Factors involved in the success of Castanea henryi stem cuttings in different cutting mediums and cutting selection periods

Chinquapin(Castanea henryi) is a dual-purpose tree species in China valued for as a source of timber and starch.We investigated the effect of four cutting mediums(pure vermiculite;peat:river sand at 3:1 v/v;peat:krasnozem at 1:1 v/v;and pure krasnozem) and three stem cutting periods(March,May,and July) on rooting performance of C.henryi cuttings.Different cutting periods and cutting mediums greatly influenced the rooting rate of C.henryi,ranging from 3.35 to 77.31%.Principal component analysis indicated that the best combination of cutting period and cutting medium was semi-hardwood cuttings(May cuttings)+krasnozem.Histological evidence indicated that adventitious root initials were present by week 5-6,and that the site of root primordia initiation was observed in the vascular cambium.Stem anatomical structures observed at different periods indicated that a xylem/radius ratio of29.90-37.42% and a fractured phloem fiber ring are indicative of rooting success.The relational model between rooting index and medium properties indicated that nutrient content and porosity significantly influenced callus production.However,pH strongly affected C.henryi root formation,with the Pearson correlation coefficients for May and July cuttings of-0.856 and-0.947,respectively.Our protocol is helpful to achieve mass clone propagation of improved C.henryi genotypes,thus overcoming a common hurdle in chinquapin breeding programs.

Effect of Carbon Content on Ti Inclusion Precipitated in Tire Cord Steel

The precipitation of TiN inclusion during solidification of different carbon content of 0.72%, 0.82% and 0.95% in tire cord steel is thermodynamically studied respectively. The results show that the carbon content has obvious effect on TiN inclusion precipitated in tire cord steel of different strength levels. With the carbon content of tire cord steel increasing, the temperature before solidifying reduced gradually and the required activity product of titanium and nitrogen for TiN inclusion precipitation also declined gradually. With the same condition of initial Ti and N content in liquid steel, the size of TiN inclusion precipitated in tire cord steel of higher carbon content is bigger than that of lower carbon content. In order to control the harmful effects on processability of TiN inclusion precipitated in hypereutectoid tire cord steel of the ultra high strength level, the measures of smelting process must be taken to further reduce the titanium and nitrogen content in liquid steel.

A Class of Robust Independence Tests Based on Weighted Integrals of Empirical Characteristic Functions

In this paper,we propose a class of robust independence tests for two random vectors based on weighted integrals of empirical characteristic functions.By letting weight functions be probability density functions of a class of special distributions,the proposed test statistics have simple closed forms and do not require moment conditions on the random vectors.Moreover,we derive the asymptotic distributions of the test statistics under the null hypothesis.The proposed testing method is computationally feasible and easy to implement.Based on a data-driven bandwidth selection method,Monte Carlo simulation studies indicate that our tests have a relatively good performance compared with the competitors.A real data example is also presented to illustrate the application of our tests.

A non-antibiotic organic coating on ZA6-1 surface releasing different concentrations of sodium dodecyl sulphate/levulinic acid for orthopaedic application

Bone implantation surgery is often accompanied by bacterial infection,resulting in infectious bone non-union,pathological fracture and other serious consequences,which will aggravate the pain of patients.A non-antibiotic coating consisting of sodium dodecyl sulphate(SDS)and levulinic acid(LA)with different concentrations was prepared by the authors on the zinc–aluminium alloy(ZA6-1)using a wet chemistry treatment for orthopaedic application.The influence of SDS/LA concentrations on the surface morphology,composition and performance of the developed coating was investigated.The results showed that as-prepared coating on a zinc alloy surface could improve the substrate's corrosion resistance and increase the degradation rate from 0.82 to 19.70μm/year upon raising the SDS/LA concentration.Furthermore,higher hydrophilicity(<14°),better cell proliferation(>100%)and morphology,as well as good cell adhesion and differentiation(ALP>95%for 7 days)were observed on coated zinc alloys.The increased SDS/LA concentration slightly weakens the biocompatibility and enhances the antibacterial performance of coated zinc alloys due to the synergistic effect of SDS/LA.Overall,the coating comprising 6 wt.%SDS and 9 wt.%LA showed excellent antibacterial action with a high level of biocompatibility,confirming its potential application for orthopaedic implants.

RCV-based error density estimation in the ultrahigh dimensional additive model

In this paper,we mainly study how to estimate the error density in the ultrahigh dimensional sparse additive model,where the number of variables is larger than the sample size.First,a smoothing method based on B-splines is applied to the estimation of regression functions.Second,an improved two-stage refitted crossvalidation(RCV)procedure by random splitting technique is used to obtain the residuals of the model,and then the residual-based kernel method is applied to estimate the error density function.Under suitable sparse conditions,the large sample properties of the estimator,including the weak and strong consistency,as well as normality and the law of the iterated logarithm,are obtained.Especially,the relationship between the sparsity and the convergence rate of the kernel density estimator is given.The methodology is illustrated by simulations and a real data example,which suggests that the proposed method performs well.

Robust Error Density Estimation in Ultrahigh Dimensional Sparse Linear Model

This paper focuses on error density estimation in ultrahigh dimensional sparse linear model,where the error term may have a heavy-tailed distribution.First,an improved two-stage refitted crossvalidation method combined with some robust variable screening procedures such as RRCS and variable selection methods such as LAD-SCAD is used to obtain the submodel,and then the residual-based kernel density method is applied to estimate the error density through LAD regression.Under given conditions,the large sample properties of the estimator are also established.Especially,we explicitly give the relationship between the sparsity and the convergence rate of the kernel density estimator.The simulation results show that the proposed error density estimator has a good performance.A real data example is presented to illustrate our methods.

Improving anti-Gram-positive-bacterial performance and osteogenesis for zinc alloy via mussel mimetic polydopamine with non-antibiotic lysozyme and parathyroid hormone

In this work,a novel coating with a non-antibiotic agent for inhibiting Gram-positive bacteria and promoting osteogenesis was prepared on zinc-aluminium alloy(ZA6-1)via mussel mimetic polydopamine(PDA)containing lysozyme(LYS)and parathyroid hormone(PTH).The results indicate that as-deposited coatings can efficiently decrease the degradation rate of ZA6-1 from 0.52 to 0.16 mm/year,and the addition of LYS weakens the coating resistance,while the addition of PTH enhances the coating resis-tance.In spite that no obvious inhibition of Escherichia coli is observed,the coated zinc alloys show good in vitro antibacterial performance against Staphylococcus aureus.Compared with ZA6-1 zinc alloys,the increase of antibacterial efficacy reaches 86.9%-90.1%.Furthermore,the lower hydrophilicity(26.4°),higher osteoblast cell viability(>100%),good osteoblast cell morphology and better osteoblast cell differentiation(ALP=107.7%)for PDA-LYS/PTH coated samples support that as-prepared coating is promising for modifying biodegradable zinc implants.