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Nishimoto R, Sato Y, Wu J, Saizaki T, Kubo M, Wang M, Abe H, Richard I, Yoshinobu T, Sorin F, Guo Y. Thermally Drawn CNT-Based Hybrid Nanocomposite Fiber for Electrochemical Sensing. Biosensors (Basel) 2022; 12:559. [PMID: 35892456 PMCID: PMC9394265 DOI: 10.3390/bios12080559] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Revised: 07/20/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Nowadays, bioelectronic devices are evolving from rigid to flexible materials and substrates, among which thermally-drawn-fiber-based bioelectronics represent promising technologies thanks to their inherent flexibility and seamless integration of multi-functionalities. However, electrochemical sensing within fibers remains a poorly explored area, as it imposes new demands for material properties-both the electrochemical sensitivity and the thermomechanical compatibility with the fiber drawing process. Here, we designed and fabricated microelectrode fibers made of carbon nanotube (CNT)-based hybrid nanocomposites and further evaluated their detailed electrochemical sensing performances. Carbon-black-impregnated polyethylene (CB-CPE) was chosen as the base material, into which CNT was loaded homogeneously in a concentration range of 3.8 to 10 wt%. First, electrical impedance characterization of CNT nanocomposites showed a remarkable decrease of the resistance with the increase in CNT loading ratio, suggesting that CNTs notably increased the effective electrical current pathways inside the composites. In addition, the proof-of-principle performance of fiber-based microelectrodes was characterized for the detection of ferrocenemethanol (FcMeOH) and dopamine (DA), exhibiting an ultra-high sensitivity. Additionally, we further examined the long-term stability of such composite-based electrode in exposure to the aqueous environment, mimicking the in vivo or in vitro settings. Later, we functionalized the surface of the microelectrode fiber with ion-sensitive membranes (ISM) for the selective sensing of Na+ ions. The miniature fiber-based electrochemical sensor developed here holds great potential for standalone point-of-care sensing applications. In the future, taking full advantage of the thermal drawing process, the electrical, optical, chemical, and electrochemical modalities can be all integrated together within a thin strand of fiber. This single fiber can be useful for fundamental multi-mechanistic studies for biological applications and the weaved fibers can be further applied for daily health monitoring as functional textiles.
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Affiliation(s)
- Rino Nishimoto
- Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan; (R.N.); (J.W.); (M.W.); (H.A.); (T.Y.)
| | - Yuichi Sato
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Sendai 980-0845, Japan;
| | - Jingxuan Wu
- Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan; (R.N.); (J.W.); (M.W.); (H.A.); (T.Y.)
| | - Tomoki Saizaki
- School of Engineering, Tohoku University, Sendai 980-8579, Japan; (T.S.); (M.K.)
| | - Mahiro Kubo
- School of Engineering, Tohoku University, Sendai 980-8579, Japan; (T.S.); (M.K.)
| | - Mengyun Wang
- Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan; (R.N.); (J.W.); (M.W.); (H.A.); (T.Y.)
| | - Hiroya Abe
- Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan; (R.N.); (J.W.); (M.W.); (H.A.); (T.Y.)
| | - Inès Richard
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; (I.R.); (F.S.)
| | - Tatsuo Yoshinobu
- Graduate School of Engineering, Tohoku University, Sendai 980-8579, Japan; (R.N.); (J.W.); (M.W.); (H.A.); (T.Y.)
- Graduate School of Biomedical Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Fabien Sorin
- Institute of Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL), 1015 Lausanne, Switzerland; (I.R.); (F.S.)
| | - Yuanyuan Guo
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Sendai 980-0845, Japan;
- Graduate School of Biomedical Engineering, Tohoku University, Sendai 980-8579, Japan
- Graduate School of Medicine, Tohoku University, Sendai 980-8575, Japan
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Yoshinobu T, Miyamoto KI. Efficient Illumination for a Light-Addressable Potentiometric Sensor. Sensors (Basel) 2022; 22:4541. [PMID: 35746324 PMCID: PMC9227191 DOI: 10.3390/s22124541] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 06/15/2023]
Abstract
A light-addressable potentiometric sensor (LAPS) is a chemical sensor that is based on the field effect in an electrolyte-insulator-semiconductor structure. It requires modulated illumination for generating an AC photocurrent signal that responds to the activity of target ions on the sensor surface. Although high-power illumination generates a large signal, which is advantageous in terms of the signal-to-noise ratio, excess light power can also be harmful to the sample and the measurement. In this study, we tested different waveforms of modulated illuminations to find an efficient illumination for a LAPS that can enlarge the signal as much as possible for the same input light power. The results showed that a square wave with a low duty ratio was more efficient than a sine wave by a factor of about two.
