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Sample records for dual patch clamp

  1. Automated planar patch-clamp.

    Science.gov (United States)

    Milligan, Carol J; Möller, Clemens

    2013-01-01

    Ion channels are integral membrane proteins that regulate the flow of ions across the plasma membrane and the membranes of intracellular organelles of both excitable and non-excitable cells. Ion channels are vital to a wide variety of biological processes and are prominent components of the nervous system and cardiovascular system, as well as controlling many metabolic functions. Furthermore, ion channels are known to be involved in many disease states and as such have become popular therapeutic targets. For many years now manual patch-clamping has been regarded as one of the best approaches for assaying ion channel function, through direct measurement of ion flow across these membrane proteins. Over the last decade there have been many remarkable breakthroughs in the development of technologies enabling the study of ion channels. One of these breakthroughs is the development of automated planar patch-clamp technology. Automated platforms have demonstrated the ability to generate high-quality data with high throughput capabilities, at great efficiency and reliability. Additional features such as simultaneous intracellular and extracellular perfusion of the cell membrane, current clamp operation, fast compound application, an increasing rate of parallelization, and more recently temperature control have been introduced. Furthermore, in addition to the well-established studies of over-expressed ion channel proteins in cell lines, new generations of planar patch-clamp systems have enabled successful studies of native and primary mammalian cells. This technology is becoming increasingly popular and extensively used both within areas of drug discovery as well as academic research. Many platforms have been developed including NPC-16 Patchliner(®) and SyncroPatch(®) 96 (Nanion Technologies GmbH, Munich), CytoPatch™ (Cytocentrics AG, Rostock), PatchXpress(®) 7000A, IonWorks(®) Quattro and IonWorks Barracuda™, (Molecular Devices, LLC); Dynaflow(®) HT (Cellectricon

  2. How Does Patch Clamp Work?--An easy approach to understanding patch clamp mechanism

    Institute of Scientific and Technical Information of China (English)

    关兵才; 李之望

    2003-01-01

    In order to help patch clamp users,most of whom are not good enough at electrics and electronics,to understandthe complicated principles of patch clamp technique,we present a readily accessible explanation of patch clamp mechanism,in-cluding basic analysis of membrane currents under voltage clamp,achievement of voltage clamp and current recording,capaci-tance compensation,series resistance compensation,voltage offset correction,leak subtraction and current clamp,based on ourworking and teaching experience and with the aid of some useful formulae.

  3. Studying mechanosensitive ion channels with an automated patch clamp

    NARCIS (Netherlands)

    Barthmes, Maria; Jose, Mac Donald F; Birkner, Jan Peter; Brüggemann, Andrea; Wahl-Schott, Christian; Kocer, Armagan

    2014-01-01

    Patch clamp electrophysiology is the main technique to study mechanosensitive ion channels (MSCs), however, conventional patch clamping is laborious and success and output depends on the skills of the operator. Even though automated patch systems solve these problems for other ion channels, they cou

  4. Cell-Detection Technique for Automated Patch Clamping

    Science.gov (United States)

    McDowell, Mark; Gray, Elizabeth

    2008-01-01

    A unique and customizable machinevision and image-data-processing technique has been developed for use in automated identification of cells that are optimal for patch clamping. [Patch clamping (in which patch electrodes are pressed against cell membranes) is an electrophysiological technique widely applied for the study of ion channels, and of membrane proteins that regulate the flow of ions across the membranes. Patch clamping is used in many biological research fields such as neurobiology, pharmacology, and molecular biology.] While there exist several hardware techniques for automated patch clamping of cells, very few of those techniques incorporate machine vision for locating cells that are ideal subjects for patch clamping. In contrast, the present technique is embodied in a machine-vision algorithm that, in practical application, enables the user to identify good and bad cells for patch clamping in an image captured by a charge-coupled-device (CCD) camera attached to a microscope, within a processing time of one second. Hence, the present technique can save time, thereby increasing efficiency and reducing cost. The present technique involves the utilization of cell-feature metrics to accurately make decisions on the degree to which individual cells are "good" or "bad" candidates for patch clamping. These metrics include position coordinates (x,y) in the image plane, major-axis length, minor-axis length, area, elongation, roundness, smoothness, angle of orientation, and degree of inclusion in the field of view. The present technique does not require any special hardware beyond commercially available, off-the-shelf patch-clamping hardware: A standard patchclamping microscope system with an attached CCD camera, a personal computer with an imagedata- processing board, and some experience in utilizing imagedata- processing software are all that are needed. A cell image is first captured by the microscope CCD camera and image-data-processing board, then the image

  5. Advanced patch-clamp techniques and single-channel analysis

    NARCIS (Netherlands)

    Biskup, B; Elzenga, JTM; Homann, U; Thiel, G; Wissing, F; Maathuis, FJM

    1999-01-01

    Much of our knowledge of ion-transport mechanisms in plant cell membranes comes from experiments using voltage-clamp. This technique allows the measurement of ionic currents across the membrane, whilst the voltage is held under experimental control. The patch-clamp technique was developed to study t

  6. Planar patch-clamp force microscopy on living cells

    Energy Technology Data Exchange (ETDEWEB)

    Pamir, Evren [Center for Nano Science, Ludwig-Maximilians University, Amalienstr 54, 80799 Munich (Germany); George, Michael; Fertig, Niels [Nanion Technologies GmbH, Erzgiessereistr. 4, 80335 Munich (Germany); Benoit, Martin [Center for Nano Science, Ludwig-Maximilians University, Amalienstr 54, 80799 Munich (Germany)], E-mail: martin.benoit@physik.uni-muenchen.de

    2008-05-15

    Here we report a new combination of the patch-clamp technique with the atomic force microscope (AFM). A planar patch-clamp chip microstructured from borosilicate glass was used as a support for mechanical probing of living cells. The setup not only allows for immobilizing even a non-adherent cell for measurements of its mechanical properties, but also for simultaneously measuring the electrophysiological properties of a single cell. As a proof of principle experiment we measured the voltage-induced membrane movement of HEK293 and Jurkat cells in the whole-cell voltage clamp configuration. The results of these measurements are in good agreement with previous studies. By using the planar patch-clamp chip for immobilization, the AFM not only can image non-adhering cells, but also gets easily access to an electrophysiologically controlled cellular probe at low vibrational noise.

  7. Gigaseal formation in patch clamping with applications of nanotechnology

    CERN Document Server

    Malboubi, Majid

    2014-01-01

    This book presents an investigation of gigaseal formation using micro/nanotechnology. The aims of the book are twofold. First, it explains the mechanisms of gigaseal formation using the latest discoveries. Second, it provides practical techniques for frequent formation of high resistance seals. The formation of a high-resistance electrical seal, also known as a gigaseal, between a cell membrane and a glass micropipette tip is essential in patch-clamp experiments. Even though four decades have passed since the introduction of the patch-clamping technique by Neher and Sakmann, gigaseal formation remains an obstacle in developing the high-throughput ion channel screening systems required by the pharmaceutical industry. Here the authors share their latest methods for achieving gigaseal formation and describe techniques that are highly desirable at both research and industrial levels. Nanotechnology has been found to be a powerful tool for studying and modifying glass micropipettes and in tackling the problem of g...

  8. Cleaning patch-clamp pipettes for immediate reuse

    Science.gov (United States)

    Kolb, I.; Stoy, W. A.; Rousseau, E. B.; Moody, O. A.; Jenkins, A.; Forest, C. R.

    2016-01-01

    Patch-clamp recording has enabled single-cell electrical, morphological and genetic studies at unparalleled resolution. Yet it remains a laborious and low-throughput technique, making it largely impractical for large-scale measurements such as cell type and connectivity characterization of neurons in the brain. Specifically, the technique is critically limited by the ubiquitous practice of manually replacing patch-clamp pipettes after each recording. To circumvent this limitation, we developed a simple, fast, and automated method for cleaning glass pipette electrodes that enables their reuse within one minute. By immersing pipette tips into Alconox, a commercially-available detergent, followed by rinsing, we were able to reuse pipettes 10 times with no degradation in signal fidelity, in experimental preparations ranging from human embryonic kidney cells to neurons in culture, slices, and in vivo. Undetectable trace amounts of Alconox remaining in the pipette after cleaning did not affect ion channel pharmacology. We demonstrate the utility of pipette cleaning by developing the first robot to perform sequential patch-clamp recordings in cell culture and in vivo without a human operator. PMID:27725751

  9. Patch-clamp detection of macromolecular translocation along nuclear pores

    Directory of Open Access Journals (Sweden)

    Bustamante J.O.

    1998-01-01

    Full Text Available The present paper reviews the application of patch-clamp principles to the detection and measurement of macromolecular translocation along the nuclear pores. We demonstrate that the tight-seal 'gigaseal' between the pipette tip and the nuclear membrane is possible in the presence of fully operational nuclear pores. We show that the ability to form a gigaseal in nucleus-attached configurations does not mean that only the activity of channels from the outer membrane of the nuclear envelope can be detected. Instead, we show that, in the presence of fully operational nuclear pores, it is likely that the large-conductance ion channel activity recorded derives from the nuclear pores. We conclude the technical section with the suggestion that the best way to demonstrate that the nuclear pores are responsible for ion channel activity is by showing with fluorescence microscopy the nuclear translocation of ions and small molecules and the exclusion of the same from the cisterna enclosed by the two membranes of the envelope. Since transcription factors and mRNAs, two major groups of nuclear macromolecules, use nuclear pores to enter and exit the nucleus and play essential roles in the control of gene activity and expression, this review should be useful to cell and molecular biologists interested in understanding how patch-clamp can be used to quantitate the translocation of such macromolecules into and out of the nucleus

  10. Simultaneous patch-clamping and calcium imaging in developing dendrites.

    Science.gov (United States)

    Kleindienst, Thomas; Lohmann, Christian

    2014-03-01

    Calcium imaging has been used extensively to explore the role of action potential (AP) firing in the development of neuronal structure and synaptic function because increases in intracellular calcium ([Ca(2+)]i) reliably and, within a certain range, linearly reflect neuronal spiking activity. Patterns of APs in individual cells can be deduced from calcium recordings, which have typically been performed at the level of cell bodies. However, neurons are particularly susceptible to phototoxicity when they are illuminated at the soma. Furthermore, for some imaging experiments (e.g., those that address the interactions between dendrites and axons during synapse formation), the cell body of a given neuron may simply not be in the field of view. In these situations, it would be helpful to determine the spiking patterns of a neuron from the calcium activity in its subcellular compartments such as stretches of dendrites or axons. Here, we describe an approach for determining the relationship between AP firing and dendritic calcium transients by simultaneously imaging calcium transients in small dendritic stretches of hippocampal pyramidal neurons in slice cultures from neonatal rats and recording spiking activity with whole-cell patch-clamp recordings in these neurons. These experiments allow us to correlate the electrophysiological spiking pattern with the accompanying changes in the calcium concentration in individual dendritic segments.

  11. Characterization of potassium channel modulators with QPatch automated patch-clamp technology: system characteristics and performance

    DEFF Research Database (Denmark)

    Kutchinsky, Jonatan; Friis, Søren; Asmild, Margit

    2003-01-01

    Planar silicon chips with 1-2-microm etched holes (average resistance: 2.04 +/- 0.02 MOmega in physiological buffer, n = 274) have been developed for patch-clamp recordings of whole-cell currents from cells in suspension. An automated 16-channel parallel screening system, QPatch 16, has been...... developed using this technology. A single-channel prototype of the QPatch system was used for validation of the patch-clamp chip technology. We present here data on the quality of patch-clamp recordings and from actual drug screening studies of human potassium channels expressed in cultured cell lines...

  12. Patch Clamp: A Powerful Technique for Studying the Mechanism of Acupuncture

    Directory of Open Access Journals (Sweden)

    D. Zhang

    2012-01-01

    Full Text Available Cellular and molecular events can be investigated using electrophysiological techniques. In particular, the patch-clamp method provides detailed information. In addition, the patch-clamp technique has become a powerful method for investigating the mechanisms underlying the effects of acupuncture. In this paper, recent researches on how acupuncture might modulate electrophysiological responses in the central nervous system (CNS and affect peripheral structures are reviewed.

  13. In vivo patch clamp recording technique in the study of neurophysiology

    Institute of Scientific and Technical Information of China (English)

    Lan-Wei CUI; Yu-Rong LI

    2006-01-01

    The patch clamp recording technique in vivois a blind patch clamp recording methods to record the current of the spinal or cereral neurons of anaesthesia ( or awake) animals. This technique can be used to study the synaptic function and plasticity in central nervous system in vivoin order to understand the physiological properties of the ion channels from an integrated point of view. The advantage of this technique have already presented itself in the study of the synaptic transmission and nervous network. Nowadays, in vivo patch whole-cell recording technique in combination with other techniques is becoming a common method in the research fields.

  14. Development of planar patch clamp technology and its application in the analysis of cellular electrophysiology

    Institute of Scientific and Technical Information of China (English)

    Peihua Chen; Wei Zhang; Jun Zhou; Ping Wang; Lidan Xiao; Mo Yang

    2009-01-01

    A patch clamp chip, as a novel cell-based chip for electrophysiological recordings, has many prominent advantages such as high res-olution, accuracy, high throughput and automation. It can be used to perform multivariate and real-time measurements of cell networks in situ. Therefore, this technology will dramatically promote the research on ionic channels, neuronal networks and the application of this technology in drug screening. This paper reviews the development of planar patch clamp technology and its applications in detail. The latest progress in the research of taste cells electrophysiology and taste transduction is also presented. Finally, this paper analyzes the methodology of neural chips. Based on the current research of our laboratory, the prospective applications of a patch clamp chip in the research of taste sensation and transduction mechanisms at molecular and cellular levels are discussed.

  15. Can robots patch-clamp as well as humans? Characterization of a novel sodium channel mutation.

    Science.gov (United States)

    Estacion, M; Choi, J S; Eastman, E M; Lin, Z; Li, Y; Tyrrell, L; Yang, Y; Dib-Hajj, S D; Waxman, S G

    2010-06-01

    Ion channel missense mutations cause disorders of excitability by changing channel biophysical properties. As an increasing number of new naturally occurring mutations have been identified, and the number of other mutations produced by molecular approaches such as in situ mutagenesis has increased, the need for functional analysis by patch-clamp has become rate limiting. Here we compare a patch-clamp robot using planar-chip technology with human patch-clamp in a functional assessment of a previously undescribed Nav1.7 sodium channel mutation, S211P, which causes erythromelalgia. This robotic patch-clamp device can increase throughput (the number of cells analysed per day) by 3- to 10-fold. Both modes of analysis show that the mutation hyperpolarizes activation voltage dependence (8 mV by manual profiling, 11 mV by robotic profiling), alters steady-state fast inactivation so that it requires an additional Boltzmann function for a second fraction of total current (approximately 20% manual, approximately 40% robotic), and enhances slow inactivation (hyperpolarizing shift--15 mV by human,--13 mV robotic). Manual patch-clamping demonstrated slower deactivation and enhanced (approximately 2-fold) ramp response for the mutant channel while robotic recording did not, possibly due to increased temperature and reduced signal-to-noise ratio on the robotic platform. If robotic profiling is used to screen ion channel mutations, we recommend that each measurement or protocol be validated by initial comparison to manual recording. With this caveat, we suggest that, if results are interpreted cautiously, robotic patch-clamp can be used with supervision and subsequent confirmation from human physiologists to facilitate the initial profiling of a variety of electrophysiological parameters of ion channel mutations.

  16. Design and fabrication of a planar patch-clamp substrate using a silicon-on-insulator wafer

    Science.gov (United States)

    Zhenlong, Zhang; Xiangyang, Liu; Yanli, Mao

    2009-09-01

    The planar patch-clamp technique has been applied to high throughput screening in drug discovery. The key feature of this technique is the fabrication of a planar patch-clamp substrate using appropriate materials. In this study, a planar patch-clamp substrate was designed and fabricated using a silicon-on-insulator (SOI) wafer. The access resistance and capacitance of SOI-based planar patch-clamp substrates are smaller than those of bulk silicon-based planar substrates, which will reduce the distributed RC noise.

  17. Functional dissection of synaptic circuits: in vivo patch-clamp recording in neuroscience

    Directory of Open Access Journals (Sweden)

    Can eTao

    2015-05-01

    Full Text Available Neuronal activity is dominated by synaptic inputs from excitatory or inhibitory neural circuits. With the development of in vivo patch-clamp recording, especially in vivo voltage-clamp recording, researchers can not only directly measure neuronal activity, such as spiking responses or membrane potential dynamics, but also quantify synaptic inputs from excitatory and inhibitory circuits in living animals. This approach enables researchers to directly unravel different synaptic components and to understand their underlying roles in particular brain functions. Combining in vivo patch-clamp recording with other techniques, such as two-photon imaging or optogenetics, can provide even clearer functional dissection of the synaptic contributions of different neurons or nuclei. Here, we summarized current applications and recent research progress using the in vivo patch-clamp recording method and focused on its role in the functional dissection of different synaptic inputs. The key factors of a successful in vivo patch-clamp experiment and possible solutions based on references and our experiences were also discussed.

  18. Correlation of open cell-attached and excised patch clamp techniques.

    Science.gov (United States)

    Filipovic, D; Hayslett, J P

    1995-11-01

    The excised patch clamp configuration provides a unique technique for some types of single channel analyses, but maintenance of stable, long-lasting preparations may be confounded by rundown and/or rapid loss of seal. Studies were performed on the amiloride-sensitive Na+ channel, located on the apical surface of A6 cells, to determine whether the nystatin-induced open cell-attached patch could serve as an alternative configuration. Compared to excised inside-out patches, stable preparations were achieved more readily with the open cell-attached patch (9% vs. 56% of attempts). In both preparations, the current voltage (I-V) relation was linear, current amplitudes were equal at opposite equivalent clamped voltages, and Erev was zero in symmetrical Na+ solutions, indicating similar Na+ activities on the cytosolic and external surfaces of the patch. Moreover, there was no evidence that nystatin altered channel activity in the patch because slope conductance (3-4pS) and Erev (75 mV), when the bath was perfused with a high K:low Na solution (ENa = 80 mV), were nearly equal in both patch configurations. Our results therefore indicate that the nystatin-induced open cell-attached patch can serve as an alternative approach to the excised inside-out patch when experiments require modulation of univalent ions in the cytosol.

  19. MATLAB-based automated patch-clamp system for awake behaving mice

    OpenAIRE

    Desai, Niraj S.; Siegel, Jennifer J.; Taylor, William; Chitwood, Raymond A.; Johnston, Daniel

    2015-01-01

    Automation has been an important part of biomedical research for decades, and the use of automated and robotic systems is now standard for such tasks as DNA sequencing, microfluidics, and high-throughput screening. Recently, Kodandaramaiah and colleagues (Nat Methods 9: 585–587, 2012) demonstrated, using anesthetized animals, the feasibility of automating blind patch-clamp recordings in vivo. Blind patch is a good target for automation because it is a complex yet highly stereotyped process th...

  20. Construction, Calibration, and Validation of a Simple Patch-Clamp Amplifier for Physiology Education

    Science.gov (United States)

    Rouzrokh, Ali; Ebrahimi, Soltan Ahmed; Mahmoudian, Massoud

    2009-01-01

    A modular patch-clamp amplifier was constructed based on the Strickholm design, which was initially published in 1995. Various parts of the amplifier such as the power supply, input circuit, headstage, feedback circuit, output and nulling circuits were redesigned to use recent software advances and fabricated using the common lithographic printed…

  1. Characterization of a patch-clamp microchannel array towards neuronal networks analysis

    DEFF Research Database (Denmark)

    Alberti, Massimo; Snakenborg, Detlef; Lopacinska, Joanna M.

    2010-01-01

    for simultaneous patch clamping of cultured cells or neurons in the same network. A disposable silicon/silicon dioxide (Si/SiO2) chip with a microhole array was integrated in a microfluidic system for cell handling, perfusion and electrical recording. Fluidic characterization showed that our PC mu CA can work...

  2. A New Preparation of Pancreatic Ducts for Patch-Clamp Studies

    DEFF Research Database (Denmark)

    Novak, Ivana; Hug, M.J.

    1995-01-01

    parameters, monitored with the whole-cell patch-clamp method, and those in isolated perfused ducts, monitored with the conventional microelectrodes [Novak I, Greger R: Pflügers Arch 1988;411:58-68, 546-553], are comparable. Similar conclusion can be made about the calcium measurements [Hug M, et al: Pflügers...

  3. Evaluation of diel patterns of relative changes in cell turgor of tomato plants using leaf patch clamp pressure probes

    NARCIS (Netherlands)

    Lee, K.M.; Driever, S.M.; Heuvelink, E.; Rüger, S.; Zimmermann, U.; Gelder, de A.; Marcelis, L.F.M.

    2012-01-01

    Relative changes in cell turgor of leaves of well-watered tomato plants were evaluated using the leaf patch clamp pressure probe (LPCP) under dynamic greenhouse climate conditions. Leaf patch clamp pressure changes, a measure for relative changes in cell turgor, were monitored at three different hei

  4. Achieving Maximal Speed of Solution Exchange for Patch Clamp Experiments

    Science.gov (United States)

    Auzmendi, Jerónimo; Fernández Do Porto, Darío; Pallavicini, Carla; Moffatt, Luciano

    2012-01-01

    Background Resolving the kinetics of agonist binding events separately from the subsequent channel gating processes requires the ability of applying and removing the agonist before channel gating occurs. No reported system has yet achieved pulses shorter than 100 µs, necessary to study nicotinic ACh receptor or AMPA receptor activation. Methodology/Principal Findings Solution exchange systems deliver short agonist pulses by moving a sharp interface between a control and an experimental solution across a channel preparation. We achieved shorter pulses by means of an exchange system that combines a faster flow velocity, narrower partition between the two streams, and increased velocity and bandwidth of the movement of the interface. The measured response of the entire system was fed back to optimize the voltage signal applied to the piezoelectric actuator overcoming the spurious oscillations arising from the mechanical resonances when a high bandwidth driving function was applied. Optimization was accomplished by analyzing the transfer function of the solution exchange system. When driven by optimized command pulses the enhanced system provided pulses lasting 26 ± 1 µs and exchanging 93 ± 1% of the solution, as measured in the open tip of a patch pipette. Conclusions/Significance Pulses of this duration open the experimental study of the molecular events that occur between the agonist binding and the opening of the channel. PMID:22879927

  5. Study of transmembrane La3+ movement in rat ventricular myocytes by the patch-clamp technique

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    We have studied transmembrane La3+ movement in rat ventricular myocytes for the first time by using the whole-cell patch-clamp recording mode. La3+ (0.01-5.0 mmol/L) could not bring out inward currents through the L-type calcium channel in rat ventricular myocytes, while it could enter the cells by the same way carried by 1μmol/L ionomycin. When the outward Na+ concentration gradient is formed, La3+ can enter the cells via Na-Ca exchange, and the exchange currentsincrease with the increase of external La3+ concentrations. But compared with Na-Ca exchange currents in the same concentration, the former is only 14%-38% of the latter. The patch-clamp experiment indicates that La3+ normally can not enter ventricular myocytes through L-type calcium channel, but it can enter the cells via Na-Ca exchange.

  6. Designing a Signal Conditioning System with Software Calibration for Resistor-feedback Patch Clamp Amplifier.

    Science.gov (United States)

    Hu, Gang; Zhu, Quanhui; Qu, Anlian

    2005-01-01

    In this paper, a programmable signal conditioning system based on software calibration for resistor-feedback patch clamp amplifier (PCA) has been described, this system is mainly composed of frequency correction, programmable gain and filter whose parameters are configured by software automatically to minimize the errors, A lab-designed data acquisition system (DAQ) is used to implement data collections and communications with PC. The laboratory test results show good agreement with design specifications.

  7. Desktop Software for Patch-Clamp Raw Binary Data Conversion and Preprocessing

    Directory of Open Access Journals (Sweden)

    Ning Zhang

    2011-01-01

    Full Text Available Since raw data recorded by patch-clamp systems are always stored in binary format, electrophysiologists may experience difficulties with patch clamp data preprocessing especially when they want to analyze by custom-designed algorithms. In this study, we present desktop software, called PCDReader, which could be an effective and convenient solution for patch clamp data preprocessing for daily laboratory use. We designed a novel class module, called clsPulseData, to directly read the raw data along with the parameters recorded from HEKA instruments without any other program support. By a graphical user interface, raw binary data files can be converted into several kinds of ASCII text files for further analysis, with several preprocessing options. And the parameters can also be viewed, modified and exported into ASCII files by a user-friendly Explorer style window. The real-time data loading technique and optimized memory management programming makes PCDReader a fast and efficient tool. The compiled software along with the source code of the clsPulseData class module is freely available to academic and nonprofit users.

  8. Low noise patch-clamp current amplification by nanoparticles plasmonic-photonic coupling (analysis and modelling).

    Science.gov (United States)

    Haberal, E O; SalmanOgli, A; Nasseri, B

    2016-10-01

    In this article, a patch-clamp low noise current amplification based on nanoparticles plasmonic radiation is analyzed. It is well-known, a very small current is flowing from different membrane channels and so, for extra processing the current amplification is necessary. It is notable that there are some problems in traditional electronic amplifier due to its noise and bandwidth problem. Because of the important role of the patch-clamp current in cancer research and especially its small amplitude, it is vital to intensify it without adding any noises. In this study, the current amplification is performed firstly: from the excitement of nanoparticles by the patch-clamp pico-ampere current and then, the effect of nanoparticles plasmonic far-field radiation on conductor's carriers, which will cause the current amplification. This relates to the plasmonic-photonic coupling and their effect on conductor carriers as the current perturbation agent. In the steady state, the current amplification can reach to 1000 times of initial level. Furthermore, we investigated the nanoparticles morphology changing effect such as size, nanoparticles inter-distance, and nanoparticles distance from the conductor on the amplifier parameters. Finally, it should note that the original aim is to use nanoparticles plasmonic engineering and their coupling to photonics for output current manipulating.

  9. Characterization of potassium channel modulators with QPatch automated patch-clamp technology: system characteristics and performance.

    Science.gov (United States)

    Kutchinsky, Jonatan; Friis, Søren; Asmild, Margit; Taboryski, Rafael; Pedersen, Simon; Vestergaard, Ras K; Jacobsen, Rasmus B; Krzywkowski, Karen; Schrøder, Rikke L; Ljungstrøm, Trine; Hélix, Nathalie; Sørensen, Claus B; Bech, Morten; Willumsen, Niels J

    2003-10-01

    Planar silicon chips with 1-2-microm etched holes (average resistance: 2.04 +/- 0.02 MOmega in physiological buffer, n = 274) have been developed for patch-clamp recordings of whole-cell currents from cells in suspension. An automated 16-channel parallel screening system, QPatch 16, has been developed using this technology. A single-channel prototype of the QPatch system was used for validation of the patch-clamp chip technology. We present here data on the quality of patch-clamp recordings and from actual drug screening studies of human potassium channels expressed in cultured cell lines. Using Chinese hamster ovary (CHO) and human embryonic kidney cells (HEK), gigaseals of 4.1 +/- 0.4 GOmega (n = 146) and high-quality whole-cell current recordings were obtained from hERG and KCNQ4 potassium channels. Success rates for gigaseal recordings varied from 40 to 95%, and 67% of the whole-cell configurations lasted for >20 min. Cells were maintained in suspension up to 4 h in a cell storage facility that is integrated in the QPatch 16. No decline in patchability was observed during this time course. A series of screens was conducted with known inhibitors of the hERG and KCNQ4 potassium channels. Dose-response relationship characterizations of verapamil and rBeKm-1 blockage of hERG currents provided IC(50) values similar to values reported in the literature.

  10. MATLAB-based automated patch-clamp system for awake behaving mice.

    Science.gov (United States)

    Desai, Niraj S; Siegel, Jennifer J; Taylor, William; Chitwood, Raymond A; Johnston, Daniel

    2015-08-01

    Automation has been an important part of biomedical research for decades, and the use of automated and robotic systems is now standard for such tasks as DNA sequencing, microfluidics, and high-throughput screening. Recently, Kodandaramaiah and colleagues (Nat Methods 9: 585-587, 2012) demonstrated, using anesthetized animals, the feasibility of automating blind patch-clamp recordings in vivo. Blind patch is a good target for automation because it is a complex yet highly stereotyped process that revolves around analysis of a single signal (electrode impedance) and movement along a single axis. Here, we introduce an automated system for blind patch-clamp recordings from awake, head-fixed mice running on a wheel. In its design, we were guided by 3 requirements: easy-to-use and easy-to-modify software; seamless integration of behavioral equipment; and efficient use of time. The resulting system employs equipment that is standard for patch recording rigs, moderately priced, or simple to make. It is written entirely in MATLAB, a programming environment that has an enormous user base in the neuroscience community and many available resources for analysis and instrument control. Using this system, we obtained 19 whole cell patch recordings from neurons in the prefrontal cortex of awake mice, aged 8-9 wk. Successful recordings had series resistances that averaged 52 ± 4 MΩ and required 5.7 ± 0.6 attempts to obtain. These numbers are comparable with those of experienced electrophysiologists working manually, and this system, written in a simple and familiar language, will be useful to many cellular electrophysiologists who wish to study awake behaving mice.

  11. Visual patch clamp recording of neurons in thick portions of the adult spinal cord

    DEFF Research Database (Denmark)

    Munch, Anders Sonne; Smith, Morten; Moldovan, Mihai

    2010-01-01

    The study of visually identified neurons in slice preparations from the central nervous system offers considerable advantages over in vivo preparations including high mechanical stability in the absence of anaesthesia and full control of the extracellular medium. However, because of their relative...... enlargement of the spinal cord. With a conventional upright microscope in which the light condenser was carefully adjusted, we could visualize neurons present at the surface of the slice and record them with the whole-cell patch clamp technique. We show that neurons present in the middle of the preparation...

  12. Effect of La3+ on myocardiac potassium channels revealed by patch-clamp technique

    Institute of Scientific and Technical Information of China (English)

    XUE Shaowu; YANG Pin

    2005-01-01

    The effect of La3+ on potassium channels in rat ventricular myocytes was investigated using the whole-cell patch-clamp recording mode. The Ca2+-independent voltage- activated outward K+ current was activated by the depolarizing pulse in enzymatically isolated rat ventricular myocytes. After addition of different concentrations La3+ to the bath solution, the outward K+ current was depressed gradually. The inhibition effect was in a concentration-dependent manner. The phenomena of the outward K+ current, being the main repolarizing current suppressed by La3+, suggest that the effect of lanthanides on myocardial function should be exploited further.

  13. Visually guided whole cell patch clamp of mouse supraoptic nucleus neurons in cultured and acute conditions.

    Science.gov (United States)

    Stachniak, Tevye J E; Bourque, Charles W

    2006-07-01

    Recent advances in neuronal culturing techniques have supplied a new set of tools for studying neural tissue, providing effective means to study molecular aspects of regulatory elements in the supraoptic nucleus of the hypothalamus (SON). To combine molecular biology techniques with electrophysiological recording, we modified an organotypic culture protocol to permit transfection and whole cell patch-clamp recordings from SON cells. Neonatal mouse brain coronal sections containing the SON were dissected out, placed on a filter insert in culture medium, and incubated for at least 4 days to allow attachment to the insert. The SON was identifiable using gross anatomical landmarks, which remained intact throughout the culturing period. Immunohistochemical staining identified both vasopressinergic and oxytocinergic cells present in the cultures, typically appearing in well-defined clusters. Whole cell recordings from these cultures demonstrated that certain properties of the neonatal mouse SON were comparable to adult mouse magnocellular neurons. SON neurons in both neonatal cultures and acute adult slices showed similar sustained outward rectification above -60 mV and action potential broadening during evoked activity. Membrane potential, input resistance, and rapidly inactivating potassium current density (IA) were reduced in the cultures, whereas whole cell capacitance and spontaneous synaptic excitation were increased, perhaps reflecting developmental changes in cell physiology that warrant further study. The use of the outlined organotypic culturing procedures will allow the study of such electrophysiological properties of mouse SON using whole cell patch-clamp, in addition to various molecular, techniques that require longer incubation times.

  14. Ion channels as medicinal targets of biological toxins: the impact of automated patch-clamp electrophysiology.

    Science.gov (United States)

    Picones, Arturo

    2015-01-01

    Patch-Clamp electrophysiology, the "gold standard" for the functional study of ion channels has become automated. This innovative technology, already over a decade old, has revolutionized the strategies for the search of medicinal compounds which now can be screened at unprecedented speed, approaching the high throughput standards required by primary screening campaigns emblematic of the pharmaceutical and biotechnology industries. Consequently, an acceleration of the discovery and development of new drugs targeting ion channels is expected. These pore forming membrane proteins had been relegated as crucial therapeutic drug targets due to the difficulty of their experimental analysis. This new technological approach has begun to impact the finding of new toxins which are conspicuously relevant as medicinal agents given their extraordinary potency and specificity when acting upon ion channels. The introduction of automated patch-clamp instrumentation to academic labs and institutions pursuing the finding of new pharmacological agents, peptide toxins in particular, will certainly enrich these scientific and technological fields by contributing with their always prolific generosity of originality and innovation.

  15. Automatic Calibration of Frequency Compensation System in Computer-Controlled Patch-Clamp Amplifier

    Directory of Open Access Journals (Sweden)

    Jun Xion

    2007-01-01

    Full Text Available Computer-controlled patch-clamp amplifier is a digitally controlled analog device used to record the cellular ion channel currents in electrophysiology research. The inherent bandwidth and performance of the headstage is limited by the stray capacitance and distributed capacitance across the feedback resistors. In order to effectively improve the performance of the headstage, the paper advanced a simplified automatic calibration method of frequency compensation system in resistor-feedback patch-clamp amplifier. The dynamic model of headstage was approximate as a two poles and one zero system in the transfer function by experience and test results, so the dynamic characteristics of the headstage were obtained employing least squares parameter estimation algorithm. Further more, the compensation parameter of high frequency booster can be estimated by the time constant of main pole of headstage. And automatic adjustment of the parameters in transient response correction stage was performed as a least squares fitting problem. The software routine running on the host computer conducted all operations of frequency compensation. Experimental results demonstrate that the simplified automatic calibration method can substantially extend the bandwidth and minimize step response error of headstage.

  16. Characterization of ryanodine receptor type 1 single channel activity using "on-nucleus" patch clamp.

    Science.gov (United States)

    Wagner, Larry E; Groom, Linda A; Dirksen, Robert T; Yule, David I

    2014-08-01

    In this study, we provide the first description of the biophysical and pharmacological properties of ryanodine receptor type 1 (RyR1) expressed in a native membrane using the on-nucleus configuration of the patch clamp technique. A stable cell line expressing rabbit RyR1 was established (HEK-RyR1) using the FLP-in 293 cell system. In contrast to untransfected cells, RyR1 expression was readily demonstrated by immunoblotting and immunocytochemistry in HEK-RyR1 cells. In addition, the RyR1 agonists 4-CMC and caffeine activated Ca(2+) release that was inhibited by high concentrations of ryanodine. On nucleus patch clamp was performed in nuclei prepared from HEK-RyR1 cells. Raising the [Ca(2+)] in the patch pipette resulted in the appearance of a large conductance cation channel with well resolved kinetics and the absence of prominent subconductance states. Current versus voltage relationships were ohmic and revealed a chord conductance of ∼750pS or 450pS in symmetrical 250mM KCl or CsCl, respectively. The channel activity was markedly enhanced by caffeine and exposure to ryanodine resulted in the appearance of a subconductance state with a conductance ∼40% of the full channel opening with a Po near unity. In total, these properties are entirely consistent with RyR1 channel activity. Exposure of RyR1 channels to cyclic ADP ribose (cADPr), nicotinic acid adenine dinucleotide phosphate (NAADP) or dantrolene did not alter the single channel activity stimulated by Ca(2+), and thus, it is unlikely these molecules directly modulate RyR1 channel activity. In summary, we describe an experimental platform to monitor the single channel properties of RyR channels. We envision that this system will be influential in characterizing disease-associated RyR mutations and the molecular determinants of RyR channel modulation.

  17. Automated multi-slice extracellular and patch-clamp experiments using the WinLTP data acquisition system with automated perfusion control

    Science.gov (United States)

    Anderson, William W.; Fitzjohn, Stephen M.; Collingridge, Graham L.

    2012-01-01

    WinLTP is a data acquisition program for studying long-term potentiation (LTP) and other aspects of synaptic function. Earlier versions of WinLTP (J. Neurosci. Methods, 162:346–356, 2007) provided automated electrical stimulation and data acquisition capable of running nearly an entire synaptic plasticity experiment, with the primary exception that perfusion solutions had to be changed manually. This automated stimulation and acquisition was done by using ‘Sweep’, ‘Loop’ and ‘Delay’ events to build scripts using the ‘Protocol Builder’. However, this did not allow automatic changing of many solutions while running multiple slice experiments, or solution changing when this had to be performed rapidly and with accurate timing during patch-clamp experiments. We report here the addition of automated perfusion control to WinLTP. First, perfusion change between sweeps is enabled by adding the ‘Perfuse’ event to Protocol Builder scripting and is used in slice experiments. Second, fast perfusion changes during as well as between sweeps is enabled by using the Perfuse event in the protocol scripts to control changes between sweeps, and also by changing digital or analog output during a sweep and is used for single cell single-line perfusion patch-clamp experiments. The addition of stepper control of tube placement allows dual- or triple-line perfusion patch-clamp experiments for up to 48 solutions. The ability to automate perfusion changes and fully integrate them with the already automated stimulation and data acquisition goes a long way toward complete automation of multi-slice extracellularly recorded and single cell patch-clamp experiments. PMID:22524994

  18. Fabrication of Si-based planar type patch clamp biosensor using silicon on insulator substrate

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Z.L.; Asano, T. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Uno, H. [Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Tero, R. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Suzui, M.; Nakao, S. [Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan); Kaito, T. [SII NanoTechnology Inc., 36-1, Takenoshita, Oyama-cho, Sunto-gun, Shizuoka, 410-1393 (Japan); Shibasaki, K.; Tominaga, M. [Okazaki Institute for Integrative Bioscience, 5-1, Higashiyama, Myodaiji, Okazaki, 444-8787 (Japan); Utsumi, Y. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2, Koto, Kamigori, Ako-gun, Hyogo, 678-1205 (Japan); Gao, Y.L. [Department of Physics and Astronomy, Rochester University, Rochester, New York 14627 (United States); Urisu, T. [Graduate University for Advanced Studies, Myodaiji, Okazaki, 444-8585 (Japan); Institute for Molecular Science, Myodaiji, Okazaki, 444-8585 (Japan)], E-mail: urisu@ims.ac.jp

    2008-03-03

    The aim of this paper is to fabricate the planar type patch clamp ion-channel biosensor, which is suitable for the high throughput screening, using silicon-on-insulator (SOI) substrate. The micropore with 1.2 {mu}m diameter is formed through the top Si layer and the SiO{sub 2} box layer of the SOI substrate by focused ion beam (FIB). Then the substrate is assembled into the microfluidic circuit. The human embryonic kidney 293 (HEK-293) cell transfected with transient receptor potential vanilloid type 1 (TRPV1) is positioned on the micropore and the whole-cell configuration is formed by the suction. Capsaicin is added to the extracellular solution as a ligand molecule, and the channel current showing the desensitization unique to TRPV1 is measured successfully.

  19. An integrated, low noise patch-clamp amplifier for biological nanopore applications.

    Science.gov (United States)

    Wang, Gang; Dunbar, William B

    2010-01-01

    We present an integrated, low noise patch-clamp amplifier for biological nanopore applications. Our amplifier consists of an integrator-differentiator architecture coupled with a novel opamp design in the CMOS 0.35 µm process. The post-layout full-chip simulation shows the input referred noise of the amplifier is 0.49 pA RMS over a 5 kHz bandwidth using a verified electrical model for the biological nanopore system. In our biological nanopore experiments studying protein-DNA interactions, we encounter capacitive transients with a nominal settling time of 5 ms. Our amplifier design reduces the settling time to 0.2 ms, without requiring any compensation circuitry.

  20. Screening system for drug-induced arrhythmogenic risk combining a patch clamp and heart simulator

    Science.gov (United States)

    Okada, Jun-ichi; Yoshinaga, Takashi; Kurokawa, Junko; Washio, Takumi; Furukawa, Tetsushi; Sawada, Kohei; Sugiura, Seiryo; Hisada, Toshiaki

    2015-01-01

    To save time and cost for drug discovery, a paradigm shift in cardiotoxicity testing is required. We introduce a novel screening system for drug-induced arrhythmogenic risk that combines in vitro pharmacological assays and a multiscale heart simulator. For 12 drugs reported to have varying cardiotoxicity risks, dose-inhibition curves were determined for six ion channels using automated patch clamp systems. By manipulating the channel models implemented in a heart simulator consisting of more than 20 million myocyte models, we simulated a standard electrocardiogram (ECG) under various doses of drugs. When the drug concentrations were increased from therapeutic levels, each drug induced a concentration-dependent characteristic type of ventricular arrhythmia, whereas no arrhythmias were observed at any dose with drugs known to be safe. We have shown that our system combining in vitro and in silico technologies can predict drug-induced arrhythmogenic risk reliably and efficiently. PMID:26601174

  1. Simultaneous multi-patch-clamp and extracellular-array recordings: Single neuron reflects network activity

    Science.gov (United States)

    Vardi, Roni; Goldental, Amir; Sardi, Shira; Sheinin, Anton; Kanter, Ido

    2016-11-01

    The increasing number of recording electrodes enhances the capability of capturing the network’s cooperative activity, however, using too many monitors might alter the properties of the measured neural network and induce noise. Using a technique that merges simultaneous multi-patch-clamp and multi-electrode array recordings of neural networks in-vitro, we show that the membrane potential of a single neuron is a reliable and super-sensitive probe for monitoring such cooperative activities and their detailed rhythms. Specifically, the membrane potential and the spiking activity of a single neuron are either highly correlated or highly anti-correlated with the time-dependent macroscopic activity of the entire network. This surprising observation also sheds light on the cooperative origin of neuronal burst in cultured networks. Our findings present an alternative flexible approach to the technique based on a massive tiling of networks by large-scale arrays of electrodes to monitor their activity.

  2. Characterization of heterologously expressed transporter genes by patch- and voltage-clamp methods: Application to cyclic nucleotide-dependent responses

    KAUST Repository

    Lemtiri-Chlieh, Fouad

    2013-09-03

    The application of patch- and voltage-clamp methods to study ion transport can be limited by many hurdles: the size of the cells to be patched and/or stabbed, the subcellular localization of the molecule of interest, and its density of expression that could be too low even in their own native environment. Functional expression of genes using recombinant DNA technology not only overcomes those hurdles but also affords additional and elegant investigations such as single-point mutation studies and subunit associations/regulations. In this chapter, we give a step-by-step description of two electrophysiological methods, patch clamp and two-electrode voltage clamp (TEVC), that are routinely used in combination with heterologous gene expression to assist researchers interested in the identification and characterization of ion transporters. We describe how to (1) obtain and maintain the cells suitable for the use with each of the above-mentioned methods (i.e., HEK-293 cells and yeast spheroplasts to use with the patch-clamp methodology and Xenopus laevis oocytes with TEVC), (2) transfect/inject them with the gene of interest, and (3) record ion transport activities. © Springer Science+Business Media New York 2013.

  3. Measurement of the cell membrane capacitance and conductance of colonic crypt cells of the rat using the patch clamp technique

    CERN Document Server

    Schill, C

    2005-01-01

    Using the patch clamp technique the membrane capacitance and membrane conductance of colonic crypt cells of the rat was measured. The influence of the intracellular agonists Ca++, cAMP and of osmotic changes on the membrane capacitance and conductance was studied.

  4. The application of the Escherichia coli giant spheroplast for drug screening with automated planar patch clamp system

    Directory of Open Access Journals (Sweden)

    Kyoko Kikuchi

    2015-09-01

    Full Text Available Kv2.1, the voltage-gated ion channel, is ubiquitously expressed in variety of tissues and dysfunction of this ion channel is responsible for multiple diseases. Electrophysiological properties of ion channels are so far characterized with eukaryotic cells using the manual patch clamp which requires skilful operators and expensive equipments. In this research, we created a simple and sensitive drug screen method using bacterial giant spheroplasts and the automated patch clamp which does not require special skills. We expressed a eukaryotic voltage-gated ion channel Kv2.1 in Escherichia coli using prokaryotic codon, and prepared giant spheroplasts large enough for the patch clamp. Human Kv2.1 currents were successfully recorded from giant spheroplasts with the automated system, and Kv2.1-expressed E. coli spheroplasts could steadily reacted to the dose–response assay with TEA and 4-AP. Collectively, our results indicate for the first time that the bacterial giant spheroplast can be applied for practical pharmaceutical assay using the automated patch clamp.

  5. Dual-Band Microstrip Patch Antenna Miniaturization Using Metamaterial

    Directory of Open Access Journals (Sweden)

    Indrasen Singh

    2013-01-01

    Full Text Available A dual-band microstrip patch antenna is designed and analyzed using metamaterial artificial substrate. Metamaterial based substrate is designed using Square Split Ring Resonator (SSRR and Wire Strip. The antenna is tuned to work at two resonating frequencies in the frequency range from 1 GHz to 4 GHz depending on the geometric specifications of SSRR, strip line, radiating patch, and feed location point. Proposed antenna provides good return loss behavior at both resonating frequencies. The obtained VSWR at both resonating frequencies is very much near to 1. Proposed antenna covers applications in mobile communication and Wi-MAX. Proposed patch antenna is compared with the conventional patch antenna, which shows the significant miniaturization as compared to conventional patch antenna.

  6. State-of-the-art automated patch clamp devices: Heat activation, action potentials and high throughput in ion channel screening

    Directory of Open Access Journals (Sweden)

    Sonja eStoelzle

    2011-11-01

    Full Text Available Ion channels are essential in a wide range of cellular functions and their malfunction underlies many disease states making them important targets in drug discovery. Diverse automated patch clamp systems with high-throughput capabilities are available for drug screening, but there are limitations in the application range. For example, solution exchange time, temperature control and the availability of the current clamp mode can be limiting factors. However, further development of existing devices and introduction of new systems widen the range of possible experiments and increase throughput. Here we introduce new features and platforms that meet the needs of drug discovery researchers and basic researchers alike.The Patchliner is an automated patch clamp system capable of recording up to 8 cells simultaneously with high success rates. Novel features such as temperature control and recordings in the current clamp mode are described here. Standard cell lines and excitable cells such as stem cell-derived cardiomyocytes have been used in the voltage clamp and current clamp modes with the view to finding new drug candidates and safety testing methods in a more physiologically relevant environment. The SyncroPatch 96, is a screening platform capable of recording from 96 cells in parallel and offers a throughput of 5000 data points per day. Full dose response curves can be acquired from individual cells reducing the cost per data point. The system is an ideal tool for secondary screening efforts and for safety testing on ligand- and voltage-gated ion channels.The Patchliner and SyncroPatch 96 are ideal platforms for drug discovery, ion channel research and safety testing, combining long awaited features such as parallel action potential recordings and temperature control with extensively increased throughput.

  7. Dynamics of T-Junction Solution Switching Aimed at Patch Clamp Experiments

    Science.gov (United States)

    Auzmendi, Jerónimo A.; Smoler, Mariano; Moffatt, Luciano

    2015-01-01

    Solutions exchange systems are responsible for the timing of drug application on patch clamp experiments. There are two basic strategies for generating a solution exchange. When slow exchanges are bearable, it is easier to perform the exchange inside the tubing system upstream of the exit port. On the other hand, fast, reproducible, exchanges are usually performed downstream of the exit port. As both strategies are combinable, increasing the performance of upstream exchanges is desirable. We designed a simple method for manufacturing T-junctions (300 μm I.D.) and we measured the time profile of exchange of two saline solutions using a patch pipette with an open tip. Three factors were found to determine the timing of the solution switching: pressure, travelled distance and off-center distance. A linear relationship between the time delay and the travelled distance was found for each tested pressure, showing its dependence to the fluid velocity, which increased with pressure. The exchange time was found to increase quadratically with the delay, although a sizeable variability remains unexplained by this relationship. The delay and exchange times increased as the recording pipette moved away from the center of the stream. Those increases became dramatic as the pipette was moved close to the stream borders. Mass transport along the travelled distance between the slow fluid at the border and the fast fluid at the center seems to contribute to the time course of the solution exchange. This effect would be present in all tubing based devices. Present results might be of fundamental importance for the adequate design of serial compound exchangers which would be instrumental in the discovery of drugs that modulate the action of the physiological agonists of ion channels with the purpose of fine tuning their physiology. PMID:26177538

  8. Dynamics of T-Junction Solution Switching Aimed at Patch Clamp Experiments.

    Directory of Open Access Journals (Sweden)

    Jerónimo A Auzmendi

    Full Text Available Solutions exchange systems are responsible for the timing of drug application on patch clamp experiments. There are two basic strategies for generating a solution exchange. When slow exchanges are bearable, it is easier to perform the exchange inside the tubing system upstream of the exit port. On the other hand, fast, reproducible, exchanges are usually performed downstream of the exit port. As both strategies are combinable, increasing the performance of upstream exchanges is desirable. We designed a simple method for manufacturing T-junctions (300 μm I.D. and we measured the time profile of exchange of two saline solutions using a patch pipette with an open tip. Three factors were found to determine the timing of the solution switching: pressure, travelled distance and off-center distance. A linear relationship between the time delay and the travelled distance was found for each tested pressure, showing its dependence to the fluid velocity, which increased with pressure. The exchange time was found to increase quadratically with the delay, although a sizeable variability remains unexplained by this relationship. The delay and exchange times increased as the recording pipette moved away from the center of the stream. Those increases became dramatic as the pipette was moved close to the stream borders. Mass transport along the travelled distance between the slow fluid at the border and the fast fluid at the center seems to contribute to the time course of the solution exchange. This effect would be present in all tubing based devices. Present results might be of fundamental importance for the adequate design of serial compound exchangers which would be instrumental in the discovery of drugs that modulate the action of the physiological agonists of ion channels with the purpose of fine tuning their physiology.

  9. From understanding cellular function to novel drug discovery: the role of planar patch-clamp array chip technology

    Directory of Open Access Journals (Sweden)

    Christophe ePy

    2011-10-01

    Full Text Available All excitable cell functions rely upon ion channels that are embedded in their plasma membrane. Perturbations of ion channel structure or function result in pathologies ranging from cardiac dysfunction to neurodegenerative disorders. Consequently, to understand the functions of excitable cells and to remedy their pathophysiology, it is important to understand the ion channel functions under various experimental conditions – including exposure to novel drug targets. Glass pipette patch-clamp is the state of the art technique to monitor the intrinsic and synaptic properties of neurons. However, this technique is labor-intensive and has low data throughput. Planar patch-clamp chips, integrated into automated systems, offer high throughputs but are limited to isolated cells from suspensions, resulting in questionable models of true physiological function, and are unsuitable for studies involving neuronal communication. Multi-electrode arrays (MEA, in contrast, have the ability to monitor network activity by measuring local field potentials from multiple extracellular sites, but specific ion channel activity is challenging to extract from these multiplexed signals. Here we describe a novel planar patch-clamp chip technology that enables the simultaneous high resolution electrophysiological interrogation of individual neurons at multiple sites in synaptically connected neuronal networks, thereby combining the advantages of MEA and patch-clamp techniques. Each neuron can be probed through an aperture that connects to a dedicated subterranean microfluidic channel. Neurons growing in networks are aligned to the apertures by physisorbed or chemisorbed chemical cues. In this review, we describe the design and fabrication process of these chips, the approach to the chemical patterning for cell placement, and present physiological data from cultured neuronal cells.

  10. In vitro Imaging neokortikaler Pyramidenneuronen nach patch-clamp gestützter Beladung mit Quantum Dots

    OpenAIRE

    Bullinger, Ruben

    2013-01-01

    In dieser Arbeit wurden mit einer neueren Klasse von Fluoreszenzfarbstoffen, den sogenannten „Quantum Dots“, neokortikale Pyramidenneurone in vitro angefärbt. Als Markierungsmethoden wurden Mikroinjektion, unter Anwendung der Patch clamp-Technik und Elektroporation optimiert. Zielsetzungen waren die Darstellung einzelner Pyramidenneurone bis hin zu ganzen Zellverbänden des Kortex. Es konnte gezeigt werden, dass Mikroinjektion und Elektroporation zuverlässige Methoden sind, um einzelne Pyramid...

  11. Exploring Arterial Smooth Muscle Kv7 Potassium Channel Function using Patch Clamp Electrophysiology and Pressure Myography

    Science.gov (United States)

    Brueggemann, Lioubov I.; Mani, Bharath K.; Haick, Jennifer; Byron, Kenneth L.

    2012-01-01

    Contraction or relaxation of smooth muscle cells within the walls of resistance arteries determines the artery diameter and thereby controls flow of blood through the vessel and contributes to systemic blood pressure. The contraction process is regulated primarily by cytosolic calcium concentration ([Ca2+]cyt), which is in turn controlled by a variety of ion transporters and channels. Ion channels are common intermediates in signal transduction pathways activated by vasoactive hormones to effect vasoconstriction or vasodilation. And ion channels are often targeted by therapeutic agents either intentionally (e.g. calcium channel blockers used to induce vasodilation and lower blood pressure) or unintentionally (e.g. to induce unwanted cardiovascular side effects). Kv7 (KCNQ) voltage-activated potassium channels have recently been implicated as important physiological and therapeutic targets for regulation of smooth muscle contraction. To elucidate the specific roles of Kv7 channels in both physiological signal transduction and in the actions of therapeutic agents, we need to study how their activity is modulated at the cellular level as well as evaluate their contribution in the context of the intact artery. The rat mesenteric arteries provide a useful model system. The arteries can be easily dissected, cleaned of connective tissue, and used to prepare isolated arterial myocytes for patch clamp electrophysiology, or cannulated and pressurized for measurements of vasoconstrictor/vasodilator responses under relatively physiological conditions. Here we describe the methods used for both types of measurements and provide some examples of how the experimental design can be integrated to provide a clearer understanding of the roles of these ion channels in the regulation of vascular tone. PMID:23007713

  12. Properties of the nucleo-olivary pathway: an in vivo whole-cell patch clamp study.

    Directory of Open Access Journals (Sweden)

    Paolo Bazzigaluppi

    Full Text Available The inferior olivary nucleus (IO forms the gateway to the cerebellar cortex and receives feedback information from the cerebellar nuclei (CN, thereby occupying a central position in the olivo-cerebellar loop. Here, we investigated the feedback input from the CN to the IO in vivo in mice using the whole-cell patch-clamp technique. This approach allows us to study how the CN-feedback input is integrated with the activity of olivary neurons, while the olivo-cerebellar system and its connections are intact. Our results show how IO neurons respond to CN stimulation sequentially with: i a short depolarization (EPSP, ii a hyperpolarization (IPSP and iii a rebound depolarization. The latter two phenomena can also be evoked without the EPSPs. The IPSP is sensitive to a GABA(A receptor blocker. The IPSP suppresses suprathreshold and subthreshold activity and is generated mainly by activation of the GABA(A receptors. The rebound depolarization re-initiates and temporarily phase locks the subthreshold oscillations. Lack of electrotonical coupling does not affect the IPSP of individual olivary neurons, nor the sensitivity of its GABA(A receptors to blockers. The GABAergic feedback input from the CN does not only temporarily block the transmission of signals through the IO, it also isolates neurons from the network by shunting the junction current and re-initiates the temporal pattern after a fixed time point. These data suggest that the IO not only functions as a cerebellar controlled gating device, but also operates as a pattern generator for controlling motor timing and/or learning.

  13. Gd3+ and calcium sensitive, sodium leak currents are features of weak membrane-glass seals in patch clamp recordings.

    Science.gov (United States)

    Boone, Adrienne N; Senatore, Adriano; Chemin, Jean; Monteil, Arnaud; Spafford, J David

    2014-01-01

    The properties of leaky patch currents in whole cell recording of HEK-293T cells were examined as a means to separate these control currents from expressed sodium and calcium leak channel currents from snail NALCN leak channels possessing both sodium (EKEE) and calcium (EEEE) selectivity filters. Leak currents were generated by the weakening of gigaohm patch seals by artificial membrane rupture using the ZAP function on the patch clamp amplifier. Surprisingly, we found that leak currents generated from the weakened membrane/glass seal can be surprisingly stable and exhibit behavior that is consistent with a sodium leak current derived from an expressible channel. Leaky patch currents differing by 10 fold in size were similarly reduced in size when external sodium ions were replaced with the large monovalent ion NMDG+. Leaky patch currents increased when external Ca2+ (1.2 mM) was lowered to 0.1 mM and were inhibited (>40% to >90%) with 10 µM Gd3+, 100 µM La3+, 1 mM Co2+ or 1 mM Cd2+. Leaky patch currents were relatively insensitive (Sylgard rubber.

  14. Perforated patch-clamp analysis of the passive membrane properties of three classes of hippocampal neurons.

    Science.gov (United States)

    Spruston, N; Johnston, D

    1992-03-01

    1. Perforated patch-clamp recordings were made from the three major classes of hippocampal neurons in conventional in vitro slices prepared from adult guinea pigs. This technique provided experimental estimates of passive membrane properties (input resistance, RN, and membrane time constant, tau m) determined in the absence of the leak conductance associated with microelectrode impalement or the washout of cytoplasmic constituents associated with conventional whole-cell recordings. 2. To facilitate comparison of our data with previous results and to determine the passive membrane properties under conditions as physiological as possible, recordings were made at the resting potential, in physiological saline, and without any added blockers of voltage-dependent conductances. 3. Membrane-potential responses to current steps were analyzed, and four criteria were used to identify voltage responses that were the least affected by activation of voltage-dependent conductances. tau m was estimated from the slowest component (tau 0) of multiexponential fits of responses deemed passive by these criteria. RN was estimated from the slope of the linear region in the hyperpolarizing direction of the voltage-current relation. 4. It was not possible to measure purely passive membrane properties that were completely independent of membrane potential in any of the three classes of hippocampal neurons. Changing the membrane potential by constant current injection resulted in changes in RN and tau 0; subthreshold depolarization produced an increase, and hyperpolarization a decrease, in both RN and tau 0 for all three classes of hippocampal neurons. 5. Each of the three classes of hippocampal neurons also displayed a depolarizing "sag" during larger hyperpolarizing voltage transients. To evaluate the effect of the conductances underlying this sag on passive membrane properties, 2-5 mM Cs+ was added to the physiological saline. Extracellular Cs+ effectively blocked the sag in all three

  15. Gd3+ and calcium sensitive, sodium leak currents are features of weak membrane-glass seals in patch clamp recordings.

