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【目的】探索组蛋白H3K27me3 甲基转移酶Ezh2 在间充质干细胞内缺失对小鼠骨骼肌细胞分化及骨骼肌线粒体的影响。【方法】构建Ezh2 间充质干细胞条件性敲除小鼠（Ezh2F/FPrx1-Cre）。HE 染色、改良Gomori 三色染色及四氮唑还原酶染色（NADH-TR）法观察细胞形态及线粒体情况。电镜观察骨骼肌细胞和线粒体超微结构。Western Blot 法检测 6 周龄小鼠骨骼肌细胞中 Ezh2、H3K27me3 和骨骼肌分化相关基因 Myogenin、Myosin、Desmin 及线粒体蛋白CytC 的蛋白表达量。Realtime RT-qPCR 法检测骨骼肌分化相关基因和线粒体相关基因的表达情况。免疫组化染色检测骨骼肌中CytC 的表达量，ATP 含量测定试剂盒检测骨骼肌细胞内ATP 含量。HE和NADH-TR 染色观察2 周龄小鼠骨骼肌。检测6 周龄小鼠棕色脂肪中Ezh2 蛋白含量，电镜观察小鼠棕色脂肪中的线粒体。【结果】敲除组骨骼肌中 Ezh2 及H3K27me3 蛋白含量均明显降低。敲除组小鼠的骨骼肌肌纤维粗细不等，部分核内移，骨骼肌分化标志物 Myogenin 和 MhcIIb 的 mRNA 表达明显减少（均 P < 0.05），Myogenin 蛋白表达量减少，NADH-TR 和 CytC 免疫组化染色显示线粒体增加。电镜下敲除组骨骼肌肌原纤维粗细不等，细胞膜下及肌原纤维间线粒体数量明显增加，呈团块状聚集。线粒体无水肿，嵴无明显减少。敲除组线粒体相关基因CytC、Tfam、Pgc1α的mRNA 和CytC 蛋白表达升高（均P < 0.05），但ATP 含量明显降低（P < 0.05）。2 周龄小鼠骨骼肌纤维粗细不等，但 NADH 含量无差别。电镜下 6 周龄小鼠棕色脂肪细胞线粒体无数量增加或形态异常。【结论】Ezh2 在间充质干细胞阶段对小鼠骨骼肌细胞分化是必须的，并维持线粒体产生ATP 的功能。Ezh2 缺失小鼠骨骼肌细胞线粒体产生ATP 减少，线粒体数量代偿性增加。

The phenomena of heat and cold have long captivated human curiosity, representing some of the earliest natural observations. Among the myriad energy transformations in nature, the conversion between chemical energy and thermal energy stands out as a common occurrence. This science popularization project, guided by the principle of "Applied Chemistry, Safety First, Benefit Society", aims to ignite public interest in chemistry, foster an understanding of chemical reactions' potential safety risks, and cultivate a culture of safety awareness through simple experiments. Focused on two contrasting chemical reactions--an endothermic reaction (involving ammonium chloride and barium hydroxide) and an exothermic reaction (involving a heating packet and water) --the project employs various presentation formats tailored to audiences with different levels of knowledge. These include engaging experiments like "Balloon Ice Press" and situational skits such as "Iodine and Starch Embrace". Through a series of educational events held in kindergartens, schools, and communities, the project demonstrates the captivating interplay between chemical and thermal energy, while also disseminating essential safety knowledge. By experiencing the allure of chemistry firsthand, participants not only develop an appreciation for its wonders but also enhance their safety awareness. [ABSTRACT FROM AUTHOR]

