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Sample records for htpem-based micro combined

  1. FUEL CELL/MICRO-TURBINE COMBINED CYCLE

    SciTech Connect

    Larry J. Chaney; Mike R. Tharp; Tom W. Wolf; Tim A. Fuller; Joe J. Hartvigson

    1999-12-01

    A wide variety of conceptual design studies have been conducted that describe ultra-high efficiency fossil power plant cycles. The most promising of these ultra-high efficiency cycles incorporate high temperature fuel cells with a gas turbine. Combining fuel cells with a gas turbine increases overall cycle efficiency while reducing per kilowatt emissions. This study has demonstrated that the unique approach taken to combining a fuel cell and gas turbine has both technical and economic merit. The approach used in this study eliminates most of the gas turbine integration problems associated with hybrid fuel cell turbine systems. By using a micro-turbine, and a non-pressurized fuel cell the total system size (kW) and complexity has been reduced substantially from those presented in other studies, while maintaining over 70% efficiency. The reduced system size can be particularly attractive in the deregulated electrical generation/distribution environment where the market may not demand multi-megawatt central stations systems. The small size also opens up the niche markets to this high efficiency, low emission electrical generation option.

  2. Durable and mass producible polymer surface structures with different combinations of micro-micro hierarchy

    NASA Astrophysics Data System (ADS)

    Jiang, Yu; Suvanto, Mika; Pakkanen, Tapani A.

    2016-01-01

    Extensive studies have been performed with the aim of fabricating hierarchical surface structures inspired by nature. However, synthetic hierarchical structures have to sacrifice mechanical resistance to functionality by introducing finer scaled structures. Therefore, surfaces are less durable. Surface micro-micro hierarchy has been proven to be effective in replacing micro-nano hierarchy in the sense of superhydrophobicity. However, less attention has been paid to the combined micro-micro hierarchies with surface pillars and pits incorporated together. The fabrication of this type of hierarchy may be less straightforward, with the possibility of being a complicated multi-step process. In this study, we present a simple yet mass producible fabrication method for hierarchical structures with different combinations of surface pillars and pits. The fabrication was based on only one aluminum (Al) mold with sequential mountings. The fabricated structures exhibit high mechanical durability and structural stabilities with a normal load up to 100 kg. In addition, the theoretical estimation of the wetting state shows a promising way of stabilizing a water droplet on the surface pit structures with a more stable Cassie-Baxter state.

  3. Micro-tubular flame-assisted fuel cells for micro-combined heat and power systems

    NASA Astrophysics Data System (ADS)

    Milcarek, Ryan J.; Wang, Kang; Falkenstein-Smith, Ryan L.; Ahn, Jeongmin

    2016-02-01

    Currently the role of fuel cells in future power generation is being examined, tested and discussed. However, implementing systems is more difficult because of sealing challenges, slow start-up and complex thermal management and fuel processing. A novel furnace system with a flame-assisted fuel cell is proposed that combines the thermal management and fuel processing systems by utilizing fuel-rich combustion. In addition, the flame-assisted fuel cell furnace is a micro-combined heat and power system, which can produce electricity for homes or businesses, providing resilience during power disruption while still providing heat. A micro-tubular solid oxide fuel cell achieves a significant performance of 430 mW cm-2 operating in a model fuel-rich exhaust stream.

  4. Combined optical resolution photoacoustic and fluorescence micro-endoscopy

    NASA Astrophysics Data System (ADS)

    Shao, Peng; Shi, Wei; Hajireza, Parsin; Zemp, Roger J.

    2012-02-01

    We present a new micro-endoscopy system combining real-time C-scan optical-resolution photoacoustic micro-endoscopy (OR-PAME), and a high-resolution fluorescence micro-endoscopy system for visualizing fluorescently labeled cellular components and optically absorbing microvasculature simultaneously. With a diode-pumped 532-nm fiber laser, the OR-PAM sub-system is capable of imaging with a resolution of ~ 7μm. The fluorescence sub-system consists of a diode laser with 445 nm-centered emissions as the light source, an objective lens and a CCD camera. Proflavine, a FDA approved drug for human use, is used as the fluorescent contrast agent by topical application. The fluorescence system does not require any mechanical scanning. The scanning laser and the diode laser light source share the same light path within an optical fiber bundle containing 30,000 individual single mode fibers. The absorption of Proflavine at 532 nm is low, which mitigates absorption bleaching of the contrast agent by the photoacoustic excitation source. We demonstrate imaging in live murine models. The system is able to provide cellular morphology with cellular resolution co-registered with the structural and functional information given by OR-PAM. Therefore, the system has the potential to serve as a virtual biopsy technique, helping researchers and clinicians visualize angiogenesis, effects of anti-cancer drugs on both cells and the microcirculation, as well as aid in the study of other diseases.

  5. Combined Micro-PET/Micro-CT Imaging of Lung Tumours in SPC-raf and SPC-myc Transgenic Mice

    PubMed Central

    Rodt, Thomas; Luepke, Matthias; Boehm, Claudia; Hueper, Katja; Halter, Roman; Glage, Silke; Hoy, Ludwig; Wacker, Frank; Borlak, Juergen; von Falck, Christian

    2012-01-01

    Introduction SPC-raf and SPC-myc transgenic mice develop disseminated and circumscribed lung adenocarcinoma respectively, allowing for assessment of carcinogenesis and treatment strategies. The purpose of this study was to investigate the technical feasibility, the correlation of initial findings to histology and the administered radiation dose of combined micro-PET/micro-CT in these animal models. Material and Methods 14 C57BL/6 mice (4 nontransgenic, 4 SPC-raf transgenic, 6 SPC-myc transgenic) were examined using micro-CT and 18F-Fluoro-deoxyglucose micro-PET in-vivo. Micro-PET data was corrected for random events and scatter prior to reconstruction with a 3D-FORE/2D-OSEM iterative algorithm. Rigid micro-PET/micro-CT registration was performed. Tumour-to-non-tumour ratios were calculated for different lung regions and focal lesions. Diffuse tumour growth was quantified using a semiautomated micro-CT segmentation routine reported earlier. Regional histologic tumour load was assessed using a 4-point rating scale. Gamma radiation dose was determined using thermoluminescence dosimeters. Results Micro-CT allowed visualisation of diffuse and circumscribed tumours in SPC-raf and SPC-myc transgenic animals along with morphology, while micro-PET provided information on metabolism, but lacked morphologic detail. Mean tumour-to-non-tumour ratio was 2.47 for circumscribed lesions. No significant correlation could be shown between histological tumour load and tumour-to-nontumour ratio for diffuse tumours in SPC-raf transgenic animals. Calculation of the expected dose based on gamma dosimetry yielded approximately 140 mGy/micro-PET examination additional to approximately 200 mGy due to micro-CT. Conclusions Combined micro-PET/micro-CT imaging allows for in-vivo assessment of lung tumours in SPC-raf and SPC-myc transgenic mice. The technique has potential for the evaluation of carcinogenesis and treatment strategies in circumscribed lung tumours. PMID:23028537

  6. Preliminary Evaluation of a Combined MicroPET®-MR System

    PubMed Central

    Hawkes, R. C.; Fryer, T. D.; Siegel, S.; Ansorge, R. E.; Carpenter, T. A.

    2015-01-01

    There are many motivations for adding simultaneously acquired MR images to PET scanning. The most straight forward are, superior registration of MR and PET images, the addition of morphological detail when there is non-rigid motion and for pre-clinical studies simultaneous imaging could lead to a significant reduction in the time that animals are required to be anesthetised. In addition simultaneous MR has the potential to provide accurate motion correction for PET image reconstruction. For functional imaging simultaneous acquisition is required to assess the subject in the same physiological state, such as acute stroke studies. The elimination of the additional radiation associated with combining CT with PET, by providing anatomic detail with MR, would be a crucial advantage for cancer screening. Combining the two instruments necessitates some engineering tradeoffs, especially associated with the use of the highly developed photomultiplier tube (PMT) used for light amplification, because of its incompatibility with strong magnetic fields. Our approach is to provide a split in the magnet and gradients to locate the magnetic sensitive components, the PMTs, in regions of low magnetic field, leaving only the essential PET components, the scintillator blocks, in the strong magnetic field region. The crystals are coupled to the PMTs by extending the optical fibres. A further advantage accrues by moving the PET electronics out of the region seen by the MR radio-frequency (RF) and gradient coils as electromagnetic interference effects between the PET and MR systems, which could cause artefacts in either modality, are eliminated. Here we describe a preliminary evaluation of the system, which is essentially a microPET Focus-120 located in a 1T split magnet, and compare its performance to previous microPET instruments. PMID:20082530

  7. Combined Micro-chemical and Micro-structural Analysis of New Minerals Representing Extreme Conditions

    NASA Astrophysics Data System (ADS)

    Ma, C.; Tschauner, O. D.

    2015-12-01

    Recent improvements in micro-chemical analysis in combination with novel tools for micrometer-scale structural analysis of minerals from synchrotron X-ray diffraction open a pathway towards studies of mineral paragenesis that were previously not or barely accessible. Often mineral assemblies that represent extreme conditions also pose extreme challenges to analysis: very small size scale, complex matrix, minor amounts of material. Examples of such extreme, but also quite relevant environments are: a) High pressure shock-metamorphic minerals in meteorites and terrestrial impact sites, b) inclusions in diamonds from the deep mantle, c) ultrarefractory phases in Ca-Al-inlcusions from the solar nebula, d) presolar condensates. We show how a combination of synchrotron-based structural and semi-quantitative chemical techniques, with electron-microscopy based high-resolution imaging and fully quantitative chemical analysis and qualitative structural identification establish a powerful tool for discovery and characterization of important and interesting new minerals on micron- to submicron size scale.

  8. MicroRNA modulation combined with sunitinib as a novel therapeutic strategy for pancreatic cancer

    PubMed Central

    Passadouro, Marta; Pedroso de Lima, Maria C; Faneca, Henrique

    2014-01-01

    Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive and mortal cancer, characterized by a set of known mutations, invasive features, and aberrant microRNA expression that have been associated with hallmark malignant properties of PDAC. The lack of effective PDAC treatment options prompted us to investigate whether microRNAs would constitute promising therapeutic targets toward the generation of a gene therapy approach with clinical significance for this disease. In this work, we show that the developed human serum albumin–1-palmitoyl-2-oleoyl-sn-glycero-3-ethylphosphocholine:cholesterol/anti-microRNA oligonucleotides (+/−) (4/1) nanosystem exhibits the ability to efficiently deliver anti-microRNA oligonucleotides targeting the overexpressed microRNAs miR-21, miR-221, miR-222, and miR-10 in PDCA cells, promoting an almost complete abolishment of microRNA expression. Silencing of these microRNAs resulted in a significant increase in the levels of their targets. Moreover, the combination of microRNA silencing, namely miR-21, with low amounts of the chemotherapeutic drug sunitinib resulted in a strong and synergistic antitumor effect, showing that this combined strategy could be of great importance for therapeutic application in PDAC. PMID:25061297

  9. [Development of Sediment Micro-Interface Under Physical and Chironomus plumosus Combination Disturbance].

    PubMed

    Wang, Ren; Li, Da-peng; Huang, Yong; Liu, Yan-jian; Chen, Jun

    2015-11-01

    Synergistic effect of physical and Chironomus plumosus combination disturbance on the characteristics of the micro-environment and micro-interface was investigated by the Rhizon samplers and Unisense micro sensor system. The results showed that the oxygen penetration depth (OPD), total oxygen exchange (TOE), water content and total microbial activity increased under the combination disturbance and bioturbation and were kept at the higher level, compared with the control. These parameters increased with the physical intensity under combination disturbance. However, the content of Fe2+ decreased under the combination disturbance and bioturbation and the decrease was more obvious than that in the control. The changes of the Fe2+, the water content and the total microbial activity were large at 0-4 cm depth in the sediments. Therefore, the area might be the active area for the transformation of internal sedimentary phosphorus forms. The curve fitting was used for the OPD, TOE, the content of Fe2+, the water content and the total microbial activity with the physical intensity under combination disturbance. It was observed that the second-order polynomial equation was suitable for the curve fitting. In addition, jump type synergistic effect was presented in the above mentioned parameters under combination disturbance when the physical intensity was higher than 34 r x min(-1). The remodeling on the sediment micro-interface and micro-environment might be the main inducing mechanism for the transformation of internal phosphorus. PMID:26910997

  10. Versatile atomic force microscopy setup combined with micro-focused X-ray beam

    NASA Astrophysics Data System (ADS)

    Slobodskyy, T.; Zozulya, A. V.; Tholapi, R.; Liefeith, L.; Fester, M.; Sprung, M.; Hansen, W.

    2015-06-01

    Micro-focused X-ray beams produced by third generation synchrotron sources offer new perspective of studying strains and processes at nanoscale. Atomic force microscope setup combined with a micro-focused synchrotron beam allows precise positioning and nanomanipulation of nanostructures under illumination. In this paper, we report on integration of a portable commercial atomic force microscope setup into a hard X-ray synchrotron beamline. Details of design, sample alignment procedure, and performance of the setup are presented.

  11. Versatile atomic force microscopy setup combined with micro-focused X-ray beam

    SciTech Connect

    Slobodskyy, T. Tholapi, R.; Liefeith, L.; Hansen, W.; Zozulya, A. V. Fester, M.; Sprung, M.

    2015-06-15

    Micro-focused X-ray beams produced by third generation synchrotron sources offer new perspective of studying strains and processes at nanoscale. Atomic force microscope setup combined with a micro-focused synchrotron beam allows precise positioning and nanomanipulation of nanostructures under illumination. In this paper, we report on integration of a portable commercial atomic force microscope setup into a hard X-ray synchrotron beamline. Details of design, sample alignment procedure, and performance of the setup are presented.

  12. Evaluation of coating adhesion using a radial speckle interferometer combined with a micro-indentation test

    NASA Astrophysics Data System (ADS)

    Tendela, Lucas P.; Kaufmann, Guillermo H.

    2012-06-01

    This paper presents a technique to investigate coating adhesion which combines a radial in-plane speckle interferometer and a micro-indentation test. The proposed technique is based on the measurement of the radial in-plane displacement field produced by a micro-indentation introduced on the coated surface of the specimen. Using steel specimens coated with a thin coating of epoxy paint and subjected to different adhesive conditions, it is demonstrated that digital speckle pattern interferometry can be successfully used to measure the small local deformations generated by a micro-indentation. An empirical model, which allows to quantify the adhesion of a given coated-substrate system by the proposed combined technique, is finally presented.

  13. Accelerated Detection of Viral Particles by Combining AC Electric Field Effects and Micro-Raman Spectroscopy

    PubMed Central

    Tomkins, Matthew Robert; Liao, David Shiqi; Docoslis, Aristides

    2015-01-01

    A detection method that combines electric field-assisted virus capture on antibody-decorated surfaces with the “fingerprinting” capabilities of micro-Raman spectroscopy is demonstrated for the case of M13 virus in water. The proof-of-principle surface mapping of model bioparticles (protein coated polystyrene spheres) captured by an AC electric field between planar microelectrodes is presented with a methodology for analyzing the resulting spectra by comparing relative peak intensities. The same principle is applied to dielectrophoretically captured M13 phage particles whose presence is indirectly confirmed with micro-Raman spectroscopy using NeutrAvidin-Cy3 as a labeling molecule. It is concluded that the combination of electrokinetically driven virus sampling and micro-Raman based signal transduction provides a promising approach for time-efficient and in situ detection of viruses. PMID:25580902

  14. IR image properties measurement of new micro-mirror array structure beam combiner

    NASA Astrophysics Data System (ADS)

    Li, Yanhong; Zhang, Li; Li, Zhuo

    2014-11-01

    Microwave (MW)/Infrared(IR) dual-mode compound guidance technology has greatly developed recent years for enhancing guidance precision effectively. Here a new micro-mirror array structure is introduced as upright display for MW/IR beam combiner in HWIL simulation. The beam combiner is used in the IR/MW compound HWIL system for transmitting the MW signal while reflecting the IR signal. The spatial resolution and spatial uniformity are two important performance indicators for beam combiner in the application of HWIL simulation system. In this paper, the definitions, measurement methods, and results of spatial resolution and spatial uniformity are given. Through the measurement by multiple groups of black and white stripes, the spatial resolution and the spatial uniformity can be got. It shows the micro-mirror array beam combiner can be applied for MW/IR dual-mode common-aperture HWIL simulation system.

  15. Environmental Technology Verification Report: Climate Energy freewatt™ Micro-Combined Heat and Power System

    EPA Science Inventory

    The EPA GHG Center collaborated with the New York State Energy Research and Development Authority (NYSERDA) to evaluate the performance of the Climate Energy freewatt Micro-Combined Heat and Power System. The system is a reciprocating internal combustion (IC) engine distributed e...

  16. Combination of nonlinear ultrasonics and guided wave tomography for imaging the micro-defects.

    PubMed

    Li, Weibin; Cho, Younho

    2016-02-01

    The use of guided wave tomography has become an attractive alternative to convert ultrasonic wave raw data to visualized results for quantitative signal interpretation. For more accurate life prediction and efficient management strategies for critical structural components, there is a demand of imaging micro-damages in early stage. However, there is rarely investigation on guided wave tomographic imaging of micro-defects. One of the reasons for this might be that it becomes challenging to monitor tiny signal difference coefficient in a reliable manner for wave propagation in the specimens with micro-damages. Nonlinear acoustic signal whose frequency differs from that of the input signal can be found in the specimens with micro-damages. Therefore, the combination of guided wave tomography and nonlinear acoustic response induced by micro-damages could be a feasibility study for imaging micro-damages. In this paper, the nonlinear Rayleigh surface wave tomographic method is investigated to locate and size micro-corrosive defect region in an isotropic solid media. The variations of acoustic nonlinear responses of ultrasonic waves in the specimens with and without defects are used in guided wave tomographic algorithm to construct the images. The comparisons between images obtained by experimental signals and real defect region induced by hydrogen corrosion are presented in this paper. Results show that the images of defect regions with different shape, size and location are successfully obtained by this novel technique, while there is no visualized result constructed by conventional linear ultrasonic tomographic one. The present approach shows a potential for inspecting, locating and imaging micro-defects by nonlinear Rayleigh surface wave tomography. PMID:26552636

  17. Development of a combined microSPECT/CT system for small animal imaging

    NASA Astrophysics Data System (ADS)

    Sun, Mingshan

    Modern advances in the biomedical sciences have placed increased attention on small animals such as mice and rats as models of human biology and disease in biological research and pharmaceutical development. Their small size and fast breeding rate, their physiologic similarity to human, and, more importantly, the availability of sophisticated genetic manipulations, all have made mice and rats the laboratory mammals of choice in these experimental studies. However, the increased use of small animals in biomedical research also calls for new instruments that can measure the anatomic and metabolic information noninvasively with adequate spatial resolution and measurement sensitivity to facilitate these studies. This dissertation describes the engineering development of a combined single photon emission computed tomography (SPECT) and X-ray computed tomography (CT) system dedicated for small animals imaging. The system aims to obtain both the anatomic and metabolic images with submillimeter spatial resolution in a way that the data can be correlated to provide improved image quality and to offer more complete biological evaluation for biomedical studies involving small animals. The project requires development of complete microSPECT and microCT subsystems. Both subsystems are configured with a shared gantry and animal bed with integrated instrumentation for data acquisition and system control. The microCT employs a microfocus X-ray tube and a CCD-based detector for low noise, high resolution imaging. The microSPECT utilizes three semiconductor detectors coupled with pinhole collimators. A significant contribution of this dissertation project is the development of iterative algorithms with geometrical compensation that allows radionuclide images to be reconstructed at submillimeter spatial resolution, but with significantly higher detection efficiency than conventional methods. Both subsystems are capable of helical scans, offering lengthened field of view and improved

  18. Combined micro CT and histopathology for evaluation of skeletal metastasis in live animals

    PubMed Central

    Geffre, Christopher P; Pond, Erika; Pond, Gerald D; Sroka, Isis C; Gard, Jaime M; Skovan, Bethany A; Meek, William E; Landowski, Terry H; Nagle, Raymond B; Cress, Anne E

    2015-01-01

    Bone is a favored site for solid tumor metastasis, especially among patients with breast, lung or prostate carcinomas. Micro CT is a powerful and inexpensive tool that can be used to investigate tumor progression in xenograft models of human disease. Many previous studies have relied on terminal analysis of harvested bones to document metastatic tumor activity. The current protocol uses live animals and combines sequential micro CT evaluation of lesion development with matched histopathology at the end of the study. The approach allows for both rapid detection and evaluation of bone lesion progression in live animals. Bone resident tumors are established either by direct (intraosseous) or arterial (intracardiac) injection, and lesion development is evaluated for up to eight weeks. This protocol provides a clinically relevant method for investigating bone metastasis progression and the development of osteotropic therapeutic strategies for the treatment of bone metastases. PMID:25901201

  19. Business Case for a Micro-Combined Heat and Power Fuel Cell System in Commercial Applications

    SciTech Connect

    Brooks, Kriston P.; Makhmalbaf, Atefe; Anderson, David M.; Amaya, Jodi P.; Pilli, Siva Prasad; Srivastava, Viraj; Upton, Jaki F.

    2013-10-30

    Combined heat and power fuel cell systems (CHP-FCSs) provide consistent electrical power and hot water with greater efficiency and lower emissions than alternative sources. These systems can be used either as baseload, grid-connected, or as off-the-grid power sources. This report presents a business case for CHP-FCSs in the range of 5 to 50 kWe. Systems in this power range are considered micro-CHP-FCS. For this particular business case, commercial applications rather than residential or industrial are targeted. To understand the benefits of implementing a micro-CHP-FCS, the characteristics that determine their competitive advantage must first be identified. Locations with high electricity prices and low natural gas prices are ideal locations for micro-CHP-FCSs. Fortunately, these high spark spread locations are generally in the northeastern area of the United States and California where government incentives are already in place to offset the current high cost of the micro-CHP-FCSs. As a result of the inherently high efficiency of a fuel cell and their ability to use the waste heat that is generated as a CHP, they have higher efficiency. This results in lower fuel costs than comparable alternative small-scale power systems (e.g., microturbines and reciprocating engines). A variety of markets should consider micro-CHP-FCSs including those that require both heat and baseload electricity throughout the year. In addition, the reliable power of micro-CHP-FCSs could be beneficial to markets where electrical outages are especially frequent or costly. Greenhouse gas emission levels from micro-CHP-FCSs are 69 percent lower, and the human health costs are 99.9 percent lower, than those attributed to conventional coal-fired power plants. As a result, FCSs can allow a company to advertise as environmentally conscious and provide a bottom-line sales advantage. As a new technology in the early stages of adoption, micro-CHP-FCSs are currently more expensive than alternative

  20. Combined UV/vis and micro-tomography investigation of acetaminophen dissolution from granules.

    PubMed

    Kašpar, Ondřej; Tokárová, Viola; Oka, Sarang; Sowrirajan, Koushik; Ramachandran, Rohit; Štěpánek, František

    2013-12-31

    The X-ray micro-tomography (micro-CT) technique has been used to visualize the microstructure of granules produced by high shear wet granulation and the dynamic evolution of porosity during granule dissolution. Using acetaminophen (paracetamol) as the active pharmaceutical ingredient (API) and microcrystalline cellulose (Avicel PH-200) as an excipient, the porosity of the granules was systematically influenced by the granulation process parameters (binder/solids ratio, impeller speed and wet massing time). An increase of granule porosity from 7% to 10% and 18% lead to a decrease of the dissolution time t90 from 435 min to 98 min and 37 min, respectively. The combination of time-resolved micro-CT imaging with UV/vis detection of the quantity dissolved made it possible to evaluate the effective diffusion coefficient of the API through the granule structure, and thus establish a quantitative structure–property relationship for dissolution. A power-law dependence of the effective diffusivity on porosity (Archie's law) was found to hold. PMID:24409518

  1. Enhancement of transdermal delivery of glycerol by micro-needling method combined with sonophoresis

    NASA Astrophysics Data System (ADS)

    Yoon, Jinhee; Park, Donghee; Son, Taeyoon; Seo, Jongbum; Jung, Byungjo

    2009-02-01

    The light does not penetrate deeply into the skin tissue because of tissue turbidity. Light penetration depth in skin tissue can be increased by using optical clearing agents such as glycerol, glucose and dimethyl sulfoxide(DMSO). The stratum corneum prevents most optical skin clearing agent from diffusing into the tissue. Previous studies demonstrated the optical tissue clearing effect using optical clearing agents and presented several physical methods to improve transdermal delivery of optical clearing agents. In previous study, we introduced a micro-needling method to enhance optical clearing efficacy against skin barrier and suggested quantitative analysis method to evaluate the optical tissue clearing efficacy. In this study, we present a new physical micro-needling method combined with sonophoresis to further enhance the optical tissue clearing efficacy. The optical tissue clearing effect was quantitatively evaluated with a modulation transfer function target placed under ex-vivo porcine skin samples. To improve transdermal delivery of glycerol, 70% glycerol solution as optimal concentration was topically applied. In conclusion, the samples treated with micro-needling method and sonophoresis resulted in noticeable optical tissue clearing effect.

  2. Metal micro drilling combining high power femtosecond laser and trepanning head

    NASA Astrophysics Data System (ADS)

    Kling, R.; Dijoux, M.; Romoli, L.; Tantussi, F.; Sanabria, J.; Mottay, E.

    2013-03-01

    Trepanning heads are well known to be efficient in high aspect drilling and to provide a precise control of the hole geometry. Secondly, femtosecond lasers enable to minimize the heat effects and the recast layer on sidewalls but are typically used on thin sheet. The combination of both present a high potential for industrial applications such as injector or cooling holes where the bore sidewall topology has a major influence on the dynamics of the gas flow. In this paper we present results using this combination. The effect of pulse energy, repetition rate and revolution speed of the head on both geometry and roughness are discussed. The quality of the sidewall is checked by roughness measurement and by metallographic analysis (SEM; chemical etching, micro hardness).

  3. Measuring the mechanical properties of plant cells by combining micro-indentation with osmotic treatments

    PubMed Central

    Weber, Alain; Braybrook, Siobhan; Huflejt, Michal; Mosca, Gabriella; Routier-Kierzkowska, Anne-Lise; Smith, Richard S.

    2015-01-01

    Growth in plants results from the interaction between genetic and signalling networks and the mechanical properties of cells and tissues. There has been a recent resurgence in research directed at understanding the mechanical aspects of growth, and their feedback on genetic regulation. This has been driven in part by the development of new micro-indentation techniques to measure the mechanical properties of plant cells in vivo. However, the interpretation of indentation experiments remains a challenge, since the force measures results from a combination of turgor pressure, cell wall stiffness, and cell and indenter geometry. In order to interpret the measurements, an accurate mechanical model of the experiment is required. Here, we used a plant cell system with a simple geometry, Nicotiana tabacum Bright Yellow-2 (BY-2) cells, to examine the sensitivity of micro-indentation to a variety of mechanical and experimental parameters. Using a finite-element mechanical model, we found that, for indentations of a few microns on turgid cells, the measurements were mostly sensitive to turgor pressure and the radius of the cell, and not to the exact indenter shape or elastic properties of the cell wall. By complementing indentation experiments with osmotic experiments to measure the elastic strain in turgid cells, we could fit the model to both turgor pressure and cell wall elasticity. This allowed us to interpret apparent stiffness values in terms of meaningful physical parameters that are relevant for morphogenesis. PMID:25873663

  4. Nitrate removal and microbial analysis by combined micro-electrolysis and autotrophic denitrification.

    PubMed

    Xing, Wei; Li, Desheng; Li, Jinlong; Hu, Qianyi; Deng, Shihai

    2016-07-01

    A process combining micro-electrolysis and autotrophic denitrification (CEAD) with iron-carbon micro-electrolysis carriers was developed for nitrate removal. The process was performed using organic-free influent with a NO3(-)-N concentration of 40.0±3.0mg/L and provided an average nitrate removal efficiency of 95% in stable stages. The total nitrogen removal efficiency reached 75%, with 21% of NO3(-)-N converted into NH4(+)-N. The corresponding hydraulic retention time was 8-10h, and the optimal pH ranged from 8.5 to 9.5. Microbial analysis with high-throughput sequencing revealed that dominant microorganisms in the reactor belonged to the classes of β-, γ-, and α-Proteobacteria. The abundance of the genera Thermomonas significantly increased during the operation, comprising 21.4% and 24.1% in sludge attached to the carriers in the middle and at the bottom of the reactor, respectively. The developed CEAD achieved efficient nitrate removal from water without organics, which is suitable for practical application. PMID:27019127

  5. Accelerated testing of solid oxide fuel cell stacks for micro combined heat and power application

    NASA Astrophysics Data System (ADS)

    Hagen, Anke; Høgh, Jens Valdemar Thorvald; Barfod, Rasmus

    2015-12-01

    State-of-the-art (SoA) solid oxide fuel cell (SOFC) stacks are tested using profiles relevant for use in micro combined heat and power (CHP) units. Such applications are characterised by dynamic load profiles. In order to shorten the needed testing time and to investigate potential acceleration of degradation, the profiles are executed faster than required for real applications. Operation with fast load cycling, both using hydrogen and methane/steam as fuels, does not accelerate degradation compared to constant operation, which demonstrates the maturity of SoA stacks and enables transferring knowledge from testing at constant conditions to dynamic operation. 7.5 times more cycles than required for 80,000 h lifetime as micro CHP are achieved on one-cell-stack level. The results also suggest that degradation mechanisms that proceed on a longer time-scale, such as creep, might have a more dominating effect for long life-times than regular short time changes of operation. In order to address lifetime testing it is suggested to build a testing program consisting of defined modules that represent different application profiles, such as one module at constant conditions, followed by modules at one set of dynamic conditions etc.

  6. MicroRNAs Used in Combination with Anti-Cancer Treatments Can Enhance Therapy Efficacy

    PubMed Central

    Mognato, Maddalena; Celotti, Lucia

    2015-01-01

    MicroRNAs (miRNAs), a recently discovered class of small non-coding RNAs, constitute a promising approach to anti-cancer treatments when they are used in combination with other agents. MiRNAs are evolutionarily conserved non-coding RNAs that negatively regulate gene expression by binding to the complementary sequence in the 3’-untranslated region (UTR) of target genes. MiRNAs typically suppress gene expression by direct association with target transcripts, thus decreasing the expression levels of target proteins. The delivery to cells of synthetic miRNAs that mimic endogenous miRNA targeting genes involved in the DNA-Damage Response (DDR) can perturb the process, making cells more sensitive to chemotherapy or radiotherapy. This review examines how cells respond to combined therapy and it provides insights into the role of miRNAs in targeting the DDR repair pathway when they are used in combination with chemical compounds or ionizing radiation to enhance cellular sensitivity to treatments. PMID:26156420

  7. A methodology for understanding the impacts of large-scale penetration of micro-combined heat and power

    SciTech Connect

    Tapia-Ahumada, K.; Pérez-Arriaga, I. J.; Moniz, Ernest J.

    2013-10-01

    Co-generation at small kW-e scale has been stimulated in recent years by governments and energy regulators as one way to increasing energy efficiency and reducing CO2emissions. If a widespread adoption should be realized, their effects from a system's point of view are crucial to understand the contributions of this technology. Based on a methodology that uses long-term capacity planning expansion, this paper explores some of the implications for an electric power system of having a large number of micro-CHPs. Results show that fuel cells-based micro-CHPs have the best and most consistent performance for different residential demands from the customer and system's perspectives. As the penetration increases at important levels, gas-based technologies - particularly combined cycle units - are displaced in capacity and production, which impacts the operation of the electric system during summer peak hours. Other results suggest that the tariff design impacts the economic efficiency of the system and the operation of micro-CHPs under a price-based strategy. Finally, policies aimed at micro-CHPs should consider the suitability of the technology (in size and heat-to-power ratio) to meet individual demands, the operational complexities of a large penetration, and the adequacy of the economic signals to incentivize an efficient and sustainable operation. Highlights: Capacity displacements and daily operation of an electric power system are explored; Benefits depend on energy mix, prices, and micro-CHP technology and control scheme; Benefits are observed mostly in winter when micro-CHP heat and power are fully used; Micro-CHPs mostly displace installed capacity from natural gas combined cycle units; and, Tariff design impacts economic efficiency of the system and operation of micro-CHPs.

  8. Theragnosis-based combined cancer therapy using doxorubicin-conjugated microRNA-221 molecular beacon.

    PubMed

    Lee, Jonghwan; Choi, Kyung-Ju; Moon, Sung Ung; Kim, Soonhag

    2016-01-01

    Recently, microRNA (miRNA or miR) has emerged as a new cancer biomarker because of its high expression level in various cancer types and its role in the control of tumor suppressor genes. In cancer studies, molecular imaging and treatment based on target cancer markers have been combined to facilitate simultaneous cancer diagnosis and therapy. In this study, for combined therapy with diagnosis of cancer, we developed a doxorubicin-conjugated miR-221 molecular beacon (miR-221 DOXO MB) in a single platform composed of three different nucleotides: miR-221 binding sequence, black hole quencher 1 (BHQ1), and doxorubicin binding site. Imaging of endogenous miR-221 was achieved by specific hybridization between miR-221 and the miR-221 binding site in miR-221 DOXO MB. The presence of miR-221 triggered detachment of the quencher oligo and subsequent activation of a fluorescent signal of miR-221 DOXO MB. Simultaneous cancer therapy in C6 astrocytoma cells and nude mice was achieved by inhibition of miRNA-221 function that downregulates tumor suppressor genes. The detection of miR-221 expression and inhibition of miR-221 function by miR-221 DOXO MB provide the feasibility as a cancer theragnostic probe. Furthermore, a cytotoxic effect was induced by unloading of doxorubicin intercalated into miR-221 DOXO MB inside cells. Loss of miR-221 function and cytotoxicity induced by the miR-221 DOXO MB provides combined therapeutic efficacy against cancers. This method could be used as a new theragnostic probe with enhanced therapy to detect and inhibit many cancer-related miRNAs. PMID:26454049

  9. Modeling the Dynamics of Micro- and Macroparticles in a Combined Gas-Discharge Installation

    NASA Astrophysics Data System (ADS)

    Astashinskii, V. V.; Bogach, M. I.; Burachevskii, A. V.

    2016-05-01

    We present a model of the dynamics of micro- and macroparticles in a combined gas-discharge installation that accounts for the processes of metal explosion (heating of a metal in its solid state, melting, heating of the liquid metal, intense evaporation, ionization in metal vapor), a magnetohydrodynamic description of plasma acceleration (on the basis of the mass, momentum, and energy conservation laws neglecting the plasma viscosity and thermal conductivity), and a description of the processes of energy transfer from a high-velocity stream to accelerated particles. It has been established that the process of melting terminates in 1.3 ns after the start of the discharge and that the evaporation terminates in 480 ns. The stage of cooling starts in 21 μs. The average density of the plasma upon completion of the evaporation process can be estimated to be 1.7·10-5 g/cm3, with the pressure being of the order of 1.5·104 Pa and the total time of discharge, of about 250 μs.

  10. A Micro/Nano Composite for Combination Treatment of Melanoma Lung Metastasis.

    PubMed

    Mi, Yu; Mu, Chaofeng; Wolfram, Joy; Deng, Zaian; Hu, Tony Ye; Liu, Xuewu; Blanco, Elvin; Shen, Haifa; Ferrari, Mauro

    2016-04-01

    The successful treatment of malignant disease generally requires the use of multiple therapeutic agents that are coordinated in a spatiotemporal manner to enable synergy. Here, a porous silicon-based micro/nano composite (MNC) that is capable of simultaneously delivering chemotherapeutic agents and small interfering RNA (siRNA) to the lungs following intravenous injection is designed. The pores of the silicon microparticles are loaded with B-Raf proto-oncogene serine/threonine kinase (BRAF) siRNA-containing liposomes, while the surface is conjugated with docetaxel-encapsulated polymeric nanoparticles. The synergistic antitumor effect of the MNC is demonstrated in vitro in melanoma cells and in vivo using a mouse model for melanoma lung metastasis. The MNC displays superior therapeutic efficacy and increased accumulation in metastatic melanoma lesions in the lungs in comparison to combination therapy with liposomes and polymers. The results indicate that the MNC can be used as an effective delivery vehicle for simultaneous enrichment of multiple therapeutic agents in the lungs. PMID:26890862

  11. Modeling the Dynamics of Micro- and Macroparticles in a Combined Gas-Discharge Installation

    NASA Astrophysics Data System (ADS)

    Astashinskii, V. V.; Bogach, M. I.; Burachevskii, A. V.

    2016-06-01

    We present a model of the dynamics of micro- and macroparticles in a combined gas-discharge installation that accounts for the processes of metal explosion (heating of a metal in its solid state, melting, heating of the liquid metal, intense evaporation, ionization in metal vapor), a magnetohydrodynamic description of plasma acceleration (on the basis of the mass, momentum, and energy conservation laws neglecting the plasma viscosity and thermal conductivity), and a description of the processes of energy transfer from a high-velocity stream to accelerated particles. It has been established that the process of melting terminates in 1.3 ns after the start of the discharge and that the evaporation terminates in 480 ns. The stage of cooling starts in 21 μs. The average density of the plasma upon completion of the evaporation process can be estimated to be 1.7·10-5 g/cm3, with the pressure being of the order of 1.5·104 Pa and the total time of discharge, of about 250 μs.

  12. Combining microdilution with MicroResp™: microbial substrate utilization, antimicrobial susceptibility and respiration.

    PubMed

    Drage, Sigrid; Engelmeier, Doris; Bachmann, Gert; Sessitsch, Angela; Mitter, Birgit; Hadacek, Franz

    2012-03-01

    Pharmacological studies focus on susceptibility of pathogenic microbes against specific drugs or combinations of them, ecological studies on substrate utilization efficiency of variable microbial communities. The MicroResp™ system was especially developed to study soil microbial communities. It was slightly modified to facilitate exploring of microbial growth efficiency in a concentration-dependent fashion (microdilutions of carbohydrate mixtures or specific toxic chemicals). After turbidimetric growth assessment, colorimetric indicator plates (cresol red agar) were mounted to the assay plates. The substrate utilisation design is illustrated by glucose and a plant carbohydrate mixture, the antimicrobial susceptibility design by the naphthoquinone juglone. Dose-response effects are explored by curve fitting of nonlinear models that especially have been developed to detect hormetic effects that are characterized by stimulation at lower followed by inhibition at higher dosages (U- and inverse U-shaped effects). Multivariate analyses are presented utilizing metavariables that were obtained in the curve fitting process of the measured parameters growth and respiration and the factor growth efficiency. PMID:22265657

  13. Atomic force microscope with combined FTIR-Raman spectroscopy having a micro thermal analyzer

    DOEpatents

    Fink, Samuel D.; Fondeur, Fernando F.

    2011-10-18

    An atomic force microscope is provided that includes a micro thermal analyzer with a tip. The micro thermal analyzer is configured for obtaining topographical data from a sample. A raman spectrometer is included and is configured for use in obtaining chemical data from the sample.

  14. Towards near-permanent CoCrMo prosthesis surface by combining micro-texturing and low temperature plasma carburising.

    PubMed

    Dong, Yangchun; Svoboda, Petr; Vrbka, Martin; Kostal, David; Urban, Filip; Cizek, Jan; Roupcova, Pavla; Dong, Hanshan; Krupka, Ivan; Hartl, Martin

    2015-03-01

    An advanced surface engineering process combining micro-texture with a plasma carburising process was produced on CoCrMo femoral head, and their tribological properties were evaluated by the cutting-edge pendulum hip joint simulator coupled with thin film colorimetric interferometry. FESEM and GDOES showed that precipitation-free C S-phase with a uniform case depth of 10μm was formed across the micro-textures after duplex treatment. Hip simulator tests showed that the friction coefficient was reduced by 20% for micro-metre sized texture, and the long-term tribological property of microtexture was enhanced by the C-supersaturated crystalline microstructure formed on the surface of duplex treated CoCrMo, thereby enhancing biotribological durability significantly. In-situ colorimetric interferometry confirmed that the maximum film thickness around texture area was 530nm, indicating that the additional lubricant during sliding motion might provide exceptional bearing life. PMID:26594781

  15. Combined micro computed tomography and histology study of bone augmentation and distraction osteogenesis

    NASA Astrophysics Data System (ADS)

    Ilgenstein, Bernd; Deyhle, Hans; Jaquiery, Claude; Kunz, Christoph; Stalder, Anja; Stübinger, Stefan; Jundt, Gernot; Beckmann, Felix; Müller, Bert; Hieber, Simone E.

    2012-10-01

    Bone augmentation is a vital part of surgical interventions of the oral and maxillofacial area including dental implantology. Prior to implant placement, sufficient bone volume is needed to reduce the risk of peri-implantitis. While augmentation using harvested autologous bone is still considered as gold standard, many surgeons prefer bone substitutes to reduce operation time and to avoid donor site morbidity. To assess the osteogenic efficacy of commercially available augmentation materials we analyzed drill cores extracted before implant insertion. In younger patients, distraction osteogenesis is successfully applied to correct craniofacial deformities through targeted bone formation. To study the influence of mesenchymal stem cells on bone regeneration during distraction osteogenesis, human mesenchymal stem cells were injected into the distraction gap of nude rat mandibles immediately after osteotomy. The distraction was performed over eleven days to reach a distraction gap of 6 mm. Both the rat mandibles and the drill cores were scanned using synchrotron radiation-based micro computed tomography. The three-dimensional data were manually registered and compared with corresponding two-dimensional histological sections to assess bone regeneration and its morphology. The analysis of the rat mandibles indicates that bone formation is enhanced by mesenchymal stem cells injected before distraction. The bone substitutes yielded a wide range of bone volume and degree of resorption. The volume fraction of the newly formed bone was determined to 34.4% in the computed tomography dataset for the augmentation material Geistlich Bio-Oss®. The combination of computed tomography and histology allowed a complementary assessment for both bone augmentation and distraction osteogenesis.

  16. An all-silicon single-wafer micro-g accelerometer with a combined surface and bulk micromachining process

    NASA Technical Reports Server (NTRS)

    Yazdi, N.; Najafi, K.

    2000-01-01

    This paper reports an all-silicon fully symmetrical z-axis micro-g accelerometer that is fabricated on a single-silicon wafer using a combined surface and bulk fabrication process. The microaccelerometer has high device sensitivity, low noise, and low/controllable damping that are the key factors for attaining micro g and sub-micro g resolution in capacitive accelerometers. The microfabrication process produces a large proof mass by using the whole wafer thickness and a large sense capacitance by utilizing a thin sacrificial layer. The sense/feedback electrodes are formed by a deposited 2-3 microns polysilicon film with embedded 25-35 microns-thick vertical stiffeners. These electrodes, while thin, are made very stiff by the thick embedded stiffeners so that force rebalancing of the proof mass becomes possible. The polysilicon electrodes are patterned to create damping holes. The microaccelerometers are batch-fabricated, packaged, and tested successfully. A device with a 2-mm x 1-mm proof mass and a full bridge support has a measured sensitivity of 2 pF/g. The measured sensitivity of a 4-mm x 1-mm accelerometer with a cantilever support is 19.4 pF/g. The calculated noise floor of these devices at atmosphere are 0.23 micro g/sqrt(Hz) and 0.16 micro g/sqrt(Hz), respectively.

  17. An all-silicon single-wafer micro-g accelerometer with a combined surface and bulk micromachining process.

    PubMed

    Yazdi, N; Najafi, K

    2000-12-01

    This paper reports an all-silicon fully symmetrical z-axis micro-g accelerometer that is fabricated on a single-silicon wafer using a combined surface and bulk fabrication process. The microaccelerometer has high device sensitivity, low noise, and low/controllable damping that are the key factors for attaining micro g and sub-micro g resolution in capacitive accelerometers. The microfabrication process produces a large proof mass by using the whole wafer thickness and a large sense capacitance by utilizing a thin sacrificial layer. The sense/feedback electrodes are formed by a deposited 2-3 microns polysilicon film with embedded 25-35 microns-thick vertical stiffeners. These electrodes, while thin, are made very stiff by the thick embedded stiffeners so that force rebalancing of the proof mass becomes possible. The polysilicon electrodes are patterned to create damping holes. The microaccelerometers are batch-fabricated, packaged, and tested successfully. A device with a 2-mm x 1-mm proof mass and a full bridge support has a measured sensitivity of 2 pF/g. The measured sensitivity of a 4-mm x 1-mm accelerometer with a cantilever support is 19.4 pF/g. The calculated noise floor of these devices at atmosphere are 0.23 micro g/sqrt(Hz) and 0.16 micro g/sqrt(Hz), respectively. PMID:12194180

  18. Near-infrared confocal micro-Raman spectroscopy combined with PCA-LDA multivariate analysis for detection of esophageal cancer

    NASA Astrophysics Data System (ADS)

    Chen, Long; Wang, Yue; Liu, Nenrong; Lin, Duo; Weng, Cuncheng; Zhang, Jixue; Zhu, Lihuan; Chen, Weisheng; Chen, Rong; Feng, Shangyuan

    2013-06-01

    The diagnostic capability of using tissue intrinsic micro-Raman signals to obtain biochemical information from human esophageal tissue is presented in this paper. Near-infrared micro-Raman spectroscopy combined with multivariate analysis was applied for discrimination of esophageal cancer tissue from normal tissue samples. Micro-Raman spectroscopy measurements were performed on 54 esophageal cancer tissues and 55 normal tissues in the 400-1750 cm-1 range. The mean Raman spectra showed significant differences between the two groups. Tentative assignments of the Raman bands in the measured tissue spectra suggested some changes in protein structure, a decrease in the relative amount of lactose, and increases in the percentages of tryptophan, collagen and phenylalanine content in esophageal cancer tissue as compared to those of a normal subject. The diagnostic algorithms based on principal component analysis (PCA) and linear discriminate analysis (LDA) achieved a diagnostic sensitivity of 87.0% and specificity of 70.9% for separating cancer from normal esophageal tissue samples. The result demonstrated that near-infrared micro-Raman spectroscopy combined with PCA-LDA analysis could be an effective and sensitive tool for identification of esophageal cancer.

  19. Synthesis and characterization of hybrid micro/nano-structured NiTi surfaces by a combination of etching and anodizing

    NASA Astrophysics Data System (ADS)

    Huan, Z.; Fratila-Apachitei, L. E.; Apachitei, I.; Duszczyk, J.

    2014-02-01

    The purpose of this study was to generate hybrid micro/nano-structures on biomedical nickel-titanium alloy (NiTi). To achieve this, NiTi surfaces were firstly electrochemically etched and then anodized in fluoride-containing electrolyte. With the etching process, the NiTi surface was micro-roughened through the formation of micropits uniformly distributed over the entire surface. Following the subsequent anodizing process, self-organized nanotube structures enriched in TiO2 could be superimposed on the etched surface under specific conditions. Furthermore, the anodizing treatment significantly reduced water contact angles and increased the surface free energy compared to the surfaces prior to anodizing. The results of this study show for the first time that it is possible to create hybrid micro/nano-structures on biomedical NiTi alloys by combining electrochemical etching and anodizing under controlled conditions. These novel structures are expected to significantly enhance the surface biofunctionality of the material when compared to conventional implant devices with either micro- or nano-structured surfaces.

  20. Advantages of combined micro-XRF and micro-XRD for phase characterization of Ti-B-C ceramics compared with conventional X-ray diffraction.

    PubMed

    Jaroszewicz, Jakub; De Nolf, Wout; Janssens, Koen; Michalski, Andrzej; Falkenberg, Gerald

    2008-06-01

    Design and processing of new materials with improved high-temperature properties is one of the most challenging tasks of modern engineering. Among such materials, nonoxidic ceramics hold an important place. When optimizing the synthesis conditions of these new materials in an largely empirical manner, the use of analytical methods that can fully document the resulting phase compositions is of great importance. In this paper, we demonstrate the advantages of using combined microbeam X-ray diffraction and X-ray fluorescence over conventional X-ray diffraction as the characterization method in the specific case of Ti-B-C ceramics. Ceramic samples were synthesized by the pulse plasma method starting from high-purity powders of titanium, boron, graphite, and nickel. Different mixtures were heated in a pulsed fashion and sintered by combustion synthesis at various temperatures and time durations, as is the case during empirical optimization of a synthesis procedure. Conventional X-ray diffraction showed the presence of two phases at the end of the sintering process, TiB(2) and TiC, irrespective of the conditions employed. Scanning micro-XRF/micro-XRD on the other hand allowed one to detect and visualize the distribution of additional phases present in the sintering products, during which a dependence on sintering conditions was apparent. The micro-XRD results showed that three phases (TiB(2), TiC, and TiB) instead of two were present in samples sintered during a short time interval. The addition of metallic Ni to the initial mixture as a sintering facilitator resulted in the formation of a Ni(3)B phase. All phases proved to have strongly heterogeneous distributions above the 15-microm level with the presence of TiB(2) anticorrelated to that of TiC and TiB, emphasizing the necessity of the use of laterally resolved methods of characterization. PMID:18458886

  1. Highly Tunable Complementary Micro/Submicro-Nanopatterned Surfaces Combining Block Copolymer Self-Assembly and Colloidal Lithography.

    PubMed

    Chang, Tongxin; Du, Binyang; Huang, Haiying; He, Tianbai

    2016-08-31

    Two kinds of large-area ordered and highly tunable micro/submicro-nanopatterned surfaces in a complementary manner were successfully fabricated by elaborately combining block copolymer self-assembly and colloidal lithography. Employing a monolayer of polystyrene (PS) colloidal spheres assembled on top as etching mask, polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) or polystyrene-block-poly(4-vinylpyridine) (PS-b-P4VP) micelle films were patterned into micro/submicro patches by plasma etching, which could be further transferred into micropatterned metal nanoarrays by subsequent metal precursor loading and a second plasma etching. On the other hand, micro/submicro-nanopatterns in a complementary manner were generated via preloading a metal precursor in initial micelle films before the assembly of PS colloidal spheres on top. Both kinds of micro/submicro-nanopatterns showed good fidelity at the micro/submicroscale and nanoscale; meanwhile, they could be flexibly tuned by the sample and processing parameters. Significantly, when the PS colloidal sphere size was reduced to 250 nm, a high-resolution submicro-nanostructured surface with 3-5 metal nanoparticles in each patch or a single-nanoparticle interconnected honeycomb network was achieved. Moreover, by applying gold (Au) nanoparticles as anchoring points, micronanopatterned Au arrays can serve as a flexible template to pattern bovine serum albumin (BSA) molecules. This facile and cost-effective approach may provide a novel platform for fabrication of micropatterned nanoarrays with high tunability and controllability, which are promising in the applications of biological and microelectronic fields. PMID:27509255

  2. Technical Analysis of Installed Micro-Combined Heat and Power Fuel-Cell System

    SciTech Connect

    Brooks, Kriston P.; Makhmalbaf, Atefe

    2014-10-31

    Combined heat and power fuel cell systems (CHP-FCSs) provide consistent electrical power and hot water with greater efficiency and lower emissions than alternative sources. These systems can be used either as baseload, grid-connected, or as off-the-grid power sources. This report presents a technical analysis of 5 kWe CHP-FCSs installed in different locations in the U.S. At some sites as many as five 5 kWe system is used to provide up to 25kWe of power. Systems in this power range are considered “micro”-CHP-FCS. To better assess performance of micro-CHP-FCS and understand their benefits, the U.S. Department of Energy worked with ClearEdge Power to install fifteen 5-kWe PBI high temperature PEM fuel cells (CE5 models) in the commercial markets of California and Oregon. Pacific Northwest National Laboratory evaluated these systems in terms of their economics, operations, and technical performance. These units were monitored from September 2011 until June 2013. During this time, about 190,000 hours of data were collected and more than 17 billion data points were analyzed. Beginning in July 2013, ten of these systems were gradually replaced with ungraded systems (M5 models) containing phosphoric acid fuel cell technology. The new units were monitored until June 2014 until they went offline because ClearEdge was bought by Doosan at the time and the new manufacturer did not continue to support data collection and maintenance of these units. During these two phases, data was collected at once per second and data analysis techniques were applied to understand behavior of these systems. The results of this analysis indicate that systems installed in the second phase of this demonstration performed much better in terms of availability, consistency in generation, and reliability. The average net electrical power output increased from 4.1 to 4.9 kWe, net heat recovery from 4.7 to 5.4 kWth, and system availability improved from 94% to 95%. The average net system electric

  3. Combined Simulation of a Micro Permanent Magnetic Linear Contactless Displacement Sensor

    PubMed Central

    Gao, Jing; Müller, Wolfgang F.O.; Greiner, Felix; Eicher, Dirk; Weiland, Thomas; Schlaak, Helmut F.

    2010-01-01

    The permanent magnetic linear contactless displacement (PLCD) sensor is a new type of displacement sensor operating on the magnetic inductive principle. It has many excellent properties and has already been used for many applications. In this article a Micro-PLCD sensor which can be used for microelectromechanical system (MEMS) measurements is designed and simulated with the CST EM STUDIO® software, including building a virtual model, magnetostatic calculations, low frequency calculations, steady current calculations and thermal calculations. The influence of some important parameters such as air gap dimension, working frequency, coil current and eddy currents etc. is studied in depth. PMID:22163663

  4. Combined simulation of a micro permanent magnetic linear contactless displacement sensor.

    PubMed

    Gao, Jing; Müller, Wolfgang F O; Greiner, Felix; Eicher, Dirk; Weiland, Thomas; Schlaak, Helmut F

    2010-01-01

    The permanent magnetic linear contactless displacement (PLCD) sensor is a new type of displacement sensor operating on the magnetic inductive principle. It has many excellent properties and has already been used for many applications. In this article a Micro-PLCD sensor which can be used for microelectromechanical system (MEMS) measurements is designed and simulated with the CST EM STUDIO(®) software, including building a virtual model, magnetostatic calculations, low frequency calculations, steady current calculations and thermal calculations. The influence of some important parameters such as air gap dimension, working frequency, coil current and eddy currents etc. is studied in depth. PMID:22163663

  5. Analyzing the human liver vascular architecture by combining vascular corrosion casting and micro-CT scanning: a feasibility study

    PubMed Central

    Debbaut, Charlotte; Segers, Patrick; Cornillie, Pieter; Casteleyn, Christophe; Dierick, Manuel; Laleman, Wim; Monbaliu, Diethard

    2014-01-01

    Although a full understanding of the hepatic circulation is one of the keys to successfully perform liver surgery and to elucidate liver pathology, relatively little is known about the functional organization of the liver vasculature. Therefore, we materialized and visualized the human hepatic vasculature at different scales, and performed a morphological analysis by combining vascular corrosion casting with novel micro-computer tomography (CT) and image analysis techniques. A human liver vascular corrosion cast was obtained by simultaneous resin injection in the hepatic artery (HA) and portal vein (PV). A high resolution (110 μm) micro-CT scan of the total cast allowed gathering detailed macrovascular data. Subsequently, a mesocirculation sample (starting at generation 5; 88 × 68 × 80 mm³) and a microcirculation sample (terminal vessels including sinusoids; 2.0 × 1.5 × 1.7 mm³) were dissected and imaged at a 71-μm and 2.6-μm resolution, respectively. Segmentations and 3D reconstructions allowed quantifying the macro-and mesoscale branching topology, and geometrical features of HA, PV and hepatic venous trees up to 13 generations (radii ranging from 13.2 mm to 80 μm; lengths from 74.4 mm to 0.74 mm), as well as microvascular characteristics (mean sinusoidal radius of 6.63 μm). Combining corrosion casting and micro-CT imaging allows quantifying the branching topology and geometrical features of hepatic trees using a multiscale approach from the macro-down to the microcirculation. This may lead to novel insights into liver circulation, such as internal blood flow distributions and anatomical consequences of pathologies (e.g. cirrhosis). PMID:24433401

  6. Design, Fabrication and Prototype testing of a Chip Integrated Micro PEM Fuel Cell Accumulator combined On-Board Range Extender

    NASA Astrophysics Data System (ADS)

    Balakrishnan, A.; Mueller, C.; Reinecke, H.

    2014-11-01

    In this work we present the design, fabrication and prototype testing of Chip Integrated Micro PEM Fuel Cell Accumulator (CIμ-PFCA) combined On-Board Range Extender (O-BRE). CIμ-PFCA is silicon based micro-PEM fuel cell system with an integrated hydrogen storage feature (palladium metal hydride), the run time of CIμ-PFCA is dependent on the stored hydrogen, and in order to extend its run time an O-BRE is realized (catalytic hydrolysis of chemical hydride, NaBH4. Combining the CIμ-PFCA and O-BRE on a system level have few important design requirements to be considered; hydrogen regulation, gas -liquid separator between the CIμ-PFCA and the O-RE. The usage of traditional techniques to regulate hydrogen (tubes), gas-liquid phase membranes (porous membrane separators) are less desirable in the micro domain, due to its space constraint. Our approach is to use a passive hydrogen regulation and gas-liquid phase separation concept; to use palladium membrane. Palladium regulates hydrogen by concentration diffusion, and its property to selectively adsorb only hydrogen is used as a passive gas-liquid phase separator. Proof of concept is shown by realizing a prototype system. The system is an assembly of CIμ-PFCA, palladium membrane and the O-BRE. The CIμ-PFCA consist of 2 individually processed silicon chips, copper supported palladium membrane realized by electroplating followed by high temperature annealing process under inter atmosphere and the O-BRE is realized out of a polymer substrate by micromilling process with platinum coated structures, which functions as a catalyst for the hydrolysis of NaBH4. The functionality of the assembled prototype system is demonstrated by the measuring a unit cell (area 1 mm2) when driven by the catalytic hydrolysis of chemical hydride (NaBH4 and the prototype system shows run time more than 15 hours.

  7. Micro-Bypass Implantation for Primary Open-Angle Glaucoma Combined with Phacoemulsification: 4-Year Follow-Up

    PubMed Central

    Fea, Antonio Maria; Consolandi, Giulia; Zola, Marta; Pignata, Giulia; Cannizzo, Paola; Lavia, Carlo; Rolle, Teresa; Grignolo, Federico Maria

    2015-01-01

    Purpose. To report the long-term follow-up results in patients with cataract and primary open-angle glaucoma (POAG) randomly assigned to cataract surgery combined with micro-bypass stent implantation or phacoemulsification alone. Methods. 36 subjects with cataract and POAG were randomized in a 1 : 2 ratio to either iStent implantation and cataract surgery (combined group) or cataract surgery alone (control group). 24 subjects agreed to be evaluated again 48 months after surgery. Patients returned one month later for unmedicated washout assessment. Results. At the long-term follow-up visit we reported a mean IOP of 15,9 ± 2,3 mmHg in the iStent group and 17 ± 2,5 mmHg in the control group (p = NS). After washout, a 14,2% between group difference in favour of the combined group was statistically significant (p = 0,02) for mean IOP reduction. A significant reduction in the mean number of medications was observed in both groups compared to baseline values (p = 0,005 in the combined group and p = 0,01 in the control group). Conclusion. Patients in the combined group maintained low IOP levels after long-term follow-up. Cataract surgery alone showed a loss of efficacy in controlling IOP over time. Both treatments reduced the number of ocular hypotensive medications prescribed. This trial is registered with: NCT00847158. PMID:26587282

  8. Microwave properties of polymer composites containing combinations of micro- and nano-sized magnetic fillers.

    PubMed

    Kolev, Svetoslav; Koutzarova, Tatyana; Yanev, Andrey; Ghelev, Chavdar; Nedkov, Ivan

    2008-02-01

    We investigated the microwave absorbing properties of composite bulk samples with nanostructured and micron-sized fillers. As magnetic fillers we used magnetite powder (Fe3O4 with low magnetocrystalline anisotropy) and strontium hexaferrite (SrFe12O9 with high magnetocrystalline anisotropy). The dielectric matrix consisted of silicone rubber. The average particle size was 30 nm for the magnetite powder and 6 micro/m for the strontium hexaferrite powder. The micron-sized SrFe12O19 powder was prepared using a solid-state reaction. We investigated the influence of the filler concentration and the filler ratio (Fe3O4/SrFe12O19) in the polymer matrix on the microwave absorption in a large frequency range (1 / 18 GHz). The results obtained showed that the highly anisotropic particles become centers of clusterification and the small magnetite particles form magnetic balls with different diameter depending on the concentration. The effect of adding micron-sized SrFe12O19 to the nanosized Fe3O4 filler in composites absorbing structures has to do with the ferromagnetic resonance (FMR) shifting to the higher frequencies due to the changes in the ferrite filler's properties induced by the presence of a magnetic material with high magnetocrystalline anisotropy. The two-component filler possesses new values of the saturation magnetization and of the anisotropy constant, differing from those of both SrFe12O1919 and Fe3O4, which leads to a rise in the effective anisotropy field. The results demonstrate the possibility to vary the composite's absorption characteristics in a controlled manner by way of introducing a second magnetic material. PMID:18464386

  9. Combination of powdered activated carbon and powdered zeolite for enhancing ammonium removal in micro-polluted raw water.

    PubMed

    Liao, Zhen-Liang; Chen, Hao; Zhu, Bai-Rong; Li, Huai-Zheng

    2015-09-01

    Even zeolite is promising in ammonia pollution disposing, its removal efficiency is frequently interfered by organics. As activated carbon has good removal efficiency on organic contaminants, combination of two adsorbents may allow their respective adsorption characteristics into full play. This paper provides a performance assessment of the combination for enhancing ammonium removal in micro-polluted raw water. Gel-filtration chromatography (GFC) was carried out to quantify the molecular weight (MW) range of organic contaminants that powdered activated carbon (PAC) and powdered zeolite (PZ) can remove. The polydispersity difference which also calculated from GFC may indicate the wider organic contaminants removal range of PAC and the relatively centralized removal range of PZ. The jar tests of combination dosing confirm a synergistic effect which promotes ammonium removing. Nevertheless, it also shows an antagonism hindering the due removal performance of the two adsorbents on CODMn, while it is not much evident on UV254. Furthermore, a comparison study with simulated coagulation-sedimentation process was conducted to evaluate the optimum dosing points (spatial and temporal) of PAC and PZ among follows: suction well, pipeline mixer, early and middle phase of flocculation. We suggest to dose both two adsorbents into the early phase of flocculation to maximize the versatile removal efficiency on turbidity, ammonium and organic contaminants. PMID:25929873

  10. Combined micro-and standard percutaneous nephrolithotomy for complex renal calculi

    PubMed Central

    Buldu, İbrahim; Tepeler, Abdulkadir; Karatağ, Tuna; İnan, Ramazan; Armağan, Abdullah; İstanbulluoğlu, Okan

    2016-01-01

    Objective We aimed to present the technique of combination of standard percutaneous nephrolithotomy (PNL) with microperc for achieving higher success rates without increasing complication rates in the management of complex renal calculi. Material and methods The patients who underwent microperc procedure as a complementary procedure to standard PNL for complex kidney stones in two reference hospitals between 2013 and 2015, were evaluated retrospectively. Results All patients underwent a total of two accesses one for standard PNL and one for microperc. The mean stone size was measured as 54.3 mm. The procedures were completed after an average operative time of 88.2 minutes and fluoroscopy time of 5.3 minutes. Stone free status was achieved in 18 cases (78.2%) and small residual fragments (≤4 mm) were detected in 3 cases (13.1%). Complications were seen in three patients (13%) as hemorrhage in one and postoperative fever in two patients. Conclusion Despite the limitations of this study, the combination of standard PNL and microperc might reduce the complication rates and increase the success rates when treating complex kidney stones. Future prospective and comparative studies are needed.

  11. Removal of metals and ceramics by combined effects of micro liquid jet and laser pulse

    NASA Astrophysics Data System (ADS)

    Ahn, Daehwan; Seo, Changho; Kim, Dongsik

    2012-12-01

    In this work, we analyze a hybrid laser/liquid jet micromachining process for several metals and ceramics based on the optical breakdown of a microdroplet. In the process, materials are removed by the combined effects of a laser pulse and a high-speed pulsed microjet ejected from the microdroplet. The opto-hydrodynamic phenomena occurring during this process and the interaction of the laser/liquid jet with various materials, including copper, aluminum, stainless steel, alumina, and boron nitride, are investigated experimentally. The results show that the laser/liquid jet can remove the materials with substantially increased removal rates and reduced thermal side effects compared with the conventional pulsed laser ablation process. Visualization of the process reveals that the materials are partially ablated and melted by the laser pulse during the early stage of the process and that the molten material is subsequently eliminated by the hydrodynamic impact of the liquid jet.

  12. A multimodal micro-optrode combining field and single unit recording, multispectral detection and photolabeling capabilities.

    PubMed

    Dufour, Suzie; Lavertu, Guillaume; Dufour-Beauséjour, Sophie; Juneau-Fecteau, Alexandre; Calakos, Nicole; Deschênes, Martin; Vallée, Réal; De Koninck, Yves

    2013-01-01

    Microelectrodes have been very instrumental and minimally invasive for in vivo functional studies from deep brain structures. However they are limited in the amount of information they provide. Here, we describe a, aluminum-coated, fibre optic-based glass microprobe with multiple electrical and optical detection capabilities while retaining tip dimensions that enable single cell measurements (diameter ≤10 µm). The probe enables optical separation from individual cells in transgenic mice expressing multiple fluorescent proteins in distinct populations of neurons within the same deep brain nucleus. It also enables color conversion of photoswitchable fluorescent proteins, which can be used for post-hoc identification of the recorded cells. While metal coating did not significantly improve the optical separation capabilities of the microprobe, the combination of metal on the outside of the probe and of a hollow core within the fiber yields a microelectrode enabling simultaneous single unit and population field potential recordings. The extended range of functionalities provided by the same microprobe thus opens several avenues for multidimensional structural and functional interrogation of single cells and their surrounding deep within the intact nervous system. PMID:23469053

  13. Modelling and control synthesis of a micro-combined heat and power interface for a concentrating solar power system in off-grid rural power applications

    NASA Astrophysics Data System (ADS)

    Prinsloo, Gerro; Dobson, Robert; Brent, Alan; Mammoli, Andrea

    2016-05-01

    Concentrating solar power co-generation systems have been identified as potential stand-alone solar energy supply solutions in remote rural energy applications. This study describes the modelling and synthesis of a combined heat and power Stirling CSP system in order to evaluate its potential performance in small off-grid rural village applications in Africa. This Stirling micro-Combined Heat and Power (micro-CHP) system has a 1 kW electric capacity, with 3 kW of thermal generation capacity which is produced as waste heat recovered from the solar power generation process. As part of the development of an intelligent microgrid control and distribution solution, the Trinum micro-CHP system and other co-generation systems are systematically being modelled on the TRNSYS simulation platform. This paper describes the modelling and simulation of the Trinum micro-CHP configuration on TRNSYS as part of the process to develop the control automation solution for the smart rural microgrid in which the Trinum will serve as a solar powerpack. The results present simulated performance outputs for the Trinum micro-CHP system for a number of remote rural locations in Africa computed from real-time TRNSYS solar irradiation and weather data (yearly, monthly, daily) for the relevant locations. The focus of this paper is on the parametric modelling of the Trinum Stirling micro-CHP system, with specific reference to this system as a TRNSYS functional block in the microgrid simulation. The model is used to forecast the solar energy harvesting potential of the Trinum micro-CHP unit at a number of remote rural sites in Africa.

  14. Improving panicle exsertion of rice cytoplasmic male sterile line by combination of artificial microRNA and artificial target mimic.

    PubMed

    Chen, Hao; Jiang, Shan; Zheng, Jie; Lin, Yongjun

    2013-04-01

    The adoption of hybrid rice caused the second leap in rice yield after the 'green revolution' and contributes substantially to food security of China and the world. However, almost all cytoplasmic male sterile lines (A lines) as females of hybrid rice have a natural deficiency of 'panicle enclosure', which blocks pollination between the A line and the fertility restorer line as the male (R line) of hybrid rice and decreases seed yield. In hybrid rice seed production, exogenous '920' (the active ingredient is gibberellin A3 ) must be applied to eliminate or alleviate panicle enclosure of the A line; however, this not only increases production cost and pollutes the environment, it also decreases seed quality. In this study, we designed a transgenic approach to improve plant height and panicle exsertion of the A line to facilitate hybrid rice production and maintain the semi-dwarf plant type of the hybrid. This approach comprising two components-artificial microRNA (amiRNA) and artificial target mimicry-can manipulate the differential expression of the endogenous Eui1 gene that is associated with rice internode elongation in the A line and the hybrid. amiRNA is a recently developed gene silencing method with high specificity, while target mimicry is a natural mechanism inhibiting the miRNA function that was also recently characterized. This approach provides a paradigm to tune the expression of endogenous genes to achieve the desired phenotype by combining amiRNA and artificial target mimicry technologies. PMID:23164055

  15. Solid oxide fuel cell systems for residential micro-combined heat and power in the UK: Key economic drivers

    NASA Astrophysics Data System (ADS)

    Hawkes, Adam; Leach, Matthew

    The ability of combined heat and power (CHP) to meet residential heat and power demands efficiently offers potentially significant financial and environmental advantages over centralised power generation and heat-provision through natural-gas fired boilers. A solid oxide fuel cell (SOFC) can operate at high overall efficiencies (heat and power) of 80-90%, offering an improvement over centralised generation, which is often unable to utilise waste heat. This paper applies an equivalent annual cost (EAC) minimisation model to a residential solid oxide fuel cell CHP system to determine what the driving factors are behind investment in this technology. We explore the performance of a hypothetical SOFC system—representing expectations of near to medium term technology development—under present UK market conditions. We find that households with small to average energy demands do not benefit from installation of a SOFC micro-CHP system, but larger energy demands do benefit under these conditions. However, this result is sensitive to a number of factors including stack capital cost, energy import and export prices, and plant lifetime. The results for small and average dwellings are shown to reverse under an observed change in energy import prices, an increase in electricity export price, a decrease in stack capital costs, or an improvement in stack lifetime.

  16. Removal of nitrogen and phosphorus from the secondary effluent in tertiary denitrifying biofilters combined with micro-coagulation.

    PubMed

    Wei, Nan; Shi, Yunhong; Wu, Guangxue; Hu, Hongying; Guo, Yumei; Wu, Yihui; Wen, Hui

    2016-01-01

    Effective control of nitrogen and phosphorus in secondary effluent can reduce or avoid the eutrophication of receiving water bodies. Two denitrifying biofilters (DNBFs) packed with different sizes of quartz sands combined with micro-coagulation were operated for simultaneous removal of nitrogen and phosphorus from the secondary effluent. The quartz sand size in one DNBF was 2-4 mm (DNBFS), and in the other was 4-6 mm (DNBFL). In both DNBFs, methanol was used as the electron donor and different organic carbon to nitrogen (C/N) ratios were applied. Under C/N ratios of 1.5, 1.25, and 0.75 g/g, the nitrate nitrogen (NO3(-)-N) removal percentages were 73%, 77%, and 50% in DNBFS, and 43%, 25%, and 21% in DNBFL; the effluent total phosphorus concentrations were 0.15, 0.14, and 0.18 mg/L in DNBFS, and 0.29, 0.35, and 0.24 mg/L in DNBFL. The performance of both biofilters was quite stable within a backwashing cycle. The NO3(-)-N reduction rates were 1.31, 1.10, and 0.48 mg/(L·min) in DNBFS, and 0.97, 0.27, and 0.10 mg/(L·min) in DNBFL. For biomass detached from both biofilters, their denitrifying activities were similar. Biofilm biomass in DNBFS was higher than that in DNBFL, inducing a high denitrification efficiency in DNBFS. PMID:27232413

  17. Support schemes and ownership structures - the policy context for fuel cell based micro-combined heat and power

    NASA Astrophysics Data System (ADS)

    Schroeder, Sascha Thorsten; Costa, Ana; Obé, Elisabeth

    In recent years, fuel cell based micro-combined heat and power (mCHP) has received increasing attention due to its potential contribution to European energy policy goals, i.e., sustainability, competitiveness and security of supply. Besides technical advances, regulatory framework and ownership structures are of crucial importance in order to achieve greater diffusion of the technology in residential applications. This paper analyses the interplay of policy and ownership structures for the future deployment of mCHP. Furthermore, it regards the three country cases Denmark, France and Portugal. Firstly, the implications of different kinds of support schemes on investment risk and the diffusion of a technology are explained conceptually. Secondly, ownership arrangements are addressed. Then, a cross-country comparison on present support schemes for mCHP and competing technologies discusses the national implementation of European legislation in Denmark, France and Portugal. Finally, resulting implications for ownership arrangements on the choice of support scheme are explained. From a conceptual point of view, investment support, feed-in tariffs and price premiums are the most appropriate schemes for fuel cell mCHP. This can be used for improved analysis of operational strategies. The interaction of this plethora of elements necessitates careful balancing from a private- and socio-economic point of view.

