Synthesis of Biomorphic ZrO2-CeO2 Nanostructures by Silkworm Silk Template

A simple and green technique has been developed to prepare hierarchical biomorphic ZrO2- CeO2, using silkworm silk as the template. Different from traditional immersion technics, the whole synthesis process depends more on the restriction or direction functions of the silkworm silk template. The analytic results showed that ZrO2-CeO2 exhibited a well-crystallized hierarchically interwoven hollow fiber structure with 16-28 μm in diameter. The grain size of the sample calcined at 800 ℃ was about 14 nm. Consequently, the interwoven meshwork at three dimensions is formed due to the direction of biotemplate. The action mechanism is summarily discussed here. It may bring the biomorphic ZrO2-CeO2 nanomaterials with hierarchical interwoven structures to more applications, such as catalysts.

Silkworm silk biomaterials for spinal cord repair: promise for combinatorial therapies

Background：Traumatic injury to the adult mammalian spinal cord results in minimal axonal regrowth,cystic cavity formation at the injury site,poor functional recovery and there is no cure available.Due to the complex nature of spinal cord injury（SCI）,a combination of therapeutic strategies may offer the most promise for successful regeneration（Ahuja et al.,2017）.

Super-strong and Intrinsically Fluorescent Silkworm Silk from Carbon Nanodots Feeding

Fluorescent silk is fundamentally important for the development of future tissue engineering scaffolds.Despite great progress in the preparation of a variety of colored silks,fluorescent silk with enhanced mechanical properties has yet to be explored.In this study,we report on the fabrication of intrinsically super-strong fluorescent silk by feeding Bombyx mori silkworm carbon nanodots(CNDs).The CNDs were incorporated into silk fibroin,hindering the conformation transformation,confining crystallization,and inducing orientation of mesophase.The resultant silk exhibited super-strong mechanical properties with breaking strength of 521.9±82.7 MPa and breaking elongation of 19.2±4.3%,improvements of 55.1%and 53.6%,respectively,in comparison with regular silk.The CNDs-reinforced silk displayed intrinsic blue fluorescence when exposed to 405 nm laser and exhibited no cytotoxic effect on cells,suggesting that multi-functional silks would be potentially useful in bioimaging and other applications.

Silkworm Silk Fibers with Multiple Reinforced Properties Obtained through Feeding Ag Nanowires

Silkworm silk fbers have been woven into textiles for thousands of years,because of their attractive luster,good mechanical properties,excellent biocompatibility,and large-scale production.With the development of human society,preparation of silk fbers with modifed or enhanced properties are highly desirable for potential applications in structural materials and smart textiles.Herein,we realized the reinforcement of multiple properties of silk fbers by feeding silkworms with Ag nanowire(Ag NW)modifed diets.The obtained silk fbers show obviously enhanced comprehensive mechanical properties,including improved tensile strength,elongation at break,tensile modulus,and toughness,which are increased by 37.2%,37.6%,68.3%,and 69.8%,respectively.Furthermore,compared with unmodifed silk,the electrical conductivity and thermal conductivity of modifed silk fbers are improved by 246.4%and 32.1%,respectively.The analysis on the components and structure shows that the incorporated Ag NWs lead to increased content of random coil/α-helix,improved orientation of crystallites,and increased content of Ag compared to pristine silk fbers,which may contribute to the enhanced mechanical,electrical,and thermal properties.

Mechanical properties of cocoons constructed consecutively by a single silkworm caterpillar,Bombyx mori

Most animals have the ability to adapt, to some extends and in different ways, the variation or disturbance of environment. In our experiments, we forced a silkworm caterpillar to spin two, three or four thin cocoons by taking it out from the cocoon being constructed. The mechanical properties of these cocoons were studied by static tensile tests and dynamic mechanical thermal analysis. Though external disturbances may cause the decrease in the total weight of silk spun by the silkworm, a gradual enhancement was interestingly found in the mechanical properties of these thin cocoons. Scanning electron microscopy observations of the fractured specimens of the cocoons showed that there exist several different energy dissipation mechanisms occurred simultaneously at macro-, meso-, and micro-scales, yielding a superior capacity of cocoons to adsorb the energy of possible attacks from the outside and to protect efficiently its pupa against damage. Through evolution of millions of years, therefore, the silkworm Bombyx mori seems to have gained the ability to adapt external disturbances and to redesign a new cocoon with optimized protective function when its first cocoon has been damaged for some reasons.

