增城市母乳喂养影响因素分析

调查了增城市婴儿母亲对母乳喂养的感知和个人经历,并对当地母乳喂养状况和影响因素进行分析。自2003年12月至2004年2月对增城市妇幼保健院69位进行产后42d常规体检的婴儿家长,进行问卷调查并对结果进行分析。结果表明,喂过母乳的母亲有54人（78％）,纯母乳喂养只有3人（4％）。代乳品添加原因为自觉母乳不足51人（74％）,母亲认为初乳不能给婴儿吃8人（12％）等。过早引入淀粉类食物主要是受当地传统的喂养观念影响所致。提示地方习俗及对母乳分泌机制的错误认识是导致纯母乳喂养率低的主要原因。母乳喂养健康教育要充分了解地方习俗。教育对象除母乳本人还要包括其亲友。     

基于X射线谱学和操作链分析的煤山遗址出土陶器综合研究

采用能量色散X射线荧光光谱(ED-XRF)技术结合考古学常用的陶器操作链研究模式,对河南汝州煤山遗址出土的陶器遗存开展制作工艺和文化传承关系的综合研究。煤山遗址位于河南省汝州市(原为临汝县)北刘庄村,是研究中原地区新石器时代向文明国家转变的代表性遗址,出土了龙山时代的王湾三期文化(BC2300—BC1900)和具备早期国家形态的二里头文化(BC1750—BC1500)两个重要阶段大量具有典型考古学文化特点的陶器遗存,可以据此较为深入理解距今4000年前后社会复杂化进程和国家起源等重大问题。因此,对该遗址出土陶器的多学科综合研究具有极高的学术价值和文化意义。对煤山遗址出土具有不同文化类型的陶器样本进行化学组成与物理性能分析,将分析结果与陶器操作链分析相结合,进行比对分析。针对煤山遗址陶器遗存,谱学分析结果显示,不同时期考古学文化在制陶原料的选择上差异不大,具有同源性,暗示虽然文化类型不同,但其对粘土的认识和选择具有高度一致性。陶器操作链分析结果显示,虽然新石器时代的王湾三期文化年代较早,但其陶器制作工艺却较晚期的二里头文化更先进,体现了中原地区文化演进过程中既连续又摇摆的发展特点。陶器操...     

Cell sheet engineering: intelligent polymer patterned surfaces for tissue engineered liver

We describe a new culture system utilizing the temperature-responsive polymer grafted surface for designing of cell position and layered tissue reconstruction. Organizing of the hepatic tissue structure by controlling the culture system, that is patterned co-culture and layered cell sheet co-culture achieved by moving the cultured cells from the culture surface, resulted in regulation of the hepatocyte function. The technique for cell sheet manipulation would promote the liver tissue engineering in quality.     

传统文化融入中学化学教学——“非遗印染技艺”的教学资源开发

从染料的利用历史、传统印染工艺、印染环保创新等3个维度挖掘了非遗印染技艺的教学资源，与萃取、自然资源开发利用、还原剂、硫及其化合物、酚醇性质、配合物、电解池等化学知识结合，以印染技艺为载体将传统文化、思政教育与化学教学有机融合，落实化学学科核心素养的发展，为传统文化融入中学化学教学提供借鉴。     

Rapid isolation and quantification of extracellular vesicles from suspension-adapted human embryonic kidney cells using capillary-channeled polymer fiber spin-down tips

Exosomes, a subset of extracellular vesicles (EVs, 30–200-nm diameter), serve as biomolecular snapshots of their cell of origin and vehicles for intercellular communication, playing roles in biological processes, including homeostasis maintenance and immune modulation. The large-scale processing of exosomes for use as therapeutic vectors has been proposed, but these applications are limited by impure, low-yield recoveries from cell culture milieu (CCM). Current isolation methods are also limited by tedious and laborious workflows, especially toward an isolation of EVs from CCM for therapeutic applications. Employed is a rapid (<10 min) EV isolation method on a capillary-channeled polymer fiber spin-down tip format. EVs are isolated from the CCM of suspension-adapted human embryonic kidney cells (HEK293), one of the candidate cell lines for commercial EV production. This batch solid-phase extraction technique allows 10¹² EVs to be obtained from only 100-µl aliquots of milieu, processed using a benchtop centrifuge. The tip-isolated EVs were characterized using transmission electron microscopy, multi-angle light scattering, absorbance quantification, an enzyme-linked immunosorbent assay to tetraspanin marker proteins, and a protein purity assay. It is believed that the demonstrated approach has immediate relevance in research and analytical laboratories, with opportunities for production-level scale-up projected.     

Physical Models from Physical Templates Using Biocompatible Liquid Crystal Elastomers as Morphologically Programmable Inks For 3D Printing

Advanced manufacturing has received considerable attention as a tool for the fabrication of cell scaffolds however, finding ideal biocompatible and biodegradable materials that fit the correct parameters for 3D printing and guide cells to align remain a challenge. Herein, a photocrosslinkable smectic-A (Sm-A) liquid crystal elastomer (LCE) designed for 3D printing is presented, that promotes cell proliferation but most importantly induces cell anisotropy. The LCE-based bio-ink allows the 3D duplication of a highly complex brain structure generated from an animal model. Vascular tissue models are generated from fluorescently stained mouse tissue spatially imaged using confocal microscopy and subsequently processed to create a digital 3D model suitable for printing. The 3D structure is reproduced using a Digital Light Processing (DLP) stereolithography (SLA) desktop 3D printer. Synchrotron Small-Angle X-ray Diffraction (SAXD) data reveal a strong alignment of the LCE layering within the struts of the printed 3D scaffold. The resultant anisotropy of the LCE struts is then shown to direct cell growth. This study offers a simple approach to produce model tissues built within hours that promote cellular alignment.