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Affiliation(s)
- Tatsuo Yoshinobu
- Department of Biomedical Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Ko-ichiro Miyamoto
- Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan;
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Tsuge S, Mizushima I, Shin S, Yoshinobu T, Hoshiba R, Nishioka R, Zoshima T, Hara S, Suzuki Y, Ito K, Kawano M. AB0760 HIGH SERUM IGA LEVELS HAVE LIMITED CLINICAL SIGNIFICANCE IN PATIENTS WITH IGG4-RELATED DISEASE DIAGNOSED BY EXPERTS. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.944] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:While the diagnostic and classification criteria for IgG4-related disease (IgG4-RD) have been recently developed [1-3], it is known that, without appropriate exclusions, some non-IgG4-RDs may meet these criteria. In particular, hyper IL-6 syndromes, including Castleman disease, can be misdiagnosed as IgG4-RD. Some clinical findings, including elevated serum levels of C-reactive protein (CRP) or IgA, have been suggested to be useful for differentiating hyper IL-6 syndromes from IgG4-RD [4]. However, since few clinical studies have focused on IgG4-RD with high serum IgA levels, its clinical significance has not been well known.Objectives:This study aimed to clarify the clinical significance of high serum IgA levels in patients with IgG4-RD.Methods:We retrospectively investigated the clinical features of 170 patients with IgG4-RD on the basis of the presence or absence of elevated serum IgA levels (>410 mg/dL) at the time of diagnosis. The diagnosis of IgG4-RD was made by experts on the basis of the fulfillment of the comprehensive diagnostic criteria and/or each organ-specific diagnostic criteria.Results:Elevated serum IgA levels were observed in 18 patients (10.6%). In the patients with elevated serum IgA levels, serum CRP levels were higher (1.14 ± 1.18 vs. 0.31 ± 0.63 mg/dL, p=0.003) and the prevalence of relapse during the clinical course was lower (5.6% vs. 27.6%, p=0.046) than in those without elevated serum IgA levels. However, there were no significant differences in the other clinical features including the number of involved organs (2.4 ± 1.3 vs. 2.8 ± 1.6, p=0.443) and inclusion scores of the ACR/EULAR classification criteria (32 ± 14 vs. 36 ± 17, p=0.374). To evaluate the influence of serum IgA elevation on relapse, we performed Cox regression analysis, which showed that the elevated serum IgA levels had no significant association with lower incidence of relapse but a tendency of it (hazard ratio 0.997, 95% confidence interval 0.994-1.000, p=0.055) during the clinical course. In addition, a prompt improvement in the IgG4-RD responder index [5] during the clinical course was seen in the patients with serum IgA elevation, suggesting a similar good response to glucocorticoids as in those without it.Conclusion:The findings of the present study suggest that IgG4-RD patients with high serum IgA levels can be diagnosed and treated in the same way as those without it, although they may be characterized by mild serum CRP elevation.References:[1]Wallace ZS et al. The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-related disease. Ann Rheum Dis. 2020;79:77-87.[2]Umehara H et al. The 2020 Revised Comprehensive Diagnostic (RCD) Criteria for IgG4-RD. Mod Rheumatol. 2020 Dec 4:1-14. doi: 10.1080/14397595.2020.1859710. Online ahead of print.[3]Umehara H et al. Current approach to the diagnosis of IgG4-related disease - Combination of comprehensive diagnostic and organ - specific criteria. Mod Rheumatol. 2017;27:381-91.[4]Sato Y et al. Systemic IgG4-related lymphadenopathy: A clinical and pathologic comparison to multicentric Castleman’s disease. Mod Pathol.2009;22:589-99.[5]Carruthers MN et al. Development of an IgG4-RD Responder Index. Int J Rheumatol. 2012;2012:259408.Disclosure of Interests:None declared
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Mizushima I, Kawahara H, Yoshinobu T, Shin S, Hoshiba R, Nishioka R, Zoshima T, Hara S, Suzuki Y, Ito K, Kawano M. POS1348 MORTALITY AND ITS RELATED FACTORS IN PATIENTS WITH IGG4-RELATED DISEASE: A JAPANESE SINGLE-CENTER STUDY. Ann Rheum Dis 2021. [DOI: 10.1136/annrheumdis-2021-eular.1798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Background:In recent years, IgG4-related disease (IgG4-RD) has become a widely recognized disorder. However, mortality and its related factors in this disease are not well known.Objectives:This study aimed to clarify mortality and its related factors in patients with IgG4-RD.Methods:We retrospectively reviewed the medical records of patients with IgG4-RD diagnosed by experts based on fulfillment of the Japanese comprehensive diagnostic criteria and/or the 2019 ACR/EULAR classification criteria for IgG4-RD at a single center in Japan. Using the collected data, we calculated the crude mortality rate and the standardized mortality ratio (SMR) using national Japan mortality statistics and investigated the cause of death. We performed Cox regression analyses to assess mortality-related factors.Results:A total of 179 patients with IgG4-RD were included: 124 were male (69.3%); the median age was 68 years (interquartile range [IQR] 60-75 years); and the median follow-up from diagnosis was 47 months (IQR 17-84). Ten patients (5.6%) in our cohort died during the follow-up period. Five died of malignancy, one of respiratory failure, two of infectious pneumonia, one of sudden cardiac event, and one of suspected aortic aneurysmal rupture. The crude mortality rate was 11.1 per 1,000 person-years. According to national Japan mortality statistics, 11.6 age- and sex-matched deaths were expected to occur within the follow-up period, resulting in a SMR of 0.86 (95% confidence interval [CI] 0.41-1.59). Univariate Cox regression analyses indicated that the number of affected organs at diagnosis (hazard ratio [HR] 1.45, 95% CI 1.02-2.05), serum creatinine levels at diagnosis (HR 1.82, 95% CI 1.06-3.12), and the presence of malignancy during the clinical course (HR 3.93, 95% CI 1.10-14.02) had a significant impact on the time to death, whereas the other factors including age at diagnosis and serum C-reactive protein and IgG4 levels at diagnosis did not.Conclusion:Our findings suggest that the mortality rate of patients with IgG4-RD does not significantly differ from that of the Japanese general population. Multi-organ involvement and renal dysfunction at diagnosis as well as malignancy during the clinical course may be associated with higher mortality. An appropriate clinical evaluation for the early detection of these risk factors is required at first diagnosis and during long-term follow-up.Disclosure of Interests:None declared
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Guo Y, Werner CF, Handa S, Wang M, Ohshiro T, Mushiake H, Yoshinobu T. Miniature multiplexed label-free pH probe in vivo. Biosens Bioelectron 2021; 174:112870. [PMID: 33334636 DOI: 10.1016/j.bios.2020.112870] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2020] [Revised: 10/27/2020] [Accepted: 11/26/2020] [Indexed: 11/19/2022]
Abstract
Correlating in-brain pH fluctuations with the pathophysiology has been impeded by the lack of in vivo techniques to precisely determine local pH changes. Here, we developed an all-in-one pH probe for spatially-resolved and label-free pH sensing in vivo, based on a field-effect pH sensor, i.e., a light-addressable potentiometric sensor (LAPS), coupled to a flexible multimodal fiber. A readout photocurrent from the LAPS, elicited from a modulated light source, registers the localized surface potential change, proportional to the pH change. Upon simultaneous illuminations at multi-spot by a plurality of light sources with different modulation frequencies, pH changes at multiple designated spots are obtained via demultiplexing this photocurrent. To enable its in vivo applications, we combined the LAPS with a multimodal fiber fabricated by the convergence thermal drawing. Such fiber seamlessly integrates a multicore optical waveguide in the center for the light delivery, surrounded by electrodes for leading out photocurrent and serving as a pseudo-reference electrode, respectively. Such hybrid all-in-one pH probes can measure pH changes at 14 pixels simultaneously with a spatial resolution of 250 μm and a temporal resolution of 30 Hz. The pH sensitivity was characterized as 57.5 ± 2.2 mV/pH homogeneously across all measurable pixels. Such probes have been implanted into the hippocampal formation of rats and their capabilities to capture pH changes at multiple pixels were evaluated at both physiological and pathological conditions. Technologies developed here represents a new class of in vivo chemical sensing technologies enabling the spatially-resolved investigation of intrinsic chemical signals in deep brain structures with high spatial and temporal resolutions.
