2,068 research outputs found

    Vertically integrated visible and near-infrared metasurfaces enabling an ultra-broadband and highly angle-resolved anomalous reflection

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    An optical device with minimized dimensions, which is capable of efficiently resolving an ultra-broad spectrum into a wide splitting angle but incurring no spectrum overlap, is of importance in advancing the development of spectroscopy. Unfortunately, this challenging task cannot be easily addressed through conventional geometrical or diffractive optical elements. Herein, we propose and demonstrate vertically integrated visible and near-infrared metasurfaces which render an ultra-broadband and highly angle-resolved anomalous reflection. The proposed metasurface capitalizes on a supercell that comprises two vertically concatenated trapezoid-shaped aluminum antennae, which are paired with a metallic ground plane via a dielectric layer. Under normal incidence, reflected light within a spectral bandwidth of 1000 nm ranging from = 456 nm to 1456 nm is efficiently angle-resolved to a single diffraction order with no spectrum overlap via the anomalous reflection, exhibiting an average reflection efficiency over 70% and a substantial angular splitting of 58 degrees. In light of a supercell pitch of 1500 nm, to the best of our knowledge, the micron-scale bandwidth is the largest ever reported. It is noted that the substantially wide bandwidth has been accomplished by taking advantage of spectral selective vertical coupling effects between antennae and ground plane. In the visible regime, the upper antenna primarily renders an anomalous reflection by cooperating with the lower antenna, which in turn cooperates with the ground plane and produces phase variations leading to an anomalous reflection in the near-infrared regime. Misalignments between the two antennae have been particularly inspected to not adversely affect the anomalous reflection, thus guaranteeing enhanced structural tolerance of the proposed metasurface.This work was supported by the National Research Foundation of Korea (NRF) grants funded by the Korean government (MSIP) (No. 2016R1A2B2010170 and 2011-0030079) and by a Research Grant of Kwangwoon University in 2018. The work was partly supported by the Australian Research Council Future Fellowship (FT110100853, Dr Duk-Yong Choi), and was performed in part at the ACT node of the Australian National Fabrication Facility. The authors thank Prof. L. Shi, Prof. J. Zi and Y. Zhang from Fudan University and Dr H. Yin from Ideaoptics Inc., for their help with the Fourier-transformbased angle-resolved spectroscopy (FT-ARS) measurements

    Nitric oxide directly activates calcium-activated potassium channels from rat brain reconstituted into planar lipid bilayer

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    AbstractUsing the planar lipid bilayer technique, we tested whether NO directly activates calcium-activated potassium (Maxi-K) channels isolated from rat brain. We used streptozotocin (STZ) as NO donor, and the NO release was controlled with light. In the presence of 100–800 μM STZ, the Maxi-K channel activity increased up to 3-fold within several tens of seconds after the light was on, and reversed to the control level several minutes after shutting off the light. Similar activation was observed with other NO donors such as S-nitroso-N-acetylpenicillamine and sodium nitroprusside. The degree of activity increase was dependent upon the initial open probability (Pinit). When the Pinit was lower, the activity increase was greater. These results demonstrate that NO can directly affect the Maxi-K channel activity, and suggest that the Maxi-K channel might be one of the physiological targets of NO in brain

    Omnidirectional color filters capitalizing on a nano-resonator of Ag-TiO2-Ag integrated with a phase compensating dielectric overlay

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    We present a highly efficient omnidirectional color filter that takes advantage of an Ag-TiO2-Ag nano-resonator integrated with a phase-compensating TiO2 overlay. The dielectric overlay substantially improves the angular sensitivity by appropriately compensating for the phase pertaining to the structure and suppresses unwanted optical reflection so as to elevate the transmission efficiency. The filter is thoroughly designed, and it is analyzed in terms of its reflection, optical admittance, and phase shift, thereby highlighting the origin of the omnidirectional resonance leading to angle-invariant characteristics. The polarization dependence of the filter is explored, specifically with respect to the incident angle, by performing experiments as well as by providing the relevant theoretical explanation. We could succeed in demonstrating the omnidirectional resonance for the incident angles ranging to up to 70°, over which the center wavelength is shifted by below 3.5% and the peak transmission efficiency is slightly degraded from 69%. The proposed filters incorporate a simple multi-layered structure and are expected to be utilized as tri-color pixels for applications that include image sensors and display devices. These devices are expected to allow good scalability, not requiring complex lithographic processes.This work was supported by a National Research Foundation of Korea grant funded by the Korean government (MEST) (No. 2013-008672 and 2013-067321), and also by a research grant from Kwangwoon University in 2014. The work was partly supported by the Australian Research Council Future Fellowship (FT110100853, Dr. Duk-Yong Choi) and was performed in part at the ACT node of the Australian National Fabrication Facilit

    Association of Polymorphisms in Browzine Journal Cover Fshr, inha, Esr1, and Bmp15 With Recurrent Implantation Failure