    Directory of Open Access Journals (Sweden)

    Adrienne N Boone

    Full Text Available The properties of leaky patch currents in whole cell recording of HEK-293T cells were examined as a means to separate these control currents from expressed sodium and calcium leak channel currents from snail NALCN leak channels possessing both sodium (EKEE and calcium (EEEE selectivity filters. Leak currents were generated by the weakening of gigaohm patch seals by artificial membrane rupture using the ZAP function on the patch clamp amplifier. Surprisingly, we found that leak currents generated from the weakened membrane/glass seal can be surprisingly stable and exhibit behavior that is consistent with a sodium leak current derived from an expressible channel. Leaky patch currents differing by 10 fold in size were similarly reduced in size when external sodium ions were replaced with the large monovalent ion NMDG+. Leaky patch currents increased when external Ca2+ (1.2 mM was lowered to 0.1 mM and were inhibited (>40% to >90% with 10 µM Gd3+, 100 µM La3+, 1 mM Co2+ or 1 mM Cd2+. Leaky patch currents were relatively insensitive (<30% to 1 mM Ni2+ and exhibited a variable amount of block with 1 mM verapamil and were insensitive to 100 µM mibefradil or 100 µM nifedipine. We hypothesize that the rapid changes in leak current size in response to changing external cations or drugs relates to their influences on the membrane seal adherence and the electro-osmotic flow of mobile cations channeling in crevices of a particular pore size in the interface between the negatively charged patch electrode and the lipid membrane. Observed sodium leak conductance currents in weak patch seals are reproducible between the electrode glass interface with cell membranes, artificial lipid or Sylgard rubber.

  16. Expanding neurochemical investigations with multi-modal recording: simultaneous fast-scan cyclic voltammetry, iontophoresis, and patch clamp measurements.

    Science.gov (United States)

    Kirkpatrick, D C; McKinney, C J; Manis, P B; Wightman, R M

    2016-08-02

    Multi-modal recording describes the simultaneous collection of information across distinct domains. Compared to isolated measurements, such studies can more easily determine relationships between varieties of phenomena. This is useful for neurochemical investigations which examine cellular activity in response to changes in the local chemical environment. In this study, we demonstrate a method to perform simultaneous patch clamp measurements with fast-scan cyclic voltammetry (FSCV) using optically isolated instrumentation. A model circuit simulating concurrent measurements was used to predict the electrical interference between instruments. No significant impact was anticipated between methods, and predictions were largely confirmed experimentally. One exception was due to capacitive coupling of the FSCV potential waveform into the patch clamp amplifier. However, capacitive transients measured in whole-cell current clamp recordings were well below the level of biological signals, which allowed the activity of cells to be easily determined. Next, the activity of medium spiny neurons (MSNs) was examined in the presence of an FSCV electrode to determine how the exogenous potential impacted nearby cells. The activities of both resting and active MSNs were unaffected by the FSCV waveform. Additionally, application of an iontophoretic current, used to locally deliver drugs and other neurochemicals, did not affect neighboring cells. Finally, MSN activity was monitored during iontophoretic delivery of glutamate, an excitatory neurotransmitter. Membrane depolarization and cell firing were observed concurrently with chemical changes around the cell resulting from delivery. In all, we show how combined electrophysiological and electrochemical measurements can relate information between domains and increase the power of neurochemical investigations.

  17. Obtaining Spheroplasts of Armored Dinoflagellates and First Single-Channel Recordings of Their Ion Channels Using Patch-Clamping

    Directory of Open Access Journals (Sweden)

    Ilya Pozdnyakov

    2014-09-01

    Full Text Available Ion channels are tightly involved in various aspects of cell physiology, including cell signaling, proliferation, motility, endo- and exo-cytosis. They may be involved in toxin production and release by marine dinoflagellates, as well as harmful algal bloom proliferation. So far, the patch-clamp technique, which is the most powerful method to study the activity of ion channels, has not been applied to dinoflagellate cells, due to their complex cellulose-containing cell coverings. In this paper, we describe a new approach to overcome this problem, based on the preparation of spheroplasts from armored bloom-forming dinoflagellate Prorocentrum minimum. We treated the cells of P. minimum with a cellulose synthesis inhibitor, 2,6-dichlorobenzonitrile (DCB, and found out that it could also induce ecdysis and arrest cell shape maintenance in these microalgae. Treatment with 100–250 µM DCB led to an acceptable 10% yield of P. minimum spheroplasts and was independent of the incubation time in the range of 1–5 days. We show that such spheroplasts are suitable for patch-clamping in the cell-attached mode and can form 1–10 GOhm patch contact with a glass micropipette, allowing recording of ion channel activity. The first single-channel recordings of dinoflagellate ion channels are presented.

  18. Obtaining spheroplasts of armored dinoflagellates and first single-channel recordings of their ion channels using patch-clamping.

    Science.gov (United States)

    Pozdnyakov, Ilya; Matantseva, Olga; Negulyaev, Yuri; Skarlato, Sergei

    2014-09-05

    Ion channels are tightly involved in various aspects of cell physiology, including cell signaling, proliferation, motility, endo- and exo-cytosis. They may be involved in toxin production and release by marine dinoflagellates, as well as harmful algal bloom proliferation. So far, the patch-clamp technique, which is the most powerful method to study the activity of ion channels, has not been applied to dinoflagellate cells, due to their complex cellulose-containing cell coverings. In this paper, we describe a new approach to overcome this problem, based on the preparation of spheroplasts from armored bloom-forming dinoflagellate Prorocentrum minimum. We treated the cells of P. minimum with a cellulose synthesis inhibitor, 2,6-dichlorobenzonitrile (DCB), and found out that it could also induce ecdysis and arrest cell shape maintenance in these microalgae. Treatment with 100-250 µM DCB led to an acceptable 10% yield of P. minimum spheroplasts and was independent of the incubation time in the range of 1-5 days. We show that such spheroplasts are suitable for patch-clamping in the cell-attached mode and can form 1-10 GOhm patch contact with a glass micropipette, allowing recording of ion channel activity. The first single-channel recordings of dinoflagellate ion channels are presented.

  19. ß-adrenergic regulation of ion transport in pancreatic ducts: Patch-clamp study of isolated rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I

    1998-01-01

    much smaller effects. At comparable concentrations, it depolarized Vm by a few millivolts. Neither agonist had significant effects on intracellular Ca2+. CONCLUSIONS: This study provides the first direct evidence that adrenergic stimulation, namely, that of beta-adrenoceptors, controls ion transport....... METHODS: Small intralobular ducts were isolated from rat pancreas and studied in vitro by the whole-cell patch clamp technique. Cell membrane voltages and currents were indicators of cellular ion transport. In some ducts, intracellular Ca2+ activity was measured by fluorescence optical methods. RESULTS...... in pancreatic ducts. Similar to secretin, isoproterenol stimulation leads to opening of luminal Cl- channels, and HCO3- enters the lumen in exchange for Cl-....

  20. Compact filtering monopole patch antenna with dual-band rejection.

    Science.gov (United States)

    Kim, Sun-Woong; Choi, Dong-You

    2016-01-01

    In this paper, a compact ultra-wideband patch antenna with dual-band rejection is proposed. The proposed antenna filters 3.3-3.8 GHz WiMAX and 5.15-5.85 GHz WLAN by respectively rejecting these bands through a C-shaped slit and a λg/4 resonator. The λg/4 resonator is positioned as a pair, centered around the microstrip line, and a C-type slit is inserted into an elliptical patch. The impedance bandwidth of the proposed antenna is 2.9-9.3 GHz, which satisfies the bandwidth for ultra-wideband communication systems. Further, the proposed antenna provides dual-band rejection at two bands: 3.2-3.85 and 4.7-6.03 GHz. The radiation pattern of the antenna is omnidirectional, and antenna gain is maintained constantly while showing -8.4 and -1.5 dBi at the two rejected bands, respectively.

  1. Canine muscle cell culture and consecutive patch-clamp measurements - a new approach to characterize muscular diseases in dogs

    Directory of Open Access Journals (Sweden)

    Schenk Henning Christian

    2012-11-01

    Full Text Available Abstract Background The recognition of functional muscular disorders, (e.g. channelopathies like Myotonia is rising in veterinary neurology. Morphologic (e.g. histology and even genetic based studies in these diseases are not able to elucidate the functional pathomechanism. As there is a deficit of knowledge and skills considering this special task, the aim of the current pilot study was to develop a canine muscle cell culture system derived from muscle biopsies of healthy client-owned dogs, which allows sampling of the biopsies under working conditions in the daily veterinary practise. Results Muscular biopsies from 16 dogs of different age and breed were taken during standard surgical procedures and were stored for one to three days at 4°C in a transport medium in order to simulate shipping conditions. Afterwards biopsies were professionally processed, including harvesting of satellite cells, inducing their proliferation, differentiating them into myotubes and recultivating myotubes after long-term storage in liquid nitrogen. Myogenic origin of cultured cells was determined by immunofluorescence, immunohistology and by their typical morphology after inducing differentiation. Subsequent to the differentiation into myotubes feasibility of patch-clamp recordings of voltage gated ion channels was successfully. Conclusion We have developed a canine muscle cell culture system, which allows sampling of biopsies from young and old dogs of different breeds under practical conditions. Patch clamp measurements can be carried out with the cultured myotubes demonstrating potential of these cells as source for functional research.

  2. An optogenetics- and imaging-assisted simultaneous multiple patch-clamp recording system for decoding complex neural circuits.

    Science.gov (United States)

    Wang, Guangfu; Wyskiel, Daniel R; Yang, Weiguo; Wang, Yiqing; Milbern, Lana C; Lalanne, Txomin; Jiang, Xiaolong; Shen, Ying; Sun, Qian-Quan; Zhu, J Julius

    2015-03-01

    Deciphering neuronal circuitry is central to understanding brain function and dysfunction, yet it remains a daunting task. To facilitate the dissection of neuronal circuits, a process requiring functional analysis of synaptic connections and morphological identification of interconnected neurons, we present here a method for stable simultaneous octuple patch-clamp recordings. This method allows physiological analysis of synaptic interconnections among 4-8 simultaneously recorded neurons and/or 10-30 sequentially recorded neurons, and it allows anatomical identification of >85% of recorded interneurons and >99% of recorded principal neurons. We describe how to apply the method to rodent tissue slices; however, it can be used on other model organisms. We also describe the latest refinements and optimizations of mechanics, electronics, optics and software programs that are central to the realization of a combined single- and two-photon microscopy-based, optogenetics- and imaging-assisted, stable, simultaneous quadruple-viguple patch-clamp recording system. Setting up the system, from the beginning of instrument assembly and software installation to full operation, can be completed in 3-4 d.

  3. In situ patch-clamp recordings from Merkel cells in rat whisker hair follicles, an experimental protocol for studying tactile transduction in tactile-end organs.

    Science.gov (United States)

    Ikeda, Ryo; Ling, Jennifer; Cha, Myeounghoon; Gu, Jianguo G

    2015-04-25

    Mammals use tactile end-organs to perform sensory tasks such as environmental exploration, social interaction, and tactile discrimination. However, cellular and molecular mechanisms underlying tactile transduction in tactile end-organs remain poorly understood. The patch-clamp recording technique may be the most valuable approach for detecting and studying tactile transduction in tactile end-organs, but it is technically challenging because tactile transduction elements in an end-organ are normally inaccessible by patch-clamp recording electrodes. Here we describe an in situ patch-clamp recording protocol for the study of tactile transduction in Merkel cells of rat whisker hair follicles, one of the most sensitive tactile end-organs in mammals. This technique offers an opportunity to explore the identities and properties of ion channels that are involved in tactile transduction in whisker hair follicles, and it may also lend a useful tool for researchers to study other tactile end-organs. The experimental protocol describes procedures for 1) tissue dissection and whisker hair follicle preparation, 2) device setup and steps for performing patch-clamp recordings from Merkel cells in a whisker hair follicle, 3) methods of delivering mechanical stimuli, and 4) intra-follicle microinjection for receptor knockdown in whisker hair follicles. The main procedures in this protocol, from tissue preparation to whole-cell patch-clamp recordings, can be completed in a few hours.

  4. An operational amplifier B1404UD1A-1 in the patch-clamp current-to-voltage converter.

    Science.gov (United States)

    Korzun, A M; Rozinov, S V; Abashin, G I

    1997-01-01

    The applicability of the home-made operational amplifier B1404UD1A-1 in a patch-clamp current-to-voltage converter was analyzed. Its parameters (background noise, input bias current, and gain-bandwidth product) were estimated. Schematic solutions and practical recommendations for the use of this amplifier in a current-to-voltage converter were given. Based on the background noise and frequency parameters of the converter, we found that this device can be used for measuring ion channel currents with a high sensitivity and within a broad frequency range (0.055 pA, to 1 kHz; 0.4 pA, to 10 kHz). An example of the converter application in experiments is given.

  5. PLASMALEMMA PATCH CLAMP EXPERIMENTS IN PLANT-ROOT CELLS - PROCEDURE FOR FAST ISOLATION OF PROTOPLASTS WITH MINIMAL EXPOSURE TO CELL-WALL DEGRADING ENZYMES

    NARCIS (Netherlands)

    VOGELZANG, SA; PRINS, HBA

    1992-01-01

    A convenient and rapid isolation procedure for root cell protoplasts suitable for patch clamp experiments. was developed for root cells of tomato (Lycopersicon esculentum and Plantago species, grown on hydroculture. The procedure is based on a minimal exposure of cells to cell wall degrading enzyme

  6. RECONFIGURABLE DUAL-BAND CIRCULARLY POLARIZED MICROSTRIP PATCH ANTENNA FOR WIRELESS APPLICATIONS

    Institute of Scientific and Technical Information of China (English)

    Belhachat Messaouda; Bakir Mohammed; Zhu Shouzheng; Liu Jingao

    2004-01-01

    A new design of reconfigurable single-feed circular patch microstrip antenna for dual-band circular polarization application is proposed. The dual-band functionality is realized through incorporating cross-slots of equal slot length in the circular patch and utilizing two PIN diodes to switch the slots on or off. A pairs of tuning stubs are used to tune the circular polarization performance. The design process is presented and good results were obtained.

  7. Evaluation of diel patterns of relative changes in cell turgor of tomato plants using leaf patch clamp pressure probes.

    Science.gov (United States)

    Lee, Kang M; Driever, Steven M; Heuvelink, Ep; Rüger, Simon; Zimmermann, Ulrich; de Gelder, Arie; Marcelis, Leo F M

    2012-12-01

    Relative changes in cell turgor of leaves of well-watered tomato plants were evaluated using the leaf patch clamp pressure probe (LPCP) under dynamic greenhouse climate conditions. LPCP changes, a measure for relative changes in cell turgor, were monitored at three different heights of transpiring and non-transpiring leaves of tomato plants on sunny and cloudy days simultaneously with whole plant water uptake. Clear diel patterns were observed for relative changes of cell turgor of both transpiring and non-transpiring leaves, which were stronger on sunny days than on cloudy days. A clear effect of canopy height was also observed. Non-transpiring leaves showed relative changes in cell turgor that closely followed plant water uptake throughout the day. However, in the afternoon the relative changes of cell turgor of the transpiring leaves displayed a delayed response in comparison to plant water uptake. Subsequent recovery of cell turgor loss of transpiring leaves during the following night appeared insufficient, as the pre-dawn turgescent state similar to the previous night was not attained. Copyright © Physiologia Plantarum 2012.

  8. Patch-clamp recordings of rat neurons from acute brain slices of the somatosensory cortex during magnetic stimulation

    Directory of Open Access Journals (Sweden)

    Tamar ePashut

    2014-06-01

    Full Text Available Although transcranial magnetic stimulation (TMS is a popular tool for both basic research and clinical applications, its actions on nerve cells are only partially understood. We have previously predicted, using compartmental modeling, that magnetic stimulation of central nervous system neurons depolarized the soma followed by initiation of an action potential in the initial segment of the axon. The simulations also predict that neurons with low current threshold are more susceptible to magnetic stimulation. Here we tested these theoretical predictions by combining in vitro patch-clamp recordings from rat brain slices with magnetic stimulation and compartmental modeling. In agreement with the modeling, our recordings demonstrate the dependence of magnetic stimulation-triggered action potentials on the type and state of the neuron and its orientation within the magnetic field. Our results suggest that the observed effects of TMS are deeply rooted in the biophysical properties of single neurons in the central nervous system and provide a framework both for interpreting existing TMS data and developing new simulation-based tools and therapies.

  9. PATCH-CLAMP ANALYSIS OF THE DOMINANT PLASMA-MEMBRANE K+ CHANNEL IN ROOT CELL PROTOPLASTS OF PLANTAGO-MEDIA L - ITS SIGNIFICANCE FOR THE P-STATE AND K-STATE

    NARCIS (Netherlands)

    VOGELZANG, SA; PRINS, HBA

    1994-01-01

    Ion channels in the plasma membrane of root cell protoplasts of Plantago media L. were studied with the patch clamp technique in the cell-attached patch and outside-out patch configuration. An outward rectifying potassium channel was dominantly present in the plasma membrane. It appears responsible

  10. Intravenous administration of lidocaine directly acts on spinal dorsal horn and produces analgesic effect: An in vivo patch-clamp analysis

    OpenAIRE

    Miyuki Kurabe; Hidemasa Furue; Tatsuro Kohno

    2016-01-01

    Intravenous lidocaine administration produces an analgesic effect in various pain states, such as neuropathic and acute pain, although the underlying mechanisms remains unclear. Here, we hypothesized that intravenous lidocaine acts on spinal cord neurons and induces analgesia in acute pain. We therefore examined the action of intravenous lidocaine in the spinal cord using the in vivo patch-clamp technique. We first investigated the effects of intravenous lidocaine using behavioural measures i...

  11. The interaction of the neuroprotective compounds riluzole and phenobarbital with AMPA-type glutamate receptors: a patch-clamp study.

    Science.gov (United States)

    Jin, Ling-Jing; Schlesinger, Friedrich; Song, Yun-Ping; Dengler, Reinhard; Krampfl, Klaus

    2010-01-01

    Blockade of alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-type glutamate receptors is a promising pharmacological strategy in the treatment of neurodegenerative diseases. The aim of the study is to elucidate if there are direct interactions of riluzole and phenobarbital with AMPA-type receptor channels and to determinethe molecular pharmacological mechanisms. The patch-clamp technique was used combining an ultrafast solution exchange system to investigate the interaction of riluzole and phenobarbital with recombinant AMPA-type glutamate receptor channels (homomeric GluR2flipGQ or nondesensitizing GluR2L504Y). A dose-dependent decrease in the relative peak current amplitude (rAmp) and the relative area-under-the-current curve (rAUC) were found after preincubation with 0.1 mmol/l or higher concentrations of riluzole. Furthermore, in coapplication experiments with GluR2L504Y, the application of 1 or 3 mmol/l riluzole showed a decrease in the current decay time constant, and a reopening current was observed at 3 mmol/l riluzole. Phenobarbital blocks AMPA receptor channels dose-dependently in the coapplication experiments, and reopening currents after removing glutamate and blocker were observed. A slight block effect after preincubation should indicate an additional competitive block effect. Riluzole and phenobarbital modulate AMPA-type receptor channels separately, which could be both characterized as a combination of open-channel block and competitive-block mechanism. Copyright 2009 S. Karger AG, Basel.

  12. Effects of Tramadol on Substantia Gelatinosa Neurons in the Rat Spinal Cord: An In Vivo Patch-Clamp Analysis

    Science.gov (United States)

    Yamasaki, Hiroyuki; Funai, Yusuke; Funao, Tomoharu; Mori, Takashi; Nishikawa, Kiyonobu

    2015-01-01

    Tramadol is thought to modulate synaptic transmissions in the spinal dorsal horn mainly by activating µ-opioid receptors and by inhibiting the reuptake of monoamines in the CNS. However, the precise mode of modulation remains unclear. We used an in vivo patch clamp technique in urethane-anesthetized rats to determine the antinociceptive mechanism of tramadol. In vivo whole-cell recordings of spontaneous inhibitory postsynaptic currents (sIPSCs) and spontaneous excitatory postsynaptic currents (sEPSCs) were made from substantia gelatinosa (SG) neurons (lamina II) at holding potentials of 0 mV and -70 mV, respectively. The effects of intravenous administration (0.5, 5, 15 mg/kg) of tramadol were evaluated. The effects of superfusion of tramadol on the surface of the spinal cord and of a tramadol metabolite (M1) were further analyzed. Intravenous administration of tramadol at doses >5 mg/kg decreased the sEPSCs and increased the sIPSCs in SG neurons. These effects were not observed following naloxone pretreatment. Tramadol superfusion at a clinically relevant concentration (10 µM) had no effect, but when administered at a very high concentration (100 µM), tramadol decreased sEPSCs, produced outward currents, and enhanced sIPSCs. The effects of M1 (1, 5 mg/kg intravenously) on sEPSCs and sIPSCs were similar to those of tramadol at a corresponding dose (5, 15 mg/kg). The present study demonstrated that systemically administered tramadol indirectly inhibited glutamatergic transmission, and enhanced GABAergic and glycinergic transmissions in SG neurons. These effects were mediated primarily by the activation of μ-opioid receptors. M1 may play a key role in the antinociceptive mechanisms of tramadol. PMID:25933213

  13. Effects of tramadol on substantia gelatinosa neurons in the rat spinal cord: an in vivo patch-clamp analysis.

    Science.gov (United States)

    Yamasaki, Hiroyuki; Funai, Yusuke; Funao, Tomoharu; Mori, Takashi; Nishikawa, Kiyonobu

    2015-01-01

    Tramadol is thought to modulate synaptic transmissions in the spinal dorsal horn mainly by activating µ-opioid receptors and by inhibiting the reuptake of monoamines in the CNS. However, the precise mode of modulation remains unclear. We used an in vivo patch clamp technique in urethane-anesthetized rats to determine the antinociceptive mechanism of tramadol. In vivo whole-cell recordings of spontaneous inhibitory postsynaptic currents (sIPSCs) and spontaneous excitatory postsynaptic currents (sEPSCs) were made from substantia gelatinosa (SG) neurons (lamina II) at holding potentials of 0 mV and -70 mV, respectively. The effects of intravenous administration (0.5, 5, 15 mg/kg) of tramadol were evaluated. The effects of superfusion of tramadol on the surface of the spinal cord and of a tramadol metabolite (M1) were further analyzed. Intravenous administration of tramadol at doses >5 mg/kg decreased the sEPSCs and increased the sIPSCs in SG neurons. These effects were not observed following naloxone pretreatment. Tramadol superfusion at a clinically relevant concentration (10 µM) had no effect, but when administered at a very high concentration (100 µM), tramadol decreased sEPSCs, produced outward currents, and enhanced sIPSCs. The effects of M1 (1, 5 mg/kg intravenously) on sEPSCs and sIPSCs were similar to those of tramadol at a corresponding dose (5, 15 mg/kg). The present study demonstrated that systemically administered tramadol indirectly inhibited glutamatergic transmission, and enhanced GABAergic and glycinergic transmissions in SG neurons. These effects were mediated primarily by the activation of μ-opioid receptors. M1 may play a key role in the antinociceptive mechanisms of tramadol.

  14. F1FO ATPase vesicle preparation and technique for performing patch clamp recordings of submitochondrial vesicle membranes.

    Science.gov (United States)

    Sacchetti, Silvio; Alavian, Kambiz N; Lazrove, Emma; Jonas, Elizabeth A

    2013-05-04

    Mitochondria are involved in many important cellular functions including metabolism, survival(1), development and, calcium signaling(2). Two of the most important mitochondrial functions are related to the efficient production of ATP, the energy currency of the cell, by oxidative phosphorylation, and the mediation of signals for programmed cell death(3). The enzyme primarily responsible for the production of ATP is the F1FO-ATP synthase, also called ATP synthase(4-5). In recent years, the role of mitochondria in apoptotic and necrotic cell death has received considerable attention. In apoptotic cell death, BCL-2 family proteins such as Bax enter the mitochondrial outer membrane, oligomerize and permeabilize the outer membrane, releasing pro-apoptotic factors into the cytosol(6). In classic necrotic cell death, such as that produced by ischemia or excitotoxicity in neurons, a large, poorly regulated increase in matrix calcium contributes to the opening of an inner membrane pore, the mitochondrial permeability transition pore or mPTP. This depolarizes the inner membrane and causes osmotic shifts, contributing to outer membrane rupture, release of pro-apoptotic factors, and metabolic dysfunction. Many proteins including Bcl-xL(7) interact with F1FO ATP synthase, modulating its function. Bcl-xL interacts directly with the beta subunit of F1FO ATP synthase, and this interaction decreases a leak conductance within the F1FOATPasecomplex, increasing the net transport of H+ by F1FO during F1FO ATPase activity(8) and thereby increasing mitochondrial efficiency. To study the activity and modulation of the ATP synthase, we isolated from rodent brain submitochondrial vesicles (SMVs) containing F1FO ATPase. The SMVs retain the structural and functional integrity of the F1FO ATPase as shown in Alavian et al. Here, we describe a method that we have used successfully for the isolation of SMVs from rat brain and we delineate the patch clamp technique to analyze channel activity (ion

  15. Automated patch-clamp technique: increased throughput in functional characterization and in pharmacological screening of small-conductance Ca2+ release-activated Ca2+ channels.

    Science.gov (United States)

    Schrøder, Rikke L; Friis, Søren; Sunesen, Morten; Mathes, Chris; Willumsen, Niels J

    2008-08-01

    The suitability of an automated patch clamp for the characterization and pharmacological screening of calcium release-activated calcium (CRAC) channels endogenously expressed in RBL-2H3 cells was explored with the QPatch system. CRAC currents (I( CRAC)) are small, and thus precise recordings require high signal-to-noise ratios obtained by high seal resistances. Automated whole-cell establishment resulted in membrane resistances of 1728 +/- 226 MOmega (n = 44). CRAC channels were activated by a number of methods that raise intracellular calcium concentration, including EGTA, ionomycin, Ins(1,4,5)P3, and thapsigargin. I(CRAC) whole-cell currents ranged from 30 to 120 pA with rise times of 40 to 150 s. An initial delay in current activation was observed in particular when I(CRAC) was activated by passive store depletion using EGTA. Apparent rundown of I(CRAC) was commonly observed, and the current could be reactivated by subsequent addition of thapsigargin. I(CRAC) was blocked by SKF-96365 and 2-APB with IC50 values of 4.7 +/- 1.1 microM (n = 9) and 7.5 +/- 0.7 (n = 9) microM, respectively. The potencies of these blockers were similar to values reported for I(CRAC) in similar conventional patch-clamp experiments. The study demonstrates that CRAC channels can be rapidly and efficiently targeted with automated patch-clamp techniques for characterization of physiological and pharmacological properties.

  16. Aperture coupled stacked patch antenna for dual band

    Directory of Open Access Journals (Sweden)

    Rajesh Kumar Vishwakarma

    2012-06-01

    Full Text Available -Microstrip antennas (MAS are very useful antenna where low profile antennas are required. They are most popular due to their small size, low cost, light weight. The first aperture coupled microstrip antenna was introduced in 1985 by D M Pozar. Aperture coupled antenna is a particular antenna with high gain and wide bandwidth. This paper presents aperture coupled stacked patch antenna using air gap variation. The variation of air gap [2mm to 6mm] has been done between single patch antenna and an aperture coupled antenna. The main advantage of this antenna to increase the band width of the antenna as compared with single layered patch antenna. The resonant frequencies changes with air gap variations. The feed can be done either a conventional coaxial probe or through a coupling aperture in the ground plane as we done. This antenna works well in the frequency range (2.9 GHz to 6.0 GHz. The measured return loss exhibit an impedance bandwidth of 35%.The input impedance and VSWR return loss have been measured with the help of Network analyzer. [Agilent E8363B A.04.06] From the measured result it is found that the value of VSWR corresponding lower resonance frequencies increases from 14 to 2.2 with increasing air gap variation where as at the upper resonance frequencies is also increased from 1.8 to 2.3.

  17. Effects of environmental parameters and irrigation on the turgor pressure of banana plants measured using the non-invasive, online monitoring leaf patch clamp pressure probe.

    Science.gov (United States)

    Zimmermann, U; Rüger, S; Shapira, O; Westhoff, M; Wegner, L H; Reuss, R; Gessner, P; Zimmermann, G; Israeli, Y; Zhou, A; Schwartz, A; Bamberg, E; Zimmermann, D

    2010-05-01

    Turgor pressure provides a sensitive indicator for irrigation scheduling. Leaf turgor pressure of Musa acuminate was measured by using the so-called leaf patch clamp pressure probe, i.e. by application of an external, magnetically generated and constantly retained clamp pressure to a leaf patch and determination of the attenuated output pressure P(p) that is highly correlated with the turgor pressure. Real-time recording of P(p) values was made using wireless telemetric transmitters, which send the data to a receiver base station where data are logged and transferred to a GPRS modem linked to an Internet server. Probes functioned over several months under field and laboratory conditions without damage to the leaf patch. Measurements showed that the magnetic-based probe could monitor very sensitively changes in turgor pressure induced by changes in microclimate (temperature, relative humidity, irradiation and wind) and irrigation. Irrigation effects could clearly be distinguished from environmental effects. Interestingly, oscillations in stomatal aperture, which occurred frequently below turgor pressures of 100 kPa towards noon at high transpiration or at high wind speed, were reflected in the P(p) values. The period of pressure oscillations was comparable with the period of oscillations in transpiration and photosynthesis. Multiple probe readings on individual leaves and/or on several leaves over the entire height of the plants further emphasised the great impact of this non-invasive turgor pressure sensor system for elucidating the dynamics of short- and long-distance water transport in higher plants.

  18. The Reconstructing of Low Signal-noise Ratio Single Ion Channel Signal from Patch-clamp Recordings Sampled in the Colored Background Noise

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The single ion channel signal is an ionic current that can be recorded by the patch clamp technique. Hidden Markov model(HMM)algorithm has been used to convert the low signal-noise ra-tio (SNR) noisy recording into an idealized quantal one in the case of white background noise. The traditional HMM algorithm is extended and adapted to the colored background noise.A new algorithm called EHMM (Extended HMM) algorithm is proposed,and mainly validated by simulati-on.Results show that it's effective.

  19. Dual band multi frequency rectangular patch microstrip antenna with flyswatter shaped slot for wireless systems

    Science.gov (United States)

    Bhardwaj, Dheeraj; Saraswat, Shriti; Gulati, Gitansh; Shekhar, Snehanshu; Joshi, Kanika; Sharma, Komal

    2016-03-01

    In this paper a dual band planar antenna has been proposed for IEEE 802.16 Wi-MAX /IEEE 802.11 WLAN/4.9 GHz public safety applications. The antenna comprises a frequency bandwidth of 560MHz (3.37GHz-3.93GHz) for WLAN and WiMAX and 372MHz (4.82GHz-5.192GHz) for 4.9 GHz public safety applications and Radio astronomy services (4.8-4.94 GHz). The proposed antenna constitutes of a single microstrip patch reactively loaded with three identical steps positioned in a zig-zag manner towards the radiating edges of the patch. The coaxially fed patch antenna characteristics (radiation pattern, antenna gain, antenna directivity, current distribution, S11) have been investigated. The antenna design is primarily focused on achieving a dual band operation.

  20. Compact Dual-Band Linearly Polarized Patch Antenna using Metamaterials for Wireless Applications

    Directory of Open Access Journals (Sweden)

    Gayathri Rajaraman

    2014-12-01

    Full Text Available In this paper we present a novel miniaturized dual-band patch antenna based on the metamaterial concept. Complementary split ring resonators, which are excellent structures for miniaturization; along with spiral resonators are used in the proposed design for obtaining a compact dual-band patch antenna. The original patch which is designed to resonate at 2.86 GHz is found to resonate at 1.92 GHz & 2.44 GHz when loaded with three pairs of square complementary ring resonators. Further its ground is also loaded with a spiral resonator yielding a relatively compact antenna structure. The present design has been tuned to the above two bands which finds application in PCS and WLAN applications. The percentage of miniaturization obtained is 51.4 % & 17.6 % respectively. The proposed antenna achieves an efficiency of 80% & 37% in the two bands of resonance.

  1. Dual band multi frequency rectangular patch microstrip antenna with flyswatter shaped slot for wireless systems

    Energy Technology Data Exchange (ETDEWEB)

    Bhardwaj, Dheeraj, E-mail: dbhardwaj.bit@gmail.com [Department of Physics, BIT-Mesra-Jaipur Campus, Jaipur 302017 (India); Saraswat, Shriti, E-mail: saraswat.srishti@gmail.com; Gulati, Gitansh, E-mail: gitanshgulati@gmail.com; Shekhar, Snehanshu, E-mail: snehanshushekhar.bit@gmail.com; Joshi, Kanika, E-mail: kanika.karesh@gmail.com [Department of Electronics & Communication, BIT-Mesra-Jaipur Campus, Jaipur 302017 (India); Sharma, Komal, E-mail: kbhardwaj18@gmail.com [Department of Physics, Swami Keshvanand Institute of Technology, Jaipur 302017 (India)

    2016-03-09

    In this paper a dual band planar antenna has been proposed for IEEE 802.16 Wi-MAX /IEEE 802.11 WLAN/4.9 GHz public safety applications. The antenna comprises a frequency bandwidth of 560MHz (3.37GHz-3.93GHz) for WLAN and WiMAX and 372MHz (4.82GHz-5.192GHz) for 4.9 GHz public safety applications and Radio astronomy services (4.8-4.94 GHz). The proposed antenna constitutes of a single microstrip patch reactively loaded with three identical steps positioned in a zig-zag manner towards the radiating edges of the patch. The coaxially fed patch antenna characteristics (radiation pattern, antenna gain, antenna directivity, current distribution, S{sub 11}) have been investigated. The antenna design is primarily focused on achieving a dual band operation.

  2. Intravenous administration of lidocaine directly acts on spinal dorsal horn and produces analgesic effect: An in vivo patch-clamp analysis.

    Science.gov (United States)

    Kurabe, Miyuki; Furue, Hidemasa; Kohno, Tatsuro

    2016-05-18

    Intravenous lidocaine administration produces an analgesic effect in various pain states, such as neuropathic and acute pain, although the underlying mechanisms remains unclear. Here, we hypothesized that intravenous lidocaine acts on spinal cord neurons and induces analgesia in acute pain. We therefore examined the action of intravenous lidocaine in the spinal cord using the in vivo patch-clamp technique. We first investigated the effects of intravenous lidocaine using behavioural measures in rats. We then performed in vivo patch-clamp recording from spinal substantia gelatinosa (SG) neurons. Intravenous lidocaine had a dose-dependent analgesic effect on the withdrawal response to noxious mechanical stimuli. In the electrophysiological experiments, intravenous lidocaine inhibited the excitatory postsynaptic currents (EPSCs) evoked by noxious pinch stimuli. Intravenous lidocaine also decreased the frequency, but did not change the amplitude, of both spontaneous and miniature EPSCs. However, it did not affect inhibitory postsynaptic currents. Furthermore, intravenous lidocaine induced outward currents in SG neurons. Intravenous lidocaine inhibits glutamate release from presynaptic terminals in spinal SG neurons. Concomitantly, it hyperpolarizes postsynaptic neurons by shifting the membrane potential. This decrease in the excitability of spinal dorsal horn neurons may be a possible mechanism for the analgesic action of intravenous lidocaine in acute pain.

  3. DUAL BAND SEMI CIRCULAR DISK PATCH ANTENNA LOADED WITH L-SHAPED SLOT

    Directory of Open Access Journals (Sweden)

    Amel Boufrioua

    2014-11-01

    Full Text Available In this paper, a dual frequency resonance antenna is analysed by introducing L-shaped slot in a semi circular patch, different parametric studies have allows and the results in terms of return loss and radiation pattern are given. It is observed that various antenna parameters are obtained as a function of frequency for different value of slot length and width; it is easy to adjust the upper and the lower band by varying these different antenna parameters. The coaxial feed is used to excite the patch antenna. Theoretical results using Matlab are compared with the simulated results obtained from Ansoft HFSS and shown to be in good agreement.

  4. A lab-on-a-chip for hypoxic patch clamp measurements combined with optical tweezers and spectroscopy- first investigations of single biological cells.

    Science.gov (United States)

    Alrifaiy, Ahmed; Borg, Johan; Lindahl, Olof A; Ramser, Kerstin

    2015-04-18

    The response and the reaction of the brain system to hypoxia is a vital research subject that requires special instrumentation. With this research subject in focus, a new multifunctional lab-on-a-chip (LOC) system with control over the oxygen content for studies on biological cells was developed. The chip was designed to incorporate the patch clamp technique, optical tweezers and absorption spectroscopy. The performance of the LOC was tested by a series of experiments. The oxygen content within the channels of the LOC was monitored by an oxygen sensor and verified by simultaneously studying the oxygenation state of chicken red blood cells (RBCs) with absorption spectra. The chicken RBCs were manipulated optically and steered in three dimensions towards a patch-clamp micropipette in a closed microfluidic channel. The oxygen level within the channels could be changed from a normoxic value of 18% O 2 to an anoxic value of 0.0-0.5% O 2. A time series of 3 experiments were performed, showing that the spectral transfer from the oxygenated to the deoxygenated state occurred after about 227 ± 1 s and a fully developed deoxygenated spectrum was observed after 298 ± 1 s, a mean value of 3 experiments. The tightness of the chamber to oxygen diffusion was verified by stopping the flow into the channel system while continuously recording absorption spectra showing an unchanged deoxygenated state during 5400 ± 2 s. A transfer of the oxygenated absorption spectra was achieved after 426 ± 1 s when exposing the cell to normoxic buffer. This showed the long time viability of the investigated cells. Successful patching and sealing were established on a trapped RBC and the whole-cell access (Ra) and membrane (Rm) resistances were measured to be 5.033 ± 0.412 M Ω and 889.7 ± 1.74 M Ω respectively.

  5. Dual-band microstrip patch antenna based on metamaterial refractive surface

    Science.gov (United States)

    Salhi, Ridha; Labidi, Mondher; Boujemaa, Mohamed Ali; Choubani, Fethi

    2017-06-01

    In this paper, we present a new design of microstrip patch antenna based on metamaterial refractive surface (MRS). By optimizing the air gap between the MRS layer and the patch antenna to be 7 mm, the band width and the gain of the proposed antenna are significantly enhanced. The proposed prototype presents a dual band antenna. The center frequency for the first band is 2.44 GHz and the generated bandwidth is 25 MHz. The second band has a center frequency of 2.8 GHz and with a bandwidth of 50 MHz. The simulation results are analyzed and discussed in terms of return loss, gain and radiation pattern using electromagnetic simulator software. Finally, the designed dual band antenna is fabricated and different measurement results are performed and compared with simulation results in order to validate its performances. The proposed antenna supports WiBro (wireless broadband), ISM, WiFi, Bluetooth, WiMAX and radars services.

  6. Circularly Polarized S Band Dual Frequency Square Patch Antenna Using Glass Microfiber Reinforced PTFE Composite

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    M. Samsuzzaman

    2014-01-01

    Full Text Available Circularly polarized (CP dual frequency cross-shaped slotted patch antenna on 1.575 mm thick glass microfiber reinforced polytetrafluoroethylene (PTFE composite material substrate is designed and fabricated for satellite applications. Asymmetric cross-shaped slots are embedded in the middle of the square patch for CP radiation and four hexagonal slots are etched on the four sides of the square patch for desired dual frequency. Different substrate materials have been analysed to achieve the desired operating band. The experimental results show that the impedance bandwidth is approximately 30 MHz (2.16 GHz to 2.19 GHz for lower band and 40 MHz (3.29 GHz to 3.33 GHz for higher band with an average peak gain of 6.59 dBiC and 5.52 dBiC, respectively. Several optimizations are performed to obtain the values of the antenna physical parameters. Moreover, the proposed antenna possesses compactness, light weight, simplicity, low cost, and circularly polarized. It is an attractive candidate for dual band satellite antennas where lower band can be used for uplink and upper band can be used for downlink.

  7. Analysis of single band and dual band graphene based patch antenna for terahertz region

    Science.gov (United States)

    George, Jemima Nissiyah; Madhan, M. Ganesh

    2017-10-01

    A microstrip patch antenna is designed using a very thin layer of graphene as the radiating patch, which is fed by a microstrip transmission line. The graphene based patch is designed on a silicon substrate having a dielectric constant of 11.9, to radiate at a single frequency of 2.6 THz. Further, this antenna is made to resonate at dual frequencies of 2.48 THz and 3.35 THz, by changing the substrate height, which is reported for the first time. Various antenna parameters such as return loss, VSWR, gain, efficiency and bandwidth are also determined for the single and dual band operation. For the single band operation, a bandwidth of 145.4 GHz and an efficiency of 92% was achieved. For dual band operation, a maximum bandwidth of 140.5 GHz was obtained at 3.35 THz and an efficiency of 87.3% was obtained at the first resonant frequency of 2.48 THz. The absorption cross section of the antenna is also analysed for various substrate heights and has maximum peaks at the corresponding resonating frequencies. The simulation has been carried out by using a full wave electromagnetic simulator based on FDTD method.

  8. Patch Antenna based on a Photovoltaic Cell with a Dual resonance Frequency

    Directory of Open Access Journals (Sweden)

    C. Baccouch

    2016-11-01

    Full Text Available The present work was to use photovoltaic solar cells in patch antenna structures. The radiating patch element of a patch antenna was replaced by a solar cell. Direct Current (DC generation remained the original feature of the solar cell, but additionally   it was now able to receive and transmit electromagnetic waves. Here, we used a new patch antenna structure based on a photovoltaic solar cell. It was then used to collect photo-generated current as well as Radio Frequency (RF transmission. A mathematical model which would serve the minimization of power losses of the cell and therefore the improvement in the conversion efficiency was studied. A simulation allowed analysing the performance of the antenna, with a silicon material, and testing its parameters such as the reflection coefficient (S11, gain, directivity and radiated power. The performance analysis of the solar cell patch antenna was conducted using Advanced Design System (ADS software. Simulation results for this antenna showed a dual resonance frequency of 5.77 GHz and of 6.18 GHz with an effective return loss of -38.22dB and a gain of 1.59dBi.

  9. A simple method of fast extracellular solution exchange for the study of whole-cell or single channel currents using patch-clamp technique.

    Science.gov (United States)

    Hering, S; Beech, D J; Bolton, T B

    1987-10-01

    A new concentration-jump technique was devised for the rapid application of drugs to single, isolated cells attached to the base of the experimental chamber while recording from them with patch-clamp technique. Cells were placed in a micro-drop (less than 0.1 microliter) in a small inner bath which was separated from an outer bath by a ring of "Sylgard" polymer. Stable whole-cell recordings were made in the micro-drop and rapid solution exchange took place when a much larger volume of test solution from the outer bath was flooded over the Sylgard ring and mixed with the micro-drop. Complete equilibration occurred within less than 10 ms.

  10. Mouse sperm patch-clamp recordings reveal single Cl- channels sensitive to niflumic acid, a blocker of the sperm acrosome reaction.

    Science.gov (United States)

    Espinosa, F; de la Vega-Beltrán, J L; López-González, I; Delgado, R; Labarca, P; Darszon, A

    1998-04-10

    Ion channels lie at the heart of gamete signaling. Understanding their regulation will improve our knowledge of sperm physiology, and may lead to novel contraceptive strategies. Sperm are tiny (approximately 3 microm diameter) and, until now, direct evidence of ion channel activity in these cells was lacking. Using patch-clamp recording we document here, for the first time, the presence of cationic and anionic channels in mouse sperm. Anion selective channels were blocked by niflumic acid (NA) (IC50 = 11 microM). The blocker was effective also in inhibiting the acrosome reaction induced by the zona pellucida, GABA or progesterone. These observations suggest that Cl- channels participate in the sperm acrosome reaction in mammals.

  11. Direct Effect of Remifentanil and Glycine Contained in Ultiva® on Nociceptive Transmission in the Spinal Cord: In Vivo and Slice Patch Clamp Analyses.

    Directory of Open Access Journals (Sweden)

    Makoto Sumie

    Full Text Available Ultiva® is commonly administered intravenously for analgesia during general anaesthesia and its main constituent remifentanil is an ultra-short-acting μ-opioid receptor agonist. Ultiva® is not approved for epidural or intrathecal use in clinical practice. Previous studies have reported that Ultiva® provokes opioid-induced hyperalgesia by interacting with spinal dorsal horn neurons. Ultiva® contains glycine, an inhibitory neurotransmitter but also an N-methyl-D-aspartate receptor co-activator. The presence of glycine in the formulation of Ultiva® potentially complicates its effects. We examined how Ultiva® directly affects nociceptive transmission in the spinal cord.We made patch-clamp recordings from substantia gelatinosa (SG neurons in the adult rat spinal dorsal horn in vivo and in spinal cord slices. We perfused Ultiva® onto the SG neurons and analysed its effects on the membrane potentials and synaptic responses activated by noxious mechanical stimuli.Bath application of Ultiva® hyperpolarized membrane potentials under current-clamp conditions and produced an outward current under voltage-clamp conditions. A barrage of excitatory postsynaptic currents (EPSCs evoked by the stimuli was suppressed by Ultiva®. Miniature EPSCs (mEPSCs were depressed in frequency but not amplitude. Ultiva®-induced outward currents and suppression of mEPSCs were not inhibited by the μ-opioid receptor antagonist naloxone, but were inhibited by the glycine receptor antagonist strychnine. The Ultiva®-induced currents demonstrated a specific equilibrium potential similar to glycine.We found that intrathecal administration of Ultiva® to SG neurons hyperpolarized membrane potentials and depressed presynaptic glutamate release predominantly through the activation of glycine receptors. No Ultiva®-induced excitatory effects were observed in SG neurons. Our results suggest different analgesic mechanisms of Ultiva® between intrathecal and intravenous

  12. Direct Effect of Remifentanil and Glycine Contained in Ultiva® on Nociceptive Transmission in the Spinal Cord: In Vivo and Slice Patch Clamp Analyses

    Science.gov (United States)

    Sumie, Makoto; Shiokawa, Hiroaki; Yamaura, Ken; Karashima, Yuji; Hoka, Sumio; Yoshimura, Megumu

    2016-01-01

    Background Ultiva® is commonly administered intravenously for analgesia during general anaesthesia and its main constituent remifentanil is an ultra-short-acting μ-opioid receptor agonist. Ultiva® is not approved for epidural or intrathecal use in clinical practice. Previous studies have reported that Ultiva® provokes opioid-induced hyperalgesia by interacting with spinal dorsal horn neurons. Ultiva® contains glycine, an inhibitory neurotransmitter but also an N-methyl-D-aspartate receptor co-activator. The presence of glycine in the formulation of Ultiva® potentially complicates its effects. We examined how Ultiva® directly affects nociceptive transmission in the spinal cord. Methods We made patch-clamp recordings from substantia gelatinosa (SG) neurons in the adult rat spinal dorsal horn in vivo and in spinal cord slices. We perfused Ultiva® onto the SG neurons and analysed its effects on the membrane potentials and synaptic responses activated by noxious mechanical stimuli. Results Bath application of Ultiva® hyperpolarized membrane potentials under current-clamp conditions and produced an outward current under voltage-clamp conditions. A barrage of excitatory postsynaptic currents (EPSCs) evoked by the stimuli was suppressed by Ultiva®. Miniature EPSCs (mEPSCs) were depressed in frequency but not amplitude. Ultiva®-induced outward currents and suppression of mEPSCs were not inhibited by the μ-opioid receptor antagonist naloxone, but were inhibited by the glycine receptor antagonist strychnine. The Ultiva®-induced currents demonstrated a specific equilibrium potential similar to glycine. Conclusions We found that intrathecal administration of Ultiva® to SG neurons hyperpolarized membrane potentials and depressed presynaptic glutamate release predominantly through the activation of glycine receptors. No Ultiva®-induced excitatory effects were observed in SG neurons. Our results suggest different analgesic mechanisms of Ultiva® between intrathecal

  13. The firing patterns of spinal neurons: in situ patch-clamp recordings reveal a key role for potassium currents.

    Science.gov (United States)

    Winlove, Crawford I P; Roberts, Alan

    2012-10-01

    Neuron firing patterns underpin the detection and processing of stimuli, influence synaptic interactions, and contribute to the function of networks. To understand how intrinsic membrane properties determine firing patterns, we investigated the biophysical basis of single and repetitive firing in spinal neurons of hatchling Xenopus laevis tadpoles, a well-understood vertebrate model; experiments were conducted in situ. Primary sensory Rohon-Beard (RB) neurons fire singly in response to depolarising current, and dorsolateral (DL) interneurons fire repetitively. RB neurons exhibited a large tetrodotoxin-sensitive sodium current; in DL neurons, the sodium current density was significantly lower. High-voltage-activated calcium currents were similar in both neuron types. There was no evidence of persistent sodium currents, low-voltage-activated calcium currents, or hyperpolarisation-activated currents. In RB neurons, the potassium current was dominated by a tetraethylammonium-sensitive slow component (I(Ks) ); a fast component (I(Kf) ), sensitive to 4-aminopyridine, predominated in DL neurons. Sequential current-clamp and voltage-clamp recordings in individual neurons suggest that high densities of I(Ks) prevent repetitive firing; where I(Ks) is small, I(Kf) density determines the frequency of repetitive firing. Intermediate densities of I(Ks) and I(Kf) allow neurons to fire a few additional spikes on strong depolarisation; this property typifies a novel subset of RB neurons, and may activate escape responses. We discuss how this ensemble of currents and firing patterns underpins the operation of the Xenopus locomotor network, and suggest how simple mechanisms might underlie the similar firing patterns seen in the neurons of diverse species.

  14. A New Fractal-Based Miniaturized Dual Band Patch Antenna for RF Energy Harvesting

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    Sika Shrestha

    2014-01-01

    Full Text Available The growth of wireless communications in recent years has made it necessary to develop compact, lightweight multiband antennas. Compact antennas can achieve the same performance as large antennas do with low price and with greater system integration. Dual-frequency microstrip antennas for transmission and reception represent promising approach for doubling the system capacity. In this work, a miniaturized dual band antenna operable at 2.45 and 5.8 GHz is constructed by modifying the standard microstrip patch antenna geometry into a fractal structure. In addition to miniaturization and dual band nature, the proposed antenna also removes unwanted harmonics without the use of additional filter component. Using a finite-element-method-based high frequency structure simulator (HFSS, the antenna is designed and its performance in terms of return loss, impedance matching, radiation pattern, and voltage standing wave ratio (VSWR is demonstrated. Simulation results are shown to be in close agreement with performance measurements from an actual antenna fabricated on an FR4 substrate. The proposed antenna can be integrated with a rectifier circuit to develop a compact rectenna that can harvest RF energy in both of these frequency bands at a reduction in size of 25.98% relative to a conventional rectangular patch antenna.

  15. Wideband Dual-linear Polarized Stacked Patch Antenna with Asymmery Feeding

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    Song Lizhong

    2013-07-01

    Full Text Available The narrow working bandwidth of microstrip antennas limits their applications in in radar and communication systems. Staked patch antenna based on aperture coupling and asymmetry feeding technique was proposed in this paper. A cross-shape aperture imbedded in the ground plane with asymmetry feeding structure provided a relative wideband electromagnetic coupling and allowed a high isolation between two orthogonal ports.The asymmetry feeding structure was composed of two microtrip lines locating above and under the ground plane. U-shape microtrip line adjusted microstrip feeding line characteristic impendence with antenna input impendence in a broad band. Experimental results indicated that an impendence bandwidth of 35.3%, better than 4.5dBi antenna gain, better than 30dB isolation and good cross-polarization were available. Measured results proved that stacked patches using asymmetry feeding structure through aperture coupling to expand working frequency and realize dual-linear polarization was effective.

  16. Patch clamp studies of human sperm under physiological ionic conditions reveal three functionally and pharmacologically distinct cation channels.

    Science.gov (United States)

    Mansell, S A; Publicover, S J; Barratt, C L R; Wilson, S M

    2014-05-01

    Whilst fertilizing capacity depends upon a K(+) conductance (GK) that allows the spermatozoon membrane potential (Vm) to be held at a negative value, the characteristics of this conductance in human sperm are virtually unknown. We therefore studied the biophysical/pharmacological properties of the K(+) conductance in spermatozoa from normal donors held under voltage/current clamp in the whole cell recording configuration. Our standard recording conditions were designed to maintain quasi-physiological, Na(+), K(+) and Cl(-) gradients. Experiments that explored the effects of ionic substitution/ion channel blockers upon membrane current/potential showed that resting Vm was dependent upon a hyperpolarizing K(+) current that flowed via channels that displayed only weak voltage dependence and limited (∼7-fold) K(+) versus Na(+) selectivity. This conductance was blocked by quinidine (0.3 mM), bupivacaine (3 mM) and clofilium (50 µM), NNC55-0396 (2 µM) and mibefradil (30 µM), but not by 4-aminopyridine (2 mM, 4-AP). Progesterone had no effect upon the hyperpolarizing K(+) current. Repolarization after a test depolarization consistently evoked a transient inward 'tail current' (ITail) that flowed via a second population of ion channels with poor (∼3-fold) K(+) versus Na(+) selectivity. The activity of these channels was increased by quinidine, 4-AP and progesterone. Vm in human sperm is therefore dependent upon a hyperpolarizing K(+) current that flows via channels that most closely resemble those encoded by Slo3. Although 0.5 µM progesterone had no effect upon these channels, this hormone did activate the pharmacologically distinct channels that mediate ITail. In conclusion, this study reveals three functionally and pharmacologically distinct cation channels: Ik, ITail, ICatSper.

  17. In vivo patch-clamp analysis of response properties of rat primary somatosensory cortical neurons responding to noxious stimulation of the facial skin

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    Nasu Masanori

    2010-05-01

    Full Text Available Abstract Background Although it has been widely accepted that the primary somatosensory (SI cortex plays an important role in pain perception, it still remains unclear how the nociceptive mechanisms of synaptic transmission occur at the single neuron level. The aim of the present study was to examine whether noxious stimulation applied to the orofacial area evokes the synaptic response of SI neurons in urethane-anesthetized rats using an in vivo patch-clamp technique. Results In vivo whole-cell current-clamp recordings were performed in rat SI neurons (layers III-IV. Twenty-seven out of 63 neurons were identified in the mechanical receptive field of the orofacial area (36 neurons showed no receptive field and they were classified as non-nociceptive (low-threshold mechanoreceptive; 6/27, 22% and nociceptive neurons. Nociceptive neurons were further divided into wide-dynamic range neurons (3/27, 11% and nociceptive-specific neurons (18/27, 67%. In the majority of these neurons, a proportion of the excitatory postsynaptic potentials (EPSPs reached the threshold, and then generated random discharges of action potentials. Noxious mechanical stimuli applied to the receptive field elicited a discharge of action potentials on the barrage of EPSPs. In the case of noxious chemical stimulation applied as mustard oil to the orofacial area, the membrane potential shifted depolarization and the rate of spontaneous discharges gradually increased as did the noxious pinch-evoked discharge rates, which were usually associated with potentiated EPSP amplitudes. Conclusions The present study provides evidence that SI neurons in deep layers III-V respond to the temporal summation of EPSPs due to noxious mechanical and chemical stimulation applied to the orofacial area and that these neurons may contribute to the processing of nociceptive information, including hyperalgesia.

  18. Inventing a co-axial atomic resolution patch clamp to study a single resonating protein complex and ultra-low power communication deep inside a living neuron cell.

    Science.gov (United States)

    Ghosh, Subrata; Sahu, Satyajit; Agrawal, Lokesh; Shiga, Takashi; Bandyopadhyay, Anirban

    2016-12-01

    To read the signals of single molecules in vitro on a surface, or inside a living cell or organ, we introduce a coaxial atom tip (coat) and a coaxial atomic patch clamp (COAPAP). The metal-insulator-metal cavity of these probes extends to the atomic scale (0.1[Formula: see text]nm), it eliminates the cellular or environmental noise with a S/N ratio 10(5). Five ac signals are simultaneously applied during a measurement by COAT and COAPAP to shield a true signal under environmental noise in five unique ways. The electromagnetic drive in the triaxial atomic tips is specifically designed to sense anharmonic vibrational and transmission signals for any system between 0.1[Formula: see text]nm and 50[Formula: see text]nm where the smallest nanopatch clamp cannot reach. COAT and COAPAP reliably pick up the atomic scale vibrations under the extreme noise of a living cell. Each protein's distinct electromagnetic, mechanical, electrical and ionic vibrational signature studied in vitro in a protected environment is found to match with the ones studied inside a live neuron. Thus, we could confirm that by using our probe blindly we could hold on to a single molecule or its complex in the invisible domain of a living cell. Our decade long investigations on perfecting the tools to measure bio-resonance of all forms and simultaneously in all frequency domains are summarized. It shows that the ratio of emission to absorption resonance frequencies of a biomaterial is around [Formula: see text], only a few in the entire em spectrum are active that regulates all other resonances, like mechanical, ionic, etc.

  19. Induction of pancreatic duct cells of neonatal rats into insulin-producing cells with fetal bovine serum: A natural protocol and its use for patch clamp experiments

    Institute of Scientific and Technical Information of China (English)

    San-Hua Leng; Fu-Er Lu

    2005-01-01

    AIM: To induce the pancreatic duct cells into endocrine cells with a new natural protocol for electrophysiological study.METHODS: The pancreatic duct cells of neonatal rats were isolated, cultured and induced into endocrine oells with 15% fetal bovine serum for a period of 20 d. During this period, insulin secretion, MTT value, and morphological change of neonatal and adult pancreatic islet cells were comparatively investigated. Pancreatic β-cells were identified by morphological and electrophysiological characteristics, while ATP sensitive potassium channels(KATP), voltage-dependent potassium channels (KV), and voltage-dependent calcium channels (KCA) in β-cells were identified by patch clamp technique.RESULTS: After incubation with fetal bovine serum, the neonatal duct cells budded out, changed from duct-like cells into islet clusters. In the first 4 d, MTT value and insulin secretion increased slowly (MTT value from 0.024±0.003 to0.028±0.003, insulin secretion from 2.6±0.6to 3.1±0.8 mIU/L). Then MTT value and insulin secretion increased quickly from d 5 to d 10 (MTT value from 0.028±0.003 to 0.052±0.008, insulin secretion from 3.1±0.8to 18.3±2.6 mIU/L), then reached high plateau (MTT value >0.052±0.008, insulin secretion >18.3±2.6 mIU/L).In contrast, for the isolated adult pancreatic islet cells,both insulin release and MTT value were stable in the first 4 d (MTT value from 0.029±0.01 to 0.031±0.011,insulin secretion from 13.9±3.1 to 14.3±3.3 mIU/L), but afterwards they reduced gradually (MTT value <0.031±0.011, insulin secretion <8.2±1.5 mIU/L), and the pancrearic islet cells became dispersed, broken or atrophied correspondingly. The differentiated neonatal cells were identified as pancreatic islet cells by dithizone staining method, and pancreatic β-cells were further identified by both morphological features and electrophysiological characteristics, i.e. the existence of recording currents from KATP KV, and KCA.CONCLUSION: Islet

  20. Patch clamp studies on root cell vacuoles of a salt-tolerant and a salt-sensitive plantago species : regulation of channel activity by salt stress.

