854 resultados para silk powder
Resumo:
Several studies have shown that UV-C irradiation promotes the bioactive compounds and antioxidants of fresh fruits and vegetables. The aim of this study was to apply UV irradiation in lemon pomace dried powder for enhancing its phenolic content and antioxidant properties, thus more bioactive compounds should be available for extraction and utilization. Lemon pomace dried powder was placed above the UV lamp and treated with dosages of 4, 19, 80 and 185 kJ m-2, while untreated powder was used as a control. UV-C irradiation significantly affected the total phenolic content, total flavonoid content, proanthocyanidins and antioxidant capacity measured by CUPRAC and FRAP of the lemon pomace dried powder, while it did not affect the vitamin C content. UV-C irradiation of 19 kJ m-2 resulted in 19% higher total phenolic content than the control, while UV-C irradiation of 180 kJ m-2 resulted in 28% higher total flavonoid content than the control. The antioxidant capacity was reduced when UV-C irradiation more than 4 kJ m-2 was applied. The results of this study indicate that UV-C treatment has the potential to increase the extraction of bioactive compounds of lemon dried pomace at relatively high dosages.
Resumo:
Background: In the field of Plastic Reconstructive Surgery the development of new innovative matrices for skin repair is in urgent need. The ideal biomaterial should promote attachment, proliferation and growth of cells. Additionally, it should degrade in an appropriate time period without releasing harmful substances, but not exert a pathological immune response. Spider dragline silk from Nephila spp meets these demands to a large extent. Methodology/Principal Findings: Native spider dragline silk, harvested directly out of Nephila spp spiders, was woven on steel frames. Constructs were sterilized and seeded with fibroblasts. After two weeks of cultivating single fibroblasts, keratinocytes were added to generate a bilayered skin model, consisting of dermis and epidermis equivalents. For the next three weeks, constructs in co-culture were lifted on an originally designed setup for air/liquid interface cultivation. After the culturing period, constructs were embedded in paraffin with an especially developed program for spidersilk to avoid supercontraction. Paraffin cross-sections were stained in Haematoxylin & Eosin (H&E) for microscopic analyses. Conclusion/Significance: Native spider dragline silk woven on steel frames provides a suitable matrix for 3 dimensional skin cell culturing. Both fibroblasts and keratinocytes cell lines adhere to the spider silk fibres and proliferate. Guided by the spider silk fibres, they sprout into the meshes and reach confluence in at most one week. A well-balanced, bilayered cocultivation in two continuously separated strata can be achieved by serum reduction, changing the medium conditions and the cultivation period at the air/liquid interphase. Therefore spider silk appears to be a promising biomaterial for the enhancement of skin regeneration.
Resumo:
Background: Several materials have been used for tissue engineering purposes, since the ideal matrix depends on the desired tissue. Silk biomaterials have come to focus due to their great mechanical properties. As untreated silkworm silk has been found to be quite immunogenic, an alternative could be spider silk. Not only does it own unique mechanical properties, its biocompatibility has been shown already in vivo. In our study, we used native spider dragline silk which is known as the strongest fibre in nature. Methodology/Principal Findings: Steel frames were originally designed and manufactured and woven with spider silk, harvesting dragline silk directly out of the animal. After sterilization, scaffolds were seeded with fibroblasts to analyse cell proliferation and adhesion. Analysis of cell morphology and actin filament alignment clearly revealed adherence. Proliferation was measured by cell count as well as determination of relative fluorescence each after 1, 2, 3, and 5 days. Cell counts for native spider silk were also compared with those for trypsin-digested spider silk. Spider silk specimens displayed less proliferation than collagen-and fibronectin-coated cover slips, enzymatic treatment reduced adhesion and proliferation rates tendentially though not significantly. Nevertheless, proliferation could be proven with high significance (p<0.01). Conclusion/Significance: Native spider silk does not require any modification to its application as a biomaterial that can rival any artificial material in terms of cell growth promoting properties. We could show adhesion mechanics on intracellular level. Additionally, proliferation kinetics were higher than in enzymatically digested controls, indicating that spider silk does not require modification. Recent findings concerning reduction of cell proliferation after exposure could not be met. As biotechnological production of the hierarchical composition of native spider silk fibres is still a challenge, our study has a pioneer role in researching cellular mechanics on native spider silk fibres.
Resumo:
The first section of this unfinished novel, titled Silk Butterflies is a diptych about a woman named Sarah, and her desire to acquire ancestral truth regarding her identity to negate the pain she feels from losing her unborn child. Her story, told in a guarded, first person point-of-view is paralleled with Ling’s story, an unconventional, ninety-two year old Shanghainese woman who, against her desires, had her feet bound in China during the early 1920’s. Ling’s story is also told from a lyrical first-person perspective that focuses especially on sensory details, and delves into the sacrifices we make to attain standards of beauty, and the loss Ling has never recovered from. As this historical fiction progresses, their stories overlap in an unexpected way, as both Sarah and Ling attempt to revitalize forgotten histories, including how Sarah’s grandparents fled to Shanghai in the 1930’s to escape Nazi persecution during World War II.
Resumo:
China's Silk Road Economic Belt plan is a part of One Belt, One Road initiative that aims to create trade routes from China all the way to Europe. Despite the potential benefits, there are also problems along the way. In this research I am examining the adverse effects of one part of the Silk Road Economic Belt with my focus on Xinjiang Uyghur minority and their rights and Central Asian regional stability. Moreover, I suggest that China's past commitments in the international society as well as her actions in relations to the undertaking can give an insight into a regime where China would be the dominant power in international society. I have used qualitative analysis to study the topics. My most important methodological tools to examine the topics are as follows. I utilise conceptual analysis to borrow concepts from international relations field. I use method of situation analysis when I am describing the current circumstances in China's Xinjiang and Central Asia. Inductive analysis is the overall method since I suggest that the content I have examined could give an insight to how China regards and relates to international law in the future. Moreover, my theoretical framework of the research sees international law as a tool that a state can use to gain more power but at the same time international law restricts state's behaviour. Based on the findings of this research, in case of Xinjiang the New Silk Road is likely to worsen Uyghurs situation because of Beijing's worries and harsh actions to prevent any disturbance. However, the New Silk Road could bring stability and maintain regional security in Central Asia when the states could see it beneficial to unite for cooperation which can result with greater benefits. China's potential future regime will emphasize sovereignty and non-interference to states’ domestic matters. Moreover, there will be no room for minority rights in China's concept of human rights. Human rights are meant to protect rights of masses but are of secondary importance since development and security will be more important goals to pursue. In the field of cooperation, China is increasingly using multilateral forums to discuss the matters but reserves bilateral negotiations for executing the plans.