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101.
与传统的涂覆、沉积等加工手段相比,使用3D打印技术可制造复杂立体功能结构的传感器,将3D打印与柔性传感技术结合可以促进未来生物医疗、人工智能等领域的发展。本文介绍了国内外基于3D打印技术制造柔性传感器的最新进展,其中包括聚酰亚胺等多种基底材料、纳米金属等多种打印传感材料;按照熔融沉积、黏弹性墨水沉积、粉末烧结熔化、还原光聚合和材料喷射的制造原理分别阐述了多种传感器的材料选择、成型特点,并对制造方法进行总结分析。虽然3D打印制造柔性传感器件存在着缺乏行业标准及多种类打印材料等问题,但经过不断创新与发展,3D打印将成为柔性传感领域极佳的制造手段。 相似文献
102.
103.
Wan‐Xia Wu 《Polymer International》2019,68(11):1848-1855
A series of novel aliphatic poly(β‐thioether ester)s with various methylene group contents were prepared by direct lipase‐catalyzed polycondensation of the monomer with an acid‐labile β‐thiopropionate group. The polycondensation reaction using immobilized lipase B from Candida antarctica was carried out in diphenyl ether at 90 °C. Poly(β‐thioether ester)s with high molecular weights of 20 500–57 000 Da and narrow polydispersities in the range 1.40–1.48 were obtained. Thermogravimetric analysis, differential scanning calorimetry and wide‐angle X‐ray diffraction were used to investigate the thermal properties and crystal structures of these polyesters. All the poly(β‐thioether ester)s were semicrystalline polymers and thermally stable up to at least 200 °C. In vitro degradation studies showed that they can rapidly degrade under acidic conditions by the hydrolysis of the β‐thiopropionate groups, suggesting their potential as acid‐degradable polymeric materials. © 2019 Society of Chemical Industry 相似文献
104.
Bing Yang Yu Zhou Wenjie Yu Song Zhang Hongxiang Chen Ju Ye 《Polymer International》2019,68(4):675-683
In order to improve the dispersity and stability of the nano‐SiO2 aqueous system with high solid content, a kind of polyacrylic acid dispersant with methoxysilicon end groups (KH590‐PAA) was synthesized by photopolymerization of acrylic acid (AA) initiated with (3‐mercaptopropyl)trimethoxysilane (KH590). After adding KH590‐PAA into the nano‐SiO2 aqueous dispersion system (20 wt% solid content), the viscosity and the curing time of the system were measured with a rotational viscometer and the inverted bottle method. Moreover, the dispersion mechanism of KH590‐PAA for the nano‐SiO2 aqueous system was researched by measuring the adsorption capacity, the particle size and the zeta potential of the nanoparticles with a conductivity meter, dynamic light scattering, SEM and TEM, respectively. The results showed that the methoxysilicon groups in KH590‐PAA could react with hydroxyl groups on the surface of nano‐SiO2 in the process of stirring, which enhanced the adsorption capacity of the dispersant and then increased the surface charge of the particles. Therefore, electrostatic repulsion and steric hindrance effects between the SiO2 nanoparticles could be further enhanced by adding the KH590‐PAA dispersant, and then the nano‐SiO2 aqueous system exhibited better dispersity and stability. Besides, the dispersion properties of SiO2 nanoparticles in water were closely related to the addition amount and the molecular weight of the KH590‐PAA dispersant. © 2018 Society of Chemical Industry 相似文献
105.
Marta Gabasa Marselina Arshakyan Alejandro Llorente Lourdes Chuli-Peris Irina Pavelescu Antoni Xaubet Javier Pereda Jordi Alcaraz 《International journal of molecular sciences》2020,21(22)
Pro-inflammatory cytokines like interleukin-1β (IL-1β) are upregulated during early responses to tissue damage and are expected to transiently compromise the mechanical microenvironment. Fibroblasts are key regulators of tissue mechanics in the lungs and other organs. However, the effects of IL-1β on fibroblast mechanics and functions remain unclear. Here we treated human pulmonary fibroblasts from control donors with IL-1β and used Atomic Force Microscopy to unveil that IL-1β significantly reduces the stiffness of fibroblasts concomitantly with a downregulation of filamentous actin (F-actin) and alpha-smooth muscle (α-SMA). Likewise, COL1A1 mRNA was reduced, whereas that of collagenases MMP1 and MMP2 were upregulated, favoring a reduction of type-I collagen. These mechanobiology changes were functionally associated with reduced proliferation and enhanced migration upon IL-1β stimulation, which could facilitate lung repair by drawing fibroblasts to sites of tissue damage. Our observations reveal that IL-1β may reduce local tissue rigidity by acting both intracellularly and extracellularly through the downregulation of fibroblast contractility and type I collagen deposition, respectively. These IL-1β-dependent mechanical effects may enhance lung repair further by locally increasing pulmonary tissue compliance to preserve normal lung distension and function. Moreover, our results support that IL-1β provides innate anti-fibrotic protection that may be relevant during the early stages of lung repair. 相似文献
106.
