We explore adhesive loose packings of dry small spherical particles of micrometer size using 3D discrete-element simulations with adhesive contact mechanics. A dimensionless adhesion parameter (Ad) successfully combines the effects of particle velocities, sizes and the work of adhesion, identifying a universal regime of adhesive packings for Ad > 1. The structural properties of the packings in this regime are well described by an ensemble approach based on a coarse-grained volume function that includes correlations between bulk and contact spheres. Our theoretical and numerical results predict: (i) An equation of state for adhesive loose packings that appears as a continuation from the frictionless random close packing (RCP) point in the jamming phase diagram; (ii) The existence of a maximal loose packing point at the coordination number Z = 2 and packing fraction φ = 1/2 3 . Our results highlight that adhesion leads to a universal packing regime at packing fractions much smaller than the random loose packing, which can be described within a statistical mechanical framework. We present a general phase diagram of jammed matter comprising frictionless, frictional, adhesive as well as non-spherical particles, providing a classification of packings in terms of their continuation from the spherical frictionless RCP.Jammed particle packings have been studied to understand the microstructure and bulk properties of liquids, glasses and crystals [1, 2] and frictional granular materials [3,4]. Two packing limits have been identified for disordered uniform spheres: The random close packing (RCP) and random loose packing (RLP) limits [1,[5][6][7][8][9][10][11]. The upper RCP limit is reproduced for frictionless spheres at volume fractions φ ≈ 0.64 and has been associated with a freezing point of a 1st order phase transition [12][13][14][15], among other interpretations [2,16]. In the presence of friction, packings reach lower volume fraction up to the RLP limit φ RLP ≈ 0.55 for mechanically stable packings [6,8,11]. However, most packings of dry small micrometer-sized particles in nature are not only subject to friction, but also adhesion forces. In fact, van der Waals forces generally dominate interactions between particles with diameters of around 10µm or smaller. In this case, the adhesive forces begin to overcome the gravitational and elastic contact forces acting on the particles and change macroscopic structural properties [17,18].Despite the ubiquity of adhesive particle packings in almost all areas of engineering, biology, agriculture and physical sciences [18][19][20][21], these packings have so far not been systematically investigated. The multi-coupling of adhesion, elastic contact forces and friction within the short-range particle-particle interaction zone and their further couplings with fluid forces (e.g., buoyancy, drag and lubrication) across long-range scales make it highly difficult to single out the effect of the adhesion forces * lishuiqing@tsinghua.edu.cn † hmakse@lev.ccny.cuny.edu alone. Previous stud...

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given refractive indices. The limited refractive indices of natural materials prevent the generation of new optical phenomena. The size and weight of traditional optical devices also prevent optical system miniaturization and integration. Nowadays, there is an everincreasing demand for new approaches to implement the effective manipulation of optical waves in different dimensions and to get the novel optical devices on demand.With the development of nanofabrication technology, artificial nanostructures become approachable which offer a promising solution to the achievement of efficient manipulation of optical waves in different dimensions. Metamaterials, which attain their optical functionalities from the subwavelength structures rather than their constitutive materials, provided intriguing possibilities for the evolution of modern optics and have attracted great interest from the scientific community over the past twenty years. [1][2][3] By judiciously modulating their subwavelength structure parameters, the effective values of the permeability and permittivity of the metamaterials can be designed on purpose to realize the manipulation of optical waves in a spectific dimension and to get the desirable optical functionalities, which are even not achievable with natural materials. Previous works have demonstrated that metamaterials can be widely applied in realizing negative refractive index, [4][5][6] electromagnetic invisibility cloaks, [7,8] optical black holes, [9] chiral media, [10,11] and so on. However, the commercialization of metamaterial-based optical devices in real applications is still challenging, which we ascribe to the strong dispersion and high losses associated with typically used metallic structures, and also the difficult and costly fabrication for 3D designs.Recently, planar metamaterials or metasurfaces have received great attention for their advantages to meet these challenges. [12][13][14] Compared to metamaterials, metasurfaces, as artificial planar designs, have dramatically reduced the fabrication complexity. Moreover, the thickness of metasurfaces is less than or similar to the wavelength of operating waves, which results in the reduction of the undesirable losses and offers an effective manner for implementing tunable and reconfigurable optical devices. Overall, metasurfaces provide an effective way to overcome the challenges in metamaterials, and it has been successfully proven that metasurfaces are more feasible for the engineering of the fundamental dimensions of optical Metasurfaces, 2D artificial arrays of subwavelength elements, have attracted great interest from the optical scientific community in recent years because they provide versatile possibilities for the manipulation of optical waves and promise an effective way for miniaturization and integration of optical devices. In the past decade, the main efforts were focused on the realization of single-dimensional (amplitude, frequency, polarization, or phase) manipulation of optical waves. Compared to the metasurfaces with sing...

