ANALYSIS AND DISCRETIZATION FOR AN OPTIMAL CONTROL PROBLEM OF A VARIABLE-COEFFICIENT RIESZ-FRACTIONAL DIFFUSION EQUATION WITH POINTWISE CONTROL CONSTRAINTS

We present a mathematical and numerical study for a pointwise optimal control problem governed by a variable-coefficient Riesz-fractional diffusion equation.Due to the impact of the variable diffusivity coefficient,existing regularity results for their constantcoefficient counterparts do not apply,while the bilinear forms of the state(adjoint)equation may lose the coercivity that is critical in error estimates of the finite element method.We reformulate the state equation as an equivalent constant-coefficient fractional diffusion equation with the addition of a variable-coefficient low-order fractional advection term.First order optimality conditions are accordingly derived and the smoothing properties of the solutions are analyzed by,e.g.,interpolation estimates.The weak coercivity of the resulting bilinear forms are proven via the Garding inequality,based on which we prove the optimal-order convergence estimates of the finite element method for the(adjoint)state variable and the control variable.Numerical experiments substantiate the theoretical predictions.

Electronic modulation of two-dimensional bismuth-based nanosheets for electrocatalytic CO_(2) reduction to formate: A review

Electrocatalytic CO_(2) reduction reaction(eCO_(2) RR)has significant relevance to settle the global energy crisis and abnormal climate problem via mitigating the excess emission of waste CO_(2) and producing high-value-added chemicals.Currently,eCO_(2) RR to formic acid or formate is one of the most technologically and economically viable approaches to realize high-efficiency CO_(2) utilization,and the development of efficient electrocatalysts is very urgent to achieve efficient and stable catalytic performance.In this review,the recent advances for two-dimensional bismuth-based nanosheets(2D Bi-based NSs)electrocatalysts are concluded from both theoretical and experimental perspectives.Firstly,the preparation strategies of 2D Bi-based NSs in aspects to precisely control the thickness and uniformity are summarized.In addition,the electronic regulation strategies of 2D Bi-based NSs are highlighted to gain insight into the effects of the structure-property relationship on facilitating CO_(2) activation,improving product selectivity,and optimizing carrier transport dynamics.Finally,the considerable challenges and opportunities of 2D Bi-based NSs are discussed to lighten new directions for future research of eCO_(2) RR.

Intestinal toxicity of deoxynivalenol is limited by supplementation with Lactobacillus plantarum JM113 and consequentially altered gut microbiota in broiler chickens

Background: Limited research has focused on the effect of Lactobacillus on the intestinal toxicity of deoxynivalenol(DON).The present study was conducted to investigate the role of Lactobacillus plantarum(L.plantarum) JM113 in protecting against the intestinal toxicity caused by DON.Methods: A total of 144 one-day-old healthy Arbor Acres broilers were randomly distributed into 3 treatments,including the CON(basal diet),the DON(extra 10 mg/kg deoxynivalenol),and the DL(extra 1 × 109 CFU/kg L.plantarum JM113 based on DON group) treatments.The growth performance,organ indexes,intestinal morphology,pancreatic digestive enzymes,intestinal secreted immunoglobulin A(sIgA),jejunal transcriptome,and intestinal microbiota were evaluated.Results: Compared with the CON and DL groups,the DON supplementation altered intestinal morphology,especially in duodenum and jejunum,where villi were shorter and crypts were deeper(P < 0.05).Meanwhile,the significantly decreased mRNA expression of jejunal claudin-1 and occludin(P < 0.05),ileal rBAT and jejunal GLUT1 of 21-day-old broilers(P < 0.05),as well as duodenal PepT1 and ileal rBAT of 42-day-old broilers were identified in the DON group.Moreover,supplementation with L.plantarum JM113 could increase duodenal expression of IL-10 and IL-12 of 21-dayold broilers,ileal s IgA of 42-day-old broilers,and the bursa of Fabricius index of 21-day-old broilers.Further jejunal transcriptome proved that the genes related to the intestinal absorption and metabolism were significantly reduced in the DON group but a significant increase when supplemented with extra L.plantarum JM113.Furthermore,the bacteria related to nutrient utilization,including the Proteobacteria,Escherichia,Cc-115(P < 0.05),Lactobacillus and Prevotella(P < 0.1) were all decreased in the DON group.By contrast,supplementation with L.plantarum JM113 increased the relative abundance of beneficial bacterium,including the Bacteroidetes,Roseburia,Anaerofustis,Anaerostipe,and Ruminococcus bromi(P < 0.05).Specifically,the increased abundance of bacteria in the DL group could be proved by the significantly increased caecal content of propionic acid,n-Butyric acid,and total short-chain fatty acid.Conclusions: L.plantarum JM113 enhanced the digestion,absorption,and metabolic functions of the gut when challenged with DON by reducing the injury to intestinal barriers and by increasing the abundance of beneficial bacterium.

