Realization of Graphene-Based Tunable Plasmon-Induced Transparency by the Dipole-Dipole Coupling

A numerical and theoretical study is presented on the realization of tunable plasmon-induced transparency (PIT) phenomenon in the three-dimensional patterned graphene nanostrips. The simulation results reveal that the PIT effect is generated due to the excitation of dark mode which can be considered a dipole. The three-level plasmonic system is employed to explain the physical mechanism of the PIT effect. Different from previous reported form (dipole-quadrupole coupling), the proposed is attributed to the dipole-dipole coupling. The PIT effect can be tuned by changing the coupling length between bright and dark mode as well as the Fermi energy of graphene. Our studies provide guidance for fabricating ultra-compact devices in practical application.     

沙井地区384例支原体药敏试验结果及分析

目的:了解本地区社区感染支原体的药物敏感情况。方法:对门诊标本培养出的384例支原体进行药敏试验(微量肉汤法)。结果:Uu对交沙霉素、克拉霉素及罗红霉素敏感性高,敏感率分别为98%、94%及93%;对环丙沙星、大观霉素耐药性高,敏感率分别为8%及11%。Mh对交沙霉素敏感率为89%、对大现霉素、多西环素、美满霉素的敏感率均为78%;对罗红霉素、红霉素耐药性高,敏感率分别为0%及11%。Uu合并Mh对交沙霉素、多西环素、美满霉素敏感性高,敏感率分别为85%、73%及69%,对红霉素、克拉霉素、大观霉素的敏感性均为0%,对罗红霉素、阿奇霉素、环丙沙星的敏感率均为4%。结论:支原体的敏感性存在时空差异,且不同类型的支原体对抗菌素的敏感性是不同的,应采用实验室结果而非经验指导用药。     

RP-HPLC法测定阿托伐他汀在新西兰兔体内的药代动力学

目的:研究阿托伐他汀片在新西兰兔体内的药代动力学.方法:18只成年健康雄性新西兰兔.随机分为正常对照组、10mg/kg·d阿托伐他汀片组与15 mg/kg·d阿托伐他汀片组,每组6只,采用RP-HPLC法测定血药浓度,计算药代动力学参数.结果:10mg/kg·d组与15 mg/kg·d组的主要药代动力学参数分别为:AUC0～t/μ g·L-1·h为(619.58±215.45)与(1138.34±422.32)、AUC0～∞/μ g·L-1·h为(655.68±242.83)与(1216.57±353.64)、Cmax/μ g·L-1为(455.81±168.52)和(896.53±168.5.8)、MRT0～t/h为(3.68±0.75)与(5.73±0.56)、MRT0～∞/h为(3.83±0.91)与(5.25±0.48)、Tmax/h为(2.51±0.82)与(3.68±0.33)、T1/2/h为(4.22±0.55)与(9.51±0.67).结论:RP-HPLC法适用于阿托伐他汀片动物药代动力学的研究.     

脑外伤后血清和脑脊液中髓鞘磷脂碱性蛋白含量变化及临床意义

目的:研究脑外伤后血清、脑脊液中髓鞘碱性蛋白(myelin basic protein,MBP)浓度变化,探讨该变化与脑损伤程度及预后情况的关系.方法:采用酶联免疫吸附法对65例脑外伤患者伤后24h、3d、7d血清及脑脊液中MBP浓度检测,并结合颅脑损伤程度和格拉斯哥预后计分(GOS)进行比较分析.结果:病例组患者血清和脑脊液中MBP含量升高程度与脑损伤程度及预后情况密切相关.结论:血清、脑脊液MBP对于判断脑外伤程度和预后情况具有较高的特异性和敏感性,可作为脑外伤治疗及病情转归的重要客观依据.     

