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Lightweight porous silica foams with extreme-low dielectric permittivity and loss for future 6G wireless communication technologies

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nano Research 2021年第5期14卷 1450-1456页

作者： Petra S.Pálvölgyi daniel sebők Imre Szenti Eva Bozo Henri Ervasti Olli Pitkänen Jari Hannu Heli Jantunen Marko E.Leinonen Sami Myllymäki Akos Kukovecz Krisztian Kordas Microelectronics Research Unit Faculty of Information and Electrical EngineeringUniversity of OuluP.O.Box 4500FI-90570OuluFinland Interdisciplinary Excellence Centre Department of Applied and Environmental ChemistryUniversity of SzegedRerrich Béla tér 1H-6720SzegedHungary Centre for Wireless Communications University of OuluP.O.Box 4500FI-90570OuluFinland

In the next generation wireless communication systems operating at near terahertz frequencies, dielectric substrates with the lowest possible permittivity and loss factor are becoming essential. In this work, highly porous (98.9% ± 0.1%) and lightweight silica foams (0.025 ± 0.005 g/cm3), that have extremely low relative permittivity (εr = 1.018 ± 0.003 at 300 GHz) and corresponding loss factor (tan δnthetized by a template-assisted sol-gel method. After dip-coating the slabs of foams with a thin film of cellulose nanofibers, sufficiently smooth surfaces are obtained, on which it is convenient to deposit electrically conductive planar thin films of metals important for applications in electronics and telecommunication devices. Here, micropatterns of Ag thin films are sputtered on the substrates through a shadow mask to demonstrate double split-ring resonator metamaterial structures as radio frequency filters operating in the sub-THz band.

关键词： low-permittivity materials low-loss dielectrics templated sol-gel synthesis silica foams 6G telecommunication

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过氧化物酶增殖活化受体增加皮脂分泌

世界核心医学期刊文摘（皮肤病学分册） 2006年第12期2卷 35-36页

作者： Trivedi n.R. Cong Z. nelson A.M d.M. Thiboutot 董平 department of dermatology UPC-2 Pennsylvania State University College of Medicine 500UniversityDrive Hershey PA 17033 United States Dr.

sebum production is key in the pathophysiology of acne, an extremely common condition, which when severe, may require treatment with isotretinoin, a known teratogen. Apart from isotretinoin and hormonal therapy, no agents are available to reduce sebum. Increasing our understanding of the regulation of sebum production is a milestone in identifying alternative therapeutic targets. Studies in sebocytes and human sebaceous glands indicate that agonists of peroxisome proliferator-activated receptors (PPARs) alter sebaceous lipid production. The goal of this study is to verify the expression and activity of PPARs in human skin and seb-1 sebocytes and to assess the effects of PPAR ligands on sebum production in patients. To investigate the contribution of each receptor subtype to sebum production, lipogenesis assays were performed in seb-1 sebocytes that were treated with PPAR ligands and isotretinoin. Isotretinoin significantly decreased lipogenesis, while the PPARαagonist-GW7647, PPARδagonist-GW0742, PPARα/δagonist-GW2433, PPARγagonist rosiglitazone, and the panagonist-GW4148, increased lipogenesis. Patients treated with thiazolidinediones or fibrates had significant increases in sebum production (37 and 77%, respectively) when compared to age-, disease-, and sex-matched controls. These data indicate that PPARs play a role in regulating sebum production and that selective modulation of their activity may represent a novel therapeutic strategy for the treatment of acne.

关键词：皮脂 PPARs 过氧化物酶皮脂腺细胞活化受体

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高频工作的扩散外延GaAlAs—GaAs异质结双极晶体管

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微纳电子技术 1984年第5期 24-26页

作者： d.Ankri 杨宪明

采用发射区掺杂很低的液相外延作出了GaAlAs-GaAs异质结双极晶体管（HBT）。研究了一种扩散外延结构。I;=10mA时,测出的转移频率接近5GHz,尽管发射极基极的面积较大(seb～4×10;cm;),在小电流时也获得高的转移频率（I;=1mA时,f;=1.3GHz... 详细信息

采用发射区掺杂很低的液相外延作出了GaAlAs-GaAs异质结双极晶体管（HBT）。研究了一种扩散外延结构。I;=10mA时,测出的转移频率接近5GHz,尽管发射极基极的面积较大(seb～4×10;cm;),在小电流时也获得高的转移频率（I;=1mA时,f;=1.3GHz）。这些数据是目前有关HBT报导中最好的,而且很有希望用于低功率高速逻辑。

关键词：异质结双极晶体管基极 HBT 发射极 GaAlAs GaAs

自嵌入行为:自嵌入软组织异物的放射学处理方式

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国际医学放射学杂志 2010年第6期 578-579页

作者： A.S.Young W.E.Shiels II J.W.Murakami B.d.Coley M.J.Hogan 赵学媛 department of Radiology and Children's Radiological Institute Nationwide Children's Hospital700 Children's DrColumbusOH 43201

目的报道一系列自嵌入行为(seb),论证影像引导下异物取出术(IGFBR)对于治疗嵌入软组织内异物(STFBs)的有效性和临床作用,并且评价影像医师在seb临床处理中

关键词：异物自嵌入放射学