    Science.gov (United States)

    Maathuis, F J; Prins, H B

    1990-01-01

    Plantago media L. and Plantago maritima L. differ in their strategy toward salt stress, a major difference being the uptake and distribution of ions. Patch clamp techniques were applied to root cell vacuoles to study the tonoplast channel characteristics. In both species the major channel found was a 60 to 70 picosiemens channel with a low ion selectivity. The conductance of this channel for Na(+) was the same as for K(+), P(K) (+)/P(Na) (+) = 1, whereas the cation/anion selectivity (P(K) (+)/P(c1) (-)) was about 5. Gating characteristics were voltage and calcium dependent. An additional smaller channel of 25 picosiemens was present in P. maritima. In the whole vacuole configuration, the summation of the single channel currents resulted in slowly activated inward currents (t((1/2)) = 1.2 second). Inwardly directed, ATP-dependent currents could be measured against a DeltapH gradient of 1.5 units over the tonoplast. This observation strongly indicated the physiological intactness of the used vacuoles. The open probability of the tonoplast channels dramatically decreased when plants were grown on NaCl, although single channel conductance and selectivity were not altered.

  1. Structural and Functional Diversity of Peptide Toxins from Tarantula Haplopelma hainanum (Ornithoctonus hainana) Venom Revealed by Transcriptomic, Peptidomic, and Patch Clamp Approaches.

    Science.gov (United States)

    Zhang, Yi-Ya; Huang, Yong; He, Quan-Ze; Luo, Ji; Zhu, Li; Lu, Shan-Shan; Liu, Jin-Yan; Huang, Peng-Fei; Zeng, Xiong-Zhi; Liang, Song-Ping

    2015-05-29

    Spider venom is a complex mixture of bioactive peptides to subdue their prey. Early estimates suggested that over 400 venom peptides are produced per species. In order to investigate the mechanisms responsible for this impressive diversity, transcriptomics based on second generation high throughput sequencing was combined with peptidomic assays to characterize the venom of the tarantula Haplopelma hainanum. The genes expressed in the venom glands were identified, and the bioactivity of their protein products was analyzed using the patch clamp technique. A total of 1,136 potential toxin precursors were identified that clustered into 90 toxin groups, of which 72 were novel. The toxin peptides clustered into 20 cysteine scaffolds that included between 4 and 12 cysteines, and 14 of these groups were newly identified in this spider. Highly abundant toxin peptide transcripts were present and resulted from hypermutation and/or fragment insertion/deletion. In combination with variable post-translational modifications, this genetic variability explained how a limited set of genes can generate hundreds of toxin peptides in venom glands. Furthermore, the intraspecies venom variability illustrated the dynamic nature of spider venom and revealed how complex components work together to generate diverse bioactivities that facilitate adaptation to changing environments, types of prey, and milking regimes in captivity.

  2. In vivo whole-cell patch-clamp recording of sensory synaptic responses of cingulate pyramidal neurons to noxious mechanical stimuli in adult mice

    Directory of Open Access Journals (Sweden)

    Descalzi Giannina

    2010-09-01

    Full Text Available Abstract The anterior cingulate cortex (ACC plays important roles in emotion, learning, memory and persistent pain. Our previous in vitro studies have demonstrated that pyramidal neurons in layer II/III of the adult mouse ACC can be characterized into three types: regular spiking (RS, intermediate (IM and intrinsic bursting (IB cells, according to their action potential (AP firing patterns. However, no in vivo information is available for the intrinsic properties and sensory responses of ACC neurons of adult mice. Here, we performed in vivo whole-cell patch-clamp recordings from pyramidal neurons in adult mice ACC under urethane anesthetized conditions. First, we classified the intrinsic properties and analyzed their slow oscillations. The population ratios of RS, IM and IB cells were 10, 62 and 28%, respectively. The mean spontaneous APs frequency of IB cells was significantly greater than those of RS and IM cells, while the slow oscillations were similar among ACC neurons. Peripheral noxious pinch stimuli induced evoked spike responses in all three types of ACC neurons. Interestingly, IB cells showed significantly greater firing frequencies than RS and IM cells. In contrast, non-noxious brush did not induce any significant response. Our studies provide the first in vivo characterization of ACC neurons in adult mice, and demonstrate that ACC neurons are indeed nociceptive. These findings support the critical roles of ACC in nociception, from mice to humans.

  3. Gain Enhancement and comparison of rectangular slot patch antenna circular slot patch antenna using dual FSS superstrate Layer

    Directory of Open Access Journals (Sweden)

    Preeti Chaudhary,

    2013-10-01

    Full Text Available In this paper, Circular Microstrip Patch Antenna and Rectangular Slot Patch Antenna comparison of present and an effort is made to optimize the gain to show better performance analysis on the basis of design and simulation results by implementing FSS structured superstrate layer at operating frequency of 5.8 GHz for ISM Band. The proposed design will be fed by coaxial probe feed, in order to get proper impedance matching. Design technique for enhancing Bandwidth that improves the performance of a conventional microstrip patch antenna is proposed. In order to show our results better, we have made a comparative analysis with conventional microstrip patch antenna, at the same frequency band to increase the gain, directivity and minimize the return loss of the desired antenna. This simulation results are carried out by using Ansoft based HFSS software.

  4. Isolation and culture of sinus node cells and identification of patch clamp technique in neonatal rabbits%乳兔窦房结细胞的分离及鉴定

    Institute of Scientific and Technical Information of China (English)

    刘如秀; 刘宇; 汪艳丽; 彭杰; 徐利亚

    2013-01-01

    Objective To summarize the isolation, purification, culture and identification of sinus node cells ( SNC ) in neonatal rabbits. Methods New Zealand neonatal rabbits ( n=5 ) were selected and from them SNC were digested and isolated by using dual anzymolysis. The isolated SNC were purified and cultured by using differential adherence combining 5-BrdU. The morphological changes of SNC were observed and action potential was recorded by using patch clamp technique. Results The morphological forms of cultured SNC were mainly spindle cells, triangular cells and irregular cells and fusiformis was the most with the fastest beating rate, which was accorded with the characteristics of SNC. Among action potential recorded from 10 spindle cells by patch clamp technique, the average maximum diastolic potential was ( -50.9 ± 5.3 ) mV and amplitude of action potential was ( 61.9 ±4.8 ) mV. Conclusion The active condition of SNC digested, isolated and purified by using dual enzymolysis, differential adherenc and 5-BrdU are quite good with typical action potential.%目的 乳兔窦房结细胞(sinus node cell,SNC)的分离、纯化、培养与鉴定.方法 选用新生新西兰乳兔5只,采用双酶解法对细胞进行消化分离,差速贴壁结合5-BrdU对分离的细胞进行纯化培养,观察SNC形态变化并采用全细胞膜片钳技术对SNC进行动作电位的记录.结果 培养得到的SNC主要有3种形态:梭形、三角形与不规则形,而梭形细胞最多,搏动频率最快,符合窦房结细胞的特征.采用膜片钳技术记录10个梭形细胞的动作电位中,平均最大舒张电位为(-50.9±5.3)mV,动作电位幅度为(61.9±4.8)mV.结论 采用双酶解、差速贴壁及BrdU对乳兔窦房结细胞进行消化、分离可得到纯化的SNC,此种方法得到的SNC状态活性良好,且具有典型特征的动作电位.

  5. Development of a patch type embedded cardiac function monitoring system using dual microprocessor for arrhythmia detection in heart disease patient.

    Science.gov (United States)

    Jang, Yongwon; Noh, Hyung Wook; Lee, I B; Jung, Ji-Wook; Song, Yoonseon; Lee, Sooyeul; Kim, Seunghwan

    2012-01-01

    A patch type embedded cardiac function monitoring system was developed to detect arrhythmias such as PVC (Premature Ventricular Contraction), pause, ventricular fibrillation, and tachy/bradycardia. The overall system is composed of a main module including a dual processor and a Bluetooth telecommunication module. The dual microprocessor strategy minimizes power consumption and size, and guarantees the resources of embedded software programs. The developed software was verified with standard DB, and showed good performance.

  6. A Double Inverted F-Shape Patch Antenna for Dual-Band Operation

    Directory of Open Access Journals (Sweden)

    M. M. Islam

    2014-01-01

    Full Text Available A double inverted F-shape patch antenna is presented for dual-band operation. The proposed antenna is comprised of circular and rectangular slots on a printed circuit board of 40 mm × 40 mm × 1.6 mm with a 50 Ω microstrip transmission line. Commercially available high frequency structural simulator (HFSS based on the finite element method (FEM has been adopted in this investigation. It has a measured impedance bandwidths (2 : 1 VSWR of 18.53% on the lower band and 7.8% on the upper band, respectively. It has achieved stable radiation efficiencies of 79.76% and 80.36% with average gains of 7.82 dBi and 5.66 dBi in the operating frequency bands. Moreover, numerical simulations have been indicated as an important uniformity with measured results.

  7. Stabilizing dual-energy X-ray computed tomography reconstructions using patch-based regularization

    CERN Document Server

    Tracey, Brian H

    2014-01-01

    Recent years have seen growing interest in exploiting dual- and multi-energy measurements in computed tomography (CT) in order to characterize material properties as well as object shape. Material characterization is performed by decomposing the scene into constitutive basis functions, such as Compton scatter and photoelectric absorption functions. While well motivated physically, the joint recovery of the spatial distribution of photoelectric and Compton properties is severely complicated by the fact that the data are several orders of magnitude more sensitive to Compton scatter coefficients than to photoelectric absorption, so small errors in Compton estimates can create large artifacts in the photoelectric estimate. To address these issues, we propose a model-based iterative approach which uses patch-based regularization terms to stabilize inversion of photoelectric coefficients, and solve the resulting problem though use of computationally attractive Alternating Direction Method of Multipliers (ADMM) solu...

  8. Design and analysis of inverted H shape dual band patch antenna for microwave application

    Science.gov (United States)

    Ullah, M. Habib; Islam, M. T.; Mandeep, J. S.; Misran, N.; Reaz, M. B. I.

    2013-04-01

    Design and analysis of an inverted H shape printed dual band patch antenna has been presented in this paper. The proposed antenna has designed by 3-D full wave high frequency electromagnetic simulator HFSS and printed in low cost, durable epoxy polymer resin composite material substrate. The printed antenna prototype has been measured in a standard far field anechoic electromagnetic field measurement chamber. The measured results have analyzed by using computer aided plotting tool OriginPro 8.5. Measured -10 dB return loss bandwidth 3.25 GHz from 9.75 GHz to 13 GHz with peak gain 8.5 dBi have been achieved. The proposed antenna has obtained 0.63 dBi gain with 96% efficiency at lower band 10.3 GHz and 6.03 dBi gain with 84.2% efficiency at upper band 12.5 GHz. The almost steady radiation pattern makes the proposed antenna appropriate for part of X and Ku band applications. Moreover, the input impedance and current distribution along the radiating patch of the proposed antenna have also been analyzed in this paper.

  9. High-Throughput Screening of Na(V)1.7 Modulators Using a Giga-Seal Automated Patch Clamp Instrument.

    Science.gov (United States)

    Chambers, Chris; Witton, Ian; Adams, Cathryn; Marrington, Luke; Kammonen, Juha

    2016-03-01

    Voltage-gated sodium (Na(V)) channels have an essential role in the initiation and propagation of action potentials in excitable cells, such as neurons. Of these channels, Na(V)1.7 has been indicated as a key channel for pain sensation. While extensive efforts have gone into discovering novel Na(V)1.7 modulating compounds for the treatment of pain, none has reached the market yet. In the last two years, new compound screening technologies have been introduced, which may speed up the discovery of such compounds. The Sophion Qube(®) is a next-generation 384-well giga-seal automated patch clamp (APC) screening instrument, capable of testing thousands of compounds per day. By combining high-throughput screening and follow-up compound testing on the same APC platform, it should be possible to accelerate the hit-to-lead stage of ion channel drug discovery and help identify the most interesting compounds faster. Following a period of instrument beta-testing, a Na(V)1.7 high-throughput screen was run with two Pfizer plate-based compound subsets. In total, data were generated for 158,000 compounds at a median success rate of 83%, which can be considered high in APC screening. In parallel, IC50 assay validation and protocol optimization was completed with a set of reference compounds to understand how the IC50 potencies generated on the Qube correlate with data generated on the more established Sophion QPatch(®) APC platform. In summary, the results presented here demonstrate that the Qube provides a comparable but much faster approach to study Na(V)1.7 in a robust and reliable APC assay for compound screening.

  10. 用于膜片钳研究的大鼠背根神经节细胞急性分离技术的改良%Modification of the procedure for dissociating rats' dorsal root ganglion cells used for patch clamp

    Institute of Scientific and Technical Information of China (English)

    邱方; 刘艳红; 姜雨鸽; 张树卓; 刘晓燕; 米卫东

    2012-01-01

    目的 通过技术改良,进一步摸索适于膜片钳实验的成年大鼠背根神经节(dorsal root ganglion,DRG)细胞的急性分离方法.方法 应用显微外科技术获取成年大鼠DRG,采用改良的双酶顺序消化(先胶原酶,后胰蛋白酶)及双血清(胎牛血清+马血清)共同培养法,急性分离培养DRG.倒置显微镜下观察神经元的形态,选取已贴壁的细胞,用全细胞膜片钳技术记录其基本膜电生理特性.加入河豚毒素(tetrodotoxin,TTX)后再次记录DRG神经元的钠离子电流变化.结果 本实验可获得形态良好、结构完整的单个DRG神经元,表面光亮,胞膜完整清晰,呈圆形或椭圆形.其静息膜电位为(55.22±4.39)mV,加入TTX后可记录到缓慢失活的河豚毒素不敏感(tetrodotoxin-resistant,TTX-r)的钠离子电流.其中,中等直径DRG神经元高阻封接成功率为73.2%,高于小直径和大直径DRG神经元的封接成功率(P<0.05).结论 经改良的DRG急性分离方法分离效率高、可操作性强.分离得到的中等直径DRG神经元状态良好,更适合膜片钳实验.%Objective To modify the previous procedure for dissociating rats' dorsal root ganglion (DRG) cells used for whole-cell patch-clamp studies. Methods The rats' DRGs were obtained by microsurgical techniques, and then the DRG cells were acutely dissociated and acquired with optimized culture method including dual enzyme digestion and dual serum incubation. After a short-time of culture, the DRG neurons were observed under inverted microscope and those with normal morphologic characterstics were selected for the further studies. The basic electrophysiological membrane characteristics and sodium channel currents were recorded by whole-cell patch-clamp technique before and after the administration of TTX, respectively. Results The cultured DRG cells, which were acutely dissociated and acquired with optimized method, were morphologically intact with a round or oval shape and smooth

  11. Late cardiac sodium current can be assessed using automated patch-clamp [v1; ref status: indexed, http://f1000r.es/4kj

    Directory of Open Access Journals (Sweden)

    Morgan Chevalier

    2014-10-01

    Full Text Available The cardiac late Na+ current is generated by a small fraction of voltage-dependent Na+ channels that undergo a conformational change to a burst-gating mode, with repeated openings and closures during the action potential (AP plateau. Its magnitude can be augmented by inactivation-defective mutations, myocardial ischemia, or prolonged exposure to chemical compounds leading to drug-induced (di-long QT syndrome, and results in an increased susceptibility to cardiac arrhythmias. Using CytoPatch™ 2 automated patch-clamp equipment, we performed whole-cell recordings in HEK293 cells stably expressing human Nav1.5, and measured the late Na+ component as average current over the last 100 ms of 300 ms depolarizing pulses to -10 mV from a holding potential of -100 mV, with a repetition frequency of 0.33 Hz. Averaged values in different steady-state experimental conditions were further corrected by the subtraction of current average during the application of tetrodotoxin (TTX 30 μM. We show that ranolazine at 10 and 30 μM in 3 min applications reduced the late Na+ current to 75.0 ± 2.7% (mean ± SEM, n = 17 and 58.4 ± 3.5% (n = 18 of initial levels, respectively, while a 5 min application of veratridine 1 μM resulted in a reversible current increase to 269.1 ± 16.1% (n = 28 of initial values. Using fluctuation analysis, we observed that ranolazine 30 μM decreased mean open probability p from 0.6 to 0.38 without modifying the number of active channels n, while veratridine 1 μM increased n 2.5-fold without changing p. In human iPSC-derived cardiomyocytes, veratridine 1 μM reversibly increased APD90 2.12 ± 0.41-fold (mean ± SEM, n = 6. This effect is attributable to inactivation removal in Nav1.5 channels, since significant inhibitory effects on hERG current were detected at higher concentrations in hERG-expressing HEK293 cells, with a 28.9 ± 6.0% inhibition (mean ± SD, n = 10 with 50 μM veratridine.      

  12. Reduction of the spatially mutual coupling between dual-polarized patch antennas using coupled metamaterial slabs

    Science.gov (United States)

    Pan, Bai Cao; Tang, Wen Xuan; Qi, Mei Qing; Ma, Hui Feng; Tao, Zui; Cui, Tie Jun

    2016-01-01

    Mutual coupling inside antenna array is usually caused by two routes: signal leakage via conducting currents on the metallic background or surface wave along substrates; radio leakage received from space between antenna elements. The former one can be depressed by changing the distribution of surface currents, as reported in literatures. But when it comes to the latter one, the radiation-leakage-caused coupling, traditional approaches using circuit manipulation may be inefficient. In this article, we propose and design a new type of decoupling module, which is composed of coupled metamaterial (MTM) slabs. Two classes of MTM particles, the interdigital structure (IS) and the split-ring resonators (SRRs), are adopted to provide the first and second modulations of signal. We validate its function to reduce the radiation leakage between two dual-polarized patch antennas. A prototype is fabricated in a volume with subwavelength scale (0.6λ × 0.3λ × 0.053λ) to provide 7dB improvement for both co-polarization and cross-polarization isolations from 1.95 to 2.2 GHz. The design has good potential for wireless communication and radar systems. PMID:27444147

  13. Reduction of the spatially mutual coupling between dual-polarized patch antennas using coupled metamaterial slabs.

    Science.gov (United States)

    Pan, Bai Cao; Tang, Wen Xuan; Qi, Mei Qing; Ma, Hui Feng; Tao, Zui; Cui, Tie Jun

    2016-07-22

    Mutual coupling inside antenna array is usually caused by two routes: signal leakage via conducting currents on the metallic background or surface wave along substrates; radio leakage received from space between antenna elements. The former one can be depressed by changing the distribution of surface currents, as reported in literatures. But when it comes to the latter one, the radiation-leakage-caused coupling, traditional approaches using circuit manipulation may be inefficient. In this article, we propose and design a new type of decoupling module, which is composed of coupled metamaterial (MTM) slabs. Two classes of MTM particles, the interdigital structure (IS) and the split-ring resonators (SRRs), are adopted to provide the first and second modulations of signal. We validate its function to reduce the radiation leakage between two dual-polarized patch antennas. A prototype is fabricated in a volume with subwavelength scale (0.6λ × 0.3λ × 0.053λ) to provide 7dB improvement for both co-polarization and cross-polarization isolations from 1.95 to 2.2 GHz. The design has good potential for wireless communication and radar systems.

  14. The assessment of electrophysiological activity in human-induced pluripotent stem cell-derived cardiomyocytes exposed to dimethyl sulfoxide and ethanol by manual patch clamp and multi-electrode array system.

    Science.gov (United States)

    Hyun, Soo-Wang; Kim, Bo-Ram; Hyun, Sung-Ae; Seo, Joung-Wook

    2017-09-01

    Recently, electrophysiological activity has been effectively measured in human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to predict drug-induced arrhythmia. Dimethyl sulfoxide (DMSO) and ethanol have been used as diluting agents in many experiments. However, the maximum DMSO and ethanol concentrations that can be effectively used in the measurement of electrophysiological parameters in hiPSC-CMs-based patch clamp and multi-electrode array (MEA) have not been fully elucidated. We investigated the effects of varying concentrations of DMSO and ethanol used as diluting agents on several electrophysiological parameters in hiPSC-CMs using patch clamp and MEA. Both DMSO and ethanol at concentrations>1% in external solution resulted in osmolality >400mOsmol/kg, but pH was not affected by either agent. Neither DMSO nor ethanol led to cell death at the concentrations examined. However, resting membrane potential, action potential amplitude, action potential duration at 90% and 40%, and corrected field potential duration were decreased significantly at 1% ethanol concentration. DMSO at 1% also significantly decreased the sodium spike amplitude. In addition, the waveform of action potential and field potential was recorded as irregular at 3% concentrations of both DMSO and ethanol. Concentrations of up to 0.3% of either agent did not affect osmolality, pH, cell death, or electrophysiological parameters in hiPSC-CMs. Our findings suggest that 0.3% is the maximum concentration at which DMSO or ethanol should be used for dilution purposes in hiPSC-CMs-based patch clamp and MEA. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Effect of temperature on the activation of myocardial KATP channel in guinea pig ventricular myocytes: a pilot study by whole cell patch clamp recording

    Institute of Scientific and Technical Information of China (English)

    JIN San-qing; NIU Li-jun; DENG Chun-yu; YAO Zhi-bin; ZHOU Ying-jie

    2006-01-01

    Background The myocardial ATP sensitive potassium channel (KATP channel) has been known for more than two decades, the properties of this channel have been intensively investigated, especially the myocardial protection effect by opening this channel. Numerous studies, including hypothermic, using KATP agonists to achieve a hyperpolarizing cardioplegic arrest, have shown a better myocardial protection than potassium arrest.However, there is no evidence showing that KATP channel could be opened by its agonists under profound hypothermia. We investigated the effect of temperature on activation of myocardial KATP channel by nicorandil.Methods Isolated ventricular myocytes were obtained by collagenase digestion of the hearts of guinea pigs and stored in KB solution at 4℃. With a steady ground current, the myocytes were perfused with 1 mmol/L nicorandil until a steady IKATP occurred. Then the cells were perfused with 1 mmol/L nicorandil plus 1 μmol/L glybenclamide. Currents signals were recorded on whole cells using patch clamp technique at several temperatures. The temperature of the bath solution around myocytes was monitored and was controlled at 4℃,10℃, 20℃, 25℃ and 35℃ respectively. About 10 cells were tested at each temperature, the cells were considered useful only when the outward current could be induced by nicorandil and blocked by glybenclamide.All data were analyzed using Graphpad PRISM 3.0 (Graphpad, San Diego, CA, USA). Nonlinear curve fitting was done in Clampfit (Axon) or Sigmaplot (SPSS).Results At 4℃, 10℃, 20℃, 25℃ and 35℃, the time needed to open the myocardial KATP channel was (81.0±0)minutes, (50.5±11.7) minutes, (28.8±2.3) minutes, (9.4±10.2) minutes and (2.3± 1.0) minutes respectively (P=0.003). The linear relationship between temperature and time needed to open the channel was y (min) =(4348.790-124.277x)/60, where y (min) is time needed to open KATP channel, x is temperature, correlation coefficient r =-0.942 (P=0

  16. Modified low temperature Czochralski growth of xylenol orange doped benzopheone single crystal for fabricating dual band patch antenna

    Science.gov (United States)

    Yadav, Harsh; Sinha, Nidhi; Kumar, Binay

    2016-09-01

    Organic non-linear optical pure and xylenol orange (XO) doped benzophenone (BP) single crystals have been grown by a modified Czochralski technique. A low cost CZ system was designed and fabricated that is suitable for the growth of single crystals of low melting point organic materials. Structural analysis was performed by powder and single crystal XRD. LC-HRMS spectra reveal that the dye molecules are present in the doped crystal. The linear optical characterization was carried out by UV-vis spectroscopy. In the case of the XO doped BP crystal, two absorption peaks were found at 504 nm and 620 nm. The enhancement of photoluminescence intensity of blue emission was observed in the dye doped crystal. Dielectric studies reveal that the XO doped BP has shown improved a dielectric constant with low dielectric loss. A dual band compact circular patch antenna was simulated and fabricated using the XO doped crystal. Resonant frequencies of the dual bands at 4.80 GHz and 9.22 GHz were achieved by introducing a defect ground state in the circular patch antenna. The piezoelectric coefficient (d33) value was increased from 1 to 4 pC/N by XO dye doping, which opens up the possibilities of simultaneous transducer applications.

  17. Application of Patch-clamp Technique in Insect Toxin Action Mechanism%膜片钳技术在昆虫毒素作用机理研究中的应用

    Institute of Scientific and Technical Information of China (English)

    王瑞兰

    2013-01-01

    On the basis of introducing the function of patch-clamp technique and ion channel, the insecticide action mechanism (insect Na + channel toxin) was reviewed,as well as its application in new type safety insecticides development,which can provide reference for the research and development of insecticides.%在介绍膜片钳技术和离子通道的作用的基础上,综述了膜片钳技术在杀虫作用机理(昆虫Na+通道毒素)及新型安全生物杀虫剂研发中的应用,为新型安全生物杀虫剂的研发提供了参考.

  18. Broadband matching of dual-linear polarisation stacked probe-fed microstrip patch antenna

    DEFF Research Database (Denmark)

    Jaworski, G.; Krozer, Viktor

    2004-01-01

    A novel approach for impedance matching of probe-fed, stacked microstrip patch antenna elements is demonstrated. The matching structure is compact and enables more than doubling of the operational bandwidth. A circuit model for the feeding probes is developed and its impact on antenna impedance...

  19. 穿孔膜片钳方法记录L型钙通道及脱氢紫堇碱对其影响的研究%Recording L-type calcium channel current by perforated patch clamp and effect of dehydrocorydaline on L-type calcium channel

    Institute of Scientific and Technical Information of China (English)

    孟红旭; 王宝; 刘建勋

    2011-01-01

    Aim To observe the difference of recording L-type calcium channel currents over time through by whole cell patch clamp and perforated patch clamp method and the effect of dehydrocorydaline on L-type calcium channel by perforated patch clamp method.Methods Whole cell patch clamp and perforated patch clamp were used to record L-type calcium channel current in acutely isolated rat ventricular myocytes.Results The L-type calcium channel current peak recorded by whole cell patch clamp decayed of the ( 34 ±23 )% ( n =10 ) within 15 minutes, while using perforated patch clamp, L-type calcium channel current peak attenuated ( 2. 7 ±3. 4 )% ( n =9 ) within 15 minutes; The inhibitory effect of ginsenoside Re( 100μmol · L-1 ) could be clearlv recorded by perforated patch clamp method. while the current decaying produced by whole cell patch clamp almost completely overshadowed the effects of ginsenoside Re. Dehydrocorydaline ( 10, 100 μmol · L-1 ) could inhibit L-type calcium channel current peak and the inhibitory rates were ( 9 ±7. 5 )%( n =5 )and ( 28. 6 ±8. 5 )%( n =5 )individually. Conclusions Perforated patch clamp method has more stability and accuracy than ordinary whole-cell patch clamp technique in recording L-type calcium channel current; dehydrocorydaline can suppress L-type calcium channel in a concentration-dependent manner.%目的 比较全细胞膜片钳和穿孔膜片钳方法记录大鼠心室肌细胞L型钙通道电流随时间经过的变化差异,并观察脱氢紫堇碱对L型钙通道的影响.方法 采用全细胞膜片钳和穿孔膜片钳方法记录急性分离的大鼠心室肌细胞L型钙通道电流.结果 采用全细胞膜片钳法记录到的L型钙通道电流峰值在15 min内衰减了(34±23)%(n=10),采用穿孔膜片钳方法记录到的L型钙通道电流峰值15 min内仅衰减了(2.7±3.4)%(n=9);采用穿孔膜片钳方法能够记录到人参皂苷Re(100 μmol·L-1)的抑制效应,而采用全细胞膜片钳方法产

  20. Nanogenerator-based dual-functional and self-powered thin patch loudspeaker or microphone for flexible electronics

    Science.gov (United States)

    Li, Wei; Torres, David; Díaz, Ramón; Wang, Zhengjun; Wu, Changsheng; Wang, Chuan; Lin Wang, Zhong; Sepúlveda, Nelson

    2017-05-01

    Ferroelectret nanogenerators were recently introduced as a promising alternative technology for harvesting kinetic energy. Here we report the device's intrinsic properties that allow for the bidirectional conversion of energy between electrical and mechanical domains; thus extending its potential use in wearable electronics beyond the power generation realm. This electromechanical coupling, combined with their flexibility and thin film-like form, bestows dual-functional transducing capabilities to the device that are used in this work to demonstrate its use as a thin, wearable and self-powered loudspeaker or microphone patch. To determine the device's performance and applicability, sound pressure level is characterized in both space and frequency domains for three different configurations. The confirmed device's high performance is further validated through its integration in three different systems: a music-playing flag, a sound recording film and a flexible microphone for security applications.

  1. MATLAB implementation of a dynamic clamp with bandwidth >125 KHz capable of generating INa at 37°C

    Science.gov (United States)

    Clausen, Chris; Valiunas, Virginijus; Brink, Peter R.; Cohen, Ira S.

    2012-01-01

    We describe the construction of a dynamic clamp with bandwidth >125 KHz that utilizes a high performance, yet low cost, standard home/office PC interfaced with a high-speed (16 bit) data acquisition module. High bandwidth is achieved by exploiting recently available software advances (code-generation technology, optimized real-time kernel). Dynamic-clamp programs are constructed using Simulink, a visual programming language. Blocks for computation of membrane currents are written in the high-level matlab language; no programming in C is required. The instrument can be used in single- or dual-cell configurations, with the capability to modify programs while experiments are in progress. We describe an algorithm for computing the fast transient Na+ current (INa) in real time, and test its accuracy and stability using rate constants appropriate for 37°C. We then construct a program capable of supplying three currents to a cell preparation: INa, the hyperpolarizing-activated inward pacemaker current (If), and an inward-rectifier K+ current (IK1). The program corrects for the IR drop due to electrode current flow, and also records all voltages and currents. We tested this program on dual patch-clamped HEK293 cells where the dynamic clamp controls a current-clamp amplifier and a voltage-clamp amplifier controls membrane potential, and current-clamped HEK293 cells where the dynamic clamp produces spontaneous pacing behavior exhibiting Na+ spikes in otherwise passive cells. PMID:23224681

  2. Dual Polarization Stacked Microstrip Patch Antenna Array With Very Low Cross-Polarization

    DEFF Research Database (Denmark)

    Granholm, Johan; Woelders, Kim

    2001-01-01

    This paper describes the development and performance of a wideband dual linear polarization microstrip antenna array used in the Danish high-resolution airborne multifrequency polarimetric synthetic aperture radar, EMISAR. The antenna was designed for an operating frequency of 1.25 GHz±50 MHz and...

  3. Permeability of R6G across C×43 hemichannels through a novel combination of patch clamp and surface enhanced Raman spectroscopy

    Indian Academy of Sciences (India)

    C madhavan Nair; C Sabna; K V G K Murty; S V Ramanan

    2005-10-01

    We have measured the permeability of rhodamine-6G across C×43 hemichannels reconstituted on a pipette tip. C×43 hemichannels were overexpressed in Sf9 cells, and affinity-purified. The hemichannels were reconstituted in a lipid bilayer on a pipette tip by the tip-dip method. R6G in the pipette permeated across the channels into the bath. The permeability of R6G was quantified by measuring R6G concentration in the bath after several hours by surface enhanced Raman spectroscopy (SERS) with 100 nm silver colloid particles. The ratio of the permeability of dye to salt, as extracted by this combined electrical-SERS technique, is compatible with similar ratios for other dyes across whole gap junction channels. The results for the permeability ratio were further compared to fluorescence measurements. The novel combination of patch and SERS techniques can be extended to quantifying the transport of biologically significant non-fluorescent molecules, such as cAMP and IP3, across 1 nm sized pores, such as the gap junction channel.

  4. Dual Band Parasitic Element Patch Antenna for LTE/WLAN Applications

    Directory of Open Access Journals (Sweden)

    BAG Biplab

    2017-05-01

    Full Text Available In this paper, a single layer coaxial fed dual band slotted microstrip antenna is proposed. The proposed antenna consists of two direct couple parasitic elements and L-shape slots on the main resonating element. Two resonant modes are excited and it covers 4G LTE and WLAN middle band. The -10dB impedance bandwidth for resonant frequency of 2.35GHz and 5.28GHz are 140MHz (2.25-2.39GHz and 570MHz (5.18-5.75GHz, respectively. The measured VSWR at 2.35GHz is 1.27 and at 5.28GHz is 1.41. The proposed antenna is simple in design and compact in size. The simulated and measured results are in good agreement.

  5. All-Metal Dual-Polarized W-band Patch Element for Phased Array Antenna Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Metal patches were developed for the Juno Microwave radiometer instrument at P-band and L-band. The absence of dielectric in the metal patch design obviated issues...

  6. 一种适合膜片钳试验的新生大鼠背根神经节细胞的培养方法%A culture method of dosal root ganglion cells from new-born rats in patch clamp experiments

    Institute of Scientific and Technical Information of China (English)

    马涛; 冯泽国; 张宏; 王维; 陶颖

    2011-01-01

    目的 建立一种适合膜片钳实验的大鼠乳鼠背根神经节细胞的培养方法.方法 在显微镜及显微外科手术器械的辅助下,分离并培养新生大鼠的背根神经元(Dorsal Root Ganglion,DRG),观察培养细胞的形态,膜片钳记录细胞静息电位水平.结果 DRG神经元细胞形态结构完整,静息电位水平正常,可记录到动作电位及钠电流.结论 培养的新生大鼠DRG细胞适合膜片钳试验.%Objective To establish a culture method of dorsal root ganglion (DRG) cells from rats in patch clamp experiments. Methods DRG cells from rats were isolated using microsurgical instruments under microscope and cultured. Morphology of the cultured cells was observed and their resting electric potential was recorded using patch-clamps. Results The morphological structure of cultured ORG cells was intact, their resting electric potential was normal, and the Na+ channel current could be recorded. Conclusion Cultured DRG cells from new-born rats can be used in patch-clamp experiments.

  7. To clamp or not to clamp late?

    Directory of Open Access Journals (Sweden)

    Nicoletta Iacovidou

    2013-04-01

    Full Text Available When resuscitating a neonate, one encounters controversial issues and a great deal of confusion. These issues include the question as to when should the umbilical cord be clamped. Clamping and cutting the umbilical cord at birth is the oldest intervention in humans. Even though many aspects of the timing for cord clamping have been clarified, some questions still remain unanswered. If delayed cord clamping is to become a standard approach which timing is the optimal? And depending on the mode of delivery should timing be the same or different for normal vaginal delivery or for caesarean section? What about  the compromised neonate, or the very preterm one? We have more questions than answers. More randomized controlled studies are needed in normal and pathologic neonates, in order to address these questions, before we practice delayed cord clamping with safety for the babies and the mothers.

  8. Simulation of thin slot spirals and dual circular patch antennas using the finite element method with mixed elements

    Science.gov (United States)

    Gong, Jian; Volakis, John L.; Nurnberger, Michael W.

    1995-01-01

    This semi-annual report describes progress up to mid-January 1995. The report contains five sections all dealing with the modeling of spiral and patch antennas recessed in metallic platforms. Of significance is the development of decomposition schemes which separate the different regions of the antenna volume. Substantial effort was devoted to improving the feed model in the context of the finite element method (FEM). Finally, an innovative scheme for truncating finite element meshes is presented.

  9. A Design Of Feeding Network For A Dual-Linear Polarization, Stacked, Probe-Fed Microstrip Patch Antenna Array

    DEFF Research Database (Denmark)

    Jaworski, G.; Krozer, Viktor

    2004-01-01

    Components of multilayer feed network are presented for application in broad-band dual-linear polarized stacked C-band antenna. Measurement results of wide band matching circuits and different types of power divider networks constituting parts of BFN demonstrate wideband operation. Suitable...

  10. Photovoltaic panel clamp

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Malcolm P.; Mittan, Margaret Birmingham; Miros, Robert H. J.; Stancel, Robert

    2013-03-19

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  11. Photovoltaic panel clamp

    Science.gov (United States)

    Mittan, Margaret Birmingham; Miros, Robert H. J.; Brown, Malcolm P.; Stancel, Robert

    2012-06-05

    A photovoltaic panel clamp includes an upper and lower section. The interface between the assembled clamp halves and the module edge is filled by a flexible gasket material, such as EPDM rubber. The gasket preferably has small, finger like protrusions that allow for easy insertion onto the module edge while being reversed makes it more difficult to remove them from the module once installed. The clamp includes mounting posts or an integral axle to engage a bracket. The clamp also may include a locking tongue to secure the clamp to a bracket.

  12. Radial wedge flange clamp

    Science.gov (United States)

    Smith, Karl H.

    2002-01-01

    A radial wedge flange clamp comprising a pair of flanges each comprising a plurality of peripheral flat wedge facets having flat wedge surfaces and opposed and mating flat surfaces attached to or otherwise engaged with two elements to be joined and including a series of generally U-shaped wedge clamps each having flat wedge interior surfaces and engaging one pair of said peripheral flat wedge facets. Each of said generally U-shaped wedge clamps has in its opposing extremities apertures for the tangential insertion of bolts to apply uniform radial force to said wedge clamps when assembled about said wedge segments.

  13. Piezoresistive cantilever force-clamp system

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung-Jin; Petzold, Bryan C.; Pruitt, Beth L. [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Goodman, Miriam B. [Department of Molecular and Cellular Physiology, Stanford University, Stanford, California 94305 (United States)

    2011-04-15

    We present a microelectromechanical device-based tool, namely, a force-clamp system that sets or ''clamps'' the scaled force and can apply designed loading profiles (e.g., constant, sinusoidal) of a desired magnitude. The system implements a piezoresistive cantilever as a force sensor and the built-in capacitive sensor of a piezoelectric actuator as a displacement sensor, such that sample indentation depth can be directly calculated from the force and displacement signals. A programmable real-time controller operating at 100 kHz feedback calculates the driving voltage of the actuator. The system has two distinct modes: a force-clamp mode that controls the force applied to a sample and a displacement-clamp mode that controls the moving distance of the actuator. We demonstrate that the system has a large dynamic range (sub-nN up to tens of {mu}N force and nm up to tens of {mu}m displacement) in both air and water, and excellent dynamic response (fast response time, <2 ms and large bandwidth, 1 Hz up to 1 kHz). In addition, the system has been specifically designed to be integrated with other instruments such as a microscope with patch-clamp electronics. We demonstrate the capabilities of the system by using it to calibrate the stiffness and sensitivity of an electrostatic actuator and to measure the mechanics of a living, freely moving Caenorhabditis elegans nematode.

  14. Novel Microstrip Patch Antennas with Frequency Agility, Polarization Reconfigurability, Dual Null Steering Capability and Phased Array Antenna with Beam Steering Performance

    Science.gov (United States)

    Babakhani, Behrouz

    Nowadays the wireless communication technology is playing an important role in our daily life. People use wireless devices not only as a conventional communication device but also as tracking and navigation tool, web browsing tool, data storage and transfer tool and so for many other reasons. Based on the user demand, wireless communication engineers try to accommodate as many as possible wireless systems and applications in a single device and therefore, creates a multifunctional device. Antenna, as an integral part of any wireless communication systems, should also be evolved and adjusted with development of wireless transceiver systems. Therefore multifunctional antennas have been introduced to support and enhance the functionality on modern wireless systems. The main focus and contribution of this thesis is design of novel multifunctional microstrip antennas with frequency agility, polarization reconfigurablity, dual null steering capability and phased array antenna with beam steering performance. In this thesis, first, a wide bandwidth(1.10 GHz to 1.60 GHz) right-handed circularly polarized (RHCP) directional antenna for global positioning system (GPS) satellite receive application has been introduced which covers all the GPS bands starting from L1 to L5. This design consists of two crossed bow-tie dipole antennas fed with sequentially phase rotated feed network backed with an artificial high impedance surface (HIS) structure to generate high gain directional radiation patterns. This design shows good CP gain and axial ratio (AR) and wide beamwidth performance. Although this design has good radiation quality, the size and the weight can be reduced as future study. In the second design, a frequency agile antenna was developed which also covers the L-band (L1 to L5) satellite communication frequencies. This frequency agile antenna was designed and realized by new implementation of varactor diodes in the geometry of a circular patch antenna. Beside wide frequency

  15. A dual potassium channel activator improves repolarization reserve and normalizes ventricular action potentials

    DEFF Research Database (Denmark)

    Calloe, Kirstine; Di Diego, José M; Hansen, Rie Schultz

    2016-01-01

    in cultured canine cardiac myocytes and determined whether a dual K(+) current activator can normalize K(+) currents and restore action potential (AP) configuration. METHODS AND RESULTS: Ventricular myocytes were isolated and cultured for up to 48h. Current and voltage clamp recordings were made using patch...... of EADs. Our results suggest a potential benefit of K(+) current activators under conditions of reduced repolarization reserve including heart failure....

  16. 脊髓切片中运动神经元的膜片箝技术研究:一种分析药物作用的高效工具%Patch clamp studies of motor neurons in spinal cord slices: a toolfor high-resolution analysis of drug actions

    Institute of Scientific and Technical Information of China (English)

    WANG Meng-Ya; Joan J KENDIG

    2000-01-01

    AIM: To develop a tool for detailed analysis of spinally acting anesthetic and analgesic agents. METHODS:Studies were done on visually identified motor neurons in 400 μm thick spinal cord slices from 14- 23 d old rats using patch clamp techniques. Ethanol was used as a prototype general anesthetic agent. RESULTS: Cell bodies in the ventrolateral horn identified as motor neurons by retrograde fluorescent labeling had a mean dimension of 32 ±5μm (x±s, n = 25). Mean resting potential was - 62.8 ± 2.4 mV; input resistance was 44±24MΩ (n=19). Threshold was -44±7 mV,and action potential amplitude 101 ± 9 mV from baseline.Ethanol concentrations at and below 50-200 mmol/L decreased motor neuron excitability to the injected current; there was no effect on resting potential, but a variable reversible increase in input resistance. Ethanol reversibly depressed the excitatory postsynaptic potential,with a dose-response relationship similar to that previously observed for the population excitatory postsynaptic potential in intact spinal cord in vitro. Ethanol also reversibly depressed currents evoked by glutamate, reducing total charge transfer to 40%±26% of control (x±s; n= 4). CONCLUSION: Reduction of connectivity in this relatively thick slice preparation does not significantly modify drag actions. The actions of ethanol on excitatory synaptic transmission observed in intact spinal cord are

  17. Establishment of patch clamp and laser scanning confocal microscope synchronous real-time control system and its application in study of membranaceous calcium channel%膜片钳-激光扫描共聚焦显微镜同步实时控制系统的建立及其在心肌细胞膜钙离子通道研究中的应用

    Institute of Scientific and Technical Information of China (English)

    刘红; 王晔; 汤莹; 沈亚峰; 杨勇骥; 雷长海

    2012-01-01

    Objective To establish a patch clamp and laser scanning confocal microscope synchronous real-time control system, and apply it in study of membranaceous calcium channel, so as to verify its effects. Methods By adding the patch clamp on the laser scanning confocal microscope, we established a patch clamp and laser scanning confocal microscope synchronous real-time control system using computer autocontrol technique. The system was used to observe the male rat membranaceous calcium channel in vitro, and the observation results were analyzed. Results We successfully established the patch clamp and laser scanning confocal microscope synchronous real-time control system. When the myocardial cells were stimulated, the system could observe the myocardial calcium spark by laser scanning confocal microscope and at the same time record calcium channel current signal by patch-clamp. Quantitative analysis showed that the time intervals between 2 adjacent calcium sparks were (10.055 + 0.021), (10.079 + 0.021) and (10.087 + 0.021) s, which met the stimulus interval for patch-clamp set (10 s). A single calcium spark had a diameter within 2 μm, and it experienced an average period of about 30 ms. It needed an average of 10 ms from the appearance of the spark to its peak concentrations, and it needed an average of 20 ms from its peak concentration to disappearance, which was consistent with the calcium spark theory. Conclusion A patch clamp and laser scanning confocal microscope synchronous real-time control system has been successfully established. The system is capable of performing whole-cell observation recording and determining the membranaceous calcium channel currents and its closing process by patch clamp; at the same time it can synchronously obtain the micro images of the calcium spark with laserscanning confocal microscope, locating changes of calcium ions and helping to understand the internal mechanism of the membrane calcium channels.%目的 建立膜片钳-激光

  18. 一种改进的适用于膜片钳记录的成年大鼠海马神经元急性分离法%An improved method for acute isolation of neurons from the hippocampus of adult rats suitable for patch-clamping study

    Institute of Scientific and Technical Information of China (English)

    李晓明; 李建国; 杨建明; 胡平; 李晓文; 王颖; 覃鲁宁; 高天明

    2004-01-01

    An improved method is described for fast and reliable isolation of neurons from hippocampus of adult rats by acombination of mechanical and enzymatic means. The procedure allows the isolation of neurons from 500~600-d-old rats (over300 g), preserving the proximal dendritic structure without impairing the electrical characteristics of the cells. Morphologicallydistinct neurons can be recognized. Using cell-attached, inside-out and whole-cell configurations of patch clamp technique, it wasshown that the enzymatically isolated neurons in hippocampus from rats weighing more than 300 g exhibited voltage-gatedcalcium, sodium and potassium currents, outwardly rectifying chloride channel and large conductance Ca2+-activated potassiumchannel currents. Approximately, 95% of healthy cells allowed the formation of giga-ohm seals.%本文建立了一种快速、可靠的急性分离成年大鼠海马神经细胞的方法.此法可将实验大鼠的年龄提高到500 d以上,体重300 g以上;不损伤神经细胞膜的电学特性;形态上有差异的细胞易于分辨.用膜片钳技术的单通道和全细胞模式证实,在本实验条件下,约95%左右的健康细胞均能形成高阻抗封接,并成功地记录了电压依赖性钾、钠、钙通道,外向整流氯通道和大电导的钙激活钾通道电流.

  19. RF MEMS reconfigurable triangular patch antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Christodoulou, Christos George (The University of New Mexico, Albuquerque, NM); Nordquist, Christopher Daniel; Feldner, Lucas Matthew

    2005-07-01

    A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

  20. RF MEMS reconfigurable triangular patch antenna.

    Energy Technology Data Exchange (ETDEWEB)

    Nordquist, Christopher Daniel; Christodoulou, Christos George (University of New Mexico, Albuquerque, NM); Feldner, Lucas Matthew

    2005-01-01

    A Ka-band RF MEMS enabled frequency reconfigurable triangular microstrip patch antenna has been designed for monolithic integration with RF MEMS phase shifters to demonstrate a low-cost monolithic passive electronically scanned array (PESA). This paper introduces our first prototype reconfigurable triangular patch antenna currently in fabrication. The aperture coupled patch antenna is fabricated on a dual-layer quartz/alumina substrate using surface micromachining techniques.

  1. Single electrode dynamic clamp with StdpC.

    Science.gov (United States)

    Samu, David; Marra, Vincenzo; Kemenes, Ildiko; Crossley, Michael; Kemenes, György; Staras, Kevin; Nowotny, Thomas

    2012-10-15

    Dynamic clamp is a powerful approach for electrophysiological investigations allowing researchers to introduce artificial electrical components into target neurons to simulate ionic conductances, chemical or electrotonic inputs or connections to other cells. Due to the rapidly changing and potentially large current injections during dynamic clamp, problematic voltage artifacts appear on the electrode used to inject dynamic clamp currents into a target neuron. Dynamic clamp experiments, therefore, typically use two separate electrodes in the same cell, one for recording membrane potential and one for injecting currents. The requirement for two independent electrodes has been a limiting factor for the use of dynamic clamp in applications where dual recordings of this kind are difficult or impossible to achieve. The recent development of an active electrode compensation (AEC) method has overcome some of these prior limitations, permitting artifact-free dynamic clamp experimentation with a single electrode. Here we describe an AEC method for the free dynamic clamp software StdpC. The AEC component of StdpC is the first such system implemented for the use of non-expert users and comes with a set of semi-automated configuration and calibration procedures that facilitate its use. We briefly introduce the AEC method and its implementation in StdpC and then validate it with an electronic model cell and in two different biological preparations.

  2. Polysaccharide-Containing Macromolecules in a Kampo (Traditional Japanese Herbal Medicine, Hochuekkito: Dual Active Ingredients for Modulation of Immune Functions on Intestinal Peyer's Patches and Epithelial cells

    Directory of Open Access Journals (Sweden)

    Hiroaki Kiyohara

    2011-01-01

    Full Text Available A traditional Japanese herbal (Kampo medicine, Hochuekkito (Bu-Zhong-Yi-Qi-Tang in Chinese, TJ-41 is a well-known Kampo formula, and has been found to enhance antigen-specific antibody response in not only local mucosal immune system in upper respiratory tract, but also systemic immune system through upper respiratory mucosal immune system. Although this immunopharmacological effect has been proposed to express by modulation of intestinal immune system including Peyer's patches and intestinal epithelial cells, active ingredients are not known. TJ-41 directly affected the production of bone marrow cell-proliferative growth factors from murine Peyer's patch immunocompetent cells in vitro. Among low molecular, intermediate size and macromolecular weight fractions prepared from TJ-41, only fraction containing macromolecular weight ingredients showed Peyer's patch-mediated bone marrow cell-proliferation enhancing activity. Anion-exchange chromatography and gel filtration gave 17 subfractions comprising polysaccharides and lignins from the macromolecular weight fraction of TJ-41, and some of the subfractions showed significant enhancing activities having different degrees. Some of the subfractions also expressed stimulating activity on G-CSF-production from colonic epithelial cells, and statistically significant positive correlation was observed among enhancing activities of the subfractions against Peyer's patch immunocompetent cells and epithelial cells. Among the fractions from TJ-41 oral administration of macromolecular weight ingredient fraction to mice succeeded to enhance antigen-specific antibody response in systemic immune system through upper respiratory mucosal immune system, but all the separated fractions failed to enhance the in vivo antibody response in upper respiratory tract.

  3. Implementing dynamic clamp with synaptic and artificial conductances in mouse retinal ganglion cells.

    Science.gov (United States)

    Huang, Jin Y; Stiefel, Klaus M; Protti, Dario A

    2013-05-16

    Ganglion cells are the output neurons of the retina and their activity reflects the integration of multiple synaptic inputs arising from specific neural circuits. Patch clamp techniques, in voltage clamp and current clamp configurations, are commonly used to study the physiological properties of neurons and to characterize their synaptic inputs. Although the application of these techniques is highly informative, they pose various limitations. For example, it is difficult to quantify how the precise interactions of excitatory and inhibitory inputs determine response output. To address this issue, we used a modified current clamp technique, dynamic clamp, also called conductance clamp (1, 2, 3) and examined the impact of excitatory and inhibitory synaptic inputs on neuronal excitability. This technique requires the injection of current into the cell and is dependent on the real-time feedback of its membrane potential at that time. The injected current is calculated from predetermined excitatory and inhibitory synaptic conductances, their reversal potentials and the cell's instantaneous membrane potential. Details on the experimental procedures, patch clamping cells to achieve a whole-cell configuration and employment of the dynamic clamp technique are illustrated in this video article. Here, we show the responses of mouse retinal ganglion cells to various conductance waveforms obtained from physiological experiments in control conditions or in the presence of drugs. Furthermore, we show the use of artificial excitatory and inhibitory conductances generated using alpha functions to investigate the responses of the cells.

  4. The World-Line Quantum Mechanics Model at Finite Temperature which is Dual to the Static Patch Observer in de Sitter Space

    CERN Document Server

    Nakayama, Ryuichi

    2011-01-01

    A simple conformal quantum mechanics model of a d-component variable is proposed, which exactly reproduces the retarded Green functions and conformal weights of conformally coupled scalar fields in de Sitter spacetime seen by a static patch observer. It is found that the action integral of this model is automatically expressed by a complex integral over the time variable t along a closed contour in a way which is typical to the Schwinger-Keldysh formalism of a thermofield theory. Hence this model is at finite temperature. The case of conformally coupled scalar fields in 3d Schwarzschild de Sitter space is also considered and then a large-N matrix model is obtained.

  5. Capacitance of circular patch resonator

    Energy Technology Data Exchange (ETDEWEB)

    Miano, G.; Verolino, L. [Dip. di Ingegneria Elettrica, Ist. Nazionale di Fisica Nucleare, Naples (Italy); Panariello, G. [Dip. di Ingegneria Elettronica, Naples (Italy); Vaccaro, V.G. [Ist. Nazionale di Fisica Nucleare, Naples (Italy). Dipt. di Scienze Fisiche

    1995-11-01

    In this paper the capacitance of the circular microstrip patch resonator is computed. It is shown that the electrostatic problem can be formulated as a system of dual integral equations, and the most interesting techniques of solutions of these systems are reviewed. Some useful approximated formulas for the capacitance are derived and plots of the capacitance are finally given in a wide range of dielectric constants.

  6. Management of umbilical cord clamping.

    Science.gov (United States)

    Webbon, Lucy

    2013-02-01

    The Royal College of Midwives (RCM) has updated its third stage of labour guidelines (RCM 2012) to be clearly supportive of a delay in umbilical cord clamping, although specific guidance on timing is yet to be announced. It is therefore imperative that both midwives and student midwives understand and are able to integrate delaying into their practice, as well as communicating to women the benefits; only in this way can we give women fully informed choices on this aspect of care. The main benefit of delayed cord clamping is the protection it can provide in reducing childhood anaemia, which is a major issue, especially in poorer countries. A review of the evidence found no risks linked to delayed clamping, and no evidence that it cannot be used in combination with the administration of uterotonic drugs. Delayed cord clamping can be especially beneficial for pre term and compromised babies.

  7. Diclofenac Transdermal Patch

    Science.gov (United States)

    Transdermal diclofenac comes as a patch to apply to the skin. Diclofenac patches are usually applied two times a day, once every ... your regular schedule. Do not apply an extra diclofenac patch to make up for a missed dose.

  8. Robotic Partial Nephrectomy Using Robotic Bulldog Clamps

    OpenAIRE

    2011-01-01

    Background and Objectives: The need for a skilled assistant to perform hilar clamping during robotic partial nephrectomy is a potential limitation of the technique. We describe our experience using robotic bulldog clamps applied by the console surgeon for hilar clamping. Methods: A total of 60 consecutive patients underwent robotic partial nephrectomy, 30 using laparoscopic bulldog clamps applied by the assistant and 30 using robotic bulldog clamps applied with the robotic Prograsp instrument...

  9. Clamp wins pipe repair prize

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    2001-04-01

    This paper describes the permanent pipeline repair system, developed by Tekmar, which is powered by seawater hydraulics and is easily installed and tested by any workclass remotely operated vehicle (rov). Details are given of the two main components of the system, namely, the diverless high pressure split repair clamp and the rov-operated tool to install it.

  10. Multifrequency Excitation of a Clamped-Clamped Microbeam

    KAUST Repository

    Jaber, Nizar R.

    2016-01-20

    We present analytical and experimental investigation of an electrically actuated clamped-clamped microbeam under a twosource harmonic excitation. The first frequency is swept around the first mode of vibration where the second one is fixed. These microbeams are fabricated using polyimide as structural layer coated with nickel form top and chromium and gold layers from bottom. We demonstrate the excitation of additive and subtractive type resonance. We show that by properly tuning the frequency and the amplitude of the excitation force, the frequency bandwidth of the resonator is increased. Theoretically, we solved the eigenvalue problem for different axial forces to find the natural frequencies ratio that match the experimental values. Using Galerkin method, a reduced order model is derived to simulate the static and dynamic response of the device where using three symmetric mode shapes provided a good agreement with experimental data. © Copyright 2015 by ASME.

  11. Metal Patch Antenna

    Science.gov (United States)

    Chamberlain, Neil F. (Inventor); Hodges, Richard E. (Inventor); Zawadzki, Mark S. (Inventor)

    2012-01-01

    Disclosed herein is a patch antenna comprises a planar conductive patch attached to a ground plane by a support member, and a probe connector in electrical communication with the conductive patch arranged to conduct electromagnetic energy to or from the conductive patch, wherein the conductive patch is disposed essentially parallel to the ground plane and is separated from the ground plane by a spacing distance; wherein the support member comprises a plurality of sides disposed about a central axis oriented perpendicular to the conductive patch and the ground plane; wherein the conductive patch is solely supported above the ground plane by the support member; and wherein the support member provides electrical communication between the planer conductive patch and the ground plane.

  12. A Microstripe Slotted Patch Antenna Using Amc

    Directory of Open Access Journals (Sweden)

    Manju Saini,

    2014-04-01

    Full Text Available Microstrip patch antenna offer an attractive solution to compact and ease-low-cost design of modern wireless communication system due to their many advantages as light weight and low volume, low profile, planer configuration which can be easily made conformal to low fabrication cost and capability of obtaining dual and triple frequency operations. A microstrip patch antenna with bandwidth enhancement by means of artificial magnetic conductor (AMC/electromagnetic band-gap structure (EBG is studied in this paper. The three different geometry shapes, the U, E and H are developed from rectangular patch. The antennas studied in this paper are simulated using sonnet software and results compared with the conventional rectangular patch antenna. The results obtained clearly shows that , bandwidth of conventional rectangular microstrip antenna can be enhanced has been studied

  13. Analysis list: Clamp [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Clamp Cell line + dm3 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clamp.1....tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clamp.5.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/target/Clam...p.10.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Clamp.Cell_line.tsv http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/colo/Cell_line.gml ...

  14. Sleep Sleeping Patch

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    The Sleep Sleeping Patch is a new kind of external patch based on modern sleep medicine research achievements, which uses the internationally advanced transdermal therapeutic system (TTS). The Sleep Sleeping Patch transmits natural sleep inducers such as peppermint and liquorice extracts and melatonin through the skin to induce sleep. Clinical research proves that the Sleep Sleeping Patch can effectively improve insomnia and the quality of sleep. Highly effective: With the modern TTS therapy,

  15. Birth Control Patch

    Science.gov (United States)

    ... Surgery? A Week of Healthy Breakfasts Shyness Birth Control Patch KidsHealth > For Teens > Birth Control Patch Print A A A What's in this ... Does It Cost? What Is It? The birth control patch is a thin, beige, 1¾-inch (4½- ...

  16. Birth Control Patch

    Science.gov (United States)

    ... Loss Surgery? A Week of Healthy Breakfasts Shyness Birth Control Patch KidsHealth > For Teens > Birth Control Patch A A A What's in this article? ... Much Does It Cost? What Is It? The birth control patch is a thin, beige, 1¾-inch (4½- ...