  18. Modeling the combined effect of RNA-binding proteins and microRNAs in post-transcriptional regulation.

    PubMed

    HafezQorani, Saber; Lafzi, Atefeh; de Bruin, Ruben G; van Zonneveld, Anton Jan; van der Veer, Eric P; Son, Yeşim Aydın; Kazan, Hilal

    2016-05-19

    Recent studies show that RNA-binding proteins (RBPs) and microRNAs (miRNAs) function in coordination with each other to control post-transcriptional regulation (PTR). Despite this, the majority of research to date has focused on the regulatory effect of individual RBPs or miRNAs. Here, we mapped both RBP and miRNA binding sites on human 3'UTRs and utilized this collection to better understand PTR. We show that the transcripts that lack competition for HuR binding are destabilized more after HuR depletion. We also confirm this finding for PUM1(2) by measuring genome-wide expression changes following the knockdown of PUM1(2) in HEK293 cells. Next, to find potential cooperative interactions, we identified the pairs of factors whose sites co-localize more often than expected by random chance. Upon examining these results for PUM1(2), we found that transcripts where the sites of PUM1(2) and its interacting miRNA form a stem-loop are more stabilized upon PUM1(2) depletion. Finally, using dinucleotide frequency and counts of regulatory sites as features in a regression model, we achieved an AU-ROC of 0.86 in predicting mRNA half-life in BEAS-2B cells. Altogether, our results suggest that future studies of PTR must consider the combined effects of RBPs and miRNAs, as well as their interactions. PMID:26837572

  19. [Protective effect of combined administration of active ingredients of Danhong on cerebral micro-vascular endothelial cell injured by hypoxia].

    PubMed

    Zhou, Hui-fen; He, Yu; Zhang, Yu-yan; Yang, Jie-hong; Zhao, Tao; Fu, Wei; Zhou, Peng; Wan, Hai-tong

    2014-11-01

    To study the protective effect of combined administration of active ingredients of Danhong on cultured primary mice's brain microvascular endothelial cells (rBMECs) injured by hypoxia. Primary mice's brain micro-vascular endothelial cells were cultured to establish the 4 h hypoxia model. Meanwhile, active ingredients (protocatechuic aldehyde, salvianolic acid B, hydroxysafflor yellow A and tanshinol) of Danhong were administered in rBMECs. The non-toxic dosage was determined by MTT. The leakage of lactate dehydrogenase(LDH), cell superoxide dismutase (SOD) activity and MDA level were detected by the colorimetric method. The expressions of ICAM-1, MMP-9, P53 mRNA were detected by RT-PCR method. Changes in rBMECs cell cycle and early apoptosis were detected by flow cytometry. Danhong's active ingredients and prescriptions 1, 2, 3, 7, 8, 9 could be combined to significantly restrain LDH in hypoxic cells supernatant. Prescriptions 1, 2, 3, 7, 8, 9 could significantly enhance SOD activity in anoxic cells; Prescriptions 1, 2, 3, 8, 9 could significantly decrease the MDA level; Prescriptions 1, 2, 6, 7, 9 could significantly inhibit the early rB-MECs apoptosis induced by hypoxia. After hypoxia, the up-regulated P53 mRNA expression could cause retardation in G, phase and promote cell apoptosis. This proved that the regulatory function of P53 gene lay in monitoring of calibration points in G, phase. Prescriptions 1, 2, 5, 6, 7, 8, 9 could significantly down-regulate the P53 mRNA expression; Prescriptions 1, 4, 7, 8, 9 could significantly down-regulate the ICAM-1 mRNA expression; Prescriptions 1, 3, 6, 9 could significantly down-regulate the MMP-9 mRNA expression. The combined administration of Danhong's active ingredients showed a significant protective effect on primary cultured rBMECs injury induced by hypoxia Its mechanism may be related to the enhancement of cellular antioxidant capacity and the inhibition of inflammatory response and cell apoptosis. This study could

  20. Reconstruction of muscle fascicle architecture from iodine-enhanced microCT images: A combined texture mapping and streamline approach.

    PubMed

    Kupczik, Kornelius; Stark, Heiko; Mundry, Roger; Neininger, Fabian T; Heidlauf, Thomas; Röhrle, Oliver

    2015-10-01

    Skeletal muscle models are used to investigate motion and force generation in both biological and bioengineering research. Yet, they often lack a realistic representation of the muscle's internal architecture which is primarily composed of muscle fibre bundles, known as fascicles. Recently, it has been shown that fascicles can be resolved with micro-computed tomography (µCT) following staining of the muscle tissue with iodine potassium iodide (I2KI). Here, we present the reconstruction of the fascicular spatial arrangement and geometry of the superficial masseter muscle of a dog based on a combination of pattern recognition and streamline computation. A cadaveric head of a dog was incubated in I2KI and µCT-scanned. Following segmentation of the masseter muscle a statistical pattern recognition algorithm was applied to create a vector field of fascicle directions. Streamlines were then used to transform the vector field into a realistic muscle fascicle representation. The lengths of the reconstructed fascicles and the pennation angles in two planes (frontal and sagittal) were extracted and compared against a tracked fascicle field obtained through cadaver dissection. Both fascicle lengths and angles were found to vary substantially within the muscle confirming the complex and heterogeneous nature of skeletal muscle described by previous studies. While there were significant differences in the pennation angle between the experimentally derived and µCT-reconstructed data, there was congruence in the fascicle lengths. We conclude that the presented approach allows for embedding realistic fascicle information into finite element models of skeletal muscles to better understand the functioning of the musculoskeletal system. PMID:26141643

  1. Longitudinal in vivo evaluation of bone regeneration by combined measurement of multi-pinhole SPECT and micro-CT for tissue engineering

    NASA Astrophysics Data System (ADS)

    Lienemann, Philipp S.; Metzger, Stéphanie; Kiveliö, Anna-Sofia; Blanc, Alain; Papageorgiou, Panagiota; Astolfo, Alberto; Pinzer, Bernd R.; Cinelli, Paolo; Weber, Franz E.; Schibli, Roger; Béhé, Martin; Ehrbar, Martin

    2015-05-01

    Over the last decades, great strides were made in the development of novel implants for the treatment of bone defects. The increasing versatility and complexity of these implant designs request for concurrent advances in means to assess in vivo the course of induced bone formation in preclinical models. Since its discovery, micro-computed tomography (micro-CT) has excelled as powerful high-resolution technique for non-invasive assessment of newly formed bone tissue. However, micro-CT fails to provide spatiotemporal information on biological processes ongoing during bone regeneration. Conversely, due to the versatile applicability and cost-effectiveness, single photon emission computed tomography (SPECT) would be an ideal technique for assessing such biological processes with high sensitivity and for nuclear imaging comparably high resolution (<1 mm). Herein, we employ modular designed poly(ethylene glycol)-based hydrogels that release bone morphogenetic protein to guide the healing of critical sized calvarial bone defects. By combined in vivo longitudinal multi-pinhole SPECT and micro-CT evaluations we determine the spatiotemporal course of bone formation and remodeling within this synthetic hydrogel implant. End point evaluations by high resolution micro-CT and histological evaluation confirm the value of this approach to follow and optimize bone-inducing biomaterials.

  2. Precise deformation measurement of prestressed concrete beam during a strain test using the combination of intersection photogrammetry and micro-network measurement

    NASA Astrophysics Data System (ADS)

    Urban, Rudolf; Braun, Jaroslav; Štroner, Martin

    2015-05-01

    The prestressed thin-walled concrete elements enable the bridge a relatively large span. These structures are advantageous in economic and environmental way due to their thickness and lower consumption of materials. The bending moments can be effectively influenced by using the pre-stress. The experiment was done to monitor deformation of the under load. During the experiment the discrete points were monitored. To determine a large number of points, the intersection photogrammetry combined with precise micro-network were chosen. Keywords:

  3. Combination of Methods for the Fractionation, Investigation, and Analysis of Micro/Nano Particles in Volcanic Ash

    NASA Astrophysics Data System (ADS)

    Valeriy, Shkinev; Michail, Ermolin; Peter, Fedotov; Aleksander, Rudnev; Nikolay, Bulychev; Vitaliy, Linnik; Gerardo, Moreno

    2013-04-01

    Micro and nanoparticles play a very important role in environment, in biology and medicine, in various technologies. The investigation of particles is often based on the fractionation according to particle size, density and charge followed by the analysis of the separated fractions. Such studies are needed in the analysis of environmental samples (natural and waste waters, soils, sediments, ashes) to assess the soil formation processes as well as distribution, transport, and biological uptake of pollutants. Recently, the review dealing with the fractionation and investigation of particles in liquid media has been published [Anal. Bioanal. Chem., 2011, v. 400, no 6, p. 1787-1804]. The present report gives a brief overview of the state-of-the-art and describes some new methods, approaches, and devices developed in the Laboratory for Concentration Methods of Vernadsky Institute for the studies of volcanic ash samples. The ash is attributed to the volcanic activity of Cordón Caulle. Puyehue and Cordón Caulle (40°35'25″S -72°07'02″W) are two coalesced volcanic vents that form a major mountain massif in Puyehue National Park in the Andes of Ranco Province, Chile. In volcanology, this group is known under the name of Puyehue-Cordón Caulle Volcanic Complex. Four different volcanoes constitute the volcanic group or complex, the Cordillera Nevada caldera, the Pliocene Mencheca volcano, Cordón Caulle fissure vents, and the Puyehue stratovolcano. Most stratovolcanoes on the Southern Volcanic Zone of the Andes, Puyehue and Cordón Caulle are located along the intersection of traverse fault with the larger north-south Liquiñe-Ofqui Fault. A new eruption started on 04 June 2011. By 15 June a dense column of ash (9 km height) was still erupting into the air, with the ash cloud spreading across the Southern Hemisphere. Actually the volcano activity continues. The samples were collected before and after the acidic rain which occurred due to the release of sulfur gases

  4. Fetal Gene Therapy for Ornithine Transcarbamylase Deficiency by Intrahepatic Plasmid DNA-Micro-Bubble Injection Combined with Hepatic Ultrasound Insonation.

    PubMed

    Oishi, Yoshie; Kakimoto, Takashi; Yuan, Wenji; Kuno, Shuichi; Yamashita, Hiromasa; Chiba, Toshio

    2016-06-01

    We evaluated the therapeutic efficacy of hepatic transfection of plasmid DNA using micro-bubbles and ultrasound insonation for fetal correction of ornithine transcarbamylase (OTC) deficiency in mice. Twenty-three sparse-fur heterozygous pregnant mice (day 16 of gestation) were divided into three groups: injection of plasmid-DNA micro-bubble mixture into fetal liver with ultrasound insonation (Tr, n = 11); control group 1 (C1), injection of plasmid-DNA micro-bubble mixture into fetal liver with no insonation (n = 5); and control group 2 (C2), injection of saline-micro-bubble mixture into fetal liver with ultrasound insonation (n = 7). Levels of blood ammonia and urinary orotic acid were significantly lower in the Tr group than in the C1 and C2 groups (p < 0.05, p < 0.01, respectively), whereas OTC activity was not different between groups. Therefore, ultrasound insonation with micro-bubbles enhanced plasmid DNA transfection into fetal mouse liver, leading to one of the therapeutic methods in ammonia metabolism. This might provide more time for OTC-deficient infants until liver transplantation. PMID:26995155

  5. Development of the dynamic motion simulator of 3D micro-gravity with a combined passive/active suspension system

    NASA Technical Reports Server (NTRS)

    Yoshida, Kazuya; Hirose, Shigeo; Ogawa, Tadashi

    1994-01-01

    The establishment of those in-orbit operations like 'Rendez-Vous/Docking' and 'Manipulator Berthing' with the assistance of robotics or autonomous control technology, is essential for the near future space programs. In order to study the control methods, develop the flight models, and verify how the system works, we need a tool or a testbed which enables us to simulate mechanically the micro-gravity environment. There have been many attempts to develop the micro-gravity testbeds, but once the simulation goes into the docking and berthing operation that involves mechanical contacts among multi bodies, the requirement becomes critical. A group at the Tokyo Institute of Technology has proposed a method that can simulate the 3D micro-gravity producing a smooth response to the impact phenomena with relatively simple apparatus. Recently the group carried out basic experiments successfully using a prototype hardware model of the testbed. This paper will present our idea of the 3D micro-gravity simulator and report the results of our initial experiments.

  6. Three-dimensional micro/nano-scale structure fabricated by combination of non-volatile polymerizable RTIL and FIB irradiation

    PubMed Central

    Kuwabata, Susumu; Minamimoto, Hiro; Inoue, Kosuke; Imanishi, Akihito; Hosoya, Ken; Uyama, Hiroshi; Torimoto, Tsukasa; Tsuda, Tetsuya; Seki, Shu

    2014-01-01

    Room-temperature ionic liquid (RTIL) has been widely investigated as a nonvolatile solvent as well as a unique liquid material because of its interesting features, e.g., negligible vapor pressure and high thermal stability. Here we report that a non-volatile polymerizable RTIL is a useful starting material for the fabrication of micro/nano-scale polymer structures with a focused-ion-beam (FIB) system operated under high-vacuum condition. Gallium-ion beam irradiation to the polymerizable 1-allyl-3-ethylimidazolium bis((trifluoromethane)sulfonyl)amide RTIL layer spread on a Si wafer induced a polymerization reaction without difficulty. What is interesting to note is that we have succeeded in provoking the polymerization reaction anywhere on the Si wafer substrate by using FIB irradiation with a raster scanning mode. By this finding, two- and three-dimensional micro/nano-scale polymer structure fabrications were possible at the resolution of 500,000 dpi. Even intricate three-dimensional micro/nano-figures with overhang and hollow moieties could be constructed at the resolution of approximately 100 nm. PMID:24430465

  7. Micro-lens array based 3-D color image encryption using the combination of gravity model and Arnold transform

    NASA Astrophysics Data System (ADS)

    You, Suping; Lu, Yucheng; Zhang, Wei; Yang, Bo; Peng, Runling; Zhuang, Songlin

    2015-11-01

    This paper proposes a 3-D image encryption scheme based on micro-lens array. The 3-D image can be reconstructed by applying the digital refocusing algorithm to the picked-up light field. To improve the security of the cryptosystem, the Arnold transform and the Gravity Model based image encryption method are employed. Experiment results demonstrate the high security in key space of the proposed encryption scheme. The results also indicate that the employment of light field imaging significant strengthens the robustness of the cipher image against some conventional image processing attacks.

  8. Combination of micro-dialysis and infrared spectroscopy: a multianalyte assay for accurate biofluid analysis and patient monitoring

    NASA Astrophysics Data System (ADS)

    Vahlsing, Thorsten; Delbeck, Sven; Budde, Janpeter; Ihrig, Dieter; Heise, H. Michael

    2016-03-01

    Micro-dialysis can be used for continuously harvesting body fluids, while a multi-component analysis of the dialysates by infrared spectrometry offers splendid opportunities for monitoring substrates and metabolites such as glucose, lactate and others small enough to penetrate the semi-permeable dialysis membranes. However, a drawback of this process are variable recovery rates, which can be observed especially for subcutaneously implanted catheters in human subjects. Isotonic perfusates were investigated with acetate and mannitol as recovery markers for the dialysis of human serum at 37°C to mimic in vivo patient monitoring. The latter non-ionic substance has been suggested for application when other ionic substances such as bicarbonate or pH are also to be determined. Simultaneously for acetate and mannitol, the depletion of the marker substances from the perfusates using different micro-dialysis devices was investigated under various flow-rates. Relationships between relative dialysate marker concentrations and glucose recovery rates were determined based on multivariate calibrations. For quantification, classical least squares with reference spectra for modelling the serum dialysates was used, rendering a basis for reliable blood glucose and lactate measurements.

  9. A novel dispersive micro solid phase extraction using zein nanoparticles as the sorbent combined with headspace solid phase micro-extraction to determine chlorophenols in water and honey samples by GC-ECD.

    PubMed

    Farhadi, Khalil; Matin, Amir Abbas; Amanzadeh, Hatam; Biparva, Pourya; Tajik, Hossein; Farshid, Amir Abbas; Pirkharrati, Hossein

    2014-10-01

    This study presents a new technique, dispersive micro solid phase extraction (DMSPE) combined with headspace solid phase micro-extraction (HS-SPME) for extraction and determination of chlorophenols (CPs) in water and honey samples using a Gas Chromatography-Electron Capture Detector (GC-ECD). Zein nanoparticles were made by liquid-liquid dispersion and applied for the first time as the sorbent phase in DMSPE. In the proposed DMSPE-HS-SPME method, 1% w/v of ethanolic zein solution was added to an aqueous sample and then a dose of the in-situ generated zein nanoparticles was applied to a pre-concentration of target analytes. Thermal desorption of analytes was performed after the isolating sorbent phase, and then HS-SPME was applied for enrichment prior to introducing to gas chromatography. All the important parameters influencing efficiency of the extraction process such effects of salt, pH, sorbent concentration, temperature, sorbent solution volume in DMSPE procedure, extraction temperature, extraction time, desorption temperature and time in the HS-SPME procedure were investigated and optimized. Results showed that under optimum extraction conditions, detection limits (signal to noise ratio=3) were in the range of 0.08-0.6 ng mL(-1) and evaluations for relative standard deviations (RSDs %) were between 6.62% and 8.36%. PMID:25059191

  10. Combined RT-qPCR of mRNA and microRNA Targets within One Fluidigm Integrated Fluidic Circuit

    PubMed Central

    Baldwin, Don A.; Horan, Annamarie D.; Hesketh, Patrick J.

    2016-01-01

    The ability to profile expression levels of a large number of mRNAs and microRNAs (miRNAs) within the same sample, using a single assay method, would facilitate investigations of miRNA effects on mRNA abundance and streamline biomarker screening across multiple RNA classes. A protocol is described for reverse transcription of long RNA and miRNA targets, followed by preassay amplification of the pooled cDNAs and quantitative PCR (qPCR) detection for a mixed panel of candidate RNA biomarkers. The method provides flexibility for designing custom target panels, is robust over a range of input RNA amounts, and demonstrated a high assay success rate. PMID:26977138

  11. Combined RT-qPCR of mRNA and microRNA Targets within One Fluidigm Integrated Fluidic Circuit.

    PubMed

    Baldwin, Don A; Horan, Annamarie D; Hesketh, Patrick J; Mehta, Samir

    2016-07-01

    The ability to profile expression levels of a large number of mRNAs and microRNAs (miRNAs) within the same sample, using a single assay method, would facilitate investigations of miRNA effects on mRNA abundance and streamline biomarker screening across multiple RNA classes. A protocol is described for reverse transcription of long RNA and miRNA targets, followed by preassay amplification of the pooled cDNAs and quantitative PCR (qPCR) detection for a mixed panel of candidate RNA biomarkers. The method provides flexibility for designing custom target panels, is robust over a range of input RNA amounts, and demonstrated a high assay success rate. PMID:26977138

  12. A Combined Micro-CT Imaging/Microfluidic Approach for Understating Methane Recovery in Coal Seam Gas Reservoirs

    NASA Astrophysics Data System (ADS)

    Mostaghimi, P.; Armstrong, R. T.; Gerami, A.; Lamei Ramandi, H.; Ebrahimi Warkiani, M.

    2015-12-01

    Coal seam methane is a form of natural gas stored in coal beds and is one of the most important unconventional resources of energy. The flow and transport in coal beds occur in a well-developed system of natural fractures that are also known as cleats. We use micro-Computed Tomography (CT) imaging at both dry and wet conditions to resolve the cleats below the resolution of the image. Scanning Electron Microscopy (SEM) is used for calibration of micro-CT data. Using soft lithography technique, the cleat system is duplicated on a silicon mould. We fabricate a microfluidic chip using Polydimethylsiloxane (PDMS) to study both imbibition and drainage in generated coal structures for understating gas and water transport in coal seam reservoirs. First, we use simple patterns observed on coal images to analyse the effects of wettability, cleat size and distribution on flow behaviour. Then, we study transport in a coal by injecting both distilled water and decane with a rate of 1 microliter/ min into the fabricated cleat structure (Figure 1), initially saturated with air. We repeat the experiment for different contact angles by plasma treating the microfluidic chip, and results show significant effects of wettability on the displacement efficiency. The breakthrough time in the imbibition setup is significantly longer than in the drainage. Using rapid video capturing, and high resolution microscopy, we measure the saturation of displacing fluid with respect to time. By measuring gas and liquid recovery in the outlet at different saturation, we predict relative permeability of coal. This work has important applications for optimising gas recovery and our results can serve as a benchmark in the verification of multiphase numerical models used in coal seam gas industry.

  13. Combining micro computed tomography and three-dimensional registration to evaluate local strains in shape memory scaffolds.

    PubMed

    Bormann, Therese; Schulz, Georg; Deyhle, Hans; Beckmann, Felix; de Wild, Michael; Küffer, Jürg; Münch, Christoph; Hoffmann, Waldemar; Müller, Bert

    2014-02-01

    Appropriate mechanical stimulation of bony tissue enhances osseointegration of load-bearing implants. Uniaxial compression of porous implants locally results in tensile and compressive strains. Their experimental determination is the objective of this study. Selective laser melting is applied to produce open-porous NiTi scaffolds of cubic units. To measure displacement and strain fields within the compressed scaffold, the authors took advantage of synchrotron radiation-based micro computed tomography during temperature increase and non-rigid three-dimensional data registration. Uniaxial scaffold compression of 6% led to local compressive and tensile strains of up to 15%. The experiments validate modeling by means of the finite element method. Increasing the temperature during the tomography experiment from 15 to 37°C at a rate of 4 K h(-1), one can locally identify the phase transition from martensite to austenite. It starts at ≈ 24°C on the scaffolds bottom, proceeds up towards the top and terminates at ≈ 34°C on the periphery of the scaffold. The results allow not only design optimization of the scaffold architecture, but also estimation of maximal displacements before cracks are initiated and of optimized mechanical stimuli around porous metallic load-bearing implants within the physiological temperature range. PMID:24257506

  14. An electrochemical biosensor for sensitive detection of microRNA-155: combining target recycling with cascade catalysis for signal amplification.

    PubMed

    Wu, Xiaoyan; Chai, Yaqin; Zhang, Pu; Yuan, Ruo

    2015-01-14

    In this work, a new electrochemical biosensor based on catalyzed hairpin assembly target recycling and cascade electrocatalysis (cytochrome c (Cyt c) and alcohol oxidase (AOx)) for signal amplification was constructed for highly sensitive detection of microRNA (miRNA). It is worth pointing out that target recycling was achieved only based on strand displacement process without the help of nuclease. Moreover, porous TiO2 nanosphere was synthesized, which could offer more surface area for Pt nanoparticles (PtNPs) enwrapping and enhance the amount of immobilized DNA strand 1 (S1) and Cyt c accordingly. With the mimicking sandwich-type reaction, the cascade catalysis amplification strategy was carried out by AOx catalyzing ethanol to acetaldehyde with the concomitant formation of high concentration of H2O2, which was further electrocatalyzed by PtNPs and Cyt c. This newly designed biosensor provided a sensitive detection of miRNA-155 from 0.8 fM to 1 nM with a relatively low detection limit of 0.35 fM. PMID:25495913

  15. iMiRNA-SSF: Improving the Identification of MicroRNA Precursors by Combining Negative Sets with Different Distributions

    PubMed Central

    Chen, Junjie; Wang, Xiaolong; Liu, Bin

    2016-01-01

    The identification of microRNA precursors (pre-miRNAs) helps in understanding regulator in biological processes. The performance of computational predictors depends on their training sets, in which the negative sets play an important role. In this regard, we investigated the influence of benchmark datasets on the predictive performance of computational predictors in the field of miRNA identification, and found that the negative samples have significant impact on the predictive results of various methods. We constructed a new benchmark set with different data distributions of negative samples. Trained with this high quality benchmark dataset, a new computational predictor called iMiRNA-SSF was proposed, which employed various features extracted from RNA sequences. Experimental results showed that iMiRNA-SSF outperforms three state-of-the-art computational methods. For practical applications, a web-server of iMiRNA-SSF was established at the website http://bioinformatics.hitsz.edu.cn/iMiRNA-SSF/. PMID:26753561

  16. Design and validation of a novel bioreactor principle to combine online micro-computed tomography monitoring and mechanical loading in bone tissue engineering

    NASA Astrophysics Data System (ADS)

    Hagenmüller, Henri; Hitz, Marco; Merkle, Hans P.; Meinel, Lorenz; Müller, Ralph

    2010-01-01

    Mechanical loading plays an important role in bone remodeling in vivo and, therefore, has been suggested as a key parameter in stem cell-based engineering of bone-like tissue in vitro. However, the optimization of loading protocols during stem cell differentiation and subsequent bone-like tissue formation is challenged by multiple input factors, which are difficult to control and validate. These include the variable cellular performance of cells harvested from different patients, nonstandardized culture media components, the choice of the biomaterial forming the scaffold, and its morphology, impacting a broader validity of mechanical stimulation regimens. To standardize the cell culture of bone-like tissue constructs, we suggest the involvement of time-lapsed feedback loops. For this purpose we present a prototype bioreactor that combines online, nondestructive monitoring using micro-computed tomography and direct mechanical loading of three-dimensional tissue engineering constructs. Validation of this system showed displacement steps down to 1 μm and cyclic sinusoidal loadings of up to 10 Hz. Load detection resolution was 0.01 N, and micro-computed tomography data were of high quality. For the first time, the developed bioreactor links time-lapsed, nondestructive, and dynamic imaging with mechanical stimulation, designed for cell culture under sterile conditions. This system is believed to substantially improve today's experimental options to study and optimize osteogenic stem cell culture and differentiation at the interface with mechanical stimulation.

  17. Local atomic structure of chromium bearing precipitates in chromia doped uranium dioxide investigated by combined micro-beam X-ray diffraction and absorption spectroscopy

    NASA Astrophysics Data System (ADS)

    Kuri, G.; Mieszczynski, C.; Martin, M.; Bertsch, J.; Borca, C. N.; Delafoy, Ch.

    2014-06-01

    Experimental studies have evidenced the presence of some chromium oxide precipitates in chromia (Cr2O3) doped UO2 fuels, currently being used in many light water reactors. The main objective of this study was to analyze the atomic scale microstructure of these precipitates in a non-destructive way employing modern synchrotron-based X-ray radiation. To investigate UO2 microstructures and chemical compositions of the precipitates an industrial grade fresh Cr2O3-doped UO2 pellet (produced with an initial amount of 0.16 wt.% Cr2O3 powder) was examined using scanning electron microscopy (SEM) and electron probe micro analysis (EPMA). Average grain diameter of the UO2 matrix was measured by SEM image analysis method. Precipitates were detected by EPMA. For all precipitates of micrometer scale analyzed by EPMA the composition was determined to be very close to Cr2O3. The structural property and the next neighbor Cr atomic environment in these precipitates were studied by a combination of more sensitive tools such as micro-focused X-ray diffraction (μ-XRD) and absorption spectroscopy (μ-XAS). According to the XRD data, the chromia precipitates contain structural disorder and have a somewhat distorted lattice structure as compared to that of standard and crystalline α-Cr2O3 hexagonal crystal unit cell. The μ-XAS results provide insight into the local atomic environment of chromium including the oxidation state assignment.

  18. Three dimensional visualization of engineered bone and soft tissue by combined x-ray micro-diffraction and phase contrast tomography

    NASA Astrophysics Data System (ADS)

    Cedola, Alessia; Campi, Gaetano; Pelliccia, Daniele; Bukreeva, Inna; Fratini, Michela; Burghammer, Manfred; Rigon, Luigi; Arfelli, Fulvia; Chen, Rong Chang; Dreossi, Diego; Sodini, Nicola; Mohammadi, Sara; Tromba, Giuliana; Cancedda, Ranieri; Mastrogiacomo, Maddalena

    2014-01-01

    Computed x-ray phase contrast micro-tomography is the most valuable tool for a three dimensional (3D) and non destructive analysis of the tissue engineered bone morphology. We used a Talbot interferometer installed at SYRMEP beamline of the ELETTRA synchrotron (Trieste, Italy) for a precise 3D reconstruction of both bone and soft connective tissue, regenerated in vivo within a porous scaffold. For the first time the x-ray tomographic reconstructions have been combined with x-ray scanning micro-diffraction measurement on the same sample, in order to give an exhaustive identification of the different tissues participating to the biomineralization process. As a result, we were able to investigate in detail the different densities in the tissues, distinguishing the 3D organization of the amorphous calcium phosphate from the collagen matrix. Our experimental approach allows for a deeper understanding of the role of collagen matrix in the organic-mineral transition, which is a crucial issue for the development of new bio-inspired composites.

  19. Three dimensional visualization of engineered bone and soft tissue by combined x-ray micro-diffraction and phase contrast tomography.

    PubMed

    Cedola, Alessia; Campi, Gaetano; Pelliccia, Daniele; Bukreeva, Inna; Fratini, Michela; Burghammer, Manfred; Rigon, Luigi; Arfelli, Fulvia; Chang Chen, Rong; Dreossi, Diego; Sodini, Nicola; Mohammadi, Sara; Tromba, Giuliana; Cancedda, Ranieri; Mastrogiacomo, Maddalena

    2014-01-01

    Computed x-ray phase contrast micro-tomography is the most valuable tool for a three dimensional (3D) and non destructive analysis of the tissue engineered bone morphology. We used a Talbot interferometer installed at SYRMEP beamline of the ELETTRA synchrotron (Trieste, Italy) for a precise 3D reconstruction of both bone and soft connective tissue, regenerated in vivo within a porous scaffold. For the first time the x-ray tomographic reconstructions have been combined with x-ray scanning micro-diffraction measurement on the same sample, in order to give an exhaustive identification of the different tissues participating to the biomineralization process. As a result, we were able to investigate in detail the different densities in the tissues, distinguishing the 3D organization of the amorphous calcium phosphate from the collagen matrix. Our experimental approach allows for a deeper understanding of the role of collagen matrix in the organic-mineral transition, which is a crucial issue for the development of new bio-inspired composites. PMID:24334371

  20. A new on-axis micro-spectrophotometer for combining Raman, fluorescence and UV/Vis absorption spectroscopy with macromolecular crystallography at the Swiss Light Source

    PubMed Central

    Pompidor, Guillaume; Dworkowski, Florian S. N.; Thominet, Vincent; Schulze-Briese, Clemens; Fuchs, Martin R.

    2013-01-01

    The combination of X-ray diffraction experiments with optical methods such as Raman, UV/Vis absorption and fluorescence spectroscopy greatly enhances and complements the specificity of the obtained information. The upgraded version of the in situ on-axis micro-spectrophotometer, MS2, at the macromolecular crystallography beamline X10SA of the Swiss Light Source is presented. The instrument newly supports Raman and resonance Raman spectroscopy, in addition to the previously available UV/Vis absorption and fluorescence modes. With the recent upgrades of the spectral bandwidth, instrument stability, detection efficiency and control software, the application range of the instrument and its ease of operation were greatly improved. Its on-axis geometry with collinear X-ray and optical axes to ensure optimal control of the overlap of sample volumes probed by each technique is still unique amongst comparable facilities worldwide and the instrument has now been in general user operation for over two years. PMID:23955041

  1. High-throughput deep screening and identification of four peripheral leucocyte microRNAs as novel potential combination biomarkers for preeclampsia

    PubMed Central

    Wang, Yonghong; Yang, Xukui; Yang, Yuanyuan; Wang, Wenjun; Zhao, Meiling; Liu, Huiqiang; Li, Dongyan; Hao, Min

    2016-01-01

    Objective: To identify the specific microRNA (miRNA) biomarkers of preeclampsia (PE), the miRNA profiles analysis were performed. Study Design: The blood samples were obtained from five PE patients and five normal healthy pregnant women. The small RNA profiles were analyzed to identify miRNA expression levels and find out miRNAs that may associate with PE. The quantitative reverse transcriptase–PCR (qRT-PCR) assay was used to validate differentially expressed peripheral leucocyte miRNAs in a new cohort. Result: The data analysis showed that 10 peripheral leucocyte miRNAs were significantly differently expressed in severe PE patients. Four differently expressed miRNAs were successfully validated using qRT-PCR method. Conclusion: We successfully constructed a model with high accuracy to predict PE. A combination of four peripheral leucocyte miRNAs has great potential to serve as diagnostic biomarkers of PE. PMID:26675000

  2. Elemental and spectroscopic characterization of plasters from Fatih Mosque-Istanbul (Turkey) by combined micro-Raman, FTIR and EDXRF techniques.

    PubMed

    Akyuz, Tanil; Akyuz, Sevim; Gulec, Ahmet

    2015-10-01

    The characterization of the plasters and coloring agents of the wall paintings of Fatih Mosque have been performed using combined micro-Raman, FTIR and EDXRF techniques. The investigations show that the plaster used on the walls has mixed gypsum-lime binders. Cinnabar {HgS}, lead red {Pb3O4} and hematite {α-Fe2O3} were identified in the red surfaces. Blue color is attributed to ultramarine blue {Na8-10Al6Si6O24S2-4}. Green color is assigned to mixtures of green earth, copper phthalocyanine {Cu(C32Cl16N8)} and brochantite {CuSO4·3Cu(OH)2}. Strontium yellow {SrCrO4} and zinc white {ZnO} were also used to ensure the color tone. The results provide a basis for future restoration of wall paints. PMID:25989612

  3. Freezing nucleation of levitated single sulfuric acid/H 2O micro-droplets. A combined Raman- and Mie spectroscopic study

    NASA Astrophysics Data System (ADS)

    Mund, C.; Zellner, R.

    2003-12-01

    The phase behaviour of single sulfuric acid/H 2O micro-droplets upon supercooling has been studied using optical levitation of such droplets in combination with Raman- and Mie spectroscopy for chemical and size analysis. It is found that the freezing nucleation behaviour depends on the sulfuric acid concentration of the droplets and hence the region of the phase diagram which is reached upon cooling. Whereas for diluted droplets (c H2SO4<30 wt%) instantaneous ice nucleation is observed, more concentrated droplets tend to supercool with no tendency to nucleate the thermodynamically stable hydrate phase sulfuric acid tetrahydrate (SAT) or sulfuric acid monohydrate (SAM). The upper limits of the nucleation rate in this regime were determined to be J≤5×10 5 cm -3 s -1.

  4. Endogenous MCM7 MicroRNA Cluster as a Novel Platform to Multiplex Small Interfering and Nucleolar RNAs for Combinational HIV-1 Gene Therapy

    PubMed Central

    Chung, Janet; Zhang, Jane; Li, Haitang; Ouellet, Dominique L.; DiGiusto, David L.

    2012-01-01

    Abstract Combinational therapy with small RNA inhibitory agents against multiple viral targets allows efficient inhibition of viral production by controlling gene expression at critical time points. Here we explore combinations of different classes of therapeutic anti-HIV-1 RNAs expressed from within the context of an intronic MCM7 (minichromosome maintenance complex component-7) platform that naturally harbors 3 microRNAs (miRNAs). We replaced the endogenous miRNAs with anti-HIV small RNAs, including small interfering RNAs (siRNAs) targeting HIV-1 tat and rev messages that function to induce post-transcriptional gene silencing by the RNA interference pathway, a nucleolar-localizing RNA ribozyme that targets the conserved U5 region of HIV-1 transcripts for degradation, and finally nucleolar trans-activation response (TAR) and Rev-binding element (RBE) RNA decoys designed to sequester HIV-1 Tat and Rev proteins inside the nucleolus. We demonstrate the versatility of the MCM7 platform in expressing and efficiently processing the siRNAs as miRNA mimics along with nucleolar small RNAs. Furthermore, three of the combinatorial constructs tested potently suppressed viral replication during a 1-month HIV challenge, with greater than 5-log inhibition compared with untransduced, HIV-1-infected CEM T lymphocytes. One of the most effective constructs contains an anti-HIV siRNA combined with a nucleolar-localizing U5 ribozyme and TAR decoy. This represents the first efficacious example of combining Drosha-processed siRNAs with small nucleolar ribonucleoprotein (snoRNP)-processed nucleolar RNA chimeras from a single intron platform for effective inhibition of viral replication. Moreover, we demonstrated enrichment/selection for cells expressing levels of the antiviral RNAs that provide optimal inhibition under the selective pressure of HIV. The combinations of si/snoRNAs represent a new paradigm for combinatorial RNA-based gene therapy applications. PMID:22834872

  5. Combined use of direct analysis in real-time/Orbitrap mass spectrometry and micro-Raman spectroscopy for the comprehensive characterization of real explosive samples.

    PubMed

    Bridoux, Maxime C; Schwarzenberg, Adrián; Schramm, Sébastien; Cole, Richard B

    2016-08-01

    Direct Analysis in Real Time (DART™) high-resolution Orbitrap™ mass spectrometry (HRMS) in combination with Raman microscopy was used for the detailed molecular level characterization of explosives including not only the charge but also the complex matrix of binders, plasticizers, polymers, and other possible organic additives. A total of 15 defused military weapons including grenades, mines, rockets, submunitions, and mortars were examined. Swabs and wipes were used to collect trace (residual) amounts of explosives and their organic constituents from the defused military weapons and micrometer-size explosive particles were transferred using a vacuum suction-impact collection device (vacuum impactor) from wipe and swap samples to an impaction plate made of carbon. The particles deposited on the carbon plate were then characterized using micro-Raman spectroscopy followed by DART-HRMS providing fingerprint signatures of orthogonal nature. The optical microscope of the micro-Raman spectrometer was first used to localize and characterize the explosive charge on the impaction plate which was then targeted for identification by DART-HRMS analysis in both the negative and positive modes. Raman spectra of the explosives TNT, RDX and PETN were acquired from micrometer size particles and characterized by the presence of their characteristic Raman bands obtained directly at the surface of the impaction plate nondestructively without further sample preparation. Negative mode DART-HRMS confirmed the types of charges contained in the weapons (mainly TNT, RDX, HMX, and PETN; either as individual components or as mixtures). These energetic compounds were mainly detected as deprotonated species [M-H](-), or as adduct [M + (35)Cl](-), [M + (37)Cl](-), or [M + NO3](-) anions. Chloride adducts were promoted in the heated DART reagent gas by adding chloroform vapors to the helium stream using an "in-house" delivery method. When the polarity was switched to positive mode

  6. Short-Term Intraocular Pressure Elevations after Combined Phacoemulsification and Implantation of Two Trabecular Micro-Bypass Stents: Prednisolone versus Loteprednol

    PubMed Central

    Wang, Qianqian; Harasymowycz, Paul

    2015-01-01

    Objective. To compare the effects of prednisolone and of loteprednol after combined phacoemulsification and trabecular micro-bypass stent implantation (phaco-iStent). Methods. Patients who underwent phaco-iStent between April 2013 and November 2014 were identified by retrospective chart review. Postoperatively, they received either prednisolone (n = 38) or loteprednol (n = 58). Baseline data was compared. Primary outcomes including intraocular pressure (IOP) and number of glaucoma medications (NGM) were analyzed at preoperative visit, postoperative day 1, weeks 1-2, weeks 3-4, and months 2-3. Results. Both groups had similar preoperative parameters (p > 0.05). The mean IOP spike occurred at postoperative weeks 1-2 with an increase of 2.21 ± 7.30 mmHg in the loteprednol group and 2.54 ± 9.28 mmHg in the prednisolone group. It decreased by weeks 3-4 in both groups and continued to improve at months 2-3. NGM showed significant reduction (p < 0.0001) after the surgery and remained stable in both groups. No significant group effect or time-group interaction in IOP and NGM evolution was detected (p > 0.05). The proportions of patients needing paracentesis were similar between the two groups. Conclusion. Similar early IOP elevations after combined phaco-iStent occurred with both prednisolone and loteprednol. Facilitated glucocorticoid infusion, altered aqueous humor outflow, and local inflammation may be contributing factors. PMID:26266045

  7. Water quality deterioration at a karst spring (Gallusquelle, Germany) due to combined sewer overflow: evidence of bacterial and micro-pollutant contamination

    NASA Astrophysics Data System (ADS)

    Heinz, B.; Birk, S.; Liedl, R.; Geyer, T.; Straub, K. L.; Andresen, J.; Bester, K.; Kappler, A.

    2009-04-01

    The concurrent use of karst aquifers as drinking water resources and receptors of combined sewer overflow lacking appropriate pre-treatment may cause conflicts between drinking water supply and storm water management. A storm water tank (SWT) for combined wastewater is identified as the source of sporadic contamination of a karst spring (Gallusquelle, “Schwäbische Alb”, SW Germany) used for public water supply. Spring water quality was examined by routine and event sampling and by evaluating physicochemical and microbiological parameters. The total number of microbial colonies growing at 20°C and the number of Escherichia coli colonies rose to values up to four orders of magnitude higher than background, 2-5 days after overflow of the SWT. High concentrations of chloride, sodium, and total organic carbon (TOC) and high values of turbidity coincide with this increase. However, high bacterial contamination is also observed while turbidity and TOC are low. Several wastewater-related organic micro-pollutants such as chlorinated and non-chlorinated organophosphates were detected in the SWT and, depending on their K ow values and their biodegradability, in lower concentrations at the spring.

  8. Combination of microRNA expression profiling with genome-wide SNP genotyping to construct a coronary artery disease-related miRNA-miRNA synergistic network.

    PubMed

    Hua, Lin; Xia, Hong; Zhou, Ping; Li, Dongguo; Li, Lin

    2014-12-01

    In recent years, microRNAs (miRNAs) were found to play critical roles in many important biological processes. On the other hand, the rapid development of genome-wide association studies (GWAS) help identify potential genetic variants associated with the disease phenotypic variance. Therefore, we suggested a combined analysis of microRNA expression profiling with genome-wide Single Nucleotide Polymorphism (SNP) genotyping to identify potential disease-related biomarkers. Considering functional SNPs in miRNA genes or target sites might be important signals associated with human complex diseases, we constructed a miRNA-miRNA synergistic network related to coronary artery disease (CAD) by performing a genome-wide scan for SNPs in human miRNA 3' -untranslated regions (UTRs) target sites and computed potential SNP cooperation effects contributing to disease based on potential miRNA-SNP interactions reported recently. Furthermore, we identified some potential CAD-related miRNAs by analyzing the constructed miRNAmiRNA synergistic network. As a result, the predicted miRNA-miRNA network and miRNA clusters were validated by significantly high interaction effects of CAD-related miRNAs. Accurate classification performances were obtained for all of the identified miRNA clusters, and the sensitivity and specificity were all more than 90%. The network topological analysis confirmed some novel CAD-related miRNAs identified recently by experiments. Our method might help to understand miRNA function and CAD disease, as well as to explore the novel mechanisms involved. PMID:25641175

  9. Wild 2 grains characterized combining MIR/FIR/Raman micro-spectroscopy and FE-SEM/EDS analyses

    NASA Astrophysics Data System (ADS)

    Ferrari, M.; Rotundi, A.; Rietmeijer, F. J. M.; Della Corte, V.; Baratta, G. A.; Brunetto, R.; Dartois, E.; Djouadi, Z.; Merouane, S.; Borg, J.; Brucato, J. R.; Le Sergeant d'Hendecourt, L.; Mennella, V.; Palumbo, M. E.; Palumbo, P.

    We present the results of the analyses \\cite{Rotundi14} of two bulk terminal particles (TPs), C2112,7,171,0,0 (TP2) and C2112,9,171,0,0 (TP3), derived from the Jupiter-Family comet 81P/Wild 2 returned by the NASA Stardust mission \\cite{Brownlee06}. Each particle, embedded in a slab of silica aerogel, was pressed in a diamond cell. Aerogel is usually cause of problems when characterizing the minerals and organic materials present in the embedded particles. We overcame this common issue by means of the combination of FE-SEM/EDS, IR and Raman mu -spectroscopy, three non-destructive analytical techniques, which provided bulk mineralogical and organic information on TP2 and TP3. This approach proved to be a practical solution for preliminary characterization, i.e. scanning particles for chemical and mineralogical heterogeneity. Using this type of bulk characterization prior to more detailed studies, could be taken into account as a standard procedure to be followed for selecting Stardust particles-of-interest. TP2 and TP3 are dominated by Ca-free and low-Ca, Mg-rich, Mg,Fe-olivine. The presence of melilite in both particles is supported by IR mu -spectroscopy and corroborated by FE-SEM/EDS analyses, but is not confirmed by Raman mu -spectroscopy possibly because the amount of this mineral is too small to be detected. TP2 and TP3 show similar silicate mineral compositions, but Ni-free, low-Ni, sub-sulfur (Fe,Ni)S grains are present only in TP2. TP2 contains indigenous amorphous carbon hot spots, while no indigenous carbon was identified in TP3. These non-chondritic particles probably originated in a differentiated body. The presence of high temperature melilite group minerals (incl. gehlenite) in TP2 and TP3 reinforces the notion that collisionally-ejected refractory debris from differentiated asteroids may be common in Jupiter-Family comets. This raises the question whether similar debris and other clearly asteroidal particles could be present in Halley-type comets

  10. Wild 2 grains characterized combining MIR/FIR/Raman micro-spectroscopy and FE-SEM/EDS analyses

    NASA Astrophysics Data System (ADS)

    Rotundi, Alessandra; Rietmeijer, Frans J. M.; Ferrari, Marco; Della Corte, Vincenzo; Baratta, Giuseppe A.; Brunetto, Rosario; Dartois, Emmanuel; Djouadi, Zahia; Merouane, Sihane; Borg, Janet; Brucato, John R.; Le Sergeant d'Hendecourt, Louis; Mennella, Vito; Palumbo, Maria Elisabetta; Palumbo, Pasquale

    2014-05-01

    We present the analyses results of two bulk Terminal Particles, C2112,7,171,0,0 and C2112,9,171,0,0, derived from the Jupiter-Family comet 81P/Wild 2 returned by the Stardust mission. Each particle embedded in a slab of silica aerogel was pressed in a diamond cell. The aerogel, as expected, caused problems to identify the minerals and organic materials present in these particles. These problems were overcome by means of the combination of FE-SEM/EDS, IR and Raman μ-spectroscopy, three non-destructive analytical techniques, which allowed the mineral and organic information on the two bulk particles. Indeed, this approach proved to be practical for preliminary characterization, i.e. scanning particles for chemical and mineralogical heterogeneity. It can be considered as a procedure to be followed for selecting Stardust particles-of- interest using this type of bulk characterization prior to more detailed studies. TP2 and TP3 are dominated by Ca-free and low-Ca, Mg-rich, Mg,Fe-olivine. The presence of melilite in both particles is supported by IR μ-spectroscopy, but is not confirmed by Raman μ-spectroscopy possibly because the amounts are too small to be detected. TP2 and TP3 show similar silicate mineral compositions but Ni-free and low-Ni, sub-sulfur (Fe,Ni)S grains are present in TP2 only. TP2 contains indigenous amorphous carbon hot spots; no indigenous carbon was identified in TP3. These non-chondritic particles probably originated in a differentiated body. The presence of high temperature melilite group minerals (incl. gehlenite) in TP2 and TP3 reinforces the notion that collisionally-ejected refractory debris from differentiated asteroids may be common in Jupiter-Family comets. It does raise the question if similar debris and other clearly asteroidal dust could be present in Halley-type comets and if so what fractions of the dust in these comets are truly non-processed silicates and organic material. The results of this study will be relevant to the ROSETTA

  11. Structure and properties of a duplex coating combining micro-arc oxidation and baking layer on AZ91D Mg alloy

    NASA Astrophysics Data System (ADS)

    Cui, Xue-Jun; Li, Ming-Tian; Yang, Rui-Song; Yu, Zu-Xiao

    2016-02-01

    A duplex coating (called MAOB coating) was fabricated on AZ91D Mg alloy by combining the process of micro-arc oxidation (MAO) with baking coating (B-coating). The structure, composition, corrosion resistance, and tribological behaviour of the coatings were investigated using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electrochemical and long-term immersion test, and ball-on-disc friction test. The results show that a dense 92 μm thick B-coating was tightly deposited onto the MAO-coated Mg alloy and exhibited a good mechanical interlock along the rough interface. Compared with the MAO-coated sample, the corrosion current density of the MAOB-coated Mg alloy decreased by two or three orders of magnitude and no corrosion phenomenon was observed during a long-term immersion test of about 500 h (severe corrosion pits were found for MAO-treated samples after about 168 h of immersion). The frictional coefficient values of the MAOB coating were similar to those of the MAO coating using dry sliding tests, while the B-coating on the MAO-coated surface significantly improved the wear resistance of the AZ91D Mg alloy. All of these results indicate that a B-coating can be used to further protect Mg alloys from corrosion and wear by providing a thick, dense barrier.

  12. Highly sensitive determination of sulfonamides in environmental water samples by sodium dodecylbenzene sulfonate enhanced micro-solid phase extraction combined with high performance liquid chromatography.

    PubMed

    Zhou, Qingxiang; Fang, Zhi

    2015-08-15

    Sulfonamides are important antibiotics, and have achieved great applications. However they also impose serious threat on the environment and human health when they enter into environment by various ways. Present study developed a new determination method for six sulfonamides such as sulfadiazine, sulfamerazine, sulfamethazine, sulfadimethoxine, sulfamethoxazole and sulfafurazole in water samples, which was based on micro-solid phase extraction (μ-SPE) using TiO2 nanotube arrays as the adsorbent in combination with high performance liquid chromatography. Surfactant sodium dodecylbenzene sulfonate (SDBS) was used to enhance the extraction performance in this enrichment procedure. The parameters that affected the extraction efficiency had been investigated. Under the optimal conditions, it was observed that there were good linear relationships between the peak areas and the concentrations of the sulfonamides. The linear ranges were 1-200μg L(-1) for the six sulfonamides with the correlation coefficients in the range of 0.998-0.999. The repeatability of the proposed method was satisfactory in the range of 2.1-4.4% (RSD, n=6). The limits of detection (LODs) were in the range of 0.27-0.6μg L(-1). The proposed method was validated with real environmental samples, and the spiked recoveries were satisfied. These results indicated that the proposed method was a good tool for monitoring sulfonamides in the water samples. PMID:25966398

  13. Illustration of compositional variations over time of Chinese porcelain glazes combining micro-X-ray Fluorescence spectrometry, multivariate data analysis and Seger formulas

    NASA Astrophysics Data System (ADS)

    Van Pevenage, J.; Verhaeven, E.; Vekemans, B.; Lauwers, D.; Herremans, D.; De Clercq, W.; Vincze, L.; Moens, L.; Vandenabeele, P.

    2015-01-01

    In this research, the transparent glaze layers of Chinese porcelain samples were investigated. Depending on the production period, these samples can be divided into two groups: the samples of group A dating from the Kangxi period (1661-1722), and the samples of group B produced under emperor Qianlong (1735-1795). Due to the specific sample preparation method and the small spot size of the X-ray beam, investigation of the transparent glaze layers is enabled. Despite the many existing research papers about glaze investigations of ceramics and/or porcelain ware, this research reveals new insights into the glaze composition and structure of Chinese porcelain samples. In this paper it is demonstrated, using micro-X-ray Fluorescence (μ-XRF) spectrometry, multivariate data analysis and statistical analysis (Hotelling's T-Square test) that the transparent glaze layers of the samples of groups A and B are significantly different (95% confidence level). Calculation of the Seger formulas, enabled classification of the glazes. Combining all the information, the difference in composition of the Chinese porcelain glazes of the Kangxi period and the Qianlong period can be demonstrated.

  14. The n-MAO/EPD bio-ceramic composite coating fabricated on ZK60 magnesium alloy using combined micro-arc oxidation with electrophoretic deposition

    NASA Astrophysics Data System (ADS)

    Xiong, Ying; Lu, Chao; Wang, Chao; Song, Renguo

    2014-12-01

    A bio-ceramic composite coating was fabricated on ZK60 magnesium (Mg) alloy using combined micro-arc oxidation (MAO) with electrophoretic deposition (EPD) technique. The MAO coating as the basal layer was produced in alkaline electrolyte with (n-MAO coating) and without (MAO coating) the addition of CeO2 and ZrO2 nano-particles, respectively. A hydroxyapatite (HA) coating as the covering layer was deposited on the n-MAO coating to improve the biological properties of the coating (n-MAO/EPD composite coating). The morphology and phase composition of three treated coatings were investigated by scanning electron microscope (SEM) and X-ray diffraction (XRD). The corrosion resistance of these coatings was evaluated with potentiodynamic polarization tests and immersion tests in simulated body fluid (SBF) at 36.5 ± 0.5 °C. The XRD spectra showed that the CeO2 and ZrO2 peaks can be collected in the n-MAO coating, and HA particles exists in the n-MAO/EPD composite coating. The results of corrosion tests indicated that the n-MAO/EPD composite coating owned increased bioactivity and long-term protective ability compared with the MAO coating and the n-MAO coating. Thus Mg alloy coated with the n-MAO/EPD composite coating should be more suited as biodegradable bone implants.

  15. 4E analysis and multi objective optimization of a micro gas turbine and solid oxide fuel cell hybrid combined heat and power system

    NASA Astrophysics Data System (ADS)

    Sanaye, Sepehr; Katebi, Arash

    2014-02-01

    Energy, exergy, economic and environmental (4E) analysis and optimization of a hybrid solid oxide fuel cell and micro gas turbine (SOFC-MGT) system for use as combined generation of heat and power (CHP) is investigated in this paper. The hybrid system is modeled and performance related results are validated using available data in literature. Then a multi-objective optimization approach based on genetic algorithm is incorporated. Eight system design parameters are selected for the optimization procedure. System exergy efficiency and total cost rate (including capital or investment cost, operational cost and penalty cost of environmental emissions) are the two objectives. The effects of fuel unit cost, capital investment and system power output on optimum design parameters are also investigated. It is observed that the most sensitive and important design parameter in the hybrid system is fuel cell current density which has a significant effect on the balance between system cost and efficiency. The selected design point from the Pareto distribution of optimization results indicates a total system exergy efficiency of 60.7%, with estimated electrical energy cost 0.057 kW-1 h-1, and payback period of about 6.3 years for the investment.

  16. One-step approach for hydroxyapatite-incorporated TiO 2 coating on titanium via a combined technique of micro-arc oxidation and electrophoretic deposition

    NASA Astrophysics Data System (ADS)

    Bai, Yu; Park, Il Song; Lee, Sook Jeong; Bae, Tae Sung; Duncan, Warwick; Swain, Michael; Lee, Min Ho

    2011-05-01

    A porous hydroxyapatite (HA) - incorporated TiO 2 coating layer was deposited on the titanium substrate using a combination of micro-arc oxidation and electrophoretic deposition. The size of the synthesized HA nano-particles was approximately 10-20 nm in width and 30-40 nm in length. The microstructure, as well as elemental and phase composition of the coating layers were examined by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). XRD showed that the coating layers were composed mainly of HA and anatase phases. The composition and surface morphologies were strongly dependent on the applied voltages. The amount of HA deposited into the coating increased with increasing applied voltage. The corrosion behavior of the coating layers in the simulated body fluids (SBF) was evaluated using a potentiodynamic polarization test. The corrosion resistance of the coated sample was higher than that of the untreated titanium sample. Moreover, the corrosion resistance of the coated samples also showed a positive correlation with the applied voltage. In addition, the in vitro cellular responses to the coated samples were assessed to investigate the proliferation, differentiation and morphology of the osteoblast cell line.

  17. Evaluating misoprostol content in pregnant women with hourly oral administration during labor induction by microElution solid phase extraction combined with liquid chromatography tandem mass spectrometry.

    PubMed

    Hung, Cheng-Han; Cheng, Shi-Yann; Chan, Tzu-Min; Lee, Maw-Rong

    2015-09-01

    Misoprostol is a widely used alternative of prostaglandin for labor induction. Based on previous studies, we envision that small and frequent oral dosage of misoprostol is an effective method for labor induction. To monitor the misoprostol content during labor induction, a rapid, sensitive, and selective microElution solid phase extraction (μElution SPE) combined with liquid chromatography tandem mass spectrometry (LC-MS/MS) was developed. Using μElution SPE could minimize the sample consumption and elution volume in order to maximize the sample enrichment and throughput. The misoprostol acid, a metabolite of misoprostol, was gradient separated in a Bidentate C18 column, then quantified by highly-selective reaction monitoring (H-SRM) in a total run time of 6min. The developed method was optimized and validated in human plasma, and showed linear range of 0.01-10ng/mL. The limit of detection (LOD) was 0.001ng/mL. The recovery ranged from 89.0 to 96.0%, and no significant matrix effect or carryover was observed. The precision, accuracy and stability were met with the criteria of U.S. FDA guidance. The developed method was successfully applied to evaluate misoprostol concentration during labor induction in pregnant women. The concentration-time profiles approves that hourly oral administration of misoprostol is a safe and effective method without drug accumulation for labor induction. PMID:26245361

  18. Analysis of inorganic cations in biological samples by the combination of micro-electrodialysis and capillary electrophoresis with capacitively coupled contactless conductivity detection.

    PubMed

    Doan, Thi Kieu Oanh; Kubáň, Pavel; Kubáň, Petr; Kiplagat, Isaac K; Boček, Petr

    2011-02-01

    Micro-electrodialysis (μED) and CE were combined for rapid pretreatment and subsequent determination of inorganic cations in biological samples. Combination of μED with CE greatly improved the analytical performance of the latter as the adsorption of high molecular weight compounds present in real samples on the inner capillary wall was eliminated. Fifty microliter of 80-fold diluted human body fluids such as plasma, serum and whole blood was used in the donor compartment of the μED system requiring less than 1 μL of the original body fluid per analysis. Inorganic cations that migrated through a cellulose acetate dialysis membrane with molecular weight cut-off value of 500 Da were collected in the acceptor solution and were then analyzed using CE-C⁴D. Baseline separation of inorganic cations was achieved in a BGE solution consisting of 12.5 mM maleic acid, 15 mM L-arginine and 3 mM 18-crown-6 at pH 5.5. Repeatability of the CE-C⁴D method was better than 0.5% and 2.5% for migration times and peak areas, respectively; limits of detection of all inorganic cations in the presence of 2 mM excess of Na(+) were around 1 μM and calibration curves were linear with correlation coefficients better than 0.998. Repeatability of the sample pretreatment procedure was calculated for six independent electrodialysis runs of artificial and real samples and was better than 11.8%. Recovery values between 96.3 and 110% were achieved for optimized electrodialysis conditions of standard solutions and real samples; lifetime of the dialysis membranes for pretreatment of real samples was estimated to 100 runs. PMID:21298671

  19. Combining Heavy Ion Radiation and Artificial MicroRNAs to Target the Homologous Recombination Repair Gene Efficiently Kills Human Tumor Cells

    SciTech Connect

    Zheng Zhiming; Wang Ping; Wang Hongyan; Zhang Xiangming; Wang Minli; Cucinotta, Francis A.; Wang Ya

    2013-02-01

    Purpose: Previously, we demonstrated that heavy ions kill more cells at the same dose than X-rays because DNA-clustered lesions produced by heavy ions affect nonhomologous end-joining (NHEJ) repair but not homologous recombination repair (HRR). We have also shown that our designed artificial microRNAs (amiRs) could efficiently target XRCC4 (an essential factor for NHEJ) or XRCC2 (an essential factor for HRR) and sensitize human tumor cells to X-rays. Based on these data, we were interested in testing the hypothesis that combining heavy ions and amiRs to target HRR but not NHEJ should more efficiently kill human tumor cells. Methods and Materials: Human tumor cell lines (U87MG, a brain tumor cell line, and A549, a lung cancer cell line) and their counterparts, overexpressed with amiR to target XRCC2, XRCC4 or both, were used in this study. Survival sensitivities were examined using a clonogenic assay after these cells were exposed to X-rays or heavy ions. In addition, these cell lines were subcutaneously injected into nude mice to form xenografts and the tumor size was compared after the tumor areas were exposed to X-rays or heavy ions. Results: Although targeting either XRCC4 (NHEJ factor) or XRCC2 (HRR factor) sensitized the human tumor cells to X-rays, in vitro and the xenograft animal model, targeting only XRCC2 but not XRCC4 sensitized the human tumor cells to heavy ions in vitro and in the xenograft animal model. Conclusions: Combining heavy ions with targeting the HRR pathway, but not the NHEJ pathway, could significantly improve the efficiency of tumor cell death.

  20. Combination wt-p53 and MicroRNA-125b Transfection in a Genetically Engineered Lung Cancer Model Using Dual CD44/EGFR-targeting Nanoparticles.

    PubMed

    Talekar, Meghna; Trivedi, Malav; Shah, Parin; Ouyang, Qijun; Oka, Adwait; Gandham, Srujan; Amiji, Mansoor M

    2016-04-01

    Mutations in KRAS and p53 signaling pathways contribute to loss of responsiveness to current therapies and a decreased survival in lung cancer. In this study, we have investigated the delivery and transfection of wild-type (wt-) p53 and microRNA-125b (miR-125b) expressing plasmid DNA, in SK-LU-1 human lung adenocarcinoma cells as well as in Kras(G12D)/p53(fl/fl) (KP) genetically engineered mouse model of lung cancer. Systemic plasmid DNA delivery with dual CD44/EGFR-targeted hyaluronic acid (HA)-based nanoparticles (NPs) resulted in a 2- to 20-fold increase in wt-p53 and miR-125b gene expression in SK-LU-1 cells. This resulted in enhanced apoptotic activity as seen with increased APAF-1 and caspase-3 gene expression. Similarly, in vivo evaluations in KP mouse model indicated successful CD44/EGFR-targeted delivery. Tumor growth inhibition and apoptotic induction were also observed with (wt-p53+miR125b) combination therapy in KP tumor model. Lastly, J774.A1 murine macrophages co-cultured with transfected SK-LU-1 cells showed a 14- to 35-fold increase in the iNOS-Arg-1 ratio, supportive of previous results demonstrating a role of miR-125b in macrophage repolarization. Overall, these results show tremendous promise of wt-p53 and miR-125b gene therapy using dual CD44/EGFR-targeting HA NP vector for effective treatment of lung cancer. PMID:26686386

  1. Nano/micro hybrid scaffold of PCL or P3HB nanofibers combined with silk fibroin for tendon and ligament tissue engineering.

    PubMed

    Naghashzargar, Elham; Farè, Silvia; Catto, Valentina; Bertoldi, Serena; Semnani, Dariush; Karbasi, Saeed; Tanzi, Maria Cristina

    2015-01-01

    A novel biodegradable nano/micro hybrid structure was obtained by electrospinning P3HB or PCL nanofibers onto a twisted silk fibroin (SF) structure, with the aim of fabricating a suitable scaffold for tendon and ligament tissue engineering. The electrospinning (ES) processing parameters for P3HB and PCL were optimized on 2D samples, and applied to produce two different nano/micro hybrid constructs (SF/ES-PCL and SF/ES-P3HB).Morphological, chemico-physical and mechanical properties of the novel hybrid scaffolds were evaluated by SEM, ATR FT-IR, DSC, tensile and thermodynamic mechanical tests. The results demonstrated that the nanofibers were tightly wrapped around the silk filaments, and the crystallinity of the SF twisted yarns was not influenced by the presence of the electrospun polymers. The slightly higher mechanical properties of the hybrid constructs confirmed an increase of internal forces due to the interaction between nano and micro components. Cell culture tests with L929 fibroblasts, in the presence of the sample eluates or in direct contact with the hybrid structures, showed no cytotoxic effects and a good level of cytocompatibility of the nano/micro hybrid structures in term of cell viability, particularly at day 1. Cell viability onto the nano/micro hybrid structures decreased from the first to the third day of culture when compared with the control culture plastic, but appeared to be higher when compared with the uncoated SF yarns. Although additional in vitro and in vivo tests are needed, the original fabrication method here described appears promising for scaffolds suitable for tendon and ligament tissue engineering. PMID:25589157

  2. Surface Characterization and Osteoconductivity Evaluation of Micro/Nano Surface Formed on Titanium Using Anodic Oxidation Combined with H2O2 Etching and Hydrothermal Treatment.

    PubMed

    Park, Eun-Jin; Song, Yo-Han; Hwang, Moon-Jin; Song, Ho-Jun; Park, Yeong-Joon

    2015-08-01

    In this study, surface characteristics and osteoconductivity were investigated for the micro/nanostructured oxide layers fabricated on titanium using anodic oxidation (ANO), chemical etching (Et), and hydrothermal treatment (HT). Commercially pure titanium (CP-Ti) disks were anodic-oxidized using DC-type power supply in 1 M phosphoric acid electrolyte (P-ANO group). These specimens were further chemically etched using 30% H2O2 solution at 60 °C for 10 min (P-ANO-Et group). The P-ANO-Et-HT group was fabricated by hydrothermally treating the P-ANO-Et specimens in phosphorus-containing alkaline solution at 190 °C for 8 hrs. The P-ANO group showed a porous surface that was evenly covered with micro- and sub-micro pores. The size of these pores was decreased in the P-ANO-Et group. The P-ANO-Et-HT group showed a porous surface that was covered with nano-sized crystallites. Anatase TiO2 structure was observed in P-ANO-Et-HT group. The results of XPS demonstrated that the P-ANO-Et-HT group had a well-crystallized TiC2 structure, while the P-ANO and P-ANO-Et groups had an amorphous and phosphate-containing structure. Hydrophilicity of the P-ANO-Et-HT group was the highest. After MG63 osteoblast-like cells were cultured on the specimens for 3 hrs, SEM images of the cells cultured on P-ANO-Et-HT group specimens showed low initial adhesion. However, the osteoconductivity of these specimens increased more rapidly compared to that of the micro-structured surfaces. These results could be applied to fabricate titanium implants with an optimum micro/nano-surface for enhancing their osteoconductivity. PMID:26369213

  3. Search for Fluid Inclusions in a Carbonaceous Chondrite Using a New X-Ray Micro-Tomography Technique Combined with FIB Sampling

    NASA Technical Reports Server (NTRS)

    Tsuchiyama, A.; Miyake, A.; Zolensky, M. E.; Uesugi, K.; Nakano, T.; Takeuchi, A.; Suzuki, Y.; Yoshida, K.

    2014-01-01

    Early solar system aqueous fluids are preserved in some H chondrites as aqueous fluid inclusions in halite (e.g., [1]). Although potential fluid inclusions are also expected in carbonaceous chondrites [2], they have not been surely confirmed. In order to search for these fluid inclusions, we have developped a new X-ray micro-tomography technique combined with FIB sampling and applied this techniqu to a carbanaceous chondrite. Experimental: A polished thin section of Sutter's Mill meteorite (CM) was observed with an optical microscope and FE-SEM (JEOL 7001F) for chosing mineral grains of carbonates (mainly calcite) and sulfides (FeS and ZnS) 20-50 microns in typical size, which may have aqueous fluid inclusions. Then, a "house" similar to a cube with a roof (20-30 microns in size) is sampled from the mineral grain by using FIB (FEI Quanta 200 3DS). Then, the house was atached to a thin W-needle by FIB and imaged by a SR-based imaging microtomography system with a Fresnel zone plate at beamline BL47XU, SPring-8, Japan. One sample was imaged at two X-ray energies, 7 and 8 keV, to identify mineral phases (dual-enegy microtomography: [3]). The size of voxel (pixel in 3D) was 50-80 nm, which gave the effective spatial resolution of approx. 200 nm. A terrestrial quartz sample with an aqueous fluid inclusion with a bubble was also examined as a test sample by the same method. Results and discussion: A fluid inclusion of 5-8 microns in quartz was clearly identified in a CT image. A bubble of approx. 4 microns was also identified as refraction contrast although the X-ray absorption difference between fluid and bubble is small. Volumes of the fluid and bubble were obtained from the 3D CT images. Fourteen grains of calcite, two grains of iron sulfide and one grain of (Zn,Fe)S were examined. Ten calcite, one iron sulfide and one (Zn,Fe)S grains have inclusions >1 micron in size (the maximum: approx. 5 microns). The shapes are spherical or irregular. Tiny inclusions (<1 micron

  4. Self-aliquoting micro-grooves in combination with laser ablation-ICP-mass spectrometry for the analysis of challenging liquids: quantification of lead in whole blood.

    PubMed

    Nischkauer, Winfried; Vanhaecke, Frank; Limbeck, Andreas

    2016-08-01

    We present a technique for the fast screening of the lead concentration in whole blood samples using laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS). The whole blood sample is deposited on a polymeric surface and wiped across a set of micro-grooves previously engraved into the surface. The engraving of the micro-grooves was accomplished with the same laser system used for LA-ICP-MS analysis. In each groove, a part of the liquid blood is trapped, and thus, the sample is divided into sub-aliquots. These aliquots dry quasi instantly and are then investigated by means of LA-ICP-MS. For quantification, external calibration against aqueous standard solutions was relied on, with iron as an internal standard to account for varying volumes of the sample aliquots. The (208)Pb/(57)Fe nuclide ratio used for quantification was obtained via a data treatment protocol so far only used in the context of isotope ratio determination involving transient signals. The method presented here was shown to provide reliable results for Recipe ClinChek® Whole Blood Control levels I-III (nos. 8840-8842), with a repeatability of typically 3 % relative standard deviation (n = 6, for Pb at 442 μg L(-1)). Spiked and non-spiked real whole blood was analysed as well, and the results were compared with those obtained via dilution and sectorfield ICP-MS. A good agreement between both methods was observed. The detection limit (3 s) for lead in whole blood was established to be 10 μg L(-1) for the laser ablation method presented here. Graphical Abstract Micro-grooves are filled with whole blood, dried, and analyzed by laser ablation ICP-mass spectrometry. Notice that the laser moves in perpendicular direction with regard to the micro-grooves. PMID:27363841

  5. Reduced dental calcium expression and dental mass in chronic sleep deprived rats: Combined EDS, TOF-SIMS, and micro-CT analysis

    NASA Astrophysics Data System (ADS)

    Kuo, Yi-Jie; Huang, Yung-Kai; Chou, Hsiu-Chu; Pai, Man-Hui; Lee, Ai-Wei; Mai, Fu-Der; Chang, Hung-Ming

    2015-08-01

    Teeth are the hardest tissue in the body. The growth of teeth is closely regulated by circadian rhythmicity. Considering that sleep deprivation (SD) is a severe condition that disrupts normal circadian rhythmicity, this study was conducted to determine whether calcium expression (the major element participating in teeth constitution), and dental mass would be significantly impaired following SD. Adolescent rats subjected to 3 weeks of SD were processed for energy dispersive spectrum (EDS), time-of-flight secondary ion mass spectrometry (TOF-SIMS), and micro-computed tomography (micro-CT) analyses. The EDS and TOF-SIMS results indicated that high calcium intensity was detected in both the upper and lower incisors of untreated rats. Micro-CT analysis corresponded closely with spectral data in which an enhanced dental mass was calculated in intact animals. However, following SD, both calcium expression and the dental mass were remarkably decreased to nearly half those of the untreated values. Because SD plays a detrimental role in impairing dental structure, establishing satisfactory sleep behavior would therefore serve as a crucial strategy for preventing or improving prevalent dental dysfunctions.

