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Sample records for high sensitivity micro

  1. High sensitivity PCR assay in plastic micro reactors.

    Science.gov (United States)

    Yang, Jianing; Liu, Yingjie; Rauch, Cory B; Stevens, Rauch L; Liu, Randall H; Lenigk, Robin; Grodzinski, Piotr

    2002-11-01

    Small volume operation and rapid thermal cycling have been subjects of numerous reports in micro reactor chip development. Sensitivity aspects of the micro PCR reactor have not been studied in detail, however, despite the fact that detection of rare targets or trace genomic material from clinical and/or environmental samples has been a great challenge for microfluidic devices. In this study, a serpentine shaped thin (0.75 mm) polycarbonate plastic PCR micro reactor was designed, constructed, and tested for not only its rapid operation and efficiency, but also its detection sensitivity and specificity, in amplification of Escherichia coli (E. coli) K12-specific gene fragment. At a template concentration as low as 10 E. coli cells (equivalent to 50 fg genomic DNA), a K12-specific gene product (221 bp) was adequately amplified with a total of 30 cycles in 30 min. Sensitivity of the PCR micro reactor was demonstrated with its ability to amplify K12-specific gene from 10 cells in the presence of 2% blood. Specificity of the polycarbonate PCR micro reactor was also proven through multiplex PCR and/or amplification of different pathogen-specific genes. This is, to our knowledge, the first systematic study of assay sensitivity and specificity performed in plastic, disposable micro PCR devices.

  2. [A high sensitivity micro-ring humidity sensor based on U-shaped waveguide coupled single micro-ring structure].

    Science.gov (United States)

    Li, Zhi-quan; Wang, Lu-na; Li, Xin; Zhang, Xin

    2015-02-01

    The paper proposes a novel high sensitivity humidity sensor based on a U-shaped waveguide-coupled single micro-ring, Polyimide is used as the wet material, the refractive index of humidity-sensing part changes as relative humidity changes, thus leading to a obvious peak drift. The transfer function of the structure is derived basing on transfer matrix method and the paper mainly discusses the influence on the output spectrum with different humidity-sensing parts. Through the theoretical simulation of Matlab, the whole structure of U-shaped waveguide coupled single micro-ring is proved to be the best humidity-sensing part. The free spectral range (FSR) will be doubled compared to the traditional single micro ring structure while the length between the two coupling points of the U-shaped waveguide is an integer multiple of circumference of the micro-ring. When the relative humidity of external environment changes from 10% RH to 100% RH, the output spectrum appears a obvious drift from 0.027 to 0.191 microm and the sensitivity reaches up to 0.0018 microm/% RH. Compared to FBG humidity sensor with high sensitivity, the sensitivity in this article is increased by 10 to 100 times, achieving a high sensitivity in the sense of humidity when the wide range of filter frequency selection is taken into account.

  3. High-Q Fabry–Pérot Micro-Cavities for High-Sensitivity Volume Refractometry

    Directory of Open Access Journals (Sweden)

    Noha Gaber

    2018-01-01

    Full Text Available This work reports a novel structure for a Fabry–Pérot micro cavity that combines the highest reported quality factor for an on-chip Fabry–Pérot resonator that exceeds 9800, and a very high sensitivity for an on-chip volume refractometer based on a Fabry–Pérot cavity that is about 1000 nm/refractive index unit (RIU. The structure consists of two cylindrical Bragg micromirrors that achieve confinement of the Gaussian beam in the plan parallel to the chip substrate, while for the perpendicular plan, external fiber rod lenses (FRLs are placed in the optical path of the input and the output of the cavity. This novel structure overcomes number of the drawbacks presented in previous designs. The analyte is passed between the mirrors, enabling its detection from the resonance peak wavelengths of the transmission spectra. Mixtures of ethanol and deionized (DI-water with different ratios are used as analytes with different refractive indices to exploit the device as a micro-opto-fluidic refractometer. The design criteria are detailed and the modeling is based on Gaussian-optics equations, which depicts a scenario closer to reality than the usually used ray-optics modeling.

  4. High temperature gradient nanogap-Pirani micro-sensor with maximum sensitivity around atmospheric pressure

    Science.gov (United States)

    Ghouila-Houri, C.; Talbi, A.; Viard, R.; Moutaouekkil, M.; Elmazria, O.; Gallas, Q.; Garnier, E.; Merlen, A.; Pernod, P.

    2017-09-01

    This letter describes and discusses the design and testing of an efficient nanogap Pirani micro-sensor for pressure measurements in a wide range with a maximum sensitivity around atmospheric pressure. The structure combines a substrate-free heated wire and a mechanical support made of silicon oxide micro-bridges allowing both a constant nanoscale gap between the wire and the substrate and a 1 mm long and 3 μm wide wire. The high aspect ratio of the wire provides a uniform heating profile along the wire and contributes to low pressure detection. On the contrary, both the nanoscale gap and the short wire length between two micro-bridges contribute to shift the high limit of the pressure range. When tested between 10 kPa and 800 kPa, the sensor presents a wide measurement range, not fully reached by the experiments, with a maximum of sensitivity close to the atmospheric pressure and performances with up to 38%/dec sensitivity when operating in a constant temperature mode with an overheat of 20 °C.

  5. High-Sensitivity Encoder-Like Micro Area-Changed Capacitive Transducer for a Nano-g Micro Accelerometer.

    Science.gov (United States)

    Wu, Wenjie; Zheng, Panpan; Liu, Jinquan; Li, Zhu; Fan, Ji; Liu, Huafeng; Tu, Liangcheng

    2017-09-20

    Encoder-like micro area-changed capacitive transducers are advantageous in terms of their better linearity and larger dynamic range compared to gap-changed capacitive transducers. Such transducers have been widely applied in rectilinear and rotational position sensors, lab-on-a-chip applications and bio-sensors. However, a complete model accounting for both the parasitic capacitance and fringe effect in area-changed capacitive transducers has not yet been developed. This paper presents a complete model for this type of transducer applied to a high-resolution micro accelerometer that was verified by both simulations and experiments. A novel optimization method involving the insertion of photosensitive polyimide was used to reduce the parasitic capacitance, and the capacitor spacing was decreased to overcome the fringe effect. The sensitivity of the optimized transducer was approximately 46 pF/mm, which was nearly 40 times higher than that of our previous transducer. The displacement detection resolution was measured as 50 pm/√Hz at 0.1 Hz using a precise capacitance detection circuit. Then, the transducer was applied to a sandwich in-plane micro accelerometer, and the measured level of the accelerometer was approximately 30 ng/√Hz at 1Hz. The earthquake that occurred in Taiwan was also detected during a continuous gravity measurement.

  6. High-Sensitivity Encoder-Like Micro Area-Changed Capacitive Transducer for a Nano-g Micro Accelerometer

    Directory of Open Access Journals (Sweden)

    Wenjie Wu

    2017-09-01

    Full Text Available Encoder-like micro area-changed capacitive transducers are advantageous in terms of their better linearity and larger dynamic range compared to gap-changed capacitive transducers. Such transducers have been widely applied in rectilinear and rotational position sensors, lab-on-a-chip applications and bio-sensors. However, a complete model accounting for both the parasitic capacitance and fringe effect in area-changed capacitive transducers has not yet been developed. This paper presents a complete model for this type of transducer applied to a high-resolution micro accelerometer that was verified by both simulations and experiments. A novel optimization method involving the insertion of photosensitive polyimide was used to reduce the parasitic capacitance, and the capacitor spacing was decreased to overcome the fringe effect. The sensitivity of the optimized transducer was approximately 46 pF/mm, which was nearly 40 times higher than that of our previous transducer. The displacement detection resolution was measured as 50 pm/√Hz at 0.1 Hz using a precise capacitance detection circuit. Then, the transducer was applied to a sandwich in-plane micro accelerometer, and the measured level of the accelerometer was approximately 30 ng/√Hz at 1Hz. The earthquake that occurred in Taiwan was also detected during a continuous gravity measurement.

  7. A Micro Saddle Coil with Switchable Sensitivity for Local High-Resolution Imaging of Luminal Tissue

    Directory of Open Access Journals (Sweden)

    Tetsuji Dohi

    2016-04-01

    Full Text Available This paper reports on a micro saddle coil for local high-resolution magnetic resonance imaging (MRI fabricated by embedding a flexible coil pattern into a polydimethyilsiloxane (PDMS tube. We can change the sensitivity of the micro coil by deforming the shape of the coil from a saddle-shaped mode to a planar-shaped mode. The inductance, the resistance, and the Q-factor of the coil in the saddle-shaped mode were 2.45 μH, 3.31 Ω, and 39.9, respectively. Those of the planar-shaped mode were 3.07 μH, 3.92 Ω, and 42.9, respectively. In MRI acquired in saddle-shaped mode, a large visible area existed around the coil. Although the sensitive area was considerably reduced in the planar-shaped mode, clear MRI images were obtained. The signal-to-noise ratios (SNR of the saddle-shaped and planar-shaped modes were 194.9 and 505.9, respectively, at voxel size of 2.0 × 2.0 × 2.0 mm3 and 11.7 and 37.4, respectively, at voxel size of 0.5 × 0.5 × 1.0 mm3. The sensitivity of the saddle-shaped and the planar-shaped modes were about 3 times and 10 times higher, respectively, than those of the medical head coil at both voxel sizes. Thus, the micro saddle coil enabled large-area imaging and highly sensitive imaging by switching the shape of the coil.

  8. Malaria pigment crystals as magnetic micro-rotors: key for high-sensitivity diagnosis

    CERN Document Server

    Butykai, A; Kocsis, V; Szaller, D; Bordacs, S; Tatrai-Szekeres, E; Kiss, L F; Bota, A; Vertessy, B G; Zelles, T; Kezsmarki, I

    2012-01-01

    The need to develop new methods for the high-sensitivity diagnosis of malaria has initiated a global activity in medical and interdisciplinary sciences. Most of the diverse variety of emerging techniques are based on research-grade instruments, sophisticated reagent-based assays or rely on expertise. Here, we suggest an alternative optical methodology with an easy-to-use and cost-effective instrumentation, which takes advantage of the unique properties of malaria pigment revealed in the present study. Malaria pigment, also called hemozoin, is an insoluble microcrystalline form of heme. We found that these crystallites show remarkable magnetic and optical anisotropy distinctly from any other components of blood. In suspensions they can simultaneously act as magnetically driven micro-rotors and spinning polarizers. These properties can gain fundamental importance not only in the diagnosis of malaria and in therapies, where hemozoin is considered as drug target or immune modulator, but generally in the magnetic ...

  9. A facile and high sensitive micro fluorimeter based on light emitting diode and photodiode.

    Science.gov (United States)

    Geng, Xuhui; Gao, Yan; Feng, Chunbo; Guan, Yafeng

    2017-12-01

    A facile and high sensitive micro fluorimeter was developed and evaluated. It employed light emitting diode (LED) as light source, cuvette as detection cell, and photodiode (PD) as optoelectronic detector. Optical and electronic parameters were optimized and demonstrated. A high power LED was chosen, which could irradiate the inner area of the cuvette completely at the same time with divergence angle as small as possible. The optimum LED brought 2.5 times signal-to-noise ratio (SNR) enhancement. Using reflector at the opposite direction of excitation light path doubled SNR. The amplifier circuit of PD was deeply investigated to achieve high sensitivity, low noise, and good stability. The limit of detection (LOD) of fluorescein isothiocyanate (FITC) and chlorophyll at SNR = 3 were 10pM ~ 0.004 ppb and 0.05 ppb, respectively. Basing on the principle structure, a portable fluorimeter for fungimycin detection was developed using a low power UV LED as light source. The LOD for aflatoxin B1 was 0.1 ppb. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Molecular structure and thermodynamic predictions to create highly sensitive microRNA biosensors

    Energy Technology Data Exchange (ETDEWEB)

    Larkey, Nicholas E.; Brucks, Corinne N.; Lansing, Shan S.; Le, Sophia D.; Smith, Natasha M.; Tran, Victoria; Zhang, Lulu; Burrows, Sean M., E-mail: sean.burrows@oregonstate.edu

    2016-02-25

    Many studies have established microRNAs (miRNAs) as post-transcriptional regulators in a variety of intracellular molecular processes. Abnormal changes in miRNA have been associated with several diseases. However, these changes are sometimes subtle and occur at nanomolar levels or lower. Several biosensing hurdles for in situ cellular/tissue analysis of miRNA limit detection of small amounts of miRNA. Of these limitations the most challenging are selectivity and sensor degradation creating high background signals and false signals. Recently we developed a reporter+probe biosensor for let-7a that showed potential to mitigate false signal from sensor degradation. Here we designed reporter+probe biosensors for miR-26a-2-3p and miR-27a-5p to better understand the effect of thermodynamics and molecular structures of the biosensor constituents on the analytical performance. Signal changes from interactions between Cy3 and Cy5 on the reporters were used to understand structural aspects of the reporter designs. Theoretical thermodynamic values, single stranded conformations, hetero- and homodimerization structures, and equilibrium concentrations of the reporters and probes were used to interpret the experimental observations. Studies of the sensitivity and selectivity revealed 5–9 nM detection limits in the presence and absence of interfering off-analyte miRNAs. These studies will aid in determining how to rationally design reporter+probe biosensors to overcome hurdles associated with highly sensitive miRNA biosensing. - Highlights: • Challenges facing highly sensitive miRNA biosensor designs are addressed. • Thermodynamic and molecular structure design metrics for reporter+probe biosensors are proposed. • The influence of ideal and non-ideal reporter hairpin structures on reporter+probe formation and signal change are discussed. • 5–9 nM limits of detection were observed with no interference from off-analytes.

  11. Highly sensitive methane catalytic combustion micro-sensor based on mesoporous structure and nano-catalyst.

    Science.gov (United States)

    Su, Jiacan; Cao, Liehu; Li, Liang; Wei, Jie; Li, Gengnan; Yuan, Yinyin

    2013-10-21

    In order to get a methane catalytic combustion micro-sensor, two different catalytic systems used in traditional methane catalytic combustion sensors were fabricated into a mesoporous structure and their catalytic activities were investigated. In comparison, the Rh2O3-Al2O3 system can form more a uniform mesoporous structure and has a much higher specific surface area. Even more importantly, it has relatively higher catalytic activity and stability for the methane catalytic combustion reaction. After being coated on a microelectro-mechanical system (MEMS) micro-heater, a catalytic combustion type methane micro-sensor was fabricated. The meso-structured Rh2O3-Al2O3 hybrid based MEMS sensor demonstrated a short T90 response time, relatively high signal output, high enough signal/noise ratio for practical detecting and strong anti-poison properties.

  12. A Concept for a Sensitive Micro Total Analysis System for High Throughput Fluorescence Imaging

    OpenAIRE

    Rabner, Arthur; Shacham, Yosi

    2006-01-01

    This paper discusses possible methods for on-chip fluorescent imaging for integrated bio-sensors. The integration of optical and electro-optical accessories, according to suggested methods, can improve the performance of fluorescence imaging. It can boost the signal to background ratio by a few orders of magnitudes in comparison to conventional discrete setups. The methods that are present in this paper are oriented towards building reproducible arrays for high-throughput micro total analysis...

  13. High sensitive temperature sensor based on a polymer waveguide integrated in an optical fibre micro-cavity

    Science.gov (United States)

    Liu, Yi; Li, Min; Zhao, Panjuan; Wang, Xinshun; Qu, Shiliang

    2018-01-01

    A Mach–Zehnder interferometer (MZI) based on a polymer waveguide integrated in an optical fibre micro-cavity was proposed. The micro-cavity with two symmetric openings was fabricated in single mode fibre by using femtosecond laser micromachining and fibre splicing. Then, the polymer waveguide with a length of 70 μm was integrated into the micro-cavity by using a two-photon polymerization fabrication method. The MZI exhibited a perfect interference spectrum with a fringe visibility of almost 25 dB. Owing to the high thermo-optical coefficient of the polymer material, the temperature sensitivity of the proposed MZI reached 447 pm/°C. Meanwhile, it can be used as a reliable temperature sensor as its perfect linearity (99.7%) and repeatability.

  14. A Concept for a Sensitive Micro Total Analysis System for High Throughput Fluorescence Imaging

    Directory of Open Access Journals (Sweden)

    Yosi Shacham

    2006-04-01

    Full Text Available This paper discusses possible methods for on-chip fluorescent imaging forintegrated bio-sensors. The integration of optical and electro-optical accessories, accordingto suggested methods, can improve the performance of fluorescence imaging. It can boostthe signal to background ratio by a few orders of magnitudes in comparison to conventionaldiscrete setups. The methods that are present in this paper are oriented towards buildingreproducible arrays for high-throughput micro total analysis systems (μTAS. The firstmethod relates to side illumination of the fluorescent material placed into micro-compartments of the lab-on-chip. Its significance is in high utilization of excitation energyfor low concentration of fluorescent material. The utilization of a transparent μLED chip,for the second method, allows the placement of the excitation light sources on the sameoptical axis with emission detector, such that the excitation and emission rays are directedcontroversly. The third method presents a spatial filtering of the excitation background.

  15. Micro-Spec: An Ultracompact, High-sensitivity Spectrometer for Far-Infrared and Submillimeter Astronomy

    Science.gov (United States)

    Cataldo, Giuseppe; Hsieh, Wen-Ting; Huang, Wei-Chung; Moseley, S. Harvey; Stevenson, Thomas R.; Wollack, Edward J.

    2014-01-01

    High-performance, integrated spectrometers operating in the far-infrared and submillimeter ranges promise to be powerful tools for the exploration of the epochs of reionization and initial galaxy formation. These devices, using high-efficiency superconducting transmission lines, can achieve the performance of a meter-scale grating spectrometer in an instrument implemented on a 4 inch silicon wafer. Such a device, when combined with a cryogenic telescope in space, provides an enabling capability for studies of the early universe. Here, the optical design process for Micro-Spec (micron-Spec) is presented, with particular attention given to its two-dimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the stigmatization and minimization of the light path function in this bounded region, which results in an optimized geometrical configuration. A point design with an efficiency of (is) approximately 90% has been developed for initial demonstration and can serve as the basis for future instruments. Design variations on this implementation are also discussed, which can lead to lower efficiencies due to diffractive losses in the multimode region.

  16. Sensitive, High-Throughput, and Robust Trapping-Micro-LC-MS Strategy for the Quantification of Biomarkers and Antibody Biotherapeutics.

    Science.gov (United States)

    Zhang, Ming; An, Bo; Qu, Yang; Shen, Shichen; Fu, Wei; Chen, Yuan-Ju; Wang, Xue; Young, Rebeccah; Canty, John M; Balthasar, Joseph P; Murphy, Keeley; Bhattacharyya, Debadeep; Josephs, Jonathan; Ferrari, Luca; Zhou, Shaolian; Bansal, Surendra; Vazvaei, Faye; Qu, Jun

    2018-01-08

    For LC-MS-based targeted quantification of biotherapeutics and biomarkers in clinical and pharmaceutical environments, high sensitivity, high throughput, and excellent robustness are all essential but remain challenging. For example, though nano-LC-MS has been employed to enhance analytical sensitivity, it falls short because of its low loading capacity, poor throughput, and low operational robustness. Furthermore, high chemical noise in protein bioanalysis typically limits the sensitivity. Here we describe a novel trapping-micro-LC-MS (T-μLC-MS) strategy for targeted protein bioanalysis, which achieves high sensitivity with exceptional robustness and high throughput. A rapid, high-capacity trapping of biological samples is followed by μLC-MS analysis; dynamic sample trapping and cleanup are performed using pH, column chemistry, and fluid mechanics separate from the μLC-MS analysis, enabling orthogonality, which contributes to the reduction of chemical noise and thus results in improved sensitivity. Typically, the selective-trapping and -delivery approach strategically removes >85% of the matrix peptides and detrimental components, markedly enhancing sensitivity, throughput, and operational robustness, and narrow-window-isolation selected-reaction monitoring further improves the signal-to-noise ratio. In addition, unique LC-hardware setups and flow approaches eliminate gradient shock and achieve effective peak compression, enabling highly sensitive analyses of plasma or tissue samples without band broadening. In this study, the quantification of 10 biotherapeutics and biomarkers in plasma and tissues was employed for method development. As observed, a significant sensitivity gain (up to 25-fold) compared with that of conventional LC-MS was achieved, although the average run time was only 8 min/sample. No appreciable peak deterioration or loss of sensitivity was observed after >1500 injections of tissue and plasma samples. The developed method enabled, for the

  17. A high sensitivity micro format chemiluminescence enzyme inhibition assay for determination of Hg(II).

    Science.gov (United States)

    Deshpande, Kanchanmala; Mishra, Rupesh K; Bhand, Sunil

    2010-01-01

    A highly sensitive and specific enzyme inhibition assay based on alcohol oxidase (AlOx) and horseradish peroxidase (HRP) for determination of mercury Hg(II) in water samples has been presented. This article describes the optimization and miniaturization of an enzymatic assay using a chemiluminescence reaction. The analytical performance and detection limit for determination of Hg(II) was optimized in 96 well plates and further extended to 384 well plates with a 10-fold reduction in assay volume. Inhibition of the enzyme activity by dissolved Hg(II) was found to be linear in the range 5-500 pg·mL(-1) with 3% CV in inter-batch assay. Due to miniaturization of assay in 384 well plates, Hg(II) was measurable as low as 1 pg·mL(-1) within 15 min. About 10-fold more specificity of the developed assay for Hg(II) analysis was confirmed by challenging with interfering divalent metal ions such as cadmium Cd(II) and lead Pb(II). Using the proposed assay we could successfully demonstrate that in a composite mixture of Hg(II), Cd(II) and Pb(II), inhibition by each metal ion is significantly enhanced in the presence of the others. Applicability of the proposed assay for the determination of the Hg(II) in spiked drinking and sea water resulted in recoveries ranging from 100-110.52%.

  18. Simple G-quadruplex-based 2-aminopurine fluorescence probe for highly sensitive and amplified detection of microRNA-21.

    Science.gov (United States)

    Li, Shiyu; Liu, Chan; Gong, Hang; Chen, Chunyan; Chen, Xiaoming; Cai, Changqun

    2018-02-01

    Based on 2-aminopurine (2-AP) probe in conjunction with a G-quadruplex structure and signal amplification technique, a simple and highly sensitive fluorescence sensor for detecting microRNA (miRNA) is developed for high signal-to-background ratio and wide linear range. The proposed sensor contains two hairpins DNA: H1 and H2. H1 is labeled by 2-AP incorporated into a G-rich sequence. Upon the addition of a target miRNA, H1 is unfolded and forms DNA/RNA complexes that contain a G-quadruplex, thereby significantly enhancing 2-AP fluorescence due to the protection provided by the G-quadruplex. Subsequently, H2 can displace the miRNA from the DNA/RNA complexes and induce signal amplification, resulting in further enhanced fluorescence intensity. Hence, the sensor is highly sensitive and its low limit of detection (L.O.D.) can reach as low as 1.48pM. Furthermore, the proposed sensor is used to detect overexpressed miRNA-21 from human breast cancer cell lysate. The result demonstrates the potential of the proposed sensor to monitor different miRNA biomarkers for the early diagnosis of various cancers. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Temperature sensitivity of silica micro-resonators

    Energy Technology Data Exchange (ETDEWEB)

    Ma Qiulin; Rossmann, Tobias; Guo Zhixiong [Department of Mechanical and Aerospace Engineering, Rutgers, State University of New Jersey, Piscataway, NJ 08854 (United States)], E-mail: guo@jove.rutgers.edu

    2008-12-21

    Optical resonance shifts are measured against temperature changes for different silica beads ranging from 80 to 450 {mu}m in diameter. A micro-bead is fabricated by hydrogen flame fusing the tip of a single mode silica fibre/taper, and coupled to a fibre taper of submicrometre diameter. The coupling system in whispering-gallery modes is placed in an insulated cell. The air in the cell is slowly heated up from room temperature to about 10 K higher, and red shifts of a resonance wavelength during the heating process are recorded. Linear dependence of the wavelength shift versus the temperature rise is observed for all the tested micro-resonators. The measured sensitivity for beads greater than 200 {mu}m in size closely matches the analytical value based on bulk material properties of silica thermal expansion and the thermo-optic effect. For smaller micro-beads, however, the measured sensitivity increases with shrinking bead size. The ultra-high resolution of such a kind of temperature micro-sensor and its potential applications are addressed.

  20. TU-H-CAMPUS-TeP2-03: High Sensitivity and High Resolution Fiber Based Micro-Detector for Sub-Millimeter Preclinical Dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Izaguirre, E; Pokhrel, S; Knewtson, T [University of Tennessee Medical Science Center, Memphis, TN (United States); University of Missouri, Columbia, MO (United States); Hedrick, S [Provision Center for Proton Therapy, Knoxville, TN (United States)

    2016-06-15

    Purpose: Current precision of small animal and cell micro-irradiators has continuously increased during the past years. Currently, preclinical irradiators can deliver sub-millimeter fields with micrometric precision but there are no water equivalent dosimeters to determine small field profiles and dose in the orthovoltage range of energies with micrometric resolution and precision. We have developed a fiber based micro-dosimeter with the resolution and dosimetric accuracy required for radiobiological research. Methods: We constructed two prototypes of micro-dosimeters based on different compositions of fiber scintillators to study the spatial resolution and dosimetric precision of small animal and cell micro-irradiators. The first has green output and the second has blue output. The blue output dosimeter has the highest sensitivity because it matches the spectral sensitivity of silicon photomultipliers. A blue detector with 500um cross section was built and tested respect to a CC01 ion chamber, film, and the 1500um green output detector. Orthovoltage fields from 1×1mm2 to 5×5mm2 were used for detector characteristics comparison. Results: The blue fiber dosimeter shows great agreement with films and matches dose measurements with the gold-standard ion chamber for 5×5mm2 fields. The detector has the appropriate sensitivity to measure fields from 1×1mm2 to larger sizes with a 1% dosimetric accuracy. The spatial resolution is in the sub-millimeter range and the spectral matching with the photomultiplier allows reducing the sensor cross section even further than the presented prototype. These results suggest that scintillating fibers combined with silicon photomultipliers is the appropriate technology to pursue micro-dosimetry for small animals and disperse cell samples. Conclusion: The constructed detectors establish a new landmark for the resolution and sensitivity of fiber based microdetectors. The validation of the detector in our small animal and cell

  1. LabVIEW graphical user interface for a new high sensitivity, high resolution micro-angio-fluoroscopic and ROI-CBCT system

    Science.gov (United States)

    Keleshis, C.; Ionita, C. N.; Yadava, G.; Patel, V.; Bednarek, D. R.; Hoffmann, K. R.; Verevkin, A.; Rudin, S.

    2008-03-01

    A graphical user interface based on LabVIEW software was developed to enable clinical evaluation of a new High-Sensitivity Micro-Angio-Fluoroscopic (HSMAF) system for real-time acquisition, display and rapid frame transfer of high-resolution region-of-interest images. The HSMAF detector consists of a CsI(Tl) phosphor, a light image intensifier (LII), and a fiber-optic taper coupled to a progressive scan, frame-transfer, charged-coupled device (CCD) camera which provides real-time 12 bit, 1k × 1k images capable of greater than 10 lp/mm resolution. Images can be captured in continuous or triggered mode, and the camera can be programmed by a computer using Camera Link serial communication. A graphical user interface was developed to control the camera modes such as gain and pixel binning as well as to acquire, store, display, and process the images. The program, written in LabVIEW, has the following capabilities: camera initialization, synchronized image acquisition with the x-ray pulses, roadmap and digital subtraction angiography acquisition (DSA), flat field correction, brightness and contrast control, last frame hold in fluoroscopy, looped play-back of the acquired images in angiography, recursive temporal filtering and LII gain control. Frame rates can be up to 30 fps in full-resolution mode. The user friendly implementation of the interface along with the high frame-rate acquisition and display for this unique high-resolution detector should provide angiographers and interventionalists with a new capability for visualizing details of small vessels and endovascular devices such as stents and hence enable more accurate diagnoses and image guided interventions.

  2. LabVIEW Graphical User Interface for a New High Sensitivity, High Resolution Micro-Angio-Fluoroscopic and ROI-CBCT System.

    Science.gov (United States)

    Keleshis, C; Ionita, Cn; Yadava, G; Patel, V; Bednarek, Dr; Hoffmann, Kr; Verevkin, A; Rudin, S

    2008-01-01

    A graphical user interface based on LabVIEW software was developed to enable clinical evaluation of a new High-Sensitivity Micro-Angio-Fluoroscopic (HSMAF) system for real-time acquisition, display and rapid frame transfer of high-resolution region-of-interest images. The HSMAF detector consists of a CsI(Tl) phosphor, a light image intensifier (LII), and a fiber-optic taper coupled to a progressive scan, frame-transfer, charged-coupled device (CCD) camera which provides real-time 12 bit, 1k × 1k images capable of greater than 10 lp/mm resolution. Images can be captured in continuous or triggered mode, and the camera can be programmed by a computer using Camera Link serial communication. A graphical user interface was developed to control the camera modes such as gain and pixel binning as well as to acquire, store, display, and process the images. The program, written in LabVIEW, has the following capabilities: camera initialization, synchronized image acquisition with the x-ray pulses, roadmap and digital subtraction angiography acquisition (DSA), flat field correction, brightness and contrast control, last frame hold in fluoroscopy, looped playback of the acquired images in angiography, recursive temporal filtering and LII gain control. Frame rates can be up to 30 fps in full-resolution mode. The user friendly implementation of the interface along with the high framerate acquisition and display for this unique high-resolution detector should provide angiographers and interventionalists with a new capability for visualizing details of small vessels and endovascular devices such as stents and hence enable more accurate diagnoses and image guided interventions. (Support: NIH Grants R01NS43924, R01EB002873).

  3. LabVIEW Graphical User Interface for a New High Sensitivity, High Resolution Micro-Angio-Fluoroscopic and ROI-CBCT System

    Science.gov (United States)

    Keleshis, C; Ionita, CN; Yadava, G; Patel, V; Bednarek, DR; Hoffmann, KR; Verevkin, A; Rudin, S

    2008-01-01

    A graphical user interface based on LabVIEW software was developed to enable clinical evaluation of a new High-Sensitivity Micro-Angio-Fluoroscopic (HSMAF) system for real-time acquisition, display and rapid frame transfer of high-resolution region-of-interest images. The HSMAF detector consists of a CsI(Tl) phosphor, a light image intensifier (LII), and a fiber-optic taper coupled to a progressive scan, frame-transfer, charged-coupled device (CCD) camera which provides real-time 12 bit, 1k × 1k images capable of greater than 10 lp/mm resolution. Images can be captured in continuous or triggered mode, and the camera can be programmed by a computer using Camera Link serial communication. A graphical user interface was developed to control the camera modes such as gain and pixel binning as well as to acquire, store, display, and process the images. The program, written in LabVIEW, has the following capabilities: camera initialization, synchronized image acquisition with the x-ray pulses, roadmap and digital subtraction angiography acquisition (DSA), flat field correction, brightness and contrast control, last frame hold in fluoroscopy, looped playback of the acquired images in angiography, recursive temporal filtering and LII gain control. Frame rates can be up to 30 fps in full-resolution mode. The user friendly implementation of the interface along with the high framerate acquisition and display for this unique high-resolution detector should provide angiographers and interventionalists with a new capability for visualizing details of small vessels and endovascular devices such as stents and hence enable more accurate diagnoses and image guided interventions. (Support: NIH Grants R01NS43924, R01EB002873) PMID:18836570

  4. Micro-Spec: An Ultra-Compact, High-Sensitivity Spectrometer for Far-Infrared and Sub-Millimeter Astronomy

    Science.gov (United States)

    Cataldo, Giuseppe; Hsieh, Wen-Ting; Huang, Wei-Chung; Moseley, S. Harvey; Stevenson, Thomas R.; Wollack, Edward J.

    2013-01-01

    High-performance, integrated spectrometers operating in the far-infrared and sub-millimeter promise to be powerful tools for the exploration of the epochs of reionization and initial galaxy formation. These devices, using high-efficiency superconducting transmission lines, can achieve the performance of a meter-scale grating spectrometer in an instrument implemented on a four-inch silicon wafer. Such a device, when combined with a cryogenic telescope in space, provides an enabling capability for studies of the early universe. Here, the optical design process for Micro-Spec (mu-Spec) is presented, with particular attention given to its two-dimensional diffractive region, where the light of different wavelengths is focused on the different detectors. The method is based on the stigmatization and minimization of the light path function in this bounded region, which results in an optimized geometrical configuration. A point design with an efficiency of approx. 90% has been developed for initial demonstration, and can serve as the basis for future instruments. Design variations on this implementation are also discussed, which can lead to lower efficiencies due to diffractive losses in the multimode region.

  5. Highly-sensitive microRNA detection based on bio-bar-code assay and catalytic hairpin assembly two-stage amplification.

    Science.gov (United States)

    Tang, Songsong; Gu, Yuan; Lu, Huiting; Dong, Haifeng; Zhang, Kai; Dai, Wenhao; Meng, Xiangdan; Yang, Fan; Zhang, Xueji

    2018-04-03

    Herein, a highly-sensitive microRNA (miRNA) detection strategy was developed by combining bio-bar-code assay (BBA) with catalytic hairpin assembly (CHA). In the proposed system, two nanoprobes of magnetic nanoparticles functionalized with DNA probes (MNPs-DNA) and gold nanoparticles with numerous barcode DNA (AuNPs-DNA) were designed. In the presence of target miRNA, the MNP-DNA and AuNP-DNA hybridized with target miRNA to form a "sandwich" structure. After "sandwich" structures were separated from the solution by the magnetic field and dehybridized by high temperature, the barcode DNA sequences were released by dissolving AuNPs. The released barcode DNA sequences triggered the toehold strand displacement assembly of two hairpin probes, leading to recycle of barcode DNA sequences and producing numerous fluorescent CHA products for miRNA detection. Under the optimal experimental conditions, the proposed two-stage amplification system could sensitively detect target miRNA ranging from 10 pM to 10 aM with a limit of detection (LOD) down to 97.9 zM. It displayed good capability to discriminate single base and three bases mismatch due to the unique sandwich structure. Notably, it presented good feasibility for selective multiplexed detection of various combinations of synthetic miRNA sequences and miRNAs extracted from different cell lysates, which were in agreement with the traditional polymerase chain reaction analysis. The two-stage amplification strategy may be significant implication in the biological detection and clinical diagnosis. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. MicroRNA-21 Increases Proliferation and Cisplatin Sensitivity of Osteosarcoma-Derived Cells.

    Directory of Open Access Journals (Sweden)

    Vanita Vanas

    Full Text Available Osteosarcoma is the most common primary bone tumor and poor prognosis for osteosarcoma patients is mainly due to chemotherapy resistance. MicroRNAs are important to maintain pathophysiological mechanisms of cancer and influence cell sensitivity to chemotherapy. In this study, we tested the functions of microRNA-21 for malignant features as well as for drug resistance of osteosarcoma. We used Northern blot to measure microRNA-21 levels in osteosarcoma-derived cell lines. MicroRNA-21 activity was modulated by either expressing a sponge to decrease its activity in an osteosarcoma-derived cell line expressing high levels of microRNA-21 or by introducing pri-microRNA-21 in a cell line with low endogenous levels. Cell migration was determined in a scratch assay and cell proliferation was measured by performing growth curve analysis. Sensitivity of the cells towards chemotherapeutics was investigated by performing cell viability assays and calculating the IC50 values. While cell migration was unaffected by modulated microRNA-21 levels, microRNA-21 inhibition slowed proliferation and exogenously expressed microRNA-21 promoted this process. Modulated microRNA-21 activity failed to effect sensitivity of osteosarcoma-derived cell lines to doxorubicin or methotrexate. Contrarily, reduction of microRNA-21 activity resulted in enhanced resistance towards cisplatin while ectopic expression of microRNA-21 showed the opposite effect. Increased microRNA-21 levels repressed the expression of Sprouty2 and ectopic expression of Sprouty2 was able to largely rescue the observed effects of microRNA-21 in osteosarcoma. In summary, our data indicate that in osteosarcoma microRNA-21 expression is an important component for regulation of cell proliferation and for determining sensitivity to cisplatin.

  7. High-Sensitivity Spectrophotometry.

    Science.gov (United States)

    Harris, T. D.

    1982-01-01

    Selected high-sensitivity spectrophotometric methods are examined, and comparisons are made of their relative strengths and weaknesses and the circumstances for which each can best be applied. Methods include long path cells, noise reduction, laser intracavity absorption, thermocouple calorimetry, photoacoustic methods, and thermo-optical methods.…

  8. Highly sensitive MicroRNA 146a detection using a gold nanoparticle-based CTG repeat probing system and isothermal amplification.

    Science.gov (United States)

    Le, Binh Huy; Seo, Young Jun

    2018-01-25

    We have developed a gold nanoparticle (AuNP)-based CTG repeat probing system displaying high quenching capability and combined it with isothermal amplification for the detection of miRNA 146a. This method of using a AuNP-based CTG repeat probing system with isothermal amplification allowed the highly sensitive (14 aM) and selective detection of miRNA 146a. A AuNP-based CTG repeat probing system having a hairpin structure and a dT F fluorophore exhibited highly efficient quenching because the CTG repeat-based stable hairpin structure imposed a close distance between the AuNP and the dT F residue. A small amount of miRNA 146a induced multiple copies of the CAG repeat sequence during rolling circle amplification; the AuNP-based CTG repeat probing system then bound to the complementary multiple-copy CAG repeat sequence, thereby inducing a structural change from a hairpin to a linear structure with amplified fluorescence. This AuNP-based CTG probing system combined with isothermal amplification could also discriminate target miRNA 146a from one- and two-base-mismatched miRNAs (ORN 1 and ORN 2, respectively). This simple AuNP-based CTG probing system, combined with isothermal amplification to induce a highly sensitive change in fluorescence, allows the detection of miRNA 146a with high sensitivity (14 aM) and selectivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Vortex-assisted liquid-liquid micro-extraction and high-performance liquid chromatography for a higher sensitivity methyl methacrylate determination in biological matrices.

    Science.gov (United States)

    Sousa, Tiago F A; Aniceto, Marta C; Amorim, Célia G; Souto-Lopes, Mariana; Pérez-Mongiovi, Daniel; Montenegro, Maria C B S M; Araújo, Alberto N

    2014-05-01

    A vortex-assisted liquid-liquid micro-extraction coupled with high-performance liquid chromatography, with UV-vis, is proposed to pre-concentrate methyl methacrylate and to improve separation in biological matrices. The use of 1-octanol as extracting phase, its volume, the need for a dispersant agent, the agitation conditions and the cooling time before phase separation were evaluated. In optimum conditions, enrichment factors of 20 (±0.5) and enrichment recovery of 99% were obtained. The straightforward association of this extraction process with the HPLC method, previously regulated by the International Organization for Standardization, afforded a detection limit of 122 ng/mL and a quantification limit of 370 ng/mL. The within-batch precision, relative standard deviation, was 3% for a sample with 1.49 µg/mL and 4% for a sample with 13.4 µg/mL. The results showed a between batch-precision of 21% for experiments performed on five different days, for a sample with a concentration of 1.10 µg/mL in methyl methacrylate. Copyright © 2013 John Wiley & Sons, Ltd.

  10. Highly Efficient Micro Cathode Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Busek Company, Inc. proposes to develop a micro thermionic cathode that requires extremely low power and provides long lifetime. The basis for the cathode is a...

  11. Miniaturization of a micro-optics array for highly sensitive and parallel detection on an injection moulded lab-on-a-chip

    DEFF Research Database (Denmark)

    Hung, Tran Quang; Sun, Yi; Poulsen, Carl Esben

    2015-01-01

    A miniaturised array of supercritical angle fluorescence (SAF) micro-optics embedded in a microfluidic chamber was fabricated by injection moulding. The fabricated chip could enhance the fluorescence signal around 46 times compared to a conventional microscope. Collection of the fluorescence signal...

  12. Micro-pulverized extraction pretreatment for highly sensitive analysis of 11-nor-9-carboxy-Δ(9)-tetrahydrocannabinol in hair by liquid chromatography/tandem mass spectrometry.

    Science.gov (United States)

    Kuwayama, Kenji; Miyaguchi, Hajime; Yamamuro, Tadashi; Tsujikawa, Kenji; Kanamori, Tatsuyuki; Iwata, Yuko T; Inoue, Hiroyuki

    2015-11-30

    A primary metabolite of Δ(9) -tetrahydrocannabinol, 11-nor-9-carboxytetrahydrocannabinol (THC-COOH), serves as an effective indicator for cannabis intake. According to the recommendations of the Society of Hair Testing, at least 0.2 pg/mg of THC-COOH (cut-off level) must be present in a hair sample to constitute a positive result in a drug test. Typically, hair is digested with an alkaline solution and is subjected to gas chromatography/tandem mass spectrometry (GC/MS/MS) with negative ion chemical ionization (NICI). It is difficult to quantify THC-COOH at the cut-off level using liquid chromatography/tandem mass spectrometry (LC/MS/MS) without acquisition of second-generation product ions in triple quadrupole-ion trap mass spectrometers, because large amounts of matrix components in the low-mass range produced by digestion interfere with the THC-COOH peak. Using the typical pretreatment method (alkaline dissolution) and micro-pulverized extraction (MPE) with a stainless bullet, we compared the quantification of THC-COOH using GC/MS/MS and LC/MS/MS. MPE reduced the amount of matrix components in the low-mass range and enabled the quantification of THC-COOH at 0.2 pg/mg using a conventional triple quadrupole liquid chromatograph coupled to a mass spectrometer. On the other hand, the MPE pretreatment was unsuitable for GC/MS/MS, probably due to matrix components in the high-mass range. The proper combination of pretreatments and instrumental analyses was shown to be important for detecting trace amounts of THC-COOH in hair. In MPE, samples can be prepared rapidly, and LC/MS/MS is readily available, unlike GC/MS/MS with NICI. The combination of MPE and LC/MS/MS might therefore be used in the initial screening for THC-COOH in hair prior to confirmatory analysis using GC/MS/MS with NICI. Copyright © 2015 John Wiley & Sons, Ltd.

  13. Note: A charge sensitive spectroscopy amplifier for position sensitive micro-channel plate detectors.

    Science.gov (United States)

    Wang, Wei; Yu, Deyang; Liu, Junliang; Lu, Rongchun; Cai, Xiaohong

    2014-10-01

    A compact and low noise charge sensitive spectroscopy amplifier which can be integrated into position sensitive micro-channel plate (MCP) detectors has been constructed. The amplifier was optimized by using a wave form generator and tested by a chevron shape MCP detector. The output noise of 4 mV(rms) was achieved while the gain is 10(12) V/C and the shaping time is 700 ns.

  14. Implementation of a high-sensitivity micro-angiographic fluoroscope (HS-MAF) for in-vivo endovascular image guided interventions (EIGI) and region-of-interest computed tomography (ROI-CT)

    Science.gov (United States)

    Ionita, C. N.; Keleshis, C.; Patel, V.; Yadava, G.; Hoffmann, K. R.; Bednarek, D. R.; Jain, A.; Rudin, S.

    2008-03-01

    New advances in catheter technology and remote actuation for minimally invasive procedures are continuously increasing the demand for better x-ray imaging technology. The new x-ray high-sensitivity Micro-Angiographic Fluoroscope (HS-MAF) detector offers high resolution and real-time image-guided capabilities which are unique when compared with commercially available detectors. This detector consists of a 300 μm CsI input phosphor coupled to a dual stage GEN2 micro-channel plate light image intensifier (LII), followed by minifying fiber-optic taper coupled to a CCD chip. The HS-MAF detector image array is 1024X1024 pixels, with a 12 bit depth capable of imaging at 30 frames per second. The detector has a round field of view with 4 cm diameter and 35 microns pixels. The LII has a large variable gain which allows usage of the detector at very low exposures characteristic of fluoroscopic ranges while maintaining very good image quality. The custom acquisition program allows real-time image display and data storage. We designed a set of in-vivo experimental interventions in which placement of specially designed endovascular stents were evaluated with the new detector and with a standard x-ray image intensifier (XII). Capabilities such fluoroscopy, angiography and ROI-CT reconstruction using rotational angiography data were implemented and verified. The images obtained during interventions under radiographic control with the HS-MAF detector were superior to those with the XII. In general, the device feature markers, the device structures, and the vessel geometry were better identified with the new detector. High-resolution detectors such as HS-MAF can vastly improve the accuracy of localization and tracking of devices such stents or catheters.

  15. pH-Sensitive Hydrogel for Micro-Fluidic Valve

    Directory of Open Access Journals (Sweden)

    Zhengzhi Yang

    2012-07-01

    Full Text Available The deformation behavior of a pH-sensitive hydrogel micro-fluidic valve system is investigated using inhomogeneous gel deformation theory, in which the fluid-structure interaction (FSI of the gel solid and fluid flow in the pipe is considered. We use a finite element method with a well adopted hydrogel constitutive equation, which is coded in commercial software, ABAQUS, to simulate the hydrogel valve swelling deformation, while FLUENT is adopted to model the fluid flow in the pipe of the hydrogel valve system. The study demonstrates that FSI significantly affects the gel swelling deformed shapes, fluid flow pressure and velocity patterns. FSI has to be considered in the study on fluid flow regulated by hydrogel microfluidic valve. The study provides a more accurate and adoptable model for future design of new pH-sensitive hydrogel valves, and also gives a useful guideline for further studies on hydrogel fluidic applications.

  16. High resolution capacitance detection circuit for rotor micro-gyroscope

    Directory of Open Access Journals (Sweden)

    Ming-Yuan Ren

    2014-03-01

    Full Text Available Conventional methods for rotor position detection of micro-gyroscopes include common exciting electrodes (single frequency and common sensing electrodes (frequency multiplex, but they have encountered some problems. So we present a high resolution and low noise pick-off circuit for micro-gyroscopes which utilizes the time multiplex method. The detecting circuit adopts a continuous-time current sensing circuit for capacitance measurement, and its noise analysis of the charge amplifier is introduced. The equivalent output noise power spectral density of phase-sensitive demodulation is 120 nV/Hz1/2. Tests revealed that the whole circuitry has a relative capacitance resolution of 1 × 10−8.

  17. Hepatocyte-derived microRNAs as sensitive serum biomarkers of hepatocellular injury in Labrador retrievers.

    Science.gov (United States)

    Dirksen, K; Verzijl, T; van den Ingh, T S G A M; Vernooij, J C M; van der Laan, L J W; Burgener, I A; Spee, B; Fieten, H

    2016-05-01

    Common parenchymal liver diseases in dogs include reactive hepatopathies and primary hepatitis (acute or chronic). In chronic hepatitis, there is usually a long subclinical phase. Specific clinical signs become overt only when liver damage is severe and in this phase, treatment is usually less effective. Limited data are available regarding the sensitivity of liver enzyme activity or biomarkers for early detection of subclinical hepatitis. Hepatocyte-derived microRNAs (HDmiRs) were recently identified as promising biomarkers for hepatocellular injury in multiple species. Here, the potential of the HDmiRs miR-122 and miR-148a as sensitive diagnostic biomarkers for hepatocellular injury in Labrador retrievers was investigated. Samples from 66 Labrador retrievers with histologically normal livers, high hepatic copper, and with various forms of liver injury were evaluated for serum alanine aminotransferase (ALT) activity and microRNA values. Median values of HDmiR-122 were 34.6 times higher in dogs with liver injury and high ALT than in normal dogs (95% confidence intervals [CI], 13-95; P dogs with liver injury and normal ALT (4.2 times; 95% CI, 2-12; P dogs with high hepatic copper concentrations and unremarkable histopathology (2.9 times; 95% CI, 1.1-8.0; P Labrador retrievers (P Labrador retrievers and is a promising new biomarker that may be used for early detection of subclinical hepatitis in dogs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Novel Micro/Nano Approaches for Glucose Measurement Using pH-Sensitive Hydrogels

    Science.gov (United States)

    2005-06-01

    AD Award Number: W81XWH-04-1-0596 TITLE: Novel Micro / Nano Approaches for Glucose Measurement Using pH-Sensitive Hydrogels PRINCIPAL INVESTIGATOR...May 2005 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Novel Micro / Nano Approaches for Glucose Measurement Using pH- 5b. GRANT NUMBER Sensitive Hydrogels...Initially, the NaCI solution was circulated through the cell using a syringe pump . A schematic diagram of the apparatus used in this study was

  19. Highly sensitive fiber loop ringdown strain sensor with low temperature sensitivity

    Science.gov (United States)

    Ghimire, Maheshwar; Wang, Chuji

    2017-10-01

    We report a highly sensitive strain sensor with low temperature sensitivity based on the fiber loop ringdown technique. An innovative approach that employs a micro air-gap as the strain sensor head is described. The sensor has demonstrated the static strain sensitivity of 0.26 µs/µɛ, corresponding to the detection limit of 65 nɛ with the low temperature cross sensitivity of 37 nɛ/°C. This is the highest static strain sensitivity achieved without using a combination of fiber optic sensing components, such as fiber Bragg gratings or Fabry-Perot interferometers. Moreover, the sensor design allows the strain sensitivity and measuring range to be adjusted by changing the length of the sensor.

  20. Techno-economic sensitivity study of heliostat field parameters for micro-gas turbine CSP

    Science.gov (United States)

    Landman, Willem A.; Gauché, Paul; Dinter, Frank; Myburgh, J. T.

    2017-06-01

    Concentrating solar power systems based on micro-gas turbines potentially offer numerous benefits should they become commercially viable. Heliostat fields for such systems have unique requirements in that the number of heliostats and the focal ratios are typically much lower than conventional central receiver systems. This paper presents a techno-economic sensitivity study of heliostat field parameters for a micro-gas turbine central receiver system. A 100 kWe minitower system is considered for the base case and a one-at-a-time strategy is used to investigate parameter sensitivities. Increasing heliostat focal ratios are found to have significant optical performance benefits due to both a reduction in astigmatic aberrations and a reduction in the number of facet focal lengths required; confirming the hypothesis that smaller heliostats offer a techno-economic advantage. Fixed Horizontal Axis tracking mechanism is shown to outperform the conventional Azimuth Zenith tracking mechanism in high density heliostat fields. Although several improvements to heliostat field performance are discussed, the capex fraction of the heliostat field for such system is shown to be almost half that of a conventional central receiver system and optimum utilization of the higher capex components, namely; the receiver and turbine subsystems, are more rewarding than that of the heliostat field.

  1. Micro-resonator-based electric field sensors with long durations of sensitivity

    Science.gov (United States)

    Ali, Amir R.

    2017-05-01

    In this paper, we present a new fabrication method for the whispering gallery mode (WGM) micro-sphere based electric field sensor that which allows for longer time periods of sensitivity. Recently, a WGM-based photonic electric field sensor was proposed using a coupled dielectric microsphere-beam. The external electric field imposes an electrtrostriction force on the dielectric beam, deflecting it. The beam, in turn compresses the sphere causing a shift in its WGM. As part of the fabrication process, the PDMS micro-beams and the spheres are curied at high-temperature (100oC) and subsequently poled by exposing to strong external electric field ( 8 MV/m) for two hours. The poling process allows for the deposition of surface charges thereby increasing the electrostriction effect. This methodology is called curing-then-poling (CTP). Although the sensors do become sufficiently sensitive to electric field, they start de-poling after a short period (within 10 minutes) after poling, hence losing sensitivity. In an attempt to mitigate this problem and to lock the polarization for a longer period, we use an alternate methodology whereby the beam is poled and cured simultaneously (curing-while-poling or CWP). The new fabrication method allows for the retention of polarization (and hence, sensitivity to electric field) longer ( 1500 minutes). An analysis is carried out along with preliminary experiments. Results show that electric fields as small as 100 V/m can be detected with a 300 μm diameter sphere sensor a day after poling.

  2. High-efficiency approach for fabricating MTE rotor by micro-EDM and micro-extrusion

    Science.gov (United States)

    Geng, Xuesong; Chi, Guanxin; Wang, Yukui; Wang, Zhenlong

    2014-07-01

    Micro-gas turbine engine (MTE) rotor is an important indicator of its property, therefore, the manufacturing technology of the microminiature rotor has become a hot area of research at home and abroad. At present, the main manufacturing technologies of the MTE rotor are directed forming fabrication technologies. However, these technologies have a series of problems, such as complex processing technology high manufacturing cost, and low processing efficiency, and so on. This paper takes advantage of micro electric discharge machining (micro-EDM) in the field of microminiature molds manufacturing, organizes many processing technologies of micro-EDM reasonably to improve processing accuracy, presents an integrated micro-EDM technology and its process flow to fabricate MTE rotor die, and conducts a series of experiments to verify efficiency of this integrated micro-EDM. The experiments results show that the MTE rotor die has sharp outline and ensure the good consistency of MTE rotor blades. Meanwhile, the MTE rotor die is applied to micro extrusion equipment, and technologies of micro-EDM and micro forming machining are combined based on the idea of the molds manufacturing, so the MTE rotor with higher aspect ratio and better consistency of blades can be manufactured efficiently. This research presents an integrated micro-EDM technology and its process flow, which promotes the practical process of MTE effectively.

  3. High-Salt Intake Suppressed MicroRNA-133a Expression in Dahl SS Rat Myocardium

    Directory of Open Access Journals (Sweden)

    Tong-Shuai Guo

    2014-06-01

    Full Text Available Salt-sensitive individuals show earlier and more serious cardiac damage than nonsalt-sensitive ones. Some studies have suggested that microRNA-133a could reduce cardiac hypertrophy and myocardial fibrosis. The current study aims to investigate the different functions of high-salt intake on salt-sensitive (SS rats and Sprague-Dawley (SD rats and the involvement of microRNA-133a in these roles. After high-salt intervention, the left ventricular mass (LVW and left ventricular mass index (LVMI of the salt-sensitive high salt (SHS group were obviously higher than those of the salt-sensitive low salt (SLS group. However, the difference between the Sprague-Dawley high salt (DHS group and the Sprague-Dawley low salt (DLS group was not significant. Compared with SLS group, collagen I and connective tissue growth factor (CTGF in the heart of SHS group were significantly higher, whereas no statistical difference was observed between the DHS group and the DLS group. Compared with low-salt diet, microRNA-133a in the heart of both strains were significantly decreased, but that in the SHS group decreased more significantly. These results suggest that high salt intervention could down-regulate the expression of myocardial microRNA-133a, which may be one of the mechanisms involved in myocardial fibrosis in salt-sensitive hypertension.

  4. Thermo-optical characterization of fluorescent rhodamine B based temperature-sensitive nanosensors using a CMOS MEMS micro-hotplate☆

    Science.gov (United States)

    Chauhan, Veeren M.; Hopper, Richard H.; Ali, Syed Z.; King, Emma M.; Udrea, Florin; Oxley, Chris H.; Aylott, Jonathan W.

    2014-01-01

    A custom designed microelectromechanical systems (MEMS) micro-hotplate, capable of operating at high temperatures (up to 700 °C), was used to thermo-optically characterize fluorescent temperature-sensitive nanosensors. The nanosensors, 550 nm in diameter, are composed of temperature-sensitive rhodamine B (RhB) fluorophore which was conjugated to an inert silica sol–gel matrix. Temperature-sensitive nanosensors were dispersed and dried across the surface of the MEMS micro-hotplate, which was mounted in the slide holder of a fluorescence confocal microscope. Through electrical control of the MEMS micro-hotplate, temperature induced changes in fluorescence intensity of the nanosensors was measured over a wide temperature range. The fluorescence response of all nanosensors dispersed across the surface of the MEMS device was found to decrease in an exponential manner by 94%, when the temperature was increased from 25 °C to 145 °C. The fluorescence response of all dispersed nanosensors across the whole surface of the MEMS device and individual nanosensors, using line profile analysis, were not statistically different (p nanosensors could find potential application in the measurement of temperature in biological and micro-electrical systems. PMID:25844025

  5. Thermo-optical characterization of fluorescent rhodamine B based temperature-sensitive nanosensors using a CMOS MEMS micro-hotplate.

    Science.gov (United States)

    Chauhan, Veeren M; Hopper, Richard H; Ali, Syed Z; King, Emma M; Udrea, Florin; Oxley, Chris H; Aylott, Jonathan W

    2014-03-01

    A custom designed microelectromechanical systems (MEMS) micro-hotplate, capable of operating at high temperatures (up to 700 °C), was used to thermo-optically characterize fluorescent temperature-sensitive nanosensors. The nanosensors, 550 nm in diameter, are composed of temperature-sensitive rhodamine B (RhB) fluorophore which was conjugated to an inert silica sol-gel matrix. Temperature-sensitive nanosensors were dispersed and dried across the surface of the MEMS micro-hotplate, which was mounted in the slide holder of a fluorescence confocal microscope. Through electrical control of the MEMS micro-hotplate, temperature induced changes in fluorescence intensity of the nanosensors was measured over a wide temperature range. The fluorescence response of all nanosensors dispersed across the surface of the MEMS device was found to decrease in an exponential manner by 94%, when the temperature was increased from 25 °C to 145 °C. The fluorescence response of all dispersed nanosensors across the whole surface of the MEMS device and individual nanosensors, using line profile analysis, were not statistically different (p nanosensors could find potential application in the measurement of temperature in biological and micro-electrical systems.

  6. microRNA Biomarkers to Generate Sensitivity to Abiraterone-Resistant Prostate Cancer

    Science.gov (United States)

    2017-09-01

    AWARD NUMBER: W81XWH-15-1-0353 TITLE: microRNA Biomarkers to Generate Sensitivity to Abiraterone-Resistant Prostate Cancer PRINCIPAL...TITLE AND SUBTITLE microRNA Biomarkers to Generate Sensitivity to Abiraterone- Resistant Prostate Cancer 5a. CONTRACT NUMBER 5b. GRANT NUMBER...15 8. Special Reporting Requirements……………………………………16 9. Appendices……………………………………………………………17 1. INTRODUCTION: Prostate cancer (PCa) is the most

  7. High precision laser forming for micro actuation

    NARCIS (Netherlands)

    Folkersma, Ger; Römer, Gerardus Richardus, Bernardus, Engelina; Brouwer, Dannis Michel; Huis in 't Veld, Bert; Nakata, Yoshiki; Xu, Xianfan; Roth, Stephan; Neuenschwander, Beat

    2014-01-01

    For assembly of micro-devices, such as photonic devices, the precision alignment of components is often critical for their performance. Laser forming, also known as laser-adjusting, can be used to create an integrated microactuator to align the components with sub-micron precision after bonding. In

  8. MicroCT Bone Densitometry: Context Sensitivity, Beam Hardening Correction and the Effect of Surrounding Media

    Directory of Open Access Journals (Sweden)

    Philip L. Salmon

    2014-12-01

    Full Text Available The context-sensitivity of microCT bone densitometry due to beam hardening artefacts was assessed. Bones and teeth are scanned with varying thickness of surrounding media (water, alcohol, biological tissue and it is important to understand how this affects reconstructed attenuation (“density” of the mineralized tissue. Aluminium tubes and rods with thickness 0.127mm–5mm were scanned both in air or surrounded by up to 2cm of water. Scans were performed with different energy filters and degrees of software beam hardening correction (BHC. Also tested were the effects of signal-to-noise ratio, magnification and truncation. The thickness of an aluminium tube significantly affected its mean reconstructed attenuation. This effect of thickness could be reduced substantially by BHC for scans in air, but not for scans in water. Varying thickness of surrounding water also changed the mean attenuation of an aluminium tube. This artefact could be almost eliminated by an optimal BHC value. The “cupping” artefact of heterogeneous attenuation (elevated at outer surfaces could be corrected if aluminium was scanned in air, but in water BHC was much less effective. Scan truncation, changes to magnification and signal-to-noise ratio also caused artificial changes to measured attenuation. Measurement of bone mineral density by microCT is highly context sensitive. A surrounding layer of liquid or biological tissue reduces the ability of software BHC to remove bone density artefacts. Sample thickness, truncation, magnification and signal to noise ratio also affect reconstructed attenuation. Thus it is important for densitometry that sample and calibration phantom dimensions and mounting materials are standardised.

  9. High-sensitivity nanosensors for biomarker detection.

    Science.gov (United States)

    Swierczewska, Magdalena; Liu, Gang; Lee, Seulki; Chen, Xiaoyuan

    2012-04-07

    High sensitivity nanosensors utilize optical, mechanical, electrical, and magnetic relaxation properties to push detection limits of biomarkers below previously possible concentrations. The unique properties of nanomaterials and nanotechnology are exploited to design biomarker diagnostics. High-sensitivity recognition is achieved by signal and target amplification along with thorough pre-processing of samples. In this tutorial review, we introduce the type of detection signals read by nanosensors to detect extremely small concentrations of biomarkers and provide distinctive examples of high-sensitivity sensors. The use of such high-sensitivity nanosensors can offer earlier detection of disease than currently available to patients and create significant improvements in clinical outcomes.

  10. High-sensitivity nanosensors for biomarker detection†

    Science.gov (United States)

    Swierczewska, Magdalena; Liu, Gang

    2013-01-01

    High sensitivity nanosensors utilize optical, mechanical, electrical, and magnetic relaxation properties to push detection limits of biomarkers below previously possible concentrations. The unique properties of nanomaterials and nanotechnology are exploited to design biomarker diagnostics. High-sensitivity recognition is achieved by signal and target amplification along with thorough pre-processing of samples. In this tutorial review, we introduce the type of detection signals read by nanosensors to detect extremely small concentrations of biomarkers and provide distinctive examples of high-sensitivity sensors. The use of such high-sensitivity nanosensors can offer earlier detection of disease than currently available to patients and create significant improvements in clinical outcomes. PMID:22187721

  11. 5-Fluorouracil sensitivity varies among oral micro-organisms

    National Research Council Canada - National Science Library

    Vanlancker, Eline; Vanhoecke, Barbara; Smet, Rozel; Props, Ruben; Van de Wiele, Tom

    2016-01-01

    .... Although 5-FU has been shown to elicit antibacterial effects at high concentrations (>100 µM), its antibacterial effect at physiologically relevant concentrations in the oral cavity is unknown...

  12. Urinary microRNA-10a and microRNA-30d serve as novel, sensitive and specific biomarkers for kidney injury.

    Directory of Open Access Journals (Sweden)

    Nan Wang

    Full Text Available The steadily increasing incidence of kidney injury is a significant threat to human health. The current tools available for the early detection of kidney injury, however, have limited sensitivity or specificity. Thus, the development of novel biomarkers to detect early kidney injury is of high importance. Employing mouse renal ischemia-reperfusion and streptozotocin (STZ-induced renal injury as acute and chronic kidney injury model, respectively, we assessed the alteration of microRNA (miRNA in mouse urine, serum and kidney tissue by TaqMan probe-based qRT-PCR assay. Our results demonstrated that kidney-enriched microRNA-10a (miR-10a and microRNA-30d (miR-30d were readily detected in mouse urine and the levels of urinary miR-10a and miR-30d were positively correlated with the degree of kidney injury induced by renal ischemia-reperfusion or STZ diabetes. In contrast, no such alteration of miR-10a and miR-30d levels was observed in mouse serum after kidney injury. Compared with the blood urea nitrogen (BUN assay, the test for urinary miR-10a and miR-30d levels was more sensitive for the detection of acute kidney injury. Furthermore, the substantial elevation of the urinary miR-10a and miR-30d levels was also observed in focal segmental glomerulosclerosis (FSGS patients compared to healthy donors. In conclusion, the present study collectively demonstrates that urinary miR-10a and miR-30d represent a novel noninvasive, sensitive, specific and potentially high-throughput method for detecting renal injury.

  13. MicroRNA-26a regulates insulin sensitivity and metabolism of glucose and lipids.

    Science.gov (United States)

    Fu, Xianghui; Dong, Bingning; Tian, Yan; Lefebvre, Philippe; Meng, Zhipeng; Wang, Xichun; Pattou, François; Han, Weidong; Wang, Xiaoqiong; Lou, Fang; Jove, Richard; Staels, Bart; Moore, David D; Huang, Wendong

    2015-06-01

    Type 2 diabetes (T2D) is characterized by insulin resistance and increased hepatic glucose production, yet the molecular mechanisms underlying these abnormalities are poorly understood. MicroRNAs (miRs) are a class of small, noncoding RNAs that have been implicated in the regulation of human diseases, including T2D. miR-26a is known to play a critical role in tumorigenesis; however, its function in cellular metabolism remains unknown. Here, we determined that miR-26a regulates insulin signaling and metabolism of glucose and lipids. Compared with lean individuals, overweight humans had decreased expression of miR-26a in the liver. Moreover, miR-26 was downregulated in 2 obese mouse models compared with control animals. Global or liver-specific overexpression of miR-26a in mice fed a high-fat diet improved insulin sensitivity, decreased hepatic glucose production, and decreased fatty acid synthesis, thereby preventing obesity-induced metabolic complications. Conversely, silencing of endogenous miR-26a in conventional diet-fed mice impaired insulin sensitivity, enhanced glucose production, and increased fatty acid synthesis. miR-26a targeted several key regulators of hepatic metabolism and insulin signaling. These findings reveal miR-26a as a regulator of liver metabolism and suggest miR-26a should be further explored as a potential target for the treatment of T2D.

  14. High accuracy and precision micro injection moulding of thermoplastic elastomers micro ring production

    DEFF Research Database (Denmark)

    Calaon, Matteo; Tosello, Guido; Elsborg, René

    2016-01-01

    /product monitoring and metrology. The study represent a new concept yet to be developed with great potential for high precision mass-manufacturing of highly functional 3D multi-material (i.e. including metal/soft polymer) micro components. The activities related to HINMICO project objectives proves the importance...

  15. High sensory-processing sensitivity at work

    NARCIS (Netherlands)

    Evers, A.; Rasche, J.; Schabracq, M.J.

    2008-01-01

    In this study, the construct validity of an instrument for the measurement of sensory-processing sensitivity (SPS), the Highly Sensitive Person Scale (HSPS), was examined. Among the outcomes, first, the results confirm an earlier conclusion of researchers that the HSPS does not measure a

  16. Ultra-sensitive chemical vapor detection using micro-cavity photothermal spectroscopy.

    Science.gov (United States)

    Hu, Juejun

    2010-10-11

    In this paper, I systematically investigated Micro-Cavity PhotoThermal Spectroscopy (MC-PTS), a novel technique for ultra-sensitive detection of chemical molecular species. I first derive the photothermal enhancement factor and noise characteristics of the technique using a generic theoretical model, followed by numerical analysis of a design example using chalcogenide glass micro-disk cavities. Guidelines for sensor material selection and device design are formulated based on the theoretical insight. The numerical analysis shows that this technique features a record photothermal enhancement factor of 10(4) with respect to conventional cavity-enhanced (multi-pass) infrared absorption spectroscopy, and is capable of detecting non-preconcentrated chemical vapor molecules down to the ppt level with a moderate cavity quality factor of 10(5) and a pump laser power of 0.1 W. Such performance qualifies this technique as one of the most sensitive methods for chemical vapor spectroscopic analysis.

  17. Aluminum nanocantilevers for high sensitivity mass sensors

    DEFF Research Database (Denmark)

    Davis, Zachary James; Boisen, Anja

    2005-01-01

    We have fabricated Al nanocantilevers using a simple, one mask contact UV lithography technique with lateral and vertical dimensions under 500 and 100 nm, respectively. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Furthermore, it is shown...... that Al has a potential higher sensitivity than Si based dynamic sensors. Initial testing of these devices has been conducted using a scanning electron microscope setup were the devices were tested under high vacuum conditions. The Q factor was measured to be approximately 200 and the mass sensitivity...

  18. Inhibition of Src by microRNA-23b increases the cisplatin sensitivity of chondrosarcoma cells.

    Science.gov (United States)

    Huang, Kai; Chen, Jun; Yang, Mo-Song; Tang, Yu-Jun; Pan, Feng

    2017-01-01

    Chondrosarcomas are malignant cartilage-forming tumors from low-grade to high-grade aggressive tumors characterized by metastasis. Cisplatin is an effective DNA-damaging anti-tumor agent for the treatment against a wide variety of solid tumors. However, chondrosarcomas are notorious for their resistance to conventional chemo- and radio- therapies. In this study, we report miR-23b acts as a tumor suppressor in chondrosarcoma. The expressions of miR-23b are down-regulated in chondrosarcoma patient samples and cell lines compared with adjacent normal tissues and human primary chondrocytes. In addition, overexpression of miR-23b suppresses chondrosarcoma cell proliferation. By comparison of the cisplatin resistant chondrosarcoma cells and parental cells, we observed miR-23b was significantly down regulated in cisplatin resistant cells. Moreover, we demonstrate here Src kinase is a direct target of miR-23b in chondrosarcoma cells. Overexpression of miR-23b suppresses Src-Akt pathway, leading to the sensitization of cisplatin resistant chondrosarcoma cells to cisplatin. This chemo-sensitivity effect by the miR-23b-mediated inhibition of Src-Akt pathway is verified with the restoration of Src kinase in miR-23b-overespressing chondrosarcoma cells, resulting in the acquirement of resistance to cisplatin. In summary, our study reveals a novel role of miR-23b in cisplatin resistance in chondrosarcoma and will contribute to the development of the microRNA-targeted anti-cancer therapeutics.

  19. Helix Electrohydrodynamic Printing of Highly Aligned Serpentine Micro/Nanofibers

    Directory of Open Access Journals (Sweden)

    Yongqing Duan

    2017-09-01

    Full Text Available Micro/nano serpentine structures have widespread applications in flexible/stretchable electronics; however, challenges still exist for low-cost, high-efficiency and controllable manufacturing. Helix electrohydrodynamic printing (HE-printing has been proposed here to realize controllable direct-writing of large area, highly aligned serpentine micro/nanofibers by introducing the rope coiling effect into printing process. By manipulating the flying trajectory and solidification degree of the micro/nano jet, the solidified micro/nanofiber flying in a stabilized helical manner and versatile serpentine structures deposited on a moving collector have been achieved. Systematic experiments and theoretical analysis were conducted to study the transformation behavior and the size changing rules for various deposited microstructures, and highly aligned serpentine microfibers were directly written by controlling the applied voltage, nozzle-to-collector distance and collector velocity. Furthermore, a hyper-stretchable piezoelectric device that can detect stretching, bending and pressure has been successfully fabricated using the printed serpentine micro/nanofibers, demonstrating the potential of HE-printing in stretchable electronics manufacturing.

  20. Comparison of radiation sensitivity for three cell lines as measured by the cloning assay and the micro-nucleus test

    NARCIS (Netherlands)

    Stap, J.; Aten, J. A.

    1990-01-01

    The correlation between cell killing and the induction of micro-nuclei was studied for three cell lines after treatment with gamma radiation to investigate whether the frequency of micro-nucleated cells can be used to determine the radiation sensitivity of a cell type. R1 rat rhabdomyosarcoma cells

  1. Micro-meso hierarchical porous carbon as low-cost counter electrode for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Wang Guiqiang, E-mail: wgqiang123@163.com [School of Chemical Engineering, Shandong University of Technology, Zhangzhou Road, Zibo 255049 (China); Huang Congcong; Xing Wei; Zhuo Shuping [School of Chemical Engineering, Shandong University of Technology, Zhangzhou Road, Zibo 255049 (China)

    2011-06-30

    Highlights: > Micro-meso hierarchical porous carbon is used as a low-cost counter electrode. > Hierarchical porous carbon counter electrode shows a high electrocatalytic activity. > The conversion efficiency similar to that of Pt electrode cell is achieved. - Abstract: A micro-meso hierarchical porous carbon with low crystallinity was prepared by a combination of self-assembly and post activation and explored as a counter electrode in dye-sensitized solar cells. Pore structure analysis showed that the pristine mesopores were basically preserved during activation and the micropores were mainly generated within the mesopore wall. Due to its low crystallinity and unique pore-structure including both mesopores and micropores, hierarchical porous carbon exhibited a relatively higher electrocatalytic activity for triiodide reduction, as compared with the pristine mesoporous carbon electrode. This enhanced electrocatalytic activity is beneficial for improving the photovoltaic performance of dye-sensitized solar cells. Under irradiation of 100 mW cm{sup -2}, the dye-sensitized solar cell with hierarchical porous carbon counter electrode showed an overall conversion efficiency of 6.48%, which was 11.5% higher than that of the cell with pristine mesoporous carbon counter electrode.