  17. Is early cord clamping, delayed cord clamping or cord milking best?

    Science.gov (United States)

    Vatansever, Binay; Demirel, Gamze; Ciler Eren, Elif; Erel, Ozcan; Neselioglu, Salim; Karavar, Hande Nur; Gundogdu, Semra; Ulfer, Gozde; Bahadir, Selcen; Tastekin, Ayhan

    2017-03-20

    To compare the antioxidant status of three cord clamping procedures (early clamping, delayed clamping and milking) by analyzing the thiol-disulfide balance. This randomized controlled study enrolled 189 term infants who were divided into three groups according to the cord clamping procedure: early clamping, delayed clamping and milking. Blood samples were collected from the umbilical arteries immediately after clamping, and the thiol/disulfide homeostasis was analyzed. The native and total thiol levels were significantly (p cord clamping group compared with the other two groups. The disulfide/total thiol ratio was significantly (p = .026) lower in the delayed cord clamping and milking groups compared with the early clamping groups. Early cord clamping causes the production of more disulfide bonds and lower thiol levels, indicating that oxidation reactions are increased in the early cord clamping procedure compared with the delayed cord clamping and milking procedures. The oxidant capacity is greater with early cord clamping than with delayed clamping or cord milking. Delayed cord clamping or milking are beneficial in neonatal care, and we suggest that they be performed routinely in all deliveries.

  18. Delayed umbilical cord clamping in premature neonates.

    Science.gov (United States)

    Kaempf, Joseph W; Tomlinson, Mark W; Kaempf, Andrew J; Wu, YingXing; Wang, Lian; Tipping, Nicole; Grunkemeier, Gary

    2012-08-01

    Delayed umbilical cord clamping is reported to increase neonatal blood volume. We estimated the clinical outcomes in premature neonates who had delayed umbilical cord clamping compared with a similar group who had early umbilical cord clamping. This was a before-after investigation comparing early umbilical cord clamping with delayed umbilical cord clamping (45 seconds) in two groups of singleton neonates, very low birth weight (VLBW) (401-1,500 g) and low birth weight (LBW) (greater than 1,500 g but less than 35 weeks gestation). Neonates were excluded from delayed umbilical cord clamping if they needed immediate major resuscitation. Primary outcomes were provision of delivery room resuscitation, hematocrit, red cell transfusions, and the principle Vermont Oxford Network outcomes. In VLBW neonates (77 delayed umbilical cord clamping, birth weight [mean±standard deviation] 1,099±266 g; 77 early umbilical cord clamping 1,058±289 g), delayed umbilical cord clamping was associated with less delivery room resuscitation, higher Apgar scores at 1 minute, and higher hematocrit. Delayed umbilical cord clamping was not associated with significant differences in the overall transfusion rate, peak bilirubin, any of the principle Vermont Oxford Network outcomes, or mortality. In LBW neonates (172 delayed umbilical cord clamping, birth weight [mean±standard deviation] 2,159±384 g; 172 early umbilical cord clamping 2,203±447 g), delayed umbilical cord clamping was associated with higher hematocrit and was not associated with a change in delivery room resuscitation or Apgar scores or with changes in the transfusion rate or peak bilirubin. Regression analysis showed increasing gestational age and birth weight and delayed umbilical cord clamping were the best predictors of higher hematocrit and less delivery room resuscitation. Delayed umbilical cord clamping can safely be performed in singleton premature neonates and is associated with a higher hematocrit, less delivery room

  19. Loading dynamics of a sliding DNA clamp.

    KAUST Repository

    Cho, Won-Ki

    2014-05-22

    Sliding DNA clamps are loaded at a ss/dsDNA junction by a clamp loader that depends on ATP binding for clamp opening. Sequential ATP hydrolysis results in closure of the clamp so that it completely encircles and diffuses on dsDNA. We followed events during loading of an E. coli β clamp in real time by using single-molecule FRET (smFRET). Three successive FRET states were retained for 0.3 s, 0.7 s, and 9 min: Hydrolysis of the first ATP molecule by the γ clamp loader resulted in closure of the clamp in 0.3 s, and after 0.7 s in the closed conformation, the clamp was released to diffuse on the dsDNA for at least 9 min. An additional single-molecule polarization study revealed that the interfacial domain of the clamp rotated in plane by approximately 8° during clamp closure. The single-molecule polarization and FRET studies thus revealed the real-time dynamics of the ATP-hydrolysis-dependent 3D conformational change of the β clamp during loading at a ss/dsDNA junction.

  20. The RFC clamp loader: structure and function.

    Science.gov (United States)

    Yao, Nina Y; O'Donnell, Mike

    2012-01-01

    The eukaryotic RFC clamp loader couples the energy of ATP hydrolysis to open and close the circular PCNA sliding clamp onto primed sites for use by DNA polymerases and repair factors. Structural studies reveal clamp loaders to be heteropentamers. Each subunit contains a region of homology to AAA+ proteins that defines two domains. The AAA+ domains form a right-handed spiral upon binding ATP. This spiral arrangement generates a DNA binding site within the center of RFC. DNA enters the central chamber through a gap between the AAA+ domains of two subunits. Specificity for a primed template junction is achieved by a third domain that blocks DNA, forcing it to bend sharply. Thus only DNA with a flexible joint can bind the central chamber. DNA entry also requires a slot in the PCNA clamp, which is opened upon binding the AAA+ domains of the clamp loader. ATP hydrolysis enables clamp closing and ejection of RFC, completing the clamp loading reaction.

  1. Performance of NBPE in Rectangular Microstrip Patch Antenna

    Directory of Open Access Journals (Sweden)

    Tushar

    2014-02-01

    Full Text Available In this paper we use a rectangular microstrip patch antenna with fed patch contains four notches of equal Length and width (L×W and having one parasitic patch, to achieve dual band operation of proposed microstrip patch antenna, is analyzed using circuit theory concept. The theoretical and simulated results of proposed antenna are compared. The return loss of NBPE using rectangular microstrip patch antenna decreased and bandwidth at dual operating frequency 1.44 GHz & 1.80 GHz are increased at a substrate height of 1.6 mm. This paper shows the decreased in return loss & improves in Gain as well as bandwidth using NBPE. These structures are simulated using IE3D version 12.29 Zeland software incorporation.

  2. Granisetron Transdermal Patch

    Science.gov (United States)

    ... are pregnant, plan to become pregnant, or are breastfeeding. If you become pregnant while using transdermal granisetron, call your doctor.plan to protect the granisetron patch and the skin around it from real and artificial sunlight (tanning beds, sunlamps). Keep the patch covered ...

  3. Electrostatic clamp manufactured by novel method

    NARCIS (Netherlands)

    Sligte, E. te; Storm, A.; Koster, N.B.

    2011-01-01

    Electrostatic clamps (ESCs), used in reticle and wafer handling, are presently manufactured using glass bonding and polishing technologies. We present a patented alternative concept to this process, relying on coating and etching processes rather than bonding. We manufactured a first prototype clamp

  4. 21 CFR 870.4450 - Vascular clamp.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Vascular clamp. 870.4450 Section 870.4450 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CARDIOVASCULAR DEVICES Cardiovascular Surgical Devices § 870.4450 Vascular clamp. (a) Identification. A vascular...

  5. Time to implement delayed cord clamping.

    Science.gov (United States)

    McAdams, Ryan M

    2014-03-01

    Immediate umbilical cord clamping after delivery is routine in the United States despite little evidence to support this practice. Numerous trials in both term and preterm neonates have demonstrated the safety and benefit of delayed cord clamping. In premature neonates, delayed cord clamping has been shown to stabilize transitional circulation, lessening needs for inotropic medications and reducing blood transfusions, necrotizing enterocolitis, and intraventricular hemorrhage. In term neonates, delayed cord clamping has been associated with decreased iron-deficient anemia and increased iron stores with potential valuable effects that extend beyond the newborn period, including improvements in long-term neurodevelopment. The failure to more broadly implement delayed cord clamping in neonates ignores published benefits of increased placental blood transfusion at birth and may represent an unnecessary harm for vulnerable neonates.

  6. Combat ready clamp medic technique.

    Science.gov (United States)

    Tovmassian, Robert V; Kragh, John F; Dubick, Michael A; Baer, David G; Blackbourne, Lorne H

    2012-01-01

    Junctional hemorrhage control device use on the battlefield might be lifesaving, but little experience is reported. The purpose of the present case report is to detail prehospital use of the Combat Ready Clamp (called the CRoC by its users, Combat Medical Systems, Fayetteville, NC; Instructions for Use, 2010) in casualty care in order to increase awareness of junctional hemorrhage control. The CRoC was used to control difficult inguinal bleeding on the battlefield for an Afghani man with a hindquarter traumatic amputation. The device promptly controlled exsanguination from a critical injury when placed during rotary-wing casualty evacuation. The flight medic applied the device in 90 seconds. The device performed well without complications to control bleeding. The CRoC, a new junctional hemorrhage control device, was used as indicated on the battlefield with mechanical and physiologic success and without device problems. By controlling difficult inguinal bleeding resulting from battlefield trauma, the device facilitated casualty stabilization and delivery to a surgical facility. The device facilitated the ability of a new flight medic to focus his expertise on a critically injured battlefield casualty with demonstrable success. 2012.

  7. Oxybutynin Transdermal Patch

    Science.gov (United States)

    ... clothing, and where it will be protected from sunlight by clothing. After you apply a patch to ... stomach extreme tiredness drowsiness headache blurred vision flushing back pain Some side effects can be serious. The following ...

  8. Windows Security patch required

    CERN Multimedia

    2003-01-01

    This concerns Windows PCs (XP, 2000, NT) which are NOT centrally managed at CERN for security patches, e.g. home PCs, experiment PCs, portables, ... A security hole which can give full privileges on Windows systems needs to be URGENTLY patched. Details of the security hole and hotfix are at: http://cern.ch/it-div/news/hotfix-MS03-026.asp http://www.microsoft.com/technet/security/bulletin/MS03-026.asp

  9. Windows Security patch required

    CERN Multimedia

    2003-01-01

    This concerns Windows PCs which are NOT centrally managed at CERN for security patches, e.g. home PCs, experiment PCs, portables, ... A security hole which can give full privileges on Windows systems needs to be URGENTLY patched. Details of the security hole and hotfix are at: http://cern.ch/it-div/news/hotfix-MS03-026.asp http://www.microsoft.com/technet/security/bulletin/MS03-026.asp

  10. Windows Security patch required

    CERN Multimedia

    3004-01-01

    This concerns Windows PCs (XP, 2000, NT) which are NOT centrally managed at CERN for security patches, e.g. home PCs, experiment PCs, portables,... A security hole which can give full privileges on Windows systems needs to be URGENTLY patched. Details of the security hole and hotfix are at: http://cern.ch/it-div/news/hotfix-MS03-026.asp http://www.microsoft.com/technet/security/bulletin/MS03-026.asp

  11. Windows Security patch required

    CERN Multimedia

    2003-01-01

    This concerns Windows PCs (XP, 2000, NT) which are NOT centrally managed at CERN for security patches, e.g. home PCs, experiment PCs, portables,... A security hole which can give full privileges on Windows systems needs to be URGENTLY patched. Details of the security hole and hotfix are at: http://cern.ch/it-div/news/hotfix-MS03-026.asp http://www.microsoft.com/technet/security/bulletin/MS03-026.asp

  12. 用膜片箝技术比较大鼠分离细胞和完整结状神经节的动作电位%Comparisons of somatic action potentials from dispersed and intact rat nodose ganglia using patch-clamp technique

    Institute of Scientific and Technical Information of China (English)

    LI BaiYan; John H SCHILD

    2002-01-01

    AIM: To differentiate the electrophysiological characteristics of somatic action potentials (AP) from isolated Neo and Juv nodose sensory neurons (NSN) and those from slices of intact Juv and adult rat nodose ganglia.METHODS: For isolated cell recordings nodose ganglia from 3- 8 d old Neo and 4 weeks old Juv rats were dissociated using trypsin and collagenase, respectively.Nodose ganglia slices with attached vagus were prepared using a sequential treatment of collagenase and trypsin for both Juv and adult rats. Conduction velocity (CV) was collected by vagal stimulation. Whole-cell patch was applied for somatic AP recordings. RESULTS: (1)281 NSN from both isolated cells and nodose slices were studied. Across all age groups, there was no difference observed among either C- or A-types. The difference between C- and A-type was significant. (2) Neurons exhibiting AP with prominent repolarization hump,broader APD50 ( > 2.0 ms), upstroke velocity at the point of APD50(UVAPD50) and downstroke velocity at the point of APD50(DVAPD50) below 100 V@s-1 and 50 V@s-1 were classified as C-type ( n = 222). Those without a hump,brief APD50 ( < 1.0 ms), and UVAPD50 and DVAPD50greater than 200 V@s-1 and 100 V@s-1 were classified as A-type ( n = 59). (3) With slices, except for hump,APD, UV, and DV, significant differences were also observed (C- vs A-type) in CV from both Juv (0.56±0.15 vs 15.6 m@s-1) and adult (0.9±0.4 vs 14.5±1.0 m@ s- 1 ) nodose slices, discharge rate ( single or burst vs repetitive), and frequency follow ( <20 Hz vs > 100Hz). (4) Phase analysis showed that C-type had higher AP firing threshold, and lower total in- and outward peak currents than A-type. CONCLUSION: C- and A-type AP from isolated NSN of Neo or Juv rats exhibited electrophysiological characteristics that closely followed those of AP recorded in nodose slices. Therefore,isolated NSN can effectively serve as an experimental surrogate for electrophysiological studies of NSN requiring prior

  13. Dynamic clamp with StdpC software.

    Science.gov (United States)

    Kemenes, Ildikó; Marra, Vincenzo; Crossley, Michael; Samu, Dávid; Staras, Kevin; Kemenes, György; Nowotny, Thomas

    2011-03-01

    Dynamic clamp is a powerful method that allows the introduction of artificial electrical components into target cells to simulate ionic conductances and synaptic inputs. This method is based on a fast cycle of measuring the membrane potential of a cell, calculating the current of a desired simulated component using an appropriate model and injecting this current into the cell. Here we present a dynamic clamp protocol using free, fully integrated, open-source software (StdpC, for spike timing-dependent plasticity clamp). Use of this protocol does not require specialist hardware, costly commercial software, experience in real-time operating systems or a strong programming background. The software enables the configuration and operation of a wide range of complex and fully automated dynamic clamp experiments through an intuitive and powerful interface with a minimal initial lead time of a few hours. After initial configuration, experimental results can be generated within minutes of establishing cell recording.

  14. Molecular Mechanisms of DNA Polymerase Clamp Loaders

    Science.gov (United States)

    Kelch, Brian; Makino, Debora; Simonetta, Kyle; O'Donnell, Mike; Kuriyan, John

    Clamp loaders are ATP-driven multiprotein machines that couple ATP hydrolysis to the opening and closing of a circular protein ring around DNA. This ring-shaped clamp slides along DNA, and interacts with numerous proteins involved in DNA replication, DNA repair and cell cycle control. Recently determined structures of clamp loader complexes from prokaryotic and eukaryotic DNA polymerases have revealed exciting new details of how these complex AAA+ machines perform this essential clamp loading function. This review serves as background to John Kuriyan's lecture at the 2010 Erice School, and is not meant as a comprehensive review of the contributions of the many scientists who have advanced this field. These lecture notes are derived from recent reviews and research papers from our groups.

  15. Clamp force and alignment checking device

    Energy Technology Data Exchange (ETDEWEB)

    Spicer, John Patrick; Cai, Wayne W.; Chakraborty, Debejyo; Mink, Keith

    2017-04-11

    A check fixture measures a total clamp force applied by a welder device. The welder device includes a welding horn having a plurality of weld pads and welding anvil having a plurality of weld pads. The check fixture includes a base member operatively supporting a plurality of force sensors. The base member and the force sensors are received between the weld pads of the welding horn and the anvil pads of the welding anvil. Each force sensor is configured to measure an individual clamp force applied thereto by corresponding weld and anvil pads when the base member is received between the welding horn and the welding anvil and the welder device is in the clamped position. The individual clamp forces are used to determine whether the weld and/or anvil pads are worn or misaligned.

  16. Topical ketoprofen patch.

    Science.gov (United States)

    Mazières, Bernard

    2005-01-01

    Although oral nonsteroidal anti-inflammatory drugs (NSAIDs) are effective in the treatment of a variety of acute and chronic pain conditions, their use may be associated with serious systemic adverse effects, particularly gastrointestinal disorders. In order to minimise the incidence of systemic events related to such agents, topical NSAIDs have been developed. Topical NSAIDs, applied as gels, creams or sprays, penetrate the skin, subcutaneous fatty tissue and muscle in amounts that are sufficient to exert a therapeutic effect on peripheral and central mechanisms in the absence of high plasma concentrations. Data indicate that topical NSAIDs are effective at relieving pain in a number of acute and chronic pain indications. This review article discusses the pharmacokinetics, efficacy and tolerability of a new formulation of ketoprofen available as a topical patch. The topical patch containing ketoprofen 100mg as the active principle has been developed using a novel delivery system that dispenses therapeutic doses of the drug directly to the site of injury. Pharmacokinetic data indicate that although plasma levels of ketoprofen are higher when the drug is administered as a patch versus a gel, the total systemic bioavailability of ketoprofen 100 mg administered via a patch is no more than 10% of that reported for ketoprofen 100 mg administered orally. Because the patch facilitates ketoprofen delivery over a 24-hour period, the drug remains continually present in the tissue subjacent to the site of application. High tissue but low plasma ketoprofen concentrations mean that while tissue concentrations are high enough to exert a therapeutic effect, plasma concentrations remain low enough to not result in systemic adverse events caused by elevated serum NSAID levels. Phase III clinical trials in patients with non-articular rheumatism and traumatic painful soft tissue injuries showed that the topical ketoprofen patch was significantly more effective than placebo at

  17. Esophageal Inlet Patch

    Directory of Open Access Journals (Sweden)

    C. Behrens

    2011-01-01

    Full Text Available An inlet patch is a congenital anomaly consisting of ectopic gastric mucosa at or just distal to the upper esophageal sphincter. Most inlet patches are largely asymptomatic, but in problematic cases complications related to acid secretion such as esophagitis, ulcer, web and stricture may occur. The diagnosis of inlet patch is strongly suggested on barium swallow where the most common pattern consists of two small indentations on the wall of the esophagus. The diagnosis of inlet patch is confirmed via endoscopy with biopsy. At endoscopy, the lesion appears salmon-coloured and velvety and is easily distinguished from the normal grey-white squamous epithelium of the esophagus. The prominent margins correlate with the radiological findings of indentations and rim-like shadows on barium swallow. Histopathology provides the definitive diagnosis by demonstrating gastric mucosa adjacent to normal esophageal mucosa. No treatment is required for asymptomatic inlet patches. Symptomatic cases are treated with proton pump inhibitors to relieve symptoms related to acid secretion. Strictures and webs are treated with serial dilatation and should be biopsied to rule out malignancy.

  18. Ergonomic redesign and evaluation of a clamping tool handle.

    Science.gov (United States)

    Jung, Myung-Chul; Hallbeck, M Susan

    2005-09-01

    The handle of a commercial bar clamp was redesigned using ergonomic principles and then compared with an original clamp. Ten male and ten female students participated in simulated clamping tasks under various conditions, including different clamping heights, clamping methods, and handle-gripping methods, with respect to the dependent variables of clamping and handle-squeezing forces. The results showed that the redesigned clamp produced larger clamping force with lower handle-squeezing forces than the original clamp. As expected, males exerted more force than females in both clamping and squeezing forces. A pistol grip method was superior to an upside-down handle-gripping method. Two-handed operation was recommended for this type of clamp by simultaneously pulling the trigger and sliding the bar in order to initially tighten around objects. This study shows that the application of ergonomic guidelines increases the efficiency and usability of manual handtools.

  19. Generic patch inference

    DEFF Research Database (Denmark)

    Andersen, Jesper; Lawall, Julia

    2010-01-01

    A key issue in maintaining Linux device drivers is the need to keep them up to date with respect to evolutions in Linux internal libraries. Currently, there is little tool support for performing and documenting such changes. In this paper we present a tool, spdiff, that identifies common changes...... developers can use it to extract an abstract representation of the set of changes that others have made. Our experiments on recent changes in Linux show that the inferred generic patches are more concise than the corresponding patches found in commits to the Linux source tree while being safe with respect...

  20. Patching for corneal abrasion.

    Science.gov (United States)

    Lim, Chris H L; Turner, Angus; Lim, Blanche X

    2016-07-26

    Published audits have demonstrated that corneal abrasions are a common presenting eye complaint. Eye patches are often recommended for treating corneal abrasions despite the lack of evidence for their use. This systematic review was conducted to determine the effects of the eye patch when used to treat corneal abrasions. The objective of this review was to assess the effects of patching for corneal abrasion on healing and pain relief. We searched CENTRAL (which contains the Cochrane Eyes and Vision Trials Register) (2016, Issue 4), Ovid MEDLINE, Ovid MEDLINE In-Process and Other Non-Indexed Citations, Ovid MEDLINE Daily, Ovid OLDMEDLINE (January 1946 to May 2016), EMBASE (January 1980 to May 2016), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to May 2016), System for Information on Grey Literature in Europe (OpenGrey) (January 1995 to May 2016), the ISRCTN registry (www.isrctn.com/editAdvancedSearch), ClinicalTrials.gov (www.clinicaltrials.gov) and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en). We did not use any date or language restrictions in the electronic searches for trials. We last searched the electronic databases on 9 May 2016. We also searched the reference lists of included studies, unpublished 'grey' literature and conference proceedings and contacted pharmaceutical companies for details of unpublished trials. We included randomised and quasi-randomised controlled trials that compared patching the eye with no patching to treat simple corneal abrasions. Two authors independently assessed the risk of bias and extracted data. Investigators were contacted for further information regarding the quality of trials. The primary outcome was healing at 24, 48 and 72 hours while secondary outcomes included measures of pain, quality of life and adverse effects. We graded the certainty of the evidence using GRADE. We included 12 trials which

  1. Biocide patch tests

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Veien, Niels

    1985-01-01

    Routine patch testing with a series of 6 industrial biocides containing methylene-bis-thiocyanate (Cytox 3522), benzisothiazolin-3-one (BIT), chlorocresol (Preventol CMK), 2-n-octyl-4-isothiazolin-3-one (Kathon 893), polyhydroxymethylene monobenzylether (Preventol D2) or 1,3,5-tris (hydroxy-ethyl...

  2. Polar Cap Patch Dynamics

    Science.gov (United States)

    2013-04-25

    cap arcs Citation: Hosokawa, K., J. I. Moen, K. Shiokawa, and Y. Otsuka ( 2011 ), Motion of polar cap arcs , J. Geophys. Res. , 116 , A01305, doi...K., J. I. Moen, K. Shiokawa, and Y. Otsuka , (2011), Decay of polar cap patch, J. Geophys. Res., 116, A05308, doi:10.1029/2010JA016287, Abstract. We

  3. Century Tide Nicotine Patch

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Century Tide Nicotine Patch, a hi-tech smoking control therapy, is designed in accordance with the scientific principle of nicotine replacement. The therapy is promoted by the World Health Organization. Meanwhile, it also integrates traditional Chinese medical therapy and adopts advanced TTS technology.

  4. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H. R.; Pol, Robert A.; Hulsebos, Robin G.; van Det, Rob J.; van der Palen, Job; Zeebregts, Clark J.; Geelkerken, Robert H.

    2015-01-01

    BACKGROUND: To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. METHODS: Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inl

  5. Arterial clamping leads to stenosis at clamp sites after femoropopliteal bypass surgery

    NARCIS (Netherlands)

    Vriens, Bianca H.R.; Pol, Robert A.; Hulsebos, Robin G.; Det, van Rob J.; Palen, van der Job; Zeebregts, Clark J.; Geelkerken, Robert H.

    2015-01-01

    Background To date, the incidence and clinical relevance of arterial stenosis at clamp sites after femoropopliteal bypass surgery is unknown. Methods Ninety-four patients underwent a femoropopliteal bypass in which the arterial inflow and outflow clamp sites were controlled by the Fogarty-Soft-Inla

  6. Simulation Based Performance analysis of Active Clamp DHB ZVZCS Bidirectional DC-DC converter for Low Power Applications

    Directory of Open Access Journals (Sweden)

    V.V.Subrahmanya Kumar Bhajana

    2012-06-01

    Full Text Available A novel active clamp dual half bridge DC/DC converter with bidirectional power flow is proposed in this paper and comparative analysis between active clamp DHB ZVZCS and ZVS-ZCS bidirectional DC-DC converter topologies is also presented. By adding active clamping circuits to both bridges, zero voltage and zero current switching are achieved to improve the performance of the bidirectional DC/DC converter. The principle of operation is analyzed and simulated. With the proposed active clamp ZVZCS concept, the MATLAB simulation results of the applications of the fuel cell and battery have been obtained and compared with those of ZVS-ZCS bidirectional converter. The simulation results of proposed converter is compared with the ZVS-ZCS bidirectional DC-DC converter, efficiency, switching losses are the key parameters compared.

  7. Vascular clamping in liver surgery: physiology, indications and techniques

    Directory of Open Access Journals (Sweden)

    Cherqui Daniel

    2010-03-01

    Full Text Available Abstract This article reviews the historical evolution of hepatic vascular clamping and their indications. The anatomic basis for partial and complete vascular clamping will be discussed, as will the rationales of continuous and intermittent vascular clamping. Specific techniques discussed and described include inflow clamping (Pringle maneuver, extra-hepatic selective clamping and intraglissonian clamping and outflow clamping (total vascular exclusion, hepatic vascular exclusion with preservation of caval flow. The fundamental role of a low Central Venous Pressure during open and laparoscopic hepatectomy is described, as is the difference in their intra-operative measurements. The biological basis for ischemic preconditioning will be elucidated. Although the potential dangers of vascular clamping and the development of modern coagulation devices question the need for systemic clamping; the pre-operative factors and unforseen intra-operative events that mandate the use of hepatic vascular clamping will be highlighted.

  8. Pericardial patch angioplasty heals via an Ephrin-B2 and CD34 positive cell mediated mechanism.

    Directory of Open Access Journals (Sweden)

    Xin Li

    Full Text Available OBJECTIVE: Pericardial patches are commonly used in vascular surgery to close arteriotomies. The mechanism of early healing after patch implantation is still not well defined. We used a rat aortic patch model to assess pericardial patch healing and examined Ephrin-B2, a marker of arterial identity, expression within the post-implantation patch. We also determined whether endothelial progenitor cells (EPC are associated with early patch healing in the arterial environment. METHODS: Wistar rats (200-250 grams underwent infrarenal aortic arteriotomy and then closure via bovine or porcine pericardial patch angioplasty. Control groups included subcutaneously implanted patches. Patches were harvested at 0-30 days and analyzed by histology, immunohistochemistry, immunofluorescence and Western blot as well as quantitative PCR. RESULTS: Prior to implantation, pericardial patches are largely composed of collagen and are acellular. Following arterial implantation, increasing numbers of CD68-positive cells as well as Ephrin-B2 and CD34 dual-positive cells are found within both bovine and porcine pericardial patches, whereas the infiltrating cells are negative for vWF and α-actin. Porcine patches have a luminal monolayer of cells at day 7, compared to bovine patches that have fewer luminal cells. Subcutaneously implanted patches do not attract Ephrin-B2/CD34-positive cells. By day 30, both bovine and porcine pericardial patches develop a neointima that contains Ephrin-B2, CD34, and VEGFR2-positive cells. CONCLUSION: Both CD68-positive and Ephrin-B2 and CD34 dual-positive cells infiltrate the pericardial patch early after implantation. Arteriotomy closure via pericardial patch angioplasty shows patch adaptation to the arterial environment that may involve a foreign body response as well as localization of EPC. Arterial remodeling of pericardial patches support endothelialization and may represent a paradigm of healing of scaffolds used for tissue engineering.

  9. Compact, Stiff, Remotely-Actuable Quick-Release Clamp

    Science.gov (United States)

    Tsai, Ted W. (Inventor)

    2000-01-01

    The present invention provides a clamp that is compact and lightweight, yet provides high holding strength and stiffness or rigidity. The clamp uses a unique double slant interface design which provides mechanical advantages to resist forces applied to the clamp member as the load increases. The clamp allows for rapid and remote-activated release of the clamp jaws by applying only a small operating force to an over-center lock/release mechanism, such as by pulling a manual tether.

  10. IMPORTANT: Fluke is recalling Digital Clamp Meters

    CERN Multimedia

    2013-01-01

    Fluke is voluntarily recalling four models of Digital Clamp Meters: Fluke 373, 374, 375 and 376. If you own one of these clamp meters, please stop using it and send it back to Fluke for repair even if you have not experienced problems.   Description of the problem: "The printed circuit assembly may not be properly fastened to the test lead input jack. This may result in inaccurate voltage readings, including a low or no-voltage reading on a circuit energised with a hazardous voltage, presenting a shock, electrocution or thermal burn hazard." To determine if your clamp meter is affected by this recall notice, and for more information, click here.

  11. Design and application of multifunctional stomach clamp

    Institute of Scientific and Technical Information of China (English)

    Yun Fu Lu; Pi Wu Li; Xir Xin Zhang

    2000-01-01

    AIM Pylorus and pyloric vagus preserving gastrectomy (PPVPG) is an efficient operation mode for treatinggastric and duodenal ulcers. For its better application and popularization, we have designed andmanufactured a special multifunctional stomach clamp.METHODS The clamp has been designed carefully in view of the different sizes of the patients' stomachsand the different starting points of Latarjer nerves so as to facilitate the execution of the present operationmode, which requires the preservation of the vagus innervated pyloric region so as to make the remnantstomach maintain its normal physiological function and the vagus branches clinging antral seromuscular flapkept in proper size so that avoiding too much remaining antral mucosa is removed to cause greater difficultyin operation. With this in view, we observed and measured the distance between the Latarjer nerves distribution and the pyloric rings of 42 patients' stomachs in the course of operations. We bent an aluminumstring 3 mm thick for each stomach according to the size of antral seromuecular flap and chose an optimalcurvature from the 42 sizes for manufacturing the clamp. The clamp is made of 3 Cr13 stainless steel,consisting of three parts, the curved head, the fastening ring and the handle. The curved head is shapedalmost exactly like the remained antral seromuscular flap. The ring at its tip when in place fastens the twosides of the clamp so that the tissue of the stomach between will be clutched by an even force. On one sideare three cuts for moving the ring upwards, each cut representing 1 mm for fastening and adjustments can bemade in view of the thickness or thinness of the tissue. The handles bend backward for fighting shy of thecuts so as to facilitate the operation.RESULTS With the stomach disassociated in the light of PPVPG procedures, the clamp may easily beapplied from the upper part of the Latarjer nerves. The following merits can be noted. ① The curving line ofthe flap can be precisely

  12. Security of Patched DNS

    CERN Document Server

    Herzberg, Amir

    2012-01-01

    In spite of the availability of DNSSEC, which protects against cache poisoning even by MitM attackers, many caching DNS resolvers still rely for their security against poisoning on merely validating that DNS responses contain some 'unpredictable' values, copied from the re- quest. These values include the 16 bit identifier field, and other fields, randomised and validated by different 'patches' to DNS. We investigate the prominent patches, and show how attackers can circumvent all of them, namely: - We show how attackers can circumvent source port randomisation, in the (common) case where the resolver connects to the Internet via different NAT devices. - We show how attackers can circumvent IP address randomisation, using some (standard-conforming) resolvers. - We show how attackers can circumvent query randomisation, including both randomisation by prepending a random nonce and case randomisation (0x20 encoding). We present countermeasures preventing our attacks; however, we believe that our attacks provide ...

  13. Patch test with preservatives

    Directory of Open Access Journals (Sweden)

    Kar Sumit

    1992-01-01

    Full Text Available Of the 705 patients patch tested between March 88 to March 91, 317 were tested for sensitivity to preservatives with antigens obtained from Chemo technique AB, Sweden. Paraben was the commonest sensitizer (22.4% followed by Groton B K (8.1% and Triclosan (6.5%. We stress the need to consider these allergens as source of dermatitis and advocate complete labelling of topical preparations marketed.

  14. Properties of the Nucleo-Olivary Pathway: An In Vivo Whole-Cell Patch Clamp Study

    NARCIS (Netherlands)

    P. Bazzigaluppi (Paolo); T.J.H. Ruigrok (Tom); P. Saisan (Payam); C.I. de Zeeuw (Chris); M.T.G. de Jeu (Marcel)

    2012-01-01

    textabstractThe inferior olivary nucleus (IO) forms the gateway to the cerebellar cortex and receives feedback information from the cerebellar nuclei (CN), thereby occupying a central position in the olivo-cerebellar loop. Here, we investigated the feedback input from the CN to the IO in vivo in mic

  15. Firing clamp: A novel method for single-trial estimation of excitatory and inhibitory synaptic neuronal conductances

    Directory of Open Access Journals (Sweden)

    Anton eChizhov

    2014-03-01

    Full Text Available Understanding non-stationary neuronal activity as seen in vivo requires estimation of both excitatory and inhibitory synaptic conductances from a single trial of recording. We propose a new intracellular recording method for this purpose called firing clamp. Synaptic conductances are estimated from the characteristics of artificially evoked probe spikes, namely the spike amplitude and the mean subthreshold potential, which are sensitive to both excitatory and inhibitory synaptic input signals. The probe spikes, timed at a fixed rate, are evoked in the dynamic-clamp mode by injected meander-like current steps, with the step duration depending on neuronal membrane voltage. We test the method with perforated-patch recordings from isolated cells stimulated by external application or synaptic release of transmitter, and validate the method with simulations of a biophysically-detailed neuron model. The results are compared with the conductance estimates based on conventional current-clamp recordings.

  16. Prolonged penile strangulation with metal clamps

    Institute of Scientific and Technical Information of China (English)

    Chirag Patel; Richard Kim; Michael Delterzo; Run Wang

    2006-01-01

    Various different objects have been reported to strangulate the penis. We reported on a patient who used metal radiator clamps for an extended period of time. Workup included history, physical examination and urinalysis. The patient was taken to the operating room for further evaluation with cystourethroscopy and orthopedic wire cutters were used to break the metal bands.

  17. Cerebral haemodynamics during carotid cross-clamping.

    Science.gov (United States)

    Pistolese, G R; Ippoliti, A; Appolloni, A; Ronchey, S; Faraglia, V

    1993-03-01

    Carotid artery cross-clamping ischaemia during carotid endarterectomy (CEA) causes 5-30% of perioperative neurological deficits. This study was performed to identify possible clinical situations at higher risk for carotid cross-clamping ischaemia. 606 consecutive patients underwent CEA and were retrospectively studied; they were grouped according to risk factors, presence of associated vascular diseases, clinical pattern, angiographic and CT scan findings. Stump pressure measurement was provided in all patients, perioperative monitoring during CEA was performed by electroencephalogram (EEG) in 469 (77%) and somatosensorial evoked potentials (SEP) in 137 (23%). Local anaesthesia was used in 88 (14.5%) patients. Ischaemic changes during carotid cross-clamping were registered in 118 patients (19.5%). The incidence of cross-clamping ischaemia was then related to different factors; it affected 5.6% of asymptomatics, 25.4% of patients with fixed stroke and 38.5% of those with stenosis and contralateral occlusion. Angiographic and clinical correlation showed that patients with more severe lesions are mostly affected by clamping ischaemia (up to 55% in those with stroke and stenosis with contralateral occlusion). Age, hypertension and diabetes do not significantly affect incidence of ischaemic changes. Positive CT scan increased this risk; statistical relevance was found in regard to patients with unilateral or bilateral stenosis and in those with transient ischaemic attacks. A higher risk can be expected for subjects with more severe clinical and instrumental findings, even if no patients can be considered completely at risk or risk free. Perioperative monitoring is always mandatory and is of great importance in detecting ischaemic changes and preventing cerebral damage using a temporary intraluminal shunt.

  18. Dynamics and Stability of Pinned-Clamped and Clamped-Pinned Cylindrical Shells Conveying Fluid

    Science.gov (United States)

    Misra, A. K.; Wong, S. S. T.; Païdoussis, M. P.

    2001-11-01

    The paper examines the dynamics and stability of fluid-conveying cylindrical shells having pinned-clamped or clamped-pinned boundary conditions, where ``pinned'' is an abbreviation for ``simply supported''. Flügge's equations are used to describe the shell motion, while the fluid-dynamic perturbation pressure is obtained utilizing the linearized potential flow theory. The solution is obtained using two methods - the travelling wave method and the Fourier-transform approach. The results obtained by both methods suggest that the negative damping of the clamped-pinned systems and positive damping of the pinned-clamped systems, observed by previous investigators for any arbitrarily small flow velocity, are simply numerical artefacts; this is reinforced by energy considerations, in which the work done by the fluid on the shell is shown to be zero. Hence, it is concluded that both systems are conservative.

  19. Dual-Frequency, Dual-Polarization Microstrip Antenna Development for High-Resolution, Airborne SAR

    DEFF Research Database (Denmark)

    Granholm, Johan; Skou, N.

    2000-01-01

    synthetic aperture radar (SAR) system. The dual-frequency array concept adopted relies on the use of probe-fed perforated, stacked patches for L-band (1.2-1.3 GHz). Inside these perforations probe-fed, wideband stacked microstrip patches for C-band (4.9-5.7 GHz) are placed. Measured impedance and radiation...

  20. Patch antenna terahertz photodetectors

    Energy Technology Data Exchange (ETDEWEB)

    Palaferri, D.; Todorov, Y., E-mail: yanko.todorov@univ-paris-diderot.fr; Chen, Y. N.; Madeo, J.; Vasanelli, A.; Sirtori, C. [Laboratoire Matériaux et Phénomènes Quantiques, Université Paris Diderot, Sorbonne Paris Cité, CNRS-UMS 7162, 75013 Paris (France); Li, L. H.; Davies, A. G.; Linfield, E. H. [School of Electronic and Electrical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2015-04-20

    We report on the implementation of 5 THz quantum well photodetector exploiting a patch antenna cavity array. The benefit of our plasmonic architecture on the detector performance is assessed by comparing it with detectors made using the same quantum well absorbing region, but processed into a standard 45° polished facet mesa. Our results demonstrate a clear improvement in responsivity, polarization insensitivity, and background limited performance. Peak detectivities in excess of 5 × 10{sup 12} cmHz{sup 1/2}/W have been obtained, a value comparable with that of the best cryogenic cooled bolometers.

  1. Imperfect space clamp permits electrotonic interactions between inhibitory and excitatory synaptic conductances, distorting voltage clamp recordings.

    Directory of Open Access Journals (Sweden)

    Alon Poleg-Polsky

    Full Text Available The voltage clamp technique is frequently used to examine the strength and composition of synaptic input to neurons. Even accounting for imperfect voltage control of the entire cell membrane ("space clamp", it is often assumed that currents measured at the soma are a proportional indicator of the postsynaptic conductance. Here, using NEURON simulation software to model somatic recordings from morphologically realistic neurons, we show that excitatory conductances recorded in voltage clamp mode are distorted significantly by neighboring inhibitory conductances, even when the postsynaptic membrane potential starts at the reversal potential of the inhibitory conductance. Analogous effects are observed when inhibitory postsynaptic currents are recorded at the reversal potential of the excitatory conductance. Escape potentials in poorly clamped dendrites reduce the amplitude of excitatory or inhibitory postsynaptic currents recorded at the reversal potential of the other conductance. In addition, unclamped postsynaptic inhibitory conductances linearize the recorded current-voltage relationship of excitatory inputs comprising AMPAR and NMDAR-mediated components, leading to significant underestimation of the relative contribution by NMDARs, which are particularly sensitive to small perturbations in membrane potential. Voltage clamp accuracy varies substantially between neurons and dendritic arbors of different morphology; as expected, more reliable recordings are obtained from dendrites near the soma, but up to 80% of the synaptic signal on thin, distant dendrites may be lost when postsynaptic interactions are present. These limitations of the voltage clamp technique may explain how postsynaptic effects on synaptic transmission could, in some cases, be attributed incorrectly to presynaptic mechanisms.

  2. Collaboratively Patching Linked Data

    CERN Document Server

    Knuth, Magnus; Sack, Harald

    2012-01-01

    Today's Web of Data is noisy. Linked Data often needs extensive preprocessing to enable efficient use of heterogeneous resources. While consistent and valid data provides the key to efficient data processing and aggregation we are facing two main challenges: (1st) Identification of erroneous facts and tracking their origins in dynamically connected datasets is a difficult task, and (2nd) efforts in the curation of deficient facts in Linked Data are exchanged rather rarely. Since erroneous data often is duplicated and (re-)distributed by mashup applications it is not only the responsibility of a few original publishers to keep their data tidy, but progresses to be a mission for all distributers and consumers of Linked Data too. We present a new approach to expose and to reuse patches on erroneous data to enhance and to add quality information to the Web of Data. The feasibility of our approach is demonstrated by example of a collaborative game that patches statements in DBpedia data and provides notifications ...

  3. Statistics for Patch Observations

    Science.gov (United States)

    Hingee, K. L.

    2016-06-01

    In the application of remote sensing it is common to investigate processes that generate patches of material. This is especially true when using categorical land cover or land use maps. Here we view some existing tools, landscape pattern indices (LPI), as non-parametric estimators of random closed sets (RACS). This RACS framework enables LPIs to be studied rigorously. A RACS is any random process that generates a closed set, which encompasses any processes that result in binary (two-class) land cover maps. RACS theory, and methods in the underlying field of stochastic geometry, are particularly well suited to high-resolution remote sensing where objects extend across tens of pixels, and the shapes and orientations of patches are symptomatic of underlying processes. For some LPI this field already contains variance information and border correction techniques. After introducing RACS theory we discuss the core area LPI in detail. It is closely related to the spherical contact distribution leading to conditional variants, a new version of contagion, variance information and multiple border-corrected estimators. We demonstrate some of these findings on high resolution tree canopy data.

  4. Towards a Dynamic Clamp for Neurochemical Modalities

    Directory of Open Access Journals (Sweden)

    Catalina Maria Rivera

    2015-05-01

    Full Text Available The classic dynamic clamp technique uses a real-time electrical interface between living cells and neural simulations in order to investigate hypotheses about neural function and structure. One of the acknowledged drawbacks of that technique is the limited control of the cells’ chemical microenvironment. In this manuscript, we use a novel combination of nanosensor and microfluidic technology and microfluidic and neural simulations to add sensing and control of chemical concentrations to the dynamic clamp technique. Specifically, we use a microfluidic lab-on-a-chip to generate distinct chemical concentration gradients (ions or neuromodulators, to register the concentrations with embedded nanosensors and use the processed signals as an input to simulations of a neural cell. The ultimate goal of this project is to close the loop and provide sensor signals to the microfluidic lab-on-a-chip to mimic the interaction of the simulated cell with other cells in its chemical environment.

  5. Mechanical and metallurgical properties of carotid artery clamps.

    Science.gov (United States)

    Dujovny, M; Kossovsky, N; Kossowsky, R; Segal, R; Diaz, F G; Kaufman, H; Perlin, A; Cook, E E

    1985-11-01

    The mechanical and metallurgical properties of carotid artery clamps were evaluated. The pressure plate retreat propensity, metallurgical composition, surface morphology, magnetic properties, and corrosion resistance of the Crutchfield, Selverstone, Salibi, and Kindt clamps were tested. None of the clamps showed evidence of pressure plate retreat. The clamps differed significantly in their composition, surface cleanliness, magnetic properties, and corrosion resistance. The Crutchfield clamp was the only one manufactured from an ASTM-ANSI-approved implantable stainless steel (AISI 316) and the only clamp in which the surfaces were clean and free of debris. The Selverstone clamp was made principally from AISI 304 stainless steel, as was one Salibi clamp. The pressure plate on another Salibi clamp was made from a 1% chromium and 1% manganese steel. Machining and surface debris consisting principally of aluminum, silicon, and sulfur was abundant on the Selverstone and Salibi clamps. The Kindt clamp was manufactured from AISI 301 stainless steel with a silicate-aluminized outer coating. The Crutchfield and Selverstone clamps were essentially nonferromagnetic, whereas the Salibi and Kindt clamps were sensitive to magnetic flux. In the pitting potential corrosion test, the Crutchfield clamp demonstrated good corrosion resistance with a pitting potential of 310 mV and no surface corrosion or pitting by scanning electron microscopy examination. The Selverstone clamp had lower pitting potentials and showed various degrees of corrosion and surface pitting by scanning electron microscopy. The Salibi pressure plate had a very low pitting potential of -525 mV and showed severe corrosion. By metallurgical criteria, only the Crutchfield clamp is suitable for long term implantation.

  6. Γ-source Neutral Point Clamped Inverter

    DEFF Research Database (Denmark)

    Mo, Wei; Loh, Poh Chiang; Blaabjerg, Frede

    Transformer based Z-source inverters are recently proposed to achieve promising buck-boost capability. They have improved higher buck-boost capability, smaller size and less components count over Z-source inverters. On the other hand, neutral point clamped inverters have less switching stress...... and better output performance comparing with traditional two-level inverters. Integrating these two types of configurations can help neutral point inverters achieve enhanced votlage buck-boost capability....

  7. AN ACTIVE VALVE WITH A CLAMPED MEMBRANE

    DEFF Research Database (Denmark)

    2009-01-01

    An active valve for use e.g. in fluidic microsystems is provided, wherein the active valve comprises a membrane having at least one flow gate, arranged between a first and a second substantially rigid element. Adjusting means provides an adjustment of the clamping force on membrane arranged between...... the first and second substantially rigid element. Hereby the flow rate through the active valve can be continuously and precisely controlled....

  8. Vibration of an eccentrically clamped annular plate

    Science.gov (United States)

    Tseng, J.-G.; Wickert, J. A.

    1994-04-01

    Small amplitude vibration of an eccentric annular plate, which is free along its outer edge and clamped along the interior, is investigated through experimental and analytical methods. A disk with this geometry, or a stacked array in which the clamping and symmetry axes of each disk are nominally coincident, is common in data storage and brake systems applications. In the present case, the geometric imperfections on the boundary can have important implications for the disk's dynamic response. Changes that occur in the natural frequency spectrum, the mode shapes, and the free response under eccentric mounting are studied through laboratory measurements and an approximate discrete model of the plate. The natural frequencies and modes are found through global discretization of the Kamke quotient for a classical thin plate. For the axisymmetric geometry, the natural frequencies of the sine and cosine vibration modes for a specified number of nodal diameters are repeated. With increasing eccentricity, on the other hand, each pair of repeated frequencies splits at a rate that depends on the number of nodal diameters. Over a range of clamping and eccentricity ratios, the model's predictions are compared to the measured results.

  9. Multilevel-clamped multilevel converters (MLC2)

    DEFF Research Database (Denmark)

    Rodriguez, Pedro; Bellar, Maria Dias; Muñoz-Aguliar, Raúl Santiago;

    2012-01-01

    This letter introduces a new series of multilevel (ML) converters based on the ML clamping concept. By applying this technique, a ML clamping unit (MCU) conveys additional levels for synthesizing the output waveforms of a diode-clampedML dc– ac power converter. The basic building block of the ML ...

  10. Analysis of the Pallet Clamping Conditions in Work Positioning

    Directory of Open Access Journals (Sweden)

    L. A. Kolesnikov

    2016-01-01

    Full Text Available Pallets of automatic transfer lines serve as the technological and work-transfer equipment. However, their design is based on the general principles of designing machine accessories. Calculation of the basic design parameters of work based on their functioning features is fairly relevant.In pallet transfer movement over work positioning there is a mismatch between axes of the basic bushing of a pallet and the clamping locks of positioning. The paper identifies the factors influencing it, and defines the conditions to ensure the trouble-free clamping lock. The circular and rhombic clamping of pallet is simultaneous. Further, a clamping load is calculated from the pallet mass (together with the work-piece and the geometric parameters of the pallet clamping.The paper reveals three movement stages of the clamping lock in a vertical plane when setting the pallet in work positioning:- a clamping lock free play till it encounters with the location bushing;- a clamping lock play length when the lead-in chamfer contacts the bushing chamfer;- a clamping lock play length over the circular surface of bushing.The study of this process has allowed us to calculate the time of pallet clamping and dynamic loads acting on the clamping lock. These calculations made it possible to calculate the required diameter of the clamping lock. The presented calculations allow a reasonable assigning the main design parameters of work positioning for the pallet automatic lines.

  11. Single molecule study of a processivity clamp sliding on DNA

    Energy Technology Data Exchange (ETDEWEB)

    Laurence, T A; Kwon, Y; Johnson, A; Hollars, C; O?Donnell, M; Camarero, J A; Barsky, D

    2007-07-05

    Using solution based single molecule spectroscopy, we study the motion of the polIII {beta}-subunit DNA sliding clamp ('{beta}-clamp') on DNA. Present in all cellular (and some viral) forms of life, DNA sliding clamps attach to polymerases and allow rapid, processive replication of DNA. In the absence of other proteins, the DNA sliding clamps are thought to 'freely slide' along the DNA; however, the abundance of positively charged residues along the inner surface may create favorable electrostatic contact with the highly negatively charged DNA. We have performed single-molecule measurements on a fluorescently labeled {beta}-clamp loaded onto freely diffusing plasmids annealed with fluorescently labeled primers of up to 90 bases. We find that the diffusion constant for 1D diffusion of the {beta}-clamp on DNA satisfies D {le} 10{sup -14} cm{sup 2}/s, much slower than the frictionless limit of D = 10{sup -10} cm{sup 2}/s. We find that the {beta} clamp remains at the 3-foot end in the presence of E. coli single-stranded binding protein (SSB), which would allow for a sliding clamp to wait for binding of the DNA polymerase. Replacement of SSB with Human RP-A eliminates this interaction; free movement of sliding clamp and poor binding of clamp loader to the junction allows sliding clamp to accumulate on DNA. This result implies that the clamp not only acts as a tether, but also a placeholder.

  12. 21 CFR 882.4460 - Neurosurgical head holder (skull clamp).

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Neurosurgical head holder (skull clamp). 882.4460 Section 882.4460 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES... holder (skull clamp). (a) Identification. A neurosurgical head holder (skull clamp) is a device used...

  13. Strategic Analysis for Patch Ltd.

    OpenAIRE

    Louis, Owen

    2012-01-01

    This paper is a strategic analysis for the start-up Patch Ltd. Patch has developed innovative products for growing produce in homes and will compete in the consumer containergrowing industry. The industry and the company are introduced along with urban agriculture trends. The industry is analysed using Porter’s 5 forces analysis, and a competitive analysis compares Patch to its competitors in key success factors found in the 5 forces analysis. A strategy is developed using opportunities and t...

  14. Timing of umbilical cord clamping of term infants.

    Science.gov (United States)

    Ceriani Cernadas, José María

    2017-04-01

    For at least over 200 years, multiple controversies have arisen around the timing of umbilical cord clamping. In the past decades, early cord clamping (within the first 15 seconds) had markedly prevailed. Only in the 21st century, randomized controlled trials have demonstrated the benefits of delayed cord clamping (at 2-3 minutes). Delayed cord clamping has been practiced in obstetrics based on the recommendations made by scientific societies and in systematic reviews, which have provided solid evidence to support this practice in term infants. This review describes the most relevant factors supporting the use of delayed cord clamping in term infants. It points out the essential role played by physiological mechanisms which, undoubtedly, allow us to understand the benefits of delayed cord clamping and advise us to wait for what nature has established. Other relevant aspects supporting delayed cord clamping are also described here. Sociedad Argentina de Pediatría.

  15. Testing of New Materials and Computer Aided Optimization of Process Parameters and Clamping Device During Predevelopment of Laser Welding Processes

    Science.gov (United States)

    Weidinger, Peter; Günther, Kay; Fitzel, Martin; Logvinov, Ruslan; Ilin, Alexander; Ploshikhin, Vasily; Hugger, Florian; Mann, Vincent; Roth, Stephan; Schmidt, Michael

    The necessity for weight reduction in motor vehicles in order to save fuel consumption pushes automotive suppliers to use materials of higher strength. Due to their excellent crash behavior high strength steels are increasingly applied in various structures. In this paper some predevelopment steps for a material change from a micro alloyed to dual phase and complex phase steels of a T-joint assembly are displayed. Initially the general weldability of the materials regarding pore formation, hardening in the heat affected zone and hot cracking susceptibility is discussed. After this basic investigation, the computer aided design optimization of a clamping device is shown, in which influences of the clamping jaw, the welding position and the clamping forces upon weld quality are presented. Finally experimental results of the welding process are displayed, which validate the numerical simulation.

  16. Polymer concrete patching materials

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, J.J.

    1977-09-01

    The increased use of deicing salts is causing rapid deterioration of portland cement concrete bridge decks. Soluble chlorides cause corrosion of the steel reinforcing rods with a corresponding increase in volume of the rods. This expansion causes stresses in the concrete which result in delaminations and surface spalling. The repair of surface spalls with portland cement concrete can only be made if traffic can be avoided for several days. A patching material which would allow traffic to resume over the repaired area in a few hours was needed. Polymer concrete (PC) was developed to repair deteriorated portland cement concrete. Polymer concrete is defined as a composite material in which the aggregate is bound together in a dense matrix with a polymer binder. The aggregate is mixed with a monomer mixture and subsequently cured in place. Polymer concrete combines the premix characteristics of portland cement concrete with high strength, long term durability properties and fast cure times. PC placed at temperatures between 35/sup 0/F and 95/sup 0/F attains strengths greater than 5000 psi in 2 hours. The high early strength of PC is suitable for use in the repair of highway structures where traffic conditions allow closing of the area for only a few hours.

  17. Optimization of a clamped plate silencer.

    Science.gov (United States)

    Wang, Chunqi; Han, Jun; Huang, Lixi

    2007-02-01

    A previous theoretical study [L. Huang, J. Acoust. Soc. Am. 119, 2628-2638 (2006)] shows that, in a duct, a simply supported plate covering a side-branch rigid cavity can function effectively as a wave reflector over a broad range of low to medium frequencies. In this study, analytical formulation is extended to the boundary condition of clamped plate, which is easier to implement in practice. The theoretical model is tested experimentally using balsawood, which has a very high stiffness to mass ratio. The spectral peaks and shapes of the measured TL are in agreement with those calculated theoretically, attempts are also made to account for the considerable sound absorption in the rig. Further numerical studies based on the validated model show that, for a uniform plate, the optimal stopband is narrower and the lower band limit is worse than that of the simply supported configuration. However, a wave reflector using nonuniform, clamped plates with thinner ends out-performs the simply supported configuration in every aspect. Analyses show that the improvement is attributed to the increased acoustic radiation efficiency over the bulk length of the nonuniform plate, which behaves more like a rigid plate.

  18. A DOUBLE E SHAPED MICROSTRIP PATCH ANTENNA FOR MULTIBAND APPLICATIONS

    Directory of Open Access Journals (Sweden)

    Pristin K Mathew

    2014-06-01

    Full Text Available This paper presents a dual band Compact double E shaped Microstrip Patch antenna with enhanced gain for Worldwide Interoperability for Microwave Access (WI-MAX, Universal Mobile Telecommunication Systems (UMTS and Satellite applications. The modified E shaped patch antenna is designed using CADFEKO and the results of return loss, Voltage Standing Wave Ratio (VSWR, gain of the proposed antenna are compared with a conventional E shaped patch antenna. The results show that the double E shaped wideband patch antenna has an impedance bandwidth of 10.7 % with a return loss of -13.6dB, -12.4 dB, -12.1dB and -14.2dB at resonant frequencies of 1.96 GHz, 3.62 GHz, 5.76 GHz and 6.82 GHz, whereas a conventional E shaped patch antenna operates at 2.5 GHz, 3.4 GHz and 5.5 GHz with a return loss of -16 dB each and impedance bandwidth of 10.6 %. Both the antennas uses Coaxial Probe feeding technique and Flame Retardant 4 (FR-4 as the substrate material with a thickness of 2.87 mm. A parametric study has been done so as to understand the effect of each parameter to obtain a better performance and optimised results.

  19. *New* CRITICAL Windows Security patch

    CERN Multimedia

    2003-01-01

    On 10 September 2003, Microsoft issued a new CRITICAL security patch, MS03-039. It must be URGENTLY applied on ALL WINDOWS systems, which are not centrally managed for security patches. This includes Experiment computers, Home computers and Windows Portable and Desktop systems not running NICE. Details of the security hole and patch for MS03-039 (which also includes MS03-026) are at: http://cern.ch/it-div/news/hotfix-MS03-039.asp http://www.microsoft.com/technet/security/bulletin/MS03-039.asp

  20. *New*: CRITICAL Windows Security patch

    CERN Multimedia

    2003-01-01

    On 10 September 2003, Microsoft issued a new CRITICAL security patch, MS03-039. It must be URGENTLY applied on ALL WINDOWS systems, which are not centrally managed for security patches. This includes Experiment computers, Home computers and Windows Portable and Desktop systems not running NICE. Details of the security hole and patch for MS03-039 (which also includes MS03-026) are at: http://cern.ch/it-div/news/hotfix-MS03-039.asp http://www.microsoft.com/technet/security/bulletin/MS03-039.asp

  1. Toric degenerations of Bezier patches

    CERN Document Server

    Garcia-Puente, Luis David; Zhu, Chungang

    2010-01-01

    The control polygon of a Bezier curve is well-defined and meaningful---there is a sequence of weights under which the limiting position of the curve is the control polygon. For a Bezier surface patch, there are many possible polyhedral control structures, and none are canonical. We propose a not necessarily polyhedral control structure for surface patches, regular control surfaces, which are certain C^0 spline surfaces. While not unique, regular control surfaces are exactly the possible limiting positions of a Bezier patch when the weights are allowed to vary, but the control points are fixed.

  2. Experimental and computational laser tissue welding using a protein patch.

    Science.gov (United States)

    Small, W; Heredia, N J; Maitland, D J; Eder, D C; Celliers, P M; Da Silva, L B; London, R A; Matthews, D L

    1998-01-01

    An in vitro study of laser tissue welding mediated with a dye-enhanced protein patch was conducted. Fresh sections of porcine aorta were used for the experiments. Arteriotomies were treated using an indocyanine green dye-enhanced collagen patch activated by an 805-nm continuous-wave fiber-delivered diode laser. Temperature histories of the surface of the weld site were obtained using a hollow glass optical fiber-based two-color infrared thermometer. The experimental effort was complemented by simulations with the LATIS (LAser-TISsue) computer code, which uses coupled Monte Carlo, thermal transport, and mass transport models. Comparison of simulated and experimental thermal data indicated that evaporative cooling clamped the surface temperature of the weld site below 100 °C. For fluences of approximately 200 J/cm2, peak surface temperatures averaged 74°C and acute burst strengths consistently exceeded 0.14×106 dyn/cm (hoop tension). The combination of experimental and simulation results showed that the inclusion of water transport and evaporative losses in the computer code has a significant impact on the thermal distributions and hydration levels throughout the tissue volume. The solid-matrix protein patch provided a means of controllable energy delivery and yielded consistently strong welds. © 1998 Society of Photo-Optical Instrumentation Engineers.