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Affiliation(s)
- Yuanyuan Guo
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Tohoku University, Sendai, Miyagi 9800845, Japan; Department of Physiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, 9808575, Japan; Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan.
| | - Carl Frederik Werner
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
| | - Shoma Handa
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
| | - Mengyun Wang
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
| | - Tomokazu Ohshiro
- Department of Physiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, 9808575, Japan
| | - Hajime Mushiake
- Department of Physiology, Graduate School of Medicine, Tohoku University, Sendai, Miyagi, 9808575, Japan
| | - Tatsuo Yoshinobu
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan; Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
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Nose K, Miyamoto KI, Yoshinobu T. Estimation of Potential Distribution during Crevice Corrosion through Analysis of I-V Curves Obtained by LAPS. Sensors (Basel) 2020; 20:s20102873. [PMID: 32438584 PMCID: PMC7287995 DOI: 10.3390/s20102873] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/19/2020] [Revised: 05/12/2020] [Accepted: 05/14/2020] [Indexed: 11/27/2022]
Abstract
Crevice corrosion is a type of local corrosion which occurs when a metal surface is confined in a narrow gap on the order of 10 μm filled with a solution. Because of the inaccessible geometry, experimental methods to analyze the inner space of the crevice have been limited. In this study, a light-addressable potentiometric sensor (LAPS) was employed to estimate the potential distribution inside the crevice owing to the IR drop by the anodic current flowing out of the structure. Before crevice corrosion, the I–V curve of the LAPS showed a potential shift, depending on the distance from the perimeter. The shift reflected the potential distribution due to the IR drop by the anodic current flowing out of the crevice. After crevice corrosion, the corrosion current increased exponentially, and a local pH change was detected where the corrosion was initiated. A simple model of the IR drop was used to calculate the crevice gap, which was 12 μm—a value close to the previously reported values. Thus, the simultaneous measurement of the I–V curves obtained using a LAPS during potentiostatic electrolysis could be applied as a new method for estimating the potential distribution in the crevice.
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Affiliation(s)
- Kiyomi Nose
- Material Performance Solution Center, Nippon Steel Technology Corporation, 20-1, Shintomi, Futtu 293-0011, Japan
- Correspondence:
| | - Ko-ichiro Miyamoto
- Department of Electronic Engineering, Tohoku University, 6-6, Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan; (K.-i.M.); (T.Y.)
| | - Tatsuo Yoshinobu
- Department of Electronic Engineering, Tohoku University, 6-6, Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan; (K.-i.M.); (T.Y.)
- Department of Biomedical Engineering, Tohoku University, 6-6, Aza-Aoba, Aramaki, Aoba-ku, Sendai 980-8579, Japan
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Guo Y, Werner CF, Canales A, Yu L, Jia X, Anikeeva P, Yoshinobu T. Polymer-fiber-coupled field-effect sensors for label-free deep brain recordings. PLoS One 2020; 15:e0228076. [PMID: 31978197 PMCID: PMC6980412 DOI: 10.1371/journal.pone.0228076] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 01/07/2020] [Indexed: 11/30/2022] Open
Abstract
Electrical recording permits direct readout of neural activity but offers limited ability to correlate it to the network topography. On the other hand, optical imaging reveals the architecture of neural circuits, but relies on bulky optics and fluorescent reporters whose signals are attenuated by the brain tissue. Here we introduce implantable devices to record brain activities based on the field effect, which can be further extended with capability of label-free electrophysiological mapping. Such devices reply on light-addressable potentiometric sensors (LAPS) coupled to polymer fibers with integrated electrodes and optical waveguide bundles. The LAPS utilizes the field effect to convert electrophysiological activity into regional carrier redistribution, and the neural activity is read out in a spatially resolved manner as a photocurrent induced by a modulated light beam. Spatially resolved photocurrent recordings were achieved by illuminating different pixels within the fiber bundles. These devices were applied to record local field potentials in the mouse hippocampus. In conjunction with the raster-scanning via the single modulated beam, this technology may enable fast label-free imaging of neural activity in deep brain regions.