  2. Design Optimization of Cantilever Based MEMS Micro-accelerometer for High-g Applications

    Directory of Open Access Journals (Sweden)

    B. D. PANT

    2009-11-01

    Full Text Available Design optimization study of micro-cantilever based MEMS accelerometer is presented in this paper. The cantilever structure is dc biased with an ac signal to extract output voltage generated due to the change in capacitance. This signal modifies the behavior of the sensing element. The cantilever performance under a combined inertial and electrostatic force has been considered for estimating the dimensional dependence of cantilever sensitivity, non-linearity, off-set and critical acceleration and operating voltages. The cantilever performance has been verified using ANSYSTM Multiphysics software. Finally, a micro-accelerometer based on an array of 15 cantilevers has been designed and fabricated with a high sensitivity of 3 - 4 mV/g with a non-linearity of < 1 % for high-g (50 g applications.

  3. High-Frequency Fiber-Optic Ultrasonic Sensor Using Air Micro-Bubble for Imaging of Seismic Physical Models

    Directory of Open Access Journals (Sweden)

    Tingting Gang

    2016-12-01

    Full Text Available A micro-fiber-optic Fabry-Perot interferometer (FPI is proposed and demonstrated experimentally for ultrasonic imaging of seismic physical models. The device consists of a micro-bubble followed by the end of a single-mode fiber (SMF. The micro-structure is formed by the discharging operation on a short segment of hollow-core fiber (HCF that is spliced to the SMF. This micro FPI is sensitive to ultrasonic waves (UWs, especially to the high-frequency (up to 10 MHz UW, thanks to its ultra-thin cavity wall and micro-diameter. A side-band filter technology is employed for the UW interrogation, and then the high signal-to-noise ratio (SNR UW signal is achieved. Eventually the sensor is used for lateral imaging of the physical model by scanning UW detection and two-dimensional signal reconstruction.

  4. High-Frequency Fiber-Optic Ultrasonic Sensor Using Air Micro-Bubble for Imaging of Seismic Physical Models.

    Science.gov (United States)

    Gang, Tingting; Hu, Manli; Rong, Qiangzhou; Qiao, Xueguang; Liang, Lei; Liu, Nan; Tong, Rongxin; Liu, Xiaobo; Bian, Ce

    2016-12-14

    A micro-fiber-optic Fabry-Perot interferometer (FPI) is proposed and demonstrated experimentally for ultrasonic imaging of seismic physical models. The device consists of a micro-bubble followed by the end of a single-mode fiber (SMF). The micro-structure is formed by the discharging operation on a short segment of hollow-core fiber (HCF) that is spliced to the SMF. This micro FPI is sensitive to ultrasonic waves (UWs), especially to the high-frequency (up to 10 MHz) UW, thanks to its ultra-thin cavity wall and micro-diameter. A side-band filter technology is employed for the UW interrogation, and then the high signal-to-noise ratio (SNR) UW signal is achieved. Eventually the sensor is used for lateral imaging of the physical model by scanning UW detection and two-dimensional signal reconstruction.

  5. High-Frequency Fiber-Optic Ultrasonic Sensor Using Air Micro-Bubble for Imaging of Seismic Physical Models

    Science.gov (United States)

    Gang, Tingting; Hu, Manli; Rong, Qiangzhou; Qiao, Xueguang; Liang, Lei; Liu, Nan; Tong, Rongxin; Liu, Xiaobo; Bian, Ce

    2016-01-01

    A micro-fiber-optic Fabry-Perot interferometer (FPI) is proposed and demonstrated experimentally for ultrasonic imaging of seismic physical models. The device consists of a micro-bubble followed by the end of a single-mode fiber (SMF). The micro-structure is formed by the discharging operation on a short segment of hollow-core fiber (HCF) that is spliced to the SMF. This micro FPI is sensitive to ultrasonic waves (UWs), especially to the high-frequency (up to 10 MHz) UW, thanks to its ultra-thin cavity wall and micro-diameter. A side-band filter technology is employed for the UW interrogation, and then the high signal-to-noise ratio (SNR) UW signal is achieved. Eventually the sensor is used for lateral imaging of the physical model by scanning UW detection and two-dimensional signal reconstruction. PMID:27983639

  6. Microstructural, Micro-hardness and Sensitization Evaluation in HAZ of Type 316L Stainless Steel Joint with Narrow Gap Welds

    Energy Technology Data Exchange (ETDEWEB)

    Islam, Faisal Shafiqul; Jang, Changheui [KAIST, Daejeon (Korea, Republic of); Kang, Shi Chull [Korea Institute of Nuclear Safety, Daejeon (Korea, Republic of)

    2015-10-15

    From Micro-hardness measurement HAZ zone was found approximately 1-1.5 mm in NGW and DL-EPR test confirmed that 316L NGW HAZ was not susceptible to sensitization as DOS <1% according to sensitization criteria based on reference. In nuclear power plants 316L stainless steels are commonly used material for their metallurgical stability, high corrosion resistance, and good creep and ductility properties at elevated temperatures. Welding zone considered as the weakest and failure initiation source of the components. For safety and economy of nuclear power plants accurate and dependable structural integrity assessment of main components like pressure vessels and piping are need as it joined by different welding process. In similar and dissimilar metal weld it has been observed that weld microstructure cause the variation of mechanical properties through the thickness direction. In the Heat Affected Zone (HAZ) relative to the fusion line face a unique thermal experience during welding.

  7. High precision micro-scale Hall Effect characterization method using in-line micro four-point probes

    DEFF Research Database (Denmark)

    Petersen, Dirch Hjorth; Hansen, Ole; Lin, Rong

    2008-01-01

    Accurate characterization of ultra shallow junctions (USJ) is important in order to understand the principles of junction formation and to develop the appropriate implant and annealing technologies. We investigate the capabilities of a new micro-scale Hall effect measurement method where Hall...... effect is measured with collinear micro four-point probes (M4PP). We derive the sensitivity to electrode position errors and describe a position error suppression method to enable rapid reliable Hall effect measurements with just two measurement points. We show with both Monte Carlo simulations...... and experimental measurements, that the repeatability of a micro-scale Hall effect measurement is better than 1 %. We demonstrate the ability to spatially resolve Hall effect on micro-scale by characterization of an USJ with a single laser stripe anneal. The micro sheet resistance variations resulting from...

  8. Micro injection moulding process validation for high precision manufacture of thermoplastic elastomer micro suspension rings

    DEFF Research Database (Denmark)

    Calaon, M.; Tosello, G.; Elsborg Hansen, R.

    Micro injection moulding (μIM) is one of the most suitable micro manufacturing processes for flexible mass-production of multi-material functional micro components. The technology was employed in this research used to produce thermoplastic elastomer (TPE) micro suspension rings identified...

  9. High-Resolution Macromolecular Structure Determination by MicroED, a cryo-EM Method

    Science.gov (United States)

    Rodriguez, J.A.; Gonen, T.

    2017-01-01

    Microelectron diffraction (MicroED) is a new cryo-electron microscopy (cryo-EM) method capable of determining macromolecular structures at atomic resolution from vanishingly small 3D crystals. MicroED promises to solve atomic resolution structures from even the tiniest of crystals, less than a few hundred nanometers thick. MicroED complements frontier advances in crystallography and represents part of the rebirth of cryo-EM that is making macromolecular structure determination more accessible for all. Here we review the concept and practice of MicroED, for both the electron microscopist and crystallographer. Where other reviews have addressed specific details of the technique (Hattne et al., 2015; Shi et al., 2016; Shi, Nannenga, Iadanza, & Gonen, 2013), we aim to provide context and highlight important features that should be considered when performing a MicroED experiment. PMID:27572734

  10. High throughput sequencing of microRNAs in chicken somites.

    Science.gov (United States)

    Rathjen, Tina; Pais, Helio; Sweetman, Dylan; Moulton, Vincent; Munsterberg, Andrea; Dalmay, Tamas

    2009-05-06

    High throughput Solexa sequencing technology was applied to identify microRNAs in somites of developing chicken embryos. We obtained 651,273 reads, from which 340,415 were mapped to the chicken genome representing 1701 distinct sequences. Eighty-five of these were known microRNAs and 42 novel miRNA candidates were identified. Accumulation of 18 of 42 sequences was confirmed by Northern blot analysis. Ten of the 18 sequences are new variants of known miRNAs and eight short RNAs are novel miRNAs. Six of these eight have not been reported by other deep sequencing projects. One of the six new miRNAs is highly enriched in somite tissue suggesting that deep sequencing of other specific tissues has the potential to identify novel tissue specific miRNAs.

  11. Shape control of Co3O4 micro-structures for high-performance gas sensor

    Science.gov (United States)

    Zhou, Qu; Zeng, Wen

    2018-01-01

    Recently, spinel cobalt oxide (Co3O4) structure has been widely investigated due to its excellent sensitivity towards various noxious gases and good response/recovery speed at low concentration. In this work, we designed and synthesized two kinds of different Co3O4 micro-structure (cube and octahedron) with a similar size. After fabricating them into gas sensors, we found that the crystal plane structure of Co3O4 has an important effect on its gas sensing performance. Furthermore, the {111} planes of Co3O4may be more sensitive than {100} planes to various testing gases. Co3O4 octahedrons micro-structure exhibits an excellent sensitivity (about 12.6), good response/recovery speed and cycling stability (no decline even after 2 days) under 50 ppm ethanol gases at working temperature of 200 °C. As such, thisCo3O4 octahedrons micro-structure is a promising candidate for a high-performance gas sensing material.

  12. The Effect of MicroRNA-124 Overexpression on Anti-Tumor Drug Sensitivity.

    Directory of Open Access Journals (Sweden)

    Shiau-Mei Chen

    Full Text Available MicroRNAs play critical roles in regulating various physiological processes, including growth and development. Previous studies have shown that microRNA-124 (miR-124 participates not only in regulation of early neurogenesis but also in suppression of tumorigenesis. In the present study, we found that overexpression of miR-124 was associated with reduced DNA repair capacity in cultured cancer cells and increased sensitivity of cells to DNA-damaging anti-tumor drugs, specifically those that cause the formation of DNA strand-breaks (SBs. We then examined which DNA repair-related genes, particularly the genes of SB repair, were regulated by miR-124. Two SB repair-related genes, encoding ATM interactor (ATMIN and poly (ADP-ribose polymerase 1 (PARP1, were strongly affected by miR-124 overexpression, by binding of miR-124 to the 3¢-untranslated region of their mRNAs. As a result, the capacity of cells to repair DNA SBs, such as those resulting from homologous recombination, was significantly reduced upon miR-124 overexpression. A particularly important therapeutic implication of this finding is that overexpression of miR-124 enhanced cell sensitivity to multiple DNA-damaging agents via ATMIN- and PARP1-mediated mechanisms. The translational relevance of this role of miR-124 in anti-tumor drug sensitivity is suggested by the finding that increased miR-124 expression correlates with better breast cancer prognosis, specifically in patients receiving chemotherapy. These findings suggest that miR-124 could potentially be used as a therapeutic agent to improve the efficacy of chemotherapy with DNA-damaging agents.

  13. MicroRNA-203 Modulates the Radiation Sensitivity of Human Malignant Glioma Cells

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Ji Hyun [Department of Radiation Oncology, Graduate School of Medicine, Seoul National University, Seoul (Korea, Republic of); Hwang, Yeo Hyun; Lee, David J.; Kim, Dan Hyo; Park, Ji Min [Medical Science Research Institute, Seoul National University Bundang Hospital, Kyeonggido (Korea, Republic of); Wu, Hong-Gyun [Department of Radiation Oncology, Graduate School of Medicine, Seoul National University, Seoul (Korea, Republic of); Kim, In Ah, E-mail: inah228@snu.ac.kr [Department of Radiation Oncology, Graduate School of Medicine, Seoul National University, Seoul (Korea, Republic of); Medical Science Research Institute, Seoul National University Bundang Hospital, Kyeonggido (Korea, Republic of); Cancer Research Institute, Seoul National University, Seoul (Korea, Republic of)

    2016-02-01

    Purpose: We investigated whether miR-203 could modulate the radiation sensitivity of glioblastoma (GBM) cells and which target gene(s) could be involved. Methods and Materials: Three human malignant glioma (MG) cell lines and normal human astrocytes were transfected with control microRNA, pre-miR-203, or antisense miR-203. Real-time PCR (RT-PCR), clonogenic assays, immunofluorescence, and invasion/migration assays were performed. To predict the target(s), bioinformatics analyses using microRNA target databases were performed. Results: Overexpression of miR-203 increased the radiation sensitivity of all 3 human MG cell lines and prolonged radiation-induced γ-H2AX foci formation. Bioinformatics analyses suggested that miR-203 could be involved in post-transcriptional control of DNA repair, PI3K/AKT, SRC, and JAK/STAT3 and the vascular signaling pathway. Western blot analysis validated the fact that miR-203 downregulated ATM, RAD51, SRC, PLD2, PI3K-AKT, JAK-STAT3, VEGF, HIF-1α, and MMP2. Overexpression of miR-203 inhibited invasion and migration potentials, downregulated SLUG and Vimentin, and upregulated Claudin-1 and ZO1. Conclusions: These data demonstrate that miR-203 potentially controls DNA damage repair via the PI3K/AKT and JAK/STAT3 pathways and may collectively contribute to the modulation of radiation sensitivity in MG cells by inhibiting DNA damage repair, prosurvival signaling, and epithelium-mesenchyme transition. Taken together, these findings demonstrate that miR-203 could be a target for overcoming the radiation resistance of GBM.

  14. Thermal analysis of high pressure micro plasma discharge

    Science.gov (United States)

    Mobli, Mostafa

    High pressure micro plasma discharge has been at the center of interest in recent years, because of their vast applications, ease of access and cost efficiency. This attributes to atmospheric discharges that are generated in ambient conditions and therefore can be readily applicable to everyday use. The absence of vacuum makes these high pressure discharges to be inexpensive to operate. Despite the ease of operation, the high pressure is a source of enhanced gas heating as the gas temperature cannot be controlled by diffusion alone. Gas heating is therefore an important factor when it comes to the simulation of high pressure micro plasma discharge, unlike their low pressure counterpart where the heat generation is almost negligible. Low pressure discharge due to their low degree of collisionality generates ionic species and electrons at small concentrations, whereas high pressure discharge due to their higher gas density produces ions and electrons at higher concentrations which is a direct consequence of increase collision. The higher gas density and consequential large concentration of ionic species and electron contributes directly to higher heat generation rates. . In this thesis the gas temperature transport of high pressure micro plasma discharge has been studied with a special focus on the heat source terms, temperature boundary conditions, temperature distribution in the solid phase electrodes and the gas phase and their overall influence on the plasma characteristics. For this purpose a multi-physics mathematical model has been developed that comprised of a plasma module, neutral gas temperature module, external circuit module and conjugate heat transfer module. The plasma module consisted of conservation of the different ionic, electronically excited species, radicals, neutrals and electrons, conservation of the electron temperature, and electric field. The external circuit module resolved the coupled driving circuit comprised of a voltage source, ballast

  15. Cooled membrane for high sensitivity gas sampling.

    Science.gov (United States)

    Jiang, Ruifen; Pawliszyn, Janusz

    2014-04-18

    A novel sample preparation method that combines the advantages of high surface area geometry and cold surface effect was proposed to achieve high sensitivity gas sampling. To accomplish this goal, a device that enables the membrane to be cooled down was developed for sampling, and a gas chromatograph-mass spectrometer was used for separation and quantification analysis. Method development included investigation of the effect of membrane temperature, membrane size, gas flow rate and humidity. Results showed that high sensitivity for equilibrium sampling, such as limonene sampling in the current study could be achieved by either cooling down the membrane and/or using a large volume extraction phase. On the other hand, for pre-equilibrium extraction, in which the extracted amount was mainly determined by membrane surface area and diffusion coefficient, high sensitivity could be obtained by using thinner membranes with a larger surface and/or a higher sampling flow rate. In addition, humidity showed no significant influence on extraction efficiency, due to the absorption property of the liquid extraction phase. Next, the limit of detection (LOD) was found, and the reproducibility of the developed cooled membrane gas sampling method was evaluated. Results showed that LODs with a membrane diameter of 19mm at room temperature sampling were 9.2ng/L, 0.12ng/L, 0.10ng/L for limonene, cinnamaldehyde and 2-pentadecanone, respectively. Intra- and inter-membrane sampling reproducibility revealed RSD% lower than 8% and 13%, respectively. Results uniformly demonstrated that the proposed cooled membrane device could serve as an alternative powerful tool for future gas sampling. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. A simple and sensitive method for lipoprotein and lipids profiles analysis of individual micro-liter scale serum samples.

    Science.gov (United States)

    Yang, Liu; Fan, Baoyan; Yang, Kangmin; Zhu, Haibo

    2012-02-01

    A simple and sensitive method to determine lipoprotein and lipids profiles in micro-liter scale individual serum sample is not presently available. Traditional lipoprotein separation techniques either by ultra-centrifugation or by liquid chromatography methods have their disadvantages in both lipoprotein separation and lipids component quantification. In this study we used small volume needing size-exclusion fast protein liquid chromatography to separate different lipoprotein subclasses in 50μL serum. And lipids contents, such as cholesterol, cholesterol ester and triacylglycerol, were measured by using two different fluorescence-based lipid detection methods. With this method, very low density lipoprotein, low density lipoprotein and high density lipoprotein could be easily separated, and follow-up lipid detection was completed by simple kinds of reactions. Serum lipoprotein and lipids profiling from C57BL/6 mice (n=5) and human (n=5) were analyzed. The elution profiles of five individuals were highly reproducible, and there were lipoprotein and lipids distribution variations between C57BL/6 mice and human beings. In conclusion, this method which combined small volume needing size-exclusion fast protein liquid chromatography and fluorescence-based lipids measurement, provided a simple, efficient, integrity and reproducible procedure for determining serum lipoprotein and lipids profiles in micro-liter scale levels. It becomes possible that determination of lipoprotein profiles and gaining information of lipids in different lipoproteins can be accomplished simultaneously. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  17. High temperature x-ray micro-tomography

    Energy Technology Data Exchange (ETDEWEB)

    MacDowell, Alastair A., E-mail: aamacdowell@lbl.gov; Barnard, Harold; Parkinson, Dilworth Y.; Gludovatz, Bernd [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); Haboub, Abdel [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); current –Lincoln Univ., Jefferson City, Missouri, 65101 (United States); Larson, Natalie; Zok, Frank [University California Santa Barbara, Santa Barbara CA 93106 (United States); Panerai, Francesco; Mansour, Nagi N. [NASA Ames Research Centre, Moffett Field, CA, 94035 (United States); Bale, Hrishikesh [University California Berkeley, Berkeley, CA 94720 (United States); current - Carl Zeiss X-ray Microscopy, 4385 Hopyard Rd #100, Pleasanton, CA 94588 (United States); Acevedo, Claire [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); University California San Francisco, San Francisco, CA 94143 (United States); Liu, Dong [University of Bristol, Bristol BS8 1TH (United Kingdom); Ritchie, Robert O. [Lawrence Berkeley National Lab., Berkeley, CA 94720 (United States); University California Berkeley, Berkeley, CA 94720 (United States)

    2016-07-27

    There is increasing demand for 3D micro-scale time-resolved imaging of samples in realistic - and in many cases extreme environments. The data is used to understand material response, validate and refine computational models which, in turn, can be used to reduce development time for new materials and processes. Here we present the results of high temperature experiments carried out at the x-ray micro-tomography beamline 8.3.2 at the Advanced Light Source. The themes involve material failure and processing at temperatures up to 1750°C. The experimental configurations required to achieve the requisite conditions for imaging are described, with examples of ceramic matrix composites, spacecraft ablative heat shields and nuclear reactor core Gilsocarbon graphite.

  18. Challenges in high accuracy surface replication for micro optics and micro fluidics manufacture

    DEFF Research Database (Denmark)

    Tosello, Guido; Hansen, Hans Nørgaard; Calaon, Matteo

    2014-01-01

    Patterning the surface of polymer components with microstructured geometries is employed in optical and microfluidic applications. Mass fabrication of polymer micro structured products is enabled by replication technologies such as injection moulding. Micro structured tools are also produced by r...

  19. Correlation of oxygenation and perfusion sensitive MRI with invasive micro probe measurements in healthy mice brain

    Energy Technology Data Exchange (ETDEWEB)

    Sedlacik, Jan; Fiehler, Jens [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Neuroradiology; Reitz, Matthias; Schmidt, Nils O. [University Medical Center Hamburg-Eppendorf, Hamburg (Germany). Neurosurgery; Bolar, Divya S. [Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging, Charlestown, MA (United States). Radiology; Adalsteinsson, Elfar [Massachusetts Institute of Technology, Cambridge, MA (United States). Electrical Engineering and Computer Science

    2015-05-01

    The non-invasive assessment of (patho-)physiological parameters such as, perfusion and oxygenation, is of great importance for the characterization of pathologies e.g., tumors, which may be helpful to better predict treatment response and potential outcome. To better understand the influence of physiological parameters on the investigated oxygenation and perfusion sensitive MRI methods, MRI measurements were correlated with subsequent invasive micro probe measurements during free breathing conditions of air, air+10% CO2 and 100% O2 in healthy mice brain. MRI parameters were the irreversible (R2), reversible (R2') and effective (R2*) transverse relaxation rates, venous blood oxygenation level assessed by quantitative blood oxygenation level dependent (qBOLD) method and cerebral blood flow (CBF) assessed by arterial spin labeling (ASL) using a 7T small animal MRI scanner. One to two days after MRI, tissue perfusion and pO2 were measured by Laser-Doppler flowmetry and fluorescence quenching micro probes, respectively. The tissue pO2 values were converted to blood oxygen saturation by using the Hill equation. The animals were anesthetized by intra peritoneal injection of ketamine-xylazine-acepromazine (10-2-0.3 mg/ml.kg). Results for normal/hypercapnia/hyperoxia conditions were: R2[s {sup and} -1] = 20.7/20.4/20.1, R2*[s {sup and} -1] = 31.6/29.6/25.9, R2'[s {sup and} 1] = 10.9/9.2/5.7, qBOLD venous blood oxygenation level = 0.43/0.51/0.56, CBF[ml.min {sup and} -1.100g {sup and} -1] = 70.6/105.5/81.8, Laser-Doppler flowmetry[a.u.] = 89.2/120.2/90.6 and pO2[mmHg] = 6.3/32.3/46.7. All parameters were statistically significantly different with P < 0.001 between all breathing conditions. All MRI and the corresponding micro probe measurements were also statistically significantly (P ≤ 0.03) correlated with each other. However, converting the tissue pO2 to blood oxygen saturation = 0.02/0.34/0.63, showed only very limited agreement with the qBOLD venous blood

  20. microRNA160 dictates stage-specific auxin and cytokinin sensitivities and directs soybean nodule development.

    Science.gov (United States)

    Nizampatnam, Narasimha Rao; Schreier, Spencer John; Damodaran, Suresh; Adhikari, Sajag; Subramanian, Senthil

    2015-10-01

    Legume nodules result from coordinated interactions between the plant and nitrogen-fixing rhizobia. The phytohormone cytokinin promotes nodule formation, and recent findings suggest that the phytohormone auxin inhibits nodule formation. Here we show that microRNA160 (miR160) is a key signaling element that determines the auxin/cytokinin balance during nodule development in soybean (Glycine max). miR160 appears to promote auxin activity by suppressing the levels of the ARF10/16/17 family of repressor ARF transcription factors. Using quantitative PCR assays and a fluorescence miRNA sensor, we show that miR160 levels are relatively low early during nodule formation and high in mature nodules. We had previously shown that ectopic expression of miR160 in soybean roots led to a severe reduction in nodule formation, coupled with enhanced sensitivity to auxin and reduced sensitivity to cytokinin. Here we show that exogenous cytokinin restores nodule formation in miR160 over-expressing roots. Therefore, low miR160 levels early during nodule development favor cytokinin activity required for nodule formation. Suppression of miR160 levels using a short tandem target mimic (STTM160) resulted in reduced sensitivity to auxin and enhanced sensitivity to cytokinin. In contrast to miR160 over-expressing roots, STTM160 roots had increased nodule formation, but nodule maturation was significantly delayed. Exogenous auxin partially restored proper nodule formation and maturation in STTM160 roots, suggesting that high miR160 activity later during nodule development favors auxin activity and promotes nodule maturation. Therefore, miR160 dictates developmental stage-specific sensitivities to auxin and cytokinin to direct proper nodule formation and maturation in soybean. © 2015 The Authors The Plant Journal © 2015 John Wiley & Sons Ltd.

  1. Review of high-sensitivity Radon studies

    Science.gov (United States)

    Wojcik, M.; Zuzel, G.; Simgen, H.

    2017-10-01

    A challenge in many present cutting-edge particle physics experiments is the stringent requirements in terms of radioactive background. In peculiar, the prevention of Radon, a radioactive noble gas, which occurs from ambient air and it is also released by emanation from the omnipresent progenitor Radium. In this paper we review various high-sensitivity Radon detection techniques and approaches, applied in the experiments looking for rare nuclear processes happening at low energies. They allow to identify, quantitatively measure and finally suppress the numerous sources of Radon in the detectors’ components and plants.

  2. The high sensitivity double beta spectrometer TGV

    Science.gov (United States)

    Briancon, Ch.; Brudanin, V. B.; Egorov, V. G.; Janout, Z.; Koníček, J.; Kovalík, A.; Kovalenko, V. E.; Kubašta, J.; Pospíšil, S.; Revenko, A. V.; Rukhadze, N. I.; Salamatin, A. V.; Sandukovsky, V. G.; Štekl, I.; Timkin, V. V.; Tsupko-Sitnikov, V. V.; Vorobel, V.; Vylov, Ts.

    1996-02-01

    A high sensitivity double beta spectrometer TGV (Telescope Germanium Vertical) has been developed. It is based on 16 HPGe detectors of volume 1200 × 6 mm 3 each in the same cryostat. The TGV spectrometer was proposed for the study of ultrarare nuclear processes (e.g. 2νββ, 0νββ, 2νEC/EC). Details of the TGV spectrometer construction are described, the principles of background suppression, the results of Monte Carlo simulations and the results of test background measurements (in Dubna and Modane underground laboratory) are provided.

  3. [Clinical interpretation of high sensitivity troponin T].

    Science.gov (United States)

    Alquézar Arbé, Aitor; Santaló Bel, Miguel; Sionis, Alessandro

    2015-09-21

    Determination of cardiac troponin (cTn) is necessary for the diagnosis of acute myocardial infarction without ST segment elevation. However Tnc can be released in other clinical situations. The development of high-sensitive cTn T assays (hs-cTnT) improves the management of patients with suspected acute coronary syndrome. Here, we provide an overview of the diverse causes of hs-cTnT elevation and recommend strategies for the clinical interpretation of the test result. Copyright © 2014 Elsevier España, S.L.U. All rights reserved.

  4. Sensitivity enhancement of a micro-scale biomimetic tactile sensor with epidermal ridges

    Science.gov (United States)

    Zhang, Yuhua

    2010-08-01

    A microscale biomimetic tactile sensor with epidermal ridges is proposed to enhance the sensitivity of force detection. Guided by the principles of the human tactile perception mechanism, specifically the epidermal ridges, artificial epidermal ridges made of polydimethylsiloxane (PDMS) were designed and placed on micro-fabricated metal strain gauge arrays. A polyimide layer was fabricated to facilitate attachment between the metal and PDMS, so that patterned copper could be deposited on the polyimide to function as the strain gauges. The aspect ratio of the artificial epidermal ridges was optimized using material stability calculations and finite element method (FEM) simulations, and the optimal structure obtained was 400 µm in width and 110 µm in height. Experiments verified the effectiveness of enhancing the sensitivity of such a tactile sensor with the artificial epidermal ridges, in that the outputs of the strain gauges were 1.8 times more sensitive than those of a tactile sensor without ridges. The proposed artificial epidermal ridges are readily applicable to any developed tactile sensors for performance enhancement.

  5. High resolution micro-pattern gaseous tracking detectors

    CERN Document Server

    Bachmann, S; Ropelewski, Leszek; Sauli, Fabio

    2000-01-01

    Micro-strip gas chambers have excellent localization properties, high rate capability and good granularity, and have been adopted for may experimental set-ups. Two recurrent problems hower have been reported: slow degradation under sustained irradiation, and damaging accidental discharges. New breeds of detectors aim at improving on these crucial points: CAT, micromegas, gas electron multiplier are examples. Very performing, they are more robust and reliable. Two- stage devices, making use of a gas electron multiplier as first element, permit to sustain larger gains in presence of high rates and heavily ionizing tracks. (16 refs).

  6. Novel Analytic Method for Determining Micro-Doppler Measurement Sensitivity in Life-detection Radar

    Directory of Open Access Journals (Sweden)

    Hu Cheng

    2016-10-01

    Full Text Available In recent years, a new non-contact life detecting device has been developed, known as life-detection radar, which can measure bodily movement and locate human subjects. Typically, the amplitude of the vibration being measured is quite small, so the measurement is easily contaminated by noise in the radar system. To date, there is no effective index for judging the influence of noise on the vibration measurements in this radar system. To solve this problem, in this paper, we define the micro-Doppler measurement sensitivity to analyze the influence of noise on the measurement. We then perform a simulation to generate a performance curve for the radar system.

  7. High sensitivity troponin and valvular heart disease.

    Science.gov (United States)

    McCarthy, Cian P; Donnellan, Eoin; Phelan, Dermot; Griffin, Brian P; Enriquez-Sarano, Maurice; McEvoy, John W

    2017-07-01

    Blood-based biomarkers have been extensively studied in a range of cardiovascular diseases and have established utility in routine clinical care, most notably in the diagnosis of acute coronary syndrome (e.g., troponin) and the management of heart failure (e.g., brain-natriuretic peptide). The role of biomarkers is less well established in the management of valvular heart disease (VHD), in which the optimal timing of surgical intervention is often challenging. One promising biomarker that has been the subject of a number of recent VHD research studies is high sensitivity troponin (hs-cTn). Novel high-sensitivity assays can detect subclinical myocardial damage in asymptomatic individuals. Thus, hs-cTn may have utility in the assessment of asymptomatic patients with severe VHD who do not have a clear traditional indication for surgical intervention. In this state-of-the-art review, we examine the current evidence for hs-cTn as a potential biomarker in the most commonly encountered VHD conditions, aortic stenosis and mitral regurgitation. This review provides a synopsis of early evidence indicating that hs-cTn has promise as a biomarker in VHD. However, the impact of its measurement on clinical practice and VHD outcomes needs to be further assessed in prospective studies before routine clinical use becomes a reality. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.

    Science.gov (United States)

    Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart; Cornelissen, Ria

    2014-01-01

    The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.

  9. High throughput micro-well generation of hepatocyte micro-aggregates for tissue engineering.

    Directory of Open Access Journals (Sweden)

    Elien Gevaert

    Full Text Available The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the high throughput generation of hepatocyte aggregates, uniform in size. In our study we observed that aggregation of hepatocytes had a beneficial effect on the expression of certain hepatocyte specific markers. Moreover we observed that the beneficial effect was dependent on the aggregate dimensions, indicating that aggregate parameters should be carefully considered. In a second part of the study, the selected aggregates were immobilized by encapsulation in methacrylamide-modified gelatin. Phenotype evaluations revealed that a stable hepatocyte phenotype could be maintained during 21 days when encapsulated in the hydrogel. In conclusion we have demonstrated the beneficial use of micro-well chips for hepatocyte aggregation and the size-dependent effects on hepatocyte phenotype. We also pointed out that methacrylamide-modified gelatin is suitable for the encapsulation of these aggregates.

  10. MicroRNA-218 Increases the Sensitivity of Bladder Cancer to Cisplatin by Targeting Glut1

    Directory of Open Access Journals (Sweden)

    Peng Li

    2017-02-01

    Full Text Available Background/Aims: MicroRNA-218 (miR-218 is down-regulated in many malignancies that have been implicated in the regulation of diverse processes in cancer cells. However, the involvement of miR-218 in chemo-sensitivity to cisplatin and the precise mechanism of this action remained unknown in bladder cancer. Methods: qRT-PCR was used to detect miR-218 and its target Glut1 expression in bladder cancer cell lines T24 and EJ. CCK-8 method was utilized to measure the cell viability. IC 50 was calculated via a probit regression model. Glut1 was detected by western blotting for analysis of potential mechanism. Luciferase reporter assay was utilized to validate Glut1 as a direct target gene of miR-218. The intracellular level of GSH and ROS were determined using a commercial colorimetric assay kit and 2’, 7’-dichlorodihydro-fluorescein diacetate, respectively. Results: Over-expression of miR-218 significantly reduced the rate of glucose uptake and total level of GSH and enhanced the chemo-sensitivity of bladder cancer to cisplatin. Mechanistically, Glut1 was found to be a direct and functional target of miR-218. Up-regulation of Glut1 could restore chemo-resistance in T24 and EJ cells. On the contrary, knockdown of Glut1 could generate a similar effect as up-regulating the expression of miR-218. Conclusions: MiR-218 increases the sensitivity of bladder cancer to cisplatin by targeting Glut1. Restoration of miR-218 and repression of glut1 may provide a potential strategy to restore chemo-sensitivity in bladder cancer.

  11. High-precision micro/nano-scale machining system

    Science.gov (United States)

    Kapoor, Shiv G.; Bourne, Keith Allen; DeVor, Richard E.

    2014-08-19

    A high precision micro/nanoscale machining system. A multi-axis movement machine provides relative movement along multiple axes between a workpiece and a tool holder. A cutting tool is disposed on a flexible cantilever held by the tool holder, the tool holder being movable to provide at least two of the axes to set the angle and distance of the cutting tool relative to the workpiece. A feedback control system uses measurement of deflection of the cantilever during cutting to maintain a desired cantilever deflection and hence a desired load on the cutting tool.

  12. Highly Sensitive Electro-Optic Modulators

    Energy Technology Data Exchange (ETDEWEB)

    DeVore, Peter S [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-26

    There are very important diagnostic and communication applications that receive faint electrical signals to be transmitted over long distances for capture. Optical links reduce bandwidth and distance restrictions of metal transmission lines; however, such signals are only weakly imprinted onto the optical carrier, resulting in low fidelity transmission. Increasing signal fidelity often necessitates insertion of radio-frequency (RF) amplifiers before the electro-optic modulator, but (especially at high frequencies) RF amplification results in large irreversible distortions. We have investigated the feasibility of a Sensitive and Linear Modulation by Optical Nonlinearity (SALMON) modulator to supersede RF-amplified modulators. SALMON uses cross-phase modulation, a manifestation of the Kerr effect, to enhance the modulation depth of an RF-modulated optical wave. This ultrafast process has the potential to result in less irreversible distortions as compared to a RF-amplified modulator due to the broadband nature of the Kerr effect. Here, we prove that a SALMON modulator is a feasible alternative to an RFamplified modulator, by demonstrating a sensitivity enhancement factor greater than 20 and significantly reduced distortion.

  13. High resolution micro-pattern gas detectors for particle physics

    Science.gov (United States)

    Shekhtman, L.; Aulchenko, V.; Bobrovnikov, V.; Bondar, A.; Fedotovich, G.; Kudryavtsev, V.; Maltsev, T.; Nikolenko, D.; Rachek, I.; Zhilich, V.; Zhulanov, V.

    2017-07-01

    Micro-pattern gaseous detectors (MPGDs) allow operation at very high background particle flux with high efficiency and spatial resolution. This combination of parameters determines the main application of these detectors in particle physics experiments: precise tracking in the areas close to the beam and in the end-cap regions of general-purpose detectors. MPGDs of different configurations have been developed and are under development for several experiments in the Budker INP. The system of eight two-coordinate detectors based on a cascade of Gas Electron Multipliers (GEM) is working in the KEDR experiment at the VEPP-4M collider in the tagging system that detects electrons and positrons that lost their energy in two-photon interactions and left the equilibrium orbit due to a dedicated magnetic system. Another set of cascaded GEM detectors is developed for the almost-real Photon Tagging System (PTS) of the DEUTRON facility at the VEPP-3 storage ring. The PTS contains three very light detectors with very high spatial resolution (below 50 μm). Dedicated detectors based on cascaded GEMs are developed for the extracted electron beam facility at the VEPP-4M collider. These devices will allow precise particle tracking with minimal multiple scattering due to very low material content. An upgrade of the coordinate system of the CMD-3 detector at the VEPP-2000 collider is proposed on the basis of the resistive micro-WELL (μ-rWELL). A research activity on this subject has just started.

  14. High sensitive radiation detector for radiology dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Valente, M.; Malano, F. [Instituto de Fisica Enrique Gaviola, Oficina 102 FaMAF - UNC, Av. Luis Medina Allende, Ciudad Universitaria, 5000 Cordoba (Argentina); Molina, W.; Vedelago, J., E-mail: valente@famac.unc.edu.ar [Laboratorio de Investigaciones e Instrumentacion en Fisica Aplicada a la Medicina e Imagenes por Rayos X, Laboratorio 448 FaMAF - UNC, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2014-08-15

    Fricke solution has a wide range of applications as radiation detector and dosimetry. It is particularly appreciated in terms of relevant comparative advantages, like tissue equivalence when prepared in aqueous media like gel matrix, continuous mapping capability, dose rate recorded and incident direction independence as well as linear dose response. This work presents the development and characterization of a novel Fricke gel system, based on modified chemical compositions making possible its application in clinical radiology. Properties of standard Fricke gel dosimeter for high dose levels are used as starting point and suitable chemical modifications are introduced and carefully investigated in order to attain high resolution for low dose ranges, like those corresponding to radiology interventions. The developed Fricke gel radiation dosimeter system achieves the expected typical dose dependency, actually showing linear response in the dose range from 20 up to 4000 mGy. Systematic investigations including several chemical compositions are carried out in order to obtain a good enough dosimeter response for low dose levels. A suitable composition among those studied is selected as a good candidate for low dose level radiation dosimetry consisting on a modified Fricke solution fixed to a gel matrix containing benzoic acid along with sulfuric acid, ferrous sulfate, xylenol orange and ultra-pure reactive grade water. Dosimeter samples are prepared in standard vials for its in phantom irradiation and further characterization by spectrophotometry measuring visible light transmission and absorbance before and after irradiation. Samples are irradiated by typical kV X-ray tubes and calibrated Farmer type ionization chamber is used as reference to measure dose rates inside phantoms in at vials locations. Once sensitive material composition is already optimized, dose-response curves show significant improvement regarding overall sensitivity for low dose levels. According to

  15. Direct detection of microRNAs using isothermal amplification and molecular beacon with excellent sensitivity and specificity

    Science.gov (United States)

    Zhang, Wancun; Zhang, Qi; Qian, Zhiyu; Gu, Yueqing

    2017-02-01

    MicroRNAs (miRNAs) play important roles in a wide range of biological processes, including proliferation, development, metabolism, immunological response, tumorigenesis, and viral infection. The detection of miRNAs is imperative for gaining a better understanding of the functions of these biomolecules and has great potential for the early diagnosis of human disease as well as the discovery of new drugs through the use of miRNAs as targets. In this article, we develop a highly sensitive, and specific miRNA assay based on the two-stage isothermal amplification reactions and molecular beacon. The two-stage isothermal amplification reactions involves two templates and two-stage amplification reactions under isothermal conditions. The first template enables the amplification of miRNA, and the second template enables the conversion of miRNA to the reporter oligonucleotide(Y). Importantly, different miRNAs can be converted to the same Y seperately, which can hybridize with the same set of molecular beacon to generate fluorescent signals. This assay is highly sensitive and specific with a detection limit of 1 fM and can even discriminate single-nucleotide differences. Moreover, in combination with the specific templates, this method can be applied for multiplex miRNA assay by simply using the same molecular beacon. This method has potential to become a promising miRNA quantification method in biomedical research and clinical diagnosis.

  16. Catalytic Hairpin Assembly Actuated DNA Nanotweezer for Logic Gate Building and Sensitive Enzyme-Free Biosensing of MicroRNAs.

    Science.gov (United States)

    Li, Dandan; Cheng, Wei; Li, Yujian; Xu, YongJie; Li, Xinmin; Yin, Yibing; Ju, Huangxian; Ding, Shijia

    2016-08-02

    A target-switched DNA nanotweezer is designed for AND logic gate operation and enzyme-free detection of microRNAs (miRNAs) by catalytic hairpin assembly (CHA) and proximity-dependent DNAzyme formation. The double crossover motif-based nanotweezer consists of an arched structure as the set strand for target inputs and two split G-rich DNAs at the termini of two arms for signal output. Upon a CHA, a small amount of binary target inputs can switch numerous open nanotweezers to a closed state, which leads to the formation of proximity-dependent DNAzyme in the presence of hemin to produce a highly sensitive biosensing system. The binary target inputs can be used for successful building of AND logic gate, which is validated by polyacrylamide gel electrophoresis, surface plasmon resonance and the biosensing signal. The developed biosensing system shows a linear response of the output chemiluminescence signal to input binary miRNAs with a detection limit of 30 fM. It can be used for miRNAs analysis in complex sample matrix. This system provides a simple and reusable platform for logic gate operation and enzyme-free, highly sensitive, and specific multianalysis of miRNAs.

  17. High aspect ratio micro tool manufacturing for polymer replication using mu EDM of silicon, selective etching and electroforming

    DEFF Research Database (Denmark)

    Tosello, Guido; Bissacco, Giuliano; Tang, Peter Torben

    2008-01-01

    Mass fabrication of polymer micro components with high aspect ratio micro-structures requires high performance micro tools allowing the use of low cost replication processes such as micro injection moulding. In this regard an innovative process chain, based on a combination of micro electrical...... discharge machining (mu EDM) of a silicon substrate, electroforming and selective etching was used for the manufacturing of a micro tool. The micro tool was employed for polymer replication by means of the injection moulding process....

  18. High sensitivity field asymmetric ion mobility spectrometer.

    Science.gov (United States)

    Chavarria, Mario A; Matheoud, Alessandro V; Marmillod, Philippe; Liu, Youjiang; Kong, Deyi; Brugger, Jürgen; Boero, Giovanni

    2017-03-01

    A high sensitivity field asymmetric ion mobility spectrometer (FAIMS) was designed, fabricated, and tested. The main components of the system are a 10.6 eV UV photoionization source, an ion filter driven by a high voltage/high frequency n-MOS inverter circuit, and a low noise ion detector. The ion filter electronics are capable to generate square waveforms with peak-to-peak voltages up to 1000 V at frequencies up to 1 MHz with adjustable duty cycles. The ion detector current amplifier has a gain up to 10 12 V/A with an effective equivalent input noise level down to about 1 fA/Hz 1/2 during operation with the ion filter at the maximum voltage and frequency. The FAIMS system was characterized by detecting different standard chemical compounds. Additionally, we investigated the use of a synchronous modulation/demodulation technique to improve the signal-to-noise ratio in FAIMS measurements. In particular, we implemented the modulation of the compensation voltage with the synchronous demodulation of the ion current. The analysis of the measurements at low concentration levels led to an extrapolated limit of detection for acetone of 10 ppt with an averaging time of 1 s.

  19. High sensitivity field asymmetric ion mobility spectrometer

    Science.gov (United States)

    Chavarria, Mario A.; Matheoud, Alessandro V.; Marmillod, Philippe; Liu, Youjiang; Kong, Deyi; Brugger, Jürgen; Boero, Giovanni

    2017-03-01

    A high sensitivity field asymmetric ion mobility spectrometer (FAIMS) was designed, fabricated, and tested. The main components of the system are a 10.6 eV UV photoionization source, an ion filter driven by a high voltage/high frequency n-MOS inverter circuit, and a low noise ion detector. The ion filter electronics are capable to generate square waveforms with peak-to-peak voltages up to 1000 V at frequencies up to 1 MHz with adjustable duty cycles. The ion detector current amplifier has a gain up to 1012 V/A with an effective equivalent input noise level down to about 1 fA/Hz1/2 during operation with the ion filter at the maximum voltage and frequency. The FAIMS system was characterized by detecting different standard chemical compounds. Additionally, we investigated the use of a synchronous modulation/demodulation technique to improve the signal-to-noise ratio in FAIMS measurements. In particular, we implemented the modulation of the compensation voltage with the synchronous demodulation of the ion current. The analysis of the measurements at low concentration levels led to an extrapolated limit of detection for acetone of 10 ppt with an averaging time of 1 s.

  20. MicroRNA-181a enhances the chemotherapeutic sensitivity of chronic myeloid leukemia to imatinib

    Science.gov (United States)

    WANG, GUANGYU; ZHAO, RAN; ZHAO, XINGSHENG; CHEN, XI; WANG, DONG; JIN, YINJI; LIU, XI; ZHAO, CI; ZHU, YUANYUAN; REN, CHENGCHENG; LI, MINGHUI; JIN, XIAOMING; ZHANG, FENGMIN; ZHONG, ZHAOHUA; WANG, TIANZHEN; LI, XIAOBO

    2015-01-01

    MicroRNA-181 (miR-181) has been recently demonstrated to participate in the differentiation and development of immune cells, including natural killer cells and B and T lymphocytes, and myeloid linages, including erythroid and megakaryocytic cells. The aberrant expression of miR-181, particularly low expression levels, has been observed in a number of leukemia types, including B-cell chronic lymphocytic leukemia and cytogenetically abnormal acute myeloid leukemia. However, the expression and function of miR-181 in chronic myeloid leukemia (CML) remains unknown. In the present study, the aberrant expression of miR-181a was analyzed in a patient with CML and in the CML K562 cell line. In addition, the function and potential mechanisms of miR-181a in K562 cells with regard to their chemotherapeutic sensitivity to imatinib were investigated. The expression levels of miR-181a were significantly reduced in the patient with CML and in the CML K562 cell line. Furthermore, the overexpression of miR-181a in the K562 cells enhanced the chemotherapeutic sensitivity of these cells to imatinib. The potential mechanism mediating these effects may be associated with the capacity of miR-181a to inhibit cell growth and/or to induce cells apoptosis and differentiation in K562 cells. The results of the present study suggested that miR-181a may be a target for the treatment of CML and a useful indicator of the therapeutic sensitivity of CML to imatinib. PMID:26722250

  1. A three-fingered, touch-sensitive, metrological micro-robotic assembly tool

    Science.gov (United States)

    Torralba, Marta; Hastings, D. J.; Thousand, Jeffery D.; Nowakowski, Bartosz K.; Smith, Stuart T.

    2015-12-01

    This article describes a metrological, robotic hand to manipulate and measure micrometer size objects. The presented work demonstrates not only assembly operations, but also positioning control and metrology capability. Sample motion is achieved by a commercial positioning stage, which provides XYZ-displacements for assembly of components. A designed and manufactured gripper tool that incorporates 21 degrees-of-freedom for independent alignment of actuators, sensors, and the three fingers of this hand is presented. These fingers can be opened and closed by piezoelectric actuators through levered flexures providing an 80 μm displacement range measured with calibrated opto-interrupter based, knife-edge sensors. The operational ends of the fingers comprise of a quartz tuning fork with a 7 μm diameter 3.2 mm long carbon fiber extending from the end of one tuning fork tine. Finger-tip force-sensing is achieved by the monitoring of individual finger resonances typically at around 32 kHz. Experimental results included are focused on probe performance analysis. Pick and place operation using the three fingers is demonstrated with all fingers being continuously oscillated, a capability not possible with the previous single or two finger tweezer type designs. By monitoring electrical feedback during pick and place operations, changes in the response of the three probes demonstrate the ability to identify both grab and release operations. Component metrology has been assessed by contacting different micro-spheres of diameters 50(±7.5) μm, 135(±20) μm, and 140(±20) μm. These were measured by the micro robot to have diameters of 67, 133, and 126 μm respectively with corresponding deviations of 4.2, 4.9, and 4.3 μm. This deviation in the measured results was primarily due to the manual, joystick-based, contacting of the fingers, difficulties associated with centering the components to the axis of the hand, and lower contact sensitivity for the smallest sphere

  2. Parametric amplification in a micro Coriolis mass flow sensor: reduction of power dissipation without loss of sensitivity

    NARCIS (Netherlands)

    Groenesteijn, Jarno; Droogendijk, H.; Wiegerink, Remco J.; Lammerink, Theodorus S.J.; Lötters, Joost Conrad; Sanders, Remco G.P.; Krijnen, Gijsbertus J.M.

    2013-01-01

    We report on the application of parametric amplification to a micro Coriolis mass flow sensor to reduce the system’s power dissipation while retaining sensitivity to flow. By reducing this power dissipation, less heat will be transferred to the fluid and channel, potentially resulting in more

  3. Designing a Broadband Pump for High-Quality Micro-Lasers via Modified Net Radiation Method

    CERN Document Server

    Nechayev, Sergey; Baldo, Marc A; Rotschild, Carmel

    2016-01-01

    High-quality micro-lasers are key ingredients in non-linear optics, communication, sensing and low-threshold solar-pumped lasers. However, such micro-lasers exhibit negligible absorption of free-space broadband pump light. Recently, this limitation was lifted by cascade energy transfer, in which the absorption and quality factor are modulated with wavelength, enabling non-resonant pumping of high-quality micro-lasers and solar-pumped laser to operate at record low solar concentration. Here, we present a generic theoretical framework for modeling the absorption, emission and energy transfer of incoherent radiation between cascade sensitizer and laser gain media. Our model is based on linear equations of the modified net radiation method and is therefore robust, fast converging and has low complexity. We apply this formalism to compute the optimal parameters of low-threshold solar-pumped lasers. It is revealed that the interplay between the absorption and self-absorption of such lasers defines the optimal pump ...

  4. Gold Nanoparticle Coated Silica Nanorods for Sensitive Visual Detection of microRNA on a Lateral Flow Strip Biosensor.

    Science.gov (United States)

    Takalkar, Sunitha; Xu, Hui; Chen, Jiao; Baryeh, Kwaku; Qiu, Wanwei; Zhao, Julia X; Liu, And Guodong

    2016-01-01

    We present a rapid and highly sensitive approach for visual detection of microRNA (miRNA) using a gold nanoparticles coated silica nanorod label and lateral flow strip biosensor. Gold nanoparticles were decorated on the silica nanorod surface by a seeding and growth procedure. A single strand DNA probe was immobilized on the gold nanoparticles-silica nanorod surface by a self-assembling process, and the formed DNA-gold nanoparticles-silica nanorod conjugate was used to construct the lateral flow nucleic acid biosensor for detecting miRNA. The captured gold nanoparticles-silica nanorods by sandwich-type hybridization reactions (DNA-RNA-DNA) on the test zone of the lateral flow nucleic acid biosensor produced the characteristic color bands, enabling visual detection of miRNA. After systematic optimization, the new lateral flow nucleic acid biosensor was capable of detecting 10 pM of the miRNA target without instrumentation, which is six times lower than that obtained with the gold nanoparticle-based lateral flow nucleic acid biosensor. The gold nanoparticles coated silica nanorod thus provides a new and sensitive nanolabel for visual detection of biological molecules on the lateral flow biosensor.

  5. Micro-vision-based displacement measurement with high accuracy

    Science.gov (United States)

    Lu, Qinghua; Zhang, Xianmin; Fan, Yanbin

    2011-12-01

    The micro-motion stages are widely used in micro/nano manufacturing technology. In this paper, an integrated approach for measuring micro-displacement of micro-motion stage that incorporates motion estimation algorithm into the computer microvision is proposed. At first, the basic principle of the computer microvision measurement is analyzed. Then, a robust multiscale motion estimation algorithm for micro-motion measurement is proposed. Finally, the microdisplacement of the micro-motion stage based on the piezoelectric ceramic actuators and the compliant mechanisms is measured using the integrated approach. The maximal bias of the proposed approach reached 13 nm. Experimental results show that the new integrated method can measure micro-displacement with nanometer accuracy.

  6. Development of high sensitivity radon detectors

    CERN Document Server

    Takeuchi, Y; Kajita, T; Tasaka, S; Hori, H; Nemoto, M; Okazawa, H

    1999-01-01

    High sensitivity detectors for radon in air and in water have been developed. We use electrostatic collection and a PIN photodiode for these detectors. Calibration systems have been also constructed to obtain collection factors. As a result of the calibration study, the absolute humidity dependence of the radon detector for air is clearly observed in the region less than about 1.6 g/m sup 3. The calibration factors of the radon detector for air are 2.2+-0.2 (counts/day)/(mBq/m sup 3) at 0.08 g/m sup 3 and 0.86+-0.06 (counts/day)/(mBq/m sup 3) at 11 g/m sup 3. The calibration factor of the radon detector for water is 3.6+-0.5 (counts/day)/(mBq/m sup 3). The background level of the radon detector for air is 2.4+-1.3 counts/day. As a result, one standard deviation excess of the signal above the background of the radon detector for air should be possible for 1.4 mBq/m sup 3 in a one-day measurement at 0.08 g/m sup 3.

  7. In vivo micro-CT assessment of airway remodeling in a flexible OVA-sensitized murine model of asthma.

    Directory of Open Access Journals (Sweden)

    Mathieu Lederlin

    Full Text Available Airway remodeling is a major pathological feature of asthma. Up to now, its quantification still requires invasive methods. In this study, we aimed at determining whether in vivo micro-computed tomography (micro-CT is able to demonstrate allergen-induced airway remodeling in a flexible mouse model of asthma. Sixty Balb/c mice were challenged intranasally with ovalbumin or saline at 3 different endpoints (Days 35, 75, and 110. All mice underwent plethysmography at baseline and just prior to respiratory-gated micro-CT. Mice were then sacrificed to assess bronchoalveolar lavage and lung histology. From micro-CT images (voxel size = 46×46×46 µm, the numerical values of total lung attenuation, peribronchial attenuation (PBA, and PBA normalized by total lung attenuation were extracted. Each parameter was compared between OVA and control mice and correlation coefficients were calculated between micro-CT and histological data. As compared to control animals, ovalbumin-sensitized mice exhibited inflammation alone (Day 35, remodeling alone (Day 110 or both inflammation and remodeling (Day 75. Normalized PBA was significantly greater in mice exhibiting bronchial remodeling either alone or in combination with inflammation. Normalized PBA correlated with various remodeling markers such as bronchial smooth muscle size or peribronchial fibrosis. These findings suggest that micro-CT may help monitor remodeling non-invasively in asthmatic mice when testing new drugs targeting airway remodeling in pre-clinical studies.

  8. Micro-damage propagation in ultra-high vacuum seals

    CERN Document Server

    Lutkiewicz, P; Garion, C

    2010-01-01

    The paper addresses a fundamental problem of tightness of ultra-high vacuum systems (UHV) at cryogenic temperatures in the light of continuum damage mechanics (CDM). The problem of indentation of a rigid punch into an elastic-plastic half-space is investigated based on rate independent plasticity with mixed kinematic and isotropic hardening. The micro-damage fields are modeled by using an anisotropic approach with a kinetic law of damage evolution suitable for ductile materials and cryogenic temperatures. The model has been experimentally validated and the results are used to predict the onset of macro-cracking (loss of tightness) and the corresponding load (contact pressure). The algorithm is applied in the design of UHV systems for particle accelerators. (C) 2009 Published by Elsevier Ltd.

  9. High temperature superconducting current leads for micro-SMES application

    Energy Technology Data Exchange (ETDEWEB)

    Niemann, R.C.; Cha, Y.S.; Hull, J.R. [Argonne National Lab., IL (United States); Buckles, W.E.; Weber, B.R. [Suerconductivity, Inc., Madison, WI (United States); Daugherty, M.A. [Los Alamos National Lab., NM (United States)

    1993-09-01

    SMES is being applied on a microscale (1--10 Mj stored energy) to improve electrical power quality. A major portion of the SMES refrigeration load is for cooling the conventional (copper, vapor- cooled) current leads that transfer energy between the magnet and the power-conditioning equipment. The lead refrigeration load can be reduced significantly by the use of high-temperature superconductors (HTSs). A HTS current lead suitable for micro-SMES application has been designed. The lower stage of the lead employs HTSs. A transition between the lower stage and the conventional upper-stage lead is heat-intercepted by a cryocooler. Details of the design are presented. Construction and operating experiences are discussed.

  10. The Design and Optimization of a Highly Sensitive and Overload-Resistant Piezoresistive Pressure Sensor

    Directory of Open Access Journals (Sweden)

    Xiawei Meng

    2016-03-01

    Full Text Available A piezoresistive pressure sensor with a beam-membrane-dual-island structure is developed for micro-pressure monitoring in the field of aviation, which requires great sensitivity and overload resistance capacity. The design, fabrication, and test of the sensor are presented in this paper. By analyzing the stress distribution of sensitive elements using the finite element method, a novel structure incorporating sensitive beams with a traditional bossed diaphragm is built up. The proposed structure proved to be advantageous in terms of high sensitivity and high overload resistance compared with the conventional bossed diaphragm and flat diaphragm structures. Curve fittings of surface stress and deflection based on ANSYS simulation results are performed to establish the sensor equations. Fabricated on an n-type single crystal silicon wafer, the sensor chips are wire-bonded to a printed circuit board (PCB and packaged for experiments. The static and dynamic characteristics are tested and discussed. Experimental results show that the sensor has a sensitivity as high as 17.339 μV/V/Pa in the range of 500 Pa at room temperature, and a high overload resistance of 200 times overpressure. Due to the excellent performance, the sensor can be applied in measuring micro-pressure lower than 500 Pa.

  11. Dandelions, tulips and orchids: evidence for the existence of low-sensitive, medium-sensitive and high-sensitive individuals.

    Science.gov (United States)

    Lionetti, Francesca; Aron, Arthur; Aron, Elaine N; Burns, G Leonard; Jagiellowicz, Jadzia; Pluess, Michael

    2018-01-22

    According to empirical studies and recent theories, people differ substantially in their reactivity or sensitivity to environmental influences with some being generally more affected than others. More sensitive individuals have been described as orchids and less-sensitive ones as dandelions. Applying a data-driven approach, we explored the existence of sensitivity groups in a sample of 906 adults who completed the highly sensitive person (HSP) scale. According to factor analyses, the HSP scale reflects a bifactor model with a general sensitivity factor. In contrast to prevailing theories, latent class analyses consistently suggested the existence of three rather than two groups. While we were able to identify a highly sensitive (orchids, 31%) and a low-sensitive group (dandelions, 29%), we also detected a third group (40%) characterised by medium sensitivity, which we refer to as tulips in keeping with the flower metaphor. Preliminary cut-off scores for all three groups are provided. In order to characterise the different sensitivity groups, we investigated group differences regarding the Big Five personality traits, as well as experimentally assessed emotional reactivity in an additional independent sample. According to these follow-up analyses, the three groups differed in neuroticism, extraversion and emotional reactivity to positive mood induction with orchids scoring significantly higher in neuroticism and emotional reactivity and lower in extraversion than the other two groups (dandelions also differed significantly from tulips). Findings suggest that environmental sensitivity is a continuous and normally distributed trait but that people fall into three distinct sensitive groups along a sensitivity continuum.

  12. High Q-factor micro-cavity laser: Fabrication and lasing emission properties

    Energy Technology Data Exchange (ETDEWEB)

    Pham Van Hoi; Ha Xuan Vinh; Chu Thi Thu Ha; Tran Thi Cham [Institute of Materials Science, Vietname Academy of Science and Technology 18 Hoang Quoc Viet Road, Cau Giay District, Hanoi (Viet Nam); Bui Van Thien [Faculty of Natural Science, College of Medicine, Thai Nguyen (Viet Nam); Gruzintsev, A N [Institute of Microelectronics Technology and High Purity Materials, Russian Academy of Sciences (IPMT-RAS) (Russian Federation)], E-mail: hoipv@ims.vast.ac.vn

    2009-09-01

    In this article the fabrication method and lasing emission properties of High-Q micro-cavity lasers based on High-concentration Erbium-doped silica-alumina glasses are presented in detail. The configurations of micro-cavities were spherical and/or modified toroidal forms. The lasing threshold of micro-cavity laser pumped by laser diodes was of hundred micro-watts and Q-factor of cavity had been achieved up-to 10{sup 8} in experiment. The emission power of one whispering-gallery-mode (WGM) lasing from micro-cavity laser was of 0.05-0.5 mW that would be enough for applying in the quantum information and optical sensor techniques. The modified toroidal micro-cavity permits to decrease the polar-mode of WGMs, which help to obtain the single-mode emission from micro-cavity lasers.

  13. A high-content morphological screen identifies novel microRNAs that regulate neuroblastoma cell differentiation.

    Science.gov (United States)

    Zhao, Zhenze; Ma, Xiuye; Hsiao, Tzu-Hung; Lin, Gregory; Kosti, Adam; Yu, Xiaojie; Suresh, Uthra; Chen, Yidong; Tomlinson, Gail E; Pertsemlidis, Alexander; Du, Liqin

    2014-05-15

    Neuroblastoma, the most common extracranial solid tumor of childhood, arises from neural crest cell precursors that fail to differentiate. Inducing cell differentiation is an important therapeutic strategy for neuroblastoma. We developed a direct functional high-content screen to identify differentiation-inducing microRNAs, in order to develop microRNA-based differentiation therapy for neuroblastoma. We discovered novel microRNAs, and more strikingly, three microRNA seed families that induce neuroblastoma cell differentiation. In addition, we showed that microRNA seed families were overrepresented in the identified group of fourteen differentiation-inducing microRNAs, suggesting that microRNA seed families are functionally more important in neuroblastoma differentiation than microRNAs with unique sequences. We further investigated the differentiation-inducing function of the microRNA-506-3p/microRNA-124-3p seed family, which was the most potent inducer of differentiation. We showed that the differentiation-inducing function of microRNA-506-3p/microRNA-124-3p is mediated, at least partially, by down-regulating expression of their targets CDK4 and STAT3. We further showed that expression of miR-506-3p, but not miR-124-3p, is dramatically upregulated in differentiated neuroblastoma cells, suggesting the important role of endogenous miR-506-3p in differentiation and tumorigenesis. Overall, our functional screen on microRNAs provided the first comprehensive analysis on the involvements of microRNA species in neuroblastoma cell differentiation and identified novel differentiation-inducing microRNAs. Further investigations are certainly warranted to fully characterize the function of the identified microRNAs in order to eventually benefit neuroblastoma therapy.

  14. A new UHV micro positioning system for high load

    Energy Technology Data Exchange (ETDEWEB)

    Colldelram, Carles, E-mail: ccolldelram@cells.es; Nicolas, Josep, E-mail: jnicolas@cells.es; Nikitina, Liudmila, E-mail: lnikitina@cells.es [ALBA Synchrotron, Carretera BP 1413, de Cerdanyola del Vallès a Sant Cugat del Vallès, Km. 3,3, 08290 Cerdanyola del Vallès, Barcelona (Spain)

    2016-07-27

    In this work we report the design and performance of a novel compact in-vacuum actuator, designed to be compatible with all the motions required for the scissor-type ESRF mirror bender. These mirror benders include several linear actuators, which drive the mirror bending torques, as well as the main alignment motions such as pitch and translation along the normal to the mirror surface. The motions are provided by compact linear actuators, which consist of motor, reduction, spindle and nut, encapsulated on a closed air volume to provide vacuum compatibility. The actuator includes a hydroformed bellows to transmit the force to the actuator tip, and an electrical feedthrough for the motor cables. The design boundaries for these actuators are quite tight, as they must be integrated in a narrow volume, must be UHV compatible and must provide high resolution, for a relatively high load. As a result, they have limited mechanical performance, and in some cases poor reliability. To overcome these problems, we designed and implemented a different concept. In the proposed concept, the motor rotation is converted onto a linear motion by means of a cam instead of a spindle and a nut. This allows for much shorter and stiffer transmission system, with similar dimensions. The vacuum compatibility is intrinsic for this solution, since the whole mechanism of the actuator is UHV compatible. All motions are preloaded and guided by vacuum compatible (hybrid metal-ceramics) ball bearings. This allows the system reaching a repeatability and backlash well within the micron. The absence of friction allows for a high reliability and releases the maintenance needs of the system. The transmission is intrinsically irreversible, and the system can hold a load of 250 N within a few nanometers without any holding current on the motors. This allows the system to move reliably also in micro-stepping mode, providing a resolution well below the half-step nominal resolution of 100 nm. Performances

  15. High throughput generated micro-aggregates of chondrocytes stimulate cartilage formation in vitro and in vivo.

    Science.gov (United States)

    Moreira Teixeira, L S; Leijten, J C H; Sobral, J; Jin, R; van Apeldoorn, A A; Feijen, J; van Blitterswijk, C; Dijkstra, P J; Karperien, M

    2012-06-05

    Cell-based cartilage repair strategies such as matrix-induced autologous chondrocyte implantation (MACI) could be improved by enhancing cell performance. We hypothesised that micro-aggregates of chondrocytes generated in high-throughput prior to implantation in a defect could stimulate cartilaginous matrix deposition and remodelling. To address this issue, we designed a micro-mould to enable controlled high-throughput formation of micro-aggregates. Morphology, stability, gene expression profiles and chondrogenic potential of micro-aggregates of human and bovine chondrocytes were evaluated and compared to single-cells cultured in micro-wells and in 3D after encapsulation in Dextran-Tyramine (Dex-TA) hydrogels in vitro and in vivo. We successfully formed micro-aggregates of human and bovine chondrocytes with highly controlled size, stability and viability within 24 hours. Micro-aggregates of 100 cells presented a superior balance in Collagen type I and Collagen type II gene expression over single cells and micro-aggregates of 50 and 200 cells. Matrix metalloproteinases 1, 9 and 13 mRNA levels were decreased in micro-aggregates compared to single-cells. Histological and biochemical analysis demonstrated enhanced matrix deposition in constructs seeded with micro-aggregates cultured in vitro and in vivo, compared to single-cell seeded constructs. Whole genome microarray analysis and single gene expression profiles using human chondrocytes confirmed increased expression of cartilage-related genes when chondrocytes were cultured in micro-aggregates. In conclusion, we succeeded in controlled high-throughput formation of micro-aggregates of chondrocytes. Compared to single cell-seeded constructs, seeding of constructs with micro-aggregates greatly improved neo-cartilage formation. Therefore, micro-aggregation prior to chondrocyte implantation in current MACI procedures, may effectively accelerate hyaline cartilage formation.

  16. High throughput vegetable oil-in-water emulsification with a high porosity micro-engineered membrane

    NARCIS (Netherlands)

    Wagdare, N.A.; Marcelis, A.T.M.; Ho, O.B.; Boom, R.M.; Rijn, van C.J.M.

    2010-01-01

    Emulsification with high porosity micro-engineered membranes leads to stable emulsions with a low droplet span when, besides a surfactant in the continuous phase, an additional, suitable surfactant is used in the dispersed phase. This surfactant should exhibit relatively fast adsorption dynamics,

  17. High sensitivity optical measurement of skin gloss

    NARCIS (Netherlands)

    Ezerskaia, A.; Ras, Arno; Bloemen, Pascal; Pereira, S.F.; Urbach, Paul; Varghese, Babu

    2017-01-01

    We demonstrate a low-cost optical method for measuring the gloss properties with improved sensitivity in the low gloss regime, relevant for skin gloss properties. The gloss estimation method is based on, on the one hand, the slope of the intensity gradient in the transition regime between

  18. Environmental Sensitivity in Children: Development of the Highly Sensitive Child Scale and Identification of Sensitivity Groups

    Science.gov (United States)

    Pluess, Michael; Assary, Elham; Lionetti, Francesca; Lester, Kathryn J.; Krapohl, Eva; Aron, Elaine N.; Aron, Arthur

    2018-01-01

    A large number of studies document that children differ in the degree they are shaped by their developmental context with some being more sensitive to environmental influences than others. Multiple theories suggest that "Environmental Sensitivity" is a common trait predicting the response to negative as well as positive exposures.…

  19. High sensitivity optical biosensor based on polymer materials and using the Vernier effect.

    Science.gov (United States)

    Azuelos, Paul; Girault, Pauline; Lorrain, Nathalie; Poffo, Luiz; Guendouz, Mohammed; Thual, Monique; Lemaître, Jonathan; Pirasteh, Parastesh; Hardy, Isabelle; Charrier, Joël

    2017-11-27

    We demonstrate the fabrication of a Vernier effect SU8/PMATRIFE polymer optical biosensor with high homogeneous sensitivity using a standard photolithography process. The sensor is based on one micro-resonator embedded on each arm of a Mach-Zehnder interferometer. Measurements are based on the refractive index variation of the optical waveguide superstrate with different concentrations of glucose solutions. The sensitivity of the sensor has been measured as 17558 nm/RIU and the limit of detection has been estimated to 1.1.10-6 RIU.

  20. High resolution laser micro sintering / melting using q-switched and high brilliant laser radiation

    Science.gov (United States)

    Exner, H.; Streek, A.

    2015-03-01

    Since the discovery of selective laser sintering/melting, numerous modifications have been made to upgrade or customize this technology for industrial purposes. Laser micro sintering (LMS) is one of those modifications: Powders with particles in the range of a few micrometers are used to obtain products with highly resolved structures. Pulses of a q-switched laser had been considered necessary in order to generate sinter layers from the micrometer scaled metal powders. LMS has been applied with powders from metals as well as from ceramic and cermet feedstock's to generate micro parts. Recent technological progress and the application of high brilliant continuous laser radiation have now allowed an efficient laser sintering/melting of micrometer scaled metal powders. Thereby it is remarkable that thin sinter layers are generated using high continuous laser power. The principles of the process, the state of the art in LMS concerning its advantages and limitations and furthermore the latest results of the recent development of this technology will be presented. Laser Micro Sintering / Laser Micro Melting (LMM) offer a vision for a new dimension of additive fabrication of miniature and precise parts also with application potential in all engineering fields.

  1. Towards Mass Production by High Performance Transfer Press in Micro Bulk Forming

    DEFF Research Database (Denmark)

    Mahshid, Rasoul; Hansen, Hans Nørgaard; Arentoft, Mogens

    2014-01-01

    Multi-step micro bulk forming is characterized by complex processes and high precision requirements. Several process parameters influence on accuracy of micro forged parts where small tolerances in the order of few μm are in demand. The paper introduces a high performance transfer press for micro....... A forged part with three different diameters in height was produced in a two-stage forming process using the introduced transfer press....

  2. A Sensitive Alternative for MicroRNA In Situ Hybridizations Using Probes of 2'-O-Methyl RNA + LNA

    DEFF Research Database (Denmark)

    Søe, Martin Jensen; Møller, Trine; Dufva, Martin

    2011-01-01

    The use of short, high-affinity probes consisting of a combination of DNA and locked nucleic acid (LNA) has enabled the specific detection of microRNAs (miRNAs) by in situ hybridization (ISH). However, detection of low–copy number miRNAs is still not always possible. Here the authors show...... that probes consisting of 2'-O-methyl RNAs (2OMe) and LNA at every third base (2:1 ratio), under optimized hybridization conditions, excluding yeast RNA from the hybridization buffer, can provide superior performance in detection of miRNA targets in terms of sensitivity and signal-to-noise ratio compared...... to DNA + LNA probes. Furthermore, they show that hybridizations can be performed in buffers of 4M urea instead of 50% formamide, thereby yielding an equally specific but nontoxic assay. The use of 2OMe + LNA–based probes and the optimized ISH assay enable simple and fast detection of low–copy number mi...

  3. High Throughput Micro-Well Generation of Hepatocyte Micro-Aggregates for Tissue Engineering

    NARCIS (Netherlands)

    Gevaert, Elien; Dollé, Laurent; Billiet, Thomas; Dubruel, Peter; van Grunsven, Leo; van Apeldoorn, Aart A.; Cornelissen, Ria

    2014-01-01

    The main challenge in hepatic tissue engineering is the fast dedifferentiation of primary hepatocytes in vitro. One successful approach to maintain hepatocyte phenotype on the longer term is the cultivation of cells as aggregates. This paper demonstrates the use of an agarose micro-well chip for the

  4. Mismatch negativity (MMN) in high and low noise sensitive individuals

    NARCIS (Netherlands)

    White, Kim; Meeter, Martijn

    2015-01-01

    Although noise sensitivity is known to be an important determinant of noise annoyance, its neural underpinnings are not yet well established. In the present study, high and low noise sensitive participants were selected based on their scores on the Noise Sensitivity Scale (NSS) and the Noise

  5. Hybrid Micro-Electro-Mechanical Systems for Highly Reliable and Selective Characterization of Tank Waste

    Energy Technology Data Exchange (ETDEWEB)

    Panos G. Datskos; Michael J. Sepaniak; Nickolay Lavrik; Pampa Dutta; Mustafa Culha

    2005-12-28

    The main objective of this research program is to develop robust and reliable micro-electro-mechanical sensing systems, based on microcantilevers (MCs), that can operate in liquid environments with high levels of sensitivity and selectivity. The chemical responses of MCs result from analyte-induced differential stress at the cantilever surfaces. We aim to employ various surface nanostructuring strategies that enhance these stresses and hence the degree of static bending of the cantilevers. Receptor phases as self assembled monolayers (SAMs) and thin films are being synthesized and tested to provide selectivity. Selectivity is chemically enhanced by using different phases on individual MCs in arrays and by adding a spectroscopic component, surface enhanced Raman spectrometry (SERS), in hybrid approaches to sensing. Significant progress was made in tasks that were listed in the work plan for DOE EMSP project ''Hybrid Micro-Electro-Mechanical Systems for Highly Reliable and Selective Characterization of Tank Waste''. Several project areas are listed below and discussed and referenced to our literature on the topics.

