Multiscale Simulation of Microstructure Evolution during Preparation and Service Processes of Physical Vapor Deposited c-TiAlN Coatings

Physical Vapor Deposited(PVD)TiAlN coatings are extensively utilized as protective layers for cutting tools,renowned for their excellent comprehensive performance.To optimize quality control of TiAlN coatings for cutting tools,a multi-scale simulation approach is proposed that encompasses the microstructure evolution of coatings considering the entire preparation and service lifecycle of PVD TiAlN coatings.This scheme employs phase-field simulation to capture the essential microstructure of the PVD-prepared TiAlN coatings.Moreover,cutting simulation is used to determine the service temperature experienced during cutting processes at varying rates.Cahn-Hilliard modeling is finally utilized to consume the microstructure and service condition data to acquaint the microstructure evolution of TiAlN coatings throughout the cutting processes.This methodology effectively establishes a correlation between service temperature and its impact on the microstructure evolution of TiAlN coatings.It is expected that the present multi-scale numerical simulation approach will provide innovative strategies for assisting property design and lifespan prediction of TiAlN coatings.

用于大功率紫外LED的圆柱扰流散热器设计仿真

如何降低芯片结温成为大功率紫外LED应用的关键。本文提出了一种新型圆柱扰流水冷散热器,对光源模块进行高效热管理。采用COMSOL软件对散热系统进行热场和流场分析,分别从散热器盖板厚度、扰流柱直径、增加档板结构、流速设置四个方面进行优化仿真,有效改善流动均匀性、提高换热效果,将功率密度643 W/cm^(2)的串联紫外LED光源模块的芯片结温由120℃降至95℃。

开角型青光眼患者结膜微血管结构的临床研究

目的应用功能裂隙灯活体显微镜(FSLB)探究开角型青光眼患者结膜微循环的血流动力学情况。方法采用FSLB对18例开角型青光眼患者的结膜微血管血流动力学进行测量并将其分为两组,右眼为A组,左眼为B组。球结膜经数字相机进行较高清晰度的视野成像后,形成非侵入性球结膜微循环血流灌注图(n MPMs),同时以60帧/s高成像速率和×210高放大率对血流动力学成像。应用定制软件,进一步对结膜n MPMs进行分形分析,进行血管密度及血流动力学测定。结果与A组比较,B组结膜的微血管各方位密度、长度、直径、微动脉及微静脉血流速度均无改变,差异无统计学意义(P>0.05);A、B两组上、下侧微动脉和微静脉的血流速度<鼻、颞侧微动及静脉血流速度,差异有统计学意义(P<0.05);A、B两组内结膜的各方位微血管密度、长度、直径比较,差异有统计学意义(P<0.05)。结膜微血管密度、长度、直径由大到小排列为:颞侧/鼻侧>下方>上方。结论功能性裂隙灯生物显微镜能用于检测开角型青光眼患者球结膜微循环血流动力学改变情况。

Diagnostic performance of magnifying narrow-band imaging for early gastric cancer: A meta-analysis

AIM: To investigate the performance of magnifying endoscopy with narrow-band imaging(ME-NBI) in the diagnosis of early gastric cancer(EGC).METHODS: Systematic literature searches were conducted until February 2014 in Pub Med, EMBASE, Web of Science, Ovid, Scopus and the Cochrane Library databases by two independent reviewers. Meta-analysis was performed to calculate the pooled sensitivity, specificity and diagnostic odds ratio and to construct a summary receiver operating characteristic(ROC) curve. Subgroup analyses were performed based on the morphology type of lesions, diagnostic standard, the size of lesions, type of assessment, country and sample size to explore possible sources of heterogeneity. A Deeks' asymmetry test was used to evaluate the publication bias.RESULTS: Fourteen studies enrolling 2171 patients were included. The pooled sensitivity, specificity and diagnostic odds ratio for ME-NBI diagnosis of EGC were 0.86(95%CI: 0.83-0.89), 0.96(95%CI: 0.95-0.97) and 102.75(95%CI: 48.14-219.32), respectively, with the area under ROC curve being 0.9623. Among the 14 studies, six also evaluated the diagnostic value of conventional white-light imaging, with a sensitivityof 0.57(95%CI: 0.50-0.64) and a specificity of 0.79(95%CI: 0.76-0.81). When using "VS"(vessel plus surface) ME-NBI diagnostic systems in gastric lesions of depressed macroscopic type, the pooled sensitivity and specificity were 0.64(95%CI: 0.52-0.75) and 0.96(95%CI: 0.95-0.98). For the lesions with a diameter less than 10 mm, the sensitivity and specificity were 0.74(95%CI: 0.65-0.82) and 0.98(95%CI: 0.97-0.98).CONCLUSION: ME-NBI is a promising endoscopic tool in the diagnosis of early gastric cancer and might be helpful in further target biopsy.