POCD 发病机制的研究进展

术后认知功能障碍(Postoperative Cognitive Dysfunction,POCD)的特征性表现是麻醉和手术后认知功能的持续性下降。这种多认知领域的功能需要感觉和广泛的神经学检测来评估,由于不同的检测仪器、不同的时间点和应用不同的统计学方法,因而对POCD一直没有统一的定义,各POCD间的研究也缺乏比较性。因此,进一步阐述POCD的影响因素及发病机制,有利于对POCD的研究建立标准的检测、诊断和防治方法。     

Actively Tunable Fano Resonance Based on a T-Shaped Graphene Nanodimer

We present the strength modulation and frequency tuning of Fano resonance by employing a graphene nanodimer formed by two coplanar perpendicular nanostrips with different dimensions. The Fano resonance is induced by destructive interference between the bright dipole mode of a short nanostrip and the dark quadrupole mode of a long nanostrip. The strength, line width, and resonance frequency of the Fano resonance can be actively modulated by changing the spatial separation of those two graphene nanostrips and the Fermi energy of the graphene nanodimer, respectively, without re-fabricating the nanostructures. The tuning of the strength and resonance frequency can be attributed to the coupling strength and optical properties of graphene, respectively. Importantly, a figure of merit value as high as 39 is achieved in the proposed nanostructures. Our results may provide potential applications in optical switching and bio-chemical sensing.     

乳腺浸润性癌患者血清标记物B7-H4分子含量变化的临床意义研究

目的:探讨新发现的血清标记物B7-H4在乳腺浸润性癌患者血清中的含量变化及其临床诊断价值.方法:通过RT-PCR技术检测确诊为乳腺浸润性癌的58例患者治疗前后及30例健康妇女的血清中B7-H4mRNA含量变化,用ELISA夹心法检测患者血清中的B7-H4分子的水平变化,采用CA125 Ⅱ试剂盒检测所有患者CA125水平的变化,分析比较检测过程中B7-H4分子与CA125分子的特异性与敏感度.结果:RT-PCR检测结果发现大部分乳腺浸润性癌患者血清中B7-H4基因的mRNA含量明显升高(P<0.05);治疗后其水平明显下降但一般仍高于正常水平(P<0.05),Western-blot检测也得到了类似的结果.在乳腺浸润性癌的检测过程中:B7-H4分子的特异度明显低于CA125分子,而其敏感度却明显高于CA125分子;二者联合使用时检测的特异度与敏感度均显著提高(P<0.05).结论:血清中B7-H4分子的含量升高可以作为一个癌变的高危指标.     

A Terahertz Tunable Metamaterial Reflective Polarization Converter Based On Vanadium Oxide Film

In this paper, on the basis of metamaterial, a simply single-layer and tunable reflective polarization converter has been numerically investigated, which is composed of vanadium dioxide film (VO₂) component combined with two-corner-cut square patch cut by a slit and reflective ground layer. Calculated results obtained by the CST Microwave Studio show that in the frequency of 2.22–5.42 THz, high polarization conversion efficiency (polarization conversion ratio (PCR) above 90%) can be normally achieved at the temperature about 25 °C for both the linearly and circularly polarized wave incidence. At the same time, the cross-polarization converter can be analyzed and obtained from the view on qualitative variable of polarization azimuth angle (θ) and ellipticity (η). Moreover, a tunable polarization conversion property can be realized by the designed device with vanadium dioxide utilizing changing different conductivities. Even so, to be demonstrated, the physical mechanism of the merits of controllability and uniqueness has been discussed by the distributions of current densities and E-field map, respectively. According to the prior results, the designed metamaterial could be applied in the area of temperature-controlled sensing, THz wireless communication, tunable polarized devices.

     

Numerical Investigation of a Tunable Fano-Like Resonance in the Hybrid Construction Between Graphene Nanorings and Graphene Grating

Plasmonics - A tunable Fano-like resonance in the hybrid construction between graphene nanorings and graphene grating is proposed. The simulation results reveal that the Fano-like resonance is...