  6. Design and performance evaluation of a high resolution IRI-microPET preclinical scanner

    Energy Technology Data Exchange (ETDEWEB)

    Islami rad, S.Z., E-mail: szislami@yahoo.com [Department of Physic, Faculty of Science, University of Qom, Qom (Iran, Islamic Republic of); Peyvandi, R. Gholipour; Lehdarboni, M. Askari; Ghafari, A.A. [Instrumentation Research Group, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2015-05-01

    PET for small animal, IRI-microPET, was designed and built at the NSTRI. The scanner is made of four detectors positioned on a rotating gantry at a distance 50 mm from the center. Each detector consists of a 10×10 crystal matrix of 2×2×10 mm{sup 3} directly coupled to a PS-PMT. A position encoding circuit for specific PS-PMT has been designed, built and tested with a PD-MFS-2MS/s-8/14 data acquisition board. After implementing reconstruction algorithms (FBP, MLEM and SART) on sinograms, images quality and system performance were evaluated by energy resolution, timing resolution, spatial resolution, scatter fraction, sensitivity, RMS contrast and SNR parameters. The energy spectra were obtained for the crystals with an energy window of 300–700 keV. The energy resolution in 511 keV averaged over all modules, detectors, and crystals, was 23.5%. A timing resolution of 2.4 ns FWHM obtained by coincidence timing spectrum was measured with crystal LYSO. The radial and tangential resolutions for {sup 18}F (1.15-mm inner diameter) at the center of the field of view were 1.81 mm and 1.90 mm, respectively. At a radial offset of 5 mm, the FWHM values were 1.96 and 2.06 mm. The system scatter fraction was 7.1% for the mouse phantom. The sensitivity was measured for different energy windows, leading to a sensitivity of 1.74% at the center of FOV. Also, images quality was evaluated by RMS contrast and SNR factors, and the results show that the reconstructed images by MLEM algorithm have the best RMS contrast, and SNR. The IRI-microPET presents high image resolution, low scatter fraction values and improved SNR for animal studies.

  7. GaAs Coupled Micro Resonators with Enhanced Sensitive Mass Detection

    Directory of Open Access Journals (Sweden)

    Tony Chopard

    2014-12-01

    Full Text Available This work demonstrates the improvement of mass detection sensitivity and time response using a simple sensor structure. Indeed, complicated technological processes leading to very brittle sensing structures are often required to reach high sensitivity when we want to detect specific molecules in biological fields. These developments constitute an obstacle to the early diagnosis of diseases. An alternative is the design of coupled structures. In this study, the device is based on the piezoelectric excitation and detection of two GaAs microstructures vibrating in antisymmetric modes. GaAs is a crystal which has the advantage to be micromachined easily using typical clean room processes. Moreover, we showed its high potential in direct biofunctionalisation for use in the biological field. A specific design of the device was performed to improve the detection at low mass and an original detection method has been developed. The principle is to exploit the variation in amplitude at the initial resonance frequency which has in the vicinity of weak added mass the greatest slope. Therefore, we get a very good resolution for an infinitely weak mass: relative voltage variation of 8%/1 fg. The analysis is based on results obtained by finite element simulation.

  8. Differences between the detonation behavior of emulsion explosives sensitized with glass or with polymeric micro-balloons

    Science.gov (United States)

    Mendes, R.; Ribeiro, J.; Plaksin, I.; Campos, J.; Tavares, B.

    2014-05-01

    The differences between the detonation behaviour of ammonium nitrate based emulsion explosives sensitized with polymeric and those sensitized with glass micro-balloons is presented and discussed. Expancel® are hollow polymeric micro-balloons that contain a hydrocarbon gas. The mean particle size of these particles is 30 μm with a wall thickness of about 0.1 μm. The detonation velocity and the failure diameter of the emulsion explosive sensitized with different amounts of these particles have been measured in cylindrical charges by optical fibers. The detonation velocity demonstrates non-linear behaviour in relation to density and reaches the maximum value for a density lower than that of the matrix. The detonation fails when the density approaches that of the matrix. The detonation in the emulsion explosives extinguishes itself at a porosity value that seems to be independent from the nature of the sensitizing agent. For low densities, the detonation velocity is almost independent of the charge diameter, and is close to the values predicted by BKW equation of state.

  9. Strain relief InGaN/GaN MQW micro-pillars for high brightness LEDs

    KAUST Repository

    Shen, Chao

    2013-01-01

    Micro-structured group-III-nitrides are considered as promising strain relief structures for high efficiency solid state lighting. In this work, the strain field in InGaN/GaN multi-quantum wells (MQWs) micro-pillars is investigated using micro-Raman spectroscopy and the design of micro-pillars were studied experimentally. We distinguished the strained and strain-relieved signatures of the GaN layer from the E2 phonon peak split from the Raman scattering signatures at 572 cm-1 and 568 cm-1, respectively. The extent of strain relief is examined considering the height and size of micro-pillars fabricated using focused ion beam (FIB) micro-machining technique. A significant strain relief can be achieved when one micro-machined through the entire epi-layers, 3 μm in our study. The dependence of strain relief on micro-pillar diameter (D) suggested that micro-pillar with D < 3 μm showed high degree of strain relief. Our results shed new insights into designing strain-relieved InGaN/GaN microstructures for high brightness light emitting diode arrays. © 2013 IEEE.

  10. Scalloped electrodes for highly sensitive electrical measurements

    DEFF Research Database (Denmark)

    Vazquez Rodriguez, Patricia; Dimaki, Maria; Svendsen, Winnie Edith

    2011-01-01

    In this work we introduce a novel out-of-plane electrode with pronounced scalloped surface and high aspect ratio for electrical recordings of brain tissue in vitro, with the aim to reduce significantly the impedance of the measuring system. The profile and height of the structures is tailored by ...

  11. Highly linear, sensitive analog-to-digital converter

    Science.gov (United States)

    Cox, J.; Finley, W. R.

    1969-01-01

    Analog-to-digital converter converts 10 volt full scale input signal into 13 bit digital output. Advantages include high sensitivity, linearity, low quantitizing error, high resistance to mechanical shock and vibration loads, and temporary data storage capabilities.

  12. A novel detection platform for parallel monitoring of DNA hybridization with high sensitivity and specificity

    DEFF Research Database (Denmark)

    Yi, Sun; Perch-Nielsen, Ivan R.; Wang, Zhenyu

    We developed a high-sensitive platform to monior multiple hybridization events in real time. By creating a microoptical array in a polymeric chip, the system combine the excellent discriminative power of supercritical angle fluorescence (SAF) microscopy with high-throughput capabilities of microa......We developed a high-sensitive platform to monior multiple hybridization events in real time. By creating a microoptical array in a polymeric chip, the system combine the excellent discriminative power of supercritical angle fluorescence (SAF) microscopy with high-throughput capabilities...... of microarrays. The micro-optical array is easy to fabricate, and exhibits significantly improved analytical performance. It has a potential to become a basic tool for applications such as gene expression or single nucleotide polymorphism (SNP) detection....

  13. Micro- and Macrosystem Predictors of High School Male Suicidal Behaviors

    Science.gov (United States)

    Beck-Cross, Cathy; Cooper, Robyn

    2015-01-01

    Suicide is the third leading cause of death among young people ages 15 to 19 years, with male adolescents four times more likely to die than their female peers. This study used Bronfenbrenner's bioecological model to examine micro- and macrosystems as predictors of suicidal behaviors through responses by male adolescents (N = 9,910) to a statewide…

  14. Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts

    Science.gov (United States)

    Liao, Yunn-Shiuan; Chen, Shun-Tong; Lin, Chang-Sheng

    2005-02-01

    The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel micro-wire-cutting mechanism is designed, an approach to control wire tension by magnetic force is proposed and a servo feed control strategy, in accordance with the measured gap voltage, is designed and implemented. To verify the functions and capabilities of the machine developed, several thick micro outer and internal spur gears and rack are machined. It shows that the taper angle along the wall or cavity of a part that appears when other micro-EDM processes are applied can be avoided. A very good dimensional accuracy of 1 µm and a surface finish of Rmax equal to 0.64 µm are achieved. The satisfactory cutting of a miniature 3D pagoda with a micro-hooked structure also reveals that the machine developed is versatile, and can be used as a new tool for making intricate micro parts.

  15. Heterogeneous catalysis in highly sensitive microreactors

    DEFF Research Database (Denmark)

    Olsen, Jakob Lind

    oxygen surplus, is presented. The e_ect of pretreating the catalyst, CuZnO, in a mixture of H2 and CO before methanol synthesis, is presented. Transient increased methanol production is seen after pretreatment, with a maximum in the transient for a pretreatment with a one to one CO to H2 ratio...... of adsorbates readily converted to methanol as the source of the transient increase in methanol production, is eliminated. A study of mass selected ruthenium nanoparticles from a magnetron-sputter gas-aggregation source, deposited in microreactors, is presented. It is, shown that CO methanation can be measured....... The highly active state of the catalyst after pretreatment in a CO and H2 mixture is shown to have transient methanol synthesis capabilities at 60.. Estimates of the area of the catalytic surface, is obtained using formate temperature programmed desorption measurements. From these, the possibility...

  16. micro-RNA screening and prediction model construction for diagnosis of salt-sensitive essential hypertension.

    Science.gov (United States)

    Qi, Han; Liu, Zheng; Liu, Bin; Cao, Han; Sun, Weiping; Yan, Yuxiang; Zhang, Ling

    2017-04-01

    Commonly used tests for diagnosis of salt-sensitive hypertension (SSH) are complex and time-consuming, so new methods are required. Many studies have demonstrated roles for miRNAs in hypertension; however, the diagnostic value of miRNAs has yet to be determined for human SSH. In this study, we examined miRNA expression profiles by initial high-throughput miRNA sequencing of samples from patients with salt-sensitive and salt-resistant hypertension (SSH and SRH, respectively; n = 6, both groups), followed by validation by quantitative real-time polymerase chain reaction (qRT-PCR) in a larger cohort (n = 91). We also evaluated differences in baseline characteristics (e.g., age, sex, body mass index, consumption of specific foods) between the SSH and SRH groups. Of 36 miRNAs identified as differentially expressed between SSH and SRH groups by RNA-Seq, 8 were analyzed by qRT-PCR. There were significant differences in the expression levels of hsa-miR-361-5p and hsa-miR-362-5p between the 2 groups (P = .023 and.049, respectively). In addition, there were significant differences in sauce and poultry consumption between the 2 groups (P = .004 and.001, respectively). The areas under the curve (AUC) determined by receptor operating characteristic (ROC) analysis for hsa-miR-361-5p and all 8 miRNAs were 0.793 (95% CI, 0.698-0.888; sensitivity = 73.9%, specificity = 74.4%; P SSH.

  17. Research and Development of Micro-Alloying High-Strength Shipbuilding Plate

    Science.gov (United States)

    Chen, Zhenye

    Based on the technological requirements and market demand, Nb micro-alloying D36 grade high strength shipbuilding plate has been successfully developed in HBIS. In this papers, the rational chemical compositions design, smelting and rolling process of Nb micro-alloying D36 grade high strength shipbuilding plate were introduced. Its various performance figures not only comply with the rules of nine classification societies of CCS, LR, ABS NK, DNV, BV, GL, KR and RINA but meet users' requirements. It indicates that HBIS have capacity producing Nb micro-alloying D36 grade high strength shipbuilding plate.

  18. Epigenetics of amphetamine-induced sensitization: HDAC5 expression and microRNA in neural remodeling.

    Science.gov (United States)

    Liu, Philip K; Liu, Christina H

    2016-12-08

    Histone deacetylase (HDAC) activities modify chromatin structure and play a role in learning and memory during developmental processes. Studies of adult mice suggest HDACs are involved in neural network remodeling in brain repair, but its function in drug addiction is less understood. We aimed to examine in vivo HDAC5 expression in a preclinical model of amphetamine-induced sensitization (AIS) of behavior. We generated specific contrast agents to measure HDAC5 levels by in vivo molecular contrast-enhanced (MCE) magnetic resonance imaging (MRI) in amphetamine-naïve mice as well as in mice with AIS. To validate the MRI results we used ex vivo methods including in situ hybridization, RT-PCR, immunohistochemistry, and transmision electron microscopy. We compared the expression of HDAC5 mRNA in an acute exposure paradigm (in which animals experienced a single drug exposure [A1]) and in a chronic-abstinence-challenge paradigm (in which animals were exposed to the drug once every other day for seven doses, then underwent 2 weeks of abstinence followed by a challenge dose [A7WA]). Control groups for each of these exposure paradigms were given saline. To delineate how HDAC5 expression was related to AIS, we compared the expression of HDAC5 mRNA at sequences where no known microRNA (miR) binds (hdac5AS2) and at sequences where miR-2861 is known to bind (miD2861). We synthesized and labeled phosphorothioated oligonucleic acids (sODN) of hdac5AS2 or miD2861 linked to superparamagentic iron oxide nanoparticles (SPION), and generated HDAC5-specific contrast agents (30 ± 20 nm, diameter) for MCE MRI; the same sequences were used for primers for TaqMan® analysis (RT-qPCR) in ex vivo validation. In addition, we used subtraction R2* maps to identify regional HDAC5 expression. Naïve C57black6 mice that experience acute exposure to amphetamine (4 mg/kg, by injection intraperitoneally) show expression of both total and phosphorylated (S259) HDAC5 antigens in GFAP+ and GFAP

  19. High density, optically corrected, micro-channel cooled, v-groove monolithic laser diode array

    Science.gov (United States)

    Freitas, Barry L.

    1998-01-01

    An optically corrected, micro-channel cooled, high density laser diode array achieves stacking pitches to 33 bars/cm by mounting laser diodes into V-shaped grooves. This design will deliver>4kW/cm2 of directional pulsed laser power. This optically corrected, micro-channel cooled, high density laser is usable in all solid state laser systems which require efficient, directional, narrow bandwidth, high optical power density pump sources.

  20. High-throughput and reliable protocols for animal microRNA library cloning.

    Science.gov (United States)

    Xiao, Caide

    2011-01-01

    MicroRNAs are short single-stranded RNA molecules (18-25 nucleotides). Because of their ability to silence gene expressions, they can be used to diagnose and treat tumors. Experimental construction of microRNA libraries was the most important step to identify microRNAs from animal tissues. Although there are many commercial kits with special protocols to construct microRNA libraries, this chapter provides the most reliable, high-throughput, and affordable protocols for microRNA library construction. The high-throughput capability of our protocols came from a double concentration (3 and 15%, thickness 1.5 mm) polyacrylamide gel electrophoresis (PAGE), which could directly extract microRNA-size RNAs from up to 400 μg total RNA (enough for two microRNA libraries). The reliability of our protocols was assured by a third PAGE, which selected PCR products of microRNA-size RNAs ligated with 5' and 3' linkers by a miRCat™ kit. Also, a MathCAD program was provided to automatically search short RNAs inserted between 5' and 3' linkers from thousands of sequencing text files.

  1. High sensitivity probe absorption technique for time-of-flight ...

    Indian Academy of Sciences (India)

    We report on a phase-sensitive probe absorption technique with high sensitivity, capable of detecting a few hundred ultra-cold atoms in flight in an observation time of a few milliseconds. The large signal-to-noise ratio achieved is sufficient for reliable measurements on low intensity beams of cold atoms. We demonstrate the ...

  2. High sensitivity probe absorption technique for time-of-flight ...

    Indian Academy of Sciences (India)

    Absorption imaging using a high sensitivity CCD camera gives the size of the expanding cloud and hence ... (LVIS) [2], the peak signal in a 1 mm thick resonant probe beam corresponds to the absorption by 3 × 105 ... used in our atom optics experiments on the reflection of atoms from magnetic thin films [13]. The sensitivity ...

  3. New insights for identification of doping with recombinant human erythropoietin micro-doses after high hydration

    DEFF Research Database (Denmark)

    Martin, L.; Ashenden, M; Bejder, Jacob

    2016-01-01

    To minimize the chances of being caught after doping with recombinant human erythropoietins (rhEPO), athletes have turned to new practices using micro-doses and excess fluid ingestion to accelerate elimination and decrease the probability of detection. Our objective was to test the sensitivity of...

  4. High performance micro-flow cytometer based on optical fibres.

    Science.gov (United States)

    Etcheverry, S; Faridi, A; Ramachandraiah, H; Kumar, T; Margulis, W; Laurell, F; Russom, A

    2017-07-17

    Flow cytometry is currently the gold standard for analysis of cells in the medical laboratory and biomedical research. Fuelled by the need of point-of-care diagnosis, a significant effort has been made to miniaturize and reduce cost of flow cytometers. However, despite recent advances, current microsystems remain less versatile and much slower than their large-scale counterparts. In this work, an all-silica fibre microflow cytometer is presented that measures fluorescence and scattering from particles and cells. It integrates cell transport in circular capillaries and light delivery by optical fibres. Single-stream cell focusing is performed by Elasto-inertial microfluidics to guarantee accurate and sensitive detection. The capability of this technique is extended to high flow rates (up to 800 µl/min), enabling a throughput of 2500 particles/s. The robust, portable and low-cost system described here could be the basis for a point-of-care flow cytometer with a performance comparable to commercial systems.

  5. High numerical aperture imaging by using multimode fibers with micro-fabricated optics

    KAUST Repository

    Bianchi, Silvio

    2014-01-01

    Controlling light propagation into multimode optical fibers through spatial light modulators provides highly miniaturized endoscopes and optical micromanipulation probes. We increase the numerical aperture up to nearly 1 by micro-optics fabricated on the fiber-end.

  6. Highly sensitive humidity sensor based on graphene oxide foam

    Science.gov (United States)

    Zhang, Kai-Lun; Hou, Zhi-Ling; Zhang, Bao-Xun; Zhao, Quan-Liang

    2017-10-01

    Since sensitive humidity sensing is strongly desired, we present a highly sensitive humidity sensor fabricated from graphene oxide (GO) foam based on low-frequency dielectric properties. The GO foam shows humidity- and compression-dependent dielectric. Upon applying compression on GO foam, the humidity sensitivity increases and the maximum humidity sensitivity of dielectric loss is more than 12-fold higher than that of direct-current electrical conductivity. The highly sensitive humidity response originates from the generation of local conductive networks, which is the result of the connected isolated conductive regions by water cluster. Additionally, the dielectric properties of fabricated GO foam show a stable and repeatable humidity response, suggesting a carbon prototype with great potential in humidity sensors.

  7. Manufacture of high aspect ratio micro-pillar wall shear stress sensor arrays

    Science.gov (United States)

    Gnanamanickam, Ebenezer P.; Sullivan, John P.

    2012-12-01

    In the field of experimental fluid mechanics the measurement of unsteady, distributed wall shear stress has proved historically challenging. Recently, sensors based on an array of flexible micro-pillars have shown promise in carrying out such measurements. Similar sensors find use in other applications such as cellular mechanics. This work presents a manufacturing technique that can manufacture micro-pillar arrays of high aspect ratio. An electric discharge machine (EDM) is used to manufacture a micro-drilling tool. This micro-drilling tool is used to form holes in a wax sheet which acts as the mold for the micro-pillar array. Silicone rubber is cast in these molds to yield a micro-pillar array. Using this technique, micro-pillar arrays with a maximum aspect ratio of about 10 have been manufactured. Manufacturing issues encountered, steps to alleviate them and the potential of the process to manufacture similar micro-pillar arrays in a time-efficient manner are also discussed.

  8. A high accuracy algorithm of displacement measurement for a micro-positioning stage

    OpenAIRE

    Xiang Zhang; Xianmin Zhang; Heng Wu; Jinqiang Gan; Hai Li

    2017-01-01

    A high accuracy displacement measurement algorithm for a two degrees of freedom compliant precision micro-positioning stage is proposed based on the computer micro-vision technique. The algorithm consists of an integer-pixel and a subpixel matching procedure. Series of simulations are conducted to verify the proposed method. The results show that the proposed algorithm possesses the advantages of high precision and stability, the resolution can attain to 0.01 pixel theoretically. In addition,...

  9. Handling High-Dimension (High-Feature) MicroRNA Data.

    Science.gov (United States)

    Hu, Yue; Lan, Wenjun; Miller, Daniel

    2017-01-01

    High-dimensional data, or high-feature variables, are often used to describe the characteristics of microRNA sequence and microarray data. As a consequence, the curse of high dimension often becomes a problem. High-dimension variables lead to many difficulties in processing and can be hard to understand. On the other aspect, as the sample size rather limited, the more variables, the more statistical error would be produced in the data processing. For the purpose of decreasing the dimension of variables, a degenerated k-mer method was suggested. To enhance the statistical robustness, the gapped k-mer method was introduced. In the last part of this chapter, some traditional supervised and unsupervised mathematical methods that used to decrease the dimensionality of the data are also described.

  10. Murine High Specificity/Sensitivity Competitive Europium Insulin Autoantibody Assay

    Science.gov (United States)

    Babaya, Naru; Liu, Edwin; Miao, DongMei; Li, Marcella; Yu, Liping

    2009-01-01

    Abstract Background Most insulin autoantibody assays for both human and animal models are in a radioassay format utilizing 125I-insulin, but despite the radioassay format international workshops have documented difficulty in standardization between laboratories. There is thus a need for simpler assay formats that do not utilize radioactivity, yet retain the high specificity and sensitivity of radioassays. Methods To establish an easier enzyme-linked immunosorbent assay (ELISA) for insulin autoantibodies of non-obese diabetic (NOD) mice, we used an ELISA format, competition with unlabeled insulin, europium-avidin, and time-resolved fluorescence detection (competitive europium insulin autoantibody assay). Results The competitive europium assay of insulin autoantibodies when applied to sera from NOD mice had high sensitivity and specificity (92% sensitivity, 100% specificity) compared to our standard insulin autoantibody radioassay (72% sensitivity, 100% specificity) in analyzing blind workshop sera. It is noteworthy that though the assay has extremely high sensitivity for murine insulin autoantibodies and utilizes human insulin as target autoantigen, human sera with high levels of insulin autoantibodies are not detected. Conclusions Our results clearly indicate that low levels of insulin autoantibodies can be detected in an ELISA-like format. Combining a europium-based ELISA with competition with fluid-phase autoantigen can be applicable to many autoantigens to achieve high specificity and sensitivity in an ELISA format. PMID:19344197

  11. Wafer-scale integrated micro-supercapacitors on an ultrathin and highly flexible biomedical platform.

    Science.gov (United States)

    Maeng, Jimin; Meng, Chuizhou; Irazoqui, Pedro P

    2015-02-01

    We present wafer-scale integrated micro-supercapacitors on an ultrathin and highly flexible parylene platform, as progress toward sustainably powering biomedical microsystems suitable for implantable and wearable applications. All-solid-state, low-profile (microsystem. The system discharging rate is shown to improve by ~17 times in the presence of the integrated micro-supercapacitors. This result suggests that the integrated micro-supercapacitor technology described herein is a promising strategy for sustainably powering biomedical microsystems dedicated to implantable and wearable applications.

  12. High Accuracy Three-dimensional Simulation of Micro Injection Moulded Parts

    DEFF Research Database (Denmark)

    Tosello, Guido; Costa, F. S.; Hansen, Hans Nørgaard

    2011-01-01

    Micro injection moulding (μIM) is the key replication technology for high precision manufacturing of polymer micro products. Data analysis and simulations on micro-moulding experiments have been conducted during the present validation study. Detailed information about the μIM process was gathered...... and used to establish a reliable simulation methodology suitable for μIM parts. Various Simulation set-up parameters that have been considered in order to improve the simulation accuracy: injection speed profile, melt and mould temperatures, 3D mesh, material rheology, inertia effect and shrinkage...

  13. Micro-heterogeneity and micro-rheological properties of high-viscosity barley beta-glucan solutions studied by diffusion wave spectroscopy (DWS)

    Science.gov (United States)

    Soluble fiber ß-glucan is one of the key dietary materials in healthy food products known for reducing serum cholesterol levels. The micro-structural heterogeneity and micro-rheology of high-viscosity barley ß-glucan solutions were investigated by the diffusing wave spectroscopy (DWS) technology. By...

  14. The micro-Ames test: A direct comparison of the performance and sensitivities of the standard and 24-well plate versions of the bacterial mutation test.

    Science.gov (United States)

    Proudlock, Raymond; Evans, Kristie

    2016-12-01

    "Ames" bacterial mutation tests are widely performed for evaluation and registration of new materials including industrial chemicals, agrochemicals, medical devices, pharmaceuticals, pharmaceutical impurities and other materials. Tests are used to predict their potential long-term adverse health effects (including carcinogenicity). Given their importance, pre-screening 'miniaturized' versions have been developed which allow higher throughput and use less test material, including the widely-employed 24-well micro-Ames (µAmes) test which uses 20 times less material. However, little quantitative information has been published on the methodology or sensitivity of this system. We describe methods and results used in direct comparisons of the sensitivity of micro and standard systems using the same cultures, formulations, etc. Initial testing utilized the plate incorporation method and, later, the pre-incubation method. In a subsequent phase of testing, a four-way direct comparison was made between the pre-incubation and plate incorporation methods in both systems using some direct-acting mutagens. Tests used only those strain/S9/chemical combinations where a response was expected. Historical control results accumulated during testing are also presented. Spontaneous and induced revertant colony counts for the µAmes system were consistently proportionate and approximately 1/20th those for the standard Ames test. Sensitivities of the two systems were found to be nearly identical in almost all cases for a wide variety of weak and strong inorganic and organic mutagens. Standardized procedures and increased reliability of the estimate of the background revertant frequency in the µAmes system means that the two systems give equivalent results and are expected to be highly predictive of one another. Environ. Mol. Mutagen. 57:687-705, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  15. High-energy-surface engineered metal oxide micro- and nanocrystallites and their applications.

    Science.gov (United States)

    Kuang, Qin; Wang, Xue; Jiang, Zhiyuan; Xie, Zhaoxiong; Zheng, Lansun

    2014-02-18

    Because many physical and chemical processes occur at surfaces, surface atomic structure is a critical factor affecting the properties of materials. Due to the presence of high-density atomic steps and edges and abundant unsaturated coordination sites, micro- and nanocrystallites with high-energy surfaces usually exhibit greater reactivity than those with low-energy surfaces. However, high-energy crystal surfaces are usually lost during crystal growth as the total surface energy is minimized. Therefore, the selective exposure of high-energy facets at the surface of micro- and nanocrystallites is an important and challenging research topic. Metal oxides play important roles in surface-associated applications, including catalysis, gas sensing, luminescence, and antibiosis. The synthesis of metal oxide micro- and nanocrystallites with specific surfaces, particularly those with high surface energies, is more challenging than the synthesis of metal crystals due to the presence of strong metal-oxygen bonds and diverse crystal structures. In this Account, we briefly summarize recent progress in the surface-structure-controlled synthesis of several typical metal oxide micro- and nanocrystallites, including wurtzite ZnO, anatase TiO2, rutile SnO2, and rocksalt-type metal oxides. We also discuss the improvement of surface properties, focusing on high-energy surfaces. Because of the huge quantity and diverse structure of metal oxides, this Account is not intended to be comprehensive. Instead, we discuss salient features of metal oxide micro- and nanocrystallites using examples primarily from our group. We first discuss general strategies for tuning the surface structure of metal oxide micro- and nanocrystallites, presenting several typical examples. For each example, we describe the basic crystallographic characteristics as well as the thermodynamic (i.e., tuning surface energy) or kinetic (i.e., tuning reaction rates) strategies we have used to synthesize micro- and

  16. Comparison of high-resolution X-ray and micro-CT for experimental evaluation of intracranial stent prototypes: quality evaluation beyond CE mark

    Energy Technology Data Exchange (ETDEWEB)

    Keuler, Andreas; Taschner, Christian; Schumacher, Martin [University Medical Center Freiburg, Department of Neuroradiology, Freiburg (Germany); Brockmann, Marc Alexander [University Hospital of RWTH Aachen, Department of Diagnostic and Interventional Neuroradiology, Aachen (Germany); University of Heidelberg, Department of Neuroradiology, University Medical Center Mannheim, Mannheim (Germany); Boll, Hanne [University of Heidelberg, Department of Neuroradiology, University Medical Center Mannheim, Mannheim (Germany); Foerster, Katharina [University Medical Center Freiburg, Department of Cardiovascular Surgery, Freiburg (Germany); Lutz, Lisa [University Medical Center Freiburg, Department of Pathology, Freiburg (Germany); Herrmann-Frank, Annegret; Lelgemann, Monika [Medical Advisory Service of Social Health Insurance, Department of Evidence-Based Medicine, Essen (Germany)

    2014-04-15

    As digital mammography and micro-computed tomography (CT) have been used for evaluation of stents deployed in experimental animal models, we compared the two methods regarding their sensitivity to detect abnormalities in three prototypes of intracranial stents. Three different prototypes of intracranial stents (n = 84) were implanted in various animal models. Explanted stents were examined using digital mammography and micro-CT. The images were compared with respect to maintenance of material and form and the stents were compared to one another. Histological analysis was performed as well. In the open-cell stents, expansion of the stent cells was detected in the majority of cases (57.1 %) using micro-CT and less frequently using mammography (42.3 %). The closed-cell stent revealed kink stenoses in mammography as well as in micro-CT (3/7, 42.9 %). Detailed reconstructions of micro-CT images showed high-grade kink stenoses of the flow-diverter stent in two extremely curved vessels. Strut breaks were observed more frequently using micro-CT (6/84, 7.1 %) than by mammography (4/84, 4.8 %). Histology confirmed all changes of stent architecture. Significant changes of stent architecture can be observed and assessed even in the two-dimensional mammographic images. The use of micro-CT is recommended to detect subtle changes like single strut breaks and for three-dimensional information. (orig.)

  17. Comparison of high-resolution X-ray and micro-CT for experimental evaluation of intracranial stent prototypes: quality evaluation beyond CE mark.

    Science.gov (United States)

    Keuler, Andreas; Taschner, Christian; Brockmann, Marc Alexander; Boll, Hanne; Förster, Katharina; Lutz, Lisa; Herrmann-Frank, Annegret; Lelgemann, Monika; Schumacher, Martin

    2014-04-01

    As digital mammography and micro-computed tomography (CT) have been used for evaluation of stents deployed in experimental animal models, we compared the two methods regarding their sensitivity to detect abnormalities in three prototypes of intracranial stents. Three different prototypes of intracranial stents (n = 84) were implanted in various animal models. Explanted stents were examined using digital mammography and micro-CT. The images were compared with respect to maintenance of material and form and the stents were compared to one another. Histological analysis was performed as well. In the open-cell stents, expansion of the stent cells was detected in the majority of cases (57.1 %) using micro-CT and less frequently using mammography (42.3 %). The closed-cell stent revealed kink stenoses in mammography as well as in micro-CT (3/7, 42.9 %). Detailed reconstructions of micro-CT images showed high-grade kink stenoses of the flow-diverter stent in two extremely curved vessels. Strut breaks were observed more frequently using micro-CT (6/84, 7.1 %) than by mammography (4/84, 4.8 %). Histology confirmed all changes of stent architecture. Significant changes of stent architecture can be observed and assessed even in the two-dimensional mammographic images. The use of micro-CT is recommended to detect subtle changes like single strut breaks and for three-dimensional information.

  18. High-Performance Micro-Rover for Planetary Surface Exploration

    Science.gov (United States)

    Gao, Y.; Chen, X.

    2009-04-01

    Planetary robotic missions rely on rovers to produce surface mobility for multiple sites sampling and exploration. For example, the Mars Exploration Rovers (MER) have been extremely successful in the exploring a wide area of the Martian surface in the past four years. Each of the MER has the size of a golf car and weights ~170 kg. They both result in a massive launch of nearly 1100 kg. Small rovers (5-30 kg) can help to provide moderate surface traverse and greatly reduce cost of the mission, e.g. the Sojourner rover of the Mars Pathfinder mission. There is a growing interest in the micro-rover design and how to maximize performance of a miniaturized system. For example, the rover traversability and locomotion capability will be compromised if the objective is to reduce the size of the vehicle. Undoubtedly, this affects the rover performance in terms of mobility and usefulness to the mission. We propose to overcome this problem by investigating a new generation of rover chassis design to maximize its terrian capability. This paper presents a chassis concept suited for a micro-rover system and negotiating with different planetary terrains such as the Moon and Mars. The proposed tracked-wheel is motivated by bringing together advantages of wheels and tracks, in the same time keeping the design simple and easy to implement. The chassis is built based on four tracked-wheels and offers 10 DOF for the vehicle. Analysis based on Bekker theories suggests this design can generate larger tractive effort (drawbar pull) compared to the wheeled design for the same rover dimensions. As a result, a more effective and efficent chassis can be achieved and leave a large design margin for the science payload.

  19. Achieving sensitive, high-resolution laser spectroscopy at CRIS

    Energy Technology Data Exchange (ETDEWEB)

    Groote, R. P. de [Instituut voor Kern- en Stralingsfysica, KU Leuven (Belgium); Lynch, K. M., E-mail: kara.marie.lynch@cern.ch [EP Department, CERN, ISOLDE (Switzerland); Wilkins, S. G. [The University of Manchester, School of Physics and Astronomy (United Kingdom); Collaboration: the CRIS collaboration

    2017-11-15

    The Collinear Resonance Ionization Spectroscopy (CRIS) experiment, located at the ISOLDE facility, has recently performed high-resolution laser spectroscopy, with linewidths down to 20 MHz. In this article, we present the modifications to the beam line and the newly-installed laser systems that have made sensitive, high-resolution measurements possible. Highlights of recent experimental campaigns are presented.

  20. Achieving sensitive, high-resolution laser spectroscopy at CRIS

    Science.gov (United States)

    de Groote, R. P.; Lynch, K. M.; Wilkins, S. G.

    2017-11-01

    The Collinear Resonance Ionization Spectroscopy (CRIS) experiment, located at the ISOLDE facility, has recently performed high-resolution laser spectroscopy, with linewidths down to 20 MHz. In this article, we present the modifications to the beam line and the newly-installed laser systems that have made sensitive, high-resolution measurements possible. Highlights of recent experimental campaigns are presented.

  1. High-sensitivity troponin after running--a systematic review.

    Science.gov (United States)

    Vilela, E M; Bastos, J C C; Rodrigues, R P; Nunes, J P L

    2014-01-01

    A systematic review was carried out to study the pattern of high-sensitivity cardiac troponin release after running (search performed on PubMed, ISI Web of Knowledge and Scopus databases). A total of ten reports were identified as meeting the pre-specified criteria (eight using high-sensitivity troponin T and two using high-sensitivity troponin I). The papers were published between 2009 and 2013, amounting to a total of 479 participants under study. Eight reports provided data comparing post-running troponin levels with the 99th percentile reference value. A total number of 296 participants, out of 424, showed post-running high-sensitivity troponin values higher than the 99th percentile reference value (69.8%). In conclusion, using high-sensitivity cardiac troponin assays, studies have shown that elevated post-running values are seen in more than two-thirds of runners. Whether troponin release in this setting represents a fully reversible phenomenon is currently unknown; the effects of strenuous running on long-term health are also uncertain.

  2. An improved Ras sensor for highly sensitive and quantitative FRET-FLIM imaging.

    Directory of Open Access Journals (Sweden)

    Ana F Oliveira

    Full Text Available Ras is a signaling protein involved in a variety of cellular processes. Hence, studying Ras signaling with high spatiotemporal resolution is crucial to understanding the roles of Ras in many important cellular functions. Previously, fluorescence lifetime imaging (FLIM of fluorescent resonance energy transfer (FRET-based Ras activity sensors, FRas and FRas-F, have been demonstrated to be useful for measuring the spatiotemporal dynamics of Ras signaling in subcellular micro-compartments. However the predominantly nuclear localization of the sensors' acceptor has limited its sensitivity. Here, we have overcome this limitation and developed two variants of the existing FRas sensor with different affinities: FRas2-F (K(d∼1.7 µM and FRas2-M (K(d∼0.5 µM. We demonstrate that, under 2-photon fluorescence lifetime imaging microscopy, FRas2 sensors provide higher sensitivity compared to previous sensors in 293T cells and neurons.

  3. Damping mechanisms in high-Q micro and nanomechanical string resonators

    DEFF Research Database (Denmark)

    Schmid, Silvan; Jensen, K. D.; Nielsen, K. H.

    2011-01-01

    Resonant micro and nanostrings were found to have extraordinarily high quality factors (Qs). Since the discovery of the high Qs of silicon nitride nanostrings, the understanding of the underlying mechanisms allowing such high quality factors has been a topic of several investigations. So far it has...

  4. High-sensitivity Compton imaging with position-sensitive Si and Ge detectors

    Energy Technology Data Exchange (ETDEWEB)

    Vetter, K. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)], E-mail: kvetter@llnl.gov; Burks, M.; Cork, C.; Cunningham, M.; Chivers, D.; Hull, E. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Krings, T. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Manini, H.; Mihailescu, L.; Nelson, K. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Protic, D. [Institut fuer Kernphysik, Forschungszentrum Juelich, 52425 Juelich (Germany); Valentine, J.; Wright, D. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2007-08-21

    We report on the development of high-sensitivity and compact Compton imaging systems built of large and position-sensitive Si(Li) and HPGe detectors. The primary goal of this effort is to provide improved capabilities in the passive detection of nuclear materials for homeland security. Our detectors are implemented in double-sided strip configuration, which-along with digital signal processing-provides energies and three-dimensional position information of individual {gamma}-ray interactions. {gamma}-Ray tracking algorithms then determine the scattering sequence of the {gamma}-ray, which in turn allows us-employing the Compton scattering formula-to reconstruct a cone of possible incident angles and ultimately an image. This Compton imaging concept enables large-field-of-view {gamma}-ray imaging without the use of a heavy collimator or aperture. The intrinsically high-energy resolution of the detectors used, the excellent position resolution we have demonstrated, both combined with the high efficiency of large-volume detectors is the basis for high Compton imaging sensitivity. These capabilities are being developed to identify and localize potential threat sources and to potentially increase the sensitivity in detecting weak sources out of the midst of natural, medical, or commercial sources. {gamma}-ray imaging provides a new degree of freedom to distinguish between spatial and temporal background fluctuations and compact threat sources.

  5. A highly aromatic and sulfonated ionomer for high elastic modulus ionic polymer membrane micro-actuators

    Science.gov (United States)

    Hatipoglu, Gokhan; Liu, Yang; Zhao, Ran; Yoonessi, Mitra; Tigelaar, Dean M.; Tadigadapa, Srinivas; Zhang, Q. M.

    2012-05-01

    A high modulus, sulfonated ionomer synthesized from 4,6-bis(4-hydroxyphenyl)-N,N-diphenyl-1,3,5-triazin-2-amine and 4,4‧-biphenol with bis(4-fluorophenyl)sulfone (DPA-PS:BP) is investigated for ionic polymer actuators. The uniqueness of DPA-PS:BP is that it can have a high ionic liquid (IL) uptake and consequently generates a high intrinsic strain response, which is >1.1% under 1.6 V while maintaining a high elastic modulus (i.e. 600 MPa for 65 vol% IL uptake). Moreover, such a high modulus of the active ionomer, originating from the highly aromatic backbone and side-chain-free structure, allows for the fabrication of free-standing thin film micro-actuators (down to 5 µm thickness) via the solution cast method and focused-ion-beam milling, which exhibits a much higher bending actuation, i.e. 43 µm tip displacement and 180 kPa blocking stress for a 200 µm long and 5 µm thick cantilever actuator, compared with the ionic actuators based on traditional ionomers such as Nafion, which has a much lower elastic modulus (50 MPa) and actuation strain.

  6. High-sensitivity, high-speed continuous imaging system

    Science.gov (United States)

    Watson, Scott A; Bender, III, Howard A

    2014-11-18

    A continuous imaging system for recording low levels of light typically extending over small distances with high-frame rates and with a large number of frames is described. Photodiode pixels disposed in an array having a chosen geometry, each pixel having a dedicated amplifier, analog-to-digital convertor, and memory, provide parallel operation of the system. When combined with a plurality of scintillators responsive to a selected source of radiation, in a scintillator array, the light from each scintillator being directed to a single corresponding photodiode in close proximity or lens-coupled thereto, embodiments of the present imaging system may provide images of x-ray, gamma ray, proton, and neutron sources with high efficiency.

  7. Large pi-aromatic molecules as potential sensitizers for highly efficient dye-sensitized solar cells.

    Science.gov (United States)

    Imahori, Hiroshi; Umeyama, Tomokazu; Ito, Seigo

    2009-11-17

    Recently, dye-sensitized solar cells have attracted much attention relevant to global environmental issues. Thus far, ruthenium(II) bipyridyl complexes have proven to be the most efficient TiO(2) sensitizers in dye-sensitized solar cells. However, a gradual increment in the highest power conversion efficiency has been recognized in the past decade. More importantly, considering that ruthenium is a rare metal, novel dyes without metal or using inexpensive metal are desirable for highly efficient dye-sensitized solar cells. Large pi-aromatic molecules, such as porphyrins, phthalocyanines, and perylenes, are important classes of potential sensitizers for highly efficient dye-sensitized solar cells, owing to their photostability and high light-harvesting capabilities that can allow applications in thinner, low-cost dye-sensitized solar cells. Porphyrins possess an intense Soret band at 400 nm and moderate Q bands at 600 nm. Nevertheless, the poor light-harvesting properties relative to the ruthenium complexes have limited the cell performance of porphyrin-sensitized TiO(2) cells. Elongation of the pi conjugation and loss of symmetry in porphyrins cause broadening and a red shift of the absorption bands together with an increasing intensity of the Q bands relative to that of the Soret band. On the basis of the strategy, the cell performance of porphyrin-sensitized solar cells has been improved intensively by the enhanced light absorption. Actually, some push-pull-type porphyrins have disclosed a remarkably high power conversion efficiency (6-7%) that was close to that of the ruthenium complexes. Phthalocyanines exhibit strong absorption around 300 and 700 nm and redox features that are similar to porphyrins. Moreover, phthalocyanines are transparent over a large region of the visible spectrum, thereby enabling the possibility of using them as "photovoltaic windows". However, the cell performance was poor, owing to strong aggregation and lack of directionality in the

  8. Performance of terahertz metamaterials as high-sensitivity sensor

    Science.gov (United States)

    He, Yanan; Zhang, Bo; Shen, Jingling

    2017-09-01

    A high-sensitivity sensor based on the resonant transmission characteristics of terahertz (THz) metamaterials was investigated, with the proposal and fabrication of rectangular bar arrays of THz metamaterials exhibiting a period of 180 μm on a 25 μm thick flexible polyimide. Varying the size of the metamaterial structure revealed that the length of the rectangular unit modulated the resonant frequency, which was verified by both experiment and simulation. The sensing characteristics upon varying the surrounding media in the sample were tested by simulation and experiment. Changing the surrounding medium from that of air to that of alcohol or oil produced resonant frequency redshifts of 80 GHz or 150 GHz, respectively, which indicates that the sensor possessed a high sensitivity of 667 GHz per unit of refractive index. Finally, the influence of the sample substrate thickness on the sensor sensitivity was investigated by simulation. It may be a reference for future sensor design.

  9. A highly sensitive method for quantification of iohexol

    DEFF Research Database (Denmark)

    Schulz, A.; Boeringer, F.; Swifka, J.

    2014-01-01

    lohexol (1-N,3-N-bis(2,3-dihydroxypropyl)-5-IN-(2,3-dihydroxypropyl) acetamide-2,4,6-triiodobenzene1,3-dicarboxamide) is used for accurate determination of the glomerular filtration rate (GFR) in chronic kidney disease (CKD) patients. However, high iohexol amounts might lead to adverse effects in...... in organisms. In order to minimize the iohexol dosage required for the GFR determination in humans, the development of a sensitive quantification method is essential. Therefore, the objective of our preclinical study was to establish and validate a simple and robust liquid......-spectrometry based method has been proved to be sensitive, selective and suitable for the quantification of iohexol in serum. Due to high sensitivity of this novel method the iohexol application dose as well as the sampling time in the clinical routine could be reduced in the future in order to further minimize side...

  10. A systematic approach to fabricate high aspect ratio silicon micro-needles for transdermal drug delivery

    Science.gov (United States)

    Ng, H. B.; Shearwood, C.

    2007-12-01

    The successful development of micro-needles can help transport drugs and vaccines both effectively and painlessly across the skin. However, not all micro-needles are strong enough to withstand the insertion forces and viscoelasticity of the skin. The work here focuses on the micro-fabrication of high aspect ratio needles with careful control of needle-profile using dry etching technologies. Silicon micro-needles, 150μm in length with base-diameters ranging from 90 to 240μm have been investigated in this study. A novel, multiple-sacrificial approach has been demonstrated as suited to the fabrication of long micro-needle bodies with positive profiles. The parameters that control the isotropic etching are adjusted to control the ratio of the needle-base diameter to needle length. By careful control of geometry, the needle profile can be engineered to give a suitable tip size for penetration, as well as a broad needle base to facilitate the creation of either single or multiple-through holes. This approach allows the mechanical properties of the otherwise brittle needles to be optimized. Finite element analysis indicates that the micro-needles will fracture prematurely due to buckling, with forces ranging from 10 to 30mN.

  11. Portable High Sensitivity and High Resolution Sensor to Determine Oxygen Purity Levels Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The objective of this Phase I STTR project is to develop a highly sensitive oxygen (O2) sensor, with high accuracy and precision, to determine purity levels of high...

  12. Clinical observation of micro-coaxial phacoemulsification for axial high myopia with cataract

    Directory of Open Access Journals (Sweden)

    Rui-Fan Zhang

    2014-11-01

    Full Text Available AIM: To observe the clinical effect of micro-coaxial phacoemulsification combined with intraocular lens implantation in axial high myopia with cataract.METHODS: Fifty-three patients(74 eyeswith axial high myopia and cataract underwent micro-coaxial phacoemulsification combined with intraocular lens implantation between April 2013 and December 2013. The best corrected visual acuity(BCVAwas observed at 1 and 3mo after operation, and the complications were recorded.RESULTS: Compared with the preoperative, BCVA was improved at 1 and 3mo after operation, and the differences were statistically significant(PP>0.05. There was no incidence of complications, such as retinal detachment, iris damage, pupil deformation, cystoid macular edema, endophthalmitis after operation in all patients.CONCLUSION:Micro-coaxial phacoemulsification combined with intraocular lens implantation is an effective and safe method for axial high myopia with cataract.

  13. Circulating microRNAs are new and sensitive biomarkers of myocardial infarction

    Science.gov (United States)

    D'Alessandra, Yuri; Devanna, Paolo; Limana, Federica; Straino, Stefania; Di Carlo, Anna; Brambilla, Paola G.; Rubino, Mara; Carena, Maria Cristina; Spazzafumo, Liana; De Simone, Marco; Micheli, Barbara; Biglioli, Paolo; Achilli, Felice; Martelli, Fabio; Maggiolini, Stefano; Marenzi, Giancarlo; Pompilio, Giulio; Capogrossi, Maurizio C.

    2010-01-01

    Aims Circulating microRNAs (miRNAs) may represent a novel class of biomarkers; therefore, we examined whether acute myocardial infarction (MI) modulates miRNAs plasma levels in humans and mice. Methods and results Healthy donors (n = 17) and patients (n = 33) with acute ST-segment elevation MI (STEMI) were evaluated. In one cohort (n = 25), the first plasma sample was obtained 517 ± 309 min after the onset of MI symptoms and after coronary reperfusion with percutaneous coronary intervention (PCI); miR-1, -133a, -133b, and -499-5p were ∼15- to 140-fold control, whereas miR-122 and -375 were ∼87–90% lower than control; 5 days later, miR-1, -133a, -133b, -499-5p, and -375 were back to baseline, whereas miR-122 remained lower than control through Day 30. In additional patients (n = 8; four treated with thrombolysis and four with PCI), miRNAs and troponin I (TnI) were quantified simultaneously starting 156 ± 72 min after the onset of symptoms and at different times thereafter. Peak miR-1, -133a, and -133b expression and TnI level occurred at a similar time, whereas miR-499-5p exhibited a slower time course. In mice, miRNAs plasma levels and TnI were measured 15 min after coronary ligation and at different times thereafter. The behaviour of miR-1, -133a, -133b, and -499-5p was similar to STEMI patients; further, reciprocal changes in the expression levels of these miRNAs were found in cardiac tissue 3–6 h after coronary ligation. In contrast, miR-122 and -375 exhibited minor changes and no significant modulation. In mice with acute hind-limb ischaemia, there was no increase in the plasma level of the above miRNAs. Conclusion Acute MI up-regulated miR-1, -133a, -133b, and -499-5p plasma levels, both in humans and mice, whereas miR-122 and -375 were lower than control only in STEMI patients. These miRNAs represent novel biomarkers of cardiac damage. PMID:20534597

  14. Aluminum nano-cantilevers for high sensitivity mass sensors

    DEFF Research Database (Denmark)

    Davis, Zachary James; Boisen, Anja

    2005-01-01

    We have fabricated Al nano-cantilevers using a very simple one mask contact UV lithography technique with lateral dimensions under 500 nm and vertical dimensions of approximately 100 nm. These devices are demonstrated as highly sensitive mass sensors by measuring their dynamic properties. Further...

  15. Sensitive high performance liquid chromatographic method for the ...

    African Journals Online (AJOL)

    A new simple, sensitive, cost-effective and reproducible high performance liquid chromatographic (HPLC) method for the determination of proguanil (PG) and its metabolites, cycloguanil (CG) and 4-chlorophenylbiguanide (4-CPB) in urine and plasma is described. The extraction procedure is a simple three-step process ...

  16. High-sensitivity C-reactive protein, lipid profile, malondialdehyde ...

    African Journals Online (AJOL)

    High-sensitivity C-reactive protein, lipid profile, malondialdehyde and total antioxidant capacity in psoriasis. ... Abstract. Psoriasis is a chronic inflammatory skin disease characterized by epidermal hyperproliferation and lymphocytic infiltration. The ongoing inflammatory process in psoriasis affects the arterial wall promoting ...

  17. Performance studies on high pressure 1-D position sensitive ...

    Indian Academy of Sciences (India)

    Performance studies on high pressure 1-D position sensitive neutron detectors. S S DESAI and A M SHAIKH∗. Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India. *Corresponding author. E-mail: shaikham@barc.gov.in. Abstract. The powder diffractometer and Hi-Q diffractometer at ...

  18. High Throughput Integrated Technologies for Multimaterial Functional Micro Components (EU FP7 HINMICO 2013-2016)

    DEFF Research Database (Denmark)

    Azcarate, Sabino; Esmoris, Joseba; Dimov, Stefan

    2016-01-01

    The objective of the HINMICO project is the development and optimization of manufacturing processes for the production of high-added value high quality multi-material micro-components, with the possibility of additional, functionalities, through more integrated, efficient and cost-effective proce...

  19. Identification of sensitive serum microRNA biomarkers for radiation biodosimetry.

    Directory of Open Access Journals (Sweden)

    Naduparambil Korah Jacob

    Full Text Available Exposure to ionizing radiation through environmental, occupational or a nuclear reactor accident such as the recent Fukushima Daiichi incident often results in major consequences to human health. The injury caused by radiation can manifest as acute radiation syndromes within weeks in organs with proliferating cells such as hematopoietic and gastrointestinal systems. Cancers, fibrosis and degenerative diseases are also reported in organs with differentiated cells, months or years later. Studies conducted on atom bomb survivors, nuclear reactor workers and animal models have shown a direct correlation of these effects with the absorbed dose. Physical dosimeters and the available radio-responsive biologics in body fluids, whose responses are rather indirect, have limitations to accurately evaluate the extent of post exposure damage. We have used an amplification-free, hybridization based quantitative assay utilizing the nCounter multiplex platform developed by nanoString Technologies to compare the levels of over 600 miRNAs in serum from mice irradiated at a range of 1 to 12 Gy at 24 and 48 hr time points. Development of a novel normalization strategy using multiple spike-in oligonucleotides allowed accurate measurement of radiation dose and time dependent changes in serum miRNAs. The response of several evolutionarily conserved miRNAs abundant in serum, were found to be robust and sensitive in the dose range relevant for medical triage and in patients who receive total body radiation as preparative regimen for bone marrow transplantation. Notably, miRNA-150, abundant in lymphocytes, exhibited a dose and time dependent decrease in serum, which we propose as a sensitive marker indicative of lymphocyte depletion and bone marrow damage. Our study has identified several markers useful for evaluation of an individual's response by minimally invasive methods, relevant to triage in case of a radiation accident and evaluation of toxicity and response

  20. High-throughput functional microRNAs profiling by recombinant AAV-based microRNA sensor arrays.

    Directory of Open Access Journals (Sweden)

    Wenhong Tian

    Full Text Available BACKGROUND: microRNAs (miRNAs are small and non-coding RNAs which play critical roles in physiological and pathological processes. A number of methods have been established to detect and quantify miRNA expression. However, method for high-throughput miRNA function detection is still lacking. PRINCIPAL FINDINGS: We describe an adeno-associated virus (AAV vector-based microRNA (miRNA sensor (Asensor array for high-throughput functional miRNA profiling. Each Asensor contains a Gaussia luciferase (Gluc and a firefly luciferase (Fluc expression cassette to sense functional miRNA and to serve as an internal control respectively. Using this array, we acquired functional profiles of 115 miRNAs for 12 cell lines and found "functional miRNA signatures" for several specific cell lines. The activities of specific miRNAs including the let-7 family, miR-17-92 cluster, miR-221, and miR-222 in HEK 293 cells were compared with their expression levels determined by quantitative reverse transcriptase polymerase chain reaction (QRT-PCR. We also demonstrate two other practical applications of the array, including a comparison of the miRNA activity between HEK293 and HEK293T cells and the ability to monitor miRNA activity changes in K562 cells treated with 12-O-tetradecanoylphorbol-13-acetate (TPA. CONCLUSIONS/SIGNIFICANCE: Our approach has potential applications in the identification of cell types, the characterization of biological and pathological processes, and the evaluation of responses to interventions.

  1. Highly sensitive detection using microring resonator and nanopores

    Science.gov (United States)

    Bougot-Robin, K.; Hoste, J. W.; Le Thomas, N.; Bienstman, P.; Edel, J. B.

    2016-04-01

    One of the most significant challenges facing physical and biological scientists is the accurate detection and identification of single molecules in free-solution environments. The ability to perform such sensitive and selective measurements opens new avenues for a large number of applications in biological, medical and chemical analysis, where small sample volumes and low analyte concentrations are the norm. Access to information at the single or few molecules scale is rendered possible by a fine combination of recent advances in technologies. We propose a novel detection method that combines highly sensitive label-free resonant sensing obtained with high-Q microcavities and position control in nanoscale pores (nanopores). In addition to be label-free and highly sensitive, our technique is immobilization free and does not rely on surface biochemistry to bind probes on a chip. This is a significant advantage, both in term of biology uncertainties and fewer biological preparation steps. Through combination of high-Q photonic structures with translocation through nanopore at the end of a pipette, or through a solid-state membrane, we believe significant advances can be achieved in the field of biosensing. Silicon microrings are highly advantageous in term of sensitivity, multiplexing, and microfabrication and are chosen for this study. In term of nanopores, we both consider nanopore at the end of a nanopipette, with the pore being approach from the pipette with nanoprecise mechanical control. Alternatively, solid state nanopores can be fabricated through a membrane, supporting the ring. Both configuration are discussed in this paper, in term of implementation and sensitivity.

  2. Highly Mass-Sensitive Thin Film Plate Acoustic Resonators (FPAR

    Directory of Open Access Journals (Sweden)

    Ventsislav Yantchev

    2011-07-01

    Full Text Available The mass sensitivity of thin aluminum nitride (AlN film S0 Lamb wave resonators is theoretically and experimentally studied. Theoretical predictions based on modal and finite elements method analysis are experimentally verified. Here, two-port 888 MHz synchronous FPARs are micromachined and subsequently coated with hexamethyl-disiloxane(HMDSO-plasma-polymerized thin films of various thicknesses. Systematic data on frequency shift and insertion loss versus film thickness are presented. FPARs demonstrate high mass-loading sensitivity as well as good tolerance towards the HMDSO viscous losses. Initial measurements in gas phase environment are further presented.

  3. Instruction manual for ORNL tandem high abundance sensitivity mass spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Smith, D.H.; McKown, H.S.; Chrisite, W.H.; Walker, R.L.; Carter, J.A.

    1976-06-01

    This manual describes the physical characteristics of the tandem mass spectrometer built by Oak Ridge National Laboratory for the International Atomic Energy Agency. Specific requirements met include ability to run small samples, high abundance sensitivity, good precision and accuracy, and adequate sample throughput. The instrument is capable of running uranium samples as small as 10/sup -12/ g and has an abundance sensitivity in excess of 10/sup 6/. Precision and accuracy are enhanced by a special sweep control circuit. Sample throughput is 6 to 12 samples per day. Operating instructions are also given.

  4. Electrooptic modulation methods for high sensitivity tunable diode laser spectroscopy

    Science.gov (United States)

    Glenar, David A.; Jennings, Donald E.; Nadler, Shacher

    1990-01-01

    A CdTe phase modulator and low power RF sources have been used with Pb-salt tunable diode lasers operating near 8 microns to generate optical sidebands for high sensitivity absorption spectroscopy. Sweep averaged, first-derivative sample spectra of CH4 were acquired by wideband phase sensitive detection of the electrooptically (EO) generated carrier-sideband beat signal. EO generated beat signals were also used to frequency lock the TDL to spectral lines. This eliminates low frequency diode jitter, and avoids the excess laser linewidth broadening that accompanies TDL current modulation frequency locking methods.

  5. High-sensitivity imaging with lateral resonance mode atomic force microscopy.

    Science.gov (United States)

    Ding, Ren-Feng; Yang, Chih-Wen; Huang, Kuang-Yuh; Hwang, Ing-Shouh

    2016-11-03

    In the operation of a dynamic mode atomic force microscope, a micro-fabricated rectangular cantilever is typically oscillated at or near its mechanical resonance frequency. Lateral bending resonances of cantilevers are rarely used because the resonances are not expected to be detected by the beam-deflection method. In this work, we found that micro-cantilevers with a large tip produced an out-of-plane displacement in lateral resonance (LR), which could be detected with the beam-deflection method. Finite-element analysis indicated that the presence of a large tip is the major source of the out-of-plane coupling for the LR. We also imaged a heterogeneous sample by operating a cantilever in LR, torsional resonance, and tapping modes. LR mode yielded a small deformation and noise level in the height maps as well as a high contrast and small noise level in the phase maps. LR mode also had a resonance frequency that was orders of magnitude higher than that of tapping mode. Operation with LR mode may have the benefits of high-speed scanning, high-sensitivity imaging, and mapping of in-plane mechanical properties of the sample surface. In general, LR mode may become a powerful new atomic force microscopy technique for characterizing sample materials.

  6. High Sensitivity Very Low Frequency Receiver for Earthquake Data Acquisition.

    Science.gov (United States)

    Munir, A.; Najmurrokhman, A.

    2017-03-01

    high sensitivity very low frequency (VLF) receiver is developed based on AD744 monolithic operational amplifier (Op-Amp) for earthquake data acquisition. In research related natural phenomena such as atmospheric noise, lightning and earthquake, a VLF receiver particularly with high sensitivity is utterly required due to the low power of VLF wave signals received by the antenna. The developed receiver is intended to have high sensitivity reception for the signals in frequency range of 10-30kHz allocated for earthquake observation. The VLF receiver which is portably designed is also equipped with an output port connectable to the soundcard of personal computer for further data acquisition. After obtaining the optimum design, the hardware realization is implemented on a printed circuit board (PCB) for experimental characterization. It shows that the sensitivity of realized VLF receiver is almost linear in the predefined frequency range for the input signals lower than -12dBm and to be quadratic for the higher level input signals.

  7. High Sensitivity Polymer Optical Fiber-Bragg-Grating-Based Accelerometer

    DEFF Research Database (Denmark)

    Stefani, Alessio; Andresen, Søren; Yuan, Wu

    2012-01-01

    We report on the fabrication and characterization of the first accelerometer based on a polymer optical fiber Bragg grating (FBG) for operation at both 850 and 1550 nm. The devices have a flat frequency response over a 1-kHz bandwidth and a resonance frequency of about 3 kHz. The response is linear...... up to at least 15 g and sensitivities as high as 19 pm/g (shift in resonance wavelength per unit acceleration) have been demonstrated. Given that 15 g corresponds to a strain of less than 0.02% and that polymer fibers have an elastic limit of more than 1%, the polymer FBG accelerometer can measure...... very strong accelerations. We compare with corresponding silica FBG accelerometers and demonstrate that using polymer FBGs improves the sensitivity by more than a factor of four and increases the figure of merit, defined as the sensitivity times the resonance frequency squared....

  8. A Micro CO2 Gas Sensor Based on Sensing of pH-Sensitive Hydrogel Swelling by Means of a Pressure Sensor

    NARCIS (Netherlands)

    Herber, S.; Bomer, Johan G.; Olthuis, Wouter; Bergveld, Piet; van den Berg, Albert

    2005-01-01

    In this paper a sensor is presented for the detection of carbon dioxide gas inside the stomach in order to diagnose gastrointestinal ischemia. The operational principle of the sensor is measuring the CO2 induced pressure generation of a confined pH-sensitive hydrogel by means of a micro pressure

  9. Clinical Impact of a Novel MicroRNA Chemo-Sensitivity Predictor in Gastrooesophageal Cancer.

    Directory of Open Access Journals (Sweden)

    Mette Winther

    Full Text Available miRNAs might be potentially useful biomarkers for prediction of response to chemotherapeutic agents, radiotherapy and survival. The aim of this retrospective study was to validate miRNA response predictors in a cohort of patients with gastrooesophageal cancer in order to predict overall survival (OS and disease-specific survival (DSS.The study population encompassed 53 patients treated with curative intend for loco-regional gastrooesophageal cancer. miRNA expression was quantified from pre-therapeutic and diagnostic, formalin-fixed, paraffin embedded tumour specimens using Affymetrix GeneChip miRNA 1.0 Array. Based on growth inhibition of the NCI60 panel in the presence of cisplatin, epirubicine and capecitabine, a miRNA based response predictor was developed. The Cox proportional hazards model was applied to assess the correlations of the response predictor with OS and DSS.A univariate analysis demonstrated a statistical significant improvement of OS for patients who had undergone surgical resection with prediction scores above the median prediction score (HR: 0.41 (95% CI: 0.17-0.96. Adjusting for surgery and stage, this predictor was identified to be independently associated with both OS (HR: 0.37 (95% CI: 0.16-0.87 and DSS (HR: 0.32 (0.12-0.87.The miRNA profile predictive for sensitivity to cisplatin, epirubicine and capecitabine was shown to be independently associated with OS and DSS in patients with gastrooesophageal cancer.

  10. Heat transfer and structure stress analysis of micro packaging component of high power light emitting diode

    Directory of Open Access Journals (Sweden)

    Hsu Chih-Neng

    2013-01-01

    Full Text Available This paper focuses on the heat transfer and structural stress analysis of the micro- scale packaging structure of a high-power light emitting diode. The thermal-effect and thermal-stress of light emitting diode are determined numerically. Light emitting diode is attached to the silicon substrate through the wire bonding process by using epoxy as die bond material. The silicon substrate is etched with holes at the bottom and filled with high conductivity copper material. The chip temperature and structure stress increase with input power consumption. The micro light emitting diode is mounted on the heat sink to increase the heat dissipation performance, to decrease chip temperature, to enhance the material structure reliability and safety, and to avoid structure failure as well. This paper has successfully used the finite element method to the micro-scale light emitting diode heat transfer and stress concentration at the edges through etched holes.

  11. MicroRNA-330-5p as a Putative Modulator of Neoadjuvant Chemoradiotherapy Sensitivity in Oesophageal Adenocarcinoma.

    LENUS (Irish Health Repository)

    Bibby, Becky A S

    2015-01-01

    Oesophageal adenocarcinoma (OAC) is the sixth most common cause of cancer deaths worldwide, and the 5-year survival rate for patients diagnosed with the disease is approximately 17%. The standard of care for locally advanced disease is neoadjuvant chemotherapy or, more commonly, combined neoadjuvant chemoradiation therapy (neo-CRT) prior to surgery. Unfortunately, ~60-70% of patients will fail to respond to neo-CRT. Therefore, the identification of biomarkers indicative of patient response to treatment has significant clinical implications in the stratification of patient treatment. Furthermore, understanding the molecular mechanisms underpinning tumour response and resistance to neo-CRT will contribute towards the identification of novel therapeutic targets for enhancing OAC sensitivity to CRT. MicroRNAs (miRNA\\/miR) function to regulate gene and protein expression and play a causal role in cancer development and progression. MiRNAs have also been identified as modulators of key cellular pathways associated with resistance to CRT. Here, to identify miRNAs associated with resistance to CRT, pre-treatment diagnostic biopsy specimens from patients with OAC were analysed using miRNA-profiling arrays. In pre-treatment biopsies miR-330-5p was the most downregulated miRNA in patients who subsequently failed to respond to neo-CRT. The role of miR-330 as a potential modulator of tumour response and sensitivity to CRT in OAC was further investigated in vitro. Through vector-based overexpression the E2F1\\/p-AKT survival pathway, as previously described, was confirmed as a target of miR-330 regulation. However, miR-330-mediated alterations to the E2F1\\/p-AKT pathway were insufficient to significantly alter cellular sensitivity to chemotherapy (cisplatin and 5-flurouracil). In contrast, silencing of miR-330-5p enhanced, albeit subtly, cellular resistance to clinically relevant doses of radiation. This study highlights the need for further investigation into the potential of

  12. High-Resolution Northern Blot for a Reliable Analysis of MicroRNAs and Their Precursors

    Directory of Open Access Journals (Sweden)

    Edyta Koscianska

    2011-01-01

    Full Text Available This protocol describes how to perform northern blot analyses to detect microRNAs and their precursors with single-nucleotide resolution, which is crucial for analyzing individual length variants and for evaluating relative quantities of unique microRNAs in cells. Northern blot analysis consists of resolving RNAs by gel electrophoresis, followed by transferring and fixing to nylon membranes as well as detecting by hybridization with radioactive probes. Earlier efforts to improve this method focused mainly on altering the sensitivity of short RNA detection. We have enhanced the resolution of the northern blot technique by optimizing the electrophoresis step. We have also investigated other steps of the procedure with the goal of enhancing the resolution of RNAs; herein, we present several recommendations to do so. Our protocol is applicable to analyses of all kinds of endogenous and exogenous RNAs, falling within length ranges of 20–30 and 50–70 nt, corresponding to microRNA and pre-microRNA lengths, respectively.

  13. High-Speed Video System for Micro-Expression Detection and Recognition

    Directory of Open Access Journals (Sweden)

    Diana Borza

    2017-12-01

    Full Text Available Micro-expressions play an essential part in understanding non-verbal communication and deceit detection. They are involuntary, brief facial movements that are shown when a person is trying to conceal something. Automatic analysis of micro-expression is challenging due to their low amplitude and to their short duration (they occur as fast as 1/15 to 1/25 of a second. We propose a fully micro-expression analysis system consisting of a high-speed image acquisition setup and a software framework which can detect the frames when the micro-expressions occurred as well as determine the type of the emerged expression. The detection and classification methods use fast and simple motion descriptors based on absolute image differences. The recognition module it only involves the computation of several 2D Gaussian probabilities. The software framework was tested on two publicly available high speed micro-expression databases and the whole system was used to acquire new data. The experiments we performed show that our solution outperforms state of the art works which use more complex and computationally intensive descriptors.

  14. Laser direct writing of carbon/Au composite electrodes for high-performance micro-supercapacitors

    Science.gov (United States)

    Cai, Jinguang; Watanabe, Akira; Lv, Chao

    2017-02-01

    Micro-supercapacitors with small size, light weight, flexibility while maintaining high energy and power output are required for portable miniaturized electronics. The fabrication methods and materials should be cost-effective, scalable, and easily integrated to current electronic industry. Carbon materials have required properties for high-performance flexible supercapacitors, including high specific surface areas, electrochemical stability, and high electrical conductivity, as well as the high mechanical tolerance. Laser direct writing method is a non-contact, efficient, single-step fabrication technique without requirements of masks, post-processing, and complex clean room, which is a useful patterning technique, and can be easily integrated with current electronic product lines for commercial use. Previously we have reported micro-supercapacitors fabricated by laser direct writing on polyimide films in air or Ar, which showed highcapacitive performance. However, the conductivity of the carbon materials is still low for fast charge-discharge use. Here, we demonstrated the fabrication of flexible carbon/Au composite high-performance MSCs by first laser direct writing on commercial polyimide films followed by spin-coating Au nanoparticles ink and second in-situ laser direct writing using the low-cost semiconductor laser. As-prepared micro-supercapacitors show an improved conductivity and capacitance of 1.17 mF/cm2 at a high scanning rate of 10,000 mV/s, which is comparable to the reported capacitance of carbon-based micro-supercapacitors. In addition, the micro-supercapacitors have high bend tolerance and long-cycle stability.

  15. Anticipation of interoceptive threat in highly anxiety sensitive persons.

    Science.gov (United States)

    Melzig, Christiane A; Michalowski, Jaroslaw M; Holtz, Katharina; Hamm, Alfons O

    2008-10-01

    Anticipatory anxiety plays a major role in the etiology of panic disorder. Although anticipatory anxiety elicited by expectation of interoceptive cues is specifically relevant for panic patients, it has rarely been studied. Using a population analogue in high fear of such interoceptive arousal sensations (highly anxiety sensitive persons) we evaluated a new experimental paradigm to assess anticipatory anxiety during anticipation of interoceptive (somatic sensations evoked by hyperventilation) and exteroceptive (electric shock) threat. Symptom reports, autonomic arousal, and defensive response mobilization (startle eyeblink response) were monitored during threat and matched safe conditions in 26 highly anxiety sensitive persons and 22 controls. The anticipation of exteroceptive threat led to a defensive and autonomic mobilization as indexed by a potentiation of the startle response and an increase in skin conductance level in both experimental groups. During interoceptive threat, however, only highly anxiety sensitive persons but not the controls exhibited a startle response potentiation as well as autonomic activation. The anticipation of a hyperventilation procedure thus seems a valid paradigm to investigate anticipatory anxiety elicited by interoceptive cues in the clinical context.

  16. On-Electrode Synthesis of Shape-Controlled Hierarchical Flower-Like Gold Nanostructures for Efficient Interfacial DNA Assembly and Sensitive Electrochemical Sensing of MicroRNA.

    Science.gov (United States)

    Su, Shao; Wu, Yan; Zhu, Dan; Chao, Jie; Liu, Xingfen; Wan, Ying; Su, Yan; Zuo, Xiaolei; Fan, Chunhai; Wang, Lianhui

    2016-07-01

    The performance for biomolecular detection is closely associated with the interfacial structure of a biosensor, which profoundly affects both thermodynamics and kinetics of the assembly, binding and signal transduction of biomolecules. Herein, it is reported on a one-step and template-free on-electrode synthesis method for making shape-controlled gold nanostructures on indium tin oxide substrates, which provide an electrochemical sensing platform for ultrasensitive detection of nucleic acids. Thus-prepared hierarchical flower-like gold nanostructures (HFGNs) possess large surface area that can readily accommodate the assembly of DNA probes for subsequent hybridization detection. It is found that the sensitivity for electrochemical DNA sensing is critically dependent on the morphology of HFGNs. By using this new strategy, a highly sensitive electrochemical biosensor is developed for label-free detection of microRNA-21 (miRNA-21), a biomarker for lung cancers. Importantly, it is demonstrated that this biosensor can be employed to measure the miRNA-21 expression level from human lung cancer cell (A549) lysates and worked well in 100% serum, suggesting its potential for applications in clinical diagnosis and a wide range of bioanalysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. High-Performance Ruthenium Sensitizers Containing Imidazolium Counterions for Efficient Dye Sensitization in Water.

