Concentration of lambda concatemers using a 3D printed device

Identifying significant variations in genomes can be cumbersome, as the variations span a multitude of base pairs and can make genome assembly difficult. However, large DNA molecules that span the variation aid in assembly. Due to the DNA molecule's large size, routine molecular biology techniques can break DNA. Therefore, a method is required to concentrate large DNA. A bis-acrylamide roadblock was cured in a proof-of-principle 3D printed device to concentrate DNA at the interface between the roadblock and solution. Lambda concatemer DNA was stained with YOYO-1 and loaded into the 3D printed device. A dynamic range of voltages and acrylamide concentrations were tested to determine how much DNA was concentrated and recovered. The fluorescence of the original solution and the concentrated solution was measured, the recovery was 37% of the original sample, and the volume decreased by a factor of 3 of the original volume.     

Recent Advances in 3D Printing of Photocurable Polymers: Types,Mechanism, and Tissue Engineering Application

The conversion of liquid resin into solid structures upon exposure to light of a specific wavelength is known as photopolymerization. In recent years, photopolymerization-based 3D printing has gained enormous attention for constructing complex tissue-specific constructs. Due to the economic and environmental benefits of the biopolymers employed, photo-curable 3D printing is considered an alternative method for replacing damaged tissues. However, the lack of suitable bio-based photopolymers, their characterization, effective crosslinking strategies, and optimal printing conditions are hindering the extensive application of 3D printed materials in the global market. This review highlights the present status of various photopolymers, their synthesis, and their optimization parameters for biomedical applications. Moreover, a glimpse of various photopolymerization techniques currently employed for 3D printing is also discussed. Furthermore, various naturally derived nanomaterials reinforced polymerization and their influence on printability and shape fidelity are also reviewed. Finally, the ultimate use of those photopolymerized hydrogel scaffolds in tissue engineering is also discussed. Taken together, it is believed that photopolymerized 3D printing has a great future, whereas conventional 3D printing requires considerable sophistication, and this review can provide readers with a comprehensive approach to developing light-mediated 3D printing for tissue-engineering applications.     

Incorporation of Cell-Adhesive Proteins in 3D-Printed Lipoic Acid-Maleic Acid-Poly(Propylene Glycol)-Based Tough Gel Ink for Cell-Supportive Microenvironment

In extrusion-based 3D printing, the use of synthetic polymeric hydrogels can facilitate fabrication of cellularized and implanted scaffolds with sufficient mechanical properties to maintain the structural integrity and physical stress within the in vivo conditions. However, synthetic hydrogels face challenges due to their poor properties of cellular adhesion, bioactivity, and biofunctionality. New compositions of hydrogel inks have been designed to address this limitation. A viscous poly(maleate-propylene oxide)-lipoate-poly(ethylene oxide) (MPLE) hydrogel is recently developed that shows high-resolution printability, drug-controlled release, excellent mechanical properties with adhesiveness, and biocompatibility. In this study, the authors demonstrate that the incorporation of cell-adhesive proteins like gelatin and albumin within the MPLE gel allows printing of biologically functional 3D scaffolds with rapid cell spreading (within 7 days) and high cell proliferation (twofold increase) as compared with MPLE gel only. Addition of proteins (10% w/v) supports the formation of interconnected cell clusters (≈1.6-fold increase in cell areas after 7-day) and spreading of cells in the printed scaffolds without additional growth factors. In in vivo studies, the protein-loaded scaffolds showed excellent biocompatibility and increased angiogenesis without inflammatory response after 4-week implantation in mice, thus demonstrating the promise to contribute to the printable tough hydrogel inks for tissue engineering.     

27种有机溶剂的气相色谱同时分析

采用气相色谱一氢火焰离子化检测器（GC-FID）技术,分别使用中性（AC-10、DB-1701）和极性（DB-WAX）石英毛细管柱对27种有机溶剂进行了同时分析。结果表明,AC～10色谱柱的分离效果最好。另外,在对27种有机溶剂色谱分析的基础上,采用内标法初步对密封胶、涂料和油墨样品中常见有机溶剂的含量进行了测定。     

中国印刷术在越南的传播及其影响

中国与越南是两个山水相连的邻邦,两国之间有着悠久的交往历史。印刷术是中国古代四大发明之一。作为中国传统文化的重要组成部分,印刷术的传播在两国的交往历史中扮演着重要角色,为中越两国传统友谊的构建和发展起到了重要作用。     

Enhanced Field Emission from Printed Carbon Nanotubes by Hard Hairbrush

A method, the morphology of screen printed carbon nanotube pastes is modified using a hard hairbrush, is presented. In this way, the organic matrix material is preferentially removed. Compared to those untreated films, the turn-on electric field of the treated film decreases from 2.2V/μm to 1.6V/μm, while the total emission current of the treated increases from 0.6mA/cm2 to 3mA/cm2, and uniform emission site density image has also been observed.     

一种基于视觉特征的鞋底图像识别方法

提出了一种基于视觉特征的鞋底识别方法,即提取鞋底的形状、直方图、纹理特征,将这些特征进行内部和外部归一化形成鞋底图像的视觉特征,实验结果表明根据鞋底图像视觉特征进行识别是很有效的.     

丝网印刷电解镍扣极板绝缘油墨的性能和影响因素

以电解镍扣极板丝网印刷技术研发适合油墨为目的,采用环氧树脂、氨基树脂、蓖麻油醇酸树脂共混复合体系为成膜材料,与专用的助剂(触变增稠剂、流平剂、催干剂),经研磨复配得到单组分热固型电解镍扣极板丝网油墨.研究表明:该油墨体系组成中环氧树脂E-44、氨基树脂、蓖麻油醇酸树脂的质量分数分别为15%、20%、35%,流平剂甲基硅油(H201)、固化交联催化剂对甲苯磺酸(p-TSA)、触变增稠剂纳米凹凸棒分别占油墨总物料质量的1.5‰、3‰、3.5%时,复配的丝网油墨用于电解镍扣极板印刷,印刷墨层在固化温度150 ℃、固化时间5 min的条件下,制备的绝缘墨层形态结构致密均匀、镍扣生长形貌规整、极板绝缘层漏电点数目较低,具有较好的镍扣电解生产适应性.     

Amphiphilic egg-derived carbon dots: rapid plasma fabrication, pyrolysis process, and multicolor printing patterns

How do you like your eggs? Amphiphilic carbon dots (CDs) with intense blue fluorescence have been produced from chicken eggs by treatment with plasma. They are used as effective "fluorescent carbon inks" for multicolor luminescent inkjet and silk-screen printing.