Stem cells in gastric cancer

Gastric cancer(GC) is one of the leading causes of cancerrelated mortality worldwide.Cancer stem cells(CSCs),which were first identified in acute myeloid leukemia and subsequently in a large array of solid tumors,play important roles in cancer initiation,dissemination and recurrence.CSCs are often transformed tissue-specific stem cells or de-differentiated transit amplifying progenitor cells.Several populations of multipotent gastric stem cells(GSCs) that reside in the stomach have been determined to regulate physiological tissue renewal and injury repair.These populations include the Villin+ and Lgr5+ GSCs in the antrum,the Troy+ chief cells in the corpus,and the Sox2+ GSCs that are found in both the antrum and the corpus.The disruption of tumor suppressors in Villin+ or Lgr5+ GSCs leads to GC in mouse models.In addition to residing GSCs,bone marrow-derived cells can initiate GC in a mouse model of chronic Helicobacter infection.Furthermore,expression of the cell surface markers CD133 or CD44 defines gastric CSCs in mouse models and in human primary GC tissues and cell lines.Targeted elimination of CSCs effectively reduces tumor size and grade in mouse models.In summary,the recent identification of normal GSCs and gastric CSCs has greatly improved our understanding of the molecular and cellular etiology of GC and will aid in the development of effective therapies to treat patients.

支撑层与亚胺化条件对聚酰亚胺纳滤膜结构和性能的影响

支撑层的选择及制备方法改进对均匀分离层的形成及高分离性能纳滤(NF)膜的制备具有重要影响。文中对比了由聚对苯二甲酸乙二酯(PET)膜、聚丙烯腈(PAN)膜、聚四氟乙烯(PTFE)膜为支撑层制备的纳滤膜,通过扫描电镜、热重分析等对聚酰亚胺纳滤(PI NF)膜进行结构表征及分离性能测试。筛选出以PTFE为支撑层获得的聚酰亚胺(PI)纳滤膜具有均匀的分离层。以间苯二胺(MPDA)、均苯四甲酰氯(BTAC)分别作为水相及有机相单体,通过界面聚合法(IP)结合不同亚胺化方式获得PI分离层,筛选出了以化学亚胺化方式获得的PI NF膜具有较高的水通量。结果表明,采用孔径为0.22μm的PTFE作为支撑体,通过化学亚胺化方式,制备的PI NF膜在400 kPa下,具有36.4 L/(m^(2)·h)的水通量。实验结果将为高分离性能PI NF膜的制备提供一定的参考。

Emerging molecular basis of hematogenous metastasis in gastric cancer

Lymphatic metastasis is commonly observed in gastric cancer(GC), but hematogenous metastasis is more likely responsible for the cancer-related mortality. Since Stephen Paget first introduced the "seed and soil hypothesis" a century ago, growing evidence recognizes that numerous essential secreted factors and signaling pathway effectors participate in the pre-metastatic niche formation and distant organ metastasis. The cross-talk between GC cells and surrounding microenvironment may consist of a series of interrelated steps, including epithelial mesenchymal transition, intravasation into blood vessels, circulating tumor cell translocation, and secondary organ metastasis. Secreted factors including vascular endothelial growth factor(VEGF), matrix metalloproteinases and cancer-derived extracellular vesicles, especially exosomes, are essential in formation of premetastatic niche. Circulating tumor cells and micro RNAs represent as ‘‘metastatic intermediates' ' between primary tumors and sites of dissemination. Many biomarkers have been identified as novel metastatic markers and prognostic effectors. In addition, molecular therapy has been designed to target biomarkers such as growth factors(human epidermal growth factor receptor 2, VEGF) and chemokines, although they have not clearly proven to be effective in inhibiting GC metastasis in clinical trials. In this review, we will systematically discuss the emerging molecules and their microenvironment in hematogenous metastasis of GC, which may help us to find new therapeutic strategies in the future.

