A Class of Weighted Low Rank Approximation of the Positive Semidefinite Hankel Matrix

We consider the weighted low rank approximation of the positive semidefinite Hankel matrix problem arising in signal processing. By using the Vandermonde representation, we firstly transform the problem into an unconstrained optimization problem and then use the nonlinear conjugate gradient algorithm with the Armijo line search to solve the equivalent unconstrained optimization problem. Numerical examples illustrate that the new method is feasible and effective

p21-activated kinase is involved in the sporulation, pathogenicity, and stress response of Arthrobotrys oligospora under the indirect regulation of Rho GTPase-activating protein

The p21-GTPase-activated protein kinases (PAKs) participate in signal transduction downstream of Rho GTPases, which are regulated by Rho GTPase-activating proteins (Rho-GAP). Herein, we characterized two orthologous Rho-GAPs (AoRga1 and AoRga2) and two PAKs (AoPak1 and AoPak2) through bioinformatics analysis and reverse genetics in Arthrobotrys oligospora, a typical nematode-trapping (NT) fungus. The transcription analyses performed at different development stages suggested that Aopaks and Aorga1 play a crucial role during sporulation and trap formation, respectively. In addition, we successfully deleted Aopak1 and Aorga1 via the homologous recombination method. The disruption of Aopak1 and Aorga1 caused a remarkable reduction in spore yield and the number of nuclei per cell, but did not affect mycelial growth. In ∆Aopak1 mutants, the trap number was decreased at 48 h after the introduction of nematodes, but nematode predatory efficiency was not affected because the extracellular proteolytic activity was increased. On the contrary, the number of traps in ∆Aorga1 mutants was significantly increased at 36 h and 48 h. In addition, Aopak1 and Aorga1 had different effects on the sensitivity to cell-wall-disturbing reagent and oxidant. A yeast two-hybrid assay revealed that AoPak1 and AoRga1 both interacted with AoRac, and AoPak1 also interacted with AoCdc42. Furthermore, the Aopaks were up-regulated in ∆Aorga1 mutants, and Aorga1 was down-regulated in ∆Aopak1 mutants. These results reveal that AoRga1 indirectly regulated AoPAKs by regulating small GTPases

Optimization of Extraction Process of Polysaccharide from Black Corn Kernel by Response Surface Method and Analysis of Its Antioxidant Activity

In order to explore the optimum extraction process of polysaccharide and antioxidant activity in vitro in black corn kernel. In this study, black corn kernel was used as raw material, ultrasonic-assisted extraction was applied to extract polysaccharides from black corn kernel. To explore the effects of ultrasonic power, solid-liquid ratio, extraction time, temperature and frequency on the yield of polysaccharide. The extraction process of polysaccharide from black corn kernel was optimized by response surface methodology. Besides, the antioxidant activity of the polysaccharide was investigated by measuring its scavenging ability on DPPH·, ABTS+·, and ·OH. The results showed that the extraction yield of polysaccharide from black corn kernel could reach up to 41.09%±0.59%, in these conditions: The solid-liquid ratio was 1:20 g/mL, the extraction temperature was 74 ℃, the extraction time was 60 min and the extraction frequency was 3 times. The IC50 values of scavenging rates on DPPH·, ABTS+· and ·OH were 1.959, 1.529 and 0.3554 mg/mL, respectively. Moreover, the scavenging rates showed a certain dose-effect relationship with the sample concentration, indicating that the polysaccharide had a strong antioxidant activity, thus providing a theoretical basis for further research and utilization

Computational cytometer based on magnetically modulated coherent imaging and deep learning.

