chemical compositions of Biqi capsule and 56 metabolites in rats were identified by high-performance liquid chromatography coupled with high-resolution hybrid mass spectrometry (HPLC-HRMS/MSn). On the other hand, 15 prototype compounds and 22 metabolites at low level in plasma were detected by high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (HPLC-QQQ-MS/MS) with high sensitivity and selectivity. Total 44 absorbed components in plasma were used to dock protein targets to reveal the probable active effects and mechanism of action of Biqi capsule, and rheumatic arthritis-related pathways were constructed by Kyoto Encyclopedia of Genes and Genomes (KEGG) database. In this study, an integrative approach combining with chemical compositions and metabolites analysis, plasma pharmacochemistry and network pharmacology was tried to clarify the chemical compositions, rat metabolites, probable active components and action mechanism of Biqi capsule.

We report, for the first time, the long-awaited detection of diffuse gamma rays with energies between 100 TeV and 1 PeV in the Galactic disk. Particularly, all gamma rays above 398 TeV are observed apart from known TeV gamma-ray sources and compatible with expectations from the hadronic emission scenario in which gamma rays originate from the decay of $\pi^0$'s produced through the interaction of protons with the interstellar medium in the Galaxy. This is strong evidence that cosmic rays are accelerated beyond PeV energies in our Galaxy and spread over the Galactic disk., Comment: Accepted for publication in the Physical Review Letters

We report observations of gamma-ray emissions with energies in the 100 TeV energy region from the Cygnus region in our Galaxy. Two sources are significantly detected in the directions of the Cygnus OB1 and OB2 associations. Based on their positional coincidences, we associate one with a pulsar PSR J2032+4127 and the other mainly with a pulsar wind nebula PWN G75.2+0.1 with the pulsar moving away from its original birthplace situated around the centroid of the observed gamma-ray emission. This work would stimulate further studies of particle acceleration mechanisms at these gamma-ray sources., Accepted for publication in the Physical Review Letters

A series of policies aimed toward rational resource allocation of long‐term care have being actively discussed since the launch of the social long‐term care insurance in Shanghai, and it is important to take a societal perspective for informed decision‐making. This study aims to explore factors that are associated with well‐being of informal caregivers in Shanghai, and to provide empirical evidence of application of an established well‐being valuation method to monetise informal caregivers' well‐being losses in a developing country. 310 informal caregivers of applicants for social long‐term care insurance in Shanghai were interviewed. Univariate and multivariate analyses were conducted to explore the associated factors with life satisfaction of the caregivers. The monetary values of an additional hour of caregiving with and without specification of care tasks were estimated by the well‐being valuation method. Life satisfaction was consistently associated with monthly income, health status, and caring hours of the caregivers. The money needed to compensate one additional hour of caring per week was 12.58 CNY (0.3% of the monthly income), and 96.95 CNY (2.0% of the monthly income) for activities of daily living (ADL) tasks. Income, health status, and caregiving are significantly associated with well‐being of informal caregivers. Caregivers in relatively poor health condition and/or involved in more ADL tasks should be particularly considered in supporting policies in Shanghai.

Sampling and interpolation have been extensively studied, in order to reconstruct or estimate the entire graph signal from the signal values on a subset of vertexes, of which most achievements are about continuous signals. While in a lot of signal processing tasks, signals are not fully observed, and only the signs of signals are available, for example a rating system may only provide several simple options. In this paper, the reconstruction of band-limited graph signals based on sign sampling is discussed and a greedy sampling strategy is proposed. The simulation experiments are presented, and the greedy sampling algorithm is compared with random sampling algorithm, which verify the validity of the proposed approach.

Cosmic rays (protons and other atomic nuclei) are believed to gain energies of petaelectronvolts (PeV) and beyond at astrophysical particle accelerators called 'PeVatrons' inside our Galaxy. Although a characteristic feature of a PeVatron is expected to be a hard gamma-ray energy spectrum that extends beyond 100 teraelectronvolts (TeV) without a cutoff, none of the currently known sources exhibits such a spectrum due to the low maximum energy of accelerated cosmic rays or insufficient detector sensitivity around 100 TeV. Here we report the observation of gamma-ray emission from the supernova remnant G106.3+2.7 above 10 TeV. This work provides flux data points up to and above 100 TeV and indicates that the very-high-energy gamma-ray emission above 10 TeV is well correlated with a molecular cloud rather than the pulsar PSR J2229+6114. Regarding the gamma-ray emission mechanism of G106.3+2.7, this morphological feature appears to favor a hadronic origin via the {\pi}0 decay caused by accelerated relativistic protons over a leptonic one via the inverse-Compton scattering by relativistic electrons. Furthermore, we point out that an X-ray flux upper limit on the synchrotron spectrum would provide important information to firmly establish the hadronic scenario as the mechanism of particle acceleration at the source., Comment: Published in Nature Astronomy