Evaluation of dynamic stereopsis in intermittent exotropia patients

AIM: To delineate the characteristics of the dynamic stereopsis test and analyze related parameters in intermittent exotropia [X(T)] patients. METHODS: Fifty-seven X(T) patients and 55 normal subjects were enrolled in this study. The normal and X(T) groups were used to test the reproducibility and reliability of the dynamic stereopsis test, and Bangerter filters with densities of 0.2 were then used to simulate suppression to test for traditional and dynamic stereopsis. In the X(T) group, the measurements included 1) dynamic stereopsis test comprising three parts: motion+disparity, motion only and disparity only; 2) ocular deviation angle; 3) Bagolini striated lens test; 4) disease course; and 5) Titmus stereopsis test. RESULTS: The test-retest reliability of the dynamic stereopsis method was 0.901 in the normal and X(T) groups, and none of the X(T) patients were able to pass the static and dynamic stereopsis tests after using the 0.2 Bangerter filter. The accuracy rate was greater than 80% in the normal group and 31.81%, 36.36%, and 45.45% for the motion+disparity, motion-only and disparityonly components of the traditional test for X(T) patients diagnosed with stereoblindness via traditional tests,respectively. Patients with a long disease course(>1 y) had worse dynamic stereopsis than those with a short disease course(<1 y; P<0.05, Chi-square test). The deviation angle was not correlated with the motion+disparity, disparityonly, or the motion-only test components(all P>0.05, Chisquare test). CONCLUSION: Dynamic stereopsis is preserved in certain X(T) patients diagnosed with stereoblindness via traditional tests. A long disease course was shown to be a negative factor for dynamic stereopsis in X(T) patients which might be associated with worse progression, and provide good references clinically.

全串联高功率密度紫外LED结构和散热研究

提高紫外LED光源模块的功率密度和辐照度已成为光固化应用的迫切需求。本文设计制作了一种6颗芯片串联的高功率密度UV-LED光源模块,加装了循环水冷散热器对其进行有效散热。通过仿真和实验对该模块的各项参数进行测试,证实仿真模型的预测能力。实验结果表明,全串联光源模块输入功率最高可以达到325.8 W,功率密度达到646.5 W/cm 2,此时芯片结温能够维持在130℃左右。

儿童淫秽制品网络传播的刑法规制

儿童淫秽制品以未成年人为摄制对象,包含边缘性色情或直接性行为,是用以满足性欲的淫秽制品。儿童淫秽制品的网络传播可能增加未成年人成为犯罪对象的几率,亦会对被害儿童产生循环往复和不可预估的伤害。我国在立法上有必要借鉴其他国家或地区刑法对儿童淫秽制品规制的方式,将制作、传播、持有儿童淫秽制品的行为区别于普通淫秽制品犯罪,并对其使用更为严厉的刑法处罚标准。当网络服务提供者具有干预设备实际使用的能力而拒不履行必要监管义务时,应以拒不履行网络安全管理义务罪和传播淫秽物品牟利罪的想象竞合犯追究其刑事责任。

Development of hybrid-type modified chitosan derivative nanoparticles for the intracellular delivery of midkine-siR NA in hepatocellular carcinoma cells