Wearing smoothness is one of the key factors affecting the appearance of clothing. The smooth appearance of clothing can not only show the texture and grade of clothing, but also improve the overall image and temperament of the wearer. The objective test and evaluation of smoothness is very important to the optimization of clothing design and the rational selection of materials, so it has been the focus of research in the field of textile testing. At present, the research of smoothness mainly focuses on the evaluation of flatness after washing and sewing, and pays little attention to the wrinkling of clothing during daily wearing. However, the wearing smoothness is more important than other kinds of smoothness in a sense, as the wrinkling of the dress directly affects the appearance of the clothing while the clothing can be worn after ironing, and the flattening effect of the stitches can also be improved by improving the equipment and the skills of the sewing personnel. In addition, in the analysis of the factors affecting the smoothness of the fabric, most of the studies focus on the influence of core wire types and spinning methods on the smoothness of fabrics, whereas there is a lack of in-depth research on the relationship between the fabric properties and the wrinkle patterns of clothing. As a typical representative of professional bottoms, the A-line skirt has extremely high requirements for appearance smoothness and aesthetics due to the wearing occasion, but due to its well-fitting design, it is easy to form folds during activities. In view of the practical problems faced in the wearing process, this paper takes the A-line skirt as the research object. Due to the three-dimensional spatial distribution of clothing wrinkles, it is difficult to reproduce its true shape as the conventional two-dimensional image processing technology does not contain spatial information, while the three- dimensional laser scanning technology can quickly and accurately obtain the three-dimensional coordinates of the surface of the measured object, so as to capture the true shape of wrinkles. Therefore, this paper used 3D scanning technology to extract wrinkles formed on A-line skirts in sitting position, and established a series of new indexes for smoothness evaluation from four aspects: wrinkle area, wrinkle type, wrinkle size and wrinkle sharpness. The difference of fold shape among different fabrics was compared by single factor analysis of variance, and the relationship between fabric properties and wrinkle shape index was explored by correlation analysis. The multidimensional evaluation index can describe the real shape effect of wrinkling in a more comprehensive way, and the correlation analysis with fabric properties can better grasp the essence, internal connection and influencing factors of wrinkling formation. The experimental results show that the wrinkling patterns of A-line skirts formed in sitting position are different, and they can be divided into simple strip pleats and complex Y pleats, Z pleats, ring pleats and X-shaped pleats according to types. Among complex pleats. Y pleats are the most common, followed by Z pleats. Ring pleats. X pleats and compound pleats usually only appear in cotton fabrics. There is a significant difference in wrinkle formation between fabrics with different components, that is, the wrinkle effect of the fabric can be predicted by the composition. Specifically, cotton fabrics have the largest wrinkle area, complex wrinkle ratio and wrinkle sharpness, and the smallest wrinkle width; the wrinkles of hemp fabrics are gentler than those of cotton ones, the number of wrinkles is less, and the area of wrinkles is slightly smaller, polyester, wool, hemp fabrics have wide wrinkles; polyester and wool have gentle wrinkles; the wrinkles of regenerated fibers are numerous and complex, and the creases are obvious; silk fabrics have simple and neat wrinkles. The results of correlation analysis show more clearly the correlation between the physical and mechanical properties of fabrics and each wrinkle shape index. The larger the shear stiffness of the fabric, and the larger the wrinkle area, the more complex the formation of wrinkles is; the crease area formed by the fabric with good crease recovery is small; the higher the warp and weft density and the larger the warp and weft wrinkle recovery angle, the easier it is to form neat and fine folds; thick fabrics with large flexural stiffness are easy to form wide and flat wrinkles; fabrics with small square meter mass, small warp and weft bending stiffness and small wrinkle recovery angle are easy to form sharp folds. Three-dimensional scanning technology provides a new way to extract the three-dimensional wrinkle, so that the wrinkle can show its more real shape. The research results will help guide the reasonable selection of clothing materials, improve the quality of clothing, provide strong support for the development of virtual display technology of clothing, and enhance the authenticity and accuracy of display. [ABSTRACT FROM AUTHOR]

