孜然挥发油GC-MS指纹图谱的构建及主成分分析和聚类分析

目的 采用GC-MS指纹图谱并结合多元统计等方法评价不同产地孜然质量。方法 采用气相色谱-四极杆飞行时间质谱（GC-Q-TOF/MS）技术对孜然挥发油进行定性和定量分析，建立20批不同产地孜然的指纹图谱；运用"中药色谱指纹图谱相似度评价系统软件（2012年版）"进行相似度评价，并进行聚类分析和主成分分析。结果 建立的指纹图谱确定了33个共有峰，相似度均>0.961，主要成分包括枯茗醛、γ-松油烯-7-醛、α-松油烯-7-醛、γ-松油烯、o-伞花烃、桧烯、枯茗醇、3-p-孟烯-7-醛等，其相对含量约占总含量的99.7%。通过聚类分析可将20批孜然分为5大类。主成分分析得到4个主成分的累积方差贡献率为88.946%，其结果显示S20号样品综合得分较高。主成分分析与聚类分析结果基本一致。结论 该方法特征性强，仪器精密度、重复性和稳定性良好，可用于孜然挥发油及其相关产品的质量控制和评价。     

3D bioprinting in orthopedics translational research

Abstract

The repair of critical-size bone defect remains a challenge for orthopedic surgeons. With the advent of an aging society and their accompanying chronic diseases, it is becoming more difficult to treat bone defects, especially large segmental bone defects that are caused by trauma, tumors, infections, and congenital malformations. New materials and technologies need to be developed to address these conditions. 3D bioprinting is a novel technology that bridges the biomaterial and living cells and is an important method in tissue engineering projects. 3D bioprinting has the advantages of replacing or repairing damaged tissue and organs. The progress in material science and 3D printing devices make 3D bioprinting a technology which can be used to create various scaffolds with a large range of advanced material and cell types. However, in regard to the widespread use of bioprinting, biosafety, immunogenicity and rising costs are rising to be concerned. This article reviews the developments and applications of 3D bioprinting and highlights newly applied techniques and materials and the recent achievements in the orthopedic field. This paper also briefly reviews the difference between the methods of 3D bioprinting. The challenges are also elaborated with the aim to research materials, manufacture scaffolds, promote vascularization and maintain cell viability.     

Eyes-Open/Eyes-Closed Dataset Sharing for Reproducibility Evaluation of Resting State fMRI Data Analysis Methods

The multi-scan resting state fMRI (rs-fMRI) dataset was recently released; thus the test-retest (TRT) reliability of rs-fMRI measures can be assessed. However, because this dataset was acquired only from a single group under a single condition, we cannot directly evaluate whether the rs-fMRI measures can generate reproducible between-condition or between-group results. Because the modulation of resting state activity has gained increasing attention, it is important to know whether one rs-fMRI metric can reliably detect the alteration of the resting activity. Here, we shared a public Eyes-Open (EO)/Eyes-Closed (EC) dataset for evaluating the split-half reproducibility of the rs-fMRI measures in detecting changes of the resting state activity between EO and EC. As examples, we assessed the split-half reproducibility of three widely applied rs-fMRI metrics: amplitude of low frequency fluctuation, regional homogeneity, and seed-based correlation analysis. Our results demonstrated that reproducible patterns of EO-EC differences can be detected by all three measures, suggesting the feasibility of the EO/EC dataset for performing reproducibility assessment for other rs-fMRI measures.     

MicroRNAs can effectively induce formation of insulin‐producing cells from mesenchymal stem cells

MicroRNAs regulate insulin secretion, pancreatic development and beta cell differentiation. However, the function of microRNAs in the formation of insulin‐producing cells (IPCs) from adult stem cells is poorly understood. We examine the microRNA expression profile in nestin‐positive umbilical cord‐derived mesenchymal stem cells (N‐UCMSCs) and nestin‐positive pancreatic mesenchymal stem cells using a deep sequencing approach. We also selected specific microRNAs for overexpression in N‐UCMSCs and found that miR‐375 and miR‐26a induced IPCs differentiation from N‐UCMSCs by downregulating target genes including mtpn, sox6, bhlhe22 and ccnd1. Small interfering RNAs were also used to knock down these genes in N‐UCMSCs to induce the formation of IPCs. These results suggest that endogenous microRNAs involved in the formation of IPCs from adult stem cells show promise for advancing the development of an effective cell transplant therapy for diabetes. Copyright © 2017 John Wiley & Sons, Ltd.     

Carcinogenicity of acrylamide in B6C3F1 mice and F344/N rats from a 2-year drinking water exposure

Acrylamide is a component of roasted coffee and certain baked and fried carbohydrate-rich foods prepared at high temperatures. We have assessed the carcinogenicity of acrylamide in male and female B6C3F₁ mice and F344/N rats administered 0, 0.0875, 0.175, 0.35, or 0.70 mM acrylamide in the drinking water ad libitum for 2 years. Acrylamide caused significant dose-related decreasing trends in the body weights of F344/N rats. Acrylamide administration resulted in significant dose-related decreasing trends in survival in both sexes of B6C3F₁ mice and in female F344/N rats. Histopathological analyses indicated significant dose-related increases in Harderian gland and lung tumors in male and female B6C3F₁ mice. Male B6C3F₁ mice also had a significantly increased incidence of forestomach tumors, while female B6C3F₁ mice had significant dose-related increases in mammary gland, ovary, and skin tumors. In male and female F344/N rats, there were significant increases in thyroid tumors. Male F344/N rats also had significant dose-related increases in testes, heart, and pancreas tumors, while female F344 rats demonstrated significant increases in clitoral gland, mammary gland, oral cavity, and skin tumors. These results, combined with previous mechanistic studies, provide strong support for the concept that acrylamide is activated to a carcinogen through metabolism to glycidamide.     

岛津胃肠机的日常维护与保养

良好的设备日常维护与保养可以降低维修成本,减少设备故障率,延长设备使用寿命,提高开机率,本文根据一台岛津胃肠机来介绍一些设备维修及保养中的注意事项,以期对广大工程人员提供帮助。