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The effect of birefringence in anisotropic materials has been a long‐term issue for polarized Raman scattering. In this work, the polarization‐dependent Raman scattering in anisotropically birefringent materials is modeled with birefringence considered in the fundamental polarization selection rule. The birefringence‐induced polarization transformation is treated as a tensor in the calculation of Raman scattering intensity. The validity of this theory is further demonstrated in experiments by taking angle‐resolved polarized Raman measurements on the basal and cross planes of α‐MoO3—a typical biaxial van der Waals crystal with strong in‐plane and out‐of‐plane anisotropy. The anomalous angular dependency of polarized Raman scattering intensity can be well reproduced by the modified theoretical model with fitted real‐valued Raman tensors and birefringence‐related parameters. It can be concluded that this work can provide a valuable reference and guidance for quantitative analyses of anisotropic materials by using polarization‐resolved Raman scattering spectroscopy. [ABSTRACT FROM AUTHOR]

Because of affections from fluctuation, the migration or reaction rate of bio-molecules is mainly related to the time-memory effect. This kinetic phenomenon is primarily dominated by dynamic ductility and molecular crowding in the solvent. These two important elements directly connect with the affections of the random force and systematic friction (ζ) in a real solvent. They can affect fluctuation characteristics of bio-molecules. Properties of bio-molecular kinetics are mainly submitted to the configuration quality and random collision. The multidimensional landscape must be needed in typical research processes for kinetics of bio-molecules. The random collision affection in the x dimension and the typical ductility for the free-energy surface in the Q dimension have been abstracted in our work. The two-dimensional generalized Langevin equation including fractional Gaussian noise or white noise is used to study the migration rate or the mean waiting time. The essential quality of the bio-molecules' kinetic properties can be revealed by the comparative study between dynamic disorder (DD) and common diffusion. We have found that there are sharp dynamic differences between DD and normal kinetics. Moreover, dynamic ductility and solvent friction can lead to great affections to the bio-molecular dynamics. [ABSTRACT FROM AUTHOR]

The recent discovery of in‐plane hyperbolic phonon polaritons in biaxial polar crystal—α‐MoO3, has aroused a huge research upsurge on anisotropic photonic quasiparticles in van der Waals materials. The physical origin of these highly anisotropic phonon polaritons is attributed to the strong anisotropy of crystal phonons. However, the orientation‐dependent phonon modes have not been fully understood from crystallographic point of view. This work systematically performs in situ angle‐resolved polarized Raman spectroscopy on α‐MoO3 to investigate its anisotropic photo‐phonon interactions. The sample orientation and Raman tensors are unambiguously determined under different polarization configurations. Specifically, the in‐plane anisotropic phonon modes of α‐MoO3 can be well characterized from the highly polarization‐dependent Raman‐active modes with periodic intensity variation. It can be concluded that these findings cannot only offer a better understanding of anisotropic phonon modes in α‐MoO3, but also provide a valuable reference for other anisotropic van der Waals crystals. [ABSTRACT FROM AUTHOR]

Hyperbolic phonon polaritons in optically uniaxial hexagonal boron nitride (hBN) have shown considerable potential for manipulating light on the deep‐subwavelength scale, but the inherent in‐plane isotropy of hBN hinders their further application in planar polariton meta‐optics. Engineering these polaritons to achieve ultraconfined in‐plane anisotropic propagation is of scientific significance for facilitating light–matter interactions toward an extreme scale. Here, the polariton features are systematically investigated in a vertically stacked van der Waals heterostructure consisting of hBN and tellurium (Te), a highly birefringent van der Waals crystal in the mid‐infrared region. Polaritons in this heterostructure exhibit Te‐thickness‐dependent anisotropic dispersion, and the configurable in‐plane anisotropy and enhanced field confinement are experimentally demonstrated using scanning near‐field optical microscopy. It is concluded that these findings contribute to the fundamental understanding of anisotropic polaritons in hBN van der Waals heterostructures, providing a practical avenue for effectively engineering anisotropic PhPs in an intrinsically isotropic van der Waals material. [ABSTRACT FROM AUTHOR]