  6. Combined use of the non-destructive XRF and low energy micro-XRF techniques for the analysis of silvered nummi belonging to the Treasure of Misurata (Libya)

    NASA Astrophysics Data System (ADS)

    Romano, Francesco Paolo; Garraffo, Salvatore; Pappalardo, Lighea; Rizzo, Francesca

    2013-04-01

    Roman coinage underwent a severe debasement of silver during the time and the production of plated coins became a common practice for giving the impression of a high finesses of the alloy. In 294 AD, Diocletian introduced the nummus, manufactured with the same standard in all the mints by using an internal Cu-Sn-Pb-Ag core and presenting a thin silvered patina (about 2 micron) on its surface. The silver plating of the nummi have been investigated in the past and different methods have been suggested for its manufacturing (e.g. segregation during casting, chemical treatments, mercury-silvering). However, previous analyses were focused on few samples and, consequently, this technological issue remained unresolved. In the present work, the BSC-XRF (Beam Stability Controlled -XRF) and a LE-micro-XRF portable spectrometers developed at the LANDIS laboratory of IBAM-CNR and LNS-INFN in Catania (Italy), have been applied for the in-situ analysis of the silvered nummi belonging to the Misurata Treasure (Museum of Leptis Magna, El-Khomes, Libya). The treasure is composed of 108 thousand coins manufactured in 19 Imperial mints operating in the period 294-333 AD. In order to establish if, and at what extent, the mercury-silvering was used to produce the thin Ag-patina of the nummi, the non-destructive investigation was extended to 1050 well preserved coins. Measurements allowed to explore the presence of Hg and the Hg-Ag correlation at the coin surface. The portable BSC-XRF and the LE-micro XXRF techniques are suited to approach this study. A new version of the BSC-XRF spectrometer, consisting of a compact high-intensity x-ray tube (50 kV; 4 mA) coupled to a 80 mm2 SDD detector (138 eV @ 5.9 keV), was developed for the fast determination of mercury traces in a large number of coins (measurement time is 150 seconds; MDL for Hg is 100 ppm). The investigation allowed to identify the Imperial mints and the periods where the mercury-silvering were probably used. However the BSC

  7. Combined effects of suction/injection and wall surface curvature on natural convection flow in a vertical micro-porous annulus

    NASA Astrophysics Data System (ADS)

    Jha, B. K.; Aina, B.; Muhammad, S. A.

    2015-03-01

    This study investigates analytically the hydrodynamic and thermal behaviour of a fully developed natural convection flow in a vertical micro-porous-annulus (MPA) taking into account the velocity slip and temperature jump at the outer surface of inner porous cylinder and inner surface of outer porous cylinder. A closed — form solution is presented for velocity, temperature, volume flow rate, skin friction and rate of heat transfer expressed as a Nusselt number. The influence of each governing parameter on hydrodynamic and thermal behaviour is discussed with the aid of graphs. During the course of investigation, it is found that as suction/injection on the cylinder walls increases, the fluid velocity and temperature is enhanced. In addition, it is observed that wall surface curvature has a significant effect on flow and thermal characteristics.

  8. On-line identification of the bioactive compounds from Blumea gariepina by HPLC-UV-MS and HPLC-UV-NMR, combined with HPLC-micro-fractionation.

    PubMed

    Queiroz, E F; Ioset, J R; Ndjoko, K; Guntern, A; Foggin, C M; Hostettmann, K

    2005-01-01

    The dichloromethane extract of the aerial parts of Blumea gariepina (Asteraceae) was shown to be active against the phytopathogenic fungus Cladosporium cucumerinum and to inhibit acetylcholinesterase. In order rapidly to identify the active principles, the crude extract was analysed by on-flow HPLC-1H-NMR. HPLC-micro-fractionation was performed and all peaks collected were submitted to assays against C. cucumerinum and acetylcholinesterase. By this means, the biological activities could be efficiently associated with selected HPLC peaks. Complementary on-line structural data for all peaks of interest in the crude extract were obtained from HPLC-MS and from HPLC-UV with post-column addition of UV shift reagents. This chemical screening strategy with integrated bioassays permitted the on-line identification of a number of constituents and gave useful information for an efficient isolation procedure. PMID:15997849

  9. Eupolybothrus cavernicolus Komerički & Stoev sp. n. (Chilopoda: Lithobiomorpha: Lithobiidae): the first eukaryotic species description combining transcriptomic, DNA barcoding and micro-CT imaging data

    PubMed Central

    2013-01-01

    Abstract We demonstrate how a classical taxonomic description of a new species can be enhanced by applying new generation molecular methods, and novel computing and imaging technologies. A cave-dwelling centipede, Eupolybothrus cavernicolus Komerički & Stoev sp. n. (Chilopoda: Lithobiomorpha: Lithobiidae), found in a remote karst region in Knin, Croatia, is the first eukaryotic species for which, in addition to the traditional morphological description, we provide a fully sequenced transcriptome, a DNA barcode, detailed anatomical X-ray microtomography (micro-CT) scans, and a movie of the living specimen to document important traits of its ex-situ behaviour. By employing micro-CT scanning in a new species for the first time, we create a high-resolution morphological and anatomical dataset that allows virtual reconstructions of the specimen and subsequent interactive manipulation to test the recently introduced ‘cybertype’ notion. In addition, the transcriptome was recorded with a total of 67,785 scaffolds, having an average length of 812 bp and N50 of 1,448 bp (see GigaDB). Subsequent annotation of 22,866 scaffolds was conducted by tracing homologs against current available databases, including Nr, SwissProt and COG. This pilot project illustrates a workflow of producing, storing, publishing and disseminating large data sets associated with a description of a new taxon. All data have been deposited in publicly accessible repositories, such as GigaScience GigaDB, NCBI, BOLD, Morphbank and Morphosource, and the respective open licenses used ensure their accessibility and re-usability. PMID:24723752

  10. Micro Navigator

    NASA Technical Reports Server (NTRS)

    Blaes, B. R.; Kia, T.; Chau, S. N.

    2001-01-01

    Miniature high-performance low-mass space avionics systems are desired for planned future outer planetary exploration missions (i.e. Europa Orbiter/Lander, Pluto-Kuiper Express). The spacecraft fuel and mass requirements enabling orbit insertion is the driving requirement. The Micro Navigator is an integrated autonomous Guidance, Navigation & Control (GN&C)micro-system that would provide the critical avionics function for navigation, pointing, and precision landing. The Micro Navigator hardware and software allow fusion of data from multiple sensors to provide a single integrated vehicle state vector necessary for six degrees of freedom GN&C. The benefits of this MicroNavigator include: 1) The Micro Navigator employs MEMS devices that promise orders of magnitude reductions in mass power and volume of inertial sensors (accelerometers and gyroscopes), celestial sensing devices (startracker, sun sensor), and computing element; 2) The highly integrated nature of the unit will reduce the cost of flight missions. a) The advanced miniaturization technologies employed by the Micro Navigator lend themselves to mass production, and therefore will reduce production cost of spacecraft. b) The integral approach simplifies interface issues associated with discrete components and reduces cost associated with integration and test of multiple components; and 3) The integration of sensors and processing elements into a single unit will allow the Micro Navigator to encapsulate attitude information and determination functions into a single object. This is particularly beneficial for object-oriented software architectures that are used in advanced spacecraft. Additional information is contained in the original extended abstract.

  11. Preventive effects of butyric acid, nicotinamide, calcium glucarate alone or in combination during the 7, 12-dimethylbenz (a) anthracene induced mouse skin tumorigenesis via modulation of K-Ras-PI3K-AKTpathway and associated micro RNAs.

    PubMed

    Tiwari, Prakash; Sahay, Satya; Pandey, Manuraj; Qadri, Syed S Y H; Gupta, Krishna P

    2016-02-01

    Skin cancer is among the most common cancers worldwide and identifiable molecular changes for early and late stage of skin tumorigenesis can suggest the better targets for its control. In this study, we investigated the status of K-Ras-PI3K-AKTpathway followed by NF-κB, cyclin D1, MMP-9 and regulatory micro RNA during 7, 12-dimethylbenz[a]anthracene (DMBA) induced mouse skin tumorigenesis and its prevention by butyric acid (BA), nicotinamide (NA) and calcium glucarate (CAG), individually or in combination with respect to time. DMBA upregulated the K-Ras, PI3K, Akt, NF-κB, cyclin D1 and MMP-9, but downregulated the PTEN in a time dependent manner. DMBA also reduced the levels of micoRNA let-7a but induced the levels of miR-21 and miR-20a as a function of time. BA, NA and CAG were found to prevent DMBA induced changes, but they were most effective when used together in a combination. Reduced let-7a and miR-211 were correlated with the overexpression of K-Ras and MMP-9. Overexpression of miR-21 and miR-20a was correlated with the down regulation of PTEN and overexpression of Cyclin D1. Collectively, the enhanced chemopreventive potential of natural compound in combination via regulation of K-Ras-PI3K-AKTpathway along with regulatory micro RNAs provide a newer and effective mean for cancer management. PMID:26655363

  12. 3D electrostatic charge distribution on finitely thick busbars in micro-acoustic devices: combined regularization in the near- and far-field.

    PubMed

    Baghai-Wadji, Alireza

    2015-06-01

    The original work for 3-D charge distributions in micro-acoustic devices has been manifestly extended to account for finitely thick busbars. The work has been initiated to create a platform for simulating the electric charge localization and field enhancement at the electrode/busbar gaps depending on the thickness of the metalization in submicrometer geometries. A recipe for the construction of relevant Green's functions has been provided. A universal function (UF) for setting up system matrices in the method-of-moments' implementations has been constructed. Universal functions (moments of Green's functions) are by construction highly smooth and easy to compute. This work also presents a comprehensive completion of earlier work. For the first time, the calculation of the UF for a 3-D problem has been presented in great detail, highlighting the underlying regularization techniques. It is shown that the singular Fourier-type integrals involved can be regularized simultaneously in the near- and far-field. The pinnacle of the work is the detailed demonstration of the property that Hadamard's finite part regularization naturally arises in the construction of UFs. Three lemmata facilitate the understanding of the underlying concepts. PMID:26067048

  13. A methodology for the combined in situ analyses of the precursor and mature forms of microRNAs and correlation with their putative targets

    PubMed Central

    Nuovo, Gerard J; Elton, Terry S; Nana-Sinkam, Patrick; Volinia, Stefano; Croce, Carlo M; Schmittgen, Thomas D

    2009-01-01

    There are relatively few protocols described for the in situ detection of microRNA (miRNA) and they often use cryostat sections, signal amplification and hybridization or washes of 50−60 °C. This protocol describes in situ miRNA detection that can be done in paraffin-embedded, formalin-fixed tissue. Detection of the miRNA precursors can be done by RT in situ PCR, which can theoretically detect one copy per cell. The key variable for the RT in situ PCR protocol is optimal protease digestion, which is then followed by overnight DNase digestion and target specific incorporation of the reported nucleotide into the amplified cDNA. Detection of mature miRNAs is achieved by in situ hybridization with locked nucleic acid probes. This part of the protocol involves a brief protease digestion, followed by an overnight hybridization, short low stringency wash and detection of the labeled probe. The key variables for this method include probe concentration and stringency conditions. Each miRNA in situ method takes 1 d. The final step of the protocol involves colabeling by immunohistochemistry for the putative target of the miRNA, which is done after the in situ hybridization step and takes a few hours. PMID:19131963

  14. A Micro-Preconcentrator Combined Olfactory Sensing System with a Micromechanical Cantilever Sensor for Detecting 2,4-Dinitrotoluene Gas Vapor

    PubMed Central

    Chae, Myung-Sic; Kim, Jinsik; Yoo, Yong Kyoung; Kang, Ji Yoon; Lee, Jeong Hoon; Hwang, Kyo Seon

    2015-01-01

    Preventing unexpected explosive attacks and tracing explosion-related molecules require the development of highly sensitive gas-vapor detection systems. For that purpose, a micromechanical cantilever-based olfactory sensing system including a sample preconcentrator was developed to detect 2,4-dinitrotoluene (2,4-DNT), which is a well-known by-product of the explosive molecule trinitrotoluene (TNT) and exists in concentrations on the order of parts per billion in the atmosphere at room temperature. A peptide receptor (His-Pro-Asn-Phe-Ser-Lys-Tyr-Ile-Leu-His-Gln-Arg) that has high binding affinity for 2,4-DNT was immobilized on the surface of the cantilever sensors to detect 2,4-DNT vapor for highly selective detection. A micro-preconcentrator (µPC) was developed using Tenax-TA adsorbent to produce higher concentrations of 2,4-DNT molecules. The preconcentration was achieved via adsorption and thermal desorption phenomena occurring between target molecules and the adsorbent. The µPC directly integrated with a cantilever sensor and enhanced the sensitivity of the cantilever sensor as a pretreatment tool for the target vapor. The response was rapidly saturated within 5 min and sustained for more than 10 min when the concentrated vapor was introduced. By calculating preconcentration factor values, we verified that the cantilever sensor provides up to an eightfold improvement in sensing performance. PMID:26213944

  15. Combined Label-Free Quantitative Proteomics and microRNA Expression Analysis of Breast Cancer Unravel Molecular Differences with Clinical Implications.

    PubMed

    Gámez-Pozo, Angelo; Berges-Soria, Julia; Arevalillo, Jorge M; Nanni, Paolo; López-Vacas, Rocío; Navarro, Hilario; Grossmann, Jonas; Castaneda, Carlos A; Main, Paloma; Díaz-Almirón, Mariana; Espinosa, Enrique; Ciruelos, Eva; Fresno Vara, Juan Ángel

    2015-06-01

    Better knowledge of the biology of breast cancer has allowed the use of new targeted therapies, leading to improved outcome. High-throughput technologies allow deepening into the molecular architecture of breast cancer, integrating different levels of information, which is important if it helps in making clinical decisions. microRNA (miRNA) and protein expression profiles were obtained from 71 estrogen receptor-positive (ER(+)) and 25 triple-negative breast cancer (TNBC) samples. RNA and proteins obtained from formalin-fixed, paraffin-embedded tumors were analyzed by RT-qPCR and LC/MS-MS, respectively. We applied probabilistic graphical models representing complex biologic systems as networks, confirming that ER(+) and TNBC subtypes are distinct biologic entities. The integration of miRNA and protein expression data unravels molecular processes that can be related to differences in the genesis and clinical evolution of these types of breast cancer. Our results confirm that TNBC has a unique metabolic profile that may be exploited for therapeutic intervention. PMID:25883093

  16. A study on the aerosol extinction-to-backscatter ratio with combination of micro-pulse LIDAR and MODIS over Hong Kong

    NASA Astrophysics Data System (ADS)

    He, Q. S.; Li, C. C.; Mao, J. T.; Lau, A. K. H.; Li, P. R.

    2006-08-01

    The aerosol extinction-to-backscatter ratio is an important parameter for inverting LIDAR signals in the LIDAR equation. It is a complicated function of the aerosol microphysical characteristics. In this paper, a method to retrieve the column-averaged aerosol extinction-to-backscatter ratio by constraining the aerosol optical depths (AOD) from a Micro-pulse LIDAR (MPL) by the AOD measurements from the Moderate Resolution Imaging Spectroradiometer (MODIS) is presented. Both measurements were taken on cloud free days between 1 May 2003 and 30 June 2004 over Hong Kong, a coastal city in south China. Simultaneous measurements of aerosol scattering coefficients with a forward scattering visibility sensor are compared with the LIDAR retrieval of aerosol extinction coefficients. The data are then analyzed to determine seasonal trends of the aetrosol extinction-to-backscatter ratio. In addition, the relationships between the extinction-to-backscatter ratio and wind conditions as well as other aerosol microphysical parameters are presented. The mean aerosol extinction-to-backscatter ratio for the whole period was found to be 29.1±5.8 sr, with a minimum of 18 sr in July 2003 and a maximum of 44 sr in March 2004. The ratio is lower in summer because of the dominance of oceanic aerosols in association with the prevailing southwesterly monsoon. In contrast, relatively larger ratios are noted in spring and winter because of the increased impact of local and regional industrial pollutants associated with the northerly monsoon. The extended LIDAR measurements over Hong Kong provide not only a more accurate retrieval of aerosol extinction coefficient profiles, but also significant substantial information for air pollution and climate studies in the region.

  17. A study on aerosol extinction-to-backscatter ratio with combination of micro-pulse lidar and MODIS over Hong Kong

    NASA Astrophysics Data System (ADS)

    He, Q. S.; Li, C. C.; Mao, J. T.; Lau, A. K. H.

    2006-04-01

    The aerosol extinction-to-backscatter ratio is an important parameter for inverting LIDAR signals in the LIDAR equation. It is also a complicated function of aerosol microphysical characteristics depending on geographical and meteorological conditions. In this paper, a method to retrieve the column-averaged aerosol extinction-to-backscatter ratio by constraining the aerosol optical depths (AOD) recorded by the Moderate Resolution Imaging Spectroradiometer (MODIS) to the ones measured by a Micro-pulse LIDAR (MPL) is presented. Both measurements were taken between 1 May 2003 and 30 June 2004 over Hong Kong, a coastal city in south China. Simultaneous scattering coefficients measured by a forward scattering visibility sensor are compared with the LIDAR retrieval. The data are then analyzed in terms of monthly and seasonal trends. In addition, the relationships between the extinction-to-backscatter ratio and wind conditions as well as other aerosol microphysical parameters are also presented. The mean aerosol extinction-to-backscatter ratio for the whole period is found to be 28.9±6.1 sr, with the minimum of 12 sr in August 2003 and the maximum of 44 sr in March 2004. The ratio is lower in the summer because of the dominance of oceanic aerosols in association with the prevailing southwesterly monsoon. In contrast, relatively larger ratios are noted in spring and winter because of the increased impact of local and regional industrial pollutants associated with the northerly monsoon. The extended LIDAR measurements over Hong Kong provide not only a more accurate retrieval of aerosol extinction coefficient profiles, but also significant information for air pollution and climate studies in the region.

  18. Elimination and fate of selected micro-organic pollutants in a full-scale anaerobic/anoxic/aerobic process combined with membrane bioreactor for municipal wastewater reclamation.

    PubMed

    Xue, Wenchao; Wu, Chunying; Xiao, Kang; Huang, Xia; Zhou, Haidong; Tsuno, Hiroshi; Tanaka, Hiroaki

    2010-12-01

    The occurrence and elimination of 19 micro-organic pollutants including endocrine disrupting chemicals (EDCs) and pharmaceuticals and personal care products (PPCPs) in a full-scale anaerobic/anoxic/aerobic-membrane bioreactor process was investigated. The investigated process achieved over 70% removal of the target EDCs and 50%-100% removal of most of the PPCPs, with influent concentration ranging from ng/L to μg/L. Three PPCPs, carbamazepine, diclofenac and sulpiride were not well removed, with the removal efficiency below 20%. A rough mass balance suggests that the targets were eliminated through sludge-adsorption and/or biodegradation, the former of which was particularly significant for the removal of hydrophobic compounds. The two-phase fate model was employed to describe the kinetics of sludge-adsorption and biodegradation. It was found that the fast sludge adsorption (indicated by mass-transfer rates greater than 10 for most compounds) is responsible for the rapid decline of the aqueous concentration of the targets in the first compartment of the treatment process (i.e. in the anaerobic tank). In contrast, the slow biodegradation proved to be the rate-determining step for the entire degradation process, and the rates are generally positively related to the dissolved oxygen level. On the other hand, this study showed that the removal rates of most targets can reach a quasi-plateau in 5 h under aerobic conditions, indicating that hydraulic retention time of ca. 5 h in aerobic tanks should be sufficient for the elimination of most targets. PMID:20723962

  19. Void and phase evolution during the processing of Bi-2212 superconducting wires monitored by combined fast synchrotron micro-tomography and x-ray diffraction

    NASA Astrophysics Data System (ADS)

    Scheuerlein, C.; Di Michiel, M.; Scheel, M.; Jiang, J.; Kametani, F.; Malagoli, A.; Hellstrom, E. E.; Larbalestier, D. C.

    2011-11-01

    Recent study of the current-limiting mechanisms in Bi-2212 round wires has suggested that agglomeration of the residual Bi-2212 powder porosity into bubbles of filament-diameter size occurs on melting the Bi-2212 filaments. These pores introduce a major obstacle to current flow, which greatly reduces the critical current density (Jc). Here we present an in situ non-destructive tomographic and diffraction study of the changes occurring during the heat treatment of wires and starting powder, as well as a room temperature study of ex situ processed wires. The in situ through-process study shows that the agglomeration of residual porosity is more complex than previously seen. Filament changes start with coalescence of the quasi-uniform and finely divided powder porosity into lens-shaped defects at about 850 °C when the Bi-2201 impurity phase decomposes before the Bi-2212 starts to melt. These lens-shaped voids grow to bubbles of a filament diameter on melting of the Bi-2212 and continue to lengthen and then to agglomerate across multiple filaments while the filaments are in the liquid state. The experiment makes clear why melt processing is vital to developing high Jc and also shows how rearrangement of the residual filament porosity on melting imposes a strong longitudinal inhomogeneity in each filament. Reducing the bubble density is clearly an important path to reaching much higher Jc values in Bi-2212 round wires. Synchrotron micro-tomography is an exceptionally powerful technique for studying the spatial extent of the porosity on a scale of about 2 µm and larger.

  20. Mesoporous silica based MCM-41 as solid-phase extraction sorbent combined with micro-liquid chromatography-quadrupole-mass spectrometry for the analysis of pharmaceuticals in waters.

    PubMed

    Dahane, S; Martínez Galera, M; Marchionni, M E; Socías Viciana, M M; Derdour, A; Gil García, M D

    2016-05-15

    This paper reports the first application of the silica based mesoporous material MCM-41 as a sorbent in solid phase extraction, to pre-concentrate pharmaceuticals of very different polarity (atenolol, nadolol, pindolol, timolol, bisoprolol, metoprolol, betaxolol, ketoprofen, naproxen, ibuprofen, diclofenac, tolfenamic acid, flufenamic acid and meclofenamic acid) in surface waters. The analytes were extracted from 100mL water samples at pH 2.0 (containing 10(-3)mol/L of sodium chloride) by passing the solution through a cartridge filled with 100mg of MCM-41. Following elution, the pharmaceuticals were determined by micro-liquid chromatography and triple quadrupole-mass spectrometry. Two selected reaction monitoring transitions were monitored per compound, the most intense one being used for quantification and the second one for confirmation. Matrix effect was found in real waters for most analytes and was overcome using the standard addition method, which compared favorably with the matrix matched calibration method. The detection limits in solvent (acetonitrile:water 10:90, v/v) ranged from 0.01 to 1.48μg/L and in real water extracts from 0.10 to 3.85μg/L (0.001-0.0385μg/L in the water samples). The quantitation limits in solvent were in the range 0.02-4.93μg/L, whereas in real water extracts were between 0.45 and 10.00μg/L (0.0045 and 0.1000μg/L in the water samples). When ultrapure water samples were spiked at two concentration levels of each pharmaceutical (0.1 and 0.2μg/L) and quantified using solvent based calibration graphs, recoveries were near 100%. However, recoveries for most pharmaceuticals were comparable or better than de described above, when river water samples (spiked at the same concentration levels) were quantified by the standard addition method and slightly worse using the matrix matched calibration method. Five real samples (two rivers, one dam and two fountain water samples) were analyzed by the developed method, atenolol, timolol

  1. Ion pair-based liquid-phase microextraction combined with cuvetteless UV-vis micro-spectrophotometry as a miniaturized assay for monitoring ammonia in waters.

    PubMed

    Senra-Ferreiro, Sonia; Pena-Pereira, Francisco; Costas-Mora, Isabel; Romero, Vanesa; Lavilla, Isela; Bendicho, Carlos

    2011-09-15

    A miniaturized method based on liquid-phase microextraction (LPME) in combination with microvolume UV-vis spectrophotometry for monitoring ammonia in waters is proposed. The methodology is based on the extraction of the ion pair formed between the blue indophenol obtained according to the Berthelot reaction and a quaternary ammonium salt into a microvolume of organic solvent. Experimental parameters affecting the LPME performance such as type and concentration of the quaternary ammonium ion salt required to form the ion pair, type and volume of extractant solvent, effect of disperser solvent, ionic strength and extraction time, were optimized. A detection limit of 5.0 μg L(-1) ammonia and an enrichment factor of 30 can be attained after a microextraction time of 4 min. The repeatability, expressed as relative standard deviation, was 7.6% (n=7). The proposed method can be successfully applied to the determination of trace amounts of ammonia in several environmental water samples. PMID:21807208

  2. Non-uniform temperature distribution in Li-ion batteries during discharge - A combined thermal imaging, X-ray micro-tomography and electrochemical impedance approach

    NASA Astrophysics Data System (ADS)

    Robinson, James B.; Darr, Jawwad A.; Eastwood, David S.; Hinds, Gareth; Lee, Peter D.; Shearing, Paul R.; Taiwo, Oluwadamilola O.; Brett, Dan J. L.

    2014-04-01

    Thermal runaway is a major cause of failure in Li-ion batteries (LIBs), and of particular concern for high energy density transport applications, where safety concerns have hampered commercialisation. A clear understanding of electro-thermal properties and how these relate to structure and operation is vital to improving thermal management of LIBs. Here a combined thermal imaging, X-ray tomography and electrochemical impedance spectroscopy (EIS) approach was applied to commercially available 18650 cells to study their thermal characteristics. Thermal imaging was used to characterise heterogeneous temperature distributions during discharge above 0.75C; the complementary information provided by 3D X-ray tomography was utilised to evaluate the internal structure of the battery and identify the regions causing heating, specifically the components of the battery cap.

  3. Fabrication of long-focal-length plano-convex microlens array by combining the micro-milling and injection molding processes.

    PubMed

    Chen, Lei; Kirchberg, Stefan; Jiang, Bing-Yan; Xie, Lei; Jia, Yun-Long; Sun, Lei-Lei

    2014-11-01

    A uniform plano-convex spherical microlens array with a long focal length was fabricated by combining the micromilling and injection molding processes in this work. This paper presents a quantitative study of the injection molding process parameters on the uniformity of the height of the microlenses. The variation of the injection process parameters, i.e., barrel temperature, mold temperature, injection speed, and packing pressure, was found to have a significant effect on the uniformity of the height of the microlenses, especially the barrel temperature. The filling-to-packing switchover point is also critical to the uniformity of the height of the microlenses. The optimal uniformity was achieved when the polymer melts completely filled the mold cavity, or even a little excessively filled the cavity, during the filling stage. In addition, due to the filling resistance, the practical filling-to-packing switchover point can vary with the change of the filling processing conditions and lead to a non-negligible effect on the uniformity of the height of the microlenses. Furthermore, the effect of injection speed on the uniformity of the height of the microlenses was analyzed in detail. The results indicated that the effect of injection speed on the uniformity of the height of the microlenses is mainly attributed to the two functions of injection speed: transferring the filling-to-packing switchover point and affecting the distribution of residual flow stress in the polymer melt. PMID:25402902

  4. Infrared micro-optics technologies

    NASA Astrophysics Data System (ADS)

    Krogmann, Dirk; Tholl, Hans D.

    2004-08-01

    Bodenseewerk GmbH generally works on challenging projects comprising Microsystems, e.g. micro-optics (micro-lenses, micro-mirrors). We utilize state-of-the-art laboratory equipment and simulation software (e.g. optical design with ZEMAX, ASAP and GLAD). Our recent activities on the development of several infrared micro-optical devices focus on high speed imaging of scenes with high angular resolution including the analysis of physical properties of the detected light (e.g. spectral content, polarization) utilizing staring IR sensors with focal-plane-arrays operating in a snap shot mode at high frame rates. We report about the development of so called micro-optical multiplexers which: (a) comprise micro-optical arrays and electro-mechanical micro-actuators, (b) image several fields of view with high resolution onto a single focal-plane-array, (c) image several fields of view with enhanced spatial resolution [by the factor of four compared to (b)] in a modified realization onto one focal-plane-array and (d) analyze the spectral content of an image using a single-band photon detector-array and multi-frame processing. The micro-opto-electro-mechanical multiplexer (MOEM) systems all consist of a primary objective, a MOEM image-steering respectively image coding device and a secondary objective. The primary objective images one or more suitable formed individual fields of view onto a common intermediate image plane. The MOEM devices comprise combinations of focusing and defocusing micro-lens-arrays, micro-shutter-arrays and micro-filter-arrays which are mounted parallel to each other near the intermediate image plane. The MOEM devices exhibit their above mentioned function modes by laterally displacing the micro-arrays with the help of modern micro-actuators. The secondary objective is utilized as relay optical stage. A modern common focal-plane-array is used as detector device. The micro-actuators responsible for the relative displacement of the micro-arrays are highly

  5. In situ investigation of the surface silvering of late Roman coins by combined use of high energy broad-beam and low energy micro-beam X-ray fluorescence techniques

    NASA Astrophysics Data System (ADS)

    Romano, F. P.; Garraffo, S.; Pappalardo, L.; Rizzo, F.

    2012-07-01

    The compositional analysis of archeological metals performed with the X-ray Fluorescence technique (XRF) provides information on the ancient technology. One of the most interesting case-study concerns the techniques used by Romans for silvering the surface of coins. Different metallurgical processes have been suggested in previous studies. Recently the investigation has been addressed to the mercury-silvering and to its possible use in the mass-production of coins minted during the late period (after 294 AD). In the present paper the non-destructive investigation of the silvering process used for manufacturing the Roman nummi - the important typology of coin introduced by Diocletian in his monetary reform - is approached by the combined use of the standard X-Ray Fluorescence (XRF) and the low energy micro-X-Ray Fluorescence (LE-μXRF) portable methods. The research was focused on the systematic determination of the mercury presence in a large number of samples and on its correlation with silver in the surface of the coins. 1041 Roman nummi belonging to the Misurata Treasure were analyzed in situ, at the Leptis Magna Museum (Al Khums, Libya). The treasure, composed of about 108 thousand silvered coins, gives the unique opportunity to study the Roman coinage in a wide interval of time (about 40 years in the period 294-333 AD) and in almost all the imperial mints operating in the Roman world.

  6. Proteomic analysis of cellular soluble proteins from human bronchial smooth muscle cells by combining nondenaturing micro 2DE and quantitative LC-MS/MS. 2. Similarity search between protein maps for the analysis of protein complexes.

    PubMed

    Jin, Ya; Yuan, Qi; Zhang, Jun; Manabe, Takashi; Tan, Wen

    2015-09-01

    Human bronchial smooth muscle cell soluble proteins were analyzed by a combined method of nondenaturing micro 2DE, grid gel-cutting, and quantitative LC-MS/MS and a native protein map was prepared for each of the identified 4323 proteins [1]. A method to evaluate the degree of similarity between the protein maps was developed since we expected the proteins comprising a protein complex would be separated together under nondenaturing conditions. The following procedure was employed using Excel macros; (i) maps that have three or more squares with protein quantity data were selected (2328 maps), (ii) within each map, the quantity values of the squares were normalized setting the highest value to be 1.0, (iii) in comparing a map with another map, the smaller normalized quantity in two corresponding squares was taken and summed throughout the map to give an "overlap score," (iv) each map was compared against all the 2328 maps and the largest overlap score, obtained when a map was compared with itself, was set to be 1.0 thus providing 2328 "overlap factors," (v) step (iv) was repeated for all maps providing 2328 × 2328 matrix of overlap factors. From the matrix, protein pairs that showed overlap factors above 0.65 from both protein sides were selected (431 protein pairs). Each protein pair was searched in a database (UniProtKB) on complex formation and 301 protein pairs, which comprise 35 protein complexes, were found to be documented. These results demonstrated that native protein maps and their similarity search would enable simultaneous analysis of multiple protein complexes in cells. PMID:26031785

  7. Characterization of calcium and zinc spatial distributions at the fibrocartilage zone of bone-tendon junction by synchrotron radiation-based micro X-ray fluorescence analysis combined with backscattered electron imaging

    NASA Astrophysics Data System (ADS)

    Lu, Hongbin; Chen, Can; Wang, Zhanwen; Qu, Jin; Xu, Daqi; Wu, Tianding; Cao, Yong; Zhou, Jingyong; Zheng, Cheng; Hu, Jianzhong

    2015-09-01

    Tendon attaches to bone through a functionally graded fibrocartilage zone, including uncalcified fibrocartilage (UF), tidemark (TM) and calcified fibrocartilage (CF). This transition zone plays a pivotal role in relaxing load transfer between tendon and bone, and serves as a boundary between otherwise structurally and functionally distinct tissue types. Calcium and zinc are believed to play important roles in the normal growth, mineralization, and repair of the fibrocartilage zone of bone-tendon junction (BTJ). However, spatial distributions of calcium and zinc at the fibrocartilage zone of BTJ and their distribution-function relationship are not totally understood. Thus, synchrotron radiation-based micro X-ray fluorescence analysis (SR-μXRF) in combination with backscattered electron imaging (BEI) was employed to characterize the distributions of calcium and zinc at the fibrocartilage zone of rabbit patella-patellar tendon complex (PPTC). For the first time, the unique distributions of calcium and zinc at the fibrocartilage zone of the PPTC were clearly mapped by this method. The distributions of calcium and zinc at the fibrocartilage zone of the PPTC were inhomogeneous. A significant accumulation of zinc was exhibited in the transition region between UF and CF. The highest zinc content (3.17 times of that of patellar tendon) was found in the TM of fibrocartilage zone. The calcium content began to increase near the TM and increased exponentially across the calcified fibrocartilage region towards the patella. The highest calcium content (43.14 times of that of patellar tendon) was in the transitional zone of calcified fibrocartilage region and the patella, approximately 69 μm from the location with the highest zinc content. This study indicated, for the first time, that there is a differential distribution of calcium and zinc at the fibrocartilage zone of PPTC. These observations reveal new insights into region-dependent changes across the fibrocartilage zone of

  8. Compressibility and phase transition studies for amorphous materials under high pressure: Approach combined of synchrotron high energy x-ray diffraction and micro tomography techniques using diamond anvil cell

    NASA Astrophysics Data System (ADS)

    Liu, H.; Wang, L.; Xiao, X.; Lee, P.; Hemley, R.; Mao, H.

    2007-12-01

    The structural evolution of amorphous materials under high pressure conditions is a virgin field that has not been extensively explored. Investigations by reaching large Q range using synchrotron high energy x-ray diffraction and diamond anvil cell (DAC) techniques were performed. The study of polyamorphism will undoubtedly broaden our horizons and perspectives of the states of matter in general, and may have a significant impact on the existing theories about the structure, formation, and evolution of amorphous materials. The procedure of the pressure- induced amorphous state to crystalline state is another interesting subject. Combine the high energy x-ray diffraction with the time resolved area detector, we not only could accurately measure the structural factors evolution of amorphous materials under pressure, but also could record the time dependence of the crystallization procedure. These will provide new insight on the nature of crystallization, provide new invitation for the electronic theoretical studies for the phase stability and competition in time and spatial domains, and improve our understanding of the kinetic process of the common pressure induced crystallization. Another technical development effort is the micro tomography study using DAC at radial geometrical setting. Although the two-dimensional imaging, i. e. x-ray radiography, is used in routine way for high pressure DAC experiments, the ¡®volume imaging', i. e. x-ray tomography, will offer us more information regarding direct volume measurement, relative density measurement, and shear deformation under high pressure. The application in high pressure conditions by using DAC will greatly push our understanding of deformation mechanism down to lower mantle conditions. Another major application for DAC tomography will be the relative density measurement for the amorphous materials, metallic glasses, and liquid or melt in DAC under pressure, which will provide better information for the density

  9. Metal-organic framework MIL-101(Cr) as a sorbent of porous membrane-protected micro-solid-phase extraction for the analysis of six phthalate esters from drinking water: a combination of experimental and computational study.

    PubMed

    Wang, Ting; Wang, Jian; Zhang, Conglu; Yang, Zhao; Dai, Xinpeng; Cheng, Maosheng; Hou, Xiaohong

    2015-08-01

    An attractive metal-organic framework (MOF) MIL-101(Cr) material was synthesized at the nanoscale and applied as a sorbent in the porous membrane-protected micro-solid-phase extraction (μ-SPE) device for the pre-concentration of phthalate esters (PAEs) in drinking water samples for the first time. Parameters influencing the extraction efficiency, such as the selection of sorbent materials, pH adjustment, the effect of salt, magnetic-stirring extraction time, the desorption solvent and the desorption time, were investigated. Under the optimum conditions, the limits of detection from gas chromatography-mass spectrometric analysis for PAEs varied from 0.004 to 0.02 μg L(-1). The linear ranges were from 0.1 to 50 μg L(-1) or from 0.2 to 50 μg L(-1) for the analytes with the relative standard deviations fluctuating from 0.8 to 10.9% (n = 5). The enrichment factors (EFs) for the target PAEs were varied from 143 to 187. MIL-101(Cr) exhibited remarkable advantages compared to activated carbon and MIL-100(Fe). On the other hand, the computational method was first used to predict the adsorption of MIL-101(Cr) towards PAEs. The molecular interactions and the free binding energies between MIL-101(Cr) and PAEs were observed and calculated in terms of the molecular modeling method. MIL-101(Cr) showed high potential in the analysis of PAEs at trace levels in drinking water. The computational result was consistent with the detected enrichment factors. The computational modeling accurately predicted the extraction efficiency of MOF-based material towards the target analytes. Therefore, the combination of experimental and computational study provided a new strategy on the trace contaminant analysis. PMID:26076497

  10. MicroED data collection and processing

    SciTech Connect

    Hattne, Johan; Reyes, Francis E.; Nannenga, Brent L.; Shi, Dan; Cruz, M. Jason de la; Leslie, Andrew G. W.; Gonen, Tamir

    2015-07-01

    The collection and processing of MicroED data are presented. MicroED, a method at the intersection of X-ray crystallography and electron cryo-microscopy, has rapidly progressed by exploiting advances in both fields and has already been successfully employed to determine the atomic structures of several proteins from sub-micron-sized, three-dimensional crystals. A major limiting factor in X-ray crystallography is the requirement for large and well ordered crystals. By permitting electron diffraction patterns to be collected from much smaller crystals, or even single well ordered domains of large crystals composed of several small mosaic blocks, MicroED has the potential to overcome the limiting size requirement and enable structural studies on difficult-to-crystallize samples. This communication details the steps for sample preparation, data collection and reduction necessary to obtain refined, high-resolution, three-dimensional models by MicroED, and presents some of its unique challenges.

  11. Circulating microRNA profiles and the identification of miR-593 and miR-511 which directly target the PROP1 gene in children with combined pituitary hormone deficiency

    PubMed Central

    HU, YANYAN; WANG, QIAN; WANG, ZENGMIN; WANG, FENGXUE; GUO, XIAOBO; LI, GUIMEI

    2015-01-01

    Since the tissue of children with combined pituitary hormone deficiency (CPHD) is not readily accessible, a new focus in children with CPHD is the blood-based expression profiling of non-protein coding genes, such as microRNAs (miRNAs or miRs), which regulate gene expression by inhibiting the translation of mRNAs. In this study, to address this, we identified potential miRNA signatures for CPHD by comparing genome-wide miRNA expression profiles in the serum of children with CPHD vs. normal (healthy) controls. Human embryonic kidney 293T cells were transfected with miR-593 or miR-511 oligonucleotides. Potential target gene expression was validated by western blot analysis for proteins and by miR-593 or miR-511 reporter assay using PROP1 gene 3′-untranslated region (3′-UTR) reporter. The miR-593 and miR-511 levels in the serum of 103 children with CPHD were assessed using the reverse transcription-quantitative polymerase chain reaction (RT-qPCR) method. We found 23 upregulated and 19 down-regulated miRNAs with abnormal expression in children with CPHD compared with the normal controls using miRNA microarray analysis and RT-qPCR. miR-593 and miR-511 targeted the 3′-UTR of the PROP1 gene and attenuated the expression of PROP1. The levels of miR-593 and miR-511 in the serum of children with CPHD were increased compared with those in the control subjects. According to Youden’s index, the sensitivity was 82.54 and 84.86%, and the specificity was 98.15 and 91.36% for miR-593 and miR-511, respectively. The various levels of specific miRNAs, particularly miR-593 and miR-511 whose direct target is the PROP1 gene, may serve as a non-invasive diagnostic biomarkers for children with CPHD. PMID:25434367

  12. A study of lubrication, processing conditions, and material combinations that affect the wear of micro-textured-carbide coated cobalt-chromium-molybdenum alloy surfaces used for artificial joints implants

    NASA Astrophysics Data System (ADS)

    Ettienne-Modeste, Geriel A.

    Total joint replacement remains one of the most successful treatments for arthritis. The most common materials used for artificial joints are metals (e.g., cobalt-chrome alloys or titanium alloys), which articulate against ultra-high molecular weight polyethylene. Wear related failures of artificial joints may be reduced with the use of novel micro-textured carbide surfaces. The micro-textured carbide surfaces were deposited on a CoCrMo alloy using microwave plasma-assisted chemical vapor deposition. Wear tests were conducted to determine wear mechanisms and properties of the micro-textured surfaces. The research presented in this thesis addresses: (1) rheolgoical behavior of bovine calf serum with and without antibacterial agents to determine whether they can be used as appropriate models for synovial fluid, (2) the wear behavior of the micro-textured CoCrMo surface system, and (3) the mechanical and material properties of the micro-textured CoCrMo alloy surface relevant to wear performance. The rheological studies showed that the apparent viscosity of bovine calf serum increased with an increase in concentration before and after the serum was used for wear testing. The wear analysis showed that the processing conditions (2hr deposition vs. 4hr deposition times) affected the wear properties. The 2hr carbide-on-carbide lubricated in 50% BCS produced the lowest wear factor and rate for the five wear couple systems containing the carbide disk or plate material. Greater wear was produced in serum without penicillin/streptomycin (P/S) compared to the serum containing P/S. A greater carbide coating thickness 10 (micrometers) was produced during the 4hr deposition time than for the 2hr deposition (˜3mum). The nano-hardness value was higher than the micro-hardness for both the 4hr and 2hr carbide surfaces. The micro-hardness results of the worn carbide surfaces showed that an increase in BCS concentration from 0% to 100% increased the micro-hardness (HV) for carbide

  13. MicroED data collection and processing

    PubMed Central

    Hattne, Johan; Reyes, Francis E.; Nannenga, Brent L.; Shi, Dan; de la Cruz, M. Jason; Leslie, Andrew G. W.; Gonen, Tamir

    2015-01-01

    MicroED, a method at the intersection of X-ray crystallography and electron cryo-microscopy, has rapidly progressed by exploiting advances in both fields and has already been successfully employed to determine the atomic structures of several proteins from sub-micron-sized, three-dimensional crystals. A major limiting factor in X-ray crystallography is the requirement for large and well ordered crystals. By permitting electron diffraction patterns to be collected from much smaller crystals, or even single well ordered domains of large crystals composed of several small mosaic blocks, MicroED has the potential to overcome the limiting size requirement and enable structural studies on difficult-to-crystallize samples. This communication details the steps for sample preparation, data collection and reduction necessary to obtain refined, high-resolution, three-dimensional models by MicroED, and presents some of its unique challenges. PMID:26131894

  14. MicroRNAs and oncolytic viruses.

    PubMed

    Ruiz, Autumn J; Russell, Stephen J

    2015-08-01

    MicroRNAs regulate gene expression in mammalian cells and often exhibit tissue-specific expression patterns. Incorporation of microRNA target sequences can be used to control exogenous gene expression and viral tropism in specific tissues to enhance the therapeutic indices of oncolytic viruses expressing therapeutic transgenes. Continued development of this targeting strategy has resulted in the generation of unattenuated oncolytic viruses with enhanced potency, broad species-tropisms and reduced off-target toxicities in multiple-tissues simultaneously. Furthermore, oncolytic viruses have been used to enhance the delivery, duration and therapeutic efficacy of microRNA-based therapeutics designed to either restore or inhibit the function of dysregulated microRNAs in cancer cells. Recent efforts focused on combining oncolytic virotherapy and microRNA regulation have generated increasingly potent and safe cancer therapeutics. PMID:25863717

  15. All-solid-state flexible ultrathin micro-supercapacitors based on graphene.

    PubMed

    Niu, Zhiqiang; Zhang, Li; Liu, Lili; Zhu, Bowen; Dong, Haibo; Chen, Xiaodong

    2013-08-01

    Flexible, compact, ultrathin and all-solid-state micro-supercapacitors are prepared by coating H₃PO₄/PVA gel electrolyte onto micro-patterned rGO interdigitated electrodes prepared by combining photolithography with selective electrophoretic deposition. PMID:23716279

  16. Zirconia-coated graphite adsorption bar micro-extraction combined with ETV-ICP-MS for the determination of trace amounts of Cd, Hg and Pb in environmental and biological samples.

    PubMed

    Pu, Xuli; Jiang, Zucheng; Hu, Bin

    2006-07-01

    In this work, a new and simple micro-extraction method termed graphite adsorption bar micro-extraction was developed, for the first time, for electrothermal vaporization inductively coupled plasma mass spectrometry (ETV-ICP-MS) determination of trace Cd, Hg and Pb. In this method, the graphite bar was first coated with zirconia and then inserted into the sample solution for extraction. The graphite bar enriched with the analytes was inserted directly into a graphite tube, and subsequently analyzed by ETV-ICP-MS according to an established temperature program. The experimental parameters, which had influence on the extraction and vaporization, were systematically investigated and the optimal experimental conditions were established. Under the optimized conditions, the detection limits of the method were 0.05, 0.42 and 0.06 pg/ml for Cd, Hg and Pb and the relative standard deviations (RSDs) for 11 replicates at the 0.1 ng/ml level were 7.4, 8.2 and 7.7%, respectively. The proposed method was successfully applied to the determination of trace Cd, Hg and Pb in environmental and biological samples. The results of the experiments indicate that the method has a high enrichment factor and sample utilization efficiency. Furthermore, the method is fast and environment-friendly. PMID:16810641

  17. High resolution rare-earth elements analyses of natural apatite and its application in geo-sciences: Combined micro-PIXE, quantitative CL spectroscopy and electron spin resonance analyses

    NASA Astrophysics Data System (ADS)

    Habermann, D.; Götte, T.; Meijer, J.; Stephan, A.; Richter, D. K.; Niklas, J. R.

    2000-03-01

    The rare-earth element (REE) distribution in natural apatite is analysed by micro-PIXE, cathodoluminescence (CL) microscopy and spectroscopy and electron spin resonance (ESR) spectroscopy. The micro-PIXE analyses of an apatite crystal from Cerro de Mercado (Mexico) and the summary of 20 analyses of six francolite (conodonts of Triassic age) samples indicate that most of the REEs are enriched in apatite and francolite comparative to average shale standard (NASC). The analyses of fossil francolite revealing the REE-distribution not to be in balance with the REE-distribution of seawater and fish bone debris. Strong inhomogenous lateral REE-distribution in fossil conodont material is shown by CL-mapping and most probably not being a vital effect. Therefore, the resulting REE-signal from fossil francolite is the sum of vital and post-mortem incorporation. The necessary charge compensation for the substitution of divalent Ca by trivalent REE being done by different kind of electron defects and defect ions.

  18. Updating the Micro-Tom TILLING platform.

    PubMed

    Okabe, Yoshihiro; Ariizumi, Tohru; Ezura, Hiroshi

    2013-03-01

    The dwarf tomato variety Micro-Tom is regarded as a model system for functional genomics studies in tomato. Various tomato genomic tools in the genetic background of Micro-Tom have been established, such as mutant collections, genome information and a metabolomic database. Recent advances in tomato genome sequencing have brought about a significant need for reverse genetics tools that are accessible to the larger community, because a great number of gene sequences have become available from public databases. To meet the requests from the tomato research community, we have developed the Micro-Tom Targeting-Induced Local Lesions IN Genomes (TILLING) platform, which is comprised of more than 5000 EMS-mutagenized lines. The platform serves as a reverse genetics tool for efficiently identifying mutant alleles in parallel with the development of Micro-Tom mutant collections. The combination of Micro-Tom mutant libraries and the TILLING approach enables researchers to accelerate the isolation of desirable mutants for unraveling gene function or breeding. To upgrade the genomic tool of Micro-Tom, the development of a new mutagenized population is underway. In this paper, the current status of the Micro-Tom TILLING platform and its future prospects are described. PMID:23641180

  19. High range resolution micro-Doppler analysis

    NASA Astrophysics Data System (ADS)

    Cammenga, Zachary A.; Smith, Graeme E.; Baker, Christopher J.

    2015-05-01

    This paper addresses use of the micro-Doppler effect and the use of high range-resolution profiles to observe complex targets in complex target scenes. The combination of micro-Doppler and high range-resolution provides the ability to separate the motion of complex targets from one another. This ability leads to the differentiation of targets based on their micro-Doppler signatures. Without the high-range resolution, this would not be possible because the individual signatures would not be separable. This paper also addresses the use of the micro-Doppler information and high range-resolution profiles to generate an approximation of the scattering properties of a complex target. This approximation gives insight into the structure of the complex target and, critically, is created without using a pre-determined target model.

  20. Micro-laser

    DOEpatents

    Hutchinson, Donald P.; Richards, Roger K.

    2003-07-22

    A micro-laser is disclosed which includes a waveguide, a first and a second subwavelength resonant grating in the waveguide, and at least one photonic band gap resonant structure (PBG) in the waveguide and at least one amplifying medium in the waveguide. PBG features are positioned between the first and second subwavelength resonant gratings and allow introduction of amplifying mediums into the highly resonant guided micro-laser microcavity. The micro-laser may be positioned on a die of a bulk substrate material with one or more electronic and optical devices and may be communicably connected to the same. A method for fabricating a micro-laser is disclosed. A method for tuning the micro-laser is also disclosed. The micro-laser may be used as an optical regenerator, or a light source for data transfer or for optical computing.

  1. MicroSight Optics

    SciTech Connect

    2010-01-01

    MicroSight is an innovative gunsight technology that allows a marksman's eye to focus on both the front gunsight and the intended target. The MicroSight improves both firearm safety and performance by imaging two objects at different focal distances. The MicroSight was developed at Idaho National Laboratory, and has been licensed by Apollo Optical Systems. You can learn more about INL's research programs at http://www.facebook.com/idahonationallaboratory.

  2. MicroSight Optics

    ScienceCinema

    None

    2013-05-28

    MicroSight is an innovative gunsight technology that allows a marksman's eye to focus on both the front gunsight and the intended target. The MicroSight improves both firearm safety and performance by imaging two objects at different focal distances. The MicroSight was developed at Idaho National Laboratory, and has been licensed by Apollo Optical Systems. You can learn more about INL's research programs at http://www.facebook.com/idahonationallaboratory.

  3. The Use of Light/Chemically Hardened Polymethylmethacrylate, Polyhydroxylethylmethacrylate, and Calcium Hydroxide Graft Material in Combination With Polyanhydride Around Implants and Extraction Sockets in Minipigs: Part II: Histologic and Micro-CT Evaluations

    PubMed Central

    Hasturk, Hatice; Kantarci, Alpdogan; Ghattas, Mazen; Dangaria, Smit J.; Abdallah, Rima; Morgan, Elise F.; Diekwisch, Thomas G.H.; Ashman, Arthur; Van Dyke, Thomas

    2015-01-01

    Background This report is the second part of the previously published study on the impact of light/chemical hardening technology and a newly formulated composite graft material for crestal augmentation during immediate implant placement. Methods A total of 48 implants were placed into the sockets of the mesial roots of freshly extracted mandibular premolar teeth in three minipigs. Crestal areas and intrabony spaces were randomly augmented with light-hardened graft materials including a composite graft consisting of polymethylmethacrylate, polyhydroxylethylmethacrylate, and calcium hydroxide (PPCH) plus polyanhydride (PA); PPCH graft; and PA graft, or left untreated. Distal sockets not receiving implants and the sockets of first molars (n = 60) were randomly treated with one of the graft materials or left empty. In addition, two molar sockets were treated with the original PPCH graft material. Quantitative microcomputed tomography (micro-CT) was used to assess alveolar bone structure and tissue compositions. Histologic evaluations included descriptive histology to assess the peri-implant wound healing, as well as histomorphometric measurements to determine bone-to-implant contact (BIC). Results Both trabecular and cortical bone measurements by micro-CT did not reveal any significant differences among the groups. Sites augmented with PPCH+PA resulted in significantly greater BIC surface than PPCH alone and no-graft-treated implants (P <0.05) histologically. Stained ground sections showed complete bone formation between bone and implant surface in the PPCH+PA group, whereas sites without augmentation showed large gaps between bone and implant surfaces, indicating a slower bone apposition and less BIC surface compared to all other groups. Similar to implant sections, all materials showed positive outcome on trabecular and cortical bone formation in extraction sockets with an intact crestal cortical bone. Conclusion Histologic evaluations supported the previous findings

  4. Micro-organ device

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); von Gustedt-Gonda, legal representative, Iris (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

    2013-01-01

    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  5. Micro-Organ Device

    NASA Technical Reports Server (NTRS)

    Gonda, Steve R. (Inventor); Chang, Robert C. (Inventor); Starly, Binil (Inventor); Culbertson, Christopher (Inventor); Holtorf, Heidi L. (Inventor); Sun, Wei (Inventor); Leslie, Julia (Inventor)

    2013-01-01

    A method for fabricating a micro-organ device comprises providing a microscale support having one or more microfluidic channels and one or more micro-chambers for housing a micro-organ and printing a micro-organ on the microscale support using a cell suspension in a syringe controlled by a computer-aided tissue engineering system, wherein the cell suspension comprises cells suspended in a solution containing a material that functions as a three-dimensional scaffold. The printing is performed with the computer-aided tissue engineering system according to a particular pattern. The micro-organ device comprises at least one micro-chamber each housing a micro-organ; and at least one microfluidic channel connected to the micro-chamber, wherein the micro-organ comprises cells arranged in a configuration that includes microscale spacing between portions of the cells to facilitate diffusion exchange between the cells and a medium supplied from the at least one microfluidic channel.

  6. High speed micro scanner for 3D in-volume laser micro processing

    NASA Astrophysics Data System (ADS)

    Schaefer, D.; Gottmann, J.; Hermans, M.; Ortmann, J.; Kelbassa, I.

    2013-03-01

    Using an in-house developed micro scanner three-dimensional micro components and micro fluidic devices in fused silica are realized using the ISLE process (in-volume selective laser-induced etching). With the micro scanner system the potential of high average power femtosecond lasers (P > 100 W) is exploited by the fabrication of components with micrometer precision at scan speeds of several meters per second. A commercially available galvanometer scanner is combined with an acousto-optical and/or electro-optical beam deflector and translation stages. For focusing laser radiation high numerical aperture microscope objectives (NA > 0.3) are used generating a focal volume of a few cubic micrometers. After laser exposure the materials are chemically wet etched in aqueous solution. The laser-exposed material is etched whereas the unexposed material remains nearly unchanged. Using the described technique called ISLE the fabrication of three-dimensional micro components, micro holes, cuts and channels is possible with high average power femtosecond lasers resulting in a reduced processing time for exposure. By developing the high speed micro scanner up-scaling of the ISLE process is demonstrated. The fabricated components made out of glass can be applied in various markets like biological and medical diagnostics as well as in micro mechanics.

  7. Fabrication of Biochips with Micro Fluidic Channels by Micro End-milling and Powder Blasting

    PubMed Central

    Yun, Dae Jin; Seo, Tae Il; Park, Dong Sam

    2008-01-01

    For microfabrications of biochips with micro fluidic channels, a large number of microfabrication techniques based on silicon or glass-based Micro-Electro-Mechanical System (MEMS) technologies were proposed in the last decade. In recent years, for low cost and mass production, polymer-based microfabrication techniques by microinjection molding and micro hot embossing have been proposed. These techniques, which require a proper photoresist, mask, UV light exposure, developing, and electroplating as a pre-process, are considered to have some problems. In this study, we propose a new microfabrication technology which consists of micro end-milling and powder blasting. This technique could be directly applied to fabricate the metal mold without any preprocesses. The metal mold with micro-channels is machined by micro end-milling, and then, burrs generated in the end-milling process are removed by powder blasting. From the experimental results, micro end-milling combined with powder blasting could be applied effectively for fabrication of the injection mold of biochips with micro fluidic channels.

  8. Micro-Kelvin cold molecules.

    SciTech Connect

    Strecker, Kevin E.; Chandler, David W.

    2009-10-01

    We have developed a novel experimental technique for direct production of cold molecules using a combination of techniques from atomic optical and molecular physics and physical chemistry. The ability to produce samples of cold molecules has application in a broad spectrum of technical fields high-resolution spectroscopy, remote sensing, quantum computing, materials simulation, and understanding fundamental chemical dynamics. Researchers around the world are currently exploring many techniques for producing samples of cold molecules, but to-date these attempts have offered only limited success achieving milli-Kelvin temperatures with low densities. This Laboratory Directed Research and Development project is to develops a new experimental technique for producing micro-Kelvin temperature molecules via collisions with laser cooled samples of trapped atoms. The technique relies on near mass degenerate collisions between the molecule of interest and a laser cooled (micro-Kelvin) atom. A subset of collisions will transfer all (nearly all) of the kinetic energy from the 'hot' molecule, cooling the molecule at the expense of heating the atom. Further collisions with the remaining laser cooled atoms will thermally equilibrate the molecules to the micro-Kelvin temperature of the laser-cooled atoms.

  9. The MicroObservatory Net

    NASA Astrophysics Data System (ADS)

    Brecher, K.; Sadler, P.

    1994-12-01

    A group of scientists, engineers and educators based at the Harvard-Smithsonian Center for Astrophysics (CfA) has developed a prototype of a small, inexpensive and fully integrated automated astronomical telescope and image processing system. The project team is now building five second generation instruments. The MicroObservatory has been designed to be used for classroom instruction by teachers as well as for original scientific research projects by students. Probably in no other area of frontier science is it possible for a broad spectrum of students (not just the gifted) to have access to state-of-the-art technologies that would allow for original research. The MicroObservatory combines the imaging power of a cooled CCD, with a self contained and weatherized reflecting optical telescope and mount. A microcomputer points the telescope and processes the captured images. The MicroObservatory has also been designed to be used as a valuable new capture and display device for real time astronomical imaging in planetariums and science museums. When the new instruments are completed in the next few months, they will be tried with high school students and teachers, as well as with museum groups. We are now planning to make the MicroObservatories available to students, teachers and other individual users over the Internet. We plan to allow the telescope to be controlled in real time or in batch mode, from a Macintosh or PC compatible computer. In the real-time mode, we hope to give individual access to all of the telescope control functions without the need for an "on-site" operator. Users would sign up for a specific period of time. In the batch mode, users would submit jobs for the telescope. After the MicroObservatory completed a specific job, the images would be e-mailed back to the user. At present, we are interested in gaining answers to the following questions: (1) What are the best approaches to scheduling real-time observations? (2) What criteria should be used

  10. An Overview of MICRO-CMI.

    ERIC Educational Resources Information Center

    McIsaac, Donald; And Others

    The MICRO-CMI system designed at the University of Wisconsin combines the grouping, diagnosis, and prescription functions of two previously designed systems, with the additional dimension of a sheet scanner to input grades and to score tests. Moreover, the user may specify a unique program of studies for each student, thus enabling the support of…

  11. Ultrasound-assisted extraction combined with reverse phase-dispersive liquid-liquid micro extraction as a new approach for preconcentration and spectrophotometric determination of total phenol in marine sediments of Chabahar Bay.

    PubMed

    Ziyaadini, Morteza; Zahedi, Mir Mahdi; Khosravinia, Saeid

    2016-08-15

    In this study, Reverse phase dispersive liquid-liquid micro extraction (RP-DLLME) technique have been successfully developed to preconcentrate trace amount of phenol from sediment samples as a prior step to its derivatization with 4-aminoantipyrine and enhanced determination by UV-Vis spectrophotometry after primary ultrasonic extraction. In this procedure, 50μL 0.7M NaOH solution was chosen as extraction solvent and other factors including pH, extraction time, concentration of 4-aminoantipyrine, type and volume of dispersive solvents were optimized. Under selected conditions, the limit of detection, the linearity range, relative standard deviation and enrichment factor of method were obtained 15μg·kg(-1), 50-1800μg·kg(-1), 4.8% (n=10) and 33, respectively. Finally, using the high sensitivity, low organic solvent consumption and waste generation method, total phenol content in marine sediments from several locations in Chabahar Bay (southeast Iran) was estimated at 55.8-73.2μg·kg(-1). PMID:27293075

  12. Liquid-liquid extraction of uranium(VI) with Aliquat® 336 from HCl media in microfluidic devices: Combination of micro-unit operations and online ICP-MS determination.

    PubMed

    Hellé, Gwendolyne; Mariet, Clarisse; Cote, Gérard

    2015-07-01

    The analysis of radionuclides is carried out according to operating protocols which include a series of chemical operations such as separation/purification steps and therefore is usually time-consuming, complex and difficult to put in place in a hostile environment (gloves box). In the present work, the liquid-liquid extraction of uranium in HCl media by Aliquat® 336 was performed in microsystem to demonstrate the potential of miniaturization in radiochemistry compared to classical protocols (decrease in volumes, analysis time, radiations received and feasibility of automation). Through the investigation of the influence of different parameters (flow rates, length of the microchannel, specific interfacial area), it was shown that the same performances of liquid-liquid extraction can be obtained in microsystem and in batch. Then, the coupling of different micro-unit operations for continuous process was performed to highlight the advantages of the miniaturized analytical techniques. The online ICP-MS determination of uranium(VI) was successfully coupled with the stripping of the latter from pre-loaded organic phases in microsystem, which constitutes a proof of concept and a first step towards a global analytical process with continuous flow. PMID:25882417

  13. Combined urea-thin layer chromatography and silver nitrate-thin layer chromatography for micro separation and determination of hard-to-detect branched chain fatty acids in natural lipids.

    PubMed

    Yan, Yuanyuan; Wang, Xingguo; Liu, Yijun; Xiang, Jingying; Wang, Xiaosan; Zhang, Huijun; Yao, Yunping; Liu, Ruijie; Zou, Xiaoqiang; Huang, Jianhua; Jin, Qingzhe

    2015-12-18

    A simple, fast and efficient procedure was developed for micro separation and enrichment of branched chain fatty acids (BCFA) from natural products using successive thin layer chromatography (TLC) technique coupling novel urea-TLC with AgNO3-TLC, which rely on the formation of urea adduction and AgNO3 bonding in methanol. These natural lipids contain a significant amount of straight chain fatty acids (FA). Fresh and fast urea-TLC and AgNO3-TLC plate making techniques were developed with more even coating and less coating material contamination before being utilized for separation. Goat milk fat was used as a model. Various experimental parameters that affect urea-TLC and AgNO3-TLC separation of BCFA were investigated and optimized, including coating of urea, concentration of original oil sample, mobile phase and sample application format. High efficiency of removal of straight chain FA was achieved with a low amount of sample in an easy and fast way. A total BCFA mix with much higher purity than previous studies was successfully achieved. The developed method has also been applied for the concentration and analysis of BCFA in cow milk fat and Anchovy oil. PMID:26614174

  14. Native protein mapping and visualization of protein interactions in the area of human plasma high-density lipoprotein by combining nondenaturing micro 2DE and quantitative LC-MS/MS.

    PubMed

    Jin, Ya; Bu, Shujie; Zhang, Jun; Yuan, Qi; Manabe, Takashi; Tan, Wen

    2014-07-01

    A human plasma sample was subjected to nondenaturing micro 2DE and a gel area (5 mm × 18 mm) that includes high-density lipoprotein (HDL) was cut into 1 mm × 1 mm squares, then the proteins in the 90 gel pieces were analyzed by quantitative LC-MS/MS. Grid-cutting of the gel was employed to; (i) ensure the total analysis of the proteins in the area, (ii) standardize the conditions of analysis by LC-MS/MS, (iii) reconstruct the protein distribution patterns from the quantity data. Totally 154 proteins were assigned in the 90 gel pieces and the quantity distribution of each was reconstructed as a color density pattern (a native protein map). The map of apolipoprotein (Apo) A-I showed a wide apparent mass distribution characteristic to HDL and was compared with the maps of the other 153 proteins. Eleven proteins showed maps of wide distribution that overlapped with the map of Apo A-I, and all have been reported to be the components of HDL. Further, seven minor proteins associated with HDL were detected at the gel positions of high Apo A-I quantity. These results for the first time visualized the localization of HDL apolipoproteins on a nondenaturing 2DE gel and strongly suggested their interactions. PMID:24668886

  15. Search for Bs0 --> micro+ micro- and B0 --> micro+ micro- decays with 2 fb-1 of pp collisions.

    PubMed

    Aaltonen, T; Adelman, J; Akimoto, T; Albrow, M G; Alvarez González, B; Amerio, S; Amidei, D; Anastassov, A; Annovi, A; Antos, J; Aoki, M; Apollinari, G; Apresyan, A; Arisawa, T; Artikov, A; Ashmanskas, W; Attal, A; Aurisano, A; Azfar, F; Azzi-Bacchetta, P; Azzurri, P; Bacchetta, N; Badgett, W; Barbaro-Galtieri, A; Barnes, V E; Barnett, B A; Baroiant, S; Bartsch, V; Bauer, G; Beauchemin, P-H; Bedeschi, F; Bednar, P; Behari, S; Bellettini, G; Bellinger, J; Belloni, A; Benjamin, D; Beretvas, A; Beringer, J; Berry, T; Bhatti, A; Binkley, M; Bisello, D; Bizjak, I; Blair, R E; Blocker, C; Blumenfeld, B; Bocci, A; Bodek, A; Boisvert, V; Bolla, G; Bolshov, A; Bortoletto, D; Boudreau, J; Boveia, A; Brau, B; Bridgeman, A; Brigliadori, L; Bromberg, C; Brubaker, E; Budagov, J; Budd, H S; Budd, S; Burkett, K; Busetto, G; Bussey, P; Buzatu, A; Byrum, K L; Cabrera, S; Campanelli, M; Campbell, M; Canelli, F; Canepa, A; Carlsmith, D; Carosi, R; Carrillo, S; Carron, S; Casal, B; Casarsa, M; Castro, A; Catastini, P; Cauz, D; Cavalli-Sforza, M; Cerri, A; Cerrito, L; Chang, S H; Chen, Y C; Chertok, M; Chiarelli, G; Chlachidze, G; Chlebana, F; Cho, K; Chokheli, D; Chou, J P; Choudalakis, G; Chuang, S H; Chung, K; Chung, W H; Chung, Y S; Ciobanu, C I; Ciocci, M A; Clark, A; Clark, D; Compostella, G; Convery, M E; Conway, J; Cooper, B; Copic, K; Cordelli, M; Cortiana, G; Crescioli, F; Cuenca Almenar, C; Cuevas, J; Culbertson, R; Cully, J C; Dagenhart, D; Datta, M; Davies, T; de Barbaro, P; De Cecco, S; Deisher, A; De Lentdecker, G; De Lorenzo, G; Dell'orso, M; Demortier, L; Deng, J; Deninno, M; De Pedis, D; Derwent, P F; Di Giovanni, G P; Dionisi, C; Di Ruzza, B; Dittmann, J R; D'Onofrio, M; Donati, S; Dong, P; Donini, J; Dorigo, T; Dube, S; Efron, J; Erbacher, R; Errede, D; Errede, S; Eusebi, R; Fang, H C; Farrington, S; Fedorko, W T; Feild, R G; Feindt, M; Fernandez, J P; Ferrazza, C; Field, R; Flanagan, G; Forrest, R; Forrester, S; Franklin, M; Freeman, J C; Furic, I; Gallinaro, M; Galyardt, J; Garberson, F; Garcia, J E; Garfinkel, A F; Genser, K; Gerberich, H; Gerdes, D; Giagu, S; Giakoumopolou, V; Giannetti, P; Gibson, K; Gimmell, J L; Ginsburg, C M; Giokaris, N; Giordani, M; Giromini, P; Giunta, M; Glagolev, V; Glenzinski, D; Gold, M; Goldschmidt, N; Golossanov, A; Gomez, G; Gomez-Ceballos, G; Goncharov, M; González, O; Gorelov, I; Goshaw, A T; Goulianos, K; Gresele, A; Grinstein, S; Grosso-Pilcher, C; Grundler, U; Guimaraes da Costa, J; Gunay-Unalan, Z; Haber, C; Hahn, K; Hahn, S R; Halkiadakis, E; Hamilton, A; Han, B-Y; Han, J Y; Handler, R; Happacher, F; Hara, K; Hare, D; Hare, M; Harper, S; Harr, R F; Harris, R M; Hartz, M; Hatakeyama, K; Hauser, J; Hays, C; Heck, M; Heijboer, A; Heinemann, B; Heinrich, J; Henderson, C; Herndon, M; Heuser, J; Hewamanage, S; Hidas, D; Hill, C S; Hirschbuehl, D; Hocker, A; Hou, S; Houlden, M; Hsu, S-C; Huffman, B T; Hughes, R E; Husemann, U; Huston, J; Incandela, J; Introzzi, G; Iori, M; Ivanov, A; Iyutin, B; James, E; Jayatilaka, B; Jeans, D; Jeon, E J; Jindariani, S; Johnson, W; Jones, M; Joo, K K; Jun, S Y; Jung, J E; Junk, T R; Kamon, T; Kar, D; Karchin, P E; Kato, Y; Kephart, R; Kerzel, U; Khotilovich, V; Kilminster, B; Kim, D H; Kim, H S; Kim, J E; Kim, M J; Kim, S B; Kim, S H; Kim, Y K; Kimura, N; Kirsch, L; Klimenko, S; Klute, M; Knuteson, B; Ko, B R; Koay, S A; Kondo, K; Kong, D J; Konigsberg, J; Korytov, A; Kotwal, A V; Kraus, J; Kreps, M; Kroll, J; Krumnack, N; Kruse, M; Krutelyov, V; Kubo, T; Kuhlmann, S E; Kuhr, T; Kulkarni, N P; Kusakabe, Y; Kwang, S; Laasanen, A T; Lai, S; Lami, S; Lammel, S; Lancaster, M; Lander, R L; Lannon, K; Lath, A; Latino, G; Lazzizzera, I; Lecompte, T; Lee, J; Lee, J; Lee, Y J; Lee, S W; Lefèvre, R; Leonardo, N; Leone, S; Levy, S; Lewis, J D; Lin, C; Lin, C S; Linacre, J; Lindgren, M; Lipeles, E; Lister, A; Litvintsev, D O; Liu, T; Lockyer, N S; Loginov, A; Loreti, M; Lovas, L; Lu, R-S; Lucchesi, D; Lueck, J; Luci, C; Lujan, P; Lukens, P; Lungu, G; Lyons, L; Lys, J; Lysak, R; Lytken, E; Mack, P; Macqueen, D; Madrak, R; Maeshima, K; Makhoul, K; Maki, T; Maksimovic, P; Malde, S; Malik, S; Manca, G; Manousakis, A; Margaroli, F; Marino, C; Marino, C P; Martin, A; Martin, M; Martin, V; Martínez, M; Martínez-Ballarín, R; Maruyama, T; Mastrandrea, P; Masubuchi, T; Mattson, M E; Mazzanti, P; McFarland, K S; McIntyre, P; McNulty, R; Mehta, A; Mehtala, P; Menzemer, S; Menzione, A; Merkel, P; Mesropian, C; Messina, A; Miao, T; Miladinovic, N; Miles, J; Miller, R; Mills, C; Milnik, M; Mitra, A; Mitselmakher, G; Miyake, H; Moed, S; Moggi, N; Moon, C S; Moore, R; Morello, M; Movilla Fernandez, P; Mülmenstädt, J; Mukherjee, A; Muller, Th; Mumford, R; Murat, P; Mussini, M; Nachtman, J; Nagai, Y; Nagano, A; Naganoma, J; Nakamura, K; Nakano, I; Napier, A; Necula, V; Neu, C; Neubauer, M S; Nielsen, J; Nodulman, L; Norman, M; Norniella, O; Nurse, E; Oh, S H; Oh, Y D; Oksuzian, I; Okusawa, T; Oldeman, R; Orava, R; Osterberg, K; Pagan Griso, S; Pagliarone, C; Palencia, E; Papadimitriou, V; Papaikonomou, A; Paramonov, A A; Parks, B; Pashapour, S; Patrick, J; Pauletta, G; Paulini, M; Paus, C; Pellett, D E; Penzo, A; Phillips, T J; Piacentino, G; Piedra, J; Pinera, L; Pitts, K; Plager, C; Pondrom, L; Portell, X; Poukhov, O; Pounder, N; Prakoshyn, F; Pronko, A; Proudfoot, J; Ptohos, F; Punzi, G; Pursley, J; Rademacker, J; Rahaman, A; Ramakrishnan, V; Ranjan, N; Redondo, I; Reisert, B; Rekovic, V; Renton, P; Rescigno, M; Richter, S; Rimondi, F; Ristori, L; Robson, A; Rodrigo, T; Rogers, E; Rolli, S; Roser, R; Rossi, M; Rossin, R; Roy, P; Ruiz, A; Russ, J; Rusu, V; Saarikko, H; Safonov, A; Sakumoto, W K; Salamanna, G; Saltó, O; Santi, L; Sarkar, S; Sartori, L; Sato, K; Savoy-Navarro, A; Scheidle, T; Schlabach, P; Schmidt, E E; Schmidt, M A; Schmidt, M P; Schmitt, M; Schwarz, T; Scodellaro, L; Scott, A L; Scribano, A; Scuri, F; Sedov, A; Seidel, S; Seiya, Y; Semenov, A; Sexton-Kennedy, L; Sfyria, A; Shalhout, S Z; Shapiro, M D; Shears, T; Shepard, P F; Sherman, D; Shimojima, M; Shochet, M; Shon, Y; Shreyber, I; Sidoti, A; Sinervo, P; Sisakyan, A; Slaughter, A J; Slaunwhite, J; Sliwa, K; Smith, J R; Snider, F D; Snihur, R; Soderberg, M; Soha, A; Somalwar, S; Sorin, V; Spalding, J; Spinella, F; Spreitzer, T; Squillacioti, P; Stanitzki, M; St Denis, R; Stelzer, B; Stelzer-Chilton, O; Stentz, D; Strologas, J; Stuart, D; Suh, J S; Sukhanov, A; Sun, H; Suslov, I; Suzuki, T; Taffard, A; Takashima, R; Takeuchi, Y; Tanaka, R; Tecchio, M; Teng, P K; Terashi, K; Thom, J; Thompson, A S; Thompson, G A; Thomson, E; Tipton, P; Tiwari, V; Tkaczyk, S; Toback, D; Tokar, S; Tollefson, K; Tomura, T; Tonelli, D; Torre, S; Torretta, D; Tourneur, S; Trischuk, W; Tu, Y; Turini, N; Ukegawa, F; Uozumi, S; Vallecorsa, S; van Remortel, N; Varganov, A; Vataga, E; Vázquez, F; Velev, G; Vellidis, C; Veszpremi, V; Vidal, M; Vidal, R; Vila, I; Vilar, R; Vine, T; Vogel, M; Volobouev, I; Volpi, G; Würthwein, F; Wagner, P; Wagner, R G; Wagner, R L; Wagner-Kuhr, J; Wagner, W; Wakisaka, T; Wallny, R; Wang, S M; Warburton, A; Waters, D; Weinberger, M; Wester, W C; Whitehouse, B; Whiteson, D; Wicklund, A B; Wicklund, E; Williams, G; Williams, H H; Wilson, P; Winer, B L; Wittich, P; Wolbers, S; Wolfe, C; Wright, T; Wu, X; Wynne, S M; Yagil, A; Yamamoto, K; Yamaoka, J; Yamashita, T; Yang, C; Yang, U K; Yang, Y C; Yao, W M; Yeh, G P; Yoh, J; Yorita, K; Yoshida, T; Yu, G B; Yu, I; Yu, S S; Yun, J C; Zanello, L; Zanetti, A; Zaw, I; Zhang, X; Zheng, Y; Zucchelli, S

    2008-03-14

    We have performed a search for B(s)(0) --> micro(+) micro(-) and B(0) --> micro(+) micro(-) decays in pp collisions at square root s = 1.96 TeV using 2 fb(-1) of integrated luminosity collected by the CDF II detector at the Fermilab Tevatron Collider. The observed number of B(s)(0) and B0 candidates is consistent with background expectations. The resulting upper limits on the branching fractions are B(B(s)0) --> micro(+) micro(-)) <5.8 x 10(-8) and B(B(0) --> micro(+) micro(-))<1.8 x 10(-8) at 95% C.L. PMID:18352173

  16. Proteomic analysis of cellular soluble proteins from human bronchial smooth muscle cells by combining nondenaturing micro 2DE and quantitative LC-MS/MS. 1. Preparation of more than 4000 native protein maps.

