Considering the discontinuous square pulse wave and continuous sine pulsating wave, we report a distinctive supercharging phenomenon of fluid in a water-filled semi-enclosed pipe and reveal the ...supercharging regularity. We demonstrate that there can be significant supercharging phenomena at the pipe end-face if the water is periodically injected at the pipe inlet with certain frequency. Compared to the traditional pulsating injection method, the present injection strategy can remarkably enhance the peak pressure of the water at the end face of the pipe. We explained this phenomenon by numerical simulations based on the computational fluid dynamic method. It's found that there is a quantitative relationship between the optimal pulse frequency, pipe length and wave speed. The proposed frequency model is suitable for the multi-waveform, such as sine wave, square wave and arcuate wave. The fluid pressure at the pipe end-face intermittently increases and the end-face peak pressure is largest when the inlet injection frequency equals to the optimal frequency.
3D bioprinting additively assembles bio‐inks to manufacture tissue‐mimicking biological constructs, but with the typical building blocks limited to 1D filaments. Here, it is developed a voxelated ...bioprinting technique for the digital assembly of spherical particles (DASP), which are effectively 0D voxels—the basic unit of 3D structures. It is shown that DASP enables on‐demand generation, deposition, and assembly of viscoelastic bio‐ink droplets. A two‐parameter diagram is developed to outline the viscoelasticity of bio‐inks required for printing spherical particles of good fidelity. Moreover, a strategy is developed for engineering bio‐inks with independently controllable viscoelasticity and mesh size, two of the most important yet intrinsically coupled physical properties of biomaterials. Using DASP, mechanically robust, multiscale porous scaffolds composed of interconnected yet distinguishable hydrogel particles are created. Finally, it is demonstrated the application of the scaffolds in encapsulating human pancreatic islets for sustained responsive insulin release. Together with the knowledge of bio‐ink design, DASP might be used to engineer highly heterogeneous, yet tightly organized tissue constructs for therapeutic applications.
A 3D bioprinting technology is developed to enable on‐demand generation, deposition, and assembly of viscoelastic bio‐ink droplets in a cytocompatible environment. A strategy is developed to independently control viscoelasticity and mesh size of bio‐inks. The technique allows for easy manufacturing mechanically robust multiscale porous scaffolds, which can be used to encapsulate human pancreatic islets for sustained responsive insulin release.
Catalytic asymmetric allylation of ketones under proton‐transfer conditions is a challenging issue due to the limited pronucleophiles and the electrophilic inertness of ketones. Herein, a ...copper(I)‐catalyzed asymmetric allylation of ketones with 2‐aza‐1,4‐dienes (N‐allyl‐1,1‐diphenylmethanimines) is disclosed, which affords a series of functionalized homoallyl tertiary alcohols in high to excellent enantioselectivity. Interestingly, N‐allyl‐1,1‐diphenylmethanimines work as synthetic equivalents of propanals. Upon the acidic workup, a formal asymmetric β‐addition of propanals to ketones is achieved. An investigation on KIE effect indicates that the deprotonation of N‐allyl‐1,1‐diphenylmethanimines is the rate‐determining step, which generates nucleophilic allyl copper(I) species. Finally, the synthetic utility of the present method is demonstrated by the asymmetric synthesis of (R)‐boivinianin A and (R)‐gossonorol.
A copper(I)‐catalyzed asymmetric allylation of ketones with 2‐aza‐1,4‐dienes (N‐allyl‐1,1‐diphenylmethanimines) is disclosed, which affords a series of functionalized homoallyl tertiary alcohols in high to excellent enantioselectivity.
Background
Immunohistochemistry (IHC) is an essential technique in surgical and clinical pathology for detecting diagnostic, prognostic, and predictive biomarkers for personalized cancer therapy. ...However, the lack of standardization and reference controls results in poor reproducibility, and a reliable tool for IHC quantification is urgently required. The objective of this study was to describe a novel approach in which H3F3B (histone H3, family 3B) can be used as an internal reference standard to quantify protein expression levels using IHC.
Methods
The authors enrolled 89 patients who had human epidermal growth factor receptor 2 (HER2)‐positive breast cancer (BC). They used a novel IHC‐based assay to measure protein expression using H3F3B as the internal reference standard. H3F3B was uniformly expressed at the protein level in all tumor regions in cancer tissues. HER2 expression levels were measured with the H‐score using HALO software.
Results
Kaplan–Meier analysis indicated that, among patients who had HER2‐positive BC in The Cancer Genome Atlas data set and the authors' data set, the subgroup with low HER2 expression had a significantly better prognosis than the subgroup with high HER2 expression. Furthermore, the authors observed that HER2 expression levels were precisely evaluated using the proposed method, which can classify patients who are at higher risk of HER2‐positive BC to receive trastuzumab‐based adjuvant therapy. Dual‐color IHC with H3F3B is an excellent tool for internal and external quality control of HER2 expression assays.
Conclusions
The proposed IHC‐based quantification method accurately assesses HER2 expression levels and provides insights for predicting clinical prognosis in patients with HER2‐positive BC who receive trastuzumab‐based adjuvant therapy.
The proposed immunohistochemistry‐based quantification method allows accurate assessment of human epidermal growth factor receptor 2 (HER2) protein expression levels. The approach provides insights for predicting the clinical prognosis of patients with HER2‐positive breast cancer who receive trastuzumab‐based adjuvant therapy.
