Pit density reduction for AlN epilayers grown by molecular beam epitaxy using Al modulation method

We have investigated homoepitaxy of AlN films grown by molecular beam epitaxy on AlN/sapphire templates byadopting both the continuous growth method and the Al modulation epitaxy(AME)growth method.The continuous growthmethod encounters significant challenges in controlling the growth mode.As the precise Al/N=1.0 ratio is difficult toachieve,either the excessive Al-rich or N-rich growth mode occurs.In contrast,by adopting the AME growth method,sucha difficulty has been effectively overcome.By manipulating the supply time of the Al and nitrogen sources,we were able toproduce AlN films with much improved surface morphology.The first step of the AME method,only supplying Al atoms,is important to wet the surface and the Al adatoms can act as a surfactant.Optimization of the initial Al supply time caneffectively reduce the pit density on the grown AlN surface.The pits density dropped from 12 pits/μm^(2)to 1 pit/μm^(2)andthe surface roughness reduced from 0.72 nm to 0.3 nm in a 2×2μm^(2)area for the AME AlN film homoepitaxially grownon an AlN template.

Effect of bone marrow mesenchymal stem cells on the Smad expression of hepatic fibrosis rats

Objective:To investigate the impact of bone marrow mesenchymal stem cells on Smad expression of hepatic fibrosis rats.Methods:A total of 48 adult female SD rats were randomly divided into three groups,normal control group(n=10),observation group(n=19)with liver fibrosis model rats injected with BMSCs cells:model group(n=19),with liver fibrosis model rats injected with physiological saline.Serum index,TGF-β1 and Smad expression were detected.Results:TypeⅢprocollagen,Ⅳcollagen,hyaluronic acid,laminin levels of observation group were significantly lower than those of model group(P<0.05).The content and expression of TGF-β1in serum and liver tissue of observation group were significantly lower than those of model group(P<0.05).Compared with normal control group,the Smad3,Smad4 mRNA and protein expression of model group were significantly increased,the Smad7 mRNA and protein expression were significantly reduced(P<0.05).Compared with model group.Smad3,Smad4 mRNA and protein expression of observation group were significantly reduced,and Smad7 mRNA expression were significantly increased(P<0.05).Conclusions:BMSCs can regulate Smad expression to some extent,and reduce the degree of liver fibrosis.

Effect of Rougan Huaqian granules combined with human mesenchymal stem cell transplantation on liver fibrosis in cirrhosis rats

Objective:To observe the effect of Rougan Huaqian granules combined with human mesenchymal stem cell(hMSC)transplantation on the liver fibrosis in carbon tetrachlorideinduced cirrhosis rats.Methods:Sixty SD rats were randomly divided into live groups.The rats in control group received intraperitoneal injection of saline,while those in model control group,treatment group A,group B and group C received intraperitoneal injection of carbon tetrachloride oily solution to induce liver cirrhosis within 8 weeks.Then,the rats in the model control group,treatment group A,treatment group B,treatment group C received vein tail injection of saline,Rougan Huaqian granules,hMSC suspension and Rougan Huaqian granules combined with hMSC suspension.Results:The treatment groups had significantly different liver function(AST levels),liver fibrosis index(laminin and HA),hepatic sinusoidal wallsα-smooth muscle actin,Ⅳcollagen and laminin protein expression andⅠ,Ⅲcollagen from the model group(P<0.05).The transplanted cells showed human hepatocyte-like cells differentiation trend in the liver.Conclusions:The Rougan Huaqian granules combined with hMSC transplantation can alleviate liver fibrosis in cirrhosis rats.