Detecting rare cells within blood has numerous applications in disease diagnostics. Existing rare cell detection techniques are typically hindered by their high cost and low throughput. Here, we present a computational cytometer based on magnetically modulated lensless speckle imaging, which introduces oscillatory motion to the magnetic-bead-conjugated rare cells of interest through a periodic magnetic force and uses lensless time-resolved holographic speckle imaging to rapidly detect the target cells in three dimensions (3D). In addition to using cell-specific antibodies to magnetically label target cells, detection specificity is further enhanced through a deep-learning-based classifier that is based on a densely connected pseudo-3D convolutional neural network (P3D CNN), which automatically detects rare cells of interest based on their spatio-temporal features under a controlled magnetic force. To demonstrate the performance of this technique, we built a high-throughput, compact and cost-effective prototype for detecting MCF7 cancer cells spiked in whole blood samples. Through serial dilution experiments, we quantified the limit of detection (LoD) as 10 cells per millilitre of whole blood, which could be further improved through multiplexing parallel imaging channels within the same instrument. This compact, cost-effective and high-throughput computational cytometer can potentially be used for rare cell detection and quantification in bodily fluids for a variety of biomedical applications

A Class of Weighted Low Rank Approximation of the Positive Semidefinite Hankel Matrix

We consider the weighted low rank approximation of the positive semidefinite Hankel matrix problem arising in signal processing. By using the Vandermonde representation, we firstly transform the problem into an unconstrained optimization problem and then use the nonlinear conjugate gradient algorithm with the Armijo line search to solve the equivalent unconstrained optimization problem. Numerical examples illustrate that the new method is feasible and effective

Global Mild Solutions and Attractors for Stochastic Viscous Cahn-Hilliard Equation

This paper is devoted to the study of mild solutions for the initial and boundary value problem of stochastic viscous Cahn-Hilliard equation driven by white noise. Under reasonable assumptions we first prove the existence and uniqueness result. Then, we show that the existence of a stochastic global attractor which pullback attracts each bounded set in appropriate phase spaces

The Effects of Demographic Trends on the High-Quality Development of the Chinese Sports Industry

Demographic change is a fundamental characteristic of China’s demographic development. The primary problem in China’s population development has shifted in recent years from overall pressure to structural challenges. Using data from China’s seventh demographic census, this study examines the dynamics of sports consumption growth from the perspective of population structure, analyzes the characteristics of the current population structure and the current state of sports consumption development, and establishes a regression to examine the impact of population structure change trends on sports industry development. The study demonstrates that there are varying degrees of correlation between different demographic trends and the sports industry in China’s aging population: the added value per capita of the sports industry is significantly (p < 0.01), positively correlated with the proportion of the elderly population and the number of graduates from general higher education institutions. While the expansion of the sports sector continues to be positive, there are numerous issues that need to be addressed. To encourage the development of a high-quality sports industry, proactive countermeasures are proposed to adjust population policy, increase population quality, and promote the comprehensive upgrading of sports consumption

Malignant pleural effusion supernatant is an alternative liquid biopsy specimen for comprehensive mutational profiling

Background The clinical utility of malignant pleural effusion (MPE) to detect mutation has been well documented; however, routine practice of the use of MPE involves collection of the cell pellet to detect mutation, and limited studies have interrogated the MPE supernatant as an alternative source of tumor‐derived DNA for mutation profiling. In this study, we investigated the potential of MPE supernatant as a liquid biopsy specimen by comparing its mutation profile with that of matched MPE cell pellets, tissue, and plasma samples. Methods Sequencing data from 17 patients with matched lung tissue, plasma, and MPE samples were retrospectively analyzed. Capture‐based targeted sequencing was performed on matched plasma and MPE supernatant samples obtained from 154 patients with advanced lung adenocarcinoma. Results MPE supernatants had significantly higher median maximum allelic fractions (maxAFs) than their corresponding cell pellets (P = 0.008) and plasma samples (P = 0.036), and a comparable maxAF value to that of tissue samples (P = 0.675). Comparison of MPE supernatant and matched plasma samples from the larger cohort (n = 154) revealed a comparable mutation detection rate; however, MPE supernatant had a significantly higher median maxAF than plasma (20.3% vs. 1.13%; P < 0.001). Furthermore, the concordance rates between MPE supernatant and plasma for single‐nucleotide and copy number variations were 56% and 18%, respectively, suggesting that MPE supernatant reveals a more comprehensive mutation spectrum, particularly for copy number variations. Conclusion Overall, our study shows that MPE supernatant is an optimal alternative source of tumor‐derived DNA for comprehensive mutation profiling