Clinical usefulness of linked color imaging in identifying Helicobacter pylori infection:A systematic review and meta-analysis

BACKGROUND Accurate diagnosis of Helicobacter pylori(H.pylori)infection status is a crucial premise for eradication therapy,as well as evaluation of risk for gastric cancer.Recent progress on imaging enhancement endoscopy(IEE)made it possible to not only detect precancerous lesions and early gastrointestinal cancers but also to predict H.pylori infection in real time.As a novel IEE modality,linked color imaging(LCI)has exhibited its value on diagnosis of lesions of gastric mucosa through emphasizing minor differences of color tone.AIM To compare the efficacy of LCI for H.pylori active infection vs conventional white light imaging(WLI).METHODS PubMed,Embase,Embase and Cochrane Library were searched up to the end of April 11,2022.The random-effects model was adopted to calculate the diagnostic efficacy of LCI and WLI.The calculation of sensitivity,specificity,and likelihood ratios were performed;symmetric receiver operator characteristic(SROC)curves and the areas under the SROC curves were computed.Quality of the included studies was chosen to assess using the quality assessment of diagnostic accuracy studies-2 tool.RESULTS Seven original studies were included in this study.The pooled sensitivity,specificity,positive likelihood rate,and negative likelihood rate of LCI for the diagnosis of H.pylori infection of gastric mucosa were 0.85[95%confidence interval(CI):0.76-0.92],0.82(95%CI:0.78-0.85),4.71(95%CI:3.7-5.9),and 0.18(95%CI:0.10-0.31)respectively,with diagnostic odds ratio=26(95%CI:13-52),SROC=0.87(95%CI:0.84-0.90),which showed superiority of diagnostic efficacy compared to WLI.CONCLUSION Our results showed LCI can improve efficacy of diagnosis on H.pylori infection,which represents a useful endoscopic evaluation modality for clinical practice.

Modeling of interphases in multiple heterogeneities reinforced composites using Voronoi cell finite elements

In this paper,a Voronoi cell finite element model is developed to study the microscopic and macroscopic mechanical behaviors of heterogenous materials,including arbitrary distributed heterogeneity(inclusions or fibers)coated with interphase layers,based on linear elasticity theory.The interphase between heterogeneity and a matrix are regarded as in the third phase(elastic layers),in contrast to the perfect interface of the spring-like Voronoi cell finite element model(VCFEM)in the literature.In this model,both stress and the displacement field are assumed to be independent in an element.Formulations of stress are derived for each of the three phases in an element,as is the type of functional.Numerical examples were used to study the microscopic and macroscopic properties,such as the effective modulus,of the composites.The results of the proposed VCFEM were compared with analytical solution and numerical results obtained from a standard finite element analysis to confirm its effectiveness.

A New Hybrid Stress Element with Fluid

In the process of shale gas exploitation,there exits two difficult problems:one is the real numerical simulation of a tremendous number of holes in actual shale;the other is the fluid–solid coupling problem involved in holes,where the difficulty of transition at the interface between the Eulerian grid and the Lagrangian grid becomes the most important.In response to these two problems,this paper establishes an element model with both fluid and solid.At the fluid–solid interface,the equilibrium condition of the surface force is introduced to obtain the modified complementary energy functional,and a new hybrid stress element with fluid is derived.The comparison of the simulation results with those of the ordinary commercial finite element software verifies the effectiveness and efficiency of this element,and proves its applicability in the problem of shale with numerous holes.Furthermore,this element can be extended to general problems of solid with fluid in.