  3. Formulation optimization of arecoline patches.

    Science.gov (United States)

    Wu, Pao-Chu; Tsai, Pi-Ju; Lin, Shin-Chen; Huang, Yaw-Bin

    2014-01-01

    The response surface methodology (RSM) including polynomial equations has been used to design an optimal patch formulation with appropriate adhesion and flux. The patch formulations were composed of different polymers, including Eudragit RS 100 (ERS), Eudragit RL 100 (ERL) and polyvinylpyrrolidone K30 (PVP), plasticizers (PEG 400), and drug. In addition, using terpenes as enhancers could increase the flux of the drug. Menthol showed the highest enhancement effect on the flux of arecoline.

  4. Formulation Optimization of Arecoline Patches

    Directory of Open Access Journals (Sweden)

    Pao-Chu Wu

    2014-01-01

    Full Text Available The response surface methodology (RSM including polynomial equations has been used to design an optimal patch formulation with appropriate adhesion and flux. The patch formulations were composed of different polymers, including Eudragit RS 100 (ERS, Eudragit RL 100 (ERL and polyvinylpyrrolidone K30 (PVP, plasticizers (PEG 400, and drug. In addition, using terpenes as enhancers could increase the flux of the drug. Menthol showed the highest enhancement effect on the flux of arecoline.

  5. Obstetricians' attitudes and beliefs regarding umbilical cord clamping.

    Science.gov (United States)

    Jelin, Angie C; Kuppermann, Miriam; Erickson, Kristine; Clyman, Ronald; Schulkin, Jay

    2014-09-01

    Although delayed umbilical cord clamping has been demonstrated to reduce the incidence of intraventricular hemorrhage and neonatal sepsis, and decrease the need for neonatal transfusions (without affecting cord pH, Apgar scores or the need for phototherapy), the extent to which this practice is being employed is unknown. We conducted a survey of US obstetricians to assess their attitudes and beliefs about cord clamping. Questionnaires were randomly mailed to members of the American College of Obstetricians and Gynecologists (ACOG), and the Collaborative Ambulatory Research Network (CARN). The data were analyzed using Chi-square and Student t tests. The response rates for the CARN and other ACOG members were 47% and 21%, respectively. Most (88%) responders reported their hospital had no umbilical cord clamping policy. The most frequent response for optimal timing of umbilical cord clamping, regardless of gestational age, was "don't know". Potential for neonatal red blood cell transfusion was the only concern cited as a reason for being somewhat or very inclined to delay umbilical cord clamping (51%). Delayed neonatal resuscitation (76%) was listed as a reason to clamp the cord immediately, despite the paucity of literature to support immediate cord clamping in this cohort. Despite substantial evidence supporting the practice of delayed cord clamping, few institutions have policies regarding this practice. Moreover, obstetricians' beliefs about the appropriate timing for umbilical cord clamping are not consistent with the evidence that demonstrates its beneficial impact on neonatal outcomes.

  6. Delayed cord clamping and cord gas analysis at birth.

    Science.gov (United States)

    Xodo, Serena; Xodo, Luigi; Berghella, Vincenzo

    2017-09-16

    Delayed cord clamping for at least 60 seconds in both term and preterm babies is a major recent change in clinical care. Delayed cord clamping has several effects on other possible interventions. One of these is the effect of delayed cord clamping on umbilical artery gas analysis. When indicated, umbilical artery gas analysis can safely be done either with early cord clamping, or, probably most of the times it is necessary, during delayed cord clamping with the cord still unclamped. Paired blood samples (one from the umbilical artery and one from the umbilical vein) can be taken from the pulsating and unclamped cord, immediately after birth, during delayed cord clamping, without any effect on either the accuracy of umbilical artery gas analysis or on the transfusion of blood through delayed cord clamping. Umbilical artery gas analysis should instead not be done after delayed cord clamping, since delayed cord clamping alters several acid-based parameters and lactate values. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  7. Patch photopatch test at Manipal

    Directory of Open Access Journals (Sweden)

    Panja Arindrajit

    1994-01-01

    Full Text Available Patch and photopatch testing was performed on 55 patients with history of photosensitivity using Scandanavian photo patch test antigens obtained from Chemotechnique Diagnostics AB Sweden. The commonest reactions were seen to perfume mix 4 (21.0%, PABA 3 (15.78%, promethazine hydrochloride 3 (15.78%, chlorpromazine hydrochloride 3 (15.78%, balsam of peru 2 (10.52%, usnic acid, hexachlorophane, musk ambrette and 6 methyl coumarin showed 1 positive reaction each (5.26% suggesting either phototoxicity or photo sensitization. Patch and photo patch test positive reaction suggesting allergic sensitisation was seen to balsam of peru 3 (23.0% perfume mix 3 (23.0% promethazine hydrochloride 2 (15.3% and PABA, 6 methyl coumarin, tribromosalicylanilide, atranorin and wood mix showed positive reaction in one case each (7.69%. We conclude that photoxic or photo allergic reaction is a problem in India and patch photo patch test should be performed in all cases of idiopathic light eruptions to rule out photo sensitisation and in cases where photo sensitivity of exogenous origin is suspected.

  8. Thermal stiffening of clamped elastic ribbons

    Science.gov (United States)

    Wan, Duanduan; Nelson, David R.; Bowick, Mark J.

    2017-07-01

    We use molecular dynamics to study the vibrations of a thermally fluctuating two-dimensional elastic membrane clamped at both ends. We directly extract the eigenmodes from resonant peaks in the frequency domain of the time-dependent height and measure the dependence of the corresponding eigenfrequencies on the microscopic bending rigidity of the membrane, taking care also of the subtle role of thermal contraction in generating a tension when the projected area is fixed. At finite temperatures we show that the effective (macroscopic) bending rigidity tends to a constant as the bare bending rigidity vanishes, consistent with theoretical arguments that the large-scale bending rigidity of the membrane arises from a strong thermal renormalization of the microscopic bending rigidity. Experimental realizations include covalently bonded two-dimensional atomically thin membranes such as graphene and molybdenum disulfide or soft matter systems such as the spectrin skeleton of red blood cells or diblock copolymers.

  9. Demonstration of an instrumented patch

    Science.gov (United States)

    Martinez, M.; Renaud, G.; Backman, D.; Genest, M.; Delannoy, M.

    2007-04-01

    The primary objective of this study was to demonstrate the effectiveness of various strain measurement techniques at detecting the disbonding of a composite repair patch and then using this information to validate a new capacitance based disbond detection technique. The instrumented repair patch was parametrically designed with the help of Finite Element Analysis (FEA) software to have a stress concentration at its tip. This stress concentration was designed to produce a disbond during fatigue testing, without the need for the introduction of any foreign material to create an artificial disbond condition. The aluminum substrate was grit blasted and the instrumented patch was bonded using FM ®73 adhesive, and was cured following the recommendations of the manufacturer. The geometric characteristics of the patch followed standard repair guidelines for such variables as material selection, taper angles and loading conditions, with the exception of the area designed for premature disbond. All test specimens were inspected using non-destructive testing technique (ultrasound pulse echo) to guarantee that no disbonding had occurred during curing of the specimen. The specimens were placed under fatigue loading to induce a disbond condition between the aluminum substrate and the patch. The specimens were cyclically loaded and strain gauges bonded to strategic locations on the aluminum and composite patch surface to be able to measure changes in surface strains as the disbond progressed. A Digital Image Correlation (DIC) system was also used to measure full field strains over the gauge length of the coupon. The DIC results were compared with the strain gauge data and were used to provide a qualitative measure of the load transfer in the bonded specimen, which clearly demonstrated the change in surface strain that occurred as the composite patch disbonded from the aluminum substrate. Thermoelastic Stress Analysis (TSA) was also used to measure surface strains on the

  10. The PCNA-RFC families of DNA clamps and clamp loaders.

    Science.gov (United States)

    Majka, Jerzy; Burgers, Peter M J

    2004-01-01

    The proliferating cell nuclear antigen PCNA functions at multiple levels in directing DNA metabolic pathways. Unbound to DNA, PCNA promotes localization of replication factors with a consensus PCNA-binding domain to replication factories. When bound to DNA, PCNA organizes various proteins involved in DNA replication, DNA repair, DNA modification, and chromatin modeling. Its modification by ubiquitin directs the cellular response to DNA damage. The ring-like PCNA homotrimer encircles double-stranded DNA and slides spontaneously across it. Loading of PCNA onto DNA at template-primer junctions is performed in an ATP-dependent process by replication factor C (RFC), a heteropentameric AAA+ protein complex consisting of the Rfc1, Rfc2, Rfc3, Rfc4, and Rfc5 subunits. Loading of yeast PCNA (POL30) is mechanistically distinct from analogous processes in E. coli (beta subunit by the gamma complex) and bacteriophage T4 (gp45 by gp44/62). Multiple stepwise ATP-binding events to RFC are required to load PCNA onto primed DNA. This stepwise mechanism should permit editing of this process at individual steps and allow for divergence of the default process into more specialized modes. Indeed, alternative RFC complexes consisting of the small RFC subunits together with an alternative Rfc1-like subunit have been identified. A complex required for the DNA damage checkpoint contains the Rad24 subunit, a complex required for sister chromatid cohesion contains the Ctf18 subunit, and a complex that aids in genome stability contains the Elg1 subunit. Only the RFC-Rad24 complex has a known associated clamp, a heterotrimeric complex consisting of Rad17, Mec3, and Ddc1. The other putative clamp loaders could either act on clamps yet to be identified or act on the two known clamps.

  11. Constructing parametric triangular patches with boundary conditions

    Institute of Scientific and Technical Information of China (English)

    Hui Liu; Jun Ma; Fuhua Cheng

    2008-01-01

    The problem of constructing a parametric triangular patch to smoothly connect three surface patches is studied. Usually, these surface patches are defined on different parameter spaces. Therefore, it is necessary to define interpolation conditions, with values from the given surface patches, on the boundary of the triangular patch that can ensure smooth transition between different parameter spaces. In this paper we present a new method to define boundary conditions. Boundary conditions defined by the new method have the same parameter space if the three given surface patches can be converted into the same form through affine transformation. Consequently, any of the classic methods for constructing functional triangular patches can be used directly to construct a parametric triangular patch to connect given surface patches with G continuity. The resulting parametric triangular patch preserves precision of the applied classic method.

  12. Analysis of Contact Characteristic of Overhead Line and Suspension Clamp

    Directory of Open Access Journals (Sweden)

    Zhao Xinze

    2013-01-01

    Full Text Available In this paper, a LGJ150/25 type ACSR transmission line and a CGU-3 type suspension clamp are taken as research objects. A contact model of the conductor and the clamp was established by using finite element method. The effects of sag angle of the conductor, holding force and tension force in section are analyzed. The results showed that the contact area in the middle of the clamp is of belt-like type. The extreme values of tress were observed on the edge of the contact area and near the edge of keeper. In clamp section, suspension angle had the greatest influence on contact stress, and then the clamp force. The tension force in section played a most important role in these affecting factors. In the exit section of clamp, the biggest impact factor was tension force in this section, then the suspension angle, the third was clamp force. The results provide theoretical basis on reducing corona loss, optimization the clamp. Doubtlessly, the conclusion has important theoretical significance and application value.

  13. Applications of alcohol clamping in early drug development

    NARCIS (Netherlands)

    Zoethout, Remco Wiebe Martijn

    2012-01-01

    This thesis describes the development of a novel alcohol clamp, a new method to obtain stable plasma levels of alcohol and its application in CNS-research. The method might have several advantages that were explored in subsequent studies described in this thesis. The stability of the alcohol clamp w

  14. OPTIMAL TIMING FOR CLAMPING THE UMBILICAL CORD AFTER BIRTH

    Science.gov (United States)

    Raju, Tonse N. K.; Singal, Nalini

    2013-01-01

    Synopsis This paper provides a brief overview of pros and cons of clamping the cord too early (within seconds) after birth. It also highlights evolving data that suggests that delaying cord clamping for 30–60 seconds after birth is beneficial to the baby and the mother, with no measurable negative effects. PMID:23164185

  15. 21 CFR 876.5160 - Urological clamp for males.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Urological clamp for males. 876.5160 Section 876.5160 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES GASTROENTEROLOGY-UROLOGY DEVICES Therapeutic Devices § 876.5160 Urological clamp for...

  16. Ten-year comparative analysis of bovine pericardium and autogenous vein for patch angioplasty in patients undergoing carotid endarterectomy.

    Science.gov (United States)

    Kim, Ji-Hoon; Cho, Yong-Pil; Kwon, Tae-Won; Kim, Hyangkyoung; Kim, Geun-Eun

    2012-04-01

    To evaluate early and late clinical outcomes of carotid endarterectomy (CEA) with bovine pericardium patch in comparison with autogenous vein. During a 10-year period, 456 CEAs were performed using patch closure of the arteriotomy with bovine pericardium (252 cases) and autogenous vein (204 cases). Retrospectively, surgical outcomes were evaluated and compared regarding CEA-related parameters, early and late mortality and morbidity rates, and the incidence of restenosis and aneurysmal dilatation between patients with bovine pericardium patch closure and those with autogenous vein closure. The two groups were comparable regarding basic demographics, clinical data, and anatomic data, except the incidence of coronary or peripheral arterial diseases. In patients with bovine pericardium patch closure, the total operating time and carotid clamping duration were statistically significantly shorter than in those with autogenous vein closure (P pericardium patch closure (5.6% vs. 10.8%; P pericardium patch closure and 67 months for autogenous vein closure, the incidence of restenosis was similar, but aneurysmal dilatation was higher in patients with autogenous vein closure with a statistically significant difference (0% vs. 2.0%; P pericardium patch angioplasty showed excellent early and late clinical outcomes. Our results demonstrated bovine pericardium to be a suitable patch material for routine use in CEA. Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.

  17. A clamp fixture with interdigital capacitive sensor for in situ evaluation of wire insulation

    Science.gov (United States)

    Sheldon, Robert T.; Bowler, Nicola

    2014-02-01

    An interdigital capacitive sensor has been designed and optimized for testing aircraft wires by applying a quasinumerical model developed and reported previously. The sensor consists of two patches of interdigitated electrodes, connected by a long signal bus strip, that are intended to conform to two sides of an insulated wire. The electrodes are deposited using photolithography upon a 25.4-μm-thick Kapton® polyimide film. The two electrode patches are attached to the two jaws of a plastic spring-loaded clamp, with each jaw having a milled groove designed such that the electrodes conform to the curved surface of the insulated wire. An SMA connector and cable connect between the electrodes on the clamp and an LCR meter. Segments of pristine M5086/2 aircraft wire, each 10 cm long, were immersed in fluids commonly found in aircraft environments, to cause accelerated chemical degradation. The effects of Jet A fuel, deicing fluid, hydraulic fluid, aircraft cleaner, isopropyl alcohol and distilled water were studied. The frequency-dependent capacitance and dissipation factor of one pristine wire segment and of those degraded in the six fluid environments were measured within the frequency range 100 Hz to 1 MHz. Significant changes in capacitance and dissipation factor were observed for all degraded wires, compared with results for the pristine sample, suggesting the feasibility of detecting insulation degradation in the field. The results were also consistent with those of a similar experiment performed on sheets of Nylon 6, the material that comprises the outermost layer of M5086/2 wire.

  18. *NEW* CRITICAL Windows Security patches

    CERN Multimedia

    2003-01-01

    On 3 October and 10 September 2003, Microsoft issued new CRITICAL security patches MS03-040 and MS03-039. They must be URGENTLY applied on ALL WINDOWS systems, which are not centrally managed for security patches. This includes Experiment computers, Home computers and Windows Portable and Desktop systems not running NICE. Details of the security holes and patches are at: MS03-039: http://cern.ch/it-div/news/hotfix-MS03-039.asp http://www.microsoft.com/technet/security/bulletin/MS03-039.asp MS03-040: http://cern.ch/it-div/news/hotfix-MS03-040.asp http://www.microsoft.com/technet/security/bulletin/MS03-040.asp

  19. Trends in Aortic Clamp Use During Coronary Artery Bypass Surgery: The Effect of Aortic Clamping Strategies on Neurologic Outcomes

    Science.gov (United States)

    Daniel, William T.; Kilgo, Patrick; Puskas, John D.; Thourani, Vinod H.; Lattouf, Omar M.; Guyton, Robert A.; Halkos, Michael E.

    2013-01-01

    Objective The purpose of this study was to determine the impact of different clamping strategies during CABG on the incidence of postoperative stroke. Methods In this case-control study, all patients at Emory hospitals from 2002–2009 with postoperative stroke after isolated CABG (N=141) were matched 1:4 to a contemporaneous cohort of patients without postoperative stroke (N=565). Patients were matched according to the Society of Thoracic Surgeons (STS) Predicted Risk of Postoperative Stroke (PROPS), which is based on 26 variables. On- (ONCAB) and off-pump (OPCAB) patients were matched separately. Multiple logistic regression analysis with adjusted odds ratios (OR) was performed to identify operative variables associated with postoperative stroke. Results Among the ONCAB cohort, the single cross-clamp technique was associated with a decreased risk of stroke compared to the double clamp (cross clamp + partial clamp) technique (OR=0.385, p=0.044). Within the OPCAB cohort, there was no significant difference in stroke according to clamp use. Epiaortic ultrasound of the ascending aorta increased from 45.3% in 2002 to 89.4% in 2009. From 2002–2009, clamp use decreased from 97.7% of cases to 72.7%. Conclusions During ONCAB, the use of a single cross-clamp compared to the double clamp technique decreases the risk of postoperative stroke. The use of any aortic clamp has decreased and epiaortic ultrasound use has increased from 2002–2009, indicating a change in operative technique and surgeon awareness of the potential complications associated with manipulation of the aorta. PMID:23477689

  20. Committee Opinion No. 684: Delayed Umbilical Cord Clamping After Birth.

    Science.gov (United States)

    2017-01-01

    Delayed umbilical cord clamping appears to be beneficial for term and preterm infants. In term infants, delayed umbilical cord clamping increases hemoglobin levels at birth and improves iron stores in the first several months of life, which may have a favorable effect on developmental outcomes. There is a small increase in jaundice that requires phototherapy in this group of infants. Consequently, health care providers adopting delayed umbilical cord clamping in term infants should ensure that mechanisms are in place to monitor for and treat neonatal jaundice. In preterm infants, delayed umbilical cord clamping is associated with significant neonatal benefits, including improved transitional circulation, better establishment of red blood cell volume, decreased need for blood transfusion, and lower incidence of necrotizing enterocolitis and intraventricular hemorrhage. Delayed umbilical cord clamping was not associated with an increased risk of postpartum hemorrhage or increased blood loss at delivery, nor was it associated with a difference in postpartum hemoglobin levels or the need for blood transfusion. Given the benefits to most newborns and concordant with other professional organizations, the American College of Obstetricians and Gynecologists now recommends a delay in umbilical cord clamping in vigorous term and preterm infants for at least 30-60 seconds after birth. The ability to provide delayed umbilical cord clamping may vary among institutions and settings; decisions in those circumstances are best made by the team caring for the mother-infant dyad.

  1. Effect of delayed umbilical cord clamping on blood gas analysis.

    Science.gov (United States)

    Valero, Javier; Desantes, Domingo; Perales-Puchalt, Alfredo; Rubio, Juan; Diago Almela, Vicente J; Perales, Alfredo

    2012-05-01

    To ascertain if there are differences in umbilical cord blood gas analysis between immediate and delayed cord clamping. In a prospective observational study on 60 vaginally delivered healthy term newborns, we sampled umbilical cord blood immediately after delivery and at the time umbilical cord pulsation spontaneously ceased. There were significant decreases in pH, oxygen saturation (sO(2)), glycemia, oxygen content (ctO(2)), bicarbonate (HCO(3)(-)) and base excess (BE). Lactate and [Formula: see text] increased. Delayed cord clamping pH correlated with immediate cord clamping pH, [Formula: see text] , ctHb, sO(2) and time (r(2)=0.77, pcord clamping lactate was associated with immediate cord clamping lactate and time (r(2)=0.83, pcord clamping alters acid-base parameters and lactate values compared to immediate cord clamping. Those variations depend mainly on time, prior pH and lactate. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  2. Avoiding aortic clamping during CABG reduces postoperative stroke

    Science.gov (United States)

    Moss, Emmanuel; Puskas, John D; Thourani, Vinod H; Kilgo, Patrick; Chen, Edward P; Leshnower, Bradley G; Lattouf, Omar M; Guyton, Robert A.; Glas, Kathryn E; Halkos, Michael E.

    2014-01-01

    Objective The purpose of this study was to determine whether the incidence of postoperative stroke (PS) could be reduced by eliminating aortic clamping during CABG. Methods From 2002–2013, 12,079 patients underwent primary, isolated CABG at a single US academic institution. Aortic manipulation was completely avoided by using in-situ internal mammary arteries for inflow in 1,552 (12.9%) patients (no-touch), a clampless facilitating device (CFD) was used for proximal anastomoses in 1,548 (12.8%) patients, and aortic clamping was used in 8,979 (74.3%) patients. These strategies were assessed in a logistic regression model controlling for relevant variables. Results The overall incidence of PS was 1.4% (n=165), with an unadjusted incidence of 0.6% (n=10) in the no-touch group, 1.2% (n=18) in the CFD group, and 1.5% (n=137) in the clamp group (p<0.01 for no-touch vs clamp). The ratio of observed to expected stroke rate increased as the degree of aortic manipulation increased, from 0.48 in the no-touch group, to 0.61 in the CFD group, and 0.95 in the clamp group. Aortic clamping was independently associated with an increase in PS compared to a no-touch technique (AOR 2.50, p<0.01). When separated by CPB utilization, both the off-pump partial clamp and on-pump cross-clamp techniques increased the risk of PS compared to no-touch (AOR 2.52, p<0.01 and AOR 4.25, p<0.001, respectively). Conclusion A no-aortic touch technique has the lowest risk for postoperative stroke for patients undergoing CABG. Clamping the aorta during CABG increases the risk of PS, regardless of the severity of aortic disease. PMID:25293356

  3. Is "Delayed Umbilical Cord Clamping" Beneficial for Premature Newborns?

    Directory of Open Access Journals (Sweden)

    Amir-Mohammad Armanian

    2017-05-01

    Full Text Available Background: The appropriate moment for clamping the umbilical cord is controversial. Immediate cord clamping (ICC is an item of active management of the third stage of labor (AMTSL. Unclamped umbilical cord may cause inconvenience in preterm neonates because they commonly need some levels of emergent services. Some studies revealed delayed cord clamping (DCC of preterm neonates results in better health conditions like lower rates of respiratory distress syndrome (RDS, less morbidities in labor room and lower risk of postpartum hemorrhage. The aim of the present study was to determine the effect of delayed umbilical cord clamping on premature neonatal outcomes. Materials and Methods: In this single‑center randomized control trial study, sixty premature neonates (gestational age ≤ 34 weeks were randomly assigned to ICC (cord clamped at 5–10 seconds or DCC (30–45 seconds groups and followed up in neonatal intensive care unit (NICU. Primary outcomes were 1st and 5th minute Apgar score, average of level of hematocrit after birth, intra ventricle hemorrhage and need some levels of resuscitation. Results: Differences in demographic characteristics were not statistically significant. After birth, neonates who had delayed clamping had significantly higher mean hematocrit after at 4-hour of birth (49.58+5.15gr/dl vs. 46.58+5.40gr/dlin DCC vs. ICC groups, respectively (P=0.031. Delayed cord clamping reduced the duration of need to nasal continues positive airway pressure (NCPAP (86.7% and 60.0% in ICC and DCC groups, respectively, P= 0.039. Attractively, the results showed lower incidence of clinical sepsis in delayed cord clamping neonates (53.3% vs. 23.3% in ICC and DCC groups, respectively, P=0.033. Conclusion: Prematurity complications might decrease by delay umbilical cord clamping which improve the hematocrit, duration of need to NCPAP and incidence of clinical sepsis. Furthermore, DCC may have no negative impact on neonatal resuscitation.

  4. Improved Gain Microstrip Patch Antenna

    Science.gov (United States)

    2015-08-06

    same as one half wavelength, λ, of a design frequency for reception or transmission by the antenna 10. Patch 16 can be joined to a coaxial feed 18. A...expressed in the appended claims. [0024] The foregoing description of the preferred embodiments of the invention has been presented for purposes of

  5. Probe-Fed Stacked Microstrip Patch Antenna for High-Resolution Polarimetric C-Band SAR

    DEFF Research Database (Denmark)

    Granholm, Johan; Skou, Niels

    2000-01-01

    The paper describes a C-band, dual-linear polarization wideband antenna for use in the next-generation of the Danish high-resolution, airborne polarimetric synthetic aperture radar (SAR) system, EMISAR. The design and performance of a probe-fed, stacked microstrip patch element, operating from 4...

  6. Integral transform solutions of dynamic response of a clamped-clamped pipe conveying fluid

    Energy Technology Data Exchange (ETDEWEB)

    Gu Jijun; An Chen [Ocean Engineering Program, COPPE, Universidade Federal do Rio de Janeiro, CP 68508, Rio de Janeiro 21941-972 (Brazil); Duan Menglan [Offshore Oil/Gas Research Center, China University of Petroleum, Beijing 102249 (China); Levi, Carlos [Ocean Engineering Program, COPPE, Universidade Federal do Rio de Janeiro, CP 68508, Rio de Janeiro 21941-972 (Brazil); Su Jian, E-mail: sujian@nuclear.ufrj.br [Nuclear Engineering Program, COPPE, Universidade Federal do Rio de Janeiro, CP 68509, Rio de Janeiro 21941-972 (Brazil)

    2013-01-15

    Highlights: Black-Right-Pointing-Pointer Dynamic response of pipe conveying fluid was studied numerically. Black-Right-Pointing-Pointer The generalized integral transform technique (GITT) was applied. Black-Right-Pointing-Pointer Numerical solutions with automatic global accuracy control were obtained. Black-Right-Pointing-Pointer Excellent convergence behavior was shown. Black-Right-Pointing-Pointer Modal separation analysis was carried out and the influence of mass ratio was analyzed. - Abstract: Analysis of dynamic response of pipe conveying fluid is an important aspect in nuclear power plant design. In the present paper, dynamic response of a clamped-clamped pipe conveying fluid was solved by the generalized integral transform technique (GITT). The governing partial differential equation was transformed into a set of second-order ordinary differential equations which is then numerically solved by making use of the subroutine DIVPAG from IMSL Library. A thorough convergence analysis was performed to yield sets of reference results of the transverse deflection at different time and spanwise position. We found good agreement between the computed natural frequencies at mode 1-3 and those obtained by previous theoretical study. Besides, modal separation analysis was carried out and the influence of mass ratio on deflection and natural frequencies was qualitatively and quantitatively assessed.

  7. Dynamic Study of a Capacitive MEMS Switch with Double Clamped-Clamped Microbeams

    Directory of Open Access Journals (Sweden)

    Hatem Samaali

    2014-01-01

    Full Text Available We study a capacitive MEMS switch composed of two clamped-clamped exible microbeams. We first develop a mathematical model for the MEMS switch where the upper microbeam represents the ground transmission line and the lower one represents the central transmission line. An electrostatic force is applied between the two microbeams to yield the switch to its ON and OFF states. We derive the equations of motion of the system and associated boundary conditions and solve the static and dynamic problems using the differential quadratic method. We show that using only nine grid points gives relatively accurate results when compared to those obtained using FEM. We also examine the transient behavior of the microswitch and obtain results indicating that subsequent reduction in actuation voltage, switching time, and power consumption are expected along with relatively good RF performances. ANSYS HFSS simulator is used in this paper to extract the RF characteristics of the microswitch. HFSS simulation results show that the insertion loss is as low as −0.31 dB and that the return loss is better than −12.41 dB at 10 GHz in the ON state. At the OFF state, the isolation is lower than −23 dB in the range of 10 to 50 GHz.

  8. A clamp-like biohybrid catalyst for DNA oxidation

    Science.gov (United States)

    van Dongen, Stijn F. M.; Clerx, Joost; Nørgaard, Kasper; Bloemberg, Tom G.; Cornelissen, Jeroen J. L. M.; Trakselis, Michael A.; Nelson, Scott W.; Benkovic, Stephen J.; Rowan, Alan E.; Nolte, Roeland J. M.

    2013-11-01

    In processive catalysis, a catalyst binds to a substrate and remains bound as it performs several consecutive reactions, as exemplified by DNA polymerases. Processivity is essential in nature and is often mediated by a clamp-like structure that physically tethers the catalyst to its (polymeric) template. In the case of the bacteriophage T4 replisome, a dedicated clamp protein acts as a processivity mediator by encircling DNA and subsequently recruiting its polymerase. Here we use this DNA-binding protein to construct a biohybrid catalyst. Conjugation of the clamp protein to a chemical catalyst with sequence-specific oxidation behaviour formed a catalytic clamp that can be loaded onto a DNA plasmid. The catalytic activity of the biohybrid catalyst was visualized using a procedure based on an atomic force microscopy method that detects and spatially locates oxidized sites in DNA. Varying the experimental conditions enabled switching between processive and distributive catalysis and influencing the sliding direction of this rotaxane-like catalyst.

  9. The cardiovascular effects of aortic clamping and unclamping

    African Journals Online (AJOL)

    An increase in the slope of the Ea line represents an increase in ... increase. (for example as the subject exercises), stroke work ... aortic clamping is that afterload and blood pressure increase ..... nitroglycerine does not increase heart rate nor.

  10. Delay in Clamping Umbilical Cord Benefits Babies, Doctors Say

    Science.gov (United States)

    ... doctors' group said. Although delayed clamping increases the newborn's risk of jaundice that will require treatment, ACOG said there's no evidence that waiting increases the mother's risk of hemorrhage. The guidelines are to be published in the ...

  11. [Time of cord clamping and neonatal complications, a prospective study].

    Science.gov (United States)

    Rincón, D; Foguet, A; Rojas, M; Segarra, E; Sacristán, E; Teixidor, R; Ortega, A

    2014-09-01

    To assess the effects of early or late clamping of the umbilical cord in term newborns, assessing the levels of hemoglobin, hematocrit, and ferritin, and their correlation with some of the complications. A prospective study of healthy newborns at term or born by dystotic or eutocic delivery in our hospital between May 2009 until May 2010. Patients were assigned according to the time of clamping, group 1 (clamping (g1: 111 mg/dl, g2: 125 mg/dl, g3: 173 mg/dl; pcord clamping is associated with an increase in hematocrit, hemoglobin and ferritin at 48 hours of life, as well as an increased risk of polycythemia present with symptoms. Copyright © 2013 Asociación Española de Pediatría. Published by Elsevier Espana. All rights reserved.

  12. Choosing the wire clamp microdrive for termosonic microwelding equipments

    Directory of Open Access Journals (Sweden)

    Lanin V. L.

    2010-06-01

    Full Text Available The article describes research of three types of wire clamp microdrive for termosonic microwelding equipment, covering an expanded range microconductors from 12,5 up to 75 mm. The most preferable, in the light of their high-speed and easy-programming qualities, proved to be the mechanisms of conductor clamp with piezoelement drives and the loading system based on "voice-coil" type electromagnet.

  13. Prehospital Emergency Inguinal Clamp Controls Hemorrhage in Cadaver Model

    Science.gov (United States)

    2013-07-01

    the CRoC preassembled for quick use. The clamp compresses the casualty’s tissues and is unat- tached to things like a litter. When screwed down, it is...for use on the battlefield to control difficult bleeds in the inguinal area. Study Design The study design was a sequence of experiments of clamp...temperature 4 hours before testing. The torso was rotated onto a wood block to intubate the aorta through a left thoracotomy incision. The thoracic aorta

  14. Lotus birth, a holistic approach on physiological cord clamping.

    Science.gov (United States)

    Zinsser, Laura A

    2017-09-04

    The positive effects of delayed cord clamping (DCC) has been extensively researched. DCC means: waiting at least one minute after birth before clamping and cutting the cord or till the pulsation has stopped. With physiological clamping and cutting (PCC) the clamping and cutting can happen at the earliest after the pulsation has stopped. With a Lotus birth, no clamping and cutting of the cord is done. A woman called Clair Lotus Day imitated the holistic approach of PCC from an anthropoid ape in 1974. The chimpanzee did not separate the placenta from the newborn. The aim of this case report is to discuss and learn a different approach in the third stage of labour. Three cases of Lotus birth by human beings were observed. All three women gave birth in an out-of-hospital setting and had ambulant postnatal care. The placenta was washed, salted and herbs were put on 2-3h post partum. The placenta was wrapped in something that absorbs the moisture. The salting was repeated with a degreasing frequency depending on moistness of the placenta. On life day six all three Lotus babies experiences a natural separation of the cord. All three Lotus birth cases were unproblematic, no special incidence occurred. One should differentiate between early cord clamping (ECC), delayed cord clamping (DCC) and physiological cord clamping (PCC). Lotus birth might lead to an optimisation of the bonding and attachment. Research is needed in the areas of both PCC and Lotus birth. Copyright © 2017 Australian College of Midwives. Published by Elsevier Ltd. All rights reserved.

  15. Patch stage of mycosis fungoides

    Directory of Open Access Journals (Sweden)

    Mavarkar Laxman

    2001-01-01

    Full Text Available Parapsoriasis is aeon troversial topic. There are many studies regarding the relationship of parapsoriasis to lymphoma but no correlation between histology and clinical appearance. Parapsoriasis satisfies histologic criteria for mycosis fungoides and therefore it should be considered as patch stage of mycosis fungoides. A 30-year-old man presented with scaly skin lesions over the trunk since 4 years. Routine blood and urine investigations were normal. Skin biopsy from the lesion revealed atypical lymphocytes within the epidermis without spongiosis.

  16. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping) improves systemic and cerebral oxygenation in preterm lambs.

    Science.gov (United States)

    Polglase, Graeme R; Dawson, Jennifer A; Kluckow, Martin; Gill, Andrew W; Davis, Peter G; Te Pas, Arjan B; Crossley, Kelly J; McDougall, Annie; Wallace, Euan M; Hooper, Stuart B

    2015-01-01

    As measurement of arterial oxygen saturation (SpO2) is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known. We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs. Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2) were measured continuously in apnoeic preterm lambs (126±1 day gestation). Positive pressure ventilation was initiated either 1) prior to umbilical cord clamping, or 2) after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping. Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping. The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  17. Ventilation onset prior to umbilical cord clamping (physiological-based cord clamping improves systemic and cerebral oxygenation in preterm lambs.

    Directory of Open Access Journals (Sweden)

    Graeme R Polglase

    Full Text Available As measurement of arterial oxygen saturation (SpO2 is common in the delivery room, target SpO2 ranges allow clinicians to titrate oxygen therapy for preterm infants in order to achieve saturation levels similar to those seen in normal term infants in the first minutes of life. However, the influence of the onset of ventilation and the timing of cord clamping on systemic and cerebral oxygenation is not known.We investigated whether the initiation of ventilation, prior to, or after umbilical cord clamping, altered systemic and cerebral oxygenation in preterm lambs.Systemic and cerebral blood-flows, pressures and peripheral SpO2 and regional cerebral tissue oxygenation (SctO2 were measured continuously in apnoeic preterm lambs (126±1 day gestation. Positive pressure ventilation was initiated either 1 prior to umbilical cord clamping, or 2 after umbilical cord clamping. Lambs were monitored intensively prior to intervention, and for 10 minutes following umbilical cord clamping.Clamping the umbilical cord prior to ventilation resulted in a rapid decrease in SpO2 and SctO2, and an increase in arterial pressure, cerebral blood flow and cerebral oxygen extraction. Ventilation restored oxygenation and haemodynamics by 5-6 minutes. No such disturbances in peripheral or cerebral oxygenation and haemodynamics were observed when ventilation was initiated prior to cord clamping.The establishment of ventilation prior to umbilical cord clamping facilitated a smooth transition to systemic and cerebral oxygenation following birth. SpO2 nomograms may need to be re-evaluated to reflect physiological management of preterm infants in the delivery room.

  18. Palmar herald patch in pityriasis rosea.

    Science.gov (United States)

    Polat, Mualla; Yildirim, Yasemin; Makara, Anil

    2012-08-01

    Pityriasis rosea is an acute self-limited inflammatory disorder of the skin. The initial clinical features of typical cases are the appearance of a herald patch. The herald patch is commonly located on the thigh, upper arm, trunk or neck; rarely the patch may be on the face, scalp or penis. There are no reports of a palmar herald patch in pityriasis rosea. In this article we present a 14-year-old male patient who had a palmar herald patch with truncal lesions of pityriasis rosea. © 2012 The Authors. Australasian Journal of Dermatology © 2012 The Australasian College of Dermatologists.

  19. Patching. Restitching business portfolios in dynamic markets.

    Science.gov (United States)

    Eisenhardt, K M; Brown, S L

    1999-01-01

    In turbulent markets, businesses and opportunities are constantly falling out of alignment. New technologies and emerging markets create fresh opportunities. Converging markets produce more. And of course, some markets fade. In this landscape of continuous flux, it's more important to build corporate-level strategic processes that enable dynamic repositioning than it is to build any particular defensible position. That's why smart corporate strategists use patching, a process of mapping and remapping business units to create a shifting mix of highly focused, tightly aligned businesses that can respond to changing market opportunities. Patching is not just another name for reorganizing; patchers have a distinctive mindset. Traditional managers see structure as stable; patching managers believe structure is inherently temporary. Traditional managers set corporate strategy first, but patching managers keep the organization focused on the right set of business opportunities and let strategy emerge from individual businesses. Although the focus of patching is flexibility, the process itself follows a pattern. Patching changes are usually small in scale and made frequently. Patching should be done quickly; the emphasis is on getting the patch about right and fixing problems later. Patches should have a test drive before they're formalized but then be tightly scripted after they've been announced. And patching won't work without the right infrastructure: modular business units, fine-grained and complete unit-level metrics, and companywide compensation parity. The authors illustrate how patching works and point out some common stumbling blocks.

  20. Formaldehyde concentration in diagnostic patch testing

    DEFF Research Database (Denmark)

    Trattner, A; Johansen, J D; Menné, T

    1998-01-01

    Exposure to formaldehyde is common from both consumer products and industry. The reliability of the patch test is essential for the diagnosis of formaldehyde allergy as it is difficult to suspect from the patient's history. The recommended formaldehyde patch test concentration has been reduced over......% in consecutively patch-tested patients, with respect to frequency of positive patch test reactions, strength of patch test reactions to different formaldehyde test concentrations, irritancy and relevance. The study included 3734 consecutively patch tested patients. 121 gave a positive reaction to 1% and/or 2...... gave few additional positive cases compared to D 3/4. Problems related to relevance are discussed. Based on present knowledge, a 1% patch test concentration for formaldehyde is recommended....

  1. Design of dual-band reflectarray using genetic algorithm

    Science.gov (United States)

    Maruyama, Tamami

    2017-07-01

    This paper proposes novel design method of dual-band reflectarray using genetic algorithm (GA). Ordinary, each elements of reflectarray are designed to have desired reflection phase. However, when we adopt same polarization in dual frequencies, the element configuration designed to satisfy desired reflection phase in one frequency influences the characteristics in other frequency. Therefore, it is difficult to achieve dual-band reflectarray. To address the issues, we adopt two layer patches for element to increase flexibility of design and optimize the patches configuration using GA. As a result, we achieve novel reflectarray that reflect wave towards the direction of theta equal to 27 deg. and phi equal to 0 deg. in dual frequency simultaneously when incidence wave is coming from the direction of theta equal to 0 deg. and phi equal to 0 deg. in dual frequency.

  2. Patched2 modulates tumorigenesis in patched1 heterozygous mice.

    Science.gov (United States)

    Lee, Youngsoo; Miller, Heather L; Russell, Helen R; Boyd, Kelli; Curran, Tom; McKinnon, Peter J

    2006-07-15

    The sonic hedgehog (SHH) receptor Patched 1 (Ptch1) is critical for embryonic development, and its loss is linked to tumorigenesis. Germ line inactivation of one copy of Ptch1 predisposes to basal cell carcinoma and medulloblastoma in mouse and man. In many cases, medulloblastoma arising from perturbations of Ptch1 function leads to a concomitant up-regulation of a highly similar gene, Patched2 (Ptch2). As increased expression of Ptch2 is associated with medulloblastoma and other tumors, we investigated the role of Ptch2 in tumor suppression by generating Ptch2-deficient mice. In striking contrast to Ptch1-/- mice, Ptch2-/- animals were born alive and showed no obvious defects and were not cancer prone. However, loss of Ptch2 markedly affected tumor formation in combination with Ptch1 haploinsufficiency. Ptch1+/-Ptch2-/- and Ptch1+/-Ptch2+/- animals showed a higher incidence of tumors and a broader spectrum of tumor types compared with Ptch1+/- animals. Therefore, Ptch2 modulates tumorigenesis associated with Ptch1 haploinsufficiency.

  3. Investigating ion channel distribution using a combination of spatially limited photolysis, Ca(2+) imaging, and patch clamp recording.

    Science.gov (United States)

    Almassy, Janos; Yule, David I

    2013-01-01

    The production of saliva by parotid acinar cells is stimulated by Ca(2+) activation of Cl(-) and K(+) channels located in the apical plasma membrane of these polarized cells. Here, we utilize a combination of spatially limited flash photolysis, Ca(2+) imaging, and electrophysiological recording to investigate the distinct distribution of Ca(2+)-dependent ion channels in the plasma membrane (PM) of enzymatically isolated murine parotid acinar cells. In these experiments, the aim of photolysis is to selectively target and modify the activity of ion channels, thereby revealing membrane-domain-specific differences in distribution. Specifically, the relative distribution of channels to either apical or basal PM can be investigated. Since there is substantial evidence that Ca(2+)-dependent Cl(-) channels are exclusively localized to the apical membrane of acinar cells, this provides an important electrophysiological verification that a particular membrane has been specifically targeted.

  4. Impedance spectra of patch clamp scenarios for single cells immobilized on a lab-on-a-chip

    DEFF Research Database (Denmark)

    Alberti, Massimo; Snakenborg, Detlef; Lopacinska, Joanna M.

    2014-01-01

    and simulated impedance spectra proved that the presented method could distinguish between a cell-attached mode and a whole-cell mode even with low-quality seals. In physiological conditions, the capacitance of HeLa cells was measured to *38 pF. The first gigaseal was recorded and maintained for 40 min. Once...... membrane. After incubating the chip for 24 h, HeLa cells adhered and grew on the chip surface but did not survive when trapped on the microapertures. The microfluidic system proved to work as a micro electrophysiological analysis system, and the IS-based method can be used for further studies on the post...

  5. ß-adrenergic regulation of ion transport in pancreatic ducts: Patch-clamp study of isolated rat pancreatic ducts

    DEFF Research Database (Denmark)

    Novak, I

    1998-01-01

    BACKGROUND & AIMS: In the intact pancreas, bicarbonate secretion is thought to be controlled by a number of regulators, including adrenergic agonists. The aim of this study was to investigate the effects of adrenergic agonists on pancreatic ducts, which are the site of bicarbonate secretion. METH...

  6. Modification of glial response in hibernation: a patch-clamp study on glial cells acutely isolated from hibernating land snail.

    Science.gov (United States)

    Nikolic, Ljiljana; Bataveljic, Danijela; Andjus, Pavle R; Moldovan, Ivana; Nedeljkovic, Miodrag; Petkovic, Branka

    2014-12-01

    Hibernation is a dormant state of some animal species that enables them to survive harsh environmental conditions during the winter seasons. In the hibernating state, preservation of neuronal rhythmic activity at a low level is necessary for maintenance of suspended forms of behavior. As glial cells support rhythmic activity of neurons, preservation of brain function in the hibernating state implies accompanying modification of glial activity. A supportive role of glia in regulating neuronal activity is reflected through the activity of inwardly rectifying K+ channels (Kir). Therefore, we examined electrophysiological response, particularly Kir current response, of glial cells in mixture with neurons acutely isolated from active and hibernating land snail Helix pomatia. Our data show that hibernated glia have significantly lower inward current density, specific membrane conductance, and conductance density compared with active glia. The observed reduction could be attributed to the Kir currents, since the Ba2+-sensitive Kir current density was significantly lower in hibernated glia. Accordingly, a significant positive shift of the current reversal potential indicated a more depolarized state of hibernated glia. Data obtained show that modification of glial current response could be regulated by serotonin (5-HT) through an increase of cGMP as a secondary messenger, since extracellular addition of 5-HT or intracellular administration of cGMP to active glia induced a significant reduction of inward current density and thus mimicked the reduced response of hibernated glia. Lower Kir current density of hibernated glia accompanied the lower electrical activity of hibernated neurons, as revealed by a decrease in neuronal fast inward Na+ current density. Our findings reveal that glial response is reduced in the hibernating state and suggest seasonal modulation of glial activity. Maintenance of low glial activity in hibernation could be important for preservation of brain rhythmic activity and survival of the animal.

  7. Enhanced patch test of finite element methods

    Institute of Scientific and Technical Information of China (English)

    CHEN; Wanji

    2006-01-01

    Theoretically, the constant stress patch test is not rigorous. Also, either the patch test of non-zero constant shear for Mindlin plate problem or non-zero strain gradient curvature of the microstructures cannot be performed. To improve the theory of the patch test, in this paper, based on the variational principle with relaxed continuity requirement of nonconforming element for homogeneous differential equations, the author proposed the individual element condition for passing the patch test and the convergence condition of the element: besides passing the patch test, the element function should include the rigid body modes and constant strain modes and satisfy the weak continuity condition, and no extra zero energy modes occur. Moreover, the author further established a variational principle with relaxed continuity requirement of nonconforming element for inhomogeneous differential equations, the enhanced patch test condition and the individual element condition. To assure the convergence of the element that should pass the enhanced patch test, the element function should include the rigid body modes and non-zero strain modes which satisfied the equilibrium equations, and no spurious zero energy modes occur and should satisfy new weak continuity condition. The theory of the enhanced patch test proposed in this paper can be applied to both homogeneous and inhomogeneous differential equations. Based on this theory, the patch test of the non-zero constant shear stress for Mindlin plate and the C0-1 patch test of the non-zero constant curvature for the couple stress/strain gradient theory were established.

  8. In vivo laser assisted end-to-end anastomosis with ICG-infused chitosan patches

    Science.gov (United States)

    Rossi, Francesca; Matteini, Paolo; Esposito, Giuseppe; Scerrati, Alba; Albanese, Alessio; Puca, Alfredo; Maira, Giulio; Rossi, Giacomo; Pini, Roberto

    2011-07-01

    Laser assisted vascular repair is a new optimized technique based on the use of ICG-infused chitosan patch to close a vessel wound, with or even without few supporting single stitches. We present an in vivo experimental study on an innovative end-to-end laser assisted vascular anastomotic (LAVA) technique, performed with the application of ICGinfused chitosan patches. The photostability and the mechanical properties of ICG-infused chitosan films were preliminary measured. The in vivo study was performed in 10 New Zealand rabbits. After anesthesia, a 3-cm segment of the right common carotid artery was exposed, thus clamped proximally and distally. The artery was then interrupted by means of a full thickness cut. Three single microsutures were used to approximate the two vessel edges. The ICG-infused chitosan patch was rolled all over the anastomotic site and welded by the use of a diode laser emitting at 810 nm and equipped with a 300 μm diameter optical fiber. Welding was obtained by delivering single laser spots to induce local patch/tissue adhesion. The result was an immediate closure of the anastomosis, with no bleeding at clamps release. Thus animals underwent different follow-up periods, in order to evaluate the welded vessels over time. At follow-up examinations, all the anastomoses were patent and no bleeding signs were documented. Samples of welded vessels underwent histological examinations. Results showed that this technique offer several advantages over conventional suturing methods: simplification of the surgical procedure, shortening of the operative time, better re-endothelization and optimal vascular healing process.

  9. Umbilical cord clamping. An analysis of a usual neonatological conduct.

    Science.gov (United States)

    Papagno, L

    1998-01-01

    Here we described a critical analysis of the neonatological procedure of early cord clamping, meaning this, within 40 seconds after birth. Fifty three cases are here analysed, in which this practice was not performed, but instead a late umbilical cord clamping was done after birth or after the cord had stopped beating. Variations in hematocrito values within 24 to 36 hours after birth were studied. A transitory polycithemia, with a maximum peak 12 hours post-delivery was observed. These values returned to normal levels between 24 and 36 hours after birth. K vitamin was not administered to any of the newborns. No pathology appeared related to this transitory polycithemia. In can be concluded that the late umbilical cord clamping represents no risk to the new-born and that the pathological phenomena described under these circumstances may be attributed to the increase in K vitamin dependent coagulation factors that are induced by the routinary administration of phitonadione to all normal newborns.

  10. Arterial Clamping Increases Central Renal Cryoablation Efficacy: An Animal Study

    DEFF Research Database (Denmark)

    Nonboe, Lasse Larsen; Nielsen, Tommy Kjaergaard; Høyer, Søren;

    2017-01-01

    INTRODUCTION: The minimally invasive treatment of small renal masses with cryoablation has become increasingly widespread during the past 15 years. Studies with long-term follow-up are beginning to emerge, showing good oncological control, however, tumors with a central and endophytic location seem...... to possess an increased risk of treatment failure. Such tumors are likely to be subjected to a high volume of blood giving thermal protection to the cancerous cells. Arterial clamping during freezing might reduce this effect but at the same time subject the kidney to ischemia. The aim of this study...... was to evaluate the effect of renal artery clamping during cryoablation in a porcine survival model. METHODS: Ten Danish Landrace pigs (approximately 40 kg) underwent bilateral laparoscopic cryoablation with clamping of the right renal artery during freezing. The cryoablation consisted of a standard double...

  11. [Advantage of delayed umbilical cord clamping in the newborn infant].

    Science.gov (United States)

    Menget, A; Mougey, C; Thiriez, G; Riethmuller, D

    2013-09-01

    The timing of umbilical cord clamping remains controversial. Although most maternity wards use the early clamping (5-15s), randomized studies and meta-analyses have demonstrated the benefit of delayed clamping for term and preterm newborn infants over the past 10 years. Indeed, placentofetal transfusion of 20-30 ml/kg in 2-3 min improves the iron status of term infants and prevents infant hypochromic anemia. Infant anemia is a public health problem in many developing countries. For preterm newborns, placental transfusion for 45 s or milking the cord for 15 s improves cardiovascular adaptation, with better hemodynamic stability, as well as decreased intraventricular hemorrhages, need for transfusion, and late-onset sepsis. A new look at this symbolic act is needed and professionals need to be persuaded of the importance of the "wait a minute" policy for a better physiological delivery.

  12. Using physiology to guide time to cord clamping.

    Science.gov (United States)

    Kluckow, Martin; Hooper, Stuart B

    2015-08-01

    Immediate clamping and cutting of the umbilical cord at birth has been the accepted standard of care for decades. The physiologic rationale relating umbilical cord clamping (UCC) to the events of the circulatory transition is not considered in arbitrarily recommended cord clamping times. Systematic review of early versus deferred UCC shows significant hemodynamic benefits to the deferred group. Mechanisms for this protective effect are considered in this review. The original concept of a placental transfusion with a volume load and prevention of low cardiac output relies on the physiological end point of the amount of blood transfused. The newer concept of an ordered physiological transition is increasingly supported. This model places aeration of the lungs and an increase in pulmonary blood flow back at the centre of the circulatory transition with timing of UCC being related to establishment of respiration. The need for "physiologically based" UCC is discussed. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  13. Statistical study of auroral fragmentation into patches

    Science.gov (United States)

    Hashimoto, Ayumi; Shiokawa, Kazuo; Otsuka, Yuichi; Oyama, Shin-ichiro; Nozawa, Satonori; Hori, Tomoaki; Lester, Mark; Johnsen, Magnar Gullikstad

    2015-08-01

    The study of auroral dynamics is important when considering disturbances of the magnetosphere. Shiokawa et al. (2010, 2014) reported observations of finger-like auroral structures that cause auroral fragmentation. Those structures are probably produced by macroscopic instabilities in the magnetosphere, mainly of the Rayleigh-Taylor type. However, the statistical characteristics of these structures have not yet been investigated. Here based on observations by an all-sky imager at Tromsø (magnetic latitude = 67.1°N), Norway, over three winter seasons, we statistically analyzed the occurrence conditions of 14 large-scale finger-like structures that developed from large-scale auroral regions including arcs and 6 small-scale finger-like structures that developed in auroral patches. The large-scale structures were seen from midnight to dawn local time and usually appeared at the beginning of the substorm recovery phase, near the low-latitude boundary of the auroral region. The small-scale structures were primarily seen at dawn and mainly occurred in the late recovery phase of substorms. The sizes of these large- and small-scale structures mapped in the magnetospheric equatorial plane are usually larger than the gyroradius of 10 keV protons, indicating that the finger-like structures could be caused by magnetohydrodynamic instabilities. However, the scale of small structures is only twice the gyroradius of 10 keV protons, suggesting that finite Larmor radius effects may contribute to the formation of small-scale structures. The eastward propagation velocities of the structures are -40 to +200 m/s and are comparable with those of plasma drift velocities measured by the colocating Super Dual Auroral Radar Network radar.

  14. Ion channelopathies in human induced pluripotent stem cell derived cardiomyocytes: a dynamic clamp study with virtual IK1

    Directory of Open Access Journals (Sweden)

    Rosalie M.E. Meijer van Putten

    2015-02-01

    Full Text Available Human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs are widely used in studying basic mechanisms of cardiac arrhythmias that are caused by ion channelopathies. Unfortunately, the action potential profile of hiPSC-CMs—and consequently the profile of individual membrane currents active during that action potential—differs substantially from that of native human cardiomyocytes, largely due to almost negligible expression of the inward rectifier potassium current (IK1.In the present study, we attempted to ‘normalize’ the action potential profile of our hiPSC-CMs by inserting a voltage dependent in silico IK1 into our hiPSC-CMs, using the dynamic clamp configuration of the patch clamp technique. Recordings were made from single hiPSC-CMs, using the perforated patch clamp technique at physiological temperature.We assessed three different models of IK1, with different degrees of inward rectification, and systematically varied the magnitude of the inserted IK1. Also, we modified the inserted IK1 in order to assess the effects of loss- and gain-of-function mutations in the KCNJ2 gene, which encodes the Kir2.1 protein that is primarily responsible for the IK1 channel in human ventricle.For our experiments, we selected spontaneously beating hiPSC-CMs, with negligible IK1 as demonstrated in separate voltage clamp experiments, which were paced at 1 Hz. Upon addition of in silico IK1 with a peak outward density of 4–6 pA/pF, these hiPSC-CMs showed a ventricular-like action potential morphology with a stable resting membrane potential near −80 mV and a maximum upstroke velocity >150 V/s (n=9. Proarrhythmic action potential changes were observed upon injection of both loss-of-function and gain-of-function IK1, as associated with Andersen-Tawil syndrome type 1 and short QT syndrome type 3, respectively (n=6.We conclude that injection of in silico IK1 makes the hiPSC-CM a more reliable model for investigating mechanisms underlying

  15. New active load voltage clamp for HF-link converters

    Energy Technology Data Exchange (ETDEWEB)

    Ljusev, P.; Andersen, M.A.E.

    2005-07-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path during malfunctions of the secondary bidirectional bridge. The feasibility of the approach is shown on audio power amplifier prototype. New integrated magnetics design is presented that incorporates both the main power and auxiliary transformer on the same magnetic core. (au)

  16. Plasma temperature clamping in filamentation laser induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Harilal, Sivanandan S.; Yeak, J.; Phillips, Mark C.

    2015-10-19

    Ultrafast laser filament induced breakdown spectroscopy is a very promising method for remote material detection. We present characteristics of plasmas generated in a metal target by laser filaments in air. Our measurements show that the temperature of the ablation plasma is clamped along the filamentation channel due to intensity clamping in a filament. Nevertheless, significant changes in radiation intensity are noticeable, and this is essentially due to variation in the number density of emitting atoms. The present results also partly explains the reason for the occurrence of atomic plume during fs LIBS in air compared to long-pulse ns LIBS.

  17. New active load voltage clamp for HF-link converters

    DEFF Research Database (Denmark)

    Ljusev, Petar; Andersen, Michael Andreas E.

    2005-01-01

    This paper proposes a new active clamp for HF-link converters, which features very high efficiency by returning the clamped energy back to the primary side through a small auxiliary converter. It also increases the reliability of HF-link converters by providing an alternative load current path du...... during malfunctions of the secondary bidirectional bridge. The feasibility of the approach is shown on audio power amplifier prototype. New integrated magnetics design is presented that incorporates both the main power and auxiliary transformer on the same magnetic core....

  18. The problem of isotropic rectangular plate with four clamped edges

    Indian Academy of Sciences (India)

    C Erdem İmrak; Ismail Gerdemeli

    2007-06-01

    The examination of the exact solution of the governing equation of the rectangular plate is important for many reasons. This report discusses in exact solution of the governing equation of an isotropic rectangular plate with four clamped edges. A numerical method for clamped isotropic rectangular plate under distributed loads and an exact solution of the governing equation in terms of trigonometric and hyperbolic function are given. Finally, an illustrative example is given and the results are compared with those reported earlier. This method is found to be easier and effective. The results show reasonable agreement with other available results, but with a simpler and practical approach.

  19. Opto-current-clamp actuation of cortical neurons using a strategically designed channelrhodopsin.

    Directory of Open Access Journals (Sweden)

    Lei Wen

    Full Text Available BACKGROUND: Optogenetic manipulation of a neuronal network enables one to reveal how high-order functions emerge in the central nervous system. One of the Chlamydomonas rhodopsins, channelrhodopsin-1 (ChR1, has several advantages over channelrhodopsin-2 (ChR2 in terms of the photocurrent kinetics. Improved temporal resolution would be expected by the optogenetics using the ChR1 variants with enhanced photocurrents. METHODOLOGY/PRINCIPAL FINDINGS: The photocurrent retardation of ChR1 was overcome by exchanging the sixth helix domain with its counterpart in ChR2 producing Channelrhodopsin-green receiver (ChRGR with further reform of the molecule. When the ChRGR photocurrent was measured from the expressing HEK293 cells under whole-cell patch clamp, it was preferentially activated by green light and has fast kinetics with minimal desensitization. With its kinetic advantages the use of ChRGR would enable one to inject a current into a neuron by the time course as predicted by the intensity of the shedding light (opto-current clamp. The ChRGR was also expressed in the motor cortical neurons of a mouse using Sindbis pseudovirion vectors. When an oscillatory LED light signal was applied sweeping through frequencies, it robustly evoked action potentials synchronized to the oscillatory light at 5-10 Hz in layer 5 pyramidal cells in the cortical slice. The ChRGR-expressing neurons were also driven in vivo with monitoring local field potentials (LFPs and the time-frequency energy distribution of the light-evoked response was investigated using wavelet analysis. The oscillatory light enhanced both the in-phase and out-phase responses of LFP at the preferential frequencies of 5-10 Hz. The spread of activity was evidenced by the fact that there were many c-Fos-immunoreactive neurons that were negative for ChRGR in a region of the motor cortex. CONCLUSIONS/SIGNIFICANCE: The opto-current-clamp study suggests that the depolarization of a small number of neurons

  20. Compliance and patching and atropine amblyopia treatments.

    Science.gov (United States)

    Wang, Jingyun

    2015-09-01

    In the past 20 years, there has been a great advancement in knowledge pertaining to compliance with amblyopia treatments. The occlusion dose monitor introduced quantitative monitoring methods in patching, which sparked our initial understanding of the dose-response relationship for patching amblyopia treatment. This review focuses on current compliance knowledge and the impact it has on patching and atropine amblyopia treatment. Copyright © 2015 Elsevier Ltd. All rights reserved.

