Dynamic mechanochemical feedback between curved membranes and BAR protein self-organization

In many physiological situations, BAR proteins reshape membranes with pre-existing curvature (templates), contributing to essential cellular processes. However, the mechanism and the biological implications of this reshaping process remain unclear. Here we show, both experimentally and through modelling, that BAR proteins reshape low curvature membrane templates through a mechanochemical phase transition. This phenomenon depends on initial template shape and involves the co-existence and progressive transition between distinct local states in terms of molecular organization (protein arrangement and density) and membrane shape (template size and spherical versus cylindrical curvature). Further, we demonstrate in cells that this phenomenon enables a mechanotransduction mode, in which cellular stretch leads to the mechanical formation of membrane templates, which are then reshaped into tubules by BAR proteins. Our results demonstrate the interplay between membrane mechanics and BAR protein molecular organization, integrating curvature sensing and generation in a comprehensive framework with implications for cell mechanical responses.

Systematic study of precursor effects on structure and oxygen reduction reaction activity of FeNC catalysts

In this work, the effect of porphyrin loading and template size is varied systematically to study its impact on the oxygen reduction reaction (ORR) activity and selectivity as followed by rotating ring disc electrode experiments in both acidic and alkaline electrolytes. The structural composition and morphology are investigated by 57 Fe Mössbauer spectroscopy, transmission electron microscopy, Raman spectroscopy and Brunauer–Emmett–Teller analysis. It is shown that with decreasing template size, specifically the ORR performance towards fuel cell application gets improved, while at constant area loading of the iron precursor (here expressed in number of porphyrin layers), the iron signature does not change much. Moreover, it is well illustrated that too large area loadings result in the formation of undesired side phases that also cause a decrease in the performance, specifically in acidic electrolyte. Thus, if the impact of morphology is the focus of research it is important to consider the area loading rather than its weight loading. At constant weight loading, beside morphology the structural composition can also change and impact the catalytic performance. This article is part of the theme issue ‘Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 2)’.

TADBD: a sensitive and fast method for detection of typologically associated domain boundaries

A topologically associated domain (TAD) is a self-interacting genomic block. Detection of TAD boundaries on Hi-C contact matrix is one of the most important issues in the analysis of 3D genome architecture at TAD level. Here, we present TAD boundary detection (TADBD), a sensitive and fast computational method for detection of TAD boundaries on Hi-C contact matrix. This method implements a Haar-based algorithm by considering Haar diagonal template, acceleration via a compact integrogram, multi-scale aggregation at template size and statistical filtering. In most cases, comparison results from simulated and experimental data show that TADBD outperforms the other five methods. In addition, a new R package for TADBD is freely available online.

Evaluation of an Intelligent Computer Method for the Automatic Mosaic of Sequential Slub Yarn Images

This paper is the second part of a series reporting the recent development of a computerised method for automatic mosaic sequential yarn images. In our earlier work, an effective method for stitching sequence slub yarn images automatically was developed based on image processing and the normalised cross correlation (NCC) method. 100 image pairs of two kinds of slub yarn were measured in certain specific conditions, such as the frame rate, size of stitching template, etc., and the measurement results were evaluated with the manual method. In this paper, the effects of various influencing factors are numerically examined, including the stitching template size, threshold value, frame rate, and computing time of the mosaic algorithm. The feasibility and accuracy of the fully computerized method were evaluated further under the various influencing parameters. One hundred percent cotton ring spun single slub yarns of 27.8, 15.6, and 9.7 tex were prepared and used for the evaluation. The measurement results obtained by the method proposed are analysed and compared with those measured manually by Adobe Photoshop. The experimental results show that the method proposed can accurately find the stitch position and has a high consistency with the manual method when the matching template is 100 × N pixels, the threshold value T1 ∈ [20, 40] and T2 ∈ [51, 80], and the frame rate is greater than 40 fps.

