Simple, Rapid and Sensitive Detection of Pseudomonas aeruginesa by Colorimetric Multiple Cross Displacement Amplification

Pseudomonas aeruginosa(P:aeruginosa)is a major opportunistic pathogen in hospital-acquired infections.Thus,carly diagnosis is the best strategy for fighting against these infections.In this report,we incorporated multiple crOsS displacement amplification(MCDA)combined with the malachite green(MG)for rapid,sensitive,specific and visual detection of P.aeruginosa by targeting the oprl gene.The MCDA-MG assay was conducted at 67°C for only 40 min during the amplification stage,and then products were directly detected by using colorimetric indicators(MG),eliminating the use of an electrophoresis instrument or amplicon analysis equipment.The entire process,including specimen processing(35 min),amplification(40 min)and detection(5 min),can be finished within 80 min.All 30 non-P.aeruginosa strains tested negative,indicating the high specificity of the MCDA primers.The analytical sensitivity of the MCDA-MG assay was 100 fg of genomic templates per reaction in pure culture,which was in complete accordance with MCDA by gel clectrophoresis and real-time turbidity.The assay was also successfully applied to detecting P.aeruginosa in stool samples.Therefore,the rapidity,simplicity,and nearly equipment free platform of the MCDA-MG technique make it possible for clinical diagnosis,and more.

Stability of multiple fans in mine ventilation networks

In large mines,single fan is usually not enough to ventilate all the working areas.Single mine-fan approach cannot be directly applied to multiple-fan networks because the present of multiple pressures and air quantities associated with each fan in the network.Accordingly,each fan in a multiple-fan system has its own mine characteristic curve,or a subsystem curve.Under some consideration,the conventional concept of a mine characteristic curve of a single-fan system can be directly extended to that of a particular fan within a multiple-fan system.In this paper the mutual effect of the fans on each other and their effect on the stability of the ventilation network were investigated by Hardy Cross algorithm combined with a switching-parameters technique.To show the validity and reliability of this algorithm,the stability of the ventilation system of Abu-Tartur Mine(one of the largest underground mine in Egypt)has been studied.

Border collision bifurcations in 3D piecewise smooth chaotic circuit

A variety of border collision bifurcations in a three-dimensional （3D） piecewise smooth chaotic electrical circuit are investigated. The existence and stability of the equilibrium points are analyzed. It is found that there are two kinds of non-smooth fold bifurcations. The existence of periodic orbits is also proved to show the occurrence of non-smooth Hopf bifurcations. As a composite of non-smooth fold and Hopf bifurcations, the multiple crossing bifurcation is studied by the generalized Jacobian matrix. Some interesting phenomena which cannot occur in smooth bifurcations are also considered.

Study on the influencing factors of piecewise multi-strain crossover epidemic spread under data contamination

The ongoing impact of the novel coronavirus disease 2019(COVID-19)on work and daily life persists as we transition from emergency to normal circumstances.The continuous mutation of viral strains has resulted in a shift from a single strain to multiple cross-strains,contributing to the spread of the epidemic.Variations in infection rates of the same strain occur because of the implementation of diverse preventive measures at different times.This study investigated the dynamics of the pandemic in the presence of concurrent strains.Building on the classical Susceptible,Exposed,Infected,and Recovered(SEIR)model,a robust piecewise multi-strain cross-epidemic trend prediction model was proposed that employs the Hodges–Lehmann estimator to handle uncertain and contamination-prone epidemic information.A comparative analysis of epidemic spread trend curves across diverse populations using different robust methods revealed the superiority of the Hodges–Lehmann estimator-based model over the traditional method.The accurate prediction results of the model demonstrate its high reliability in tracking the changing trend of the COVID-19 outbreak,thereby supporting its implementation in subsequent epidemic prevention and control measures.

Antarctic thermolabile uracil-DNA-glycosylase- supplemented multiple cross displacement amplification using a label-based nanoparticle lateral flow biosensor for the simultaneous detection of nucleic acid sequences and elimination of carryover contamination

Here, we report a novel and universal methodology,termed ＂ntarctic thermolabile uracil-DNA-glycosylase （AUDG）-supplemented nucleic acid amplification techniques （NAAs） using a labeled-based nanoparticle lateral flow biosensor （LFB）＂ （AUDG-NAAs-LFB）, which merges enzymatic （AUDG） digestion of contaminant amplicons with different nucleic acid amplification techniques （NAAs）, and uses a lateral flow biosensor （LFB） for the rapid and visual confirmation of the presence of a target nucleic acid sequence. AUDG-NNAs-LFB is a one-pot, closedvessel assay, that can effectively eliminate false-positive signals arising from either carryover contaminants or the interaction between labeled primers. A new LFB was devised for detecting three targets （two amplicons generated from amplification of target sequences, and a chromatography control）, without the need for probe- hybridization or additional incubation steps. As a proof of concept, multiple cross displacement amplification （MCDA）, which is a specific, sensitive, and rapid isothermal amplification method, was selected as the model amplification technique to demonstrate the feasibility of AUDG-NAAs-LFB. As a result, we demonstrate the applicability of the AUDG-MCDA-LFB method for simultaneously detecting high-risk human papillomaviruses genotypes 16 and 18, which are the most and second-most prevalent strains of the virus reported in women worldwide. We also confirm the principle behind the AUDG-MCDA- LFB assay and validate its sensitivity, reproducibility, and specificity using serial dilutions of the type-specific plasmids, as well as clinical samples. This proof- of-concept method （AUDG-MCDA-LFB） can be easily reconfigured to detect various nudeic acid sequences by redesigning the specific MCDA primers.

k-Walk-Regular Digraphs

In this paper, we define a class of strongly connected digraph, called the k-walk- regular digraph, study some properties of it, provide its some algebraic characterization and point out that the 0-walk-regular digraph is the same as the walk-regular digraph discussed by Liu and Lin in 2010 and the D-walk-regular digraph is identical with the weakly distance-regular digraph defined by Comellas et al in 2004.