  1. Multi-Mode Broadband Patch Antenna

    Science.gov (United States)

    Romanofsky, Robert R. (Inventor)

    2001-01-01

    A multi-mode broad band patch antenna is provided that allows for the same aperture to be used at independent frequencies such as reception at 19 GHz and transmission at 29 GHz. Furthermore, the multi-mode broadband patch antenna provides a ferroelectric film that allows for tuning capability of the multi-mode broadband patch antenna over a relatively large tuning range. The alternative use of a semiconductor substrate permits reduced control voltages since the semiconductor functions as a counter electrode.

  2. Smart thermal patch for adaptive thermotherapy

    KAUST Repository

    Hussain, Muhammad Mustafa

    2015-11-12

    A smart thermal patch for adaptive thermotherapy is provided. In an embodiment, the patch can be a stretchable, non-polymeric, conductive thin film flexible and non-invasive body integrated mobile thermal heater with wireless control capabilities that can be used to provide adaptive thermotherapy. The patch can be geometrically and spatially tunable on various pain locations. Adaptability allows the amount of heating to be tuned based on the temperature of the treated portion.

  3. [Post-translational ligation and function of dual-vector transferred split CFTR gene].

    Science.gov (United States)

    Zhu, Fu-Xiang; Liu, Ze-Long; Qu, Hui-Ge; Chi, Xiao-Yan

    2010-01-01

    The mutation of cystic fibrosis transmembrane conductance regulator (CFTR) gene leads to an autosomal recessive genetic disorder cystic fibrosis (CF). The gene therapy for CF using adeno-associated virus (AAV) vectors delivering CFTR gene is restricted by the contents limitation of AAV vectors. In this study the split CFTR genes severed at its regulatory domain were delivered by a dual-vector system with an intein-mediated protein trans-splicing as a technique to investigate the post-translational ligation of CFTR half proteins and its function as a chloride ion channel. A pair of eukaryotic expression vectors was constructed by breaking the human CFTR cDNA before Ser712 codon and fusing with Ssp DnaB intein coding sequences. After co-transfection into baby hamster kidney (BHK) cells followed by transient expression, patch clamps were carried out to record the chloride current of whole-cell and the activity of a single channel, and the ligation of two halves of CFTR was observed by Western blotting. The results showed that the intein-fused half genes co-transfected cells displayed a high whole cell chloride current and activity of a single channel indicating the functional recovery of chloride channel, and an intact CFTR protein band was figured out by CFTR-specific antibodies indicating that intein can efficiently ligate the separately expressed half CFTR proteins. The data demonstrated that protein splicing strategy could be used as a strategy in delivering CFTR gene by two vectors, encouraging our ongoing research program on dual AAV vector system based gene transfer in gene therapy for cystic fibrosis.

  4. IVC CLAMP: infrahepatic inferior vena cava clamping during hepatectomy - a randomised controlled trial in an interdisciplinary setting

    Directory of Open Access Journals (Sweden)

    Reissfelder Christoph

    2009-10-01

    Full Text Available Abstract Background Intraoperative haemorrhage is a known predictor for perioperative outcome of patients undergoing hepatic resection. While anaesthesiological lowering of central venous pressure (CVP by fluid restriction is known to reduce bleeding during transection of the hepatic parenchyma its potential side effects remain poorly investigated. In theory it may have negative effects on kidney function and tissue perfusion and bears the risk to result in severe haemodynamic instability in case of profound intraoperative blood loss. The present randomised controlled trial evaluates efficacy and safety of infrahepatic inferior vena cava (IVC clamping as an alternative surgical technique to reduce CVP during hepatic resection. Methods/Design The proposed IVC CLAMP trial is a single-centre randomised controlled trial with a two-group parallel design. Patients and outcome-assessors are blinded for the treatment intervention. Patients undergoing elective hepatic resection due to any reason are enrolled in IVC CLAMP. All patients admitted to the Department of General-, Visceral-, and Transplant Surgery, University of Heidelberg for elective hepatic resection are consecutively screened for eligibility and written informed consent is obtained on the day before surgery. The primary objective of this trial is to assess and compare the amount of blood loss during hepatic resection in patients receiving surgical CVP reduction by clamping of the IVC as compared to anaesthesiological CVP without infrahepatic IVC clamping reduction. In addition to blood loss a set of general as well as surgical variables are analysed. Discussion This is a randomised controlled patient and observer blinded two-group parallel trial designed to assess efficacy and safety of infrahepatic IVC clamping during elective hepatectomy. Trial registration ClinicalTrials NCT00732979

  5. Patch layout generation by detecting feature networks

    KAUST Repository

    Cao, Yuanhao

    2015-02-01

    The patch layout of 3D surfaces reveals the high-level geometric and topological structures. In this paper, we study the patch layout computation by detecting and enclosing feature loops on surfaces. We present a hybrid framework which combines several key ingredients, including feature detection, feature filtering, feature curve extension, patch subdivision and boundary smoothing. Our framework is able to compute patch layouts through concave features as previous approaches, but also able to generate nice layouts through smoothing regions. We demonstrate the effectiveness of our framework by comparing with the state-of-the-art methods.

  6. The "edge effect" with patch test materials.

    Science.gov (United States)

    Fyad, A; Masmoudi, M L; Lachapelle, J M

    1987-03-01

    A positive "edge effect", i.e., the accumulation on the skin of a chemical solution (such as fluorescein 0.01% in a 50/50 water-ethanol solution) at the periphery of the patch test sites has been demonstrated. It occurs with different test materials (Finn Chamber; Silver Patch Test; Patch Test Chamber). Practical implications are discussed: this observation could be important when discussing results of laboratory investigations. In clinical practice, it could explain the occurrence of "ring-shaped" positive allergic patch test reactions to chemicals used in solution, i.e., Kathon CG or hydrocortisone.

  7. COMPARISON OF VIBRATION PERFORMANCE OF A SANDWICH CLAMPED-CLAMPED BEAM WITH MAGNETS VERSUS CONVENTIONAL CONSTRAINED DAMPING TREATMENTS

    Institute of Scientific and Technical Information of China (English)

    ZhengHuiming; HeZeng; LiMing; ZhaoGaoyu

    2004-01-01

    This paper investigates how the magnetic constrained layer damping (MCLD) treatment suppresses the displacement and acceleration resonant peak of a clamped-clamped beam. Because MCLI) treatment reduces input work and gives more dissipation energy, the vibration from external excitation can be effectively suppressed.The vibration reduction effects of MCLD and other conventional constrained damping treatments are also evaluated. In many cases, using MCLD treatments can yield smaller displacement and acceleration resonant peak especially in mode 1 compared to the other treatments without greatly changing the natural frequencies of the base beam.

  8. INOVASI SAMBUNGAN MEKANIS MENGGUNAKAN CLAMP BAJA UNTUK TULANGAN BETON

    Directory of Open Access Journals (Sweden)

    Parmo

    2015-12-01

    Full Text Available In the last few years, Indonesian urban growth has tends to be lead to the overground space. This was caused by the significant population increasement the lackness of land availability. The phenomenon is also marked with the increasing number of high-rise buildings and skyscrapers. However, high-rise buildings and skyscrapers have the potential dangers against earthquakes, even more Indonesia lay on an earthquake-prone areas. There are two main things that need to be considered in the planning of earthquake-resistant buildings, which is strength and ductility. Deformation capability and the connection strength between the reinforcement taken into consideration in the design of earthquake-resistant structures. From the steel clamp tensile test results for D13’s mechanical connection reinforcement, it gained 270.69 Mpa for yield strength, 351.45 MPa for ultimate tensile strength and 4757 kg for maximum load with 40% elongation. As for the D16’s mechanical connection reinforcement gained 217.80 MPa for yield strength, 327 605 MPa for ultimate tensile strength and 6717 kg for maximum load with 32% elongation. This study uses two pieces of steel clamp, but in order to obtain a better result then it need to be add more clamps while increasing the steel clamp material quality.

  9. Do not overlook an umbilical cord hernia before clamping.

    Science.gov (United States)

    Cizmeci, Mehmet Nevzat; Kanburoglu, Mehmet Kenan; Akelma, Ahmet Zulfikar; Tatli, Mustafa Mansur

    2013-08-01

    An umbilical cord hernia is a rare midline abdominal defect. These masses may be easily overlooked at birth, which may result in an intestinal injury due to careless proximal application of the cord clamp. Herein, we present a newborn infant with an umbilical cord hernia who was managed by primary closure of the lesion.

  10. A piezoelectric vibration harvester based on clamped-guided beams

    NARCIS (Netherlands)

    Wang, Z.; Matova, S.; Elfrink, R.; Jambunathan, M.; Nooijer, C. de; Schaijk, R. van; Vullers, R.J.M.

    2012-01-01

    The paper addresses the design, modeling, fabrication and experimental results of a piezoelectric energy harvester based on clamped-guided beams. The design is featured by shorter mass displacement and higher reliability than cantilever beams. Two separate sets of capacitors allow exploiting both te

  11. Microstrip Yagi Antenna with Dual Aperture-Coupled Feed

    Science.gov (United States)

    Pogorzelski, Ronald; Venkatesan, Jaikrishna

    2008-01-01

    A proposed microstrip Yagi antenna would operate at a frequency of 8.4 GHz (which is in the X band) and would feature a mechanically simpler, more elegant design, relative to a prior L-band microstrip Yagi antenna. In general, the purpose of designing a microstrip Yagi antenna is to combine features of a Yagi antenna with those of a microstrip patch to obtain an antenna that can be manufactured at low cost, has a low profile, and radiates a directive beam that, as plotted on an elevation plane perpendicular to the antenna plane, appears tilted away from the broadside. Such antennas are suitable for flush mounting on surfaces of diverse objects, including spacecraft, aircraft, land vehicles, and computers. Stated somewhat more precisely, what has been proposed is a microstrip antenna comprising an array of three Yagi elements. Each element would include four microstrip-patch Yagi subelements: one reflector patch, one driven patch, and two director patches. To obtain circular polarization, each driven patch would be fed by use of a dual offset aperture-coupled feed featuring bow-tie-shaped apertures. The selection of the dual offset bow-tie aperture geometry is supported by results found in published literature that show that this geometry would enable matching of the impedances of the driven patches to the 50-Omega impedance of the microstrip feedline while maintaining a desirably large front-to-back lobe ratio.

  12. Fast exact nearest patch matching for patch-based image editing and processing.

    Science.gov (United States)

    Xiao, Chunxia; Liu, Meng; Nie, Yongwei; Dong, Zhao

    2011-08-01

    This paper presents an efficient exact nearest patch matching algorithm which can accurately find the most similar patch-pairs between source and target image. Traditional match matching algorithms treat each pixel/patch as an independent sample and build a hierarchical data structure, such as kd-tree, to accelerate nearest patch finding. However, most of these approaches can only find approximate nearest patch and do not explore the sequential overlap between patches. Hence, they are neither accurate in quality nor optimal in speed. By eliminating redundant similarity computation of sequential overlap between patches, our method finds the exact nearest patch in brute-force style but reduces its running time complexity to be linear on the patch size. Furthermore, relying on recent multicore graphics hardware, our method can be further accelerated by at least an order of magnitude (≥10×). This greatly improves performance and ensures that our method can be efficiently applied in an interactive editing framework for moderate-sized image even video. To our knowledge, this approach is the fastest exact nearest patch matching method for high-dimensional patch and also its extra memory requirement is minimal. Comparisons with the popular nearest patch matching methods in the experimental results demonstrate the merits of our algorithm. © 2011 IEEE

  13. Gravity Survey of the Rye Patch KGRA, Rye Patch, Nevada

    Science.gov (United States)

    Mcdonald, M. R.; Gosnold, W. D.

    2011-12-01

    The Rye Patch Known Geothermal Resource Area (KGRA) is located in Pershing County Nevada on the west side of the Humboldt Range and east of the Rye Patch Reservoir approximately 200 km northeast of Reno, Nevada. Previous studies include an earlier gravity survey, 3-D seismic reflection, vertical seismic profiling (VSP) on a single well, 3-D seismic imaging, and a report of the integrated seismic studies. Recently, Presco Energy conducted an aeromagnetic survey and is currently in the process of applying 2-D VSP methods to target exploration and production wells at the site. These studies have indicated that geothermal fluid flow primarily occurs along faults and fractures and that two potential aquifers include a sandstone/siltstone member of the Triassic Natchez Pass Formation and a karst zone that occurs at the interface between Mesozoic limestone and Tertiary volcanics. We hypothesized that addition of a high-resolution gravity survey would better define the locations, trends, lengths, and dip angles of faults and possible solution cavity features. The gravity survey encompassed an area of approximately 78 km2 (30 mi2) within the boundary of the KGRA along with portions of 8 sections directly to the west and 8 sections directly to the east. The survey included 203 stations that were spaced at 400 m intervals. The simple Bouguer anomaly patterns were coincident with elevation, and those patterns remained after terrain corrections were performed. To remove this signal, the data were further processed using wave-length (bandpass) filtering techniques. The results of the filtering and comparison with the recent aeromagnetic survey indicate that the location and trend of major fault systems can be identified using this technique. Dip angles can be inferred by the anomaly contour gradients. By further reductions in the bandpass window, other features such as possible karst solution channels may also be recognizable. Drilling or other geophysical methods such as a

  14. Analysis of failed and nickel-coated 3093 beam clamp components at the East Tennessee Technology Park (ETTP).

    Energy Technology Data Exchange (ETDEWEB)

    Singh, D.; Pappacena, K.; Gaviria, J.; Burtsteva, T.; Nuclear Engineering Division

    2010-10-11

    was also explored as a failure mechanism. Corroded and failed yoke samples had hydrogen concentrations of 20-60 ppm. However, the hydrogen content reduced to 4-11 ppm (similar to baseline as-received yoke samples) when the corrosion products were polished off. The hydrogen content in the scraped off corrosion product powders was >7000 ppm. These results indicate that hydrogen is primarily present in the corrosion products and not in the underlying steel. Rockwell hardness values on the corroded yoke and D-rings were R{sub c} {approx} 41-46. It was recommended to the beam clamp manufacturer that the beam clamp components be annealed to reduce the hardness values so that they are less susceptible to brittle failure. Upon annealing, hardness values of the beam clamp components reduced to R{sub c} {approx} 25. Several strategies were recommended and put in place to mitigate failure of the beam clamp components: (a) maintain hardness levels of both yokes and D-rings at R{sub c} < 35, (b) coat the yoke and D-rings with a dual coating of nickel (with 10% phosphorus) to delay corrosion and aluminum to prevent galvanic corrosion since it is more anodic to zinc, and (c) optimize coating thicknesses for nickel and aluminum while maintaining the physical integrity of the coatings. Evaluation of the Al- and Ni-coated yoke and D-ring specimens indicated they appear to have met the recommendations. Average hardness values of the dual-coated yokes were R{sub c} {approx} 25-35. Hardness values of dual-coated D-ring were R{sub c} {approx} 32. Measured average coating thicknesses for the aluminum and nickel coatings for yoke samples were 22 {micro}m (0.9 mils) and 80 {micro}m (3 mils), respectively. The D-rings also showed similar coating thicknesses. Microscopic examination showed that the aluminum coating was well bonded to the underlying nickel coating. Some observed damage was believed to be an artifact of the cutting-and-polishing steps during sample preparation for microscopy.

  15. L-SHAPED SLOT LOADED SEMICIRCULAR PATCH ANTENNA FOR WIDEBAND OPERATION

    Directory of Open Access Journals (Sweden)

    AMEL BOUFRIOUA

    2014-12-01

    Full Text Available In this paper, a dual frequency resonance antenna is analysed by introducing L-shaped slot in a semi circular patch, different parametric studies have allows and the results in terms of return loss and radiation pattern are given. The results show that dual wide bands are achieved and a better impedance matching for the upper and lower resonance are obtained. Also, it is observed that various antenna parameters are obtained as a function of frequency for different value of slot length and width; it is easy to adjust the upper and the lower band by varying these different antenna parameters. The coaxial feed is used to excite the patch antenna. Theoretical results using Matlab are compared with the simulated results obtained from Ansoft HFSS software and shown to be in good agreement.

  16. Transdermal patches: history, development and pharmacology.

    Science.gov (United States)

    Pastore, Michael N; Kalia, Yogeshvar N; Horstmann, Michael; Roberts, Michael S

    2015-05-01

    Transdermal patches are now widely used as cosmetic, topical and transdermal delivery systems. These patches represent a key outcome from the growth in skin science, technology and expertise developed through trial and error, clinical observation and evidence-based studies that date back to the first existing human records. This review begins with the earliest topical therapies and traces topical delivery to the present-day transdermal patches, describing along the way the initial trials, devices and drug delivery systems that underpin current transdermal patches and their actives. This is followed by consideration of the evolution in the various patch designs and their limitations as well as requirements for actives to be used for transdermal delivery. The properties of and issues associated with the use of currently marketed products, such as variability, safety and regulatory aspects, are then described. The review concludes by examining future prospects for transdermal patches and drug delivery systems, such as the combination of active delivery systems with patches, minimally invasive microneedle patches and cutaneous solutions, including metered-dose systems.

  17. Formulation study of tea tree oil patches.

    Science.gov (United States)

    Minghetti, Paola; Casiraghi, Antonella; Cilurzo, Francesco; Gambaro, Veniero; Montanari, Luisa

    2009-01-01

    The antimicrobial, antifungal and anti-inflammatory properties of tea tree oil (TTO), the essential oil of Melaleuca alternifolia are well documented. In order to optimize its therapeutic activity, TTO patches were designed. The aim of this work was the formulation of monolayer patches containing TTO. Moreover, the performance of oleic acid (OA) as a skin penetration enhancer in patches was evaluated. Terpinen-4-ol (T4OL), the main component of TTO, was the marker used to evaluate TTO skin permeability. The permeation study was performed through human epidermis by using Franz diffusion cells. Patches were prepared by using methacrylic copolymers, Eudragit E100 (EuE100) or Eudragit NE (EuNE), and a silicone resin, BioPSA7-4602 (Bio-PSA). TTO and OA contents were fixed at 10% w/w and 3% w/w, respectively. The patches were prepared by a casting method and characterised in terms of T4OL content and skin permeability. All the selected polymers were suitable as the main component of the patch matrix. Since the main critical issue in the use of TTO is related to its toxicity after absorption, the local administration of TTO can take advantage of the use of patches based on EuE100 because of the high retained amount and the low permeation of T4OL. In this matrix, OA slightly increased the T4OL retained amount, improving the efficacy and safety of TTO patches.

  18. Streamlining of Plant Patches in Streams

    DEFF Research Database (Denmark)

    Sand-Jensen, Kaj; Pedersen, Morten Lauge

    2008-01-01

    area or root area was significantly lower in shallow water . Canopy shape and indices of streamlining did not change significantly with approach velocity (0.02-0.40 m s)1), either because canopy shape is not sensitive to approach velocity or summer velocities were too low to induce such changes. 3......1. Plants in shallow streams often grow in well-defined monospecific patches experiencing a predictable unidirectional flow, though of temporally variable velocity. During maximum patch development in summer we studied: (i) the shape and streamlining of 59 patches of Callitriche cophocarpa, (ii...... averaged 0.25. The canopy and root area of the patches were more elongate and slender in sites with shallow water, where currents accelerate alongside patches and restrict lateral expansion, compared to deeper sites where currents can pass above the canopy. Similarly, the frontal area relative to planform...

  19. Higher-spin realization of a de Sitter static patch/cut-off CFT correspondence

    Science.gov (United States)

    Karch, Andreas; Uhlemann, Christoph F.

    2013-08-01

    We derive a holographic relation for the de Sitter (dS) static patch with the dual field theory defined on the observer horizon. The starting point is the duality of higher-spin theory on AdS4 and the O(N) vector model. We build on a similar analytic continuation as used recently to obtain a realization of dS/CFT and adapt it to the static patch. The resulting duality relates higher-spin theory on the dS4 static patch to a cutoff conformal field theory on the cylinder R×S2. The construction permits a derivation of the finite thermodynamic entropy associated to the horizon of the static patch from the dual field theory. As a further brick, we recover the spectrum of quasinormal frequencies from the correlation functions of the boundary theory. In the last part, we incorporate the dS/dS correspondence as an independent proposal for holography on dS and show that a concrete realization can be obtained by similar reasoning.

  20. Patch scales in coastal ecosystems

    Science.gov (United States)

    Broitman, Bernardo R.

    Quantifying the spatial and temporal scales over which ecological processes are coupled to environmental variability is a major challenge for ecologists. Here, I assimilate patterns of oceanographic variability with ecological field studies in an attempt to quantify spatial and temporal scales of coupling. Using coastal time series of chlorophyll-a concentration from remote sensing, the first chapter examines the alongshore extent of coastal regions subject to similar temporal patterns of oceanographic variability in Western North America (WNA) and North-Central Chile (Chile). I found striking interhemispherical differences in the length of coastal sections under similar oceanographic regimes, with the Chile region showing longshore coherency over much smaller spatial scales (˜60 km) than on the coast of WNA (˜140 km). Through a spatial analysis of coastal orientation I suggest that the characteristic length scales may be traced to the geomorphologic character of the ocean margins. The second chapter examines spatial patterns of primary production through long-term means of coastal chlorophyll-a concentration and kelp (Macrocystis pyrifera) cover and explores their relationship with coastal geomorphology and sea surface temperature (SST). Spatial analyses showed a striking match in length scales around 180--250 km. Strong anticorrelations at small spatial lags and positive correlations at longer distances suggest little overlap between patches of kelp and coastal chlorophyll-a. In agreement with findings from the previous chapter, I found that coastal patches could be traced back to spatial patterns of coastal geomorphology. Through SST time series and long-term datasets of larval recruitment in Santa Cruz Island, California, the third chapter examines temporal patterns of oceanographic variability as determinants of ecological patterns. SST time series from sites experiencing low larval recruitment rates were dominated by strong temporal variability. These sites

  1. Gain Enhancement of a Microstrip Patch Antenna Using a Reflecting Layer

    Directory of Open Access Journals (Sweden)

    Anwer Sabah Mekki

    2015-01-01

    Full Text Available A low profile, unidirectional, dual layer, and narrow bandwidth microstrip patch antenna is designed to resonate at 2.45 GHz. The proposed antenna is suitable for specific applications, such as security and military systems, which require a narrow bandwidth and a small antenna size. This work is mainly focused on increasing the gain as well as reducing the size of the unidirectional patch antenna. The proposed antenna is simulated and measured. According to the simulated and measured results, it is shown that the unidirectional antenna has a higher gain and a higher front to back ratio (F/B than the bidirectional one. This is achieved by using a second flame retardant layer (FR-4, coated with an annealed copper of 0.035 mm at both sides, with an air gap of 0.04λ0 as a reflector. A gain of 5.2 dB with directivity of 7.6 dBi, F/B of 9.5 dB, and −18 dB return losses (S11 are achieved through the use of a dual substrate layer of FR-4 with a relative permittivity of 4.3 and a thickness of 1.6 mm. The proposed dual layer microstrip patch antenna has an impedance bandwidth of 2% and the designed antenna shows very low complexity during fabrication.

  2. Image quality assessment based on inter-patch and intra-patch similarity.

    Directory of Open Access Journals (Sweden)

    Fei Zhou

    Full Text Available In this paper, we propose a full-reference (FR image quality assessment (IQA scheme, which evaluates image fidelity from two aspects: the inter-patch similarity and the intra-patch similarity. The scheme is performed in a patch-wise fashion so that a quality map can be obtained. On one hand, we investigate the disparity between one image patch and its adjacent ones. This disparity is visually described by an inter-patch feature, where the hybrid effect of luminance masking and contrast masking is taken into account. The inter-patch similarity is further measured by modifying the normalized correlation coefficient (NCC. On the other hand, we also attach importance to the impact of image contents within one patch on the IQA problem. For the intra-patch feature, we consider image curvature as an important complement of image gradient. According to local image contents, the intra-patch similarity is measured by adaptively comparing image curvature and gradient. Besides, a nonlinear integration of the inter-patch and intra-patch similarity is presented to obtain an overall score of image quality. The experiments conducted on six publicly available image databases show that our scheme achieves better performance in comparison with several state-of-the-art schemes.

  3. Four- year thyroidectomy procedures: Ligasure Vs. clamp & tie

    Directory of Open Access Journals (Sweden)

    Pazoki AR

    2010-01-01

    Full Text Available "n Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Arial; mso-bidi-theme-font:minor-bidi;} Background: The electrothermal bipolar vessel sealing system is an adjunct to the hemostatic technique, which has been successfully used in many abdominal operation, recently made available to thyroid surgery. The purpose of this was compare the outcomes of new hemostatic technique with traditional method of clamp and tie."n"nMethods: In this retrospective cross-sectional study has been done in surgery's wards of Milad & Rasul- Akram hospitals in Tehran, Iran. During three- year period between 2005-2008 all patients with different kind of pathology that need operation were assessed. Time duration of surgery and hospital stay and post surgery complication in two group, ligasure (n=45 and clamp & tie (n=145 were compared with each others."n"nResults: No difference was seen between two groups in time duration of surgery. Significant difference was seen in hospital stay and complications of surgery. Time of operation in Ligasure group was 132/22 minute and in clamp and tie group was 130/10 minute. There was found significant difference in duration of hospital stay and postoperative complication. Hypocalcemia were seen in two and 24 cases in Ligasure and Clamp & Tie group, respectively (p<0.05. Hospital stay was 2

  4. Robustness of metacommunities with omnivory to habitat destruction: disentangling patch fragmentation from patch loss.

    Science.gov (United States)

    Liao, Jinbao; Bearup, Daniel; Wang, Yeqiao; Nijs, Ivan; Bonte, Dries; Li, Yuanheng; Brose, Ulrich; Wang, Shaopeng; Blasius, Bernd

    2017-06-01

    Habitat destruction, characterized by patch loss and fragmentation, is a major driving force of species extinction, and understanding its mechanisms has become a central issue in biodiversity conservation. Numerous studies have explored the effect of patch loss on food web dynamics, but ignored the critical role of patch fragmentation. Here we develop an extended patch-dynamic model for a tri-trophic omnivory system with trophic-dependent dispersal in fragmented landscapes. We found that species display different vulnerabilities to both patch loss and fragmentation, depending on their dispersal range and trophic position. The resulting trophic structure varies depending on the degree of habitat loss and fragmentation, due to a tradeoff between bottom-up control on omnivores (dominated by patch loss) and dispersal limitation on intermediate consumers (dominated by patch fragmentation). Overall, we find that omnivory increases system robustness to habitat destruction relative to a simple food chain. © 2017 by the Ecological Society of America.

  5. Timing of umbilical cord clamping: effect on iron endowment of the newborn and later iron status.

    Science.gov (United States)

    Chaparro, Camila M

    2011-11-01

    The optimal timing of umbilical cord clamping has been debated in the scientific literature for at least the last century, when cord clamping practices shifted from delayed towards immediate clamping. Recent research provides evidence for the beneficial effect of delayed cord clamping on infant iron status. The present review describes the physiological basis for the impact of cord clamping time on total body iron at birth and the relationship between birth body iron, as affected by cord clamping time, and iron status later in infancy. This research is discussed in the context of current clamping practices, which tend towards early cord clamping in most settings, as well as the high levels of anemia present in young infants in many countries worldwide. © 2011 International Life Sciences Institute.

  6. Dual-band low profile antennas for body-centric communications

    NARCIS (Netherlands)

    Chandran, A.R.; Scanlon, W.G.

    2010-01-01

    Dual-band operation is highly desirable for wearable devices that need to connect with a range of wireless systems. We present a series of microstrip-line fed, dual-band compact patch antennas designed to operate in the common 2.45 GHz and 5.8 GHz bands for body-centric communications. All of the de

  7. A new configuration for multilevel converters with diode clamped topology

    DEFF Research Database (Denmark)

    Nami, A.; Zare, F.; Ledwich, G.

    2008-01-01

    of load changes which can avoid neutral point balancing problem in such converters. In addition, the presented topology is suitable for renewable energy systems to boost the low rectified output-voltage. In order to verify the proposed topology, steady state analysis, modelling and simulations are carried......Due to the increased use of renewable energy and power elctronic applications, more multilevel converters (MLC) are developed. A Neutral Point Clamped (NPC) inverter is one of the most used multilevel topologies for wind turbine (WT) and photovoltaic (PV) applications. One of the most crucial...... points in this type of converter is dc-voltage control. In this paper, a novel multi output dc-dc converter connected to a diode clamped topology is presented. This converter, for a given duty cycles, is able to regulate the capacitor voltage to provide an appropriate input voltage for NPC regardless...

  8. Active energy recovery clamping circuit to improve the performance of power converters

    Energy Technology Data Exchange (ETDEWEB)

    Whitaker, Bret; Barkley, Adam

    2017-05-09

    A regenerative clamping circuit for a power converter using clamping diodes to transfer charge to a clamping capacitor and a regenerative converter to transfer charge out of the clamping capacitor back to the power supply input connection. The regenerative converter uses a switch connected to the midpoint of a series connected inductor and capacitor. The ends of the inductor and capacitor series are connected across the terminals of the power supply to be in parallel with the power supply.

  9. Timing of umbilical cord clamping and neonatal haematological status.

    Science.gov (United States)

    Jaleel, Riffat; Deeba, Farah; Khan, Ayesha

    2009-07-01

    To determine the effect of delayed umbilical cord clamping on Hb (haemoglobin) and bilirubin levels of neonates and to identify newborn babies with anaemia and refer them for treatment. This Randomized Controlled Trial was conducted in the Department of Obstetrics and Gynaecology, Unit V, Dow Medical College and Lyari General Hospital and Department of Pathology, Lyari General Hospital, between 1st November, 2006 and 15th July, 2007. Patients admitted to labour ward were selected according to inclusion criteria of the study. They were randomly allocated to 2 groups. Group A included women in whom umbilical cord was clamped immediately after birth. In Group B, clamping was delayed until cessation of pulsations in the cord. After cutting the cord, sample of blood was collected from the cut end of cord of the newborn for Hb and bilirubin. After 6 hours of birth, another sample of blood was drawn from antecubital vein for serum bilirubin. Samples were sent to laboratory for analysis. All data were entered and analyzed using SPSS version 11. Two hundred women were studied, 100 in each of the 2 groups. Mean maternal Hb was 9.75 g/dl in Group A and 9.95 g/dl in Group B. The average neonatal Hb was 14.1 g/dl in Group A and 15.2 g/dl in Group B (p = 0.008). In all 49% neonates in Group A and 37% in Group B had Hb umbilical cord clamping at birth seems to be safe and can be expected to reduce the prevalence of anaemic newborn babies in our community.

  10. Indentation metrology of clamped, ultra-thin elastic sheets

    OpenAIRE

    Vella, Dominic; Davidovitch, Benny

    2017-01-01

    We study the indentation of ultrathin elastic sheets clamped to the edge of a circular hole. This classical setup has received considerable attention lately, being used by various experimental groups as a probe to measure the surface properties and stretching modulus of thin solid films. Despite the apparent simplicity of this method, the geometric nonlinearity inherent in the mechanical response of thin solid objects renders the analysis of the resulting data a nontrivial task. Importantly, ...

  11. A Differentially Driven Dual-Polarized Dual-Wideband Complementary Antenna for 2G/3G/LTE Applications

    Directory of Open Access Journals (Sweden)

    Botao Feng

    2014-01-01

    Full Text Available A novel differentially driven dual-polarized dual-wideband complementary patch antenna with high isolation is proposed for 2G/3G/LTE applications. In order to generate dual-polarization and dual-wideband properties, a pair of biorthogonal dual-layer η-shaped tapered line feeding structures is utilized to feed two pairs of dual-layer U-shaped patches, respectively. The upper-layer U-shaped patches mainly serve the upper frequency band, while the lower-layer ones chiefly work for the lower frequency band. Besides, a horned reflector is introduced to improve radiation patterns and provide stable gain. The prototype antenna can achieve a bandwidth of 25.7% (0.78 GHz–1.01 GHz with a stable gain of 7.8±0.7 dBi for the lower band, and a bandwidth of 45.7% (1.69 GHz–2.69 GHz with a gain of 9.5±1.1 dBi for the upper band. Input isolation exceeding 30 dB has been obtained in the wide bandwidth. Thus, it can be potentially used as a base station antenna for 2G/3G/LTE networks.

  12. POLYCYTHEMIA RISK IN NEONATES WITH DELAYED CORD CLAMPING

    Directory of Open Access Journals (Sweden)

    I Gusti Agung Ayu Sri Wulandari Pramana

    2013-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE Delayed Cord Clamping is still a controversial issue in the world of medicine. Until recently, the perfect times to do a Delayed Cord Clamping in various parts of the Earth in the world are still very diverse. There are a few things that became a major concern associated with Delayed Cord Clamping, one of which is the increase in blood volume due to an increase in the number of erythrocytes which led to occurrence of neonatal polycythemia which later can lead to various complications. Polycythemia in neonates is a situation where the value of venous blood hematokrit over 65% (0.65 or the amount of hemoglobin more than 22gr/Dl. However, to date the data from a variety of the latest research and analysis of the studies mention that the polycythemia that occurs in neonates with umbilical cord pinching the flush delay was mild polycythemia that can improve after 48 to 72 hours after the baby is born.

  13. MEMS-based clamp with a passive hold function for precision position retaining of micro manipulators

    NARCIS (Netherlands)

    Brouwer, D.M.; Jong, de B.R.; Boer, de M.J.; Jansen, H.V.; Dijk, van J.; Krijnen, G.J.M.; Soemers, H.M.J.R.

    2009-01-01

    In this paper the design, modeling and fabrication of a precision MEMS-based clamp with a relatively large clamping force are presented. The purpose of the clamp is to mechanically fix a six-degree-of-freedom (DOF) MEMS-based sample manipulator (Brouwer et al J. Int. Soc. Precis. Eng. Nanotechnol. s

  14. MEMS-based clamp with a passive hold function for precision position retaining of micromanipulators

    NARCIS (Netherlands)

    Brouwer, Dannis Michel; de Jong, B.R.; de Boer, Meint J.; Jansen, Henricus V.; van Dijk, Johannes A.G.M.; van Dijk, Johannes; Krijnen, Gijsbertus J.M.; Soemers, Herman

    2009-01-01

    In this paper the design, modeling and fabrication of a precision MEMS-based clamp with arelatively large clamping force are presented. The purpose of the clamp is to mechanically fixa six-degree-of-freedom (DOF) MEMS-based sample manipulator (Brouwer et al J. Int. Soc. Precis. Eng. Nanotechnol. sub

  15. File list: Oth.ALL.10.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.10.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159170,SRX15917...2,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.10.Clamp.AllCell.bed ...

  16. File list: Oth.ALL.05.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.05.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159172,SRX15917...0,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.05.Clamp.AllCell.bed ...

  17. File list: Oth.CeL.10.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CeL.10.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159170,SRX159172,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.10.Clamp.AllCell.bed ...

  18. File list: Oth.CeL.20.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CeL.20.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159172,SRX159170,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.20.Clamp.AllCell.bed ...

  19. File list: Oth.ALL.50.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.50.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159172,SRX15917...0,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.50.Clamp.AllCell.bed ...

  20. File list: Oth.ALL.20.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.ALL.20.Clamp.AllCell dm3 TFs and others Clamp All cell types SRX159172,SRX15917...0,SRX159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.ALL.20.Clamp.AllCell.bed ...

  1. File list: Oth.CeL.05.Clamp.AllCell [Chip-atlas[Archive

    Lifescience Database Archive (English)

    Full Text Available Oth.CeL.05.Clamp.AllCell dm3 TFs and others Clamp Cell line SRX159172,SRX159170,SRX...159174,SRX159166,SRX159173 http://dbarchive.biosciencedbc.jp/kyushu-u/dm3/assembled/Oth.CeL.05.Clamp.AllCell.bed ...

  2. The early effects of delayed cord clamping in term infants born to Libyan mothers

    NARCIS (Netherlands)

    Emhamed, Musbah Omar; van Rheenen, Patrick; Brabin, Bernard J

    2004-01-01

    This study was conducted to evaluate the haematological effects of the timing of umbilical cord clamping in term infants 24 h after birth in Libya. Mother-infant pairs were randomly assigned to early cord clamping (within 10s after delivery) or delayed clamping (after the cord stopped pulsating). Ma

  3. A new patch antenna with metamaterial cover

    Institute of Scientific and Technical Information of China (English)

    HU Jun; YAN Chun-sheng; LIN Qing-chun

    2006-01-01

    A metamaterial was introduced into the cover of a patch antenna and its band structure was analyzed. The metamaterial cover with correct selection of the working frequency increases by 9.14 dB the patch antenna's directivity. The mechanism of metamaterial cover is completely different from that of a photonic bandgap cover. The mechanism of the metamaterial cover,the number of the cover's layers, and the distance between the layers, were analyzed in detail. The results showed that the metamaterial cover, which works like a lens, could effectively improve the patch antenna's directivity. The physical reasons for the improvement are also given.

  4. Dual diagnosis

    OpenAIRE

    2013-01-01

    Dual diagnosis denotes intertwining of intellectual disabilities with mental disorders. With the help of systematic examination of literature, intellectual disabilities are determined (they are characterized by subaverage intellectual activity and difficulties in adaptive skills), along side mental disorders. Their influence is seen in changes of thinking, perception, emotionality, behaviour and cognition. Mental disorders often occur with people with intellectual disabilities (data differs f...

  5. A numerical approach to ion channel modelling using whole-cell voltage-clamp recordings and a genetic algorithm.

    Directory of Open Access Journals (Sweden)

    Meron Gurkiewicz

    2007-08-01

    Full Text Available The activity of trans-membrane proteins such as ion channels is the essence of neuronal transmission. The currently most accurate method for determining ion channel kinetic mechanisms is single-channel recording and analysis. Yet, the limitations and complexities in interpreting single-channel recordings discourage many physiologists from using them. Here we show that a genetic search algorithm in combination with a gradient descent algorithm can be used to fit whole-cell voltage-clamp data to kinetic models with a high degree of accuracy. Previously, ion channel stimulation traces were analyzed one at a time, the results of these analyses being combined to produce a picture of channel kinetics. Here the entire set of traces from all stimulation protocols are analysed simultaneously. The algorithm was initially tested on simulated current traces produced by several Hodgkin-Huxley-like and Markov chain models of voltage-gated potassium and sodium channels. Currents were also produced by simulating levels of noise expected from actual patch recordings. Finally, the algorithm was used for finding the kinetic parameters of several voltage-gated sodium and potassium channels models by matching its results to data recorded from layer 5 pyramidal neurons of the rat cortex in the nucleated outside-out patch configuration. The minimization scheme gives electrophysiologists a tool for reproducing and simulating voltage-gated ion channel kinetics at the cellular level.

  6. Investigation of the Dynamics of a Clamped-Clamped Microbeam Near the Third Mode Using a Partial Electrode

    KAUST Repository

    Masri, Karim M.

    2014-08-17

    We present an investigation of the dynamics of a clamped-clamped microbeam excited electrostatically near its third mode. To maximize the response at the third mode, a partial electrode configuration is utilized. A multi-mode Galerkin method is used to develop a reduced order model (ROM) of the beam. A shooting method to find the periodic motion is utilized to generate frequency response curves. The curves show hardenining behavior and dynamic pull-in. We show that the dynamic amplitude of the partial configuration is higher than that of a full electrode configuration. These results are promising for the use of higher-order modes for mass detection and for ultra sensitive resonant sensors.

  7. Performance study of cavity-backed dual-band radiators

    NARCIS (Netherlands)

    Amaldoss, S.E.; Yarovoy, A.

    2011-01-01

    The effectiveness of a cavity for dual-band patch radiator with a frequency ratio of 1.65:1 is analysed. The use of cavities can help in maintaining impedance matching, reducing the levels of mutual coupling between the elements as well as in containing the surface waves, aspects vital to array perf

  8. Can Stem Cell 'Patch' Help Heart Failure?

    Science.gov (United States)

    ... https://medlineplus.gov/news/fullstory_164475.html Can Stem Cell 'Patch' Help Heart Failure? Small improvement seen over ... Scientists report another step in the use of stem cells to help treat people with debilitating heart failure. ...

  9. Shallow ATRIS Seafloor Images - West Turtle Shoal Patch Reef, Rawa PatchReef, Dustan Rocks Patch Reef, and Thor Patch Reef, Florida, 2011

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — Underwater digital images, single-beam bathymetry, and global-positioning system (GPS) data were collected September 29-30, 2011 around Dustan Rocks Patch Reef, Thor...

  10. Timing of umbilical cord clamping: new thoughts on an old discussion.

    Science.gov (United States)

    Arca, Gemma; Botet, Francesc; Palacio, Montse; Carbonell-Estrany, Xavier

    2010-11-01

    The optimal time to clamp the umbilical cord in preterm and full-term neonates after birth continues to be a matter of debate. A review of randomised controlled trials comparing the effects of early versus late cord clamping on maternal and infant outcomes was performed to assess data in favor of immediate or delayed clamping. Although there is no conclusive evidence, delayed cord clamping seems to be beneficial in preterm and full-term neonates without compromising the initial postpartum adaptation phase or affecting the mother in the short term. However, further randomised clinical studies are needed to confirm the benefits of delayed cord clamping.

  11. U-Slotted Microstrip Patch Antenna

    Directory of Open Access Journals (Sweden)

    Yogesh Bhomia

    2013-05-01

    Full Text Available A new U–slotted microstrip antenna is proposed. A patch antenna is a narrowband, wide-beam antenna These antennas are low profile, conformal to planar and non-planar surface, simple and inexpensive to manufacture using modern printed circuit technology, mechanically robust when mounted on rigid surface, compatible with MMIC designs and when the particular shape and mode are selected they are very versatile in terms of resonant frequency, polarization, field pattern and impedance. Microstrip antenna consist of a very thin metallic strip (patch placed a small fraction of a wavelength above a ground plane. The patch is generally made of conducting material such as copper or gold and can take any possible shape. This paper presents a design of U - slotted microstrip patch antenna and experimentally studied on IE3D software. This design is achieved by cutting U shape in a patch. With U - slotted shapes patch antenna is designed on a FR4 substrate of thickness 1.524 mm and relative permittivity of 4.4 and mounted above the ground plane at a height of 6 mm. Bandwidth as high as 39% are achieved with stable pattern characteristics, such as gain and cross polarization, within its bandwidth. Impedance bandwidth, antenna gain and return loss are observed for the proposed antenna. Details of the measured and simulated results are presented and discussed

  12. Clamping stiffness and its influence on load distribution between paired internal spinal fixation devices.

    Science.gov (United States)

    Rohlmann, A; Calisse, J; Bergmann, G; Radvan, J; Mayer, H M

    1996-06-01

    The load distribution between two internal spinal fixation devices depends, besides other factors, on their stiffness. The stiffness ranges were determined experimentally for the clamps of the AO internal fixator with lateral nut and with posterior nut as well as for the clamps of the SOCON fixator. The stiffness of eight devices each differed by a factor of 3.1 for the clamp with lateral nut, by a factor of 1.5 for the clamp with posterior nut, and by a factor of 1.4 for the clamp of the SOCON fixator. For the AO clamp with lateral nut, the influence of the nut-tightening torque on the stiffness was determined. Using instrumented internal spinal fixation devices mounted to plastic vertebrae and simulating a corpectomy, the load distribution between the implants was measured for different tightening torques. It could be shown that, for the AO internal fixator whose clamps have a lateral nut, a nut-tightening torque > 5 Nm has only a negligible influence on load-sharing between the implants. Tooth damage occurs when the teeth of the clamp body and clamping jaw of the clamp with lateral nut do not gear together exactly, which leads to changes in the clamping stiffness and load-sharing between the two implants.

  13. The timing of cord clamping and oxidative stress in term newborns.

    Science.gov (United States)

    Díaz-Castro, Javier; Florido, Jesus; Kajarabille, Naroa; Garrido-Sánchez, Maria; Padilla, Carmen; de Paco, Catalina; Navarrete, Luis; Ochoa, Julio J

    2014-08-01

    Clamping and cutting of the umbilical cord is the most prevalent of all operations, but the optimal timing of cord clamping is controversial, with different timings offering advantages and disadvantages. This study, for the first time, compares the influence of early and late cord clamping in correlation with oxidative stress and inflammation signaling, Because cord clamping timing may have a significant influence on placenta-to-infant blood transfer, thereby modifying oxygenation of maternal and fetal tissues, and on the transfer of inflammatory mediators throughout the placenta. Sixty-four pregnant subjects were selected at the Gynecology and Obstetrics Services Department of the Clinico San Cecilio Hospital, Granada, Spain, based on disease-free women who experienced a normal course of pregnancy and a spontaneous, vaginal, single delivery. Half of the subjects had deliveries with early-clamped newborn infants (at 10 s), and the other half had late-clamped deliveries (at 2 min). Erythrocyte catalase activity was significantly greater in the late-clamped group than in the early-clamped group (P umbilical vein and P clamped group compared with the early-clamped group (P cord clamping, produced by an increase in antioxidant capacity and moderation of the inflammatory-mediated effects induced during delivery of term neonates. Copyright © 2014 by the American Academy of Pediatrics.

  14. Short-term monocular patching boosts the patched eye’s response in visual cortex

    Science.gov (United States)

    Zhou, Jiawei; Baker, Daniel H.; Simard, Mathieu; Saint-Amour, Dave; Hess, Robert F.

    2015-01-01

    Abstract Purpose: Several recent studies have demonstrated that following short-term monocular deprivation in normal adults, the patched eye, rather than the unpatched eye, becomes stronger in subsequent binocular viewing. However, little is known about the site and nature of the underlying processes. In this study, we examine the underlying mechanisms by measuring steady-state visual evoked potentials (SSVEPs) as an index of the neural contrast response in early visual areas. Methods: The experiment consisted of three consecutive stages: a pre-patching EEG recording (14 minutes), a monocular patching stage (2.5 hours) and a post-patching EEG recording (14 minutes; started immediately after the removal of the patch). During the patching stage, a diffuser (transmits light but not pattern) was placed in front of one randomly selected eye. During the EEG recording stage, contrast response functions for each eye were measured. Results: The neural responses from the patched eye increased after the removal of the patch, whilst the responses from the unpatched eye remained the same. Such phenomena occurred under both monocular and dichoptic viewing conditions. Conclusions: We interpret this eye dominance plasticity in adult human visual cortex as homeostatic intrinsic plasticity regulated by an increase of contrast-gain in the patched eye. PMID:26410580

  15. QCD Dual

    DEFF Research Database (Denmark)

    Sannino, Francesco

    2009-01-01

    We uncover a novel solution of the 't Hooft anomaly matching conditions for QCD. Interestingly in the perturbative regime the new gauge theory, if interpreted as a possible QCD dual, predicts the critical number of flavors above which QCD in the nonperturbative regime, develops an infrared stable...... fixed point. Remarkably this value is identical to the maximum bound predicted in the nonpertubative regime via the all-orders conjectured beta function for nonsupersymmetric gauge theories.......We uncover a novel solution of the 't Hooft anomaly matching conditions for QCD. Interestingly in the perturbative regime the new gauge theory, if interpreted as a possible QCD dual, predicts the critical number of flavors above which QCD in the nonperturbative regime, develops an infrared stable...

  16. Umbilical cord clamping at birth--practice in Norwegian maternity wards.

    Science.gov (United States)

    Lundberg, Camilla; Øian, Pål; Klingenberg, Claus

    2013-11-26

    The timing and practice used for umbilical cord clamping of neonates are controversial internationally as well as in Norway. We therefore wished to investigate routines and practices for umbilical cord clamping of neonates in Norway. A web-based questionnaire was sent to heads of departments of all maternity wards in Norway (n = 52). They were asked about their practice with regard to umbilical cord clamping of neonates and whether written routines had been prepared for this purpose. We defined early umbilical cord clamping as immediate or within 30 seconds and late clamping as ≥ 1 minute or not until pulsation in the umbilical cord had ceased. Fifty (96%) of the maternity institutions returned a completed questionnaire. Twelve institutions (24%) reported to clamp the umbilical cord of full-term neonates early, and 38 (76%) reported to practise late clamping. Nineteen maternity wards (38%) followed written routines for umbilical cord clamping of full-term neonates, and among these, early umbilical cord clamping was practised in nine (47%). In the 31 maternity wards that had no written routines, early umbilical cord clamping was practised in three (10%). Twenty-seven of the maternity wards reported that the child is placed on the maternal abdomen before clamping of the umbilical cord, 14 reported that the child commonly is held below the introitus before umbilical cord clamping, and the rest did not report any consistent practice. There is wide variation in the practice for umbilical cord clamping in Norwegian maternity wards, many of which have no written guidelines. We argue that national guidelines for umbilical cord clamping of neonates should be established.

  17. Clamped seismic metamaterials: ultra-low frequency stop bands

    Science.gov (United States)

    Achaoui, Y.; Antonakakis, T.; Brûlé, S.; Craster, R. V.; Enoch, S.; Guenneau, S.

    2017-06-01

    The regularity of earthquakes, their destructive power, and the nuisance of ground vibration in urban environments, all motivate designs of defence structures to lessen the impact of seismic and ground vibration waves on buildings. Low frequency waves, in the range 1-10 Hz for earthquakes and up to a few tens of Hz for vibrations generated by human activities, cause a large amount of damage, or inconvenience; depending on the geological conditions they can travel considerable distances and may match the resonant fundamental frequency of buildings. The ultimate aim of any seismic metamaterial, or any other seismic shield, is to protect over this entire range of frequencies; the long wavelengths involved, and low frequency, have meant this has been unachievable to date. Notably this is scalable and the effects also hold for smaller devices in ultrasonics. There are three approaches to obtaining shielding effects: bragg scattering, locally resonant sub-wavelength inclusions and zero-frequency stop-band media. The former two have been explored, but the latter has not and is examined here. Elastic flexural waves, applicable in the mechanical vibrations of thin elastic plates, can be designed to have a broad zero-frequency stop-band using a periodic array of very small clamped circles. Inspired by this experimental and theoretical observation, all be it in a situation far removed from seismic waves, we demonstrate that it is possible to achieve elastic surface (Rayleigh) wave reflectors at very large wavelengths in structured soils modelled as a fully elastic layer periodically clamped to bedrock. We identify zero frequency stop-bands that only exist in the limit of columns of concrete clamped at their base to the bedrock. In a realistic configuration of a sedimentary basin 15 m deep we observe a zero frequency stop-band covering a broad frequency range of 0-30 Hz.

  18. Accelerated commutation for passive clamp isolated boost converters

    OpenAIRE

    2002-01-01

    An efficient and cost effective bidirectional DC/DC converter reduces switch voltage stress via accelerated commutation allowing use of a low-cost passive clamp circuit in boost mode. The converter includes a primary circuit, transformer and secondary circuit. The primary circuit takes the form of a “full bridge converter,” a “push-pull converter,” or an “L-type converter.”. The primary circuit may include a dissipator such as a snubber circuit or small buck converter. A secondary side of the...

  19. Potassium Chloride Versus Voltage Clamp Contractures in Ventricular Muscle

    Science.gov (United States)

    Morad, M.; Reeck, S.; Rao, M.

    1981-01-01

    In frog ventricle, developed tension was markedly larger in response to depolarization caused by a voltage clamp step than to depolarization induced by high concentrations of potassium chloride. Measurement of extracellular potassium activity at the surface and at the depth of muscle during the development of contractures showed that the diffusion of potassium is much slower than the spread of depolarization through the cross section of muscle. These two observations suggest that competition between the depolarizing and the negative inotropic effects of an increase in the extracellular potassium ion concentration may determine the time course and magnitude of contractile tension in heart muscle.

  20. Effect of Clamping Rigidity of the Armour on Ballistic Performance

    Directory of Open Access Journals (Sweden)

    S. N. Dikshit

    1992-04-01

    Full Text Available Influence of the manner in which the armour plates are held during their ballistic testing on the armour performance, has been evaluated. One armour plate was clamped rigidly to the test stand while a second plate of identical composition, hardness, and dimensions was hung loosely from the target holder. Both these plates were impacted with the same type of projectiles and over the same impact velocity range. The nature of ballistic damage evaluated indicates that the manner in which the armour is held during ballistic testing has a negligible influence on its performance at least when the mass of the plate is substantially higher than that of the projectile.

  1. Euglycemic clamp insulin sensitivity and longitudinal systolic blood pressure

    DEFF Research Database (Denmark)

    Petrie, John R; Malik, Muhammad Omar; Balkau, Beverley

    2013-01-01

    Insulin resistance may be an independent risk factor for the development of hypertension, but change in blood pressure (BP) over time has not been adequately studied in healthy individuals fully characterized for insulin sensitivity. In the Relationship between Insulin Sensitivity...... and Cardiovascular disease (RISC) study, we measured insulin sensitivity (M/I) using the euglycemic clamp technique in 1073 healthy European adults (587 women, 486 men) aged 30 to 60 years followed up 3 years later. Systolic BP (SBP) at baseline was higher in insulin-resistant women (ie, those in the low sex...

  2. Pulsewidth Modulation of Neutral-Point-Clamped Indirect Matrix Converter

    DEFF Research Database (Denmark)

    Blaabjerg, Frede; Poh Chiang, Loh; Gao, Feng

    2008-01-01

    discussed in the existing literature. Addressing the previously described issues, this paper focuses on the operational mode analysis of a three-level indirect matrix converter implemented using a neutral-point-clamped inversion stage and the design of a number of PWM and modulation ratio compensation...... schemes for controlling the converter with improved waveform quality. The performances and practicalities of the designed schemes are verified in simulation and experimentally using an implemented laboratory prototype with some representative results captured and presented in this paper....

  3. Individual colour patches as multicomponent signals.

    Science.gov (United States)

    Grether, Gregory F; Kolluru, Gita R; Nersissian, Karen

    2004-08-01

    Colour patches are complex traits, the components of which may evolve independently through a variety of mechanisms. Although usually treated as simple, two-dimensional characters and classified as either structural or pigmentary, in reality colour patches are complicated, three-dimensional structures that often contain multiple pigment types and structural features. The basic dermal chromatophore unit of fishes, reptiles and amphibians consists of three contiguous cell layers. Xanthophores and erythrophores in the outermost layer contain carotenoid and pteridine pigments that absorb short-wave light; iridophores in the middle layer contain crystalline platelets that reflect light back through the xanthophores; and melanophores in the basal layer contain melanins that absorb light across the spectrum. Changes in any one component of a chromatophore unit can drastically alter the reflectance spectrum produced, and for any given adaptive outcome (e.g. an increase in visibility), there may be multiple biochemical or cellular routes that evolution could take, allowing for divergent responses by different populations or species to similar selection regimes. All of the mechanisms of signal evolution that previously have been applied to single ornaments (including whole colour patches) could potentially be applied to the individual components of colour patches. To reach a complete understanding of colour patch evolution, however, it may be necessary to take an explicitly multi-trait approach. Here, we review multiple trait evolution theory and the basic mechanisms of colour production in fishes, reptiles and amphibians, and use a combination of computer simulations and empirical examples to show how multiple trait evolution theory can be applied to the components of single colour patches. This integrative perspective on animal colouration opens up a host of new questions and hypotheses. We offer specific, testable functional hypotheses for the most common pigmentary

  4. Deformation of vortex patches by boundaries

    CERN Document Server

    Crosby, A; Morrison, P J

    2013-01-01

    The deformation of two-dimensional vortex patches in the vicinity of fluid boundaries is investigated. The presence of a boundary causes an initially circular patch of uniform vorticity to deform. Sufficiently far away from the boundary, the deformed shape is well approximated by an ellipse. This leading order elliptical deformation is investigated via the elliptic moment model of Melander, Zabusky & Styczek [M. V. Melander, N. J. Zabusky & A. S. Styczek, J. Fluid. Mech., 167, 95 (1986)]. When the boundary is straight, the centre of the elliptic patch remains at a constant distance from the boundary, and the motion is integrable. Furthermore, since the straining flow acting on the patch is constant in time, the problem is that of an elliptic vortex patch in constant strain, which was analysed by Kida [S. Kida, J. Phys. Soc. Japan, 50, 3517 (1981)]. For more complicated boundary shapes, such as a square corner, the motion is no longer integrable. Instead, there is an adiabatic invariant for the motion....

  5. Measles vaccination using a microneedle patch.

    Science.gov (United States)

    Edens, Chris; Collins, Marcus L; Ayers, Jessica; Rota, Paul A; Prausnitz, Mark R

    2013-07-25

    Measles vaccination programs would benefit from delivery methods that decrease cost, simplify logistics, and increase safety. Conventional subcutaneous injection is limited by the need for skilled healthcare professionals to reconstitute and administer injections, and by the need for safe needle handling and disposal to reduce the risk of disease transmission through needle re-use and needlestick injury. Microneedles are micron-scale, solid needles coated with a dry formulation of vaccine that dissolves in the skin within minutes after patch application. By avoiding the use of hypodermic needles, vaccination using a microneedle patch could be carried out by minimally trained personnel with reduced risk of blood-borne disease transmission. The goal of this study was to evaluate measles vaccination using a microneedle patch to address some of the limitations of subcutaneous injection. Viability of vaccine virus dried onto a microneedle patch was stabilized by incorporation of the sugar, trehalose, and loss of viral titer was less than 1 log10(TCID50) after storage for at least 30 days at room temperature. Microneedle patches were then used to immunize cotton rats with the Edmonston-Zagreb measles vaccine strain. Vaccination using microneedles at doses equaling the standard human dose or one-fifth the human dose generated neutralizing antibody levels equivalent to those of a subcutaneous immunization at the same dose. These results show that measles vaccine can be stabilized on microneedles and that vaccine efficiently reconstitutes in vivo to generate a neutralizing antibody response equivalent to that generated by subcutaneous injection.