BACKGROUND： Hepatocellular carcinoma（HCC） is one of the most common cancers worldwide. Most of the patients with HCC lose the surgical opportunity at the time of diagno sis. Some novel therapeutic modalities, like gene therapy, are promising for the treatment of HCC. However, the success of gene therapy depends on two aspects： efficient gene materials and gene delivery vectors. The present study was to develop new chitosan-based nanoparticles for a midkine-si RNA（anti HCC gene drug） delivery.METHODS： The novel gene delivery vector（MixN CH） was syn thesized by hybrid-type modification of chitosan with 2-chloro ethylamine hydrochloride and N, N-dimethyl-2-chloroethylamine hydrochloride. The chemical structure of Mix NCH was char acterized by FT-IR and 1HNMR. The cytotoxicity of Mix NCH was determined by MTS assay. The gene condensation ability and size, zeta potential and morphology of Mix NCH/MK si RNA nanoparticles were measured. The in vitro transfection and gene knockdown efficiency of midkine by Mix NCH/MK si RNA nanoparticles was detected by q RT-PCR and Western blotting. Gene knockdown effect at the molecule level on the proliferation of Hep G2 in vitro was determined by MTS assay.RESULTS： Mix NCH was successfully acquired by aminoalkyl ation modification of chitosan. The Mix NCH could condense MK-siR NA well above the weight ratio of 3. The average size of Mix NCH/MK-si RNA nanoparticles was 100-200 nm, and thesurface charge was about ＋5 m V. Morphologically, Mix NCH/MK-si RNA nanoparticles were in regular spherical shape-with no aggregation. Regarding to the in vitro transfection of nanoparticles, the MixN CH/MK-siR NA nanoparticles reduced MK m RNA level to 14.03%±4.03%, which were comparable to Biotrans（8.94%±3.77%）. Mix NCH/MK-si RNA effectively inhibited the proliferation of Hep G2 in vitro.-CONCLUSION： Mix NCH/MK-si RNA nanoparticles could be effective for the treatment of hepatocellular carcinoma.

Image Quality Stability of Whole-body Diffusion Weighted Imaging

Objective To assess the reproducibility of whole-body diffusion weighted imaging(WB-DWI) technique in healthy volunteers under normal breathing with background body signal suppression.Methods WB-DWI was performed on 32 healthy volunteers twice within two-week period using short TI inversion-recovery diffusion-weighted echo-planar imaging sequence and built-in body coil.The volunteers were scanned across six stations continuously covering the entire body from the head to the feet under normal breathing.The bone apparent diffusion coefficient(ADC) and exponential ADC(eADC) of regions of interest(ROIs) were measured.We analyzed correlation of the results using paired-t-test to assess the reproducibility of the WB-DWI technique.Results We were successful in collecting and analyzing data of 64 WB-DWI images.There was no significant difference in bone ADC and eADC of 824 ROIs between the paired observers and paired scans(P>0.05).Most of the images from all stations were of diagnostic quality.Conclusion The measurements of bone ADC and eADC have good reproducibility.WB-DWI technique under normal breathing with background body signal suppression is adequate.

Construction of eukaryotic expression vector of human S100A13 gene and its effect on proliferation of human thyroid cancer cell line TT

Objective To investigate the effect of exogenous S100A13 gene overexpression on the proliferation of human thyroid cancer cell line TT.Methods The recombinant ORF of S100A13 tagged with six histidines at the 5' end was subcloned into the pcDNA3.2/V5/GW/D-TOPO vector and sequenced.The eukaryotic expression plasmid pcDNA3.2/V5 /GW/D-S100A13 and empty vector pcDNA3.2/V5/GW/D were transfected into TT cells.The positive clones were selected by G418.The expressions of S100A13 mRNA and protein were detected by real time reverse transcription-polymerase chain reaction(RT-PCR) and Western blot.The effect of S100A13 on cell proliferation and cell cycle was evaluated by cell growth curve,MTT colorimetric assay and flow cytometry.Results S100A13 gene tagged with six histidines at the 5 ' end was confirmed to be inserted into the pcDNA3.2/V5/GW/D vector correctly.TT-S100A13-V5 cells,which over-expressed S100A13,were constructed successfully.TT-S100A13-V5 cells grew much faster than TT-V5 and TT cells(P <0.001).The proportions of both S and G2/M phase cells were significantly higher in TT-S100A13-V5 cells than those in TT-V5 and TT cells(P <0.001).Conclusion The eukaryotic expression vector containing human S100A13 gene has been successfully constructed,which highly expresses S100A13 in TT cells.Exogenous S100A13 gene overexpression accelerates TT cell proliferation and drives the cell cycle progression of TT cells from G0/G1 phase to S and G2/M phases.