Analysis of Two-Dimensional Gel Electrophoresis Images of Protein from Posterior Silk Gland of Silkworm (Bombyx mori) on Day 1 and Day 4 in the 5th Instar Stage

The posterior silk gland （PSG） of silkworm is an important organ where fibroin is synthesized and secreted exclusively. Because fibroin constitutes 75-80% of the silk filament, the mechanism governing fibroin secretion, quality and yield of cocoon can be elucidated by the study on the PSG. Using two-dimensional gel electrophoresis （2-DE） and image analysis system, the changes in the protein composition in the PSG cell were investigated on the day 1 （D1） and day 4 （D4） in the 5th instar stage from five different strains of silkworm （Bombyx mori）. While differences at protein level between days and strains were far less than those observed at the gene level using EST analysis. The change trends in protein composition from D1 to D4 were diverse among the different strains. The results suggest that the secretion of fibroin is regulated by multiple proteins. The site of regulation and the proteins responsible for the regulation vary with the strain, which leads to differences between strains in the capacity of fibroin secretion in the PSG cell.

Analysis of Protein Expression Patterns of Silkworm Jinqiu and Its Cross Parents

The differences of protein expression between the improved cross breeding race Jinqiu and its parents were analyzed to discuss the gene construction, and to form a base for illuminating the molecular mechanisms of successful cross breeding in silkworm. Protein samples from silk gland, hemolymph, and midgut were separated by 2-dimensional gel electrophoresis （2-DE）. In the three tissues the matched protein spots between Jinqiu and its cross parents were approximately 70% with approximately 30% specific protein spots. In the matched protein spots, 9-24% was differentially expressed representing up- and down-regulated expression. These specific protein spots might be either the newly appeared, which were produced from the genic interaction of cross parents＇ genes in cross breeding, or posttranscriptionally modified, which were produced from the different modifications on the same original proteins. These results indicate that it is important for a new successful breed, by cross breeding, relying on the actions of some newly produced functional proteins from genic interaction, in addition to marshaling excellent genes of cross parents.

Highly efficient expression of human extracellular superoxide dismutase(rhEcSOD)with ultraviolet-B-induced damage-resistance activity in transgenic silkworm cocoons

Extracellular superoxide dismutase(EcSOD)protects tissues from oxidative stress,and thus is considered as a therapeutic agent for many diseases such as atherosclerosis,hypertension,and cancer.However,cost-effective production of bioactive recombinant human EcSOD(rhEcSOD)remains a challenge.Herein,we developed an efficient strategy for producing active rhEcSOD by transgenic silkworms.rhEcSOD was successfully synthesized as homodimers and homotetramers in the middle silk gland and spun into the cocoons with a concentration of 9.48±0.21 mg/g.Purification of rhEcSOD from the cocoons could be conveniently achieved with a purity of 99.50%and a yield of 3.5±0.5 mg/g.Additionally,N-glycosylation at the only site of N89 in rhEcSOD with 10 types were identified.The purified rhEcSOD gained the potent enzymatic activity of 4162±293 U/mg after Cu/Zn ions incorporation.More importantly,rhEcSOD was capable of penetrating and accumulating in the nuclei of cells to maintain cell morphology and attenuate ultraviolet B-induced cell apoptosis by eliminating reactive oxygen species and inhibiting the C-Jun N-terminal kinase signaling pathway.These results demonstrated that the transgenic silkworm could successfully produce rhEcSOD with enzymatic and biological activities for biomedical applications.