It is of great significance to develop efficient platforms for the detection of hypertoxic Hg2+. Colorimetric probes have received much attention for the detection of Hg2+ in the last decades. In this work, a colorimetric probe composed of MnO2 nanosheets and monothioglycerol (MTG) was rationally designed for Hg2+ detection, which was facially prepared via one‐step reaction at room temperature. The formation of Hg−S bond between Hg2+ and MTG inhibited the decomposition ability of MTG toward MnO2 nanosheets, thus resulting in a color change from colorless to brown. On this basis, the probe quantified Hg2+ in the concentration range from 2 to 60 μM with a low detection limit of 0.75 μM. The probe was applied to the detection of Hg2+ in tap water successfully, and was further fabricated into test strips for the convenience of use. Thereby, a simple and sensitive colorimetric probe for Hg2+ is developed in this work, which holds future promise for monitoring Hg2+ in the environment. [ABSTRACT FROM AUTHOR]

Current photoacoustic (PA) imaging modalities typically require either serial detection with a single-element transducer or parallel detections with an ultrasonic array, indicating a dilemma between system cost and imaging throughput. PA topography through ergodic relay (PATER) was recently developed to address this bottleneck. However, PATER requires object-specific calibration due to varied boundary condition and must be recalibrated through pointwise scanning for each object before measurements, which is time-consuming and severely limits practical application. We aim to develop a new single-shot PA imaging technique that only requires a one-time calibration for imaging different objects using a single-element transducer. We develop an imaging method, PA imaging through a spatiotemporal encoder (PAISE), to address the above issue. The spatial information is effectively coded into unique temporal features by the spatiotemporal encoder, which allows for compressive image reconstruction. An ultrasonic waveguide is proposed as a critical element to guide the PA waves from the object into the prism, which effectively accounts for the varied boundary condition of different objects. We further add irregular-shaped edges on the prism to introduce randomized internal reflections and further facilitate the scrambling of acoustic waves. The proposed technique is validated through comprehensive numerical simulations and experiments, and it is demonstrated that PAISE can successfully overcome the changed boundary condition and can image different samples given a single calibration. The proposed PAISE technique is capable of single-shot widefield PA imaging with a single-element transducer and does not require sample-specific calibration, which successfully overcomes the major limitation of previous PATER technology. [ABSTRACT FROM AUTHOR]

We sequenced the complete mitochondrial genome (mitogenome) of Neochauliodes parasparsus . The 15,995-bp mitogenome contained the standard set of 13 protein-coding genes, 22 transfer RNA genes (tRNAs), 2 ribosomal RNA genes (rRNAs), and a putative control region, with a gene arrangement that was identical to that reported for most other megalopteran species. We also predicted the secondary structure of all the RNA genes and analysed the preferred codon usage of the protein-coding genes. The putative 1265-bp control region contained two tandem repeated regions and several microsatellite-like elements. The phylogenetic analysis of available neuropteridan mitogenomes, based on the 13 protein-coding genes, appeared to support the current view of the neuropteridan phylogeny, and among the Neochauliodes spp., N. parasparsus was the most closely related to N. punctatolosus . [ABSTRACT FROM AUTHOR]

This paper presents a computational model to address one prominent psychological behavior of human beings to recognize images. The basic pursuit of our method can be concluded as that differences among multiple images help visual recognition. Generally speaking, we propose a statistical framework to distinguish what kind of image features capture sufficient category information and what kind of image features are common ones shared in multiple classes. Mathematically, the whole formulation is subject to a generative probabilistic model. Meanwhile, a discriminative functionality is incorporated into the model to interpret the differences among all kinds of images. The whole Bayesian formulation is solved in an Expectation-Maximization paradigm. After finding those discriminative patterns among different images, we design an image categorization algorithm to interpret how these differences help visual recognition within the bag-of-feature framework. The proposed method is verified on a variety of image categorization tasks including outdoor scene images, indoor scene images as well as the airborne SAR images from different perspectives. [ABSTRACT FROM AUTHOR]

A xylanase gene, xyn- b39, coding for a multidomain glycoside hydrolase (GH) family 10 protein was cloned from the genomic DNA of the alkaline wastewater sludge of a paper mill. Its deduced amino acid sequence of 1,481 residues included two carbohydrate-binding modules (CBM) of family CBM_4_9, one catalytic domain of GH 10, one family 9 CBM and three S-layer homology (SLH) domains. xyn- b39 was expressed heterologously in Escherichia coli, and the recombinant enzyme was purified and characterized. Xyn-b39 exhibited maximum activity at pH 7.0 and 60 °C, and remained highly active under alkaline conditions (more than 80 % activity at pH 9.0 and 40 % activity at pH 10.0). The enzyme was thermostable at 55 °C, retaining more than 90 % of the initial activity after 2 h pre-incubation. Xyn-b39 had wide substrate specificity and hydrolyzed soluble substrates (birchwood xylan, beechwood xylan, oat spelt xylan, wheat arabinoxylan) and insoluble substrates (oat spelt xylan and wheat arabinoxylan). Hydrolysis product analysis indicated that Xyn-b39 was an endo-type xylanase. The K and V values of Xyn-b39 for birchwood xylan were 1.01 mg/mL and 73.53 U/min/mg, respectively. At the charge of 10 U/g reed pulp for 1 h, Xyn-b39 significantly reduced the Kappa number ( P < 0.05) with low consumption of chlorine dioxide alone. [ABSTRACT FROM AUTHOR]