Controlling the Size of Interior Core of Silicon Nanowires

As the physical and electrical properties of silicon nanowires (SiNWs) are determined by their dimension, it is necessary to control their dimension to integrate them in a device. SiNWs were synthesized via Vapor-Liquid-Solid (VLS) mechanism in hot-wire chemical vapor process (HWCVP) technique using silane as a Si source and Sn as a catalyst. Different sizes of nano-template have been made by depositing of different amount of Sn using thermal evaporation method. The size of nano-template is found to be increased with the quantity of Sn. The diameter of resulted SiNWs depends on the size of the nano-template and it increases with the nano-template size. However, the diameter of SiNWs is found to be much larger than the used nano-template which is due to the deposition of silicon film on the sidewalls of the growing SiNWs. It is demonstrated here that the diameter of the interior core of SiNWs can be controlled desirable by adjusting the size of the nano-template.

An Improved Adaptive Template Size Pixel-Tracking Method for Monitoring Large-Gradient Mining Subsidence

The monitoring of large-gradient deformation caused by coal mining is of great significance to the prevention and management of disasters in mining areas. The interferometric synthetic aperture radar (InSAR) method captures the small-gradient ground deformation on the edge of the subsidence basin accurately but is unreliable for capturing large-gradient deformation. The intensity-based pixel-tracking method (e.g., the normalized cross-correlation (NCC) method) can overcome the limitations of InSAR’s maximum detectable displacement gradient and incoherence. However, the pixel-tracking method is sensitive to template size. It is difficult to estimate ground subsidence accurately by the conventional pixel-tracking method with fixed template size. In this paper, the signal-to-noise ratio (SNR) is redefined and an improved locally adaptive template size method is proposed by identifying optimal template adaptively based on maximization of the redefined SNR. The constraint radius is used to constrain the search area in this improved method. The frequency of misrepresentation is reduced by finding the peak of the correlation coefficient surface within the search area. Both simulation data and real ground subsidence data are used to test this algorithm. The results show that this method can improve monitoring accuracy compared with the traditional pixel-tracking method for fixed template size.

Scale Adaptive Kernelized Correlation Filter Tracker with Feature Fusion

Visual tracking is one of the most important components in numerous applications of computer vision. Although correlation filter based trackers gained popularity due to their efficiency, there is a need to improve the overall tracking capability. In this paper, a tracking algorithm based on the kernelized correlation filter (KCF) is proposed. First, fused features including HOG, color-naming, and HSV are employed to boost the tracking performance. Second, to tackle the fixed template size, a scale adaptive scheme is proposed which strengthens the tracking precision. Third, an adaptive learning rate and an occlusion detection mechanism are presented to update the target appearance model in presence of occlusion problem. Extensive evaluation on the OTB-2013 dataset demonstrates that the proposed tracker outperforms the state-of-the-art trackers significantly. The results show that our tracker gets a 14.79% improvement in success rate and a 7.43% improvement in precision rate compared to the original KCF tracker, and our tracker is robust to illumination variations, scale variations, occlusion, and other complex scenes.

Molecular imprinting in particle-stabilized emulsions: enlarging template size from small molecules to proteins and cells

Molecular imprinting of small organic compounds is now a standard procedure for preparation of tailor-designed affinity materials. Molecularly imprinted polymers (MIPs) have outstanding stability and can be prepared in a large quantity, therefore are useful replacements for biological receptors for a number of applications including product purification, analytical separation, chemical sensing and controlled delivery and biomineralization. Although preparation of MIPs, in particular using the non-covalent imprinting strategy, has become a routine practice in many research laboratories, new synthetic methods continued to be invented, which contribute to new MIPs with unprecedented functional performances. As the size of the template increases from small organic compounds to biomacromolecules to large virus particles and cells, the traditional methods of imprinting often fail to give useful MIP products. Another important aspect is the shift from organic solvents to water for MIPs designed for treatment or analysis of biological samples. The demand on water-compatibility and recognition of larger entities for MIPs call for new and efficient synthetic methods. This mini review will summarize the recent progress of molecular imprinting using particle-stabilized emulsion as a general synthetic platform to furnish the new MIPs with the desired functions.