    PubMed

    Jin, Ya; Zhang, Jun; Yuan, Qi; Manabe, Takashi; Tan, Wen

    2015-08-01

    Soluble proteins of human bronchial smooth muscle cells (HBSMC) were separated by nondenaturing micro 2DE and a 30 mm × 40 mm area of the CBB-stained slab gel (1.0 mm thick) was cut into 1.1 mm × 1.1 mm squares, then the proteins in the 972 gel pieces (squares) were applied to quantitative LC-MS/MS. Grid-cutting of the gel was employed to; (i) ensure the total analysis of the proteins in the area, (ii) standardize the conditions of analysis by LC-MS/MS, (iii) reconstruct the protein distribution patterns from the quantity data [1]. Totally 4323 proteins were identified in successfully analyzed 967 squares and the quantity distribution of each was reconstructed as a color density pattern (a native protein map). The quantity of the proteins distributed from 3.6% to 1 × 10(-5) % of the total protein quantity in the grid area. Each protein map was characterized by several features, including the position of quantity peak square, number of detected squares, and degree of concentration (focused or dispersed). About 4% of the proteins were detected in 100 or more squares, suggesting that they might be ubiquitous and interacting with other proteins. In contrast, many proteins showed more concentrated quantity distribution and the quantity peak positions of 565 proteins with a defined degree of concentration were summarized into a quantity peak map. These results for the first time visualized the distribution patterns of cellular proteins on a nondenaturing 2D gel. PMID:25931155

  17. Micro-algal biosensors.

    PubMed

    Brayner, Roberta; Couté, Alain; Livage, Jacques; Perrette, Catherine; Sicard, Clémence

    2011-08-01

    Fighting against water pollution requires the ability to detect pollutants for example herbicides or heavy metals. Micro-algae that live in marine and fresh water offer a versatile solution for the construction of novel biosensors. These photosynthetic microorganisms are very sensitive to changes in their environment, enabling the detection of traces of pollutants. Three groups of micro-algae are described in this paper: chlorophyta, cyanobacteria, and diatoms. PMID:21626188

  18. Chlorophenol's ultra-trace analysis in environmental samples by chitosan-zinc oxide nanorod composite as a novel coating for solid phase micro-extraction combined with high performance liquid chromatography.

    PubMed

    Alizadeh, Reza

    2016-01-01

    In this study, a simple, novel, and efficient preconcentration method has been developed for the determination of some chlorophenols (4-chlorophenol, 2,5-dichlorophenol, 2,3-dichlorophenol, and 2,4,6-trichlorophenol) using a direct solid phase microextraction (D-SPME) based on chitosan-ZnO nanorod composite combined with high performance liquid chromatography (HPLC). A one step-novel hydrothermal method was demonstrated on the fabrication of ZnO nanorods arrayed on the fused silica fiber in the chitosan hydrogel solution (CZNC) as a new coating of SPME fiber. The coating was characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) instruments. The CZNC coating has combined the merits of both ZnO nanorods and chitosan hydrogel; it has several improvements such as increased extraction efficiency of chlorophenols and longer life time (over 80 cycles of D-SPME-HPLC operation). Experimental design method was used for optimization of extraction conditions and determination of four chlorophenols in water samples by SPME-HPLC-UV method. The calibration curves were linear from 5 to 1000 µg L(-1) for analytes, and the limits of detection were between 0.1 and 2 µg L(-1). Single fiber repeatability and fiber-to-fiber reproducibility were in the range of 5.8-10.2% and 8.8-14.5%, respectively. The spiked recoveries at 50 µg L(-1) for environmental water sample were in the range of 93-102%. PMID:26695336

  19. Full-field optical micro-angiography

    NASA Astrophysics Data System (ADS)

    Wang, Mingyi; Zeng, Yaguang; Liang, Xianjun; Lu, Xuanlong; Feng, Guanping; Han, Dingan; Yang, Guojian

    2014-02-01

    We present a detailed description of full-field optical micro-angiography on the basis of frequency-domain laser speckle imaging with intensity fluctuation modulation (LSI-IFM). The imaging approach works based on the instantaneous local intensity fluctuation realized via the combination of short exposure and low sampling rate of a camera and appropriate magnification of a microscope. In vivo experiments on mouse ear verify the theoretical description we made for the imaging mechanism and demonstrate the ability of LSI-IFM as optical micro-angiography. By introducing a fundus camera into LSI-IFM system, our approach has a potential application in label-free retina optical micro-angiography.

  20. Laser based micro forming and assembly.

    SciTech Connect

    MacCallum, Danny O'Neill; Wong, Chung-Nin Channy; Knorovsky, Gerald Albert; Steyskal, Michele D.; Lehecka, Tom; Scherzinger, William Mark; Palmer, Jeremy Andrew

    2006-11-01

    It has been shown that thermal energy imparted to a metallic substrate by laser heating induces a transient temperature gradient through the thickness of the sample. In favorable conditions of laser fluence and absorptivity, the resulting inhomogeneous thermal strain leads to a measurable permanent deflection. This project established parameters for laser micro forming of thin materials that are relevant to MESA generation weapon system components and confirmed methods for producing micrometer displacements with repeatable bend direction and magnitude. Precise micro forming vectors were realized through computational finite element analysis (FEA) of laser-induced transient heating that indicated the optimal combination of laser heat input relative to the material being heated and its thermal mass. Precise laser micro forming was demonstrated in two practical manufacturing operations of importance to the DOE complex: micrometer gap adjustments of precious metal alloy contacts and forming of meso scale cones.

  1. Micro-Expression Recognition Using Color Spaces.

    PubMed

    Wang, Su-Jing; Yan, Wen-Jing; Li, Xiaobai; Zhao, Guoying; Zhou, Chun-Guang; Fu, Xiaolan; Yang, Minghao; Tao, Jianhua

    2015-12-01

    Micro-expressions are brief involuntary facial expressions that reveal genuine emotions and, thus, help detect lies. Because of their many promising applications, they have attracted the attention of researchers from various fields. Recent research reveals that two perceptual color spaces (CIELab and CIELuv) provide useful information for expression recognition. This paper is an extended version of our International Conference on Pattern Recognition paper, in which we propose a novel color space model, tensor independent color space (TICS), to help recognize micro-expressions. In this paper, we further show that CIELab and CIELuv are also helpful in recognizing micro-expressions, and we indicate why these three color spaces achieve better performance. A micro-expression color video clip is treated as a fourth-order tensor, i.e., a four-dimension array. The first two dimensions are the spatial information, the third is the temporal information, and the fourth is the color information. We transform the fourth dimension from RGB into TICS, in which the color components are as independent as possible. The combination of dynamic texture and independent color components achieves a higher accuracy than does that of RGB. In addition, we define a set of regions of interests (ROIs) based on the facial action coding system and calculated the dynamic texture histograms for each ROI. Experiments are conducted on two micro-expression databases, CASME and CASME 2, and the results show that the performances for TICS, CIELab, and CIELuv are better than those for RGB or gray. PMID:26540689

  2. Micro-micro hierarchy replacing micro-nano hierarchy: a precisely controlled way to produce wear-resistant superhydrophobic polymer surfaces.

    PubMed

    Huovinen, Eero; Hirvi, Janne; Suvanto, Mika; Pakkanen, Tapani A

    2012-10-16

    Superhydrophobic polymer surfaces are typically fabricated by combining hierarchical micro-nanostructures. The surfaces have a great technological potential because of their special water-repellent and self-cleaning properties. However, the poor mechanical robustness of such surfaces has severely limited their use in practical applications. This study presents a simple and swift mass production method for manufacturing hierarchically structured polymer surfaces at micrometer scale. Polypropylene surface structuring was done using injection molding, where the microstructured molds were made with a microworking robot. The effect of the micro-microstructuring on the polymer surface wettability and mechanical robustness was studied and compared to the corresponding properties of micro-nanostructured surfaces. The static contact angles of the micro-microstructured surfaces were greater than 150° and the contact angle hysteresis was low, showing that the effect of hierarchy on the surface wetting properties works equally well at micrometer scale. Hierarchically micro-microstructured polymer surfaces exhibited the same superhydrophobic wetting properties as did the hierarchically micro-nanostructured surfaces. Micro-microstructures had superior mechanical robustness in wear tests as compared to the micro-nanostructured surfaces. The new microstructuring technique offers a precisely controlled way to produce superhydrophobic wetting properties to injection moldable polymers with sufficiently high intrinsic hydrophobicity. PMID:23009694

  3. Micro heat barrier

    DOEpatents

    Marshall, Albert C.; Kravitz, Stanley H.; Tigges, Chris P.; Vawter, Gregory A.

    2003-08-12

    A highly effective, micron-scale micro heat barrier structure and process for manufacturing a micro heat barrier based on semiconductor and/or MEMS fabrication techniques. The micro heat barrier has an array of non-metallic, freestanding microsupports with a height less than 100 microns, attached to a substrate. An infrared reflective membrane (e.g., 1 micron gold) can be supported by the array of microsupports to provide radiation shielding. The micro heat barrier can be evacuated to eliminate gas phase heat conduction and convection. Semi-isotropic, reactive ion plasma etching can be used to create a microspike having a cusp-like shape with a sharp, pointed tip (<0.1 micron), to minimize the tip's contact area. A heat source can be placed directly on the microspikes. The micro heat barrier can have an apparent thermal conductivity in the range of 10.sup.-6 to 10.sup.-7 W/m-K. Multiple layers of reflective membranes can be used to increase thermal resistance.

  4. Gas-surface interactions using accommodation coefficients for a dilute and a dense gas in a micro- or nanochannel: heat flux predictions using combined molecular dynamics and Monte Carlo techniques.

    PubMed

    Nedea, S V; van Steenhoven, A A; Markvoort, A J; Spijker, P; Giordano, D

    2014-05-01

    The influence of gas-surface interactions of a dilute gas confined between two parallel walls on the heat flux predictions is investigated using a combined Monte Carlo (MC) and molecular dynamics (MD) approach. The accommodation coefficients are computed from the temperature of incident and reflected molecules in molecular dynamics and used as effective coefficients in Maxwell-like boundary conditions in Monte Carlo simulations. Hydrophobic and hydrophilic wall interactions are studied, and the effect of the gas-surface interaction potential on the heat flux and other characteristic parameters like density and temperature is shown. The heat flux dependence on the accommodation coefficient is shown for different fluid-wall mass ratios. We find that the accommodation coefficient is increasing considerably when the mass ratio is decreased. An effective map of the heat flux depending on the accommodation coefficient is given and we show that MC heat flux predictions using Maxwell boundary conditions based on the accommodation coefficient give good results when compared to pure molecular dynamics heat predictions. The accommodation coefficients computed for a dilute gas for different gas-wall interaction parameters and mass ratios are transferred to compute the heat flux predictions for a dense gas. Comparison of the heat fluxes derived using explicit MD, MC with Maxwell-like boundary conditions based on the accommodation coefficients, and pure Maxwell boundary conditions are discussed. A map of the heat flux dependence on the accommodation coefficients for a dense gas, and the effective accommodation coefficients for different gas-wall interactions are given. In the end, this approach is applied to study the gas-surface interactions of argon and xenon molecules on a platinum surface. The derived accommodation coefficients are compared with values of experimental results. PMID:25353885

  5. Silicon micro-mold

    DOEpatents

    Morales, Alfredo M.

    2006-10-24

    The present invention describes a method for rapidly fabricating a robust 3-dimensional silicon-mold for use in preparing complex metal micro-components. The process begins by depositing a conductive metal layer onto one surface of a silicon wafer. A thin photoresist and a standard lithographic mask are then used to transfer a trace image pattern onto the opposite surface of the wafer by exposing and developing the resist. The exposed portion of the silicon substrate is anisotropically etched through the wafer thickness down to conductive metal layer to provide an etched pattern consisting of a series of rectilinear channels and recesses in the silicon which serve as the silicon micro-mold. Microcomponents are prepared with this mold by first filling the mold channels and recesses with a metal deposit, typically by electroplating, and then removing the silicon micro-mold by chemical etching.

  6. Micro-machining.

    PubMed

    Brinksmeier, Ekkard; Preuss, Werner

    2012-08-28

    Manipulating bulk material at the atomic level is considered to be the domain of physics, chemistry and nanotechnology. However, precision engineering, especially micro-machining, has become a powerful tool for controlling the surface properties and sub-surface integrity of the optical, electronic and mechanical functional parts in a regime where continuum mechanics is left behind and the quantum nature of matter comes into play. The surprising subtlety of micro-machining results from the extraordinary precision of tools, machines and controls expanding into the nanometre range-a hundred times more precise than the wavelength of light. In this paper, we will outline the development of precision engineering, highlight modern achievements of ultra-precision machining and discuss the necessity of a deeper physical understanding of micro-machining. PMID:22802498

  7. Micro-machined resonator

    DOEpatents

    Godshall, N.A.; Koehler, D.R.; Liang, A.Y.; Smith, B.K.

    1993-03-30

    A micro-machined resonator, typically quartz, with upper and lower micro-machinable support members, or covers, having etched wells which may be lined with conductive electrode material, between the support members is a quartz resonator having an energy trapping quartz mesa capacitively coupled to the electrode through a diaphragm; the quartz resonator is supported by either micro-machined cantilever springs or by thin layers extending over the surfaces of the support. If the diaphragm is rigid, clock applications are available, and if the diaphragm is resilient, then transducer applications can be achieved. Either the thin support layers or the conductive electrode material can be integral with the diaphragm. In any event, the covers are bonded to form a hermetic seal and the interior volume may be filled with a gas or may be evacuated. In addition, one or both of the covers may include oscillator and interface circuitry for the resonator.

  8. Micro-machined resonator

    DOEpatents

    Godshall, Ned A.; Koehler, Dale R.; Liang, Alan Y.; Smith, Bradley K.

    1993-01-01

    A micro-machined resonator, typically quartz, with upper and lower micro-machinable support members, or covers, having etched wells which may be lined with conductive electrode material, between the support members is a quartz resonator having an energy trapping quartz mesa capacitively coupled to the electrode through a diaphragm; the quartz resonator is supported by either micro-machined cantilever springs or by thin layers extending over the surfaces of the support. If the diaphragm is rigid, clock applications are available, and if the diaphragm is resilient, then transducer applications can be achieved. Either the thin support layers or the conductive electrode material can be integral with the diaphragm. In any event, the covers are bonded to form a hermetic seal and the interior volume may be filled with a gas or may be evacuated. In addition, one or both of the covers may include oscillator and interface circuitry for the resonator.

  9. Micro-Organ Devices

    NASA Technical Reports Server (NTRS)

    Gonda, Steven R.; Leslie, Julia; Chang, Robert C.; Starly, Binil; Sun, Wei; Culbertson, Christopher; Holtorf, Heidi

    2009-01-01

    Micro-organ devices (MODs) are being developed to satisfy an emerging need for small, lightweight, reproducible, biological-experimentati on apparatuses that are amenable to automated operation and that imp ose minimal demands for resources (principally, power and fluids). I n simplest terms, a MOD is a microfluidic device containing a variety of microstructures and assemblies of cells, all designed to mimic a complex in vivo microenvironment by replicating one or more in vivo micro-organ structures, the architectures and composition of the extr acellular matrices in the organs of interest, and the in vivo fluid flows. In addition to microscopic flow channels, a MOD contains one or more micro-organ wells containing cells residing in microscopic e xtracellular matrices and/or scaffolds, the shapes and compositions o f which enable replication of the corresponding in vivo cell assembl ies and flows.

  10. Method of fabricating a micro machine

    DOEpatents

    Stalford, Harold L

    2014-11-11

    A micro machine may be in or less than the micrometer domain. The micro machine may include a micro actuator and a micro shaft coupled to the micro actuator. The micro shaft is operable to be driven by the micro actuator. A tool is coupled to the micro shaft and is operable to perform work in response to at least motion of the micro shaft.

  11. Extracting and analyzing micro-Doppler from ladar signatures

    NASA Astrophysics Data System (ADS)

    Tahmoush, Dave

    2015-05-01

    Ladar and other 3D imaging modalities have the capability of creating 3D micro-Doppler to analyze the micro-motions of human subjects. An additional capability to the recognition of micro-motion is the recognition of the moving part, such as the hand or arm. Combined with measured RCS values of the body, ladar imaging can be used to ground-truth the more sensitive radar micro-Doppler measurements and associate the moving part of the subject with the measured Doppler and RCS from the radar system. The 3D ladar signatures can also be used to classify activities and actions on their own, achieving an 86% accuracy using a micro-Doppler based classification strategy.

  12. Structure of catalase determined by MicroED.

    PubMed

    Nannenga, Brent L; Shi, Dan; Hattne, Johan; Reyes, Francis E; Gonen, Tamir

    2014-01-01

    MicroED is a recently developed method that uses electron diffraction for structure determination from very small three-dimensional crystals of biological material. Previously we used a series of still diffraction patterns to determine the structure of lysozyme at 2.9 Å resolution with MicroED (Shi et al., 2013). Here we present the structure of bovine liver catalase determined from a single crystal at 3.2 Å resolution by MicroED. The data were collected by continuous rotation of the sample under constant exposure and were processed and refined using standard programs for X-ray crystallography. The ability of MicroED to determine the structure of bovine liver catalase, a protein that has long resisted atomic analysis by traditional electron crystallography, demonstrates the potential of this method for structure determination. PMID:25303172

  13. Three-dimensional mapping of soil chemical characteristics at micrometric scale: Statistical prediction by combining 2D SEM-EDX data and 3D X-ray computed micro-tomographic images

    NASA Astrophysics Data System (ADS)

    Hapca, Simona

    2015-04-01

    Many soil properties and functions emerge from interactions of physical, chemical and biological processes at microscopic scales, which can be understood only by integrating techniques that traditionally are developed within separate disciplines. While recent advances in imaging techniques, such as X-ray computed tomography (X-ray CT), offer the possibility to reconstruct the 3D physical structure at fine resolutions, for the distribution of chemicals in soil, existing methods, based on scanning electron microscope (SEM) and energy dispersive X-ray detection (EDX), allow for characterization of the chemical composition only on 2D surfaces. At present, direct 3D measurement techniques are still lacking, sequential sectioning of soils, followed by 2D mapping of chemical elements and interpolation to 3D, being an alternative which is explored in this study. Specifically, we develop an integrated experimental and theoretical framework which combines 3D X-ray CT imaging technique with 2D SEM-EDX and use spatial statistics methods to map the chemical composition of soil in 3D. The procedure involves three stages 1) scanning a resin impregnated soil cube by X-ray CT, followed by precision cutting to produce parallel thin slices, the surfaces of which are scanned by SEM-EDX, 2) alignment of the 2D chemical maps within the internal 3D structure of the soil cube, and 3) development, of spatial statistics methods to predict the chemical composition of 3D soil based on the observed 2D chemical and 3D physical data. Specifically, three statistical models consisting of a regression tree, a regression tree kriging and cokriging model were used to predict the 3D spatial distribution of carbon, silicon, iron and oxygen in soil, these chemical elements showing a good spatial agreement between the X-ray grayscale intensities and the corresponding 2D SEM-EDX data. Due to the spatial correlation between the physical and chemical data, the regression-tree model showed a great potential

  14. Coherent Synchrotron-Based Micro-Imaging Employed for Studies of Micro-Gap Formation in Dental Implants

    NASA Astrophysics Data System (ADS)

    Rack, T.; Zabler, S.; Rack, A.; Stiller, M.; Riesemeier, H.; Cecilia, A.; Nelson, K.

    2011-09-01

    Biocompatible materials such as titanium are regularly applied in oral surgery. Titanium-based implants for the replacement of missing teeth demand a high mechanical precision in order to minimize micro-bacterial leakage, especially when two-piece concepts are used. Synchrotron-based hard x-ray radiography, unlike conventional laboratory radiography, allows high spatial resolution in combination with high contrast even when micro-sized features in such highly attenuating objects are visualized. Therefore, micro-gap formation at interfaces in two-piece dental implants with the sample under different mechanical loads can be studied. We show the existence of micro-gaps in implants with conical connections and study the mechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential source of implant failure, i.e., bacterial leakage, which can be a stimulus for an inflammatory process.

  15. Coherent Synchrotron-Based Micro-Imaging Employed for Studies of Micro-Gap Formation in Dental Implants

    SciTech Connect

    Rack, T.; Stiller, M.; Nelson, K.; Zabler, S.; Rack, A.; Riesemeier, H.; Cecilia, A.

    2011-09-09

    Biocompatible materials such as titanium are regularly applied in oral surgery. Titanium-based implants for the replacement of missing teeth demand a high mechanical precision in order to minimize micro-bacterial leakage, especially when two-piece concepts are used. Synchrotron-based hard x-ray radiography, unlike conventional laboratory radiography, allows high spatial resolution in combination with high contrast even when micro-sized features in such highly attenuating objects are visualized. Therefore, micro-gap formation at interfaces in two-piece dental implants with the sample under different mechanical loads can be studied. We show the existence of micro-gaps in implants with conical connections and study the mechanical behavior of the mating zone of conical implants during loading. The micro-gap is a potential source of implant failure, i.e., bacterial leakage, which can be a stimulus for an inflammatory process.

  16. Eye vision system using programmable micro-optics and micro-electronics

    NASA Astrophysics Data System (ADS)

    Riza, Nabeel A.; Amin, M. Junaid; Riza, Mehdi N.

    2014-02-01

    Proposed is a novel eye vision system that combines the use of advanced micro-optic and microelectronic technologies that includes programmable micro-optic devices, pico-projectors, Radio Frequency (RF) and optical wireless communication and control links, energy harvesting and storage devices and remote wireless energy transfer capabilities. This portable light weight system can measure eye refractive powers, optimize light conditions for the eye under test, conduct color-blindness tests, and implement eye strain relief and eye muscle exercises via time sequenced imaging. Described is the basic design of the proposed system and its first stage system experimental results for vision spherical lens refractive error correction.

  17. The Micro-Shop.

    ERIC Educational Resources Information Center

    Steele, Barbara

    1992-01-01

    To reduce teacher isolation and encourage sharing of expertise, schools should consider brief workshops or 15-minute "micro-shops" on various topics ranging from making electrical circuit boards to setting up a salt-water aquarium. This article and accompanying sidebar discuss benefits and set-up strategies. (MLH)

  18. Micro acoustic spectrum analyzer

    DOEpatents

    Schubert, W. Kent; Butler, Michael A.; Adkins, Douglas R.; Anderson, Larry F.

    2004-11-23

    A micro acoustic spectrum analyzer for determining the frequency components of a fluctuating sound signal comprises a microphone to pick up the fluctuating sound signal and produce an alternating current electrical signal; at least one microfabricated resonator, each resonator having a different resonant frequency, that vibrate in response to the alternating current electrical signal; and at least one detector to detect the vibration of the microfabricated resonators. The micro acoustic spectrum analyzer can further comprise a mixer to mix a reference signal with the alternating current electrical signal from the microphone to shift the frequency spectrum to a frequency range that is a better matched to the resonant frequencies of the microfabricated resonators. The micro acoustic spectrum analyzer can be designed specifically for portability, size, cost, accuracy, speed, power requirements, and use in a harsh environment. The micro acoustic spectrum analyzer is particularly suited for applications where size, accessibility, and power requirements are limited, such as the monitoring of industrial equipment and processes, detection of security intrusions, or evaluation of military threats.

  19. Miniature modified Faraday cup for micro electron beams

    DOEpatents

    Teruya, Alan T.; Elmer, John W.; Palmer, Todd A.; Walton, Chris C.

    2008-05-27

    A micro beam Faraday cup assembly includes a refractory metal layer with an odd number of thin, radially positioned traces in this refractory metal layer. Some of the radially positioned traces are located at the edge of the micro modified Faraday cup body and some of the radially positioned traces are located in the central portion of the micro modified Faraday cup body. Each set of traces is connected to a separate data acquisition channel to form multiple independent diagnostic networks. The data obtained from the two diagnostic networks are combined and inputted into a computed tomography algorithm to reconstruct the beam shape, size, and power density distribution.

  20. Rotary Apparatus Concentrates And Separates Micro-Organisms

    NASA Technical Reports Server (NTRS)

    Noever, David A.

    1992-01-01

    Apparatus concentrates and separates swimming micro-organisms of different species into concentric rings in fluid. Fluid containing high concentration of desired species removed by use of small scoop placed into fluid at radius of one of rings formed by that species. Micro-organisms concentrated into concentric rings by combined dynamic effects of upward and horizontal components of swimming, rotation of dish, gravitation, and viscosity.

  1. Micro-turbo-generator design and fabrication: A preliminary study

    SciTech Connect

    Wiegele, T.G.

    1996-12-31

    The size and weight of portable electronic products are often dictated by the physical characteristics of the power supply system. The design of energy storage systems is therefore critical to market competitiveness. An alternative to energy storage is proposed in this paper which relies on a very small power generation system which converts a pressure difference in a gas into electrical power: a micro-turbo-generator. The design of the micro-turbo-generator involved combining two very different machines, a micro-generator and a micro-turbine, into a single device which could be fabricated within the constraints of current microelectronic processing techniques. Research into power generation on the micro-scale has begun to take place in the form of electromagnetic micro-motor design and fabrication. These variable reluctance machines can be transformed into power generation devices by implementing accurate rotor position sensing, high-speed current switching and a means for inducing rotor motion. This leads to the implementation of a switched reluctance generator, which is well-understood on the macro-scale but has not been attempted on the micro-scale. The most significant hurdle facing researchers is the task of coupling a prime mover, such as a micro-turbine, to the rotor of a power generation device efficiently and effectively while maintaining relative simplicity in the fabrication procedures. The design presented here offers a potential solution to this problem.

  2. Accurate microRNA target prediction correlates with protein repression levels

    PubMed Central

    Maragkakis, Manolis; Alexiou, Panagiotis; Papadopoulos, Giorgio L; Reczko, Martin; Dalamagas, Theodore; Giannopoulos, George; Goumas, George; Koukis, Evangelos; Kourtis, Kornilios; Simossis, Victor A; Sethupathy, Praveen; Vergoulis, Thanasis; Koziris, Nectarios; Sellis, Timos; Tsanakas, Panagiotis; Hatzigeorgiou, Artemis G

    2009-01-01

    Background MicroRNAs are small endogenously expressed non-coding RNA molecules that regulate target gene expression through translation repression or messenger RNA degradation. MicroRNA regulation is performed through pairing of the microRNA to sites in the messenger RNA of protein coding genes. Since experimental identification of miRNA target genes poses difficulties, computational microRNA target prediction is one of the key means in deciphering the role of microRNAs in development and disease. Results DIANA-microT 3.0 is an algorithm for microRNA target prediction which is based on several parameters calculated individually for each microRNA and combines conserved and non-conserved microRNA recognition elements into a final prediction score, which correlates with protein production fold change. Specifically, for each predicted interaction the program reports a signal to noise ratio and a precision score which can be used as an indication of the false positive rate of the prediction. Conclusion Recently, several computational target prediction programs were benchmarked based on a set of microRNA target genes identified by the pSILAC method. In this assessment DIANA-microT 3.0 was found to achieve the highest precision among the most widely used microRNA target prediction programs reaching approximately 66%. The DIANA-microT 3.0 prediction results are available online in a user friendly web server at PMID:19765283

  3. Fused fiber micro-knots.

    PubMed

    Shahal, Shir; Klein, Avi; Masri, Gilad; Fridman, Moti

    2016-06-10

    We present fusing of a fiber micro-knot by a CO2 laser beam. We demonstrate tuning of the coupling strength and tuning of the spectral resonance of the micro-knot by the fusing process. The experimental results reveal that fusing the fiber micro-knots increases the coupling efficiency and improves the robustness and the stability of the micro-knots. PMID:27409009

  4. Breakthrough: micro-electronic photovoltaics

    ScienceCinema

    Okandan, Murat; Gupta, Vipin

    2014-06-23

    Sandia developed tiny glitter-sized photovoltaic (PV) cells that could revolutionize solar energy collection. The crystalline silicon micro-PV cells will be cheaper and have greater efficiencies than current PV collectors. Micro-PV cells require relatively little material to form well-controlled, highly efficient devices. Cell fabrication uses common microelectric and micro-electromechanical systems (MEMS) techniques.

  5. Breakthrough: micro-electronic photovoltaics

    SciTech Connect

    Okandan, Murat; Gupta, Vipin

    2012-04-23

    Sandia developed tiny glitter-sized photovoltaic (PV) cells that could revolutionize solar energy collection. The crystalline silicon micro-PV cells will be cheaper and have greater efficiencies than current PV collectors. Micro-PV cells require relatively little material to form well-controlled, highly efficient devices. Cell fabrication uses common microelectric and micro-electromechanical systems (MEMS) techniques.

  6. Power combiner

    DOEpatents

    Arnold, Mobius; Ives, Robert Lawrence

    2006-09-05

    A power combiner for the combining of symmetric and asymmetric traveling wave energy comprises a feed waveguide having an input port and a launching port, a reflector for reflecting launched wave energy, and a final waveguide for the collection and transport of launched wave energy. The power combiner has a launching port for symmetrical waves which comprises a cylindrical section coaxial to the feed waveguide, and a launching port for asymmetric waves which comprises a sawtooth rotated about a central axis.

  7. Methods and systems for micro bearings

    SciTech Connect

    Stalford, Harold L

    2015-01-27

    A micro drive assembly may comprise a substrate, a micro shaft oriented in-plane with the substrate and at least one micro bearing to support rotation of the micro shaft. The micro shaft and micro bearing may be in or less than the micrometer domain.

  8. Methods and systems for micro transmissions

    DOEpatents

    Stalford, Harold L

    2014-12-23

    Methods and systems for micro transmissions for a micro machine may comprise an input shaft assembly coupled to a micro actuator, an output shaft assembly coupled to a micro shaft, and one or more power conversion elements operable to convert a first type of movement from the micro actuator into a second, disparate type of movement for the micro shaft.

  9. Methods and systems for micro bearings

    SciTech Connect

    Stalford, Harold L.

    2012-10-09

    A micro drive assembly may comprise a substrate, a micro shall oriented in-plane with the substrate and at least one micro bearing to support rotation of the micro shaft. The micro shaft and micro bearing may be in or less than the micrometer domain.

  10. Micro pulse laser radar

    NASA Technical Reports Server (NTRS)

    Spinhirne, James D. (Inventor)

    1993-01-01

    An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering is disclosed. The transmitter of the micro pulse lidar is a diode pumped micro-J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited to optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that micropulse lider systems are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere. The intended applications are scientific studies and environmental monitoring which require full time, unattended measurements of the cloud and aerosol height structure.

  11. Combining micro dry column chromatography and mass spectrometry

    NASA Technical Reports Server (NTRS)

    Bauman, A. J.

    1970-01-01

    Dry column chromatography principles applied in microscale produce technique to minimize time in preparing and analyzing colorless constituents of soluble mixtures. Glass pipette microcolumns filled with finely sieved adsorbents permit capillary attraction and separation in 3 to 15 minutes. Technique is adaptable to gas chromatography.

  12. Scanning micro-sclerometer

    DOEpatents

    Oliver, Warren C.; Blau, Peter J.

    1994-01-01

    A scanning micro-sclerometer measures changes in contact stiffness and correlates these changes to characteristics of a scratch. A known force is applied to a contact junction between two bodies and a technique employing an oscillating force is used to generate the contact stiffness between the two bodies. As the two bodies slide relative to each other, the contact stiffness changes. The change is measured to characterize the scratch.

  13. Micro coring apparatus

    NASA Technical Reports Server (NTRS)

    Collins, David; Brooks, Marshall; Chen, Paul; Dwelle, Paul; Fischer, Ben

    1989-01-01

    A micro-coring apparatus for lunar exploration applications, that is compatible with the other components of the Walking Mobile Platform, was designed. The primary purpose of core sampling is to gain an understanding of the geological composition and properties of the prescribed environment. This procedure has been used extensively for Earth studies and in limited applications during lunar explorations. The corer is described and analyzed for effectiveness.

  14. Micro borehole drilling platform

    SciTech Connect

    1996-10-01

    This study by CTES, L.C. meets two main objectives. First, evaluate the feasibility of using coiled tubing (CT) to drill 1.0 inches-2.5 inches diameter directional holes in hard rocks. Second, develop a conceptual design for a micro borehole drilling platform (MBDP) meeting specific size, weight, and performance requirements. The Statement of Work (SOW) in Appendix A contains detailed specifications for the feasibility study and conceptual design.

  15. Scanning micro-sclerometer

    DOEpatents

    Oliver, W.C.; Blau, P.J.

    1994-11-01

    A scanning micro-sclerometer measures changes in contact stiffness and correlates these changes to characteristics of a scratch. A known force is applied to a contact junction between two bodies and a technique employing an oscillating force is used to generate the contact stiffness between the two bodies. As the two bodies slide relative to each other, the contact stiffness changes. The change is measured to characterize the scratch. 2 figs.

  16. Quantitative micro-CT

    NASA Astrophysics Data System (ADS)

    Prevrhal, Sven

    2005-09-01

    Micro-CT for bone structural analysis has progressed from an in-vitro laboratory technique to devices for in-vivo assessment of small animals and the peripheral human skeleton. Currently, topological parameters of bone architecture are the primary goals of analysis. Additional measurement of the density or degree of mineralization (DMB) of trabecular and cortical bone at the microscopic level is desirable to study effects of disease and treatment progress. This information is not commonly extracted because of the challenges of accurate measurement and calibration at the tissue level. To assess the accuracy of micro-CT DMB measurements in a realistic but controlled situation, we prepared bone-mimicking watery solutions at concentrations of 100 to 600 mg/cm3 K2PO4H and scanned them with micro-CT, both in glass vials and microcapillary tubes with inner diameters of 50, 100 and 150 μm to simulate trabecular thickness. Values of the linear attenuation coefficients μ in the reconstructed image are commonly affected by beam hardening effects for larger samples and by partial volume effects for small volumes. We implemented an iterative reconstruction technique to reduce beam hardening. Partial voluming was sought to be reduced by excluding voxels near the tube wall. With these two measures, improvement on the constancy of the reconstructed voxel values and linearity with solution concentration could be observed to over 90% accuracy. However, since the expected change in real bone is small more measurements are needed to confirm that micro-CT can indeed be adapted to assess bone mineralization at the tissue level.

  17. Combined acoustic and optical trapping

    PubMed Central

    Thalhammer, G.; Steiger, R.; Meinschad, M.; Hill, M.; Bernet, S.; Ritsch-Marte, M.

    2011-01-01

    Combining several methods for contact free micro-manipulation of small particles such as cells or micro-organisms provides the advantages of each method in a single setup. Optical tweezers, which employ focused laser beams, offer very precise and selective handling of single particles. On the other hand, acoustic trapping with wavelengths of about 1 mm allows the simultaneous trapping of many, comparatively large particles. With conventional approaches it is difficult to fully employ the strengths of each method due to the different experimental requirements. Here we present the combined optical and acoustic trapping of motile micro-organisms in a microfluidic environment, utilizing optical macro-tweezers, which offer a large field of view and working distance of several millimeters and therefore match the typical range of acoustic trapping. We characterize the acoustic trapping forces with the help of optically trapped particles and present several applications of the combined optical and acoustic trapping, such as manipulation of large (75 μm) particles and active particle sorting. PMID:22025990

  18. Modeling and control for micro and nano manipulation

    NASA Astrophysics Data System (ADS)

    Wejinya, Uchechukwu C.

    handling and deposition of micro and nano entities such as carbon nanotubes (CNT), DNA, and for droplet control. The novel microfluidic end effector system with force sensing can significantly improve the success rate for handling/depositing micro/nano entities in the case of carbon nanotubes between micro electrodes. The design, calibration, and experimental implementation of the novel microfluidic end effector is carried out in this research. The experimental results show the success rate for carbon nanotube(s) deposition between micro electrodes can reach close to 80%. Furthermore, carbon nanotubes are of particular interest because they are good candidates for many electronics and sensing applications. The interests in using carbon nanotubes to manufacture electronics and sensors have increased in recent years because of the increase need for making electronics smaller, and their excellent electrical and mechanical properties. These potentials can be achieved if CNTs with semiconducting and metallic band structure can be successfully deposited and separated. The use of dielectrophoresis (DEP) has been established as a course towards the efficient deposition and separation of metallic carbon nanotubes from semiconducting carbon nanotubes. For this reason, this research presents a new mathematical model for dielectrophoresis and electrorotation of carbon nanotubes. Simulation results are presented in this research to validate the developed model. The combination of both the micro robotic manipulation system and the atomic force microscopy (AFM) based nano-robotic system will provide a powerful tool for micro and nano manipulation. Additional applications of this research are endless considering the rapid development of micro and nano technologies.

  19. Lessons from the MicroObservatory Net

    NASA Astrophysics Data System (ADS)

    Brecher, K.; Sadler, P.; Gould, R.; Leiker, S.; Antonucci, P.; Deutsch, F.

    1998-12-01

    Over the past several years, we have developed a fully integrated automated astronomical telescope system which combines the imaging power of a cooled CCD, with a self-contained and weatherized 15 cm reflecting optical telescope and mount. Each telescope can be pointed and focused remotely, and filters, field of view and exposure times can be changed easily. The MicroObservatory Net consists of five of these telescopes. They are being deployed around the world at widely distributed longitudes for access to distant night skies during local daytime. Remote access to the MicroObservatories over the Internet has been available to select schools since 1995. The telescopes can be controlled in real time or in delay mode, from any computer using Web-based software. Individuals have access to all of the telescope control functions without the need for an `on-site' operator. After a MicroObservatory completes a job, the user is automatically notified by e-mail that the image is available for viewing and downloading from the Web site. Images are archived at the Web site, along with sample challenges and a user bulletin board, all of which encourage collaboration between schools. The Internet address of the telescopes is http://mo-www.harvard.edu/MicroObservatory/. The telescopes were designed for classroom instruction by teachers, as well as for use by students and amateur astronomers for original scientific research projects. In this talk, we will review some of the experiences we, students and teachers have had in using the telescopes. Support for the MicroObservatory Net has been provided by the NSF, Apple Computer, Inc. and Kodak, Inc.

  20. Fiber optic engine for micro projection display.

    PubMed

    Arabi, Hesam Edin; An, Sohee; Oh, Kyunghwan

    2010-03-01

    A novel compact optical engine for a micro projector display is experimentally demonstrated, which is composed of RGB light sources, a tapered 3 x 1 Fiber Optic Color Synthesizer (FOCS) along with a fiberized ball-lens, and a two dimensional micro electromechanical scanning mirror. In the proposed optical engine, we successfully employed an all-fiber beam shaping technique combining optical fiber taper and fiberized ball lens that can render a narrow beam and enhance the resolution of the screened image in the far field. Optical performances of the proposed device assembly are investigated in terms of power loss, collimating strength of the collimator assembly, and color gamut of the output. PMID:20389477

  1. Electromagnetic micro-actuators, micro-motors, and micro-robots

    NASA Astrophysics Data System (ADS)

    Feldmann, M.; Waldschik, A.; Büttgenbach, S.

    2007-12-01

    Due to the development of new technologies, more and more complex MEMS applications can be realized. Especially electromagnetic micro actuators have reached a growing interest in micro technology in addition to commercial applications during the last years. Their basic construction exists of electric conductors and coil systems as well as of soft-magnetic and/or hard-magnetic materials that were fabricated in additive technology via UV-depth lithography and electroplating. For UV-depth lithography, photo resists like Epon SU-8, AZ9260, Intervia-3D-N and CAR44 were applied and optimized. Layer thickness up to 1 mm and aspect ratios over 60 were achieved. Special micro composites were developed. This allowed the fabrication of micro magnets with arbitrary shape and properties, revealing a complete compatibility to existing process chains. With these potential technologies, several complex 3-D micro actuators like micro motors and micro robots were developed and successfully tested. These developments include in detail: linear and rotatory reluctance micro stepper motors with compensated attraction force as well as a special "Lorentz force actuator", which was used for micro robots and micro motors. The micro robots were deployed for assembling and for micro-/nano positioning. Furthermore "plunger coil actuators" were realized based on a voice coil principle, which were used e.g. for a micro switch or a micro mirror. Moreover, rotatory synchronous motors were developed and successfully tested. All these devices have been realized by outstanding fabrication technologies and can be used for a wide range of applications.

  2. The dual protection of a micro land snail against a micro predatory snail.

    PubMed

    Wada, Shinichiro; Chiba, Satoshi

    2013-01-01

    Defense against a single predatory attack strategy may best be achieved not by a single trait but by a combination of different traits. We tested this hypothesis experimentally by examining the unique shell traits (the protruded aperture and the denticles within the aperture) of the micro land snail Bensonella plicidens. We artificially altered shell characteristics by removing the denticles and/or cutting the protruded aperture. These snails were offered to the carnivorous micro land snail Indoennea bicolor, which preys on the snails by gaining entry to their shell. B. plicidens exhibited the best defence when both of the traits studied were present; the defensive ability of B. plicidens decreased if either trait was removed and was further reduced if both traits were removed. These results suggest that a combination of different traits provides more effective defence against attack by the predator than either single trait by itself. PMID:23326582

  3. The Dual Protection of a Micro Land Snail against a Micro Predatory Snail

    PubMed Central

    Wada, Shinichiro; Chiba, Satoshi

    2013-01-01

    Defense against a single predatory attack strategy may best be achieved not by a single trait but by a combination of different traits. We tested this hypothesis experimentally by examining the unique shell traits (the protruded aperture and the denticles within the aperture) of the micro land snail Bensonella plicidens. We artificially altered shell characteristics by removing the denticles and/or cutting the protruded aperture. These snails were offered to the carnivorous micro land snail Indoennea bicolor, which preys on the snails by gaining entry to their shell. B. plicidens exhibited the best defence when both of the traits studied were present; the defensive ability of B. plicidens decreased if either trait was removed and was further reduced if both traits were removed. These results suggest that a combination of different traits provides more effective defence against attack by the predator than either single trait by itself. PMID:23326582

  4. Array servo scanning micro EDM of 3D micro cavities

    NASA Astrophysics Data System (ADS)

    Tong, Hao; Li, Yong; Yi, Futing

    2010-12-01

    Micro electro discharge machining (Micro EDM) is a non-traditional processing technology with the special advantages of low set-up cost and few cutting force in machining any conductive materials regardless of their hardness. As well known, die-sinking EDM is unsuitable for machining the complex 3D micro cavity less than 1mm due to the high-priced fabrication of 3D microelectrode itself and its serous wear during EDM process. In our former study, a servo scanning 3D micro-EDM (3D SSMEDM) method was put forward, and our experiments showed it was available to fabricate complex 3D micro-cavities. In this study, in order to improve machining efficiency and consistency accuracy for array 3D micro-cavities, an array-servo-scanning 3D micro EDM (3D ASSMEDM) method is presented considering the complementary advantages of the 3D SSMEDM and the array micro electrodes with simple cross-section. During 3D ASSMEDM process, the array cavities designed by CAD / CAM system can be batch-manufactured by servo scanning layer by layer using array-rod-like micro tool electrodes, and the axial wear of the array electrodes is compensated in real time by keeping discharge gap. To verify the effectiveness of the 3D ASSMEDM, the array-triangle-micro cavities (side length 630 μm) are batch-manufactured on P-doped silicon by applying the array-micro-electrodes with square-cross-section fabricated by LIGA process. Our exploratory experiment shows that the 3D ASSMEDM provides a feasible approach for the batch-manufacture of 3D array-micro-cavities of conductive materials.

  5. Array servo scanning micro EDM of 3D micro cavities

    NASA Astrophysics Data System (ADS)

    Tong, Hao; Li, Yong; Yi, Futing

    2011-05-01

    Micro electro discharge machining (Micro EDM) is a non-traditional processing technology with the special advantages of low set-up cost and few cutting force in machining any conductive materials regardless of their hardness. As well known, die-sinking EDM is unsuitable for machining the complex 3D micro cavity less than 1mm due to the high-priced fabrication of 3D microelectrode itself and its serous wear during EDM process. In our former study, a servo scanning 3D micro-EDM (3D SSMEDM) method was put forward, and our experiments showed it was available to fabricate complex 3D micro-cavities. In this study, in order to improve machining efficiency and consistency accuracy for array 3D micro-cavities, an array-servo-scanning 3D micro EDM (3D ASSMEDM) method is presented considering the complementary advantages of the 3D SSMEDM and the array micro electrodes with simple cross-section. During 3D ASSMEDM process, the array cavities designed by CAD / CAM system can be batch-manufactured by servo scanning layer by layer using array-rod-like micro tool electrodes, and the axial wear of the array electrodes is compensated in real time by keeping discharge gap. To verify the effectiveness of the 3D ASSMEDM, the array-triangle-micro cavities (side length 630 μm) are batch-manufactured on P-doped silicon by applying the array-micro-electrodes with square-cross-section fabricated by LIGA process. Our exploratory experiment shows that the 3D ASSMEDM provides a feasible approach for the batch-manufacture of 3D array-micro-cavities of conductive materials.

  6. Bio-barcode gel assay for microRNA

    NASA Astrophysics Data System (ADS)

    Lee, Hyojin; Park, Jeong-Eun; Nam, Jwa-Min

    2014-02-01

    MicroRNA has been identified as a potential biomarker because expression level of microRNA is correlated with various cancers. Its detection at low concentrations would be highly beneficial for cancer diagnosis. Here, we develop a new type of a DNA-modified gold nanoparticle-based bio-barcode assay that uses a conventional gel electrophoresis platform and potassium cyanide chemistry and show this assay can detect microRNA at aM levels without enzymatic amplification. It is also shown that single-base-mismatched microRNA can be differentiated from perfectly matched microRNA and the multiplexed detection of various combinations of microRNA sequences is possible with this approach. Finally, differently expressed microRNA levels are selectively detected from cancer cells using the bio-barcode gel assay, and the results are compared with conventional polymerase chain reaction-based results. The method and results shown herein pave the way for practical use of a conventional gel electrophoresis for detecting biomolecules of interest even at aM level without polymerase chain reaction amplification.

  7. Hybrid micromachining using a nanosecond pulsed laser and micro EDM

    NASA Astrophysics Data System (ADS)

    Kim, Sanha; Kim, Bo Hyun; Chung, Do Kwan; Shin, Hong Shik; Chu, Chong Nam

    2010-01-01

    Micro electrical discharge machining (micro EDM) is a well-known precise machining process that achieves micro structures of excellent quality for any conductive material. However, the slow machining speed and high tool wear are main drawbacks of this process. Though the use of deionized water instead of kerosene as a dielectric fluid can reduce the tool wear and increase the machine speed, the material removal rate (MRR) is still low. In contrast, laser ablation using a nanosecond pulsed laser is a fast and non-wear machining process but achieves micro figures of rather low quality. Therefore, the integration of these two processes can overcome the respective disadvantages. This paper reports a hybrid process of a nanosecond pulsed laser and micro EDM for micromachining. A novel hybrid micromachining system that combines the two discrete machining processes is introduced. Then, the feasibility and characteristics of the hybrid machining process are investigated compared to conventional EDM and laser ablation. It is verified experimentally that the machining time can be effectively reduced in both EDM drilling and milling by rapid laser pre-machining prior to micro EDM. Finally, some examples of complicated 3D micro structures fabricated by the hybrid process are shown.

  8. Non-corrosive micro coolers with matched CTE

    NASA Astrophysics Data System (ADS)

    Ebert, Thomas; Meiners, Wilhelm

    2007-02-01

    New technology regarding manufacturing of micro cooling systems and selective laser melting was presented at Photonics West 2005; at Photonics West 2006 the first non-corrosive active micro coolers manufactured by this procedure were introduced to the auditorium. This presentation shows the latest results regarding active micro cooling systems for high power diode laser with a matched CTE. After the first non corrosive micro coolers passed the tests regarding cooling performance, there were still two tasks which had to be accomplished: First one was the homogeneity of cooling. In order to achieve the homogeneity, the design of the supporting structure in front of the micro cooling structures was modified. Measurements of cooling performance and the range of the wavelength along the laser bar showed that with the modified structure a homogeneous inflow was achieved as well as homogeneous cooling along the laser bar. The presentation highlights the measurements and results. Second point of development was the quest for a material combination with an adequate thermal conductivity for keeping the cooling performance, but with a coefficient of thermal expansion that matches with the CTE of diode laser bar material. After testing several materials fitting to these requirements, only one material was left, which was capable to machine workable micro coolers with the SLM procedure. The presentation contains the first results of the micro coolers with a matched CTE regarding thermal resistance, CTE and packaging with gold - tin solder.

  9. Optical assembly of bio-hybrid micro-robots.

    PubMed

    Barroso, Álvaro; Landwerth, Shirin; Woerdemann, Mike; Alpmann, Christina; Buscher, Tim; Becker, Maike; Studer, Armido; Denz, Cornelia

    2015-04-01

    The combination of micro synthetic structures with bacterial flagella motors represents an actual trend for the construction of self-propelled micro-robots. The development of methods for fabrication of these bacteria-based robots is a first crucial step towards the realization of functional miniature and autonomous moving robots. We present a novel scheme based on optical trapping to fabricate living micro-robots. By using holographic optical tweezers that allow three-dimensional manipulation in real time, we are able to arrange the building blocks that constitute the micro-robot in a defined way. We demonstrate exemplarily that our method enables the controlled assembly of living micro-robots consisting of a rod-shaped prokaryotic bacterium and a single elongated zeolite L crystal, which are used as model of the biological and abiotic components, respectively. We present different proof-of-principle approaches for the site-selective attachment of the bacteria on the particle surface. The propulsion of the optically assembled micro-robot demonstrates the potential of the proposed method as a powerful strategy for the fabrication of bio-hybrid micro-robots. PMID:25681045

  10. Recent progress in micro and nano-joining

    NASA Astrophysics Data System (ADS)

    Zhou, Y.; Hu, A.; Khan, M. I.; Wu, W.; Tam, B.; Yavuz, M.

    2009-05-01

    Micro and nano-joining has been identified as a key enabling technology in the construction of micromechanical and microelectronic devices. The current article reviews recent progress in micro and nano-joining. In particular, laser micro-welding (LMW) of crossed 316 LVM stainless steel (SS) wire was compared to conventional resistance micro-welding (RMW) and was successfully employed in welding a Pt-Ir /SS dissimilar combination. Welding of Au nanoparticles was realized using femtosecond laser irradiation and its application in the surface enhanced Raman spectroscopy was investigated. Brazing between carbon nanotube (CNT) bundles and Ni electrodes was attained in vacuum, resulting in the development of a novel CNT filament of incandescent lamps.

  11. Functional regulatory roles of microRNAs in atherosclerosis.

    PubMed

    Gao, Ya; Peng, Juan; Ren, Zhong; He, Ni-Ya; Li, Qing; Zhao, Xue-Shan; Wang, Mei-Mei; Wen, Hong-Yan; Tang, Zhi-Han; Jiang, Zhi-Sheng; Wang, Gui-Xue; Liu, Lu-Shan

    2016-09-01

    MicroRNAs are a group of endogenously small non-coding RNA molecules that downregulate gene expression at the post-transcriptional level through binding to the 3'UTR of target mRNAs. Recent findings have revealed a key role for microRNAs in the pathophysiological processes of atherosclerosis. As a complex disease, atherosclerosis is influenced by a combination of multiple genes and environmental factors. Both of them play a role in atherogenesis by affecting different types of cells (such as endothelial cell, vascular smooth muscle cell and monocyte/macrophage) function. MicroRNAs control the senescence and dysfunction of endothelial cells, proliferation and migration of vascular smooth muscle cells, and macrophage-driven cytokine production and polarization. By these effects, microRNAs can influence the processes of atherosclerosis and may represent new molecular targets for therapy. PMID:27384386

  12. A novel diamond micro-/nano-machining process for the generation of hierarchical micro-/nano-structures

    NASA Astrophysics Data System (ADS)

    Zhu, Zhiwei; To, Suet; Ehmann, Kornel F.; Xiao, Gaobo; Zhu, Wule

    2016-03-01

    A new mechanical micro-/nano-machining process that combines rotary spatial vibrations (RSV) of a diamond tool and the servo motions of the workpiece is proposed and applied for the generation of multi-tier hierarchical micro-/nano-structures. In the proposed micro-/nano-machining system, the servo motion, as the primary cutting motion generated by a slow-tool-servo, is adopted for the fine generation of the primary surfaces with complex shapes. The RSV, as the tertiary cutting operation, is superimposed on the secondary fundamental rotary cutting motion to construct secondary nano-structures on the primary surface. Since the RSV system generally works at much higher frequencies and motion resolution than the primary and secondary motions, it leads to an inherent hierarchical cutting architecture. To investigate the machining performance, complex micro-/nano-structures were generated and explored by both numerical simulations and actual cutting tests. Rotary vibrations of the diamond tool at a constant rotational distance offer an inherent constant cutting velocity, leading to the ability for the generation of homogeneous micro-/nano-structures with fixed amplitudes and frequencies of the vibrations, even over large-scale surfaces. Furthermore, by deliberately combining the non-resonant three-axial vibrations and the servo motion, the generation of a variety of micro-/nano-structures with complex shapes and with flexibly tunable feature sizes can be achieved.

  13. Phenotypic MicroRNA Microarrays

    PubMed Central

    Kwon, Yong-Jun; Heo, Jin Yeong; Kim, Hi Chul; Kim, Jin Yeop; Liuzzi, Michel; Soloveva, Veronica

    2013-01-01

    Microarray technology has become a very popular approach in cases where multiple experiments need to be conducted repeatedly or done with a variety of samples. In our lab, we are applying our high density spots microarray approach to microscopy visualization of the effects of transiently introduced siRNA or cDNA on cellular morphology or phenotype. In this publication, we are discussing the possibility of using this micro-scale high throughput process to study the role of microRNAs in the biology of selected cellular models. After reverse-transfection of microRNAs and siRNA, the cellular phenotype generated by microRNAs regulated NF-κB expression comparably to the siRNA. The ability to print microRNA molecules for reverse transfection into cells is opening up the wide horizon for the phenotypic high content screening of microRNA libraries using cellular disease models.

  14. Electrochemical micro sensor

    DOEpatents

    Setter, Joseph R.; Maclay, G. Jordan

    1989-09-12

    A micro-amperometric electrochemical sensor for detecting the presence of a pre-determined species in a fluid material is disclosed. The sensor includes a smooth substrate having a thin coating of solid electrolytic material deposited thereon. The working and counter electrodes are deposited on the surface of the solid electrolytic material and adhere thereto. Electrical leads connect the working and counter electrodes to a potential source and an apparatus for measuring the change in an electrical signal caused by the electrochemical oxidation or reduction of the species. Alternatively, the sensor may be fabricated in a sandwich structure and also may be cylindrical, spherical or other shapes.

  15. Micro-fluidic interconnect

    DOEpatents

    Okandan, Murat; Galambos, Paul C.; Benavides, Gilbert L.; Hetherington, Dale L.

    2006-02-28

    An apparatus for simultaneously aligning and interconnecting microfluidic ports is presented. Such interconnections are required to utilize microfluidic devices fabricated in Micro-Electromechanical-Systems (MEMS) technologies, that have multiple fluidic access ports (e.g. 100 micron diameter) within a small footprint, (e.g. 3 mm.times.6 mm). Fanout of the small ports of a microfluidic device to a larger diameter (e.g. 500 microns) facilitates packaging and interconnection of the microfluidic device to printed wiring boards, electronics packages, fluidic manifolds etc.

  16. Micro-materials processing

    NASA Astrophysics Data System (ADS)

    Cohen, M. G.; Kaplan, R. A.; Arthurs, E. G.

    1982-06-01

    A model analysis of the absorption of laser energy in the millijoule range by a thin film on a substrate is presented to illustrate the underlying physical mechanism of laser micro-materials processing. The analysis is followed by a discussion of several applications from the electronics and semiconductor industries, including resistor trimming, laserscribing, laser damage gettering, laser marking, ablation of metal films, and mask repair. Finally, several uses of lasers in the diamond industry, such as removal of flaws from gemstone diamonds, diamond sawing, and diamond inscription, are briefly reviewed.

  17. Combinations Therapies.

    PubMed

    Reinmuth, Niels; Reck, Martin

    2015-01-01

    Immunotherapy of cancer encompasses different strategies that elicit or enhance the immune response against tumors. The first results from clinical studies have provided promising data for the treatment of lung cancer patients with immunomodulating monotherapies. To improve the potential benefit of cancer immunotherapy, synergistic combinations of the various immunotherapy approaches or of different elements within each of the immunotherapy approaches are being explored. The rationale typically involves different but complementary mechanisms of action, eventually impinging on more than one immune system mechanism. As a prominent example, the simultaneous blockade of PD-1 and CTLA-4 is giving rise to therapeutic synergy, while still offering room for efficacy improvement. Moreover, combinations of immunomodulating agents with chemotherapy or targeted molecules are being tested. Animal models suggest that immunotherapies in combination with these various options offer evidence for synergistic effects and are likely to radically change cancer treatment paradigms. However, data obtained so far indicate that toxic side effects are also potentiated, which may even restrict the selection of patients that are suitable for these combinational approaches. Advancing the field of combinatorial immunotherapy will require changes in the way investigational agents are clinically developed as well as novel experimental end-points for efficacy evaluation. However, this combined therapeutic manipulation of both tumor and stromal cells may lead to a dramatic change in the therapeutic options of lung cancer patients in any disease stage that can only grossly be appreciated by the current studies. PMID:26384009

  18. Uranium speciation as a function of depth in contaminated hanford sediments--a micro-XRF, micro-XRD, and micro- and bulk-XAFS study.

    PubMed

    Singer, David M; Zachara, John M; Brown, Gordon E

    2009-02-01

    The distribution and speciation of U and Cu in contaminated vadose zone and aquifer sediments from the U.S. DOE Hanford site (300 Area) were determined using a combination of synchrotron-based micro-X-ray fluorescence (microXRF) imaging, micro-X-ray absorption near edge structure (microXANES) spectroscopy, and micro-X-ray diffraction (microXRD) techniques combined with bulk U LIII-edge X-ray absorption fine structure (XAFS) spectroscopy. Samples were collected from within the inactive North Process Pond (NPP2) at 8 ft (2.4 m, NPP2-8) depth and 12 ft (3.7 m, NPP2-12) depth in the vadose zone, and fines were isolated from turbid groundwater just below the water Table (12-14 ft, approximately 4 m, NPP2-GW). microXRF imaging, microXRD, and microXANES spectroscopy revealed two major U occurrences within the vadose and groundwater zones: (1) low to moderate concentrations of U(VI) associated with fine-textured grain coatings that were consistently found to contain clinochlore (referred to here as chlorite) observed in all three samples, and (2) U(VI)-Cu(II) hotspots consisting of micrometer-sized particles associated with surface coatings on grains of muscovite and chlorite observed in samples NPP2-8' and NPP2-GW. In the aquifer fines (NPP2-GW), these particles were identified as cuprosklodowskite (cps: Cu[(UO2)(SiO2OH)]2 x 6H2O) and metatorbernite (mtb: Cu(UO2)2(PO4)2 x 8H2O). In contrast, the U-Cu-containing particles in the vadose zone were X-ray amorphous. Analyses of U LIII-edge XAFS spectra by linear-combination fitting indicated that U speciation consisted of (1) approximately 75% uranyl sorbed to chlorite and approximately 25% mtb-like X-ray amorphous U-Cu-phosphates (8 ft depth), (2) nearly 100% sorbed uranyl (12 ft depth), and (3) approximately 70% uranyl sorbed to chlorite and approximately 30% cps/mtb (groundwater zone). These findings suggest that dissolution of U(VI)-Cu(II)-bearing solids as well as desorption of U(VI), mainly from phyllosilicates, are

  19. microRNAs as neuroregulators, biomarkers and therapeutic agents in neurodegenerative diseases.

    PubMed

    Basak, Indranil; Patil, Ketan S; Alves, Guido; Larsen, Jan Petter; Møller, Simon Geir

    2016-02-01

    The last decade has experienced the emergence of microRNAs as a key molecular tool for the diagnosis and prognosis of human diseases. Although the focus has mostly been on cancer, neurodegenerative diseases present an exciting, yet less explored, platform for microRNA research. Several studies have highlighted the significance of microRNAs in neurogenesis and neurodegeneration, and pre-clinical studies have shown the potential of microRNAs as biomarkers. Despite this, no bona fide microRNAs have been identified as true diagnostic or prognostic biomarkers for neurodegenerative disease. This is mainly due to the lack of precisely defined patient cohorts and the variability within and between individual cohorts. However, the discovery that microRNAs exist as stable molecules at detectable levels in body fluids has opened up new avenues for microRNAs as potential biomarker candidates. Furthermore, technological developments in microRNA biology have contributed to the possible design of microRNA-mediated disease intervention strategies. The combination of these advancements, with the availability of well-defined longitudinal patient cohort, promises to not only assist in developing invaluable diagnostic tools for clinicians, but also to increase our overall understanding of the underlying heterogeneity of neurodegenerative diseases. In this review, we present a comprehensive overview of the existing knowledge of microRNAs in neurodegeneration and provide a perspective of the applicability of microRNAs as a basis for future therapeutic intervention strategies. PMID:26608596

  20. A micro-coupling for micro mechanical systems

    NASA Astrophysics Data System (ADS)

    Li, Wei; Zhou, Zhixiong; Zhang, Bi; Xiao, Yunya

    2016-05-01

    The error motions of micro mechanical systems, such as micro-spindles, increase with the increasing of the rotational speed, which not only decreases the rotational accuracy, but also promotes instability and limits the maximum operational speed. One effective way to deal with it is to use micro-flexible couplings between the drive and driven shafts so as to reduce error motions of the driven shaft. But the conventional couplings, such as diaphragm couplings, elastomeric couplings, bellows couplings, and grooved couplings, etc, cannot be directly used because of their large and complicated structures. This study presents a novel micro-coupling that consists of a flexible coupling and a shape memory alloy (SMA)-based clamp for micro mechanical systems. It is monolithic and can be directly machined from a shaft. The study performs design optimization and provides manufacturing considerations, including thermo-mechanical training of the SMA ring for the desired Two-Way-Shape-Memory effect (TWSMe). A prototype micro-coupling and a prototype micro-spindle using the proposed coupling are fabricated and tested. The testing results show that the prototype micro-coupling can bear a torque of above 5 N • mm and an axial force of 8.5 N and be fitted with an SMA ring for clamping action at room temperature (15 °C) and unclamping action below-5 °C. At the same time, the prototype micro-coupling can work at a rotational speed of above 200 kr/min with the application to a high-speed precision micro-spindle. Moreover, the radial runout error of the artifact, as a substitute for the micro-tool, is less than 3 μm while that of turbine shaft is above 7 μm. It can be concluded that the micro-coupling successfully accommodates misalignment errors of the prototype micro-spindle. This research proposes a micro-coupling which is featured with an SMA ring, and it is designed to clamp two shafts, and has smooth transmission, simple assembly, compact structure, zero-maintenance and

  1. A micro-coupling for micro mechanical systems

    NASA Astrophysics Data System (ADS)

    Li, Wei; Zhou, Zhixiong; Zhang, Bi; Xiao, Yunya

    2016-04-01

    The error motions of micro mechanical systems, such as micro-spindles, increase with the increasing of the rotational speed, which not only decreases the rotational accuracy, but also promotes instability and limits the maximum operational speed. One effective way to deal with it is to use micro-flexible couplings between the drive and driven shafts so as to reduce error motions of the driven shaft. But the conventional couplings, such as diaphragm couplings, elastomeric couplings, bellows couplings, and grooved couplings, etc, cannot be directly used because of their large and complicated structures. This study presents a novel micro-coupling that consists of a flexible coupling and a shape memory alloy (SMA)-based clamp for micro mechanical systems. It is monolithic and can be directly machined from a shaft. The study performs design optimization and provides manufacturing considerations, including thermo-mechanical training of the SMA ring for the desired Two-Way-Shape-Memory effect (TWSMe). A prototype micro-coupling and a prototype micro-spindle using the proposed coupling are fabricated and tested. The testing results show that the prototype micro-coupling can bear a torque of above 5 N • mm and an axial force of 8.5 N and be fitted with an SMA ring for clamping action at room temperature (15 °C) and unclamping action below-5 °C. At the same time, the prototype micro-coupling can work at a rotational speed of above 200 kr/min with the application to a high-speed precision micro-spindle. Moreover, the radial runout error of the artifact, as a substitute for the micro-tool, is less than 3 μm while that of turbine shaft is above 7 μm. It can be concluded that the micro-coupling successfully accommodates misalignment errors of the prototype micro-spindle. This research proposes a micro-coupling which is featured with an SMA ring, and it is designed to clamp two shafts, and has smooth transmission, simple assembly, compact structure, zero-maintenance and

  2. Methods and systems for positioning micro elements

    SciTech Connect

    Stalford, Harold L

    2015-04-28

    A micro device may comprise a substrate, a first micro structure coupled to the substrate, a second micro structure coupled to the substrate, and port configured to receive an input. The first micro structure is configured to move into engagement with the second micro structure in response to the input.

  3. Methods and systems for positioning micro elements

    DOEpatents

    Stalford; Harold L.

    2012-03-13

    A micro device may comprise a substrate, a first micro structure coupled to the substrate, a second micro structure coupled to the substrate, and port configured to receive an input. The first micro structure is configured to move into engagement with the second micro structure in response to the input.