Polarization plays a key role in both optics and photonics. Generally, the polarization states of light are measured with birefringent or dichroic optical elements paired with a power meter. Here we propose a direct polarization detection method based on colorimetric asymmetrical all-dielectric metasurfaces to obtain the polarization angles of the incident light. The independently tunable periods and diameters along the x and y axes enables double-layer nanopillars to realize high-performance dual-color palettes with arbitrary combinations under orthogonal polarization states. The polarization detection network based on residual networks is used to deeply learn the regulations between color palette variations and incident polarization angles, which can accurately recognize extremely slight polarization variations in about 1 s with an accuracy of 81.4% within 0.7° error and 99.5% within 1.4° error. Our strategy significantly improves the compactness of polarization detection, and it can be readily expanded to polarization distribution measurement and colorimetric polarization imaging on an intelligent platform.

Background In order to make optimal long-term care-related decisions, it is important to take a societal perspective. Shanghai is one of the pilot cities of social long-term care insurance in China. However, little knowledge exists about the economic value of the informal care provided to dependent elderly people in China. This paper aims to evaluate the economic value of informal caregiving in Shanghai using the contingent valuation method by their least-preferred care tasks, and identify the associated factors of willingness-to-pay (WTP) and willingness-to-accept (WTA) of the informal caregivers. Methods This study employed the contingent valuation method to elicit 371 informal caregivers’ WTP and WTA for 1 hour of reduction or increase of least-preferred caring tasks in Shanghai. Univariate and multivariate analyses were conducted to explore the associated factors with the WTP and WTA values. Results The average WTP and WTA were 25.31 CNY and 38.66 CNY, respectively. The associated factors with WTP include caregiver’s income and caregiver’s relationship to the recipient. Care recipient’s age, income, least-preferred task by the caregiver, and subscales of Caregiver Reaction Assessment were found to be associated with WTA. The non-responsiveness rates were 26.1 and 33.2% for WTP and WTA questions, respectively. Conclusions The findings of the current study demonstrated that decision-makers and researchers should take the economic valuation results of informal care into account to make more informed and effective long-term care-related policies and analyses.

Metasurfaces, which are planar arrays of subwavelength artificial structures, have emerged as excellent platforms for the integration and miniaturization of electromagnetic devices and provided ample possibilities for single-dimensional and multidimensional manipulations of electromagnetic waves. However, owing to the limited interactions between planar thin metallic nanostructures and electromagnetic waves as well as intrinsic losses in metals, metasurfaces exhibit disadvantages in terms of efficiency, controllability, and functionality. Recent advances in this field show that few-layer metasurfaces can overcome these drawbacks. Few-layer metasurfaces composed of more than one functional layer enable more degrees of design freedom. Hence, they possess unprecedented capabilities for electromagnetic wave manipulation, which have considerable impact in the area of nanophotonics. This article reviews recent advances in few-layer metasurfaces from the viewpoint of their scattering properties. The scattering matrix theory is briefly introduced, and the advantages and drawbacks of few-layer metasurfaces for the realization of arbitrary scattering properties are discussed. Then, a detailed overview of typical few-layer metasurfaces with various scattering properties and their design principles is provided. Finally, an outlook on the future directions and challenges in this promising research area is presented.