Fluorescent probes with in-situ visual feature have received numerous attentions for detecting doxycycline (DC), a semisynthetic tetracycline antibiotic widely used in animal husbandry. However, reported fluorescent probes commonly fail to selectively detect DC among tetracycline antibiotics due to their structural similarity. In this work, bovine serum albumin-capped gold nanoclusters (BSA-AuNCs) were ingeniously used as the ratiometric fluorescent probe for detecting DC over other tetracycline antibiotics through the selective sensitization effect of BSA on DC. After adding DC, the red fluorescence of BSA-AuNCs almost remained unchanged, while the green fluorescence of DC also emerged under the sensitization of BSA. BSA-AuNCs showed the highest response toward DC among tetracycline antibiotics ascribed to the strongest sensitization effect of BSA on DC. BSA-AuNCs also displayed the features of simple synthesis, short response time (1 min) and low detection limit (36 nM). BSA-AuNCs were finally applied to detecting DC in fish samples, and further fabricated into test strips for ease of carrying. Thus, this work proposes an efficient strategy to design fluorescent probe for selectively detecting DC among tetracycline antibiotics. [Display omitted] • BSA-AuNCs could selectively detect doxycycline (DC) among tetracycline antibiotics. • The selective fluorescence sensitization effect of BSA on DC caused this phenomenon. • Fluorescent test strips were further fabricated using BSA-AuNCs for ease of carrying. [ABSTRACT FROM AUTHOR]

• A model-free method of permittivity analysis to reveal EMR response of biomaterial. • A featured signal of cells/lipid membranes relevant to β-dispersion is observed. • The results of our method and the model-fitting method are positively correlated. • Our method requires less computing resource and is applicable to other materials. Electromagnetic radiation (EMR) is omnipresent on earth and may interact with the biological systems in diverse manners. But the scope and nature of such interactions remain poorly understood. In this study, we have measured the permittivity of cells and lipid membranes over the EMR frequency range of 20 Hz to 4.35 × 1010 Hz. To identify EMR frequencies that display physically intuitive permittivity features, we have developed a model-free method that relies on a potassium chloride reference solution of direct-current (DC) conductivity equal to that of the target sample. The dielectric constant, which reflects the capacity to store energy, displays a characteristic peak at 105–106 Hz. The dielectric loss factor, which represents EMR absorption, is markedly enhanced at 107–109 Hz. The fine characteristic features are influenced by the size and composition of these membraned structures. Mechanical disruption results in abrogation of these characteristic features. Enhanced energy storage at 105–106 Hz and energy absorption at 107–109 Hz may affect certain membrane activity relevant to cellular function. [ABSTRACT FROM AUTHOR]

The rapid growth of wireless electronic devices has raised concerns about the harmful effects of leaked electromagnetic radiation (EMR) on human health. Even though numerous studies have been carried out to explore the biological effects of EMR, no clear conclusions have been drawn about the effect of radio frequency (RF) EMR on oligodendrocytes. To this end, we exposed oligodendroglia and three other types of brain cells to 2.4 GHz EMR for 6 or 48 h at an average input power of 1 W in either a continuous wave (CW-RF) or a pulse-modulated wave (PW-RF, 50 Hz pulse frequency, 1/3 duty cycle) pattern. RNA sequencing, RT-qPCR, and Western blot were used to examine the expression of C/EBPβ and its related genes. Multiple reaction monitoring (MRM) was used to examine the levels of expression of C/EBPβ-interacting proteins. Our results showed that PW-RF EMR significantly increased the mRNA level of C/EBPβ in oligodendroglia but not in other types of cells. In addition, the expression of three isoforms and several interacting proteins and targeted genes of C/EBPβ were markedly changed after 6-h PW-RF but not CW-RF. Our results indicated that RF EMR regulated the expression and functions of C/EBPβ in a waveform- and cell-type-dependent manner. [ABSTRACT FROM AUTHOR]

