Biofabrication of nanocomposite-based scaffolds containing human bone extracellularmatrix for the differentiation of skeletal stem and progenitor cells

Autograft or metal implants are routinely used in skeletal repair.However,they fail to provide long-term clinical resolution,necessitating a functional biomimetic tissue engineering alternative.The use of native human bone tissue for synthesizing a biomimeticmaterial inkfor three-dimensional(3D)bioprintingof skeletal tissueis anattractivestrategyfor tissueregeneration.Thus,human bone extracellular matrix(bone-ECM)offers an exciting potential for the development of an appropriate microenvironment for human bone marrow stromal cells(HBMSCs)to proliferate and differentiate along the osteogenic lineage.In this study,we engineered a novel material ink(LAB)by blending human bone-ECM(B)with nanoclay(L,Laponite®)and alginate(A)polymers using extrusion-based deposition.The inclusion of the nanofiller and polymeric material increased the rheology,printability,and drug retention properties and,critically,the preservation of HBMSCs viability upon printing.The composite of human bone-ECM-based 3D constructs containing vascular endothelial growth factor(VEGF)enhanced vascularization after implantation in an ex vivo chick chorioallantoic membrane(CAM)model.The inclusion of bone morphogenetic protein-2(BMP-2)with the HBMSCs further enhanced vascularization and mineralization after only seven days.This study demonstrates the synergistic combination of nanoclay with biomimetic materials(alginate and bone-ECM)to support the formation of osteogenic tissue both in vitro and ex vivo and offers a promising novel 3D bioprinting approach to personalized skeletal tissue repair.

Fiber Traction Printing:A 3D Printing Method of Continuous Fiber Reinforced Metal Matrix Composite

A novel metal matrix composite freeform fabrication approach,fiber traction printing(FTP),is demonstrated through controlling the wetting behavior between fibers and the matrix.This process utilizes the fiber bundle to control the cross-sectional shape of the liquid metal,shaping it from circular to rectangular which is more precise.The FTP process could resolve manufacturing difficulties in the complex structure of continuous fiber reinforced metal matrix composites.The printing of the first layer monofilament is discussed in detail,and the effects of the fibrous coating thickness on the mechanical properties and microstructures of the composite are also investigated in this paper.The composite material prepared by the FTP process has a tensile strength of 235.2 MPa,which is close to that of composites fabricated by conventional processes.The complex structures are printed to demonstrate the advantages and innovations of this approach.Moreover,the FTP method is suited to other material systems with good wettability,such as modified carbon fiber,surfactants,and aluminum alloys.

腹膜透析患者腹膜冲洗液MMPs/TIMPs、25(OH)D 3水平变化与腹膜透析相关性腹膜炎、腹膜纤维化的关系

目的探究腹膜透析(PD)患者腹膜冲洗液基质金属蛋白酶(MMPs)/金属蛋白酶组织抑制因子(TIMPs)、血25-羟基维生素D_(3)[25(OH)D_(3)]水平变化与腹膜透析相关性腹膜炎(PDAP)、腹膜纤维化的关系。方法收集2018年1月—2020年1月收治的58例PD为研究对象,根据是否发生PDAP分为PDAP组和无PDAP组,根据是否出现腹膜纤维化分为腹膜纤维化组和无腹膜纤维化组,查阅患者临床病历资料,检测各组腹膜冲洗液中MMPs/TIMPs、25(OH)D_(3)水平,分析影响PD患者PDAP或腹膜纤维化发生的易感因素,采用受试者工作特征(ROC)曲线分析腹膜冲洗液MMPs/TIMPs、25(OH)D_(3)水平变化对PDAP或腹膜纤维化发生的预测价值。结果58例PD中13例(22.41%)出现PDAP,10例(17.24%)出现腹膜纤维化。多因素Logistic回归分析显示,年龄、透析时间、MMPs/TIMPs、25(OH)D_(3)是PD患者PDAP发生的影响因素(P<0.05,P<0.01);透析时间、MMPs/TIMPs、25(OH)D_(3)是PD患者腹膜纤维化发生的影响因素(P<0.05,P<0.01)。ROC曲线分析显示,腹膜冲洗液MMPs/TIMPs、25(OH)D_(3)联合检测预测PD患者PDAP、腹膜纤维化发生的曲线下面积、敏感度分别为0.840、0.835和0.892、0.811,均较二者单一检测高。结论PD患者发生PDAP、腹膜纤维化的风险不容忽视,加强对年龄≥60岁、PD时间较长高危人群的重视,通过监测腹膜冲洗液MMPs/TIMPs、25(OH)D_(3)水平,对PD患者PDAP、腹膜纤维化的有效防治十分重要。