高度近视患者SMILE和FS-LASIK术后早期视觉质量的比较

目的:应用双通道视觉质量分析系统(OQASⅡ)及Pentacam角膜地形图对比研究高度近视患者分别行小切口飞秒激光角膜基质透镜取出术(SMILE)和飞秒激光辅助制瓣的准分子激光原位角膜磨镶术(FS-LASIK)后早期视觉质量的变化。方法:前瞻性非随机对照研究。选取2020-03/09于我院行手术矫治的高度近视患者74例148眼,其中SMILE组43例86眼,FS-LASIK组31例62眼。分析患者术前、术后1、7d裸眼视力(UCVA)、调制传递函数截止频率(MTF cut off)、斯特列尔比值(SR)、客观散射指数(OSI)、模拟对比度视力(VA 100%、VA 20%、VA 9%)、高阶像差(HOA)、水平彗差(Z_(3)^(1))、垂直彗差(Z_(3)^(-1))和球差(Z_(4)^(0))情况。结果:两组患者术前年龄、等效球镜、UCVA、MTF cut off、SR、OSI、VA 100%、VA 20%、VA 9%、HOA、Z_(3)^(1)、Z_(3)^(-1)和Z_(4)^(0)均无差异(P>0.05)。SMILE组术后1d OSI值高于FS-LASIK组(2.3±2.1 vs 1.8±1.1),术后7d无差异(1.2±0.7 vs1.3±0.7)。FS-LASIK组术后1、7d HOA和Z_(4)^(0)均高于SMILE组(P<0.001),但术后1、7d两组患者UCVA、Z_(3)^(1)、Z_(3)^(-1)、MTF cut off、SR、VA 100%、VA 20%、VA 9%均无差异(P>0.05)。结论:FS-LASIK术后早期更易引入角膜高阶像差和球差,而2mm切口的SMILE术仅在术后1d引入更高的散射,因此,高度近视患者行角膜屈光手术矫正采用SMILE术较FS-LASIK术后早期能够获得更佳的视觉质量。

Development of a 50K SNP Array for Japanese Flounder and Its Application in Genomic Selection for Disease Resistance

Single nucleotide polymorphism(SNP)armays are a powerful genotyping tool used in genetic research and genomic breeding programs.Japanese flounder(Paralichthys olivaceus)is an economically-important aquaculture flatfish in many countries.However,the lack of high-efficient genotyping tools has impeded the genomic breeding programs for Japanese flounder.We developed a 50K Japanese flounder SNP array,"Yuxin No.1,"and report its utility in genomic selection(GS)for disease resistance to bacterial pathogens.We screened more than 42,.2 million SNPs from the whole-genome resequencing data of 1099 individuals and selected 48697 SNPs that were evenly distributed across the genome to anchor the array with Affymetrix Axiom genotyping technology.Evaluation of the array performance with 168 fishs howed that 74.7%of the loci were successfully genotyped with high call rates(>98%)and that the poly-morphic SNPs had good cluster separations.More than 85%of the SNPs were concordant with SNPs obtained from the whole-genome resequencing data.To validate"Yuxin No.1"for GS,the arrayed geno-typing data of 27 individuals from a candidate population and 931 individuals from a reference popula-tion were used to calculate the genomic estimated breeding values(GEBVs)for disease resistance toEdwardsiella tarda.There was a 21.2%relative increase in the accuracy of GEBV using the weighted geno-mic best linear unpiased prediction(wGBLUJP),compared to traditional pedigree-based best linear unbi-ased prediction(ABLUP),suggesting good performance of the'Yuxin No.1"SNP array for GS.In summary,we developed the"Yuxin No.1"50K SNP array,which provides a useful platform for high-quality geno-typing that may be beneficial to the genomic selective breeding of Japanese flounder.

Establishment and characterization of an astroglial cell line derived from the brain of half-smooth tongue sole(Cynoglossus semilaevis)

An astroglial cell line was established from the brain of half smooth tongue sole （Cynoglossus semilaevis） and was designated as CSAC. CSAC shows the morphological homogeneity of epithelial cells. The cell identity was tested by the presence of glial fibrillary acidic protein （GFAP）, which was revealed by RT-PCR and immunofluorescence. The cell line was optimally maintained at 24 ℃ in minimum essential medium supplemented with HEPES, antibiotics, 20% fetal bovine serum, 2- Mercaptoethanol （2-Me） and basic fibroblast growth factor. Chromosome analysis revealed that the CSAC cells maintained a normal diploid chromosome number （2n=42）. The fluorescent signals were observed in CSAC after the cells were transfected with green fluorescent protein （GFP） reporter plasmids. The CSAC cell line may serve as a valuable tool for studies on the potential functions of fish astroglial cells.