The salamander Pachyhynobius shangchengensis (Hynobiidae) is a vulnerable species restricted to a patchy distribution associated with small mountain streams surrounded by forested slopes in the Mount Dabieshan region in southeastern China. However, molecular phylogeography and population genetic structure of P. shangchengensis remain poorly investigated. In this study, we explored the genetic structure and phylogeography of P. shangchengensis based on partial sequences of the mitochondrial DNA (mtDNA) cytochrome b and cytochrome c oxidase subunit I genes. Fifty-one haplotypes and four clades were found among 93 samples. Phylogenetic analyses revealed four deeply divergent and reciprocally monophyletic mtDNA lineages that approximately correspond to four geographic regions separated by complicated topography and long distances. The distinct geographic distributions of all lineages and the estimated divergence time suggest spatial and temporal separation coinciding with climatic changes during the Pleistocene. Analysis of molecular variance indicated that most of the observed genetic variation occurred among the four groups, implying long-term interruption of gene flow, and the possible separation of P. shangchengensis into four management units for conservation. [ABSTRACT FROM AUTHOR]

A physical water model based on the similarity principle is established to investigate the fluid flow and mixing phenomena during the Ruhrstahl–Heraeus (RH) steel refining process. The velocity distribution and the turbulent features on the center section are obtained using particle image velocimetry (PIV) measurement. Two vortexes between the down‐leg snorkel and the ladle sidewall are observed. The effects of the number of gas‐injection nozzles and the liquid levels in the vacuum chamber on the fluid phenomena are performed. More injected nozzles and a higher liquid level in the vacuum chamber generate larger velocity in the ladle. Twenty monitors in the ladle are used to monitor the variation of the conductivity to obtain the mixing time, indicating that the mixing time varies much with locations. The distribution of the mixing time on the vertical center section of the ladle is obtained. Moreover, the relationship between the circulation rate and the mixing time is obtained, indicating that the mixing time decreases with increasing circulation rate, and the slope of their relationship is −0.35. [ABSTRACT FROM AUTHOR]

Plain strain deformation is performed on solid steel samples at 1473 K and semi‐solid samples at 1743 K. The deformation of inclusions under the reductions of 10%, 20%, and 30% is studied. In the solid steel, the average aspect ratio of inclusions increases from 1.23 in the original slab to 2.07, 2.23, and 2.30 under the reduction of 10%, 20%, and 30%. The deformation of inclusions in the semi‐solid steel, which is much smaller than that in the solid steel, is hardly influenced by the reduction. Inclusion deformation is explained by the difference of hardness between the inclusion phase and the steel matrix. Though inclusions in steel samples deformed at 1473 K are a little harder than those in steel samples deformed at 1743 K due to the thicker CaS shell formed by the transformation of inclusion composition. Stress–strain curves indicate that the semi‐solid steel matrix at is much softer. In the semi‐solid steel at 1743 K, the soft steel matrix deforms more than inclusions, leading, in turn, to a smaller deformation of inclusions. [ABSTRACT FROM AUTHOR]

Genome-wide association studies (GWASs) generally focus on a single marker, which limits the elucidation of the genetic architecture of complex traits. Herein, we present a new computational framework, termed probabilistic natural mapping (PALM), for performing gene-level association tests. PALM robustly reveals the inherent genomic structures of genes and generates feature representations that can be seamlessly incorporated into conventional statistic tests. Our approach substantially improves the effectiveness of uncovering associations derived from a subgroup of variants with weak effects, which represents a known challenge associated with existing methods. We applied PALM in a gastric cancer GWAS and identified two additional gastric cancer-associated susceptibility genes, NOC3L and RUNDC2A. The robust susceptibility discoveries of PALM are widely supported by existing studies from other biological perspectives. PALM will be useful for further GWAS analytical strategies that use gene-level analyses. [ABSTRACT FROM AUTHOR]

The article informs about research to study the spread the opened nuclear envelope (NE) onto the grids with minimal force and used the chemical cross-linker glutaraldehyde to stabilize the nuclear pore complex (NPC) resides on the NE and mediates nucleocytoplasmic cargo transport to reduce conformational heterogeneity of the sample. It mentions that cytoplasmic ring (CR) subunit of human NPC reconstructed by cryo–electron tomography through subtomogram averaging.