    Science.gov (United States)

    Li, Xiaoyu; Li, Shiqing; Gao, Ge; Wu, Di; Lan, Jingbo; Wang, Ruilin; You, Jingsong

    2017-07-21

    A new type of water-soluble ruthenium sensitizers incorporating imidazolium counterions, denoted [DMPI]2 -Ru and [DMHI]2 -Ru, has been developed, which can be efficiently adsorbed onto TiO2 photoanodes in aqueous solution. Owing to the good thermal stability of imidazolium, [DMPI]2 -Ru adsorbed on TiO2 has a higher decomposition temperature than N719 dye [di(tetrabutylammonium) cis-di(thiocyanato)bis(2,2'-bipyridine-4,4'-dicarboxylato)ruthenium(II)]. When using organic solvent-based I- /I3- electrolytes, solars cell based on [DMPI]2 -Ru-sensitized TiO2 in water show high power conversion efficiencies (PCE) of up to 10.2 %, which is higher than that of N719 (9.9 %) under the common conditions for dye sensitization in organic solvent. [DMHI]2 -Ru, with poorer water solubility than [DMPI]2 -Ru, gives a smaller dye-adsorption amount on TiO2 and thus a lower PCE of 9.4 %. From the viewpoint of safety and environmental impact, the fabrication of dye-sensitized solar cells (DSSCs) by using water as solvent is undoubtedly a preferable strategy. Although the [DMPI]2 -Ru-based device fabricated by using water as the solvent for both the dye-sensitization process and the electrolyte gives a relatively low efficiency, it provides a promising approach for the practical application of DSSCs. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  18. General machining concept for producing micro-optics with high-power UV lasers

    Science.gov (United States)

    Toenshoff, Hans K.; Overmeyer, Ludger; Ostendorf, Andreas; Wais, Johannes

    1997-03-01

    The development of new processes for the micro-treatment of material is the basis for increasing integration and miniaturization of mechanical, optical and electronic components. Pulsed high power excimer lasers offer in combination with a micro-machining system, the possibility of manufacturing highly complex components in different materials like ceramics, glass or metals, Because of the increasing number of technical applications, the need for automatic processing has grown in the last few years. While complete working stations are available for Nd:YAG and CO2 lasers, there is a lack for automatic micro-removal with excimer lasers. For complex microstructures like micro- optics, manual programming of the workpiece handling system becomes uneconomic because of the very high number of laser pulses required. Especially for prototypes and small batches where the workpiece geometries change quickly, the development of a universal and automatic machining concept plays a key role for this technology. For this reason, a general machining concept based on excimer laser removal has been realized beginning with the possibility to construct the workpiece geometry by CAD-design tools. A preprocessor allows to calculate the removal volume based on laser specific ablation volumes. The superposition of each laser pulse removal leads to complex 3D surface structures. Moreover, a general movement strategy optimizes the processing speed. For closing the process chain the realized preprocessor automatically generates the necessary NC-data for the implemented CNC-control system. Functionality of this concept has been proven by manufacturing different two and three dimensional micro-structures like micro-optical components.

  19. A flexible thermal lens microscope for highly sensitive detection in microfluidic chips

    Science.gov (United States)

    Liu, Mingqiang

    2017-08-01

    A flexible thermal lens microscope (TLM), which combines the advantages of both conventional thermal lens spectrometry and TLM, is reported in this paper. The flexibility lies in the fact that the TLM can be configured in diffraction-limited (DL) or non-DL excitation mode: in small micro spaces (LOD) of 2  ×  10‒5 cm‒1 in large micro spaces (50-1000 µm),the setup working in non-DL mode was demonstrated to be much more advantageous. Compared with the case in DL mode, the TLM in non-DL mode shows up to an eight times lower LOD under 100-1000-fold less intense excitation, and better resistivity to flow-induced signal reduction and fluctuation to beam misalignment and background scattering, making it particularly suitable for detecting photolabile samples in highly flowing scattering mediums. For photostable samples, excitation laser powers of watt scale (in contrast to 100 mW in DL mode) could be employed to further decrease the LOD. This flexible TLM can therefore be applied for highly sensitive on-chip analysis of a broad range of analytes in different mediums.

  20. Micro-crack detection in high-performance cementitious materials

    DEFF Research Database (Denmark)

    Lura, Pietro; Guang, Ye; Tanaka, Kyoji

    2005-01-01

    Detection and quantification of microcracks due to autogenous shrinkage in high-performance concrete represents a problematic issue. Techniques based on crack impregnation typically require drying of the samples, which may introduce further cracks. Other non-destructive techniques, such as x......-ray tomography, do not allow sufficient resolution of microcracks. A new technique presented in this paper allows detection of microcracks in cement paste while avoiding artefacts induced by unwanted restraint, drying or temperature variations. The technique consists in casting small circular cylindrical samples...... of high-performance cement pastes in silicone moulds that exert minimal external restraint. Cast-in steel rods with varying diameter internally restrain the autogenous shrinkage and lead to crack formation. Dimensions of the steel rods are chosen so that the size of this restraining inclusion resembles...

  1. Highly sensitive troponin T in patients with acute ischemic stroke

    DEFF Research Database (Denmark)

    Jensen, J K; Ueland, T; Aukrust, P

    2012-01-01

    in decedents than in survivors. After adjustment for stroke severity, C-reactive protein, age, NT-proBNP and prior heart and/or renal failure, hsTnT levels were not a significant predictor of long-term all-cause or cardiovascular mortality. Conclusion: Elevated levels of hsTnT are frequently present......Background: Newly developed troponin assays have superior diagnostic and prognostic performance in acute coronary syndrome (ACS), when compared to conventional troponin assays; however, highly sensitive troponin has not been evaluated in patients with acute ischemic stroke. Methods: Highly...... sensitive troponin T (hsTnT) was measured daily during the first 4 days in 193 consecutive patients with acute ischemic stroke without overt ACS or atrial fibrillation. The patients were previously tested normal with a fourth-generation TnT assay. The patients were followed for 47 months, with all...

  2. Surface-sensitive conductivity measurement using a micro multi-point probe approach

    DEFF Research Database (Denmark)

    Perkins, Edward; Barreto, Lucas; Wells, Justin

    2013-01-01

    An instrument for microscale electrical transport measurements in ultra-high vacuum is presented. The setup is constructed around collinear lithographically-created multi-point probes with a contact spacing down to 500 nm. Most commonly, twelve-point probes are used. These probes are approached...... measurements with an equidistant four-point probe for a wide range of contact spacings. In this way, it is possible to distinguish between bulk-like and surface-like conduction. The paper describes the design of the instrument and the approach to data and error analysis. Application examples are given...

  3. Highly strained Ge micro-blocks bonded on Si platform for Mid-Infrared photonic applications

    OpenAIRE

    Gassenq, Alban; Guilloy, Kevin; Pauc, Nicolas; Rouchon, Denis; Widiez, Julie; Rothman, Johan; Hartmann, Jean-Michel; Chelnokov, Alexei; Reboud, Vincent; Calvo, Vincent

    2017-01-01

    Adding sufficient tensile strain to Ge can turn the material to a direct bandgap group IV semiconductor emitting in the mid-infrared wavelength range. However, highly strained-Ge cannot be directly grown on Si due to its large lattice mismatch. In this work, we have developed a process based on Ge micro-bridge strain redistribution intentionally landed to the Si substrate. Traction arms can be then partially etched to keep only localized strained-Ge micro-blocks. Large tunable uniaxial stress...

  4. Aircraft micro-doppler feature extraction from high range resolution profiles

    CSIR Research Space (South Africa)

    Berndt, RJ

    2015-10-01

    Full Text Available The use of high range resolution measurements and the micro-Doppler effect produced by rotating or vibrating parts of a target has been well documented. This paper presents a technique for extracting features related to helicopter rotors...

  5. Metal additive manufacturing of a high-pressure micro-pump

    NARCIS (Netherlands)

    Wits, Wessel Willems; Weitkamp, Sander J.; van Es, J.; van Es, Johannes

    2013-01-01

    For the thermal control of future space applications pumped two-phase loops are an essential part to handle the increasing thermal power densities. This study investigates the design of a reliable, leak tight, low-weight and high-pressure micro-pump for small satellite applications. The developed

  6. High throughput generated micro-aggregates of chondrocytes stimulate cartilage formation in vitro and in vivo

    NARCIS (Netherlands)

    Moreira Teixeira, Liliana; Leijten, Jeroen Christianus Hermanus; Sobral, J.; Jin, R.; van Apeldoorn, Aart A.; Feijen, Jan; van Blitterswijk, Clemens; Dijkstra, Pieter J.; Karperien, Hermanus Bernardus Johannes

    2012-01-01

    Cell-based cartilage repair strategies such as matrix-induced autologous chondrocyte implantation (MACI) could be improved by enhancing cell performance. We hypothesised that micro-aggregates of chondrocytes generated in high-throughput prior to implantation in a defect could stimulate cartilaginous

  7. Characterization of precision of a handling system in high performance transfer press for micro forming

    DEFF Research Database (Denmark)

    Mahshid, Rasoul; Hansen, Hans Nørgaard; Arentoft, Mogens

    2014-01-01

    Multi-step micro bulk forming is characterized by complex processes and high precision requirements. In particular the demands regarding handling accuracy between different forming steps are of the order of a few mm. The paper introduces a methodology for the analysis and characterization of this...... inside the forming press is obtained. © 2014 CIRP....

  8. High rate behavior and discharge limits in micro-pattern detectors

    CERN Document Server

    Bressan, A; Pagano, P; Ropelewski, Leszek; Sauli, Fabio; Biagi, S F; Buzulutskov, A F; Gruwé, M; De Lentdecker, G; Mörmann, D; Sharma, A

    1999-01-01

    We present and discuss a set of systematic measurements, carried out with gaseous proportional micro-pattern detectors, in order to assess their maximum gain when irradiated with high-rate soft X-rays and heavily ionizing alpha particles. The inventory of detectors tested includes: micro-strip micromegas, micro-dot, gas electron multiplier, CAT (compteur à trous), trench (or groove), micro-CAT (or WELL) detectors, as well as systems with two elements of gaseous amplification in cascade. We confirm the general trend of all single-stage detectors to follow Raether's criterion, i.e. a spontaneous transition from avalanche to streamer, followed by a discharge, when the avalanche size reaches a value of a few 10 7 ; a noticeable exception is the micro-dot counter holding more than 10 8. In multiple structures, where the gain under irradiation is increased by at least one order of magnitude; we speculate this to be a consequence of a voltage dependence of Raether's limit, larger for low operating potentials. Our c...

  9. Structural Glycomic Analyses at High Sensitivity: A Decade of Progress

    Science.gov (United States)

    Alley, William R.; Novotny, Milos V.

    2014-01-01

    The field of glycomics has recently advanced in response to the urgent need for structural characterization and quantification of complex carbohydrates in biologically and medically important applications. The recent success of analytical glycobiology at high sensitivity reflects numerous advances in biomolecular mass spectrometry and its instrumentation, capillary and microchip separation techniques, and microchemical manipulations of carbohydrate reactivity. The multimethodological approach appears to be necessary to gain an in-depth understanding of very complex glycomes in different biological systems. PMID:23560930

  10. Sensitivity to Envelope Interaural Time Differences at High Modulation Rates

    Science.gov (United States)

    Bleeck, Stefan; McAlpine, David

    2015-01-01

    Sensitivity to interaural time differences (ITDs) conveyed in the temporal fine structure of low-frequency tones and the modulated envelopes of high-frequency sounds are considered comparable, particularly for envelopes shaped to transmit similar fidelity of temporal information normally present for low-frequency sounds. Nevertheless, discrimination performance for envelope modulation rates above a few hundred Hertz is reported to be poor—to the point of discrimination thresholds being unattainable—compared with the much higher (>1,000 Hz) limit for low-frequency ITD sensitivity, suggesting the presence of a low-pass filter in the envelope domain. Further, performance for identical modulation rates appears to decline with increasing carrier frequency, supporting the view that the low-pass characteristics observed for envelope ITD processing is carrier-frequency dependent. Here, we assessed listeners’ sensitivity to ITDs conveyed in pure tones and in the modulated envelopes of high-frequency tones. ITD discrimination for the modulated high-frequency tones was measured as a function of both modulation rate and carrier frequency. Some well-trained listeners appear able to discriminate ITDs extremely well, even at modulation rates well beyond 500 Hz, for 4-kHz carriers. For one listener, thresholds were even obtained for a modulation rate of 800 Hz. The highest modulation rate for which thresholds could be obtained declined with increasing carrier frequency for all listeners. At 10 kHz, the highest modulation rate at which thresholds could be obtained was 600 Hz. The upper limit of sensitivity to ITDs conveyed in the envelope of high-frequency modulated sounds appears to be higher than previously considered. PMID:26721926

  11. GEM detector performance with innovative micro-TPC readout in high magnetic field

    Science.gov (United States)

    Garzia, I.; Alexeev, M.; Amoroso, A.; Baldini Ferroli, R.; Bertani, M.; Bettoni, D.; Bianchi, F.; Calcaterra, A.; Canale, N.; Capodiferro, M.; Cassariti, V.; Cerioni, S.; Chai, J. Y.; Chiozzi, S.; Cibinetto, G.; Cossio, F.; Cotta Ramusino, A.; De Mori, F.; Destefanis, M.; Dong, J.; Evangelisti, F.; Evangelisti, F.; Farinelli, R.; Fava, L.; Felici, G.; Fioravanti, E.; Gatta, M.; Greco, M.; Lavezzi, L.; Leng, C. Y.; Li, H.; Maggiora, M.; Malaguti, R.; Marcello, S.; Melchiorri, M.; Mezzadri, G.; Mignone, M.; Morello, G.; Pacetti, S.; Patteri, P.; Pellegrino, J.; Pelosi, A.; Rivetti, A.; Rolo, M. D.; Savrié, M.; Scodeggio, M.; Soldani, E.; Sosio, S.; Spataro, S.; Tskhadadze, E.; Verma, S.; Wheadon, R.; Yan, L.

    2018-01-01

    Gas detector development is one of the pillars of the research in fundamental physics. Since several years, a new concept of detectors, called Micro Pattern Gas Detector (MPGD), allowed to overcome several problems related to other types of commonly used detectors, like drift chamber and micro strips detectors, reducing the rate of discharges and providing better radiation tolerance. Among the most used MPGDs are the Gas Electron Multipliers (GEMs). Invented by Sauli in 1997, nowadays GEMs have become an important reality for particle detectors in high energy physics. Commonly deployed as fast timing detectors and triggers, their fast response, high rate capability and high radiation hardness make them also suitable as tracking detectors. The readout scheme is one of the most important features in tracking technology. Analog readout based on the calculation of the center of gravity technique allows to overcome the limit imposed by digital pads, whose spatial resolution is limited by the pitch dimensions. However, the presence of high external magnetic fields can distort the electronic cloud and affect the performance. The development of the micro-TPC reconstruction method brings GEM detectors into a new prospective, improving significantly the spatial resolutionin presence of high magnetic fields. This innovative technique allows to reconstruct the 3-dimensional particle position, as Time Projection Chamber, but within a drift gap of a few millimeters. In these report, the charge centroid and micro-TPC methods are described in details. We discuss the results of several test beams performed with planar chambers in magnetic field. These results are one of the first developments of micro-TPC technique for GEM detectors, which allows to reach unprecedented performance in a high magnetic field of 1 T.

  12. High Performance Transfer Press for Precision Manufacturing of Micro Metal Parts

    DEFF Research Database (Denmark)

    Mahshid, Rasoul

    for measuring the ovality of the sheared surfaces. An upsetting test was used to determine the flow stress curve of the material. Additionally, the initial condition of specimens were indicated for roughness and microstructure parameters. A transport device was manufactured which consisted of a linear motor......Micro forming technology has several notable benefits such as yielding remarkable accuracy, high production speed, material saving and good mechanical properties of formed parts which allows complex micro parts to be manufactured by this technology. There are also presses fabricated appropriately......, it is important to investigate the process parameters such as billet preparation, automation, forming machine and forming process which influence on geometrical accuracy and surface quality of formed parts. Previous studies have indicated handling devices for micro forming based on different strategies...

  13. High resolution projection micro stereolithography system and method

    Energy Technology Data Exchange (ETDEWEB)

    Spadaccini, Christopher M.; Farquar, George; Weisgraber, Todd; Gemberling, Steven; Fang, Nicholas; Xu, Jun; Alonso, Matthew; Lee, Howon

    2016-11-15

    A high-resolution P.mu.SL system and method incorporating one or more of the following features with a standard P.mu.SL system using a SLM projected digital image to form components in a stereolithographic bath: a far-field superlens for producing sub-diffraction-limited features, multiple spatial light modulators (SLM) to generate spatially-controlled three-dimensional interference holograms with nanoscale features, and the integration of microfluidic components into the resin bath of a P.mu.SL system to fabricate microstructures of different materials.

  14. MicroRNA-101 regulates T-cell acute lymphoblastic leukemia progression and chemotherapeutic sensitivity by targeting Notch1.

    Science.gov (United States)

    Qian, Lu; Zhang, Wanggang; Lei, Bo; He, Aili; Ye, Lianhong; Li, Xingzhou; Dong, Xin

    2016-11-01

    The present study aimed to investigate the role of microRNA (miR)-101 in acute lymphoblastic leukemia progression and chemoresistance. Furthermore, a novel target gene of miR-101 was identified. Here, we confirmed that miR-101 was significantly downregulated in the blood samples of patients with T-cell acute lymphoblastic leukemia (T-ALL) compared with the healthy controls, as determined by reverse transcription quantitative polymerase chain reaction (RTqPCR) analysis. The in vitro experiments demonstrated that miR-101 significantly repressed the proliferation and invasion, and induced potent apoptosis in Jurkat cells, as determined by CCK-8, flow cytometer and cell invasion assays. Luciferase assay confirmed that Notch1 was a target gene of miR-101, and western blotting showed that miR-101 suppressed the expression of Notch1 at the protein level. Moreover, functional restoration assays revealed that Notch1 mediates the effects of miR-101 on Jurkat cell proliferation, apoptosis and invasion. miR-101 enhanced the sensitivity of Jurkat cells to the chemotherapeutic agent adriamycin. Taken together, our results show for the first time that miR-101 acts as a tumor suppressor in T-cell acute lymphoblastic leukaemia and it could enhance chemotherapeutic sensitivity. Furthermore, Notch1 was identified to be a novel target of miR-101. This study indicates that miR-101 may represent a potential therapeutic target for T-cell acute lymphoblastic leukemia intervention.

  15. Freely suspended nanocomposite membranes as highly sensitive sensors.

    Science.gov (United States)

    Jiang, Chaoyang; Markutsya, Sergiy; Pikus, Yuri; Tsukruk, Vladimir V

    2004-10-01

    Highly sensitive sensor arrays are in high demand for prospective applications in remote sensing and imaging. Measuring microscopic deflections of compliant micromembranes and cantilevers is developing into one of the most versatile approaches for thermal, acoustic and chemical sensing. Here, we report on an innovative fabrication of compliant nanocomposite membranes with nanoscale thickness showing extraordinary sensitivity and dynamic range, which makes them candidates for a new generation of membrane-based sensor arrays. These nanomembranes with a thickness of 25-70 nm, which can be freely suspended over large (hundred micrometres) openings are fabricated with molecular precision by time-efficient, spin-assisted layer-by-layer assembly. They are designed as multilayered molecular composites made of a combination of polymeric monolayers and a metal nanoparticle intralayer. We demonstrate that these nanocomposite membranes possess unparalleled sensitivity and a unique autorecovering ability. The membrane nanostructure that is responsible for these outstanding properties combines multilayered polymer/nanoparticle organization, high polymer-chain orientation, and a pre-stretched state.

  16. Recent trends in high spin sensitivity magnetic resonance

    Science.gov (United States)

    Blank, Aharon; Twig, Ygal; Ishay, Yakir

    2017-07-01

    new ideas, show how these limiting factors can be mitigated to significantly improve the sensitivity of induction detection. Finally, we outline some directions for the possible applications of high-sensitivity induction detection in the field of electron spin resonance.

  17. High-sensitivity active pixel sensor with variable threshold photodetector

    Science.gov (United States)

    Jo, Sung-Hyun; Bae, Myunghan; Choi, Byoung-Soo; Lyu, Hong-Kun; Shin, Jang-Kyoo

    2015-05-01

    A novel high-sensitivity active pixel sensor (APS) with a variable threshold photodetector has been presented and for the first time, a simple SPICE model for the variable threshold photodetector is presented. Its SPICE model is in good agreement with measurements and is more simpler than the conventional model. The proposed APS has a gate/body-tied PMOSFET-type photodetector with an overlapping control gate that makes it possible to control the sensitivity of the proposed APS. It is a hybrid device composed of a metal-oxide-semiconductor field-effect transistor (MOSFET), a lateral bipolar junction transistor (BJT) and a vertical BJT. Using sufficient overlapping control gate bias to operate the MOSFET in inversion mode, the variable threshold photodetector allows for increasing the photocurrent gain by 105 at low light intensities when the control gate bias is -3 V. Thus, the proposed APS with a variable threshold photodetector has better low-light-level sensitivity than the conventional APS operating mode, and it has a variable sensitivity which is determined by the control gate bias. The proposed sensor has been fabricated by using 0.35 μm 2-poly 4-metal standard complementary MOS (CMOS) process and its characteristics have been evaluated.

  18. High-sensitivity bend angle measurements using optical fiber gratings.

    Science.gov (United States)

    Rauf, Abdul; Zhao, Jianlin; Jiang, Biqiang

    2013-07-20

    We present a high-sensitivity and more flexible bend measurement method, which is based on the coupling of core mode to the cladding modes at the bending region in concatenation with optical fiber grating serving as band reflector. The characteristics of a bend sensing arm composed of bending region and optical fiber grating is examined for different configurations including single fiber Bragg grating (FBG), chirped FBG (CFBG), and double FBGs. The bend loss curves for coated, stripped, and etched sections of fiber in the bending region with FBG, CFBG, and double FBG are obtained experimentally. The effect of separation between bending region and optical fiber grating on loss is measured. The loss responses for single FBG and CFBG configurations are compared to discover the effectiveness for practical applications. It is demonstrated that the sensitivity of the double FBG scheme is twice that of the single FBG and CFBG configurations, and hence acts as sensitivity multiplier. The bend loss response for different fiber diameters obtained through etching in 40% hydrofluoric acid, is measured in double FBG scheme that resulted in a significant increase in the sensitivity, and reduction of dead-zone.

  19. Highly Sensitive Detection of Protein Biomarkers with Organic Electrochemical Transistors.

    Science.gov (United States)

    Fu, Ying; Wang, Naixiang; Yang, Anneng; Law, Helen Ka-Wai; Li, Li; Yan, Feng

    2017-11-01

    The analysis of protein biomarkers is of great importance in the diagnosis of diseases. Although many convenient and low-cost electrochemical approaches have been extensively investigated, they are not sensitive enough in the detection of protein biomarkers with low concentrations in physiological environments. Here, this study reports a novel organic-electrochemical-transistor-based biosensor that can successfully detect cancer protein biomarkers with ultrahigh sensitivity. The devices are operated by detecting electrochemical activity on gate electrodes, which is dependent on the concentrations of proteins labeled with catalytic nanoprobes. The protein sensors can specifically detect a cancer biomarker, human epidermal growth factor receptor 2, down to the concentration of 10(-14) g mL(-1) , which is several orders of magnitude lower than the detection limits of previously reported electrochemical approaches. Moreover, the devices can successfully differentiate breast cancer cells from normal cells at various concentrations. The ultrahigh sensitivity of the protein sensors is attributed to the inherent amplification function of the organic electrochemical transistors. This work paves a way for developing highly sensitive and low-cost biosensors for the detection of various protein biomarkers in clinical analysis in the future. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Optimized high-throughput microRNA expression profiling provides novel biomarker assessment of clinical prostate and breast cancer biopsies

    Directory of Open Access Journals (Sweden)

    Fedele Vita

    2006-06-01

    Full Text Available Abstract Background Recent studies indicate that microRNAs (miRNAs are mechanistically involved in the development of various human malignancies, suggesting that they represent a promising new class of cancer biomarkers. However, previously reported methods for measuring miRNA expression consume large amounts of tissue, prohibiting high-throughput miRNA profiling from typically small clinical samples such as excision or core needle biopsies of breast or prostate cancer. Here we describe a novel combination of linear amplification and labeling of miRNA for highly sensitive expression microarray profiling requiring only picogram quantities of purified microRNA. Results Comparison of microarray and qRT-PCR measured miRNA levels from two different prostate cancer cell lines showed concordance between the two platforms (Pearson correlation R2 = 0.81; and extension of the amplification, labeling and microarray platform was successfully demonstrated using clinical core and excision biopsy samples from breast and prostate cancer patients. Unsupervised clustering analysis of the prostate biopsy microarrays separated advanced and metastatic prostate cancers from pooled normal prostatic samples and from a non-malignant precursor lesion. Unsupervised clustering of the breast cancer microarrays significantly distinguished ErbB2-positive/ER-negative, ErbB2-positive/ER-positive, and ErbB2-negative/ER-positive breast cancer phenotypes (Fisher exact test, p = 0.03; as well, supervised analysis of these microarray profiles identified distinct miRNA subsets distinguishing ErbB2-positive from ErbB2-negative and ER-positive from ER-negative breast cancers, independent of other clinically important parameters (patient age; tumor size, node status and proliferation index. Conclusion In sum, these findings demonstrate that optimized high-throughput microRNA expression profiling offers novel biomarker identification from typically small clinical samples such as breast

  1. Micro-mechanism of vapor film collapse on high temperature particle surface

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Yutaka; Tochio, Daisuke [Dept. of Mechanical Systems Engineering, Yamagata Univ., Yonezawa, Yamagata (Japan)

    1999-07-01

    Thermal detonation model is proposed to describe vapor explosion. According to this model, vapor film on pre-mixed high temperature droplet surface is needed to be collapsed for the trigger of the vapor explosion. It is pointed out that the vapor film collapse behavior is significantly affected by the subcooling of low temperature liquid. However, the effect of subcooling on micro-mechanism of vapor film collapse behavior is not experimentally well identified. The objective of the present research is to experimentally investigate the effect of subcooling on micro-mechanism of film boiling collapse behavior. As the results, it is experimentally clarified that the vapor film collapse behavior in low subcool condition is qualitatively different from the vapor film collapse behavior in high subcooling condition. In high subcooling condition, instability of the vapor film dominates the vapor film collapse on the particle surface. On the other hand, micro-mechanism at the interface between vapor and liquid such as micro-jet is dominant in low subcool condition in case of vapor film collapse by pressure pulse. (author)

  2. Position-Sensitive MCP-based Detectors with High Timing Resolution: Some Results and Perspectives

    CERN Document Server

    Stolyarov, O I; CERN. Geneva; Valiev, F F; Vinogradov, L I

    1995-01-01

    The microelectronic design and some results of experimental tests of three types of coordinate sensitive Micro-Channel-Plate (MCP)-based detectors with high timing properties are presented. The electrodynamic structures that could be used for the MCP fast signal readout (strips, delay lines and discrete pads) are always a compromise between the amplitude of the induced signal, propagation time delay, cross-talk and distortions of the signal at the output. In-lab tests of these structures and experimental tests of the detectors done with the beams of MIPs and with the alpha-source have shown the 130 microns spatial and 110 ps timing resolution obtained simultaneously for one detector.

  3. A multichannel single-photon sensitive detector for high-energy physics: the megapixel EBCCD

    CERN Document Server

    Benussi, L; Frekers, D; Frenkel, A; Giannini, G; Golovkin, S V; Kozarenko, E N; Kreslo, I E; Liberti, B; Martellotti, G; Medvedkov, A M; Mondardini, M R; Penso, G; Polizzi, A; Santacesaria, R; Santini, G; Spinetti, M; Vilain, P; Votano, L; Wilquet, G; Winter, Klaus

    2000-01-01

    We present a study of the characteristics of a hybrid image intensifier tube based on a thinned backside Electron Bombarded CCD (EBCCD) with better performance in spatial resolution, single photoelectron detection and gain stability than the conventional intensified systems based on a Micro Channel Plate followed by a CCD. Single photon detection sensitivity has been studied and a procedure to correct the gain non-uniformity of the EBCCD has been developed. The EBCCD, operating at 14 kV, has an average gain of approx 3000 electrons/photoelectron and a noise of the order of 100 electron/pixel. These characteristics make the EBCCD a very attractive device for many applications in high-energy physics, astrophysics and biomedicine. A possible application in a neutrino oscillation experiment is presented.

  4. Development of next generation micro-CHP system: Based on high temperature proton exchange membrane fuel cell technology

    Energy Technology Data Exchange (ETDEWEB)

    Arsalis, A.

    2012-01-15

    Novel proposals for the modeling and operation of a micro-CHP (combined-heat-and-power) residential system based on HT-PEMFC (High Temperature-Proton Exchange Membrane Fuel Cell) technology are described and analyzed to investigate the technical feasibility of such systems. The proposed systems must provide electricity, hot water, and space heating for an average single-family household in Denmark. A complete fuel processing subsystem, with all necessary BOP (balance-of-plant) components, is modeled and coupled to the fuel cell stack subsystem. The research project is divided into five main study topics: (a) Modeling, simulation and validation of the system in LabVIEW environment to provide the ability of Data Acquisition of actual components, and thereby more realistic design in the future; (b) Modeling, parametric study, and sensitivity analysis of the system in EES (Engineering Equation Solver). The parametric study is conducted to determine the most viable system/component design based on maximizing total system efficiency; (c) An improved operational strategy is formulated and applied in an attempt to minimize operational implications, experienced when using conventional operational strategies; (d) Application of a GA (Genetic Algorithm) optimization strategy. The objective function of the single-objective optimization strategy is the net electrical efficiency of the micro-CHP system. The implemented optimization procedure attempts to maximize the objective function by variation of nine decision variables; (e) The micro-CHP system is optimized by formulating and applying a process integration methodology. The methodology involves system optimization targeting in net electrical efficiency maximization. Subsequently a MINLP (Mixed Integer Non-Linear Programming) problem optimization strategy is applied to minimize the annual cost of the HEN (Heat Exchanger Network). The results obtained throughout this research work indicate the high potential of the proposed

  5. Highly-sensitive gas pressure sensor using twin-core fiber based in-line Mach-Zehnder interferometer.

    Science.gov (United States)

    Li, Zhengyong; Liao, Changrui; Wang, Yiping; Xu, Lei; Wang, Dongning; Dong, Xiaopeng; Liu, Shen; Wang, Qiao; Yang, Kaiming; Zhou, Jiangtao

    2015-03-09

    A Mach-Zehnder interferometer based on a twin-core fiber was proposed and experimentally demonstrated for gas pressure measurements. The in-line Mach-Zehnder interferometer was fabricated by splicing a short section of twin-core fiber between two single mode fibers. A micro-channel was created to form an interferometer arm by use of a femtosecond laser to drill through one core of the twin-core fiber. The other core of the fiber was remained as the reference arm. Such a Mach-Zehnder interferometer exhibited a high gas pressure sensitivity of -9.6 nm/MPa and a low temperature cross-sensitivity of 4.4 KPa/°C. Moreover, ultra-compact device size and all-fiber configuration make it very suitable for highly-sensitive gas pressure sensing in harsh environments.

  6. Polymer-Particle Pressure-Sensitive Paint with High Photostability

    Directory of Open Access Journals (Sweden)

    Yu Matsuda

    2016-04-01

    Full Text Available We propose a novel fast-responding and paintable pressure-sensitive paint (PSP based on polymer particles, i.e. polymer-particle (pp-PSP. As a fast-responding PSP, polymer-ceramic (PC-PSP is widely studied. Since PC-PSP generally consists of titanium (IV oxide (TiO2 particles, a large reduction in the luminescent intensity will occur due to the photocatalytic action of TiO2. We propose the usage of polymer particles instead of TiO2 particles to prevent the reduction in the luminescent intensity. Here, we fabricate pp-PSP based on the polystyrene particle with a diameter of 1 μm, and investigate the pressure- and temperature-sensitives, the response time, and the photostability. The performances of pp-PSP are compared with those of PC-PSP, indicating the high photostability with the other characteristics comparable to PC-PSP.

  7. High derivatives for fast sensitivity analysis in linear magnetodynamics

    Energy Technology Data Exchange (ETDEWEB)

    Petin, P. [ENSIEG, Saint Martin d`Heres (France). Lab. d`Electrotechnique de Grenoble]|[FRMASOFT+CSI, Lyon (France); Coulomb, J.L. [ENSIEG, Saint Martin d`Heres (France). Lab. d`Electrotechnique de Grenoble; Conraux, P. [FRAMASOFT+CSI, Lyon (France)

    1997-03-01

    In this article, the authors present a method of sensitivity analysis using high derivatives and Taylor development. The principle is to find a polynomial approximation of the finite elements solution towards the sensitivity parameters. While presenting the method, they explain why this method is applicable with special parameters only. They applied it on a magnetodynamic problem, simple enough to be able to find the analytical solution with a formal calculus tool. They then present the implementation and the good results obtained with the polynomial, first by comparing the derivatives themselves, then by comparing the approximate solution with the theoretical one. After this validation, the authors present results on a real 2D application and they underline the possibilities of reuse in other fields of physics.

  8. Preparation and characterization of EPDM-silica nano/micro composites for high voltage insulation applications

    OpenAIRE

    Ali Muhammad; Choudhry Muhammad Ahmad

    2015-01-01

    The rising market for substitute materials in high voltage insulation components is stimulated largely by the need to reduce overall costs. In this respect, polymer insulators offer significant advantages over old traditional materials. In the present research, efforts have been made to quantify the effect of silica (having different particle size nano, micro and hybrid) loading on the mechanical and thermal behaviors of Ethylene-Propylene-Diene Monomer (EPDM) based high voltage electrical in...

  9. Dimensional measurement of micro parts with high aspect ratio in HIT-UOI

    Science.gov (United States)

    Dang, Hong; Cui, Jiwen; Feng, Kunpeng; Li, Junying; Zhao, Shiyuan; Zhang, Haoran; Tan, Jiubin

    2016-11-01

    Micro parts with high aspect ratios have been widely used in different fields including aerospace and defense industries, while the dimensional measurement of these micro parts becomes a challenge in the field of precision measurement and instrument. To deal with this contradiction, several probes for the micro parts precision measurement have been proposed by researchers in Center of Ultra-precision Optoelectronic Instrument (UOI), Harbin Institute of Technology (HIT). In this paper, optical fiber probes with structures of spherical coupling(SC) with double optical fibers, micro focal-length collimation (MFL-collimation) and fiber Bragg grating (FBG) are described in detail. After introducing the sensing principles, both advantages and disadvantages of these probes are analyzed respectively. In order to improve the performances of these probes, several approaches are proposed. A two-dimensional orthogonal path arrangement is propounded to enhance the dimensional measurement ability of MFL-collimation probes, while a high resolution and response speed interrogation method based on differential method is used to improve the accuracy and dynamic characteristics of the FBG probes. The experiments for these special structural fiber probes are given with a focus on the characteristics of these probes, and engineering applications will also be presented to prove the availability of them. In order to improve the accuracy and the instantaneity of the engineering applications, several techniques are used in probe integration. The effectiveness of these fiber probes were therefore verified through both the analysis and experiments.

  10. Fabrication, Micro-structural Analysis, and Mechanical Testing of High Density Polymeric Foam

    Science.gov (United States)

    Marks, Trevor Gustov

    Foams, or what are often called cellular solids, are some of the most widely used materials in the modern era. In general, foam is a porous substance formed by the introduction of gas filled pores into condensed matter; the result is typically a light weight substance with properties related to the base (non-porous) medium. Applications of foams include: vibration dampening, energy mitigation (such as packaging and bike helmets), insulation, filtration, and flotation. The focus of this work is on the properties of flexible elastomeric foam of high relative-density. The bulk of existing literature on elastomeric foam is concerned with foam of low relative-density (ratio of the foam density to the density of the material from which the foam is formed ≤ 0.1). The relationship between the micro-structure of high relative-density foam and its mechanical response has, in large part, not been subjected to systematic investigation heretofore. The present work examines how the micro-structural features of pore shape, size, and location affect the macro-structural response of relative high density foam to compressive loading. In order to carry out this study, methods were developed and employed to control a foam's micro-structure, and hence its mechanical response, with the use of temporary pore forming particles and micron scale inclusions. Advanced microscopy techniques were used to observe, in situ, the evolution of a foam's micro-structure under compressive loading, and the results were correlated with the evolution of the foam's stress - strain response. Additionally, quantitative methods were developed and employed to describe numerically the foam's micro-structural features, such as: (i), pore shape, (ii), pore size, and (iii), the arrangement of the pores with respect to each other. Numerous foams were produced, tested, and subjected to the methodology developed for this study.

  11. Sensitivity of clear-sky direct radiative effect of the aerosol to micro-physical properties by using 6SV radiative transfer model: preliminary results

    Science.gov (United States)

    Bassani, Cristiana; Tirelli, Cecilia; Manzo, Ciro; Pietrodangelo, Adriana; Curci, Gabriele

    2015-04-01

    The aerosol micro-physical properties are crucial to analyze their radiative impact on the Earth's radiation budget [IPCC, 2007]. The 6SV model, last generation of the Second Simulation of a Satellite Signal in the Solar Spectrum (6S) radiative transfer code [Kotchenova et al., 2007; Vermote et al., 1997] has been used to perform physically-based atmospheric correction of hyperspectral airborne and aircraft remote sensing data [Vermote et al., 2009; Bassani et al. 2010; Tirelli et al., 2014]. The atmospheric correction of hyperspectral data has been shown to be sensitive to the aerosol micro-physical properties, as reported in Bassani et al., 2012. The role of the aerosol micro-physical properties on the accuracy of the atmospheric correction of hyperspectral data acquired over water and land targets is investigated within the framework of CLAM-PHYM (Coasts and Lake Assessment and Monitoring by PRISMA HYperspectral Mission) and PRIMES (Synergistic use of PRISMA products with high resolution meteo-chemical simulations and their validation on ground and from satellite) projects, both funded by Italian Space Agency (ASI). In this work, the results of the radiative field of the Earth/Atmosphere coupled system simulated by using 6SV during the atmospheric correction of hyperspectral data are presented. The analysis of the clear-sky direct radiative effect is performed considering the aerosol micro-physical properties used to define the aerosol model during the atmospheric correction process. In particular, the AERONET [Holben et al., 1998] and FLEXAOD [Curci et al., 2014] micro-physical properties are used for each image to evaluate the contribution of the size distribution and refractive index of the aerosol type on the surface reflectance and on the direct radiative forcing. The results highlight the potential of the hyperspectral remote sensing data for atmospheric studies as well as for environmental studies. Currently, the future hyperspectral missions, such as the

  12. High sensitivity chemically amplified EUV resists through enhanced EUV absorption

    Science.gov (United States)

    Ongayi, Owendi; Christianson, Matthew; Meyer, Matthew; Coley, Suzanne; Valeri, David; Kwok, Amy; Wagner, Mike; Cameron, Jim; Thackeray, Jim

    2012-03-01

    Resolution, line edge roughness, sensitivity and low outgassing are the key focus points for extreme ultraviolet (EUV) resist materials. Sensitivity has become increasingly important so as to address throughput concerns in device manufacturing and compensate for the low power of EUV sources. Recent studies have shown that increasing the polymer linear absorption absorption coefficient in EUV resists translates to higher acid generation efficiency and good pattern formation. In this study, novel high absorbing polymer platforms are evaluated. The contributing effect of the novel absorbing chromophore to the resultant chemically amplified photoresist is evaluated and compared with a standard methacrylate PAG Bound Polymer (PBP) platform. We report that by increasing EUV absorption, we cleanly resolved 17 nm 1:1 line space can be achieved at a sensitivity of 14.5 mJ/cm2, which is consistent with dose requirements dictated by the ITRS roadmap. We also probe the effect of fluorinated small molecule additives on acid yield generation (Dil C) at EUV of a PBP platform.

  13. Highly strain-sensitive magnetostrictive tunnel magnetoresistance junctions

    Science.gov (United States)

    Tavassolizadeh, Ali; Hayes, Patrick; Rott, Karsten; Reiss, Günter; Quandt, Eckhard; Meyners, Dirk

    2015-06-01

    Tunnel magnetoresistance (TMR) junctions with CoFeB/MgO/CoFeB layers are promising for strain sensing applications due to their high TMR effect and magnetostrictive sense layer (CoFeB). TMR junctions available even in submicron dimensions can serve as strain sensors for microelectromechanical systems devices. Upon stress application, the magnetization configuration of such junctions changes due to the inverse magnetostriction effect resulting in strain-sensitive tunnel resistance. Here, strain sensitivity of round-shaped junctions with diameters of 11.3 μm, 19.2 μm, 30.5 μm, and 41.8 μm were investigated on macroscopic cantilevers using a four-point bending apparatus. This investigation mainly focuses on changes in hard-axis TMR loops caused by the stress-induced anisotropy. A macrospin model is proposed, supported by micromagnetic simulations, which describes the complete rotation of the sense layer magnetization within TMR loops of junctions, exposed to high stress. Below 0.2‰ tensile strain, a representative junction with 30.5 μm diameter exhibits a very large gauge factor of 2150. For such high gauge factor a bias field H = - 3.2 kA / m is applied in an angle equal to 3 π / 2 toward the pinned magnetization of the reference layer. The strain sensitivity strongly depends on the bias field. Applying stress along π / 4 against the induced magnetocrystalline anisotropy, both compressive and tensile strain can be identified by a unique sensor. More importantly, a configuration with a gauge factor of 400 at zero bias field is developed which results in a straightforward and compact measuring setup.

  14. Interface engineering of a highly sensitive solution processed organic photodiode.

    Science.gov (United States)

    Kim, Yu Jin; Park, Chan Eon; Chung, Dae Sung

    2014-09-14

    We report on tuning of the interfacial properties of a highly sensitive organic photodiode by introducing a buffer layer between the anode and the semiconductor layer. The effects of different buffer layers consisting of a self-assembled monolayer (SAM), PEDOT:PSS, and pentacene on the morphology and crystallinity of the upper-deposited bulk heterojunction semiconductor layer are carefully analyzed combined with electrical analysis. The active layer is controlled to be nearly homogeneous and to have low crystallinity by using a SAM or PEDOT:PSS buffer layers, whereas a highly crystalline morphology is realized by using the pentacene buffer layer. When exposed to light pulses, the external quantum efficiency and thus the photocurrent are slightly higher for the PEDOT:PSS-based photodiode; however the dark current is the lowest for the pentacene-based photodiode. We discuss the origin of the high sensitivity (a detectivity of 1.3 × 10(12) Jones and a linear dynamic range of 95 dB) of the pentacene-based photodiode, particularly in terms of the morphology-driven low dark current.

  15. High-Sensitivity Measurement of Density by Magnetic Levitation.

    Science.gov (United States)

    Nemiroski, Alex; Kumar, A A; Soh, Siowling; Harburg, Daniel V; Yu, Hai-Dong; Whitesides, George M

    2016-03-01

    This paper presents methods that use Magnetic Levitation (MagLev) to measure very small differences in density of solid diamagnetic objects suspended in a paramagnetic medium. Previous work in this field has shown that, while it is a convenient method, standard MagLev (i.e., where the direction of magnetization and gravitational force are parallel) cannot resolve differences in density mm) because (i) objects close in density prevent each other from reaching an equilibrium height due to hard contact and excluded volume, and (ii) using weaker magnets or reducing the magnetic susceptibility of the medium destabilizes the magnetic trap. The present work investigates the use of weak magnetic gradients parallel to the faces of the magnets as a means of increasing the sensitivity of MagLev without destabilization. Configuring the MagLev device in a rotated state (i.e., where the direction of magnetization and gravitational force are perpendicular) relative to the standard configuration enables simple measurements along the axes with the highest sensitivity to changes in density. Manipulating the distance of separation between the magnets or the lengths of the magnets (along the axis of measurement) enables the sensitivity to be tuned. These modifications enable an improvement in the resolution up to 100-fold over the standard configuration, and measurements with resolution down to 10(-6) g/cm(3). Three examples of characterizing the small differences in density among samples of materials having ostensibly indistinguishable densities-Nylon spheres, PMMA spheres, and drug spheres-demonstrate the applicability of rotated Maglev to measuring the density of small (0.1-1 mm) objects with high sensitivity. This capability will be useful in materials science, separations, and quality control of manufactured objects.

  16. High Sensitivity Surface Enhanced Raman Scattering Detection of Tryptophan

    Science.gov (United States)

    Kandakkathara, Archana

    Raman spectroscopy has the capability of providing detailed information about molecular structure, but the extremely small cross section of Raman scattering prevents this technique from applications requiring high sensitivity. Surface enhanced Raman scattering (SERS) on the other hand provides strongly increased Raman signal from molecules attached to metallic nanostructures. SERS is thus a promising technique for high sensitivity analytical applications. One particular area of interest is the application of such techniques for the analysis of the composition of biological cells. However, there are issues which have to be addressed in order to make SERS a reliable technique such as the optimization of conditions for any given analyte, understanding the kinetic processes of binding of the target molecules to the nanostructures and understanding the evolution and coagulation of the nanostructures, in the case of colloidal solutions. The latter processes introduce a delay time for the observation of maximum enhancement factors which must be taken into account for any given implementation of SERS. In the present thesis the goal was to develop very sensitive SERS techniques for the measurement of biomolecules of interest for analysis of the contents of cells. The techniques explored could be eventually be applicable to microfluidic systems with the ultimate goal of analyzing the molecular constituents of single cells. SERS study of different amino acids and organic dyes were performed during the course of this thesis. A high sensitivity detection system based on SERS has been developed and spectrum from tryptophan (Trp) amino acid at very low concentration (10-8 M) has been detected. The concentration at which good quality SERS spectra could be detected from Trp is 4 orders of magnitude smaller than that previously reported in literature. It has shown that at such low concentrations the SERS spectra of Trp are qualitatively distinct from the spectra commonly reported in

  17. High energy green nanosecond and picosecond pulse delivery through a negative curvature fiber for precision micro-machining.

    Science.gov (United States)

    Jaworski, Piotr; Yu, Fei; Carter, Richard M; Knight, Jonathan C; Shephard, Jonathan D; Hand, Duncan P

    2015-04-06

    In this paper we present an anti-resonant guiding, low-loss Negative Curvature Fiber (NCF) for the efficient delivery of high energy short (ns) and ultrashort (ps) pulsed laser light in the green spectral region. The fabricated NCF has an attenuation of 0.15 dB/m and 0.18 dB/m at 532 nm and 515 nm respectively, and provided robust transmission of nanosecond and picosecond pulses with energies of 0.57 mJ (10.4 kW peak power) and 30 µJ (5 MW peak power) respectively. It provides single-mode, stable (low bend-sensitivity) output and maintains spectral and temporal properties of the source laser beam. The practical application of fiber-delivered pulses has been demonstrated in precision micro-machining and marking of metals and glass.

  18. New approach for sensitive photothermal detection of C60 and C70 fullerenes on micro-thin-layer chromatographic plates.

    Science.gov (United States)

    Suszyński, Zbigniew; Zarzycki, Paweł K

    2015-03-10

    In this paper the pulse thermovision (photothermal) detection and quantification methods of C60 and C70 fullerenes are presented. Quantification results are compared with optical and fluorescence measurements. Target components were separated under isothermal conditions (30 °C) on micro-TLC plates (RP18WF254S) using n-hexane as the mobile phase. The principle of described analytical protocol is based on sensitive measurement of the temperature contrast generated within TLC stationary phase and fullerenes spots after white light pulse excitation. It has been demonstrated that observed temperature contrast is mainly driven by the optical properties of fullerenes (UV-vis absorption spectra). Contrary to the commonly applied optical reflection or transmission techniques the proposed thermovision method involves dissipated light. The results of presented experimental work have revealed that both types of quantitative measurements provide similar outcome despite the key differences in the signal origin. However, it has been found that thermovision method was characterized by smaller value of LOD, particularly for C60 molecule. We demonstrated that application of correlation technique to post-acquisition analysis of the sequence of temperature contrast images significantly increase detection limits of fullerenes, even in comparison to fluorescence quenching detection mode. Moreover, the thermal contrast images and particularly, computed correlation image, allow detection of stationary phase layer nonuniformities, including changes in the adsorbent thickness and thermal conductivity. Therefore, invented pulsed thermovision methodology can be additionally used for fast quality screening of home made and commercially available TLC plates. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Drought responsive microRNAs in two barley cultivars differing in their level of sensitivity to drought stress.

    Science.gov (United States)

    Fard, Ehsan Mohseni; Bakhshi, Behnam; Keshavarznia, Reza; Nikpay, Nava; Shahbazi, Maryam; Salekdeh, Ghasem Hosseini

    2017-09-01

    MicroRNAs (miRNAs) are known to be involved in the regulation of gene expression, including that of genes involved in the response to stress. Here, a comparison has been drawn between the miRNA profiles of a drought susceptible, 'Morocco 9-75', and a drought tolerant, 'Yousef', barley cultivars. Leaf water content, shoot dry matter and chlorophyll content decreased in 'Morocco 9-75' more considerably compared with 'Yousef' under drought stress. Furthermore, lower stomatal conductance and higher leaf temperature were observed in 'Morocco 9-75' compared with 'Yousef'. Based on the criteria set for differential abundance, 118 of conserved and novel miRNAs were identified as being responsive to soil water status. Although drought stress resulted in an altered abundance of more miRNAs in 'Morocco 9-75' than in 'Yousef', drought stress was generally associated with an increased miRNA abundance in 'Yousef' and a decreased abundance in 'Morocco 9-75'. An in silico analysis identified 645 genes as putative targets for the drought-responsive miRNAs in 'Yousef' and 3735 in 'Morocco 9-75'. Gene ontology analysis showed that drought stress was associated with the altered abundance of miRNAs targeting growth, development, the juvenile to adult transition and hormone signaling. Some miRNAs which became more abundant in 'Yousef' are thought to target genes intimately involved in development and stress adaptation. In 'Morocco 9-75', drought stress induced changes in the abundance of miRNAs associated with genes affecting growth, development, the juvenile to adult transition and ABA signaling. The data imply that miRNAs may affect the tolerance/sensitivity of barley to drought stress by modulating the expression of a wide set of genes and induction of some physiological changes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  20. High pressure-sensitive gene expression in Lactobacillus sanfranciscensis

    Directory of Open Access Journals (Sweden)

    R.F. Vogel

    2005-08-01

    Full Text Available Lactobacillus sanfranciscensis is a Gram-positive lactic acid bacterium used in food biotechnology. It is necessary to investigate many aspects of a model organism to elucidate mechanisms of stress response, to facilitate preparation, application and performance in food fermentation, to understand mechanisms of inactivation, and to identify novel tools for high pressure biotechnology. To investigate the mechanisms of the complex bacterial response to high pressure we have analyzed changes in the proteome and transcriptome by 2-D electrophoresis, and by microarrays and real time PCR, respectively. More than 16 proteins were found to be differentially expressed upon high pressure stress and were compared to those sensitive to other stresses. Except for one apparently high pressure-specific stress protein, no pressure-specific stress proteins were found, and the proteome response to pressure was found to differ from that induced by other stresses. Selected pressure-sensitive proteins were partially sequenced and their genes were identified by reverse genetics. In a transcriptome analysis of a redundancy cleared shot gun library, about 7% of the genes investigated were found to be affected. Most of them appeared to be up-regulated 2- to 4-fold and these results were confirmed by real time PCR. Gene induction was shown for some genes up-regulated at the proteome level (clpL/groEL/rbsK, while the response of others to high hydrostatic pressure at the transcriptome level seemed to differ from that observed at the proteome level. The up-regulation of selected genes supports the view that the cell tries to compensate for pressure-induced impairment of translation and membrane transport.

  1. Highly sensitive detection of Staphylococcus aureus directly from patient blood.

    Directory of Open Access Journals (Sweden)

    Padmapriya P Banada

    Full Text Available Rapid detection of bloodstream infections (BSIs can be lifesaving. We investigated the sample processing and assay parameters necessary for highly-sensitive detection of bloodstream bacteria, using Staphylococcus aureus as a model pathogen and an automated fluidic sample processing-polymerase chain reaction (PCR platform as a model diagnostic system.We compared a short 128 bp amplicon hemi-nested PCR and a relatively shorter 79 bp amplicon nested PCR targeting the S. aureus nuc and sodA genes, respectively. The sodA nested assay showed an enhanced limit of detection (LOD of 5 genomic copies per reaction or 10 colony forming units (CFU per ml blood over 50 copies per reaction or 50 CFU/ml for the nuc assay. To establish optimal extraction protocols, we investigated the relative abundance of the bacteria in different components of the blood (white blood cells (WBCs, plasma or whole blood, using the above assays. The blood samples were obtained from the patients who were culture positive for S. aureus. Whole blood resulted in maximum PCR positives with sodA assay (90% positive as opposed to cell-associated bacteria (in WBCs (71% samples positive or free bacterial DNA in plasma (62.5% samples positive. Both the assays were further tested for direct detection of S. aureus in patient whole blood samples that were contemporaneous culture positive. S. aureus was detected in 40/45 of culture-positive patients (sensitivity 89%, 95% CI 0.75-0.96 and 0/59 negative controls with the sodA assay (specificity 100%, 95% CI 0.92-1.We have demonstrated a highly sensitive two-hour assay for detection of sepsis causing bacteria like S. aureus directly in 1 ml of whole blood, without the need for blood culture.

  2. Photon-trapping micro/nanostructures for high linearity in ultra-fast photodiodes

    Science.gov (United States)

    Cansizoglu, Hilal; Gao, Yang; Perez, Cesar Bartolo; Ghandiparsi, Soroush; Ponizovskaya Devine, Ekaterina; Cansizoglu, Mehmet F.; Yamada, Toshishige; Elrefaie, Aly F.; Wang, Shih-Yuan; Islam, M. Saif

    2017-08-01

    Photodetectors (PDs) in datacom and computer networks where the link length is up to 300 m, need to handle higher than typical input power used in other communication links. Also, to reduce power consumption due to equalization at high speed (>25Gb/s), the datacom links will use PAM-4 signaling instead of NRZ with stringent receiver linearity requirements. Si PDs with photon-trapping micro/nanostructures are shown to have high linearity in output current verses input optical power. Though there is less silicon material due to the holes, the micro-/nanostructured holes collectively reradiate the light to an in-plane direction of the PD surface and can avoid current crowding in the PD. Consequently, the photocurrent per unit volume remains at a low level contributing to high linearity in the photocurrent. We present the effect of design and lattice patterns of micro/nanostructures on the linearity of ultra-fast silicon PDs designed for high speed multi gigabit data networks.

  3. Investigation into high-frequency-vibration assisted micro-blanking of pure copper foils

    Directory of Open Access Journals (Sweden)

    Wang Chunju

    2015-01-01

    Full Text Available The difficulties encountered during the manufacture of microparts are often associated with size effects relating to material, process and tooling. Utilizing acoustoplastic softening, achieved through a high-frequency vibration assisted micro-blanking process, was introduced to improve the surface finish in micro-blanking. A frequency of 1.0 kHz was chosen to activate the longitudinal vibration mode of the horn tip, using a piezoelectric actuator. A square hole with dimensions of 0.5 mm × 0.5 mm was made, successfully, from a commercial rolled T2 copper foil with 100 μm in thickness. It was found that the maximum blanking force could be reduced by 5% through utilizing the high-frequency vibration. Proportion of the smooth, burnished area in the cut cross-section increases with an increase of the plasticity to fracture, under the high-frequency vibration, which suggests that the vibration introduced is helpful for inhibiting evolution of the crack due to its acoustoplastic softening effect. During blanking, roughness of the burnished surface could be reduced by increasing the vibration amplitude of the punch, which played a role as surface polishing. The results obtained suggest that the high-frequency vibration can be adopted in micro-blanking in order to improve quality of the microparts.

  4. High-throughput micro-scale cultivations and chromatography modeling: Powerful tools for integrated process development.

    Science.gov (United States)

    Baumann, Pascal; Hahn, Tobias; Hubbuch, Jürgen

    2015-10-01

    Upstream processes are rather complex to design and the productivity of cells under suitable cultivation conditions is hard to predict. The method of choice for examining the design space is to execute high-throughput cultivation screenings in micro-scale format. Various predictive in silico models have been developed for many downstream processes, leading to a reduction of time and material costs. This paper presents a combined optimization approach based on high-throughput micro-scale cultivation experiments and chromatography modeling. The overall optimized system must not necessarily be the one with highest product titers, but the one resulting in an overall superior process performance in up- and downstream. The methodology is presented in a case study for the Cherry-tagged enzyme Glutathione-S-Transferase from Escherichia coli SE1. The Cherry-Tag™ (Delphi Genetics, Belgium) which can be fused to any target protein allows for direct product analytics by simple VIS absorption measurements. High-throughput cultivations were carried out in a 48-well format in a BioLector micro-scale cultivation system (m2p-Labs, Germany). The downstream process optimization for a set of randomly picked upstream conditions producing high yields was performed in silico using a chromatography modeling software developed in-house (ChromX). The suggested in silico-optimized operational modes for product capturing were validated subsequently. The overall best system was chosen based on a combination of excellent up- and downstream performance. © 2015 Wiley Periodicals, Inc.

  5. Highly sensitive reduced graphene oxide microelectrode array sensor.

    Science.gov (United States)

    Ng, Andrew M H; Kenry; Teck Lim, Chwee; Low, Hong Yee; Loh, Kian Ping

    2015-03-15

    Reduced graphene oxide (rGO) has been fabricated into a microelectrode array (MEA) using a modified nanoimprint lithography (NIL) technique. Through a modified NIL process, the rGO MEA was fabricated by a self-alignment of conducting Indium Tin Oxide (ITO) and rGO layer without etching of the rGO layer. The rGO MEA consists of an array of 10μm circular disks and microelectrode signature has been found at a pitch spacing of 60μm. The rGO MEA shows a sensitivity of 1.91nAμm(-1) to dopamine (DA) without the use of mediators or functionalization of the reduced graphene oxide (rGO) active layer. The performance of rGO MEA remains stable when tested under highly resistive media using a continuous flow set up, as well as when subjecting it to mechanical stress. The successful demonstration of NIL for fabricating rGO microelectrodes on flexible substrate presents a route for the large scale fabrication of highly sensitive, flexible and thin biosensing platform. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. A simple, tunable, and highly sensitive radio-frequency sensor.

    Science.gov (United States)

    Cui, Yan; Sun, Jiwei; He, Yuxi; Wang, Zheng; Wang, Pingshan

    2013-08-05

    We report a radio frequency (RF) sensor that exploits tunable attenuators and phase shifters to achieve high-sensitivity and broad band frequency tunability. Three frequency bands are combined to enable sensor operations from ∼20 MHz to ∼38 GHz. The effective quality factor (Qeff ) of the sensor is as high as ∼3.8 × 10(6) with 200 μl of water samples. We also demonstrate the measurement of 2-proponal-water-solution permittivity at 0.01 mole concentration level from ∼1 GHz to ∼10 GHz. Methanol-water solution and de-ionized water are used to calibrate the RF sensor for the quantitative measurements.

  7. Highly sensitive and specific radioimmunoassays for dihydroergotoxine components in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Pradelles, P.; Collignon, F.

    1984-01-01

    The development of three analogous radioimmunoassay (RIA) procedures for dihydroergotoxine components is described. The antisera were produced by immunization of rabbits with immunogens obtained by coupling egg albumin to the indole group of each ergot alkaloid derivative. In each radioimmunoassay, antibodies do not cross-react more than 5% with the two other derivatives. The tracers iodinated with iodine 125 were prepared by the chloramine-T method and purified by thin layer chromatography. Both antibody affinity and high specific radioactivity of tracers allow a sensitive assay (detection limit less than 20 pg/ml) in human plasma. After high performance liquid chromatography of extracted plasma, immunoreactive materials other than those corresponding to the elution of the three dihydroergotoxine components were not detected. Two preliminary pharmacokinetic profiles obtained in dog and human for each derivative are shown.

  8. Development of high sensitive radon detector with electrostatic collection

    Energy Technology Data Exchange (ETDEWEB)

    Nemoto, Machiko [Tokai Univ., Hiratsuka, Kanagawa (Japan). Faculty of Science; Tasaka, Shigeki; Hori, Hidemitsu; Okumura, Kimihiro; Kajita, Takaaki; Takeuchi, Yasuo

    1997-10-01

    One of the main purposes of Super-Kamiokande is the observation of solar neutrinos. The radon concentration in the detector water should be less than about 5 mBq/m{sup 3}, because low energy background events in this experiment are dominated by radon daughters. We developed a high sensitive radon detector with an electrostatic collection method and a PIN photodiode to measure the energy of {alpha} particles from the daughter nuclei of {sup 222}Rn. We constructed a calibration system to study high voltage dependence and absolute humidity dependence of the detector. As a result, the absolute humidity dependence was clearly observed at the region less than 1.6 g/m{sup 3}. The calibration factor at 0.08 g/m{sup 3} was 1.8{+-}0.1 (count/d)/(mBq/m{sup 3}). The detection limit was 13 mBq/m{sup 3} by the Curie`s method. (author)

  9. Micro-scanning mirrors for high-power laser applications in laser surgery

    Science.gov (United States)

    Sandner, Thilo; Kimme, Simon; Grasshoff, Thomas; Todt, Ulrich; Graf, Alexander; Tulea, Cristian; Lenenbach, Achim; Schenk, Harald

    2014-03-01

    We present two novel micro scanning mirrors with large aperture and HR dielectric coatings suitable for high power laser applications in a miniaturized laser-surgical instrument for neurosurgery to cut skull tissue. An electrostatic driven 2D-raster scanning mirror with 5x7.1mm aperture is used for dynamic steering of a ps-laser beam of the laser cutting process. A second magnetic 2D-beam steering mirror enables a static beam correction of a hand guided laser instrument. Optimizations of a magnetic gimbal micro mirror with 6 mm x 8 mm mirror plate are presented; here static deflections of 3° were reached. Both MEMS devices were successfully tested with a high power ps-laser at 532nm up to 20W average laser power.

  10. Micro-Spec: A High Performance Compact Spectrometer for Submillimeter Astronomy

    Science.gov (United States)

    Hsieh, Wen-Ting; Moseley, Harvey; Stevenson, Thomas; Brown, Ari; Patel, Amil; U-Yen, Kongpop; Ehsan, Negar; Caltado, Giuseppe; Wollock, Edward

    2012-01-01

    We describe the micro-Spec, an extremely compact high performance spectrometer for the submillimeter and millimeter spectral ranges. We have designed a fully integrated submillimeter spectrometer based on superconducting microstrip technology and fabricated its critical elements. Using low loss transmission lines, we can produce a fully integrated high resolution submillimeter spectrometer on a single four inch Si wafer. A resolution of 500 can readily be achieved with standard fabrication tolerance, higher with phase trimming. All functions of the spectrometer are integrated - light is coupled to the micro strip circuit with a planar antenna, the spectra discrimination is achieved using a synthetic grating, orders are separated using a built-in planar filter, and the light is detected using photon counting Microwave Kinetic Inductance Detectors (MKID). We will discus the design principle of the instrument, describe its technical advantages, and report the progress on the development of the instrument.

  11. Study on the strength characteristics of High strength concrete with Micro steel fibers

    Science.gov (United States)

    Gowdham, K.; Sumathi, A.; Saravana Raja Mohan, K.

    2017-07-01

    The study of High Strength Concrete (HSC) has become interesting as concrete structures grow taller and larger. The usage of HSC in structures has been increased worldwide and has begun to make an impact in India. Ordinary cementitious materials are weak under tensile loads and fiber reinforced cementitious composites (FRCCs) have been developed to improve this weak point. High Strength concrete containing Alccofine as mineral admixture and reinforced with micro steel fibers were cast and tested to study the mechanical properties. The concrete were designed to have compressive strength of 60 MPa. Mixtures containing 0% and 10% replacement of cement by Alccofine and with 1%, 2% and 3% of micro steel fibers by weight of concrete were prepared. Mixtures incorporating Alccofine with fibers developed marginal increase in strength properties at all curing days when compared to control concrete.

  12. Development of a micro flow-through cell for high field NMR spectroscopy.

    Energy Technology Data Exchange (ETDEWEB)

    Alam, Todd Michael; McIntyre, Sarah K.

    2011-05-01

    A highly transportable micro flow-through detection cell for nuclear magnetic resonance (NMR) spectroscopy has been designed, fabricated and tested. This flow-through cell allows for the direct coupling between liquid chromatography (LC) and gel permeation chromatography (GPC) resulting in the possibility of hyphenated LC-NMR and GPC-NMR. The advantage of the present flow cell design is that it is independent and unconnected to the detection probe electronics, is compatible with existing commercial high resolution NMR probes, and as such can be easily implemented at any NMR facility. Two different volumes were fabricated corresponding to between {approx}3.8 and 10 {micro}L detection volume. Examples of the performance of the cell on different NMR instruments, and using different NMR detection probes were demonstrated.

  13. Highly Sensitive Hot-Wire Anemometry Based on Macro-Sized Double-Walled Carbon Nanotube Strands.

    Science.gov (United States)

    Wang, Dingqu; Xiong, Wei; Zhou, Zhaoying; Zhu, Rong; Yang, Xing; Li, Weihua; Jiang, Yueyuan; Zhang, Yajun

    2017-08-01

    This paper presents a highly sensitive flow-rate sensor with carbon nanotubes (CNTs) as sensing elements. The sensor uses micro-size centimeters long double-walled CNT (DWCNT) strands as hot-wires to sense fluid velocity. In the theoretical analysis, the sensitivity of the sensor is demonstrated to be positively related to the ratio of its surface. We assemble the flow sensor by suspending the DWCNT strand directly on two tungsten prongs and dripping a small amount of silver glue onto each contact between the DWCNT and the prongs. The DWCNT exhibits a positive TCR of 1980 ppm/K. The self-heating effect on the DWCNT was observed while constant current was applied between the two prongs. This sensor can evidently respond to flow rate, and requires only several milliwatts to operate. We have, thus far, demonstrated that the CNT-based flow sensor has better sensitivity than the Pt-coated DWCNT sensor.

  14. NEET Enhanced Micro-Pocket Fission Detector for High Temperature Reactors - FY16 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Unruh, Troy [Idaho National Lab. (INL), Idaho Falls, ID (United States); Reichenberger, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Stevenson, Sarah [Idaho National Lab. (INL), Idaho Falls, ID (United States); Tsai, Kevin [Idaho National Lab. (INL), Idaho Falls, ID (United States); McGregor, Douglas [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2016-09-01

    A collaboration between the Idaho National Laboratory (INL), the Kansas State University (KSU), and the French Atomic Energy Agency, Commissariat à l'Énergie Atomique et aux Energies Alternatives, (CEA), has been initiated by the Nuclear Energy Enabling Technologies (NEET) Advanced Sensors and Instrumentation (ASI) program for developing and testing High Temperature Micro-Pocket Fission Detectors (HT MPFD), which are compact fission chambers capable of simultaneously measuring thermal neutron flux, fast neutron flux and temperature within a single package for temperatures up to 800 °C. The MPFD technology utilizes a small, multi-purpose, robust, in-core fission chambers and thermocouple. As discussed within this report, the small size, variable sensitivity, and increased accuracy of the MPFD technology represent a revolutionary improvement over current methods used to support irradiations in US Material Test Reactors (MTRs). Previous research conducted through NEET ASI1-3 has shown that the MPFD technology could be made robust and was successfully tested in a reactor core. This new project will further the MPFD technology for higher temperature regimes and other reactor applications by developing a HT MPFD suitable for temperatures up to 800 °C. This report summarizes the research progress for year two of this three year project. Highlights from research accomplishments include: • Continuation of a joint collaboration between INL, KSU, and CEA. Note that CEA is participating at their own expense because of interest in this unique new sensor. • An updated parallel wire HT MPFD design was developed. • Program support for HT MPFD deployments was given to Accident Tolerant Fuels (ATF) and Advanced Gas-cooled Reactor (AGR) irradiation test programs. • Quality approved materials for HT MPFD construction were procured by irradiation test programs for upcoming deployments. • KSU improved and performed electrical contact and fissile material plating.

  15. High-pressure generation using double stage micro-paired diamond anvils shaped by focused ion beam

    Energy Technology Data Exchange (ETDEWEB)

    Sakai, Takeshi, E-mail: sakai@sci.ehime-u.ac.jp; Ohfuji, Hiroaki [Geodynamics Research Center, Ehime University, Matsuyama 790-8577 (Japan); Yagi, Takehiko [Geochemical Research Center, Graduate School of Science, The University of Tokyo, Tokyo 113-0033 (Japan); Irifune, Tetsuo [Geodynamics Research Center, Ehime University, Matsuyama 790-8577 (Japan); Earth-Life Science Institute, Tokyo Institute of Technology, Tokyo 152-8550 (Japan); Ohishi, Yasuo; Hirao, Naohisa [Japan Synchrotron Radiation Research Institute, Hyogo 679-5198 (Japan); Suzuki, Yuya; Kuroda, Yasushi; Asakawa, Takayuki; Kanemura, Takashi [HITACHI High-Technologies, Hitachinaka 312-0033 (Japan)

    2015-03-15

    Micron-sized diamond anvils with a 3 μm culet were successfully processed using a focused ion beam (FIB) system and the generation of high pressures was confirmed using the double stage diamond anvil cell technique. The difficulty of aligning two second-stage micro-anvils was solved via the paired micro-anvil method. Micro-manufacturing using a FIB system enables us to control anvil shape, process any materials, including nano-polycrystalline diamond and single crystal diamond, and assemble the sample exactly in a very small space between the second-stage anvils. This method is highly reproducible. High pressures over 300 GPa were achieved, and the pressure distribution around the micro-anvil culet was evaluated by using a well-focused synchrotron micro-X-ray beam.

  16. Homogenization-based topology optimization for high-resolution manufacturable micro-structures

    DEFF Research Database (Denmark)

    Groen, Jeroen Peter; Sigmund, Ole

    2017-01-01

    This paper presents a projection method to obtain high-resolution, manufacturable structures from efficient and coarse-scale, homogenization-based topology optimization results. The presented approach bridges coarse and fine scale, such that the complex periodic micro-structures can be represented...... designs are almost equal to the homogenization-based solutions. A significant reduction in computational cost is observed compared to conventional topology optimization approaches....

  17. Identification and Analysis of C. annuum microRNAs by High-throughput Sequencing and Their Association with High Temperature and High Air Humidity Stress

    Directory of Open Access Journals (Sweden)

    Xiao-wan Xu

    2015-12-01

    Full Text Available MicroRNAs (miRNAs play an important role in many developmental processes and stress responses in plants. In this study, tolerant hot pepper cultivar 'R597' (CaR and sensitive cultivar 'S590' (CaS were used to detected differentially expressed miRNAs under high temperatures and high air humidity. The length distribution of obtained small RNAs was significantly different between libraries. There were a total of 71 miRNA families identified in two genotypes, and 24 conserved miRNA families were detected in all four sRNA libraries. MIR166, MIR156/157, MIR167, MIR168, MIR2118, and MIR5301 were highly expressed in four libraries, and 93 miRNAs had a species-specific expression. Among them, 60 miRNAs were preferentially expressed in S590 leaves and 33 miRNAs were preferentially expressed in R597 leaves. Mostly miRNAs were less-conserved miRNAs. The most abundant miRNAs with different expressions between two pepper species was miR6149b, which exhibited a high level (read count 42,443 in CaSCK but no expressed in CaRCK. We found 650 (CaRCK, 1054 (CaRHH, 914 (CaSCK, 1045 (CaSHH potential targets for 92 (CaRCK, 124 (CaRHH, 128 (CaSCK, 117 (CaSHH hot pepper miRNAs, respectively. These findings facilitate in better understanding of the molecular mechanism underlying high temperature and high air humidity condition in different pepper genotypes.