桑蚕的强制牵伸抽丝及其纤维性能

为提升蚕丝的力学性能,采用一种圆锥斜面牵伸装置对五龄桑蚕进行强制牵伸抽丝以制备高强牵伸丝,研究不同牵伸速度对桑蚕牵伸丝形貌、力学性能的影响,并将牵伸丝与蚕丝进行对比与分析。结果表明:由强制抽丝获得的牵伸丝表面光滑平坦,丝胶均匀附着;随着牵伸速度的增加,牵伸丝截面逐渐向弓形转变;牵伸丝的综合力学性能显著优于蚕丝,且其断裂强度、弹性模量、断裂比功与断裂伸长率随着牵伸速度的增加均有不同程度的增加;其中,以接近桑蚕自然吐丝速度(1 cm/s)牵伸制备的牵伸丝的断裂强度与蚕丝相当,约为3.00 cN/dtex,但其弹性模量(93.10 cN/dtex)远高于蚕丝(76.90 cN/dtex);当牵伸速度增加至4 cm/s时,可获得力学性能最佳的牵伸丝,其断裂伸长率为22.49%,断裂强度为3.39 cN/dtex,弹性模量为95.76 cN/dtex,断裂比功为0.62 cN/dtex,相比于蚕丝的平均值分别提高了7%、13.76%、24.53%、31.91%。

基于家蚕平板丝结构的柔性压力传感器制备及其传感性能

为获得基于天然平板丝结构的柔性压力传感器,以家蚕平板丝为柔性基底,在家蚕吐丝过程中循环喷洒过渡金属碳化物/氮化物和银纳米线作为导电材料,制备出具有天然多层结构的导电传感层复合材料。借助扫描电子显微镜和傅里叶红外光谱仪对制备的平板丝传感层进行形貌观察和结构分析,并通过优化传感层的层数开发出性能更优异的传感器。结果表明:具有2层传感层的传感器的灵敏度最高,在42.03~60.00 kPa的高压范围内灵敏度可达0.20 kPa^(-1),比仅有1层传感层的传感器灵敏度提高了20倍;该传感器响应/恢复时间均在1 s以内,且在施加不同压缩速率时仍能保持电流值稳定,可准确响应动态变化的压力,在超过1500次压力加载/卸载循环后传感性能依旧保持稳定;该传感器可很好地贴附到人体关节表面用于监测人体运动状态,通过按压时间长短来模拟摩斯密码,可用于信息加密传输和困境救援;将传感器制成传感阵列,可应用于压力位置轨迹追踪。

过表达BmAbl1基因促进家蚕茧丝产量

在过去5000多年的驯化过程中,家蚕茧丝的产量是人们努力改进的重要指标之一。研究发现,在家蚕BmN细胞中过表达非受体酪氨酸蛋白激酶基因BmAbl1时,部分谷胱甘肽S转移酶(glutathione S-transferase)编码基因的表达水平显著上升。基于piggyBac转座系统构建了过表达BmAbl1的转基因家蚕品系,发现其与对照品系家蚕相比,5龄幼虫的体重显著增加,全茧量、蛹重、茧层量以及茧层率均显著上升。且后部丝腺中谷胱甘肽S转移酶编码基因的转录水平显著上调,丝素重链和丝素轻链基因表达量分别是对照品系的3.3倍和1.3倍。上述结果表明,过表达BmAbl1提高了家蚕的茧丝产量。