  4. Lead resistance in micro-organisms.

    PubMed

    Jarosławiecka, Anna; Piotrowska-Seget, Zofia

    2014-01-01

    Lead (Pb) is an element present in the environment that negatively affects all living organisms. To diminish its high toxicity, micro-organisms have developed several mechanisms that allow them to survive exposure to Pb(II). The main mechanisms of lead resistance involve adsorption by extracellular polysaccharides, cell exclusion, sequestration as insoluble phosphates, and ion efflux to the cell exterior. This review describes the various lead resistance mechanisms, and the regulation of their expression by lead binding regulatory proteins. Special attention is given to the Pbr system from Cupriavidus metallidurans CH34, which involves a unique mechanism combining efflux and lead precipitation. PMID:24124204

  5. Micro-optic lens for data storage

    NASA Technical Reports Server (NTRS)

    Milster, T. D.; Trusty, R. M.; Wang, M. S.; Froehlich, F. F.; Erwin, J. Kevin

    1991-01-01

    A new type of microlens for data storage applications that has improved off-axis performance is described. The lens consists of a micro Fresnel pattern on a curved substrate. The radius of the substrate is equal to the focal length of the lens. If the pattern and substrate are thin, the combination satisfies the Abbe sine condition. Therefore, the lens is free of coma. We analyze a 0.5 numerical aperture, 0.50 mm focal length lens in detail. A 0.16 numerical aperture lens was fabricated holographically, and results are presented.

  6. MicroProbe Small Unmanned Aerial System

    NASA Technical Reports Server (NTRS)

    Bland, Geoffrey; Miles, Ted

    2012-01-01

    The MicroProbe unmanned aerial system (UAS) concept incorporates twin electric motors mounted on the vehicle wing, thus enabling an aerodynamically and environmentally clean nose area for atmospheric sensors. A payload bay is also incorporated in the fuselage to accommodate remote sensing instruments. A key feature of this concept is lightweight construction combined with low flying speeds to minimize kinetic energy and associated hazards, as well as maximizing spatial resolution. This type of aerial platform is needed for Earth science research and environmental monitoring. There were no vehicles of this type known to exist previously.

  7. A Micro-Ultrastable Oscillator (micro-US0) for Micro/Nano Sciencecraft

    NASA Technical Reports Server (NTRS)

    2003-01-01

    Syntonics LLC developed a prototype micro-Ultra Stable Oscillator (micro-USO) under a Space Base Technology Grant (NAGS-10395). Syntonics conducted the micro-USO Program in two phases. In Phase I, we developed a set of verified analytical models (including thermal, electrical, and control models) for a baseline USO, conducted a series of six technology studies, and built three approx.9OOg prototype units. These prototypes provided a tool for evaluating competing design topologies. In Phase II we prepared the conceptual design of a approx.100-15Og micro-USO.

  8. Micro rotary machine and methods for using same

    DOEpatents

    Stalford, Harold L.

    2012-04-17

    A micro rotary machine may include a micro actuator and a micro shaft coupled to the micro actuator. The micro shaft comprises a horizontal shaft and is operable to be rotated by the micro actuator. A micro tool is coupled to the micro shaft and is operable to perform work in response to motion of the micro shaft.

  9. Micro rotary machine and methods for using same

    DOEpatents

    Stalford, Harold

    2015-01-13

    A micro rotary machine may include a micro actuator and a micro shaft coupled to the micro actuator. The micro shaft comprises a horizontal shaft and is operable to be rotated by the micro actuator. A micro tool is coupled to the micro shaft and is operable to perform work in response to motion of the micro shaft.

  10. Design of micro robots with microgrippers for manipulation of micro-parts

    NASA Astrophysics Data System (ADS)

    Nah, Siew Kuan; Zhong, Zhaowei

    2005-04-01

    In this paper, a design of a micro-robot system with microgrippers for the purpose of manipulation of micro-parts is proposed. The methodology includes the integration of micro-actuators for micromanipulation tasks of requirements that will involve small size, low weight, high resolution, high linearity and high accuracy. The combination of micro-assembly stages and microgrippers with CNC technology will allow the fixing of a microgripper onto a CNC robot. In order to minimize the size of the microgripper, the structure is fabricated as a monolithic piece with elastic flexure hinges. The microgripper mechanism consists of flexure notch hinges and parallel movement of the gripping arms. These elements transmit the gripping force and gripping motion and realize a good mechanical advantage ratio. The compliant mechanism system of the microgrippers is analyzed using a theoretical pseudo-rigid-body model and flexural hinge equation to investigate and predict the displacement and force relationships between the inputs and the outputs. In addition, a finite element study is done on the mechanism model to compare with the theoretical results.

  11. Micro-EDM for silicon microstructure fabrication

    NASA Astrophysics Data System (ADS)

    Song, Xiaozhong; Reynaerts, Dominiek; Meeusen, Wim; Van Brussel, Hendrik

    1999-03-01

    Currently, most silicon microstructures used in microstructures are produced by photolithographic methods. The reason for this is the well-developed etching technology, used in microelectronics, that has been transferred to the microsystem domain. But since the making of an arbitrary shape or angle on silicon mainly depends on the crystal orientation, some severe limits exist in the production of 3D structures. Electro-discharge machining (EDM) is basically a thermal process. During the EDM process material is removed by electric sparking. It is therefore completely different from etching. In this work, micro-EDM is introduce as a potential approach for solving the above mentioned drawbacks. First, this work presents several testing experiments with different process parameters to investigate the influence of the micro-EDM process on the silicon structure. Main emphasis is put on the surface roughness and on avoiding microcracks generated by the sparking process. It is found that microstructures with a sufficiently low surface roughness and with small microcracks can be produced. The remainder of the work concentrates on making small beam structures, which is a common structure in many microsensor designs. It is found that for a wafer thickness of 650 micrometers , the thinnest beam that can be produced is about 30 micrometers wide. This means that micro-EDM can offer an aspect ratio of 20 in combination with a god dimensional control.

  12. Programming in Micro-PROLOG

    SciTech Connect

    DeSaram, H.

    1985-01-01

    Programming in Micro-PROLOG enables readers to carry out substantial projects of their own devising. It offers an explanation of how Micro-PROLOG works and a wide range of examples. Contents: Basic Processes; Some Built-in Commands; List Processing; Modules; Games and Puzzles; Augmented Turtle Graphics; Databases; Natural Language; Appendix.

  13. Micro-channel plate detector

    DOEpatents

    Elam, Jeffrey W.; Lee, Seon W.; Wang, Hsien -Hau; Pellin, Michael J.; Byrum, Karen; Frisch, Henry J.

    2015-09-22

    A method and system for providing a micro-channel plate detector. An anodized aluminum oxide membrane is provided and includes a plurality of nanopores which have an Al coating and a thin layer of an emissive oxide material responsive to incident radiation, thereby providing a plurality of radiation sensitive channels for the micro-channel plate detector.

  14. Combination Light

    NASA Technical Reports Server (NTRS)

    1990-01-01

    The Rayovac TANDEM is an advanced technology combination work light and general purpose flashlight that incorporates several NASA technologies. The TANDEM functions as two lights in one. It features a long range spotlight and wide angle floodlight; simple one-hand electrical switching changes the beam from spot to flood. TANDEM developers made particular use of NASA's extensive research in ergonomics in the TANDEM's angled handle, convenient shape and different orientations. The shatterproof, water resistant plastic casing also draws on NASA technology, as does the shape and beam distance of the square diffused flood. TANDEM's heavy duty magnet that permits the light to be affixed to any metal object borrows from NASA research on rare earth magnets that combine strong magnetic capability with low cost. Developers used a NASA-developed ultrasonic welding technique in the light's interior.

  15. Micro pulse lidar

    NASA Technical Reports Server (NTRS)

    Spinhirne, James D.

    1993-01-01

    An eye safe, compact, solid state lidar for profiling atmospheric cloud and aerosol scattering has been demonstrated. The transmitter of the micropulse lidar is a diode pumped micro-J pulse energy, high repetition rate Nd:YLF laser. Eye safety is obtained through beam expansion. The receiver employs a photon counting solid state Geiger mode avalanche photodiode detector. Data acquisition is by a single card multichannel scaler. Daytime background induced quantum noise is controlled by a narrow receiver field-of-view and a narrow bandwidth temperature controlled interference filter. Dynamic range of the signal is limited by optical geometric signal compression. Signal simulations and initial atmospheric measurements indicate that systems built on the micropulse lidar concept are capable of detecting and profiling all significant cloud and aerosol scattering through the troposphere and into the stratosphere. The intended applications are scientific studies and environmental monitoring which require full time, unattended measurements of the cloud and aerosol height structure.

  16. Micro Environmental Concrete

    NASA Astrophysics Data System (ADS)

    Lanez, M.; Oudjit, M. N.; Zenati, A.; Arroudj, K.; Bali, A.

    Reactive powder concretes (RPC) are characterized by a particle diameter not exceeding 600 μm and having very high compressive and tensile strengths. This paper describes a new generation of micro concrete, which has an initial as well as a final high physicomechanical performance. To achieve this, 15% by weight of the Portland cement have been substituted by materials rich in Silica (Slag and Dune Sand). The results obtained from the tests carried out on the RPC show that compressive and tensile strengths increase when incorporating the addition, thus improving the compactness of mixtures through filler and pozzolanic effects. With a reduction in the aggregate phase in the RPC and the abundance of the dune sand (southern of Algeria) and slag (industrial by-product of the blast furnace), the use of the RPC will allow Algeria to fulfil economical as well as ecological requirements.

  17. Chemical micro-sensor

    DOEpatents

    Ruggiero, Anthony J.

    2005-05-03

    An integrated optical capillary electrophoresis system for analyzing an analyte. A modulated optical pump beam impinges on an capillary containing the analyte/buffer solution which is separated by electrophoresis. The thermally-induced change in the index of refraction of light in said electrophoresis capillary is monitored using an integrated micro-interferometer. The interferometer includes a first interferometer arm intersecting the electrophoresis capillary proximate the excitation beam and a second, reference interferometer arm. Changes in index of refraction in the analyte measured by interrogating the interferometer state using white light interferometry and a phase-generated carrier demodulation technique. Background thermo-optical activity in the buffer solution is cancelled by splitting the pump beam and exciting pure buffer solution in a second section of capillary where it crosses the reference arm of the interferometer.

  18. Micro thrust and heat generator

    DOEpatents

    Garcia, Ernest J.

    1998-01-01

    A micro thrust and heat generator has a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator's ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachining techniques (LIGA).

  19. Micro thrust and heat generator

    DOEpatents

    Garcia, E.J.

    1998-11-17

    A micro thrust and heat generator have a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator`s ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachining techniques (LIGA). 30 figs.

  20. Micro UV detector

    NASA Astrophysics Data System (ADS)

    Cabalo, Jerry B.; Sickenberger, Richard; Underwood, William J.; Sickenberger, David W.

    2004-09-01

    A lightweight, tactical biological agent detection network offers the potential for a detect-to-warn capability against biological aerosol attacks. Ideally, this capability can be achieved by deploying the sensors upwind from the protected assets. The further the distance upwind, the greater the warning time. The technological challenge to this concept is the biological detection technology. Here, cost, size and power are major factors in selecting acceptable technologies. This is in part due to the increased field densities needed to cover the upwind area and the fact that the sensors, when deployed forward, must operate autonomously for long periods of time with little or no long-term logistical support. The Defense Advanced Research Project Agency"s (DARPA) Solid-state Ultraviolet Optical Source (SUVOS) program offers an enabling technology to achieving a detector compatible with this mission. As an optical source, these devices emit excitation wavelengths known to be useful in the detection of biological aerosols. The wavelength band is absorbed by the biological aerosol and results in visible fluorescence. Detection of a biological aerosol is based on the observed intensity of this fluorescence signal compared to a background reference. Historically this has been accomplished with emission sources that are outside the boundaries for low cost, low power sensors. The SUVOS technology, on the other hand, provides the same basic wavelengths needed for the detection process in a small, low power package. ECBC has initiated an effort to develop a network array based on micro UV detectors that utilize the SUVOS technology. This paper presents an overview of the micro UV detector and some of the findings to date. This includes the overall design philosophy, fluid flow calculations to maximize presentation of aerosol particles to the sources, and the fluorescence measurements.

  1. Micro-UV detector

    NASA Astrophysics Data System (ADS)

    Cabalo, Jerry B.; Sickenberger, Richard; Underwood, William J.; Sickenberger, David W.

    2004-12-01

    A lightweight, tactical biological agent detection network offers the potential for a detect-to-warn capability against biological aerosol attacks. Ideally, this capability can be achieved by deploying the sensors upwind from the protected assets. The further the distance upwind, the greater the warning time. The technological challenge to this concept is the biological detection technology. Here, cost, size and power are major factors in selecting acceptable technologies. This is in part due to the increased field densities needed to cover the upwind area and the fact that the sensors, when deployed forward, must operate autonomously for long periods of time with little or no long-term logistical support. The Defense Advanced Research Project Agency"s (DARPA) Solid-state Ultraviolet Optical Source (SUVOS) program offers an enabling technology to achieving a detector compatible with this mission. As an optical source, these devices emit excitation wavelengths known to be useful in the detection of biological aerosols. The wavelength band is absorbed by the biological aerosol and results in visible fluorescence. Detection of a biological aerosol is based on the observed intensity of this fluorescence signal compared to a background reference. Historically this has been accomplished with emission sources that are outside the boundaries for low cost, low power sensors. The SUVOS technology, on the other hand, provides the same basic wavelengths needed for the detection process in a small, low power package. ECBC has initiated an effort to develop a network array based on micro UV detectors that utilize the SUVOS technology. This paper presents an overview of the micro UV detector and some of the findings to date. This includes the overall design philosophy, fluid flow calculations to maximize presentation of aerosol particles to the sources, and the fluorescence measurements.

  2. Hybrid micro-/nanogels for optical sensing and intracellular imaging

    PubMed Central

    Wu, Weitai; Zhou, Shuiqin

    2010-01-01

    Hybrid micro-/nanogels are playing an increasing important part in a diverse range of applications, due to their tunable dimensions, large surface area, stable interior network structure, and a very short response time. We review recent advances and challenges in the developments of hybrid micro-/nanogels toward applications for optical sensing of pH, temperature, glucose, ions, and other species as well as for intracellular imaging. Due to their unique advantages, hybrid micro-/nanogels as optical probes are attracting substantial interests for continuous monitoring of chemical parameters in complex samples such as blood and bioreactor fluids, in chemical research and industry, and in food quality control. In particular, their intracellular probing ability enables the monitoring of the biochemistry and biophysics of live cells over time and space, thus contributing to the explanation of intricate biological processes and the development of novel diagnoses. Unlike most other probes, hybrid micro-/nanogels could also combine other multiple functions into a single probe. The rational design of hybrid micro-/nanogels will not only improve the probing applications as desirable, but also implement their applications in new arenas. With ongoing rapid advances in bionanotechnology, the well-designed hybrid micro-/nanogel probes will be able to provide simultaneous sensing, imaging diagnosis, and therapy toward clinical applications. PMID:22110866

  3. Micro/nanofabricated solid-state thermoelectric generator devices for integrated high voltage power sources

    NASA Technical Reports Server (NTRS)

    Fleurial, J. P.; Snyder, G. J.; Patel, J.; Huang, C. K.; Ryan, M. A.; Averback, R.; Chen, G.; Hill, C.

    2002-01-01

    The Jet Propulsion Laboratory has been actively pursuing the development of thermoelectric micro/nanodevices that can be fabricated using a combination of electrochemical deposition and integrated circuit processing techniques.

  4. A High-accuracy Micro-deformation Measurement Method

    NASA Astrophysics Data System (ADS)

    Jiang, Li

    2016-07-01

    The requirement for ever-increasing-resolution space cameras drives focal length and diameter of optical lenses be increasing. High-frequency vibration in the process of launching and complex environmental conditions of the outer space generate micro deformation in components of space cameras. As a result, images from the space cameras are blurred. Therefore, it is necessary to measure the micro deformations in components of space cameras in various experiment conditions. This paper presents a high-accuracy micro deformation measurement method. The method is implemented as follows: (1) fix Tungsten-steel balls onto a space camera being measured and measure the coordinate for each ball under the standard condition; (2) simulate high-frequency vibrations and environmental conditions like the outer space to measure coordinates for each ball under each combination of test conditions; and (3) compute the deviation of a coordinate of a ball under a test condition combination from the coordinate of the ball under the standard condition and the deviation is the micro deformation of the space camera component associated with the ball. This method was applied to micro deformation measurement for space cameras of different models. Measurement data for these space cameras validated the proposed method.

  5. Analysis of the Multi Strategy Goal Programming for Micro-Grid Based on Dynamic ant Genetic Algorithm

    NASA Astrophysics Data System (ADS)

    Qiu, J. P.; Niu, D. X.

    Micro-grid is one of the key technologies of the future energy supplies. Take economic planning. reliability, and environmental protection of micro grid as a basis for the analysis of multi-strategy objective programming problems for micro grid which contains wind power, solar power, and battery and micro gas turbine. Establish the mathematical model of each power generation characteristics and energy dissipation. and change micro grid planning multi-objective function under different operating strategies to a single objective model based on AHP method. Example analysis shows that in combination with dynamic ant mixed genetic algorithm can get the optimal power output of this model.

  6. Micro-Raman spectroscopy for meat type detection

    NASA Astrophysics Data System (ADS)

    De Biasio, M.; Stampfer, P.; Leitner, R.; Huck, C. W.; Wiedemair, V.; Balthasar, D.

    2015-06-01

    The recent horse meat scandal in Europe increased the demand for optical sensors that can identify meat type. Micro-Raman spectroscopy is a promising technique for the discrimination of meat types. Here, we present micro-Raman measurements of chicken, pork, turkey, mutton, beef and horse meat test samples. The data was analyzed with different combinations of data normalization and classification approaches. Our results show that Raman spectroscopy can discriminate between different meat types. Red and white meat are easily discriminated, however a sophisticated chemometric model is required to discriminate species within these groups.

  7. Fiber laser micro-cutting of stainless steel sheets

    NASA Astrophysics Data System (ADS)

    Baumeister, M.; Dickmann, K.; Hoult, T.

    2006-11-01

    The authors report on laser micro-cutting results for stainless steel foils with the aid of a 100 W fiber laser. This novel laser source combines a high output power in relation to conventional laser sources for micro-processing applications with an excellent beam quality (M2=1.1). Different material thicknesses were evaluated (100 μm to 300 μm). Processing was carried out with cw operation of the laser source, and with nitrogen and oxygen as assisting gases. Besides the high processing rate of oxygen assisted cutting, a better cutting performance in terms of a lower kerf width was obtained.

  8. Fabrication and measurement of a flexoelectric micro-pyramid composite

    NASA Astrophysics Data System (ADS)

    Huang, Wenbin; Shu, Longlong; Ryung Kwon, Seol; Zhang, Shujun; Yuan, Fuh-Gwo; Jiang, Xiaoning

    2014-12-01

    A fabrication method by combining precision mechanical dicing and wet etching was developed to prepare micro-pyramid structures based on (Ba0.67Sr0.33)TiO3 ceramics. The effective piezoelectric properties of flexoelectric pyramid structures in ten micrometers scale were investigated and measured through converse flexoelectric effect. The scaling effect of the flexoelectric response was demonstrated as the structure size shrinks down. The results do suggest the great potential of flexoelectric micro pyramids as an alternative to lead-free piezoelectric material.

  9. Levitated micro-accelerometer.

    SciTech Connect

    Warne, Larry Kevin; Schmidt, Carrie Frances; Peterson, Kenneth Allen; Kravitz, Stanley H.; Renn, Rosemarie A.; Peter, Frank J.; Kinney, Ragon D.; Gilkey, Jeffrey C.

    2004-06-01

    The objective is a significant advancement in the state-of-the-art of accelerometer design for tactical grade (or better) applications. The design goals are <1 milli-G bias stability across environments and $200 cost. This quantum leap in performance improvement and cost reduction can only be achieved by a radical new approach, not incremental improvements to existing concepts. This novel levitated closed-loop accelerometer is implemented as a hybrid micromachine. The hybrid approach frees the designer from the limitations of any given monolithic process and dramatically expands the available design space. The design can be tailored to the dynamic range, resolution, bandwidth, and environmental requirements of the application while still preserving all of the benefits of monolithic MEMS fabrication - extreme precision, small size, low cost, and low power. An accelerometer was designed and prototype hardware was built, driving the successful development and refinement of several 'never been done before' fabrication processes. Many of these process developments are commercially valuable and are key enablers for the realization of a wide variety of useful micro-devices. While controlled levitation of a proof mass has yet to be realized, the overall design concept remains sound. This was clearly demonstrated by the stable and reliable closed-loop control of a proof mass at the test structure level. Furthermore, the hybrid MEMS implementation is the most promising approach for achieving the ambitious cost and performance targets. It is strongly recommended that Sandia remain committed to the original goal.

  10. Micro thrust and heat generator

    SciTech Connect

    Garcia, E.J.

    1995-12-31

    The present invention relates generally to micromachines such as microengines or micromotors. More specifically, the invention is directed to a micro rocket which functions as a source of heat and thrust, and utilizes chemical energy to drive or power micromechanical apparatuses. The invention is adaptable to applications involving defense, bio-medical, manufacturing, consumer product, aviation, automotive, computer, inspection, and safety systems. A micro thrust and heat generator has a means for providing a combustion fuel source to an ignition chamber of the micro thrust and heat generator. The fuel is ignited by a ignition means within the micro thrust and heat generator`s ignition chamber where it burns and creates a pressure. A nozzle formed from the combustion chamber extends outward from the combustion chamber and tappers down to a narrow diameter and then opens into a wider diameter where the nozzle then terminates outside of said combustion chamber. The pressure created within the combustion chamber accelerates as it leaves the chamber through the nozzle resulting in pressure and heat escaping from the nozzle to the atmosphere outside the micro thrust and heat generator. The micro thrust and heat generator can be microfabricated from a variety of materials, e.g., of polysilicon, on one wafer using surface micromachining batch fabrication techniques or high aspect ratio micromachine techniques (LIGA).

  11. Micro Weather Station

    NASA Technical Reports Server (NTRS)

    Hoenk, Michael E.

    1999-01-01

    Improved in situ meteorological measurements in the troposphere and stratosphere are needed for studies of weather and climate, both as a primary data source and as validation for remote sensing instruments. Following the initial development and successful flight validation of the surface acoustic wave (SAW) hygrometer, the micro weather station program was directed toward the development of an integrated instrument, capable of accurate, in situ profiling of the troposphere, and small enough to fly on a radiosonde balloon for direct comparison with standard radiosondes. On April 23, 1998, working with Frank Schmidlin and Bob Olson of Wallops Island Flight Facility, we flew our instrument in a dual payload experiment, for validation and direct comparison with a Vaisala radiosonde. During that flight, the SAW dewpoint hygrometer measured frostpoint down to -76T at 44,000 feet. Using a laptop computer in radio contact with the balloon, we monitored data in real time, issued the cutdown command, and recovered the payload less than an hour after landing in White Sands Missile Range, 50 miles from the launch site in Hatch, New Mexico. Future flights will extend the intercomparison, and attempt to obtain in situ meteorological profiles from the surface through the tropopause. The SAW hygrometer was successfully deployed on the NASA DC8 as part of NASA's Third Convection and Moisture Experiment (CAMEX-3) during August and September, 1998. This field campaign was devoted to the study of hurricane tracking and intensification using NASA-funded aircraft. In situ humidity data from the SAW hygrometer are currently being analyzed and compared with data from other instruments on the DC8 and ER2 aircraft. Additional information is contained in the original.

  12. Micro-calorimetric sensor for trace explosive particle detection

    NASA Astrophysics Data System (ADS)

    Olsen, Jesper K.; Greve, Anders; Privorotskaya, N.; Senesac, L.; Thundat, T.; King, W. P.; Boisen, A.

    2010-04-01

    A micro differential thermal analysis (DTA) system is used for detection of trace explosive particles. The DTA system consists of two silicon micro chips with integrated heaters and temperature sensors. One chip is used for reference and one for the measurement sample. The sensor is constructed as a small silicon nitride bridge incorporating heater elements and a temperature measurement resistor. In this manuscript the DTA system is described and tested by measuring calorimetric response of DNT (2,4-Dinitrotoluene). The design of the senor is described and the temperature uniformity investigated using finite element modelings and Raman temperature measurements. The functionality is tested using two different kinds of explosive deposition techniques and calorimetric responses are obtained. Under the framework of the Xsense project at the Technical University of Denmark (DTU) which combines four independent sensing techniques, these micro DNT sensors will be included in handheld explosives detectors with applications in homeland security and landmine clearance.

  13. Micro-Particles as Electrostatic Probes for Plasma Sheath Diagnostic

    SciTech Connect

    Wolter, Matthias; Haass, Moritz; Ockenga, Taalke; Kersten, Holger; Blazec, Joseph; Basner, Ralf

    2008-09-07

    An interesting aspect in the research of complex (dusty) plasmas is the experimental study of the interaction of micro-particles of different sizes with the surrounding plasma for diagnostic purpose. In the plasma micro-disperse particles are negatively charged and confined in the sheath. The particles are trapped by an equilibrium of gravity, electric field force and ion drag force. From the behavior, local electric fields can be determined, e.g. particles are used as electrostatic probes. In combination with additional measurements of the plasma parameters with Langmuir probes and thermal probes as well as by comparison with an analytical sheath model, the structure of the sheath can be described. In the present work we focus on the behavior of micro-particles of different sizes and several plasma parameters e.g. the gas pressure and the rf-power.

  14. Progress with MEMS x-ray micro pore optics

    NASA Astrophysics Data System (ADS)

    Ezoe, Yuichiro; Moriyama, Teppei; Ogawa, Tomohiro; Kakiuchi, Takuya; Ohashi, Takaya; Mitsuishi, Ikuyuki; Mitsuda, Kazuhisa; Horade, Mitsuhiro; Sugiyama, Susumu; Riveros, Raul E.; Yamaguchi, Hitomi; Kanamori, Yoshiaki; Morishita, Kohei; Nakajima, Kazuo; Maeda, Ryutaro

    2012-09-01

    Our development of ultra light-weight X-ray micro pore optics based on MEMS (Micro Electro Mechanical System) technologies is described. Using dry etching or X-ray lithography and electroplating, curvilinear sidewalls through a flat wafer are fabricated. Sidewalls vertical to the wafer surface are smoothed by use of high temperature annealing and/or magnetic field assisted finishing to work as X-ray mirrors. The wafer is then deformed to a spherical shape. When two spherical wafers with different radii of curvature are stacked, the combined system will be an approximated Wolter type-I telescope. This method in principle allows high angular resolution and ultra light-weight X-ray micro pore optics. In this paper, performance of a single-stage optic, coating of a heavy metal on sidewalls with atomic layer deposition, and assembly of a Wolter type-I telescope are reported.

  15. MEMS: A new approach to micro-optics

    SciTech Connect

    Sniegowski, J.J.

    1997-12-31

    MicroElectroMechanical Systems (MEMS) and their fabrication technologies provide great opportunities for application to micro-optical systems (MOEMS). Implementing MOEMS technology ranges from simple, passive components to complicated, active systems. Here, an overview of polysilicon surface micromachining MEMS combined with optics is presented. Recent advancements to the technology, which may enhance its appeal for micro-optics applications are emphasized. Of all the MEMS fabrication technologies, polysilicon surface micromachining technology has the greatest basis in and leverages the most the infrastructure for silicon integrated circuit fabrication. In that respect, it provides the potential for very large volume, inexpensive production of MOEMS. This paper highlights polysilicon surface micromachining technology in regards to its capability to provide both passive and active mechanical elements with quality optical elements.

  16. An osmolyte-based micro-volume ultrafiltration technique.

    PubMed

    Ghosh, Raja

    2014-12-01

    This paper discusses a novel, simple, and inexpensive micro-volume ultrafiltration technique for protein concentration, desalting, buffer exchange, and size-based protein purification. The technique is suitable for processing protein samples in a high-throughput mode. It utilizes a combination of capillary action, and osmosis for drawing water and other permeable species from a micro-volume sample droplet applied on the surface of an ultrafiltration membrane. A macromolecule coated on the permeate side of the membrane functions as the osmolyte. The action of the osmolyte could, if required, be augmented by adding a supersorbent polymer layer over the osmolyte. The mildly hydrophobic surface of the polymeric ultrafiltration membrane used in this study minimized sample droplet spreading, thus making it easy to recover the retained material after separation, without sample interference and cross-contamination. High protein recoveries were observed in the micro-volume ultrafiltration experiments described in the paper. PMID:25284741

  17. Controlled delivery of acyclovir from porous silicon micro- and nanoparticles

    NASA Astrophysics Data System (ADS)

    Maniya, Nalin H.; Patel, Sanjaykumar R.; Murthy, Z. V. P.

    2015-03-01

    In this work, micro- and nanoparticles of porous silicon (PSi) are demonstrated to act as effective carrier for the controlled delivery of acyclovir (ACV). PSi films prepared by electrochemical etching were fractured by ultrasonication to prepare micro- and nanoparticles. PSi native particles were thermally oxidized (TOPSi) and thermally hydrosilylated using undecylenic acid (UnPSi). PSi particles with three different surface chemistries were then loaded with ACV by physical adsorption and covalent attachment. Such particles were characterized by scanning electron microscopy, dynamic light scattering, and Fourier transform infrared spectroscopy. In vitro ACV release experiments in phosphate buffered saline showed sustained release behaviour from both micro- and nanoparticles and order of release was found to be native PSi > TOPSi > UnPSi. Drug release kinetics study using Korsmeyer-Peppas model suggested a combination of both drug diffusion and Si scaffold erosion based drug release mechanisms.

  18. Review of Micro/Nanotechnologies for Microbial Biosensors

    PubMed Central

    Lim, Ji Won; Ha, Dogyeong; Lee, Jongwan; Lee, Sung Kuk; Kim, Taesung

    2015-01-01

    A microbial biosensor is an analytical device with a biologically integrated transducer that generates a measurable signal indicating the analyte concentration. This method is ideally suited for the analysis of extracellular chemicals and the environment, and for metabolic sensory regulation. Although microbial biosensors show promise for application in various detection fields, some limitations still remain such as poor selectivity, low sensitivity, and impractical portability. To overcome such limitations, microbial biosensors have been integrated with many recently developed micro/nanotechnologies and applied to a wide range of detection purposes. This review article discusses micro/nanotechnologies that have been integrated with microbial biosensors and summarizes recent advances and the applications achieved through such novel integration. Future perspectives on the combination of micro/nanotechnologies and microbial biosensors will be discussed, and the necessary developments and improvements will be strategically deliberated. PMID:26029689

  19. The Laser MicroJet (LMJ): a multi-solution technology for high quality micro-machining

    NASA Astrophysics Data System (ADS)

    Mai, Tuan Anh; Richerzhagen, Bernold; Snowdon, Paul C.; Wood, David; Maropoulos, Paul G.

    2007-02-01

    The field of laser micromachining is highly diverse. There are many different types of lasers available in the market. Due to their differences in irradiating wavelength, output power and pulse characteristic they can be selected for different applications depending on material and feature size [1]. The main issues by using these lasers are heat damages, contamination and low ablation rates. This report examines on the application of the Laser MicroJet(R) (LMJ), a unique combination of a laser beam with a hair-thin water jet as a universal tool for micro-machining of MEMS substrates, as well as ferrous and non-ferrous materials. The materials include gallium arsenide (GaAs) & silicon wafers, steel, tantalum and alumina ceramic. A Nd:YAG laser operating at 1064 nm (infra red) and frequency doubled 532 nm (green) were employed for the micro-machining of these materials.

  20. Alkali Metal Based Micro Combustion Using Graphene Micro-valve Trigger

    NASA Astrophysics Data System (ADS)

    Ruyack, A.; Gund, V.; Camera, K.; Ardanuç, S.; Ober, C.; Lal, A.

    2015-12-01

    Controllable combustion of alkali metals offers a pathway to high energy density, high power density scalable thermal systems. The volatile nature of these materials however, has limited their incorporation into useable devices. Recent findings in low trigger power MEMS one-shot valves offer a viable pathway forward for creating systems in which to exploit the unique properties of alkali metals as thermal energy sources. By miniaturizing and combining these fuels with such a valve, and incorporating them with a polymer substrate, a micro-packet of combustible metal can be created. Here we report such a device utilizing a graphene based micro-valve trigger and a rubidium metal fuel source to realize an arrayable micro-scale electrical to thermal energy amplification scheme. Using this approach we can react nanoliter droplets of rubidium with ambient air on demand, producing electrical to thermal energy gains of seventy five times. By arraying the fuel into discrete packets, we can also achieve temporal control of the fuel source, allowing for tailored peak and average power output.

  1. Identification of Reference Genes for Relative Quantification of Circulating MicroRNAs in Bovine Serum

    PubMed Central

    Bae, In-Seon; Chung, Ki Yong; Yi, Jongmin; Kim, Tae Il; Choi, Hwa-Sik; Cho, Young-Moo; Choi, Inho; Kim, Sang Hoon

    2015-01-01

    Circulating microRNAs in body fluids have been implicated as promising biomarkers for physiopathology disorders. Currently, the expression levels of circulating microRNAs are estimated by reverse transcription quantitative real-time polymerase chain reaction. Use of appropriate reference microRNAs for normalization is critical for accurate microRNA expression analysis. However, no study has systematically investigated reference genes for evaluating circulating microRNA expression in cattle. In this study, we describe the identification and characterization of appropriate reference microRNAs for use in the normalization of circulating microRNA levels in bovine serum. We evaluated the expression stability of ten candidate reference genes in bovine serum by using reverse transcription quantitative real-time polymerase chain reaction. Data were analyzed using geNorm, NormFinder, and BestKeeper statistical algorithms. The results consistently showed that a combination of miR-93 and miR-127 provided the most stably expressed reference. The suitability of these microRNAs was validated, and even when compared among different genders or breeds, the combination of miR-93 and miR-127 was ranked as the most stable microRNA reference. Therefore, we conclude that this combination is the optimal endogenous reference for reverse transcription quantitative real-time polymerase chain reaction-based detection of microRNAs in bovine serum. The data presented in this study are crucial to successful biomarker discovery and validation for the diagnosis of physiopathological conditions in cattle. PMID:25826387

  2. Enhanced selection of micro-aerobic pentachlorophenol degrading granular sludge.

    PubMed

    Lv, Yuancai; Chen, Yuancai; Song, Wenzhe; Hu, Yongyou

    2014-09-15

    Column-type combined reactors were designed to cultivate micro-aerobic pentachlorophenol (PCP) degrading granular sludge under oxygen-limited conditions (0.1-0.2 mgL(-1)) over 39-day experimental period. Micro-aerobic granular had both anaerobic activity (SMA: 2.34 mMCH4/hg VSS) and aerobic activity (SOUR: 2.21 mMO2/hg VSS). Metabolite analysis results revealed that PCP was sequentially dechlorinated to TCP, DCP, and eventually to MCP. Methanogens were not directly involved in the dechlorination of PCP, but might played a vital role in stabilizing the overall structure of the granule sludge. For Eubacteria, the Shannon Index (2.09 in inoculated granular sludge) increased both in micro-aerobic granular sludge (2.61) and PCP-degradation granular sludge (2.55). However, for Archaea, it decreased from 2.53 to 1.85 and 1.84, respectively. Although the Shannon Index demonstrated slight difference between micro-aerobic granular sludge and PCP-degradation granular sludge, the Principal Component Analysis (PCA) indicated obvious variance of the microbial composition, revealing significant effect of micro-aerobic condition and PCP on microbial community. Furthermore, nucleotide sequencing indicated that the main microorganisms for PCP degradation might be related to Actinobacterium and Sphingomonas. These results provided insights into situ bioremediation of environments contaminated by PCP and had practical implications for the strategies of PCP degradation. PMID:25151236

  3. Vacuum isostatic micro molding of diffractive structures into PTFE materials

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd E.; Ohar, Orest

    2007-09-01

    Polytetrafluoroethylene (PTFE) is an ideal material for use in industrial, automotive and consumer electronics. Specifically, PTFE has outstanding physical properties; such as chemical inertness and resistance to chemical corrosion, even when exposed to a strong acid, alkali and oxidants. Its properties provide for superior electrical insulation and thermal stability, which is not affected by wide ranges in temperature and frequency. Its non-absorption of moisture makes it a perfect material for consideration in micro optical, retro-reflector or diffuser type devices used in handheld displays, flat panel displays as well as automotive, industrial and home lighting. This paper presents an overview of a unique fabrication method that incorporates a variety of elements to establish a processing technique that can form micro diffractive, holographic and reflective structures into PTFE materials. By means of modifying an existing known molding process, this new technique incorporates the addition of a vacuum to assist in the reliable molding and densification of the PTFE as well the use of a micro-structured electroformed shim to form small microstructures into the surface of the PTFE material. The combination of the vacuum and the electroformed shim within the molding process noticeably increases the precision, reproducibility and resolution of micro-structures that can be realized. The paper will describe the molding hardware involved, process parameters and the resulting structures formed. Optical function testing and metrology of the micro-structure geometry formed on each sample will be compared to the original design mandrel geometry [1].

  4. A micro solar heater for portable energy generation

    NASA Astrophysics Data System (ADS)

    Zimmerman, Raúl; Morrison, Graham; The, Owen; Rosengarten, Gary

    2007-12-01

    This study presents a new concept that combines microtechnology with solar thermal energy to provide a free portable energy source. A water-methanol mixture flows through an array of parallel microchannels which are fabricated into a silicon matrix using conventional micro-fabrication techniques. A vacuum layer is interposed between the channels and the external surface to thermally insulate the channels from the ambient temperature. A selective coating is deposited on one of the vacuum walls to absorb the short wavelength incoming radiation and reduce the long wavelength radiation, hence reducing the heat losses. A geometry and material optimization is still being developed in order to obtain the highest possible efficiency for the micro-heater, while keeping a low pressure drop in the micro-channels. The methanol outlet temperature is predicted to be higher than 250°C. This temperature is required for hydrogen production in a methanol reforming micro-reactor. Therefore, it is envisaged that the micro-solar heater will supply the thermal energy needed for hydrogen generation, that can later be used as fuel for microfuel cells. Both technologies can be integrated in a portable device.

  5. Depth elemental imaging of forensic samples by confocal micro-XRF method.

    PubMed

    Nakano, Kazuhiko; Nishi, Chihiro; Otsuki, Kazunori; Nishiwaki, Yoshinori; Tsuji, Kouichi

    2011-05-01

    Micro-XRF is a significant tool for the analysis of small regions. A micro-X-ray beam can be created in the laboratory by various focusing X-ray optics. Previously, nondestructive 3D-XRF analysis had not been easy because of the high penetration of fluorescent X-rays emitted into the sample. A recently developed confocal micro-XRF technique combined with polycapillary X-ray lenses enables depth-selective analysis. In this paper, we applied a new tabletop confocal micro-XRF system to analyze several forensic samples, that is, multilayered automotive paint fragments and leather samples, for use in the criminaliztics. Elemental depth profiles and mapping images of forensic samples were successfully obtained by the confocal micro-XRF technique. Multilayered structures can be distinguished in forensic samples by their elemental depth profiles. However, it was found that some leather sheets exhibited heterogeneous distribution. To confirm the validity, the result of a conventional micro-XRF of the cross section was compared with that of the confocal micro-XRF. The results obtained by the confocal micro-XRF system were in approximate agreement with those obtained by the conventional micro-XRF. Elemental depth imaging was performed on the paint fragments and leather sheets to confirm the homogeneity of the respective layers of the sample. The depth images of the paint fragment showed homogeneous distribution in each layer expect for Fe and Zn. In contrast, several components in the leather sheets were predominantly localized. PMID:21438498

  6. Birth control pills - combination

    MedlinePlus

    The pill - combination; Oral contraceptives - combination; OCP - combination; Contraception - combination ... Birth control pills help keep you from getting pregnant. When taken daily, they are one of the most ...

  7. Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)

    SciTech Connect

    Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han

    2012-05-10

    The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO{sub 4}) solution. As a tissue-staining contrast agent, OsO{sub 4} is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO{sub 4} preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE{sup -/-}) mice at 10 {mu}m resolution. The results show that walls of coronary arteries as small as 45 {mu}m in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO{sub 4} and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

  8. Experimental investigation of electrohydrodynamic instabilities in micro channels

    NASA Astrophysics Data System (ADS)

    Eribol, P.; Uguz, A. K.

    2015-03-01

    An electric field is applied to destabilize the interface between two Newtonian and immiscible liquids flowing in a rectangular micro channel. The liquids are pumped into the micro channel with a syringe pump and a DC electric field is applied either parallel or normal to the flat interface between these liquids. The two liquids used in the experiments are a combination of ethylene glycol, different viscosity silicone oils, castor oil, and olive oil. The onset of electrohydrodynamic instability is investigated for various parameters, including the ratios of the flow rates, and viscosities of the liquids, the width of the micro channel, and the direction of the applied electric field. The order of the voltage applied to destabilize the interface is in the range 95 and 1190 V. The results of the experiments show that an increase in the viscosity ratio and the flow rate ratio of silicone oil to ethylene glycol have a stabilizing effect. It is also found that the important parameter to determine the critical voltage is the flow rate ratio, not the individual flow rates of the liquids. Also, as the width of the micro channel increases, the critical voltage increases. Lastly, for the liquid combinations used in the experiments, the interface could not be destabilized under the influence of a parallel electric field.

  9. Development and evaluation of micro push-pull tests to investigate micro-scale processes in porous media.

    PubMed

    Knecht, Kajsa; Schroth, Martin H; Schulin, Rainer; Nowack, Bernd

    2011-08-01

    Soils and sediments are porous media characterized by heterogeneities across a wide range of spatial scales. Physical, chemical, and biological properties have been found to show great variation even at subcentimeter scales. Here we present a new micro technique for the in situ study of chemical and microbiological reactions in water-saturated porous media at the mm-scale. This technique combines micro suction cups with the principle of single-well injection-withdrawal tests ("push-pull" tests). Push-pull tests have been used extensively on larger scales in groundwater research to obtain quantitative information of physical, chemical, and microbiological characteristics of an aquifer. The micro push-pull technique presented here was developed and validated using a thin-slab chamber filled with sand. A porous micro cup was used to inject about 250 μL of a test solution into the water-saturated sand pack and then to slowly extract about 850 μL water from the same point. The extraction-phase breakthrough curves of the solutes were modeled considering advection, dispersion, and molecular diffusion without fitting any parameters. As an example we quantified the degradation of citrate injected into the water-saturated sand pack inoculated with denitrifying bacteria. The results show that the new technique can be used to assess local microbial degradation processes under in situ conditions on the micro scale. PMID:21710991

  10. Targeting the microRNA-21/AP1 axis by 5-fluorouracil and pirarubicin in human hepatocellular carcinoma

    PubMed Central

    He, Xiaodong; Li, Jingjing; Guo, Weidong; Liu, Wei; Yu, Jia; Song, Wei; Dong, Lei; Wang, Fang; Yu, Shuangni; Zheng, Yi; Chen, Songsen; Kong, Yan; Liu, Changzheng

    2015-01-01

    MicroRNAs function as oncomiRs and tumor suppressors in diverse cancers. However, the utility of specific microRNAs in predicting the clinical benefit of chemotherapy has not been well-established. Here, we investigated the correlation between microRNA-21 expression and hepatic arterial infusion chemotherapy with 5-fluorouracil and pirarubicin (HAIC) for hepatocellular carcinoma (HCC). We found that HCC patients with low microRNA-21 levels in tumors tended to have a longer time to recurrence and disease-free survival. We demonstrated that microRNA-21 suppression in combination with 5-fluorouracil and pirarubicin treatment inhibited tumor growth in subcutaneous xenograft mice models. Mechanistically, the AP-1 and microRNA-21-mediated axis was verified to be a therapeutic target of cytotoxic drugs and deregulation of this axis led to an enhanced cell growth in HCC. Taken together, our findings demonstrate that microRNA-21 is a chemotherapy responsive microRNA and can serve as a prognostic biomarker for HCC patients undergoing HAIC. Targeting microRNA-21 enhances the effect of chemotherapeutic drugs, thereby suggesting that microRNA-21 suppression in combination with HAIC may be a novel approach for HCC treatment. PMID:25544773

  11. Mechano-micro/nano systems

    NASA Astrophysics Data System (ADS)

    Horie, Mikio

    2004-10-01

    In recent years, the researches about Micro/Nano Systems are down actively in the bio-medical research fields, DNA research fields, chemical analysis systems fields, etc. In the results, a new materials and new functions in the systems are developed. In this invited paper, Mechano-Micro/Nano Systems, especially, motion systems are introduced. First, the research activities concerning the Mechano-Micro/Nano Systems in the world(MST2003, MEMS2003 and MEMS2004) and in Japan(Researech Projects on Nanotechnology and Materials in Ministry of Education, Culture, Sports, Science and Technology) are shown. Secondary, my research activities are introduced. As my research activities, (1) a comb-drive static actuator for the motion convert mechanisms, (2) a micro-nano fabrication method by use of FAB(Fast Atom Beam) machines, (3) a micro optical mirror manipulator for inputs-outputs optical switches, (4) a miniature pantograph mechanism with large-deflective hinges and links made of plastics are discussed and their performances are explained.

  12. Tunable Micro- and Nanomechanical Resonators

    PubMed Central

    Zhang, Wen-Ming; Hu, Kai-Ming; Peng, Zhi-Ke; Meng, Guang

    2015-01-01

    Advances in micro- and nanofabrication technologies have enabled the development of novel micro- and nanomechanical resonators which have attracted significant attention due to their fascinating physical properties and growing potential applications. In this review, we have presented a brief overview of the resonance behavior and frequency tuning principles by varying either the mass or the stiffness of resonators. The progress in micro- and nanomechanical resonators using the tuning electrode, tuning fork, and suspended channel structures and made of graphene have been reviewed. We have also highlighted some major influencing factors such as large-amplitude effect, surface effect and fluid effect on the performances of resonators. More specifically, we have addressed the effects of axial stress/strain, residual surface stress and adsorption-induced surface stress on the sensing and detection applications and discussed the current challenges. We have significantly focused on the active and passive frequency tuning methods and techniques for micro- and nanomechanical resonator applications. On one hand, we have comprehensively evaluated the advantages and disadvantages of each strategy, including active methods such as electrothermal, electrostatic, piezoelectrical, dielectric, magnetomotive, photothermal, mode-coupling as well as tension-based tuning mechanisms, and passive techniques such as post-fabrication and post-packaging tuning processes. On the other hand, the tuning capability and challenges to integrate reliable and customizable frequency tuning methods have been addressed. We have additionally concluded with a discussion of important future directions for further tunable micro- and nanomechanical resonators. PMID:26501294

  13. Micro Machining Enhances Precision Fabrication

    NASA Technical Reports Server (NTRS)

    2007-01-01

    Advanced thermal systems developed for the Space Station Freedom project are now in use on the International Space Station. These thermal systems employ evaporative ammonia as their coolant, and though they employ the same series of chemical reactions as terrestrial refrigerators, the space-bound coolers are significantly smaller. Two Small Business Innovation Research (SBIR) contracts between Creare Inc. of Hanover, NH and Johnson Space Center developed an ammonia evaporator for thermal management systems aboard Freedom. The principal investigator for Creare Inc., formed Mikros Technologies Inc. to commercialize the work. Mikros Technologies then developed an advanced form of micro-electrical discharge machining (micro-EDM) to make tiny holes in the ammonia evaporator. Mikros Technologies has had great success applying this method to the fabrication of micro-nozzle array systems for industrial ink jet printing systems. The company is currently the world leader in fabrication of stainless steel micro-nozzles for this market, and in 2001 the company was awarded two SBIR research contracts from Goddard Space Flight Center to advance micro-fabrication and high-performance thermal management technologies.

  14. Designing a Micro-Mechanical Transistor

    SciTech Connect

    Mainieri, R.

    1999-06-03

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Micro-mechanical electronic systems are chips with moving parts. They are fabricated with the same techniques that are used to manufacture electronic chips, sharing their low cost. Micro-mechanical chips can also contain electronic components. By combining mechanical parts with electronic parts it becomes possible to process signal mechanically. To achieve designs comparable to those obtained with electronic components it is necessary to have a mechanical device that can change its behavior in response to a small input - a mechanical transistor. The work proposed will develop the design tools for these complex-shaped resonant structures using the geometrical ray technique. To overcome the limitations of geometrical ray chaos, the dynamics of the rays will be studied using the methods developed for the study of nonlinear dynamical systems. T his leads to numerical methods that execute well in parallel computer architectures, using a limited amount of memory and no inter-process communication.

  15. Nonlinear acoustics of micro-inhomogeneous media

    NASA Astrophysics Data System (ADS)

    Nazarov, Veniamin E.; Ostrovsky, Lev A.; Soustova, Irina A.; Sutin, Aleksandr M.

    1988-01-01

    Acoustic waves can interact in micro-inhomogeneous media much more intensively than in homogeneous media. This has been repeatedly observed in experiments with ground species, marine sediments, porous materials and metals. This paper considers two models of such media which seem to be applicable to the description of these results. One of them is based on the consideration of nonlinear sound scattering by separate spherical cavities in liquids and solids. The second model is based on the phenomenological stress-deformation relation in solids with microplasticity which often has hysteresis (heritage) properties associated with the micro-inhomogeneities. In metals, for example, it is caused by the movement of dislocations. Different nonlinear effects in such media (harmonic and combination frequency generation, nonlinear, variations of resonance frequency amplitude-dependent losses) are considered. Some results of experiments with metallic resonators supporting the theory developed here are also presented. These mechanisms may determine the nonlinear properties of real soils and rocks summarized in a table given in the paper.

  16. MicroRNAs are potential therapeutic targets in fibrosing kidney disease: lessons from animal models.

    PubMed

    Duffield, Jeremy S; Grafals, Monica; Portilla, Didier

    2013-01-01

    Chronic disease of the kidneys has reached epidemic proportions in industrialized nations. New therapies are urgently sought. Using a combination of animal models of kidney disease and human biopsy samples, a pattern of dysregulated microRNA expression has emerged which is common to chronic diseases. A number of these dysregulated microRNA have recently been shown to have functional consequences for the disease process and therefore may be potential therapeutic targets. We highlight microRNA-21, the most comprehensively studied microRNA in the kidney so far. MicroRNA-21 is expressed widely in healthy kidney but studies from knockout mice indicate it is largely inert. Although microRNA-21 is upregulated in many cell compartments including leukocytes, epithelial cells and myofibroblasts, the inert microRNA-21 also appears to become activated, by unclear mechanisms. Mice lacking microRNA-21 are protected from kidney injury and fibrosis in several distinct models of kidney disease, and systemically administered oligonucleotides that specifically bind to the active site in microRNA-21, inhibiting its function, recapitulate the genetic deletion of microRNA-21, suggesting inhibitory oligonucleotides may have therapeutic potential. Recent studies of microRNA-21 targets in kidney indicate that it normally functions to silence metabolic pathways including fatty acid metabolism and pathways that prevent Reactive Oxygen Species generation in peroxisomes and mitochondria in epithelial cells and myofibroblasts. Targeting specific pathogenic microRNAs in a specific manner is feasible in vivo and may be a new therapeutic target in disease of the kidney. PMID:25018773

  17. MicroRNAs are potential therapeutic targets in fibrosing kidney disease: lessons from animal models

    PubMed Central

    Duffield, Jeremy S; Grafals, Monica; Portilla, Didier

    2012-01-01

    Chronic disease of the kidneys has reached epidemic proportions in industrialized nations. New therapies are urgently sought. Using a combination of animal models of kidney disease and human biopsy samples, a pattern of dysregulated microRNA expression has emerged which is common to chronic diseases. A number of these dysregulated microRNA have recently been shown to have functional consequences for the disease process and therefore may be potential therapeutic targets. We highlight microRNA-21, the most comprehensively studied microRNA in the kidney so far. MicroRNA-21 is expressed widely in healthy kidney but studies from knockout mice indicate it is largely inert. Although microRNA-21 is upregulated in many cell compartments including leukocytes, epithelial cells and myofibroblasts, the inert microRNA-21 also appears to become activated, by unclear mechanisms. Mice lacking microRNA-21 are protected from kidney injury and fibrosis in several distinct models of kidney disease, and systemically administered oligonucleotides that specifically bind to the active site in microRNA-21, inhibiting its function, recapitulate the genetic deletion of microRNA-21, suggesting inhibitory oligonucleotides may have therapeutic potential. Recent studies of microRNA-21 targets in kidney indicate that it normally functions to silence metabolic pathways including fatty acid metabolism and pathways that prevent Reactive Oxygen Species generation in peroxisomes and mitochondria in epithelial cells and myofibroblasts. Targeting specific pathogenic microRNAs in a specific manner is feasible in vivo and may be a new therapeutic target in disease of the kidney PMID:25018773

  18. Flight Qualified Micro Sun Sensor

    NASA Technical Reports Server (NTRS)

    Liebe, Carl Christian; Mobasser, Sohrab; Wrigley, Chris; Schroeder, Jeffrey; Bae, Youngsam; Naegle, James; Katanyoutanant, Sunant; Jerebets, Sergei; Schatzel, Donald; Lee, Choonsup

    2007-01-01

    A prototype small, lightweight micro Sun sensor (MSS) has been flight qualified as part of the attitude-determination system of a spacecraft or for Mars surface operations. The MSS has previously been reported at a very early stage of development in NASA Tech Briefs, Vol. 28, No. 1 (January 2004). An MSS is essentially a miniature multiple-pinhole electronic camera combined with digital processing electronics that functions analogously to a sundial. A micromachined mask containing a number of microscopic pinholes is mounted in front of an active-pixel sensor (APS). Electronic circuits for controlling the operation of the APS, readout from the pixel photodetectors, and analog-to-digital conversion are all integrated onto the same chip along with the APS. The digital processing includes computation of the centroids of the pinhole Sun images on the APS. The spacecraft computer has the task of converting the Sun centroids into Sun angles utilizing a calibration polynomial. The micromachined mask comprises a 500-micron-thick silicon wafer, onto which is deposited a 57-nm-thick chromium adhesion- promotion layer followed by a 200-nm-thick gold light-absorption layer. The pinholes, 50 microns in diameter, are formed in the gold layer by photolithography. The chromium layer is thin enough to be penetrable by an amount of Sunlight adequate to form measurable pinhole images. A spacer frame between the mask and the APS maintains a gap of .1 mm between the pinhole plane and the photodetector plane of the APS. To minimize data volume, mass, and power consumption, the digital processing of the APS readouts takes place in a single field-programmable gate array (FPGA). The particular FPGA is a radiation- tolerant unit that contains .32,000 gates. No external memory is used so the FPGA calculates the centroids in real time as pixels are read off the APS with minimal internal memory. To enable the MSS to fit into a small package, the APS, the FPGA, and other components are mounted

  19. High-resolution structure determination by continuous rotation data collection in MicroED

    PubMed Central

    Leslie, Andrew G. W.; Gonen, Tamir

    2014-01-01

    MicroED uses very small three-dimensional protein crystals and electron diffraction for structure determination. An improved data collection protocol for MicroED called “continuous rotation” is presented. Here microcrystals are continuously rotated during data collection yielding improved data, and allowing data processing with MOSFLM resulting in improved resolution for the model protein lysozyme. These improvements pave the way for the implementation and application of MicroED with wide applicability in structural biology. PMID:25086503

  20. Micro electric propulsion feasibility

    NASA Technical Reports Server (NTRS)

    Aston, Graeme; Aston, Martha

    1992-01-01

    , minimal detectability and low cost are requirements. All these miniature spacecraft share a common characteristic: because of their on-board electronic equipment they have, by design, solar order 50-100 W. In a relative sense, such spacecraft are power rich when compared to other larger spacecraft. This power rich situation is offset by very tight mass budgets, which make reductions in propellant mass requirements a key issue in meeting overall spacecraft minimum mass goals. In principle, power rich and propellant poor brilliant pebbles class spacecraft can benefit from using high specific impulse electric propulsion to reduce chemical propellant mass requirements. However, at power levels of order 50 W, arcjets cannot be made to function, ion thrusters are too complex and heavy and resistojets have too low a specific impulse. Recognizing these capability limitations in existing electric propulsion technology, the SDIO/IST sponsored the Phase I SBIR Micro Electric Propulsion (MEP) thruster study described in this report. The objective of this study was to examine the feasibility of developing a very simple, low mass and small volume, electric thruster for operation on hydrazine at less than 100 W of input power. The feasibility of developing such a MEP thruster was successfully demonstrated by EPL by the discovery of a novel plasma acceleration process. The sections in this report summarize the approach, test results and major accomplishments of this proof-of-concept program.

  1. Development of Micro UAV Swarms

    NASA Astrophysics Data System (ADS)

    Bürkle, Axel; Leuchter, Sandro

    Some complex application scenarios for micro UAVs (Unmanned Aerial Vehicles) call for the formation of swarms of multiple drones. In this paper a platform for the creation of such swarms is presented. It consists of modified commercial quadrocopters and a self-made ground control station software architecture. Autonomy of individual drones is generated through a micro controller equipped video camera. Currently it is possible to fly basic maneuvers autonomously, such as take-off, fly to position, and landing. In the future the camera's image processing capabilities will be used to generate additional control information. Different co-operation strategies for teams of UAVs are currently evaluated with an agent based simulation tool. Finally complex application scenarios for multiple micro UAVs are presented.

  2. Micro and nanomotors in diagnostics.

    PubMed

    Chałupniak, Andrzej; Morales-Narváez, Eden; Merkoçi, Arben

    2015-12-01

    Synthetic micro/nanomotors are tiny devices than can be self-propelled or externally powered in the liquid phase by different types of energy source including but not limited to: catalytic, magnetic or acoustic. Showing a myriad of mechanical movements, building block materials, sizes, shapes and propulsion mechanisms micro/nanomotors are amenable to diagnostics and therapeutics. Herein we describe the most relevant micro/nanomotors, their fabrication pathways, propulsion strategies as well as in vivo and in vitro applications related with oligonucleotides, proteins, cells and tissues. We also discuss the main challenges in these applications such as the influence of complex media and toxicity issues as well as future perspectives. PMID:26408790

  3. Micro-column plasma emission liquid chromatograph

    DOEpatents

    Gay, Don D.

    1984-01-01

    In a direct current plasma emission spectrometer for use in combination with a micro-column liquid chromatograph, an improved plasma source unit. The plasma source unit includes a quartz capillary tube having an inlet means, outlet off gas means and a pair of spaced electrodes defining a plasma region in the tube. The inlet means is connected to and adapted to receive eluant of the liquid chromatograph along with a stream of plasma-forming gas. There is an opening through the wall of the capillary tube penetrating into the plasma region. A soft glass capillary light pipe is disposed at the opening, is connected to the spectrometer, and is adapted to transmit light passing from the plasma region to the spectrometer. There is also a source of electromotive force connected to the electrodes sufficient to initiate and sustain a plasma in the plasma region of the tube.

  4. An ISOPHOT Study of the Disk of Galaxy NGC6946: 60(micro)m Infrared and Radio Continuum Correlation

    NASA Technical Reports Server (NTRS)

    Lu, N. Y.; Helou, G.; Tuffs, R.; Xu, C.; Malhotra, S.; Werner, M. W.; Thronson, H.

    1996-01-01

    We combine the ISOPHOT 60(micro)m image of Tuffs, et al. (1996) and VLA radio continuum images at 6 and 20cm from the literature to study the 60(micro)m light distribution and its correlation with radio continuum within the disk of nearby spiral galaxy NGC6946, at an effective resolution of + - 52.

  5. Window-assisted nanosphere lithography for vacuum micro-nano-electronics

    SciTech Connect

    Li, Nannan; Pang, Shucai; Yan, Fei; Chen, Lei; Jin, Dazhi; Xiang, Wei; Zhang, De; Zeng, Baoqing

    2015-04-15

    Development of vacuum micro-nano-electronics is quite important for combining the advantages of vacuum tubes and solid-state devices but limited by the prevailing fabricating techniques which are expensive, time consuming and low-throughput. In this work, window-assisted nanosphere lithography (NSL) technique was proposed and enabled the low-cost and high-efficiency fabrication of nanostructures for vacuum micro-nano-electronic devices, thus allowing potential applications in many areas. As a demonstration, we fabricated high-density field emitter arrays which can be used as cold cathodes in vacuum micro-nano-electronic devices by using the window-assisted NSL technique. The details of the fabricating process have been investigated. This work provided a new and feasible idea for fabricating nanostructure arrays for vacuum micro-nano-electronic devices, which would spawn the development of vacuum micro-nano-electronics.

  6. Micro-machined calorimetric biosensors

    DOEpatents

    Doktycz, Mitchel J.; Britton, Jr., Charles L.; Smith, Stephen F.; Oden, Patrick I.; Bryan, William L.; Moore, James A.; Thundat, Thomas G.; Warmack, Robert J.

    2002-01-01

    A method and apparatus are provided for detecting and monitoring micro-volumetric enthalpic changes caused by molecular reactions. Micro-machining techniques are used to create very small thermally isolated masses incorporating temperature-sensitive circuitry. The thermally isolated masses are provided with a molecular layer or coating, and the temperature-sensitive circuitry provides an indication when the molecules of the coating are involved in an enthalpic reaction. The thermally isolated masses may be provided singly or in arrays and, in the latter case, the molecular coatings may differ to provide qualitative and/or quantitative assays of a substance.

  7. MicroRNA expression profiling using microarrays.

    PubMed

    Love, Cassandra; Dave, Sandeep

    2013-01-01

    MicroRNAs are small noncoding RNAs which are able to regulate gene expression at both the transcriptional and translational levels. There is a growing recognition of the role of microRNAs in nearly every tissue type and cellular process. Thus there is an increasing need for accurate quantitation of microRNA expression in a variety of tissues. Microarrays provide a robust method for the examination of microRNA expression. In this chapter, we describe detailed methods for the use of microarrays to measure microRNA expression and discuss methods for the analysis of microRNA expression data. PMID:23666707

  8. The collection of MicroED data for macromolecular crystallography.

    PubMed

    Shi, Dan; Nannenga, Brent L; de la Cruz, M Jason; Liu, Jinyang; Sawtelle, Steven; Calero, Guillermo; Reyes, Francis E; Hattne, Johan; Gonen, Tamir

    2016-05-01

    The formation of large, well-ordered crystals for crystallographic experiments remains a crucial bottleneck to the structural understanding of many important biological systems. To help alleviate this problem in crystallography, we have developed the MicroED method for the collection of electron diffraction data from 3D microcrystals and nanocrystals of radiation-sensitive biological material. In this approach, liquid solutions containing protein microcrystals are deposited on carbon-coated electron microscopy grids and are vitrified by plunging them into liquid ethane. MicroED data are collected for each selected crystal using cryo-electron microscopy, in which the crystal is diffracted using very few electrons as the stage is continuously rotated. This protocol gives advice on how to identify microcrystals by light microscopy or by negative-stain electron microscopy in samples obtained from standard protein crystallization experiments. The protocol also includes information about custom-designed equipment for controlling crystal rotation and software for recording experimental parameters in diffraction image metadata. Identifying microcrystals, preparing samples and setting up the microscope for diffraction data collection take approximately half an hour for each step. Screening microcrystals for quality diffraction takes roughly an hour, and the collection of a single data set is ∼10 min in duration. Complete data sets and resulting high-resolution structures can be obtained from a single crystal or by merging data from multiple crystals. PMID:27077331

  9. Fabrication of a Flexible Micro Temperature Sensor for Micro Reformer Applications

    PubMed Central

    Lee, Chi-Yuan; Lin, Chien-Hen; Lo, Yi-Man

    2011-01-01

    Micro reformers still face obstacles in minimizing their size, decreasing the concentration of CO, conversion efficiency and the feasibility of integrated fabrication with fuel cells. By using a micro temperature sensor fabricated on a stainless steel-based micro reformer, this work attempts to measure the inner temperature and increase the conversion efficiency. Micro temperature sensors on a stainless steel substrate are fabricated using micro-electro-mechanical systems (MEMS) and then placed separately inside the micro reformer. Micro temperature sensors are characterized by their higher accuracy and sensitivity than those of a conventional thermocouple. To the best of our knowledge, micro temperature sensors have not been embedded before in micro reformers and commercial products, therefore, this work presents a novel approach to integrating micro temperature sensors in a stainless steel-based micro reformer in order to evaluate inner local temperature distributions and enhance reformer performance. PMID:22163817

  10. Murillo's paintings revealed by spectroscopic techniques and dedicated laboratory-made micro X-ray diffraction.

    PubMed

    Duran, A; Siguenza, M B; Franquelo, M L; Jimenez de Haro, M C; Justo, A; Perez-Rodriguez, J L

    2010-06-25

    This paper describes one of the first case studies using micro-diffraction laboratory-made systems to analyse painting cross-sections. Pigments, such as lead white, vermilion, red ochre, red lac, lapis lazuli, smalt, lead tin yellow type I, massicot, ivory black, lamp black and malachite, were detected in cross-sections prepared from six Bartolomé Esteban Murillo paintings by micro-Raman and micro-XRD combined with complementary techniques (optical microscopy, SEM-EDS, and FT-IR). The use of micro-XRD was necessary due to the poor results obtained with conventional XRD. In some cases, pigment identification was only possible by combining results from the different analytical techniques utilised in this study. PMID:20541637

  11. Interior micro-CT with an offset detector

    SciTech Connect

    Sharma, Kriti Sen; Gong, Hao; Ghasemalizadeh, Omid; Yu, Hengyong; Wang, Ge

    2014-06-15

    Purpose: The size of field-of-view (FOV) of a microcomputed tomography (CT) system can be increased by offsetting the detector. The increased FOV is beneficial in many applications. All prior investigations, however, have been focused to the case in which the increased FOV after offset-detector acquisition can cover the transaxial extent of an object fully. Here, the authors studied a new problem where the FOV of a micro-CT system, although increased after offset-detector acquisition, still covers an interior region-of-interest (ROI) within the object. Methods: An interior-ROI-oriented micro-CT scan with an offset detector poses a difficult reconstruction problem, which is caused by both detector offset and projection truncation. Using the projection completion techniques, the authors first extended three previous reconstruction methods from offset-detector micro-CT to offset-detector interior micro-CT. The authors then proposed a novel method which combines two of the extended methods using a frequency split technique. The authors tested the four methods with phantom simulations at 9.4%, 18.8%, 28.2%, and 37.6% detector offset. The authors also applied these methods to physical phantom datasets acquired at the same amounts of detector offset from a customized micro-CT system. Results: When the detector offset was small, all reconstruction methods showed good image quality. At large detector offset, the three extended methods gave either visible shading artifacts or high deviation of pixel value, while the authors’ proposed method demonstrated no visible artifacts and minimal deviation of pixel value in both the numerical simulations and physical experiments. Conclusions: For an interior micro-CT with an offset detector, the three extended reconstruction methods can perform well at a small detector offset but show strong artifacts at a large detector offset. When the detector offset is large, the authors’ proposed reconstruction method can outperform the three

  12. Switch on Micro*scope!

    ERIC Educational Resources Information Center

    Roland, Sarah; Bahr, Michele; Olendzenski, Lorraine; Patterson, David J.

    2005-01-01

    Scientists at the Marine Biological Laboratory in Woods Hole, Massachusetts, have created micro*scope, a free, searchable knowledge environment for exploring the microbial world. Microbiology can easily be incorporated into the curriculum, because microbial communities are easy to access. Organisms grow quickly, making certain arrays of…

  13. Micro-Encapsulation of Probiotics

    NASA Astrophysics Data System (ADS)

    Meiners, Jean-Antoine

    Micro-encapsulation is defined as the technology for packaging with the help of protective membranes particles of finely ground solids, droplets of liquids or gaseous materials in small capsules that release their contents at controlled rates over prolonged periods of time under the influences of specific conditions (Boh, 2007). The material encapsulating the core is referred to as coating or shell.

  14. Seed microRNA Research

    Technology Transfer Automated Retrieval System (TEKTRAN)

    MicroRNAs (miRNAs) are key regulatory molecules that play critical roles in gene expression. The biological functions of miRNAs are important for developmental processes in plants and animals. Little is known about the functions of miRNAs in seeds. To gain a better understand-ing of the regulation o...

  15. Micro-machined resonator oscillator

    DOEpatents

    Koehler, D.R.; Sniegowski, J.J.; Bivens, H.M.; Wessendorf, K.O.

    1994-08-16

    A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a telemetered sensor beacon'' that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20--100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available. 21 figs.

  16. Micro-machined resonator oscillator

    DOEpatents

    Koehler, Dale R.; Sniegowski, Jeffry J.; Bivens, Hugh M.; Wessendorf, Kurt O.

    1994-01-01

    A micro-miniature resonator-oscillator is disclosed. Due to the miniaturization of the resonator-oscillator, oscillation frequencies of one MHz and higher are utilized. A thickness-mode quartz resonator housed in a micro-machined silicon package and operated as a "telemetered sensor beacon" that is, a digital, self-powered, remote, parameter measuring-transmitter in the FM-band. The resonator design uses trapped energy principles and temperature dependence methodology through crystal orientation control, with operation in the 20-100 MHz range. High volume batch-processing manufacturing is utilized, with package and resonator assembly at the wafer level. Unique design features include squeeze-film damping for robust vibration and shock performance, capacitive coupling through micro-machined diaphragms allowing resonator excitation at the package exterior, circuit integration and extremely small (0.1 in. square) dimensioning. A family of micro-miniature sensor beacons is also disclosed with widespread applications as bio-medical sensors, vehicle status monitors and high-volume animal identification and health sensors. The sensor family allows measurement of temperatures, chemicals, acceleration and pressure. A microphone and clock realization is also available.

  17. Micro Cooling, Heating, and Power (Micro-CHP) and Bio-Fuel Center, Mississippi State University

    SciTech Connect

    Louay Chamra

    2008-09-26

    specifications is observed. Case study data for various micro-CHP system configurations have been discussed and compared. Comparisons are made of the different prime mover/fuel combinations. Also, micro- CHP monthly energy cost results are compared for each system configuration to conventional monthly utility costs for equivalent monthly building power, heating, and cooling requirements.

  18. MicroRNA processing without Dicer

    PubMed Central

    2010-01-01

    The canonical processing of precursor microRNAs requires the endonuclease Dicer. A recent study shows that microRNAs can be processed independently of Dicer but instead require Argonaute 2. PMID:20565849

  19. Micro-Rockets for the Classroom.

    ERIC Educational Resources Information Center

    Huebner, Jay S.; Fletcher, Alice S.; Cato, Julia A.; Barrett, Jennifer A.

    1999-01-01

    Compares micro-rockets to commercial models and water rockets. Finds that micro-rockets are more advantageous because they are constructed with inexpensive and readily available materials and can be safely launched indoors. (CCM)

  20. Micro/Nanoscale Parallel Patterning of Functional Biomolecules, Organic Fluorophores and Colloidal Nanocrystals

    NASA Astrophysics Data System (ADS)

    Sabella, S.; Brunetti, V.; Vecchio, G.; Torre, A. Della; Rinaldi, R.; Cingolani, R.; Pompa, P. P.

    2009-10-01

    We describe the design and optimization of a reliable strategy that combines self-assembly and lithographic techniques, leading to very precise micro-/nanopositioning of biomolecules for the realization of micro- and nanoarrays of functional DNA and antibodies. Moreover, based on the covalent immobilization of stable and versatile SAMs of programmable chemical reactivity, this approach constitutes a general platform for the parallel site-specific deposition of a wide range of molecules such as organic fluorophores and water-soluble colloidal nanocrystals.