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Affiliation(s)
- Yuanyuan Guo
- Frontier Research Institute for Interdisciplinary Sciences (FRIS), Graduate School of Medicine, Graduate School of Biomedical Engineering, Tohoku University, Sendai, Miyagi 9800845, Japan
| | - Carl F Werner
- Department of Electronic Engineering, Department of Biomedical Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
| | - Andres Canales
- Department of Materials Science and Engineering, Research Laboratory of Electronics, and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 24139, United States of America
| | - Li Yu
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, United States of America
| | - Xiaoting Jia
- Department of Materials Science and Engineering, Research Laboratory of Electronics, and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 24139, United States of America.,Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University, Blacksburg, VA 24060, United States of America
| | - Polina Anikeeva
- Department of Materials Science and Engineering, Research Laboratory of Electronics, and McGovern Institute for Brain Research, Massachusetts Institute of Technology, Cambridge, MA 24139, United States of America
| | - Tatsuo Yoshinobu
- Department of Electronic Engineering, Department of Biomedical Engineering, Tohoku University, Sendai, Miyagi, 9808579, Japan
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Guo Y, Jiang S, Grena BJB, Kimbrough IF, Thompson EG, Fink Y, Sontheimer H, Yoshinobu T, Jia X. Polymer Composite with Carbon Nanofibers Aligned during Thermal Drawing as a Microelectrode for Chronic Neural Interfaces. ACS Nano 2017; 11:6574-6585. [PMID: 28570813 DOI: 10.1021/acsnano.6b07550] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Microelectrodes provide a direct pathway to investigate brain activities electrically from the external world, which has advanced our fundamental understanding of brain functions and has been utilized for rehabilitative applications as brain-machine interfaces. However, minimizing the tissue response and prolonging the functional durations of these devices remain challenging. Therefore, the development of next-generation microelectrodes as neural interfaces is actively progressing from traditional inorganic materials toward biocompatible and functional organic materials with a miniature footprint, good flexibility, and reasonable robustness. In this study, we developed a miniaturized all polymer-based neural probe with carbon nanofiber (CNF) composites as recording electrodes via the scalable thermal drawing process. We demonstrated that in situ CNF unidirectional alignment can be achieved during the thermal drawing, which contributes to a drastic improvement of electrical conductivity by 2 orders of magnitude compared to a conventional polymer electrode, while still maintaining the mechanical compliance with brain tissues. The resulting neural probe has a miniature footprint, including a recording site with a reduced size comparable to a single neuron and maintained impedance that was able to capture neural activities. Its stable functionality as a chronic implant has been demonstrated with the long-term reliable electrophysiological recording with single-spike resolution and the minimal tissue response over the extended period of implantation in wild-type mice. Technology developed here can be applied to basic chronic electrophysiological studies as well as clinical implementation for neuro-rehabilitative applications.
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Affiliation(s)
- Yuanyuan Guo
- Department of Biomedical Engineering, Tohoku University , Sendai, Miyagi 9808579, Japan
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24060, United States
| | - Shan Jiang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24060, United States
| | - Benjamin J B Grena
- Department of Material Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 24139, United States
| | - Ian F Kimbrough
- Virginia Tech Carilion Research Institute , Roanoke, Virginia 14016, United States
| | - Emily G Thompson
- Virginia Tech Carilion Research Institute , Roanoke, Virginia 14016, United States
| | - Yoel Fink
- Department of Material Science and Engineering, Massachusetts Institute of Technology , Cambridge, Massachusetts 24139, United States
| | - Harald Sontheimer
- Virginia Tech Carilion Research Institute , Roanoke, Virginia 14016, United States
| | - Tatsuo Yoshinobu
- Department of Biomedical Engineering, Tohoku University , Sendai, Miyagi 9808579, Japan
| | - Xiaoting Jia
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State University , Blacksburg, Virginia 24060, United States
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Yoshinobu T, Miyamoto KI, Werner CF, Poghossian A, Wagner T, Schöning MJ. Light-Addressable Potentiometric Sensors for Quantitative Spatial Imaging of Chemical Species. Annu Rev Anal Chem (Palo Alto Calif) 2017; 10:225-246. [PMID: 28375701 DOI: 10.1146/annurev-anchem-061516-045158] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
A light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor, in which a measurement site on the sensing surface is defined by illumination. This light addressability can be applied to visualize the spatial distribution of pH or the concentration of a specific chemical species, with potential applications in the fields of chemistry, materials science, biology, and medicine. In this review, the features of this chemical imaging sensor technology are compared with those of other technologies. Instrumentation, principles of operation, and various measurement modes of chemical imaging sensor systems are described. The review discusses and summarizes state-of-the-art technologies, especially with regard to the spatial resolution and measurement speed; for example, a high spatial resolution in a submicron range and a readout speed in the range of several tens of thousands of pixels per second have been achieved with the LAPS. The possibility of combining this technology with microfluidic devices and other potential future developments are discussed.
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Affiliation(s)
- Tatsuo Yoshinobu
- Department of Biomedical Engineering, Tohoku University, Sendai 980-8579, Japan;
- Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| | - Ko-Ichiro Miyamoto
- Department of Electronic Engineering, Tohoku University, Sendai 980-8579, Japan
| | | | - Arshak Poghossian
- Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Jülich Campus, Jülich 52428, Germany
- Peter Grünberg Institute, Research Centre Jülich GmbH, Jülich 52425, Germany
| | - Torsten Wagner
- Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Jülich Campus, Jülich 52428, Germany
- Peter Grünberg Institute, Research Centre Jülich GmbH, Jülich 52425, Germany
| | - Michael J Schöning
- Institute of Nano- and Biotechnologies, Aachen University of Applied Sciences, Jülich Campus, Jülich 52428, Germany
- Peter Grünberg Institute, Research Centre Jülich GmbH, Jülich 52425, Germany
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Li XL, Liu SB, Fan PP, Werner CF, Miyamoto K, Yoshinobu T. An on-chip electroosmotic micropump with a light- addressable potentiometric sensor. ACTA ACUST UNITED AC 2017. [DOI: 10.1007/s11801-017-6264-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Miyamoto KI, Sakakita S, Wagner T, Schöning MJ, Yoshinobu T. Application of chemical imaging sensor to in-situ pH imaging in the vicinity of a corroding metal surface. Electrochim Acta 2015. [DOI: 10.1016/j.electacta.2015.07.184] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Miyamoto KI, Hirayama Y, Wagner T, Schöning MJ, Yoshinobu T. Visualization of enzymatic reaction in a microfluidic channel using chemical imaging sensor. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.08.089] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Kanoh S, Miyamoto K, Yoshinobu T. A P300-based BCI system for controlling computer cursor movement. Annu Int Conf IEEE Eng Med Biol Soc 2012; 2011:6405-8. [PMID: 22255804 DOI: 10.1109/iembs.2011.6091581] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
A P300-based BCI (brain-computer interface) system for controlling the movement of the cursor displayed on the computer screen was proposed and evaluated. On the LCD computer screen, the cursor was displayed with the surrounded eight small circles, each of which was blinked sequentially in a random order. Five healthy subjects were requested to gaze at one of the circles placed in the preferred direction. The P300 activities elicited by the random blink of the target circle were detected by pattern classifier and they were used to move the cursor to the same direction as the target circle. It was shown that all of the subjects could control the movement of the cursor to their preferred direction by moving their gaze point in a short distance. This system can be applied to the voluntary control of the movement of the computer cursor, and the navigation of robot or video camera, without using users' extremities.