“All‐In‐One” integrated ultrathin SnS2@3D multichannel carbon matrix power high‐areal–capacity lithium battery anode

Construction of a thickness‐independent electrode with high active material mass loading is crucial for the development of high energy rechargeable lithium battery.Herein,we fabricate an all‐in‐one integrated SnS2@3D multichannel carbon matrix(SnS2@3DMCM)electrode with in‐situ growth of ultrathin SnS2 nanosheets inside the inner walls of three dimensional(3D)multichannels.The interconnected conductive carbon matrix derived from natural wood acts as an integrated porous current collector to avail the electrons transport and accommodate massive SnS2 nanosheets,while plenty of 3D aligned multichannels facilitate fast ions transport with electrode thickness‐independent even under high mass loading.As expected,the integrated SnS2@3DMCM electrode exhibits remarkable electrochemical lithium storage performance,such as exceptional high‐areal‐capacity of 6.4 mAh cm−2,high rate capability of 3 mAh cm−2 under current of 6.8 mAcm−2(10 C),and stable cycling performance of 6.8 mAcm−2 with a high mass loading of 7mg cm−2.The 3D integrated porous electrode constructing conveniently with the natural source paves new avenues towards future high‐performance lithium batteries.

3D Gray Level Co-Occurrence Matrix Based Classification of Favor Benign and Borderline Types in Follicular Neoplasm Images

Since the efficiency of treatment of thyroid disorder depends on the risk of malignancy, indeterminate follicular neoplasm (FN) images should be classified. The diagnosis process has been done by visual interpretation of experienced pathologists. However, it is difficult to separate the favor benign from borderline types. Thus, this paper presents a classification approach based on 3D nuclei model to classify favor benign and borderline types of follicular thyroid adenoma (FTA) in cytological specimens. The proposed method utilized 3D gray level co-occurrence matrix (GLCM) and random forest classifier. It was applied to 22 data sets of FN images. Furthermore, the use of 3D GLCM was compared with 2D GLCM to evaluate the classification results. From experimental results, the proposed system achieved 95.45% of the classification. The use of 3D GLCM was better than 2D GLCM according to the accuracy of classification. Consequently, the proposed method probably helps a pathologist as a prescreening tool.

3D printed aluminum matrix composites with well-defined ordered structures of shear-induced aligned carbon fibers

Carbon fiber reinforced aluminum composites with ordered architectures of shear-induced aligned carbon fibers were fabricated by 3D printing.The microstructures of the printed and sintered samples and mechanical properties of the composites were investigated.Carbon fibers and aluminum powder were bonded together with resin.The spatial arrangement of the carbon fibers was fixed in the aluminum matrix by shear-induced alignment in the3D printing process.As a result,the elongation of the composites with a parallel arrangement of aligned fibers and the impact toughness of the composites with an orthogonal arrangement were 0.82%and 0.41 J/cm^(2),respectively,about 0.4 and 0.8 times higher than that of the random arrangement.

Efficient solution of large-scale matrix of acoustic wave equations in 3D frequency domain

In 3D frequency domain seismic forward and inversion calculation,the huge amount of calculation and storage is one of the main factors that restrict the processing speed and calculation efficiency.The frequency domain finite-difference forward simulation algorithm based on the acoustic wave equation establishes a large bandwidth complex matrix according to the discretized acoustic wave equation,and then the frequency domain wave field value is obtained by solving the matrix equation.In this study,the predecessor's optimized five-point method is extended to a 3D seven-point finite-difference scheme,and then a perfectly matched layer absorbing boundary condition(PML)is added to establish the corresponding matrix equation.In order to solve the complex matrix,we transform it to the equivalent real number domain to expand the solvable range of the matrix,and establish two objective functions to transform the matrix solving problem into an optimization problem that can be solved using gradient methods,and then use conjugate gradient algorithm to solve the problem.Previous studies have shown that in the conjugate gradient algorithm,the product of the matrix and the vector is the main factor that affects the calculation efficiency.Therefore,this study proposes a method that transform bandwidth matrix and vector product problem into some equivalent vector and vector product algorithm,thereby reducing the amount of calculation and storage.