  18. NEET Enhanced Micro Pocket Fission Detector for High Temperature Reactors - FY15 Status Report

    Energy Technology Data Exchange (ETDEWEB)

    Unruh, Troy [Idaho National Lab. (INL), Idaho Falls, ID (United States); McGregor, Douglas [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ugorowski, Phil [Idaho National Lab. (INL), Idaho Falls, ID (United States); Reichenberger, Michael [Idaho National Lab. (INL), Idaho Falls, ID (United States); Ito, Takashi [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2015-09-01

    A new project, that is a collaboration between the Idaho National Laboratory (INL), the Kansas State University (KSU), and the French Atomic Energy Agency, Commissariat à l'Énergie Atomique et aux Energies Alternatives, (CEA), has been initiated by the Nuclear Energy Enabling Technologies (NEET) Advanced Sensors and Instrumentation (ASI) program for developing and testing High Temperature Micro-Pocket Fission Detectors (HT MPFD), which are compact fission chambers capable of simultaneously measuring thermal neutron flux, fast neutron flux and temperature within a single package for temperatures up to 800 °C. The MPFD technology utilizes a small, multi-purpose, robust, in-core parallel plate fission chamber and thermocouple. As discussed within this report, the small size, variable sensitivity, and increased accuracy of the MPFD technology represent a revolutionary improvement over current methods used to support irradiations in US Material Test Reactors (MTRs). Previous research conducted through NEET ASI1-3 has shown that the MPFD technology could be made robust and was successfully tested in a reactor core. This new project will further the MPFD technology for higher temperature regimes and other reactor applications by developing a HT MPFD suitable for temperatures up to 800 °C. This report summarizes the research progress for year one of this three year project. Highlights from research accomplishments include: A joint collaboration was initiated between INL, KSU, and CEA. Note that CEA is participating at their own expense because of interest in this unique new sensor. An updated HT MPFD design was developed. New high temperature-compatible materials for HT MPFD construction were procured. Construction methods to support the new design were evaluated at INL. Laboratory evaluations of HT MPFD were initiated. Electrical contact and fissile material plating has been performed at KSU. Updated detector electronics are undergoing evaluations at KSU. A

  19. New application of superconductors: High sensitivity cryogenic light detectors

    Energy Technology Data Exchange (ETDEWEB)

    Cardani, L., E-mail: laura.cardani@roma1.infn.it [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Physics Department, Princeton University, Washington Road, 08544 Princeton, NJ (United States); Bellini, F.; Casali, N. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); Castellano, M.G. [Istituto di Fotonica e Nanotecnologie – CNR, Via Cineto Romano 42, 00156 Roma (Italy); Colantoni, I.; Coppolecchia, A. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); Cosmelli, C.; Cruciani, A. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); D' Addabbo, A. [INFN – Laboratori Nazionali del Gran Sasso, Assergi (L' Aquila) 67010 (Italy); Di Domizio, S. [INFN – Sezione di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Dipartimento di Fisica, Università degli Studi di Genova, Via Dodecaneso 33, 16146 Genova (Italy); Martinez, M. [Dipartimento di Fisica, Sapienza Università di Roma, Piazzale Aldo Moro 2, 00185 Roma (Italy); INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); Laboratorio de Fisica Nuclear y Astroparticulas, Universidad de Zaragoza, Zaragoza 50009 (Spain); Tomei, C. [INFN – Sezione di Roma, Piazzale Aldo Moro 2, 00185 Roma, Italy (Italy); and others

    2017-02-11

    In this paper we describe the current status of the CALDER project, which is developing ultra-sensitive light detectors based on superconductors for cryogenic applications. When we apply an AC current to a superconductor, the Cooper pairs oscillate and acquire kinetic inductance, that can be measured by inserting the superconductor in a LC circuit with high merit factor. Interactions in the superconductor can break the Cooper pairs, causing sizable variations in the kinetic inductance and, thus, in the response of the LC circuit. The continuous monitoring of the amplitude and frequency modulation allows to reconstruct the incident energy with excellent sensitivity. This concept is at the basis of Kinetic Inductance Detectors (KIDs) that are characterized by natural aptitude to multiplexed read-out (several sensors can be tuned to different resonant frequencies and coupled to the same line), resolution of few eV, stable behavior over a wide temperature range, and ease in fabrication. We present the results obtained by the CALDER collaboration with 2×2 cm{sup 2} substrates sampled by 1 or 4 Aluminum KIDs. We show that the performances of the first prototypes are already competitive with those of other commonly used light detectors, and we discuss the strategies for a further improvement.

  20. Luminescent Lanthanide Reporters for High-Sensitivity Novel Bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Anstey, Mitchell R. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Fruetel, Julia A. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Foster, Michael E. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Hayden, Carl C. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Buckley, Heather L. [Sandia National Lab. (SNL-CA), Livermore, CA (United States); Arnold, John [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2013-09-01

    Biological imaging and assay technologies rely on fluorescent organic dyes as reporters for a number of interesting targets and processes. However, limitations of organic dyes such as small Stokes shifts, spectral overlap of emission signals with native biological fluorescence background, and photobleaching have all inhibited the development of highly sensitive assays. To overcome the limitations of organic dyes for bioassays, we propose to develop lanthanide-based luminescent dyes and demonstrate them for molecular reporting applications. This relatively new family of dyes was selected for their attractive spectral and chemical properties. Luminescence is imparted by the lanthanide atom and allows for relatively simple chemical structures that can be tailored to the application. The photophysical properties offer unique features such as narrow and non-overlapping emission bands, long luminescent lifetimes, and long wavelength emission, which enable significant sensitivity improvements over organic dyes through spectral and temporal gating of the luminescent signal.Growth in this field has been hindered due to the necessary advanced synthetic chemistry techniques and access to experts in biological assay development. Our strategy for the development of a new lanthanide-based fluorescent reporter system is based on chelation of the lanthanide metal center using absorbing chromophores. Our first strategy involves "Click" chemistry to develop 3-fold symmetric chelators and the other involves use of a new class of tetrapyrrole ligands called corroles. This two-pronged approach is geared towards the optimization of chromophores to enhance light output.

  1. A highly sensitive fiber Bragg grating diaphragm pressure transducer

    Science.gov (United States)

    Allwood, Gary; Wild, Graham; Lubansky, Alex; Hinckley, Steven

    2015-10-01

    In this work, a novel diaphragm based pressure transducer with high sensitivity is described, including the physical design structure, in-depth analysis of optical response to changes in pressure, and a discussion of practical implementation and limitations. A flat circular rubber membrane bonded to a cylinder forms the body of the transducer. A fiber Bragg grating bonded to the center of the diaphragm structure enables the fractional change in pressure to be determined by analyzing the change in Bragg wavelength of the reflected spectra. Extensive evaluation of the physical properties and optical characteristics of the transducer has been performed through experimentation, and modeling using small deformation theory. The results show the transducer has a sensitivity of 0.116 nm/kPa, across a range of 15 kPa. Ultra-low cost interrogation of the optical signal was achieved through the use of an optically mismatched Bragg grating acting as an edge filter to convert the spectral change into an intensity change. A numerical model of the intensity based interrogation was implemented in order to validate the experimental results. Utilizing this interrogation technique and housing both the sensing and reference Bragg gratings within the main body of the transducer means it is effectively temperature insensitive and easily connected to electronic systems.

  2. Sensitivity of once-shocked, weathered high explosives

    Energy Technology Data Exchange (ETDEWEB)

    Williams, K.L.; Harris, B.W.

    1998-07-01

    Effects caused by stimulating once-shocked, weathered high explosives (OSW-HE) are investigated. The sensitivity of OSW-HE to mechanical stimuli was determined using standard industry tests. Some initial results are given. Pieces of OSW-HE were collected from active and inactive firing sites and from an area surrounding a drop tower at Los Alamos where skid and spigot tests were done. Samples evaluated were cast explosives or plastic bonded explosive (PBX) formulations containing cyclotrimethylenetrinitramine (RDX), cyclotetramethylene tetranitramine (HMX), 2,4,6-trinitrotoluene (TNT), mock or inert HE [tris(beta-chloroethyl)phosphate (CEF)], barium nitrate, cyanuric acid, talc, and Kel-F. Once-shocked, weathered LX-10 Livermore explosive [HMX/Viton A, (95/5 wt %)], PBX 9011 [HMX/Estane, (90/10 wt %)], PBX 9404 [HMX/nitrocellulose, tris(beta-chloroethyl) phosphate, (94/3/3 wt %)], Composition B or cyclotol (TNT/RDX explosives), and PBX 9007 (90% RDX, 9.1% styrene, 0.5% dioctyl phthalate, and 0.45 resin) were subjected to the hammer test, the drop-weight impact sensitivity test, differential thermal analysis (DTA), the spark test, the Henkin`s critical temperature test, and the flame test. Samples were subjected to remote, wet cutting and drilling; remote, liquid-nitrogen-cooled grinding and crushing; and scanning electron microscope (SEM) surface analyses for morphological changes.

  3. High-sensitivity open-loop electronics for gravimetric acoustic-wave-based sensors.

    Science.gov (United States)

    Rabus, David; Friedt, Jean-Michel; Ballandras, Sylvain; Martin, Gilles; Carry, Emile; Blondeau-Patissier, Virginie

    2013-06-01

    Detecting chemical species in gas phase has recently received an increasing interest mainly for security control, trying to implement new systems allowing for extended dynamics and reactivity. In this work, an open-loop interrogation strategy is proposed to use radio-frequency acoustic transducers as micro-balances for that purpose. The resulting system is dedicated to the monitoring of chemical compounds in gaseous or liquid-phase state. A 16 Hz standard deviation is demonstrated at 125 MHz, with a working frequency band in the 60 to 133 MHz range, answering the requirements for using Rayleigh- and Love-wave-based delay lines operating with 40-μm acoustic wavelength transducers. Moreover, this electronic setup was used to interrogate a high-overtone bulk acoustic wave resonator (HBAR) microbalance, a new sensor class allowing for multi-mode interrogation for gravimetric measurement improvement. The noise source still limiting the system performance is due to the analog-to-digital converter of the microcontroller, thus leaving open degrees-of-freedom for improving the obtained results by optimizing the voltage reference and board layout. The operation of the system is illustrated using a calibrated galvanic deposition at the surface of Love-wave delay lines to assess theoretical predictions of their gravimetric sensitivity and to compare them with HBAR-based sensor sensitivity.

  4. High efficiency solid-state sensitized heterojunction photovoltaic device

    KAUST Repository

    Wang, Mingkui

    2010-06-01

    The high molar extinction coefficient heteroleptic ruthenium dye, NaRu(4,4′-bis(5-(hexylthio)thiophen-2-yl)-2,2′-bipyridine) (4-carboxylic acid-4′-carboxylate-2,2′-bipyridine) (NCS) 2, exhibits certified 5% electric power conversion efficiency at AM 1.5 solar irradiation (100 mW cm-2) in a solid-state dye-sensitized solar cell using 2,2′,7,7′-tetrakis-(N,N-di-pmethoxyphenylamine)-9, 9′-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. This demonstration elucidates a class of photovoltaic devices with potential for low-cost power generation. © 2010 Elsevier Ltd. All rights reserved.

  5. High-Sensitivity AGN Polarimetry at Sub-Millimeter Wavelengths

    Directory of Open Access Journals (Sweden)

    Ivan Martí-Vidal

    2017-10-01

    Full Text Available The innermost regions of radio loud Active Galactic Nuclei (AGN jets are heavily affected by synchrotron self-absorption, due to the strong magnetic fields and high particle densities in these extreme zones. The only way to overcome this absorption is to observe at sub-millimeter wavelengths, although polarimetric observations at such frequencies have so far been limited by sensitivity and calibration accuracy. However, new generation instruments such as the Atacama Large mm/sub-mm Array (ALMA overcome these limitations and are starting to deliver revolutionary results in the observational studies of AGN polarimetry. Here we present an overview of our state-of-the-art interferometric mm/sub-mm polarization observations of AGN jets with ALMA (in particular, the gravitationally-lensed sources PKS 1830−211 and B0218+359, which allow us to probe the magneto-ionic conditions at the regions closest to the central black holes.

  6. Magnetic probe array with high sensitivity for fluctuating field.

    Science.gov (United States)

    Kanamaru, Yuki; Gota, Hiroshi; Fujimoto, Kayoko; Ikeyama, Taeko; Asai, Tomohiko; Takahashi, Tsutomu; Nogi, Yasuyuki

    2007-03-01

    A magnetic probe array is constructed to measure precisely the spatial structure of a small fluctuating field included in a strong confinement field that varies with time. To exclude the effect of the confinement field, the magnetic probes consisting of figure-eight-wound coils are prepared. The spatial structure of the fluctuating field is obtained from a Fourier analysis of the probe signal. It is found that the probe array is more sensitive to the fluctuating field with a high mode number than that with a low mode number. An experimental demonstration of the present method is attempted using a field-reversed configuration plasma, where the fluctuating field with 0.1% of the confinement field is successfully detected.

  7. Highly Sensitive Filter Paper Substrate for SERS Trace Explosives Detection

    Directory of Open Access Journals (Sweden)

    Pedro M. Fierro-Mercado

    2012-01-01

    Full Text Available We report on a novel and extremely low-cost surface-enhanced Raman spectroscopy (SERS substrate fabricated depositing gold nanoparticles on common lab filter paper using thermal inkjet technology. The paper-based substrate combines all advantages of other plasmonic structures fabricated by more elaborate techniques with the dynamic flexibility given by the inherent nature of the paper for an efficient sample collection, robustness, and stability. We describe the fabrication, characterization, and SERS activity of our substrate using 2,4,6-trinitrotoluene, 2,4-dinitrotoluene, and 1,3,5-trinitrobenzene as analytes. The paper-based SERS substrates presented a high sensitivity and excellent reproducibility for analytes employed, demonstrating a direct application in forensic science and homeland security.

  8. Highly efficient silicon solar cells designed with photon trapping micro/nano structures

    Science.gov (United States)

    Bartolo-Perez, Cesar; Gao, Yang; Cansizoglu, Hilal; Ghandiparsi, Soroush; Kaya, Ahmet; Mayet, Ahmed; Ponizovskaya Devine, Ekaterina; Yamada, Toshishige; Elrefaie, Aly; Wang, Shih-Yuan; Islam, M. Saif

    2017-08-01

    Crystalline silicon (c-Si) remains the most commonly used material for photovoltaic (PV) cells in the current commercial solar cells market. However, current technology requires "thick" silicon due to the relative weak absorption of Si in the solar spectrum. We demonstrate several CMOS compatible fabrication techniques including dry etch, wet etch and their combination to create different photon trapping micro/nanostructures on very thin c-silicon surface for light harvesting of PVs. Both, the simulation and experimental results show that these photon trapping structures are responsible for the enhancement of the visible light absorption which leads to improved efficiency of the PVs. Different designs of micro/nanostructures via different fabrication techniques are correlated with the efficiencies of the PVs. Our method can also drastically reduce the thickness of the c-Si PVs, and has great potential to reduce the cost, and lead to highly efficient and flexible PVs.

  9. Micro-cone targets for producing high energy and low divergence particle beams

    Science.gov (United States)

    Le Galloudec, Nathalie

    2013-09-10

    The present invention relates to micro-cone targets for producing high energy and low divergence particle beams. In one embodiment, the micro-cone target includes a substantially cone-shaped body including an outer surface, an inner surface, a generally flat and round, open-ended base, and a tip defining an apex. The cone-shaped body tapers along its length from the generally flat and round, open-ended base to the tip defining the apex. In addition, the outer surface and the inner surface connect the base to the tip, and the tip curves inwardly to define an outer surface that is concave, which is bounded by a rim formed at a juncture where the outer surface meets the tip.

  10. Shape Memory Micro- and Nanowire Libraries for the High-Throughput Investigation of Scaling Effects.

    Science.gov (United States)

    Oellers, Tobias; König, Dennis; Kostka, Aleksander; Xie, Shenqie; Brugger, Jürgen; Ludwig, Alfred

    2017-09-11

    The scaling behavior of Ti-Ni-Cu shape memory thin-film micro- and nanowires of different geometry is investigated with respect to its influence on the martensitic transformation properties. Two processes for the high-throughput fabrication of Ti-Ni-Cu micro- to nanoscale thin film wire libraries and the subsequent investigation of the transformation properties are reported. The libraries are fabricated with compositional and geometrical (wire width) variations to investigate the influence of these parameters on the transformation properties. Interesting behaviors were observed: Phase transformation temperatures change in the range from 1 to 72 °C (austenite finish, (A f ), 13 to 66 °C (martensite start, M s ) and the thermal hysteresis from -3.5 to 20 K. It is shown that a vanishing hysteresis can be achieved for special combinations of sample geometry and composition.

  11. Implementation of micro-ball nanodiamond anvils for high-pressure studies above 6 Mbar.

    Science.gov (United States)

    Dubrovinsky, Leonid; Dubrovinskaia, Natalia; Prakapenka, Vitali B; Abakumov, Artem M

    2012-01-01

    Since invention of the diamond anvil cell technique in the late 1950s for studying materials at extreme conditions, the maximum static pressure generated so far at room temperature was reported to be about 400 GPa. Here we show that use of micro-semi-balls made of nanodiamond as second-stage anvils in conventional diamond anvil cells drastically extends the achievable pressure range in static compression experiments to above 600 GPa. Micro-anvils (10-50 μm in diameter) of superhard nanodiamond (with a grain size below ∼50 nm) were synthesized in a large volume press using a newly developed technique. In our pilot experiments on rhenium and gold we have studied the equation of state of rhenium at pressures up to 640 GPa and demonstrated the feasibility and crucial necessity of the in situ ultra high-pressure measurements for accurate determination of material properties at extreme conditions.

  12. Precise 3D printing of micro/nanostructures using highly conductive carbon nanotube-thiol-acrylate composites

    Science.gov (United States)

    Liu, Y.; Xiong, W.; Jiang, L. J.; Zhou, Y. S.; Lu, Y. F.

    2016-04-01

    Two-photon polymerization (TPP) is of increasing interest due to its unique combination of truly three-dimensional (3D) fabrication capability and ultrahigh spatial resolution of ~40 nm. However, the stringent requirements of non-linear resins seriously limit the material functionality of 3D printing via TPP. Precise fabrication of 3D micro/nanostructures with multi-functionalities such as high electrical conductivity and mechanical strength is still a long-standing challenge. In this work, TPP fabrication of arbitrary 3D micro/nanostructures using multi-walled carbon nanotube (MWNT)-thiolacrylate (MTA) composite resins has been developed. Up to 0.2 wt% MWNTs have been incorporated into thiol-acrylate resins to form highly stable and uniform composite photoresists without obvious degradation for one week at room temperature. Various functional 3D micro/nanostructures including woodpiles, micro-coils, spiral-like photonic crystals, suspended micro-bridges, micro-gears and complex micro-cars have been successfully fabricated. The MTA composite resin offers significant enhancements in electrical conductivity and mechanical strength, and on the same time, preserving high optical transmittance and flexibility. Tightly controlled alignment of MWNTs and the strong anisotropy effect were confirmed. Microelectronic devices including capacitors and resistors made of the MTA composite polymer were demonstrated. The 3D micro/nanofabrication using the MTA composite resins enables the precise 3D printing of micro/nanostructures of high electrical conductivity and mechanical strength, which is expected to lead a wide range of device applications, including micro/nano-electromechanical systems (MEMS/NEMS), integrated photonics and 3D electronics.

  13. Laser-engraved carbon nanotube paper for instilling high sensitivity, high stretchability, and high linearity in strain sensors

    KAUST Repository

    Xin, Yangyang

    2017-06-29

    There is an increasing demand for strain sensors with high sensitivity and high stretchability for new applications such as robotics or wearable electronics. However, for the available technologies, the sensitivity of the sensors varies widely. These sensors are also highly nonlinear, making reliable measurement challenging. Here we introduce a new family of sensors composed of a laser-engraved carbon nanotube paper embedded in an elastomer. A roll-to-roll pressing of these sensors activates a pre-defined fragmentation process, which results in a well-controlled, fragmented microstructure. Such sensors are reproducible and durable and can attain ultrahigh sensitivity and high stretchability (with a gauge factor of over 4.2 × 10(4) at 150% strain). Moreover, they can attain high linearity from 0% to 15% and from 22% to 150% strain. They are good candidates for stretchable electronic applications that require high sensitivity and linearity at large strains.

  14. Centimeter-deep tissue fluorescence microscopic imaging with high signal-to-noise ratio and picomole sensitivity

    CERN Document Server

    Cheng, Bingbing; Wei, Ming-Yuan; Pei, Yanbo; DSouza, Francis; Nguyen, Kytai T; Hong, Yi; Tang, Liping; Yuan, Baohong

    2015-01-01

    Fluorescence microscopic imaging in centimeter-deep tissue has been highly sought-after for many years because much interesting in vivo micro-information, such as microcirculation, tumor angiogenesis, and metastasis, may deeply locate in tissue. In this study, for the first time this goal has been achieved in 3-centimeter deep tissue with high signal-to-noise ratio (SNR) and picomole sensitivity under radiation safety thresholds. These results are demonstrated not only in tissue-mimic phantoms but also in actual tissues, such as porcine muscle, ex vivo mouse liver, ex vivo spleen, and in vivo mouse tissue. These results are achieved based on three unique technologies: excellent near infrared ultrasound-switchable fluorescence (USF) contrast agents, a sensitive USF imaging system, and an effective correlation method. Multiplex USF fluorescence imaging is also achieved. It is useful to simultaneously image multiple targets and observe their interactions. This work opens the door for future studies of centimeter...

  15. Micro-Structural Response of DP 600 to High Strain Rate Deformation

    Science.gov (United States)

    Hamburg, Brian; Schneider, Judy; Jones, Stanley E.

    2008-01-01

    The object of this study was to investigate the micro-structural response of DP 600 subjected to high strain rate, ballistic impact tests. The ballistic tests were conducted using normal impact of a hardened steel penetrator into a 2 mm thick sheet of DP 600. The average strain rates produced from this test method are on the order of 10(exp 5)/s. Electron microscopy was used to investigate the microstructure before and after high strain rate deformation. A variation in material response was observed between tests conducted at 0.8 x 105 and 25 x 10(exp 5)/s.

  16. LTE Micro-cell Deployment for High-Density Railway Areas

    DEFF Research Database (Denmark)

    Sniady, Aleksander; Kassab, Mohamed; Soler, José

    2014-01-01

    Long Term Evolution (LTE) is a serious candidate for the future releases of the European Rail Traffic Management System (ERTMS). LTE offers more capacity and supports new communication-based applications and services for railways. Nevertheless, even with this technology, the classical macro......-cell radio deployments reach overload, especially in high-density areas, such as major train stations. In this paper, an LTE micro-cell deployment is investigated in high-density railway areas. Copenhagen Main Station is considered as a realistic deployment study case, with a set of relevant railway...

  17. The laser micro-machining system for diamond anvil cell experiments and general precision machining applications at the High Pressure Collaborative Access Team.

    Science.gov (United States)

    Hrubiak, Rostislav; Sinogeikin, Stanislav; Rod, Eric; Shen, Guoyin

    2015-07-01

    We have designed and constructed a new system for micro-machining parts and sample assemblies used for diamond anvil cells and general user operations at the High Pressure Collaborative Access Team, sector 16 of the Advanced Photon Source. The new micro-machining system uses a pulsed laser of 400 ps pulse duration, ablating various materials without thermal melting, thus leaving a clean edge. With optics designed for a tight focus, the system can machine holes any size larger than 3 μm in diameter. Unlike a standard electrical discharge machining drill, the new laser system allows micro-machining of non-conductive materials such as: amorphous boron and silicon carbide gaskets, diamond, oxides, and other materials including organic materials such as polyimide films (i.e., Kapton). An important feature of the new system is the use of gas-tight or gas-flow environmental chambers which allow the laser micro-machining to be done in a controlled (e.g., inert gas) atmosphere to prevent oxidation and other chemical reactions in air sensitive materials. The gas-tight workpiece enclosure is also useful for machining materials with known health risks (e.g., beryllium). Specialized control software with a graphical interface enables micro-machining of custom 2D and 3D shapes. The laser-machining system was designed in a Class 1 laser enclosure, i.e., it includes laser safety interlocks and computer controls and allows for routine operation. Though initially designed mainly for machining of the diamond anvil cell gaskets, the laser-machining system has since found many other micro-machining applications, several of which are presented here.

  18. Transition between bulk and surface refractive index sensitivity of micro-cavity in-line Mach-Zehnder interferometer induced by thin film deposition.

    Science.gov (United States)

    Śmietana, Mateusz; Janik, Monika; Koba, Marcin; Bock, Wojtek J

    2017-10-16

    In this work we discuss the refractive index (RI) sensitivity of a micro-cavity in-line Mach-Zehnder interferometer in the form of a cylindrical hole (40-50 μm in diameter) fabricated in a standard single-mode optical fiber using a femtosecond laser. The surface of the micro-cavity was coated with up to 400 nm aluminum oxide thin film using the atomic layer deposition method. Next, the film was progressively chemically etched and the influence on changes in the RI of liquid in the micro-cavity was determined at different stages of the experiment, i.e., at different thicknesses of the film. An effect of transition between sensitivity to the film thickness (surface) and the RI of liquid in the cavity (bulk) is demonstrated for the first time. We have found that depending on the interferometer working conditions determined by thin film properties, the device can be used for investigation of phenomena taking place at the surface, such as in case of specific label-free biosensing applications, or for small-volume RI analysis as required in analytical chemistry.

  19. Graphene nanomesh as highly sensitive chemiresistor gas sensor

    Science.gov (United States)

    Paul, Rajat Kanti; Badhulika, Sushmee; Saucedo, Nuvia M.; Mulchandani, Ashok

    2016-01-01

    Graphene is a one atom thick carbon allotrope with all surface atoms that has attracted significant attention as a promising material as the conduction channel of a field-effect transistor and chemical field-effect transistor sensors. However, the zero bandgap of semimetal graphene still limits its application for these devices. In this work, ethanol-chemical vapor deposition (CVD) grown p-type semiconducting large-area monolayer graphene film was patterned into nanomesh by the combination of nanosphere lithography and reactive ion etching and evaluated as field-effect transistor and chemiresistor gas sensors. The resulting neck-width of the synthesized nanomesh was about ~20 nm comprised of the gap between polystyrene spheres that was formed during the reactive ion etching process. The neck-width and the periodicities of the graphene nanomesh could be easily controlled depending the duration/power of RIE and the size of PS nanospheres. The fabricated GNM transistor device exhibited promising electronic properties featuring high drive current and ION/IOFF ratio of about 6, significantly higher than its film counterpart. Similarly, when applied as chemiresistor gas sensor at room temperature, the graphene nanomesh sensor showed excellent sensitivity towards NO2 and NH3, significantly higher than their film counterparts. The ethanol-based graphene nanomesh sensors exhibited sensitivities of about 4.32%/ppm in NO2 and 0.71%/ppm in NH3 with limit of detections of 15 ppb and 160 ppb, respectively. Our demonstrated studies on controlling the neck width of the nanomesh would lead to further improvement of graphene-based transistors and sensors. PMID:22931286

  20. Innovative nanostructures for highly sensitive vibrational biosensing (Conference Presentation)

    Science.gov (United States)

    Popp, Juergen; Mayerhöfer, Thomas; Cialla-May, Dana; Weber, Karina; Huebner, Uwe

    2016-03-01

    Employing vibrational spectroscopy (IR-absorption and Raman spectroscopy) allows for the labelfree detection of molecular specific fingerprints of inorganic, organic and biological substances. The sensitivity of vibrational spectroscopy can be improved by several orders of magnitude via the application of plasmonic active surfaces. Within this contribution we will discuss two such approaches, namely surface enhanced Raman spectroscopy (SERS) as well as surface enhanced IR absorption (SEIRA). It will be shown that SERS using metal colloids as SERS active substrate in combination with a microfluidic lab-on-a-chip (LOC) device enables high throughput and reproducible measurements with highest sensitivity and specificity. The application of such a LOC-SERS approach for therapeutic drug monitoring (e.g. quantitative detection of antibiotics in a urine matrix) will be presented. Furthermore, we will introduce innovative bottom-up strategies to prepare SERS-active nanostructures coated with a lipophilic sensor layer as one-time use SERS substrates for specific food analysis (e.g. quantitative detection of toxic food colorants). The second part of this contribution presents a slit array metamaterial perfect absorber for IR sensing applications consisting of a dielectric layer sandwiched between two metallic layers of which the upper layer is perforated with a periodic array of slits. Light-matter interaction is greatly amplified in the slits, where also the analyte is concentrated, as the surface of the substrate is covered by a thin silica layer. Thus, already small concentrations of analytes down to a monolayer can be detected by refractive index sensing and identified by their spectral fingerprints with a standard mid-infrared lab spectrometer.

  1. Comprehensive characterization and understanding of micro-fuel cells operating at high methanol concentrations.

    Science.gov (United States)

    Gago, Aldo S; Esquivel, Juan-Pablo; Sabaté, Neus; Santander, Joaquín; Alonso-Vante, Nicolas

    2015-01-01

    We report on the analysis of the performance of each electrode of an air-breathing passive micro-direct methanol fuel cell (µDMFC) during polarization, stabilization and discharge, with CH3OH (2-20 M). A reference electrode with a microcapillary was used for separately measuring the anode the cathode potential. Information about the open circuit potential (OCP), the voltage and the mass transport related phenomena are available. Using 2 M CH3OH, the anode showed mass transport problems. With 4 and 6 M CH3OH both electrodes experience this situation, whereas with 10 and 20 M CH3OH the issue is attributed to the cathode. The stabilization and fuel consumption time depends mainly on the cathode performance, which is very sensitive to fuel crossover. The exposure to 20 M CH3OH produced a loss in performance of more than 75% of the highest power density (16.3 mW·cm(-2)).

  2. High Sensitivity Detection of Broadband Acoustic Vibration Using Optical Demodulation Method

    Science.gov (United States)

    Zhang, Zhen

    Measuring the high frequency acoustic vibrations represents the fundamental interest in revealing the intrinsic dynamic characteristic of board range of systems, such as the growth of the fetus, blood flow in human palms, and vibrations of carbon nanotube. However, the acoustic wave detection capability is limited by the detection bandwidth and sensitivity of the commonly used piezoelectric based ultrasound detectors. To overcome these limitations, this thesis focuses on exploring the optical demodulation method for highly sensitive detection of broadband acoustic vibration. First, a transparent optical ultrasonic detector has been developed using micro-ring resonator (MRR) made of soft polymeric materials. It outperforms the traditional piezoelectric detectors with broader detection bandwidth, miniaturized size and wide angular sensitivity. Its ease of integration into photoacoustic microscopy system has resulted in the great improvement of the imaging resolution. A theoretic framework has been developed to establish the quantitative understanding of its unique distance and angular dependent detection characteristics and was subsequently validated experimentally. The developed theoretic framework provides a guideline to fully accounts for the trade-offs between axial and lateral resolution, working distance, and the field of view in developing optimal imaging performance for a wide range of biological and clinical applications. MRR-based ultrasonic detector is further integrated into confocal fluorescence microscopy to realize the simultaneous imaging of fluorescence and optical absorption of retinal pigment epithelium, achieving multi-contrast imaging at sub-cellular level. The needs to resolve the fine details of the biological specimen with the resolution beyond the diffraction limit further motivate the development of optical demodulated ultrasonic detection method based on near-field scanning optical microscopy (NSOM). The nano-focusing probe was developed

  3. Photoelectrochemical properties of hierarchical ZnO micro-nanostructure sensitized with Sb2S3 nanoparticles

    Directory of Open Access Journals (Sweden)

    Zhimin GUO

    2016-02-01

    Full Text Available By using electrochemical deposition method, and assisted with additions of PEG-400 and EDA, well-aligned ZnO nanorods and hierarchical ZnO micro-nanostructure are fabricated directly on indium doped tin oxide coated conducting glass (ITO substrate. The shell-core Sb2S3/ZnO nanorod structure and the shell-core hierarchical Sb2S3/ZnO micro-nanostructure are prepared by chemical bath deposition method. SEM, XRD, UV-Vis and photocurrent test are used to characterize the morphology, nanostructures and their photoelectrochemical properties. The studies show that the photocurrent on the array membranes with shell-core hierarchical Sb2S3/ZnO micro-nanostructure is apparently higher than that with shell-core Sb2S3/ZnO nanorods array.

  4. Micro-scaled high-throughput digestion of plant tissue samples for multi-elemental analysis

    Directory of Open Access Journals (Sweden)

    Husted Søren

    2009-09-01

    Full Text Available Abstract Background Quantitative multi-elemental analysis by inductively coupled plasma (ICP spectrometry depends on a complete digestion of solid samples. However, fast and thorough sample digestion is a challenging analytical task which constitutes a bottleneck in modern multi-elemental analysis. Additional obstacles may be that sample quantities are limited and elemental concentrations low. In such cases, digestion in small volumes with minimum dilution and contamination is required in order to obtain high accuracy data. Results We have developed a micro-scaled microwave digestion procedure and optimized it for accurate elemental profiling of plant materials (1-20 mg dry weight. A commercially available 64-position rotor with 5 ml disposable glass vials, originally designed for microwave-based parallel organic synthesis, was used as a platform for the digestion. The novel micro-scaled method was successfully validated by the use of various certified reference materials (CRM with matrices rich in starch, lipid or protein. When the micro-scaled digestion procedure was applied on single rice grains or small batches of Arabidopsis seeds (1 mg, corresponding to approximately 50 seeds, the obtained elemental profiles closely matched those obtained by conventional analysis using digestion in large volume vessels. Accumulated elemental contents derived from separate analyses of rice grain fractions (aleurone, embryo and endosperm closely matched the total content obtained by analysis of the whole rice grain. Conclusion A high-throughput micro-scaled method has been developed which enables digestion of small quantities of plant samples for subsequent elemental profiling by ICP-spectrometry. The method constitutes a valuable tool for screening of mutants and transformants. In addition, the method facilitates studies of the distribution of essential trace elements between and within plant organs which is relevant for, e.g., breeding programmes aiming at

  5. Micro-scaled high-throughput digestion of plant tissue samples for multi-elemental analysis.

    Science.gov (United States)

    Hansen, Thomas H; Laursen, Kristian H; Persson, Daniel P; Pedas, Pai; Husted, Søren; Schjoerring, Jan K

    2009-09-26

    Quantitative multi-elemental analysis by inductively coupled plasma (ICP) spectrometry depends on a complete digestion of solid samples. However, fast and thorough sample digestion is a challenging analytical task which constitutes a bottleneck in modern multi-elemental analysis. Additional obstacles may be that sample quantities are limited and elemental concentrations low. In such cases, digestion in small volumes with minimum dilution and contamination is required in order to obtain high accuracy data. We have developed a micro-scaled microwave digestion procedure and optimized it for accurate elemental profiling of plant materials (1-20 mg dry weight). A commercially available 64-position rotor with 5 ml disposable glass vials, originally designed for microwave-based parallel organic synthesis, was used as a platform for the digestion. The novel micro-scaled method was successfully validated by the use of various certified reference materials (CRM) with matrices rich in starch, lipid or protein. When the micro-scaled digestion procedure was applied on single rice grains or small batches of Arabidopsis seeds (1 mg, corresponding to approximately 50 seeds), the obtained elemental profiles closely matched those obtained by conventional analysis using digestion in large volume vessels. Accumulated elemental contents derived from separate analyses of rice grain fractions (aleurone, embryo and endosperm) closely matched the total content obtained by analysis of the whole rice grain. A high-throughput micro-scaled method has been developed which enables digestion of small quantities of plant samples for subsequent elemental profiling by ICP-spectrometry. The method constitutes a valuable tool for screening of mutants and transformants. In addition, the method facilitates studies of the distribution of essential trace elements between and within plant organs which is relevant for, e.g., breeding programmes aiming at improvement of the micronutrient density in edible

  6. Folded cladding porous shaped photonic crystal fiber with high sensitivity in optical sensing applications: Design and analysis

    Directory of Open Access Journals (Sweden)

    Bikash Kumar Paul

    2017-02-01

    Full Text Available A micro structure folded cladding porous shaped with circular air hole photonic crystal fiber (FP-PCF is proposed and numerically investigated in a broader wavelength range from 1.4 µm to 1.64 µm (E+S+C+L+U for chemical sensing purposes. Employing finite element method (FEM with anisotropic perfectly matched layer (PML various properties of the proposed FP-PCF are numerically inquired. Filling the hole of core with aqueous analyte ethanol (n = 1.354 and tuning different geometric parameters of the fiber, the sensitivity order of 64.19% and the confinement loss of 2.07 × 10-5 dB/m are attained at 1.48 µm wavelength in S band. The investigated numerical simulation result strongly focuses on sensing purposes; because this fiber attained higher sensitivity with lower confinement loss over the operating wavelength. Measuring time of sensitivity, simultaneously confinement loss also inquired. It reflects that confinement loss is highly dependable on PML depth but not for sensitivity. Beside above properties numerical aperture (NA, nonlinearity, and effective area are also computed. This FP-PCF also performed as sensor for other alcohol series (methanol, propanol, butanol, pentanol. Optimized FP-PCF shows higher sensitivity and low confinement loss carrying high impact in the area of chemical as well as gas sensing purposes. Surely it is clear that install such type of sensor will flourish technology massively.

  7. Acceleration sensitivity compensation in high performance crystal oscillators

    Science.gov (United States)

    Emmons, D. A.

    1978-01-01

    Two approaches to achieving reduced acceleration sensitivity of crystal oscillators are discussed. The first involves electronic compensation within the frequency control loop. The second utilizes two resonators of comparable acceleration sensitivity to compensate each other. Problems encountered in matching and tuning the resonators are discussed, as well as orientation symmetry of the frequency deviation patterns. Results on frequency stability which reflect an improved static sensitivity are presented.

  8. Steady high viscosity liquid micro-jet production and fiber spinning using co-flowing gas conformation

    Science.gov (United States)

    Gañán-Calvo, A. M.; Pérez-Saborid, M.; López-Herrera, J. M.; Gordillo, J. M.

    2004-05-01

    Here we propose a new physical approach to the high-speed conformation of a Newtonian viscous liquid into a fiber (high speed fiber drawing), which suppresses all well-known axisymmetric and asymmetric instabilities during the fiber drawing. Our approach is based on the application of an appropriate gas pressure profile along the viscous jet or fiber axis, provided by a special subsonic micro-nozzle concentric with the fiber. The micro-nozzle design and optimization is mathematically provided.

  9. MicroRNA-185 regulates chemotherapeutic sensitivity in gastric cancer by targeting apoptosis repressor with caspase recruitment domain.

    Science.gov (United States)

    Li, Q; Wang, J-X; He, Y-Q; Feng, C; Zhang, X-J; Sheng, J-Q; Li, P-F

    2014-04-24

    Gastric cancer remains the second leading cause of cancer deaths worldwide. Resistance to chemotherapy is a significant barrier for effective cancer treatment. Here, we identified miR-185 to be a contributor to chemosensitivity in gastric cancer. We observed low levels of miR-185 in gastric cancer cell lines and clinical tissues, compared with gastric epithelium cell line and noncancerous tissues. Furthermore, enforced expression of miR-185 increased the sensitivity of gastric cancer cells to low-dose chemotherapeutic agents, which alone cannot trigger significant apoptosis. Conversely, knockdown of endogenous miR-185 prevented high-dose chemotherapy-induced apoptosis. In elucidating the molecular mechanism by which miR-185 participated in the regulation of chemosensitivity in gastric cancer, we discovered that apoptosis repressor with caspase recruitment domain (ARC) is a direct target of miR-185. The role of miR-185 was confirmed in gastric tumor xenograft model. The growth of established tumors was suppressed by a combination therapy using enforced miR-185 expression and a low dose of anticancer drugs. Finally, we found that RUNX3 (Runt-related transcription factor) was involved in the activation of miR-185 at the transcriptional level. Taken together, our results reveal that RUNX3, miR-185 and ARC regulate the sensitivity of gastric cancer cells to chemotherapy.

  10. Development of Gas Micro-Strip Chambers for Radiation Detection and Tracking at High Rates

    CERN Multimedia

    2002-01-01

    % RD28 \\\\ \\\\ Micro-Strip Gas Chambers (GMSC) are a promising high rate, high resolution position detector suited for use in high luminosity hadron collider experiments, as general purpose tracker or to improve the performances of preshower counters, transition radiation and inner muon detectors. Large GMSC arrays have been included in proposed LHC and SSC experimental setups. The operating characteristics of GMSC make their use very attractive also for detectors at tau/beauty/charm factories, as well as for synchrotron radiation facilities and medical applications. At the present state of the art, some problems limiting the usefulness of microstrip chambers are the observed gain changes due to charging up of the support, possible long-term degradation due to ageing, limited sizes imposed by fabrication technologies and unavailability of dedicated high-speed, high-density readout electronics. Limited experience exists of operation of GMSC in real experimental conditions, and little if anything is known about p...

  11. Development of gas micro-strip chambers for high rate radiation detection and tracking

    CERN Document Server

    Bouclier, Roger; Gaudaen, J; Florent, J J; Ropelewski, Leszek; Sauli, Fabio; Bondar, A E; Groshev, V R; Minakov, G D; Onuchin, A P; Pestov, Yu N; Shekhtman, L I; Sidorov, V A; Dixit, M S; Oakham, G K; Møller, S; Sørensen, G; Uggerhøj, Erik; Brons, S; Brückner, W; Godbersen, M; Heidrich, M; Paul, S; Trombini, A; Werding, R; Armitage, J A; Karlen, D A; Stewart, G; Barasch, E F; McIntyre, P; Pang, Y; Trost, H J; Salomon, M; Breskin, Amos; Chechik, R; Pansky, A; CERN. Geneva. Detector Research and Development Committee

    1992-01-01

    Gas Micro-Strip Chambers (GMSC) are a promising high-rate, high resolution position detector suited for use in high luminosity hadron collider experiments, as general purpose tracker or to improve the performances of pre-shower counters, transition radiation and inner muon detectors. Large GMSC arrays have been included in proposed LHC and SSC experimental setups. The operating characteristics of GMSC make their use very attractive also for detectors at tau/charm/beauty factories, as well as for synchrotron radiation facilities and for medical applications. At the present state of the art, some problems limiting the usefulness of microstrip chambers are the observed gain changes due to charging up of the support, possible long-term degradation due to ageing, limited sizes imposed by fabrication technologies and unavailability of dedicated high-speed, high-density readout electronics. Limited experience exists of operation of GMSC in real experimental conditions, and little if anything is known about performan...

  12. Highly sensitive and multiplexed platforms for allergy diagnostics

    Science.gov (United States)

    Monroe, Margo R.

    Allergy is a disorder of the immune system caused by an immune response to otherwise harmless environmental allergens. Currently 20% of the US population is allergic and 90% of pediatric patients and 60% of adult patients with asthma have allergies. These percentages have increased by 18.5% in the past decade, with predicted similar trends for the future. Here we design sensitive, multiplexed platforms to detect allergen-specific IgE using the Interferometric Reflectance Imaging Sensor (IRIS) for various clinical settings. A microarray platform for allergy diagnosis allows for testing of specific IgE sensitivity to a multitude of allergens, while requiring only small volumes of patient blood sample. However, conventional fluorescent microarray technology is limited by i) the variation of probe immobilization, which hinders the ability to make quantitative, assertive, and statistically relevant conclusions necessary in immunodiagnostics and ii) the use of fluorophore labels, which is not suitable for some clinical applications due to the tendency of fluorophores to stick to blood particulates and require daily calibration methods. This calibrated fluorescence enhancement (CaFE) method integrates the low magnification modality of IRIS with enhanced fluorescence sensing in order to directly correlate immobilized probe (major allergens) density to allergen-specific IgE in patient serum. However, this platform only operates in processed serum samples, which is not ideal for point of care testing. Thus, a high magnification modality of IRIS was adapted as an alternative allergy diagnostic platform to automatically discriminate and size single nanoparticles bound to specific IgE in unprocessed, characterized human blood and serum samples. These features make IRIS an ideal candidate for clinical and diagnostic applications, such a POC testing. The high magnification (nanoparticle counting) modality in conjunction with low magnification of IRIS in a combined instrument

  13. Resolution, sensitivity, and in vivo application of high-resolution computed tomography for titanium-coated polymethyl methacrylate (PMMA) dental implants.

    Science.gov (United States)

    Cuijpers, Vincent M J I; Jaroszewicz, Jacub; Anil, Sukumaran; Al Farraj Aldosari, Abdullah; Walboomers, X Frank; Jansen, John A

    2014-03-01

    The aims of this study were (i) to determine the spatial resolution and sensitivity of micro- versus nano-computed tomography (CT) techniques and (ii) to validate micro- versus nano-CT in a dog dental implant model, comparative to histological analysis. To determine spatial resolution and sensitivity, standardized reference samples containing standardized nano- and microspheres were prepared in polymer and ceramic matrices. Thereafter, 10 titanium-coated polymer dental implants (3.2 mm in Ø by 4 mm in length) were placed in the mandible of Beagle dogs. Both micro- and nano-CT, as well as histological analyses, were performed. The reference samples confirmed the high resolution of the nano-CT system, which was capable of revealing sub-micron structures embedded in radiodense matrices. The dog implantation study and subsequent statistical analysis showed equal values for bone area and bone-implant contact measurements between micro-CT and histology. However, because of the limited sample size and field of view, nano-CT was not rendering reliable data representative of the entire bone-implant specimen. Micro-CT analysis is an efficient tool to quantitate bone healing parameters at the bone-implant interface, especially when using titanium-coated PMMA implants. Nano-CT is not suitable for such quantification, but reveals complementary morphological information rivaling histology, yet with the advantage of a 3D visualization. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  14. Proposal of a gas sensor with high sensitivity, birefringence and nonlinearity for air pollution monitoring

    Directory of Open Access Journals (Sweden)

    Sayed Asaduzzaman

    2016-09-01

    Full Text Available Flammable or poisonous gasses in the air are capable of destroying a geographical area of causing a fire, fulmination, and venomous exposure. This paper presents a micro-cored photonic crystal fiber based gas sensor for detecting colorless or toxic gasses and monitoring air pollution by measuring gas condensate components in production facilities. The numerical investigation of the proposed PCF takes place using the finite element method (FEM. The geometrical parameters of proposed PCF are varied to optimize and observe the dependence of guiding properties on them. According to simulated results, the high relative sensitivity of 53.07% is obtained at 1.33 μm wavelength for optimum parameters. In addition, high birefringence of the order 6.9 × 10−3; lower confinement loss of 3.21 × 10−6 dB/m is also gained at the same wavelength. Moreover, nonlinear coefficient, effective area, splice loss, V parameters and beat length are reported briefly.

  15. Thermal and hydrodynamic studies for micro-channel cooling for large area silicon sensors in high energy physics experiments

    Science.gov (United States)

    Flaschel, Nils; Ariza, Dario; Díez, Sergio; Gerboles, Marta; Gregor, Ingrid-Maria; Jorda, Xavier; Mas, Roser; Quirion, David; Tackmann, Kerstin; Ullan, Miguel

    2017-08-01

    Micro-channel cooling initially aiming at small-sized high-power integrated circuits is being transferred to the field of high energy physics. Today's prospects of micro-fabricating silicon opens a door to a more direct cooling of detector modules. The challenge in high energy physics is to save material in the detector construction and to cool large areas. In this paper, we are investigating micro-channel cooling as a candidate for a future cooling system for silicon detectors in a generic research and development approach. The work presented in this paper includes the production and the hydrodynamic and thermal testing of a micro-channel equipped prototype optimized to achieve a homogeneous flow distribution. Furthermore, the device was simulated using finite element methods.

  16. Sensitive absorption detection for micro-column liquid chromatography by ultraviolet forward-scattering degenerate four-wave mixing.

    NARCIS (Netherlands)

    de Beer, T.; Beso, P.; Velthorst, N.H.; Brinkman, U.A.T.; Gooijer, C.; Hoornweg, G.Ph.

    1999-01-01

    The performance of forward-scattering degenerate four-wave mixing (F-D4WM) in the mid-ultraviolet (UV) region (351nm) as a detection technique for micro-column liquid chromatography (μLC) is studied, using nitro-substituted polycyclic aromatic hydrocarbons (NO

  17. Adjoint sensitivity analysis of high frequency structures with Matlab

    CERN Document Server

    Bakr, Mohamed; Demir, Veysel

    2017-01-01

    This book covers the theory of adjoint sensitivity analysis and uses the popular FDTD (finite-difference time-domain) method to show how wideband sensitivities can be efficiently estimated for different types of materials and structures. It includes a variety of MATLAB® examples to help readers absorb the content more easily.

  18. Characterization of three high efficiency and blue sensitive silicon photomultipliers

    Science.gov (United States)

    Otte, Adam Nepomuk; Garcia, Distefano; Nguyen, Thanh; Purushotham, Dhruv

    2017-02-01

    We report about the optical and electrical characterization of three high efficiency and blue sensitive Silicon photomultipliers from FBK, Hamamatsu, and SensL. Key features of the tested devices when operated at 90% breakdown probability are peak photon detection efficiencies between 40% and 55%, temperature dependencies of gain and PDE that are less than 1%/°C, dark rates of ∼50 kHz/mm2 at room temperature, afterpulsing of about 2%, and direct optical crosstalk between 6% and 20%. The characteristics of all three devices impressively demonstrate how the Silicon-photomultiplier technology has improved over the past ten years. It is further demonstrated how the voltage and temperature characteristics of a number of quantities can be parameterized on the basis of physical models. The models provide a deeper understanding of the device characteristics over a wide bias and temperature range. They also serve as examples how producers could provide the characteristics of their SiPMs to users. A standardized parameterization of SiPMs would enable users to find the optimal SiPM for their application and the operating point of SiPMs without having to perform measurements thus significantly reducing design and development cycles.

  19. Improvement of sensitivity in high-resolution Rutherford backscattering spectroscopy.

    Science.gov (United States)

    Hashimoto, H; Nakajima, K; Suzuki, M; Sasakawa, K; Kimura, K

    2011-06-01

    The sensitivity (limit of detection) of high-resolution Rutherford backscattering spectroscopy (HRBS) is mainly determined by the background noise of the spectrometer. There are two major origins of the background noise in HRBS, one is the stray ions scattered from the inner wall of the vacuum chamber of the spectrometer and the other is the dark noise of the microchannel plate (MCP) detector which is commonly used as a focal plane detector of the spectrometer in HRBS. In order to reject the stray ions, several barriers are installed inside the spectrometer and a thin Mylar foil is mounted in front of the detector. The dark noise of the MCP detector is rejected by the coincidence measurement with the secondary electrons emitted from the Mylar foil upon the ion passage. After these improvements, the background noise is reduced by a factor of 200 at a maximum. The detection limit can be improved down to 10 ppm for As in Si at a measurement time of 1 h under ideal conditions. © 2011 American Institute of Physics

  20. Ultra-high sensitivity imaging of cancer using SERRS nanoparticles

    Science.gov (United States)

    Kircher, Moritz F.

    2016-05-01

    "Surface-enhanced Raman spectroscopy" (SERS) nanoparticles have gained much attention in recent years for in silico, in vitro and in vivo sensing applications. Our group has developed novel generations of biocompatible "surfaceenhanced resonance Raman spectroscopy" (SERRS) nanoparticles as novel molecular imaging agents. Via rigorous optimization of the different variables contributing to the Raman enhancement, we were able to design SERRS nanoparticles with so far unprecedented sensitivity of detection under in vivo imaging conditions (femto-attomolar range). This has resulted in our ability to visualize, with a single nanoparticle, many different cancer types (after intravenous injection) in mouse models. The cancer types we have tested so far include brain, breast, esophagus, stomach, pancreas, colon, sarcoma, and prostate cancer. All mouse models used are state-of-the-art and closely mimic the tumor biology in their human counterparts. In these animals, we were able to visualize not only the bulk tumors, but importantly also microscopic extensions and locoregional satellite metastases, thus delineating for the first time the true extent of tumor spread. Moreover, the particles enable the detection of premalignant lesions. Given their inert composition they are expected to have a high chance for clinical translation, where we envision them to have an impact in various scenarios ranging from early detection, image-guidance in open or minimally invasive surgical procedures, to noninvasive imaging in conjunction with spatially offset (SESORS) Raman detection devices.

  1. Ag-In transient liquid phase bonding for high temperature stainless steel micro actuators

    OpenAIRE

    Andersson, Martin

    2013-01-01

    A stainless steel, high temperature, phase change micro actuator has been demonstrated using the solid-liquid phase transition of mannitol at 168°C and In-Ag transient liquid phase diffusion bonding. Joints created with this bonding technique can sustain temperatures up to 695°C, while being bonded at only 180°C, and have thicknesses between 1.4 to 6.0 μm. Physical vapour deposition, inkjet printing and electroplating have been evaluated as deposition methods for bond layers. For actuation, c...

  2. Highly sensitive NIR PtSi/Si-nanostructure detectors

    Science.gov (United States)

    Li, Hua-gao; Guo, Pei; Yuan, An-bo; Long, Fei; Li, Rui-zhi; Li, Ping; Li, Yi

    2016-10-01

    We report a high external quantum efficiency (EQE) photodiode detector with PtSi/Si-nanostructures. Black silicon nanostructures were fabricated by metal-assist chemical etching (MCE), a 2 nm Pt layer was subsequently deposited on black silicon surface by DC magnetron sputtering system, and PtSi/Si-nanostructures were formed in vacuum annealing at 450 oC for 5 min. As the PtSi/Si-nanostructures presented a spiky shape, the absorption of incident light was remarkably enhanced for the repeat reflection and absorption. The breakdown voltage, dark current, threshold voltage and responsivity of the device were investigated to evaluate the performance of the PtSi/Si-nanostructures detector. The threshold voltage and dark currents of the PtSi/Si-nanostructure photodiode tends to be slightly higher than those of the standard diodes. The breakdown voltage remarkably was reduced because of existing avalanche breakdown in PtSi/Si-nanostructures. However, the photodiodes had high response at room temperature in near infrared region. At -5 V reverse bias voltage, the responsivity was 0.72 A/W in 1064 nm wavelength, and the EQE was 83.9%. By increasing the reverse bias voltage, the responsivity increased. At -60 V reverse bias voltage, the responsivity was 3.5 A/W, and the EQE was 407.5%, which means the quantum efficiency of PtSi/Si-nanostructure photodiodes was about 10 times higher than that of a standard diode. Future research includes how to apply this technology to enhance the NIR sensitivity of image sensors, such as Charge Coupled Devices (CCD).

  3. Centrifugal micro-channel array droplet generation for highly parallel digital PCR.

    Science.gov (United States)

    Chen, Zitian; Liao, Peiyu; Zhang, Fangli; Jiang, Mengcheng; Zhu, Yusen; Huang, Yanyi

    2017-01-17

    Stable water-in-oil emulsion is essential to digital PCR and many other bioanalytical reactions that employ droplets as microreactors. We developed a novel technology to produce monodisperse emulsion droplets with high efficiency and high throughput using a bench-top centrifuge. Upon centrifugal spinning, the continuous aqueous phase is dispersed into monodisperse droplet jets in air through a micro-channel array (MiCA) and then submerged into oil as a stable emulsion. We performed dPCR reactions with a high dynamic range through the MiCA approach, and demonstrated that this cost-effective method not only eliminates the usage of complex microfluidic devices and control systems, but also greatly suppresses the loss of materials and cross-contamination. MiCA-enabled highly parallel emulsion generation combines both easiness and robustness of picoliter droplet production, and breaks the technical challenges by using conventional lab equipment and supplies.

  4. High throughput modular chambers for rapid evaluation of anesthetic sensitivity

    Directory of Open Access Journals (Sweden)

    Eckmann David M

    2006-11-01

    Full Text Available Abstract Background Anesthetic sensitivity is determined by the interaction of multiple genes. Hence, a dissection of genetic contributors would be aided by precise and high throughput behavioral screens. Traditionally, anesthetic phenotyping has addressed only induction of anesthesia, evaluated with dose-response curves, while ignoring potentially important data on emergence from anesthesia. Methods We designed and built a controlled environment apparatus to permit rapid phenotyping of twenty-four mice simultaneously. We used the loss of righting reflex to indicate anesthetic-induced unconsciousness. After fitting the data to a sigmoidal dose-response curve with variable slope, we calculated the MACLORR (EC50, the Hill coefficient, and the 95% confidence intervals bracketing these values. Upon termination of the anesthetic, Emergence timeRR was determined and expressed as the mean ± standard error for each inhaled anesthetic. Results In agreement with several previously published reports we find that the MACLORR of halothane, isoflurane, and sevoflurane in 8–12 week old C57BL/6J mice is 0.79% (95% confidence interval = 0.78 – 0.79%, 0.91% (95% confidence interval = 0.90 – 0.93%, and 1.96% (95% confidence interval = 1.94 – 1.97%, respectively. Hill coefficients for halothane, isoflurane, and sevoflurane are 24.7 (95% confidence interval = 19.8 – 29.7%, 19.2 (95% confidence interval = 14.0 – 24.3%, and 33.1 (95% confidence interval = 27.3 – 38.8%, respectively. After roughly 2.5 MACLORR • hr exposures, mice take 16.00 ± 1.07, 6.19 ± 0.32, and 2.15 ± 0.12 minutes to emerge from halothane, isoflurane, and sevoflurane, respectively. Conclusion This system enabled assessment of inhaled anesthetic responsiveness with a higher precision than that previously reported. It is broadly adaptable for delivering an inhaled therapeutic (or toxin to a population while monitoring its vital signs, motor reflexes, and providing precise control

  5. Silicon photonic crystal microarrays for high throughput label-free detection of lung cancer cell line lysates with sensitivity and specificity

    Science.gov (United States)

    Chakravarty, Swapnajit; Lai, Wei-Cheng; Zou, Yi; Gemmill, Robert M.; Chen, Ray T.

    2013-03-01

    Detection of biomolecules on microarrays based on label-free on-chip optical biosensors is very attractive since this format avoids complex chemistries caused by steric hindrance of labels. Application areas include the detection of cancers and allergens, and food-borne pathogens to name a few. We have demonstrated photonic crystal microcavity biosensors with high sensitivity down to 1pM concentrations (67pg/ml). High sensitivities were achieved by slow light engineering which reduced the radiation loss and increased the stored energy in the photonic crystal microcavity resonance mode. Resonances with high quality factor Q~26,760 in liquid ambient, coupled with larger optical mode volumes allowed enhanced interaction with the analyte biomolecules which resulted in sensitivities down to 10 cells per micro-liter to lung cancer cell lysates. The specificity of detection was ensured by multiplexed detections from multiple photonic crystal microcavities arrayed on the arms of a multimode interference power splitter. Specific binding interactions and control experiments were performed simultaneously at the same instant of time with the same 60 microliter sample volume. Specificity is further ensured by sandwich assay methods in the multiplexed experiment. Sandwich assay based amplification increased the sensitivity further resulting in the detection of lung cancer cell lysates down to concentrations of 2 cells per micro-liter. The miniaturization enabled by photonic crystal biosensors coupled with waveguide interconnected layout thus offers the potential of high throughput proteomics with high sensitivity and specificity.

  6. Antisense inhibition of microRNA-21 or -221 arrests cell cycle, induces apoptosis, and sensitizes the effects of gemcitabine in pancreatic adenocarcinoma.

    Science.gov (United States)

    Park, Jong-Kook; Lee, Eun Joo; Esau, Christine; Schmittgen, Thomas D

    2009-10-01

    The contribution of overexpressed microRNA-21 and -221 (miR-21 and miR-221) to the malignant phenotype was determined by inhibiting these miRNAs using antisense oligonucleotides. The effects of antisense to miR-21 and miR-221 on cell proliferation, cell cycle arrest, induction of apoptosis, combinatorial effects with gemcitabine, and effects on target protein levels were studied. Low nanomolar concentrations of both antisense oligonucleotides reduced proliferation of pancreatic cancer cell lines. Reduced proliferation was less pronounced in the normal ductal epithelial cell line human pancreatic Nestin-expressing cell or in pancreatic cancer cell lines exposed to an irrelevant control oligonucleotide. Inhibition of miR-21 and miR-221 increased the amount of apoptosis in HS766T cells by 3- to 6-fold compared with the control oligonucleotide. HS766T cells exposed to miR-21 antisense resulted in cell cycle arrest (G1 phase). Protein levels of tumor suppressor targets of the miRNAs were increased by antisense to miR-21 (PTEN and RECK) and miR-221 (p27). Antisense to miR-21 and miR-221 sensitized the effects of gemcitabine, and the antisense-gemcitabine combinations were synergistic at high fraction affected. We demonstrate that antisense to miR-21 and miR-221 results in significant cell killing under various conditions and that antisense oligonucleotides targeted to miRNA represents a potential new therapy for pancreatic cancer.

  7. High-Q Wafer Level Package Based on Modified Tri-Layer Anodic Bonding and High Performance Getter and Its Evaluation for Micro Resonant Pressure Sensor

    Directory of Open Access Journals (Sweden)

    Liying Wang

    2017-03-01

    Full Text Available In order to achieve and maintain a high quality factor (high-Q for the micro resonant pressure sensor, this paper presents a new wafer level package by adopting cross-layer anodic bonding technique of the glass/silicon/silica (GSS stackable structure and integrated Ti getter. A double-layer structure similar to a silicon-on-insulator (SOI wafer is formed after the resonant layer and the pressure-sensitive layer are bonded by silicon direct bonding (SDB. In order to form good bonding quality between the pressure-sensitive layer and the glass cap layer, the cross-layer anodic bonding technique is proposed for vacuum package by sputtering Aluminum (Al on the combination wafer of the pressure-sensitive layer and the resonant layer to achieve electrical interconnection. The model and the bonding effect of this technique are discussed. In addition, in order to enhance the performance of titanium (Ti getter, the prepared and activation parameters of Ti getter under different sputtering conditions are optimized and discussed. Based on the optimized results, the Ti getter (thickness of 300 nm to 500 nm is also deposited on the inside of the glass groove by magnetron sputtering to maintain stable quality factor (Q. The Q test of the built testing system shows that the number of resonators with a Q value of more than 10,000 accounts for more than 73% of the total. With an interval of 1.5 years, the Q value of the samples remains almost constant. It proves the proposed cross-layer anodic bonding and getter technique can realize high-Q resonant structure for long-term stable operation.

  8. High finesse silica waveguide ring resonators for resonant micro-optic gyroscopes

    Science.gov (United States)

    Zhang, Jianjie; Li, Hanzhao; Ma, Huilian; Jin, Zhonghe

    2017-04-01

    A high-finesse silica waveguide ring resonator (WRR) is designed and a new record is demonstrated experimentally. The finesse and the resonant depth of the silica WRR with a length of 7.9 cm and a diameter of 2.5 cm are 196.7 and 98%, respectively. In addition, the silica WRR is pigtailed with single-polarization fiber to improve the polarization extinction ratio thus to reduce the polarization error. With the application of this high-finesse and high polarization extinction ratio WRR to the resonant micro-optic gyroscope (RMOG), a bias stability of 0.004°/s was observed over a one-hour timeframe.

  9. Highly sensitive and selective colorimetric sensing of antibiotics in milk.

    Science.gov (United States)

    Zhang, Xiaofang; Zhang, Yang; Zhao, Hong; He, Yujian; Li, Xiangjun; Yuan, Zhuobin

    2013-05-17

    Antibiotics residues in foods are very harmful to human beings. Determination of antibiotics residues relies largely on the availability of adequate analytical techniques. Currently, there is an urgent need for on site and real time detection of antibiotics in food. In this work, a novel one step synthesis of gold nanoparticles (AuNPs) was proposed using pyrocatechol violet (PCV) as a reducer agent. Highly sensitive and selective colorimetric detection of four antibiotics kanamycin mono sulfate (KA), neomycin sulfate (NE), streptomycin sulfate (ST) and bleomycin sulfate (BL) was realized during the formation of AuNPs. PCV has -OH groups and these antibiotics have -OH, -NH2, -NH- groups, so there may be some special hydrogen-bonding interactions between PCV and these antibiotics. Therefore, the presence of KA, NE, ST and BL would influence the synthesis of AuNPs, then the color and state of AuNPs would change, which could be observed with the naked eye or a UV-vis spectrophotometer. Results showed that A670 was linear with the logarithm of KA concentration in the range from 1.0×10(-8) to 5.0×10(-7)M and 5.0×10(-7) to 5.5×10(-5)M. The detection limit of KA was 1.0×10(-9)M (S/N=3). The coexisting substances including 1.0×10(-5)M phenylalanine, alanine, glycerol, glucose, Mg(2+), Ca(2+), Na(+), K(+), CO3(2-), SO4(2-), NO3(-), Cl(-) and Br(-) did not affect the determination of 1.0×10(-7)M antibiotics. In particular, the proposed method could be applied successfully to the detection of antibiotics in the pretreated liquid milk products. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Highly sensitive and unbiased approach for elucidating antibody repertoires.

    Science.gov (United States)

    Lin, Sherry G; Ba, Zhaoqing; Du, Zhou; Zhang, Yu; Hu, Jiazhi; Alt, Frederick W

    2016-07-12

    Developing B lymphocytes undergo V(D)J recombination to assemble germ-line V, D, and J gene segments into exons that encode the antigen-binding variable region of Ig heavy (H) and light (L) chains. IgH and IgL chains associate to form the B-cell receptor (BCR), which, upon antigen binding, activates B cells to secrete BCR as an antibody. Each of the huge number of clonally independent B cells expresses a unique set of IgH and IgL variable regions. The ability of V(D)J recombination to generate vast primary B-cell repertoires results from a combinatorial assortment of large numbers of different V, D, and J segments, coupled with diversification of the junctions between them to generate the complementary determining region 3 (CDR3) for antigen contact. Approaches to evaluate in depth the content of primary antibody repertoires and, ultimately, to study how they are further molded by secondary mutation and affinity maturation processes are of great importance to the B-cell development, vaccine, and antibody fields. We now describe an unbiased, sensitive, and readily accessible assay, referred to as high-throughput genome-wide translocation sequencing-adapted repertoire sequencing (HTGTS-Rep-seq), to quantify antibody repertoires. HTGTS-Rep-seq quantitatively identifies the vast majority of IgH and IgL V(D)J exons, including their unique CDR3 sequences, from progenitor and mature mouse B lineage cells via the use of specific J primers. HTGTS-Rep-seq also accurately quantifies DJH intermediates and V(D)J exons in either productive or nonproductive configurations. HTGTS-Rep-seq should be useful for studies of human samples, including clonal B-cell expansions, and also for following antibody affinity maturation processes.

  11. High-intensity xenon plasma discharge lamp for bulk-sensitive high-resolution photoemission spectroscopy.

    Science.gov (United States)

    Souma, S; Sato, T; Takahashi, T; Baltzer, P

    2007-12-01

    We have developed a highly brilliant xenon (Xe) discharge lamp operated by microwave-induced electron cyclotron resonance (ECR) for ultrahigh-resolution bulk-sensitive photoemission spectroscopy (PES). We observed at least eight strong radiation lines from neutral or singly ionized Xe atoms in the energy region of 8.4-10.7 eV. The photon flux of the strongest Xe I resonance line at 8.437 eV is comparable to that of the He Ialpha line (21.218 eV) from the He-ECR discharge lamp. Stable operation for more than 300 h is achieved by efficient air-cooling of a ceramic tube in the resonance cavity. The high bulk sensitivity and high-energy resolution of PES using the Xe lines are demonstrated for some typical materials.

  12. Development of high sensitivity and high speed large size blank inspection system LBIS

    Science.gov (United States)

    Ohara, Shinobu; Yoshida, Akinori; Hirai, Mitsuo; Kato, Takenori; Moriizumi, Koichi; Kusunose, Haruhiko

    2017-07-01

    The production of high-resolution flat panel displays (FPDs) for mobile phones today requires the use of high-quality large-size photomasks (LSPMs). Organic light emitting diode (OLED) displays use several transistors on each pixel for precise current control and, as such, the mask patterns for OLED displays are denser and finer than the patterns for the previous generation displays throughout the entire mask surface. It is therefore strongly demanded that mask patterns be produced with high fidelity and free of defect. To enable the production of a high quality LSPM in a short lead time, the manufacturers need a high-sensitivity high-speed mask blank inspection system that meets the requirement of advanced LSPMs. Lasertec has developed a large-size blank inspection system called LBIS, which achieves high sensitivity based on a laser-scattering technique. LBIS employs a high power laser as its inspection light source. LBIS's delivery optics, including a scanner and F-Theta scan lens, focus the light from the source linearly on the surface of the blank. Its specially-designed optics collect the light scattered by particles and defects generated during the manufacturing process, such as scratches, on the surface and guide it to photo multiplier tubes (PMTs) with high efficiency. Multiple PMTs are used on LBIS for the stable detection of scattered light, which may be distributed at various angles due to irregular shapes of defects. LBIS captures 0.3mμ PSL at a detection rate of over 99.5% with uniform sensitivity. Its inspection time is 20 minutes for a G8 blank and 35 minutes for G10. The differential interference contrast (DIC) microscope on the inspection head of LBIS captures high-contrast review images after inspection. The images are classified automatically.

  13. Determination of carbamate pesticides using micro-solid-phase extraction combined with high-performance liquid chromatography.

    Science.gov (United States)

    Basheer, Chanbasha; Alnedhary, Anass Ali; Rao, B S Madhava; Lee, Hian Kee

    2009-01-09

    We describe a simple and sensitive porous polypropylene membrane-protected micro-solid-phase extraction (mu-SPE) approach for the sample preparation and determination of carbamate pesticides in soil samples by high-performance liquid chromatography. The mu-SPE device consisted of C(18) sorbent held within a porous polypropylene envelope. In order to achieve optimum performance, several extraction parameters were optimized. Under the most favorable conditions, the extraction efficiency of the mu-SPE was very high, with detection limits in the range of 0.01-0.40 ng g(-1). This is more than two orders of magnitude lower than the limits obtained by the United States Environmental Protection Agency Methods 8321A and 8318. A linear relationship was obtained for each analyte in the range of 2 and 200 ng g(-1). The relative standard deviation for the analysis of aged soil samples spiked at 5 ng g(-1) was experiments was satisfactory (relative standard deviations ranged from 4 to 11%), indicating that the method is reliable for routine environmental analysis.

  14. High-resolution melting analysis (HRMA): a highly sensitive inexpensive genotyping alternative for population studies.

    Science.gov (United States)

    Smith, B L; Lu, C-P; Alvarado Bremer, J R

    2010-01-01

    High-resolution melting analysis (HRMA) is a highly sensitive closed-tube genotyping method used primarily in clinical studies. As the method is rapid, inexpensive and amenable to high throughput, we decided to investigate its applicability to population studies. Small amplicons and unlabelled probes were used to genotype the nuclear genes, lactate dehydrogenase-A (ldh-A), myosin light chain-2 (mlc-2), acidic ribosomal phosphoprotein P0 (ARP) and calmodulin (CaM) in populations of swordfish, Xiphias gladius. Results indicate that HRMA is a powerful genotyping tool to study wild populations. © 2009 Blackwell Publishing Ltd.

  15. High incidence of sensitization to ornamental plants in allergic rhinitis.

    Science.gov (United States)

    Mahillon, V; Saussez, S; Michel, O

    2006-09-01

    A few indoor plants have been described as potential allergens, in single case reports of allergic rhinitis. There is no data evaluating the prevalence of allergic sensitization to these plants. The relationship between owning indoor ornamental plants with the risk to be sensitized has been evaluated in atopic rhinitis. A group of 59 patients with allergic rhinitis were submitted to skin prick tests (SPT) using both the leafs of their own plant and commercial extracts of the most frequent airborne allergens. A control group of 15 healthy subjects was tested with the same allergens. While no subject from the control group developed a significant SPT to any of the tested plants, 78% of allergic rhinitis had positive SPT to at least one plant, the most frequent sensitization being Ficus benjamina, yucca, ivy and palm tree. In allergic rhinitis, indoor plants should be considered as potential allergens.

