Recent Advancements in Intestinal Microbiota Analyses:A Review for Non-Microbiologists

Microbial constituents naturally inhabiting the gastrointestinal tract may influence the homeostasis of the gut environment.The presence or overabundance of some bacterial taxa has been reported to be associated with complex diseases,and the metabolites of certain bacteria may contribute to diverse disorders by influencing signaling pathways.Therefore,the study of gut microbial population has emerged as a crucial field and a new potential area of clinical significance. Advances in the methods of microbiota analysis have shed light upon the details including species diversity,microfloral activities as well as the entire gut microbiota.Nevertheless,comprehensive reviews on this subject are still limited.For elucidating the appropriate selection strategy of the methods to address a particular research question,we comprehensively reviewed the continuously improving technologies,classical to newly developed,and dissected their relative advantages and drawbacks.In addition,aiming at the rapidly advancing next-generation sequencing,we enumerated the improvements in mainstream platforms and made the horizontal and vertical comparison among them.Additionally,we demonstrated the four main-omics methods,which may provide further mechanistic insights into the role of microbiota,to propel phylotyping analysis to functional analysis.

Experimental research on HEL and failure properties of alumina under impact loading

A series of plate impact experiments on alumina was conducted using a light gas gun in order to further investigate Hugoniot elastic limit(HEL)and failure properties of alumina under shock compression.The velocity interferometer system for any reflector(VISAR)was used to record the rear-free surface velocity histories of the alumina samples.According to the experimental results,the HELs of tested alumina samples with different thicknesses were measured,and the decay phenomenon of elastic wave in shocked alumina was studied.A phenomenological expression between HEL and thickness of sample was presented,and the causes of the decay phenomenon were discussed.The propagation of failure wave in shocked alumina was probed.The velocity and delayed time of failure wave propagation were obtained.The physical mechanism of the generation and propagation of failure was further discussed.

Microstructure and Mechanical Behavior of Mg-Based Bimetal Plates with High Formability Sleeve by Co-extrusion

In this study,microstructure and mechanical behavior of two types of Mg-based bimetal plates with a high formability sleeve were systematically studied,with a great emphasis on the effect of the interface characteristic and the sleeve fraction on the plasticity of composite plates.The rule of mixtures(ROM)for elongation was also addressed.The results show that when there is no or thin diffusion layer with thickness of about 3μm,Mg-based bimetal plates have a good plasticity with elongation of about 19-24%,and the ROM predicted elongations are very close to the experimental ones.In contrast,with a diffusion layer about 95-155μm thick,Mg-based bimetal plates exhibit a poor plasticity with elongation of about 11-17%,and the experimental elongations largely deviate from the ROM predictions.The plasticity of Mg-based bimetal plates increases with increasing sleeve fraction.This study provides new insights on the plastic deformation of Mg-based bimetal composites with a high formability sleeve.

Mechanical properties and fracture mechanism of Fe/Cu composite sheets with Al interlayer after annealing treatment

The feasibility of preparing Fe/Cu composite sheet was achieved by introducing submillimeter thickness Al sheet as an interlayer by rolling at room temperature.The shear test of the composite sheet supported that the metallurgical bonding strength between Fe/(Al)/Cu interface was stronger than that of Cu sheet at the initial state.With further 300 or 600℃ annealing treatments,the interlayer subsequently exhibited brittle shear fracture,and the shear strength significantly dropped under the shear test.Furthermore,the tensile test pointed out that the tensile fracture mechanism changed from fracture as a whole structure to interlayer-to-layer delamination mode after annealing treatment.The microstructure and X-ray diffraction observations proved that the formation of Cu–Al intermetallic compounds(IMCs)along the interlayer resulted in brittle fracture,rather than that of Fe–Al IMCs after annealing,especially under 600℃ annealing treatment.The investigation of the effect of the rolling process and annealing treatment on the mechanical properties of the Fe/(Al)/Cu composite sheet shall provide instruction for high-quality composite metallic sheet fabrication.

Efficacy and safety of itraconazole use in infants

Background:Itraconazole has been used to treat fungal infections,in particular invasive fungal infections in infants or neonates in many countries.Data sources:Literature search was conducted through Ovid EMBASE,PubMed,ISI Web of Science,CNKI and Google scholarship using the following key words:“pediatric”or“infant”or“neonate”and“fungal infection”in combination with“itraconazole”.Based on the literature and our clinical experience,we outline the administration of itraconazole in infants in order to develop evidence-based pharmacotherapy.Results:Of 45 articles on the use of itraconazole in infancy,13 are related to superficial fungal infections including tinea capitis,sporotrichosis,mucosal fungal infections and opportunistic infections.The other 32 articles are related to systemic fungal infections including candidiasis,aspergillosis,histoplasmosis,zygomycosis,trichosporonosis and opportunistic infections as caused by Myceliophthora thermophila.Conclusion:Itraconazole is safe and effective at a dose of 5 mg/kg per day in a short duration of therapy for superficial fungal infections and 10 mg/kg per day for systemic fungal infections in infants.With a good compliance,it is cost-effective in treating infantile fungal infections.The profiles of adverse events induced by itraconazole in infants are similar to those in adults and children.

Microstructure and nanoindentation hardness of shot-peened ultrafine-grained low-alloy steel

The effect of shot peening (SP) on microstructure and hardness of ultrafine-grained (UFG) low-alloy steel was investigated. With increasing shot-peening time from 0.5 to 1.5 h, grain size of UFG low-alloy steel decreases from 400 to 280 nm at surface whilst that of the layer with a depth of 160μm decreases from (230 ± 15) to (75 ± 5) nm. Interestingly, nanoindentation shows that hardness increases linearly with increasing the SP duration, reaching a value as high as (7.10 ± 0.1) GPa at the depth of 160 μm after the SP duration of 1.5 h. The thickness of the SP treated layer is measured as^300 μm. The Hall-Petch (H-P) relationship was established for the hardening layer. Correspondingly, abrasion resistance should be ~51% higher than that of as-prepared UFG low-alloy steel. As shown in SP processing, grain refinement is the key factor responsible for the strengthening of the studied steel.

On the Discrete-Time Dynamics of Cross-Coupled Hebbian Algorithm

Principal/minor component analysis(PCA/MCA),generalized principal/minor component analysis(GPCA/GMCA),and singular value decomposition(SVD)algorithms are important techniques for feature extraction.In the convergence analysis of these algorithms,the deterministic discrete-time(DDT)method can reveal the dynamic behavior of PCA/MCA and GPCA/GMCA algorithms effectively.However,the dynamic behavior of SVD algorithms has not been studied quantitatively because of their special structure.In this paper,for the first time,we utilize the advantages of the DDT method in PCA algorithms analysis to study the dynamics of SVD algorithms.First,taking the cross-coupled Hebbian algorithm as an example,by concatenating the two cross-coupled variables into a single vector,we successfully get a PCA-like DDT system.Second,we analyze the discrete-time dynamic behavior and stability of the PCA-like DDT system in detail based on the DDT method,and obtain the boundedness of the weight vectors and learning rate.Moreover,further discussion shows the universality of the proposed method for analyzing other SVD algorithms.As a result,the proposed method provides a new way to study the dynamical convergence properties of SVD algorithms.