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    Recurrent implantation failure (RIF) refers to two or more unsuccessful in vitro fertilization embryo transfers in the same individual. Embryonic characteristics, immunological factors, and coagulation factors are known to be the causes of RIF. Genetic factors have also been reported to be involved in the occurrence of RIF, and some single nucleotide polymorphisms (SNPs) may contribute to RIF. We examined SNPs i

    The Results of Cervical Nucleoplasty in Patients with Cervical Disc Disorder: A Retrospective Clinical Study of 22 Patients

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    Nucleoplasty is a minimally invasive spinal surgery using a Coblation Ⓡ technique that creates small voids within the disc. The purpose of this study was to evaluate the efficacy of cervical nucleoplasty in patients with cervical disc disorder. Methods: Between March 2008 and December 2009, 22 patients with cervical disc disorders were treated with cervical nucleoplasty after failed conservative treatment. All procedures were performed under local anesthesia, and fluoroscopic guidance and voids were created in the disc with the Perc TM DC Spine Wand TM. Clinical outcomes were evaluated by the Modified Macnab criteria and VAS score at preprocedure, postprocedure 1 month, and 6 months. Results: Six patients had one, eight patients had two and eight patients had three discs treated; a total of 46 procedures was performed. Mean VAS reduced from 9.3 at preprocedure to 3.7 at postprocedure 1 month and to 3.4 at postprocedure 6 months. There was no significant complication related to the procedure within the first month. Outcomes were good or excellent in 17/22 (77.3%) cases. Postprocedure magnetic resonance imaging was acquired in two patients after two months showing morphologic evidence of volume reduction of protruded disc material in one patient but not in the other. Conclusions: Percutaneous decompression with a nucleoplasty using a Coblation Ⓡ technique in the treatment of cervical disc disorder is a safe, minimally-invasive and less uncomfortable procedure, with an excellent short-term clinical outcome. (Korean J Pain 2011; 24: 36-43

    Incremental predictive value of the combined use of the neutrophil-to-lymphocyte ratio and systolic blood pressure difference after successful drug-eluting stent implantation

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    Background: Previous work has highlighted the importance of the neutrophil-to-lymphocyte ratio (NLR) and the difference in the ward-to-catheterization laboratory systolic blood pressure (ΔSBP) in prognostic stratification after acute coronary syndrome. However, there is paucity of data regarding the added value of combining these two variables to predict 5-year major clinical outcomes after percutaneous coronary intervention. Methods: A total of 1188 patients were classified into four groups according to the NLR and ΔSBP (high vs. low) using cutoffs derived from an analysis of receiver operating characteristic curves. A NLR > 3.0 and a ΔSBP > 25 mmHg were considered high values. The primary endpoint was the composite of all-cause death, cardiac death, and non-fatal myocardial infarction. The secondary endpoint was the composite of target lesion revascularization, target vessel revascularization, and incidence of cerebrovascular accidents. Results: The incidence of the primary endpoint was significantly higher in the high NLR and ΔSBP group than in the other three groups (2.2% vs. 4.7% vs. 4.3% vs. 13.2%, p < 0.001). The incidence of the secondary endpoint was similar among the four groups. Incorporation of high NLR and high ΔSBP into a model with conventional and meaningful clinical and procedural risk factors increased the C-statistics in predicting the primary endpoint (0.575 to 0.635, p = 0.002). Conclusions: The power to predict the primary endpoint after drug-eluting stent implantation at the 5-year follow-up was improved by combining NLR and ΔSBP

    The Bus Transit System: Its Underutilized Potential

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    The bus system represents the most widely used transit mode. Upgraded bus services, primarily those which have partially or fully separated rights-of-way, represent a very cost effective method to improve the balance between automobile and transit. Many measures for improving bus services were introduced since 1970. However, many of these improvements were not maintained: buses were gradually returned to operations in mixed traffic. The report examines the quality of bus services in various cities in North America and worldwide and analyzes the reasons for the phenomenon of “backsliding” or disappearance of bus transit priority measures

    Trichosanthes kirilowii

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    Trichosanthes kirilowii tuber is a traditional medicine which exhibits various medicinal effects including antidiabetic and anticancer activities in several cancer cells. Recently, it was reported that Cucurbitacin D (CuD) isolated from Trichosanthes kirilowii also induces apoptosis in several cancer cells. Constitutive signal transducer and activator of transcription 3 (STAT3), which is an oncogenic transcription factor, is often observed in many human malignant tumor, including breast cancer. In the present study, we tested whether Trichosanthes kirilowii ethanol extract (TKE) or CuD suppresses cell growth and induces apoptosis through inhibition of STAT3 activity in breast cancer cells. We found that both TKE and CuD suppressed proliferation and induced apoptosis and G2/M cell cycle arrest in MDA-MB-231 breast cancer cells by inhibiting STAT3 phosphorylation. In addition, both TKE and CuD inhibited nuclear translocation and transcriptional activity of STAT3. Taken together, our results indicate that TKE and its derived compound, CuD, could be potent therapeutic agents for breast cancer, blocking tumor cell proliferation and inducing apoptosis through suppression of STAT3 activity
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