  1. Characterization and differentiation of normal and abnormal semen samples using micro-Raman spectroscopy

    NASA Astrophysics Data System (ADS)

    Huang, Zufang; Chen, Xiwen; Chen, Jinhua; Li, Yongzeng; Lei, Jinping; Chen, Rong

    2012-12-01

    Growth in the percentage of male infertility has caused extensive concerns. The fast and reliable method is urgently required for diagnosis of semen samples. In our study, micro-Raman spectroscopy was employed to characterize and differentiate the normal and abnormal semen samples based on the differences of their specific Raman spectra which originated from biochemical components. Our preliminary results demonstrate that micro-Raman spectroscopy combined with multivariate analysis methods has the potential of being used to detect and differentiate semen samples.

  2. Novel micro-machining method basing on AFM and high-accuracy stage

    NASA Astrophysics Data System (ADS)

    Yan, Yongda; Sun, Tao; Dong, Shen; Cheng, Kai

    2003-01-01

    This paper presents an easy and novel mechanical micro-machining method. Combining the commercial AFM and the high accuracy stage and using a diamond tip as the cutting tool which acts as a single asperity, a mechanical micro-machining system is developed. Some experiments are carried out basing on this system. Influence of the diamond tip"s shape on micro machining is considered. And different machining techniques are compared in this paper. Using this method the intricate patterns (circle, flat, polygon flat and a gear geometry) are successfully fabricated. So the novel approach"s strength are as follows: It can machine several tens of microns micro-parts more easier and cheaper then the conventional technology. And it can image the micro-structure just after it is machined. Generally this technique can be used to machine the mask of other micro-machining process, the mold of micro-parts, or to machine on the micro-part which is fabricated by other ways.

  3. Design of a micro lapping system based on double-feedback control algorithm for manufacturing optical micro components

    NASA Astrophysics Data System (ADS)

    Che, Lin; Li, Guo; Wang, Bo; Ding, Fei; Mao, Xing; Dong, Wenxia

    2014-08-01

    This paper presents a micro lapping machine tool, which is dedicated for manufacturing the high-precision optical micro components with 3-D micro structures. And it can remove the damaged surface layer efficiently.In order to control machining process precisely, a double-feedback control system strategy is proposed and implemented. Lapping force signal from the clamp feeds back at the same time with position signal from grating scale close-looped devices. With the function of position keeping , a dual-stage drive micro-displacement servo system is used to provide the desired performance in the vertical feeding direction. Random lapping trace is formed with combinations of two mutually-perpendicular horizontal liner motion. A clamp with the function of micro force detection is designed to monitor the machining process and control the lapping force. Based on force feedback, a tool auto-checking strategy is conducted to realize the tool checking in limited tiny space. Corresponding experiments are undertaken to test the properties of the machine tool.And, the optical micro components are manufactured successfully. The optical components are measured and analysised before and after processing. The experimental results show that the position-keeping accuracy of the dual-stage feed drive system can reach to ±0.02μm, the resolution of motion control can reach to 20nm.The Sa value of the processed component can reach 0.0882um. Surface quality can be improved obviously and the damaged surface layer is removed efficiently.The theoretical and experimental results show the validity of the machine tool and the control algorithm.

  4. Feature extraction of micro-motion frequency and the maximum wobble angle in a small range of missile warhead based on micro-Doppler effect

    NASA Astrophysics Data System (ADS)

    Li, M.; Jiang, Y. S.

    2014-11-01

    Micro-Doppler effect is induced by the micro-motion dynamics of the radar target itself or any structure on the target. In this paper, a simplified cone-shaped model for ballistic missile warhead with micro-nutation is established, followed by the theoretical formula of micro-nutation is derived. It is confirmed that the theoretical results are identical to simulation results by using short-time Fourier transform. Then we propose a new method for nutation period extraction via signature maximum energy fitting based on empirical mode decomposition and short-time Fourier transform. The maximum wobble angle is also extracted by distance approximate approach in a small range of wobble angle, which is combined with the maximum likelihood estimation. By the simulation studies, it is shown that these two feature extraction methods are both valid even with low signal-to-noise ratio.

  5. Micro Channel/Multibus-II Interface Circuit

    NASA Technical Reports Server (NTRS)

    D'Ambrose, John J.; Jaworski, Richard C.; Heise, Nyles N.; Thornton, David N.

    1991-01-01

    Micro Channel/Multibus-II interface circuit provides electrical interconnections enabling communications between Micro Channels of IBM Personal System/2 computers and IEEE 1296 standard Multibus-II parallel system bus (iPSB). Made mostly of commercially available parts, interface enables independent Micro Channels to communicate over iPSB without modification.

  6. Spontaneous Calcium Changes in Micro Neuronal Networks

    NASA Astrophysics Data System (ADS)

    Saito, Aki; Moriguchi, Hiroyuki; Iwabuchi, Shin; Goto, Miho; Takayama, Yuzo; Kotani, Kiyoshi; Jimbo, Yasuhiko

    We have developed a practical experimental method to mass-produce and maintain a variation of minimal neuronal networks (“micro neuronal networks”) consisted of a single to several neurons in culture using spray-patterning technique. In this paper, we could maintain the micro-cultures for one month or more by adding conditioned medium and carried out optical recording of spontaneous activity in micro neuronal networks and considered the interactions between them. To determine the interactions between micro neuronal networks, fluorescence changes in several small networks were simultaneously measured using calcium indicator dye fluo-4 AM, and time-series analysis was carried out using surrogate arrangements. By using the spray-patterning method, a large number of cell-adhesive micro regions were formed. Neurons extended neurites along the edge of the cell-adhesive micro regions and form micro neuronal networks. In part of micro regions, some neurite was protruded from the region, and thus micro neuronal networks were connected with synapses. In these networks, a single neuron-induced network activity was observed. On the other hand, even in morphologically non-connected micro neuronal networks, synchronous oscillations between micro neuronal networks were observed. Our micro-patterning methods and results provide the possibility that synchronous activity is occurred between morphologically non-connected neuronal networks. This suggest that the humoral factor is also a important component for network-wide dynamics.

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

    PubMed

    Rodriguez, J A; Gonen, T

    2016-01-01

    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

  8. Micro- and nanostructured polymer substrates for biomedical applications

    NASA Astrophysics Data System (ADS)

    Althaus, Jasmin; Urwyler, Prabitha; Padeste, Celestino; Heuberger, Roman; Deyhle, Hans; Schift, Helmut; Gobrecht, Jens; Pieles, Uwe; Scharnweber, Dieter; Peters, Kirsten; Müller, Bert

    2012-04-01

    Polymer implants are interesting alternatives to the contemporary load-bearing implants made from metals. Polyetheretherketone (PEEK), a well-established biomaterial for example, is not only iso-elastic to bone but also permits investigating the surrounding soft tissues using magnetic resonance imaging or computed tomography, which is particularly important for cancer patients. The commercially available PEEK bone implants, however, require costly coatings, which restricts their usage. As an alternative to coatings, plasma activation can be applied. The present paper shows the plasma-induced preparation of nanostructures on polymer films and on injection-molded micro-cantilever arrays and the associated chemical modifications of the surface. In vitro cell experiments indicate the suitability of the activation process. In addition, we show that microstructures such as micro-grooves 1 μm deep and 20 μm wide cause cell alignment. The combination of micro-injection molding, simultaneous microstructuring using inserts/bioreplica and plasma treatments permits the preparation of polymer implants with nature-analogue, anisotropic micro- and nanostructures.

  9. Soft Micro-Channels for Cell Culturing and Migration Studies

    NASA Astrophysics Data System (ADS)

    Abbasirazgaleh, Sara

    Various techniques and methods have been studied and developed to aid nerve regeneration and repairing nerve injuries. Among all, nerve grafting is the gold standard for bridging the gap between the injured nerve stumps. Despite the advantages of this technique, there are also various drawbacks that have encouraged the exploration of alternative, less invasive methods for promoting nerve regeneration. In this thesis, we have fabricated soft micro-channels for cell culturing and migration studies which could act as an interface capable of long-term, reliable, and high-resolution stimulation device for nerve regeneration. Micro-channels fabrication is performed using a combination of photolithography technique and physical vapor deposition (PVD) methods. Initially, the surfaces of the micro-channels are treated with oxygen plasma to convert the surface of PDMS from hydrophobic to hydrophilic and to further provide an optimal environment for cells to adhere and grow. Next, in vitro studies were performed on the fabricated micro-channels to demonstrate feasibility of the platform to promote adherence and growth of PC12 cells (cell line derived from a pheochromocytomas of the rat adrenal medulla).

  10. Micro-Tubular Fuel Cells

    NASA Technical Reports Server (NTRS)

    Kimble, Michael C.; Anderson, Everett B.; Jayne, Karen D.; Woodman, Alan S.

    2004-01-01

    Micro-tubular fuel cells that would operate at power levels on the order of hundreds of watts or less are under development as alternatives to batteries in numerous products - portable power tools, cellular telephones, laptop computers, portable television receivers, and small robotic vehicles, to name a few examples. Micro-tubular fuel cells exploit advances in the art of proton-exchange-membrane fuel cells. The main advantage of the micro-tubular fuel cells over the plate-and-frame fuel cells would be higher power densities: Whereas the mass and volume power densities of low-pressure hydrogen-and-oxygen-fuel plate-and-frame fuel cells designed to operate in the targeted power range are typically less than 0.1 W/g and 0.1 kW/L, micro-tubular fuel cells are expected to reach power densities much greater than 1 W/g and 1 kW/L. Because of their higher power densities, micro-tubular fuel cells would be better for powering portable equipment, and would be better suited to applications in which there are requirements for modularity to simplify maintenance or to facilitate scaling to higher power levels. The development of PEMFCs has conventionally focused on producing large stacks of cells that operate at typical power levels >5 kW. The usual approach taken to developing lower-power PEMFCs for applications like those listed above has been to simply shrink the basic plate-and-frame configuration to smaller dimensions. A conventional plate-and-frame fuel cell contains a membrane/electrode assembly in the form of a flat membrane with electrodes of the same active area bonded to both faces. In order to provide reactants to both electrodes, bipolar plates that contain flow passages are placed on both electrodes. The mass and volume overhead of the bipolar plates amounts to about 75 percent of the total mass and volume of a fuel-cell stack. Removing these bipolar plates in the micro-tubular fuel cell significantly increases the power density.

  11. MicroRNAs and Epithelial Immunity

    PubMed Central

    Liu, Jun; Drescher, Kristen M.; Chen, Xian-Ming

    2009-01-01

    MicroRNAs are required for development and maintenance of the epithelial barrier. It is hypothesized that microRNAs are involved in regulating epithelial anti-microbial defenses by targeting key epithelial effector molecules and/or influencing intracellular signaling pathways. Additionally, aberrant microRNA expression has been implicated in the pathogenesis of various diseases at the skin and mucosa. Increased understanding of the role of microRNAs in epithelial immunoregulation and identification of microRNAs of pathogenetic significance will enhance our understanding of epithelial immunobiology and immunopathology. PMID:19811319

  12. Micro-/nanostructured mechanical metamaterials.

    PubMed

    Lee, Jae-Hwang; Singer, Jonathan P; Thomas, Edwin L

    2012-09-18

    Mechanical properties of materials have long been one of the most fundamental and studied areas of materials science for a myriad of applications. Recently, mechanical metamaterials have been shown to possess extraordinary effective properties, such as negative dynamic modulus and/or density, phononic bandgaps, superior thermoelectric properties, and high specific energy absorption. To obtain such materials on appropriate length scales to enable novel mechanical devices, it is often necessary to effectively design and fabricate micro-/nano- structured materials. In this Review, various aspects of the micro-/nano-structured materials as mechanical metamaterials, potential tools for their multidimensional fabrication, and selected methods for their structural and performance characterization are described, as well as some prospects for the future developments in this exciting and emerging field. PMID:22899377

  13. Impact micro-positioning actuator

    NASA Technical Reports Server (NTRS)

    Cuerden, Brian (Inventor); Angel, J. Roger P. (Inventor); Burge, James H. (Inventor); DeRigne, Scott T. (Inventor)

    2006-01-01

    An impact micro-positioning actuator. In one aspect of the invention, a threaded shaft is threadably received in a nut and the nut is impacted by an impacting device, causing the nut first to rotate relative to the shaft by slipping as a result of shaft inertia and subsequently to stick to the shaft as a result of the frictional force therebetween. The nut is returned to its initial position by a return force provided by a return mechanism after impact. The micro-positioning actuator is further improved by controlling at least one and preferably all of the following: the friction, the impact provided by the impacting device, the return force provided by the return mechanism, and the inertia of the shaft. In another aspect of the invention, a threaded shaft is threadably received in a nut and the shaft is impacted by an impacting device, causing the shaft to rotate relative to the nut.

  14. Solid Phase Micro Extraction (SPME)

    NASA Technical Reports Server (NTRS)

    1998-01-01

    Internation Flavors and Fragrances Inc. proprietary research technology, Solid Phase Micro Extraction (SPME) utilizes a special fiber needle placed directly next to the bloom of the living flower to collect the fragrance molecules. SPME was used in the Space Flower experiment aboard STS-95 space shuttle mission, after which Dr. Braja Mookherjee (left) and Subha Patel of IFF will analyze the effects of gravity on the Overnight Scentsation rose plant.

  15. Micro-optofluidic Lenses: A review

    PubMed Central

    Nguyen, Nam-Trung

    2010-01-01

    This review presents a systematic perspective on the development of micro-optofluidic lenses. The progress on the development of micro-optofluidic lenses are illustrated by example from recent literature. The advantage of micro-optofluidic lenses over solid lens systems is their tunability without the use of large actuators such as servo motors. Depending on the relative orientation of light path and the substrate surface, micro-optofluidic lenses can be categorized as in-plane or out-of-plane lenses. However, this review will focus on the tunability of the lenses and categorizes them according to the concept of tunability. Micro-optofluidic lenses can be either tuned by the liquid in use or by the shape of the lens. Micro-optofluidic lenses with tunable shape are categorized according to the actuation schemes. Typical parameters of micro-optofluidic lenses reported recently are compared and discussed. Finally, perspectives are given for future works in this field. PMID:20714369

  16. MicroBooNE Electronics

    NASA Astrophysics Data System (ADS)

    Kaleko, David

    2013-04-01

    MicroBooNE is a neutrino experiment under construction at Fermi National Lab. It employs a 10mx2.6mx(2.5m drift length) 86 ton liquid argon time projection chamber (TPC) active volume to record ionization signals from particles produced in neutrino interactions, and uses scintillation light detected by a PMT array to provide precise interaction timing information. The MicroBooNE readout electronics system includes both TPC and PMT readout electronics which digitize neutrino interaction signals at 2MHz and 64MHz, respectively. The TPC electronics readout system processes ionization signals from the three wire planes to two readout streams: one for triggered neutrino events, and a second one for continuous readout. The PMT readout system generates the trigger. This talk will describe the MicroBooNE readout system, its physics requirements, and specifications. Various tests which have been performed to exercise the data flow and integration with DAQ system, including data volume and integrity tests, will be described.

  17. Lateral translation micro-tracking of planar micro-optic solar concentrator

    NASA Astrophysics Data System (ADS)

    Hallas, Justin M.; Karp, Jason H.; Tremblay, Eric J.; Ford, Joseph E.

    2010-08-01

    High-concentration photo-voltaic systems focus incident sunlight by hundreds of times by combining focusing lenses with accurate, dual-axis solar tracking. Conventional systems mount large optical arrays on expensive tracking pedestals to maintain normal incidence throughout the day. A recently proposed micro-optic solar concentrator utilizes a twodimensional lens array focusing into a planar slab waveguide. Localized mirrors fabricated on the waveguide surface reflect focused sunlight into guided modes which propagate towards an edge-mounted photovoltaic cell. This geometry enables a new method of solar tracking by laterally translating the waveguide with respect to the lens array to capture off-axis illumination. Using short focal length lenses, translations on the order of millimeters can efficiently collect 70° full-angle incident fields. This allows for either one or two-axis tracking systems where the small physical motion is contained within the physical footprint of a fixed solar panel. Here, we experimentally demonstrate lateral micro tracking for off-axis light collection using table-mounted components. We also present a novel tracking frame based on de-centered cams and describe a lens configuration optimized for off-axis coupling.

  18. Application of Flexible Micro Temperature Sensor in Oxidative Steam Reforming by a Methanol Micro Reformer

    PubMed Central

    Lee, Chi-Yuan; Lee, Shuo-Jen; Shen, Chia-Chieh; Yeh, Chuin-Tih; Chang, Chi-Chung; Lo, Yi-Man

    2011-01-01

    Advances in fuel cell applications reflect the ability of reformers to produce hydrogen. This work presents a flexible micro temperature sensor that is fabricated based on micro-electro-mechanical systems (MEMS) technology and integrated into a flat micro methanol reformer to observe the conditions inside that reformer. The micro temperature sensor has higher accuracy and sensitivity than a conventionally adopted thermocouple. Despite various micro temperature sensor applications, integrated micro reformers are still relatively new. This work proposes a novel method for integrating micro methanol reformers and micro temperature sensors, subsequently increasing the methanol conversion rate and the hydrogen production rate by varying the fuel supply rate and the water/methanol ratio. Importantly, the proposed micro temperature sensor adequately controls the interior temperature during oxidative steam reforming of methanol (OSRM), with the relevant parameters optimized as well. PMID:22319407

  19. A Study of Micro-bubble Enhanced Sonoporation

    NASA Astrophysics Data System (ADS)

    Okamoto, A.; Tachibana, R.; Yoshinaka, K.; Osada, K.; Takagi, S.; Kataoka, K.; Chung, U.; Matsumoto, Y.

    2011-09-01

    Sonoporation is a recently developed system for gene induction that uses ultrasound. Micro-bubbles are known to aid gene transfection through the introduction of genes into cells by the collapse of cavitation-bubbles (or micro-bubbles). However, the underlying mechanism and optimal introduction conditions have not been clarified in detail. In this research, we improved the gene introduction rate by forming DNA/Block copolymer micelles. Micelle formation compacts the DNA and enhances its stability, thereby facilitating the passage of greater amounts of DNA through holes in the cell surface and improving gene expression. Cells were exposed to ultrasonic plane waves from a piezoceramic transducer with a frequency of 2.0 MHz and a duty cycle of 10% (400/3600). Mouse fibroblast cells (NIH3T3) were cultured on the bottom of 24-well plates. Plasmid DNA and Sonazoid® (micro-bubbles) were added to the culture media and the cells were subsequently exposed to ultrasound. In the system described herein, micelles are formed by combining DNA and block copolymer. Block copolymer is composed of polyethyleneglycol-group and poly-lysine. Naked DNA and polymer micelles are added to culture media with micro-bubbles, and then exposed to ultrasound. The experimental conditions were as follows: plasmid density of 15 μg/ml, micro-bubble density of 1.7×105/mm3, ultrasound intensity of 5.08 W/cm2, ultrasound exposure time of 60 seconds, and a sample number of 12. Our results show that the gene induction ratio is doubled by the formation of polymer micelles (from ˜1% to ˜2%), thereby confirming that the system is capable of generating polymer micelles for introducing DNA into cells.

  20. Stirling engines for gas fired micro-cogen and cooling

    SciTech Connect

    Lane, N.W.; Beale, W.T.

    1996-12-31

    This paper describes the design and performance of free-piston Stirling engine-alternators particularly suited for use as natural gas fired micro-cogen and cooling devices. Stirling based cogen systems offer significant potential advantages over internal combustion engines in efficiency, to maintain higher efficiencies at lower power levels than than combustion engines significantly expands the potential for micro-cogen. System cost reduction and electric prices higher than the U.S. national average will have a far greater effect on commercial success than any further increase in Stirling engine efficiency. There exist niche markets where Stirling engine efficiency. There exist niche markets where Stirling based cogen systems are competitive. Machines of this design are being considered for production in the near future as gas-fired units for combined heat and power in sufficiently large quantities to assure competitive prices for the final unit.

  1. A biodetection method using magnetic particles and micro traps

    NASA Astrophysics Data System (ADS)

    Li, Fuquan; Giouroudi, Ioanna; Kosel, Jürgen

    2012-04-01

    The general working principle of magnetoresistive sensors for biological applications is to specifically attach bioanalytesto magnetic particles and then detect the particles that are immobilized on the sensor surface. The immobilization of the particles on the sensor surface commonly uses biomolecular interactions, e.g., antigen-antibody. Thus, the sensor surface needs to be functionalized via biological treatments in order to capture certain bioanalytes. In the presented work, a new method is proposed, which does not rely on functionalization of the sensor surface. Current carrying microstructures in combination with mechanical micro traps are used to immobilize magnetic particles. Analyte detection is based on the difference in size between bare magnetic particles and particles with analyte attached, which causes a different number of particles to be captured in the micro traps.

  2. Comparison of 4D-microSPECT and microCT for murine cardiac function

    PubMed Central

    Befera, Nicholas T.; Badea, Cristian T.; Johnson, G. Allan

    2014-01-01

    Purpose The objective of this study was to compare a new generation of four-dimensional (4D) microSPECT with microCT for quantitative in vivo assessment of murine cardiac function. Procedures 4D isotropic cardiac images were acquired from normal C57BL/6 mice with either microSPECT at 350-micron resolution (n=6) or microCT at 88-micron resolution (n=6). One additional mouse with myocardial infarction (MI) was scanned with both modalities. Prior to imaging, mice were injected with either 99mTc -tetrofosmin for microSPECT, or a liposomal blood pool contrast agent for microCT. Segmentation of the left ventricle (LV) was performed using Vitrea (Vital Images) software, to derive global and regional function. Results Measures of global LV function between microSPECT and microCT groups were comparable (e.g. ejection fraction=71±6%-microSPECT and 68±4%-microCT). Regional functional indices (wall motion, wall thickening, regional ejection fraction) were also similar for the two modalities. In the mouse with MI, microSPECT identified a large perfusion defect that was not evident with microCT. Conclusions Despite lower spatial resolution, microSPECT was comparable to microCT in the quantitative evaluation of cardiac function. MicroSPECT offers an advantage over microCT in the ability to evaluate myocardial perfusion radiotracer distribution and function simultaneously. MicroSPECT should be considered as an alternative to microCT and MR for preclinical cardiac imaging in the mouse. PMID:24037175

  3. Self-assembly 'micro-origami' photon cages as hollow micro-resonators

    NASA Astrophysics Data System (ADS)

    Danescu, A.; Chevalier, C.; Artinyan, R.; Regreny, P.; Grenet, G.; Callard, S.; Rojo-Romeo, P.; Letartre, X.; Leclercq, J. L.

    2015-06-01

    Selective etching of pre-stressed multi-layered structures releases intrinsic stresses creating flexible macroscopic shapes (rolls, spirals, tubes…). Combining mechanical and photonic concepts, we develop an experimental approach by controlling material composition, mask design and etching process in order to obtain prescribed macroscopic 3D hollow optical micro-cavities. New photonic microstructures are proposed for an efficient light trapping in low index media. Cylindrical hollow cavities formed by bending a photonic crystal membrane are designed. Using numerical simulations, strong confinement of photons is demonstrated for very open resonators. The resulting strong light matter interaction can be exploited in optical devices comprising an active material embedded in a low index matrix like polymer or even gaz.

  4. Optimized planar micro-optic concentrator design

    NASA Astrophysics Data System (ADS)

    Pan, Jui-Wen; Su, Yu-Chung; Lee, Sheng-Yi

    2016-06-01

    The structural parameters of a planar micro-optic concentrator are optimized. First, the direct-loss is minimized by altering the relationship between the f-number of the lenslet, the angle of the micro-structure and the ray paths in the planar micro-optic concentrator. Second, the size of the micro-structure is made equal to the mini-blur size of the lenslet in order to reduce the non-direct loss. Last, the f-number and the entrance pupil diameter of the lenslet are determined by the relationships among the f-number, the entrance pupil diameter, the optical efficiency, the acceptance angle and the thickness of the planar micro-optic concentrator from the optical simulation results. For an optimized planar micro-optic concentrator with a 300× concentration, the f-number of the lenslet, the EPD of the lenslet, the angle of the micro-structure and the thickness of the planar micro-optic concentrator are 2.6, 1.49 mm, 120 degrees and 5.97 mm, respectively. For micro-structures 28.95 μm, 51.24 μm and 88.29 μm in size, the half acceptance angles of the planar micro-optic concentrator are 0.115 degrees, 0.275 degrees and 0.55 degrees, respectively, and the optical efficiencies are 81.23%, 71.92% and 50.02%, respectively.

  5. Charging and characterization of non-patterned organic micro electret arrays

    NASA Astrophysics Data System (ADS)

    Liu, Shuwei; Shen, Zhiyuan; Woh Lye, Sun; Miao, Jianmin

    2014-08-01

    This paper presents the charging and characterization of an organic micro electret array for vibration energy harvesting. Micro sized electrets with stable and high surface potential are essential for the long-term effectiveness of micro electrostatic power generators which harvest low-level vibration energy. In this study, a localized corona charging method to obtain micro sized electret areas on non-patterned macro sized dielectric thin film has been proposed to solve the problem of low charging efficiency and fast charge decay of micro sized electrets. This method involves using a shadow mask to transfer charge patterns and a triode corona charging configuration to facilitate charge penetration. Charging efficiency of 93.6% is achieved on an electret area of 100 µm × 100 µm, and 87% of its initial surface potential remains on the shrunken area of 50 µm × 50 µm after 240 days of storage. A technique combining SEM surface topography and non-contact measurement of the average surface potential has been developed to map the charge distribution on locally charged dielectric thin film and measure the surface potential on the micro sized charged area by incorporating the layout characteristic of a micro electret array.

  6. MicroRNAs in cancer: from developmental genes in worms to their clinical application in patients

    PubMed Central

    Pichler, M; Calin, G A

    2015-01-01

    Several discoveries have paved the way to personalise cancer medicine and a tremendous gain of knowledge in genomics and molecular mechanisms of cancer progression cumulated over the last years. Big stories in biology commonly start in a simple model system. No wonder microRNAs have been identified as regulators of embryonic development in the nematode Caenorhabditis elegans. From the first identification in worms to the first-in-man microRNA-based clinical trial in humans, almost 20 years passed. In this review we follow the story of understanding microRNA alterations in cancer, describe recent developments in the microRNA field and critically discuss their potential as diagnostic, prognostic and therapeutics factors in cancer medicine. We will explain the rationale behind the use of microRNAs in cancer diagnosis and prognosis prediction, but also discuss the limitations and pitfalls associated with this. Novel developments of combined microRNA/siRNA pharmacological approaches will be discussed and most recently data about MXR34, the first-tested microRNA drug will be described. PMID:26158421

  7. Fabrication and measurement of nanostructures on the micro ball surface using a modified atomic force microscope.

    PubMed

    Zhao, X S; Geng, Y Q; Li, W B; Yan, Y D; Hu, Z J; Sun, T; Liang, Y C; Dong, S

    2012-11-01

    In order to machine and measure nanostructures on the micro ball surface, a modified atomic force microscope (AFM) combining a commercial AFM system with a home built precision air bearing spindle is established. Based on this system, motions of both the AFM scanner and the air bearing spindle are controlled to machine nanostructures on the micro ball based on the AFM tip-based nano mechanical machining approach. The eccentric error between the axis of the micro ball and the axis of the spindle is reduced to 3-4 μm by the provided fine adjusting method. A 1000 nano lines array, 36 square pits structure, 10 square pits structure, and a zig-zag structure on the circumference of the micro ball with the diameter of 1.5 mm are machined successfully. The measurement results achieved by the same system reveal that the profiles and mode-power spectra curves of the micro ball are influenced by the artificially machined nanostructures significantly according to their distributions. This work is an useful attempt for modifying the micro ball profile and manufacture of the spherical modulation targets to study the experimental performance of the micro ball in implosion. PMID:23206095

  8. MicroRNA-regulated pathways in hematological malignancies: how to avoid cells playing out of tune.

    PubMed

    Fatica, Alessandro; Fazi, Francesco

    2013-01-01

    The coordinated expression and interplay among lineage specific transcription factors and microRNAs contribute to the regulation of gene expression and determination of cell specificity. In hematopoietic stem cells (HSCs), unique combinations of transcription factors largely control growth and maturation of different blood cell lineages through cooperative regulation of specific target genes. MicroRNAs provide an additional level of control beyond transcription factors. By acting as regulators of crucial lineage-specific genetic programs, microRNAs direct early multipotential progenitor cells to adopt a certain cell fate program. Thus, alteration of specific microRNA levels may affect proliferation, differentiation and genetic stability of HSCs, contributing to the onset of myeloproliferative disorders and leukemia. The major aim of this review is to highlight the critical role of microRNA-regulated pathways during the establishment and progression of hematological malignancies, with a particular attention to leukemia, lymphomas and myelodysplastic syndromes. This will give us the opportunity to discuss the potential use of microRNA-based therapeutic approaches in these diseases. MicroRNAs are indeed emerging as relevant tools to improve the efficacy of currently used therapeutic protocols. PMID:24145746

  9. Astronomical Research with the MicroObservatory Net

    NASA Astrophysics Data System (ADS)

    Brecher, K.; Sadler, P.; Gould, R.; Leiker, S.; Antonucci, P.; Deutsch, F.

    1997-05-01

    We have developed a fully integrated automated astronomical telescope system which combines the imaging power of a cooled CCD, with a self-contained and weatherized 15 cm reflecting optical telescope and mount. The MicroObservatory Net consists of five of these telescopes. They are currently being deployed around the world at widely distributed longitudes. Remote access to the MicroObservatories over the Internet has now been implemented. Software for computer control, pointing, focusing, filter selection as well as pattern recognition have all been developed as part of the project. The telescopes can be controlled in real time or in delay mode, from a Macintosh, PC or other computer using Web-based software. The Internet address of the telescopes is http://cfa- www.harvard.edu/cfa/sed/MicroObservatory/MicroObservatory.html. In the real-time mode, individuals have access to all of the telescope control functions without the need for an `on-site' operator. Users can sign up for a specific period of ti me. In the batch mode, users can submit requests for delayed telescope observations. After a MicroObservatory completes a job, the user is automatically notified by e-mail that the image is available for viewing and downloading from the Web site. The telescopes were designed for classroom instruction, as well as for use by students and amateur astronomers for original scientific research projects. We are currently examining a variety of technical and educational questions about the use of the telescopes including: (1) What are the best approaches to scheduling real-time versus batch mode observations? (2) What criteria should be used for allocating telescope time? (3) With deployment of more than one telescope, is it advantageous for each telescope to be used for just one type of observation, i.e., some for photometric use, others for imaging? And (4) What are the most valuable applications of the MicroObservatories in astronomical research? Support for the Micro

  10. Multilaboratory Study of the Biomic Automated Well-Reading Instrument versus MicroScan WalkAway for Reading MicroScan Antimicrobial Susceptibility and Identification Panels

    PubMed Central

    Weaver, Emily; Fossett, Rhonda; Toyras, Michele; Vanderlaan, John; Gibbs, David; Wang, Andrew; Thierjung, Nikolaus

    2013-01-01

    This study compared the Biomic automated well reader results to the MicroScan WalkAway results for reading MicroScan antimicrobial susceptibility and identification panels at four different sites. Routine fresh clinical isolates and quality control (QC) organisms were tested at each study site. A total of 46,176 MicroScan panel drug-organism combinations were read. The Biomic category agreement for 3,117 Gram-negative bacteria was 98.4%, with 1.4% minor and 0.2% major discrepancies. The Biomic category agreement for 5,233 Gram-positive bacteria was 98.7%, with 0.9% minor, 0.3% major, and 0.1% very major errors. Essential agreement, defined as Biomic results that were within ±1 2-fold dilution of the MicroScan results, was 99.3% for Gram-negative bacteria and 98.3% for Gram-positive bacteria. Biomic reading of MicroScan identification panels provided an overall agreement (first- and second-choice organism match) of 99.5% with 846 Gram-negative isolates and 99.5% with 430 Gram-positive isolates. These results suggest that the Biomic automated reader can provide accurate reading of MicroScan panels and has the capability of a visual panel read for manual adjustment of results. PMID:23486713

  11. Large-scale profiling of microRNAs for The Cancer Genome Atlas

    PubMed Central

    Chu, Andy; Robertson, Gordon; Brooks, Denise; Mungall, Andrew J.; Birol, Inanc; Coope, Robin; Ma, Yussanne; Jones, Steven; Marra, Marco A.

    2016-01-01

    The comprehensive multiplatform genomics data generated by The Cancer Genome Atlas (TCGA) Research Network is an enabling resource for cancer research. It includes an unprecedented amount of microRNA sequence data: ∼11 000 libraries across 33 cancer types. Combined with initiatives like the National Cancer Institute Genomics Cloud Pilots, such data resources will make intensive analysis of large-scale cancer genomics data widely accessible. To support such initiatives, and to enable comparison of TCGA microRNA data to data from other projects, we describe the process that we developed and used to generate the microRNA sequence data, from library construction through to submission of data to repositories. In the context of this process, we describe the computational pipeline that we used to characterize microRNA expression across large patient cohorts. PMID:26271990

  12. Three dimensional measurement of micro-optical components using digital holography and pattern recognition

    NASA Astrophysics Data System (ADS)

    Kim, Do-Hyung; Jeon, Sungbin; Cho, Janghyun; Lim, Geon; Park, No-Cheol; Park, Young-Pil

    2015-09-01

    This paper proposes a method for inspecting transparent micro-optical components that combines digital holography and pattern recognition. As many micro-optical components have array structures with numerous elements, the uniformity of each element is important. Consequently, an effective inspection requires simultaneous measurement of these elements. Pattern recognition is used to solve this issue and can be adopted effectively using the unique characteristics of digital holography to obtain both amplitude and phase information on the object. To verify this approach, an experimental demonstration was performed with a micro-lens array using a circle-detection algorithm based on the Hough Transform. As an experimental results 30 micro-lenses are detected and measured simultaneously by using proposed inspection method.

  13. Application of micro-computed tomography to microstructure studies of the medicinal fungus Hericium coralloides.

    PubMed

    Pallua, Johannes D; Kuhn, Volker; Pallua, Anton F; Pfaller, Kristian; Pallua, Anton K; Recheis, Wolfgang; Pöder, Reinhold

    2015-01-01

    The potential of 3-D nondestructive imaging techniques such as micro-computed tomography (micro-CT) was evaluated to study morphological patterns of the potential medicinal fungus Hericium coralloides (Basidiomycota). Micro-CT results were correlated with histological information gained from scanning electron microscopy (SEM) and light microscopy (LM). It is demonstrated that the combination of these imaging methods results in a more distinct picture of the morphology of the edible and potentially medicinal Hericium coralloides basidiomata. In addition we have created 3-D reconstructions and visualizations based on micro-CT imagery from a randomly selected part of the upper region of a fresh H. coralloides basidioma: Analyses for the first time allowed an approximation of the evolutionary effectiveness of this bizarrely formed basidioma type in terms of the investment of tissue biomass and its reproductive output (production of basidiospores). PMID:25376797

  14. Large-scale profiling of microRNAs for The Cancer Genome Atlas.

    PubMed

    Chu, Andy; Robertson, Gordon; Brooks, Denise; Mungall, Andrew J; Birol, Inanc; Coope, Robin; Ma, Yussanne; Jones, Steven; Marra, Marco A

    2016-01-01

    The comprehensive multiplatform genomics data generated by The Cancer Genome Atlas (TCGA) Research Network is an enabling resource for cancer research. It includes an unprecedented amount of microRNA sequence data: ~11 000 libraries across 33 cancer types. Combined with initiatives like the National Cancer Institute Genomics Cloud Pilots, such data resources will make intensive analysis of large-scale cancer genomics data widely accessible. To support such initiatives, and to enable comparison of TCGA microRNA data to data from other projects, we describe the process that we developed and used to generate the microRNA sequence data, from library construction through to submission of data to repositories. In the context of this process, we describe the computational pipeline that we used to characterize microRNA expression across large patient cohorts. PMID:26271990

  15. microRNAs and Endometrial Pathophysiology.

    PubMed

    Chill, Henry H; Dior, Uri P; Kogan, Liron; Revel, Ariel

    2015-01-01

    Embryo implantation requires a reciprocal interaction between the blastocyst and endometrium and is associated with complex regulatory mechanisms. Since their discovery, microRNAs became prominent candidates providing missing links for many biological pathways. In recent years, microRNAs were implicated as one of the important players in regulation of various biological and physiological endometrial related processes. This chapter aims to present recent knowledge pertaining to the diverse aspects of microRNAs in the embryo-endometrial relationship. We will focus on the role of microRNAs in decidualization and their part in natural and stimulated cycles. Next, we will present recent studies deliberating the role of microRNAs in recurrent pregnancy loss and in the important phenomenon of recurrent implantation failure. Lastly, demonstrating an important aspect of embryo implantation and invasion, we will outline few microRNA related shared pathways of implantation and carcinogenesis. PMID:26662990

  16. Chemically powered micro- and nanomotors.

    PubMed

    Sánchez, Samuel; Soler, Lluís; Katuri, Jaideep

    2015-01-26

    Chemically powered micro- and nanomotors are small devices that are self-propelled by catalytic reactions in fluids. Taking inspiration from biomotors, scientists are aiming to find the best architecture for self-propulsion, understand the mechanisms of motion, and develop accurate control over the motion. Remotely guided nanomotors can transport cargo to desired targets, drill into biomaterials, sense their environment, mix or pump fluids, and clean polluted water. This Review summarizes the major advances in the growing field of catalytic nanomotors, which started ten years ago. PMID:25504117

  17. Micro-unmanned aerodynamic vehicle

    DOEpatents

    Reuel, Nigel; Lionberger, Troy A.; Galambos, Paul C.; Okandan, Murat; Baker, Michael S.

    2008-03-11

    A MEMS-based micro-unmanned vehicle includes at least a pair of wings having leading wing beams and trailing wing beams, at least two actuators, a leading actuator beam coupled to the leading wing beams, a trailing actuator beam coupled to the trailing wing beams, a vehicle body having a plurality of fulcrums pivotally securing the leading wing beams, the trailing wing beams, the leading actuator beam and the trailing actuator beam and having at least one anisotropically etched recess to accommodate a lever-fulcrum motion of the coupled beams, and a power source.

  18. Injection molding and debinding of micro gears fabricated by micro powder injection molding

    NASA Astrophysics Data System (ADS)

    Ni, Xin-lei; Yin, Hai-qing; Liu, Lin; Yi, Shan-jie; Qu, Xuan-hui

    2013-01-01

    Micro powder injection molding (μPIM) was investigated for possible mass production of micro-components at relatively low cost. However, scaling down to such a level produces challenges in injection molding and debinding. Micro gears were fabricated by μPIM from in-house feedstock. The effect of injection speed and injection pressure on the replication of the micro gear cavity was investigated. Solvent debinding and thermal debinding processes were discussed. The results show that micro gears can be successfully fabricated under the injection pressure of 70 MPa and the 60% injection speed. Either too low or too high injection speed can cause incomplete filling of micro gears. The same is the case with too low injection pressure. Too high injection pressure can bring cracks. Solvent debinding of micro gears was performed in a mixture of petroleum ether and ethanol. Subsequently, micro gears were successfully debound by a multistep heating schedule.

  19. Turbo Pump Fed Micro-Rocket Engine

    NASA Astrophysics Data System (ADS)

    Miotti, P.; Tajmar, M.; Seco, F.; Guraya, C.; Perennes, F.; Soldati, A.; Lang, M.

    2004-10-01

    Micro-satellites (from 10kg up to 100kg) have mass, volume, and electrical power constraints due to their low dimensions. These limitations lead to the lack in currently available active orbit control systems in micro-satellites. Therefore, a micro-propulsion system with a high thrust to mass ratio is required to increase the potential functionality of small satellites. Mechatronic is presently working on a liquid bipropellant micro-rocket engine under contract with ESA (Contract No.16914/NL/Sfe - Micro-turbo-machinery Based Bipropellant System Using MNT). The advances in Mechatronic's project are to realise a micro-rocket engine with propellants pressurised by micro-pumps. The energy for driving the pumps would be extracted from a micro-turbine. Cooling channels around the nozzle would be also used in order to maintain the wall material below its maximum operating temperature. A mass budget comparison with more traditional pressure-fed micro-rockets shows a real benefit from this system in terms of mass reduction. In the paper, an overview of the project status in Mechatronic is presented.

  20. Micro cell isolation column for allergic diagnosis

    NASA Astrophysics Data System (ADS)

    Kobayashi, Koichiro; Sakamoto, Kenji; Yanase, Yuhki; Hide, Michihiro; Miyake, Ryo

    2016-03-01

    We suggest a new micro cell isolation column of basophils for an allergic diagnostic system for detecting human basophils activations. Surface plasmon resonance imaging (SPRI) biosensors using human basophils allow allergic diagnosis of less than 1 ml of peripheral blood. However, an isolation of basophils from a small amount of blood is not easy. In this study, we constructed a new micro cell isolation column for basophils with poly(dimethylsiloxane) (PDMS) microflow pass including magnetic particles. Furthermore, we determined whether leukocytes were captured by the micro cell isolation column from a small amount of blood. We can isolate basophils from other leukocytes by using the micro cell isolation column.

  1. Flagellar motor based micro hybrid devices.

    PubMed

    Tung, S; Kim, J-W

    2004-01-01

    We are in the process of developing a series of micro hybrid devices based on tethered flagellar motors. Examples of the devices include a microfluidic pump and a micro AC dynamo. The microfluidic pump is realized through the tethering of a harmless strain of Escherichia coli cells to a MEMS based micro channel. Each E. coli cell is about 3 mum long and 1 mum in diameter, with several flagella that are driven at the base by molecular rotary motors. The operational principle of the micro pump is based on the viscous pumping effect where continuous rotation of the tethered cells forms a fluidic conveyor belt that 'drags' fluid from one end of the channel to the other. We used hydrodynamic loading to synchronize cell rotation in order to maximize the fluid pumping capability. The micro dynamo is realized through the integration of tethered flagellar motors with micro ferromagnetic beads and micro copper coils. The micro dynamo generates AC power by using the tethered cells to create a rotating magnetic field around the copper coils. Preliminary result indicates a high power density when compared to other biologically based micro power generators. PMID:17270806

  2. Assembly planning at the micro scale

    SciTech Connect

    Feddema, J.T.; Xavier, P.; Brown, R.

    1998-05-14

    This paper investigates a new aspect of fine motion planning for the micro domain. As parts approach 1--10 {micro}m or less in outside dimensions, interactive forces such as van der Waals and electrostatic forces become major factors which greatly change the assembly sequence and path plans. It has been experimentally shown that assembly plans in the micro domain are not reversible, motions required to pick up a part are not the reverse of motions required to release a part. This paper develops the mathematics required to determine the goal regions for pick up, holding, and release of a micro-sphere being handled by a rectangular tool.

  3. Targeting microRNAs in heart failure.

    PubMed

    Duygu, Burcu; de Windt, Leon J; da Costa Martins, Paula A

    2016-02-01

    MicroRNAs play pivotal roles in cardiac disease, and their therapeutic modulation raises exciting and unique opportunities, as well as challenges in the path toward clinical development and implementation. In this review, we provide a detailed overview of recent studies highlighting the important role of microRNAs in heart failure (HF) and the potential use of microRNA-based technology for diagnosis, prevention, and treatment of HF. We will focus on the strategies presently used for microRNA-based therapy by discussing their use and drawbacks, as well as the challenges and future directions for their development in the context of human HF. PMID:26119078

  4. A mechanical micro molecular mass sensor

    PubMed Central

    Kurhekar, A. S.; Apte, P. R.

    2014-01-01

    One of the bio-sensing mechanisms is mechanical. Rather than measuring shift in resonance frequency, we adopt to measure the change in spring constant due to adsorption, as one of the fundamental sensing mechanism. This study explains determination of spring constant of a surface functionalized micro machined micro cantilever, which resonates in a trapezoidal cavity-on Silicon <100> wafer, with the resonating frequency of 7000 cycles per second. This thin-flimsy-oxide micro-cantilever has a typical shape, and the tip of the micro-cantilever is dip-coated with chemically and biologically active material. The change in mass, due to adsorption, is detected by measuring the change in spring constant. The Force-Distance spectroscopy is used to detect the change in spring constant. The experimental results, show that the mechanical sensing scheme used, permit this surface functionalized micro machined micro cantilever to be used as a molecular mass sensor. The mechanical spring behaviour of a micro-cantilever, a micro-mechanical device can be used to develop ultra-tech micro-mechanical system using computer interface. PMID:24459585

  5. Design of an optical system with large depth of field using in the micro-assembly

    NASA Astrophysics Data System (ADS)

    Li, Rong; Chang, Jun; Zhang, Zhi-jing; Ye, Xin; Zheng, Hai-jing

    2013-08-01

    Micro system currently is the mainstream of application and demand of the field of micro fabrication of civilian and national defense. Compared with the macro assembly, the requirements on location accuracy of the micro-assembly system are much higher. Usually the dimensions of the components of the micro-assembly are mostly between a few microns to several hundred microns. The general assembly precision requires for the sub-micron level. Micro system assembly is the bottleneck of micro fabrication currently. The optical stereo microscope used in the field of micro assembly technology can achieve high-resolution imaging, but the depth of field of the optical imaging system is too small. Thus it's not conducive to the three-dimensional observation process of the micro-assembly. This paper summarizes the development of micro system assembly at home and abroad firstly. Based on the study of the core features of the technology, a program is proposed which uses wave front coding technology to increase the depth of field of the optical imaging system. In the wave front coding technology, by combining traditional optical design with digital image processing creatively, the depth of field can be greatly increased, moreover, all defocus-related aberrations, such as spherical aberration, chromatic aberration, astigmatism, Ptzvel(field) curvature, distortion, and other defocus induced by the error of assembling and temperature change, can be corrected or minimized. In this paper, based on the study of theory, a set of optical microscopy imaging system is designed. This system is designed and optimized by optical design software CODE V and ZEMAX. At last, the imaging results of the traditional optical stereo microscope and the optical stereo microscope applied wave front coding technology are compared. The results show that: the method has a practical operability and the phase plate obtained by optimized has a good effect on improving the imaging quality and increasing the

  6. microRNA: Diagnostic Perspective

    PubMed Central

    Faruq, Omar; Vecchione, Andrea

    2015-01-01

    Biomarkers are biological measures of a biological state. An ideal marker should be safe and easy to measure, cost efficient, modifiable with treatment, and consistent across gender and ethnic groups. To date, none of the available biomarkers satisfy all of these criteria. In addition, the major limitations of these markers are low specificity, sensitivity, and false positive results. Recently identified, microRNAs (miRNAs) are endogenous, evolutionarily conserved small non-coding RNA (about 22–25 nt long), also known as micro-coordinators of gene expression, which have been shown to be an effective tools to study the biology of diseases and to have great potential as novel diagnostic and prognostic biomarkers with high specificity and sensitivity. In fact, it has been demonstrated that miRNAs play a pivotal role in the regulation of a wide range of developmental and physiological processes and their deficiencies have been related to a number of disease. In addition, miRNAs are stable and can be easily isolated and measured from tissues and body fluids. In this review, we provide a perspective on emerging concepts and potential usefulness of miRNAs as diagnostic markers, emphasizing the involvement of specific miRNAs in particular tumor types, subtypes, cardiovascular diseases, diabetes, infectious diseases, and forensic test. PMID:26284247

  7. Stretchable Micro-Electrode Array

    SciTech Connect

    Maghribi, M; Hamilton, J; Polla, D; Rose, K; Wilson, T; Krulevitch, P

    2002-03-08

    This paper focuses on the design consideration, fabrication processes and preliminary testing of the stretchable micro-electrode array. We are developing an implantable, stretchable micro-electrode array using polymer-based microfabrication techniques. The device will serve as the interface between an electronic imaging system and the human eye, directly stimulating retinal neurons via thin film conducting traces and electroplated electrodes. The metal features are embedded within a thin ({approx}50 micron) substrate fabricated using poly (dimethylsiloxane) (PDMS), a biocompatible elastomeric material that has very low water permeability. The conformable nature of PDMS is critical for ensuring uniform contact with the curved surface of the retina. To fabricate the device, we developed unique processes for metalizing PDMS to produce robust traces capable of maintaining conductivity when stretched (5%, SD 1.5), and for selectively passivating the conductive elements. An in situ measurement of residual strain in the PDMS during curing reveals a tensile strain of 10%, explaining the stretchable nature of the thin metalized devices.

  8. Virus-encoded microRNAs

    PubMed Central

    Grundhoff, Adam; Sullivan, Christopher S.

    2011-01-01

    microRNAs (miRNAs) are the subject of enormous interest. They are small non-coding RNAs that play a regulatory role in numerous and diverse cellular processes such as immune function, apoptosis and tumorigenesis. Several virus families have been shown to encode miRNAs, and an appreciation for their roles in the viral infectious cycle continues to grow. Despite the identification of numerous (>225) viral miRNAs, an in depth functional understanding of most virus-encoded miRNAs is lacking. Here we focus on a few viral miRNAs with well-defined functions. We use these examples to extrapolate general themes of viral miRNA activities including autoregulation of gene expression, avoidance of host defenses, and a likely important role in maintaining latent and persistent infections. We hypothesize that although the molecular mechanisms and machinery are similar, the majority of viral miRNAs may utilize a target strategy that differs from host miRNAs. That is, many viral miRNAs may have evolved to regulate viral-encoded transcripts or networks of host genes that are unique to viral miRNAs. Included in this latter category are a likely abundant class of viral miRNAs that may regulate only one or a few principal host genes. Key steps forward for the field are discussed, including the need for additional functional studies that utilize surgical viral miRNA mutants combined with relevant models of infection. PMID:21277611

  9. MicroRNAs and cardiac regeneration

    PubMed Central

    Hodgkinson, Conrad P.; Kang, Martin H.; Dal-Pra, Sophie; Mirotsou, Maria; Dzau, Victor J.

    2015-01-01

    The human heart has a very limited capacity to regenerate lost or damaged cardiomyocytes following cardiac insult. Instead, myocardial injury is characterized by extensive cardiac remodeling by fibroblasts, resulting in the eventual deterioration of cardiac structure and function. Cardiac function would be improved if these fibroblasts could be converted into cardiomyocytes. MicroRNAs (miRNAs), small non-coding RNAs that promote mRNA degradation and inhibit mRNA translation, have been shown to be important in cardiac development. Using this information various researchers have utilized miRNAs to promote the formation of cardiomyocytes through a number of approaches. Several miRNAs acting in combination promote the direct conversion of cardiac fibroblasts into cardiomyocytes. Moreover, a number of miRNAs have been identified that aid the formation of iPS cells and miRNAs also induce these cells to adopt a cardiac fate. MiRNAs have also been implicated in resident cardiac progenitor cell differentiation. In this review we will discuss the current literature as it pertains to these processes as well as discussing the therapeutic implications of these findings. PMID:25953925

  10. Laser-assisted micro sheet forming

    NASA Astrophysics Data System (ADS)

    Holtkamp, Jens; Gillner, Arnold

    2008-01-01

    The fast growing market for micro technical products requires parts with increasing complexity. While sheet metal forming enables low cost mass production with short cycle times, it is limited by the maximum degree of deformation and the quality of the cut edge. The technology of warm forming partially eliminates these deficiencies. This operation takes place at elevated temperatures before structural transformation is initiated. It combines characteristic advantages of traditional cold and hot forming processes. Lasers as heat sources provide a high, selective and controllable energy input. The general difficulty of a uniform temperature distribution during the heating process can be reached by using an Axicon which generates an annulus on the sheet metal surface. The temperature of the workpiece, measured by a pyrometer, is tuned by a PI-Controller. A tool incorporating a multistage operation die is used for the manufacturing of up to three parts at the same time. The tool is integrated into a hydraulical press. A gearwheel made of the magnesium alloy AZ31 is chosen as metal demonstrator. The quality of these punched parts could be significantly improved at elevated temperatures

  11. microRNAs and microRNA Targets Involved in Alfalfa Stem Development

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To examine the possible involvement of microRNAs in alfalfa stem development, we hybridized 32P-labled total microRNAs purified from elongating and post-elongation stem internodes (ES and PES, respectively) of the alfalfa Clone 252 to a microRNA dot blot that contains a total of 70 reference anti-mi...

  12. Aging characteristics of blue InGaN micro-light emitting diodes at an extremely high current density of 3.5 kA cm-2

    NASA Astrophysics Data System (ADS)

    Tian, Pengfei; Althumali, Ahmad; Gu, Erdan; Watson, Ian M.; Dawson, Martin D.; Liu, Ran

    2016-04-01

    The aging characteristics of blue InGaN micro-light emitting diodes (micro-LEDs) with different sizes have been studied at an extremely high current density 3.5 kA cm-2 for emerging micro-LED applications including visible light communication (VLC), micro-LED pumped organic lasers and optogenetics. The light output power of micro-LEDs first increases and then decreases due to the competition of Mg activation in p-GaN layer and defect generation in the active region. The smaller micro-LEDs show less light output power degradation compared with larger micro-LEDs, which is attributed to the lower junction temperature of smaller micro-LEDs. It is found that the high current density without additional junction temperature cannot induce significant micro-LED degradation at room temperature but the combination of the high current density and high junction temperature leads to strong degradation. Furthermore, the cluster LEDs, composed of a micro-LED array, have been developed with both high light output power and less light output degradation for micro-LED applications in solid state lighting and VLC.

  13. Micro- and Nanotechnologies for Intelligent and Responsive Biomaterial-Based Medical Systems

    PubMed Central

    Caldorera-Moore, Mary; Peppas, Nicholas A.

    2009-01-01

    Advances in medical treatments of a wide variety of pathophysiological conditions require the development of better therapeutic agents, as well as a combination of the required therapeutic agents with device-integrated biomaterials that can serve as sensors and carriers. Combination of micro- and nanofabricated systems with intelligent biomaterials that have the ability to sense and respond is a promising avenue for the development of better diagnostic and therapeutic medical systems. Micro- and nano-electromechanical systems (MEMs and NEMs) are now becoming a family of potentially powerful new technologies for drug delivery, diagnostic tools, and tissue engineering. Improvements in micro- and nano-fabrication technology have enhanced the ability to create better performing therapeutic systems for numerous pathophysiological applications. More importantly, MEMS and NEMS-based tissue regeneration scaffolds, biosensors, and drug delivery devices provide new opportunities to mimic the natural intelligence and response of biological systems. PMID:19758574

  14. Structural vibration control of micro/macro-manipulator using feedforward and feedback approaches

    SciTech Connect

    Lew, J.Y.; Cannon, D.W.; Magee, D.P.; Book, W.J.

    1995-09-01

    Pacific Northwest Laboratory (PDL) researchers investigated the combined use of two control approaches to minimize micro/macro-manipulator structural vibration: (1) modified input shaping and (2) inertial force active damping control. Modified input shaping (MIS) is used as a feedforward controller to modify reference input by canceling the vibratory motion. Inertial force active damping (IFAD) is applied as a feedback controller to increase the system damping and robustness to unexpected disturbances. Researchers implemented both control schemes in the PNL micro/macro flexible-link manipulator testbed collaborating with Georgia Institute of Technology. The experiments successfully demonstrated the effectiveness of two control approaches in reducing structural vibration. Based on the results of the experiments, the combined use of two controllers is recommended for a micro/macro manipulator to achieve the fastest response to commands while canceling disturbances from unexpected forces.

  15. Micro-ultraviolet spectrograph (Micro-UVS). Final design report

    SciTech Connect

    Stern, S.A.; Slater, D.C.

    1994-04-30

    In this report, the authors present a low-mass (<2 kg), low-power (approximately 2 W), and low-cost (< $0.5M) Far UV spectrometer design, capable of performing high-resolution ({lambda}/{delta}{lambda} approximately equal to 100-200) spectroscopy of planetary atmospheres in the extreme ultraviolet wavelength regime (700 {angstrom} < {lambda} < 1500 {angstrom}). This spectrograph, referred to in this report as the MicroUVS, is in part based on the integrated UV/VIS/IR Pluto Fast Flyby (PFF) design being developed for NASA, but is tailored to be a stand-alone instrument suitable for future BMDO/LLNL missions. Design objectives and performance of the spectrometer are discussed in detail.

  16. Micro Electron MicroProbe and Sample Analyzer

    NASA Technical Reports Server (NTRS)

    Manohara, Harish; Bearman, Gregory; Douglas, Susanne; Bronikowski, Michael; Urgiles, Eduardo; Kowalczyk, Robert; Bryson, Charles

    2009-01-01

    A proposed, low-power, backpack-sized instrument, denoted the micro electron microprobe and sample analyzer (MEMSA), would serve as a means of rapidly performing high-resolution microscopy and energy-dispersive x-ray spectroscopy (EDX) of soil, dust, and rock particles in the field. The MEMSA would be similar to an environmental scanning electron microscope (ESEM) but would be much smaller and designed specifically for field use in studying effects of geological alteration at the micrometer scale. Like an ESEM, the MEMSA could be used to examine uncoated, electrically nonconductive specimens. In addition to the difference in size, other significant differences between the MEMSA and an ESEM lie in the mode of scanning and the nature of the electron source.

  17. Hybrid subtractive micro-patterning of a self-assembled SiO2 nano/microsphere monolayer

    NASA Astrophysics Data System (ADS)

    Han, Seungyong; Hong, Sukjoon; Kang, Hyun Wook; Wanit, Manorokul; Kang, Bongchul; Ko, Seung Hwan

    2015-10-01

    Colloidal self-assembly and direct micro-patterning of functional materials have drawn intense interest as an alternative to the conventional photolithography based microelectronics fabrication process. In this paper, we introduce a facile subtractive micro contact printing method to create a patterned colloidal nano/micro sphere monolayer on a wafer scale by combining an additive ‘bottom-up’ self-assembly and subtractive ‘top-down’ printing process. A vacuum-assisted contact printing method enabled precise and uniform pressure control to directly fabricate a large-area micro-patterned hexagonally close packed structure of nano/micro spheres on the target substrate very fast, at low cost, under ambient conditions. In addition, analysis on the hybrid printing pressure and the patterning time has been conducted.

  18. Residual orientation in micro-injection molded parts

    SciTech Connect

    Healy, John; Edward, Graham H.; Knott, Robert B.

    2008-06-30

    The residual orientation following micro-injection molding of small rectangular plates with linear polyethylene has been examined using small-angle neutron scattering, and small- and wide-angle X-ray scattering. The effect of changing the molding conditions has been examined, and the residual chain orientation has been compared to the residual orientation of the crystallites as a function of position in the sample. This study has found that, for micromoldings, the orientation of the crystallites decreases with increasing injection speed and increasing mold thickness. The combined data suggest that the majority of the orientation present comes from oriented crystal growth rather than residual chain orientation.

  19. Optical Tweezers for Sample Fixing in Micro-Diffraction Experiments

    SciTech Connect

    Amenitsch, H.; Rappolt, M.; Sartori, B.; Laggner, P.; Cojoc, D.; Ferrari, E.; Garbin, V.; Di Fabrizio, E.; Burghammer, M.; Riekel, Ch.

    2007-01-19

    In order to manipulate, characterize and measure the micro-diffraction of individual structural elements down to single phospholipid liposomes we have been using optical tweezers (OT) combined with an imaging microscope. We were able to install the OT system at the microfocus beamline ID13 at the ESRF and trap clusters of about 50 multi-lamellar liposomes (< 10 {mu}m large cluster). Further we have performed a scanning diffraction experiment with a 1 micrometer beam to demonstrate the fixing capabilities and to confirm the size of the liposome cluster by X-ray diffraction.

  20. The Promise of Macromolecular Crystallization in Micro-fluidic Chips

    NASA Technical Reports Server (NTRS)

    vanderWoerd, Mark; Ferree, Darren; Pusey, Marc

    2003-01-01

    Micro-fluidics, or lab on a chip technology, is proving to be a powerful, rapid, and efficient approach to a wide variety of bio-analytical and microscale bio-preparative needs. The low materials consumption, combined with the potential for packing a large number of experiments in a few cubic centimeters, makes it an attractive technique for both initial screening and subsequent optimization of macromolecular crystallization conditions. Screening operations, which require equilibrating macromolecule solution with a standard set of premixed solutions, are relatively straightforward and have been successfully demonstrated in a micro-fluidics platform. More complex optimization methods, where crystallization solutions are independently formulated from a range of stock solutions, are considerably more complex and have yet to be demonstrated. To be competitive with either approach, a micro-fluidics system must offer ease of operation, be able to maintain a sealed environment over several weeks to months, and give ready access for the observation of crystals as they are grown.

  1. Micro Pattern Gas Detectors for Nuclear Physics Experiments

    NASA Astrophysics Data System (ADS)

    Gnanvo, Kondo

    2015-10-01

    Gaseous detectors have played a pivotal role as tracking devices in the field of particle physics experiments for the last fifty years. Nowadays, advances in photolithography and micro processing techniques have enabled the transition from the old generation of multi wire gaseous chamber (MWPCs) to a new family commonly refer to as Micro Pattern Gaseous Detectors (MPGDs). MPGD technologies combine the basic gas amplification principle with micro-structure printed circuits to provide detectors with excellent spatial and time resolution, high rate capability, low material budget and high radiation tolerance. Several technical breakthroughs over the past decade have allowed the possibility for large area MPGDs, making them cost effective and high performance detector candidates for future nuclear physics (NP) and high energy physics (HEP) experiments. We give in the present talk, an overview of the state of the art of the MPGDs. We will then briefly present the CERN-based RD51 collaboration established in 2008 with the goal of further advancing technological developments and applications of MPGDs and associated electronic-readout systems. Finally we report on the rich and diverse R&D activities on MPGDs to prepare for the detector challenges of the next generation of accelerators and for the frontiers of physics research.

  2. Micro-optical imaging concepts for an intraocular vision aid

    NASA Astrophysics Data System (ADS)

    Eix, Ilos; Stork, Wilhelm; Muller-Glaser, Klaus D.

    2004-03-01

    About 10 million people around the world are suffering from blindness, where the path of light is disturbed due to an opaque, irreversible damaged, and inoperable cornea. Although vision is not given to this group of population, the retina is still intact. To date, there is no artificial implant which is able to replace the natural cornea. The work presented here describes an approach to build and implant a micro-optical and microelectronic system to be used as an intraocular vision aid. By overcoming the disturbed light path, it yields to an improved visual acuity of the patient. The main aspect of this bio-mimetic system is to transfer information representing the patient's field of view to the retina. An image of the field of view is captured in real-time outside the eye. After employing data processing, it is wireless transferred to the implanted part of the vision aid. From there, the information emerging from a micro display is imaged to the retina via a micro-optical system. The limited display resolution available inside the eye and the limited dimensions of the eyeball build the constrains of the optical system. A combination of a spatial light modulator together with an imaging lens system realizes intelligent spatial information distribution schemes onto the retina. This ensures a high outcome of visual acuity in the central region of the retina. Various retinal acuities can be realized. The employment of in-vivo adjustment mechanisms of the focal plane is discussed.

  3. Hot gas stream application in micro-bonding technique

    NASA Astrophysics Data System (ADS)

    Andrijasevic, Daniela; Giouroudi, Ioanna; Smetana, Walter; Boehm, Stefan; Brenner, Werner

    2006-01-01

    This paper presents a new concept for bonding micro-parts with dimensions in the range of 50 μm to 300 μm. Two different kinds of adhesives - polyurethane adhesive foil and hot melt glue - were applied to a basic substrate by different techniques. The focused and concentrated hot gas stream softened glue which had been applied in a solid state. Micro-parts were then embossed in the softened glue, or covered and shielded by it. In this way, a rigid and compact bond was obtained after cooling. For the positioning of micro-parts (optical fibers), it has been necessary to manufacture adequate V-grooves. Finite element analyses using the ANSYS TM program package were performed in order to evaluate parameters which govern the heat transfer to the adhesive and substrate respectively. Experimental results are in good agreement with results obtained by the numerical simulations. The advantages of this new approach are small system size, low capital costs, simple usage, applicability to many material combinations, easy integration into existing production lines, etc.

  4. Plasmofluidics: Merging Light and Fluids at the Micro-/Nanoscale.

    PubMed

    Wang, Mingsong; Zhao, Chenglong; Miao, Xiaoyu; Zhao, Yanhui; Rufo, Joseph; Liu, Yan Jun; Huang, Tony Jun; Zheng, Yuebing

    2015-09-16

    Plasmofluidics is the synergistic integration of plasmonics and micro/nanofluidics in devices and applications in order to enhance performance. There has been significant progress in the emerging field of plasmofluidics in recent years. By utilizing the capability of plasmonics to manipulate light at the nanoscale, combined with the unique optical properties of fluids and precise manipulation via micro/nanofluidics, plasmofluidic technologies enable innovations in lab-on-a-chip systems, reconfigurable photonic devices, optical sensing, imaging, and spectroscopy. In this review article, the most recent advances in plasmofluidics are examined and categorized into plasmon-enhanced functionalities in microfluidics and microfluidics-enhanced plasmonic devices. The former focuses on plasmonic manipulations of fluids, bubbles, particles, biological cells, and molecules at the micro/nanoscale. The latter includes technological advances that apply microfluidic principles to enable reconfigurable plasmonic devices and performance-enhanced plasmonic sensors. The article is concluded with perspectives on the upcoming challenges, opportunities, and possible future directions of the emerging field of plasmofluidics. PMID:26140612

  5. Micro-Inspector Spacecraft for Space Exploration Missions

    NASA Technical Reports Server (NTRS)

    Mueller, Juergen; Alkalai, Leon; Lewis, Carol

    2005-01-01

    NASA is seeking to embark on a new set of human and robotic exploration missions back to the Moon, to Mars, and destinations beyond. Key strategic technical challenges will need to be addressed to realize this new vision for space exploration, including improvements in safety and reliability to improve robustness of space operations. Under sponsorship by NASA's Exploration Systems Mission, the Jet Propulsion Laboratory (JPL), together with its partners in government (NASA Johnson Space Center) and industry (Boeing, Vacco Industries, Ashwin-Ushas Inc.) is developing an ultra-low mass (<3.0 kg) free-flying micro-inspector spacecraft in an effort to enhance safety and reduce risk in future human and exploration missions. The micro-inspector will provide remote vehicle inspections to ensure safety and reliability, or to provide monitoring of in-space assembly. The micro-inspector spacecraft represents an inherently modular system addition that can improve safety and support multiple host vehicles in multiple applications. On human missions, it may help extend the reach of human explorers, decreasing human EVA time to reduce mission cost and risk. The micro-inspector development is the continuation of an effort begun under NASA's Office of Aerospace Technology Enabling Concepts and Technology (ECT) program. The micro-inspector uses miniaturized celestial sensors; relies on a combination of solar power and batteries (allowing for unlimited operation in the sun and up to 4 hours in the shade); utilizes a low-pressure, low-leakage liquid butane propellant system for added safety; and includes multi-functional structure for high system-level integration and miniaturization. Versions of this system to be designed and developed under the H&RT program will include additional capabilities for on-board, vision-based navigation, spacecraft inspection, and collision avoidance, and will be demonstrated in a ground-based, space-related environment. These features make the micro

  6. Acoustic emissions in rock deformation experiments under micro-CT

    NASA Astrophysics Data System (ADS)

    Tisato, Nicola; Goodfellow, Sebastian D.; Moulas, Evangelos; Di Toro, Giulio; Young, Paul; Grasselli, Giovanni

    2016-04-01

    The study of acoustic emissions (AE) generated by rocks undergoing deformation has become, in the last decades, one of the most powerful tools for boosting our understanding of the mechanisms which are responsible for rock failures. AE are elastic waves emitted by the local failure of micro- or milli-metric portions of the tested specimen. At the same time, X-ray micro computed tomography (micro-CT) has become an affordable, reliable and powerful tool for imaging the internal structure of rock samples. In particular, micro-CT coupled with a deformation apparatus offers the unique opportunity for observing, without perturbing, the sample while the deformation and the formation of internal structures, such as shear bands, is ongoing. Here we present some preliminary results gathered with an innovative apparatus formed by the X-ray transparent pressure vessel called ERDμ equipped with AE sensors, an AE acquisition system and a micro-CT apparatus available at the University of Toronto. The experiment was performed on a 12 mm diameter 36 mm long porous glass sample which was cut on a 60 deg inclined plane (i.e. saw-cut sample). Etna basaltic sand with size ~1 mm was placed between the two inclined faces forming an inclined fault zone with ~2 mm thickness. The sample assembly was jacketed with a polyefin shrink tube and two AE sensors were glued onto the glass samples above and below the fault zone. The sample was then enclosed in the pressure vessel and confined with compressed air up to 3 MPa. A third AE sensor was placed outside the vessel. The sample was saturated with water and AE were generated by varying the fluid and confining pressure or the vertical force, causing deformations concentrated in the fault zone. Mechanical data and AE traces were collected throughout the entire experiment which lasted ~24 hours. At the same time multiple micro-CT 3D datasets and 2D movie-radiographies were collected, allowing the 3D reconstruction of the deformed sample at

  7. Micro Electro Discharge Machining of Electrically Nonconductive Ceramics

    NASA Astrophysics Data System (ADS)

    Schubert, A.; Zeidler, H.; Wolf, N.; Hackert, M.

    2011-05-01

    EDM is a known process for machining of hard and brittle materials. Due to its noncontact and nearly forceless behaviour, it has been introduced into micro manufacturing and through constant development it is now an important means for producing high-precision micro geometries. One restriction of EDM is its limitation to electrically conducting materials. Today many applications, especially in the biomedical field, make use of the benefits of ceramic materials, such as high strength, very low wear and biocompatibility. Common ceramic materials such as Zirconium dioxide are, due to their hardness in the sintered state, difficult to machine with conventional cutting techniques. A demand for the introduction of EDM to these materials could so far not be satisfied because of their nonconductive nature. At the Chemnitz University of Technology and the Fraunhofer IWU, investigations in the applicability of micro-EDM for the machining of nonconductive ceramics are being conducted. Tests are undertaken using micro-EDM drilling with Tungsten carbide tool electrodes and ZrO2 ceramic workpieces. A starting layer, in literature often referred to as `assisting electrode' is used to set up a closed electric circuit to start the EDM process. Combining carbon hydride based dielectric and a specially designed low-frequency vibration setup to excite the workpiece, the process environment can be held within parameters to allow for a constant EDM process even after the starting layer is machined. In the experiments a cylindrical 120 μm diameter Tungsten carbide tool electrode and Y2O3- and MgO- stabilized ZrO2 worpieces are used. The current and voltage signals of the discharges within the different stages of the process (machining of the starting layer, machining of the base material, transition stage) are recorded and their characteristics compared to discharges in metallic material. Additionally, the electrode feed is monitored. The influences of the process parameters are

  8. Micro Electro Discharge Machining of Electrically Nonconductive Ceramics

    SciTech Connect

    Schubert, A.; Zeidler, H.; Hackert, M.; Wolf, N.