Age-related changes of lens thickness and density in different age phases

AIM: To explore the changes in lens thickness and density with age.METHODS: A Chinese population-based retrospective study was performed. A total of 497 individuals(490 right eyes and 495 left eyes), ranging from 3 to 69 years old were included. Lens images obtained from IOL Master 700 were used to measure lens thickness and density. Piecewise regression model was chosen to illustrate the relationship of lens thickness and density with age.RESULTS: The proportion of people aged 3-18, 19-40, over 40 was 38.6%, 50.9% and 10.5% respectively. The whole lens thickness decreased with age during the first 7 years of life, kept stable from 8 to 16 years old, and then increased at the rate of about 27 μm per year. The thickness of the lens cortex and nucleus tended to decrease first and then increase with age, which was dependent on age stages. The whole lens density also decreased with age until 7 years old. The increasing rate of lens density was different in different age groups. The whole lens density increased rapidly from 7 to 22 years old and slowed down after 22 years old. Similarly, the changing tendency of lens cortical and nuclear density differed in different age phases. CONCLUSION: Both lens thickness and density are significantly associated with age, whereas they do not change linearly with age. Moreover, it is necessary to increase the population over 40 years old and conduct further research.

Searching for classical Be stars in LAMOST DR1

We report on searching for Classical B-type emission-line（CBe） stars in the first data release of the Large Sky Area Multi-Object fiber Spectroscopic Telescope（LAMOST; also called the Guo Shou Jing Telescope）. A total of 192 objects（including 12 previously known CBes） were identified as CBe candidates with prominent He I λ4387, He I λ4471 and Mg II λ4481 absorption lines, as well as Hβλ4861and Hαλ6563 emission lines. These candidates significantly increase the currently known sample of CBes by about 8%. Most of the CBe candidates are distributed near the Galactic Anti-Center due to the observing strategy used for LAMOST. Only two CBes are in star clusters. These two CBes have ages of 15.8 and 398 Myr, respectively.

Efficacy of autologous conjunctival flap on repairing the late-onset filtering bleb leakage

AIM： To evaluate the effectiveness of autologous conjunctival flap surgery for repairing the late-onset filtering bleb leakage after trabeculectomy.METHODS： This study retrospectively reviewed 106 eyes from 106 patients with late-onset filtering bleb leakage after trabeculectomy who received autologous conjunctival flap surgery at the Zhongshan Ophthalmic Centre from 2005 to 2015. The basic information was recorded, and the interval time between trabeculectomy and autologous conjunctival flap surgery as well as related risk factors, intraocular pressure（IOP）, anterior chamber depth（ACD） and best corrected visual acuity（BCVA） were analysed. Moreover, 41 patients who completed the 1-year follow up were analysed to determine the IOP and BCVA changes and long-term success rates.RESULTS： The 50 male and 56 female subjects（average age 39.13±17.96 y） included 47（44.34%） and 33（31.13%） cases of primary open angle and primary angle-closure glaucoma. The mean interval between trabeculectomy and repair surgery was 60.60±56.92（3-264）mo. The mean mitomycin（MMC） concentration during trabeculectomy was 0.27±0.04（0.12-0.4） mg/m L in the fornix-based conjunctival flap group（68 patients） and 0.28±0.04（0.20-0.33） mg/m L in the limbal-based conjunctival flap group（11 patients）. After bleb leakage, the patients＇ vision remained stable while the IOP decreased from 10.25±4.76（3-20.86） to 9.44±4.33（2-21） mm Hg（P〈0.01）. In the 41 analysed patients, the IOP was controlled at 15.68±5.11（7-40） mm Hg in the 1^（st） year after autologous conjunctival flap surgery and recurrence was not observed, for a long-term success rate of 100%. CONCLUSION： Autologous conjunctival flap repairing surgery is an effective technique for sealing filtering bleb leakages and controlling IOP postoperatively.