Research Progress on the <i>Actinomyces arthrobacter</i>

The genus Arthrobacter was established in 1947 by Conn & Dimmick. So far, more than 70 recognized?species of the genus Arthrobacter have been certified. Its special functions have been widely known by researchers, such as, in agricultural, in medical, in industrial, and in environmental areas, etc. What deserves to be mentioned is that some species of genus Arthrobacter have showed the function of degrading pesticides, fixing nitrogen, producing beneficial enzyme, treating sewage, and so on. Recently, the applications of the genus Arthrobacter, especially the VBNC?(viable but non-culturable) bacteria of this genus in the field of contaminated environment repair attract people’s attention and some related research results have also been obtained. The functions that we have known are waiting for us to study about mechanism, deeply. And, we can look forward to discovering more potential functions and applications of this genus in ecological environment. In the meantime, these discoveries must bring more new changes and knowledge.

A novel TICT-based near-infrared fluorescent probe for light-up sensing and imaging of human serum albumin in real samples

Human serum albumin(HSA) has emerged as a pivotal biomarker and prognostic indicator for various human diseases. Real-time sensing and visual tracking of HSA in plasma or other biological systems will immensely facilitate the basic researchers and clinicians to better understand HSA-associated biological processes. Herein, a novel near-infrared(NIR) fluorescent probe(7-HTCF) was rationally constructed for light-up sensing and in-situ imaging of HSA in real samples, based on the principle of twisted intramolecular charge transfer(TICT). Under physiological conditions, 7-HTCF could be efficiently trapped by HSA to form a stable complex via binding on a non-drug binding site, while the complex emitted strong fluoresce signals around 670 nm. Further investigations demonstrated that 7-HTCF displayed a great combination of excellent selectivity and good chemical stability, as well as rapid fluorescent response and ultra-high sensitivity for HSA detection. Particularly, the newly developed light-up probe has been successfully utilized for quantitative detection of HSA in diluted plasma samples, while its readouts are hardly affected by the addition of therapeutic agents and herbal medicines. 7-HTCF is also successfully used for in-situ imaging of the reabsorbed HSA in living renal cells, while this dye exhibits good cell permeability and high resolution for in-situ imaging in living cells. Collectively, a novel TICT-based near-infrared fluorescent probe was devised for highly selective and ultra-sensitive sensing of HSA in plasma samples or imaging HSA in living cells, which offered a practical tool for clinical tests and for exploring HSA-associated biological processes.

Aircraft air conditioning system health state estimation and prediction for predictive maintenance

The vast potential of system health monitoring and condition based maintenance on modern commercial aircraft is being realized through the innovative use of Airplane Condition Monitoring System(ACMS) data.However there are few methods addressing the issues of failure prognostics and predictive maintenance for commercial aircraft Air Conditioning System(ACS).This study developed a Bayesian failure prognostics approach using ACMS data for predictive maintenance of ACS.First, a health index characterizing the ACS health state is inferred from a multiple sensor signals using a data driven method.Then a dynamic linear model is proposed to describe the degradation process for failure prognostics.Bayesian inference formulas are carried out for degradation estimation and prediction.The developed approach is applied on a passenger aircraft fleet with ACMS data recorded for one year.The analysis of the case study shows that the developed method can produce satisfactory prognostics results, where all the ACS failure precursors are identified in advance, and the relative errors for the failure time prediction made when just entering the degradation warning stage are less than 8%.This would allow operators to proactively plan future maintenance.