    2011-05-04

    EDM is a known process for machining of hard and brittle materials. Due to its noncontact and nearly forceless behaviour, it has been introduced into micro manufacturing and through constant development it is now an important means for producing high-precision micro geometries. One restriction of EDM is its limitation to electrically conducting materials.Today many applications, especially in the biomedical field, make use of the benefits of ceramic materials, such as high strength, very low wear and biocompatibility. Common ceramic materials such as Zirconium dioxide are, due to their hardness in the sintered state, difficult to machine with conventional cutting techniques. A demand for the introduction of EDM to these materials could so far not be satisfied because of their nonconductive nature.At the Chemnitz University of Technology and the Fraunhofer IWU, investigations in the applicability of micro-EDM for the machining of nonconductive ceramics are being conducted. Tests are undertaken using micro-EDM drilling with Tungsten carbide tool electrodes and ZrO{sub 2} ceramic workpieces. A starting layer, in literature often referred to as 'assisting electrode' is used to set up a closed electric circuit to start the EDM process. Combining carbon hydride based dielectric and a specially designed low-frequency vibration setup to excite the workpiece, the process environment can be held within parameters to allow for a constant EDM process even after the starting layer is machined. In the experiments a cylindrical 120 {mu}m diameter Tungsten carbide tool electrode and Y{sub 2}O{sub 3}- and MgO- stabilized ZrO{sub 2} worpieces are used. The current and voltage signals of the discharges within the different stages of the process (machining of the starting layer, machining of the base material, transition stage) are recorded and their characteristics compared to discharges in metallic material. Additionally, the electrode feed is monitored. The influences of the

  9. Two-phase dispersion in micro-channels

    NASA Astrophysics Data System (ADS)

    Galambos, Paul Charles

    This dissertation is concerned with dispersion between laminar fluid streams of different viscosity in micro-channels having cross-sections. Dispersion is the combined effect of diffusion and convection. Understanding dispersion micro-channels is important to the development of micro-total chemical analysis systems (muTAS), which have applications in the fields of environmental science, chemical process control, bio-technology, and medicine. The dispersion of a fluid constituent that is initially only one of two streams entering a micro-channel is investigated Eventually the constituent becomes uniformly distributed across the channel, and the streamwise variation of constituent concentration with time is well known (Taylor, 1953). The development of initially non-uniform concentration profiles across a slot has been investigated numerically (Williams et al., 1992), but no general solution applicable to an arbitrary aspect ratio rectangular duct has been reported in the literature. In addition, muTAS applications often are concerned with two entering streams of viscosity (e.g. blood and saline). This viscosity difference results in first order variations in the velocity distribution (Ong et al., 1994), and therefore in the dispersion of constituents. Mathematical models dealing with concentration distributions in micro-channels are presented. These models are verified and expanded upon using numerical techniques (CFD-Computational Fluid Dynamics) and experimental results. The channel cross-section aspect ratio and the difference in viscosity between the two streams cause a different velocity field to develop in each stream. As a result constituent dispersion proceeds at a different rate in each stream. The difference in dispersion rate is most simply described by differences in Peclet number (ratio of convective to diffusive transport) between the two streams. A two-Peclet number mathematical model is used to quantify dispersion in a channel through which two

  10. Local Luminosity Function at 15 micro m and Galaxy Evolution Seen by ISOCAM 15 micro m Surveys

    NASA Technical Reports Server (NTRS)

    Xu, C.

    2000-01-01

    A local luminosity function at 15 micro m is derived using the bivariate (15 micro m vs. 60 micro m luminosities) method, based on the newly published ISOCAM LW3-band (15 micro m) survey of the very deep IRAS 60 micro m sample in the north ecliptic pole region (NEPR).

  11. Understanding the micro structure of Berea Sandstone by the simultaneous use of micro-computed tomography (micro-CT) and focused ion beam-scanning electron microscopy (FIB-SEM).

    PubMed

    Bera, Bijoyendra; Mitra, Sushanta K; Vick, Douglas

    2011-07-01

    Berea sandstone is the building block for reservoirs containing precious hydrocarbon fuel. In this study, we comprehensively reveal the microstructure of Berea sandstone, which is often treated as a porous material with interconnected micro-pores of 2-5 μm. This has been possible due to the combined application of micro-computed tomography (CT) and focused ion beam (FIB)-scanning electron microscopy (SEM) on a Berea sample. While the use of micro-CT images are common for geological materials, the clubbing and comparison of tomography on Berea with state-of-the-art microstructure imaging techniques like FIB-SEM reveals some unforeseen features of Berea microstructure. In particular, for the first time FIB-SEM has been used to understand the micro-structure of reservoir rock material like Berea sandstone. By using these characterization tools, we are able to show that the micro-pores (less than 30 μm) are absent below the solid material matrix, and that it has small interconnected pores (30-40 μm) and large crater-like voids (100-250 μm) throughout the bulk material. Three-dimensional pore space reconstructions have been prepared from the CT images. Accordingly, characterization of Berea sandstone specimen is performed by calculation of pore-structure volumes and determination of porosity values. PMID:21208806

  12. A thermally self-sustained micro-power plant with integrated micro-solid oxide fuel cells, micro-reformer and functional micro-fluidic carrier

    NASA Astrophysics Data System (ADS)

    Scherrer, Barbara; Evans, Anna; Santis-Alvarez, Alejandro J.; Jiang, Bo; Martynczuk, Julia; Galinski, Henning; Nabavi, Majid; Prestat, Michel; Tölke, René; Bieberle-Hütter, Anja; Poulikakos, Dimos; Muralt, Paul; Niedermann, Philippe; Dommann, Alex; Maeder, Thomas; Heeb, Peter; Straessle, Valentin; Muller, Claude; Gauckler, Ludwig J.

    2014-07-01

    Low temperature micro-solid oxide fuel cell (micro-SOFC) systems are an attractive alternative power source for small-size portable electronic devices due to their high energy efficiency and density. Here, we report on a thermally self-sustainable reformer-micro-SOFC assembly. The device consists of a micro-reformer bonded to a silicon chip containing 30 micro-SOFC membranes and a functional glass carrier with gas channels and screen-printed heaters for start-up. Thermal independence of the device from the externally powered heater is achieved by exothermic reforming reactions above 470 °C. The reforming reaction and the fuel gas flow rate of the n-butane/air gas mixture controls the operation temperature and gas composition on the micro-SOFC membrane. In the temperature range between 505 °C and 570 °C, the gas composition after the micro-reformer consists of 12 vol.% to 28 vol.% H2. An open-circuit voltage of 1.0 V and maximum power density of 47 mW cm-2 at 565 °C is achieved with the on-chip produced hydrogen at the micro-SOFC membranes.

  13. Micro sun sensor for spacecraft attitude control

    NASA Technical Reports Server (NTRS)

    Mobasser, Sohrab; Liebe, Carl Christian

    2004-01-01

    A micro sun sensor is being developed for use on a Mars rover for the Mars Science Laboratory Mission. The micro sun sensor, which is basically a small pinhole camera, consists of a small mask with pinholes, placed on top of an image detector.

  14. Wafer-scale micro-optics fabrication

    NASA Astrophysics Data System (ADS)

    Voelkel, Reinhard

    2012-07-01

    Micro-optics is an indispensable key enabling technology for many products and applications today. Probably the most prestigious examples are the diffractive light shaping elements used in high-end DUV lithography steppers. Highly-efficient refractive and diffractive micro-optical elements are used for precise beam and pupil shaping. Micro-optics had a major impact on the reduction of aberrations and diffraction effects in projection lithography, allowing a resolution enhancement from 250 nm to 45 nm within the past decade. Micro-optics also plays a decisive role in medical devices (endoscopes, ophthalmology), in all laser-based devices and fiber communication networks, bringing high-speed internet to our homes. Even our modern smart phones contain a variety of micro-optical elements. For example, LED flash light shaping elements, the secondary camera, ambient light and proximity sensors. Wherever light is involved, micro-optics offers the chance to further miniaturize a device, to improve its performance, or to reduce manufacturing and packaging costs. Wafer-scale micro-optics fabrication is based on technology established by the semiconductor industry. Thousands of components are fabricated in parallel on a wafer. This review paper recapitulates major steps and inventions in wafer-scale micro-optics technology. The state-of-the-art of fabrication, testing and packaging technology is summarized.

  15. Micro/nanoscale continuous printing: direct-writing of wavy micro/nano structures via electrospinning

    NASA Astrophysics Data System (ADS)

    Fang, Feiyu; Du, Zefeng; Zeng, Jun; Zhu, Ziming; Chen, Xin; Chen, Xindu; Lv, Yuanjun; Wang, Han

    2015-07-01

    Micro/nanofibers that are created by direct-writing using an electrospinning (ES) technique have aroused much recent attention, owing to their intriguing physical properties and great potential as building blocks for micro/nanoscale devices. In this work, a wavy direct-writing (WDW) process was developed to directly write wavy micro/nanostructures suitable for the fabrication of micro/nanoscale devices. The low voltage WDW technique is anticipated to be useful for a broad range of applications including flexible/stretchable electronics, micro optoelectronics, nano-antennas, microelectromechanical systems (MEMS), and biomedical engineering.

  16. Micro bubble condensation in micro channel controlled by local electrical field method

    NASA Astrophysics Data System (ADS)

    Ohata, Shunsuke; Kawai, Akira

    2009-12-01

    Micro bubbles in several tens micrometer diameter can act as effective structural elements of micro devices. In this study, the micro device employing the bubble motion is characterized. It has been experimentally revealed that bubble motion in micro channel is trapped at the channel branches. The local electrodes are set at a part of micro channel in order to control the bubble motion. Negatively charged bubble surface is received a certain force due to Coulomb's effect. This study will provide effective information to bioscience, medical science and agriculture engineering.

  17. Hierarchically micro-patterned nanofibrous scaffolds with a nanosized bio-glass surface for accelerating wound healing

    NASA Astrophysics Data System (ADS)

    Xu, He; Lv, Fang; Zhang, Yali; Yi, Zhengfang; Ke, Qinfei; Wu, Chengtie; Liu, Mingyao; Chang, Jiang

    2015-11-01

    A composite scaffold with a controlled micro-pattern, nano-sized fiber matrix and surface-modified nanobioglass component was successfully prepared for skin wound healing by combining the patterning electrospinning with pulsed laser deposition strategies, and the hierarchical micro/nano structures and nano-sized bioglass in the scaffolds could synergistically improve the efficiency and re-epithelialization of wound healing.A composite scaffold with a controlled micro-pattern, nano-sized fiber matrix and surface-modified nanobioglass component was successfully prepared for skin wound healing by combining the patterning electrospinning with pulsed laser deposition strategies, and the hierarchical micro/nano structures and nano-sized bioglass in the scaffolds could synergistically improve the efficiency and re-epithelialization of wound healing. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr04802h

  18. MicroRNAs and atherosclerosis

    PubMed Central

    Madrigal-Matute, Julio; Rotllan, Noemi; Aranda, Juan F.; Fernández-Hernando, Carlos

    2014-01-01

    MicroRNAs (miRNAs) are small (~22nucleotide) sequences of RNA that regulate gene expression at posttranscriptional level. MiRNA/mRNA base pairing complementarity provokes mRNA decay and consequent gene silencing. These endogenous gene expression inhibitors were primarily described in cancer but recent exciting findings have also demonstrated a key role in cardiovascular diseases (CVDs) including atherosclerosis. MiRNAs controls endothelial cell (EC), vascular smooth muscle cell (VSMC) and macrophage functions, and thereby regulate the progression of atherosclerosis. MiRNAs expression is modulated by different stimuli involved in every stage of atherosclerosis and conversely miRNAs modulates several pathways implicated in plaque development such as cholesterol metabolism. In the present review, we focus on the importance of miRNAs in atherosclerosis and we further discuss their potential use as biomarkers and therapeutic targets in CVDs. PMID:23512606

  19. Micro-tensile testing system

    DOEpatents

    Wenski, Edward G.

    2006-01-10

    A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.

  20. Micro-tensile testing system

    DOEpatents

    Wenski, Edward G.

    2007-08-21

    A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.

  1. Micro-tensile testing system

    DOEpatents

    Wenski, Edward G.

    2007-07-17

    A micro-tensile testing system providing a stand-alone test platform for testing and reporting physical or engineering properties of test samples of materials having thicknesses of approximately between 0.002 inch and 0.030 inch, including, for example, LiGA engineered materials. The testing system is able to perform a variety of static, dynamic, and cyclic tests. The testing system includes a rigid frame and adjustable gripping supports to minimize measurement errors due to deflection or bending under load; serrated grips for securing the extremely small test sample; high-speed laser scan micrometers for obtaining accurate results; and test software for controlling the testing procedure and reporting results.

  2. microRNAs in cancer

    PubMed Central

    Di Leva, Gianpiero; Garofalo, Michela; Croce, Carlo M.

    2014-01-01

    MicroRNAs are small non coding RNAs that typically inhibit the translation and stability of messanger RNAs (mRNAs), controlling genes involved in cellular processes such as inflammation, cell cycle regulation, stress response, differentiation, apoptosis, and migration. Thus, miRNAs have been implicated in the regulation of virtually all signaling circuits within a cell and their dysregulation has been shown to play an essential role in the development and progression of cancer. Here, after a brief description of the miRNA genomics, biogenesis and function, we discuss the effects of miRNA deregulation in the cellular pathways that lead to the progressive conversion of normal cells into cancer cells and the potential to develop new molecular miRNA-targeted therapies. PMID:24079833

  3. MicroRNA involvement in glioblastoma pathogenesis

    SciTech Connect

    Novakova, Jana; Slaby, Ondrej; Vyzula, Rostislav; Michalek, Jaroslav

    2009-08-14

    MicroRNAs are endogenously expressed regulatory noncoding RNAs. Altered expression levels of several microRNAs have been observed in glioblastomas. Functions and direct mRNA targets for these microRNAs have been relatively well studied over the last years. According to these data, it is now evident, that impairment of microRNA regulatory network is one of the key mechanisms in glioblastoma pathogenesis. MicroRNA deregulation is involved in processes such as cell proliferation, apoptosis, cell cycle regulation, invasion, glioma stem cell behavior, and angiogenesis. In this review, we summarize the current knowledge of miRNA functions in glioblastoma with an emphasis on its significance in glioblastoma oncogenic signaling and its potential to serve as a disease biomarker and a novel therapeutic target in oncology.

  4. Biologically Inspired Micro-Flight Research

    NASA Technical Reports Server (NTRS)

    Raney, David L.; Waszak, Martin R.

    2003-01-01

    Natural fliers demonstrate a diverse array of flight capabilities, many of which are poorly understood. NASA has established a research project to explore and exploit flight technologies inspired by biological systems. One part of this project focuses on dynamic modeling and control of micro aerial vehicles that incorporate flexible wing structures inspired by natural fliers such as insects, hummingbirds and bats. With a vast number of potential civil and military applications, micro aerial vehicles represent an emerging sector of the aerospace market. This paper describes an ongoing research activity in which mechanization and control concepts for biologically inspired micro aerial vehicles are being explored. Research activities focusing on a flexible fixed- wing micro aerial vehicle design and a flapping-based micro aerial vehicle concept are presented.

  5. Micro and Nano Systems for Space Exploration

    NASA Technical Reports Server (NTRS)

    Manohara, Harish

    2007-01-01

    This slide presentation reviews the use of micro and nano systems in Space exploration. Included are: an explanation of the rationales behind nano and micro technologies for space exploration, a review of how the devices are fabricated, including details on lithography with more information on Electron Beam (E-Beam) lithography, and X-ray lithography, a review of micro gyroscopes and inchworm Microactuator as examples of the use of MicroElectoMechanical (MEMS) technology. Also included is information on Carbon Nanotubes, including a review of the CVD growth process. These micro-nano systems have given rise to the next generation of miniature X-ray Diffraction, X-ray Fluorescence instruments, mass spectrometers, and terahertz frequency vacuum tube oscillators and amplifiers, scanning electron microscopes and energy dispersive x-ray spectroscope. The nanotechnology has also given rise to coating technology, such as silicon nanotip anti-reflection coating.

  6. Micro-Scale Regenerative Heat Exchanger

    NASA Technical Reports Server (NTRS)

    Moran, Matthew E.; Stelter, Stephan; Stelter, Manfred

    2004-01-01

    A micro-scale regenerative heat exchanger has been designed, optimized and fabricated for use in a micro-Stirling device. Novel design and fabrication techniques enabled the minimization of axial heat conduction losses and pressure drop, while maximizing thermal regenerative performance. The fabricated prototype is comprised of ten separate assembled layers of alternating metal-dielectric composite. Each layer is offset to minimize conduction losses and maximize heat transfer by boundary layer disruption. A grating pattern of 100 micron square non-contiguous flow passages were formed with a nominal 20 micron wall thickness, and an overall assembled ten-layer thickness of 900 microns. Application of the micro heat exchanger is envisioned in the areas of micro-refrigerators/coolers, micropower devices, and micro-fluidic devices.

  7. Micro-bubble Enhanced Sonoporation

    NASA Astrophysics Data System (ADS)

    Tachibana, Rie; Okamoto, Akio; Yoshinaka, Kiyoshi; Takagi, Shu; Matsumoto, Yoichiro

    2010-03-01

    A gene transfer system that uses ultrasound, known as sonoporation, has recently been developed, and it is known that micro-bubbles can help gene transfection in this technique. However, the mechanism and optimal induction conditions have not yet been fully clarified. We examined the factors that affect the gene induction rate, and attempted to devise a method for high-efficiency gene induction. In vitro, we inducted a GFP-containing plasmid into fibroblast cells (NIH3T3) using an ultrasound contrast agent (Sonazoid®, or micro-bubbles) and piezoelectric transducer. Cells were cultured on 24-well plates. The GFP-containing plasmid (concentration: 15 mg/ml) and Sonazoid® were mixed with the cell suspension. Ultrasound frequency was 2.0 MHz (burst wave, duty cycle: 10%), ultrasound intensity was varied from 0 W/cm2 to 11.0 W/cm2, exposure time ranged from 0 s to 120 s, and burst repetition frequency was varied from 50 Hz to 50000 Hz. Gene induction ratio was higher with stronger or longer ultrasound exposure, and gene induction ratio was affected by ultrasound burst repetition frequency. However, the ratio was less than 1%. We also measured cell survival and visualized cells with holes using propidium iodide. We found that about 80% of cells were alive, and many cells developed holes with ultrasound exposure at a burst repetition frequency of 5 kHz. These results suggest that fewer genes enter the cells or are expressed under these conditions. These problems require further study.

  8. Direct and dry micro-patterning of nano-particles by electrospray deposition through a micro-stencil mask

    NASA Astrophysics Data System (ADS)

    Kim, J.-W.; Yamagata, Y.; Kim, B. J.; Higuchi, T.

    2009-02-01

    A new micro-pattern formation method for thin films of organic or bio-macromolecules is proposed. The method combines an electrospray deposition process with a micro-fabricated stencil mask made of a silicon nitride membrane. The highest resolution of 2 µm line and space is possible using 50 nm fluorescent latex beads. The deposited nano-structure consists of clusters of particles ranging from 100 to 200 nm, which indicates that nanometer resolution is potentially achievable. The surface roughness of the deposit is about 3.6 nm on average, and thickness uniformity is about 10 nm with 76 nm film thickness over 72 µm. Size uniformity of the 5 µm dots reaches 5.2% in the coefficient of variation (CV) value. These results indicate that the resolution and uniformity of the proposed method are high. In addition, the charged particles on the micro stencil mask of electrical insulation are proved to induce a focusing effect, which suggests that the size of the deposited pattern can be smaller than the mask aperture size.

  9. Fabrication and Characterization of Silicon Micro-Funnels and Tapered Micro-Channels for Stochastic Sensing Applications

    PubMed Central

    Archer, Marie J.; Ligler, Frances S.

    2008-01-01

    We present a simplified, highly reproducible process to fabricate arrays of tapered silicon micro-funnels and micro-channels using a single lithographic step with a silicon oxide (SiO2) hard mask on at a wafer scale. Two approaches were used for the fabrication. The first one involves a single wet anisotropic etch step in concentrated potassium hydroxide (KOH) and the second one is a combined approach comprising Deep Reactive Ion Etch (DRIE) followed by wet anisotropic etching. The etching is performed through a 500 μm thick silicon wafer, and the resulting structures are characterized by sharp tapered ends with a sub-micron cross-sectional area at the tip. We discuss the influence of various parameters involved in the fabrication such as the size and thickness variability of the substrate, dry and wet anisotropic etching conditions, the etchant composition, temperature, diffusion and micro-masking effects, the quality of the hard mask in the uniformity and reproducibility of the structures, and the importance of a complete removal of debris and precipitates. The presence of apertures at the tip of the structures is corroborated through current voltage measurements and by the translocation of DNA through the apertures. The relevance of the results obtained in this report is discussed in terms of the potential use of these structures for stochastic sensing.

  10. Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography

    PubMed Central

    Walton, Lucy A.; Bradley, Robert S.; Withers, Philip J.; Newton, Victoria L.; Watson, Rachel E. B.; Austin, Clare; Sherratt, Michael J.

    2015-01-01

    Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons. PMID:25975937

  11. Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography

    NASA Astrophysics Data System (ADS)

    Walton, Lucy A.; Bradley, Robert S.; Withers, Philip J.; Newton, Victoria L.; Watson, Rachel E. B.; Austin, Clare; Sherratt, Michael J.

    2015-05-01

    Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons.

  12. Morphological Characterisation of Unstained and Intact Tissue Micro-architecture by X-ray Computed Micro- and Nano-Tomography.

    PubMed

    Walton, Lucy A; Bradley, Robert S; Withers, Philip J; Newton, Victoria L; Watson, Rachel E B; Austin, Clare; Sherratt, Michael J

    2015-01-01

    Characterisation and quantification of tissue structures is limited by sectioning-induced artefacts and by the difficulties of visualising and segmenting 3D volumes. Here we demonstrate that, even in the absence of X-ray contrast agents, X-ray computed microtomography (microCT) and nanotomography (nanoCT) can circumvent these problems by rapidly resolving compositionally discrete 3D tissue regions (such as the collagen-rich adventitia and elastin-rich lamellae in intact rat arteries) which in turn can be segmented due to their different X-ray opacities and morphologies. We then establish, using X-ray tomograms of both unpressurised and pressurised arteries that intra-luminal pressure not only increases lumen cross-sectional area and straightens medial elastic lamellae but also induces profound remodelling of the adventitial layer. Finally we apply microCT to another human organ (skin) to visualise the cell-rich epidermis and extracellular matrix-rich dermis and to show that conventional histological and immunohistochemical staining protocols are compatible with prior X-ray exposure. As a consequence we suggest that microCT could be combined with optical microscopy to characterise the 3D structure and composition of archival paraffin embedded biological materials and of mechanically stressed dynamic tissues such as the heart, lungs and tendons. PMID:25975937

  13. Micro-Raman and micro-XRF analysis of glass beads from the Chungde site, Taiwan

    NASA Astrophysics Data System (ADS)

    Liou, Y. S.; Wang, S. C.; Liu, Y. C.

    2014-12-01

    A large number of ancient glass beads dating back from Late Neolithic Age to early Historical Period (ca. 2300-400 BP) of Taiwan have been uncovered from archaeological sites. These glass beads with variant colors, shapes, and stylistics have long been considered to possess socio-cultural significance. Due to the color and chemical composition of glass bead might be determined by raw materials, fluxing agents, colorants, opacifiers and stabilizers. In addition, ancient glass beads are rare and precious, non-destructive analysis has been employed to decipher about the provenances, manufacturing techniques, and exchange/trade routes. In this work, micro-Raman spectroscopy and micro X-ray fluorescent spectrometer (μ-XRF) were used to examine ten ancient glass beads excavated from the Chungde site, Hualien, Taiwan, dating back to 1500-800 BP, to unravel the mineralogical and chemical compositions. Micro Raman experimental results show that glass and anorthite glass are the main constituents accompanying with trace level of quartz, albite, siderite, ankerite, and amazonite. The Raman Index of Polymerization (Ip) indicate that the sintering temperature of the glass beads is in the range of 1000~1400°C. Furthermore, the chemical compositions are corresponding to the maximum stretching vibration peak wave number (νmax Si-O Stretching) and the maximum bending vibration peak wave number (δmax Si-O Bending), which are essentially consistent with that of the India-Pacific beads. The μ-XRF results indicate the presence of oxides including SiO2, Al2O3, Fe2O3, Na2O, K2O, CaO, MgO, SnO2, TiO2, CuO, etc., and could be classified to high aluminum of soda-lime glass system. According to ternary phase diagram analysis of CaO-K2O-Na2O and K2O-Al2O3-CaO, the ancient glass beads analyzed could be attributed to the India-Pacific beads, and is in accordance with that of Raman spectra. The combination of these facts leads to the conclusion that glass beads obtained from the Chungde

  14. Experimental study of micro electrical discharge machining discharges

    SciTech Connect

    Braganca, I. M. F.; Rosa, P. A. R.; Martins, P. A. F.; Dias, F. M.; Alves, L. L.

    2013-06-21

    Micro electrical discharge machining ({mu}EDM) is an atmospheric-pressure plasma-assisted technology that uses point-to-plane discharges in liquid dielectrics to remove microscopic quantities of electrically conductive materials. In this work, an innovative {mu}EDM prototype machine was specifically designed and fabricated to produce and control single spark discharges, thus, resolving the typical limitations of (multi-discharge) commercial machines. The work analyses the type of discharge and the micro-plasma electron-density values obtained for 0.5-38 {mu}m gap sizes, 3-10 000 {mu}s pulse durations, 75-250 V low breakdown voltages, and 1-20 A discharge currents, using different combinations of metallic electrodes in oil and in water. Results allow fitting, for micro-scale and low voltages, an empirical law between the maximum gap-size for breakdown, the breakdown voltage, and the effective stress-time. The electron density n{sub e} is obtained by optical emission spectroscopy diagnostics of the H{sub {alpha}}-line Stark broadening (yielding n{sub e}{approx}10{sup 16}-10{sup 17} cm{sup -3}, i.e., ionization degrees of {approx}2 Multiplication-Sign 10{sup -5}-10{sup -4}) and by a semi-empirical resistive plasma model. The model uses the experimental values of several electrical and geometrical quantities, and of the gas pressure estimated as {approx}60 bar-2 kbar from measurements of the plasma mechanical action, obtained using a force sensor. The quantitative information of this phenomenological study can assist the optimization of this micro-fabrication technique.

  15. Experimental study of micro electrical discharge machining discharges

    NASA Astrophysics Data System (ADS)

    Bragança, I. M. F.; Rosa, P. A. R.; Dias, F. M.; Martins, P. A. F.; Alves, L. L.

    2013-06-01

    Micro electrical discharge machining (μEDM) is an atmospheric-pressure plasma-assisted technology that uses point-to-plane discharges in liquid dielectrics to remove microscopic quantities of electrically conductive materials. In this work, an innovative μEDM prototype machine was specifically designed and fabricated to produce and control single spark discharges, thus, resolving the typical limitations of (multi-discharge) commercial machines. The work analyses the type of discharge and the micro-plasma electron-density values obtained for 0.5-38 μm gap sizes, 3-10 000 μs pulse durations, 75-250 V low breakdown voltages, and 1-20 A discharge currents, using different combinations of metallic electrodes in oil and in water. Results allow fitting, for micro-scale and low voltages, an empirical law between the maximum gap-size for breakdown, the breakdown voltage, and the effective stress-time. The electron density ne is obtained by optical emission spectroscopy diagnostics of the Hα-line Stark broadening (yielding ne˜1016-1017 cm-3, i.e., ionization degrees of ˜2×10-5-10-4) and by a semi-empirical resistive plasma model. The model uses the experimental values of several electrical and geometrical quantities, and of the gas pressure estimated as ˜60 bar-2 kbar from measurements of the plasma mechanical action, obtained using a force sensor. The quantitative information of this phenomenological study can assist the optimization of this micro-fabrication technique.

  16. Micro-mirror array for multi-object spectroscopy

    NASA Astrophysics Data System (ADS)

    Zamkotsian, Frederic; Waldis, Severin; Noell, Wilfried; ElHadi, Kacem; Lanzoni, Patrick; De Rooij, Nico

    2006-06-01

    Next generation MOS for space as well as ground-based instruments, including NIRSpec for JWST, require a programmable multi-slit mask. A promising solution is the use of MOEMS-based devices such as micromirror arrays (MMA) or micro-shutter arrays (MSA). Both configurations allow remote control of the multi-slit configuration in real time. Engaged in the design studies for NIRSpec, we have developed different tools for the modelling and the characterization of these devices. Since, we have continued our studies with commercial TI MMA and we show that in a 20° ON-OFF configuration, the 3000 contrast requirement is fulfilled for any F# of 8m-class telescopes as well as future ELT's. Within the framework of the JRA on Smart Focal Planes, micro-mirrors have been selected in order to get a first demonstrator of a European MOEMS-based slit mask. We have fixed several key parameters: one micromirror per astronomical object, high optical contrast of at least 3000, tilting angle of 20°, fill factor of more than 90%, size of a micro-element around 100 × 200 μm2, driving voltage below 100V. The MMA would also work in a wide range of temperature down to cryogenic temperatures. Based on these parameters, we have designed a new MMA architecture, using a combination of bulk and surface micromachining. A first small test array of micro-mirrors was successfully fabricated and shows the desired mechanical tilting angle of 20° at a driving voltage of about 100V. Preliminary measurements show a surface quality better than lambda/20. Assembly of small test arrays with their electrode chips and design of larger arrays are under way.

  17. Spectral optimization for micro-CT

    SciTech Connect

    Hupfer, Martin; Nowak, Tristan; Brauweiler, Robert; Eisa, Fabian; Kalender, Willi A.

    2012-06-15

    tube voltage. For 50 mm, voltages larger than 50 kV were preferred. For all three phantom sizes stronger filtration led to notable dose reduction for soft tissue imaging. Validation measurements were found to match simulations well, with deviations being less than 10%. Mouse measurements confirmed simulation results. Conclusions: Optimal photon energies and tube settings strongly depend on both phantom size and imaging task at hand. For in vivo CE imaging and density differences, strong filtration and voltages of 50-65 kV showed good overall results. For soft tissue imaging of animals the size of a rat or larger, voltages higher than 65 kV allow to greatly reduce scan times while maintaining dose efficiency. For imaging of bone structures, usage of only minimum filtration and low tube voltages of 40 kV and below allow exploiting the high contrast of bone at very low energies. Therefore, a combination of two filtrations could prove beneficial for micro-CT: a soft filtration allowing for bone imaging at low voltages, and a variable stronger filtration (e.g., 0.2 mm Cu) for soft tissue and contrast-enhanced imaging.

  18. Nanofocusing enhancement in a tapered slit by using a dielectric micro isosceles triangle prism and tuning the entrance aperture

    NASA Astrophysics Data System (ADS)

    Kuang, Dengfeng; Ouyang, Sheng; Du, Zhongxun

    2012-07-01

    We present a combined configuration consisting of a dielectric micro isosceles triangular prism and a metallic tapered slit for enhanced nanofocusing. The dielectric micro isosceles triangular prism collects the incident light first and then the tapered slit guides the beam to form naofocusing with higher intensity at the exit aperture of the tapered slit, which overcomes the limit of the extremely small entrance aperture diaphragm of the slit. With the help of the dielectric micro isosceles triangular prism, the intensity of the nanofocused electric field at the exit aperture of the tapered slit can be increased more than 4 folds.

  19. Micro-agglomerate flotation for deep cleaning of coal. Final report

    SciTech Connect

    Chander, S.; Hogg, R.

    1997-01-15

    The development of practical technologies for the deep cleaning of coal has been seriously hampered by the problems of carrying out efficient coal/mineral separations at the very fine sizes (often finer than 10 {micro}m) needed to achieve adequate liberation of the mineral matter from the coal matrix. In this investigation a hybrid process--Micro-agglomerate flotation--which is a combination of oil-agglomeration and froth flotation was studied. The basic concept is to use small quantities of oil to promote the formation of dense micro-agglomerates with minimal entrapment of water and mineral particles and to use froth flotation to separate these micro-agglomerates from the water/dispersed-mineral phase. Since the floating units will be relatively large agglomerates (30--50 {micro}m in size) rather than fine coal particles (1--10 {micro}m) the problems of froth overload and water/mineral carryover should be significantly alleviated. There are, however, complications. The process involves at least five phases: two or more solids (coal and mineral), two liquids (oil and water) and one gas (air). It is demonstrated in this study that the process is very sensitive to fluctuations in operating parameters. It is necessary to maintain precise control over the chemistry of the liquid phases as well as the agitation conditions in order to promote selectivity. Both kinetics as well as thermodynamic factors play a critical role in determining overall system response.

  20. Identification of Conserved and Novel MicroRNAs during Tail Regeneration in the Mexican Axolotl.

    PubMed

    Gearhart, Micah D; Erickson, Jami R; Walsh, Andrew; Echeverri, Karen

    2015-01-01

    The Mexican axolotl salamander (Ambystoma mexicanum) is one member of a select group of vertebrate animals that have retained the amazing ability to regenerate multiple body parts. In addition to being an important model system for regeneration, the axolotl has also contributed extensively to studies of basic development. While many genes known to play key roles during development have now been implicated in various forms of regeneration, much of the regulatory apparatus controlling the underlying molecular circuitry remains unknown. In recent years, microRNAs have been identified as key regulators of gene expression during development, in many diseases and also, increasingly, in regeneration. Here, we have used deep sequencing combined with qRT-PCR to undertake a comprehensive identification of microRNAs involved in regulating regeneration in the axolotl. Specifically, among the microRNAs that we have found to be expressed in axolotl tissues, we have identified 4564 microRNA families known to be widely conserved among vertebrates, as well as 59,811 reads of putative novel microRNAs. These findings support the hypothesis that microRNAs play key roles in managing the precise spatial and temporal patterns of gene expression that ensures the correct regeneration of missing tissues. PMID:26378530

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

    PubMed

    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 (<30 μm), and high-density (up to ~500 μF/mm(2)) micro-supercapacitors are formed on an ultrathin (~20 μm) freestanding parylene film by a wafer-scale parylene packaging process in combination with a polyaniline (PANI) nanowire growth technique assisted by surface plasma treatment. These micro-supercapacitors are highly flexible and shown to be resilient toward flexural stress. Further, direct integration of micro-supercapacitors into a radio frequency (RF) rectifying circuit is achieved on a single parylene platform, yielding a complete RF energy harvesting 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. PMID:25653069

  2. Science with Micro-X: the TES Microcalorimeter X-ray Imaging Rocket

    SciTech Connect

    Figueroa-Feliciano, E; Bandler, S R; Bautz, M; Boyce, K R; Brown, G V; Deiker, S; Doriese, W B; Flanagan, K; Galeazzi, M; Hilton, G C; Hwang, U; Irwin, K D; Kallman, T; Kelley, R L; Kilbourne, C A; Kissel, S; Levine, A; Loewenstein, M; Martinez-Galarce, D; McCammon, D; Mushotzky, R; Petre, R; Porter, F S; Reistema, C D; Saab, T; Serlemitsos, P; Schulz, N; Smith, R; Ullom, J N

    2006-05-16

    Micro-X is a proposed sounding rocket experiment that will combine a transition-edge-sensor X-ray-microcalorimeter array with a conical imaging mirror to obtain high-spectral-resolution images of extended and point X-ray sources. We describe the payload and the science targeted by this mission including the discussion of three possible Micro-X targets: the Puppis A supernova remnant, the Virgo Cluster, and Circinus X-1. For example, a Micro-X observation of the bright eastern knot of Puppis A will obtain a line-dominated spectrum with 90,000 counts collected in 300 seconds at 2 eV resolution across the 0.3-2.5 keV band. Micro-X will utilize plasma diagnostics to determine the thermodynamic and ionization state of the plasma, to search for line shifts and broadening associated with dynamical processes, and seek evidence of ejecta enhancement. For clusters of galaxies, Micro-X can uniquely study turbulence and the temperature distribution function. For binaries, Micro-X's high resolution spectra will separate the different processes contributing to the Fe K lines at 6 keV and give a clear view of the geometry of the gas flows and circumstellar gas.

  3. Identification of Conserved and Novel MicroRNAs during Tail Regeneration in the Mexican Axolotl

    PubMed Central

    Gearhart, Micah D.; Erickson, Jami R.; Walsh, Andrew; Echeverri, Karen

    2015-01-01

    The Mexican axolotl salamander (Ambystoma mexicanum) is one member of a select group of vertebrate animals that have retained the amazing ability to regenerate multiple body parts. In addition to being an important model system for regeneration, the axolotl has also contributed extensively to studies of basic development. While many genes known to play key roles during development have now been implicated in various forms of regeneration, much of the regulatory apparatus controlling the underlying molecular circuitry remains unknown. In recent years, microRNAs have been identified as key regulators of gene expression during development, in many diseases and also, increasingly, in regeneration. Here, we have used deep sequencing combined with qRT-PCR to undertake a comprehensive identification of microRNAs involved in regulating regeneration in the axolotl. Specifically, among the microRNAs that we have found to be expressed in axolotl tissues, we have identified 4564 microRNA families known to be widely conserved among vertebrates, as well as 59,811 reads of putative novel microRNAs. These findings support the hypothesis that microRNAs play key roles in managing the precise spatial and temporal patterns of gene expression that ensures the correct regeneration of missing tissues. PMID:26378530

  4. Micro-CT of rodents: state-of-the-art and future perspectives

    PubMed Central

    Clark, D. P.; Badea, C. T.

    2014-01-01

    Micron-scale computed tomography (micro-CT) is an essential tool for phenotyping and for elucidating diseases and their therapies. This work is focused on preclinical micro-CT imaging, reviewing relevant principles, technologies, and applications. Commonly, micro-CT provides high-resolution anatomic information, either on its own or in conjunction with lower-resolution functional imaging modalities such as positron emission tomography (PET) and single-photon emission computed tomography (SPECT). More recently, however, advanced applications of micro-CT produce functional information by translating clinical applications to model systems (e.g. measuring cardiac functional metrics) and by pioneering new ones (e.g. measuring tumor vascular permeability with nanoparticle contrast agents). The primary limitations of micro-CT imaging are the associated radiation dose and relatively poor soft tissue contrast. We review several image reconstruction strategies based on iterative, statistical, and gradient sparsity regularization, demonstrating that high image quality is achievable with low radiation dose given ever more powerful computational resources. We also review two contrast mechanisms under intense development. The first is spectral contrast for quantitative material discrimination in combination with passive or actively targeted nanoparticle contrast agents. The second is phase contrast which measures refraction in biological tissues for improved contrast and potentially reduced radiation dose relative to standard absorption imaging. These technological advancements promise to develop micro-CT into a commonplace, functional and even molecular imaging modality. PMID:24974176

  5. NEMO educational kit on micro-optics at the secondary school

    NASA Astrophysics Data System (ADS)

    Flores-Arias, M. T.; Bao-Varela, Carmen

    2014-07-01

    NEMO was the "Network of Excellence in Micro-Optics" granted in the "Sixth Framework Program" of the European Union. It aimed at providing Europe with a complete Micro-Optics food-chain, by setting up centers for optical modeling and design; measurement and instrumentation; mastering, prototyping and replication; integration and packaging and reliability and standardization. More than 300 researchers from 30 groups in 12 countries participated in the project. One of the objectives of NEMO was to spread excellence and disseminate knowledge on micro-optics and micro-photonics. To convince pupils, already from secondary school level on, about the crucial role of light and micro-optics and the opportunities this combination holds, several partners of NEMO had collaborate to create this Educational Kit. In Spain the partner involved in this aim was the "Microoptics and GRIN Optics Group" at the University of Santiago of Compostela (USC). The educational kits provided to the Secondary School were composed by two plastic cards with the following microoptical element: different kinds of diffractive optical elements or DOES and refractive optical elements or ROEs namely arrays of micro-lenses. The kit also included a DVD with a handbook for performing the experiments as well as a laser pointer source. This kit was distributed free of charge in the countries with partners in NEMO. In particular in Spain was offered to around 200 Secondary School Centers and only 80 answered accepting evaluate the kit.

  6. Hierarchically micro-patterned nanofibrous scaffolds with a nanosized bio-glass surface for accelerating wound healing.

    PubMed

    Xu, He; Lv, Fang; Zhang, Yali; Yi, Zhengfang; Ke, Qinfei; Wu, Chengtie; Liu, Mingyao; Chang, Jiang

    2015-11-28

    A composite scaffold with a controlled micro-pattern, nano-sized fiber matrix and surface-modified nanobioglass component was successfully prepared for skin wound healing by combining the patterning electrospinning with pulsed laser deposition strategies, and the hierarchical micro/nano structures and nano-sized bioglass in the scaffolds could synergistically improve the efficiency and re-epithelialization of wound healing. PMID:26503372

  7. Application of FIB with micro pick-up to microstructural study of irradiated SiC/SiC composites.

    PubMed

    Ozawa, Kazumi; Kondo, Sosuke; Kishimoto, Hirotatsu; Kohyama, Akira

    2004-01-01

    The combination of focused ion beam (FIB) micro-processing and the lift-out technique using the micro pick-up system was applied to the preparation of TEM specimens of irradiated SiC/SiC composites. The deformation caused by microstructural evolution was observed in the pyrolitic carbon interphase, and several helium bubbles and cavities were detected in the CVI matrix. PMID:15582959

  8. An overview of micro-optical components and system technology: bulk, planar, and thin-film for laser initiated devices

    NASA Astrophysics Data System (ADS)

    Lizotte, Todd

    2010-08-01

    There are a number of attractive micro optical elements or combinations of elements that are currently used or could be employed in optically initiated ordnance systems. When taking a broad-spectrum examination of optically initiated devices, the required key parameters become obviously straightforward for micro optics. Plainly stated, micro optics need to be simple, inexpensive, reliable, robust and compatible within their operational environment. This presentation focuses on the variety of optical elements and components available in the market place today that could be used to realize micro-optical beam shaping and delivery systems for optically initiated devices. A number of micro optical elements will be presented with specific bulk, planar optical and thin film optical devices, such as diffractive optics, micro prisms, axicons, waveguides, micro lenses, beam splitters and gratings. Further descriptions will be presented on the subject of coupling light from a laser beam into a multimode optical fiber. The use of micro optics for collimation of the laser source and conditioning of the laser beam to achieve the highest efficiency and matching the optical fiber NA will be explained. An emphasis on making these optical assemblies compact and rugged will be highlighted.

  9. Effects of Micro-Vibratory Modulation during Robot-Assisted Membrane Peeling*

    PubMed Central

    Gonenc, Berk; Gehlbach, Peter; Taylor, Russell H.; Iordachita, Iulian

    2016-01-01

    In retinal microsurgery, membrane peeling is a standard procedure requiring the delamination of a thin fibrous membrane adherent to the retina surface by applying very small forces. Robotic devices with combined force-sensing instruments have significant potential to assist this procedure by facilitating membrane delamination through induced micro-vibrations. However, defining the optimal frequency and amplitude for generating such vibrations, and updating these parameters during the procedure is not trivial. Automatic adjustment of these parameters via an adaptive control scheme is possible only if the individual parameter effects on delamination behavior are known. This study presents an experimental exploration of how micro-vibration amplitude and frequency affect membrane peeling forces alone. Combining a micromanipulator and a force-sensing micro-forceps, several peeling experiments were done on artificial phantoms (bandages) and inner shell membrane of raw chicken eggs. In the tested range of micro-vibration frequencies (10-50 Hz) the average delamination force was minimized mostly at 30 Hz for the bandages and at 50 Hz for the egg membranes. Increasing the micro-vibration amplitude from 50 μm up to 150 μm provided further reduction in average force, thus facilitated membrane delamination. PMID:27110431

  10. Design of a holographic micro-scale spectrum-splitting photovoltaic system

    NASA Astrophysics Data System (ADS)

    Wu, Yuechen; Vorndran, Shelby; Ayala Pelaez, Silvana; Russo, Juan M.; Kostuk, Raymond K.

    2015-09-01

    Micro-scale PV technology combines the high conversion efficiency of concentrated photovoltaics (CPV) with the low costs and the simple form of flat panel PV. Some of the benefits of micro-scale PV include: reduced semiconductor material usage; improved heat rejection capacity; and more versatile PV cell interconnect configurations. Spectrumsplitting is also a beneficial technique to increase the efficiency and reduce the cost of photovoltaic systems. It spatially separates the incident solar spectrum into spectral components and directs them to PV cells with matching bandgaps. This approach avoids the current and lattice matching problems that exist in tandem multi-junction systems. In this paper, we applied the ideas of spectrum-splitting in a micro-scale PV system, and demonstrated a holographic micro-scale spectrum-splitting photovoltaic system. This system consists of a volume transmission hologram in combination with a micro-lens array. An analysis methodology was developed to design the system and determine the performance of the resulting system. The spatial characteristics of the dispersed spectrum, the overall system conversion efficiency, and the improvement over best bandgap will be discussed.

  11. DNA damage responsive microRNAs misexpressed in human cancer modulate therapy sensitivity

    PubMed Central

    van Jaarsveld, Marijn T.M.; Wouters, Maikel D.; Boersma, Antonius W.M.; Smid, Marcel; van IJcken, Wilfred F.J.; Mathijssen, Ron H.J.; Hoeijmakers, Jan H.J.; Martens, John W. M.; van Laere, Steven; Wiemer, Erik A.C.; Pothof, Joris

    2015-01-01

    The DNA damage response (DDR) is activated upon DNA damage and prevents accumulation of mutations and chromosomal rearrangements, both driving carcinogenesis. Tumor cells often have defects in the DDR, which in combination with continuous cell proliferation are exploited by genotoxic cancer therapies. Most cancers, overcome initial sensitivity and develop drug resistance, e.g. by modulation of the DDR. Not much is known, however, about DNA damage responsive microRNAs in cancer therapy resistance. Therefore, we mapped temporal microRNA expression changes in primary breast epithelial cells upon low and high dose exposure to the DNA damaging agents ionizing radiation and cisplatin. A third of all DDR microRNAs commonly regulated across all treatments was also misexpressed in breast cancer, indicating a DDR defect. We repeated this approach in primary lung epithelial cells and non-small cell lung cancer samples and found that more than 40% of all DDR microRNAs was deregulated in non-small cell lung cancer. Strikingly, the microRNA response upon genotoxic stress in primary breast and lung epithelial cells was markedly different, although the biological outcome of DNA damage signaling (cell death/senescence or survival) was similar. Several DDR microRNAs deregulated in cancer modulated sensitivity to anti-cancer agents. In addition we were able to distinguish between microRNAs that induced resistance by potentially inducing quiescence (miR-296-5p and miR-382) or enhancing DNA repair or increased DNA damage tolerance (miR-21). In conclusion, we provide evidence that DNA damage responsive microRNAs are frequently misexpressed in human cancer and can modulate chemotherapy sensitivity. PMID:24462518

  12. Sensitive detection of melanoma metastasis using circulating microRNA expression profiles.

    PubMed

    Shiiyama, Rie; Fukushima, Satoshi; Jinnin, Masatoshi; Yamashita, Junji; Miyashita, Azusa; Nakahara, Satoshi; Kogi, Ai; Aoi, Jun; Masuguchi, Shinichi; Inoue, Yuji; Ihn, Hironobu

    2013-10-01

    Numerous studies have indicated that the serum levels of microRNAs are useful for the diagnosis or evaluation of activity in human diseases. However, determining the level of only one of the nearly 2000 microRNAs identified so far may be less significant. Accordingly, we examined the possibility that the expression pattern of multiple microRNAs in each patient may be a more reliable disease marker for melanoma, especially metastatic disease, focusing on the interaction among microRNAs. Six microRNAs (miR-9, miR-145, miR-150, miR-155, miR-203, and miR-205) were evaluated using real-time PCR in 11 patients with metastatic melanoma and in 16 patients without melanoma. The expression of the six microRNAs was significantly different between the patients with metastasis and those without it. MiR-9 and miR-205 and miR-203 and miR-205 showed significant correlations, and the combination of miR-9, miR-145, miR-150, miR-155, and miR-205 was more sensitive than when each miR was used individually to distinguish the patients with metastasis from those without it. This is the first report demonstrating the expression profiles of multiple microRNAs in melanoma patients. Clarifying the involvement of the microRNA network in the pathogenesis of melanoma may contribute to the development of new diagnostic tools and to advancing the understanding of this disease. PMID:23863473

  13. Investigation of the removing process of cathode material in micro-EDM using an atomistic-continuum model

    NASA Astrophysics Data System (ADS)

    Guo, Jianwen; Zhang, Guojun; Huang, Yu; Ming, Wuyi; Liu, Min; Huang, Hao

    2014-10-01

    In micro-electrical discharge machining (micro-EDM), the discharge duration is ultra-short, and both the electric action and the thermal action by the discharge channel play important roles in the removing process of cathode material. However, in most researches on the machining mechanism of micro-EDM, only the thermal action is concerned. In this article, a combined atomistic-continuum modeling method in which the two-temperature model and the molecular dynamics simulation model are integrated is used to construct the simulation model for cathode in single-discharge micro-EDM process. With this simulation model, removing processes of Cu cathode material in micro-EDM under pure thermal action, pure electric action and the combination of them are investigated in a simulative way. By analyzing evolutions of temperature, stress and micro-structure of material as well as the dynamical behaviors of material in the removing process, mechanisms of the cathode material removal and crater formation are revealed. In addition, the removing process of cathode material under the combination of pure thermal action and pure electric action is compared with those under the two pure actions respectively to analyze the interactive effect between the thermal action and the electric action.

  14. A novel dual-detector micro-spectrometer

    NASA Astrophysics Data System (ADS)

    Otto, Thomas; Saupe, Ray; Stock, Volker; Bruch, Reinhard; Gruska, Bernd; Gessner, Thomas

    2005-01-01

    Infrared analysis is a well-established tool for measuring composition and purity of various materials in industrial-, medical- and environmental applications. Traditional spectrometers, for example Fourier Transform Infrared (FTIR) Instruments are mainly designed for laboratory use and are generally, too large, heavy, costly and delicate to handle for remote applications. With important advances in the miniaturization, ruggedness and cost efficiency we have designed and created a new type of a micromirror spectrometer that can operate in harsh temperature and vibrating environments This device is ideally suited for environmental monitoring, chemical and biological applications as well as detection of biological warfare agents and sensing in important security locations In order to realize such compact, portable and field-deployable spectrometers we have applied MOEMS technology. Thus our novel dual detector micro mirror system is composed of a scanning micro mirror combined with a diffraction grating and other essential optical components in order to miniaturize the basic modular set-up. Especially it periodically disperses polychromatic radiation into its spectral components, which are measured by a combination of a visible (VIS) and near infrared (NIR) single element detector. By means of integrated preamplifiers high-precise measurements over a wide dynamic wavelength range are possible. In addition the spectrometer, including the radiation source, detectors and electronics can be coupled to a minimum-volume liquid or gas-flow cell. Furthermore a SMA connector as a fiber optical input allows easy attachment of fiber based probes. By utilizing rapid prototyping techniques, where all components are directly integrated, the micro mirror spectrometer is manufactured for the 700-1700 nm spectral range. In this work the advanced optical design and integration of the electronic interface will be reviewed. Furthermore we will demonstrate the performance of the system

  15. Birth control pills - combination

    MedlinePlus

    ... this page: //medlineplus.gov/ency/patientinstructions/000655.htm Birth control pills - combination To use the sharing features on ... frequency of your menstrual cycles. Types of Combination Birth Control Pills Birth control pills come in packages. You ...

  16. The evaluation of vacuum venting and variotherm process for improving the replication by injection molding of high aspect ratio micro features for biomedical application

    NASA Astrophysics Data System (ADS)

    Sorgato, Marco; Lucchetta, Giovanni

    2015-05-01

    The aspect ratio achievable in replicating micro features is one of the most important process characteristics and it is a major manufacturing constraint in applying injection molding in a range of micro engineering applications. Vacuum venting has been reported to be an effective technique in replicating micro features by microinjection molding. High surface-to-volume ratio and reduced dimensions of micro parts promote the instantaneous drop of melt temperature and consequently lead to incomplete filling. This study aims to investigate the effects of variotherm process, cavity evacuation and their interaction on the production of a micro fluidic filter for biomedical applications. A low-viscosity polystyrene and a cyclic olefin copolymer were molded applying a combination of mold evacuation and a rapid mold temperature variation that keeps the cavity temperature above the glass transition temperature during the injection phase. The research revealed the importance of these molding technologies in enhancing part filling and the replication quality for high aspect ratio micro features.

  17. Micro-Scale Heterogeneity in Biogeochemical Uranium Cycling

    SciTech Connect

    Ginder-Vogel, M.; Wu, W.-M.; Kelly, S.; Criddle, C.S.; Carley, J.; Jardine, P.; Kemner, K.M.; Fendorf, S.

    2009-06-04

    One method for the in situ remediation of uranium contaminated subsurface environments is the removal of highly soluble U(VI) from groundwater by microbial reduction to the sparingly soluble U(IV) mineral uraninite. Success of this remediation strategy will, in part, be determined by the extent and products of microbial reduction. In heterogeneous subsurface environments, microbial processes will likely yield a combination of U(IV) and U(VI) phases distributed throughout the soil matrix. Here, we use a combination of bulk X-ray absorption spectroscopy (XAS) and micro-focused XAS and X-ray diffraction to determine uranium speciation and distribution with sediment from a pilot-scale uranium remediation project located in Oak Ridge, TN.

  18. Raman Spectroscopy of Optically Trapped Single Biological Micro-Particles

    PubMed Central

    Redding, Brandon; Schwab, Mark J.; Pan, Yong-le

    2015-01-01

    The combination of optical trapping with Raman spectroscopy provides a powerful method for the study, characterization, and identification of biological micro-particles. In essence, optical trapping helps to overcome the limitation imposed by the relative inefficiency of the Raman scattering process. This allows Raman spectroscopy to be applied to individual biological particles in air and in liquid, providing the potential for particle identification with high specificity, longitudinal studies of changes in particle composition, and characterization of the heterogeneity of individual particles in a population. In this review, we introduce the techniques used to integrate Raman spectroscopy with optical trapping in order to study individual biological particles in liquid and air. We then provide an overview of some of the most promising applications of this technique, highlighting the unique types of measurements enabled by the combination of Raman spectroscopy with optical trapping. Finally, we present a brief discussion of future research directions in the field. PMID:26247952

  19. Fabrication of micro metallic valve and pump

    NASA Astrophysics Data System (ADS)

    Yang, Ming; Kabasawa, Yasunari; Ito, Kuniyoshi

    2009-12-01

    Fabrication of micro devices by using micro metal forming was proposed by the authors. We developed a desktop servo-press machine with precise tooling system. Precise press forming processes including micro forging and micro joining has been carried out in a progressive die. In this study, micro metallic valve and pump were fabricated by using the precise press forming. The components are made of sheet metals, and assembled in to a unit in the progressive die. A micro check-valve with a diameter of 3mm and a length of 3.2mm was fabricated, and the property of flow resistance was evaluated. The results show that the check valve has high property of leakage proof. Since the valve is a unit parts with dimensions of several millimeters, it has advantage to be adapted to various pump design. Here, two kinds of micro pumps with the check-valves were fabricated. One is diaphragm pump actuated by vibration of the diaphragm, and another is tube-shaped pump actuated by resonation. The flow quantities of the pumps were evaluated and the results show that both of the pumps have high pumping performance.

  20. Fabrication of micro metallic valve and pump

    NASA Astrophysics Data System (ADS)

    Yang, Ming; Kabasawa, Yasunari; Ito, Kuniyoshi

    2010-03-01

    Fabrication of micro devices by using micro metal forming was proposed by the authors. We developed a desktop servo-press machine with precise tooling system. Precise press forming processes including micro forging and micro joining has been carried out in a progressive die. In this study, micro metallic valve and pump were fabricated by using the precise press forming. The components are made of sheet metals, and assembled in to a unit in the progressive die. A micro check-valve with a diameter of 3mm and a length of 3.2mm was fabricated, and the property of flow resistance was evaluated. The results show that the check valve has high property of leakage proof. Since the valve is a unit parts with dimensions of several millimeters, it has advantage to be adapted to various pump design. Here, two kinds of micro pumps with the check-valves were fabricated. One is diaphragm pump actuated by vibration of the diaphragm, and another is tube-shaped pump actuated by resonation. The flow quantities of the pumps were evaluated and the results show that both of the pumps have high pumping performance.

  1. Microplasmas and micro-jets

    NASA Astrophysics Data System (ADS)

    Lazzaroni, C.; Aubert, X.; Marinov, D.; Guaitella, O.; Stancu, G.; Welzel, S.; Pipa, A.; Ropcke, J.; Sadeghi, N.; Rousseau, A.

    2008-07-01

    Microplasmas are now widely investigated, one of their advantages being to generate a plasma at relatively high pressure close to the Paschen minimum (Schoenbach et al. 1997). Here, the microplasma is generated in a microhollow cathode type configuration made of a hole drilled through a metal/dielectric/metal sandwich (Schoenbach et al. 1997). One of the electrodes acts as the cathode (K) and the other as the anode (A1). The hole diameter ranges from 100 to 400 mu m and the pressure ranges from 50 to 500 Torr. When a second electrode (A2) is added, a large volume of plasma plume may be generated between A1 and A2, at a low electric field (1-20Td depending upon the gas) (Stark et al. 1999). A microhollow cathode type discharge operates in three different regimes depending on the plasma current: abnormal, self-pulsing and normal regime. The self-pulsing regime is achieved in the range of 1-100 kHz, in argon, helium, nitrogen and oxygen. The self-pulsing frequency is controlled by the microplasma device capacitance, the gas breakdown voltage, and the average discharge current (Rousseau et al. 2006, Aubert et al. 2007). i) First, in pure argon, the radial dependence of atoms excitation mechanisms and of the electronic density is studied inside the micro-hole. Imaging of the emission from the microplasma is performed with a spatial resolution of few mu m. The electron density is estimated from the Stark broadening of the H beta-line. The radial distribution of the emission intensities of an Ar atomic line and an Ar^+ ionic line are used for the excitation study. Ar and Ar^+ lines are excited in the cathode sheath edge by beam electrons accelerated within the sheath. These two excitations show the decay of the energy of electrons in negative glow. The Ar line presents also production of excited atoms by recombination of argon ions with electrons at the center of the micro-hole.Work is in progress to evaluate the contribution of the static electric field on the strak

  2. Evaluation of stability and size distribution of sunflower oil-coated micro bubbles for localized drug delivery

    PubMed Central

    2012-01-01

    Background Micro bubbles were initially introduced as contrast agents for ultrasound examinations as they are able to modify the signal-to-noise ratio in imaging, thus improving the assessment of clinical information on human tissue. Recent developments have demonstrated the feasibility of using these bubbles as drug carriers in localized delivery. In micro fluidics devices for generation of micro bubbles, the bubbles are formed at interface of liquid gas through a strangulation process. A device that uses these features can produce micro bubbles with small size dispersion in a single step. Methods A T-junction micro fluidic device constructed using 3D prototyping was made for the production of mono dispersed micro bubbles. These micro bubbles use sunflower oil as a lipid layer. Stability studies for micro bubbles with diameters different generated from a liquid phase of the same viscosity were conducted to evaluate whether micro bubbles can be used as drug carriers. The biocompatibility of coating layer, the ability to withstand environmental pressure variations combined with echogenicity, are key factors that they can safely play the role of drug transporters. Results The normal distribution curve with small dispersion of the diameter of bubbles validates the process of generating micro bubbles with low value of variation coefficient, i.e., 0.381 at 1.90%. The results also showed the feasibility of using sunflower oil as the lipid matrix with stable population of bubbles over 217 minutes for micro bubbles with an average diameter of 313.04 μm and 121 minutes for micro bubbles with an average diameter of 73.74 μm, considering bubbles with air as gaseous phase. Conclusion The results indicate that the micro fluidic device designed can be used for producing micro bubbles with low variation coefficient using sunflower oil as a coating of micro bubbles. These carriers were stable for periods of time that are long enough for clinical applications even when regular

  3. Amplification-based method for microRNA detection.

    PubMed

    Shen, Yanting; Tian, Fei; Chen, Zhenzhu; Li, Rui; Ge, Qinyu; Lu, Zuhong

    2015-09-15

    Over the last two decades, the study of miRNAs has attracted tremendous attention since they regulate gene expression post-transcriptionally and have been demonstrated to be dysregulated in many diseases. Detection methods with higher sensitivity, specificity and selectivity between precursors and mature microRNAs are urgently needed and widely studied. This review gave an overview of the amplification-based technologies including traditional methods, current modified methods and the cross-platforms of them combined with other techniques. Many progresses were found in the modified amplification-based microRNA detection methods, while traditional platforms could not be replaced until now. Several sample-specific normalizers had been validated, suggesting that the different normalizers should be established for different sample types and the combination of several normalizers might be more appropriate than a single universal normalizer. This systematic overview would be useful to provide comprehensive information for subsequent related studies and could reduce the un-necessary repetition in the future. PMID:25930002

  4. Combined environmental stresses

    NASA Technical Reports Server (NTRS)

    Murray, R. H.; Mccally, M.

    1973-01-01

    Tolerance levels, physiological effects, and performance degradation during simultaneous or sequential exposures to two environmental stresses, and also three or more simultaneous stresses are described. Environmental stress combinations are characterized by four descriptors: order of occurrence, duration of exposure, severity of exposure, and type of interaction. Combined stress data and facilities for combined stress study are briefly mentioned.

  5. Formability of Micro-Tubes in Hydroforming

    SciTech Connect

    Hartl, Christoph; Anyasodor, Gerald; Lungershausen, Joern

    2011-05-04

    Micro-hydroforming is a down-scaled metal forming process, based on the expansion of micro-tubes by internal pressurization within a die cavity. The objective of micro-hydroforming is to provide a technology for the economic mass production of complex shaped hollow micro-components. Influence of size effects in metal forming processes increases with scaling down of metal parts. Investigations into the change in formability of micro-tubes due to metal part scaling down constituted an important subject within the conducted fundamental research work. Experimental results are presented, concerning the analysis of the formability of micro-tubes made from stainless steel AISI 304 with an outer diameter of 800 {mu}m and a wall thickness of 40 {mu}m. An average ratio of tube wall thickness to grain size of 1.54 of up to 2.56 was analyzed. Miniaturised mechanical standard methods as well as bulge tests with internal hydrostatic pressurization of the tubular specimens were applied to analyze the influence of size-dependent effects. A test device was developed for the bulge experiments which enabled the pressurization of micro-tubes with internal pressures up to 4000 bar. To determine the attainable maximum achievable expansion ratio the tubes were pressurized in the bulge tests with increasing internal pressure until instability due to necking and subsequent bursting occurred. Comparisons with corresponding tests of macro-tubes, made from the here investigated material, showed a change in formability of micro-tubes which was attributed to the scaling down of the hydroforming process. In addition, a restricted applicability of existing theoretical correlations for the determination of the maximum pressure at bursting was observed for down-scaled micro-hydroforming.

  6. Dual-energy micro-CT imaging of pulmonary airway obstruction: correlation with micro-SPECT

    NASA Astrophysics Data System (ADS)

    Badea, C. T.; Befera, N.; Clark, D.; Qi, Y.; Johnson, G. A.

    2014-03-01

    To match recent clinical dual energy (DE) CT studies focusing on the lung, similar developments for DE micro-CT of the rodent lung are required. Our group has been actively engaged in designing pulmonary gating techniques for micro- CT, and has also introduced the first DE micro-CT imaging method of the rodent lung. The aim of this study was to assess the feasibility of DE micro-CT imaging for the evaluation of airway obstruction in mice, and to compare the method with micro single photon emission computed tomography (micro-SPECT) using technetium-99m labeled macroaggregated albumin (99mTc-MAA). The results suggest that the induced pulmonary airway obstruction causes either atelectasis, or air-trapping similar to asthma or chronic bronchitis. Atelectasis could only be detected at early time points in DE micro-CT images, and is associated with a large increase in blood fraction and decrease in air fraction. Air trapping had an opposite effect with larger air fraction and decreased blood fraction shown by DE micro-CT. The decrease in perfusion to the hypoventilated lung (hypoxic vasoconstriction) is also seen in micro-SPECT. The proposed DE micro-CT technique for imaging localized airway obstruction performed well in our evaluation, and provides a higher resolution compared to micro-SPECT. Both DE micro-CT and micro-SPECT provide critical, quantitative lung biomarkers for image-based anatomical and functional information in the small animal. The methods are readily linked to clinical methods allowing direct comparison of preclinical and clinical results.

  7. Micro-sonicator for spore lysis

    DOEpatents

    Miles, Robin R.; Belgrader, Phillip; Nasarabadi, Shanavaz L.

    2000-01-01

    A micro-sonicator for spore lysis. Using micromachining technology, the micro-sonicator uses ultrasonic excitation of spores to perform spore and cell lysis. The micro-sonicator comprises a container with a cavity therein for retaining the sample in an ultrasonic transmission medium, the cavity being closed by a silicon membrane to which an electrode and piezoelectric material are attached, with the electrode and piezoelectric material being electrically connected to an AC signal generator which causes the membrane to flex and vibrate at the frequency of the applied voltage.

  8. Advanced packaging for Integrated Micro-Instruments

    NASA Technical Reports Server (NTRS)

    Lyke, James L.

    1995-01-01

    The relationship between packaging, microelectronics, and micro-electrical-mechanical systems (MEMS) is an important one, particularly when the edges of performance boundaries are pressed, as in the case of miniaturized systems. Packaging is a sort of physical backbone that enables the maximum performance of these systems to be realized, and the penalties imposed by conventional packing approaches is particularly limiting for MEMS devices. As such, advanced packaging approaches, such as multi-chip modules (MCM's) have been touted as a true means of electronic 'enablement' for a variety of application domains. Realizing an optimum system of packaging, however, in not as simple as replacing a set of single chip packages with a substrate of interconnections. Research at Phillips Laboratory has turned up a number of integrating options in the two- and three-dimensional rending of miniature systems with physical interconnection structures with intrinsically high performance. Not only do these structures motivate the redesign of integrated circuits (IC's) for lower power, but they possess interesting features that provide a framework for the direct integration of MEMS devices. Cost remains a barrier to the application of MEMS devices, even in space systems. Several innovations are suggested that will result in lower cost and more rapid cycle time. First, the novelty of a 'constant floor plan' MCM which encapsulates a variety of commonly used components into a stockable, easily customized assembly is discussed. Next, the use of low-cost substrates is examined. The anticipated advent of ultra-high density interconnect (UHDI) is suggested as the limit argument of advanced packaging. Finally, the concept of a heterogeneous 3-D MCM system is outlined that allows for the combination of different compatible packaging approaches into a uniformly dense structure that could also include MEMS-based sensors.

  9. Self-Transport of Condensed Liquid in Micro Cooling Device Using Distributed Meniscus Pumping.

    PubMed

    So, Hongyun; Pisano, Albert P

    2015-06-16

    This paper reports a reliable passive micro pump system combining the physical properties of a tapered microchannel and sharp microstructures. This tailored microchannel with triple-spike microstructures was created to transport condensed liquid into the reservoir chamber in a micro cooling device and in the case of chip off-mode prepare the next cooling cycle before chip on-mode, allowing the reliable and continuous circulation of coolant without liquid being trapped in the vapor channel causing dryout limitation. At the tapered channel end, the pinned liquid meniscus was distributed by a middle spike and then continued to overflow into the condenser chamber due to extended capillary action. PMID:26010771

  10. Integration of thin films with fiber micro-structures for sensing applications

    NASA Astrophysics Data System (ADS)

    Yang, Minghong; Wang, Min; Zhang, Guilin

    2013-06-01

    The combination of fiber optics with micro-structure technologies and sensitive thin films offers great potential for the realization of novel sensor concepts. Minitured optical fiber sensors with thin films as sensitive elements could open new fields for optical fiber sensor applications. Thin films work as sensitive elements and transducer to get response and feedback from environments, optical fiber here are employed to signal carrier. This paper reviews some works on the integration of thin films with fiber micro-structures for sensing application, which are currently conducted at the National Engineering Laboratory for Fiber Optic Sensing Technologies, Wuhan University of Technology.

  11. MicroBooNE: A New Liquid Argon Time Projection Chamber Experiment

    SciTech Connect

    Soderberg, M.

    2009-10-01

    Liquid Argon Time Projection Chamber detectors are well suited to study neutrino interactions, and are an intriguing option for future massive detectors capable of measuring the parameters that characterize neutrino oscillations. These detectors combine fine-grained tracking with calorimetry, allowing for excellent imaging and particle identification ability. In this talk the details of the MicroBooNE experiment, a 175 ton LArTPC which will be exposed to Fermilab's Booster Neutrino Beamline starting in 2011, will be presented. The ability of MicroBooNE to differentiate electrons from photons gives the experiment unique capabilities in low energy neutrino interaction measurements.

  12. Nanowire-integrated microporous silicon membrane for continuous fluid transport in micro cooling device

    SciTech Connect

    So, Hongyun; Pisano, Albert P.; Cheng, Jim C.

    2013-10-14

    We report an efficient passive micro pump system combining the physical properties of nanowires and micropores. This nanowire-integrated microporous silicon membrane was created to feed coolant continuously onto the surface of the wick in a micro cooling device to ensure it remains hydrated and in case of dryout, allow for regeneration of the system. The membrane was fabricated by photoelectrochemical etching to form micropores followed by hydrothermal growth of nanowires. This study shows a promising approach to address thermal management challenges for next generation electronic devices with absence of external power.

  13. Strain response of stretchable micro-electrodes: Controlling sensitivity with serpentine designs and encapsulation

    SciTech Connect

    Gutruf, Philipp; Walia, Sumeet; Nur Ali, Md; Sriram, Sharath E-mail: madhu.bhaskaran@gmail.com; Bhaskaran, Madhu E-mail: madhu.bhaskaran@gmail.com

    2014-01-13

    The functionality of flexible electronics relies on stable performance of thin film micro-electrodes. This letter investigates the behavior of gold thin films on polyimide, a prevalent combination in flexible devices. The dynamic behavior of gold micro-electrodes has been studied by subjecting them to stress while monitoring their resistance in situ. The shape of the electrodes was systematically varied to examine resistive strain sensitivity, while an additional encapsulation was applied to characterize multilayer behavior. The realized designs show remarkable tolerance to repetitive strain, demonstrating that curvature and encapsulation are excellent approaches for minimizing resistive strain sensitivity to enable durable flexible electronics.

  14. Snow Micro-Structure Model

    Energy Science and Technology Software Center (ESTSC)

    2014-06-25

    PIKA is a MOOSE-based application for modeling micro-structure evolution of seasonal snow. The model will be useful for environmental, atmospheric, and climate scientists. Possible applications include application to energy balance models, ice sheet modeling, and avalanche forecasting. The model implements physics from published, peer-reviewed articles. The main purpose is to foster university and laboratory collaboration to build a larger multi-scale snow model using MOOSE. The main feature of the code is that it is implementedmore » using the MOOSE framework, thus making features such as multiphysics coupling, adaptive mesh refinement, and parallel scalability native to the application. PIKA implements three equations: the phase-field equation for tracking the evolution of the ice-air interface within seasonal snow at the grain-scale; the heat equation for computing the temperature of both the ice and air within the snow; and the mass transport equation for monitoring the diffusion of water vapor in the pore space of the snow.« less

  15. Snow Micro-Structure Model

    SciTech Connect

    Micah Johnson, Andrew Slaughter

    2014-06-25

    PIKA is a MOOSE-based application for modeling micro-structure evolution of seasonal snow. The model will be useful for environmental, atmospheric, and climate scientists. Possible applications include application to energy balance models, ice sheet modeling, and avalanche forecasting. The model implements physics from published, peer-reviewed articles. The main purpose is to foster university and laboratory collaboration to build a larger multi-scale snow model using MOOSE. The main feature of the code is that it is implemented using the MOOSE framework, thus making features such as multiphysics coupling, adaptive mesh refinement, and parallel scalability native to the application. PIKA implements three equations: the phase-field equation for tracking the evolution of the ice-air interface within seasonal snow at the grain-scale; the heat equation for computing the temperature of both the ice and air within the snow; and the mass transport equation for monitoring the diffusion of water vapor in the pore space of the snow.