基质金属蛋白酶-3和维生素D受体的基因多态性与腰椎间盘退变的易感性

目的探索基质金属蛋白酶-3(MMP-3)和维生素D受体(VDR)的基因多态性与腰椎间盘退变的关系。方法采用病例对照研究方法,以CT确诊腰椎间盘退变患者178人为病例组,随机选择体检人员中无腰背痛史且腰椎功能正常者284人为对照。应用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)的方法分析MMP-3和VDR的基因多态性。结果MMP-3和VDR-Apa的等位基因5A和A在病例组中的分布明显高于对照组(P<0.05),其OR值分别为1.96和1.70。而VDR-Taq的等位基因t在两组间分布没有统计学差异(P>0.05)。分层分析显示男性腰椎间盘退变仅与MMP-3基因多态性有关,而女性则与MMP-3和VDR-Apa基因多态性均有关。叉生分析显示MMP-3的等位基因5A和VDR-Apa的等位基因A同时存在对腰椎间盘退变有交互促进作用。结论MMP-3和VDR-Apa的多态基因型是腰椎间盘退变的危险基因。

基于D-H矩阵的3-RSR并联机器人的误差建模(英文)

本文通过选取3-RSR并联机器人的任意一条支链作为研究对象,利用D-H矩阵建立动平台相对于静平台的位姿关系矩阵,采用矩阵微分法推导出机构原始误差到末端执行部分的误差映射模型。该模型包含了机构全部的几何原始误差,同时将末端执行部分位姿误差与原始几何误差间的非线性隐式函数关系简化为线性显式函数关系,是进一步研究误差补偿的基础。

一类3--D非线性系统的稳定性分析及函数观测器设计

本文首先研究了一类3--D非线性系统的稳定性问题,在此基础上,利用秩条件和线性矩阵不等式(LMI)方法,得到了这类系统的渐近函数观测器存在的充分条件,并给出了函数观测器的设计方法.最后,通过算例来说明这种方法是可行且有效的.

大肠癌患者组织多项基质金属蛋白、VEGF-C、VEGF-D、Ets-1、CD44v6及VEGFR-3的变化

目的：探讨大肠癌患者组织多项基质金属蛋白、血管内皮生长因子（VEGF）一C、VEGF—D、Ets一1、CD44v6及血管内皮生长因子受体一3（VEGFR一3）的变化情况。方法：选取2010年1月2012年9月于本院进行诊治的35例大肠癌患者为观察组，同期进行检查诊断的35例大肠良性病变患者为对照组，比较两组患者组织的基质金属蛋白酶（MMP）一1、MMP一2、MMP一3、MMP一7及VEGF—C、VEGF—D、Ets一1、CD44v6、VEGFR一3阳性表达率，并比较不同分期及有无转移观察纽的上述指标阳性率。结果：观察纽MMP一1、MMP一2、MMP一3、MMP一7及VEGF—C、VEGF—D、Ets一1、CD44v6、VEGFR一3阳性表达率均高于对照组，且观察组中Duke＇s分期较高者及有转移者的上述指标阳性率高于Duke’S分期较低者及无转移者，差异均有统计学意义（P均〈0．05）。结论：大肠癌患者组织多项基质金属蛋白、VEGF—C、VEGF-D、Ets一1、CD44v6及VEGFR一3的阳性表达率均较高，且不同Duke’S分期及有无转移者之间也存在差异。

结直肠癌中MMP-7、VEGF-D和VEGFR-3的表达相关性研究

目的:通过检测结直肠癌中基质金属蛋白酶-7(Matrix metalloproteinase-7,MMP-7)、血管内皮生长因子-D(Vascularendothelial growth factor-D,VEGF-D)和血管内皮生长因子受体-3(Vascular endothelial growth factor receptor-3,VEGFR-3)的表达,探讨MMP-7与淋巴管生成因子的关系。方法:应用免疫组化法检测124例结直肠癌和70例正常黏膜组织中MMP-7、VEGF-D和VEGFR-3的表达,比较两种组织中3种蛋白表达的差异,分析其与结直肠癌临床病理指标的关系及三者的相关性。结果:MMP-7、VEGF-D和VEGFR-3表达的阳性率在结直肠癌中明显高于黏膜组织(P<0.001),MMP-7的表达与结直肠癌的肿瘤体积、Dukes分期、浸润深度及淋巴结转移有关(P<0.05);VEGF-D和VEGFR-3的表达与肿瘤体积、淋巴结转移有关(P<0.05)。结直肠癌中MMP-7和VEGF-D、VEGFR-3的表达呈正相关性(均P=0.01)。MMP-7和VEGF-D、VEGFR-3的高表达与患者的不良预后相关(P<0.05)。结论:结直肠癌中MMP-7的表达与VEGF-D、VEGFR-3的表达密切相关,可能在淋巴管新生中起协同作用,促进淋巴道转移。联合检测MMP-7、VEGF-D和VEGFR-3可能对判断结直肠癌的预后有一定的指导意义。