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Affiliation(s)
- S Kanoh
- Department of Electronics and Intelligent Systems, Tohoku Institute of Technology, Yagiyama-Kasumicho 35-1, Taihaku, Sendai 982-8577, Japan.
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Wagner T, Shigiahara N, Miyamoto K, Suzurikawa J, Finger F, Schöning M, Yoshinobu T. Light-addressable Potentiometric Sensors and Light–addressable Electrodes as a Combined Sensor-and-manipulator Microsystem with High Flexibility. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.proeng.2012.09.290] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Kanoh S, Miyamoto KI, Yoshinobu T. Generation of spatial filters by ICA for detecting motor-related oscillatory EEG. Annu Int Conf IEEE Eng Med Biol Soc 2012; 2012:1703-1706. [PMID: 23366237 DOI: 10.1109/embc.2012.6346276] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
To detect the imagined limb movement from EEG for the use in BCI, the increase (ERS) and decrease (ERD) of the band power of the EEG originated from the sensorimotor cortex are commonly used. A spatial filter using neighboring channels is generally applied to the measured EEG for detecting such brain activity related to the motor imagery. However, the configuration and location of the spatial filter have been selected by the empirical method on trial-and-error basis. In this study, we recorded the EEG during motor imagery of left hand, right hand and feet from five subjects, and the ICA (independent component analysis) was applied to discover the spatial filters for extracting event-related EEG components of the motor imagery. It was suggested that the application of ICA might offer the experimenters appropriate local spatial filters, or at least, the "initial guess" for designing or selecting custom local spatial filters.
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Affiliation(s)
- Shin'ichiro Kanoh
- Department of Electronics and Intelligent Systems, Tohoku Institute of Technology, Yagiyama-Kasumicho 35-1, Taihaku, Sendai, 982-8577 Japan.
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Shanmugam K, Yoshinobu T, Moon W, Iwasaki H. Positive patterning of ferritin and fibronectin molecules on silicon by the atomic force microscopic anodic oxidation technique. J Nanosci Nanotechnol 2011; 11:3808-3813. [PMID: 21780372 DOI: 10.1166/jnn.2011.4171] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Oxide dots fabricated on silicon (111) by the Atomic Force Microscopy (AFM) anodic oxidation technique was used for the patterning of two different proteins namely, ferritin and fibronectin. Si surfaces were oxidized by the SC1 process and then modified with octadecyltrichlorosilane (OTS) for passivation. Oxide dots were fabricated by applying a bias voltage between the AFM probe and the silicon surface. Furthermore, surface functionalization of oxide dots was achieved through gamma-aminopropyltriethoxysilane (gamma-APTES) and glutaraldehye modification to establish a covalent bond between aldehydes and amino groups of protein molecules. Topographies after each modification steps were monitored by AFM. We were able to achieve positive patterning of ferritin molecules up to an average density of 6 x 10(9)/cm2 on gamma-APTES-covered dots, while 9 x 10(8)/cm2 of ferritin molecules remained on the OTS surface. In contrast to this observation, fibronectin molecules were patterned successfully only on oxide dots, and we did not observe any fibronectin molecules on the OTS surface.
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Affiliation(s)
- Kumaran Shanmugam
- Department of Biotechnology, Periyar Maniammai University, Vallam, Thanjavur 613403, Tamil Nadu, India
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Wagner T, Miyamoto K, Werner CF, Schöning MJ, Yoshinobu T. Utilising Digital Micro-Mirror Device (DMD) as Scanning Light Source for Light-Addressable Potentiometric Sensors (LAPS). ACTA ACUST UNITED AC 2011. [DOI: 10.1166/sl.2011.1620] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
ABSTRACTCarbonization dynamics of Si surfaces using a hydrocarbon gas molecular beam was investigated. In case of carbonizing atomically clean Si surfaces with C2H2, single crystalline 3C-SiC layers were obtained only In the narrow range of a substrate temperature near 780 °C. Control of surface reaction by a cap of very thin surface oxide layer and gradual increase of substrate temperature during carbonization were found to be effective in forming single crystalline 3C-SiC layers reproducibly.
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Abstract
AbstractA thin-film amorphous silicon (a-Si) deposited on a glass substrate was employed as a semiconductor material for the chemical imaging sensor, which can visualize the distribution of ion concentration in a solution. The sensing properties and the spatial resolution of the a-Si sensors were investigated. Nearly-Nernstian pH sensitivities and submicron resolution were demonstrated, which suggests the superior performance of the chemical imaging sensor based on thin-film a-Si.
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Kanoh S, Murayama YM, Miyamoto KI, Yoshinobu T, Kawashima R. A NIRS-based brain-computer interface system during motor imagery: system development and online feedback training. Annu Int Conf IEEE Eng Med Biol Soc 2010; 2009:594-7. [PMID: 19964231 DOI: 10.1109/iembs.2009.5333710] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
A brain-computer interface (BCI) to detect motor imagery from cerebrum hemodynamic data measured by NIRS (near-infrared spectroscopy) was constructed and the effect of the online feedback training for subjects was evaluated. Concentrations of Oxy- and deOxy-hemoglobin in the motor cortex during motor imagery of subject's right hand was measured by 52-channel NIRS system, and the mean magnitude of measured signal near C3 in the International 10-20 System was visually fed back online to the subject. On two out of three subjects, it was shown that the ratio between the averaged value and the standard deviation over trials (S/N ratio) of Oxy-hemoglobin signal elicited by the imagery of subject's right hand was increased by the 5-day online feedback training. Detailed investigation of the effect of the online feedback training on brain activities was left for further study.