  16. MicroRNAs and pharmacogenomics.

    PubMed

    Shomron, Noam

    2010-05-01

    Pharmacogenomics studies the influence of genomics on drug response safety and efficacy. Although research in this field was initiated many years ago, few functional applications are currently in use at the clinic. MicroRNAs (miRNAs) are short noncoding RNAs that bind genes and silence their expression. MiRNAs are encoded by the genome and expressed in all animal cells. MiRNAs are predicted to target approximately half of all human genes, and as a result regulate many cellular processes. The current focus of pharmacogenomics is the identification of polymorphisms in candidate genes coding for drug-metabolizing enzymes, drug transporters and drug targets. Here we call for the evaluation of miRNAs as an additional regulatory layer affecting pharmacogenomics. To illustrate the potential of miRNAs for affecting drug response we performed in silico evaluation of miRNA binding regions in genes known to affect drug response. We suggest that miR-133 and miR-137 may affect VKORC1 expression while miR-22 may affect MTHFR expression. We propose that miRNAs play a central role as a novel regulatory layer affecting drug metabolism and drug targets, and thus should be taken into consideration when conducting pharmacogenomic studies. PMID:20415550

  17. MicroRNA and Metastasis.

    PubMed

    Ma, L

    2016-01-01

    Noncoding RNAs are important regulatory molecules of cellular processes. MicroRNAs (miRNAs) are small noncoding RNAs that bind to complementary sequences in the 3' untranslated region of target mRNAs, leading to degradation of the target mRNAs and/or inhibition of their translation. Some miRNAs are essential for normal animal development; however, many other miRNAs are dispensable for development but play a critical role in pathological conditions, including tumorigenesis and metastasis. miRNA genes often reside at fragile chromosome sites and are deregulated in cancer. Some miRNAs function as oncogenes or tumor suppressors, collectively termed "oncomirs." Specific metastasis-regulating miRNAs, collectively termed "metastamirs," govern molecular processes and pathways in malignant progression in either a tumor cell-autonomous or a cell-nonautonomous manner. Recently, exosome-transferred miRNAs have emerged as mediators of the tumor-stroma cross talk. In this chapter, we focus on the functions, mechanisms of action, and therapeutic potential of miRNAs, particularly oncomirs and metastamirs. PMID:27613133

  18. Micro Sun Sensor for Spacecraft

    NASA Technical Reports Server (NTRS)

    Mobasser, Sohrab; Liebe, Carl; Bae, Youngsam; Schroeder, Jeffrey; Wrigley, Chris

    2004-01-01

    A report describes the development of a compact micro Sun sensor for use as a part of the attitude determination subsystem aboard future miniature spacecraft and planetary robotic vehicles. The prototype unit has a mass of only 9 g, a volume of only 4.2 cm(sup 3), a power consumption of only 30 mW, and a 120 degree field of view. The unit has demonstrated an accuracy of 1 arcminute. The unit consists of a multiple pinhole camera: A micromachined mask containing a rectangular array of microscopic pinholes, machined utilizing the microectromechanical systems (MEMS), is mounted in front of an active-pixel sensor (APS) image detector. The APS consists of a 512 x 512-pixel array, on-chip 10-bit analog to digital converter (ADC), on-chip bias generation, and on-chip timing control for self-sequencing and easy programmability. The digitized output of the APS is processed to compute the centroids of the pinhole Sun images on the APS. The Sun angle, relative to a coordinate system fixed to the sensor unit, is then computed from the positions of the centroids.

  19. MicroRNAs and photocarcinogenesis.

    PubMed

    Syed, Deeba N; Lall, Rahul K; Mukhtar, Hasan

    2015-01-01

    As a new class of sequence-specific regulators of gene expression, the microRNAs (miRNA) form a regulatory network with growth factors and transcription factors participating in various biological processes. It is now being recognized that the various key processes involved in cancer induction are under the control of these small noncoding RNAs, which regulate ~30% of all human genes by targeting sequences in their 3'-untranslated regions. Photocarcinogenesis is a complex interplay of signaling events in the UV exposed human skin including DNA damage and repair, apoptosis, cell survival, mutations and the immune system. In this review, we have scrutinized the role of miRNAs in skin cancer biology focusing on the three most common types of skin cancer namely the basal cell carcinoma, squamous cell carcinoma and cutaneous malignant melanoma. An overview of these studies will be useful in gaining insights into the mechanisms of cancer development in the human skin. A better understanding of the functionality of miRNAs will have enormous implications to risk assessment, and to target interventions against signaling events involved in photocarcinogenesis. PMID:25227270

  20. Study of Selecting on Light Source Used for Micro-algae Cultivation in Space

    NASA Astrophysics Data System (ADS)

    Ai, Weidang; Ai, Weidang; Guo, Shuang-Sheng; Gao, Feng; Tang, Yong-Kang; Qin, Li-Feng

    To select suitable light source for micro-algae cultivation in future space station, the selected Spirulina plastensis(No.7) were cultured under different lightening qualities, including six light sources that were made up of different combinations of red and blue light-emitting diode(LED). The growth, photosynthetic efficiency and nutrition quality of the Spirulina, were analyzed. From the experiments, the red light may promote the cumulation of biomass of the Spirulina, and the cumulating rate was the highest under all red light source, but the syntheses of protein, phycobiliprotein, β-carotene, VE and other nutrients needs a certain portion of blue light; yet, the complete blue light condition is not favorable to the growth of Spirulina, and may bring pollution by chlorella and other kinds of micro-algae. It is concluded that the LEDs can be used as the light resource of micro-algae cultivation. The normal growth and development of microalgae need two light sources of both red and blue LEDs. The comprehensive analyses of the various factors that affect the growth of Spirulina, such as nutrition quality and photosynthetic activities, etc., showed that the combination of 80% red and 20% blue LED is the optimum one among those tested combinations. Key word: light-emitting diode; micro-algae; controlled ecological life support system (CELSS); space cultivation

  1. Micro-Analyzer: automatic preprocessing of Affymetrix microarray data.

    PubMed

    Guzzi, Pietro Hiram; Cannataro, Mario

    2013-08-01

    A current trend in genomics is the investigation of the cell mechanism using different technologies, in order to explain the relationship among genes, molecular processes and diseases. For instance, the combined use of gene-expression arrays and genomic arrays has been demonstrated as an effective instrument in clinical practice. Consequently, in a single experiment different kind of microarrays may be used, resulting in the production of different types of binary data (images and textual raw data). The analysis of microarray data requires an initial preprocessing phase, that makes raw data suitable for use on existing analysis platforms, such as the TIGR M4 (TM4) Suite. An additional challenge to be faced by emerging data analysis platforms is the ability to treat in a combined way those different microarray formats coupled with clinical data. In fact, resulting integrated data may include both numerical and symbolic data (e.g. gene expression and SNPs regarding molecular data), as well as temporal data (e.g. the response to a drug, time to progression and survival rate), regarding clinical data. Raw data preprocessing is a crucial step in analysis but is often performed in a manual and error prone way using different software tools. Thus novel, platform independent, and possibly open source tools enabling the semi-automatic preprocessing and annotation of different microarray data are needed. The paper presents Micro-Analyzer (Microarray Analyzer), a cross-platform tool for the automatic normalization, summarization and annotation of Affymetrix gene expression and SNP binary data. It represents the evolution of the μ-CS tool, extending the preprocessing to SNP arrays that were not allowed in μ-CS. The Micro-Analyzer is provided as a Java standalone tool and enables users to read, preprocess and analyse binary microarray data (gene expression and SNPs) by invoking TM4 platform. It avoids: (i) the manual invocation of external tools (e.g. the Affymetrix Power

  2. An on-line monitoring system for a micro electrical discharge machining (micro-EDM) process

    NASA Astrophysics Data System (ADS)

    Liao, Y. S.; Chang, T. Y.; Chuang, T. J.

    2008-03-01

    A pulse-type discriminating system to monitor the process of micro electrical discharge machining (micro-EDM) is developed and implemented. The specific features are extracted and the pulses from a RC-type power source are classified into normal, effective arc, transient short circuit and complex types. An approach to discriminate the pulse type according to three durations measured at three pre-determined voltage levels of a pulse is proposed. The developed system is verified by using simulated signals. Discrimination of the pulse trains in actual machining processes shows that the pulses are mainly the normal type for micro wire-EDM and micro-EDM milling. The pulse-type distribution varies during the micro-EDM drilling process. The percentage of complex-type pulse increases monotonically with the drilling depth. It starts to drop when the gap condition is seriously deteriorated. Accordingly, an on-line monitoring strategy for the micro-EDM drilling process is proposed.

  3. Passive ring resonator micro-optical gyroscopes

    NASA Astrophysics Data System (ADS)

    Venediktov, V. Yu; Filatov, Yu V.; Shalymov, E. V.

    2016-05-01

    This paper reviews recent advances in passive micro-optical gyroscopes. In the last decade, most research effort in the area of micro-optical gyros has been concentrated on a configuration that takes advantage of a single-mode passive ring resonator, which is usually fabricated using integrated optical technologies. The dimensions of such micro-optical gyros are comparable to those of micromechanical gyroscopes (area of 10 to 100 mm2) and their sensitivity is considerably better than the sensitivity of the latter, approaching that of fibre-optic and laser gyros. Moreover, microoptical gyros can be made as a single integrated circuit, like the micromechanical gyros, but they have no movable parts, in contrast to their micromechanical counterparts. We also describe the development and investigation of micro-optical gyros produced in our studies.

  4. Evaluation of the micro-carburetor

    SciTech Connect

    Weiss, M.F.; Hall, R.A.; Mazor, S.D.

    1981-08-01

    A prototype sonic, variable-venturi automotive carburetor, developed by Micro Carburetor Corporation, was evaluated for its effects on vehicle performance, fuel economy, and exhaust emissions. A 350 CID Chevrolet Impala vehicle was tested on a chassis dynamometer over the 1975 Federal Test Procedure, urban driving cycle. The Micro-carburetor was tested and compared with stock and modified-stock engine configurations. Subsequently, the test vehicle's performance characteristics were examined with the stock carburetor and again with the Micro-carburetor in a series of on-road driveability tests. The test engine was then removed from the vehicle and installed on an engine dynamometer. Engine tests were conducted to compare the fuel economy, thermal efficiency, and cylinder-to-cylinder mixture distribution of the Micro-carburetor to that of the stock configuration. Test results show increases in thermal efficiency and improvements in fuel economy at all test conditions.

  5. Micro benchtop optics by bulk silicon micromachining

    DOEpatents

    Lee, Abraham P.; Pocha, Michael D.; McConaghy, Charles F.; Deri, Robert J.

    2000-01-01

    Micromachining of bulk silicon utilizing the parallel etching characteristics of bulk silicon and integrating the parallel etch planes of silicon with silicon wafer bonding and impurity doping, enables the fabrication of on-chip optics with in situ aligned etched grooves for optical fibers, micro-lenses, photodiodes, and laser diodes. Other optical components that can be microfabricated and integrated include semi-transparent beam splitters, micro-optical scanners, pinholes, optical gratings, micro-optical filters, etc. Micromachining of bulk silicon utilizing the parallel etching characteristics thereof can be utilized to develop miniaturization of bio-instrumentation such as wavelength monitoring by fluorescence spectrometers, and other miniaturized optical systems such as Fabry-Perot interferometry for filtering of wavelengths, tunable cavity lasers, micro-holography modules, and wavelength splitters for optical communication systems.

  6. Method for producing micro heat panels

    NASA Technical Reports Server (NTRS)

    Camarda, Charles J. (Inventor); Peterson, George P. (Inventor); Rummler, Donald R. (Inventor)

    1997-01-01

    Flat or curved micro heat pipe panels are fabricated by arranging essentially parallel filaments in the shape of the desired panel. The configuration of the filaments corresponds to the desired configuration of the tubes that will constitute the heat pipes. A thermally conductive material is then deposited on and around the filaments to fill in the desired shape of the panel. The filaments are then removed, leaving tubular passageways of the desired configuration and surface texture in the material. The tubes are then filled with a working fluid and sealed. Composite micro heat pipe laminates are formed by layering individual micro heat pipe panels and bonding them to each other to form a single structure. The layering sequence of the micro heat pipe panels can be tailored to transport heat preferentially in specific directions as desired for a particular application.

  7. Tractor beam in micro-scale

    NASA Astrophysics Data System (ADS)

    Brzobohatý, O.; Karásek, V.; Šiler, M.; Chvátal, L.; Čižmár, T.; Zemánek, P.

    2014-12-01

    Following the Keplerian idea of radiative forces one would intuitively expect that an object illuminated by sunlight radiation or a laser beam is accelerated along the direction of the photon flow. Such radiation pressure forms the basis for the concept of solar sail, or laser acceleration of micro-particles. In contrast, a hypothetical optical field known from the realm of science-fiction as the "tractor" beam attracts the matter from large distances against the beam propagation. We present a geometry of such"tractor" beam in micro-scale and experimentally demonstrate how it acts upon spherical micro-particles of various sizes or optically self-arranged structures of micro-particles.

  8. Design Methodology of Micro Vibration Energy Harvesters

    NASA Astrophysics Data System (ADS)

    Tanaka, Shuji

    Recently, micro vibration energy harvesters are attracting much attention for wireless sensor applications. To answer the power requirement of practical applications, the design methodology is important. This paper first reviews the fundamental theory of vibration energy harvesting, and then discusses how to design a micro vibration energy harvester at a concept level. For the micro vibration energy harvesters, independent design parameters at the top level are only the mass and stroke of a seismic mass and quality factor, while the frequency and acceleration of vibration input are given parameters determined by the application. The key design point is simply to make the mass and stroke of the seismic mass as large as possible within the available device size. Some case studies based on the theory are also presented. This paper provides a guideline for the development of the micro vibration energy harvesters.

  9. Micro- and nanodevices integrated with biomolecular probes.

    PubMed

    Alapan, Yunus; Icoz, Kutay; Gurkan, Umut A

    2015-12-01

    Understanding how biomolecules, proteins and cells interact with their surroundings and other biological entities has become the fundamental design criterion for most biomedical micro- and nanodevices. Advances in biology, medicine, and nanofabrication technologies complement each other and allow us to engineer new tools based on biomolecules utilized as probes. Engineered micro/nanosystems and biomolecules in nature have remarkably robust compatibility in terms of function, size, and physical properties. This article presents the state of the art in micro- and nanoscale devices designed and fabricated with biomolecular probes as their vital constituents. General design and fabrication concepts are presented and three major platform technologies are highlighted: microcantilevers, micro/nanopillars, and microfluidics. Overview of each technology, typical fabrication details, and application areas are presented by emphasizing significant achievements, current challenges, and future opportunities. PMID:26363089

  10. Micro-ecological behavior and intergroup contact.

    PubMed

    McKeown, Shelley; Cairns, Ed; Stringer, Maurice; Rae, Gordon

    2012-01-01

    Research evaluating intergroup contact has tended to rely on self-report measures. Drawing on recent micro-ecological research, the two studies reported here used a multi-method approach to examine contact in a more holistic fashion. This involved the measurement of observable behavior at the micro-level, intergroup attitudes via infrahumanization and focus groups. Participants were taking part in a community intervention program in Northern Ireland. We conclude that micro-ecological behavior is not necessarily indicative of outgroup attitudes. Although behavior and attitudes changed in line with one another in Study 1 (less aggregation and significantly less infrahumanization), there were no infrahumanization differences between those who sat beside an outgroup member and those who did not. Importantly, the work presented here illustrates a unique method that allows micro-ecological behavioral observations to be made for the first time in non-racial settings. PMID:22558828

  11. Micro- and nanodevices integrated with biomolecular probes

    PubMed Central

    Alapan, Yunus; Icoz, Kutay; Gurkan, Umut A.

    2016-01-01

    Understanding how biomolecules, proteins and cells interact with their surroundings and other biological entities has become the fundamental design criterion for most biomedical micro- and nanodevices. Advances in biology, medicine, and nanofabrication technologies complement each other and allow us to engineer new tools based on biomolecules utilized as probes. Engineered micro/nanosystems and biomolecules in nature have remarkably robust compatibility in terms of function, size, and physical properties. This article presents the state of the art in micro- and nanoscale devices designed and fabricated with biomolecular probes as their vital constituents. General design and fabrication concepts are presented and three major platform technologies are highlighted: microcantilevers, micro/nanopillars, and microfluidics. Overview of each technology, typical fabrication details, and application areas are presented by emphasizing significant achievements, current challenges, and future opportunities. PMID:26363089

  12. MicroRNA in intervertebral disc degeneration.

    PubMed

    Li, Zheng; Yu, Xin; Shen, Jianxiong; Chan, Matthew T V; Wu, William Ka Kei

    2015-06-01

    Aetiology of intervertebral disc degeneration (IDD) is complex, with genetic, developmental, biochemical and biomechanical factors contributing to the disease process. It is becoming obvious that epigenetic processes influence evolution of IDD as strongly as the genetic background. Deregulated phenotypes of nucleus pulposus cells, including differentiation, migration, proliferation and apoptosis, are involved in all stages of progression of human IDD. Non-coding RNAs, including microRNAs, have recently been recognized as important regulators of gene expression. Research into roles of microRNAs in IDD has been very active over the past 5 years. Our review summarizes current research enlightenment towards understanding roles of microRNAs in regulating nucleus pulposus cell functions in IDD. These exciting findings support the notion that specific modulation of microRNAs may represent an attractive approach for management of IDD. PMID:25736871

  13. Micro-hydropower in the United States

    NASA Astrophysics Data System (ADS)

    Haroldsen, R. O.; Simpson, F. B.

    1981-09-01

    The interest and problems relating to the development of micro-hydropower, i.e., capacities of less than 100 kW, was assessed. A total of 62 individuals from 10 states and 4 groups, i.e., developers, A/E firms, equipment manufacturers, and state and federal agencies, were polled to determine their perceptions of the advantages and disadvantages of micro-hydro developments and the needs for such developments. Financing, technical assistance, and help with the economic analysis and regulatory aspects of micro-hydro development appeared to be the paramount needs. Whether or not a specific site can be successfully developed depends on site conditions. A micro-hydro plant discussed as an example is shown to be a poor investment, e.g., maximum $200 per month return on $60,000 investment.

  14. Principles of microRNA Regulation Revealed Through Modeling microRNA Expression Quantitative Trait Loci

    PubMed Central

    Budach, Stefan; Heinig, Matthias; Marsico, Annalisa

    2016-01-01

    Extensive work has been dedicated to study mechanisms of microRNA-mediated gene regulation. However, the transcriptional regulation of microRNAs themselves is far less well understood, due to difficulties determining the transcription start sites of transient primary transcripts. This challenge can be addressed using expression quantitative trait loci (eQTLs) whose regulatory effects represent a natural source of perturbation of cis-regulatory elements. Here we used previously published cis-microRNA-eQTL data for the human GM12878 cell line, promoter predictions, and other functional annotations to determine the relationship between functional elements and microRNA regulation. We built a logistic regression model that classifies microRNA/SNP pairs into eQTLs or non-eQTLs with 85% accuracy; shows microRNA-eQTL enrichment for microRNA precursors, promoters, enhancers, and transcription factor binding sites; and depletion for repressed chromatin. Interestingly, although there is a large overlap between microRNA eQTLs and messenger RNA eQTLs of host genes, 74% of these shared eQTLs affect microRNA and host expression independently. Considering microRNA-only eQTLs we find a significant enrichment for intronic promoters, validating the existence of alternative promoters for intragenic microRNAs. Finally, in line with the GM12878 cell line derived from B cells, we find genome-wide association (GWA) variants associated to blood-related traits more likely to be microRNA eQTLs than random GWA and non-GWA variants, aiding the interpretation of GWA results. PMID:27260304

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Micro-spherules near the Kamil crater .

    NASA Astrophysics Data System (ADS)

    Bignami, L.; Guaita, C.; Pezzotta, F.; Zilioli, M.

    A large number of metallic micro-spheres has been found near the 45 m Kamil crater (22o 01'06''N, 26o05'15''E), produced about 5000 years ago by an extraordinary metallic meteorite (20% Nickel, 0.5% P as shreibersite). A complex SEM inspection inside and outside these micro-spherules provided some good indication about the source and the mechanism of formation of the spherules.

  17. Bracing micro/macro manipulators control

    SciTech Connect

    Lew, J.Y.; Book, W.J.

    1994-05-01

    This paper proposes a bracing strategy for micro/macro manipulators. The bracing micro/macro manipulator can provide advantages in accurate positioning, large work-space, and contact-task capability however, in exchange for improvement in performance one must accept the complex control problem along wit the complex dynamics. This research develops a control scheme for a bracing manipulator which makes multiple contacts with the environment. Experimental results show the feasibility of the proposed ideas for real world applications.

  18. MicroBooNE Detector Move

    SciTech Connect

    Flemming, Bonnie; Rameika, Gina

    2014-06-25

    On Monday, June 23, 2014 the MicroBooNE detector -- a 30-ton vessel that will be used to study ghostly particles called neutrinos -- was transported three miles across the Fermilab site and gently lowered into the laboratory's Liquid-Argon Test Facility. This video documents that move, some taken with time-lapse camerad, and shows the process of getting the MicroBooNE detector to its new home.

  19. MicroBooNE Detector Move

    ScienceCinema

    Flemming, Bonnie; Rameika, Gina

    2014-07-15

    On Monday, June 23, 2014 the MicroBooNE detector -- a 30-ton vessel that will be used to study ghostly particles called neutrinos -- was transported three miles across the Fermilab site and gently lowered into the laboratory's Liquid-Argon Test Facility. This video documents that move, some taken with time-lapse camerad, and shows the process of getting the MicroBooNE detector to its new home.

  20. Micro-Inspector Spacecraft: An Overview

    NASA Technical Reports Server (NTRS)

    Goldberg, Hannah; Mueller, Juergen; Alkalai, Leon

    2006-01-01

    JPL has developed a small(<5 kg) spacecraft capable of visual inspection of a host vehicle with support from NASA's Exploration Systems Mission Directorate (ESMD). This paper describes the multi-mission utility of the Micro-Inspector and presents an overview of the spacecraft system and subsystem designs, description of a typical inspection mission scenario, and initial hardware demonstrations of key subsystems, partially integrated with each other in a Micro-Inspector testbed at JPL.

  1. Diamond single micro-crystals and graphitic micro-balls’ formation in plasmoids under atmospheric pressure

    NASA Astrophysics Data System (ADS)

    Pothiraja, Ramasamy; Kartaschew, Konstantin; Bibinov, Nikita; Havenith, Martina; Awakowicz, Peter

    2015-03-01

    Plasmoids are produced in the argon filamentary discharge. By going through hydrocarbon gas, the plasmoids collect carbon material. These plasmoids produce diamond single micro-crystals upon contact on the inner surface of cavity in air atmosphere. When the plasmoid’s contact point on the substrate is in inert atmosphere, they deposit their material as micro-balls with a graphite core. The dimension and nature of the micro-materials deposited by the plasmoids are analysed using scanning electron microscopy and Raman microspectroscopy. The compressive residual stress in the deposited micro-diamonds varies in the range -7 to -21 GPa.

  2. Fabrication of high-density micro holes by upward batch micro EDM

    NASA Astrophysics Data System (ADS)

    Chen, Shun-Tong

    2008-08-01

    A large number of micro holes are needed for biomedical parts, ink-jet nozzles and micro droplet spraying parts. In this study, an inexpensive machining approach for producing a batch of micro holes is proposed. A set of previously introduced w-EDM mechanisms is employed to horizontally cut the batch micro electrodes precisely. Through the process arrangement, the micro electrodes and workpiece are not unloaded, repositioned and re-corrected until all the tasks are completed. The micro workpiece is clamped onto the specially designed jig and moved above the micro electrodes to perform machining of the mass micro holes by upward batch micro EDM. The entire procedure is carried out on a developed multifunctional tabletop CNC machine tool. An array of 400 through holes of the identical sizes is successfully fabricated on a stainless-steel plate with a thickness of 30 µm by using the modified peck-drilling method. Experimental results confirmed that the proposed approach could accelerate the removal of debris, reduce the occurrence of abnormal discharges and decrease the machining time.

  3. Fabrication of Micro Gears by Micro-Powder Injection-Compression Molding

    NASA Astrophysics Data System (ADS)

    Jang, Jin Man; Lee, Wonsik; Son, Seong-Ho; Ko, Se-Hyun; Kim, Il-Ho

    Micro-spur gears were fabricated by powder injection-compression molding and micro-two-step gears were produced through stacking and sintering of the green parts. Shrinkage of micro-gears by sintering was larger in teeth and with increase of compression pressure, shrinkage was decreased due to increase of density in green parts. Surface roughness of sintered body was reduced to a few hundreds of nanometers by ultrasonic micro-polishing. The joining of green bodies by stacking and sintering was achieved using the pressurized sintering and insert of feedstock powders between both green bodies.

  4. Homogenization in micro-magneto-mechanics

    NASA Astrophysics Data System (ADS)

    Sridhar, A.; Keip, M.-A.; Miehe, C.

    2016-07-01

    Ferromagnetic materials are characterized by a heterogeneous micro-structure that can be altered by external magnetic and mechanical stimuli. The understanding and the description of the micro-structure evolution is of particular importance for the design and the analysis of smart materials with magneto-mechanical coupling. The macroscopic response of the material results from complex magneto-mechanical interactions occurring on smaller length scales, which are driven by magnetization reorientation and associated magnetic domain wall motions. The aim of this work is to directly base the description of the macroscopic magneto-mechanical material behavior on the micro-magnetic domain evolution. This will be realized by the incorporation of a ferromagnetic phase-field formulation into a macroscopic Boltzmann continuum by the use of computational homogenization. The transition conditions between the two scales are obtained via rigorous exploitation of rate-type and incremental variational principles, which incorporate an extended version of the classical Hill-Mandel macro-homogeneity condition covering the phase field on the micro-scale. An efficient two-scale computational scenario is developed based on an operator splitting scheme that includes a predictor for the magnetization on the micro-scale. Two- and three-dimensional numerical simulations demonstrate the performance of the method. They investigate micro-magnetic domain evolution driven by macroscopic fields as well as the associated overall hysteretic response of ferromagnetic solids.

  5. MicroRNA fingerprints during human megakaryocytopoiesis

    PubMed Central

    Garzon, Ramiro; Pichiorri, Flavia; Palumbo, Tiziana; Iuliano, Rodolfo; Cimmino, Amelia; Aqeilan, Rami; Volinia, Stefano; Bhatt, Darshna; Alder, Hansjuerg; Marcucci, Guido; Calin, George A.; Liu, Chang-Gong; Bloomfield, Clara D.; Andreeff, Michael; Croce, Carlo M.

    2006-01-01

    microRNAs are a highly conserved class of noncoding RNAs with important regulatory functions in proliferation, apoptosis, development, and differentiation. To discover novel regulatory pathways during megakaryocytic differentiation, we performed microRNA expression profiling of in vitro-differentiated megakaryocytes derived from CD34+ hematopoietic progenitors. The main finding was down-regulation of miR-10a, miR-126, miR-106, miR-10b, miR-17 and miR-20. Hypothetically, the down-regulation of microRNAs unblocks target genes involved in differentiation. We confirmed in vitro and in vivo that miR-130a targets the transcription factor MAFB, which is involved in the activation of the GPIIB promoter, a key protein for platelet physiology. In addition, we found that miR-10a expression in differentiated megakaryocytes is inverse to that of HOXA1, and we showed that HOXA1 is a direct target of miR-10a. Finally, we compared the microRNA expression of megakaryoblastic leukemic cell lines with that of in vitro differentiated megakaryocytes and CD34+ progenitors. This analysis revealed up-regulation of miR-101, miR-126, miR-99a, miR-135, and miR-20. Our data delineate the expression of microRNAs during megakaryocytopoiesis and suggest a regulatory role of microRNAs in this process by targeting megakaryocytic transcription factors. PMID:16549775

  6. Laser 3D micro-manufacturing

    NASA Astrophysics Data System (ADS)

    Piqué, Alberto; Auyeung, Raymond C. Y.; Kim, Heungsoo; Charipar, Nicholas A.; Mathews, Scott A.

    2016-06-01

    Laser-based materials processing techniques are gaining widespread use in micro-manufacturing applications. The use of laser microfabrication techniques enables the processing of micro- and nanostructures from a wide range of materials and geometries without the need for masking and etching steps commonly associated with photolithography. This review aims to describe the broad applications space covered by laser-based micro- and nanoprocessing techniques and the benefits offered by the use of lasers in micro-manufacturing processes. Given their non-lithographic nature, these processes are also referred to as laser direct-write and constitute some of the earliest demonstrations of 3D printing or additive manufacturing at the microscale. As this review will show, the use of lasers enables precise control of the various types of processing steps—from subtractive to additive—over a wide range of scales with an extensive materials palette. Overall, laser-based direct-write techniques offer multiple modes of operation including the removal (via ablative processes) and addition (via photopolymerization or printing) of most classes of materials using the same equipment in many cases. The versatility provided by these multi-function, multi-material and multi-scale laser micro-manufacturing processes cannot be matched by photolithography nor with other direct-write microfabrication techniques and offer unique opportunities for current and future 3D micro-manufacturing applications.

  7. Advanced Micro Turbine System (AMTS) -C200 Micro Turbine -Ultra-Low Emissions Micro Turbine

    SciTech Connect

    Capstone Turbine Corporation

    2007-12-31

    In September 2000 Capstone Turbine Corporation commenced work on a US Department of Energy contract to develop and improve advanced microturbines for power generation with high electrical efficiency and reduced pollutants. The Advanced MicroTurbine System (AMTS) program focused on: (1) The development and implementation of technology for a 200 kWe scale high efficiency microturbine system (2) The development and implementation of a 65 kWe microturbine which meets California Air Resources Board (CARB) emissions standards effective in 2007. Both of these objectives were achieved in the course of the AMTS program. At its conclusion prototype C200 Microturbines had been designed, assembled and successfully completed field demonstration. C65 Microturbines operating on natural, digester and landfill gas were also developed and successfully tested to demonstrate compliance with CARB 2007 Fossil Fuel Emissions Standards for NOx, CO and VOC emissions. The C65 Microturbine subsequently received approval from CARB under Executive Order DG-018 and was approved for sale in California. The United Technologies Research Center worked in parallel to successfully execute a RD&D program to demonstrate the viability of a low emissions AMS which integrated a high-performing microturbine with Organic Rankine Cycle systems. These results are documented in AMS Final Report DOE/CH/11060-1 dated March 26, 2007.

  8. Micro-Doppler classification of riders and riderless horses

    NASA Astrophysics Data System (ADS)

    Tahmoush, David

    2014-05-01

    Micro-range Micro-Doppler can be used to isolate particular parts of the radar signature, and in this case we demonstrate the differences in the signature between a walking horse versus a walking horse with a rider. Using micro-range micro-Doppler, we can distinguish the radar returns from the rider as separate from the radar returns of the horse.

  9. Therapeutic evaluation of microRNA-15a and microRNA-16 in ovarian cancer

    PubMed Central

    Dhar Dwivedi, Shailendra Kumar; Mustafi, Soumyajit Banerjee; Mangala, Lingegowda S.; Jiang, Dahai; Pradeep, Sunila; Rodriguez-Aguayo, Cristian; Ling, Hui; Ivan, Cristina; Mukherjee, Priyabrata; Calin, George A.; Lopez-Berestein, Gabriel; Sood, Anil K.; Bhattacharya, Resham

    2016-01-01

    Treatment of chemo-resistant ovarian cancer (OvCa) remains clinically challenging and there is a pressing need to identify novel therapeutic strategies. Here we report that multiple mechanisms that promote OvCa progression and chemo-resistance could be inhibited by ectopic expression of miR-15a and miR-16. Significant correlations between low expression of miR-16, high expression of BMI1 and shortened overall survival (OS) were noted in high grade serous (HGS) OvCa patients upon analysis of The Cancer Genome Atlas (TCGA). Targeting BMI1, in vitro with either microRNA reduced clonal growth of OvCa cells. Additionally, epithelial to mesenchymal transition (EMT) as well as expression of the cisplatin transporter ATP7B were inhibited by miR-15a and miR-16 resulting in decreased degradation of the extra-cellular matrix and enhanced sensitization of OvCa cells to cisplatin. Nanoliposomal delivery of the miR-15a and miR-16 combination, in a pre-clinical chemo-resistant orthotopic mouse model of OvCa, demonstrated striking reduction in tumor burden compared to cisplatin alone. Thus, with the advent of miR replacement therapy some of which are in Phase 2 clinical trials, miR-15a and miR-16 represent novel ammunition in the anti-OvCa arsenal. PMID:26918603

  10. Recent Progress on Bioinspired Self-Propelled Micro/Nanomotors via Controlled Molecular Self-Assembly.

    PubMed

    Wu, Zhiguang; Lin, Xiankun; Si, Tieyan; He, Qiang

    2016-06-01

    The combination of bottom-up controllable self-assembly technique with bioinspired design has opened new horizons in the development of self-propelled synthetic micro/nanomotors. Over the past five years, a significant advances toward the construction of bioinspired self-propelled micro/nanomotors has been witnessed based on the controlled self-assembly technique. Such a strategy permits the realization of autonomously synthetic motors with engineering features, such as sizes, shapes, composition, propulsion mechanism, and function. The construction, propulsion mechanism, and movement control of synthetic micro/nanomotors in connection with controlled self-assembly in recent research activities are summarized. These assembled nanomotors are expected to have a tremendous impact on current artificial nanomachines in future and hold potential promise for biomedical applications including drug targeted delivery, photothermal cancer therapy, biodetoxification, treatment of atherosclerosis, artificial insemination, crushing kidney stones, cleaning wounds, and removing blood clots and parasites. PMID:27073065

  11. Micro-scale spatially offset Raman spectroscopy for non-invasive subsurface analysis of turbid materials.

    PubMed

    Matousek, P; Conti, C; Realini, M; Colombo, C

    2016-02-01

    This article reviews a very recent field of noninvasive analysis of turbid media using micro-scale Spatially Offset Raman Spectroscopy - micro-SORS. The technique combines conventional SORS with microscopy concepts and represents a new imaging modality in Raman microscopy. Micro-SORS facilitates analytical capability for investigating non-destructively the chemical composition of subsurface, micrometer-scale-thick diffusely scattering layers at depths more than an order of magnitude larger than those accessible with the depth resolving power of conventional confocal Raman microscopy. Potential application areas include nondestructive subsurface analysis of painted layers in cultural heritage, characterization of stratified polymer systems, analysis of layered biological samples or forensic analysis. The article discusses the basic principles of the technique, its variants and outlines emerging applications in this rapidly evolving field. PMID:26646435

  12. An optical system for monitoring the movement of a micro multipede

    NASA Astrophysics Data System (ADS)

    Pham, D. T.; Djakov, Vladislav; Packianather, Michael S.; Wang, Z.

    2007-10-01

    A micromechanical actuator has been developed using materials with different coefficients of thermal expansion combined in a sandwich cantilever structure. The actuator is thermally operated and could be used in different applications including temperature controlled electrical switches and sensors. A novel application for the microactuator is as the prime mover for a micro multipede. The latter is essentially a multicantilever array where each element can be actuated in sequence to produce planar movements. The actuation is provided by micro heaters integrated into each cantilever. This paper presents the design of an optical system for monitoring the movements of a micro multipede using two methods. The first method, triangulation was adopted to measure the downward movement and flattening of the cantilevers under load. The second method involved direct deflection measurement with an optical microscope. The paper presents both simulation and test results for temperature and mechanical loading and the relationship between electrical power and cantilever deflection.

  13. Monolithically integrated micro- and nanostructured glass surface with antiglare, antireflection, and superhydrophobic properties.

    PubMed

    Tulli, Domenico; Hart, Shandon D; Mazumder, Prantik; Carrilero, Albert; Tian, Lili; Koch, Karl W; Yongsunthon, Ruchirej; Piech, Garrett A; Pruneri, Valerio

    2014-07-23

    Hierarchical micro- and nanostructured surfaces have previously been made using a variety of materials and methods, including particle deposition, polymer molding, and the like. These surfaces have attracted a wide variety of interest for applications including reduced specular reflection and superhydrophobic surfaces. To the best of our knowledge, this paper reports the first monolithic, hierarchically structured glass surface that combines micro- and nanoscale surface features to simultaneously generate antiglare (AG), antireflection (AR), and superhydrophobic properties. The AG microstructure mechanically protects the AR nanostructure during wiping and smudging, while the uniform composition of the substrate and the micro- and nanostructured surface enables ion exchange through the surface, so that both the substrate and structured surface can be simultaneously chemically strengthened. PMID:24960031

  14. Nafion Film Based Micro-nanofluidic Device for Concurrent DNA Preconcentration and Separation in Free Solution

    PubMed Central

    Song, Hongjun; Wang, Yi; Garson, Charles; Pant, Kapil

    2014-01-01

    This paper presents a Nafion film based micro-nanofluidic device for concurrent DNA preconcentration and separation. The principle of the device is based on the combination of (a) ion concentration polarization phenomenon at the junction of the microchannel and the nanochannels in the Nafion film to form opposing electrophoretic and electroosmotic forces acting on the DNAs, and (b) end-labeled free solution electrophoresis to harness the charge-to-mass ratio for molecular differentiation. The experiments successfully demonstrated concurrent preconcentration and separation of DNA mixture in free solution within 240s, yielding concentration ratios up to 1,150X and separation resolution of 1.85. The effect of applied electric field on the concentration and separation performance was also investigated. The device can be used as a key sample preparation element in conjunction with micro- or nano-fluidic sensors for microTAS functionality. PMID:25346656

  15. Laser micro welding of copper and aluminium using filler materials

    NASA Astrophysics Data System (ADS)

    Esser, Gerd; Mys, Ihor; Schmidt, Michael H.

    2004-10-01

    The most evident trend in electronics production is towards miniaturization. Regarding the materials involved, another trend can be observed: intelligent combinations of different materials. One example is the combination of copper and aluminium. Copper is the material of choice for electronic packaging applications due to its superior electrical and thermal conductivity. On the other hand, aluminium offers technical and economical advantages with respect to cost and component weight -- still providing thermal and electrical properties acceptable for numerous applications. Especially for high volume products, the best solution often seems to be a combination of both materials. This fact raises the question of joining copper and aluminium. With respect to miniaturization laser micro welding is a very promising joining technique. Unfortunately, the metallurgical incompatibility of copper and aluminium easily results in the formation of brittle intermetallic phases and segregations during laser welding, thus generating an unacceptable quality of the joints. This paper presents investigations on enhancing the quality during laser micro welding of copper and aluminium for applications in electronics production. In order to eliminate the formation of brittle intermetallic phases, the addition of a filter material in form of a foil has been investigated. It can be shown that the addition of pure metals such as nickel and especially silver significantly reduces the occurrence of brittle phases in the joining area and therefore leads to an increase in welding quality. The proper control of the volume fractions of copper, aluminium and filler material in the melting zone helps to avoid materials segregation and reduces residual stress, consequently leading to a reduction of crack affinity and a stabilization of the mechanical and electrical properties.

  16. 3D micro-XRF for cultural heritage objects: new analysis strategies for the investigation of the Dead Sea Scrolls.

    PubMed

    Mantouvalou, Ioanna; Wolff, Timo; Hahn, Oliver; Rabin, Ira; Lühl, Lars; Pagels, Marcel; Malzer, Wolfgang; Kanngiesser, Birgit

    2011-08-15

    A combination of 3D micro X-ray fluorescence spectroscopy (3D micro-XRF) and micro-XRF was utilized for the investigation of a small collection of highly heterogeneous, partly degraded Dead Sea Scroll parchment samples from known excavation sites. The quantitative combination of the two techniques proves to be suitable for the identification of reliable marker elements which may be used for classification and provenance studies. With 3D micro-XRF, the three-dimensional nature, i.e. the depth-resolved elemental composition as well as density variations, of the samples was investigated and bromine could be identified as a suitable marker element. It is shown through a comparison of quantitative and semiquantitative values for the bromine content derived using both techniques that, for elements which are homogeneously distributed in the sample matrix, quantification with micro-XRF using a one-layer model is feasible. Thus, the possibility for routine provenance studies using portable micro-XRF instrumentation on a vast amount of samples, even on site, is obtained through this work. PMID:21711051

  17. Uranium Speciation As a Function of Depth in Contaminated Hanford Sediments - A Micro-XRF, Micro-XRD, and Micro- And Bulk-XAFS Study

    SciTech Connect

    Singer, David M.; Zachara, John M.; Brown, Gordon E.

    2009-01-05

    Processing ponds at the Hanford, Washington Area 300 site were used for storing basic sodium aluminate and acidic U(VI)-Cu(II)-containing waste from 1943 to 1975. One result of this use is a groundwater plume containing elevated levels of U and Cu beneath the dry ponds and adjacent to the Columbia River. We have used synchrotron-based micro-X-ray fluorescence (μXRF) imaging, micro-X-ray absorption fine structure (μXANES) spectroscopy, and micro-X-ray diffraction (μXRD) techniques combined with bulk U LIII-edge X-ray absorption fine structure (XAFS) spectroscopy to determine the distribution and speciation of U and Cu through the vadose and groundwater zones beneath North Processing Pond #2 (NPP2). Sediment samples were collected from the vadose zone (8’ and 12’ depths), and a sample from the groundwater zone was collected just below the water table (12’-14’ depth). μXRF imaging revealed two major U occurrences within the vadose and groundwater zones: (1) low to moderate concentrations of U(VI) associated with mineral surfaces (particularly chlorite), and (2) high concentration U(VI)-containing micron-sized particles associated with surface coatings on grains of muscovite and chlorite. These U(VI) hot spots are frequently spatially correlated with Cu(II) hot spots. In the groundwater zone, these particles were identified as the copper-uranyl-silicate cuprosklodowskite and the cupper-uranyl-phosphate metatorbernite. In contrast, the U-Cu-containing particles are X-ray amorphous in the vadose zone. Fits of U LIII-edge XAFS spectra by linear-combination fitting indicate that U speciation consists of ~ 75% uranyl sorbed to clays and ~25% metatorbernite-like X-ray amorphous U-Cu-phosphates (8’ depth); nearly 100% sorbed uranyl (12’ depth); and ~70% sorbed uranyl and ~30% cuprosklodowskite/metatorbernite (ground water zone). These findings suggest that the dissolution of U(VI)-Cu(II)-bearing solids as well as the desorption of U(VI), mainly from

  18. A comparison of sampling strategies for dual energy micro-CT

    NASA Astrophysics Data System (ADS)

    Guo, Xiaolian; Johnston, Samuel M.; Johnson, G. Allan; Badea, Cristian T.

    2012-03-01

    Micro-CT has become a powerful tool for small animal research. Many micro-CT applications require exogenous contrast agents, which are most commonly based on iodine. Despite advancements in contrast agents, single-energy micro-CT is sometimes limited in the separation of two different materials that share similar grayscale intensity values as in the case of bone and iodine. Dual energy micro-CT offers a solution to this separation problem, while eliminating the need for pre-injection scanning. Various dual energy micro-CT sampling strategies are possible, including 1) single source sequential scanning, 2) simultaneous dual source acquisition, or 3) single source with kVp switching. But, no commercial micro-CT system exists in which all these sampling strategies have been implemented. This study reports on the implementation and comparison of these scanning techniques on the same small animal imaging system. Furthermore, we propose a new sampling strategy that combines dual source and kVp switching. Post-sampling and reconstruction, a simple two-material dual energy decomposition was applied to differentiate iodine from bone. The results indicate the time differences and the potential problems associated with each sampling strategy. Dual source scanning allows for the fastest acquisition, but is prone to errors in decomposition associated with scattering and imperfect geometric alignment of the two imaging chains. KVp switching prevents these types of artifacts, but requires more time for sampling. The novel combination between the dual source and kVp switching has the potential to reduce sampling time and provide better decomposition performance.

  19. Identification of a pan-cancer oncogenic microRNA superfamily anchored by a central core seed motif

    NASA Astrophysics Data System (ADS)

    Hamilton, Mark P.; Rajapakshe, Kimal; Hartig, Sean M.; Reva, Boris; McLellan, Michael D.; Kandoth, Cyriac; Ding, Li; Zack, Travis I.; Gunaratne, Preethi H.; Wheeler, David A.; Coarfa, Cristian; McGuire, Sean E.

    2013-11-01

    MicroRNAs modulate tumorigenesis through suppression of specific genes. As many tumour types rely on overlapping oncogenic pathways, a core set of microRNAs may exist, which consistently drives or suppresses tumorigenesis in many cancer types. Here we integrate The Cancer Genome Atlas (TCGA) pan-cancer data set with a microRNA target atlas composed of publicly available Argonaute Crosslinking Immunoprecipitation (AGO-CLIP) data to identify pan-tumour microRNA drivers of cancer. Through this analysis, we show a pan-cancer, coregulated oncogenic microRNA ‘superfamily’ consisting of the miR-17, miR-19, miR-130, miR-93, miR-18, miR-455 and miR-210 seed families, which cotargets critical tumour suppressors via a central GUGC core motif. We subsequently define mutations in microRNA target sites using the AGO-CLIP microRNA target atlas and TCGA exome-sequencing data. These combined analyses identify pan-cancer oncogenic cotargeting of the phosphoinositide 3-kinase, TGFβ and p53 pathways by the miR-17-19-130 superfamily members.

  20. MicroRNA-222 regulates muscle alternative splicing through Rbm24 during differentiation of skeletal muscle cells.

    PubMed

    Cardinali, B; Cappella, M; Provenzano, C; Garcia-Manteiga, J M; Lazarevic, D; Cittaro, D; Martelli, F; Falcone, G

    2016-01-01

    A number of microRNAs have been shown to regulate skeletal muscle development and differentiation. MicroRNA-222 is downregulated during myogenic differentiation and its overexpression leads to alteration of muscle differentiation process and specialized structures. By using RNA-induced silencing complex (RISC) pulldown followed by RNA sequencing, combined with in silico microRNA target prediction, we have identified two new targets of microRNA-222 involved in the regulation of myogenic differentiation, Ahnak and Rbm24. Specifically, the RNA-binding protein Rbm24 is a major regulator of muscle-specific alternative splicing and its downregulation by microRNA-222 results in defective exon inclusion impairing the production of muscle-specific isoforms of Coro6, Fxr1 and NACA transcripts. Reconstitution of normal levels of Rbm24 in cells overexpressing microRNA-222 rescues muscle-specific splicing. In conclusion, we have identified a new function of microRNA-222 leading to alteration of myogenic differentiation at the level of alternative splicing, and we provide evidence that this effect is mediated by Rbm24 protein. PMID:26844700

  1. MicroRNA-222 regulates muscle alternative splicing through Rbm24 during differentiation of skeletal muscle cells

    PubMed Central

    Cardinali, B; Cappella, M; Provenzano, C; Garcia-Manteiga, J M; Lazarevic, D; Cittaro, D; Martelli, F; Falcone, G

    2016-01-01

    A number of microRNAs have been shown to regulate skeletal muscle development and differentiation. MicroRNA-222 is downregulated during myogenic differentiation and its overexpression leads to alteration of muscle differentiation process and specialized structures. By using RNA-induced silencing complex (RISC) pulldown followed by RNA sequencing, combined with in silico microRNA target prediction, we have identified two new targets of microRNA-222 involved in the regulation of myogenic differentiation, Ahnak and Rbm24. Specifically, the RNA-binding protein Rbm24 is a major regulator of muscle-specific alternative splicing and its downregulation by microRNA-222 results in defective exon inclusion impairing the production of muscle-specific isoforms of Coro6, Fxr1 and NACA transcripts. Reconstitution of normal levels of Rbm24 in cells overexpressing microRNA-222 rescues muscle-specific splicing. In conclusion, we have identified a new function of microRNA-222 leading to alteration of myogenic differentiation at the level of alternative splicing, and we provide evidence that this effect is mediated by Rbm24 protein. PMID:26844700

  2. Capillary optics for micro x-ray fluorescence analysis

    SciTech Connect

    Bjeoumikhov, A.; Langhoff, N.; Bjeoumikhova, S.; Wedell, R.

    2005-06-15

    Practically achieved parameters of capillary optics are presented. A micro x-ray fluorescence (XRF) arrangement was realized by using a microfocus x-ray tube and a capillary optic. Several examples for application of micro XRF are given. It was shown that polycapillary lenses free of the 'halo effect' well suited for micro XRF of heavy elements can be manufactured. Limits of opportunities for micro XRF applications and further development for micro XRF by using capillary optics are analyzed.

  3. Cortical Tubers: Windows into Dysregulation of Epilepsy Risk and Synaptic Signaling Genes by MicroRNAs.

    PubMed

    Dombkowski, Alan A; Batista, Carlos E; Cukovic, Daniela; Carruthers, Nicholas J; Ranganathan, Ramya; Shukla, Upasana; Stemmer, Paul M; Chugani, Harry T; Chugani, Diane C

    2016-03-01

    Tuberous sclerosis complex (TSC) is a multisystem genetic disorder caused by mutations in the TSC1 and TSC2 genes. Over 80% of TSC patients are affected by epilepsy, but the molecular events contributing to seizures in TSC are not well understood. Recent reports have demonstrated that the brain is enriched with microRNA activity, and they are critical in neural development and function. However, little is known about the role of microRNAs in TSC. Here, we report the characterization of aberrant microRNA activity in cortical tubers resected from 5 TSC patients surgically treated for medically intractable epilepsy. By comparing epileptogenic tubers with adjacent nontuber tissue, we identified a set of 4 coordinately overexpressed microRNAs (miRs 23a, 34a, 34b*, 532-5p). We used quantitative liquid chromatography-tandem mass spectrometry (LC-MS/MS) proteomic profiling to investigate the combined effect of the 4 microRNAs on target proteins. The proportion of repressed proteins among the predicted targets was significantly greater than in the overall proteome and was highly enriched for proteins involved in synaptic signal transmission. Among the combinatorial targets were TSC1, coding for the protein hamartin, and several epilepsy risk genes. We found decreased levels of hamartin in epileptogenic tubers and confirmed targeting of the TSC1 3' UTR by miRs-23a and 34a. PMID:25452577

  4. Microinjection of sigma-D-glucose standards and Amplex Red reagent on micro-arrays

    NASA Astrophysics Data System (ADS)

    Moerman, R.; van den Doel, L. Richard; Picioreanu, S.; Frank, J.; Marijnissen, Johannes P. A.; van Dedem, G. W. K.; Hjelt, Kari H.; Vellekoop, Michael J.; Sarro, Pasqualina M.; Young, Ian T.

    1999-06-01

    Intelligent Molecular Diagnostic Systems (IMDS)- The objective of this multidisciplinary research program is to design and develop an analytical system that is able to measure and interpret concentrations of various analytes which are dispensed on a micro-array. The analytes are detected by means of fluorescence or (chemi)luminescence measurement. Furthermore, the collected data are combined and interpreted using modern reasoning techniques. Micro-injection- Dispensing picoliters (pl) of reagents (enzymes, antibodies, etc.) and liquid samples on a micro-array requires special techniques. At the moment we are working on a technique which will allow for accurately dispensing liquid volumes less than 100 pl on a micro-array. Detection of (beta) -D-glucose- (beta) -D-glucose standards are dispensed on a micro-array, after which a solution of Amplex Red reagent, horse radish peroxidase (HARP), and glucose oxidase in a mixture of ethylene glycol and water is added. Ethylene glycol is added to prevent evaporation. The (beta) -D-glucose reacts with glucose oxidase to D-gluconolactone and H2O2. The H2O2 reacts with 10-acetyl-3,7-dihydroxyphenoxazine (Amplex Red) with a 1:1 stoichiometry to produce highly fluorescent resorufin. The formation of resorufin with time is followed with a Zeiss Axioskop microscope equipped with a KAF Photometrics CCD camera, in order to determine the sensitivity, concentrations, and volumes associated with the dispensed fluids.

  5. Manufacture of micro fluidic devices by laser welding using thermal transfer printing techniques

    NASA Astrophysics Data System (ADS)

    Klein, R.; Klein, K. F.; Tobisch, T.; Thoelken, D.; Belz, M.

    2016-03-01

    Micro-fluidic devices are widely used today in the areas of medical diagnostics and drug research, as well as for applications within the process, electronics and chemical industry. Microliters of fluids or single cell to cell interactions can be conveniently analyzed with such devices using fluorescence imaging, phase contrast microscopy or spectroscopic techniques. Typical micro-fluidic devices consist of a thermoplastic base component with chambers and channels covered by a hermetic fluid and gas tight sealed lid component. Both components are usually from the same or similar thermoplastic material. Different mechanical, adhesive or thermal joining processes can be used to assemble base component and lid. Today, laser beam welding shows the potential to become a novel manufacturing opportunity for midsize and large scale production of micro-fluidic devices resulting in excellent processing quality by localized heat input and low thermal stress to the device during processing. For laser welding, optical absorption of the resin and laser wavelength has to be matched for proper joining. This paper will focus on a new approach to prepare micro-fluidic channels in such devices using a thermal transfer printing process, where an optical absorbing layer absorbs the laser energy. Advantages of this process will be discussed in combination with laser welding of optical transparent micro-fluidic devices.

  6. Micro-bioreactors for fed-batch fermentations with integrated online monitoring and microfluidic devices.

    PubMed

    Buchenauer, A; Hofmann, M C; Funke, M; Büchs, J; Mokwa, W; Schnakenberg, U

    2009-01-01

    In this study an array of micro-bioreactors based on the format of 48-well microtiter plates (MTP) is presented. The process parameters pH-value and biomass are monitored online by a combination of different sensors, the biolector measurement technology and conductance measurements. A microfluidic device dispenses two fluids individually into each well for controlling the pH-value of fermentations. The micro-bioreactor consists of four wells and two reservoirs. In each well a polyimide foil with platinum electrodes for conductance measurements is integrated. The microfluidic device is fabricated using softlithographic techniques and utilizes pneumatically actuated microvalves. The device is able to dispense volumes below 5nl. Finally, fermentations of Escherichia coli are carried out in the micro-bioreactor system. During the fermentation, the pH-value is measured optically and the biomass development is monitored by the scattered light signal. Meanwhile, the pH-value is controlled by dispensing sodium hydroxide and phosphoric acid. This micro-bioreactor demonstrates the possibility of online monitored and pH-controlled fermentations in micro-scale. The pH-value in the uncontrolled culture varies within the range of 6.46-8.83 whereas the pH-value in the controlled cultures can be kept within 6.85-7.07. This results in an increase in biomass in the pH-controlled culture compared to the nearly completely inhibited pH-uncontrolled culture. PMID:18929478

  7. The role of microRNA in myelodysplastic syndromes: beyond DNA methylation and histone modification.

    PubMed

    Milunović, Vibor; Mandac Rogulj, Inga; Planinc-Peraica, Ana; Bulycheva, Ekaterina; Kolonić Ostojić, Slobodanka

    2016-06-01

    Myelodysplastic syndromes (MDS) are heterogeneous group of hematologic disorders of mostly elderly and based on distinct clinical phenotypes. Current paradigm of their pathogenesis relies on somatic gene mutations combined with the predisposing defective osteohematopoietic niche, but due to the breakout in epigenetic research scientific focus has steered toward two most common epigenetic modifications: methylation mechanisms and histone modification. At the same time, relatively few studies have been undertaken regarding the third epigenetic pathway - microRNAs - in MDS. The main aim of this review is to provide the basics of microRNA biology and function in oncogenesis, showing the complexity of mechanisms behind this single-stranded 22 nucleotides long RNA molecule, with further focus on its implication in MDS pathology and clinical context. By extensive literature search, we have shown enough evidence for their deregulation in MDS. However, few studies have addressed the issue on pathogenic events in MDS and its association with specific microRNAs. Preliminary research in clinical setting has shown the possible utility of microRNAs in terms of prognosis and therapy, although we are only beginning to understand various implications of microRNAs in MDS and further extensive research is warranted to answer multiple questions arising from interconnection of this epigenetic mechanism in MDS. PMID:26773284

  8. Inline chemical process analysis in micro-plants based on thermoelectric flow and impedimetric sensors

    NASA Astrophysics Data System (ADS)

    Jacobs, T.; Kutzner, C.; Kropp, M.; Brokmann, G.; Lang, W.; Steinke, A.; Kienle, A.; Hauptmann, P.

    2010-10-01

    In micro-plants, as used in chemical micro-process engineering, an integrated inline analytics is regarded as an important factor for the development and optimization of chemical processes. Up to now, there is a lack of sensitive, robust and low-priced micro-sensors for monitoring mixing and chemical conversion in micro-fluidic channels. In this paper a novel sensor system combining an impedimetric sensor and a novel pressure stable thermoelectric flow sensor for monitoring chemical reactions in micro-plants is presented. The CMOS-technology-based impedimetric sensor mainly consists of two capacitively coupled interdigital electrodes on a silicon chip. The thermoelectric flow sensor consists of a heater in between two thermopiles on a perforated membrane. The pulsed and constant current feeds of the heater were analyzed. Both sensors enable the analysis of chemical conversion by means of changes in the thermal and electrical properties of the liquid. The homogeneously catalyzed synthesis of n-butyl acetate as a chemical model system was studied. Experimental results revealed that in an overpressure regime, relative changes of less than 1% in terms of thermal and electrical properties can be detected. Furthermore, the transition from one to two liquid phases accompanied by the change in slug flow conditions could be reproducibly detected.

  9. MicroRNAs in glioblastoma: role in pathogenesis and opportunities for targeted therapies.

    PubMed

    Costa, Pedro M; Cardoso, Ana L; Mano, Miguel; de Lima, Maria C Pedroso

    2015-01-01

    Glioblastoma (GBM) is among the most lethal human cancers, being generally characterized by rapid diffuse and infiltrative growth and high level of cellular heterogeneity associated with therapeutic resistance. Despite remarkable advances in cancer theranostics, which resulted in significant improvement of clinical outcomes, patient survival remains under one year. In recent years, considerable progress has been made in understanding the role of small non-coding RNAs, designated microRNAs, in the pathogenesis of GBM. Indeed, microRNAs were found to play a critical role in multiple steps of the tumorigenic process, including cellular proliferation, apoptosis evasion, invasion, angiogenesis, and stemness. Moreover, the modulation of microRNA expression, using either antisense oligonucleotides or precursor/mimic sequences, revealed a tremendous potential for application in GBM-targeted therapeutic approaches, either per se or in combination with chemo- and/or radiotherapy. In this manuscript, we review the regulatory role of microRNAs in key cellular processes underlying GBM tumorigenesis, including migration and invasion, apoptosis evasion, angiogenesis and GBM stem-like cell proliferation/differentiation, and discuss the current knowledge on their potential as diagnostic, prognostic and predictive biomarkers in this disease. We also address the latest advances in microRNA-based therapeutic approaches for GBM, by summarizing the major achievements in in vitro and pre-clinical studies. The trends identified by these studies are highlighted in order to provide new prospects for future developments towards the successful treatment of GBM. PMID:25613511

  10. High resolution micro-XRF maps of iron oxides inside sensory dendrites of putative avian magnetoreceptors

    NASA Astrophysics Data System (ADS)

    Falkenberg, G.; Fleissner, G. E.; Fleissner, G. U. E.; Schuchardt, K.; Kühbacher, M.; Chalmin, E.; Janssens, K.

    2009-09-01

    Iron mineral containing sensory dendrites in the inner lining of the upper beak of homing pigeons [1] and various bird species [2] are the first candidate structures for an avian magnetic field receptor. A new concept of magnetoreception [3, 4] is based on detailed ultra-structural optical and electron microscopy analyses in combination with synchrotron radiation microscopic X-ray fluorescence analysis (micro-XRF) and microscopic X-ray absorption near edge structures (micro-XANES). Several behavioral experiments [5, 6] and first mathematical simulations [6] affirm our avian magnetoreceptor model. The iron minerals inside the dendrites are housed in three different subcellular compartments (bullets, platelets, vesicles), which could be clearly resolved and identified by electron microscopy on ultrathin sections [1, 3]. Micro-XRF and micro-XANES data obtained at HASYLAB beamline L added information about the elemental distribution and Fe speciation [3], but are averaged over the complete dendrite due to limited spatial resolution. Here we present recently performed micro-XRF maps with sub-micrometer resolution (ESRF ID21), which reveal for the first time subcellular structural information from almost bulk-like dendrite sample material. Due to the thickness of 30 μm the microarchitecture of the dendrites can be considered as undisturbed and artefacts introduced by sectioning might be widely reduced.

  11. Failure combination method

    SciTech Connect

    Hedin, F.; Le Coguiec, A.; Le Floch, C.; Llory, M.; Villemeur, A.

    1981-01-01

    The method described in this paper is an inductive method for combining failures (called the Failure Combination Method (FCM)). It is based on a preliminary analysis of the systems performed with an FMEA. As a study has been undertaken to test the method, the organization of the study as well as its first results from a methodological point of view are stressed. 8 refs.

  12. Embodied Conceptual Combination

    PubMed Central

    Lynott, Dermot; Connell, Louise

    2010-01-01

    Conceptual combination research investigates the processes involved in creating new meaning from old referents. It is therefore essential that embodied theories of cognition are able to explain this constructive ability and predict the resultant behavior. However, by failing to take an embodied or grounded view of the conceptual system, existing theories of conceptual combination cannot account for the role of perceptual, motor, and affective information in conceptual combination. In the present paper, we propose the embodied conceptual combination (ECCo) model to address this oversight. In ECCo, conceptual combination is the result of the interaction of the linguistic and simulation systems, such that linguistic distributional information guides or facilitates the combination process, but the new concept is fundamentally a situated, simulated entity. So, for example, a cactus beetle is represented as a multimodal simulation that includes visual (e.g., the shiny appearance of a beetle) and haptic (e.g., the prickliness of the cactus) information, all situated in the broader location of a desert environment under a hot sun, and with (at least for some people) an element of creepy-crawly revulsion. The ECCo theory differentiates interpretations according to whether the constituent concepts are destructively, or non-destructively, combined in the situated simulation. We compare ECCo to other theories of conceptual combination, and discuss how it accounts for classic effects in the literature. PMID:21833267

  13. Functional MicroRNA Involved in Endometriosis

    PubMed Central

    Creighton, Chad J.; Han, Derek Y.; Zariff, Azam; Anderson, Matthew L.; Gunaratne, Preethi H.; Matzuk, Martin M.

    2011-01-01

    Endometriosis is a common disease seen by gynecologists. Clinical features involve pelvic pain and unexplained infertility. Although endometriosis is pathologically characterized by endometrial tissue outside the normal uterine location, endometriosis is otherwise not easily explained. Endometriomas, endometriotic cysts of the ovary, typically cause pain and distortion of pelvic anatomy. To begin to understand the pathogenesis of endometriomas, we describe the first transcriptome-microRNAome analysis of endometriomas and eutopic endometrium using next-generation sequencing technology. Using this approach, we generated a total of more than 54 million independent small RNA reads from our 19 clinical samples. At the microRNA level, we found 10 microRNA that were up-regulated (miR-202, 193a-3p, 29c, 708, 509-3-5p, 574-3p, 193a-5p, 485-3p, 100, and 720) and 12 microRNA that were down-regulated (miR-504, 141, 429, 203, 10a, 200b, 873, 200c, 200a, 449b, 375, and 34c-5p) in endometriomas compared with endometrium. Using in silico prediction algorithms, we correlated these microRNA with their corresponding differentially expressed mRNA targets. To validate the functional roles of microRNA, we manipulated levels of miR-29c in an in vitro system of primary cultures of human endometrial stromal fibroblasts. Extracellular matrix genes that were potential targets of miR-29c in silico were significantly down-regulated using this biological in vitro system. In vitro functional studies using luciferase reporter constructs further confirmed that miR-29c directly affects specific extracellular matrix genes that are dysregulated in endometriomas. Thus, miR-29c and other abnormally regulated microRNA appear to play important roles in the pathophysiology of uterine function and dysfunction. PMID:21436257

  14. A Mars Micro-Meteorological Station Mission

    NASA Technical Reports Server (NTRS)

    Merrihew, Steven C.; Haberle, Robert; Lemke, Lawrence G.

    1995-01-01

    The Mars Micro-Meteorological Station (Micro-Met) Mission is designed to provide the global surface pressure measurements required to help characterize the martian general circulation and climate system. Measurements of surface pressure distributed both spatially and temporally, coupled with simultaneous measurements from orbit, will enable the determination of the general circulation, structure and driving factors of the martian atmosphere as well as the seasonal CO2 cycle. The influence of these atmospheric factors will in turn provide insight into the overall martian climate system. With the science objective defined as the long term (at least one Mars year) globally distributed measurement of surface atmospheric pressure, a straightforward, near term and low cost network mission has been designed. The Micro-Met mission utilizes a unique silicon micro-machined pressure sensor coupled with a robust and lightweight surface station to deliver to Mars 16 Micro-Met stations via a Med-Lite launch vehicle. The battery powered Micro-Met surface stations are designed to autonomously measure, record and transmit the science data via a UHF relay satellite. Entry, descent and landing is provided by an aeroshell with a new lightweight ceramic thermal protection system, a parachute and an impact absorbing structure. The robust lander is capable of surviving the landing loads imposed by the high altitude landing sites required in a global network. By trading the ability to make many measurements at a single site for the ability to make a single measurement at several sites, the Micro-Met mission design satisfies the requirement for truly global meteorological science.

  15. MicroRT - Small animal conformal irradiator

    SciTech Connect

    Stojadinovic, S.; Low, D. A.; Hope, A. J.; Vicic, M.; Deasy, J. O.; Cui, J.; Khullar, D.; Parikh, P. J.; Malinowski, K. T.; Izaguirre, E. W.; Mutic, S.; Grigsby, P. W.

    2007-12-15

    A novel small animal conformal radiation therapy system has been designed and prototyped: MicroRT. The microRT system integrates multimodality imaging, radiation treatment planning, and conformal radiation therapy that utilizes a clinical {sup 192}Ir isotope high dose rate source as the radiation source (teletherapy). A multiparameter dose calculation algorithm based on Monte Carlo dose distribution simulations is used to efficiently and accurately calculate doses for treatment planning purposes. A series of precisely machined tungsten collimators mounted onto a cylindrical collimator assembly is used to provide the radiation beam portals. The current design allows a source-to-target distance range of 1-8 cm at four beam angles: 0 deg. (beam oriented down), 90 deg., 180 deg., and 270 deg. The animal is anesthetized and placed in an immobilization device with built-in fiducial markers and scanned using a computed tomography, magnetic resonance, or positron emission tomography scanner prior to irradiation. Treatment plans using up to four beam orientations are created utilizing a custom treatment planning system--microRTP. A three-axis computer-controlled stage that supports and accurately positions the animals is programmed to place the animal relative to the radiation beams according to the microRTP plan. The microRT system positioning accuracy was found to be submillimeter. The radiation source is guided through one of four catheter channels and placed in line with the tungsten collimators to deliver the conformal radiation treatment. The microRT hardware specifications, the accuracy of the treatment planning and positioning systems, and some typical procedures for radiobiological experiments that can be performed with the microRT device are presented.

  16. The influence of selected design and operating parameters on the dynamics of the steam micro-turbine

    NASA Astrophysics Data System (ADS)

    Żywica, Grzegorz; Kiciński, Jan

    2015-10-01

    The topic of the article is the analysis of the influence of selected design parameters and operating conditions on the radial steam micro-turbine, which was adapted to operate with low-boiling agent in the Organic Rankine Cycle (ORC). In the following parts of this article the results of the thermal load analysis, the residual unbalance and the stiffness of bearing supports are discussed. Advanced computational methods and numerical models have been used. Computational analysis showed that the steam micro-turbine is characterized by very good dynamic properties and is resistant to extreme operating conditions. The prototype of micro-turbine has passed a series of test calculations. It has been found that it can be subjected to experimental research in the micro combined heat and power system.

  17. Effective Nutritional Supplement Combinations

    NASA Astrophysics Data System (ADS)

    Cooke, Matt; Cribb, Paul J.

    Few supplement combinations that are marketed to athletes are supported by scientific evidence of their effectiveness. Quite often, under the rigor of scientific investigation, the patented combination fails to provide any greater benefit than a group given the active (generic) ingredient. The focus of this chapter is supplement combinations and dosing strategies that are effective at promoting an acute physiological response that may improve/enhance exercise performance or influence chronic adaptations desired from training. In recent years, there has been a particular focus on two nutritional ergogenic aids—creatine monohydrate and protein/amino acids—in combination with specific nutrients in an effort to augment or add to their already established independent ergogenic effects. These combinations and others are discussed in this chapter.

  18. Combination therapy with statins.

    PubMed

    Gylling, Helena; Miettinen, Tatu A

    2002-09-01

    Statins effectively inhibit cholesterol synthesis and are currently the most commonly used drugs for the treatment of hypercholesterolemia. However, patients with familial hypercholesterolemia and those unwilling to take, or who cannot tolerate statins, and patients with combined hyperlipidemia require a combination treatment. Statins combined with cholesterol malabsorption, caused, e.g., by plant stanol esters or ezetimibe (Schering-Plough Corp/Merck & Co Inc), or with bile acid malabsorption, caused by bile acid binding resins or guar gum, inhibit compensatory increases in cholesterol synthesis and effectively lower LDL cholesterol levels. Combination therapy of statins with fibrates should be controlled by lipidology experts. Recent information on indications and advantages of combining statins with n-3 fatty acids, hormone replacement therapy, or niacin, will also be discussed. PMID:12498007

  19. Ion Beam Sputter Fabrication of Micro-Grooving and Micro-Threading Tools

    SciTech Connect

    ADAMS,DAVID P.; VASILE,M.J.; KRISHNAN,A.S.M.

    1999-11-05

    This paper presents techniques for fabricating microscopic, nonplanar features in a variety of materials. Micro-grooving and micro-threading tools having cutting dimensions of 10-30{micro}m are made by focused ion beam sputtering and used in ultra-precision machining. Tool fabrication involves directing a 20 keV gallium beam at polished cylindrical punches made of cobalt M42 high-speed steel or C2 tungsten carbide. This creates cutting edges having radii of curvature less than 0.4 {micro}m, and rake features similar to conventional lathe tools. Clearance for minimizing frictional drag of a tool results from the sputter yield dependence on ion herd target incidence angle. Numerically controlled, ultra-precision machining with micro-grooving tools results in a close matching between tool width and feature size. Microtools controllably machine 13 {micro}m wide, 4 {micro}m deep, helical grooves in polymethyl methacrylate and 6061-T6 Al cylindrical substrates. Micro-grooving tools also fabricate sinusoidal waveform features in polished metal substrates.

  20. Micro-Grooving and Micro-Threading Tools for Fabricating Curvilinear Features

    SciTech Connect

    ADAMS,DAVID P.; VASILE,MICHAEL J.; KRISHNAN,A.S.M.

    2000-07-24

    This paper presents techniques for fabricating microscopic, curvilinear features in a variety of workpiece materials. Micro-grooving and micro-threading tools having cutting widths as small as 13 {micro}m are made by focused ion beam sputtering and used for ultra-precision machining. Tool fabrication involves directing a 20 keV gallium beam at polished cylindrical punches made of cobalt M42 high-speed steel or C2 tungsten carbide to create a number of critically aligned facets. Sputtering produces rake facets of desired angle and cutting edges having radii of curvature equal to 0.4 {micro}m. Clearance for minimizing frictional drag of a tool results from a particular ion beam/target geometry that accounts for the sputter yield dependence on incidence angle. It is believed that geometrically specific cutting tools of this dimension have not been made previously. Numerically controlled, ultra-precision machining with micro-grooving tools results in a close match between tool width and feature size. Microtools are used to machine 13 {micro}m wide, 4 {micro}m deep, helical grooves in polymethyl methacrylate and 6061 Al cylindrical workplaces. Micro-grooving tools are also used to fabricate sinusoidal cross-section features in planar metal samples.