1,25-二羟维生素D_3诱导人成骨样细胞模型基质金属蛋白酶-1表达

目的 :研究 1,2 5 -二羟维生素D3 [1α,2 5 -dihydroxyvitaminD3 ,1α,2 5 (OH) 2 D3 ]对人成骨细胞膜型基质金属蛋白酶 - 1(membrane -typematrixmetalloproteinase - 1,MT1-MMP)表达的影响 ,探讨 1α,2 5 (OH) 2 D3 调节骨代谢作用机制。方法 :人成骨细胞用 1α ,2 5 (OH) 2 D3 干预。Western杂交检测MT1-MMP蛋白质表达。MMP - 2活性用ELISA检测。结果 :观察到 1α ,2 5 (OH) 2 D3 诱导成骨细胞MT1-MMP表达呈剂量依赖性 (均P <0 0 5 )。 1α,2 5 (OH) 2 D3 干预 12～ 2 4h促进MT1-MMP表达 (均P <0 0 5 )。 1α,2 5 (OH) 2 D3 促进MMP - 2激活呈剂量依赖性 (均P <0 0 5 )。结论 :由于MT1-MMP在骨重建过程中起着维持骨形成的关键作用 ,1α ,2 5(OH) 2 D3 可通过诱导成骨细胞MT1-MMP表达促进骨形成。此可能为 1α,2 5 (OH) 2 D3 治疗骨质疏松症机理之一。

D-二聚体与sMMP-3联合检测对类风湿关节炎患者病情活动的评估价值

目的探讨D-二聚体与血清基质金属蛋白酶3(sMMP-3)联合检测对类风湿关节炎患者病情活动的评估价值。方法回顾性分析2017年4月至2019年3月深圳市第二人民医院收治的类风湿关节炎患者140例的临床资料。根据类风湿关节炎的28个关节疾病活动评分(DAS28评分)将患者分为病情缓解期组(32例)和病情活动期组(108例)。采用免疫比浊法检测血清D-二聚体水平,采用酶联免疫吸附试验法检测sMMP-3水平,比较2组患者的血清D-二聚体、sMMP-3水平差异。采用受试者工作者特征曲线(ROC曲线)评估血清D-二聚体、sMMP-3水平对类风湿关节炎患者病情活动的临床诊断价值。结果病情缓解期组患者血清D-二聚体、C反应蛋白、红细胞沉降率(ESR)、抗环瓜氨酸肽抗体(抗CCP抗体)、sMMP-3水平显著低于病情活动期组(P<0.05)。多因素Logistic回归分析结果显示,血清D-二聚体、ESR、抗CCP抗体、sMMP-3是类风湿关节炎患者病情活动的独立影响因素(P<0.05)。血清D-二聚体、ESR、抗CCP抗体、sMMP-3水平、D-二聚体联合sMMP-3检测的曲线下面积分别为0.936、0.832、0.804、0.897、0.940,最佳临界值分别为1.740μg/mL、58.904 mm/h、350.872 RU/mL、167.965μg/L、8.511,灵敏度分别为92.4%、55.1%、57.4%、90.3%、94.7%,特异度分别为82.8%、100.0%、93.4%、87.2%、81.8%。结论相较于血清抗CCP抗体、ESR检测,血清D-二聚体、sMMP-3检测能更好地评估类风湿关节炎患者的病情活动情况,血清D-二聚体联合sMMP-3检测能进一步提高对患者病情活动的评估价值。

3D刚体摆的鲁棒控制器设计和比较分析

3D刚体摆是研究刚体复杂旋转动力学与控制问题的典型系统。针对3D刚体摆受外界扰动以及转动惯量的不确定性,根据鲁棒H∞控制理论,采用线性矩阵不等式(LMI)的方法设计了一种状态反馈H∞控制律。仿真结果表明,鲁棒控制器对系统参数的变化具有较强的鲁棒性。与PID控制器比较,鲁棒控制器对于3D刚体摆控制系统具有较好的动态特性和稳定性。

Ultrathin poly(cyclocarbonate-ether)-based composite electrolyte reinforced with high-strength functional skeleton