  6. Characterizing the morphology of protein binding patches.

    Science.gov (United States)

    Malod-Dognin, Noël; Bansal, Achin; Cazals, Frédéric

    2012-12-01

    Let the patch of a partner in a protein complex be the collection of atoms accounting for the interaction. To improve our understanding of the structure-function relationship, we present a patch model decoupling the topological and geometric properties. While the geometry is classically encoded by the atomic positions, the topology is recorded in a graph encoding the relative position of concentric shells partitioning the interface atoms. The topological-geometric duality provides the basis of a generic dynamic programming-based algorithm comparing patches at the shell level, which may favor topological or geometric features. On the biological side, we address four questions, using 249 cocrystallized heterodimers organized in biological families. First, we dissect the morphology of binding patches and show that Nature enjoyed the topological and geometric degrees of freedom independently while retaining a finite set of qualitatively distinct topological signatures. Second, we argue that our shell-based comparison is effective to perform atomic-level comparisons and show that topological similarity is a less stringent than geometric similarity. We also use the topological versus geometric duality to exhibit topo-rigid patches, whose topology (but not geometry) remains stable upon docking. Third, we use our comparison algorithms to infer specificity-related information amidst a database of complexes. Finally, we exhibit a descriptor outperforming its contenders to predict the binding affinities of the affinity benchmark. The softwares developed with this article are availablefrom http://team.inria.fr/abs/vorpatch_compatch/.

  7. Microneedle patches for vaccination in developing countries.

    Science.gov (United States)

    Arya, Jaya; Prausnitz, Mark R

    2016-10-28

    Millions of people die of infectious diseases each year, mostly in developing countries, which could largely be prevented by the use of vaccines. While immunization rates have risen since the introduction of the Expanded Program on Immunization (EPI), there remain major challenges to more effective vaccination in developing countries. As a possible solution, microneedle patches containing an array of micron-sized needles on an adhesive backing have been developed to be used for vaccine delivery to the skin. These microneedle patches can be easily and painlessly applied by pressing against the skin and, in some designs, do not leave behind sharps waste. The patches are single-dose, do not require reconstitution, are easy to administer, have reduced size to simplify storage, transportation and waste disposal, and offer the possibility of improved vaccine immunogenicity, dose sparing and thermostability. This review summarizes vaccination challenges in developing countries and discusses advantages that microneedle patches offer for vaccination to address these challenges. We conclude that microneedle patches offer a powerful new technology that can enable more effective vaccination in developing countries. Copyright © 2015. Published by Elsevier B.V.

  8. Surface patterning of nanoparticles with polymer patches

    Science.gov (United States)

    Choueiri, Rachelle M.; Galati, Elizabeth; Thérien-Aubin, Héloïse; Klinkova, Anna; Larin, Egor M.; Querejeta-Fernández, Ana; Han, Lili; Xin, Huolin L.; Gang, Oleg; Zhulina, Ekaterina B.; Rubinstein, Michael; Kumacheva, Eugenia

    2016-10-01

    Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules, serve as model systems in studies of phase transitions in liquid systems, behave as ‘colloidal surfactants’ and function as templates for the synthesis of hybrid particles. The generation of micrometre- and submicrometre-sized patchy colloids is now efficient, but surface patterning of inorganic colloidal nanoparticles with dimensions of the order of tens of nanometres is uncommon. Such nanoparticles exhibit size- and shape-dependent optical, electronic and magnetic properties, and their assemblies show new collective properties. At present, nanoparticle patterning is limited to the generation of two-patch nanoparticles, and nanoparticles with surface ripples or a ‘raspberry’ surface morphology. Here we demonstrate nanoparticle surface patterning, which utilizes thermodynamically driven segregation of polymer ligands from a uniform polymer brush into surface-pinned micelles following a change in solvent quality. Patch formation is reversible but can be permanently preserved using a photocrosslinking step. The methodology offers the ability to control the dimensions of patches, their spatial distribution and the number of patches per nanoparticle, in agreement with a theoretical model. The versatility of the strategy is demonstrated by patterning nanoparticles with different dimensions, shapes and compositions, tethered with various types of polymers and subjected to different external stimuli. These patchy nanocolloids have potential applications in fundamental research, the self-assembly of nanomaterials, diagnostics, sensing and colloidal stabilization.

  9. Dermoscopy of shagreen patch: A first report

    Directory of Open Access Journals (Sweden)

    Shivanand Gundalli

    2015-07-01

    Full Text Available The name is derived from French phrase peau chagrinee which is usually found on lower back, buttock and thigh. The major manifestations of Tuberous sclerosis include skin lesions in more than 95%, mental retardation in approximately 50%, autism, seizures in approximately 85%. The incidence at birth is estimated to be 1 in 5800. We report case of shagreen patch in a 27 year female which is present since birth. However there is no history of seizures or consanginous marriage in our case. Associated features are naevus comedonicus and naevus collagenosis, facial angiofibroma. Shagreen patch are present in mandibular area of face. Although, diagnosis is easy, it can be mistaken for inflammatory verrucous epidermal nevus, plaques of other inflammatory skin conditions. Diagnosis is usually on clinical background. Sometimes biopsy is necessary to confirm the diagnosis. Dermoscopy, a non-invasive, in vivo technique for the microscopic examination of pigmented skin lesions, has the potential to improve the diagnostic accuracy. Dermoscopy of Shagreen patch showed reddish-brown strands with white dots giving a cobblestone appearance It can be utilized as a diagnostic aide in the diagnosis of Shagreen patch. Authors evaluated the dermoscopic patterns of Shagreen patch and hence, it is useful in diagnosis.

  10. Delayed clamping of the umbilical cord after delivery and implications for public cord blood banking.

    Science.gov (United States)

    Allan, David S; Scrivens, Nicholas; Lawless, Tiffany; Mostert, Karen; Oppenheimer, Lawrence; Walker, Mark; Petraszko, Tanya; Elmoazzen, Heidi

    2016-03-01

    Public banking of umbilical cord blood units (CBUs) containing higher numbers of cells ensures timely engraftment after transplantation for increasing numbers of patients. Delayed clamping of the umbilical cord after birth may benefit some infants by preventing iron deficiency. Implications of delayed cord clamping for public cord blood banking remains unclear. CBUs collected by Canadian Blood Services at one collection site between November 1, 2014, and March 17, 2015, were analyzed. The delay in cord clamping after birth was timed and classified as "no delay," 20 to 60 seconds, more than 60 seconds, or more than 120 seconds. Of 367 collections, 100 reported no delay in clamping while clamping was delayed by 20 to 60 seconds (n = 69), more than 60 seconds (n = 98), or more than 120 seconds (n = 100) in the remaining cases. The mean volume and total nucleated cells (TNCs) in units with no delay in clamping were significantly greater than mean volumes for all categories of delayed clamping (Tukey's test, p clamping was delayed (p = 5.5 × 10(-8) ). The difference was most marked for cords that were clamped more than 120 seconds after delivery (6.2% compared with 39%). Delayed cord clamping greatly diminishes the volume and TNC count of units collected for a public cord blood bank. Creating an inventory of CBUs with high TNC content may take more time than expected. © 2015 AABB.

  11. Delayed Umbilical Cord Clamping in the 21st Century: Indications for Practice.

    Science.gov (United States)

    Bayer, Kimberly

    2016-02-01

    Health care providers have debated the timing of umbilical cord clamping since the days of Aristotle. Delayed cord clamping was the mainstay of practice until about the 1950s when it was changed to immediate clamping on the basis of a series of blood volume studies combined with the introduction of active management of the third stage of labor. However, in recent years, several systematic reviews advise that delayed cord clamping should be used in all births for at least 30 to 60 seconds. The purpose of this article is to discuss the physiology of umbilical cord clamping, the potential benefits and adverse effects of delayed cord clamping, and how this affects the advanced practice nurse. A search of PubMed, Cochrane Reviews, and Clinical Key was used to find relevant research on the topic of umbilical cord clamping. Potential benefits of delayed cord clamping include decreased frequency of iron-deficiency anemia in the first year of life with improved neurodevelopmental outcomes in term infants, reduced need for blood transfusions, possible autologous transfusion of stem cells, and a decreased incidence of intraventricular hemorrhage. Apprehension exists regarding the feasibility of the practice as well as the potential hindrance of immediate resuscitation. There is a need to begin to look for populations for which delayed cord clamping can be implemented. Recommendations are inconsistent on the patient population and timing; therefore, further studies are needed to understand the multiple variables that affect timing of umbilical cord clamping.

  12. Randomised trial of cord clamping and initial stabilisation at very preterm birth.

    Science.gov (United States)

    Duley, Lelia; Dorling, Jon; Pushpa-Rajah, Angela; Oddie, Sam J; Yoxall, Charles William; Schoonakker, Bernard; Bradshaw, Lucy; Mitchell, Eleanor J; Fawke, Joe Anthony

    2017-09-18

    For very preterm births, to compare alternative policies for umbilical cord clamping and immediate neonatal care. Parallel group randomised (1:1) trial, using sealed opaque numbered envelopes. Eight UK tertiary maternity units. 261 women expected to have a live birth before 32 weeks, and their 276 babies. Cord clamping after at least 2 min and immediate neonatal care with cord intact, or clamping within 20 s and immediate neonatal care after clamping. Intraventricular haemorrhage (IVH), death before discharge. 132 women (137 babies) were allocated clamping ≥2 min and neonatal care cord intact, and 129 (139) clamping ≤20 s and neonatal care after clamping; six mother-infant dyads were excluded (2, 4) as birth was after 35(+6) weeks, one withdrew (death data only available) (0, 1). Median gestation was 28.9 weeks for those allocated clamping ≥2 min, and 29.2 for those allocated clamping ≤20 s. Median time to clamping was 120 and 11 s, respectively. 7 of 135 infants (5.2%) allocated clamping ≥2 min died and 15 of 135 (11.1%) allocated clamping ≤20 s; risk difference (RD) -5.9% (95% CI -12.4% to 0.6%). Of live births, 43 of 134 (32%) had IVH vs 47 of 132 (36%), respectively; RD -3.5% (-14.9% to 7.8%). There were no clear differences in other outcomes for infants or mothers. This is promising evidence that clamping after at least 2 min and immediate neonatal care with cord intact at very preterm birth may improve outcome; a large trial is urgently needed. ISRCTN 21456601. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  13. Improved patch antenna performance by using a metamaterial cover

    Institute of Scientific and Technical Information of China (English)

    ZHU Fang-ming; HU Jun

    2007-01-01

    A new patch antenna system with a metamaterial cover is presented in this paper. The impedance, radiation pattern, and directivity of such an antenna are studied. A performance comparison between the conventional patch antenna and the new metamaterial patch antenna is given. The results show that the directivity of the metamaterial patch antenna is significantly improved. The effect of the metamaterial cover's layer numbers on the radiation pattern of the patch antenna is also studied.

  14. SuperPatchMatch: an Algorithm for Robust Correspondences using Superpixel Patches.

    Science.gov (United States)

    Giraud, Remi; Ta, Vinh-Thong; Bugeau, Aurelie; Coupe, Pierrik; Papadakis, Nicolas

    2017-05-29

    Superpixels have become very popular in many computer vision applications. Nevertheless, they remain underexploited since the superpixel decomposition may produce irregular and non stable segmentation results due to the dependency to the image content. In this paper, we first introduce a novel structure, a superpixel-based patch, called SuperPatch. The proposed structure, based on superpixel neighborhood, leads to a robust descriptor since spatial information is naturally included. The generalization of the PatchMatch method to SuperPatches, named SuperPatchMatch, is introduced. Finally, we propose a framework to perform fast segmentation and labeling from an image database, and demonstrate the potential of our approach since we outperform, in terms of computational cost and accuracy, the results of state-of-the-art methods on both face labeling and medical image segmentation.

  15. A stronger patch test elicitation reaction to the allergen hydroxycitronellal plus the irritant sodium lauryl sulfate

    DEFF Research Database (Denmark)

    Heydorn, S; Andersen, Klaus Ejner; Johansen, Jeanne Duus;

    2003-01-01

    elicitation reaction than patch testing with the allergen (hydroxycitronellal) alone, in patients previously patch tested positive to hydroxycitronellal. A stronger patch test elicitation reaction was defined as at least 1 day of patch test reading showing more positive patch tests...

  16. Fault-patch stress-transfer efficiency in presence of sub-patch geometric complexity

    KAUST Repository

    Zielke, Olaf

    2015-04-01

    It is well known that faults are not planar surfaces. Instead they exhibit self-similar or self-affine properties that span a wide range of spatial (sub-micrometer to tens-of-kilometer). This geometric fault roughness has a distinct impact on amount and distribution of stresses/strains induced in the medium and on other portions of the fault. However, when numerically simulated (for example in multi-cycle EQ rupture simulations or Coulomb failure stress calculations) this roughness is largely ignored: individual fault patches --the incremental elements that build the fault surface in the respective computer models-- are planar and fault roughness at this and lower spatial scales is not considered. As a result, the fault-patch stress-transfer efficiency may be systematically too large in those numerical simulations with respect to the "actual" efficiency level. Here, we investigate the effect of sub-patch geometric complexity on fault-patch stress-transfer efficiency. For that, we sub-divide a fault patch (e.g., 1x1km) into a large number of sub-patches (e.g., 20x20m) and determine amount of induced stresses at selected positions around that patch for different levels and realizations of fault roughness. For each fault roughness level, we compute mean and standard deviation of the induced stresses, enabling us to compute the coefficient of variation. We normalize those values with stresses from the corresponding single (planar) fault patch, providing scaling factors and their variability for stress transfer efficiency. Given a certain fault roughness that is assumed for a fault, this work provides the means to implement the sub-patch fault roughness into investigations based on fault-patch interaction schemes.

  17. Patch-augmented rotator cuff repair: influence of the patch fixation technique on primary biomechanical stability.

    Science.gov (United States)

    Jung, Christian; Spreiter, Gregor; Audigé, Laurent; Ferguson, Stephen J; Flury, Matthias

    2016-05-01

    There is an ongoing debate about the potential of patch augmentation to improve biomechanical stability and healing associated with rotator cuff repair. The biomechanical properties of three different patch-augmented rotator cuff repair techniques were assessed in vitro and compared with a standard repair. Dermal collagen patch augmentation may increase the primary stability and strength of the repaired tendon in vitro, depending on the technique used for patch application. Forty cadaveric sheep shoulders with dissected infraspinatus tendons were randomized into four groups (n = 10/group) for tendon repair using a knotless double-row suture anchor technique. A xenologous dermal extracellular matrix patch was used for augmentation in the three test groups using an "integrated", "cover", or "hybrid" technique. Tendons were preconditioned, cyclically loaded from 10 to 30 N at 1 Hz, and then loaded monotonically to failure. Biomechanical properties and the mode of failure were evaluated. Patch augmentation significantly increased the maximum load at failure by 61 % in the "cover" technique test group (225.8 N) and 51 % in the "hybrid" technique test group (211.4 N) compared with the non-augmented control group (140.2 N) (P ≤ 0.015). For the test group with "integrated" patch augmentation, the load at failure was 28 % lower (101.6 N) compared with the control group (P = 0.043). There was no significant difference in initial and linear stiffness among the four experimental groups. The most common mode of failure was tendon pullout. No anchor dislocation, patch disruption or knot breakage was observed. Additional patch augmentation with a collagen patch influences the biomechanical properties of a rotator cuff repair in a cadaveric sheep model. Primary repair stability can be significantly improved depending on the augmentation technique.

  18. Boolean Operations with Prism Algebraic Patches

    Science.gov (United States)

    Bajaj, Chandrajit; Paoluzzi, Alberto; Portuesi, Simone; Lei, Na; Zhao, Wenqi

    2009-01-01

    In this paper we discuss a symbolic-numeric algorithm for Boolean operations, closed in the algebra of curved polyhedra whose boundary is triangulated with algebraic patches (A-patches). This approach uses a linear polyhedron as a first approximation of both the arguments and the result. On each triangle of a boundary representation of such linear approximation, a piecewise cubic algebraic interpolant is built, using a C1-continuous prism algebraic patch (prism A-patch) that interpolates the three triangle vertices, with given normal vectors. The boundary representation only stores the vertices of the initial triangulation and their external vertex normals. In order to represent also flat and/or sharp local features, the corresponding normal-per-face and/or normal-per-edge may be also given, respectively. The topology is described by storing, for each curved triangle, the two triples of pointers to incident vertices and to adjacent triangles. For each triangle, a scaffolding prism is built, produced by its extreme vertices and normals, which provides a containment volume for the curved interpolating A-patch. When looking for the result of a regularized Boolean operation, the 0-set of a tri-variate polynomial within each such prism is generated, and intersected with the analogous 0-sets of the other curved polyhedron, when two prisms have non-empty intersection. The intersection curves of the boundaries are traced and used to decompose each boundary into the 3 standard classes of subpatches, denoted in, out and on. While tracing the intersection curves, the locally refined triangulation of intersecting patches is produced, and added to the boundary representation. PMID:21516262

  19. FORMULATION AND EVALUATION OF CARVEDILOL TRANSDERMAL PATCHES

    Directory of Open Access Journals (Sweden)

    Mandal Sonjoy

    2011-01-01

    Full Text Available The present study was carried out to develop and evaluate matrix-type transdermal formulations containing carvedilol with different ratios of hydrophilic (HPMC and hydrophobic polymeric (Eudragit RS100 combinations plasticized with glycerin and dibutyl pthalate by the solvent evaporation technique. Effect of surfactant (PEG-400 and Tween 80 and permeation enhancers (DMSO and DMF were studied. The interference of the polymers were ruled out by infrared and uv spectroscopic methods. Viscosity of the polymers was determined using Brookfield viscometer (LVDV-E. The partition coefficient study was performed using n-octanol as the organic phase and phosphate buffer pH 7.4 as an aqueous phase. The prepared patches were tested for their physicochemical characteristics such as thickness, weight, and drug content uniformity, swelling index, water vapour transmission, folding endurance, and tensile strength. In vitro release studies of carvedilol-loaded patches in phosphate buffer (pH, 7.4 exhibited drug release in the range of 80.70 to 98.56 % in 24 h. Data of in vitro release from patches were fit in to different equations and kinetic models to explain release kinetics. The models used were zero and first-order equations, Hixon-Crowell, Higuchi and Korsmeyer-Peppas models. Based on physicochemical and in vitro release studies, patches containing HPMC and Eudragit RS 100 (DMSO as permeation enhancer were chosen for in vitro skin permeation studies which were performed using a modified diffusion cell across rat abdominal skin and showed first order release mechanism. Skin studies for the transdermal patches were assessed and were found to be free of irritation. The patches were subjected to short term stability studies and were found stable. Good correlation was observed (R2 = 0.810 with in vitro release Vs in vitro skin permeation studies.

  20. Patch testing for adverse drug reactions.

    Science.gov (United States)

    Sekhon, Sahil; Nedorost, Susan T

    2017-01-01

    Adverse drug reactions result in a substantial number of hospital admissions and inpatient events. Diagnosis usually is made with clinical judgment and circumstantiality without diagnostic testing. Furthermore, even in situations where diagnostic testing is performed, no safe gold standard tests exist. Oral rechallenge is currently the gold standard but carries the risk of recrudescence of severe allergic symptoms. Other tests include skin prick tests, the lymphocyte transformation test, immunohistochemistry, and patch testing. This article provides a review of patch testing in cases of adverse drug reactions and presents new data on this topic.

  1. Assembling a Network out of Ambiguous Patches

    OpenAIRE

    Yartseva, Lyudmila; Elbert, Jefferson Simoes; Grossglauser, Matthias

    2016-01-01

    Many graph mining and network analysis problems rely on the availability of the full network over a set of nodes. But inferring a full network is sometimes non-trivial if the raw data is in the form of many small {\\em patches} or subgraphs, of the true network, and if there are ambiguities in the identities of nodes or edges in these patches. This may happen because of noise or because of the nature of data; for instance, in social networks, names are typically not unique. \\textit{Graph...

  2. Learning Dictionaries of Discriminative Image Patches

    DEFF Research Database (Denmark)

    Dahl, Anders Lindbjerg; Larsen, Rasmus

    2011-01-01

    Remarkable results have been obtained using image models based on image patches, for example sparse generative models for image inpainting, noise reduction and superresolution, sparse texture segmentation or texton models. In this paper we propose a powerful and yet simple approach for segmentation...... using dictionaries of image patches with associated label data. The approach is based on ideas from sparse generative image models and texton based texture modeling. The intensity and label dictionaries are learned from training images with associated label information of (a subset) of the pixels based...

  3. Generic Patch Inference

    DEFF Research Database (Denmark)

    Andersen, Jesper; Lawall, Julia Laetitia

    2008-01-01

    A key issue in maintaining Linux device drivers is the need to update drivers in response to evolutions in Linux internal libraries. Currently, there is little tool support for performing and documenting such changes. In this paper we present a tool, spfind, that identifies common changes made...... developers can use it to extract an abstract representation of the set of changes that others have made. Our experiments on recent changes in Linux show that the inferred generic patches are more concise than the corresponding patches found in commits to the Linux source tree while being safe with respect...

  4. Optimal timing of umbilical cord clamping for term and preterm babies.

    Science.gov (United States)

    Duley, Lelia; Batey, Natalie

    2013-11-01

    Deferring cord clamping allows blood flow between baby and placenta to continue for a few moments. This often leads to increased neonatal blood volume at birth. It also allows for longer transition to the neonatal circulation. Optimal timing for clamping the cord remains uncertain. This paper discusses the physiology of placental transfusion and presents the evidence from systematic reviews of randomised trials comparing alternative strategies for cord clamping for both term and preterm births. For healthy term infants, deferring cord clamping increases iron stores in infancy. Therefore, a more liberal approach to deferring cord clamping appears to be warranted, provided screening and treatment for jaundice requiring phototherapy is available. For preterm births, although there are few data on the main clinical outcomes, the evidence is promising that deferred cord clamping may be beneficial. For both term and preterm infants there is little information about long term development. © 2013.

  5. Application of Numerical Simulation for the Verification of Design of Clamping a Workpiece in Jaws

    Science.gov (United States)

    Oravcová, Jarmila; Riečičiarová, Eva

    2016-12-01

    This paper deals with the use of the numerical computer oriented method for the analysis and verification of the design of workpiece clamping. The inaccuracies of the positioning in clamping locating points were simulated using the FEM software ANSYS. The influence of inaccuracies in the positions of contact locating points on the displacements of the workpiece characteristic points and their position in clamped removable jaws was examined. The reaction forces in the contact locating points were also computed and analyzed.

  6. Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs.

    Science.gov (United States)

    Bhatt, Sasmira; Alison, Beth J; Wallace, Euan M; Crossley, Kelly J; Gill, Andrew W; Kluckow, Martin; te Pas, Arjan B; Morley, Colin J; Polglase, Graeme R; Hooper, Stuart B

    2013-04-15

    Delayed cord clamping improves circulatory stability in preterm infants at birth, but the underlying physiology is unclear. We investigated the effects of umbilical cord clamping, before and after ventilation onset, on cardiovascular function at birth. Prenatal surgery was performed on lambs (123 days) to implant catheters into the pulmonary and carotid arteries and probes to measure pulmonary (PBF), carotid (CaBF) and ductus arteriosus blood flows. Lambs were delivered at 126 ± 1 days and: (1) the umbilical cord was clamped at delivery and ventilation was delayed for about 2 min (Clamp 1st; n = 6), and (2) umbilical cord clamping was delayed for 3-4 min, until after ventilation was established (Vent 1st; n = 6). All lambs were subsequently ventilated for 30 min. In Clamp 1st lambs, cord clamping rapidly (within four heartbeats), but transiently, increased pulmonary and carotid arterial pressures (by ∼30%) and CaBF (from 30.2 ± 5.6 to 40.1 ± 4.6 ml min(-1) kg(-1)), which then decreased again within 30-60 s. Following ventilation onset, these parameters rapidly increased again. In Clamp 1st lambs, cord clamping reduced heart rate (by ∼40%) and right ventricular output (RVO; from 114.6 ± 14.4 to 38.8 ± 9.7 ml min(-1) kg(-1)), which were restored by ventilation. In Vent 1st lambs, cord clamping reduced RVO from 153.5 ± 3.8 to 119.2 ± 10.6 ml min(-1) kg(-1), did not affect heart rates and resulted in stable blood flows and pressures during transition. Delaying cord clamping for 3-4 min until after ventilation is established improves cardiovascular function by increasing pulmonary blood flow before the cord is clamped. As a result, cardiac output remains stable, leading to a smoother cardiovascular transition throughout the early newborn period.

  7. Delaying cord clamping until ventilation onset improves cardiovascular function at birth in preterm lambs

    Science.gov (United States)

    Bhatt, Sasmira; Alison, Beth J; Wallace, Euan M; Crossley, Kelly J; Gill, Andrew W; Kluckow, Martin; te Pas, Arjan B; Morley, Colin J; Polglase, Graeme R; Hooper, Stuart B

    2013-01-01

    Delayed cord clamping improves circulatory stability in preterm infants at birth, but the underlying physiology is unclear. We investigated the effects of umbilical cord clamping, before and after ventilation onset, on cardiovascular function at birth. Prenatal surgery was performed on lambs (123 days) to implant catheters into the pulmonary and carotid arteries and probes to measure pulmonary (PBF), carotid (CaBF) and ductus arteriosus blood flows. Lambs were delivered at 126 ± 1 days and: (1) the umbilical cord was clamped at delivery and ventilation was delayed for about 2 min (Clamp 1st; n = 6), and (2) umbilical cord clamping was delayed for 3–4 min, until after ventilation was established (Vent 1st; n = 6). All lambs were subsequently ventilated for 30 min. In Clamp 1st lambs, cord clamping rapidly (within four heartbeats), but transiently, increased pulmonary and carotid arterial pressures (by ∼30%) and CaBF (from 30.2 ± 5.6 to 40.1 ± 4.6 ml min−1 kg−1), which then decreased again within 30–60 s. Following ventilation onset, these parameters rapidly increased again. In Clamp 1st lambs, cord clamping reduced heart rate (by ∼40%) and right ventricular output (RVO; from 114.6 ± 14.4 to 38.8 ± 9.7 ml min−1 kg−1), which were restored by ventilation. In Vent 1st lambs, cord clamping reduced RVO from 153.5 ± 3.8 to 119.2 ± 10.6 ml min−1 kg−1, did not affect heart rates and resulted in stable blood flows and pressures during transition. Delaying cord clamping for 3–4 min until after ventilation is established improves cardiovascular function by increasing pulmonary blood flow before the cord is clamped. As a result, cardiac output remains stable, leading to a smoother cardiovascular transition throughout the early newborn period. PMID:23401615

  8. Design of modified pentagonal patch antenna on defective ground for Wi-Max/WLAN application

    Science.gov (United States)

    Rawat, Sanyog; Sharma, K. K.

    2016-04-01

    This paper presents the design and performance of a modified pentagonal patch antenna with defective ground plane. A pentagonal slot is inserted in the pentagonal patch and slot loaded ground through optimized dimensions is used in the antenna to resonate it at dual frequency. The geometry operates at two resonant frequencies (2.5 GHz and 5.58 GHz) and offers impedance bandwidth of 864 MHz and 554 MHz in the two bands of interest. The proposed antenna covers the lower band (2.45 to 2.484/2.495 to 2.695 GHz) and upper band (5.15 to 5.825 GHz/5.25 to 5.85 GHz) allocated for Wi-Max and WLAN communication systems.

  9. Diuretic response to acute hypertension is blunted during angiotensin II clamp

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Zhang, Yibin; Yang, Li E;

    2002-01-01

    ("ANG II clamp"). When blood pressure was acutely increased 50-60 mmHg by arterial constriction without ANG II clamp, urine output and endogenous lithium clearance increased 4.0- and 6.7-fold, respectively. With ANG II clamp, the effects of acute hypertension were reduced 50%: urine output...... and endogenous lithium clearance increased two- and threefold, respectively. We conclude that HOE-140, an inhibitor of the B(2) receptor, potentiates the sensitivity of arterial pressure to ANG II and that clamping systemic ANG II levels during acute hypertension blunts the magnitude of the pressure diuretic...

  10. Modeling of SVM Diode Clamping Three-Level Inverter Connected to Grid

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

    2011-01-01

    PLECS is used to model the diode clamping three-level inverter connected to grid and good results are obtained. First the output voltage SVM is described for diode clamping three-level inverter with loads connected to Y. Then the output voltage SVM of diode clamping three-level inverter is simply...... is very powerful tool to real power circuits and it is very easy to simulate them. They have also verified that SVM control strategy is feasible to control the diode clamping three-level inverter....

  11. Electrically integrated SU-8 clamped graphene drum resonators for strain engineering

    Science.gov (United States)

    Lee, Sunwoo; Chen, Changyao; Deshpande, Vikram V.; Lee, Gwan-Hyoung; Lee, Ilkyu; Lekas, Michael; Gondarenko, Alexander; Yu, Young-Jun; Shepard, Kenneth; Kim, Philip; Hone, James

    2013-04-01

    Graphene mechanical resonators are the ultimate two-dimensional nanoelectromechanical systems (NEMS) with applications in sensing and signal processing. While initial devices have shown promising results, an ideal graphene NEMS resonator should be strain engineered, clamped at the edge without trapping gas underneath, and electrically integratable. In this Letter, we demonstrate fabrication and direct electrical measurement of circular SU-8 polymer-clamped chemical vapor deposition graphene drum resonators. The clamping increases device yield and responsivity, while providing a cleaner resonance spectrum from eliminated edge modes. Furthermore, the clamping induces a large strain in the resonator, increasing its resonant frequency.

  12. COMPARISON OF EARLY AND DELAYED UMBILICAL CORD CLAMPING IN THE THIRD STAGE OF LABOUR

    Directory of Open Access Journals (Sweden)

    Tamara Serdinšek

    2015-09-01

    Full Text Available Background: Umbilical cord clamping in the third stage of labour is still controversial. Early cord clamping is defined as clamping at 10, 15, 30 or 60 seconds after delivery and delayed as clamping after 60 seconds or at 2-5 minutes after delivery, when the cord stops pulsating or when the placenta is visible within the birth canal. Early clamping is one of the three components of active management of the third stage of labour, which has been used widely in modern obstetrics during the last century. However, in some northern European countries, various parts of the USA and Canada and in developing countries physiological management is preferred.Conclusions: After publication of several trials describing advantages of delayed clamping, this has recently been progressively replacing early clamping. The most important advantages of delayed cord clamping are higher haemoglobin and ferritin levels, higher iron stores, lower incidence of iron deficiency anaemia, better cardiopulmonary adaptation, lower rate of respiratory distress syndrome, and longer duration of early breastfeeding in term neonates, while there is no increase in the incidence of postpartum haemorrhage. Delayed clamping seems to bring some advantages for preterm neonates as well. However, caution is still advised because of the potential adverse effects, especially polycythaemia with hyperviscosity, hyperbilirubinaemia and respiratory distress.

  13. Beliefs and practices of obstetric care providers regarding umbilical cord clamping.

    Science.gov (United States)

    Hill, Allyson L; Fontenot, Holly B

    2014-01-01

    The optimal timing for umbilical cord clamping after birth has yet to be established, and controversy exists. There is evidence of potentially significant health benefits of delayed cord clamping for both full-term and preterm newborns, but this practice has not been widely adopted. This column takes a second look at two recent studies in which researchers examined the beliefs and practices of obstetric care providers regarding umbilical cord clamping in North America. Nurses who are aware of the latest science and who understand both existing practice patterns as well as practice barriers to delayed clamping can be leaders in and advocates for change. © 2014 AWHONN.

  14. Cryogenic Clamp-on Ultrasonic Flowmeters using Single Crystal Piezoelectric Transducers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Clamp-on ultrasound cryogenic flowmeters using single crystal piezoelectric transducers are proposed to enable reliable, accurate cryogenic instrumentation needs in...

  15. Mechanism of ATP-driven PCNA clamp loading by S. cerevisiae RFC.

    Science.gov (United States)

    Chen, Siying; Levin, Mikhail K; Sakato, Miho; Zhou, Yayan; Hingorani, Manju M

    2009-05-08

    Circular clamps tether polymerases to DNA, serving as essential processivity factors in genome replication, and function in other critical cellular processes as well. Clamp loaders catalyze clamp assembly onto DNA, and the question of how these proteins construct a topological link between a clamp and DNA, especially the mechanism by which ATP is utilized for the task, remains open. Here we describe pre-steady-state analysis of ATP hydrolysis, proliferating cell nuclear antigen (PCNA) clamp opening, and DNA binding by Saccharomyces cerevisiae replication factor C (RFC), and present the first kinetic model of a eukaryotic clamp-loading reaction validated by global data analysis. ATP binding to multiple RFC subunits initiates a slow conformational change in the clamp loader, enabling it to bind and open PCNA and to bind DNA as well. PCNA opening locks RFC into an active state, and the resulting RFC.ATP.PCNA((open)) intermediate is ready for the entry of DNA into the clamp. DNA binding commits RFC to ATP hydrolysis, which is followed by PCNA closure and PCNA.DNA release. This model enables quantitative understanding of the multistep mechanism of a eukaryotic clamp loader and furthermore facilitates comparative analysis of loaders from diverse organisms.

  16. Electrothermally actuated tunable clamped-guided resonant microbeams

    KAUST Repository

    Alcheikh, Nouha

    2017-06-11

    We present simulation and experimental investigation demonstrating active alteration of the resonant and frequency response behavior of resonators by controlling the electrothermal actuation method on their anchors. In-plane clamped-guided arch and straight microbeams resonators are designed and fabricated with V-shaped electrothermal actuators on their anchors. These anchors not only offer various electrothermal actuation options, but also serve as various mechanical stiffness elements that affect the operating resonance frequency of the structures. We have shown that for an arch, the first mode resonance frequency can be increased up to 50% of its initial value. For a straight beam, we have shown that before buckling, the resonance frequency decreases to very low values and after buckling, it increases up to twice of its initial value. These results can be promising for the realization of different wide–range tunable microresonator. The experimental results have been compared to multi-physics finite-element simulations showing good agreement among them.

  17. Trans-Z-source Neutral Point Clamped inverter

    DEFF Research Database (Denmark)

    Mo, W.; Loh, P. C.; Li, D.;

    2012-01-01

    Transformer based Z-source (trans-Z-source) inverters are recently proposed by extending the traditional Z-source inverter with higher buck-boost capability as well as reducing the passive components at the same time. Multi-Level Z-source inverters are single-stage topological solutions used...... modulation scheme, the three-level trans-Z-source inverter can function with minimum of six device commutations per half carrier cycle (same as the traditional buck NPC inverter), while maintaining to produce the designed volt-sec average and inductive voltage boosting at ac output terminals. The designed...... for buck-boost energy conversion with all the favourable advantages of multi-level switching retained. This paper presents three-level trans-Z-source Neutral Point Clamped (NPC) inverter topology, which achieves both the advantages of trans-Z-source and three-level NPC inverter configuration. With proper...

  18. Umbilical Hernia Repair with Proceed Ventral Patch

    Directory of Open Access Journals (Sweden)

    Salati Sajad Ahmad

    2014-07-01

    Full Text Available Umbilical hernia is one the commonest surgical lesions and there is a variety of methods available for its repair. Proceed Ventral Patch is a recent and novel innovation in hernia management and we present a successful management of umbilical hernia in a 45 years old obese patient with this technique

  19. Wireless Arm Patch May Blunt Migraine Pain

    Science.gov (United States)

    ... electrodes and a chip in the patch produce electric impulses that block pain signals from reaching the brain, the study authors said. When a migraine starts, you can control the intensity of the electric impulses using a smartphone app, explained lead researcher ...

  20. A method for detecting hydrophobic patches protein

    NARCIS (Netherlands)

    Lijnzaad, P.; Berendsen, H.J.C.; Argos, P.

    1996-01-01

    A method for the detection of hydrophobic patches on the surfaces of protein tertiary structures is presented, it delineates explicit contiguous pieces of surface of arbitrary size and shape that consist solely of carbon and sulphur atoms using a dot representation of the solvent-accessible surface,

  1. Evidence-based diagnosis in patch testing

    NARCIS (Netherlands)

    van der Valk, PGM; Devos, SA; Coenraads, PJ

    2003-01-01

    Evidence-based medicine (EBM) is defined as the integration of the best research evidence with clinical expertise and patient values. Based on the principles of EBM, we can conclude that patch testing is cost-effective only if patients are selected on the basis of a clear-cut clinical suspicion of c

  2. Positive patch test reactions to oxidized limonene

    DEFF Research Database (Denmark)

    Bråred Christensson, Johanna; Andersen, Klaus E; Bruze, Magnus

    2014-01-01

    BACKGROUND: R-Limonene is a common fragrance terpene found in domestic and industrial products. R-Limonene autoxidizes on air exposure, and the oxidation products can cause contact allergy. In a recent multicentre study, 5.2% (range 2.3-12.1%) of 2900 patients showed a positive patch test reactio...

  3. Soil, Seeds, and the Pumpkin Patch!

    Science.gov (United States)

    Phillips, Marianne; Vowell, Julie

    2013-01-01

    "Soil, Seeds, and the Pumpkin Patch!" is an integrated unit designed to provide elementary school teachers with ideas for using hands-on activities, fostering inquiry and valuable discussion, and using technology as a learning tool. This unit integrates science with language arts, mathematics, literature, and technology. During this unit, students…

  4. Capsaicin patch (Qutenza) for postherpetic neuralgia.

    Science.gov (United States)

    2011-05-30

    The FDA has approved a topical 8% patch formulation of capsaicin (Qutenza-NeurogesX), available only by prescription, for local treatment of postherpetic neuralgia. Postherpetic neuralgia occurs after herpes zoster in about one third of patients ≥60 years old and can persist for months or even years.

  5. Juno Microwave Radiometer Patch Array Antennas

    Science.gov (United States)

    Chamberlain, N.; Chen, J.; Focardi, P.; Hodges, R.; Hughes, R.; Jakoboski, J.; Venkatesan, J.; Zawadzki, M.

    2009-01-01

    Juno is a mission in the NASA New Frontiers Program with the goal of significantly improving our understanding of the formation and structure of Jupiter. This paper discusses the modeling and measurement of the two patch array antennas. An overview of the antenna architecture, design and development at JPL is provided, along with estimates of performance and the results of measurements.

  6. Bye-Bye Flu Shot, Hello Patch?

    Science.gov (United States)

    ... for intramuscular injection [a flu shot] by a health care professional," he added. Also, "this patch does not need to be refrigerated -- it has ... National Library of Medicine 8600 Rockville Pike, Bethesda, MD 20894 U.S. Department of Health and Human Services National Institutes of Health Page ...

  7. A method for detecting hydrophobic patches protein

    NARCIS (Netherlands)

    Lijnzaad, P.; Berendsen, H.J.C.; Argos, P.

    1996-01-01

    A method for the detection of hydrophobic patches on the surfaces of protein tertiary structures is presented, it delineates explicit contiguous pieces of surface of arbitrary size and shape that consist solely of carbon and sulphur atoms using a dot representation of the solvent-accessible surface,

  8. The timing of umbilical cord clamping at birth: physiological considerations.

    Science.gov (United States)

    Hooper, Stuart B; Binder-Heschl, Corinna; Polglase, Graeme R; Gill, Andrew W; Kluckow, Martin; Wallace, Euan M; Blank, Douglas; Te Pas, Arjan B

    2016-01-01

    While it is now recognized that umbilical cord clamping (UCC) at birth is not necessarily an innocuous act, there is still much confusion concerning the potential benefits and harms of this common procedure. It is most commonly assumed that delaying UCC will automatically result in a time-dependent net placental-to-infant blood transfusion, irrespective of the infant's physiological state. Whether or not this occurs, will likely depend on the infant's physiological state and not on the amount of time that has elapsed between birth and umbilical cord clamping (UCC). However, we believe that this is an overly simplistic view of what can occur during delayed UCC and ignores the benefits associated with maintaining the infant's venous return and cardiac output during transition. Recent experimental evidence and observations in humans have provided compelling evidence to demonstrate that time is not a major factor influencing placental-to-infant blood transfusion after birth. Indeed, there are many factors that influence blood flow in the umbilical vessels after birth, which depending on the dominating factors could potentially result in infant-to-placental blood transfusion. The most dominant factors that influence umbilical artery and venous blood flows after birth are lung aeration, spontaneous inspirations, crying and uterine contractions. It is still not entirely clear whether gravity differentially alters umbilical artery and venous flows, although the available data suggests that its influence, if present, is minimal. While there is much support for delaying UCC at birth, much of the debate has focused on a time-based approach, which we believe is misguided. While a time-based approach is much easier and convenient for the caregiver, ignoring the infant's physiology during delayed UCC can potentially be counter-productive for the infant.

  9. Abundance, distribution and patch formation of zooplankton

    Science.gov (United States)

    Paffenhöfer, Gustav-Adolf; Sherman, Byron K.; Lee, Thomas N.

    The goal of studies described here was to determine the responses of zooplankton taxa to phytoplankton patches which develop in and near intrusions of cold, nutrient-rich Gulf Stream water. To achieve this goal we determined the horizontal and vertical distributions of abundant mesozooplankton taxa on the south-eastern continental shelf of the USA between 29°30‧ and 31°N. The study period was from June 23 to August 16, 1981. Highest concentrations of zooplankton usually occurred in and near patches of phytoplankton. Increased phytoplankton appeared to trigger the formation of patches of the calanoid copepod Temora turbinata and the cyclopoid copepods Oithona spp. and Oncaea spp. The patches of zooplankton had greater alongshore than cross-shelf dimensions. T. turbinata responded rapidly to increased concentrations of phytoplankton by reproducing and aggregating in and above intruded waters. Oithonidae which were often, but not always, abundant in phytoplankton patches eventually attained high concentrations over most of the middle and part of the inner shelf. Their concentration and that of Oncaeidae increased steadily. Oncaeidae were not abundant in recently upwelled waters, as was T. turbinata but reached high concentrations in older intrusions when the abundance of T. turbinata remained level or decreased slowly. Both cyclopoid taxa are thought to reproduce slowly (egg sacs) compared to T. turbinata. Another taxon, the doliolids, became abundant far more rapidly in intruded waters (by asexual reproduction) than did the other three taxa. Doliolids were the most opportunistic intrusion zooplankton form. They do not regularly occur in low abundance on the shelf, as do the three copepod taxa, but develop in pulses in regions where T. turbinata and Oncaea are not abundant. Of the four taxa studied the abundance of doliolids increased and decreased most rapidly, whereas Oithona and Oncaea increased slowly and did not decrease during the study period. T. turbinata

  10. Magnetic Patches in Internetwork Quiet Sun

    Science.gov (United States)

    De Wijn, Alfred; Lites, B.; Berger, T.; Shine, R.; Title, A.; Katsukawa, Y.; Tsuneta, S.; Suematsu, Y.; Shimizu, T.; Hinode Team

    2007-05-01

    We study strong flux elements in the quiet sun in the context of the nature of quiet-sun magnetism, its coupling to chromospheric, transition-region and coronal fields, and the nature of a local turbulent dynamo. Strong, kilogauss flux elements show up intermittently as small bright points in G-band and Ca II H images. Although bright points have been extensively studied in the magnetic network, internetwork magnetism has only come under scrutiny in recent years. A full spectrum of field strengths seems to be ubiquitously present in the internetwork at small spatial scales, with the stronger elements residing in intergranular lanes. De Wijn et al. (2005) found that bright points in quiet sun internetwork areas appear recurrently with varying intensity and horizontal motion within long-lived patches that outline cell patterns on mesogranular scales. They estimate that the "magnetic patches" have a mean lifetime of nine hours, much longer than granular timescales. We use multi-hour sequences of G-band and Ca II H images as well as magnetograms recorded by the Hinode satellite to follow up on their results. The larger field of view, the longer sequences, the addition of magnetograms, and the absence of atmospheric seeing allows us to better constrain the patch lifetime, to provide much improved statistics on IBP lifetime, to compare IBPs to network bright points, and to study field polarity of IBPs in patches and between nearby patches. Hinode is an international project supported by JAXA, NASA, PPARC and ESA. We are grateful to the Hinode team for all their efforts in the design, build and operation of the mission.

  11. Understanding patch departure rules for large carnivores: lion movements support a patch-disturbance hypothesis.

    Science.gov (United States)

    Valeix, Marion; Chamaillé-Jammes, Simon; Loveridge, Andrew J; Davidson, Zeke; Hunt, Jane E; Madzikanda, Hillary; Macdonald, David W

    2011-08-01

    We test two hypotheses that could account for patch departure by large mammalian carnivores. One hypothesis is the unsuccessful-hunt hypothesis, where carnivores leave an area after an unsuccessful hunt but continue hunting in the same area after a successful hunt. The second hypothesis is the patch-disturbance hypothesis, where carnivores depart the area after a successful hunt because of behavioral responses of prey to predator presence. We used global positioning system collars to monitor the movements of African lions (Panthera leo) and identified their kill sites to distinguish between these two hypotheses. Lions moved to a different area (≥ 5 km away) after 87% of the kills, which supports the patch-disturbance hypothesis for patch-departure behavior of large mammalian carnivores.

  12. Light transmission and preference of eye patches for occlusion treatment.

    Directory of Open Access Journals (Sweden)

    Hwan Heo

    Full Text Available PURPOSE: To investigate light transmission and preference for six eye patches for occlusion therapy. METHODS: Six patches were examined, including; Ortopad Fun Pack, Ortopad Flesh, Kawamoto A-1, Kawamoto A-2, 3M Opticlude, and Everade Eye Guard. The size and the presence of a light blocking pad of patches were investigated. The amount of light transmitted through the patches was evaluated, using a digital light meter and a model eye, in three different environments; indoors with fluorescent light, outdoors on a sunny day, and strong light from illuminator. After patching the normal eye, the flash visual evoked potential (VEP was measured. Thirty patients with amblyopia or horizontal strabismus, who received occlusion therapy as initial treatment, were included. After using all six patches, patients completed a 7-item questionnaire regarding the patch preference for size, color and shape, adhesive power, pain with removal, skin irritation after removing patch, parent's preference and overall opinion. RESULTS: All patches had a light-blocking pad, except the 3M Nexcare. Ortopad had the strongest light blocking power in the three environments, and the 3M Nexcare had the weakest power. In flash VEP, Ortopad and Kawamoto patches showed flat, but 3M Nexcare and Everade Eye Guard showed normal response. There were significant preferential differences among the patches in all the items of the questionnaire (P<0.05. In comparison between the patches respectively, 3M Nexcare received the lowest satisfaction in pain when removing a patch and skin irritation after removing a patch. Kawamoto A-2 received the lowest score in the overall satisfaction. CONCLUSIONS: We found differences in the light-blocking power and in the preference of the various patches for the occlusion treatment. This is a pilot study regarding only characteristics and preferences of patches. Further clinical studies regarding the relationship between characteristics or preferences of

  13. Effect of eye patching in rehabilitation of neglect

    Directory of Open Access Journals (Sweden)

    Nicola eSmania

    2013-09-01

    Full Text Available Eye patching (monocular or right hemifield has been proposed to improve visuospatial attention to the ignored field in patients with neglect. The aim of this paper is to review the literature on the effects of eye patching in hemispatial neglect after stroke in order to convey evidence-based recommendations to clinicians in stroke rehabilitation. Thirteen intervention studies were selected from the Medline, EMBASE, Scopus, Cochrane Library, CINAHL, PsychINFO, EBRSR and Health Star databases. Methodological quality was defined according to the Physiotherapy Evidence Database. Overall, seven studies used monocular eye patching, five used right hemifield patching and one compared right monocular with right hemifield patching. Seven studies compared normal viewing to monocular or hemifield patching conditions. Six studies included a period of treatment. Three studies included follow-up evaluations. As to the monocular eye patching, four studies reported positive effects of right monocular patching. One study showed an improvement in hemispatial neglect with left monocular patching. Two studies found no superiority of right versus left monocular patching. One study found no effects of right monocular patching. As to the right hemifield eye patching, one study showed improvements in neglect after right hemifield patching. Three studies found that right hemifield patching combined with another rehabilitation technique was more effective than that treatment alone. One study found no differences between right hemifield patching combined with another treatment and that treatment alone. One study found the same effect between right hemifield patching alone and another rehabilitation technique.Our results globally tend to support the usefulness of right hemifield eye patching in clinical practice. In order to define a level of evidence with the standard rehabilitation evidence rating tools, further properly powered randomized controlled trials or meta

  14. Current umbilical cord clamping practices and attitudes of obstetricians and midwives toward delayed cord clamping in Saudi Arabia.

    Science.gov (United States)

    Ibrahim, Nadia O; Sukkarieh, Hatouf H; Bustami, Rami T; Alshammari, Elaf A; Alasmari, Lama Y; Al-Kadri, Hanan M

    2017-01-01

    In Saudi Arabia, as in many countries, there is usually no clear definition of the timing of umbilical cord clamping (UCC) in the policies and procedures used by hospitals. The World Health Organization (WHO) recommends delayed cord clamping (DCC) ( > 1 minute after birth) as it can significantly improve hemodynamics and long-term neurodevelopment. To investigate current practices of healthcare professionals on the timing of UCC in Saudi Arabia. Cross-sectional survey. Five tertiary hospitals in Riyadh, Saudi Arabia, during May to October 2016. Obstetricians and midwives completed a widely-used questionnaire on UCC practices. Current UCC practices and attitudes of obstetricians and midwives toward DCC. Eighty-two obstetricians and 75 midwives completed the questionnaire for a response rate of 80%. The majority of respondents were aged 30 years or older (81%) and 84% were females. Most respondents were non-Saudi (66%) and had an educational level of bachelor's degree or higher (72%). Only 42% of respondents reported the existence of UCC guidelines in their practice; 38% reported the existence of a set time for UCC when the neonate was term and healthy, and only 32% had a set time for UCC in preterm neonates. While lower levels of agreement were reported among obstetricians and midwives on the benefits of DCC for babies requiring positive pressure ventilation, the majority of respondents (69-71%) thought that DCC was generally good for both term and preterm babies and that its benefits extend beyond the neonatal period. While the majority of obstetricians and midwives that participated in this study had a positive perception toward DCC, this did not translate to their daily practice as most of these professionals reported a lack of existing UCC guidelines in their institutions. Further studies are warranted to confirm these findings. Participant selection by convenience sampling.

  15. Review of Microstrip Patch Antenna for WLAN and WiMAX Application

    Directory of Open Access Journals (Sweden)

    Neha Parmar ,

    2014-01-01

    Full Text Available In this rapid changing world in wireless communication, dual or multiband antenna has been playing a key role for wireless service requirements. Wireless local area network (WLAN and Worldwide Interoperability for Microwave Access (WiMAX have been widely applied in mobile devices such as handheld computers and smart phones. These two techniques have been widely considered as a cost-effective, flexible, reliable and high-speed data connectivity solution, enabling user mobility. This paper presents a literature survey of dual band rectangular patch antenna for WLAN and WiMAX application with variety of substrate, feed techniques and slots. In this paper we also discuss the basics of microstrip antenna, various feeding techniques, design model and antenna paramerters with their advantage and disadvantages.

  16. Structural insight into β-Clamp and its interaction with DNA Ligase in Helicobacter pylori.

    Science.gov (United States)

    Pandey, Preeti; Tarique, Khaja Faisal; Mazumder, Mohit; Rehman, Syed Arif Abdul; Kumari, Nilima; Gourinath, Samudrala

    2016-08-08

    Helicobacter pylori, a gram-negative and microaerophilic bacterium, is the major cause of chronic gastritis, gastric ulcers and gastric cancer. Owing to its central role, DNA replication machinery has emerged as a prime target for the development of antimicrobial drugs. Here, we report 2Å structure of β-clamp from H. pylori (Hpβ-clamp), which is one of the critical components of DNA polymerase III. Despite of similarity in the overall fold of eubacterial β-clamp structures, some distinct features in DNA interacting loops exists that have not been reported previously. The in silico prediction identified the potential binders of β-clamp such as alpha subunit of DNA pol III and DNA ligase with identification of β-clamp binding regions in them and validated by SPR studies. Hpβ-clamp interacts with DNA ligase in micromolar binding affinity. Moreover, we have successfully determined the co-crystal structure of β-clamp with peptide from DNA ligase (not reported earlier in prokaryotes) revealing the region from ligase that interacts with β-clamp.

  17. The transducer domain is important for clamp operation in human DNA topoisomerase IIalpha

    DEFF Research Database (Denmark)

    Oestergaard, Vibe H; Bjergbaek, Lotte; Skouboe, Camilla

    2003-01-01

    the clamp to the enzyme core. Although structurally conserved, it is unclear whether the transducer domain is involved in clamp mechanism. We have purified and characterized a human topoisomerase II alpha enzyme with a two-amino acid insertion at position 408 in the transducer domain. The enzyme retains...

  18. Angiotensin II clamp prevents the second step in renal apical NHE3 internalization during acute hypertension

    DEFF Research Database (Denmark)

    Leong, Patrick K K; Yang, Li E; McDonough, Alicia A

    2002-01-01

    . Plasma ANG II concentration of anesthesized Sprague-Dawley rats was clamped by simultaneous infusion of the ANG I-converting enzyme inhibitor captopril (12 microg/min) and ANG II (20 ng. kg(-1). min(-1)). Blood pressure was increased 50 mmHg for 20 min by arterial constriction +/- ANG II clamp or by sham...

  19. Effect of delayed cord clamping on very preterm infants.

    Science.gov (United States)

    Chiruvolu, Arpitha; Tolia, Veeral N; Qin, Huanying; Stone, Genna Leal; Rich, Diana; Conant, Rhoda J; Inzer, Robert W

    2015-11-01

    Despite significant proposed benefits, delayed umbilical cord clamping (DCC) is not practiced widely in preterm infants largely because of the question of feasibility of the procedure and uncertainty regarding the magnitude of the reported benefits, especially intraventricular hemorrhage (IVH) vs the adverse consequences of delaying the neonatal resuscitation. The objective of this study was to determine whether implementation of the protocol-driven DCC process in our institution would reduce the incidence of IVH in very preterm infants without adverse consequences. We implemented a quality improvement process for DCC the started in August 2013 in infants born at ≤32 weeks' gestational age. Eligible infants were left attached to the placenta for 45 seconds after birth. Neonatal process and outcome data were collected until discharge. We compared infants who received DCC who were born between August 2013 and August 2014 with a historic cohort of infants who were born between August 2012 and August 2013, who were eligible to receive DCC, but whose cord was clamped immediately after birth, because they were born before the protocol implementation. DCC was performed on all the 60 eligible infants; 88 infants were identified as historic control subjects. Gestational age, birthweight, and other demographic variables were similar between both groups. There were no differences in Apgar scores or admission temperature, but significantly fewer infants in the DCC cohort were intubated in delivery room, had respiratory distress syndrome, or received red blood cell transfusions in the first week of life compared with the historic cohort. A significant reduction was noted in the incidence of IVH in the DCC cohort compared with the historic control group (18.3% vs 35.2%). After adjustment for gestational age, an association was found between the incidence of IVH and DCC with IVH was significantly lower in the DCC cohort compared with the historic cohort; an odds ratio of 0

  20. On the mechanism of loading the PCNA sliding clamp by RFC.

    Science.gov (United States)

    Dionne, Isabelle; Brown, Nicola J; Woodgate, Roger; Bell, Stephen D

    2008-04-01

    Sliding clamps play central roles in a broad range of DNA replication and repair processes. The clamps form circular molecules that must be opened and resealed around DNA by the clamp loader complex to fulfil their function. While most eukaryotes and many archea possess a homo-trimeric PCNA, the PCNA of Sulfolobus solfataricus is a heterotrimer. Here, we exploit the asymmetry of S. solfataricus PCNA to create a series of circularly permuted PCNA subunit fusions, thereby covalently closing defined interfaces within the heterotrimer. Using these concatamers, we investigate the requirements for loading the clamp onto DNA and reveal that a single defined interface within the heterotrimer is opened during the loading process. Subunit-specific interactions between S. solfataricus RFC clamp loader and PCNA permit us to superimpose our data upon the structure of yeast RFC-PCNA complex, thereby presenting a general model for PCNA loading by RFC in archaea and eukaryotes.

  1. A reduction clamp for an aiming component in associated acetabular fractures

    Directory of Open Access Journals (Sweden)

    Zhang-Fu Wang

    2015-01-01

    Full Text Available Background: The treatment of acetabular fractures is complex and requires specialized equipment. However, all currently available instruments have some disadvantages. A new reduction clamp that can firmly enable reduction and not hinder subsequent fixation procedures for some special fracture types is needed. Materials and Methods: In this study, we introduce a new acetabular clamp and its preliminary clinical application in three T-shaped acetabular fractures. Results: This new clamp can successfully pull the posterior column back to the anterior column and firmly maintain the reduction. This clamp′s aiming plate can facilitate the insertion of long lag screws. The clamp is also easy to assemble and use. Conclusion: This reduction clamp is a useful instrument that can facilitate open reduction and internal fixation of acetabular fractures.

  2. The deformation of an elastic rod with a clamp sliding along a smooth and curved profile

    CERN Document Server

    Misseroni, D; Zaccaria, D; Bigoni, D

    2015-01-01

    The design of compliant mechanisms is crucial in several technologies and relies on the availability of solutions for nonlinear structural problems. One of these solutions is given and experimentally validated in the present article for a compliant mechanism moving along a smooth curved profile. In particular, a deformable elastic rod is held by two clamps, one at each end. The first clamp is constrained to slide without friction along a curved profile, while the second clamp moves in a straight line transmitting its motion through the elastic rod to the first clamp. For this system it is shown that the clamp sliding on the profile imposes nontrivial boundary conditions (derived via a variational and an asymptotic approach), which strongly influence buckling and nonlinear structural behaviour. Investigation of this behaviour shows that a compliant mechanism can be designed, which gives an almost neutral response in compression. This behavior could easily be exploited to make a force limiting device. Finally a...

  3. Note: High-efficiency energy harvester using double-clamped piezoelectric beams

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yingmei; Wu, Xuan; Parmar, Mitesh; Lee, Dong-weon, E-mail: mems@jnu.ac.kr [MEMS and Nanotechnology Laboratory, School of Mechanical Systems Engineering, Chonnam National University, Gwangju (Korea, Republic of)

    2014-02-15

    In this study, an improvement in energy conversion efficiency has been reported, which is realized by using a double-clamped piezoelectric beam, based on uniaxial stretching strain. The buckling mechanism is applied to maximize axial stress in the double-clamped beam. The voltage generated by using the double-clamped piezoelectric beam is higher than that generated by using other conventional structures, such as bending cantilevers coated/sandwiched with piezoelectric film, which is proven both theoretically and experimentally. The power generation efficiency is enhanced by further optimizing the double-clamped structure. The optimized high-efficiency energy harvester utilizing double-clamped piezoelectric beams generates a peak output power of 80 μW, under an acceleration of 0.1g.