  16. Experimental study on non-woven filamentous fibre micro-filter with high filtration speed.

    Science.gov (United States)

    Niu, Siping; Park, Kisoo; Guerra, Heidi B; Kim, Youngchul

    2015-01-01

    A laboratory study was undertaken to pursue the filter performance of a micro-filter module employing highly porous fibre media under a high filtration rate (≥1,500 m/day), faster than that of any conventional filter process. The effects of filtration rate, head loss, raw water turbidity, and filter aid chemicals on filter performance were analysed. In spite of the extremely high filtration rate, the filter achieved an attractive efficiency, reducing the raw water turbidity by over 80%. As with other filter systems, the filter aid used ((polyaluminium chloride (PAC)) greatly affected the performance of this particular fibre filter. Long-term repetitive runs were additionally carried out to confirm the reproducibility of the filter performance. Also, a comparison was carried out with other high-rate filter systems which are either being tested for use in experimental studies, or are already commercially available. This study reveals that the filter performance under a high filtration speed is still attractive especially as PAC is used. Due to the high porosity of the fibre, the filter had small head loss even though the filtration rate was high. These results ascertain that it is possible to operate the filters with high filtration rate achieving reliable treatment performance.

  17. Preparation and characterization of EPDM-silica nano/micro composites for high voltage insulation applications

    Directory of Open Access Journals (Sweden)

    Ali Muhammad

    2015-03-01

    Full Text Available The rising market for substitute materials in high voltage insulation components is stimulated largely by the need to reduce overall costs. In this respect, polymer insulators offer significant advantages over old traditional materials. In the present research, efforts have been made to quantify the effect of silica (having different particle size nano, micro and hybrid loading on the mechanical and thermal behaviors of Ethylene-Propylene-Diene Monomer (EPDM based high voltage electrical insulations. The fabricated composites were subjected to mechanical, thermal and electrical properties measurements. The results of dielectric strength, surface and volume resistivities showed that all composites had insulator properties, while their mechanical and thermal properties improved considerably. EPDM was compounded with different types of silica in a two roll mill using sulphur cure system. The outcome achieved from the comparative study revealed that the EPDM nanocomposites had enhanced mechanical, thermal and electrical properties even at 5 % loadings.

  18. High accuracy position response calibration method for a micro-channel plate ion detector

    Energy Technology Data Exchange (ETDEWEB)

    Hong, R., E-mail: hongran@uw.edu [Department of Physics and Center for Experimental Nuclear Physics and Astrophysics, University of Washington, Seattle, WA 98195 (United States); High Energy Physics Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Leredde, A. [Physics Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Bagdasarova, Y. [Department of Physics and Center for Experimental Nuclear Physics and Astrophysics, University of Washington, Seattle, WA 98195 (United States); Fléchard, X. [Normandie Univ, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen (France); García, A. [Department of Physics and Center for Experimental Nuclear Physics and Astrophysics, University of Washington, Seattle, WA 98195 (United States); Müller, P. [Physics Division, Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439 (United States); Knecht, A. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland); Liénard, E. [Normandie Univ, ENSICAEN, UNICAEN, CNRS/IN2P3, LPC Caen, 14000 Caen (France); Kossin, M. [Department of Physics, Department of Physics, University of Maryland, College Park, MD 20742 (United States); Sternberg, M.G.; Swanson, H.E.; Zumwalt, D.W. [Department of Physics and Center for Experimental Nuclear Physics and Astrophysics, University of Washington, Seattle, WA 98195 (United States)

    2016-11-01

    We have developed a position response calibration method for a micro-channel plate (MCP) detector with a delay-line anode position readout scheme. Using an in situ calibration mask, an accuracy of 8 µm and a resolution of 85 µm (FWHM) have been achieved for MeV-scale α particles and ions with energies of ∼10 keV. At this level of accuracy, the difference between the MCP position responses to high-energy α particles and low-energy ions is significant. The improved performance of the MCP detector can find applications in many fields of AMO and nuclear physics. In our case, it helps reducing systematic uncertainties in a high-precision nuclear β-decay experiment.

  19. High accuracy position response calibration method for a micro-channel plate ion detector

    Science.gov (United States)

    Hong, R.; Leredde, A.; Bagdasarova, Y.; Fléchard, X.; García, A.; Müller, P.; Knecht, A.; Liénard, E.; Kossin, M.; Sternberg, M. G.; Swanson, H. E.; Zumwalt, D. W.

    2016-11-01

    We have developed a position response calibration method for a micro-channel plate (MCP) detector with a delay-line anode position readout scheme. Using an in situ calibration mask, an accuracy of 8 μm and a resolution of 85 μm (FWHM) have been achieved for MeV-scale α particles and ions with energies of ∼10 keV. At this level of accuracy, the difference between the MCP position responses to high-energy α particles and low-energy ions is significant. The improved performance of the MCP detector can find applications in many fields of AMO and nuclear physics. In our case, it helps reducing systematic uncertainties in a high-precision nuclear β-decay experiment.

  20. Adenosine Triphosphate-sensitive Micro-reentrant Atrial Tachycardia Originating from the Crista Terminalis in a Patient with Chronic Renal Failure due to Thrombotic Thrombocytopenic Purpura

    Directory of Open Access Journals (Sweden)

    Shinya Sugiura, MD

    2009-01-01

    Full Text Available A 57-year-old woman with chronic renal failure due to the thrombotic thrombocytopenic purpura complained of palpitation. A 12-lead ECG showed supraventricular tachycardia with a cycle length of 375 ms. During the electrophysiological study, a tachycardia with a cycle length of 375 ms was reproducibly induced and terminated by atrial extrastimulation. The tachycardia exhibited an inverse relationship between the coupling interval of extrastimulus initiating the tachycardia, and the first postpacing return cycle, as well as an increasing pattern of resetting the tachycardia with an atrial extrastimulus. Ventricular burst pacing during tachycardia produced AV dissociation. Intravenous injections of a low dose (4 mg of adenosine triphosphate (ATP terminated the tachycardia without a preceding atrio-His bundle block. The tachycardia was diagnosed as an ATP-sensitive micro-reentrant atrial tachycardia. Real-time endocardial activation mapping using an electroanatomical mapping system revealed that the earliest activation site of the tachycardia was located at the midlateral portion of the crista terminalis. The tachycardia was abolished by focal ablation targeting the earliest activation site during tachycardia. This is the first reported case of an ATP-sensitive micro-reentrant atrial tachycardia associated with thrombotic thrombocytopenic purpura.

  1. Development of High Temperature/High Sensitivity Novel Chemical Resistive Sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Chunrui [Univ. of Texas, San Antonio, TX (United States); Enriquez, Erik [Univ. of Texas, San Antonio, TX (United States); Wang, Haibing [Univ. of Texas, San Antonio, TX (United States); Xu, Xing [Univ. of Texas, San Antonio, TX (United States); Bao, Shangyong [Univ. of Texas, San Antonio, TX (United States); Collins, Gregory [Univ. of Texas, San Antonio, TX (United States)

    2013-08-13

    The research has been focused to design, fabricate, and develop high temperature/high sensitivity novel multifunctional chemical sensors for the selective detection of fossil energy gases used in power and fuel systems. By systematically studying the physical properties of the LnBaCo2O5+d (LBCO) [Ln=Pr or La] thin-films, a new concept chemical sensor based high temperature chemical resistant change has been developed for the application for the next generation highly efficient and near zero emission power generation technologies. We also discovered that the superfast chemical dynamic behavior and an ultrafast surface exchange kinetics in the highly epitaxial LBCO thin films. Furthermore, our research indicates that hydrogen can superfast diffuse in the ordered oxygen vacancy structures in the highly epitaxial LBCO thin films, which suggest that the LBCO thin film not only can be an excellent candidate for the fabrication of high temperature ultra sensitive chemical sensors and control systems for power and fuel monitoring systems, but also can be an excellent candidate for the low temperature solid oxide fuel cell anode and cathode materials.

  2. Optimizing synchrotron microCT for high-throughput phenotyping of zebrafish

    Science.gov (United States)

    La Rivière, Patrick J.; Clark, Darin; Rojek, Alexandra; Vargas, Phillip; Xiao, Xianghui; DeCarlo, Francesco; Kindlmann, Gordon; Cheng, Keith

    2010-09-01

    We are creating a state-of-the-art 2D and 3D imaging atlas of zebrafish development. The atlas employs both 2D histology slides and 3D benchtop and synchrotron micro CT results. Through this atlas, we expect to document normal and abnormal organogenesis, to reveal new levels of structural detail, and to advance image informatics as a form of systems biology. The zebrafish has become a widely used model organism in biological and biomedical research for studies of vertebrate development and gene function. In this work, we will report on efforts to optimize synchrotron microCT imaging parameters for zebrafish at crucial developmental stages. The aim of these studies is to establish protocols for high-throughput phenotyping of normal, mutant and diseased zebrafish. We have developed staining and embedding protocols using different heavy metal stains (osmium tetroxide and uranyl acetate) and different embedding media (Embed 812 and glycol methacrylate). We have explored the use of edge subtraction and multi-energy techniques for contrast enhancement and we have examined the use of different sample-detector distances with unstained samples to explore and optimize phase-contrast enhancement effects. We will report principally on our efforts to optimize energy choice for single- and multi-energy studies as well as our efforts to optimize the degree of phase contrast enhancement.

  3. Nonlinear dynamic analysis and optimal trajectory planning of a high-speed macro-micro manipulator

    Science.gov (United States)

    Yang, Yi-ling; Wei, Yan-ding; Lou, Jun-qiang; Fu, Lei; Zhao, Xiao-wei

    2017-09-01

    This paper reports the nonlinear dynamic modeling and the optimal trajectory planning for a flexure-based macro-micro manipulator, which is dedicated to the large-scale and high-speed tasks. In particular, a macro- micro manipulator composed of a servo motor, a rigid arm and a compliant microgripper is focused. Moreover, both flexure hinges and flexible beams are considered. By combining the pseudorigid-body-model method, the assumed mode method and the Lagrange equation, the overall dynamic model is derived. Then, the rigid-flexible-coupling characteristics are analyzed by numerical simulations. After that, the microscopic scale vibration excited by the large-scale motion is reduced through the trajectory planning approach. Especially, a fitness function regards the comprehensive excitation torque of the compliant microgripper is proposed. The reference curve and the interpolation curve using the quintic polynomial trajectories are adopted. Afterwards, an improved genetic algorithm is used to identify the optimal trajectory by minimizing the fitness function. Finally, the numerical simulations and experiments validate the feasibility and the effectiveness of the established dynamic model and the trajectory planning approach. The amplitude of the residual vibration reduces approximately 54.9%, and the settling time decreases 57.1%. Therefore, the operation efficiency and manipulation stability are significantly improved.

  4. Ultra-high speed digital micro-mirror device based ptychographic iterative engine method.

    Science.gov (United States)

    Sun, Aihui; He, Xiaoliang; Kong, Yan; Cui, Haoyang; Song, Xiaojun; Xue, Liang; Wang, Shouyu; Liu, Cheng

    2017-07-01

    To reduce the long data acquisition time of the common mechanical scanning based Ptychographic Iterative Engine (PIE) technique, the digital micro-mirror device (DMD) is used to form the fast scanning illumination on the sample. Since the transverse mechanical scanning in the common PIE is replaced by the on/off switching of the micro-mirrors, the data acquisition time can be reduced from more than 15 minutes to less than 20 seconds for recording 12 × 10 diffraction patterns to cover the same field of 147.08 mm(2). Furthermore, since the precision of DMD fabricated with the optical lithography is always higher than 10 nm (1 μm for the mechanical translation stage), the time consuming position-error-correction procedure is not required in the iterative reconstruction. These two improvements fundamentally speed up both the data acquisition and the reconstruction procedures in PIE, and relax its requirements on the stability of the imaging system, therefore remarkably improve its applicability for many practices. It is demonstrated experimentally with both USAF resolution target and biological sample that, the spatial resolution of 5.52 μm and the field of view of 147.08 mm(2) can be reached with the DMD based PIE method. In a word, by using the DMD to replace the translation stage, we can effectively overcome the main shortcomings of common PIE related to the mechanical scanning, while keeping its advantages on both the high resolution and large field of view.

  5. Fabrication of highly porous platinum electrodes for micro-scale applications by pulsed electrodeposition and dealloying

    Science.gov (United States)

    Köhler, Christian; Kloke, Arne; Drzyzga, Anna; Zengerle, Roland; Kerzenmacher, Sven

    2013-11-01

    We present the implementation and optimization of a novel electrodeposition method for the fabrication of highly porous platinum electrodes. It is based on the co-deposition of platinum and copper and the selective dealloying of copper in a pulsed manner. The new process yields mechanically stable platinum electrodes with roughness factors of up to RF = 6500 ± 700, compared to the state-of-the-art cyclic electrodeposition method this corresponds to an improvement in RF by 111%. Furthermore the time demand for fabrication is reduced by 59%, whereas the platinum utilization is increased by 53%. The method is particularly advantageous for applications such as micro fuel cells since it enables the precise deposition of catalytically active electrodes on micro-structured conductive areas. In this context the novel platinum electrodes show higher current densities for the oxidation of formic acid and glucose than state-of-the-art electrodes. In terms of methanol oxidation their catalytic activity is comparable to commercial direct methanol fuel cell (DMFC) electrodes, fabricated from Pt-Ru nanoparticles dispersed on carbon black.

  6. A novel ZVS high voltage power supply for micro-channel plate photomultiplier tubes

    Science.gov (United States)

    Pei, Chengquan; Tian, Jinshou; Liu, Zhen; Qin, Hong; Wu, Shengli

    2017-04-01

    A novel resonant high voltage power supply (HVPS) with zero voltage switching (ZVS), to reduce the voltage stress on switching devices and improve conversion efficiency, is proposed. The proposed HVPS includes a drive circuit, a transformer, several voltage multiplying circuits, and a regulator circuit. The HVPS contains several secondary windings that can be precisely regulated. The proposed HVPS performed better than the traditional resistor voltage divider, which requires replacing matching resistors resulting in resistor dispersibility in the Micro-Channel Plate (MCP). The equivalent circuit of the proposed HVPS was established and the operational principle analyzed. The entire switching element can achieve ZVS, which was validated by a simulation and experiments. The properties of this HVPS were tested including minimum power loss (240 mW), maximum power loss (1 W) and conversion efficiency (85%). The results of this research are that the proposed HVPS was suitable for driving the micro-channel plate photomultiplier tube (MCP-PMT). It was therefore adopted to test the MCP-PMT, which will be used in Daya Bay reactor neutrino experiment II in China.

  7. A novel ZVS high voltage power supply for micro-channel plate photomultiplier tubes

    Energy Technology Data Exchange (ETDEWEB)

    Pei, Chengquan [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China); Tian, Jinshou [Xi’an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi' an 710119 (China); Liu, Zhen [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China); Qin, Hong [School of Computer Science and Technology, Xi' an University of Science and Technology, Xi' an 710054 (China); Wu, Shengli, E-mail: slwu@mail.xjtu.edu.cn [Key Laboratory for Physical Electronics and Devices of the Ministry of Education, Xi' an Jiaotong University, Xi’an 710049 (China)

    2017-04-11

    A novel resonant high voltage power supply (HVPS) with zero voltage switching (ZVS), to reduce the voltage stress on switching devices and improve conversion efficiency, is proposed. The proposed HVPS includes a drive circuit, a transformer, several voltage multiplying circuits, and a regulator circuit. The HVPS contains several secondary windings that can be precisely regulated. The proposed HVPS performed better than the traditional resistor voltage divider, which requires replacing matching resistors resulting in resistor dispersibility in the Micro-Channel Plate (MCP). The equivalent circuit of the proposed HVPS was established and the operational principle analyzed. The entire switching element can achieve ZVS, which was validated by a simulation and experiments. The properties of this HVPS were tested including minimum power loss (240 mW), maximum power loss (1 W) and conversion efficiency (85%). The results of this research are that the proposed HVPS was suitable for driving the micro-channel plate photomultiplier tube (MCP-PMT). It was therefore adopted to test the MCP-PMT, which will be used in Daya Bay reactor neutrino experiment II in China.

  8. High-speed high-sensitivity infrared spectroscopy using mid-infrared swept lasers (Conference Presentation)

    Science.gov (United States)

    Childs, David T. D.; Groom, Kristian M.; Hogg, Richard A.; Revin, Dmitry G.; Cockburn, John W.; Rehman, Ihtesham U.; Matcher, Stephen J.

    2016-03-01

    Infrared spectroscopy is a highly attractive read-out technology for compositional analysis of biomedical specimens because of its unique combination of high molecular sensitivity without the need for exogenous labels. Traditional techniques such as FTIR and Raman have suffered from comparatively low speed and sensitivity however recent innovations are challenging this situation. Direct mid-IR spectroscopy is being speeded up by innovations such as MEMS-based FTIR instruments with very high mirror speeds and supercontinuum sources producing very high sample irradiation levels. Here we explore another possible method - external cavity quantum cascade lasers (EC-QCL's) with high cavity tuning speeds (mid-IR swept lasers). Swept lasers have been heavily developed in the near-infrared where they are used for non-destructive low-coherence imaging (OCT). We adapt these concepts in two ways. Firstly by combining mid-IR quantum cascade gain chips with external cavity designs adapted from OCT we achieve spectral acquisition rates approaching 1 kHz and demonstrate potential to reach 100 kHz. Secondly we show that mid-IR swept lasers share a fundamental sensitivity advantage with near-IR OCT swept lasers. This makes them potentially able to achieve the same spectral SNR as an FTIR instrument in a time x N shorter (N being the number of spectral points) under otherwise matched conditions. This effect is demonstrated using measurements of a PDMS sample. The combination of potentially very high spectral acquisition rates, fundamental SNR advantage and the use of low-cost detector systems could make mid-IR swept lasers a powerful technology for high-throughput biomedical spectroscopy.

  9. High Frequency Quartz Micro Balances: A Promising Path to Enhanced Sensitivity of Gravimetric Sensors

    Directory of Open Access Journals (Sweden)

    Jean M.J. Frèchet

    2006-04-01

    Full Text Available An array of 50 MHz quartz microbalances (QMBs coated with a dendronizedpolymer was used to detect small amounts of volatile organic compounds (VOCs in the gasphase. The results were compared to those obtained with the commonly used 10 MHzQMBs. The 50 MHz QMBs proved to be a powerful tool for the detection of VOCs in thegas phase; therefore, they represent a promising alternative to the much more delicatesurface acoustic wave devices (SAWs.

  10. New Highly-Sensitive Ultra-Performance Liquid Chromatography ...

    African Journals Online (AJOL)

    Purpose: To develop and validate a simple, rapid, sensitive and specific ultraperformance liquid chromatography mass spectrometry method for the quantification of the angiotensin II receptor antagonist, telmisartan (TEL), in human plasma. Methods: After simple protein precipitation using acetonitrile and methanol, TEL and ...

  11. Micro-morphological changes prior to adhesive bonding: high-alumina and glassy-matrix ceramics

    Directory of Open Access Journals (Sweden)

    Marco Cícero Bottino

    2008-06-01

    Full Text Available The aim of this study was to qualitatively demonstrate surface micro-morphological changes after the employment of different surface conditioning methods on high-alumina and glassy-matrix dental ceramics. Three disc-shaped high-alumina specimens (In-Ceram Alumina, INC and 4 glassy-matrix ceramic specimens (Vitadur Alpha, V (diameter: 5 mm and height: 5 mm were manufactured. INC specimens were submitted to 3 different surface conditioning methods: INC1 - Polishing with silicon carbide papers (SiC; INC2 - Chairside air-borne particle abrasion (50 µm Al2O3; INC3 - Chairside silica coating (CoJet; 30 µm SiOx. Vitadur Alpha (V specimens were subjected to 4 different surface conditioning methods: V1 - Polishing with SiC papers; V2 - HF acid etching; V3 - Chairside air-borne particle abrasion (50 µm Al2O3; V4 - Chairside silica coating (30 µm SiOx. Following completion of the surface conditioning methods, the specimens were analyzed using SEM. After polishing with SiC, the surfaces of V specimens remained relatively smooth while those of INC exhibited topographic irregularities. Chairside air-abrasion with either aluminum oxide or silica particles produced retentive patterns on both INC and V specimens, with smoother patterns observed after silica coating. V specimens etched with HF presented a highly porous surface. Chairside tribochemical silica coating resulted in smoother surfaces with particles embedded on the surface even after air-blasting. Surface conditioning using air-borne particle abrasion with either 50 µm alumina or 30 µm silica particles exhibited qualitatively comparable rough surfaces for both INC and V. HF acid gel created the most micro-retentive surface for the glassy-matrix ceramic tested.

  12. Comparison of Chemical Sensitivity of Fresh and Long-Stored Heat Resistant Neosartorya fischeri Environmental Isolates Using BIOLOG Phenotype MicroArray System.

    Directory of Open Access Journals (Sweden)

    Jacek Panek

    Full Text Available Spoilage of heat processed food and beverage by heat resistant fungi (HRF is a major problem for food industry in many countries. Neosartorya fischeri is the leading source of spoilage in thermally processed products. Its resistance to heat processing and toxigenicity makes studies about Neosartorya fischeri metabolism and chemical sensitivity essential. In this study chemical sensitivity of two environmental Neosartorya fischeri isolates were compared. One was isolated from canned apples in 1923 (DSM3700, the other from thermal processed strawberry product in 2012 (KC179765, used as long-stored and fresh isolate, respectively. The study was conducted using Biolog Phenotype MicroArray platforms of chemical sensitivity panel and traditional hole-plate method. The study allowed for obtaining data about Neosartorya fischeri growth inhibitors. The fresh isolate appeared to be much more resistant to chemical agents than the long-stored isolate. Based on phenotype microarray assay nitrogen compounds, toxic cations and membrane function compounds were the most effective in growth inhibition of N. fischeri isolates. According to the study zaragozic acid A, thallium(I acetate and sodium selenate were potent and promising N. fischeri oriented fungicides which was confirmed by both chemical sensitivity microplates panel and traditional hole-plate methods.

  13. Micro-structure Engineering of InGaN/GaN Quantum Wells for High Brightness Light Emitting Devices

    KAUST Repository

    Shen, Chao

    2013-05-01

    With experimental realization of micro-structures, the feasibility of achieving high brightness, low efficiency droop blue LED was implemented based on InGaN/GaN micro-LED-pillar design. A significantly high current density of 492 A/cm2 in a 20 μm diameter (D) micro-LED-pillar was achieved, compared to that of a 200 μm diameter LED (20 A/cm2), both at 10 V bias voltage. In addition, an increase in sustained quantum efficiency from 70.2% to 83.7% at high injection current density (200 A/cm2) was observed in micro-LED-pillars in conjunction with size reduction from 80 μm to 20 μm. A correlation between the strain relief and the electrical performance improvement was established for micro-LED-pillars with D < 50 μm, apart from current spreading effect. The degree of strain relief and its distribution were further studied in micro-LED-pillars with D ranging from 1 μm to 15 μm. Significant wavenumbers down-shifts for E2 and A1 Raman peaks, together with the blue shifted PL peak emission, were observed in as-prepared pillars, reflecting the degree of strain relief. A sharp transition from strained to relaxed epitaxy region was discernible from the competing E2 phonon peaks at 572 cm-1 and 568 cm-1, which were attributed to strain residue and strain relief, respectively. A uniform strain relief at the center of micro-pillars was achieved, i.e. merging of the competing phonon peaks, after Rapid Thermal Annealing (RTA) at 950℃ for 20 seconds, phenomenon of which was observed for the first time. The transition from maximum strain relief to a uniform strain relief was found along the narrow circumference (< 2.5 μm) of the pillars from the line-map of Raman spectroscopy. The extent of strain relief is also examined considering the height (L) of micro-LED-pillars fabricated using FIB micro-machining technique. The significant strain relief of up to 70% (from -1.4 GPa to -0.37 GPa), with a 71 meV PL peak blue shift, suggested that micro-LED-pillar with D < 3 μm and L

  14. Analysis of asymmetric resonance response of thermally excited silicon micro-cantilevers for mass-sensitive nanoparticle detection

    Science.gov (United States)

    Bertke, Maik; Hamdana, Gerry; Wu, Wenze; Suryo Wasisto, Hutomo; Uhde, Erik; Peiner, Erwin

    2017-06-01

    In this paper, the asymmetric resonance frequency (f 0) responses of thermally in-plane excited silicon cantilevers for a pocket-sized, cantilever-based airborne nanoparticle detector (Cantor) are analysed. By measuring the shift of f 0 caused by the deposition of nanoparticles (NPs), the cantilevers are used as a microbalance. The cantilever sensors are low cost manufactured from silicon by bulk-micromachining techniques and contain an integrated p-type heating actuator and a sensing piezoresistive Wheatstone bridge. f 0 is tracked by a homemade phase-locked loop (PPL) for real-time measurements. To optimize the sensor performance, a new cantilever geometry was designed, fabricated and characterized by its frequency responses. The most significant characterisation parameters of our application are f 0 and the quality factor (Q), which have high influences on sensitivity and efficiency of the NP detector. Regarding the asymmetric resonance signal, a novel fitting function based on the Fano resonance replacing the conventionally used function of the simple harmonic oscillator and a method to calculate Q by its fitting parameters were developed for a quantitative evaluation. To obtain a better understanding of the resonance behaviours, we analysed the origin of the asymmetric line shapes. Therefore, we compared the frequency response of the on-chip thermal excitation with an external excitation using an in-plane piezo actuator. In correspondence to the Fano effect, we could reconstruct the measured resonance curves by coupling two signals with constant amplitude and the expected signal of the cantilever, respectively. Moreover, the phase of the measurement signal can be analysed by this method, which is important to understand the locking process of the PLL circuit. Besides the frequency analysis, experimental results and calibration measurements with different particle types are presented. Using the described analysis method, decent results to optimize a next

  15. A CMOS-compatible high aspect ratio silicon-on-glass in-plane micro-accelerometer

    Science.gov (United States)

    Chae, Junseok; Kulah, Haluk; Najafi, Khalil

    2005-02-01

    This paper presents a post-CMOS-compatible micro-machined silicon-on-glass (SOG) in-plane capacitive accelerometer. The accelerometer is a high aspect ratio structure with a 120 µm thick single-crystal silicon proof-mass and 3.4 µm sense gap, bonded to a glass substrate. It is fabricated using a simple 3-mask, 5-step process, and is fully CMOS compatible. A CMOS switched-capacitor readout circuit and an oversampled Σ-Δ modulator are used to read out capacitance changes from the accelerometer. The CMOS chip is 2.6 × 2.4 mm2 in size, utilizes chopper stabilization and correlated double sampling techniques, has a 106 dB open-loop dynamic range, a low input offset of 370 µV, and can resolve better than 20 aF. The accelerometer system has a measured sensitivity of 40 mV g-1 and input referred noise density of 79 µg Hz-1/2. Using the SOG configuration, a post-CMOS monolithic integration technique is developed. The integration technique utilizes dielectric bridges, silicon islands and the SOG configuration to obtain a simple, robust and post-CMOS-compatible process. Utilizing this technique, an integrated SOG accelerometer has been fabricated using the University of Michigan 3 µm CMOS process.

  16. Comprehensive characterization and understanding of micro-fuel cells operating at high methanol concentrations

    Directory of Open Access Journals (Sweden)

    Aldo S. Gago

    2015-10-01

    Full Text Available We report on the analysis of the performance of each electrode of an air-breathing passive micro-direct methanol fuel cell (µDMFC during polarization, stabilization and discharge, with CH3OH (2–20 M. A reference electrode with a microcapillary was used for separately measuring the anode the cathode potential. Information about the open circuit potential (OCP, the voltage and the mass transport related phenomena are available. Using 2 M CH3OH, the anode showed mass transport problems. With 4 and 6 M CH3OH both electrodes experience this situation, whereas with 10 and 20 M CH3OH the issue is attributed to the cathode. The stabilization and fuel consumption time depends mainly on the cathode performance, which is very sensitive to fuel crossover. The exposure to 20 M CH3OH produced a loss in performance of more than 75% of the highest power density (16.3 mW·cm−2.

  17. Silicon nanowires with high-k hafnium oxide dielectrics for sensitive detection of small nucleic acid oligomers.

    Science.gov (United States)

    Dorvel, Brian R; Reddy, Bobby; Go, Jonghyun; Duarte Guevara, Carlos; Salm, Eric; Alam, Muhammad Ashraful; Bashir, Rashid

    2012-07-24

    Nanobiosensors based on silicon nanowire field effect transistors offer advantages of low cost, label-free detection, and potential for massive parallelization. As a result, these sensors have often been suggested as an attractive option for applications in point-of-care (POC) medical diagnostics. Unfortunately, a number of performance issues, such as gate leakage and current instability due to fluid contact, have prevented widespread adoption of the technology for routine use. High-k dielectrics, such as hafnium oxide (HfO(2)), have the known ability to address these challenges by passivating the exposed surfaces against destabilizing concerns of ion transport. With these fundamental stability issues addressed, a promising target for POC diagnostics and SiNWFETs has been small oligonucleotides, more specifically, microRNA (miRNA). MicroRNAs are small RNA oligonucleotides which bind to mRNAs, causing translational repression of proteins, gene silencing, and expressions are typically altered in several forms of cancer. In this paper, we describe a process for fabricating stable HfO(2) dielectric-based silicon nanowires for biosensing applications. Here we demonstrate sensing of single-stranded DNA analogues to their microRNA cousins using miR-10b and miR-21 as templates, both known to be upregulated in breast cancer. We characterize the effect of surface functionalization on device performance using the miR-10b DNA analogue as the target sequence and different molecular weight poly-l-lysine as the functionalization layer. By optimizing the surface functionalization and fabrication protocol, we were able to achieve <100 fM detection levels of the miR-10b DNA analogue, with a theoretical limit of detection of 1 fM. Moreover, the noncomplementary DNA target strand, based on miR-21, showed very little response, indicating a highly sensitive and highly selective biosensing platform.

  18. Highly sensitive lactate biosensor by engineering chitosan/PVI-Os/CNT/LOD network nanocomposite.

    Science.gov (United States)

    Cui, Xiaoqiang; Li, Chang Ming; Zang, Jianfeng; Yu, Shucong

    2007-06-15

    A novel chitosan/PVI-Os(polyvinylimidazole-Os)/CNT(carbon nanotube)/LOD (lactate oxidase) network nanocomposite was constructed on gold electrode for detection of lactate. The composite was nanoengineered by selected matched material components and optimized composition ratio to produce a superior lactate sensor. Positively charged chitosan and PVI-Os were used as the matrix and the mediator to immobilize the negatively charged LOD and to enhance the electron transfer, respectively. CNTs were introduced as the essential component in the composite for the network nanostructure. FESEM (field emission scan electron microscopy) and electrochemical characterization demonstrated that CNT behaved as a cross-linker to network PVI and chitosan due to its nanoscaled and negative charged nature. This significantly improved the conductivity, stability and electroactivity for detection of lactate. The standard deviation of the sensor without CNT in the composite was greatly reduced from 19.6 to 4.9% by addition of CNTs. With optimized conditions the sensitivity and detection limit of the lactate sensor was 19.7 microA mM(-1)cm(-2) and 5 microM, respectively. The sensitivity was remarkably improved in comparison to the newly reported values of 0.15-3.85 microA mM(-1)cm(-2). This novel nanoengineering approach for selecting matched components to form a network nanostructure could be extended to other enzyme biosensors, and to have broad potential applications in diagnostics, life science and food analysis.

  19. Highly sensitive BTX detection using surface functionalized QCM sensor

    Energy Technology Data Exchange (ETDEWEB)

    Bozkurt, Asuman Aşıkoğlu; Özdemir, Okan; Altındal, Ahmet, E-mail: altindal@yildiz.edu.tr [Department of Physics, Yildiz Technical University, Davutpasa, 34210 Istanbul (Turkey)

    2016-03-25

    A novel organic compound was designed and successfully synthesized for the fabrication of QCM based sensors to detect the low concentrations of BTX gases in indoor air. The effect of the long-range electron orbital delocalization on the BTX vapour sensing properties of azo-bridged Pcs based chemiresistor-type sensors have also been investigated in this work. The sensing behaviour of the film for the online detection of volatile organic solvent vapors was investigated by utilizing an AT-cut quartz crystal resonator. It was observed that the adsorption of the target molecules on the coating surface cause a reversible negative frequency shift of the resonator. Thus, a variety of solvent vapors can be detected by using the phthalocyanine film as sensitive coating, with sensitivity in the ppm range and response times in the order of several seconds depending on the molecular structure of the organic solvent.

  20. Extremely high frequency sensitivity in a 'simple' ear.

    Science.gov (United States)

    Moir, Hannah M; Jackson, Joseph C; Windmill, James F C

    2013-08-23

    An evolutionary war is being played out between the bat, which uses ultrasonic calls to locate insect prey, and the moth, which uses microscale ears to listen for the approaching bat. While the highest known frequency of bat echolocation calls is 212 kHz, the upper limit of moth hearing is considered much lower. Here, we show that the greater wax moth, Galleria mellonella, is capable of hearing ultrasonic frequencies approaching 300 kHz; the highest frequency sensitivity of any animal. With auditory frequency sensitivity that is unprecedented in the animal kingdom, the greater wax moth is ready and armed for any echolocation call adaptations made by the bat in the on-going bat-moth evolutionary war.

  1. Extremely high frequency sensitivity in a ‘simple’ ear

    Science.gov (United States)

    Moir, Hannah M.; Jackson, Joseph C.; Windmill, James F. C.

    2013-01-01

    An evolutionary war is being played out between the bat, which uses ultrasonic calls to locate insect prey, and the moth, which uses microscale ears to listen for the approaching bat. While the highest known frequency of bat echolocation calls is 212 kHz, the upper limit of moth hearing is considered much lower. Here, we show that the greater wax moth, Galleria mellonella, is capable of hearing ultrasonic frequencies approaching 300 kHz; the highest frequency sensitivity of any animal. With auditory frequency sensitivity that is unprecedented in the animal kingdom, the greater wax moth is ready and armed for any echolocation call adaptations made by the bat in the on-going bat–moth evolutionary war. PMID:23658005

  2. Highly Sensitive Cadmium Concentration Sensor Using Long Period Grating

    Directory of Open Access Journals (Sweden)

    A. S. Lalasangi

    2011-08-01

    Full Text Available In this paper we have proposed a simple and effective Long Period Grating chemical sensor for detecting the traces of Cadmium (Cd++ in drinking water at ppm level. Long Period gratings (LPG were fabricated by point-by-point technique with CO2 laser. We have characterized the LPG concentration sensor sensitivity for different solutions of Cd concentrations varying from 0.01 ppm to 0.04 ppm by injecting white Light source and observed transmitted spectra using Optical Spectrum Analyzer (OSA. Proper reagents have been used in the solutions for detection of the Cd species. The overall shift in wavelength is 10 nm when surrounding medium gradually changed from water to 0.04 ppm of cadmium concentrations. A comparative study has been done using sophisticated spectroscopic atomic absorption spectrometer (AAS and Inductively Coupled Plasma (ICP instruments. The spectral sensitivity enhancement was done by modifying grating surface with gold nanoparticles.

  3. The strain-rate sensitivity of high-strength high-toughness steels.

    Energy Technology Data Exchange (ETDEWEB)

    Dilmore, M.F. (AFRL/MNMW, Eglin AFB, FL); Crenshaw, Thomas B.; Boyce, Brad Lee

    2006-01-01

    The present study examines the strain-rate sensitivity of four high strength, high-toughness alloys at strain rates ranging from 0.0002 s-1 to 200 s-1: Aermet 100, a modified 4340, modified HP9-4-20, and a recently developed Eglin AFB steel alloy, ES-1c. A refined dynamic servohydraulic method was used to perform tensile tests over this entire range. Each of these alloys exhibit only modest strain-rate sensitivity. Specifically, the strain-rate sensitivity exponent m, is found to be in the range of 0.004-0.007 depending on the alloy. This corresponds to a {approx}10% increase in the yield strength over the 7-orders of magnitude change in strain-rate. Interestingly, while three of the alloys showed a concominant {approx}3-10% drop in their ductility with increasing strain-rate, the ES1-c alloy actually exhibited a 25% increase in ductility with increasing strain-rate. Fractography suggests the possibility that at higher strain-rates ES-1c evolves towards a more ductile dimple fracture mode associated with microvoid coalescence.

  4. A High-Sensitivity Current Sensor Utilizing CrNi Wire and Microfiber Coils

    Directory of Open Access Journals (Sweden)

    Xiaodong Xie

    2014-05-01

    Full Text Available We obtain an extremely high current sensitivity by wrapping a section of microfiber on a thin-diameter chromium-nickel wire. Our detected current sensitivity is as high as 220.65 nm/A2 for a structure length of only 35 μm. Such sensitivity is two orders of magnitude higher than the counterparts reported in the literature. Analysis shows that a higher resistivity or/and a thinner diameter of the metal wire may produce higher sensitivity. The effects of varying the structure parameters on sensitivity are discussed. The presented structure has potential for low-current sensing or highly electrically-tunable filtering applications.

  5. Highly Sensitive Sensors Based on Photonic Crystal Fiber Modal Interferometers

    Directory of Open Access Journals (Sweden)

    Joel Villatoro

    2009-01-01

    Full Text Available We review the research on photonic crystal fiber modal interferometers with emphasis placed on the characteristics that make them attractive for different sensing applications. The fabrication of such interferometers is carried out with different post-processing techniques such as grating inscription, tapering or cleaving, and splicing. In general photonic crystal fiber interferometers exhibit low thermal sensitivity while their applications range from sensing strain or temperature to refractive index and volatile organic compounds.

  6. Improvement in the light sensitivity of the ultrahigh-speed high-sensitivity CCD with a microlens array

    Science.gov (United States)

    Hayashida, T.,; Yonai, J.; Kitamura, K.; Arai, T.; Kurita, T.; Tanioka, K.; Maruyama, H.; Etoh, T. Goji; Kitagawa, S.; Hatade, K.; Yamaguchi, T.; Takeuchi, H.; Iida, K.

    2008-02-01

    We are advancing the development of ultrahigh-speed, high-sensitivity CCDs for broadcast use that are capable of capturing smooth slow-motion videos in vivid colors even where lighting is limited, such as at professional baseball games played at night. We have already developed a 300,000 pixel, ultrahigh-speed CCD, and a single CCD color camera that has been used for sports broadcasts and science programs using this CCD. However, there are cases where even higher sensitivity is required, such as when using a telephoto lens during a baseball broadcast or a high-magnification microscope during science programs. This paper provides a summary of our experimental development aimed at further increasing the sensitivity of CCDs using the light-collecting effects of a microlens array.

  7. High-sensitivity damage detection based on enhanced nonlinear dynamics

    Science.gov (United States)

    Epureanu, Bogdan I.; Yin, Shih-Hsun; Derriso, Mark M.

    2005-04-01

    One of the most important aspects of detecting damage in the framework of structural health monitoring is increasing the sensitivity of the monitored feature to the presence, location, and extent of damage. Distinct from previous techniques of obtaining information about the monitored structure—such as measuring frequency response functions—the approach proposed herein is based on an active interrogation of the system. This interrogation approach allows for the embedding of the monitored system within a larger system by means of a nonlinear feedback excitation. The dynamics of the larger system is then analyzed in state space, and the shape of the attractor of its dynamics is used as a complex geometric feature which is very sensitive to damage. The proposed approach is implemented for monitoring the structural integrity of a panel forced by transverse loads and undergoing limit cycle oscillations and chaos. The nonlinear von Karman plate theory is used to obtain a model for the panel combined with a nonlinear feedback excitation. The presence of damage is modeled as loss of stiffness of various levels in a portion of the plate at various locations. The sensitivity of the proposed approach to parametric changes is shown to be an effective tool in detecting damages. An earlier version was presented at the SPIE 11th International Symposium on Smart Structures and Materials.

  8. Economical Alternatives for High Sensitivity in Atomic Spectrometry Laboratory

    Directory of Open Access Journals (Sweden)

    O. Yavuz Ataman

    2007-12-01

    Full Text Available The most commonly used analytical tools for determination of elements at trace levels are atomic absorption spectrometry (AAS, inductively coupled plasma, optical emission and mass spectrometry (ICP-OES and ICP-MS and atomic fluorescence spectrometry (AFS. Although sensitive plasma techniques are becoming predominant in most of the western laboratories, AAS keeps its importance in developing countries. Simple and inexpensive ways of enhancing sensitivity will be described for laboratories equipped with only a flame AA spectrometer. Although there are many chemical preconcentration procedures to improve sensitivity of flame AAS, only some atom trapping techniques will be included here. One kind of atom trapping device is a slotted quartz tube (SQT used for in situ preconcentration of analyte species followed by a rapid revolatilization cycle to obtain an enhanced signal. These devices provide limits of detection at a level of µg L-1. Another kind of atom trapping involves use of vapor generation technique and quartz or tungsten atom trapping surfaces. The analytical steps consist of the generation of volatile species, usually by hydride formation using NaBH4, trapping these species at the surface of an atom trap held at an optimized temperature and finally re-volatilizing analyte species by rapid heating of trap. These species are transported using a carrier gas to an externally heated quartz tube as commonly used in hydride generation AAS systems; a transient signal is formed and measured. These traps have limits of detection in the order of ng L-1.

  9. Development of sealed sample containers and high resolution micro-tomography

    Energy Technology Data Exchange (ETDEWEB)

    Uesugi, Kentaro, E-mail: ueken@spring8.or.jp; Takeuchi, Akihisa; Suzuki, Yoshio [Japan synchrotron radiation research institute, JASRI/SPring-8 Kouto 1-1-1, Sayo, Hyogo 679-5198 Japan (Japan); Uesugi, Masayuki [Japan Aerospace Exploration Agency (ISAS/JAXA), Sagamihara, Kanagawa 252-5210 (Japan); Hamada, Hiroshi [NTT Advanced technology Corporation, Atsugi, Kanagawa 243-0124 (Japan)

    2016-01-28

    A sample container and a high resolution micro-tomography system have been developed at BL47XU at SPring-8. The container is made of a SiN membrane in a shape of truncated pyramid, which makes it possible to exclude oxygen and moisture in the air. The sample rotation stage for tomography is set downward to keep the sample in the container without any glue. The spatial resolution and field of view are 300 nm and 110 μm using a Fresnel zone plate objective with an outermost zone width of 100 nm at 8 keV, respectively. The scan time is about 20 minutes for 1800 projections. A 3-D image of an asteroid particle was successfully obtained without adhesive and contamination.

  10. A high rate, low radiation length Micro-Vertex-Detector for the P¯ANDA experiment

    Science.gov (United States)

    Stockmanns, Tobias

    2011-09-01

    The Micro-Vertex-Detector (MVD) of the P¯ANDA experiment is the innermost tracking detector. Its most challenging task is the identification of D-meson pairs by their delayed decay point which is about 100- 500 μm from the production point. In addition to the necessary high spatial resolution, it needs a time resolution on the order of 10 ns, a moderate radiation hardness, an untriggered readout of hit data up to 500 MBit/s and a low radiation length. To meet these challenging requirements an intense R&D program is ongoing on all parts of the MVD. This article gives an overview of the ongoing technical developments with a focus on the pixel part of the project.

  11. Development of high energy micro-tomography system at SPring-8

    Science.gov (United States)

    Uesugi, Kentaro; Hoshino, Masato

    2017-09-01

    A high energy X-ray micro-tomography system has been developed at BL20B2 in SPring-8. The available range of the energy is between 20keV and 113keV with a Si (511) double crystal monochromator. The system enables us to image large or heavy materials such as fossils and metals. The X-ray image detector consists of visible light conversion system and sCMOS camera. The effective pixel size is variable by changing a tandem lens between 6.5 μm/pixel and 25.5 μm/pixel discretely. The format of the camera is 2048 pixels x 2048 pixels. As a demonstration of the system, alkaline battery and a nodule from Bolivia were imaged. A detail of the structure of the battery and a female mold Trilobite were successfully imaged without breaking those fossils.

  12. Fluorescent Magnetic Silica Nanotubes with High Photostability Prepared by the Conventional Reverse Micro-Emulsion Method

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yuhai; Son, Sang Jun [Gachon Univ., Seongnam (Korea, Republic of)

    2012-12-15

    Magnetic fluorescent silica nanotubes were fabricated using reverse micro-emulsions coupled with conventional sol-gel methods. Anodic aluminum oxide templates were used to separate spatially the magnetic and the fluorescent moieties on individual nanotubes and so prevent quenching of the fluorescence. C18 and fluorescent layers were deposited sequentially on silica. Magnetism was then obtained by the introduction of pre-made magnetic nanoparticles inside the nanotubes. The photo- and chemical stabilities of nanotubes were demonstrated through dye release and photobleaching tests. The produced nanotubes did not show fluorescence quenching upon the addition of the nanoparticles, an advantage over conventional spherical fluorescent magnetic nanoparticles. High photostability of nanotubes, magnetism and biocompatiblily make them potentially useful in bioanalysis.

  13. μTAS (micro total analysis systems) for the high-throughput measurement of nanomaterial solubility

    Science.gov (United States)

    Tantra, R.; Jarman, J.

    2013-04-01

    There is a consensus in the nanoecotoxicology community that better analytical tools i.e. faster and more accurate ones, are needed for the physicochemical characterisation of nanomaterials in environmentally/biologically relevant media. In this study, we introduce the concept of μTAS (Micro Total Analysis Systems), which was a term coined to encapsulate the integration of laboratory processes on a single microchip. Our focus here is on the use of a capillary electrophoresis (CE) with conductivity detection microchip and how this may be used for the measurement of dissolution of metal oxide nanomaterials. Our preliminary results clearly show promise in that the device is able to: a) measure ionic zinc in various ecotox media with high selectivity b) track the dynamic dissolution events of zinc oxide (ZnO) nanomaterial when dispersed in fish medium.

  14. High-fidelity X-ray micro-tomography reconstruction of siderite-hosted Carboniferous arachnids

    Science.gov (United States)

    Garwood, Russell; Dunlop, Jason A.; Sutton, Mark D.

    2009-01-01

    A new approach to maximize data recovery from siderite-hosted fossils is presented. Late Carboniferous trigonotarbids (Arachnida: Trigonotarbida) from Coseley, UK, were chosen to assess the potential of high-resolution X-ray micro-tomography (XMT). Three-dimensional computer reconstruction visualizes the animals at 20 µm or better resolution, resolving subtle and previously unseen details. Novel data recovered includes (possibly plesiomorphic) retention of endites on leg coxae of Cryptomartus hindi (Anthracomartidae) and highlights further similarities between this family and the Devonian Palaeocharinidae. Also revealed is a flattened body with robust anterior limbs, implying a hunting stance similar to modern crab spiders (Thomisidae). Eophrynus prestvicii (Eophrynidae) had more gracile limbs but a heavily ornamented body, with newly identified upward-pointing marginal spines on the opisthosoma. Its habitus is comparable with certain modern laniatorid harvestmen (Opiliones). These findings demonstrate the potential of XMT to revolutionize the study of siderite-hosted Coal Measures fossils. PMID:19656861

  15. High-fidelity X-ray micro-tomography reconstruction of siderite-hosted Carboniferous arachnids.

    Science.gov (United States)

    Garwood, Russell; Dunlop, Jason A; Sutton, Mark D

    2009-12-23

    A new approach to maximize data recovery from siderite-hosted fossils is presented. Late Carboniferous trigonotarbids (Arachnida: Trigonotarbida) from Coseley, UK, were chosen to assess the potential of high-resolution X-ray micro-tomography (XMT). Three-dimensional computer reconstruction visualizes the animals at 20 microm or better resolution, resolving subtle and previously unseen details. Novel data recovered includes (possibly plesiomorphic) retention of endites on leg coxae of Cryptomartus hindi (Anthracomartidae) and highlights further similarities between this family and the Devonian Palaeocharinidae. Also revealed is a flattened body with robust anterior limbs, implying a hunting stance similar to modern crab spiders (Thomisidae). Eophrynus prestvicii (Eophrynidae) had more gracile limbs but a heavily ornamented body, with newly identified upward-pointing marginal spines on the opisthosoma. Its habitus is comparable with certain modern laniatorid harvestmen (Opiliones). These findings demonstrate the potential of XMT to revolutionize the study of siderite-hosted Coal Measures fossils.

  16. High throughput soft embossing process for micro-patterning of PEDOT thin films

    DEFF Research Database (Denmark)

    Fanzio, Paola; Cagliani, Alberto; Peterffy, Kristof G.

    2017-01-01

    has been characterized, finding that a post-processing treatment with Ethylene Glycol allows an increase in conductivity and a decrease in water solubility of the PEDOT film. Finally, cyclic voltammetry demonstrates that the post-treatment also ensures the electrochemical activity of the film. Our...... polymer poly(3,4-ethylenedioxythiophene) (PEDOT) by means of a low cost and high throughput soft embossing process. We were able to reproduce a functional conductive pattern with a minimum dimension of 1 μm and to fabricate electrically decoupled electrodes. Moreover, the conductivity of the PEDOT films...... technology offers a facile solution for the patterning of organic conductors with resolution in the micro scale, and can be the basis for the realization and development of polymeric microdevices with electrical and electrochemical functionalities....

  17. Improvements toward highly accurate diffraction experiments at the macromolecular micro-crystallography beamline BL-17A.

    Science.gov (United States)

    Yamada, Yusuke; Chavas, Leonard M G; Igarashi, Noriyuki; Hiraki, Masahiko; Wakatsuki, Soichi; Matsugaki, Naohiro

    2013-11-01

    BL-17A is a macromolecular crystallography beamline dedicated to diffraction experiments conducted using micro-crystals and structure determination studies using a lower energy X-ray beam. In these experiments, highly accurate diffraction intensity measurements are definitively important. Since this beamline was constructed, the beamline apparatus has been improved in several ways to enable the collection of accurate diffraction data. The stability of the beam intensities at the sample position was recently improved by modifying the monochromator. The diffractometer has also been improved. A new detector table was installed to prevent distortions in the diffractometer's base during the repositioning of the diffractometer detector. A new pinhole system and an on-axis viewing system were installed to improve the X-ray beam profile at the sample position and the centering of tiny crystal samples.

  18. Numerical investigation of fluid flow and heat transfer under high heat flux using rectangular micro-channels

    KAUST Repository

    Mansoor, Mohammad M.

    2012-02-01

    A 3D-conjugate numerical investigation was conducted to predict heat transfer characteristics in a rectangular cross-sectional micro-channel employing simultaneously developing single-phase flows. The numerical code was validated by comparison with previous experimental and numerical results for the same micro-channel dimensions and classical correlations based on conventional sized channels. High heat fluxes up to 130W/cm 2 were applied to investigate micro-channel thermal characteristics. The entire computational domain was discretized using a 120×160×100 grid for the micro-channel with an aspect ratio of (α=4.56) and examined for Reynolds numbers in the laminar range (Re 500-2000) using FLUENT. De-ionized water served as the cooling fluid while the micro-channel substrate used was made of copper. Validation results were found to be in good agreement with previous experimental and numerical data [1] with an average deviation of less than 4.2%. As the applied heat flux increased, an increase in heat transfer coefficient values was observed. Also, the Reynolds number required for transition from single-phase fluid to two-phase was found to increase. A correlation is proposed for the results of average Nusselt numbers for the heat transfer characteristics in micro-channels with simultaneously developing, single-phase flows. © 2011 Elsevier Ltd.

  19. Micro-seismicity in the Gulf of Cadiz: Is there a link between micro-seismicity, high magnitude earthquakes and active faults?

    Science.gov (United States)

    Silva, Sónia; Terrinha, Pedro; Matias, Luis; Duarte, João C.; Roque, Cristina; Ranero, César R.; Geissler, Wolfram H.; Zitellini, Nevio

    2017-10-01

    The Gulf of Cadiz seismicity is characterized by persistent low to intermediate magnitude earthquakes, occasionally punctuated by high magnitude events such as the M 8.7 1755 Great Lisbon earthquake and the M = 7.9 event of February 28th, 1969. Micro-seismicity was recorded during 11 months by a temporary network of 25 ocean bottom seismometers (OBSs) in an area of high seismic activity, encompassing the potential source areas of the mentioned large magnitude earthquakes. We combined micro-seismicity analysis with processing and interpretation of deep crustal seismic reflection profiles and available refraction data to investigate the possible tectonic control of the seismicity in the Gulf of Cadiz area. Three controlling mechanisms are explored: i) active tectonic structures, ii) transitions between different lithospheric domains and inherited Mesozoic structures, and iii) fault weakening mechanisms. Our results show that micro-seismicity is mostly located in the upper mantle and is associated with tectonic inversion of extensional rift structures and to the transition between different lithospheric/rheological domains. Even though the crustal structure is well imaged in the seismic profiles and in the bathymetry, crustal faults show low to negligible seismic activity. A possible explanation for this is that the crustal thrusts are thin-skinned structures rooting in relatively shallow sub-horizontal décollements associated with (aseismic) serpentinization levels at the top of the lithospheric mantle. Therefore, co-seismic slip along crustal thrusts may only occur during large magnitude events, while for most of the inter-seismic cycle these thrusts remain locked, or slip aseismically. We further speculate that high magnitude earthquake's ruptures may only nucleate in the lithospheric mantle and then propagate into the crust across the serpentinized layers.

  20. High-performance and high-sensitivity applications of graphene transistors with self-assembled monolayers.

    Science.gov (United States)

    Yeh, Chao-Hui; Kumar, Vinod; Moyano, David Ricardo; Wen, Shao-Hsuan; Parashar, Vyom; Hsiao, She-Hsin; Srivastava, Anchal; Saxena, Preeti S; Huang, Kun-Ping; Chang, Chien-Chung; Chiu, Po-Wen

    2016-03-15

    Charge impurities and polar molecules on the surface of dielectric substrates has long been a critical obstacle to using graphene for its niche applications that involve graphene's high mobility and high sensitivity nature. Self-assembled monolayers (SAMs) have been found to effectively reduce the impact of long-range scatterings induced by the external charges. Yet, demonstrations of scalable device applications using the SAMs technique remains missing due to the difficulties in the device fabrication arising from the strong surface tension of the modified dielectric environment. Here, we use patterned SAM arrays to build graphene electronic devices with transport channels confined on the modified areas. For high-mobility applications, both rigid and flexible radio-frequency graphene field-effect transistors (G-FETs) were demonstrated, with extrinsic cutoff frequency and maximum oscillation frequency enhanced by a factor of ~2 on SiO2/Si substrates. For high sensitivity applications, G-FETs were functionalized by monoclonal antibodies specific to cancer biomarker chondroitin sulfate proteoglycan 4, enabling its detection at a concentration of 0.01 fM, five orders of magnitude lower than that detectable by a conventional colorimetric assay. These devices can be very useful in the early diagnosis and monitoring of a malignant disease. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. High-sensitivity, portable, tunable imaging X-ray spectrometer based on a spherical crystal and MCP

    CERN Document Server

    Monot, P; Dobosz, S; D'Oliveira, P; Hulin, S; Bougeard, M; Faenov, A Y; Pikuz, T A; Skobelev, I Y

    2002-01-01

    A portable (200x100x100 mm sup 3), high-luminosity, spherically bent crystal spectrometer was designed to measure very low emissivity X-ray spectra of different elements with spatial resolution in a wide spectral range (1.2-19.6 A). A large (50x15 mm sup 2) open aperture mica spherically bent crystal with R=150 mm was used as dispersive and focusing element. This spectrometer was associated with a large sensitive area (phi=40 mm) micro-channel plates assembly. This apparatus provides simultaneously high spectral (lambda/delta lambda approx 1800) and spatial (100-200 mu m) resolutions. Its large tunability allowed, without any adjustment of the spectrometer set-up, to record spectra in the 1.38-17.5 A wavelength range. We used the X-ray emission of femtosecond laser-produced plasmas from different materials ((CF sub 2) sub n , CaF sub 2 , Cu, Al) to test the spectrometer. Thanks to the high sensitivity (high collection efficiency) of the system, high quality space-resolved X-ray spectra of Fluorine and Aluminu...

  2. Process Capability of High Speed Micro End-Milling of Inconel 718 with Minimum Quantity Lubrication

    Science.gov (United States)

    Rahman, Mohamed Abd; Yeakub Ali, Mohammad; Rahman Shah Rosli, Abdul; Banu, Asfana

    2017-03-01

    The demand for micro-parts is expected to grow and micro-machining has been shown to be a viable manufacturing process to produce these products. These micro-products may be produced from hard-to-machine materials such as superalloys under little or no metal cutting fluids to reduce machining cost or drawbacks associated with health and environment. This project aims to investigate the capability of micro end-milling process of Inconel 718 with minimum quantity lubrication (MQL). Microtools DT-110 multi-process micro machine was used to machine 10 micro-channels with MQL and 10 more under dry condition while maintaining the same machining parameters. The width of the micro-channels was measured using digital microscope and used to determine the process capability indices, Cp and Cpk. QI Macros SPC for Excel was used to analyze the resultant machining data. The results indicated that micro end-milling process of Inconel 718 was not capable under both MQL and dry cutting conditions as indicated by the Cp values of less than 1.0. However, the use of MQL helped the process to be more stable and capable. Results obtained showed that the process variation was greatly reduced by using MQL in micro end-milling of Inconel 718.

  3. High mass resolution time of flight mass spectrometer for measuring products in heterogeneous catalysis in highly sensitive microreactors

    DEFF Research Database (Denmark)

    Andersen, Thomas; Jensen, Robert; Christensen, M. K.

    2012-01-01

    We demonstrate a combined microreactor and time of flight system for testing and characterization of heterogeneous catalysts with high resolution mass spectrometry and high sensitivity. Catalyst testing is performed in silicon-based microreactors which have high sensitivity and fast thermal...

  4. Design, fabrication and characterization of a high-sensitivity pressure sensor based on nano-polysilicon thin film transistors

    Science.gov (United States)

    Zhao, Xiaofeng; Yu, Yang; Li, Dandan; Wen, Dianzhong

    2015-12-01

    Based on the nano-polysilicon thin film transistors (TFTs), a high-sensitivity pressure sensor was designed and fabricated in this paper. The pressure sensing element is composed of a Wheatstone bridge with four nano-polysilicon TFTs designed on different positions of the square silicon diaphragm. Via taking the four channel resistors of the TFTs as piezoresistors, the measurement to the external pressure can be realized according to the piezoresistive effects of channel layer. Through adopting complementary metal oxide semiconductor (CMOS) technology and micro-electromechanical system (MEMS) technology, the chips of sensor were fabricated on orientation silicon wafer with a high resistivity. At room temperature, when applying a voltage 5.0 V to the Wheatstone bridge, the full scale (100 kPa) output voltage and the sensitivity of the sensor with 35 μm-thick silicon diaphragm are 267 mV and 2.58 mV/kPa, respectively. The experimental results show that the pressure sensors can achieve a much higher sensitivity.

  5. Design, fabrication and characterization of a high-sensitivity pressure sensor based on nano-polysilicon thin film transistors

    Directory of Open Access Journals (Sweden)

    Xiaofeng Zhao

    2015-12-01

    Full Text Available Based on the nano-polysilicon thin film transistors (TFTs, a high-sensitivity pressure sensor was designed and fabricated in this paper. The pressure sensing element is composed of a Wheatstone bridge with four nano-polysilicon TFTs designed on different positions of the square silicon diaphragm. Via taking the four channel resistors of the TFTs as piezoresistors, the measurement to the external pressure can be realized according to the piezoresistive effects of channel layer. Through adopting complementary metal oxide semiconductor (CMOS technology and micro-electromechanical system (MEMS technology, the chips of sensor were fabricated on orientation silicon wafer with a high resistivity. At room temperature, when applying a voltage 5.0 V to the Wheatstone bridge, the full scale (100 kPa output voltage and the sensitivity of the sensor with 35 μm-thick silicon diaphragm are 267 mV and 2.58 mV/kPa, respectively. The experimental results show that the pressure sensors can achieve a much higher sensitivity.

  6. Highly sensitive measurement of submicron waveguides based on Brillouin scattering

    Science.gov (United States)

    Godet, Adrien; Ndao, Abdoulaye; Sylvestre, Thibaut; Beugnot, Jean-Charles; Phan Huy, Kien

    2017-02-01

    Fabrication and characterization of submicron optical waveguides is one of the major challenges in modern photonics, as they find many applications from optical sensors to plasmonic devices. Here we report on a novel technique that allows for a complete and precise characterization of silica optical nanofibers. Our method relies on the Brillouin backscattering spectrum analysis that directly depends on the waveguide geometry. Our method was applied to several fiber tapers with diameter ranging from 500 nm to 3 μm. Results were compared to scanning electron microscopy (SEM) images and numerical simulations with very good agreement and similar sensitivity.

  7. Extremely high frequency sensitivity in a ‘simple’ ear

    OpenAIRE

    Moir, Hannah M.; Jackson, Joseph C.; Windmill, James F. C.

    2013-01-01

    An evolutionary war is being played out between the bat, which uses ultrasonic calls to locate insect prey, and the moth, which uses microscale ears to listen for the approaching bat. While the highest known frequency of bat echolocation calls is 212 kHz, the upper limit of moth hearing is considered much lower. Here, we show that the greater wax moth, Galleria mellonella, is capable of hearing ultrasonic frequencies approaching 300 kHz; the highest frequency sensitivity of any animal. With a...

  8. The Relationship between Ethical Sensitivity, High Ability and Gender in Higher Education Students

    Science.gov (United States)

    Schutte, Ingrid; Wolfensberger, Marca; Tirri, Kirsi

    2014-01-01

    This study examined the ethical sensitivity of high-ability undergraduate students (n=731) in the Netherlands who completed the 28-item Ethical Sensitivity Scale Questionnaire (ESSQ) developed by Tirri & Nokelainen (2007; 2011). The ESSQ is based on Narvaez' (2001) operationalization of ethical sensitivity in seven dimensions. The following…

  9. Analysis of Cyberbullying Sensitivity Levels of High School Students and Their Perceived Social Support Levels

    Science.gov (United States)

    Akturk, Ahmet Oguz

    2015-01-01

    Purpose: The purpose of this paper is to determine the cyberbullying sensitivity levels of high school students and their perceived social supports levels, and analyze the variables that predict cyberbullying sensitivity. In addition, whether cyberbullying sensitivity levels and social support levels differed according to gender was also…

  10. Ultra-fast processing of gigapixel Tissue MicroArray images using high performance computing.

    Science.gov (United States)

    Wang, Yinhai; McCleary, David; Wang, Ching-Wei; Kelly, Paul; James, Jackie; Fennell, Dean A; Hamilton, Peter W

    2011-10-01

    Tissue MicroArrays (TMAs) are a valuable platform for tissue based translational research and the discovery of tissue biomarkers. The digitised TMA slides or TMA Virtual Slides, are ultra-large digital images, and can contain several hundred samples. The processing of such slides is time-consuming, bottlenecking a potentially high throughput platform. A High Performance Computing (HPC) platform for the rapid analysis of TMA virtual slides is presented in this study. Using an HP high performance cluster and a centralised dynamic load balancing approach, the simultaneous analysis of multiple tissue-cores were established. This was evaluated on Non-Small Cell Lung Cancer TMAs for complex analysis of tissue pattern and immunohistochemical positivity. The automated processing of a single TMA virtual slide containing 230 patient samples can be significantly speeded up by a factor of circa 22, bringing the analysis time to one minute. Over 90 TMAs could also be analysed simultaneously, speeding up multiplex biomarker experiments enormously. The methodologies developed in this paper provide for the first time a genuine high throughput analysis platform for TMA biomarker discovery that will significantly enhance the reliability and speed for biomarker research. This will have widespread implications in translational tissue based research.

  11. High Packing Density Unidirectional Arrays of Vertically Aligned Graphene with Enhanced Areal Capacitance for High-Power Micro-Supercapacitors.

    Science.gov (United States)

    Zheng, Shuanghao; Li, Zhilin; Wu, Zhong-Shuai; Dong, Yanfeng; Zhou, Feng; Wang, Sen; Fu, Qiang; Sun, Chenglin; Guo, Liwei; Bao, Xinhe

    2017-04-25

    Interfacial integration of a shape-engineered electrode with a strongly bonded current collector is the key for minimizing both ionic and electronic resistance and then developing high-power supercapacitors. Herein, we demonstrated the construction of high-power micro-supercapacitors (VG-MSCs) based on high-density unidirectional arrays of vertically aligned graphene (VG) nanosheets, derived from a thermally decomposed SiC substrate. The as-grown VG arrays showed a standing basal plane orientation grown on a (0001̅) SiC substrate, tailored thickness (3.5-28 μm), high-density structurally ordering alignment of graphene consisting of 1-5 layers, vertically oriented edges, open intersheet channels, high electrical conductivity (192 S cm(-1)), and strong bonding of the VG edges to the SiC substrate. As a result, the demonstrated VG-MSCs displayed a high areal capacitance of ∼7.3 mF cm(-2) and a fast frequency response with a short time constant of 9 ms. Furthermore, VG-MSCs in both an aqueous polymer gel electrolyte and nonaqueous ionic liquid of 1-ethyl-3-methylimidazolium tetrafluoroborate operated well at high scan rates of up to 200 V s(-1). More importantly, VG-MSCs offered a high power density of ∼15 W cm(-3) in gel electrolyte and ∼61 W cm(-3) in ionic liquid. Therefore, this strategy of producing high-density unidirectional VG nanosheets directly bonded on a SiC current collector demonstrated the feasibility of manufacturing high-power compact supercapacitors.

  12. Highly sensitive, self-powered and wearable electronic skin based on pressure-sensitive nanofiber woven fabric sensor.

    Science.gov (United States)

    Zhou, Yuman; He, Jianxin; Wang, Hongbo; Qi, Kun; Nan, Nan; You, Xiaolu; Shao, Weili; Wang, Lidan; Ding, Bin; Cui, Shizhong

    2017-10-11

    The wearable electronic skin with high sensitivity and self-power has shown increasing prospects for applications such as human health monitoring, robotic skin, and intelligent electronic products. In this work, we introduced and demonstrated a design of highly sensitive, self-powered, and wearable electronic skin based on a pressure-sensitive nanofiber woven fabric sensor fabricated by weaving PVDF electrospun yarns of nanofibers coated with PEDOT. Particularly, the nanofiber woven fabric sensor with multi-leveled hierarchical structure, which significantly induced the change in contact area under ultra-low load, showed combined superiority of high sensitivity (18.376 kPa-1, at ~100 Pa), wide pressure range (0.002-10 kPa), fast response time (15 ms) and better durability (7500 cycles). More importantly, an open-circuit voltage signal of the PPNWF pressure sensor was obtained through applying periodic pressure of 10 kPa, and the output open-circuit voltage exhibited a distinct switching behavior to the applied pressure, indicating the wearable nanofiber woven fabric sensor could be self-powered under an applied pressure. Furthermore, we demonstrated the potential application of this wearable nanofiber woven fabric sensor in electronic skin for health monitoring, human motion detection, and muscle tremor detection.

  13. Custom-made micro applicators for high-dose-rate brachytherapy treatment of chronic psoriasis

    Directory of Open Access Journals (Sweden)

    Ivan M. Buzurovic

    2017-06-01

    Full Text Available Purpose: In this study, we present the treatment of the psoriatic nail beds of patients refractory to standard therapies using high-dose-rate (HDR brachytherapy. The custom-made micro applicators (CMMA were designed and constructed for radiation dose delivery to small curvy targets with complicated topology. The role of the HDR brachytherapy treatment was to stimulate the T cells for an increased immune response. Material and methods: The patient diagnosed with psoriatic nail beds refractory to standard therapies received monthly subunguinal injections that caused significant pain and discomfort in both hands. The clinical target was defined as the length from the fingertip to the distal interphalangeal joint. For the accurate and reproducible setup in the multi-fractional treatment delivery, the CMMAs were designed. Five needles were embedded into the dense plastic mesh and covered with 5 mm bolus material for each micro applicator. Five CMMAs were designed, resulting in the usage of 25 catheters in total. Results: The prescription dose was planned to the depth of the anterior surface of the distal phalanx, allowing for the sparing of the surrounding tissue. The total number of the active dwell positions was 145 with step size of 5 mm. The total treatment time was 115 seconds with a 7.36 Ci activity of the 192Ir source. The treatment resulted in good pain control. The patient did not require further injections to the nail bed. After this initial treatment, additional two patients with similar symptoms received HDR brachytherapy. The treatment outcome was favorable in all cases. Conclusions : The first HDR brachytherapy treatment of psoriasis of the nail bed is presented. The initial experience revealed that brachytherapy treatment was well-tolerated and resulted in adequate control of the disease. A larger cohort of patients will be required for additional conclusions related to the long-term clinical benefits.

  14. Micro-texturing into DLC/diamond coated molds and dies via high density oxygen plasma etching

    Directory of Open Access Journals (Sweden)

    Yunata Ersyzario Edo

    2015-01-01

    Full Text Available Diamond-Like Carbon (DLC and Chemical Vapor Deposition (CVD-diamond films have been widely utilized not only as a hard protective coating for molds and dies but also as a functional substrate for bio-MEMS/NEMS. Micro-texturing into these hard coated molds and dies provides a productive tool to duplicate the original mother micro-patterns onto various work materials and to construct any tailored micro-textures for sensors and actuators. In the present paper, the high density oxygen plasma etching method is utilized to make micro-line and micro-groove patterns onto the DLC and diamond coatings. Our developing oxygen plasma etching system is introduced together with characterization on the plasma state during etching. In this quantitative plasma diagnosis, both the population of activated species and the electron and ion densities are identified through the emissive light spectroscopy and the Langmuir probe method. In addition, the on-line monitoring of the plasmas helps to describe the etching process. DLC coated WC (Co specimen is first employed to describe the etching mechanism by the present method. Chemical Vapor Deposition (CVD diamond coated WC (Co is also employed to demonstrate the reliable capacity of the present high density oxygen plasma etching. This oxygen plasma etching performance is discussed by comparison of the etching rates.

  15. Development of a high-speed synchronous micro motor and its application in intravascular imaging

    NARCIS (Netherlands)

    T. Wang (Tianshi); C.T. Lancée (Charles); R. Beurskens (Robert); J. Meijer (John); B. Knapen (Bart); A.F.W. van der Steen (Ton); G. van Soest (Gijs)

    2014-01-01

    textabstractIn this study, we demonstrate the design, fabrication and characterization of a synchronous micro motor. The micro motor consists of flex print coils and a permanent magnet rotor. The size of the motor is 2.0 mm length and 1.0 mm outer diameter. With 1.0 A effective driving current, the

  16. A new compact, high sensitivity neutron imaging system

    Energy Technology Data Exchange (ETDEWEB)

    Caillaud, T.; Landoas, O.; Briat, M.; Rosse, B.; Thfoin, I.; Philippe, F.; Casner, A.; Bourgade, J. L.; Disdier, L. [CEA, DAM, DIF,F-91297 Arpajon (France); Glebov, V. Yu.; Marshall, F. J.; Sangster, T. C. [Laboratory for Laser Energetics, University of Rochester, 250 East River Road, Rochester, New York 14623-1299 (United States); Park, H. S.; Robey, H. F.; Amendt, P. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

    2012-10-15

    We have developed a new small neutron imaging system (SNIS) diagnostic for the OMEGA laser facility. The SNIS uses a penumbral coded aperture and has been designed to record images from low yield (10{sup 9}-10{sup 10} neutrons) implosions such as those using deuterium as the fuel. This camera was tested at OMEGA in 2009 on a rugby hohlraum energetics experiment where it recorded an image at a yield of 1.4 Multiplication-Sign 10{sup 10}. The resolution of this image was 54 {mu}m and the camera was located only 4 meters from target chamber centre. We recently improved the instrument by adding a cooled CCD camera. The sensitivity of the new camera has been fully characterized using a linear accelerator and a {sup 60}Co {gamma}-ray source. The calibration showed that the signal-to-noise ratio could be improved by using raw binning detection.