Recently, enhancing the performance of flexible perovskite photodetectors through facile and effective means has gained greater attention. In contrast to typical approaches through modifying light-active materials, we present here a simple but effective design by improving light-matter interactions through near-field optical interference on a back-reflected substrate, whose architecture includes a morphologically flat top surface and a backscattering surface textured with micro/nanostructures by the femtosecond laser direct writing. A CH3NH3PbI3 perovskite film and poly(ethylene terephthalate) are selected as the light-active and base materials, respectively. Under a 1 V bias voltage actuation and 532 nm laser irradiation at an intensity of 10 mW cm-2, the flexible device exhibits excellent performance in photoresponsivity (47.1 mA W-1), detectivity (3.7 × 1011 Jones), and on/off ratio (4600). Due to the near-field optical enhancement of the substrate and the strong light-matter interaction, the above performance parameters are enhanced by at least 5 times over a wide spectral range of 220-780 nm. Such enhancement behaviors are independent of active material properties and therefore can be compatible with other operations such as crystalline transformation, doping, and interface modification. Moreover, the alteration of stress distribution on the structured substrate facilitates the bending robustness and stability. These features highlight the potential of back-reflected design in the development of flexible perovskite photoelectric devices, which are especially suitable for large-scale industrial production.

Transport of suspensions consisting of monodisperse adhesive micro-particles in a pressure-driven duct flow with the Reynolds number in the range of 5.4-108 is analysed by means of a coupled lattice Boltzmann method with the discrete element method. The influence of the adhesion on migration and agglomeration of particles is investigated. The results show that the suspensions undergo a transition from purely lateral focusing to completely agglomeration as the surface energy is increased. A dimensionless adhesion number, defined as the ratio of the adhesive force to the drag force, is employed to characterise the degree of agglomeration. It is found that all the particles come into agglomerates as the adhesion number reaches a critical value. Moreover, a detailed examination of size evolution and velocity illustrates that the agglomerates mainly grow spherically, and their velocities depend on the lateral positions rather than their sizes, as the Stokes number is far below one.

Scatterings and transport in Weyl semimetals have caught growing attention in condensed matter physics, with observables including chiral zero modes and the associated magnetoresistance and chiral magnetic effects. Measurement of electrical conductance is usually performed in these studies, which, however, cannot resolve the momentum of electrons, preventing direct observation of the phase singularities in scattering matrix associated with Weyl point. Here we experimentally demonstrate a helical phase distribution in the angle (momentum) resolved scattering matrix of electromagnetic waves in a photonic Weyl metamaterial. It further leads to spiraling Fermi arcs in an air gap sandwiched between a Weyl metamaterial and a metal plate. Benefiting from the alignment-free feature of angular vortical reflection, our findings establish a new platform in manipulating optical angular momenta with photonic Weyl systems., Comment: 14 pages, 3 figures

Supplemental Materials

Additional file 1. Questionnaire. The questionnaire employed in the interviews with the informal caregivers

Bi qi capsule (BQC) is a traditional Chinese medicine prescription that is clinically used for the treatment of rheumatoid arthritis. Strychnine and brucine, as two typical kinds of alkaloids, are the primary active and neurotoxic constituents of BQC. In this study, a sensitive and reliable rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) quantitative method was used to determine the concentrations of brucine and strychnine in rat brain and blood dialysates. The blood-brain barrier (BBB) penetration of free brucine and strychnine and their pharmacokinetic characteristics were investigated by the validated RRLC-MS/MS method coupled with in vivo microdialysis for the first time. The dialysate brain-blood AUC ratios of brucine were 0.098, 0.44 and 0.40 respectively at 0.4, 0.8 and 1.6 g kg−1 doses of BQC, and the dialysate brain-blood AUC ratios of strychnine were 0.20, 1.25 and 2.06 respectively at 0.4, 0.8 and 1.6 g kg−1 doses of BQC. The high brain-blood AUC ratios of brucine and strychnine were observed in medium and high dose groups of BQC. In addition, the effects of P-glycoprotein (P-gp) and breast cancer resistance protein (BCRP) on brucine and strychnine across BBB were also studied using the above method as well as molecular docking. The results prompted that brucine was the substrate of P-gp, and strychnine might be the inhibitor of P-gp. Brucine and strychnine showed high brain penetration, so it is very important to well control the clinic dosage of BQC and manufactory quality for avoiding the side effects and obtaining good therapeutic efficacy. Our study could be further used in investigating BBB penetration for other drugs caused neurotoxicity.