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Affiliation(s)
- Shin'ichiro Kanoh
- Graduate School of Engineering, Tohoku University, Aoba-yama 6-6-05, Sendai, 980-8579 Japan.
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Miyamoto KI, Kaneko K, Matsuo A, Wagner T, Kanoha S, Schöning MJ, Yoshinobu T. Miniaturized chemical imaging sensor system using an OLED display panel. ACTA ACUST UNITED AC 2010. [DOI: 10.1016/j.proeng.2010.09.160] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Kanoh S, Miyamoto KI, Yoshinobu T. A brain-computer interface (BCI) system based on auditory stream segregation. Annu Int Conf IEEE Eng Med Biol Soc 2009; 2008:642-5. [PMID: 19162737 DOI: 10.1109/iembs.2008.4649234] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
An auditory brain-computer interface (BCI) which detected event-related potential (ERP) elicited by selective attention to one of the tone streams was proposed. Each tone in two kinds of frequency oddball tone sequences with different tone frequency range was presented alternatively to subjects, and they were perceived by subjects as two kinds of segregated streams. Event-related potentials elicited by two kinds of deviant tones were classified by linear discriminant analysis (LDA) to find which streams subjects paid selective attention. By the experiments to six subjects, it was shown that this system could realize binary selection from two kinds of segregated tone streams.
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Affiliation(s)
- Shin'ichiro Kanoh
- Department of Electronic Engineering, Graduate School of Engineering, Tohoku University, 980-8579 Sendai, Miyagi, Japan.
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Wagner T, Molina R, Yoshinobu T, Kloock JP, Biselli M, Canzoneri M, Schnitzler T, Schöning MJ. Handheld multi-channel LAPS device as a transducer platform for possible biological and chemical multi-sensor applications. Electrochim Acta 2007. [DOI: 10.1016/j.electacta.2007.04.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Liu H, Nishitani R, Ie Y, Sudoh K, Nowicki M, Yoshinobu T, Aso Y, Iwasaki H. Molecular fluorescence from H2TBP porphyrin film on Ag substrate excited by tunneling electrons. Ultramicroscopy 2006; 106:785-8. [PMID: 16675124 DOI: 10.1016/j.ultramic.2006.01.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Accepted: 01/20/2006] [Indexed: 10/24/2022]
Abstract
Molecular fluorescence from H(2)TBP porphyrin (H(2)TBPP) films on Ag substrate is excited by a scanning tunneling microscope (STM) at ambient conditions. The molecular films are prepared by spin-casting method. The thickness of films can be controlled by the times of dropping H(2)TBPP solution. Molecular fluorescence of as-above prepared H(2)TBPP films with 4-14nm thickness at both polarities of applied bias voltage are well defined in good matching with its photoluminescence spectrum, which suggests the same decay channel associated with the HOMO-LUMO radiative transitions similar to H(2)TBPP/Au. The thickness dependence of light emission intensity of molecular fluorescence has been studied. The results show that for thicker film, molecular fluoresceence tends to be much stronger due to the effective decoupling of the emitter from the metal substrate.
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Affiliation(s)
- Hongwen Liu
- The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan.
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Yoshinobu T, Iwasaki H, Ui Y, Furuichi K, Ermolenko Y, Mourzina Y, Wagner T, Näther N, Schöning MJ. The light-addressable potentiometric sensor for multi-ion sensing and imaging. Methods 2005; 37:94-102. [PMID: 16199169 DOI: 10.1016/j.ymeth.2005.05.020] [Citation(s) in RCA: 126] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2005] [Accepted: 05/01/2005] [Indexed: 11/25/2022] Open
Abstract
The light-addressable potentiometric sensor (LAPS) is a semiconductor-based chemical sensor with an electrolyte-insulator-semiconductor structure. The LAPS can have many measuring points integrated on the sensing surface, which are individually accessed by a light beam. By modifying the measuring points with different materials, a single sensor plate can be used as a multi-analyte sensor. In this paper, instrumentation and application of LAPS to multi-ion sensing and imaging are described. As a new application of LAPS, potentiometric imaging of a microfluidic channel is proposed.
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Affiliation(s)
- T Yoshinobu
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan.
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Ismail ABM, Yoshinobu T, Iwasaki H, Sugihara H, Yukimasa T, Hirata I, Iwata H. Investigation on light-addressable potentiometric sensor as a possible cell-semiconductor hybrid. Biosens Bioelectron 2003; 18:1509-14. [PMID: 12941567 DOI: 10.1016/s0956-5663(03)00129-5] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
This article reports an investigation on light-addressable potentiometric sensor (LAPS) to be used as a possible biological cell-semiconductor hybrid that will enable us to make an interface between the physical and biological system. To increase the surface potential sensitivity, we used a LAPS structure with single insulator (SiO2) coated with poly-L-ornithine and laminin (PLOL) on Si. Efficient culturing of PC-12 and nerve cells of Lymnaea stagnalis on PLOL-coated Si3N4 and SiO2 was achieved. The thickness of the PLOL layer was found to be about 4 nm by the atomic force microscope (AFM) measurement. Using the advantage of this thin layer of PLOL, we compared the performance of a novel structure to the previously reported "PLOL-coated Si3N4/SiO2/Si" structure. Due to high insulating capacitance, the photocurrent response of the novel LAPS was found to be very steep. As a result, higher sensitivity was achieved. This steepness did not degrade during 10 days when the sensor surface was kept in contact with the cell culture medium and environment. The thickness of PLOL layer, its ability to improve the biological cell adhesion, enhanced sensitivity, and experiment with simulated neural action potential (AP) applied to the novel LAPS show a good promise for LAPS to be a biological cell-semiconductor hybrid.
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Affiliation(s)
- Abu Bakar Md Ismail
- Department of Applied Physics and Electronics, Rajshahi University, Rajshahi 6205, Bangladesh.