  17. Highly sensitive urea sensing with ion-irradiated polymer foils

    Energy Technology Data Exchange (ETDEWEB)

    Fink, Dietmar, E-mail: fink@daad-alumni.de [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 Mexico, D.F. (Mexico); Nuclear Physics Institute, Academy of Sciences of the Czech Republic, 250 68 Rez (Czech Republic); Munoz Hernandez, Gerardo [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, P.O. Box 55-534, 09340 Mexico, D.F. (Mexico); Division de Ciencias Naturales e Ingenieria, Universidad Autonoma Metropolitana-Cuajimalpa, Pedro Antonio de los Santos 84, Col. Sn. Miguel Chapultepec, C.P. 11850, Mexico, D.F. (Mexico); Alfonta, Lital, E-mail: alfontal@bgu.ac.il [Avram and Stella Goldstein-Goren Department of Biotechnology Engineering, Ben-Gurion University of the Negev, P.O. Box 653, Beer-Sheva 84105 (Israel)

    2012-02-15

    Recently we prepared urea-sensors by attaching urease to the inner walls of etched ion tracks within thin polymer foil. Here, alternative track-based sensor configurations are examined where the enzyme remained in solution. The conductivities of systems consisting of two parallel irradiated polymer foils and confining different urea/urease mixtures in between were examined. The correlations between conductivity and urea concentration differed strongly for foils with unetched and etched tracks, which points at different sensing mechanisms - tentatively attributed to the adsorption of enzymatic reaction products on the latent track entrances and to the enhanced conductivity of reaction product-filled etched tracks, respectively. All examined systems enable in principle, urea sensing. They point at the possibility of sensor cascade construction for more sensitive or selective sensor systems.

  18. Large scintillation cells for high sensitivity radon concentration measurements

    Science.gov (United States)

    Cohen, B. L.; El Ganayni, M.; Cohen, E. S.

    1983-07-01

    Methods for improving the sensitivity of scintillation cells for radon concentration measurements were studied with emphasis on improving light collection efficiency. This allows the length and hence the volume of the cell to be increased. Variables studied were choice of scintillator material, its method of application and thickness, length of cell, cell material, type and configuration of reflectors, choice of photomultipliers, and factors affecting background. Response from various areas of the cell surface was studied with an alpha source and with radon filling. Coating the window with phosphor was found to be counter-productive. The optimum results obtained were with the inside of the cell (other than the window) covered with a thick layer of ZnS(Ag), or with a thick layer of reflective material coated with a thin layer of phosphor. With it, a 10 cm diameter plexiglass cell can be extended to at least 50 cm length without difficulty from insufficient pulse height.

  19. The Xsense project: The application of an intelligent sensor array for high sensitivity handheld explosives detectors

    DEFF Research Database (Denmark)

    Kostesha, Natalie; Schmidt, Michael Stenbæk; Bosco, Filippo

    2011-01-01

    Multiple independent sensors are used in security and military applications in order to increase sensitivity, selectivity and data reliability. The Xsense project has been initiated at the Technical University of Denmark in collaboration with a number of partners in an effort to produce a handheld...... sensor for trace detection of explosives. We are using micro- and nano technological approaches for integrating four sensing principles into a single device. At the end of the project, the consortium aims at having delivered a sensor platform consisting of four independent detector principles capable...

  20. Nitrogen detected TROSY at high field yields high resolution and sensitivity for protein NMR.

    Science.gov (United States)

    Takeuchi, Koh; Arthanari, Haribabu; Shimada, Ichio; Wagner, Gerhard

    2015-12-01

    Detection of (15)N in multidimensional NMR experiments of proteins has sparsely been utilized because of the low gyromagnetic ratio (γ) of nitrogen and the presumed low sensitivity of such experiments. Here we show that selecting the TROSY components of proton-attached (15)N nuclei (TROSY (15)NH) yields high quality spectra in high field magnets (>600 MHz) by taking advantage of the slow (15)N transverse relaxation and compensating for the inherently low (15)N sensitivity. The (15)N TROSY transverse relaxation rates increase modestly with molecular weight but the TROSY gain in peak heights depends strongly on the magnetic field strength. Theoretical simulations predict that the narrowest line width for the TROSY (15)NH component can be obtained at 900 MHz, but sensitivity reaches its maximum around 1.2 GHz. Based on these considerations, a (15)N-detected 2D (1)H-(15)N TROSY-HSQC ((15)N-detected TROSY-HSQC) experiment was developed and high-quality 2D spectra were recorded at 800 MHz in 2 h for 1 mM maltose-binding protein at 278 K (τc ~ 40 ns). Unlike for (1)H detected TROSY, deuteration is not mandatory to benefit (15)N detected TROSY due to reduced dipolar broadening, which facilitates studies of proteins that cannot be deuterated, especially in cases where production requires eukaryotic expression systems. The option of recording (15)N TROSY of proteins expressed in H2O media also alleviates the problem of incomplete amide proton back exchange, which often hampers the detection of amide groups in the core of large molecular weight proteins that are expressed in D2O culture media and cannot be refolded for amide back exchange. These results illustrate the potential of (15)NH-detected TROSY experiments as a means to exploit the high resolution offered by high field magnets near and above 1 GHz.

  1. High sensitivity of northeastern broadleaf forest trees to water availability

    Science.gov (United States)

    Levesque, M.; Pederson, N.; Andreu-Hayles, L.

    2015-12-01

    Temperate deciduous forests of eastern US provide goods and services to millions of people and play a vital role in the terrestrial carbon and hydrological cycles. However, ongoing climate change and increased in CO2 concentration in the atmosphere (ca) are expected to alter growth and gas exchange of trees, and ultimately forest productivity. Still, the magnitude of these effects is unclear. A better comprehension of the species-specific responses to environmental changes will better inform models and managers on the vulnerability and resiliency of these forests. Tree-ring analysis was combined with δ¹³C and δ18O measurements to investigate growth and physiological responses of red oak (Quercus rubra L.) and tulip poplar (Liriodendron tulipifera L.) in northeastern US to changes in water availability and ca for the period 1950-2014. We found very strong correlations between summer climatic water balance (June-August) and isotopic tree-ring series for δ¹³C (r = -0.65 and -0.73), and δ18O (r = -0.59 and -0.70), for red oak and tulip poplar, respectively. In contrast, tree-ring width was less sensitive to summer water availability (r = 0.33-0.39). Prior to the mid 1980s, low water availability resulted in low stomatal conductance, photosynthesis, and growth. Since that period, pluvial conditions occurring in northeastern US have increased stomatal conductance, carbon uptake, and growth of both species. These findings demonstrate that broadleaf trees in this region could be more sensitive to drought than expected. This appears especially true since much of the calibration period looks wet in a multi-centennial perspective. Further, stronger spatial correlations were found between climate data with tree-ring isotopes than with tree-ring width and the geographical area of the observed δ18O-precipitation response (i.e. the area over which correlations are > 0.5) covers most of the northeastern US. Given the good fit between the isotopic time series and water

  2. Storing quantum information in spins and high-sensitivity ESR.

    Science.gov (United States)

    Morton, John J L; Bertet, Patrice

    2018-02-01

    Quantum information, encoded within the states of quantum systems, represents a novel and rich form of information which has inspired new types of computers and communications systems. Many diverse electron spin systems have been studied with a view to storing quantum information, including molecular radicals, point defects and impurities in inorganic systems, and quantum dots in semiconductor devices. In these systems, spin coherence times can exceed seconds, single spins can be addressed through electrical and optical methods, and new spin systems with advantageous properties continue to be identified. Spin ensembles strongly coupled to microwave resonators can, in principle, be used to store the coherent states of single microwave photons, enabling so-called microwave quantum memories. We discuss key requirements in realising such memories, including considerations for superconducting resonators whose frequency can be tuned onto resonance with the spins. Finally, progress towards microwave quantum memories and other developments in the field of superconducting quantum devices are being used to push the limits of sensitivity of inductively-detected electron spin resonance. The state-of-the-art currently stands at around 65 spins per Hz, with prospects to scale down to even fewer spins. Copyright © 2017. Published by Elsevier Inc.

  3. Flame Shapes of Fuel Droplet Could in High Temperature Gaseous Environment under Micro-gravity

    Science.gov (United States)

    Enomoto, Hiroshi; Nagata, Hitoshi; Segawa, Daisuke; Kadota, Toshikazu

    In order to investigate the spray combustion mechanism, a new methodology (Fine Wire Sustaining method) was established. Fine wires of 14µm in diameter were used to sustain the droplets. Any arrangement of the droplets could be performed with this method. In this study, 33 fuel droplets arranged in symmetrically were subjected to the quiescent high temperature air in an electric furnace. The temperature of the environment air was about 1000K. Fuel was n-eicosane and the mean droplet diameter was 0.58mm. The standard deviation of the droplet diameter was 0.02mm. A high-speed video camera of 250ftp was provided to observe the auto-ignition and flames of fuel droplet clouds. The experiments were done at atmospheric pressure using the JAMIC drop shaft that provides 10 seconds of effective period of time for the micro-gravity. As the results, the time histories of the diameter of the particle flames had maximum and that of the diameter of the group flame had the minimum.

  4. High-throughput sample-to-answer detection of DNA/RNA in crude samples within functionalized micro-pipette tips.

    Science.gov (United States)

    Lu, Wenjing; Wang, Jidong; Wu, Qiong; Sun, Jiashu; Chen, Yiping; Zhang, Lu; Zheng, Chunsheng; Gao, Wenna; Liu, Yi; Jiang, Xingyu

    2016-01-15

    We develop a micro-pipette tip-based nucleic acid test (MTNT) for high-throughput sample-to-answer detection of both DNA and RNA from crude samples including cells, bacteria, and solid plants, without the need of sample pretreatment and complex operation. MTNT consists of micro-pipette tips and embedded solid phase nucleic acid extraction membranes, and fully integrates the functions of nucleic acid extraction from crude samples, loop-mediated isothermal amplification (LAMP) of nucleic acids, and visual readout of assays. The total assaying time for DNA or RNA from a variety of crude samples ranges from 90 to 160 min. The limit of detection (LOD) of MTNT is 2 copies of plasmids containing the target nucleic acid fragments of Ebola virus, and 8 CFU of Escherichia coli carrying Ebola virus-derived plasmids. MTNT can also detect CK-19 mRNA from as few as 2 cancer cells without complicated procedures such as RNA extraction and purification. We further demonstrate MTNT in a high-throughput format using an eight-channel pipette and a homemade mini-heater, with a maximum throughput of 40 samples. Compared with other point-of-care (POC) nucleic acid tests (NAT), MTNT could assay both DNA and RNA directly from liquid (cells/bacteria/blood) or solid (plant) samples in a straightforward, sensitive, high-throughput, and containment-free manner, suggesting a considerable promise for low-cost and POC NAT in remote areas.

  5. Transgenic expression of microRNA-181d augments the stress-sensitivity of CD4(+CD8(+ thymocytes.

    Directory of Open Access Journals (Sweden)

    Serkan Belkaya

    Full Text Available Physiological stress resulting from infections, trauma, surgery, alcoholism, malnutrition, and/or pregnancy results in a substantial depletion of immature CD4(+CD8(+ thymocytes. We previously identified 18 distinct stress-responsive microRNAs (miRs in the thymus upon systemic stress induced by lipopolysaccharide (LPS or the synthetic glucocorticoid, dexamethasone (Dex. MiRs are short, non-coding RNAs that play critical roles in the immune system by targeting diverse mRNAs, suggesting that their modulation in the thymus in response to stress could impact thymopoiesis. MiR-181d is one such stress-responsive miR, exhibiting a 15-fold down-regulation in expression. We utilized both transgenic and gene-targeting approaches to study the impact of miR-181d on thymopoiesis under normal and stress conditions. The over-expression of miR-181d in developing thymocytes reduced the total number of immature CD4(+CD8(+ thymocytes. LPS or Dex injections caused a 4-fold greater loss of these cells when compared with the wild type controls. A knockout mouse was developed to selectively eliminate miR-181d, leaving the closely spaced and contiguous family member miR-181c intact. The targeted elimination of just miR-181d resulted in a thymus stress-responsiveness similar to wild-type mice. These experiments suggest that one or more of three other miR-181 family members have overlapping or compensatory functions. Gene expression comparisons of thymocytes from the wild type versus transgenic mice indicated that miR-181d targets a number of stress, metabolic, and signaling pathways. These findings demonstrate that selected miRs enhance stress-mediated thymic involution in vivo.

  6. Highly sensitive vacuum ion pump current measurement system

    Science.gov (United States)

    Hansknecht, John Christopher [Williamsburg, VA

    2006-02-21

    A vacuum system comprising: 1) an ion pump; 2) power supply; 3) a high voltage DC--DC converter drawing power from the power supply and powering the vacuum pump; 4) a feedback network comprising an ammeter circuit including an operational amplifier and a series of relay controlled scaling resistors of different resistance for detecting circuit feedback; 5) an optional power block section intermediate the power supply and the high voltage DC--DC converter; and 6) a microprocessor receiving feedback information from the feedback network, controlling which of the scaling resistors should be in the circuit and manipulating data from the feedback network to provide accurate vacuum measurement to an operator.

  7. High-Q Wafer Level Package Based on Modified Tri-Layer Anodic Bonding and High Performance Getter and Its Evaluation for Micro Resonant Pressure Sensor

    National Research Council Canada - National Science Library

    Liying Wang; Xiaohui Du; Lingyun Wang; Zhanhao Xu; Chenying Zhang; Dandan Gu

    2017-01-01

    In order to achieve and maintain a high quality factor (high-Q) for the micro resonant pressure sensor, this paper presents a new wafer level package by adopting cross-layer anodic bonding technique of the glass/silicon/silica (GSS...

  8. High Sensitivity Indium Phosphide Based Avalanche Photodiode Focal Plane Arrays Project

    Data.gov (United States)

    National Aeronautics and Space Administration — nLight has demonstrated highly-uniform APD arrays based on the highly sensitive InGaAs/InP material system. These results provide great promise for achieving the...

  9. Thyroglobulin measurement using highly sensitive assays in patients with differentiated thyroid cancer:

    DEFF Research Database (Denmark)

    Giovanella, Luca; Clark, Penelope M; Chiovato, Luca

    2014-01-01

    stimulation by endogenous or exogenous TSH is recommended by current clinical guidelines to detect occult disease with a maximum sensitivity due to the suboptimal sensitivity of older Tg assays. However, the development of new highly sensitive Tg assays with improved analytical sensitivity and precision...... at low concentrations now allows detection of very low Tg concentrations reflecting minimal amounts of thyroid tissue without the need for TSH stimulation. Use of these highly sensitive Tg assays has not yet been incorporated into clinical guidelines but they will, we believe, be used by physicians...... caring for patients with DTC. The aim of this clinical position paper is, therefore, to offer advice on the various aspects and implications of using these highly sensitive Tg assays in the clinical care of patients with DTC....

  10. Mass Spectrometry-based Assay for High Throughput and High Sensitivity Biomarker Verification

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Xuejiang; Tang, Keqi

    2017-06-14

    Searching for disease specific biomarkers has become a major undertaking in the biomedical research field as the effective diagnosis, prognosis and treatment of many complex human diseases are largely determined by the availability and the quality of the biomarkers. A successful biomarker as an indicator to a specific biological or pathological process is usually selected from a large group of candidates by a strict verification and validation process. To be clinically useful, the validated biomarkers must be detectable and quantifiable by the selected testing techniques in their related tissues or body fluids. Due to its easy accessibility, protein biomarkers would ideally be identified in blood plasma or serum. However, most disease related protein biomarkers in blood exist at very low concentrations (<1ng/mL) and are “masked” by many none significant species at orders of magnitude higher concentrations. The extreme requirements of measurement sensitivity, dynamic range and specificity make the method development extremely challenging. The current clinical protein biomarker measurement primarily relies on antibody based immunoassays, such as ELISA. Although the technique is sensitive and highly specific, the development of high quality protein antibody is both expensive and time consuming. The limited capability of assay multiplexing also makes the measurement an extremely low throughput one rendering it impractical when hundreds to thousands potential biomarkers need to be quantitatively measured across multiple samples. Mass spectrometry (MS)-based assays have recently shown to be a viable alternative for high throughput and quantitative candidate protein biomarker verification. Among them, the triple quadrupole MS based assay is the most promising one. When it is coupled with liquid chromatography (LC) separation and electrospray ionization (ESI) source, a triple quadrupole mass spectrometer operating in a special selected reaction monitoring (SRM) mode

  11. Maternal high-fat diet consumption modulates hepatic lipid metabolism and microRNA-122 (miR-122) and microRNA-370 (miR-370) expression in offspring

    National Research Council Canada - National Science Library

    Benatti, R O; Melo, A M; Borges, F O; Ignacio-Souza, L M; Simino, L A P; Milanski, M; Velloso, L A; Torsoni, M A; Torsoni, A S

    2014-01-01

    Maternal consumption of a high-fat diet (HFD) during pregnancy and lactation is closely related to hepatic lipid accumulation, insulin resistance and increased serum cytokine levels in offspring and into their adulthood. MicroRNA (miRNA...

  12. Study on vapor film collapse behavior on high temperature particle surface. 2. Effect of subcooling on micro-mechanism

    Energy Technology Data Exchange (ETDEWEB)

    Abe, Yutaka [Yamagata University, Dept. of Mechanical Systems Engineering, Yonezawa, Yamagata (Japan); Tochio, Daisuke [Yamagata Univ. (Japan)

    2000-02-01

    Thermal detonation model is proposed to describe vapor explosion. According to this model, vapor film on pre-mixed high temperature droplet surface should be collapsed for the trigger of the vapor explosion. It is pointed out that the vapor film collapse behavior is significantly affected by the subcooling of low temperature liquid. However, the effect of subcooling on micro-mechanism of vapor film collapse behavior is not experimentally well identified. The objective of the present research is to experimentally investigate the effect of subcooling on micro-mechanism of film boiling collapse behavior. As the results, it is experimentally clarified that the vapor film collapse behavior in low subcool condition is qualitatively different from the vapor film collapse behavior in high subcool condition. In high subcool condition, instability of the vapor film dominates the vapor film collapse on the particle surface. On the other hand, micro-mechanism at the interface between vapor and liquid such as micro-jet is dominant in low subcool condition in case of vapor film collapse by pressure pulse. (author)

  13. PCF Based Sensor with High Sensitivity, High Birefringence and Low Confinement Losses for Liquid Analyte Sensing Applications

    Directory of Open Access Journals (Sweden)

    Huseyin Ademgil

    2015-12-01

    Full Text Available In this paper, we report a design of high sensitivity Photonic Crystal Fiber (PCF sensor with high birefringence and low confinement losses for liquid analyte sensing applications. The proposed PCF structures are designed with supplementary elliptical air holes in the core region vertically-shaped V-PCF and horizontally-shaped H-PCF. The full vectorial Finite Element Method (FEM simulations performed to examine the sensitivity, the confinement losses, the effective refractive index and the modal birefringence features of the proposed elliptical air hole PCF structures. We show that the proposed PCF structures exhibit high relative sensitivity, high birefringence and low confinement losses simultaneously for various analytes.

  14. Retraction Statement: 'MicroRNA-218 increases cellular sensitivity to Rapamycin via targeting Rictor in cervical cancer' by Li J, Wang J, Wang Y, Qiu H.

    Science.gov (United States)

    2017-02-01

    The above article from APMIS, published online on 24 April 2015 in Wiley Online Library (wileyonlinelibrary.com) and in Volume 123, pp. 562-570, has been retracted by agreement between the authors, the journal Editors in Chief, Professors Bodil Norrild, Ben Vainer and Elisabeth Ralfkiaer, and John Wiley & Sons Ltd. The article has been retracted due to errors in the reported results. In this study, the authors used HeLa and SiHa cell lines to investigate the biological roles of miR-218. However, subsequently it emerged that the two cell lines were contaminated in the laboratory by other unknown cell lines. When repeating the experiments, it was found that the functions of miR-218 were not as significant as had been previously reported, especially its effects on rapamycin sensitivity. Reference Li J, Li X, Wang J, Wang Y, Qiu H. MicroRNA-218 increases cellular sensitivity to Rapamycin via targeting Rictor in cervical cancer. APMIS 2015; 123:562-570. doi: 10.1111/apm.12387. © 2016 APMIS. Published by John Wiley & Sons Ltd.

  15. Electronic Characterization of Lithographically Patterned Microcoils for High Sensitivity NMR Detection

    Energy Technology Data Exchange (ETDEWEB)

    Demas, V; Bernhardt, A; Malba, V; Adams, K L; Evans, L; Harvey, C; Maxwell, R S; Herberg, J L

    2009-01-13

    Nuclear magnetic resonance (NMR) offers a non-destructive, powerful, structure-specific analytical method for the identification of chemical and biological systems. The use of radio frequency (RF) microcoils has been shown to increase the sensitivity in mass limited samples. Recent advances in micro-receiver technology have further demonstrated a substantial increase in mass sensitivity [1]. Lithographic methods for producing solenoid microcoils possess a level of flexibility and reproducibility that exceeds previous production methods, such as hand winding microcoils. This paper presents electrical characterizations of RF microcoils produced by a unique laser lithography system that can pattern three dimensional surfaces and compares calculated and experimental results to those for wire wound RF microcoils. We show that existing optimization conditions for RF coil design still hold true for RF microcoils produced by lithography. Current lithographic microcoils show somewhat inferior performance to wire wound RF microcoils due to limitations in the existing electroplating technique. In principle, however, when the pitch of the RF microcoil is less than 100 {micro}m lithographic coils should show comparable performance to wire wound coils. In the cases of larger pitch, wire cross sections can be significantly larger and resistances lower than microfabricated conductors.

  16. High finesse hollow-core fiber resonating cavity for high sensitivity gas sensing application

    Science.gov (United States)

    Tan, Yanzhen; Jin, Wei; Yang, Fan; Ho, Hoi Lut

    2017-04-01

    We present all-fiber resonating Fabry-Perot gas cells made with a piece of hollow-core photonic bandgap fiber (HCPBF) sandwiched by two single mode fibers with mirrored ends. A HC-PBF cavity made of 6.75-cm-long HC-1550-06 fiber achieved a cavity finesse of 128, corresponding to an effective optical path length of 5.5 m. Such HC-PBF cavities can be used as absorption cells for high sensitivity gas detection with fast response. Preliminary experiment with a 9.4-cm-long resonating gas cell with a finesse of 68 demonstrated a detection limit better than 7.5 p.p.m. acetylene.

  17. Multidimensional NMR approaches towards highly resolved, sensitive and high-throughput quantitative metabolomics.

    Science.gov (United States)

    Marchand, Jérémy; Martineau, Estelle; Guitton, Yann; Dervilly-Pinel, Gaud; Giraudeau, Patrick

    2017-02-01

    Multi-dimensional NMR is an appealing approach for dealing with the challenging complexity of biological samples in metabolomics. This article describes how spectroscopists have recently challenged their imagination in order to make 2D NMR a powerful tool for quantitative metabolomics, based on innovative pulse sequences combined with meticulous analytical chemistry approaches. Clever time-saving strategies have also been explored to make 2D NMR a high-throughput tool for metabolomics, relying on alternative data acquisition schemes such as ultrafast NMR. Currently, much work is aimed at drastically boosting the NMR sensitivity thanks to hyperpolarisation techniques, which have been used in combination with fast acquisition methods and could greatly expand the application potential of NMR metabolomics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  18. Aptamer-Functionalized Fluorescent Silica Nanoparticles for Highly Sensitive Detection of Leukemia Cells

    Science.gov (United States)

    Tan, Juntao; Yang, Nuo; Hu, Zixi; Su, Jing; Zhong, Jianhong; Yang, Yang; Yu, Yating; Zhu, Jianmeng; Xue, Dabin; Huang, Yingying; Lai, Zongqiang; Huang, Yong; Lu, Xiaoling; Zhao, Yongxiang

    2016-06-01

    A simple, highly sensitive method to detect leukemia cells has been developed based on aptamer-modified fluorescent silica nanoparticles (FSNPs). In this strategy, the amine-labeled Sgc8 aptamer was conjugated to carboxyl-modified FSNPs via amide coupling between amino and carboxyl groups. Sensitivity and specificity of Sgc8-FSNPs were assessed using flow cytometry and fluorescence microscopy. These results showed that Sgc8-FSNPs detected leukemia cells with high sensitivity and specificity. Aptamer-modified FSNPs hold promise for sensitive and specific detection of leukemia cells. Changing the aptamer may allow the FSNPs to detect other types of cancer cells.

  19. Melting temperatures of MgO under high pressure by micro-texture analysis.

    Science.gov (United States)

    Kimura, T; Ohfuji, H; Nishi, M; Irifune, T

    2017-06-05

    Periclase (MgO) is the second most abundant mineral after bridgmanite in the Earth's lower mantle, and its melting behaviour under pressure is important to constrain rheological properties and melting behaviours of the lower mantle materials. Significant discrepancies exist between the melting temperatures of MgO determined by laser-heated diamond anvil cell (LHDAC) and those based on dynamic compressions and theoretical predictions. Here we show the melting temperatures in earlier LHDAC experiments are underestimated due to misjudgment of melting, based on micro-texture observations of the quenched samples. The high melting temperatures of MgO suggest that the subducted cold slabs should have higher viscosities than previously thought, suggesting that the inter-connecting textural feature of MgO would not play important roles for the slab stagnation in the lower mantle. The present results also predict that the ultra-deep magmas produced in the lower mantle are peridotitic, which are stabilized near the core-mantle boundary.

  20. Acoustic model of micro-pressure wave emission from a high-speed train tunnel

    Science.gov (United States)

    Miyachi, T.

    2017-03-01

    The micro-pressure wave (MPW) radiated from a tunnel portal can, if audible, cause serious problems around tunnel portals in high-speed railways. This has created a need to develop an acoustic model that considers the topography around a radiation portal in order to predict MPWs more accurately and allow for higher speed railways in the future. An acoustic model of MPWs based on linear acoustic theory is developed in this study. First, the directivity of sound sources and the acoustical effect of topography are investigated using a train launcher facility around a portal on infinitely flat ground and with an infinite vertical baffle plate. The validity of linear acoustic theory is then discussed through a comparison of numerical results obtained using the finite difference method (FDM) and experimental results. Finally, an acoustic model is derived that considers sound sources up to the second order and Green's function to represent the directivity and effect of topography, respectively. The results predicted by this acoustic model are shown to be in good agreement with both numerical and experimental results.

  1. Flexible and biocompatible high-performance solid-state micro-battery for implantable orthodontic system

    KAUST Repository

    Kutbee, Arwa T.

    2017-09-25

    To augment the quality of our life, fully compliant personalized advanced health-care electronic system is pivotal. One of the major requirements to implement such systems is a physically flexible high-performance biocompatible energy storage (battery). However, the status-quo options do not match all of these attributes simultaneously and we also lack in an effective integration strategy to integrate them in complex architecture such as orthodontic domain in human body. Here we show, a physically complaint lithium-ion micro-battery (236 μg) with an unprecedented volumetric energy (the ratio of energy to device geometrical size) of 200 mWh/cm3 after 120 cycles of continuous operation. Our results of 90% viability test confirmed the battery’s biocompatibility. We also show seamless integration of the developed battery in an optoelectronic system embedded in a three-dimensional printed smart dental brace. We foresee the resultant orthodontic system as a personalized advanced health-care application, which could serve in faster bone regeneration and enhanced enamel health-care protection and subsequently reducing the overall health-care cost.

  2. Deformation behavior of a high strength multiphase steel at macro- and micro-scales

    Energy Technology Data Exchange (ETDEWEB)

    Diego-Calderón, I. de, E-mail: irenedediego.calderon@imdea.org [IMDEA Materials Institute, Calle Eric Kandel 2, Getafe 28906, Madrid (Spain); Santofimia, M.J. [Department of Materials Science and Engineering, Delft University of Technology, 2628 CD Delft (Netherlands); Molina-Aldareguia, J.M.; Monclús, M.A.; Sabirov, I. [IMDEA Materials Institute, Calle Eric Kandel 2, Getafe 28906, Madrid (Spain)

    2014-08-12

    Advanced high strength steels via quenching and partitioning (Q and P) process are a mainstream trend in modern steel research. This work contributes to a better understanding of their local mechanical properties and local deformation behavior at the micro-scale in relation to their local microstructure. A low alloyed steel was subjected to Q and P heat treatments leading to the formation of complex multiphase microstructures. Nanoindentation tests were performed to measure nanohardness of individual phases and to generate 2D maps showing nanohardness distribution on the surface of the material. To study local in-plane plastic strain distribution during deformation, in situ tensile tests were carried out using the digital image correlation technique. Significant partitioning of plastic strain between phase microconstituents during tensile deformation is shown. The effect of the microstructure on the mechanical behavior of the Q and P processed steel is analyzed. The local plastic deformation behavior of individual phases is discussed with respect to their strength and their spatial orientation.

  3. High-Efficiency Food Production in a Renewable Energy Based Micro-Grid Power System

    Science.gov (United States)

    Bubenheim, David; Meiners, Dennis

    2016-01-01

    Controlled Environment Agriculture (CEA) systems can be used to produce high-quality, desirable food year round, and the fresh produce can positively contribute to the health and well being of residents in communities with difficult supply logistics. While CEA has many positive outcomes for a remote community, the associated high electric demands have prohibited widespread implementation in what is typically already a fully subscribed power generation and distribution system. Recent advances in CEA technologies as well as renewable power generation, storage, and micro-grid management are increasing system efficiency and expanding the possibilities for enhancing community supporting infrastructure without increasing demands for outside supplied fuels. We will present examples of how new lighting, nutrient delivery, and energy management and control systems can enable significant increases in food production efficiency while maintaining high yields in CEA. Examples from Alaskan communities where initial incorporation of renewable power generation, energy storage and grid management techniques have already reduced diesel fuel consumption for electric generation by more than 40% and expanded grid capacity will be presented. We will discuss how renewable power generation, efficient grid management to extract maximum community service per kW, and novel energy storage approaches can expand the food production, water supply, waste treatment, sanitation and other community support services without traditional increases of consumable fuels supplied from outside the community. These capabilities offer communities with a range of choices to enhance their communities. The examples represent a synergy of technology advancement efforts to develop sustainable community support systems for future space-based human habitats and practical implementation of infrastructure components to increase efficiency and enhance health and well being in remote communities today and tomorrow.

  4. High-Efficiency Food Production in a Renewable Energy Based Micro-Grid

    Science.gov (United States)

    Bubenheim, David L.

    2017-01-01

    Controlled Environment Agriculture (CEA) systems can be used to produce high-quality, desirable food year round, and the fresh produce can positively contribute to the health and well being of residents in communities with difficult supply logistics. While CEA has many positive outcomes for a remote community, the associated high electric demands have prohibited widespread implementation in what is typically already a fully subscribed power generation and distribution system. Recent advances in CEA technologies as well as renewable power generation, storage, and micro-grid management are increasing system efficiency and expanding the possibilities for enhancing community supporting infrastructure without increasing demands for outside supplied fuels. We will present examples of how new lighting, nutrient delivery, and energy management and control systems can enable significant increases in food production efficiency while maintaining high yields in CEA.Examples from Alaskan communities where initial incorporation of renewable power generation, energy storage and grid management techniques have already reduced diesel fuel consumption for electric generation by more than 40 and expanded grid capacity will be presented. We will discuss how renewable power generation, efficient grid management to extract maximum community service per kW, and novel energy storage approaches can expand the food production, water supply, waste treatment, sanitation and other community support services without traditional increases of consumable fuels supplied from outside the community. These capabilities offer communities with a range of choices to enhance their communities. The examples represent a synergy of technology advancement efforts to develop sustainable community support systems for future space-based human habitats and practical implementation of infrastructure components to increase efficiency and enhance health and well-being in remote communities today and tomorrow.

  5. High Sensitivity Optomechanical Reference Accelerometer over 10 kHz

    Science.gov (United States)

    2014-06-05

    Supplementary Note © 2014 . Published in Applied Physics Letters, Vol. Ed. 0 104, (22) (2014), ( (22). DoD Components reserve a royalty-free, nonexclusive and...lgn= Hz p ð1 gn ¼ 9:80665 m=s2Þ over several kHz. In experimental gravitational physics , remarkably high acceleration resolutions at levels of fgn...approximately 10 pm= Hz p .1,2 In geodesy and geophysics, superconducting gravimeters reach accelera- tion resolutions of the order of pgn= Hz p over

  6. Purification of ethanol for highly sensitive self-assembly experiments

    Directory of Open Access Journals (Sweden)

    Kathrin Barbe

    2014-08-01

    Full Text Available Ethanol is the preferred solvent for the formation of self-assembled monolayers (SAMs of thiolates on gold. By applying a thin film sensor system, we could demonstrate that even the best commercial qualities of ethanol contain surface-active contaminants, which can compete with the desired thiolates for surface sites. Here we present that gold nanoparticles deposited onto zeolite X can be used to remove these contaminants by chemisorption. This nanoparticle-impregnated zeolite does not only show high capacities for surface-active contaminants, such as thiols, but can be fully regenerated via a simple pyrolysis protocol.

  7. Graphene-based in-plane micro-supercapacitors with high power and energy densities

    Science.gov (United States)

    Wu, Zhong–Shuai; Parvez, Khaled; Feng, Xinliang; Müllen, Klaus

    2013-01-01

    Micro-supercapacitors are important on-chip micro-power sources for miniaturized electronic devices. Although the performance of micro-supercapacitors has been significantly advanced by fabricating nanostructured materials, developing thin-film manufacture technologies and device architectures, their power or energy densities remain far from those of electrolytic capacitors or lithium thin-film batteries. Here we demonstrate graphene-based in-plane interdigital micro-supercapacitors on arbitrary substrates. The resulting micro-supercapacitors deliver an area capacitance of 80.7 μF cm−2 and a stack capacitance of 17.9 F cm−3. Further, they show a power density of 495 W cm−3 that is higher than electrolytic capacitors, and an energy density of 2.5 mWh cm−3 that is comparable to lithium thin-film batteries, in association with superior cycling stability. Such microdevices allow for operations at ultrahigh rate up to 1,000 V s−1, three orders of magnitude higher than that of conventional supercapacitors. Micro-supercapacitors with an in-plane geometry have great promise for numerous miniaturized or flexible electronic applications. PMID:24042088

  8. Highly sensitive determination of atropine using cobalt oxide nanostructures: Influence of functional groups on the signal sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Soomro, Razium Ali, E-mail: raziumsoomro@gmail.com [Interface Analysis Centre, School of Physics, University of Bristol, Bristol, BS8 1TL (United Kingdom); National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080 (Pakistan); Nafady, Ayman [Department of Chemistry, College of Science, King Saud University, Riyadh (Saudi Arabia); Department of Chemistry, Faculty of Science, Sohag University, Sohag (Egypt); Hallam, Keith Richard [Interface Analysis Centre, School of Physics, University of Bristol, Bristol, BS8 1TL (United Kingdom); Jawaid, Sana [National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080 (Pakistan); Al Enizi, Abdullah [Department of Chemistry, College of Science, King Saud University, Riyadh (Saudi Arabia); Sherazi, Syed Tufail Hussain; Sirajuddin [National Centre of Excellence in Analytical Chemistry, University of Sindh, Jamshoro, 76080 (Pakistan); Ibupoto, Zafar Hussain [Dr M.A. Kazi Institute of Chemistry, University of Sindh, Jamshoro, 76080 (Pakistan); Willander, Magnus [Department of Science and Technology, Campus Norrkoping, Linkoping University, SE-60174, Norrkoping (Sweden)

    2016-12-15

    This study describes sensitive determination of atropine using glassy carbon electrodes (GCE) modified with Co{sub 3}O{sub 4} nanostructures. The as-synthesised nanostructures were grown using cysteine (CYS), glutathione (GSH) and histidine (HYS) as effective templates under hydrothermal action. The obtained morphologies revealed interesting structural features, including both cavity-based and flower-shaped structures. The as-synthesised morphologies were noted to actively participate in electro-catalysis of atropine (AT) drug where GSH-assisted structures exhibited the best signal response in terms of current density and over-potential value. The study also discusses the influence of functional groups on the signal sensitivity of atropine electro-oxidation. The functionalisation was carried with the amino acids originally used as effective templates for the growth of Co{sub 3}O{sub 4} nanostructures. The highest increment was obtained when GSH was used as the surface functionalising agent. The GSH-functionalised Co{sub 3}O{sub 4}-modified electrode was utilised for the electro-chemical sensing of AT in a concentration range of 0.01–0.46 μM. The developed sensor exhibited excellent working linearity (R{sup 2} = 0.999) and signal sensitivity up to 0.001 μM of AT. The noted high sensitivity of the sensor is associated with the synergy of superb surface architectures and favourable interaction facilitating the electron transfer kinetics for the electro-catalytic oxidation of AT. Significantly, the developed sensor demonstrated excellent working capability when used for AT detection in human urine samples with strong anti-interference potential against common co-existing species, such as glucose, fructose, cysteine, uric acid, dopamine and ascorbic acid. - Highlights: • Template-assisted growth of Co{sub 3}O{sub 4} nanostructures. • Shape-dependent electro-catalysis of atropine. • Effect of functionalisation of signal sensitivity.

  9. The highly sensitive brain: an fMRI study of sensory processing sensitivity and response to others' emotions.

    Science.gov (United States)

    Acevedo, Bianca P; Aron, Elaine N; Aron, Arthur; Sangster, Matthew-Donald; Collins, Nancy; Brown, Lucy L

    2014-07-01

    Theory and research suggest that sensory processing sensitivity (SPS), found in roughly 20% of humans and over 100 other species, is a trait associated with greater sensitivity and responsiveness to the environment and to social stimuli. Self-report studies have shown that high-SPS individuals are strongly affected by others' moods, but no previous study has examined neural systems engaged in response to others' emotions. This study examined the neural correlates of SPS (measured by the standard short-form Highly Sensitive Person [HSP] scale) among 18 participants (10 females) while viewing photos of their romantic partners and of strangers displaying positive, negative, or neutral facial expressions. One year apart, 13 of the 18 participants were scanned twice. Across all conditions, HSP scores were associated with increased brain activation of regions involved in attention and action planning (in the cingulate and premotor area [PMA]). For happy and sad photo conditions, SPS was associated with activation of brain regions involved in awareness, integration of sensory information, empathy, and action planning (e.g., cingulate, insula, inferior frontal gyrus [IFG], middle temporal gyrus [MTG], and PMA). As predicted, for partner images and for happy facial photos, HSP scores were associated with stronger activation of brain regions involved in awareness, empathy, and self-other processing. These results provide evidence that awareness and responsiveness are fundamental features of SPS, and show how the brain may mediate these traits.

  10. High Quality Rapeseed Products as Feed for Sensitive Monogastrics

    DEFF Research Database (Denmark)

    Frandsen, Heidi Blok

    . Glucosinolates can be transformed enzymatic by the enzyme myrosinase (EC. 3.2.1.147), or non-enzymatic by heat treatment or under the acidic and reducing conditions in the stomach of monogastrics. The type of transformation product depends on the parent glucosinolate and of the chemical conditions, and in some...... for cheaper protein rapeseed meal has been considered as an alternative to soya-protein. Rapeseed (Brassica napus L. spp. oleifera) has a well-balanced amino acid profile for monogastrics, but it contains several compounds which are anti-nutritional and might lower the protein quality and limit the amount...... cake was included, while losses up to 88% were observed when cold-pressed rapeseed caked was used. N-balance trials with rats clearly demonstrated effects on the biologic value caused by high glucosinolate concentrations, active myrosinase and long temperature treatments. The second study (manuscript...

  11. Color Sensitivity Multiple Exposure Fusion using High Dynamic Range Image

    Directory of Open Access Journals (Sweden)

    Varsha Borole

    2014-02-01

    Full Text Available In this paper, we present a high dynamic range imaging (HDRI method using a capturing camera image using normally exposure, over exposure and under exposure. We make three different images from a multiple input image using local histogram stretching. Because the proposed method generated three histogram-stretched images from a multiple input image, ghost artifacts that are the result of the relative motion between the camera and objects during exposure time, are inherently removed. Therefore, the proposed method can be applied to a consumer compact camera to provide the ghost artifacts free HDRI. Experiments with several sets of test images with different exposures show that the proposed method gives a better performance than existing methods in terms of visual results and computation time.

  12. Application of X-ray micro-computed tomography on high-speed cavitating diesel fuel flows

    Energy Technology Data Exchange (ETDEWEB)

    Mitroglou, N.; Lorenzi, M.; Gavaises, M. [City University London, School of Mathematics Computer Science and Engineering, London (United Kingdom); Santini, M. [University of Bergamo, Department of Engineering, Bergamo (Italy)

    2016-11-15

    The flow inside a purpose built enlarged single-orifice nozzle replica is quantified using time-averaged X-ray micro-computed tomography (micro-CT) and high-speed shadowgraphy. Results have been obtained at Reynolds and cavitation numbers similar to those of real-size injectors. Good agreement for the cavitation extent inside the orifice is found between the micro-CT and the corresponding temporal mean 2D cavitation image, as captured by the high-speed camera. However, the internal 3D structure of the developing cavitation cloud reveals a hollow vapour cloud ring formed at the hole entrance and extending only at the lower part of the hole due to the asymmetric flow entry. Moreover, the cavitation volume fraction exhibits a significant gradient along the orifice volume. The cavitation number and the needle valve lift seem to be the most influential operating parameters, while the Reynolds number seems to have only small effect for the range of values tested. Overall, the study demonstrates that use of micro-CT can be a reliable tool for cavitation in nozzle orifices operating under nominal steady-state conditions. (orig.)

  13. Thermochemical micro imprinting of single-crystal diamond surface using a nickel mold under high-pressure conditions

    Energy Technology Data Exchange (ETDEWEB)

    Imoto, Yuji; Yan, Jiwang, E-mail: yan@mech.keio.ac.jp

    2017-05-15

    Graphical abstract: A Ni mold and thermochemically imprinted microstructures on diamond. - Highlights: • A thermochemical method for micro machining/patterning of diamond is proposed. • Various kinds of microstructures were imprinted on diamond using a Ni mold. • A graphite layer is formed during imprinting which can be removed by acid. • The processing depth depends strongly on pressure and temperature. - Abstract: Single-crystal diamond is an important material for cutting tools, micro electro mechanical systems, optical devices, and semiconductor substrates. However, the techniques for producing microstructures on diamond surface with high efficiency and accuracy have not been established. This paper proposes a thermochemical imprinting method for transferring microstructures from a nickel (Ni) mold onto single-crystal diamond surface. The Ni mold was micro-structured by a nanoindenter and then pressed against the diamond surface under high temperature and pressure in argon atmosphere. Results show that microstructures on the Ni mold were successfully transferred onto the diamond surface, and their depth increased with both pressure and temperature. Laser micro-Raman spectroscopy, transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) analyses indicate that a graphite layer was formed over the contact area between diamond and Ni during pressing, and after washing by a mixed acid, the graphite layer could be completely removed. This study demonstrated the feasibility of a cost-efficient fabrication method for large-area microstructures on single-crystal diamond.

  14. Performance of smooth and micro-fin tubes in high mass flux region of R-134a during evaporation

    Science.gov (United States)

    Wongsa-ngam, Jittraporn; Nualboonrueng, Thipjak; Wongwises, Somchai

    . The two-phase heat transfer coefficient and pressure drop during evaporation of pure R-134a in smooth and micro-fin tubes are experimentally investigated. Different from most previous studies, the present experiments have been performed at high mass flux conditions. The test section is a 2.5 m long counterflow horizontal double tube heat exchanger with refrigerant flow inside the tube while hot water flows in the annulas. The inner tubes are made from smooth or micro-fin horizontal copper tubing of 9.52 mm outer diameter. The test runs are done at average saturated evaporating temperatures ranging between 10 and 20 °C. The mass fluxes are between 400 and 800 kg/m2s. The experimental results of both smooth and micro-fin tubes show that the average heat transfer coefficient tends to increase with an increase of average quality, mass flux, and evaporating temperature. The pressure drop increases with an increase of average quality and mass flux, but tends to slightly decrease with a rise of evaporating temperature. The average heat transfer coefficient of the 9.52 mm OD micro-fin tube is 50% to 100% higher than that of the 9.52 mm OD smooth tube while the pressure drop is 10% to 60% higher. New correlations for the evaporation heat transfer coefficient and pressure drop in high mass flux region of R-134a are proposed for practical use.

  15. Photonic crystal nanofiber air-mode cavity with high Q-factor and high sensitivity for refractive index sensing

    Science.gov (United States)

    Ma, Xiaoxue; Chen, Xin; Nie, Hongrui; Yang, Daquan

    2018-01-01

    Recently, due to its superior characteristics and simple manufacture, such as small size, low loss, high sensitivity and convenience to couple, the optical fiber sensor has become one of the most promising sensors. In order to achieve the most effective realization of light propagation by changing the structure of sensors, FOM(S •Q/λres) ,which is determined by two significant variables Q-factor and sensitivity, as a trade-off parameter should be optimized to a high value. In typical sensors, a high Q can be achieved by confining the optical field in the high refractive index dielectric region to make an interaction between analytes and evanescent field of the resonant mode. However, the ignored sensitivity is relatively low with a high Q achieved, which means that the resonant wavelength shift changes non-obviously when the refractive index increases. Meanwhile, the sensitivity also leads to a less desirable FOM. Therefore, a gradient structure, which can enhance the performance of sensors by achieving high Q and high sensitivity, has been developed by Kim et al. later. Here, by introducing parabolic-tapered structure, the light field localized overlaps strongly and sufficiently with analytes. And based on a one-dimensional photonic-crystal nanofiber air-mode cavity, a creative optical fiber sensor is proposed by combining good stability and transmission characteristics of fiber and strengths of tapered structure, realizing excellent FOM {4.7 x 105 with high Q-factors (Q{106) and high sensitivities (<700 nm/RIU).

  16. High sensitivity microchannel plate detectors for space extreme ultraviolet missions.

    Science.gov (United States)

    Yoshioka, K; Homma, T; Murakami, G; Yoshikawa, I

    2012-08-01

    Microchannel plate (MCP) detectors have been widely used as two-dimensional photon counting devices on numerous space EUV (extreme ultraviolet) missions. Although there are other choices for EUV photon detectors, the characteristic features of MCP detectors such as their light weight, low dark current, and high spatial resolution make them more desirable for space applications than any other detector. In addition, it is known that the photocathode can be tailored to increase the quantum detection efficiency (QDE) especially for longer UV wavelengths (100-150 nm). There are many types of photocathode materials available, typically alkali halides. In this study, we report on the EUV (50-150 nm) QDE evaluations for MCPs that were coated with Au, MgF(2), CsI, and KBr. We confirmed that CsI and KBr show 2-100 times higher QDEs than the bare photocathode MCPs, while Au and MgF(2) show reduced QDEs. In addition, the optimal geometrical parameters for the CsI deposition were also studied experimentally. The best CsI thickness was found to be 150 nm, and it should be deposited on the inner wall of the channels only where the EUV photons initially impinge. We will also discuss the techniques and procedures for reducing the degradation of the photocathode while it is being prepared on the ground before being deployed in space, as adopted by JAXA's EXCEED mission which will be launched in 2013.

  17. Nanowire-templated microelectrodes for high-sensitivity pH detection

    DEFF Research Database (Denmark)

    Antohe, V.A.; Radu, Adrian; Mátéfi-Tempfli, Mária

    2009-01-01

    A highly sensitive pH capacitive sensor has been designed by confined growth of vertically aligned nanowire arrays on interdigited microelectrodes. The active surface of the device has been functionalized with an electrochemical pH transducer (polyaniline). We easily tune the device features...... by combining lithographic techniques with electrochemical synthesis. The reported electrical LC resonance measurements show considerable sensitivity enhancement compared to conventional capacitive pH sensors realized with microfabricated interdigited electrodes. The sensitivity can be easily improved...

  18. Formation of calcium phosphates by vapour diffusion in highly concentrated ionic micro-droplets

    Energy Technology Data Exchange (ETDEWEB)

    Iafisco, M. [Alma Mater Studiorum Universita di Bologna, Dipartimento di Chimica ' ' G. Ciamician' ' , Via Selmi 2, 40126 Bologna (Italy); Universita del Piemonte Orientale, Dipartimento di Scienze Mediche, Via Solaroli 4, 28100 Novara (Italy); Delgado-Lopez, J.M.; Gomez-Morales, J.; Hernandez-Hernandez, M.A.; Rodriguez-Ruiz, I. [Laboratorio de Estudios Cristalograficos, IACT CSIC-UGR, Edificio Lopez Neyra, Avenida del Conocimiento, s/n 18100 Armilla (Spain); Roveri, N. [Alma Mater Studiorum Universita di Bologna, Dipartimento di Chimica ' ' G. Ciamician' ' , Via Selmi 2, 40126 Bologna (Italy)

    2011-08-15

    In this work we have used the sitting drop vapour diffusion technique, employing the ''crystallization mushroom '' to analyze the evolution of calcium phosphate crystallization in micro-droplets containing high initial concentrations of Ca{sup 2+} and HPO{sub 4}{sup 2-}. The decomposition of NH{sub 4}HCO{sub 3} solution produces vapours of NH{sub 3} and CO{sub 2} which diffuse through the droplets containing an aqueous solution of Ca(CH{sub 3}COO){sub 2} and (NH{sub 4}){sub 2}HPO{sub 4}. The result is the increase of pH by means of the diffusion of NH{sub 3} gas and the doping of the calcium phosphate with CO{sub 3}{sup 2-} ions by means of the diffusion of CO{sub 2} gas. The pH of the crystallization process is monitored and the precipitates at different times are characterized by XRD, FTIR, TGA, SEM and TEM techniques. The slow increase of pH and the high concentration of Ca{sup 2+} and HPO{sub 4}{sup 2-} in the droplets induce the crystallization of three calcium phosphate phases: dicalcium phosphate dihydrate (DCPD, brushite), octacalcium phosphate (OCP) and carbonate-hydroxyapatite (HA). The amount of HA nanocrystals with needle-like morphology and dimensions of about 100 nm, closely resembling the inorganic phase of bones, gradually increases, with the precipitation time up to 7 days, whereas the amount of DCPD, growing along the b axis, increases up to 3 days. Then, DCDP crystals start to hydrolyze yielding OCP nanoribbons and HA nanocrystals. (copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  19. Sensitivity of Effective Thermal Conductivity Models on Temperature Distribution of Heterogeneous media of Fully Ceramic Micro-encapsulated Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyuk; Kim, S. J.; Hwang, D. H.; Lee, W. J. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2013-10-15

    A TRISO fuel particle consists of a spherical fuel kernel with four coating layers such as buffer, Inner PyC, SiC, Outer PyC. A FCM fuel pellet contains randomly distributed 36 in a SiC matrix. Such heterogeneous and complicated structure adds difficulty in calculating the realistic temperature distributions in the FCM fuel. General practice is to use a homogenized model using an effective thermal conductivity model. For these difficulties, a realistic temperature profile on a heterogeneous media is generally calculated on a homogenization model. In this study, we investigate the influence of effective thermal conductivity models on the temperature distribution in a heterogeneous media on FCM fuel pellet. Feasibility of Single Domain Homogenization(SDH) model has been estimated for a heterogeneous media like FCM fuel. From the study, it is found that the effective thermal conductivity is a crucial parameter in analyzing the temperature distributions in SDH approach. Sensitivity of the effective thermal conductivity models indicates that the Maxwell model or an optimized conductivity models are adequate in modeling the heterogeneous FCM fuel.

  20. Recent Advances in Outdoor High-Density Cultivation of Novelty Micro-Algae Strain with High Content of Lipids

    OpenAIRE

    Kaštánek, Petr

    2012-01-01

    The objective of the study was the pilot plant examination of a newly developed integrated process for autotrophic cultivation of useful micro-algae. The process utilizes waste carbon dioxide as a source of carbon and yields simultaneously products that can be utilized in food and cosmetic industries, turned into biodiesel and/or used as a supplement in animal feed. At present, the cultivation of micro-algae merely for the production of biofuels is not economically viable. In the proposed pr...

  1. Hypoxia-sensitive reporter system for high-throughput screening.

    Science.gov (United States)

    Tsujita, Tadayuki; Kawaguchi, Shin-ichi; Dan, Takashi; Baird, Liam; Miyata, Toshio; Yamamoto, Masayuki

    2015-02-01

    The induction of anti-hypoxic stress enzymes and proteins has the potential to be a potent therapeutic strategy to prevent the progression of ischemic heart, kidney or brain diseases. To realize this idea, small chemical compounds, which mimic hypoxic conditions by activating the PHD-HIF-α system, have been developed. However, to date, none of these compounds were identified by monitoring the transcriptional activation of hypoxia-inducible factors (HIFs). Thus, to facilitate the discovery of potent inducers of HIF-α, we have developed an effective high-throughput screening (HTS) system to directly monitor the output of HIF-α transcription. We generated a HIF-α-dependent reporter system that responds to hypoxic stimuli in a concentration- and time-dependent manner. This system was developed through multiple optimization steps, resulting in the generation of a construct that consists of the secretion-type luciferase gene (Metridia luciferase, MLuc) under the transcriptional regulation of an enhancer containing 7 copies of 40-bp hypoxia responsive element (HRE) upstream of a mini-TATA promoter. This construct was stably integrated into the human neuroblastoma cell line, SK-N-BE(2)c, to generate a reporter system, named SKN:HRE-MLuc. To improve this system and to increase its suitability for the HTS platform, we incorporated the next generation luciferase, Nano luciferase (NLuc), whose longer half-life provides us with flexibility for the use of this reporter. We thus generated a stably transformed clone with NLuc, named SKN:HRE-NLuc, and found that it showed significantly improved reporter activity compared to SKN:HRE-MLuc. In this study, we have successfully developed the SKN:HRE-NLuc screening system as an efficient platform for future HTS.

  2. Sensory Processing Sensitivity: Factors of the Highly Sensitive Person Scale and Their relationships to Personality and Subjective Health Complaints.

    Science.gov (United States)

    Listou Grimen, Hanne; Diseth, Åge

    2016-12-01

    The aim of the present study was to examine the factor structure of a Norwegian version of the Highly Sensitive Person Scale (HSPS) and to investigate how sensory processing sensitivity (SPS) is related to personality traits of neuroticism, extraversion, and openness and to subjective health complaints (SHC) in a sample of 167 undergraduate psychology students. The results showed that the variance in a shortened version of the HSPS was best described by three separate factors: ease of excitation (EOE), aesthetic sensitivity (AES), and low sensory threshold (LST). Furthermore, the result showed than an overall SPS factor (EOE, LST, and AES combined) was predicted positively by neuroticism and openness and negatively by extraversion. With respect to SHC, the results showed that EOE and LST were positively associated with psychological health complaints. However, the personality trait of neuroticism contributed more than the SPS factors as predictor of SHC. In conclusion, the present study supported a shortened version of the HSPS and its relation to personality factors and SHC. © The Author(s) 2016.

  3. MicroRNA-223 Enhances Radiation Sensitivity of U87MG Cells In Vitro and In Vivo by Targeting Ataxia Telangiectasia Mutated

    Energy Technology Data Exchange (ETDEWEB)

    Liang, Liping; Zhu, Ji [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Zaorsky, Nicholas G. [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Deng, Yun [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Wu, Xingzhong [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai (China); Liu, Yong [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Liu, Fangqi; Cai, Guoxiang; Gu, Weilie [Department of Colorectal Cancer, Fudan University, Shanghai Cancer Center, Shanghai (China); Shen, Lijun [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China); Zhang, Zhen, E-mail: zhenzhang6@hotmail.com [Departments of Radiation Oncology, Fudan University Shanghai Cancer Center, Department of Oncology, Shanghai Medical College, Fudan University, Shanghai (China)

    2014-03-15

    Purpose: Ataxia telangiectasia mutated (ATM) protein is important in the DNA damage response because it repairs radiation-induced damage in cancers. We examined the effect of microRNA-223 (miR-223), a regulator of ATM expression, on radiation sensitivity of cancer cells. Methods and Materials: Human embryonic kidney 293 T (293T) cells were infected with pLL3.7-miR-223 plasmid to generate the pLL3.7-miR-223 and -empty virus (EV) lentivirus (miR-223 and EV). A dual luciferase assay in which the reporter contained wild-type 3′ untranslated region (UTR) of ATM was performed. U87MG cells were infected with miR-223 or EV to establish the overexpressed stable cell lines (U87-223 or U87-EV, respectively). Cells were irradiated in vitro, and dose enhancement ratios at 2 Gy (DER{sub 2}) were calculated. Hind legs of BALB/c athymic mice were injected with U87-223 or U87-EV cells; after 2 weeks, half of the tumors were irradiated. Tumor volumes were tracked for a total of 5 weeks. Results: The dual luciferase reporter assay showed a significant reduction in luciferase activity of 293T cells cotransfected with miR-223 and the ATM 3′UTR compared to that in EV control. Overexpression of miR-223 in U87MG cells showed that ATM expression was significantly downregulated in the U87-223 cells compared to that in U87-EV (ATM/β-actin mRNA 1.0 vs 1.5, P<.05). U87-223 cells were hypersensitive to radiation compared to U87-EV cells in vitro (DER{sub 2} = 1.32, P<.01). Mice injected with miR-223-expressing tumors had almost the same tumors after 3 weeks (1.5 cm{sup 3} vs 1.7 cm{sup 3}). However, irradiation significantly decreased tumor size in miR-223-expressing tumors compared to those in controls (0.033 cm{sup 3} vs 0.829 cm{sup 3}). Conclusions: miR-223 overexpression downregulates ATM expression and sensitizes U87 cells to radiation in vitro and in vivo. MicroRNA-223 may be a novel cancer-targeting therapy, although its cancer- and patient-specific roles are

  4. Unraveling the high- and low-sensitivity agonist responses of nicotinic acetylcholine receptors

    DEFF Research Database (Denmark)

    Harpsøe, Kasper; Ahring, Philip K; Christensen, Jeppe K

    2011-01-01

    for the observation of two distinct agonist sensitivities. Using different expression ratios of mammalian a4 and ß2 subunits and concatenated constructs, we demonstrate that a biphasic response is an intrinsic functional property of the (a4)(3)(ß2)(2) receptor. In addition to two high-sensitivity sites at a4ß2...

  5. Nanotopographic characterization of spotted micro arrays on polyvinyl alcohol films by high-resolution long-range nanoprofiling.

    Science.gov (United States)

    Thete, Aniket R; Gross, G Alexander; Hausotte, Tino; Jäger, Gerd; Dorozhovets, Nataliya; Köhler, J Michael

    2009-01-01

    The nanopositioning and nanomeasuring machine was applied for the nanotopographic characterization of polymer micro spot arrays of fluorimetric chemochips. Chemochips are arrays of fluorescence dyes in a hydrogel matrix with different response behaviors of chemical components determination of chemical and physico-chemical properties of analytes by a pattern recognition approach. For the characterization and quality control of the spots, a nanometer resolution is needed over a scan range of several millimeters. This challenge could be met by use of a scanning probe sensor in connection with a laser interferometer controlled high-precision positioning and measuring device. This way, topographic scans with the resolution of atomic force microscope could be achieved over these demandingly large ranges. The technique was used in order to determine the quality of thin film micro spots made from fluorescence dye solutions on preformed polymer films and also tested for characterization of monomolecular films in the form of micro spots. The nanotopographic measurements reflect the strong influence of solvent/matrix interaction, wetting, swelling and material transport during the application of picoliter droplets in the spotting process. The measurement clarifies the reason for the formation of roughness in the nanometer range by nano-crystal formation in the upper part of polymer film and the rim formation of micro spots during solvent evaporation. The studies show the effect of application of different numbers of droplets in a dispensing series for spot formation and prove the high importance of polymer/solvent interaction for the quality of formed micro spots as well as for spot arrays of monomolecular films. Copyright (c) 2009 Wiley Periodicals, Inc.

  6. Development of the "Highly Sensitive Dog" questionnaire to evaluate the personality dimension "Sensory Processing Sensitivity" in dogs.

    Directory of Open Access Journals (Sweden)

    Maya Braem

    Full Text Available In humans, the personality dimension 'sensory processing sensitivity (SPS', also referred to as "high sensitivity", involves deeper processing of sensory information, which can be associated with physiological and behavioral overarousal. However, it has not been studied up to now whether this dimension also exists in other species. SPS can influence how people perceive the environment and how this affects them, thus a similar dimension in animals would be highly relevant with respect to animal welfare. We therefore explored whether SPS translates to dogs, one of the primary model species in personality research. A 32-item questionnaire to assess the "highly sensitive dog score" (HSD-s was developed based on the "highly sensitive person" (HSP questionnaire. A large-scale, international online survey was conducted, including the HSD questionnaire, as well as questions on fearfulness, neuroticism, "demographic" (e.g. dog sex, age, weight; age at adoption, etc. and "human" factors (e.g. owner age, sex, profession, communication style, etc., and the HSP questionnaire. Data were analyzed using linear mixed effect models with forward stepwise selection to test prediction of HSD-s by the above-mentioned factors, with country of residence and dog breed treated as random effects. A total of 3647 questionnaires were fully completed. HSD-, fearfulness, neuroticism and HSP-scores showed good internal consistencies, and HSD-s only moderately correlated with fearfulness and neuroticism scores, paralleling previous findings in humans. Intra- (N = 447 and inter-rater (N = 120 reliabilities were good. Demographic and human factors, including HSP score, explained only a small amount of the variance of HSD-s. A PCA analysis identified three subtraits of SPS, comparable to human findings. Overall, the measured personality dimension in dogs showed good internal consistency, partial independence from fearfulness and neuroticism, and good intra- and inter

  7. Development of the "Highly Sensitive Dog" questionnaire to evaluate the personality dimension "Sensory Processing Sensitivity" in dogs.

    Science.gov (United States)

    Braem, Maya; Asher, Lucy; Furrer, Sibylle; Lechner, Isabel; Würbel, Hanno; Melotti, Luca

    2017-01-01

    In humans, the personality dimension 'sensory processing sensitivity (SPS)', also referred to as "high sensitivity", involves deeper processing of sensory information, which can be associated with physiological and behavioral overarousal. However, it has not been studied up to now whether this dimension also exists in other species. SPS can influence how people perceive the environment and how this affects them, thus a similar dimension in animals would be highly relevant with respect to animal welfare. We therefore explored whether SPS translates to dogs, one of the primary model species in personality research. A 32-item questionnaire to assess the "highly sensitive dog score" (HSD-s) was developed based on the "highly sensitive person" (HSP) questionnaire. A large-scale, international online survey was conducted, including the HSD questionnaire, as well as questions on fearfulness, neuroticism, "demographic" (e.g. dog sex, age, weight; age at adoption, etc.) and "human" factors (e.g. owner age, sex, profession, communication style, etc.), and the HSP questionnaire. Data were analyzed using linear mixed effect models with forward stepwise selection to test prediction of HSD-s by the above-mentioned factors, with country of residence and dog breed treated as random effects. A total of 3647 questionnaires were fully completed. HSD-, fearfulness, neuroticism and HSP-scores showed good internal consistencies, and HSD-s only moderately correlated with fearfulness and neuroticism scores, paralleling previous findings in humans. Intra- (N = 447) and inter-rater (N = 120) reliabilities were good. Demographic and human factors, including HSP score, explained only a small amount of the variance of HSD-s. A PCA analysis identified three subtraits of SPS, comparable to human findings. Overall, the measured personality dimension in dogs showed good internal consistency, partial independence from fearfulness and neuroticism, and good intra- and inter-rater reliability

  8. Genome-wide identification of bone metastasis-related microRNAs in lung adenocarcinoma by high-throughput sequencing.

    Directory of Open Access Journals (Sweden)

    Lin Xie

    Full Text Available BACKGROUND: MicroRNAs (miRNAs are a class of small noncoding RNAs that regulate gene expression at the post-transcriptional level. They participate in a wide variety of biological processes, including apoptosis, proliferation and metastasis. The aberrant expression of miRNAs has been found to play an important role in many cancers. RESULTS: To understand the roles of miRNAs in the bone metastasis of lung adenocarcinoma, we constructed two small RNA libraries from blood of lung adenocarcinoma patients with and without bone metastasis. High-throughput sequencing combined with differential expression analysis identified that 7 microRNAs were down-regulated and 21 microRNAs were up-regulated in lung adenocarcinoma with bone metastasis. A total of 797 target genes of the differentially expressed microRNAs were identified using a bioinformatics approach. Functional annotation analysis indicated that a number of pathways might be involved in bone metastasis, survival of the primary origin and metastatic angiogenesis of lung adenocarcinoma. These include the MAPK, Wnt, and NF-kappaB signaling pathways, as well as pathways involving the matrix metalloproteinase, cytoskeletal protein and angiogenesis factors. CONCLUSIONS: This study provides some insights into the molecular mechanisms that underlie lung adenocarcinoma development, thereby aiding the diagnosis and treatment of the disease.

  9. Optimization of a retrospective technique for respiratory-gated high speed micro-CT of free-breathing rodents

    Science.gov (United States)

    Ford, Nancy L.; Wheatley, Andrew R.; Holdsworth, David W.; Drangova, Maria

    2007-09-01

    The objective of this study was to develop a technique for dynamic respiratory imaging using retrospectively gated high-speed micro-CT imaging of free-breathing mice. Free-breathing C57Bl6 mice were scanned using a dynamic micro-CT scanner, comprising a flat-panel detector mounted on a slip-ring gantry. Projection images were acquired over ten complete gantry rotations in 50 s, while monitoring the respiratory motion in synchrony with projection-image acquisition. Projection images belonging to a selected respiratory phase were retrospectively identified and used for 3D reconstruction. The effect of using fewer gantry rotations—which influences both image quality and the ability to quantify respiratory function—was evaluated. Images reconstructed using unique projections from six or more gantry rotations produced acceptable images for quantitative analysis of lung volume, CT density, functional residual capacity and tidal volume. The functional residual capacity (0.15 ± 0.03 mL) and tidal volumes (0.08 ± 0.03 mL) measured in this study agree with previously reported measurements made using prospectively gated micro-CT and at higher resolution (150 µm versus 90 µm voxel spacing). Retrospectively gated micro-CT imaging of free-breathing mice enables quantitative dynamic measurement of morphological and functional parameters in the mouse models of respiratory disease, with scan times as short as 30 s, based on the acquisition of projection images over six gantry rotations.

  10. Micro Manufacturing

    DEFF Research Database (Denmark)

    Hansen, Hans Nørgaard

    2003-01-01

    Manufacturing deals with systems that include products, processes, materials and production systems. These systems have functional requirements, constraints, design parameters and process variables. They must be decomposed in a systematic manner to achieve the best possible system performance....... If a micro manufacturing system isn’t designed rationally and correctly, it will be high-cost, unreliable, and not robust. For micro products and systems it is a continuously increasing challenge to create the operational basis for an industrial production. As the products through product development...... processes are made applicable to a large number of customers, the pressure in regard to developing production technologies that make it possible to produce the products at a reasonable price and in large numbers is growing. The micro/nano manufacturing programme at the Department of Manufacturing...

  11. Identification of microRNAs from Eugenia uniflora by high-throughput sequencing and bioinformatics analysis.

    Science.gov (United States)

    Guzman, Frank; Almerão, Mauricio P; Körbes, Ana P; Loss-Morais, Guilherme; Margis, Rogerio

    2012-01-01

    microRNAs or miRNAs are small non-coding regulatory RNAs that play important functions in the regulation of gene expression at the post-transcriptional level by targeting mRNAs for degradation or inhibiting protein translation. Eugenia uniflora is a plant native to tropical America with pharmacological and ecological importance, and there have been no previous studies concerning its gene expression and regulation. To date, no miRNAs have been reported in Myrtaceae species. Small RNA and RNA-seq libraries were constructed to identify miRNAs and pre-miRNAs in Eugenia uniflora. Solexa technology was used to perform high throughput sequencing of the library, and the data obtained were analyzed using bioinformatics tools. From 14,489,131 small RNA clean reads, we obtained 1,852,722 mature miRNA sequences representing 45 conserved families that have been identified in other plant species. Further analysis using contigs assembled from RNA-seq allowed the prediction of secondary structures of 25 known and 17 novel pre-miRNAs. The expression of twenty-seven identified miRNAs was also validated using RT-PCR assays. Potential targets were predicted for the most abundant mature miRNAs in the identified pre-miRNAs based on sequence homology. This study is the first large scale identification of miRNAs and their potential targets from a species of the Myrtaceae family without genomic sequence resources. Our study provides more information about the evolutionary conservation of the regulatory network of miRNAs in plants and highlights species-specific miRNAs.

  12. High-resolution identification and abundance profiling of cassava (Manihot esculenta Crantz) microRNAs.

    Science.gov (United States)

    Khatabi, Behnam; Arikit, Siwaret; Xia, Rui; Winter, Stephan; Oumar, Doungous; Mongomake, Kone; Meyers, Blake C; Fondong, Vincent N

    2016-01-28

    Small RNAs (sRNAs) are endogenous sRNAs that play regulatory roles in plant growth, development, and biotic and abiotic stress responses. In plants, one subset of sRNAs, microRNAs (miRNAs) exhibit tissue-differential expression and regulate gene expression mainly through direct cleavage of mRNA or indirectly via production of secondary phased siRNAs (phasiRNAs) that silence cognate target transcripts in trans. Here, we have identified cassava (Manihot esculenta Crantz) miRNAs using high resolution sequencing of sRNA libraries from leaf, stem, callus, male and female flower tissues. To analyze the data, we built a cassava genome database and, via sequence analysis and secondary structure prediction, 38 miRNAs not previously reported in cassava were identified. These new cassava miRNAs included two miRNAs not previously been reported in any plant species. The miRNAs exhibited tissue-differential accumulation as confirmed by quantitative RT-PCR and Northern blot analysis, largely reflecting levels observed in sequencing data. Some of the miRNAs identified were predicted to trigger production of secondary phased siRNAs (phasiRNAs) from 80 PHAS loci. Cassava is a woody perennial shrub, grown principally for its starch-rich storage roots, which are rich in calories. In this study, new miRNAs were identified and their expression was validated using qRT-PCR of RNA from five different tissues. The data obtained expand the list of annotated miRNAs and provide additional new resources for cassava improvement research.

  13. Time-dependent convective flows with high viscosity contrasts under micro gravity conditions.

    Science.gov (United States)

    Zaussinger, Florian; Egbers, Christoph; Krebs, Andreas; Schwarzbach, Felix; Kunze, Christian

    2015-04-01

    Thermal driven convection in spherical geometry is of main interest in geo- and astrophysical research. To capture certain aspects of temperature dependent viscosity we investigate the micro-gravity experiment GeoFlow-IIb, located on the ISS. This unique experimental setup consists of a bottom heated and top cooled spherical gap, filled with the silicon oil 1-Nonanol. However, rotation and varying temperature gradients can be applied, to spread the experimental parameter space. The main focus of the current mission is the investigation of time dependent convective flow structures. Since the ISS requirements makes it impossible to use tracer particles, the flow structures are captured by interferometry, whose outcome is analysed by an ground based adapted image processing technique. To guarantee valid results the experimental time of each parameter is in the order of the thermal time scale, which is about 40 min. We are presenting latest results of plume-like and sheet-like time-dependent convective patterns in the spherical shell, their evolution and temporal behaviour under high viscosity contrasts. Due to an unexpected nonlinear coupling between the temperature dependent viscosity of the working fluid and the applied dielectrophoretic force field, we are able to maintain a viscosity contrast of 50 and more. This gives the chance to compare cautiously our experimental results with theoretical assumptions of the mantle convection theory. Besides, numerical simulations in the same parameter regime are performed, which give the opportunity to deduce the internal structure of the experimental flow flied. The main focus of the presented results are the long time temporal evolution of convective plumes in the spherical gap, image capturing- and processing techniques and the deduction of the internal flow field based on planar interferometry pictures.

  14. Implementation of a sliding-mode-based position sensorless drive for high-speed micro permanent-magnet synchronous motors.

    Science.gov (United States)

    Chi, Wen-Chun; Cheng, Ming-Yang

    2014-03-01

    Due to issues such as limited space, it is difficult if it is not impossible to employ a position sensor in the drive control of high-speed micro PMSMs. In order to alleviate this problem, this paper analyzes and implements a simple and robust position sensorless field-oriented control method of high-speed micro PMSMs based on the sliding-mode observer. In particular, the angular position and velocity of the rotor of the high-speed micro PMSM are estimated using the sliding-mode observer. This observer is able to accurately estimate rotor position in the low speed region and guarantee fast convergence of the observer in the high speed region. The proposed position sensorless control method is suitable for electric dental handpiece motor drives where a wide speed range operation is essential. The proposed sensorless FOC method is implemented using a cost-effective 16-bit microcontroller and tested in a prototype electric dental handpiece motor. Several experiments are performed to verify the effectiveness of the proposed method. © 2013 ISA. Published by Elsevier Ltd. All rights reserved.