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The construction of laboratory safety is essential for ensuring the efficient and orderly operation of a laboratory. Students’ safety literacy, who are the primary operators in basic teaching laboratories, directly impacts the safety status of these labs. This study proposes a comprehensive experimental teaching model that integrates laboratory managers, teachers, and students, emphasizing safety literacy development in the entire teaching process. This model has been specifically applied in the teaching of analytical chemistry experiments. It facilitates enhanced communication among laboratory managers, teachers, and students. By employing the COOP and 7S experimental teaching schemes, the model immersively engages students in maintaining and developing the experimental environment, which deeply rooting the concept of safety in their learning experience. The effectiveness of this model is evaluated using Partial Eta Squared (η2) test and multivariate Logistic regression analysis, highlighting the significant influence of procedural standardization and organizational orderliness in the experimental process on student’s safety literacy. The practice confirms that this model is instrumental in fostering good experimental habits and safety awareness among students, increasing their sense of responsibility and fulfillment in the laboratory. It achieves enhanced management quality, synergistic growth in teaching and learning, and the inculcation of safety as a core value. Consequently, laboratory personnel can maintain constant control over safety, significantly elevating the operational safety level of the laboratories. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Beijing University of Civil Engineering & Architecture is the property of Journal of Beijing University of Civil Engineering & Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objectives To investigate the proportion of different histological types and CT enhanced imaging features of primary middle mediastinal lesions in order to improve the understanding of these tumors and the accuracy of preoperative diagnosis. Methods Retrospective analysis was conducted on 84 patients with primary middle mediastinal lesions and clear histological classifications diagnosed and treated at the Cancer Hospital, Chinese Academy of Medical Sciences from January 2012 to December 2022. Clinical, imaging, and pathological data were collected and classified according to tumor histological classifications. CT imaging manifestations such as tumor location, size, morphology, edge, boundary, internal components, enhancement characteristics, and surrounding tissue invasion were evaluated and recorded. Results The histological types of the primary middle mediastinal lesions from the 84 patients included mesenchymal tumors, anterior intestinal cysts, giant lymph node hyperplasia, substernal goiter, neuroendocrine carcinoma, lymphohematopoietic system tumors, and mesothelioma, accounting for 28.6%, 27.4%, 14.3%, 3.6%, 11.9%, 9.5%, and 4.8%, respectively. Mesenchymal tumors included peripheral nerve sheath tumors, vascular tumors, adipogenic tumors, solitary fibrous tumors, and synovial sarcoma, accounting for 54.2%, 20.8%, 12.5%, 8.3%, and 4.2%, respectively. The above tumors had diverse imaging manifestations and specific imaging features. Mature fat were found in 3 cases of liposarcoma; Calcification was observed in 2 cases of thyroid nodules and 7 cases of giant lymph node hyperplasia; Enhanced scanning showed significant enhancement in 2 cases of solitary fibrous tumors, 3 cases of thyroid nodules, and 11 cases of giant lymph node hyperplasia; Mediastinal large lymph nodes was observed in 6 cases of lymphoma and 3 cases of mesothelioma; High invasiveness was observed in 4 cases of mesothelioma and 9 cases of neuroendocrine carcinoma. Conclusion Mediastinal tumors have low incidence rate and rich histological types, and their imaging manifestations are diverse. Preoperative differential diagnosis can be made according to their specific imaging characteristics. [ABSTRACT FROM AUTHOR]

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Copyright of Chinese Journal of Preventive Veterinary Medicine / Zhongguo Yufang Shouyi Xuebao is the property of Chinese Journal of Preventive Veterinary Medicine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

After the knowledge structure of general chemistry, the four modernizations teaching mode about systematic chemical principle, useful chemical knowledge, good pursuing of chemical application, interconnected about knowledge points and frontier science is built. To foster virtue through this education system, students gradually form the chemical attainment about understanding the principle of material formation and change, the ideals and convictions about harmonious coexistence of people and things, the life philosophy about advocating the virtue of life, and the responsibility mission about the "carbon peak and carbon neutrality" mission of the times. The teaching model took the realization of the same direction and frequency resonance about ideological and political education in general chemistry course and Party history learning. It also took aided for the achievement of university education goal cultivating talents for the Party and the state. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Data Acquisition & Processing / Shu Ju Cai Ji Yu Chu Li is the property of Editorial Department of Journal of Nanjing University of Aeronautics & Astronautics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)