Hardhats are an important safety measure used to protect construction workers from accidents. However, accidents caused in ignorance of wearing hardhats still occur. In order to strengthen the ...supervision of construction workers to avoid accidents, automatic non-hardhat-use (NHU) detection technology can play an important role. Existing automatic methods of detecting hardhat avoidance are commonly limited to the detection of objects in near-field surveillance videos. This paper proposes the use of a high precision, high speed and widely applicable Faster R-CNN method to detect construction workers' NHU. To evaluate the performance of Faster R-CNN, more than 100,000 construction worker image frames were randomly selected from the far-field surveillance videos of 25 different construction sites over a period of more than a year. The research analyzed various visual conditions of the construction sites and classified image frames according to their visual conditions. The image frames were input into Faster R-CNN according to different visual categories. The experimental results demonstrate that the high precision, high recall and fast speed of the method can effectively detect construction workers' NHU in different construction site conditions, and can facilitate improved safety inspection and supervision.
•An algorithm based on deep learning for non-hardhat-use (NHU) detection is developed.•A diverse, annotated and reusable training dataset is built.•Image frames in testing dataset are characterized by various visual conditions.•Results demonstrate that precision, recall rate, speed and robustness are highly improved.•The proposed method can facilitate safety inspection and supervision.
Combining rich spectral and spatial information, a hyperspectral image (HSI) can provide a more comprehensive characterization of the Earth's surface. To better exploit HSIs, a large number of ...algorithms have been developed during the past few decades. Due to their very high correlation between spectral channels and spatial pixels, HSIs have intrinsically sparse and low-rank structures. The sparse representation (SR) and low-rank representation (LRR)-based methods have proven to be powerful tools for HSI processing and are widely used in different HS fields. In this article, we present a survey of low-rank and sparse-based HSI processing methods in the fields of denoising, superresolution, dimension reduction, unmixing, classification, and anomaly detection. The purpose is to provide guidelines and inspiration to practitioners for promoting the development of HSI processing. For a listing of the key terms discussed in this article, see "Nomenclature."
A new palladium‐catalyzed reductive 5+1 cycloaddition of 3‐acetoxy‐1,4‐enynes with CO, enabled by hydrosilanes, has been developed for delivering valuable functionalized phenols. This methodology ...employs hydrosilanes as the external reagent to facilitate the 5+1 carbonylative benzannulation. The reaction is a conceptually and mechanistically novel carbonylative cycloaddition route for the construction of substituted phenols, through the formation of four new chemical bonds, with excellent functional‐group tolerance.
Pd & CO: Employing reductive palladium catalysis enables a new 5+1 carbonylative benzannulation of 3‐acetoxy‐1,4‐enynes with CO and hydrosilanes. This reaction is facilitated by hydrosilanes, and allows straightforward and practical access to functionalized phenols with excellent functional‐group tolerance and high selectivity.
Measuring the quality of digital videos viewed by human observers has become a common practice in numerous multimedia applications, such as adaptive video streaming, quality monitoring, and other ...digital TV applications. Here we explore a significant, yet relatively unexplored problem: measuring perceptual quality on videos arising from both luma and chroma distortions from compression. Toward investigating this problem, it is important to understand the kinds of chroma distortions that arise, how they relate to luma compression distortions, and how they can affect perceived quality. We designed and carried out a subjective experiment to measure subjective video quality on both luma and chroma distortions, introduced both in isolation as well as together. Specifically, the new subjective dataset comprises a total of 210 videos afflicted by distortions caused by varying levels of luma quantization commingled with different amounts of chroma quantization. The subjective scores were evaluated by 34 subjects in a controlled environmental setting. Using the newly collected subjective data, we were able to demonstrate important shortcomings of existing video quality models, especially in regards to chroma distortions. Further, we designed an objective video quality model which builds on existing video quality algorithms, by considering the fidelity of chroma channels in a principled way. We also found that this quality analysis implies that there is room for reducing bitrate consumption in modern video codecs by creatively increasing the compression factor on chroma channels. We believe that this work will both encourage further research in this direction, as well as advance progress on the ultimate goal of jointly optimizing luma and chroma compression in modern video encoders.
Abstract
Motivation
Protein-to-genome alignment is critical to annotating genes in non-model organisms. While there are a few tools for this purpose, all of them were developed over 10 years ago and ...did not incorporate the latest advances in alignment algorithms. They are inefficient and could not keep up with the rapid production of new genomes and quickly growing protein databases.
Results
Here, we describe miniprot, a new aligner for mapping protein sequences to a complete genome. Miniprot integrates recent techniques such as k-mer sketch and vectorized dynamic programming. It is tens of times faster than existing tools while achieving comparable accuracy on real data.
Availability and implementation
https://github.com/lh3/miniport.
A new, metal-free I
-catalyzed oxidative tandem annulation of 1,6-enynes by employing tert-butyl hydroperoxide (TBHP) as the oxidant and the oxygen atom resource for the synthesis of ...1H-cyclopropa-bnaphthalene-2,7-diones is developed. This reaction allows the formation of three new chemical bonds through selective radical addition across the Ctriple bond, length as m-dashC bond and tandem cyclization cascades, which features a broad 1,6-enyne scope and excellent chemo- and diastereoselectivities.
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