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Kodera S, Okajima T, Iwabuki H, Kitaguchi D, Kuroda S, Yoshinobu T, Tanizawa K, Futai M, Iwasaki H. Detection of protein-protein interactions on SiO2/Si surfaces by spectroscopic ellipsometry. Anal Biochem 2003; 321:65-70. [PMID: 12963056 DOI: 10.1016/s0003-2697(03)00422-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have applied spectroscopic ellipsometry to sensitive detection of specific protein-protein interactions on SiO2/Si substrates. First, the change of ellipticity of the reflected polarized light (600-1100 nm) was correlated with the thickness of the protein layer immobilized on SiO2/Si surfaces by measuring monomeric (myoglobin) and homotetrameric (hemoglobin) proteins with a similar monomer size. Protein-protein interactions were then measured with the antigen/antibody and cell-surface receptor/ligand systems; in each system either of the two proteins was bound to SiO2/Si substrates. Consequently, significant ellipticity changes were observed only for the cases where the interactions were specific. A specific antibody binding was also detectable with an antigen displayed on the surface of bacteriophage particles. These results show the usefulness of spectroscopic ellipsometry for sensitive detection of protein-protein interactions and its applicability to a detection method for the protein-based biochips to be developed in the future.
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Affiliation(s)
- Seigo Kodera
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Osaka 567-0047, Japan
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29
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Yoshinobu T, Suzuki J, Kurooka H, Moon W, Iwasaki H. AFM fabrication of oxide patterns and immobilization of biomolecules on Si surface. Electrochim Acta 2003. [DOI: 10.1016/s0013-4686(03)00342-6] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Yoshinobu T, Ecken H, Md. Ismail A, Iwasaki H, Lüth H, Schöning M. Chemical imaging sensor and its application to biological systems. Electrochim Acta 2001. [DOI: 10.1016/s0013-4686(01)00564-3] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Antoranz Contera S, Yoshinobu T, Iwasaki H, Bastl Z, Losták P. Atomic surface characterisation and modification of the layered compounds Bi2Se3, Bi1.9Sb0.1Se3 and Bi1.6Sb0.4Se3. Ultramicroscopy 2001; 86:55-61. [PMID: 11215634 DOI: 10.1016/s0304-3991(00)00088-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
In this work, we show atomic STM images of the layered compound Bi2Se3. We study the effect in the surface of the substitution of 5% and 20% of the Bi atoms for Sb in Bi1.9Sb0.1Se3 and Bi1.6Sb0.4Se3. The images of the three samples show similar trigonal structures corresponding probably to the van der Waals Se atoms. The distance measured between surface atoms in Bi2Se3 is 4.04 A, in Bi1.9Sb0.1Se3 is 4.16 A and in Bi1.6Sb0.4Se3 is 4.26 A. In Bi1.6Sb0.4Se3 some atomic sites appear brighter than others. The effect is accentuated at higher tunnelling currents and is not observed in the other compounds. Nanoscopic range depressions on the sample might be related to the skeletal crystal structure since the images show atomic corrugations that align slightly in one direction. We explain the results as the effects of the interactions between tip and sample, and discuss two interpretations: on the one hand, localised depression of the individual atomic sites, and on the other the possible elevation of the atoms of the surface due to a phase transition of the compounds induced by STM.
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Affiliation(s)
- S Antoranz Contera
- The Institute of Scientific and Industrial Research (ISIR), Osaka University, Ibaraki, Osaka, Japan.
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Abstract
Atomic force microscopy (AFM) has been used for tribological studies of Si surfaces covered by oxide layers of various kinds: chemical oxides prepared by the SC1 (NH4OH/H2O2/H2O) and the SC2 (HCl/H2O2/H2O) treatments and a thermal oxide. In the case of the SC1 chemical oxide, the oxide layer was scratched and the underlying Si substrate was ploughed by the Si3N4 AFM tip. On the other hand, no wear of the sample was noted on the other surfaces: the AFM often produced elevated patterns in the shape of the scanned area, which were no longer visible after HF etching. By annealing the SC1-treated surface in N2 gas at above 200 degrees C for 30 min, the oxide layer could not be scratched any more. By soaking the thermal oxide in KOH, the oxide layer was then scratched. It is concluded that the presence of OH bases is the necessary condition for the nano-scratching of the oxide layers.
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Affiliation(s)
- W C Moon
- The Institute of Scientifical and Industrial Research, Osaka University, Ibaraki, Japan.
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Akagi T, Okazaki N, Yoshinobu T, Matsumura-Inoue T. Comparative study of chemical waves and temporal oscillations in the Ru(bpy)32+-catalyzed photosensitive Belousov–Zhabotinsky reaction. Chem Phys Lett 2000. [DOI: 10.1016/s0009-2614(00)00907-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Suzuki K, Yoshinobu T, Iwasaki H. Unidirectional Propagation of Chemical Waves through Microgaps between Zones with Different Excitability. J Phys Chem A 2000. [DOI: 10.1021/jp0007078] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Kenji Suzuki
- The Institute of Scientific and Industrial Research, Osaka University, 8−1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Tatsuo Yoshinobu
- The Institute of Scientific and Industrial Research, Osaka University, 8−1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Hiroshi Iwasaki
- The Institute of Scientific and Industrial Research, Osaka University, 8−1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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Affiliation(s)
- Kenji Suzuki
- The Institute of Scientific and Industrial Research, Osaka University, 8−1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Tatsuo Yoshinobu
- The Institute of Scientific and Industrial Research, Osaka University, 8−1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Hiroshi Iwasaki
- The Institute of Scientific and Industrial Research, Osaka University, 8−1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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Abstract
DNA computing is a novel method of computing proposed by Adleman (1994), in which the data is encoded in the sequences of oligonucleotides. Massively parallel reactions between oligonucleotides are expected to make it possible to solve huge problems. In this study, reliability of the ligation process employed in the DNA computing is tested by estimating the error rate at which wrong oligonucleotides are ligated. Ligation of wrong oligonucleotides would result in a wrong answer in the DNA computing. The dependence of the error rate on the number of mismatches between oligonucleotides and on the combination of bases is investigated.