全龄人工饲料育与桑叶育蚕茧质量及生丝性能比较

为探究不同饲育方式对蚕茧质量、生丝品质及生丝结构与性能的影响,采用单因素方差分析,考察全龄人工饲料育蚕茧与桑叶育蚕茧各项性能指标的差异显著性,并进行对比分析。结果表明:在外观形态方面,全龄人工饲料育与桑叶育蚕茧的外观均为椭圆形,桑叶育蚕茧的茧幅较大;在蚕茧质量方面,全龄人工饲料育蚕茧全茧质量和茧层质量较低,但茧层率较高;生丝品质方面,全龄人工饲料育蚕茧的茧丝长和解舒率低于桑叶育蚕茧,万米吊糙次数高于桑叶育蚕茧,影响缫丝过程中生丝的产量和质量;另外,是否工厂化养蚕也会对全龄人工饲料育蚕茧的蚕茧质量、生丝品质产生影响,工厂化全龄人工饲料育蚕茧的综合性能优于非工厂化全龄人工饲料育蚕茧;在生丝结构与性能方面,全龄人工饲料育生丝含胶率较高,通过丝胶的黏附作用,全龄人工饲料育生丝表面的各根茧丝黏合更紧密,且生丝的二级结构没有明显不同。

清末吐鲁番丝织业的困境——以《清代新疆档案选辑》为中心

左宗棠收复新疆后,政府锐意推动新疆全境丝织业的发展,从工匠、资金、政策等多个角度采取了多种举措促进当地丝织业发展,由官办逐渐转变为官督商办,试图形成新疆丝织业繁荣发展的局面。吐鲁番地区蚕桑经营得到显著发展,生丝出口大量增加,成为俄国的一个重要原料产地,而丝织业则停滞不前,陷入困境。政府在推动吐鲁番丝织业发展的过程中,在经济技术上起到了重要的推广意义,将南方比较先进的工艺技术传入新疆,教授当地少数民族丝织技术,各民族在发展丝织业的过程中积极互助,共同面对现实的困境,形成了行业内的民族命运共同体。

Preparation and Characterization of PEGDE Crosslinked Silk Fibroin Film

To obtain water-insoluble silk fibroin （SF） materials, polyethylene glycol diglycidyl ether （PEG-DE） was selected as a crosslinking agent to prepare SF films （blends）. The reaction conditions were optimized for the crosslinking of the SF molecules. The hot water stability of the blends was measured using BCA protein assay and gravimetric analysis. The molecular conformation and crystalline structure of the blends were analyzed by FTIR and XRD, respectively. When the mass ratio of SF：PEG-DE was 1.0：0.8, the hot water loss rate of the SF blends was minimized. PEG-DE could induce SF molecules to form fl-sheets during the gel reaction process, resulting in improved crystallinity and hot water dissolved resistance of the blend films. In order to demonstrate the eytotoxicity of the chemical reagents used to crosslink SF, L929 cells were seeded on the blend film （SF：PEG-DE = 1：1） and cultured for 3 days. Cells of L929 readily adhered and spread in the fusiform on the blend film resulting in high cell viability. The extracted liquid from the SF porous film did not inhibit cell proliferation, as estimated by the MTT assay.

柞蚕新品种墨玉及其杂交种辽蚕988的缫丝性能测定

通过对柞蚕新品种墨玉及其杂交种辽蚕988的缫丝性能测定,明确了新品种的缫丝性能。柞蚕新品种墨玉雌茧的茧丝长1533.6 m、丝重1.03 g、纤维公量1.36 g,分别比对照种三里丝高19.9%、25.61%和20.35%,与对照种抗大的8个缫丝性状相当或略优于对照种;雄茧的茧丝长1520.1 m、丝重0.95 g、纤维公量1.26 g,分别比对照种三里丝高20.62%、26.67%和26%,与对照种抗大的缫丝性能相当。杂交种辽蚕988除在茧丝纤度与茧丝量方面略低于墨玉×9906外,其余缫丝性状与对照种抗大×9906及杂交组合墨玉×9906之间均无显著性差异。新品种墨玉及其杂交种辽蚕988的鲜茧出丝率均超过7%,达到了缫丝性能评价的优级标准。

丝绸字义文化的研究

丝绸,除了产业生产和经济活动以外,还蕴涵着文化韵味。本文列举了丝绸的字义解释,人文典故、织物术语、成语谜语和文学诗词等丝、绸相关文化知识,期望通过丝绸字义的探讨,增进蚕丝绸文化研究内涵与空间,作为蚕丝文化的微补。