  15. High-performance fault-tolerant VLSI systems using micro rollback

    Science.gov (United States)

    Tamir, Yuval; Tremblay, Marc

    1990-01-01

    A technique called micro rollback, which allows most of the performance penalty for concurrent error detection to be eliminated, is presented. Detection is performed in parallel with the transmission of information between modules, thus removing the delay for detection from the critical path. Erroneous information may thus reach its destination module several clock cycles before an error indication. Operations performed on this erroneous information are undone using a hardware mechanism for fast rollback of a few cycles. The implementation of a VLSI processor capable of micro rollback is discussed, as well as several critical issues related to its use in a complete system.

  16. Micro Injection Moulding High Accuracy Three-Dimensional Simulations and Process Control

    DEFF Research Database (Denmark)

    Tosello, Guido; Costa, F.S.; Hansen, Hans Nørgaard

    2011-01-01

    Data analysis and simulations of micro‐moulding experiments have been conducted. Micro moulding simulations have been executed by implementing in the software the actual processing conditions. Various aspects of the simulation set‐up have been considered in order to improve the simulation accuracy......, injection pressure profile, moulding mass and flow pattern. The importance of calibrated micro moulding process monitoring for an accurate implementation strategy of the simulation and its validation has been demonstrated. In fact, inconsistencies and uncertainties in the experimental data must be minimized...

  17. High-speed monodisperse droplet generation by ultrasonically controlled micro-jet breakup

    Science.gov (United States)

    Frommhold, Philipp Erhard; Lippert, Alexander; Holsteyns, Frank Ludwig; Mettin, Robert

    2014-04-01

    always achievable. Thus, the reliable and robust realization of tunable high-speed monodisperse micro-droplet trains is demonstrated. Some implication for applications is discussed.

  18. Interoceptive threat leads to defensive mobilization in highly anxiety sensitive persons.

    Science.gov (United States)

    Melzig, Christiane A; Holtz, Katharina; Michalowski, Jaroslaw M; Hamm, Alfons O

    2011-06-01

    To study defensive mobilization elicited by the exposure to interoceptive arousal sensations, we exposed highly anxiety sensitive students to a symptom provocation task. Symptom reports, autonomic arousal, and the startle eyeblink response were monitored during guided hyperventilation and a recovery period in 26 highly anxiety sensitive persons and 22 controls. Normoventilation was used as a non-provocative comparison condition. Hyperventilation led to autonomic arousal and a marked increase in somatic symptoms. While high and low anxiety sensitive persons did not differ in their defensive activation during hyperventilation, group differences were detected during early recovery. Highly anxiety sensitive students exhibited a potentiation of startle response magnitudes and increased autonomic arousal after hyper- as compared to after normoventilation, indicating defensive mobilization evoked by the prolonged presence of feared somatic sensations. Copyright © 2010 Society for Psychophysiological Research.

  19. Postsynthetic lanthanide functionalization of nanosized metal-organic frameworks for highly sensitive ratiometric luminescent thermometry.

    Science.gov (United States)

    Zhou, You; Yan, Bing; Lei, Fang

    2014-12-14

    A straightforward postsynthetic lanthanide functionalization strategy is developed for fabricating highly sensitive ratiometric luminescent nanothermometers based on nanosized MOFs, which highlights the ability of a broad range of nanosized MOFs to construct nanothermometers.

  20. Sensitivity and accuracy of high-throughput metabarcoding methods for early detection of invasive fish species

    Science.gov (United States)

    For early detection biomonitoring of aquatic invasive species, sensitivity to rare individuals and accurate, high-resolution taxonomic classification are critical to minimize detection errors. Given the great expense and effort associated with morphological identification of many...

  1. Temperature insensitive hysteresis free highly sensitive polymer optical fiber Bragg grating humidity sensor.

    Science.gov (United States)

    Woyessa, Getinet; Nielsen, Kristian; Stefani, Alessio; Markos, Christos; Bang, Ole

    2016-01-25

    The effect of humidity on annealing of poly (methyl methacrylate) (PMMA) based microstructured polymer optical fiber Bragg gratings (mPOFBGs) and the resulting humidity responsivity are investigated. Typically annealing of PMMA POFs is done in an oven without humidity control around 80°C and therefore at low humidity. We demonstrate that annealing at high humidity and high temperature improves the performances of mPOFBGs in terms of stability and sensitivity to humidity. PMMA POFBGs that are not annealed or annealed at low humidity level will have a low and highly temperature dependent sensitivity and a high hysteresis in the humidity response, in particular when operated at high temperature. PMMA mPOFBGs annealed at high humidity show higher and more linear humidity sensitivity with negligible hysteresis. We also report how annealing at high humidity can blue-shift the FBG wavelength more than 230 nm without loss in the grating strength.

  2. Temperature insensitive hysteresis free highly sensitive polymer optical fiber Bragg grating humidity sensor

    DEFF Research Database (Denmark)

    Woyessa, Getinet; Nielsen, Kristian; Stefani, Alessio

    2016-01-01

    The effect of humidity on annealing of poly (methyl methacrylate) (PMMA) based microstructured polymer optical fiber Bragg gratings (mPOFBGs) and the resulting humidity responsivity are investigated. Typically annealing of PMMA POFs is done in an oven without humidity control around 80°C...... and therefore at low humidity. We demonstrate that annealing at high humidity and high temperature improves the performances of mPOFBGs in terms of stability and sensitivity to humidity. PMMA POFBGs that are not annealed or annealed at low humidity level will have a low and highly temperature dependent...... sensitivity and a high hysteresis in the humidity response, in particular when operated at high temperature. PMMA mPOFBGs annealed at high humidity show higher and more linear humidity sensitivity with negligible hysteresis. We also report how annealing at high humidity can blue-shift the FBG wavelength more...

  3. Slow light engineering for high Q high sensitivity photonic crystal microcavity biosensors in silicon.

    Science.gov (United States)

    Chakravarty, Swapnajit; Zou, Yi; Lai, Wei-Cheng; Chen, Ray T

    2012-01-01

    Current trends in photonic crystal microcavity biosensors in silicon-on-insulator (SOI), that focus on small and smaller sensors have faced a bottleneck trying to balance two contradictory requirements of resonance quality factor and sensitivity. By simultaneous control of the radiation loss and optical mode volumes, we show that both requirements can be satisfied simultaneously. Microcavity sensors are designed in which resonances show highest Q ≈ 9300 in the bio-ambient phosphate buffered saline (PBS) as well as highest sensitivity among photonic crystal biosensors. We experimentally demonstrated mass sensitivity 8.8 atto-grams with sensitivity per unit area of 0.8 pg/mm(2). Highest sensitivity, irrespective of the dissociation constant K(d), is demonstrated among all existing label-free optical biosensors in silicon at the concentration of 0.1 μg/ml. Copyright © 2012 Elsevier B.V. All rights reserved.

  4. A highly sensitive method for the detection of Chrysanthemum virus B

    Directory of Open Access Journals (Sweden)

    Zhiyong Guan

    2017-03-01

    Conclusion: A highly specific and sensitive nested PCR-based assay has been described for detecting CVB. This new method is highly specific and sensitive for the detection of CVB, which is known to infect chrysanthemum plants in the fields. Further, this protocol has an advantage over traditional methods as it is more cost-effective. This assay is ideal for an early stage diagnosis of the disease.

  5. Desensitization protocol for highly sensitized renal transplant patients: A single-center experience

    OpenAIRE

    Kute, Vivek B.; Vanikar, Aruna V.; Trivedi, Hargovind L; Shah, Pankaj R; Kamal R Goplani; Patel, Himanshu V.; Gumber, Manoj R.; Patel, Rashmi D; Kamal V Kanodia; Kamlesh S Suthar; Trivedi, Varsha B; Pranjal R Modi

    2011-01-01

    Highly sensitized patients are destined to remain untransplanted for long. Early transplantation results in cost-saving, reduced morbidity/mortality and improved quality of life. We carried out a prospective study to evaluate the efficacy and safety of desensitization protocol vis-à-vis patient/graft survival in living donor renal transplantation in highly sensitized patients. Between December 2008 and April 2010, 34 renal transplant (RTx) patients underwent desensitization protocol. An anti-...

  6. Fast and sensitive detection of bacteria from a water droplet by means of electric field effects and micro-Raman spectroscopy

    Directory of Open Access Journals (Sweden)

    David S. Liao

    2015-12-01

    Full Text Available A surface-based method that can provide early and label-free detection of target microorganisms in water is presented. The method combines three key features, namely, (a accelerated transportation to, and focusing of bacteria on, the detection surface by means of alternating current (AC electrokinetic effects, (b selective capture of the target microorganism using surface-immobilized antibodies, and (c sensitive detection of target bacteria with micro-Raman spectroscopy. The non-uniform electric field is created by an AC signal-driven planar, quadrupolar, gold microelectrode array that is deposited on the detection surface (oxidized silicon wafer. AC electroosmosis and dielectrophoresis combine to produce the desired concentration amplification of bacteria on the capture surface within a few minutes. Bacterial detection is, subsequently, accomplished through Raman spectra acquired at pre-determined locations near the electrodes after sample removal and rinsing of the capture surface. Using this technique, detection of Escherichia coli K12 (target microorganism at concentrations as low as 102 bacteria per mL was reproducibly achieved from 50 μL sample droplets. This method also permits the selective retention of a target microorganism from polymicrobial mixtures, as demonstrated here with the capture of E. coli K12 from their mixtures with Micrococcus luteus.

  7. A buried intrusion monitoring system based on high sensitivity optical fiber geophone

    Science.gov (United States)

    Li, Shujuan; Zhang, Faxiang; Zhang, Xiaolei; Sun, Zhihui; Min, Li; Wang, Chang

    2017-10-01

    A new intrusion monitoring system is designed, based on a high sensitivity fiber grating geophone and PGC interferometric demodulation. A kind of high sensitive fiber Bragg grating geophone is designed. The sensitivity of the geophone is analyzed by finite element software. The PGC interferometric demodulation algorithm is used to detect the wavelength of the geophone, to reduce the noise of the system and improve the signal-to-noise ratio. Invasive monitoring test was carried out, the personnel and vehicles invading signal were collected and analyzed. Test results show that the intrusion monitoring system based on fiber geophone can effectively identify remote intrusion, and has low false alarm rate.

  8. Highly sensitive fiber optic Fabry-Perot geophone with graphene coated PMMA membrane

    Science.gov (United States)

    Yu, C. B.; Wu, Y.; Wu, F.; Li, C.; Zhou, J. H.; Rao, Y. J.; Chen, Y. F.

    2017-04-01

    A highly sensitive fiber-optic Fabry-Perot interferometric geophone (FFPG) with graphene coated PMMA membrane is proposed and demonstrated, where the graphene coating is used for enhancement of the mechanical strength of the membrane. It is found that the sensitivity of the FFPG is much higher than that of the conventional electrical geophone. Such a novel all-optical geophone with low cost, high sensitivity, electromagnetic interference immunity, easy fabrication and robust structure would have great potential for use in oil/gas exploration and seismic wave detection.

  9. Ultra-long high-sensitivity Φ-OTDR for high spatial resolution intrusion detection of pipelines.

    Science.gov (United States)

    Peng, Fei; Wu, Han; Jia, Xin-Hong; Rao, Yun-Jiang; Wang, Zi-Nan; Peng, Zheng-Pu

    2014-06-02

    An ultra-long phase-sensitive optical time domain reflectometry (Φ-OTDR) that can achieve high-sensitivity intrusion detection over 131.5km fiber with high spatial resolution of 8m is presented, which is the longest Φ-OTDR reported to date, to the best of our knowledge. It is found that the combination of distributed Raman amplification with heterodyne detection can extend the sensing distance and enhances the sensitivity substantially, leading to the realization of ultra-long Φ-OTDR with high sensitivity and spatial resolution. Furthermore, the feasibility of applying such an ultra-long Φ-OTDR to pipeline security monitoring is demonstrated and the features of intrusion signal can be extracted with improved SNR by using the wavelet detrending/denoising method proposed.

  10. Fabrication of high aspect ratio nanopillars and micro/nano combined structures with hydrophobic surface characteristics by injection molding

    Science.gov (United States)

    Zhou, Mingyong; Xiong, Xiang; Jiang, Bingyan; Weng, Can

    2018-01-01

    Polymer products with micro/nano-structures have excellent mechanical and optical properties, chemical resistance, and other advantages. Injection molding is one of the most potential techniques to fabricate polymer products with micro/nano-structures artificially in large numbers. In this study, a surface approach to fabricate high aspect ratio nanopillars and micro/nano combined structures was presented. Mold insert with micropillar arrays and nanopillars on its surface was prepared by combing anodic aluminum oxide (AAO) template and etched plate. Anti-sticking modification was done on the template to realize a better demolding quality. The influences of mold temperature and polymer material on the final replication quality were investigated. The results showed that the final replication quality of high aspect ratio nanopillars was greatly improved as compared with the unprocessed template. Polymer with low elongation at break was not suitable to fabricate structures with high aspect ratio via injection molding. For polypropylene surface, the experimental results of static contact angles were almost consistent with Cassie-Baxter equation. When the mold temperature reached 178 °C, hair-like polycarbonate nanopillars were observed, resulting in an excellent hydrophobic characteristic.

  11. Development of Integrated Electronics for Readout of High Frequency Micro/Nano-mechanical Resonator

    DEFF Research Database (Denmark)

    Tang, Meng

    Micro størrelse bulk type resonatorer er blevet udviklet gennern de sidste fem år til anvendelse inden for elektronikbranchen til lav strøm og billige alternativer til både passive og aktive komponenter. Dog kan denne type bulk resonator også bruges til bio/kemiske sensorer hvor, da på grund af d...

  12. A High Performance Micro Channel Interface for Real-Time Industrial Image Processing

    Science.gov (United States)

    Thomas H. Drayer; Joseph G. Tront; Richard W. Conners

    1995-01-01

    Data collection and transfer devices are critical to the performance of any machine vision system. The interface described in this paper collects image data from a color line scan camera and transfers the data obtained into the system memory of a Micro Channel-based host computer. A maximum data transfer rate of 20 Mbytes/sec can be achieved using the DMA capabilities...

  13. Micro machining workstation for a diode pumped Nd:YAG high brightness laser system

    NARCIS (Netherlands)

    Kleijhorst, R.A.; Offerhaus, Herman L.; Bant, P.

    1998-01-01

    A Nd:YAG micro-machining workstation that allows cutting on a scale of a few microns has been developed and operated. The system incorporates a telescope viewing system that allows control during the work and a software interface to translate AutoCad files. Some examples of the performance are

  14. Dimensional verification of high aspect micro structures using FIB-SEM

    DEFF Research Database (Denmark)

    Zhang, Yang; Hansen, Hans Nørgaard

    2013-01-01

    -SEM) assisted by Spip®. The micro features are circular holes 10μm in diameter and 20μm deep, with a 20μm pitch. Various inspection methods were attempted to obtain dimensional information. Due to the dimension, neither optical instrument nor atomic force microscope (AFM) was capable to perform the measurement...

  15. High strain rate sensitivity of hardness in quinary Ti-Zr-Hf-Cu-Ni high entropy metallic glass thin films

    Science.gov (United States)

    Zhao, Shaofan; Wang, Haibin; Xiao, Lin; Guo, Nan; Zhao, Delin; Yao, Kefu; Chen, Na

    2017-10-01

    Quinary Ti-Zr-Hf-Cu-Ni high-entropy metallic glass thin films were produced by magnetron sputter deposition. Nanoindentation tests indicate that the deposited film exhibits a relatively large hardness of 10.4±0.6 GPa and a high elastic modulus of 131±11 GPa under the strain rate of 0.5 s-1. Specifically, the strain rate sensitivity of hardness measured for the thin film is 0.05, the highest value reported for metallic glasses so far. Such high strain rate sensitivity of hardness is likely due to the high-entropy effect which stabilizes the amorphous structure with enhanced homogeneity.

  16. Correlation between high-sensitive collimator and quantitative analysis in lung ventilation SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jung Soo [Dept. of Radiological Technology, Dongnam Health University, Suwon (Korea, Republic of); Kim, Sang Hyun [Dept. of Diagnostic Radiology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2015-06-15

    This study investigated the correlation between the characteristics of collimator in accordance with the efficiency of detecting photon signals and the quantitative analysis of the lung function, thereby assessing the possibility of clinically applying high sensitivity lung ventilation SPECT. From March to May, 2014, 10 subjects in normal volunteers underwent an ultra high resolution, high resolution a nd high sensitivity collimator planar scan and SPECT. The experiment showed t hat compared with the collimator scan, the quantitative analysis results were significant (p=0.89), and compared to the high resolution collimator SPECT, the time was reduced by 4.9 fold. Therefore, the lung ventilation SPECT that had not been used due to an undermined effectiveness can offer usefulness when clinically applied if a high sensitivity collimator is used since the quality and quantity of information and the duration of scan time all offer an improvement.

  17. Deep proton writing of high aspect ratio SU-8 micro-pillars on glass

    Energy Technology Data Exchange (ETDEWEB)

    Ebraert, Evert, E-mail: eebraert@b-phot.org; Rwamucyo, Ben; Thienpont, Hugo; Van Erps, Jürgen

    2016-12-15

    Deep proton writing (DPW) is a fabrication technology developed for the rapid prototyping of polymer micro-structures. We use SU-8, a negative resist, spincoated in a layer up to 720 μm-thick in a single step on borosilicate glass, for irradiation with a collimated 12 MeV energy proton beam. Micro-pillars with a slightly conical profile are irradiated in the SU-8 layer. We determine the optimal proton fluence to be 1.02 × 10{sup 4} μm{sup −2}, with which we are able to repeatably achieve micro-pillars with a top-diameter of 138 ± 1 μm and a bottom-diameter of 151 ± 3 μm. The smallest fabricated pillars have a top-diameter of 57 ± 5 μm. We achieved a root-mean-square sidewall surface roughness between 19 nm and 35 nm for the fabricated micro-pillars, measured over an area of 5 × 63.7 μm. We briefly discuss initial testing of two potential applications of the fabricated micro-pillars. Using ∼100 μm-diameter pillars as waveguides for gigascale integration optical interconnect applications, has shown a 4.7 dB improvement in optical multimode fiber-to-fiber coupling as compared to the case where an air–gap is present between the fibers at the telecom wavelength of 1550 nm. The ∼140 μm-diameter pillars were used for mold fabrication with silicone casting. The resulting mold can be used for hydrogel casting, to obtain hydrogel replicas mimicking human tissue for in vitro bio-chemical applications.

  18. High-sensitivity Troponin T Assay in Asymptomatic High Cardiovascular Risk Patients. The TUSARC Registry.

    Science.gov (United States)

    Álvarez, Isabel; Hernández, Luis; García, Héctor; Villamandos, Vicente; López, María Gracia; Palazuelos Molinero, Jorge; Martín Raymondi, Diego

    2017-04-01

    High-sensitivity troponin T assays (Hs-TnT) have been carried out in selected populations in clinical trials and in registries of the general population with low cardiovascular risk (CVR). The aim of this study was to determine the proportion of individuals with detectable Hs-TnT and the proportion of individuals with elevated Hs-TnT in a Spanish population of asymptomatic individuals with very high CVR, as well as the parameters associated with Hs-TnT elevation. The study included 690 patients. Hs-TnT detection and Hs-TnT elevation (≥99th percentile value), as well the association of elevated Hs-TnT and clinical, analytical, and treatment data were analyzed. Hs-TnT was analyzed in 646 patients and was detected in 645. Elevated TnT was detected in 212 patients (32.9%). On multivariate analysis, elevated TnT was independently associated with male sex (OR, 2.81; 95%CI, 1.67-4.73; P < .001), older age (OR, 1.06; 95%CI, 1.04-1.09; P < .001), a higher body mass index (OR, 1.07; 95%CI, 1.02-1.12; P < .002), insulin therapy (OR, 1.99; 95%CI, 1.15-3.46; P = .01), history of heart failure (OR, 3.92; 95%CI, 1.24-12.39; P = .02), and estimated glomerular filtration rate calculated by CKD-EPI (OR, 0.96; 95%CI, 0.95-0.97; P < .001). In a Spanish population of asymptomatic individuals at very high CVR, Hs-TnT was associated with older age, male sex, higher body mass index, insulin therapy, history of heart failure, and lower glomerular filtration rate. Copyright © 2016 Sociedad Española de Cardiología. Published by Elsevier España, S.L.U. All rights reserved.

  19. Sensitivity of the High Altitude Water Cherenkov Experiment to observe Gamma-Ray Bursts

    Science.gov (United States)

    González, M. M.

    Ground based telescopes have marginally observed very high energy emission (>100GeV) from gamma-ray bursts(GRB). For instance, Milagrito observed GRB970417a with a significance of 3.7 sigmas over the background. Milagro have not yet observed TeV emission from a GRB with its triggered and untriggered searches or GeV emission with a triggered search using its scalers. These results suggest the need of new observatories with higher sensitivity to transient sources. The HAWC (High Altitute Water Cherenkov) observatory is proposed as a combination of the Milagro tecnology with a very high altitude (>4000m over see level) site. The expected HAWC sensitivity for GRBs is at least >10 times the Milagro sensitivity. In this work HAWC sensitivity for GRBs is discussed for different detector configurations such as altitude, distance between PMTs, depth under water of PMTs, number of PMTs required for a trigger, etc.

  20. Highly Sensitive Local Surface Plasmon Resonance in Anisotropic Au Nanoparticles Deposited on Nanofibers

    Directory of Open Access Journals (Sweden)

    Masanari Saigusa

    2015-01-01

    Full Text Available This paper reports the facile and high-throughput fabrication method of anisotropic Au nanoparticles with a highly sensitive local surface plasmon resonance (LPR using cylindrical nanofibers as substrates. The substrates consisting of nanofibers were prepared by the electrospinning of poly(vinylidene fluoride (PVDF. The Au nanoparticles were deposited on the surface of electrospun nanofibers by vacuum evaporation. Scanning electron microscopy revealed the formation of a curved Au island structure on the surface of cylindrical nanofibers. Polarized UV-visible extinction spectroscopy showed anisotropy in their LPR arising from the high surface curvature of the nanofiber. The LPR of the Au nanoparticles on the thinnest nanofiber with a diameter of ~100 nm showed maximum refractive index (RI sensitivity over 500 nm/RI unit (RIU. The close correlation between the fiber diameter dependence of the RI sensitivity and polarization dependence of the LPR suggests that anisotropic Au nanoparticles improve RI sensitivity.

  1. Two-channel highly sensitive sensors based on 4 × 4 multimode interference couplers

    Science.gov (United States)

    Le, Trung-Thanh

    2017-12-01

    We propose a new kind of microring resonators (MRR) based on 4 × 4 multimode interference (MMI) couplers for multichannel and highly sensitive chemical and biological sensors. The proposed sensor structure has advantages of compactness and high sensitivity compared with the reported sensing structures. By using the transfer matrix method (TMM) and numerical simulations, the designs of the sensor based on silicon waveguides are optimized and demonstrated in detail. We apply our structure to detect glucose and ethanol concentrations simultaneously. A high sensitivity of 9000 nm/RIU, detection limit of 2 × 10‒4 for glucose sensing and sensitivity of 6000 nm/RIU, detection limit of 1.3 × 10‒5 for ethanol sensing are achieved.

  2. Resolution, sensitivity, and in vivo application of high-resolution computed tomography for titanium-coated polymethyl methacrylate (PMMA) dental implants

    NARCIS (Netherlands)

    Cuijpers, V.M.J.I.; Jaroszewicz, J.; Anil, S.; Al Farraj Aldosari, A.; Walboomers, X.F.; Jansen, J.A.

    2014-01-01

    OBJECTIVES: The aims of this study were (i) to determine the spatial resolution and sensitivity of micro- versus nano-computed tomography (CT) techniques and (ii) to validate micro- versus nano-CT in a dog dental implant model, comparative to histological analysis. MATERIAL AND METHODS: To determine

  3. Efficient and stable solid-state dye-sensitized solar cells based on a high-molar-extinction-coefficient sensitizer.

    Science.gov (United States)

    Wang, Mingkui; Moon, Soo-Jin; Xu, Mingfei; Chittibabu, Kethineni; Wang, Peng; Cevey-Ha, Ngoc-Le; Humphry-Baker, Robin; Zakeeruddin, Shaik M; Grätzel, Michael

    2010-01-01

    The high-molar-extinction-coefficient heteroleptic ruthenium dye, cis-Ru (4,4'-bis(5-octylthieno[3,2-b] thiophen-2-yl)-2,2'-bipyridine) (4,4'-dicarboxyl-2,2'-bipyridine) (NCS)(2), exhibits an AM 1.5 solar (100 mW cm(-2))-to-electric power-conversion efficiency of 4.6% in a solid-state dye-sensitized solar cell (SSDSC) with 2,2', 7,7'-tetrakis-(N,N-di-p-methoxyphenylamine)9,9'-spirobifluorene (spiro-MeOTAD) as the organic hole-transporting material. These SSDSC devices exhibit good durability during accelerated tests under visible-light soaking for 1000 h at 60 degrees C. This demonstration elucidates a class of photovoltaic devices with potential for stable and low-cost power generation. The electron recombination dynamics and charge collection that take place at the dye-sensitized heterojunction are studied by means of impedance and transient photovoltage decay techniques.

  4. Integrated mRNA and micro RNA profiling reveals epigenetic mechanism of differential sensitivity of Jurkat T cells to AgNPs and Ag ions.

    Science.gov (United States)

    Eom, Hyun-Jeong; Chatterjee, Nivedita; Lee, Jeongsoo; Choi, Jinhee

    2014-08-17

    In our previous in vitro study of the toxicity on silver nanoparticles (AgNPs), we observed a dramatically higher sensitivity of Jurkat T cells to AgNPs than to Ag ions, and DNA damage and apoptosis were found to be involved in that toxicity. In this study, to understand underlying mechanism of different sensitivity of Jurket T cells to AgNPs and Ag ions, mRNA microarray and micro RNA microarray were concomitantly conducted on AgNPs and Ag ions exposed Jurkat T cells. Surprisingly only a small number of genes were differentially expressed by exposure to each of the silver (15 altered mRNA by AgNPs exposure, whereas 4 altered mRNA by Ag ions exposure, as determined 1.5-fold change as the cut-off value). miRNA microarray revealed that the expression of 63 miRNAs was altered by AgNPs exposure, whereas that of 32 miRNAs was altered by Ag ions exposure. An integrated analysis of mRNA and miRNA expression revealed that the expression of hsa-miR-219-5p, was negatively correlated with the expression of metallothionein 1F (MT1F) and tribbles homolog 3 (TRIB3), in cells exposed to AgNPs; whereas, the expression of hsa-miR-654-3p was negatively correlated with the expression of mRNA, endonuclease G-like 1 (EDGL1) in cells exposed to Ag ions. Network analysis were further conducted on mRNA-miRNA pairs, which revealed that miR-219-5p-MT1F and -TRIB3 pairs by AgNPs are being involved in various cellular processes, such as, oxidative stress, cell cycle and apoptosis, whereas, miR-654-3p and ENDOGL1 pair by Ag ions generated a much simpler network. The putative target genes of AgNPs-induced miR-504, miR-33 and miR-302 identified by Tarbase 6.0 are also found to be involved in DNA damage and apoptosis. These results collectively suggest that distinct epigenetic regulation may be an underlying mechanism of different sensitivity of Jurkat T cells to AgNPs and Ag ion. Further identification of putative target genes of DE miRNA by AgNPs and Ag ions may provide additional clues for the

  5. Suppression of microRNA-31 increases sensitivity to 5-FU at an early stage, and affects cell migration and invasion in HCT-116 colon cancer cells

    Directory of Open Access Journals (Sweden)

    Sun Xiao-Feng

    2010-11-01

    Full Text Available Abstract Background MicroRNAs (miRNAs are endogenously expressed noncoding RNAs with important biological and pathological functions. Although several studies have shown that microRNA-31 (miR-31 is obviously up-regulated in colorectal cancer (CRC, there is no study on the functional roles of miR-31 in CRC. Methods Anti-miR™ miRNA 31 inhibitor (anti-miR-31 is a sequence-specific and chemically modified oligonucleotide to specifically target and knockdown miR-31 molecule. The effect of anti-miR-31 transfection was investigated by real-time PCR. HCT-116p53+/+ and HCT-116p53-/-colon cancer cells were treated by anti-miR-31 with or without 5-fluorouracil (5-FU, cell proliferation was determined by MTT assay; apoptosis was detected by DAPI staining; cell cycle was evaluated by flow cytometry; colony formation, migration and invasion assays were performed to investigate the effect of suppression of miR-31 on the cell lines. Results Real-time PCR results showed that anti-miR-31 was efficiently introduced into the cells and reduced miR-31 levels to 44.1% in HCT-116p53+/+ and 67.8% in HCT-116p53-/-cell line (p = 0.042 and 0.046. MTT results showed that anti-miR-31 alone had no effect on the proliferation of HCT-116p53+/+ or HCT-116p53-/-. However, when combined with 5-FU, anti-miR-31 inhibited the proliferation of the two cell lines as early as 24 h after exposure to 5-FU (p = 0.038 and 0.044. Suppression of miR-31 caused a reduction of the migratory cells by nearly 50% compared with the negative control in both HCT-116p53+/+ and HCT-116p53-/-(p = 0.040 and 0.001. The invasive ability of the cells were increased by 8-fold in HCT-116p53+/+ and 2-fold in HCT-116p53-/- (p = 0.045 and 0.009. Suppression of miR-31 had no effect on cell cycle and colony formation (p > 0.05. Conclusions Suppression of miR-31 increases sensitivity to 5-FU at an early stage, and affects cell migration and invasion in HCT-116 colon cancer cells.

  6. Micro-CT scan reveals an unexpected high-volume and interconnected pore network in a Cretaceous Sanagasta dinosaur eggshell.

    Science.gov (United States)

    Hechenleitner, E Martín; Grellet-Tinner, Gerald; Foley, Matthew; Fiorelli, Lucas E; Thompson, Michael B

    2016-03-01

    The Cretaceous Sanagasta neosauropod nesting site (La Rioja, Argentina) was the first confirmed instance of extinct dinosaurs using geothermal-generated heat to incubate their eggs. The nesting strategy and hydrothermal activities at this site led to the conclusion that the surprisingly 7 mm thick-shelled eggs were adapted to harsh hydrothermal microenvironments. We used micro-CT scans in this study to obtain the first three-dimensional microcharacterization of these eggshells. Micro-CT-based analyses provide a robust assessment of gas conductance in fossil dinosaur eggshells with complex pore canal systems, allowing calculation, for the first time, of the shell conductance through its thickness. This novel approach suggests that the shell conductance could have risen during incubation to seven times more than previously estimated as the eggshell erodes. In addition, micro-CT observations reveal that the constant widening and branching of pore canals form a complex funnel-like pore canal system. Furthermore, the high density of pore canals and the presence of a lateral canal network in the shell reduce the risks of pore obstruction during the extended incubation of these eggs in a relatively highly humid and muddy nesting environment. © 2016 The Author(s).

  7. Micro-CT scan reveals an unexpected high-volume and interconnected pore network in a Cretaceous Sanagasta dinosaur eggshell

    Science.gov (United States)

    Grellet-Tinner, Gerald; Foley, Matthew; Thompson, Michael B.

    2016-01-01

    The Cretaceous Sanagasta neosauropod nesting site (La Rioja, Argentina) was the first confirmed instance of extinct dinosaurs using geothermal-generated heat to incubate their eggs. The nesting strategy and hydrothermal activities at this site led to the conclusion that the surprisingly 7 mm thick-shelled eggs were adapted to harsh hydrothermal microenvironments. We used micro-CT scans in this study to obtain the first three-dimensional microcharacterization of these eggshells. Micro-CT-based analyses provide a robust assessment of gas conductance in fossil dinosaur eggshells with complex pore canal systems, allowing calculation, for the first time, of the shell conductance through its thickness. This novel approach suggests that the shell conductance could have risen during incubation to seven times more than previously estimated as the eggshell erodes. In addition, micro-CT observations reveal that the constant widening and branching of pore canals form a complex funnel-like pore canal system. Furthermore, the high density of pore canals and the presence of a lateral canal network in the shell reduce the risks of pore obstruction during the extended incubation of these eggs in a relatively highly humid and muddy nesting environment. PMID:27009182

  8. Highly Sensitive, Flexible, and Wearable Pressure Sensor Based on a Giant Piezocapacitive Effect of Three-Dimensional Microporous Elastomeric Dielectric Layer.

    Science.gov (United States)

    Kwon, Donguk; Lee, Tae-Ik; Shim, Jongmin; Ryu, Seunghwa; Kim, Min Seong; Kim, Seunghwan; Kim, Taek-Soo; Park, Inkyu

    2016-07-06

    We report a flexible and wearable pressure sensor based on the giant piezocapacitive effect of a three-dimensional (3-D) microporous dielectric elastomer, which is capable of highly sensitive and stable pressure sensing over a large tactile pressure range. Due to the presence of micropores within the elastomeric dielectric layer, our piezocapacitive pressure sensor is highly deformable by even very small amounts of pressure, leading to a dramatic increase in its sensitivity. Moreover, the gradual closure of micropores under compression increases the effective dielectric constant, thereby further enhancing the sensitivity of the sensor. The 3-D microporous dielectric layer with serially stacked springs of elastomer bridges can cover a much wider pressure range than those of previously reported micro-/nanostructured sensing materials. We also investigate the applicability of our sensor to wearable pressure-sensing devices as an electronic pressure-sensing skin in robotic fingers as well as a bandage-type pressure-sensing device for pulse monitoring at the human wrist. Finally, we demonstrate a pressure sensor array pad for the recognition of spatially distributed pressure information on a plane. Our sensor, with its excellent pressure-sensing performance, marks the realization of a true tactile pressure sensor presenting highly sensitive responses to the entire tactile pressure range, from ultralow-force detection to high weights generated by human activity.

  9. High-sensitivity and high-Q-factor glass photonic crystal cavity and its applications as sensors.

    Science.gov (United States)

    Siraji, Ashfaqul Anwar; Zhao, Yang

    2015-04-01

    We investigate the properties of a planar photonic crystal cavity on glass and its applications as sensors. An airbridged twofold defect cavity on Schott glass background and Gorilla glass substrate has been designed for high Q-factor up to 4459. The average sensitivity of the cavity resonance to background refractive index is 388 nm/Refractive Index Unit. The resonant wavelength is sensitive to background temperature by 18.5 pm/°C. The designed sensors show much higher sensitivity than those based on waveguide interferometers or photonic bandgap structures without cavity resonance. The results are also useful for experimental studies of glass photonic devices.

  10. Longevity Tests of High-Sensitivity BD-PND Bubble Dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Radev, R; Carlberg, E

    2002-07-09

    Medium- and very-high-sensitivity neutron bubble dosimeters (BD-PNDs) made by Bubble Technology Industries (BTI) were used to study the life span of such dosimeters in a standard setup with a {sup 252}Cf source. Although data on the longevity of bubble dosimeters with low and medium sensitivity exist, such data for dosimeters with high and very high sensitivity are not readily available. The manufacturer guarantees optimum dosimeter performance for 3 months after receipt. However, it is important to know the change in the dosimeters' characteristics with time, especially after the first 3 months. The long-term performance of four sets of very high sensitivity and one set of medium-sensitivity bubble dosimeters was examined for periods of up to 13 months. During that time, the detectors were exposed and reset more than 20 times. Although departures from initial detection sensitivity were observed in several cases, the detectors indicated a significantly longer life span than stated in the manufacturer's warranty. In addition, the change in the number of bubbles and in evaluated neutron dose as a function of the time from the end of exposure until the dosimeters were read was investigated.

  11. Large-area imaging micro-well detectors for high-energy astrophysics

    CERN Document Server

    Deines-Jones, P; Hunter, S D; Jahoda, K; Owens, S M

    2002-01-01

    Micro-well detectors are pixelized imaging sensors that can be inexpensively fabricated in very large arrays. Owing to their intrinsic gain and operation at room temperature, they can be instrumented at very low power, per unit area, making them valuable for a variety of space-flight applications where wide-angle X-ray imaging or large-area particle tracking is required. For example, micro-well detectors have been chosen as the focal plane imager for Lobster-ISS, a proposed soft X-ray all-sky monitor. We have fabricated detectors which image X-rays with 200 mu m FWHM resolution at 3 keV. In agreement with other groups using similar geometries, we find nominal proportional counter energy resolution (20% at 6 keV in P-10), and stable operation at gas gains up to 30,000.

  12. High efficiency event-counting thermal neutron imaging using Gd doped micro channel plate

    OpenAIRE

    Tian, Yang; Yang, Yigang; Pan, Jingsheng; Li, Yulan; Li, Yuanjing

    2013-01-01

    An event-counting thermal neutron imaging detector based on 3 mol % natGd2O3 doped micro channel plate (MCP) has been developed and tested. Thermal neutron imaging experiment was carried out with a low flux neutron beam. Detection efficiency of 33 % was achieved with only one doped MCP. The spatial resolution of 72 {\\mu}m RMS is currently limited by the readout anode. A detector with larger area and improved readout method is now being developed.

  13. A highly sensitive humidity sensor based on a nanofibrous membrane coated quartz crystal microbalance.

    Science.gov (United States)

    Wang, Xianfeng; Ding, Bin; Yu, Jianyong; Wang, Moran; Pan, Fukui

    2010-02-05

    A novel humidity sensor was fabricated by electrospinning deposition of nanofibrous polyelectrolyte membranes as sensitive coatings on a quartz crystal microbalance (QCM). The results of sensing experiments indicated that the response of the sensors increased by more than two orders of magnitude with increasing relative humidity (RH) from 6 to 95% at room temperature, exhibiting high sensitivity, and that, in the range of 20-95% RH, the Log(Deltaf) showed good linearity. The sensitivity of fibrous composite polyacrylic acid (PAA)/poly(vinyl alcohol) (PVA) membranes was two times higher than that of the corresponding flat films at 95% RH. Compared with fibrous PAA/PVA membranes, the nanofibrous PAA membranes exhibited remarkably enhanced humidity sensitivity due to their high PAA content and large specific surface area caused by the formation of ultrathin nanowebs among electrospun fibers. Additionally, the resultant sensors exhibited a good reversible behavior and good long term stability.

  14. Highly sensitive detection of dipicolinic acid with a water-dispersible terbium-metal organic framework.

    Science.gov (United States)

    Bhardwaj, Neha; Bhardwaj, Sanjeev; Mehta, Jyotsana; Kim, Ki-Hyun; Deep, Akash

    2016-12-15

    The sensitive detection of dipicolinic acid (DPA) is strongly associated with the sensing of bacterial organisms in food and many types of environmental samples. To date, the demand for a sensitive detection method for bacterial toxicity has increased remarkably. Herein, we investigated the DPA detection potential of a water-dispersible terbium-metal organic framework (Tb-MOF) based on the fluorescence quenching mechanism. The Tb-MOF showed a highly sensitive ability to detect DPA at a limit of detection of 0.04nM (linear range of detection: 1nM to 5µM) and also offered enhanced selectivity from other commonly associated organic molecules. The present study provides a basis for the application of Tb-MOF for direct, convenient, highly sensitive, and specific detection of DPA in the actual samples. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings.

    Science.gov (United States)

    Benseman, Timothy M; Hao, Yang; Vlasko-Vlasov, Vitalii K; Welp, Ulrich; Koshelev, Alexei E; Kwok, Wai-Kwong; Divan, Ralu; Keiser, Courtney; Watanabe, Chiharu; Kadowaki, Kazuo

    2017-04-16

    Micro-electronic devices often undergo significant self-heating when biased to their typical operating conditions. This paper describes a convenient optical micro-imaging technique which can be used to map and quantify such behavior. Europium thenoyltrifluoroacetonate (EuTFC) has a 612 nm luminescence line whose activation efficiency drops strongly with increasing temperature, due to T-dependent interactions between the Eu3+ ion and the organic chelating compound. This material may be readily coated on to a sample surface by thermal sublimation in vacuum. When the coating is excited with ultraviolet light (337 nm) an optical micro-image of the 612 nm luminescent response can be converted directly into a map of the sample surface temperature. This technique offers spatial resolution limited only by the microscope optics (about 1 micron) and time resolution limited by the speed of the camera employed. It offers the additional advantages of only requiring comparatively simple and non-specialized equipment, and giving a quantitative probe of sample temperature.

  16. High-resolution micro-CT for morphologic and quantitative assessment of the sinusoid in human cavernous hemangioma of the liver.

    Directory of Open Access Journals (Sweden)

    Jinghao Duan

    Full Text Available Hepatic sinusoid plays a vital role in human cavernous hemangioma of the liver (CHL, and its morphologic investigation facilitates the understanding of microcirculation mechanism and pathological change of CHL. However, precise anatomical view of the hepatic sinusoid has been limited by the resolution and contrast available from existing imaging techniques. While liver biopsy has traditionally been the reliable method for the assessment of hepatic sinusoids, the invasiveness and sampling error are its inherent limitations. In this study, imaging of CHL samples was performed using in-line phase-contrast imaging (ILPCI technique with synchrotron radiation. ILPCI allowed clear visualization of soft tissues and revealed structural details that were invisible to conventional radiography. Combining the computed tomography (CT technique, ILPCI-CT was used to acquire the high-resolution micro-CT images of CHL, and three dimensional (3D microstructures of hepatic sinusoids were provided for the morphologic depiction and quantitative assessment. Our study demonstrated that ILPCI-CT could substantially improve the radiographic contrast of CHL tissues in vitro with no contrast agent. ILPCI-CT yielded high-resolution micro-CT image of CHL sample at the micron scale, corresponding to information on actual structures revealed at histological section. The 3D visualization provided an excellent view of the hepatic sinusoid. The accurate view of individual hepatic sinusoid was achieved. The valuable morphological parameters of hepatic sinusoids, such as thrombi, diameters, surface areas and volumes, were measured. These parameters were of great importance in the evaluation of CHL, and they provided quantitative descriptors that characterized anatomical properties and pathological features of hepatic sinusoids. The results highlight the high degree of sensitivity of the ILPCI-CT technique and demonstrate the feasibility of accurate visualization of hepatic

  17. Micro-scale flood risk analysis based on detailed 2D hydraulic modelling and high resolution geographic data

    OpenAIRE

    Ernst, Julien; Dewals, Benjamin; Detrembleur, Sylvain; Archambeau, Pierre; Erpicum, Sébastien; Pirotton, Michel

    2010-01-01

    The paper presents a consistent micro-scale flood risk analysis procedure, relying on detailed 2D inundation modelling as well as on high resolution topographic and land use database. The flow model is based on the shallow-water equations, solved by means of a finite volume scheme on multiblock structured grids. Using highly accurate laser altimetry, the simulations are performed with a typical grid spacing of 2m, which is fine enough to represent the flow at the scale of individual buildi...

  18. Eliminating micro-porous layer from gas diffusion electrode for use in high temperature polymer electrolyte membrane fuel cell

    OpenAIRE

    Su, H.; Xu, Q.; Chong, J.; Li, H.; Sita, C.; Pasupathi, S.

    2016-01-01

    In this work, we report a simple strategy to improve the performance of high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) by eliminating the micro-porous layer (MPL) from its gas diffusion electrodes (GDEs). Due to the absence of liquid water and the general use of high amount of catalyst, the MPL in a HT-PEMFC system works limitedly. Contrarily, the elimination of the MPL leads to an interlaced micropore/macropore composited structure in the catalyst layer (CL), which favors...

  19. Tenfold improved sensitivity using high refractive-index substrates for surface plasmon sensing

    OpenAIRE

    Micheletto, Ruggero; Hamamoto, Katsumi; Fujii, Takashi; Kawakami, Yoichi

    2008-01-01

    Surface plasmon resonance sensors exploit the high sensitivity to local perturbations of plasma waves in a thin metal layer. These devices have a wide range of applications as biomedical, environmental, industrial, and homeland security. We concentrate on the theoretical aspects of the sensing principle. By calculations at various indexes of refraction we proved that using substrate material of higher index, sensitivity and dynamics range improve conspicuously. Finally, we show experimental d...

  20. Highly sensitive protein detection by biospecific AFM-based fishing with pulsed electrical stimulation.

    Science.gov (United States)

    Pleshakova, Tatyana O; Malsagova, Kristina A; Kaysheva, Anna L; Kopylov, Arthur T; Tatur, Vadim Yu; Ziborov, Vadim S; Kanashenko, Sergey L; Galiullin, Rafael A; Ivanov, Yuri D

    2017-08-01

    We report here the highly sensitive detection of protein in solution at concentrations from 10-15 to 10-18 m using the combination of atomic force microscopy (AFM) and mass spectrometry. Biospecific detection of biotinylated bovine serum albumin was carried out by fishing out the protein onto the surface of AFM chips with immobilized avidin, which determined the specificity of the analysis. Electrical stimulation was applied to enhance the fishing efficiency. A high sensitivity of detection was achieved by application of nanosecond electric pulses to highly oriented pyrolytic graphite placed under the AFM chip. A peristaltic pump-based flow system, which is widely used in routine bioanalytical assays, was employed throughout the analysis. These results hold promise for the development of highly sensitive protein detection methods using nanosensor devices.

  1. MiR-33a Decreases High-Density Lipoprotein-Induced Radiation Sensitivity in Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, Adam R.; Bambhroliya, Arvind [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Reddy, Jay P. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Debeb, Bisrat G. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Huo, Lei [Department of Pathology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Larson, Richard; Li, Li [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Ueno, Naoto T. [Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Woodward, Wendy A., E-mail: wwoodward@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Morgan Welch Inflammatory Breast Cancer Research Program and Clinic, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-06-01

    Purpose: We previously showed that high-density lipoprotein (HDL) radiosensitizes inflammatory breast cancer (IBC) cells in vitro and is associated with better local control after radiation therapy in IBC patients. The microRNA miR-33 family negatively regulates the adenosine triphosphate binding cassette transporter subfamily A member 1. We hypothesized that variations in miR-33a expression in IBC cancer cells versus non-IBC cells would correlate with radiation sensitivity following exposure to HDL in vitro. Methods and Materials: MiR-33a expression was analyzed by reverse transcriptase–polymerase chain reaction in 4 cell lines representing common clinical breast cancer subtypes. Overexpression and knockdown of miR-33a was demonstrated via transfection of an miR-33a mimic or an anti-miR-33a construct in high- and low-expressing miR-33a cell lines. Clonogenic survival in vitro in these cells was quantified at baseline and following HDL treatment. MiR-33a expression on distant relapse-free survival (DRFS) of 210 cases downloaded from the Oxford breast cancer dataset was determined. Results: Expression levels of miR-33a were lower in IBC cell lines and IBC tumor samples than in non-IBC cell lines and normal breast tissue. Cholesterol concentrations in the cell membranes were higher in IBC cells than in non-IBC cells. Clonogenic survival following 24 hours of HDL treatment was decreased in response to irradiation in the low-miR-33a–expressing cell lines SUM149 and KPL4, but survival following HDL treatment decreased in the high-miR-33a–expressing cell lines MDA-MB-231 and SUM159. In the high-miR-33a–expressing cell lines, anti-miR-33a transfection decreased radiation resistance in clonogenic assays. Conversely, in the low-miR-33a–expressing cell lines, the miR-33a mimic reversed the HDL-induced radiation sensitization. Breast cancer patients in the top quartile based on miR-33a expression had markedly lower rates of DRFS than the bottom quartile (P

  2. The Nature and Nurture of High IQ: An Extended Sensitive Period for Intellectual Development

    NARCIS (Netherlands)

    Brant, A.M.; Munakata, Y.; Boomsma, D.I.; DeFries, J.C.; Haworth, C.M.A.; Keller, M.C.; Martin, N.G.; McGue, M.; Petrill, S.A.; Plomin, R.; Wadsworth, S.J.; Wright, M.J.; Hewitt, J.K.

    2013-01-01

    IQ predicts many measures of life success, as well as trajectories of brain development. Prolonged cortical thickening observed in individuals with high IQ might reflect an extended period of synaptogenesis and high environmental sensitivity or plasticity. We tested this hypothesis by examining the

  3. Brandaris 128: A digital 25 million frames per second camera with 128 highly sensitive frames

    NARCIS (Netherlands)

    Chin, Chien Ting; Lancée, Charles; Borsboom, Jerome; Mastik, Frits; Frijlink, Martijn E.; de Jong, N.; Versluis, Michel; Lohse, Detlef

    2003-01-01

    A high-speed camera that combines a customized rotating mirror camera frame with charge coupled device (CCD) image detectors and is practically fully operated by computer control was constructed. High sensitivity CCDs are used so that image intensifiers, which would degrade image quality, are not

  4. Ionic liquid-assisted multiwalled carbon nanotube-dispersive micro-solid phase extraction for sensitive determination of inorganic As species in garlic samples by electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grijalba, Alexander Castro; Escudero, Leticia B.; Wuilloud, Rodolfo G., E-mail: rwuilloud@mendoza-conicet.gob.ar

    2015-08-01

    A highly sensitive dispersive micro-solid phase extraction (D-μ-SPE) method combining an ionic liquid (IL) and multi-walled carbon nanotubes (MWCNTs) for inorganic As species (As(III) and As(V)) species separation and determination in garlic samples by electrothermal atomic absorption spectrometry (ETAAS) was developed. Trihexyl(tetradecil)phosphonium chloride IL was used to form an ion pair with the arsenomolybdate complex obtained by reaction of As(V) with molybdate ion. Afterwards, 1.0 mg of MWCNTs was dispersed for As(V) extraction and the supernatant was separated by centrifugation. MWCNTs were re-dispersed with tetradecyltrimethylammonium bromide surfactant and ultrasound followed by direct injection into the graphite furnace of ETAAS for As determination. Pyrolysis and atomization conditions were carefully studied for complete decomposition of MWCNTs and IL matrices. Under optimum conditions, an extraction efficiency of 100% and a preconcentration factor of 70 were obtained with 5 mL of garlic extract. The detection limit was 7.1 ng L{sup −1} and the relative standard deviations (RSDs) for six replicate measurements at 5 μg L{sup −1} of As were 5.4% and 4.8% for As(III) and As(V), respectively. The proposed D-μ-SPE method allowed the efficient separation and determination of inorganic As species in a complex matrix such as garlic extract. - Highlights: • Efficient retention and preconcentration of As by combining an IL with MWCNTs • Determination of As by ETAAS with direct injection of MWCNTs • Thermal degradation of MWCNTs in the graphite furnace of ETAAS • Highly sensitive speciation and determination of As in garlic.

  5. High-speed underwater optical wireless communication using a blue GaN-based micro-LED.

    Science.gov (United States)

    Tian, Pengfei; Liu, Xiaoyan; Yi, Suyu; Huang, Yuxin; Zhang, Shuailong; Zhou, Xiaolin; Hu, Laigui; Zheng, Lirong; Liu, Ran

    2017-01-23

    High-speed underwater optical wireless communication (UOWC) was achieved using an 80 μm blue-emitting GaN-based micro-LED. The micro-LED has a peak emission wavelength of ~440 nm and an underwater power attenuation of 1 dB/m in tap water. The -3 dB electrical-to-optical modulation bandwidth of the packaged micro-LED increases with increasing current and saturates at ~160 MHz. At an underwater distance of 0.6 m, 800 Mb/s data rate was achieved with a bit error rate (BER) of 1.3 × 10-3, below the forward error correction (FEC) criteria. And we obtained 100 Mb/s data communication speed with a received light output power of -40 dBm and a BER of 1.9 × 10-3, suggesting that UOWC with extended distance can be achieved. Through reflecting the light emission beam by mirrors within a water tank, we experimentally demonstrated a 200 Mb/s data rate with a BER of 3.0 × 10-6 at an underwater distance of 5.4 m.

  6. Development and performance analysis of a metallic micro-direct methanol fuel cell for high-performance applications

    Science.gov (United States)

    Zhang, Bo; Zhang, Yufeng; He, Hong; Li, Jianmin; Yuan, Zhenyu; Na, Chaoran; Liu, Xiaowei

    As a promising candidate for conventional micro-power sources, the micro-direct methanol fuel cell (μDMFC) is currently attracting increased attention due to its various advantages and prospective suitability for portable applications. This paper reports the design, fabrication and analysis of a high-performance μDMFC with two metal current collectors. Employing micro-stamping technology, the current collectors are fabricated on 300-μm-thick stainless steel plates. The flow fields for both cathode and anode are uniform in shape and size. Two sheets of stainless steel mesh are added between the membrane electrode assembly (MEA) and current collectors in order to improve cell performance. To avoid electrochemical corrosion, titanium nitride (TiN) layers with thickness of 500 nm are deposited onto the surface of current collectors and stainless steel mesh. The performance of this metallic μDMFC is thoroughly studied by both simulation and experimental methods. The results show that all the parameters investigated, including current collector material, stainless steel mesh, anode feeding mode, methanol concentration, anode flow rate, and operating temperature have significant effects on cell performance. Moreover, the results show that under optimal operating conditions, the metallic μDMFC exhibits promising performance, yielding a maximum power density of 65.66 mW cm -2 at 40 °C and 115.0 mW cm -2 at 80 °C.

  7. Fitting adsorption isotherms to the distribution data determined using packed micro-columns for high-performance liquid chromatography.

    Science.gov (United States)

    Jandera, P; Bunceková, S; Mihlbachler, K; Guiochon, G; Backovská, V; Planeta, J

    2001-08-03

    Knowing the adsorption isotherms of the components of a mixture on the chromatographic system used to separate them is necessary for a better understanding of the separation process and for the optimization of the production rate and costs in preparative high-performance liquid chromatography (HPLC). Currently, adsorption isotherms are usually measured by frontal analysis, using conventional analytical columns. Unfortunately, this approach requires relatively large quantities of pure compounds, and hence is expensive, especially in the case of pure enantiomers. In this work, we investigated the possible use of packed micro-bore and capillary HPLC columns for the determination of adsorption isotherms of benzophenone, o-cresol and phenol in reversed-phase systems and of the enantiomers of mandelic acid on a Teicoplanin chiral stationary phase. We found a reasonable agreement between the isotherm coefficients of the model compounds determined on micro-columns and on conventional analytical columns packed with the same material. Both frontal analysis and perturbation techniques could be used for this determination. The consumption of pure compounds needed to determine the isotherms decreases proportionally to the second power of the decrease in the column inner diameter, i.e. 10 times for a micro-bore column (1 mm I.D.) and 100 times for capillary columns (0.32 mm I.D.) with respect to 3.3 mm I.D. conventional columns.

  8. Lateral flow nucleic acid biosensor for sensitive detection of microRNAs based on the dual amplification strategy of duplex-specific nuclease and hybridization chain reaction.

    Directory of Open Access Journals (Sweden)

    Na Ying

    Full Text Available MicroRNAs (miRNAs constitute novel biomarkers for various diseases. Accurate and quantitative analysis of miRNA expression is critical for biomedical research and clinical theranostics. In this study, a method was developed for sensitive and specific detection of miRNAs via dual signal amplification based on duplex specific nuclease (DSN and hybridization chain reaction (HCR. A reporter probe (RP, comprising recognition sequence (3' end modified with biotin for a target miRNA of miR-21 and capture sequence (5' end modified with Fam for HCR product, was designed and synthesized. HCR was initiated by partial sequence of initiator probe (IP, the other part of which can hybridize with capture sequence of RP, and was assembled by hairpin probes modified with biotin (H1-bio and H2-bio. A miR-21 triggered cyclical DSN cleavage of RP, which was immobilized to a streptavidin (SA coated magnetic bead (MB. The released Fam labeled capture sequence then hybridized with the HCR product to generate a detectable dsDNA. This polymer was then dropped on lateral flow strip and positive result was observed. The proposed method allowed quantitative sequence-specific detection of miR-21 (with a detection limit of 2.1 fM, S/N = 3 in a dynamic range from 100 fM to 100 pM, with an excellent ability to discriminate differences in miRNAs. The method showed acceptable testing recoveries for the determination of miRNAs in serum.

  9. Fluid Micro-Reservoirs Array Design with Auto-Pressure Regulation for High-Speed 3D Printers

    Directory of Open Access Journals (Sweden)

    Moshe Einat

    2016-11-01

    Full Text Available Three dimensional (3D printing technology is rapidly evolving such that printing speed is now a crucial factor in technological developments and future applications. For printing heads based on the inkjet concept, the number of nozzles on the print head is a limiting factor of printing speed. This paper offers a method to practically increase the number of nozzles unlimitedly, and thus to dramatically ramp up printing speed. Fluid reservoirs are used in inkjet print heads to supply fluid through a manifold to the jetting chambers. The pressure in the reservoir’s outlet is important and influences device performance. Many efforts have been made to regulate pressure inside the fluid reservoirs so as to obtain a constant pressure in the chambers. When the number of nozzles is increased too much, the regulation of uniform pressure among all the nozzles becomes too complicated. In this paper, a different approach is taken. The reservoir is divided into an array of many micro-reservoirs. Each micro-reservoir supports one or a few chambers, and has a unique structure with auto-pressure regulation, where the outlet pressure is independent of the fluid level. The regulation is based on auto-compensation of the gravity force and a capillary force having the same dependence on the fluid level; this feature is obtained by adding a wedge in the reservoir with a unique shape. When the fluid level drops, the gravitational force and the capillary force decrease with it, but at similar rates. Terms for the force balance are derived and, consequently, a constant pressure in the fluid micro-reservoir segment is obtained automatically, with each segment being autonomous. This micro reservoir array is suggested for the enlargement of an inkjet print head and the achievement of high-speed 3D printing.

  10. Intrauterine sensitization of allergen-specific IgE analyzed by a highly sensitive new allergen microarray.

    Science.gov (United States)

    Kamemura, Norio; Tada, Hitomi; Shimojo, Naoki; Morita, Yoshinori; Kohno, Yoichi; Ichioka, Takao; Suzuki, Koichi; Kubota, Kenji; Hiyoshi, Mineyoshi; Kido, Hiroshi

    2012-07-01

    To design a rational allergy prevention program, it is important to determine whether allergic sensitization starts in utero under the maternal immune system. To investigate the origin of allergen-specific IgE antibodies in cord blood (CB) and maternofetal transfer of immunoglobulins. The levels of food and inhalant allergen-specific IgE, IgA, IgG, and IgG(4) antibodies in CB and maternal blood (MB) from 92 paired neonates and mothers were measured by using a novel allergen microarray of diamond-like-carbon-coated chip, with high-sensitivity detection of allergen-specific antibodies and allergen profiles. The levels of allergen-specific IgE antibodies against food and inhalant allergens and allergen profiles were identical in CB and newborn blood, but the levels and profiles, specifically against inhalant allergens, were different from those in MB. The level of allergen-specific IgA antibodies was below the detection levels in CB despite clear detection in MB. Therefore, contamination with MB in CB was excluded on the basis of extremely low levels of IgA antibodies in CB and the obvious mismatch of the allergen-specific IgE and IgA profiles between CB and MB. However, the levels of allergen-specific IgG and IgG(4) antibodies and their allergen profiles were almost identical in both MB and CB. Allergen-specific levels of IgE and IgA antibodies and their allergen profiles analyzed by the diamond-like-carbon allergen chip indicate that IgE antibodies in CB are of fetal origin. Food-allergen specific IgE antibodies were detected more often than inhalant-allergen specific IgE antibodies in CB, the reason of which remains unclarified. Copyright © 2012 American Academy of Allergy, Asthma & Immunology. Published by Mosby, Inc. All rights reserved.

  11. High-resolution, high sensitivity detectors for molecular imaging with radionuclides: The coded aperture option

    Energy Technology Data Exchange (ETDEWEB)

    Cusanno, F. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy)]. E-mail: francesco.cusanno@iss.infn.it; Cisbani, E. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Colilli, S. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Fratoni, R. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Garibaldi, F. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Giuliani, F. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Gricia, M. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Lo Meo, S. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Lucentini, M. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Magliozzi, M.L. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Santavenere, F. [Istituto Superiore di Sanita and INFN gruppo Sanita, Viale Regina Elena 299, 00161 Rome (Italy); Lanza, R.C. [Massachusetts Institute of Technology, Cambridge, MA (United States); Majewski, S. [Jefferson Lab, Newport News, 12000 Jefferson Avenue, 23606 VA (United States); Cinti, M.N. [University La Sapienza, Rome (Italy); Pani, R. [University La Sapienza, Rome (Italy); Pellegrini, R. [University La Sapienza, Rome (Italy); Orsini Cancelli, V. [INFN Sezione Roma III, Rome (Italy); De Notaristefani, F. [INFN Sezione Roma III, Rome (Italy); Bollini, D. [INFN Sezione di Bologna , Bologna (Italy); Navarria, F. [INFN Sezione di Bologna , Bologna (Italy); Moschini, G. [INFN Laboratori Nazionali di Legnaro, Legnaro (Italy)

    2006-12-20

    Molecular imaging with radionuclides is a very sensitive technique because it allows to obtain images with nanomolar or picomolar concentrations. This has generated a rapid growth of interest in radionuclide imaging of small animals. Indeed radiolabeling of small molecules, antibodies, peptides and probes for gene expression enables molecular imaging in vivo, but only if a suitable imaging system is used. Detecting small tumors in humans is another important application of such techniques. In single gamma imaging, there is always a well known tradeoff between spatial resolution and sensitivity due to unavoidable collimation requirements. Limitation of the sensitivity due to collimation is well known and affects the performance of imaging systems, especially if only radiopharmaceuticals with limited uptake are available. In many cases coded aperture collimation can provide a solution, if the near field artifact effect can be eliminated or limited. At least this is the case for 'small volumes' imaging, involving small animals. In this paper 3D-laminography simulations and preliminary measurements with coded aperture collimation are presented. Different masks have been designed for different applications showing the advantages of the technique in terms of sensitivity and spatial resolution. The limitations of the technique are also discussed.

  12. Highly sensitive glucose sensors based on enzyme-modified whole-graphene solution-gated transistors

    Science.gov (United States)

    Zhang, Meng; Liao, Caizhi; Mak, Chun Hin; You, Peng; Mak, Chee Leung; Yan, Feng

    2015-02-01

    Noninvasive glucose detections are convenient techniques for the diagnosis of diabetes mellitus, which require high performance glucose sensors. However, conventional electrochemical glucose sensors are not sensitive enough for these applications. Here, highly sensitive glucose sensors are successfully realized based on whole-graphene solution-gated transistors with the graphene gate electrodes modified with an enzyme glucose oxidase. The sensitivity of the devices is dramatically improved by co-modifying the graphene gates with Pt nanoparticles due to the enhanced electrocatalytic activity of the electrodes. The sensing mechanism is attributed to the reaction of H2O2 generated by the oxidation of glucose near the gate. The optimized glucose sensors show the detection limits down to 0.5 μM and good selectivity, which are sensitive enough for non-invasive glucose detections in body fluids. The devices show the transconductances two orders of magnitude higher than that of a conventional silicon field effect transistor, which is the main reason for their high sensitivity. Moreover, the devices can be conveniently fabricated with low cost. Therefore, the whole-graphene solution-gated transistors are a high-performance sensing platform for not only glucose detections but also many other types of biosensors that may find practical applications in the near future.

  13. Highly sensitive glucose sensors based on enzyme-modified whole-graphene solution-gated transistors.

    Science.gov (United States)

    Zhang, Meng; Liao, Caizhi; Mak, Chun Hin; You, Peng; Mak, Chee Leung; Yan, Feng

    2015-02-06

    Noninvasive glucose detections are convenient techniques for the diagnosis of diabetes mellitus, which require high performance glucose sensors. However, conventional electrochemical glucose sensors are not sensitive enough for these applications. Here, highly sensitive glucose sensors are successfully realized based on whole-graphene solution-gated transistors with the graphene gate electrodes modified with an enzyme glucose oxidase. The sensitivity of the devices is dramatically improved by co-modifying the graphene gates with Pt nanoparticles due to the enhanced electrocatalytic activity of the electrodes. The sensing mechanism is attributed to the reaction of H2O2 generated by the oxidation of glucose near the gate. The optimized glucose sensors show the detection limits down to 0.5 μM and good selectivity, which are sensitive enough for non-invasive glucose detections in body fluids. The devices show the transconductances two orders of magnitude higher than that of a conventional silicon field effect transistor, which is the main reason for their high sensitivity. Moreover, the devices can be conveniently fabricated with low cost. Therefore, the whole-graphene solution-gated transistors are a high-performance sensing platform for not only glucose detections but also many other types of biosensors that may find practical applications in the near future.

  14. A Flexible and Highly Sensitive Piezoresistive Pressure Sensor Based on Micropatterned Films Coated with Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Jia-lin Yao

    2016-01-01

    Full Text Available Excellent flexibility, high sensitivity, and low consumption are essential characteristics in flexible microtube pressure sensing occasion, for example, implantable medical devices, industrial pipeline, and microfluidic chip. This paper reports a flexible, highly sensitive, and ultrathin piezoresistive pressure sensor for fluid pressure sensing, whose sensing element is micropatterned films with conductive carbon nanotube layer. The flexible pressure sensor, the thickness of which is 40 ± 10 μm, could be economically fabricated by using biocompatible polydimethylsiloxane (PDMS. Experimental results show that the flexible pressure sensor has high sensitivity (0.047 kPa−1 in gas sensing and 5.6 × 10−3 kPa−1 in liquid sensing and low consumption (<180 μW, and the sensor could be used to measure the pressure in curved microtubes.

  15. Highly Sensitive and Reproducible SERS Performance from Uniform Film Assembled by Magnetic Noble Metal Composite Microspheres.

    Science.gov (United States)

    Niu, Chunyu; Zou, Bingfang; Wang, Yongqiang; Cheng, Lin; Zheng, Haihong; Zhou, Shaomin

    2016-01-26

    To realize highly sensitive and reproducible SERS performance, a new route was put forward to construct uniform SERS film by using magnetic composite microspheres. In the experiment, monodisperse Fe3O4@SiO2@Ag microspheres with hierarchical surface were developed and used as building block of SERS substrate, which not only realized fast capturing analyte through dispersion and collection under external magnet but also could be built into uniform film through magnetically induced self-assembly. By using R6G as probe molecule, the as-obtained uniform film exhibited great improvement on SERS performance in both sensitivity and reproducibility when compared with nonuniform film, demonstrating the perfect integration of high sensitivity of hierarchal noble metal microspheres and high reproducibility of ordered microspheres array. Furthermore, the as-obtained product was used to detect pesticide thiram and also exhibited excellent SERS performance for trace detection.

  16. Highly Sensitive Electro-Plasmonic Switches Based on Fivefold Stellate Polyhedral Gold Nanoparticles.

    Science.gov (United States)

    Zhong, Liubiao; Jiang, Yueyue; Liow, Chihao; Meng, Fanben; Sun, Yinghui; Chandran, Bevita K; Liang, Ziqiang; Jiang, Lin; Li, Shuzhou; Chen, Xiaodong

    2015-10-28

    Electron-photon coupling in metal nanostructures has raised a new trend for active plasmonic switch devices in both fundamental understanding and technological applications. However, low sensitivity switches with an on/off ratio less than 5 have restricted applications. In this work, an electrically modulated plasmonic switch based on a surface-enhanced Raman spectroscopy (SERS) system with a single fivefold stellate polyhedral gold nanoparticle (FSPAuNP) is reported. The reversible switch of the SERS signal shows high sensitivity with an on/off ratio larger than 30. Such a high on/off ratio arises primarily from the plasmonic resonance shift of the FSPAuNP with the incident laser due to the altered free electron density on the nanoparticle under an applied electrochemical potential. This highly sensitive electro-plasmonic switch may enable further development of plasmonic devices. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Evaluation and Analysis of Physical Properties of Nanomaterials for Highly Sensitive Mechanical Sensing Devices

    Science.gov (United States)

    Sugiyama, Susumu; Toriyama, Toshiyuki; Nakamura, Koichi; Dao, Dzung Viet

    This technical note is a review of the contract research at Ritsumeikan University for the “Highly Integrated, Complex MEMS Production Technology Development” Project (“Fine MEMS” Project) sponsored by New Energy and Industrial Technology Development Organization (NEDO). Our research focuses on characterization of physical properties of nanoscale microelectronic materials and carbon nanotube (CNT) to elucidate new effects for potential applications in advanced micro/nano electromechanical devices, and consists of two main parts. The first part deals with experimental evaluation of mechanical, thermal, and electrical properties of tungsten silicide (WSi) and CNT thin films. We have clarified that the WSi film will be promising as a structural material for high-performance capacitive micro accelerometer. In the second part, piezoresistive effect of single crystal silicon nanostructures has been theoretically and experimentally investigated. The p-type ultra-thin silicon nanowire (SiNW), in particular oriented SiNW, will be a good piezoresistor with a giant longitudinal piezoresistance coefficient. We have carried out the research in cooperation with Hitachi, Ltd. and National Institute of Advanced Industrial Science and Technology (AIST), and these cooperative relationships have greatly contributed to the advancement of the research and development. Achievements in the contract research are very promising and significant for mechanical sensing applications.

  18. High-frequency phase shift measurement greatly enhances the sensitivity of QCM immunosensors.

    Science.gov (United States)

    March, Carmen; García, José V; Sánchez, Ángel; Arnau, Antonio; Jiménez, Yolanda; García, Pablo; Manclús, Juan J; Montoya, Ángel

    2015-03-15

    In spite of being widely used for in liquid biosensing applications, sensitivity improvement of conventional (5-20MHz) quartz crystal microbalance (QCM) sensors remains an unsolved challenging task. With the help of a new electronic characterization approach based on phase change measurements at a constant fixed frequency, a highly sensitive and versatile high fundamental frequency (HFF) QCM immunosensor has successfully been developed and tested for its use in pesticide (carbaryl and thiabendazole) analysis. The analytical performance of several immunosensors was compared in competitive immunoassays taking carbaryl insecticide as the model analyte. The highest sensitivity was exhibited by the 100MHz HFF-QCM carbaryl immunosensor. When results were compared with those reported for 9MHz QCM, analytical parameters clearly showed an improvement of one order of magnitude for sensitivity (estimated as the I50 value) and two orders of magnitude for the limit of detection (LOD): 30μgl(-1) vs 0.66μgL(-1)I50 value and 11μgL(-1) vs 0.14μgL(-1) LOD, for 9 and 100MHz, respectively. For the fungicide thiabendazole, I50 value was roughly the same as that previously reported for SPR under the same biochemical conditions, whereas LOD improved by a factor of 2. The analytical performance achieved by high frequency QCM immunosensors surpassed those of conventional QCM and SPR, closely approaching the most sensitive ELISAs. The developed 100MHz QCM immunosensor strongly improves sensitivity in biosensing, and therefore can be considered as a very promising new analytical tool for in liquid applications where highly sensitive detection is required. Copyright © 2014 Elsevier B.V. All rights reserved.

  19. Effect of particle size in the TL response of natural quartz sensitized with high gamma dose

    Energy Technology Data Exchange (ETDEWEB)

    Carvalho, A B Jr; Guzzo, P L; Sullasi, H L; Khoury, H J, E-mail: alvarobcjr@yahoo.com.b

    2010-11-01

    The aim of this study is to investigate the effect of particle size in the thermoluminescence (TL) response of natural quartz sensitized with high gamma dose. For this, fragments of a single crystal taken from the Solonopole district (Brazil) were crushed and classified into ten size fractions ranging from 38 {mu}m to 5 mm. Aliquots of each size fraction were sensitized with 25 kGy of gamma dose of {sup 60}Co and heat-treated in a muffle furnace at 400{sup o}C. The non-sensitized samples were exposed to test doses between 50 Gy and 5 kGy and the sensitized samples were exposed to a unique test dose equal to 50 mGy. For non-sensitized samples, the TL peak near 325 {sup 0}C increases with the particle size decreasing. However, in the case of sensitized samples, the TL output near 280 {sup 0}C increases with the increasing of particle size up to mean grain size equal to 308 {mu}m. Above 308 {mu}m, an abrupt reduction in the TL intensity was noticed. These effects are discussed in relation to the specific surface area and the different interaction of high gamma doses with fine and coarse particles of quartz.

  20. Micro Engineering

    DEFF Research Database (Denmark)

    Alting, Leo; Kimura, F.; Hansen, Hans Nørgaard

    2003-01-01

    The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products. The implica......The paper addresses the questions of how micro products are designed and how they are manufactured. Definitions of micro products and micro engineering are discussed and the presentation is aimed at describing typical issues, possibilities and tools regarding design of micro products...