The effects of hydrodynamic interactions on random adhesive loose packings of monodisperse spherical micro-particles are investigated via a two-way coupled CFD-DEM approach. It is found out that the packing fraction and coordination number do not follow the regression of the adhesion number, which was proposed recently to well characterize the bulk properties of adhesive packings. Based on the balance between particle adhesion and fluid drag force, we propose a modified fluid adhesion number, Adf, which successfully normalizes the packing fraction and coordination number. Besides, the pressure drop through the packed bed shows a critical behavior, which validates the jamming threshold of fine powders, but occurs at a fixed packing fraction of ϕ ≈ 0.22 under the present protocol. The normalized permeability of the packed bed for different parameters is analyzed, which is in good agreement with the derivation of Kozeny-Carman equation.

Understanding the structural properties of random packings of jammed colloids requires an unprecedented high-resolution determination of the contact network providing mechanical stability to the packing. Here, we address the determination of the contact network by a novel strategy based on fluorophore signal exclusion of quantum dot nanoparticles from the contact points. We use fluorescence labeling schemes on particles inspired by biology and biointerface science in conjunction with fluorophore exclusion at the contact region. The method provides high-resolution contact network data that allows us to measure structural properties of the colloidal packing near marginal stability. We determine scaling laws of force distributions, soft modes, correlation functions, coordination number and free volume that define the universality class of jammed colloidal packings and can be compared with theoretical predictions. The contact detection method opens up further experimental testing at the interface of jamming and glass physics.

The aggregation-induced emission (AIE) behavior of metal nanoclusters has attracted much attention owing to their extensive application prospects in bio-imaging and chemical sensors. However, the intrinsic mechanism of metal nanoclusters' aggregation-induced emission is still not very clear. Herein, Cu nanoclusters S1 and Ag(i)-doped Cu/Ag nanoclusters S2 and S3 coated with d-penicillamine are designed and synthesized by a self-assembly strategy. S1-S3 show strong luminescence properties with luminescence quantum yields as high as 11.4%-14.2%. Moreover, their luminescence peak position shows an obvious hypsochromic shift from 615 (S1) to 570 nm (S3). With the introduction of Ag(i) ions, the assembly morphology also shows clear changes from the irregular assembly structure (S1) to large spherical particles with the average size of 0.18 μm for S2 and 0.47 μm for S3. A detailed investigation of high-resolution transmission electron microscopy (HRTEM) images, X-ray diffraction (XRD) patterns, ESI-TOF-mass spectra, UV-vis absorption spectra, photoluminescence spectra and luminescence lifetimes of Cu/Ag nanoclusters S2 and S3 indicates that Cu/Ag nanoclusters are actually a Cu/Ag alloy nanocluster superstructure and the microscopic arrangement of S2 and S3 is more compact and ordered relative to S1. The more compact and ordered Cu/Ag alloy nanocluster superstructure enhances the metal-metal interaction of inter-nanoclusters and intra-nanoclusters and facilitates the radiative transition of ligand-to-metal charge transfer (LMCT) and/or ligand-to-metal-metal charge transfer (LMMCT), which results in the aggregation-induced emission phenomenon. In addition, an enhanced metal-metal interaction increases the average metal-metal distance of the Cu/Ag nanocluster superstructure, leading to a hypsochromic shift of emission spectra. Furthermore, the Cu/Ag alloy nanoclusters show good stability and reversibility on pH cycling between pH = 3 and 7 and temperature cycling between 5 °C and 48 °C. The Cu/Ag alloy nanoclusters can be used as probes for Ag(i) ion and halide anion detection in real water samples by the ratiometric PL method (I570/I615).

We investigate the evolution of spherical clouds of charged particles that migrate under the action of a uniform external electrostatic field. Hydrodynamic interactions are modelled by Oseen equations and the Coulomb repulsion is calculated through pairwise summation. It is shown that strong long-range Coulomb repulsion can prevent the breakup of the clouds covering a wide range of particle Reynolds number $Re_{p}$ and cloud-to-particle size ratio $R_{0}/r_{p}$. A dimensionless charge parameter $\unicode[STIX]{x1D705}_{q}$ is constructed to quantify the effect of the repulsion, and a critical value $\unicode[STIX]{x1D705}_{q,t}$ is deduced, which successfully captures the transition of a cloud from hydrodynamically controlled regime to repulsion-controlled regime. Our results also reveal that, with sufficiently strong repulsion, the cloud undergoes a universal self-similar expansion. Scaling laws of cloud radius $R_{cl}$ and particle number density $n$ are obtained by solving a continuum convection equation.