The γ-secretase complex, comprising presenilin 1 (PS1), PEN-2, APH-1 and nicastrin, is a membrane-embedded protease that controls a number of important cellular functions through substrate cleavage. Aberrant cleavage of the amyloid precursor protein (APP) results in aggregation of amyloid-β, which accumulates in the brain and consequently causes Alzheimer's disease. Here we report the three-dimensional structure of an intact human γ-secretase complex at 4.5 Å resolution, determined by cryo-electron-microscopy single-particle analysis. The γ-secretase complex comprises a horseshoe-shaped transmembrane domain, which contains 19 transmembrane segments (TMs), and a large extracellular domain (ECD) from nicastrin, which sits immediately above the hollow space formed by the TM horseshoe. Intriguingly, nicastrin ECD is structurally similar to a large family of peptidases exemplified by the glutamate carboxypeptidase PSMA. This structure serves as an important basis for understanding the functional mechanisms of the γ-secretase complex. [ABSTRACT FROM AUTHOR]

The opportunistic pathogen P seudomonas aeruginosa uses the type VI secretion system ( T6 SS) to deliver the muramidase Tse3 into the periplasm of rival bacteria to degrade their peptidoglycan ( PG). Concomitantly, P . aeruginosa uses the periplasm-localized immunity protein Tsi3 to prevent potential self-intoxication caused by Tse3, and thus gains an edge over rival bacteria in fierce niche competition. Here, we report the crystal structures of Tse3 and the Tse3- Tsi3 complex. Tse3 contains an annexin repeat-like fold at the N-terminus and a G-type lysozyme fold at the C-terminus. One loop in the N-terminal domain ( Loop 12) and one helix (α9) from the C-terminal domain together anchor Tse3 and the Tse3- Tsi3 complex to membrane in a calcium-dependent manner in vitro, and this membrane-binding ability is essential for Tse3's activity. In the C-terminal domain, a Y-shaped groove present on the surface likely serves as the PG binding site. Two calcium-binding motifs are also observed in the groove and these are necessary for Tse3 activity. In the Tse3- Tsi3 structure, three loops of Tsi3 insert into the substrate-binding groove of Tse3, and three calcium ions present at the interface of the complex are indispensable for the formation of the Tse3- Tsi3 complex. [ABSTRACT FROM AUTHOR]

Pseudomonas aeruginosa uses the type VI secretion system (T6SS) to inject effector proteins into rival cells in niche competition. Tse3, one of the effectors of T6SS, is delivered into the periplasm of recipient cells. Tse3 functions as a muramidase that degrades the β-1,4-linkage between N-acetylmuramic acid (MurNAc) and N-acetylglucosamine (GlcNAc) in peptidoglycan, thus leading to lysis of the recipient cells and providing a competitive advantage to the donor cells. Here, the preliminary crystallographic study of Tse3 is reported. A crystal of Tse3 diffracted to 1.5 Å resolution. It belonged to space group C121, with unit-cell parameters a = 166.99, b = 70.13, c = 41.94 Å, α = 90.00, β = 90.52, γ = 90.00° and one molecule per asymmetric unit. [ABSTRACT FROM AUTHOR]

STING functions as both an adaptor protein signaling cytoplasmic double-stranded DNA and a direct immunosensor of cyclic diguanylate monophosphate (c-di-GMP). The crystal structures of the C-terminal domain of human STING (STINGCTD) and its complex with c-di-GMP reveal how STING recognizes c-di-GMP. In response to c-di-GMP binding, two surface loops, which serve as a gate and latch of the cleft formed by the dimeric STINGCTD, undergo rearrangements to interact with the ligand. [ABSTRACT FROM AUTHOR]

Summary Voltage-gated sodium (Na v ) channels initiate and propagate action potentials. Here, we present the cryo-EM structure of EeNa v 1.4, the Na v channel from electric eel, in complex with the β1 subunit at 4.0 Å resolution. The immunoglobulin domain of β1 docks onto the extracellular L5 I and L6 IV loops of EeNa v 1.4 via extensive polar interactions, and the single transmembrane helix interacts with the third voltage-sensing domain (VSD III ). The VSDs exhibit “up” conformations, while the intracellular gate of the pore domain is kept open by a digitonin-like molecule. Structural comparison with closed Na v PaS shows that the outward transfer of gating charges is coupled to the iris-like pore domain dilation through intricate force transmissions involving multiple channel segments. The IFM fast inactivation motif on the III-IV linker is plugged into the corner enclosed by the outer S4-S5 and inner S6 segments in repeats III and IV, suggesting a potential allosteric blocking mechanism for fast inactivation. [ABSTRACT FROM AUTHOR]