107.
《Ceramics International》2019,45(15):18972-18979
Kaolin/graphene oxide composite has been widely utilized in aero-space and architectural engineering applications due to its excellent mechanical property. Direct ink writing (DIW) is a freeform rapid prototyping technology that could be used to accurately fabricate the resulting size with complex shapes. In this study, we reported the DIW of kaolin/graphene oxide (GO) composite suspensions (KGCS) to assemble 3D structures at ambient temperature for the first time. The effects of GO on the chemical constitution and microstructure of kaolin suspensions were investigated. Rheology was characterized to ensure printability of KGCS. The addition of GO in kaolin suspensions quickened a flocculation structure, which dramatically changed their rheology properties. The DIW of 3D structures from the optimal KGCS sample maintained their initial shape without spreading. The flexural and compressive strengths of the dried optimal KGCS samples were obviously enhanced due to the improvement and reduction of the micro-defects compared from cured kaolin matrix. 相似文献
108.
在伯克氏菌Bth264野生株产新型抗癌药物Thailandepsin A以及调节基因tdp R正向调控Thailandepsin A生物合成的基础上,利用基因工程菌Bth264/p BMTL3-tdp R发酵生产Thailandepsin A,以提高产量。以0.5%乳糖为诱导剂,确定最佳诱导条件:发酵15 h添加乳糖,诱导时间6 h;通过单因素实验,确定葡萄糖和胰蛋白胨作为碳氮源、装液量65/250 m L以及接种量1%;同时结合优化发酵培养基进行发酵,Thailandepsin A产量达到252.14 mg·L-1,比优化前的产量提高56%;另外在发酵过程中,添加大孔树脂HP-20原位吸附产物,Thailandepsin A产量可达283.75 mg·L-1,比不加树脂提高13.8%;最后,基于RT-PCR和比较Ct值法,基因工程菌和野生菌相比,Thailandepsin A生物合成基因tdp B、tdp C1的转录水平分别提高11.4倍和6.0倍,对应的产量增加4.6倍,从而在很大程度上说明调节基因tdp R的过表达促进生物合成基因转录水平的提高以及产量的增加。 相似文献
109.
In this study, 30 subjects were exposed to different combinations of air temperature (Ta: 24, 27, and 30°C) and CO2 level (8000, 10 000, and 12 000 ppm) in a high-humidity (RH: 85%) underground climate chamber. Subjective assessments, physiological responses, and cognitive performance were investigated. The results showed that as compared with exposure to Ta = 24°C, exposure to 30°C at all CO2 levels caused subjects to feel uncomfortably warm and experience stronger odor intensity, while increased mental effort and greater intensity of acute health symptoms were reported. However, no significant effects of Ta on task performance or physiological responses were found. This indicated that subjects had to exert more effort to maintain their performance in an uncomfortably warm environment. Increasing CO2 from 8000 to 12 000 ppm at all Ta caused subjects to report higher rates of headache, fatigue, agitation, and feeling depressed, although the results were statistically significant only at 24 and 27°C. The text typing performance and systolic blood pressure (SBP) decreased significantly at this exposure, whereas diastolic blood pressure (DBP) and thermal discomfort increased significantly. These effects suggest higher arousal/stress. No significant interaction effect of Ta and CO2 concentration on human responses was identified. 相似文献
110.
《Ceramics International》2022,48(18):25933-25939
In order to gain more insights into the influence of rare earth elements on the melt structure of SiO2–CaO–Al2O3–MgO glass ceramics, Raman and X-ray photoelectron spectroscopy techniques were used to study the influence of La2O3 on the Si–O/Al–O tetrahedron structure within SiO2–CaO–Al2O3–MgO–quenched glass samples in this study. Results showed that some Raman peak shapes at low frequencies (200–840 cm?1) changed significantly after the addition of La2O3, compared to the high frequency (840–1200 cm?1) region that corresponds to the [SiO4] structure, suggesting that the depolymerization of the low-frequency T–O–T (T=Si or Al) structure was more prevalent with La3+ addition. Besides, the depolymerization extent of the Si–O/Al–O tetrahedral network varied when the melt composition altered. Most notably, depolymerization is the most significant at a low CaO/SiO2 ratio (0.25) and a high Al2O3 content (8%). Meanwhile, La3+ can promote the transformation of Si–O–Si and Al–O–Al bonds to the Si–O–Al ones, thereby forming a complex ionic cluster network interwoven with Si–O and Al–O tetrahedrons. 相似文献