Composite polymer electrolytes(CPEs)are considered to be the most promising to break through the performance and safety limitations of traditional lithium-ion batteries because of their excellent electrochemical and mechanical properties.Aiming at the performance limitations of the most common polyether matrix such as poly(ethylene oxide)(PEO),a novel poly(cyclocarbonate-ether)polymer matrix was prepared by in-situ thermal curing,the weaker interaction between its C=O bond and Li^(+)can promote the rapid transport of Li^(+).Adding ionic liquid and active filler LLZTO to the matrix can synergistically reduce the crystallinity of matrix and promote the dissociation of lithium salts.In addition,a 3D functional skeleton made of polyacrylonitrile(PAN)and lithium fluoride(LiF)can greatly improve the mechanical strength of polymer matrix after cold pressing,and Li F is also conducive to interface stability.The thickness of the optimal sample(VP6L/CPL)was only 25μm,and its ionic conductivity,lithium ion transference number,and electrochemical stability window were as high as 7.17×10^(-4)S cm^(-1)(25℃),0.54 and 5.4 V,respectively,while the mechanical strength reaches 6.1 MPa,which can fully inhibit the growth of lithium dendrites.The excellent electrochemical performance and mechanical strength enable the assembled Li|VP6L/CPL|Li battery to be continuously charged for over 200 h and cycled stably for more than 2300 h,and Li|VP6L/CPL|LFP battery can be stably cycled for more than 400 and 550 cycles at 1 C(40℃)and 0.5 C(25℃),respectively.

In situ measurement of ECM rheology and microheterogeneity in embedded and overlaid 3D pancreatic tumor stroma co-cultures via passive particle tracking

Tumor growth is regulated by a diverse set of extraellular infuences,including paracrine crosstalk with stromal partners,and biophysical interactions with surrounding cells and tissues.Studies elucidating the role of physical force and the mechanical properties of the extracellular matrix(ECM)itself as regulators of tumor growth and invasion have been greatly catalyzed by the use of in ritro three-dimensional(3D)tumor models.These systems provide the ability to systematically isolate,manipulate,and evaluate impact of stromal components and extracellular mechanics in a platform that is both conducive to imaging and biologically relevant.However,recognizing that mechanoregulatory crosstalk is bi-directional and fully utilizing these models requires complementary methods for in situ measurements of the local mechanical environment.Here,in 3D tumor/fbroblast co-culture models of pancreatic canocer,a discase characterized by its prominent stromal involvement,we evaluate the use of particle-tracking microrhoology to probe dynamic mechanical changes.Using videos of fuorescently labeled polystyrene micro-spheres embedded in ollagen I ECM,we measure spatiotemporal changes in the Brownian motion of probes to report local ECM shear modulus and microheterogeneity.This approach reveals st ffening of collagen in fibroblast co-cultures relative to cultures with cancer cells only,which exhibit degraded ECM with heterogeneous microstructure.We further show that these effects are dependent on culture geometry with contrast ing behavior for embedded and overlay cultures.In addition to potential application to screening stroma targeted therapeutics,this work also provides insight into how the compoition and plating geometry impact the mechanical propertios of 3D cell cultures that are increasingly widey used in cancer biology.

3D Multilayered Turtle Shell Models for Image Steganography

By embedding secret data into cover images,image steganography can produce non-discriminable stego-images.The turtle shell model for data hiding is an excellent method that uses a reference matrix to make a good balance between image quality and embedding capacity.However,increasing the embedding capacity by extending the area of basic structures of the turtle shell model usually leads to severe degradation of image quality.In this research,we innovatively extend the basic structure of the turtle shell model into a three-dimensional(3D)space.Some intrinsic properties of the original turtle shell model are well preserved in the 3D version.Theoretic analysis shows that the new proposed models have good performance both in the image quality and in the complexity of the reference matrix.Our experimental results justify the theoretic conclusions.

Mechanical Behavior and Microstructure Characterization of 3D Stitched Quartz Fibers-reinforced Silica Composites

The mechanical properties of silica material in the monolithic form are ;far from acceptable levels. In this paper, 3D stitched quartz preform was used for the fiber reinforcement, and quartz fibers- reinforced silica composites were prepared by the silica sol-infiltration-sintering method. The density of the composite was up to 1.71 g/cm3 after 10 infiltration-sintering cycles. The flexural strength and the in-plane shear strength were 61.7 MPa and 20.3 MPa, respectively. The flexural stress-deflection curve exhibited mostly nonlinear behavior, which was different from that of monolithic ceramics. Because of the existence of the fiber in Z axis direction, shearing property between the different layers of 3D stitched composites were greatly enhanced. Toughness effect of the 3D stitched quartz preform was conspicuous. The as-fabricated composites showed non-catastronhic failure behavior resulting from weak fiber/matrix interface.