We design and numerically analyze a high-quality (Q)-factor, high modulation depth, multiple Fano resonance device based on periodical asymmetric paired bars in the near-infrared regime. There are four sharp Fano peaks arising from the interference between subradiant modes and the magnetic dipole resonance mode that can be easily tailored by adjusting different geometric parameters. The maximal Q-factor can exceed 10 in magnitude, and the modulation depths ΔT can reach nearly 100%. Combining the narrow resonance line-widths with strong near-field confinement, we demonstrate an optical refractive index sensor with a sensitivity of 370 nm/RIU and a figure of merit of 2846. This study may provide a further step in sensing, lasing, and nonlinear optics.

The arbitrary control of the polarization states of light has attracted the interest of the scientific community because of the wide range of modern optical applications that such control can afford. However, conventional polarization control setups are bulky and very often operate only within a narrow wavelength range, thereby resisting optical system miniaturization and integration. Here, we present the basic theory, simulated demonstration, and in-depth analysis of a high-performance broadband and invertible linear-to-circular (LTC) polarization converter composed of a single-layer gold nanorod array with a total thickness of ~λ/70 for the near-infrared regime. This setup can transform a circularly polarized wave into a linearly polarized one or a linearly polarized wave with a wavelength-dependent electric field polarization angle into a circularly polarized one in the transmission mode. The broadband and invertible LTC polarization conversion can be attributed to the tailoring of the light interference at the subwavelength scale via the induction of the anisotropic optical resonance mode. This ultrathin single-layer metasurface relaxes the high-precision requirements of the structure parameters in general metasurfaces while retaining the polarization conversion performance. Our findings open up intriguing possibilities towards the realization of novel integrated metasurface-based photonics devices for polarization manipulation, modulation, and phase retardation.

Quantitative analysis of proteins is an essential part and also constitutes a major challenge in modern proteomics. Quantification of proteins by inductively coupled plasma mass spectrometry (ICPMS) offers an alternative method for quantitative proteomics. In this study, we developed a method of absolute quantification of proteins via sulfur by size exclusion chromatography (SEC) coupled to ICPMS with a collision cell (ICP-CC-MS) and postcolumn isotope dilution. Bovine serum albumin (BSA), superoxide dismutase (SOD), and metallothionein-II (MT-II) served as model proteins. Enriched 34S, 65Cu, and 67Zn isotopic solutions were continuously mixed with the eluate from the SEC. Oxygen was added as a reactive gas into the collision cell where sulfur reacts with oxygen to form sulfur-oxygen ion, the ratio of 32S16O(+)/34S16O(+) thus representing 32S(+)/34S(+). The absolute quantity of proteins could be calculated by the isotopic dilution equation and the content of sulfur in the proteins. The detection limits for BSA, SOD, and MT-II are 8, 31, and 15 pmol, respectively. The relative standard deviations for the proteins are less than 3%. The ratios of S/Cu and S/Zn in the proteins were also determined. The quantitative method was validated by comparing with gravimetric results.

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Background: Colorectal cancers with deficient DNA mismatch repair (dMMR) are presumed to uniformly have dense lymphocytic infiltration that underlies their favorable prognosis and is critical to their responsiveness to immunotherapy, as compared to MMR-proficient (pMMR) tumors. We examined T-cell densities and their potential heterogeneity in a large cohort of dMMR tumors. Experimental Design: CD3+ and CD8+ T-cell densities were quantified at the invasive margin (IM) and tumor core (CT) in 561 stage III colon cancers (dMMR, n=278; pMMR, n=283) from a phase 3 adjuvant trial (N0147). Their association with overall survival (OS) was determined using multivariable Cox analysis. Results: While CD3+ and CD8+ T-cell densities in the tumor microenvironment were higher in dMMR vs pMMR tumors overall, inter-tumoral heterogeneity in densities between tumors was significantly higher by 30–88% among dMMR vs pMMR cancers (P<.0001 for all four T-cell subtypes [CD3+IM, CD3+CT, CD8+IM, CD8+CT]). A substantial proportion of dMMR tumors (26% to 35% depending on the T-cell subtype) exhibited T-cell densities as low as that in the bottom half of pMMR tumors. All four T-cell subtypes were prognostic in dMMR with CD3+IM being the most strongly prognostic. Low (vs high) CD3+IM was independently associated with poorer OS among dMMR (HR 4.76 [95% CI 1.43–15.87]; P=.0019) and pMMR tumors (P=.0103). Conclusions: Tumor-infiltrating T-cell densities exhibited greater inter-tumoral heterogeneity among dMMR than pMMR colon cancers, with CD3+IM providing robust stratification of both dMMR and pMMR tumors for prognosis. Potentially, lower T-cell densities among dMMR tumors may contribute to immunotherapy resistance.