M-giant star candidates identified in LAMOST DR 1

We perform a discrimination procedure with the spectral index diagram of TiO 5 and Ca H2＋Ca H3 to separate M giants from M dwarfs. Using the M giant spectra identified from LAMOST DR1 with high signal-to-noise ratio, we have successfully assembled a set of M giant templates, which show more reliable spectral features. Combining with the M dwarf/subdwarf templates in Zhong et al., we present an extended library of M-type templates which includes not only M dwarfs with a well-defined temperature and metallicity grid but also M giants with subtypes from M0 to M6. Then, the template-fitting algorithm is used to automatically identify and classify M giant stars from LAMOST DR1. The resulting catalog of M giant stars is cross-matched with 2MASS J H Ks and WISE W1/W2 infrared photometry. In addition, we calculated the heliocentric radial velocity of all M giant stars by using the cross-correlation method with the template spectrum in a zero-velocity rest frame.Using the relationship between the absolute infrared magnitude MJ and our classified spectroscopic subtype, we derived the spectroscopic distance of M giants with uncertainties of about 40%. A catalog of 8639 M giants is provided. As an additional result of this analysis, we also present a catalog of 101 690 M dwarfs/subdwarfs which are processed by our classification pipeline.

Near-Infrared Light-Responsive Nitric Oxide Delivery Platform for Enhanced Radioimmunotherapy

Radiotherapy(RT)is a widely used way for cancer treatment.However,the efficiency of RT may come with various challenges such as low specificity,limitation by resistance,high dose and so on.Nitric oxide(NO)is known a very effective radiosensitizer of hypoxic tumor.However,NO cannot circulate in body with high concentration.Herein,an NIR light-responsive NO delivery system is developed for controlled and precisely release of NO to hypoxic tumors during radiotherapy.Tert-Butyl nitrite,which is an efficient NO source,is coupled to Ag2S quantum dots(QDs).NO could be generated and released from the Ag2S QDs effectively under the NIR irradiation due to the thermal effect.In addition,Ag is also a type of heavy metal that can benefit the RT therapy.We demonstrate that Ag2S NO delivery platforms remarkably maximize radiotherapy effects to inhibit tumor growth in CT26 tumor model.Furthermore,immunosuppressive tumor microenvironment is improved by our NO delivery system,significantly enhancing the anti-PD-L1 immune checkpoint blockade therapy.100% survival rate is achieved by the radio-immune combined therapy strategy based on the Ag2S NO delivery platforms.Our results suggest the promise of Ag2S NO delivery platforms for multifunctional cancer radioimmunotherapy.

Discovery of Extended Structure Around Open Cluster COIN-Gaia 13 Based on Gaia EDR3

COIN-Gaia 13 is a newly discovered open cluster revealed by Gaia DR2 data.It is a nearby open cluster with a distance of about 513 pc.Combined with the five-dimensional astrometric data of Gaia EDR3 with higher accuracy,we use the membership assignment algorithm(pyUPMASK)to determine the membership of COINGaia 13 in a large extended spatial region.The cluster has 478 identified candidate members.After obtaining reliable cluster members,we further study its basic properties and spatial distribution.Our results show that there is an obvious extended structure of the cluster in the X-Y plane.This elongated structure is distributed along the spiral arm,and the whole length is about 270 pc.The cluster age is 250 Myr,the total mass is about 439 M_(⊙) and the tidal radius of the cluster is about 11 pc.Since more than half of member stars(352 stars)are located outside twice the tidal radius,it is suspected that this cluster is undergoing the dynamic dissolution process.Furthermore,the spatial distribution and kinematic analysis indicate that the extended structure in COIN-Gaia 13 is more likely to be caused by differential rotation of the Galaxy.

Discovery of Four New Clusters in the Cygnus Cloud

We report the discovery of four new open clusters(named QC 1,QC 2,QC 3 and QC 4)in the direction of Cygnus Cloud and select their members based on five astrometric parameters(l,b,ω,μα*,μδ)of Gaia DR2.We also derive their astrophysical parameters for each new cluster.Structure parameters are generated by fitting the radial density distribution with a King’s profile.Using solar metallicity,we performed isochrone-fitting on their purified color-magnitude diagrams(CMDs)to derive the age of the clusters.The known cluster NGC 7062 in an adjacent area is chosen to verify our identification process.The estimated distance,reddening and age of NGC 7062 are in good agreement with the literature.