角蛋白替代大豆蛋白养蚕对蚕丝结构与性能的影响

角蛋白主要存在于动物的毛发中,经过处理被广泛用作动物蛋白饲料。为探究角蛋白替代大豆蛋白养蚕对蚕丝结构与性能的影响,文中以基础家蚕人工饲料养蚕为对照,分别用酶解角蛋白替代1.0%、2.5%、5.0%、7.5%、10.0%大豆蛋白饲养5龄大蚕。结果表明:随着角蛋白替代比例增加,熟蚕体重、全茧量和茧层量逐渐减少,但替代组茧层率平均提高了8.97个百分点。与对照组蚕丝相比,替代组蚕丝的基本结构并未发生改变,但α螺旋/无规卷曲和相对结晶度有所增加,蚕丝力学性能也有所提升。2.5%替代组蚕丝断裂强度和断裂伸长率比对照组分别提高了8.15%和4.49个百分点,且替代比例≤5.0%不会影响蚕丝纤度。该研究可为角蛋白用作家蚕人工饲料原料提供一定的参考。

不同品种桑蚕牵伸丝的结构与性能

利用自主研制的圆锥斜面强制牵伸抽丝装置对不同品种五龄桑蚕进行强制抽丝,通过拉伸测试、傅里叶红外光谱及X射线衍射对不同品种牵伸丝与相应原茧丝的结构与性能进行表征与分析。结果表明:两种牵伸丝的力学性能均优于其对应茧丝,黄色雄蚕牵伸丝的力学性能更佳,其初始模量、断裂强度、断裂比功与伸长率的平均值分别为117.35、4.55、0.75 cN dtex与26.54%。牵伸作用会导致丝纤维晶粒尺寸减小、结晶度提高,从而赋予丝纤维更为优异的力学性能。

纳米颗粒添食育蚕改性蚕丝纤维的染色性能

为了探究纳米颗粒添食育蚕改性蚕丝纤维的染色性能,选用2%质量分数的纳米二氧化钛和纳米氧化铜添喂家蚕,将蚕茧脱胶后进行染色并测定上染率、色深值等指标,同时探究了酸性橙Ⅱ对蚕丝纤维的染色动力学和热力学机制。结果表明:纳米颗粒添食能改善蚕丝纤维的染色性能;酸性染料和活性染料对改性蚕丝纤维的上染率和表观色深(K S值)均高于空白组,洗涤20次后K S值仍高于空白组1.5和2.0。染色动力学和热力学分析表明酸性橙Ⅱ对各组蚕丝纤维上染过程均符合准二级吸附动力学方程和朗格缪尔(Langmuir)吸附,且属于放热过程,较低温度下更适合染色;60℃下纳米TiO 2和纳米CuO改性蚕丝纤维的实际吸附平衡饱和量分别比空白组高了0.14 g kg和1.04 g kg,计算得到染料吸附的最大值分别比空白组高了5.31 g kg和14.58 g kg,显示了改性蚕丝纤维更优的染色性能。

黄帝“淳化”“虫蛾”成就与嫘祖“先蚕”“蚕神”名号

《史记》卷一《五帝本纪》所记载黄帝“淳化”“虫蛾”成就,显示了早期文明进程中丝绸生产的意义。而“嫘祖为黄帝正妃”,“嫘”的文字学分析,所谓“细丝曰糸”反映了蚕桑业的发明。黄帝事迹,其中有“嫘祖”的表现。《礼记》关于“先蚕”纪念的礼俗,体现当时对这种产业开创功绩的尊重与崇敬。现在看来,黄帝“淳化”“虫蛾”成就作为帝业基础与文明标志,有嫘祖之功的因素。后世“先蚕”“蚕神”名号,亦体现了黄帝、嫘祖在丝绸史上的重要地位。