Superhydrophobic Paper-Based Microfluidic Field-Effect Transistor Biosensor Functionalized with Semiconducting Single-Walled Carbon Nanotube and DNAzyme for Hypocalcemia Diagnosis

Hypocalcemia is caused by a sharp decline in blood calcium concentration after dairy cow calving, which can lead to various diseases or even death. It is necessary to develop an inexpensive, easy-to-operate, reliable sensor to diagnose hypocalcemia. The cellulose-paper-based microfluidic field-effect biosensor is promising for point-of-care, but it has poor mechanical strength and a short service life after exposure to an aqueous solution. Octadecyltrichlorosilane (OTS), as a popular organosilane derivative, can improve the hydrophobicity of cellulose paper to overcome the shortage of cellulose paper. In this work, OTS was used to produce the superhydrophobic cellulose paper that enhances the mechanical strength and short service life of MFB, and a microfluidic field-effect biosensor (MFB) with semiconducting single-walled carbon nanotubes (SWNTs) and DNAzyme was then developed for the Ca²⁺ determination. Pyrene carboxylic acid (PCA) attached to SWNTs through a non-covalent π-π stacking interaction provided a carboxyl group that can bond with an amino group of DNAzyme. Two DNAzymes with different sensitivities were designed by changing the sequence length and cleavage site, which were functionalized with SPFET/SWNTs-PCA to form Dual-MFB, decreasing the interference of impurities in cow blood. After optimizing the detecting parameters, Dual-MFB could determine the Ca²⁺ concentration in the range of 25 μM to 5 mM, with a detection limit of 10.7 μM. The proposed Dual-MFB was applied to measure Ca²⁺ concentration in cow blood, which provided a new method to diagnose hypocalcemia after dairy cow calving.     

长余辉发光材料研究新进展

文章系统介绍了目前各种稀土离子激活的长余辉发光材料的种类、特性、组成、结构、发光机理和制备技术等方面的最新进展。同时根据长余辉发光材料领域的研究现状,探讨了长余辉发光材料领域的发展方向与前景。     

MicroRNAs as Potential Biomarkers in the Differential Diagnosis of Lipomatous Tumors and Their Mimics

Adipocytic tumors are the most common subtype of soft tissue tumors. In current clinical practice, distinguishing benign lipomas from well-differentiated liposarcomas (WDLPS), as well as dedifferentiated liposarcomas (DDLPS) from their morphologic mimics, remains a significant diagnostic challenge. This is especially so when examining small biopsy samples and without the aid of additional ancillary tests. Recognizing the important role that microRNAs (miRNAs) play in tumorigenesis and their potential utility in tumor classification, we analyzed routine clinical tissue samples of benign and malignant lipomatous tumors, as well as other sarcoma mimics, to identify distinguishing miRNA-based signatures that can aid in the differential diagnosis of these entities. We discovered a 6-miRNA signature that separated lipomas from WDLPS with high confidence (AUC of 0.963), as well as a separate 6-miRNA signature that distinguished DDLPS from their more aggressive histologic mimics (AUC of 0.740). Functional enrichment analysis unveiled possible mechanistic involvement of these predictive miRNAs in adipocytic cancer-related biological processes and pathways such as PI3K/AKT/mTOR and MAPK signaling, further supporting the relevance of these miRNAs as biomarkers for adipocytic tumors. Our results demonstrate that miRNA expression profiling may potentially be used as an adjunctive tool for the diagnosis of benign and malignant adipocytic tumors. Further validation studies are warranted.     

弯晶谱仪在X射线探测中的应用

为了对激光等离子体进行诊断,研制了聚焦型椭圆弯晶谱仪用来探测等离子体辐射的X射线.谱仪利用从椭圆一个焦点发射出的光线经椭圆面反射必汇聚于另一焦点的性质而研制,椭圆的离心率和焦距分别为0.9586mm及1350mm.在此采用氟化锂(200)(2d=0.4027nm)作为晶体分析器,其布拉格衍射角变化范围为30～67.5°,可探测波长范嗣为0.2～O.37nm.在"神光-Ⅱ"激光装置上进行了打靶实验,利用软X射线CCD相机作为摄谱器件,该谱仪获得了钛的类He共振线(w)、磁四级M2跃迁x线、互组合跃迁y线、禁戒谱线(z)以及类Li谱线(q).实验结果表明该谱仪的最高光谱分辨率(λ/△λ)可以达到1000以上,能够用于激光等离子体X射线光谱学研究.     

异丙醇的生产工艺及应用

异丙醇是一种应用广泛的有机溶剂和化工原料,介绍了合成异丙醇生产技术路线,综合比较了丙酮加氢路线和丙烯水合路线的经济性,并分析了异丙醇的应用前景.丙酮加氢制异丙醇路线更具有经济性,异丙醇应用领域需进一步拓展.     

Liutex identification on hairpin vortex structures in a channel based on msfle and moving-PIV

The spatiotemporal evolution of hairpin vortex structures in a fully developed turbulent boundary layer is investigated qualitatively and quantitatively by usin...     

ECR结合磁控溅射——制备DLC薄膜的新方法

介绍了新型的结合电子回旋共振(ECR)微波等离子体气相沉积与磁控溅射镀膜特点的ECR-650型镀膜系统,并利用该系统通过溅射石墨靶和金属钛靶在不锈钢基底上制备了具有Ti/TiNx/TiNxCy中间层结构的C薄膜。由于镀膜工艺问题,得到的薄膜主要由石墨构成。研究了制备时不同的气压和氩气分压对薄膜表面形貌、硬度等的影响。     

切削动力学模型及其传递函数

振动现象普遍存在于工程结构和生产过程中,也是影响零件加工质量和限制生产率提高的主要因素之一。本文在切削机理的基础上,对切削的动力学模型进行了研究,并推导出切削过程闭环系统的传递函数,对于分析切削加工系统的稳定性具有重要意义。     

基于离散滑模控制的新型Buck-Boost矩阵变换器

摘要对目前矩阵变换器存在电压传输比低的缺陷进行了研究,提出了一种新型的杯为buck-boost矩阵变换器（BBMC）的电路拓扑结构。介绍了该拓扑结构的基本构成及其工作原理,分析推导了其电压传输比与占空比之间函数关系的解析表达式,阐述了离散滑模控制策略的基本设计方法,最后通过仿真对其有效性和可行性进行了验证。结果表明：该新型拓扑结构能实现输出电压和频率的任意调节,其电压传输比既可大于1,也司小于l,且直接输出高品质的正弦波而无需滤波环节,谐波含量小,从而有效解决了传统矩阵变换器申,压传输比低的难题,具有较好的应用价值。     

基于低温直接键合的血细胞计数芯片结构制备

研究了一种新颖的微流管道血细胞计数器的结构及其工作原理,采用流体动力学对其液体分层流动特性进行了仿真分析,结合图形制备和低温直接键合工艺制作了硅基微流体管道血细胞计数器结构,并采用红外透射方法对微流体管道结构进行了检测.对封闭管道的流通性及结构的键合强度也进行了测量.研究分析表明,采用上述工艺制备的微流体芯片结构与电子器件兼容性好,具有良好的化学惰性和热稳定性,而且管道结构规则,精度高,键合界面层薄,具有较好的应用前景.