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Affiliation(s)
- Y Aoi
- The Institute of Scientific and Industrial Research, Osaka University, Ibaraki, Japan
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Iwamoto A, Yoshinobu T, Iwasaki H. Kinetic roughening in electrodissolution of copper. Phys Rev E Stat Phys Plasmas Fluids Relat Interdiscip Topics 1999; 59:5133-6. [PMID: 11969469 DOI: 10.1103/physreve.59.5133] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/1998] [Indexed: 04/18/2023]
Abstract
We studied kinetic roughening of copper surfaces electrochemically dissolved at constant current densities by atomic force microscopy. The surface was found to roughen with time and the surface width increased with the length scale with the roughness exponent alpha of 0.73+/-0.05 in the stationary state. This value is different from that in electrochemical deposition, 0.87, under the stable growth condition [A. Iwamoto et al., Phys. Rev. Lett. 72, 4025 (1994)]. The observed roughening in the dissolution process is discussed in terms of nonlocal effects.
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Affiliation(s)
- A Iwamoto
- The Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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Daido H, Schulz MS, Murai K, Kodama R, Yuan G, Goto J, Tanaka KA, Kato Y, Nakai S, Shinohara K, Honda T, Kodama I, Iwasaki H, Yoshinobu T, Tsukamoto M, Niibe M, Fukuda Y, Neely D, Macphee A, Slark G. Subnanosecond In-Line Soft X-Ray Holography Using Germanium Laser in the 20 nm Wavelength Region. J Xray Sci Technol 1995; 5:105-120. [PMID: 21307481 DOI: 10.3233/xst-1995-5109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Near- and far-field characteristics of a germanium soft x-ray laser at the wavelengths of 23.2-23.6 nm (J = 2-1 transitions) and 19.6 nm (J = 0-1 transition) are given for quantitative evaluation of the germanium laser for holographic applications. In-line Gabor holography of simple structured objects, such as thin opaque fibers and a standard electron microscope test specimen, is demonstrated. The holograms were recorded on PMMA (polymethyl methacrylate) photoresists and llford Q-plates. The holograms recorded on PMMA were retrieved with an atomic force microscope. The object image was reconstructed by numerical reconstruction with phase retrieval algorithm, resulting in a clear, ghost-free image with sharp edges which infer sub-μm resolution. Future directions for x-ray laser holography are briefly discussed.
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Affiliation(s)
- H Daido
- Instituie of Laser Engineering, Osaka University, 2-6 Yamada-oka, Suita, Osaka 565, Japan
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Nakao M, Inoue S, Oishi R, Yoshinobu T, Iwasaki H. Observation of microorganism colonies using a scanning-laser-beam pH-sensing microscope. ACTA ACUST UNITED AC 1995. [DOI: 10.1016/0922-338x(95)94085-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Omori K, Ohata M, Irako M, Kitamura K, Namiki Y, Muramatsu T, Nagasaka F, Nishimura O, Sezai Y, Yoshinobu T. [Treatment of pericardial cyst under thoracoscopy]. Kyobu Geka 1992; 45:217-21. [PMID: 1552674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Thoracoscopic therapy was carried out on two cases of pericardial cyst. The first patient was a 24-year-old male. An abnormal shadow on a chest X-ray was pointed out at a regular checkup. Thoracoscopy was carried out under the local anesthesia and a thin-walled cyst was discovered. The cyst was punctured and serous fluid was aspirated. Then, several biopsy specimens were obtained from the cyst wall, a pathological diagnosis of the cyst was made as a pericardial cyst. One year after the thoracoscopy, no abnormal shadow is observed on chest X-ray. The second patient was a 26-year-old male. It was also discovered that he had an abnormal shadow on a chest X-ray at a regular medical checkup. Since a solid mass couldn't be completely denied, thoracoscopy was carried out in preparing for thoracotomy under the general anesthesia. The cyst observed between SVC and the azygos vein, and serous fluid was aspirated form the cyst. Following this, the cyst wall was biopsied and opened. Since no cases of malignant pericardial cysts have been reported, an operation is not usually required for these patients. We suggest that thoracoscopy is very useful tool for the final diagnosis and therapy of pericardial cyst because this method is easily carried out under local anesthesia.
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Affiliation(s)
- K Omori
- Second Department of Surgery, Nihon University School of Medicine
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Mogi M, Motohashi M, Hirota T, Ohshima K, Takahashi N, Kinoshita Y, Tanigawa M, Yoshinobu T, Koya Y, Masutani M. [Basic study on the chemosensitivity test by miniaturized improved nucleic acid precursor incorporation assay (MINI assay)]. Gan To Kagaku Ryoho 1990; 17:89-95. [PMID: 1688701] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
UNLABELLED Miniaturized improved nucleic acid precursor incorporation assay (MINI assay) has been developed by Kern D. H. and Tanigawa N. et al since 1985. We investigated in vitro effects of mitomycin C (MMC), cisplatin (CDDP) and bleomycin (BLM) against A 549 lung cancer cells and HeLa cells by MINI assay. RESULTS 3H-thymidine (3H-TdR) uptake in the positive control was 734.2 cpm +/- 10 cpm. The cut-off level for in vitro sensitivity was defined as more than 80% inhibition of 3H-TdR uptake in the drug treated cells compared to the positive controls. A 549 cells were sensitive to MMC (81.6%), CDDP (78.6%), but not to BLM (-57%). HeLa cells were sensitive to MMC (91%), CDDP (79.4%), but not to BLM (43%). MINI assay could be done with fewer cells than other methods and the results were obtained within 5 days. This method was considered to be useful for the chemosensitivity test with human tumors.
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Affiliation(s)
- M Mogi
- First Dept. of Internal Medicine, Nihon University School of Medicine
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Hashimoto S, Hosokawa Y, Kawamura K, Yoshinobu T, Hagiwara T, Hirano A, Kojima K, Yamaguchi M, Nagao K, Horie T. [Significance of a tuberculous ward of Nihon University Hospital--from the experience during the past 10 years]. Kekkaku 1985; 60:389-95. [PMID: 4046280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Igarashi M, Yoshinobu T. Comparative cochlear reconstruction in mammals. NSAM-931. Res Rep U S Nav Sch Aviat Med 1965:1-12. [PMID: 5294800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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