  4. Note: high-efficiency energy harvester using double-clamped piezoelectric beams.

    Science.gov (United States)

    Zheng, Yingmei; Wu, Xuan; Parmar, Mitesh; Lee, Dong-weon

    2014-02-01

    In this study, an improvement in energy conversion efficiency has been reported, which is realized by using a double-clamped piezoelectric beam, based on uniaxial stretching strain. The buckling mechanism is applied to maximize axial stress in the double-clamped beam. The voltage generated by using the double-clamped piezoelectric beam is higher than that generated by using other conventional structures, such as bending cantilevers coated/sandwiched with piezoelectric film, which is proven both theoretically and experimentally. The power generation efficiency is enhanced by further optimizing the double-clamped structure. The optimized high-efficiency energy harvester utilizing double-clamped piezoelectric beams generates a peak output power of 80 μW, under an acceleration of 0.1g.

  5. Patch testing in contact dermatitis of hands and feet

    Directory of Open Access Journals (Sweden)

    Huda M

    1996-01-01

    Full Text Available Eighty clinically diagnosed cases of allergic contact dermatitis of hands and feet when subjected to patch testing, Seventy four (92.5% cases showed positive patch test reactions to different suspected antigens. Maximum number of cases belonged to housewives and tea garden workers which showed positive patch test reaction to vegetables and soaps and detergents and pesticides, respectively.

  6. Physical properties of gum karaya-starch-essential oil patches.

    Science.gov (United States)

    Shcherbina, Yulia; Roth, Zvi; Nussinovitch, Amos

    2010-09-01

    Essential oils are used in foods, cosmetics, and pharmaceuticals. Despite the recent marketing of novel essential-oil-containing patches, there is no information on their production, constituents, or physical properties. The objectives of this study were to produce essential-oil patches and characterize their physical properties. The essential oil of Lavandula angustifolia (lavender) was included at concentrations of 2.5% to 10% in patches manufactured from the exudate gum karaya, propylene glycol, glycerol, emulsifier, and optionally, potato starch as filler. Inclusion of essential oil reduced patch strength, stiffness, and elasticity relative to patches without essential oil. Inclusion of starch in the essential-oil patches strengthened them, but reduced their elasticity. Patches' adhesion to substrate was examined by both peeling and probe-tack tests: the higher the inclusion of essential oils within the patch, the larger the decrease in its adhesion to substrate. Addition of starch to essential-oil-containing patches increased their adhesion relative to their essential-oil-only counterparts. Scanning electron micrographs of the patches provided evidence of entrapped starch granules. Although inclusion of essential oil reduced both the mechanical properties and adhesion of the patches, a high proportion of essential oil can still be included without losing patch integrity or eliminating its adhesiveness to the skin.

  7. Smooth surfaces from rational bilinear patches

    KAUST Repository

    Shi, Ling

    2014-01-01

    Smooth freeform skins from simple panels constitute a challenging topic arising in contemporary architecture. We contribute to this problem area by showing how to approximate a negatively curved surface by smoothly joined rational bilinear patches. The approximation problem is solved with help of a new computational approach to the hyperbolic nets of Huhnen-Venedey and Rörig and optimization algorithms based on it. We also discuss its limits which lie in the topology of the input surface. Finally, freeform deformations based on Darboux transformations are used to generate smooth surfaces from smoothly joined Darboux cyclide patches; in this way we eliminate the restriction to surfaces with negative Gaussian curvature. © 2013 Elsevier B.V.

  8. Bilaterally Weighted Patches for Disparity Map Computation

    Directory of Open Access Journals (Sweden)

    Laura Fernández Julià

    2015-03-01

    Full Text Available Visual correspondence is the key for 3D reconstruction in binocular stereovision. Local methods perform block-matching to compute the disparity, or apparent motion, of pixels between images. The simplest approach computes the distance of patches, usually square windows, and assumes that all pixels in the patch have the same disparity. A prominent artifact of the method is the "foreground fattening effet" near depth discontinuities. In order to find a more appropriate support, Yoon and Kweon introduced the use of weights based on color similarity and spatial distance, analogous to those used in the bilateral filter. This paper presents the theory of this method and the implementation we have developed. Moreover, some variants are discussed and improvements are used in the final implementation. Several examples and tests are presented and the parameters and performance of the method are analyzed.

  9. Metamaterial Embedded Wearable Rectangular Microstrip Patch Antenna

    Directory of Open Access Journals (Sweden)

    J. G. Joshi

    2012-01-01

    Full Text Available This paper presents an indigenous low-cost metamaterial embedded wearable rectangular microstrip patch antenna using polyester substrate for IEEE 802.11a WLAN applications. The proposed antenna resonates at 5.10 GHz with a bandwidth and gain of 97 MHz and 4.92 dBi, respectively. The electrical size of this antenna is 0.254λ×0.5λ. The slots are cut in rectangular patch to reduce the bending effect. This leads to mismatch the impedance at WLAN frequency band; hence, a metamaterial square SRR is embedded inside the slot. A prototype antenna has been fabricated and tested, and the measured results are presented in this paper. The simulated and measured results of the proposed antenna are found to be in good agreement. The bending effect on the performance of this antenna is experimentally verified.

  10. Mesh saliency with adaptive local patches

    Science.gov (United States)

    Nouri, Anass; Charrier, Christophe; Lézoray, Olivier

    2015-03-01

    3D object shapes (represented by meshes) include both areas that attract the visual attention of human observers and others less or not attractive at all. This visual attention depends on the degree of saliency exposed by these areas. In this paper, we propose a technique for detecting salient regions in meshes. To do so, we define a local surface descriptor based on local patches of adaptive size and filled with a local height field. The saliency of mesh vertices is then defined as its degree measure with edges weights computed from adaptive patch similarities. Our approach is compared to the state-of-the-art and presents competitive results. A study evaluating the influence of the parameters establishing this approach is also carried out. The strength and the stability of our approach with respect to noise and simplification are also studied.

  11. Tunable Patch Antennas Using Microelectromechanical Systems

    Science.gov (United States)

    2011-05-11

    wavelength of the desired resonant frequency [1]. (25) To aid in the design process a MATLAB script was written to solve for patch antenna...10–12, the widths of 50 Ω and 112 Ω microstrip lines were calculated using a MATLAB script included as an appendix to this report. The calculated...2009, pp. 50–55. [11] W.L. Stutzman, G.A. Thiele , Antenna Theory and Design, Second Edition, John Wiley & Sons, Inc. (Hoboken, New Jersey), 1998, pp

  12. Design of an innovative magnetostrictive patch actuator

    Science.gov (United States)

    Cinquemani, S.; Giberti, H.

    2015-04-01

    Magnetostrictive actuators can be profitably used to reduce vibration in structures. However, this technology has been exploited only to develop inertial actuators, while patches actuators have not been ever used in practice. Patches actuators consist on a layer of magnetostrictive material, which has to be stuck to the surface of the vibrating structure, and on a coil surrounding the layer itself. However, the presence of the winding severely limits the use of such devices. As a matter of fact, the scientific literature reports only theoretical uses of such actuators, but, in practice it does not seem they were ever used. This paper presents an innovative solution to improve the structure of the actuator patches, allowing their use in several practical applications. The principle of operation of these devices is rather simple. The actuator patch is able to generate a local deformation of the surface of the vibrating structure so as to introduce an equivalent damping that dissipates the kinetic energy associated to the vibration. This deformation is related to the behavior of the magnetostrictive material immersed in a variable magnetic field generated by the a variable current flowing in the winding. Contrary to what suggested in the theoretical literature, the designed device has the advantage of generating the variable magnetic field no longer in close proximity of the material, but in a different area, thus allowing a better coupling. The magnetic field is then conveyed through a suitable ferromagnetic structure to the magnetostrictive material. The device has been designed and simulated through FEA. Results confirm that the new configuration can easily overcome all the limits of traditional devices.

  13. Broadband Circularly Polarized Patch Antenna and Method

    Science.gov (United States)

    2016-09-16

    embodiment further includes a series of coupling layers 24A, 24B and 24C of low dielectric constant spacers 26 and parallel high dielectric constant...as that used to make a printed circuit board. [0005] A common means of obtaining a circularly polarized signal from a rectangular patch antenna of...in a single plane, coplanar with the emitter, and parallel to the dominant current distribution when the emitter is active. Further coupling layers

  14. Effects of Delayed Umbilical Cord Clamping vs Early Clamping on Anemia in Infants at 8 and 12 Months: A Randomized Clinical Trial.

    Science.gov (United States)

    Kc, Ashish; Rana, Nisha; Målqvist, Mats; Jarawka Ranneberg, Linda; Subedi, Kalpana; Andersson, Ola

    2017-03-01

    Delayed umbilical cord clamping has been shown to improve iron stores in infants to 6 months of age. However, delayed cord clamping has not been shown to prevent iron deficiency or anemia after 6 months of age. To investigate the effects of delayed umbilical cord clamping, compared with early clamping, on hemoglobin and ferritin levels at 8 and 12 months of age in infants at high risk for iron deficiency anemia. This randomized clinical trial included 540 late preterm and term infants born vaginally at a tertiary hospital in Kathmandu, Nepal, from October 2 to November 21, 2014. Follow-up included blood levels of hemoglobin and ferritin at 8 and 12 months of age. Follow-up was completed on December 11, 2015. Analysis was based on intention to treat. Infants were randomized to delayed umbilical cord clamping (≥180 seconds after delivery) or early clamping (≤60 seconds after delivery). Main outcomes included hemoglobin and anemia levels at 8 months of age with the power estimate based on the prevalence of anemia. Secondary outcomes included hemoglobin and anemia levels at 12 months of age and ferritin level, iron deficiency, and iron deficiency anemia at 8 and 12 months of age. In this study of 540 infants (281 boys [52.0%] and 259 girls [48.0%]; mean [SD] gestational age, 39.2 [1.1] weeks), 270 each were randomized to the delayed and early clamping groups. At 8 months of age, 212 infants (78.5%) from the delayed group and 188 (69.6%) from the early clamping group returned for blood sampling. After multiple imputation analysis, infants undergoing delayed clamping had higher levels of hemoglobin (10.4 vs 10.2 g/dL; difference, 0.2 g/dL; 95% CI, 0.1 to 0.4 g/dL). Delayed cord clamping also reduced the prevalence of anemia (hemoglobin level clamping group in 60 (22.2%) vs 103 (38.1%) patients (relative risk, 0.58; 95% CI, 0.44-0.77; NNT, 6; 95% CI, 4-13). At 12 months, delayed cord clamping still resulted in a hemoglobin level of 0.3 (95% CI, 0.04-0.5) g/dL higher

  15. Aortic aneurysm after patch aortoplasty for coarctation: analysis of patch size and wall growth.

    Science.gov (United States)

    Al-Hroob, A; Husayni, T S; Freter, A; Chiemmongkoltip, P; Ilbawi, M N; Arcilla, R A

    2003-01-01

    Aortic aneurysm may develop after surgery for coarctation of aorta especially patch aortoplasty. The size of patch and of adjacent native aortic wall was analyzed to determine whether aortic dilatation represents a true aneurysm. Electron beam tomography (EBT) was done on 19 patients, three months to 17.5 years after patch aortoplasty. Tomograms of aorta were obtained in 6-mm slices, and maximal cross-sectional area was digitized to obtain: total circumference (Ct), patch component (Cp), and aortic wall component (Cw). Ct, Cp, and Cw were normalized to the circumference of distal aorta (Cda) as: isthmus/distal aorta (Ct/Cda), patch segment/distal aorta (Cp/Cda), wall segment/distal aorta (Cw/Cda). Ct/Cda ranged from 109% to 260%. In 12 patients (group A), it varied from 168% to 260%; and in seven (group B), 109% to 133%. There was strong correlation (r = 0.92) between Ct/Cda and Cp/Cda. Ct/Cda, Cp/Cda, and Cp/Cw were higher in group A than B (p <0.001) but Cw/Cda did not differ. Cw/Cda was greater than the coarctation/distal aorta diameter ratios of preoperative angiograms, consistent with accelerated aortic wall growth postsurgery. No definite aneurysm was seen. Localized dilatation of aorta following patch aortoplasty in children is primarily due to a large synthetic patch and, partly, to increased aortic wall growth. Serial EBT or magnetic resonance imaging is indicated to monitor aortic wall growth and occurrence of aneurysm.

  16. Optimal patch code design via device characterization

    Science.gov (United States)

    Wu, Wencheng; Dalal, Edul N.

    2012-01-01

    In many color measurement applications, such as those for color calibration and profiling, "patch code" has been used successfully for job identification and automation to reduce operator errors. A patch code is similar to a barcode, but is intended primarily for use in measurement devices that cannot read barcodes due to limited spatial resolution, such as spectrophotometers. There is an inherent tradeoff between decoding robustness and the number of code levels available for encoding. Previous methods have attempted to address this tradeoff, but those solutions have been sub-optimal. In this paper, we propose a method to design optimal patch codes via device characterization. The tradeoff between decoding robustness and the number of available code levels is optimized in terms of printing and measurement efforts, and decoding robustness against noises from the printing and measurement devices. Effort is drastically reduced relative to previous methods because print-and-measure is minimized through modeling and the use of existing printer profiles. Decoding robustness is improved by distributing the code levels in CIE Lab space rather than in CMYK space.

  17. Modular assembly of thick multifunctional cardiac patches

    Science.gov (United States)

    Fleischer, Sharon; Shapira, Assaf; Feiner, Ron; Dvir, Tal

    2017-01-01

    In cardiac tissue engineering cells are seeded within porous biomaterial scaffolds to create functional cardiac patches. Here, we report on a bottom-up approach to assemble a modular tissue consisting of multiple layers with distinct structures and functions. Albumin electrospun fiber scaffolds were laser-patterned to create microgrooves for engineering aligned cardiac tissues exhibiting anisotropic electrical signal propagation. Microchannels were patterned within the scaffolds and seeded with endothelial cells to form closed lumens. Moreover, cage-like structures were patterned within the scaffolds and accommodated poly(lactic-co-glycolic acid) (PLGA) microparticulate systems that controlled the release of VEGF, which promotes vascularization, or dexamethasone, an anti-inflammatory agent. The structure, morphology, and function of each layer were characterized, and the tissue layers were grown separately in their optimal conditions. Before transplantation the tissue and microparticulate layers were integrated by an ECM-based biological glue to form thick 3D cardiac patches. Finally, the patches were transplanted in rats, and their vascularization was assessed. Because of the simple modularity of this approach, we believe that it could be used in the future to assemble other multicellular, thick, 3D, functional tissues. PMID:28167795

  18. Non-Hookean statistical mechanics of clamped graphene ribbons

    Science.gov (United States)

    Bowick, Mark J.; Košmrlj, Andrej; Nelson, David R.; Sknepnek, Rastko

    2017-03-01

    Thermally fluctuating sheets and ribbons provide an intriguing forum in which to investigate strong violations of Hooke's Law: Large distance elastic parameters are in fact not constant but instead depend on the macroscopic dimensions. Inspired by recent experiments on free-standing graphene cantilevers, we combine the statistical mechanics of thin elastic plates and large-scale numerical simulations to investigate the thermal renormalization of the bending rigidity of graphene ribbons clamped at one end. For ribbons of dimensions W ×L (with L ≥W ), the macroscopic bending rigidity κR determined from cantilever deformations is independent of the width when W ℓth , however, this thermally renormalized bending rigidity begins to systematically increase, in agreement with the scaling theory, although in our simulations we were not quite able to reach the system sizes necessary to determine the fully developed power law dependence on W . When the ribbon length L >ℓp , where ℓp is the W -dependent thermally renormalized ribbon persistence length, we observe a scaling collapse and the beginnings of large scale random walk behavior.

  19. Umbilical Cord Milking Versus Delayed Cord Clamping in Preterm Infants.

    Science.gov (United States)

    Katheria, Anup C; Truong, Giang; Cousins, Larry; Oshiro, Bryan; Finer, Neil N

    2015-07-01

    Delayed cord clamping (DCC) is recommended for premature infants to improve blood volume. Most preterm infants are born by cesarean delivery (CD), and placental transfusion may be less effective than in vaginal delivery (VD). We sought to determine whether infants umbilical cord milking (UCM) have higher measures of systemic blood flow than infants who undergo DCC. This was a 2-center trial. Infants delivered by CD were randomly assigned to undergo UCM or DCC. Infants delivered by VD were also randomly assigned separately. UCM (4 strippings) or DCC (45-60 seconds) were performed. Continuous hemodynamic measurements and echocardiography were done at site 1. A total of 197 infants were enrolled (mean gestational age 28 ± 2 weeks). Of the 154 infants delivered by CD, 75 were assigned to UCM and 79 to DCC. Of the infants delivered by CD, neonates randomly assigned to UCM had higher superior vena cava flow and right ventricular output in the first 12 hours of life. Neonates undergoing UCM also had higher hemoglobin, delivery room temperature, blood pressure over the first 15 hours, and urine output in the first 24 hours of life. There were no differences for the 43 infants delivered by VD. This is the first randomized controlled trial demonstrating higher systemic blood flow with UCM in preterm neonates compared with DCC. UCM may be a more efficient technique to improve blood volume in premature infants delivered by CD. Copyright © 2015 by the American Academy of Pediatrics.

  20. A layer-wise MITC9 finite element for the free-vibration analysis of plates with piezo-patches

    Directory of Open Access Journals (Sweden)

    Maria Cinefra

    2015-04-01

    Full Text Available The present article considers the free-vibration analysis of plate structures with piezoelectric patches by means of a plate finite element with variable through-the-thickness layer-wise kinematic. The refined models used are derived from Carrera’s Unified Formulation (CUF and they permit the vibration modes along the thickness to be accurately described. The finite-element method is employed and the plate element implemented has nine nodes, and the mixed interpolation of tensorial component (MITC method is used to contrast the membrane and shear locking phenomenon. The related governing equations are derived from the principle of virtual displacement, extended to the analysis of electromechanical problems. An isotropic plate with piezoelectric patches is analyzed, with clamped-free boundary conditions and subjected to open- and short-circuit configurations. The results, obtained with different theories, are compared with the higher-order type solutions given in the literature. The conclusion is reached that the plate element based on the CUF is more suitable and efficient compared to the classical models in the study of multilayered structures embedding piezo-patches.

  1. Miniaturization of Multiple-Layer Folded Patch Antennas

    DEFF Research Database (Denmark)

    Zhang, Jiaying; Breinbjerg, Olav

    2009-01-01

    A new folded patch antenna with multiple layers was developed in this paper, by folding the patch in a proper way, and a highly miniaturized antenna can be realized. The multiple layer patch with 4-layer and 6-layer are designed and evaluated at 2.4 GHz, 915 MHz, and 415 MHz respectively. Then a 4...... layer patch is fabricated and measured to validate the design method. The theoretical analysis, design and simulations, fabrications, as well as the measurements are presented in this paper. All the results show that the folded patch antenna is a good candidate in making a highly miniaturized compact...... antenna....

  2. Retrospective evaluation of the consequence of alleged patch test sensitization

    DEFF Research Database (Denmark)

    Jensen, Charlotte D; Paulsen, Evy; Andersen, Klaus E

    2006-01-01

    consequences in cases of possible patch test sensitization. Among 7619 consecutively tested eczema patients in a 14-year period 26 (0.3%) were identified in the database as having had a late patch test reaction, which may be an indication of patch test sensitization. 9 of these cases were not suitable....... For the remaining 11 patients we could not rule out that they were patch test sensitized, and they were investigated further. 1 was diseased and 10 were interviewed regarding the possible consequences of the alleged patch test sensitization. 9 had not experienced any dermatitis problems, and 1 could not exclude...

  3. Single image super-resolution based on image patch classification

    Science.gov (United States)

    Xia, Ping; Yan, Hua; Li, Jing; Sun, Jiande

    2017-06-01

    This paper proposed a single image super-resolution algorithm based on image patch classification and sparse representation where gradient information is used to classify image patches into three different classes in order to reflect the difference between the different types of image patches. Compared with other classification algorithms, gradient information based algorithm is simpler and more effective. In this paper, each class is learned to get a corresponding sub-dictionary. High-resolution image patch can be reconstructed by the dictionary and sparse representation coefficients of corresponding class of image patches. The result of the experiments demonstrated that the proposed algorithm has a better effect compared with the other algorithms.

  4. A Pragmatic Approach to Patch Testing Atopic Dermatitis Patients

    DEFF Research Database (Denmark)

    Chen, Jennifer K; Jacob, Sharon E; Nedorost, Susan T

    2016-01-01

    Allergic contact dermatitis (ACD) may complicate the clinical course of atopic dermatitis (AD), and patch testing remains the criterion standard for diagnosing ACD. To date, there have been no guidelines or consensus recommendations on when and how to patch test individuals with AD. Failure...... to patch test when appropriate may result in overlooking an important and potentially curable complicating comorbidity. In this article, we present consensus recommendations regarding when to perform patch testing in the AD patient, best practices, and common pitfalls. Patch testing should be considered...

  5. Dictionary-based image denoising for dual energy computed tomography

    Science.gov (United States)

    Mechlem, Korbinian; Allner, Sebastian; Mei, Kai; Pfeiffer, Franz; Noël, Peter B.

    2016-03-01

    Compared to conventional computed tomography (CT), dual energy CT allows for improved material decomposition by conducting measurements at two distinct energy spectra. Since radiation exposure is a major concern in clinical CT, there is a need for tools to reduce the noise level in images while preserving diagnostic information. One way to achieve this goal is the application of image-based denoising algorithms after an analytical reconstruction has been performed. We have developed a modified dictionary denoising algorithm for dual energy CT aimed at exploiting the high spatial correlation between between images obtained from different energy spectra. Both the low-and high energy image are partitioned into small patches which are subsequently normalized. Combined patches with improved signal-to-noise ratio are formed by a weighted addition of corresponding normalized patches from both images. Assuming that corresponding low-and high energy image patches are related by a linear transformation, the signal in both patches is added coherently while noise is neglected. Conventional dictionary denoising is then performed on the combined patches. Compared to conventional dictionary denoising and bilateral filtering, our algorithm achieved superior performance in terms of qualitative and quantitative image quality measures. We demonstrate, in simulation studies, that this approach can produce 2d-histograms of the high- and low-energy reconstruction which are characterized by significantly improved material features and separation. Moreover, in comparison to other approaches that attempt denoising without simultaneously using both energy signals, superior similarity to the ground truth can be found with our proposed algorithm.

  6. Dual Antiplatelet Therapy Does Not Increase the Risk of Bleeding After Carotid Endarterectomy: Results of a Prospective Study.

    Science.gov (United States)

    Illuminati, Giulio; Schneider, Fabrice; Pizzardi, Giulia; Masci, Federica; Calio', Francesco G; Ricco, Jean-Baptiste

    2017-04-01

    The purpose of this study was to evaluate the risk of bleeding and other postoperative complications of carotid endarterectomy (CEA) in patients receiving dual antiplatelet therapy (DAPT). From January 2005 to December 2015, 188 consecutive patients undergoing CEA and receiving DAPT (aspirin 100 mg + clopidogrel 75 mg) were enrolled in a prospective study. All of them underwent coronary artery stenting with drug-eluting stents during the 6 months preceding CEA. In the entire series, DAPT was continued until the evening before CEA and resumed on the evening of the operation. All patients received intraoperative heparinization (5,000 IU before carotid clamping), which was reversed in 5 patients. In addition, all of them were given 2,000 units of enoxaparin every 12 hr after the operation, beginning 6 hr after completion of the operation, and until discharge. All the patients presented with carotid artery stenosis >70% (North American Symptomatic Carotid Endarterectomy Trial [NASCET] criteria), which was symptomatic in 42 patients (transient ischemic attack, n = 32; minor stroke, n = 10) and asymptomatic in 146. The CEA technique was standard, with prosthetic patch closure in 109 cases (58%) and eversion in 79 (42%). The primary endpoints of the study were occurrence of a postoperative cervical hematoma requiring surgical hemostasis and occurrence of cranial nerve injuries. The secondary endpoint was the combined rate of postoperative mortality, stroke, and myocardial ischemia. No postoperative cervical hematoma requiring surgical evacuation occurred in this series. One hypoglossal nerve palsy, regressive within 2 weeks, was observed. Postoperative mortality and neurologic and cardiac morbidity were nil. CEA under DAPT yields results comparable with those obtained in patients receiving a single antiplatelet treatment. No hemorrhagic complications were observed in this prospective series. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Investigation of New Microstrip Bandpass Filter Based on Patch Resonator with Geometrical Fractal Slot.

    Science.gov (United States)

    Mezaal, Yaqeen S; Eyyuboglu, Halil T

    2016-01-01

    A compact dual-mode microstrip bandpass filter using geometrical slot is presented in this paper. The adopted geometrical slot is based on first iteration of Cantor square fractal curve. This filter has the benefits of possessing narrower and sharper frequency responses as compared to microstrip filters that use single mode resonators and traditional dual-mode square patch resonators. The filter has been modeled and demonstrated by Microwave Office EM simulator designed at a resonant frequency of 2 GHz using a substrate of εr = 10.8 and thickness of h = 1.27 mm. The output simulated results of the proposed filter exhibit 22 dB return loss, 0.1678 dB insertion loss and 12 MHz bandwidth in the passband region. In addition to the narrow band gained, miniaturization properties as well as weakened spurious frequency responses and blocked second harmonic frequency in out of band regions have been acquired. Filter parameters including insertion loss, return loss, bandwidth, coupling coefficient and external quality factor have been compared with different values of perturbation dimension (d). Also, a full comparative study of this filter as compared with traditional square patch filter has been considered.

  8. Movement of patches during thermoforming: Experiment and simulation

    Science.gov (United States)

    Schell, J. S. U.; Amory, L.; Guillon, D.

    2016-10-01

    The application of local reinforcement like uni-directional patches can locally increase the strength of composite parts without adding much weight. During design through structural analysis, shape and position of local reinforcement can easily be determined. In the thermoforming process, patches can be integrated into the ply-stack by preassembling. During forming, these patches can move and change their position reducing the structural effect of the patch. The movement of patches has been investigated experimentally. Key factors that influence this movement are orientation, size, position in the pile and slope of the mold. The forming process is simulated using HYPERFORM. The results show that this complex process needs special models which can be computationally intensive. In this work, we model the movement of patches and compare with experiments. The final goal is to have a reasonable predictive capability for movement of patches and design the process to minimize it.

  9. A Latent Source Model for Patch-Based Image Segmentation.

    Science.gov (United States)

    Chen, George H; Shah, Devavrat; Golland, Polina

    2015-10-01

    Despite the popularity and empirical success of patch-based nearest-neighbor and weighted majority voting approaches to medical image segmentation, there has been no theoretical development on when, why, and how well these nonparametric methods work. We bridge this gap by providing a theoretical performance guarantee for nearest-neighbor and weighted majority voting segmentation under a new probabilistic model for patch-based image segmentation. Our analysis relies on a new local property for how similar nearby patches are, and fuses existing lines of work on modeling natural imagery patches and theory for nonparametric classification. We use the model to derive a new patch-based segmentation algorithm that iterates between inferring local label patches and merging these local segmentations to produce a globally consistent image segmentation. Many existing patch-based algorithms arise as special cases of the new algorithm.

  10. Committee Opinion No. 684 Summary: Delayed Umbilical Cord Clamping After Birth.

    Science.gov (United States)

    2017-01-01

    Delayed umbilical cord clamping appears to be beneficial for term and preterm infants. In term infants, delayed umbilical cord clamping increases hemoglobin levels at birth and improves iron stores in the first several months of life, which may have a favorable effect on developmental outcomes. There is a small increase in jaundice that requires phototherapy in this group of infants. Consequently, health care providers adopting delayed umbilical cord clamping in term infants should ensure that mechanisms are in place to monitor for and treat neonatal jaundice. In preterm infants, delayed umbilical cord clamping is associated with significant neonatal benefits, including improved transitional circulation, better establishment of red blood cell volume, decreased need for blood transfusion, and lower incidence of necrotizing enterocolitis and intraventricular hemorrhage. Delayed umbilical cord clamping was not associated with an increased risk of postpartum hemorrhage or increased blood loss at delivery, nor was it associated with a difference in postpartum hemoglobin levels or the need for blood transfusion. Given the benefits to most newborns and concordant with other professional organizations, the American College of Obstetricians and Gynecologists now recommends a delay in umbilical cord clamping in vigorous term and preterm infants for at least 30-60 seconds after birth. The ability to provide delayed umbilical cord clamping may vary among institutions and settings; decisions in those circumstances are best made by the team caring for the mother-infant dyad.

  11. Committee Opinion No.543: Timing of umbilical cord clamping after birth.

    Science.gov (United States)

    2012-12-01

    The optimal timing for clamping the umbilical cord after birth has been a subject of controversy and debate. Although many randomized controlled trials in term and preterm infants have evaluated the benefits of delayed umbilical cord clamping versus immediate umbilical cord clamping, the ideal timing for cord clamping has yet to be established. Several systematic reviews have suggested that clamping the umbilical cord in all births should be delayed for at least 30-60 seconds, with the infant maintained at or below the level of the placenta because of the associated neonatal benefits, including increased blood volume, reduced need for blood transfusion, decreased incidence of intracranial hemorrhage in preterm infants, and lower frequency of iron deficiency anemia in term infants. Evidence exists to support delayed umbilical cord clamping in preterm infants, when feasible. The single most important clinical benefit for preterm infants is the possibility for a nearly 50% reduction in intraventricular hemorrhage. However, currently, evidence is insufficient to confirm or refute the potential for benefits from delayed umbilical cord clamping in term infants, especially in settings with rich resources.

  12. Blood gas values in clamped and unclamped umbilical cord at birth.

    Science.gov (United States)

    Di Tommaso, Mariarosaria; Seravalli, Viola; Martini, Irene; La Torre, Pasquale; Dani, Carlo

    2014-09-01

    To determine the reliability of the cord blood gas analysis on the unclamped cord compared to the standard technique of sampling on double clamped cord. Prospective observational study conducted on 46 singleton neonates vaginally delivered at term. Matched pairs of umbilical artery and vein blood samples were collected from unclamped cord within 90s after birth and from the same cord after clamping, with the clamping occurring immediately after the first blood collection. A blood gas analysis was performed on each collected sample. Arterial and venous blood samples were analyzed for pH, PO2, pCO2, SaO2, hemoglobin concentration (ctHb) and base excess (BE). The values were compared between the two groups (clamped vs unclamped) using a Wilcoxon test. No significant difference was found in pH, PO2, pCO2, SaO2 and ctHb values on arterial blood between unclamped and clamped cord. The only significant difference was related to BE (pblood, the values of pH, PO2, pCO2 were comparable between unclamped and clamped cord, while the values of SaO2, ctHb and BE were significantly different (pblood gas parameters and in the main venous blood gas parameters between unclamped and clamped cord. Sampling of cord blood for gas analysis may be performed on the unclamped cord right after birth without reducing the accuracy of the analysis. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Immunologic and infectious consequences of immediate versus delayed umbilical cord clamping in premature infants: a prospective, randomized, controlled study.

    Science.gov (United States)

    Kugelman, Amir; Borenstein-Levin, Liron; Kessel, Aharon; Riskin, Arieh; Toubi, Elias; Bader, David

    2009-01-01

    To evaluate the immunologic and infectious consequences of delayed versus immediate cord clamping in premature infants (cord clamping (ICC) at 5-10 s and 30 infants to delayed cord clamping (DCC), at 30-45 s (14 and 15 infants in each group were cord clamping did not affect the immunologic or the infectious status of infants born at <35 weeks during the neonatal period.

  14. Fine-Tuning on the Effective Patch Radius Expression of the Circular Microstrip Patch Antennas

    Directory of Open Access Journals (Sweden)

    A. E. Yilmaz

    2010-09-01

    Full Text Available In this study, the effective patch radius expression for the circular microstrip antennas is improved by means of several manipulations. Departing from previously proposed equations in the literature, one of the most accurate equations is picked up, and this equation is fine-tuned by means of Particle Swarm Optimization technique. Throughout the study, impacts of other parameters (such as the definition of the fitness/objective function, the degree-of-freedom in the proposed effective patch radius expression, the number of measured resonant frequency values are observed in a controlled manner. Finally, about 3% additional improvement is achieved over a very accurate formula, which was proposed earlier.

  15. Patch-based vehicle logo detection with patch intensity and weight matrix

    Institute of Scientific and Technical Information of China (English)

    刘海明; 黄樟灿; Ahmed Mahgoub Ahmed Talab

    2015-01-01

    A patch-based method for detecting vehicle logos using prior knowledge is proposed. By representing the coarse region of the logo with the weight matrix of patch intensity and position, the proposed method is robust to bad and complex environmental conditions. The bounding-box of the logo is extracted by a thershloding approach. Experimental results show that 93.58% location accuracy is achieved with 1100 images under various environmental conditions, indicating that the proposed method is effective and suitable for the location of vehicle logo in practical applications.

  16. Analysis of the role of PCNA-DNA contacts during clamp loading

    Directory of Open Access Journals (Sweden)

    Goedken Eric R

    2010-01-01

    Full Text Available Abstract Background Sliding clamps, such as Proliferating Cell Nuclear Antigen (PCNA in eukaryotes, are ring-shaped protein complexes that encircle DNA and enable highly processive DNA replication by serving as docking sites for DNA polymerases. In an ATP-dependent reaction, clamp loader complexes, such as the Replication Factor-C (RFC complex in eukaryotes, open the clamp and load it around primer-template DNA. Results We built a model of RFC bound to PCNA and DNA based on existing crystal structures of clamp loaders. This model suggests that DNA would enter the clamp at an angle during clamp loading, thereby interacting with positively charged residues in the center of PCNA. We show that simultaneous mutation of Lys 20, Lys 77, Arg 80, and Arg 149, which interact with DNA in the RFC-PCNA-DNA model, compromises the ability of yeast PCNA to stimulate the DNA-dependent ATPase activity of RFC when the DNA is long enough to extend through the clamp. Fluorescence anisotropy binding experiments show that the inability of the mutant clamp proteins to stimulate RFC ATPase activity is likely caused by reduction in the affinity of the RFC-PCNA complex for DNA. We obtained several crystal forms of yeast PCNA-DNA complexes, measuring X-ray diffraction data to 3.0 Å resolution for one such complex. The resulting electron density maps show that DNA is bound in a tilted orientation relative to PCNA, but makes different contacts than those implicated in clamp loading. Because of apparent partial disorder in the DNA, we restricted refinement of the DNA to a rigid body model. This result contrasts with previous analysis of a bacterial clamp bound to DNA, where the DNA was well resolved. Conclusion Mutational analysis of PCNA suggests that positively charged residues in the center of the clamp create a binding surface that makes contact with DNA. Disruption of this positive surface, which had not previously been implicated in clamp loading function, reduces RFC

  17. A Central Swivel Point in the RFC Clamp Loader Controls PCNA Opening and Loading on DNA

    OpenAIRE

    Sakato, Miho; O’Donnell, Mike; Hingorani, Manju M.

    2011-01-01

    Replication Factor C (RFC) is a 5-subunit complex that loads PCNA clamps onto primer-template DNA (ptDNA) during replication. RFC subunits belong to the AAA+ superfamily, and their ATPase activity drives interactions between the clamp loader, clamp, and ptDNA, leading to topologically linked PCNA•ptDNA. We report the kinetics of transient events in S. cerevisiae RFC catalyzed PCNA loading, including ATP-induced RFC activation, PCNA opening, ptDNA binding, ATP hydrolysis, PCNA closing and PCNA...

  18. Modelling the clamping force distribution among chips in press-pack IGBTs using the finite element method

    DEFF Research Database (Denmark)

    Hasmasan, Adrian Augustin; Busca, Christian; Teodorescu, Remus

    2012-01-01

    In this paper, a FEM (finite element method) based mechanical model for PP (press-pack) IGBTs (insulated gate bipolar transistors) is presented, which can be used to calculate the clamping force distribution among chips under various clamping conditions. The clamping force is an important paramet...

  19. Reinforcement of a plate weakened by multiple holes with several patches for different types of plate-patch attachment

    KAUST Repository

    Zemlyanova, A.

    2014-01-24

    The most general situation of the reinforcement of a plate with multiple holes by several patches is considered. There is no restriction on the number and the location of the patches. Two types of patch attachment are considered: only along the boundary of the patch or both along the boundary of the patch and the boundaries of the holes which this patch covers. The unattached boundaries of the holes may be loaded with given in-plane stresses. The mechanical problem is reduced to a system of singular integral equations which can be further reduced to a system of Fredholm equations. A new numerical procedure for the solution of the system of singular integral equations is proposed in this paper. It is demonstrated on numerical examples that this procedure has advantages in the case of multiple patches and holes and allows achievement of better numerical convergence with less computational effort.

  20. Contact Dermatitis, Patch Testing, and Allergen Avoidance.

    Science.gov (United States)

    Burkemper, Nicole M

    2015-01-01

    In patients presenting with a complaint of rash, contact dermatitis is often the underlying diagnosis making it an entity with which health care providers should be familiar. Contact dermatitis can be divided into irritant contact dermatitis and allergic contact dermatitis. In a patient suspected of having allergic contact dermatitis, patch testing can be done to identify specific allergens. Education focused on allergen avoidance and safe products is an integral part of treatment for the contact dermatitis patient. Knowledge of the most common allergens is helpful for clinicians to be able to provide this education.

  1. Patch Testing In Soldiers : An Evaluation

    Directory of Open Access Journals (Sweden)

    Walia N. S

    2004-01-01

    Full Text Available Our study concerns contact sensitization in soldiers, the frequency of which is poorly documented. During a six-year period, 128 patients of age range 17-50 years were patch tested with the Indian standard battery of 30 allergens. We obtained a reaction in 23 (18% of our patients. Nickel sulfate, fragrance mix, wool alcohol and parthenium induced most of the positive responses. In addition, an irritant reaction was seen in 16 (12.5% of our patients. Patients of atopic dermatitis and hand/foot dermatoses evoked a high sensitivity response. Adverse effects were seen in 15 patients.

  2. Patch testing with Indian standard series

    Directory of Open Access Journals (Sweden)

    Narendra G

    2002-01-01

    Full Text Available Hundred patients (61 males, 39 females suspected to have allergic contact dermatitis were patch tested with Indian standard series (ISS. Forty four showed one or more positive reactions. The frequent sensitizers observed were nickel sulphate-12 (15%, potassium dichromate-11 (13.75%, cobalt chloride and colophony-7 (8.75% each, fragrance mix and thiuram mix-6 (7.5% each. The ISS differs from the European Standard Series by inclusion of propylene glycol, nitrofurazone, gentamicin, chlorocresol, PEG-400 and ethylenediamine chloride where assesquiterpene lactone mix and primin allergens are excluded.

  3. Lidocaine patches reduce pain in trauma patients with rib fractures.

    Science.gov (United States)

    Zink, Karen A; Mayberry, John C; Peck, Ellen G; Schreiber, Martin A

    2011-04-01

    Rib fracture pain is notoriously difficult to manage. The lidocaine patch is effective in other pain scenarios with an excellent safety profile. This study assesses the efficacy of lidocaine patches for treating rib fracture pain. A prospectively gathered cohort of patients with rib fracture was retrospectively analyzed for use of lidocaine patches. Patients treated with lidocaine patches were matched to control subjects treated without patches. Subjective pain reports and narcotic use before and after patch placement, or equivalent time points for control subjects, were gathered from the chart. All patients underwent long-term follow-up, including a McGill Pain Questionnaire (MPQ). Twenty-nine patients with lidocaine patches (LP) and 29 matched control subjects (C) were analyzed. During the 24 hours before patch placement, pain scores and narcotic use were similar (LP 5.3, C 4.6, P = 0.19 and LP 51, C 32 mg morphine, P = 0.17). In the 24 hours after patch placement, LP patients had a greater decrease in pain scores (LP 1.2, C 0.0, P = 0.01) with no change in narcotic use (LP -8.4, C 0.5-mg change in morphine, P = 0.25). At 60 days, LP patients had a lower MPQ pain score (LP 7.7, C 12.2, P rib fracture pain. Lidocaine patches resulted in a sustained reduction in pain, outlasting the duration of therapy.

  4. Interpatch movement of the red milkweed beetle, Tetraopes tetraophthalmus: individual responses to patch size and isolation.

    Science.gov (United States)

    Matter, Stephen F

    1996-03-01

    Individual movement patterns and the effects of host plant patch size and isolation on patch occupancy were examined for red milkweed beetles, Tetraopes tetraophthalmus, residing in a heterogeneous landscape. Male beetles were found to move both more often and farther between host plant patches than female beetles, and this difference affected the patterns of patch occupancy observed. Overall, unoccupied milkweed patches were smaller and more isolated than patches occupied by beetles. Patches uninhabited by females tended to be more isolated, but not necessarily smaller, than patches with female beetles, indicating that females may be affected more by patch isolation than patch size. Presence of male beetles on patches showed a stronger response to patch size than to patch isolation. Differences in movement between males and females illustrate the need for demographically based dispersal data. Comparisons of Tetraopes interpatch movement patterns between landscapes composed of patches of different size revealed that landscapes with overall smaller patches may have greater rates of interpatch movement.

  5. Patch forest: a hybrid framework of random forest and patch-based segmentation

    Science.gov (United States)

    Xie, Zhongliu; Gillies, Duncan

    2016-03-01

    The development of an accurate, robust and fast segmentation algorithm has long been a research focus in medical computer vision. State-of-the-art practices often involve non-rigidly registering a target image with a set of training atlases for label propagation over the target space to perform segmentation, a.k.a. multi-atlas label propagation (MALP). In recent years, the patch-based segmentation (PBS) framework has gained wide attention due to its advantage of relaxing the strict voxel-to-voxel correspondence to a series of pair-wise patch comparisons for contextual pattern matching. Despite a high accuracy reported in many scenarios, computational efficiency has consistently been a major obstacle for both approaches. Inspired by recent work on random forest, in this paper we propose a patch forest approach, which by equipping the conventional PBS with a fast patch search engine, is able to boost segmentation speed significantly while retaining an equal level of accuracy. In addition, a fast forest training mechanism is also proposed, with the use of a dynamic grid framework to efficiently approximate data compactness computation and a 3D integral image technique for fast box feature retrieval.

  6. Electrosurgical bipolar vessel sealing versus conventional clamping and suturing for total abdominal hysterectomy: a randomized trial.

    NARCIS (Netherlands)

    Lakeman, M.; Kruitwagen, R.F.P.M.; Vos, M.C.; Roovers, J.P.

    2008-01-01

    STUDY OBJECTIVE: To compare the effects of bipolar vessel sealing versus conventional clamping and suturing in women undergoing total abdominal hysterectomy. DESIGN: A randomized controlled trial was performed. Patients were randomized to vessel sealing or conventional surgery. Postoperative pain wa

  7. Common voltage eliminating of SVM diode clamping three-level inverter connected to grid

    DEFF Research Database (Denmark)

    Guo, Yougui; Zeng, Ping; Zhu, Jieqiong

    2011-01-01

    A novel method of common voltage eliminating is put forward for SVM diode clamping three-level inverter connected to grid by calculation of common voltage of its various switching states. PLECS is used to model this three-level inverter connected to grid and good results are obtained. First...... analysis of common mode voltage for switching states of diode clamping 3-level inverter is given in detail. Second the common mode voltage eliminating control strategy of SVM is described for diode clamping three-level inverter. Third, PLECS is briefly introduced. Fourth, the modeling of diode clamping...... three-level inverter is presented with PLECS. Finally, a series of simulations are carried out. The simulation results tell us PLECS is a very powerful tool to real power circuits modeling. They have also verified that proposed common mode voltage eliminating control strategy of SVM is feasible...

  8. Renal perfusion with venous blood extends the permissible suprarenal clamp time in abdominal aortic surgery

    National Research Council Canada - National Science Library

    Pichlmaier, Maximilian; Hoy, Ludwig; Wilhelmi, Mathias; Khaladj, Nawid; Haverich, Axel; Teebken, Omke E

    2008-01-01

    ... suprarenal clamping for aortic reconstructive surgery. Renal perfusion was achieved using a roller pump supplied with venous blood from a central venous catheter under medium-level heparinization to feed two perfusion balloon catheters...

  9. Suppression of Spiral Waves by Voltage Clamp Techniques in a Conductance-Based Cardiac Tissue Model

    Institute of Scientific and Technical Information of China (English)

    YU Lian-Chun; MA Jun; ZHANG Guo-Yong; CHEN Yong

    2008-01-01

    A new control method is proposed to control the spatio-temporal dynamics in excitable media, which is described by the Morris-Lecar cells model. It is confirmed that successful suppression of spiral waves can be obtained by spatially clamping the membrane voltage of the excitable cells. The low voltage clamping induces breakup of spiral waves and the fragments are soon absorbed by low voltage obstacles, whereas the high voltage clamping generates travel waves that annihilate spiral waves through collision with them. However, each method has its shortcomings. Furthermore, a two-step method that combines both low and high voltage clamp techniques is then presented as a possible way of out this predicament.

  10. Implementation of a fast 16-Bit dynamic clamp using LabVIEW-RT.

    Science.gov (United States)

    Kullmann, Paul H M; Wheeler, Diek W; Beacom, Joshua; Horn, John P

    2004-01-01

    The dynamic-clamp method provides a powerful electrophysiological tool for creating virtual ionic conductances in living cells and studying their influence on membrane potential. Here we describe G-clamp, a new way to implement a dynamic clamp using the real-time version of the Lab-VIEW programming environment together with a Windows host, an embedded microprocessor that runs a real-time operating system and a multifunction data-acquisition board. The software includes descriptions of a fast voltage-dependent sodium conductance, delayed rectifier, M-type and A-type potassium conductances, and a leak conductance. The system can also read synaptic conductance waveforms from preassembled data files. These virtual conductances can be reliably implemented at speeds LabVIEW should make it relatively easy for others to adapt G-clamp for new experimental applications.

  11. Modeling CICR in rat ventricular myocytes: voltage clamp studies

    Directory of Open Access Journals (Sweden)

    Palade Philip T

    2010-11-01

    Full Text Available Abstract Background The past thirty-five years have seen an intense search for the molecular mechanisms underlying calcium-induced calcium-release (CICR in cardiac myocytes, with voltage clamp (VC studies being the leading tool employed. Several VC protocols including lowering of extracellular calcium to affect Ca2+ loading of the sarcoplasmic reticulum (SR, and administration of blockers caffeine and thapsigargin have been utilized to probe the phenomena surrounding SR Ca2+ release. Here, we develop a deterministic mathematical model of a rat ventricular myocyte under VC conditions, to better understand mechanisms underlying the response of an isolated cell to calcium perturbation. Motivation for the study was to pinpoint key control variables influencing CICR and examine the role of CICR in the context of a physiological control system regulating cytosolic Ca2+ concentration ([Ca2+]myo. Methods The cell model consists of an electrical-equivalent model for the cell membrane and a fluid-compartment model describing the flux of ionic species between the extracellular and several intracellular compartments (cell cytosol, SR and the dyadic coupling unit (DCU, in which resides the mechanistic basis of CICR. The DCU is described as a controller-actuator mechanism, internally stabilized by negative feedback control of the unit's two diametrically-opposed Ca2+ channels (trigger-channel and release-channel. It releases Ca2+ flux into the cyto-plasm and is in turn enclosed within a negative feedback loop involving the SERCA pump, regulating[Ca2+]myo. Results Our model reproduces measured VC data published by several laboratories, and generates graded Ca2+ release at high Ca2+ gain in a homeostatically-controlled environment where [Ca2+]myo is precisely regulated. We elucidate the importance of the DCU elements in this process, particularly the role of the ryanodine receptor in controlling SR Ca2+ release, its activation by trigger Ca2+, and its

  12. Dual-polarization, wideband microstrip antenna array for airborne C-band SAR

    DEFF Research Database (Denmark)

    Granholm, Johan; Skou, Niels

    2000-01-01

    The paper describes the development of a C-band, dual linear polarization wideband antenna array, for use in the next-generation of the Danish airborne polarimetric synthetic aperture radar (SAR) system. The array is made of probe-fed, stacked microstrip patches. The design and performance...

  13. Delayed umbilical cord clamping after childbirth: potential benefits to baby's health

    Directory of Open Access Journals (Sweden)

    Uwins C

    2014-11-01

    Full Text Available Christina Uwins,1 David JR Hutchon2 1Department of Obstetrics and Gynaecology, Croydon University Hospital, Croydon, 2Department of Obstetrics, Darlington Memorial Hospital, Darlington, UKAbstract: Early cord clamping was initially introduced as part of the package of care known as “active management of the third stage”, which was implemented to reduce postpartum hemorrhage. It has now been shown to provide no benefit to the mother and to result in harm to the neonate. The clinical trial evidence relating to delayed cord clamping compared to immediate cord clamping is presented and the physiological rationale for delayed cord clamping is discussed in this paper. Most organizations (eg World Health Organization (WHO, Royal College of Obstetricians and Gynaecologists (RCOG, Resuscitation Council (UK,The International Federation of Gynecology and Obstetrics (FIGO, International Confederation of Midwives, International Liaison Committee on Resuscitation (ILCOR and the European Resuscitation Council now advise a delay of 1–3 minutes before clamping the cord in term and preterm infants, and clinicians need to be aware of this change. Healthy neonates benefit from a more physiological and gentle transition from placental to pulmonary respiration, and we explain why this benefit should be provided to all neonates until there is any evidence to the contrary. The harm of early cord clamping is not limited to anemia and iron deficiency, and evidence for a wide range of possible harms of early cord clamping is presented. The need for resuscitation is one of the most common concerns, and ways of overcoming these concerns are described.Keywords: transition, cord clamping, hypovolemia, intraventricular hemorrhage

  14. Patch size has no effect on insect visitation rate per unit area in garden-scale flower patches

    Science.gov (United States)

    Garbuzov, Mihail; Madsen, Andy; Ratnieks, Francis L. W.

    2015-01-01

    Previous studies investigating the effect of flower patch size on insect flower visitation rate have compared relatively large patches (10-1000s m2) and have generally found a negative relationship per unit area or per flower. Here, we investigate the effects of patch size on insect visitation in patches of smaller area (range c. 0.1-3.1 m2), which are of particular relevance to ornamental flower beds in parks and gardens. We studied two common garden plant species in full bloom with 6 patch sizes each: borage (Borago officinalis) and lavender (Lavandula × intermedia 'Grosso'). We quantified flower visitation by insects by making repeated counts of the insects foraging at each patch. On borage, all insects were honey bees (Apis mellifera, n = 5506 counts). On lavender, insects (n = 737 counts) were bumble bees (Bombus spp., 76.9%), flies (Diptera, 22.4%), and butterflies (Lepidoptera, 0.7%). On both plant species we found positive linear effects of patch size on insect numbers. However, there was no effect of patch size on the number of insects per unit area or per flower and, on lavender, for all insects combined or only bumble bees. The results show that it is possible to make unbiased comparisons of the attractiveness of plant species or varieties to flower-visiting insects using patches of different size within the small scale range studied and make possible projects aimed at comparing ornamental plant varieties using existing garden flower patches of variable area.

  15. Improving Saliency Models by Predicting Human Fixation Patches

    KAUST Repository

    Dubey, Rachit

    2015-04-16

    There is growing interest in studying the Human Visual System (HVS) to supplement and improve the performance of computer vision tasks. A major challenge for current visual saliency models is predicting saliency in cluttered scenes (i.e. high false positive rate). In this paper, we propose a fixation patch detector that predicts image patches that contain human fixations with high probability. Our proposed model detects sparse fixation patches with an accuracy of 84 % and eliminates non-fixation patches with an accuracy of 84 % demonstrating that low-level image features can indeed be used to short-list and identify human fixation patches. We then show how these detected fixation patches can be used as saliency priors for popular saliency models, thus, reducing false positives while maintaining true positives. Extensive experimental results show that our proposed approach allows state-of-the-art saliency methods to achieve better prediction performance on benchmark datasets.

  16. Effect of non-ideal clamping shape on the resonance frequencies of silicon nanocantilevers

    Energy Technology Data Exchange (ETDEWEB)

    Guillon, Samuel; Saya, Daisuke; Mazenq, Laurent; Nicu, Liviu [CNRS, LAAS, 7 Avenue du Colonel Roche, F-31077 Toulouse Cedex 4 (France); Perisanu, Sorin; Vincent, Pascal [LPMCN, Universite Claude Bernard Lyon 1 et CNRS, 43 boulevard du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Lazarus, Arnaud; Thomas, Olivier, E-mail: sguillon@laas.fr [Structural Mechanics and Coupled Systems Laboratory, Conservatoire National des Arts et Metiers, 2 rue Conte, 75003 Paris (France)

    2011-06-17

    In this paper, we investigate the effects of non-ideal clamping shapes on the dynamic behavior of silicon nanocantilevers. We fabricated silicon nanocantilevers using silicon on insulator (SOI) wafers by employing stepper ultraviolet (UV) lithography, which permits a resolution of under 100 nm. The nanocantilevers were driven by electrostatic force inside a scanning electron microscope (SEM). Both lateral and out-of-plane resonance frequencies were visually detected with the SEM. Next, we discuss overhanging of the cantilever support and curvature at the clamping point in the silicon nanocantilevers, which generally arises in the fabrication process. We found that the fundamental out-of-plane frequency of a realistically clamped cantilever is always lower than that for a perfectly clamped cantilever, and depends on the cantilever width and the geometry of the clamping point structure. Using simulation with the finite-elements method, we demonstrate that this discrepancy is attributed to the particular geometry of the clamping point (non-zero joining curvatures and a flexible overhanging) that is obtained in the fabrication process. The influence of the material orthotropy is also investigated and is shown to be negligible.

  17. A novel monolithic piezoelectric actuated flexure-mechanism based wire clamp for microelectronic device packaging

    Science.gov (United States)

    Liang, Cunman; Wang, Fujun; Tian, Yanling; Zhao, Xingyu; Zhang, Hongjie; Cui, Liangyu; Zhang, Dawei; Ferreira, Placid

    2015-04-01

    A novel monolithic piezoelectric actuated wire clamp is presented in this paper to achieve fast, accurate, and robust microelectronic device packaging. The wire clamp has compact, flexure-based mechanical structure and light weight. To obtain large and robust jaw displacements and ensure parallel jaw grasping, a two-stage amplification composed of a homothetic bridge type mechanism and a parallelogram leverage mechanism was designed. Pseudo-rigid-body model and Lagrange approaches were employed to conduct the kinematic, static, and dynamic modeling of the wire clamp and optimization design was carried out. The displacement amplification ratio, maximum allowable stress, and natural frequency were calculated. Finite element analysis (FEA) was conducted to evaluate the characteristics of the wire clamp and wire electro discharge machining technique was utilized to fabricate the monolithic structure. Experimental tests were carried out to investigate the performance and the experimental results match well with the theoretical calculation and FEA. The amplification ratio of the clamp is 20.96 and the working mode frequency is 895 Hz. Step response test shows that the wire clamp has fast response and high accuracy and the motion resolution is 0.2 μm. High speed precision grasping operations of gold and copper wires were realized using the wire clamper.

  18. A High Step-Down Interleaved Buck Converter with Active-Clamp Circuits for Wind Turbines

    Directory of Open Access Journals (Sweden)

    Chih-Lung Shen

    2012-12-01

    Full Text Available In this paper, a high step-down interleaved buck coupled-inductor converter (IBCC with active-clamp circuits for wind energy conversion has been studied. In high step-down voltage applications, an IBCC can extend duty ratio and reduce voltage stresses on active switches. In order to reduce switching losses of active switches to improve conversion efficiency, a IBCC with soft-switching techniques is usually required. Compared with passive-clamp circuits, the IBCC with active-clamp circuits have lower switching losses and minimum ringing voltage of the active switches. Thus, the proposed IBCC with active-clamp circuits for wind energy conversion can significantly increase conversion efficiency. Finally, a 240 W prototype of the proposed IBCC with active-clamp circuits was built and implemented. Experimental results have shown that efficiency can reach as high as 91%. The proposed IBCC with active-clamp circuits is presented in high step-down voltage applications to verify the performance and the feasibility for energy conversion of wind turbines.

  19. The effect of early and late umbilical cord clamping on neonatal hematocrit.

    Science.gov (United States)

    Jahazi, A; Kordi, M; Mirbehbahani, N B; Mazloom, S R

    2008-08-01

    To compare the effect of early and late cord clamping (LCC) on neonatal hematocrit at 2 and 18 h of life. In this double-blind randomized trial, 64 healthy full-term vaginally born neonates were randomly allocated to either early (30 s) or late (3 min) umbilical cord clamping. During the interval between delivery and cord clamping, the attendant held the neonate supine at the level of the introitus. Neonatal venous hematocrit was measured at 2 and 18 h of life. Neonatal hematocrit at 2 h of life (61+/-4.9 vs 61.6+/-4.5%) and 18 h of life (56.9+/-4.1 vs 56.2+/-3.9%) was not significantly different between the two groups. This was also true for neonatal polycythemia (20 vs 23.5%). In the LCC group, placental residual blood volume (PRBV) was 39.5% lower and estimated neonatal blood volume (ENBV) was 7.1% higher than that in the early cord clamping (ECC) group (Pcord clamping does not lead to a significant difference in the hematocrit level of the neonate or neonatal polycythemia, but is associated with a significant increase in ENBV and a significant decrease in PRBV. Further trials should examine the effect of delaying cord clamping for a longer period of time or changing the position that the neonate is held in to determine whether these variations result in more clinically significant results.

  20. Late umbilical cord clamping, neonatal hematocrit and Apgar scores: a randomized controlled trial.

    Science.gov (United States)

    Salari, Z; Rezapour, M; Khalili, N

    2014-01-01

    Based on current evidence, there is a little agreement on the best timing for after birth umbilical cord clamping. This study was designed to compare the impact of using two different times for cord clamping on hematocrit concentration and Apgar scores of the neonate. Fifty-six healthy full-term vaginally born neonates were allocated to early (10 seconds after delivery) and late (3 minutes after delivery) umbilical cord clamping groups in this randomized clinical trial. We recorded the length of the 3rd stage of labor and Apgar score at 5 minutes. Infant's hematocrit was measured at 2 and 18 hours of age. Neonatal hematocrit differed between the two groups. Late cord clamping group had greater hematocrit at 2 hours (45.5 ± 4 vs. 49.5 ± 4.4, P = 0.0003) and 18 hours (47.7 ± 5.5 vs. 52.9 ± 4.3, P = 0.0002). Apgar scores at 5 minutes (9.3 ± 0.6 vs. 9.4 ± 0.6, p = 0.5) and duration of delivery 3rd stage (10.2 ± 3.7 min vs. 8.9 ± 5 min, P = 0.2) did not differ between early and late cord clamping groups respectively. Late cord clamping leads to a significant increase in the hematocrit of the neonate but it does not have effects on Apgar score and duration of the 3rd stage of labor.

  1. Can selective arterial clamping with fluorescence imaging preserve kidney function during robotic partial nephrectomy?

    Science.gov (United States)

    McClintock, Tyler R; Bjurlin, Marc A; Wysock, James S; Borofsky, Michael S; Marien, Tracy P; Okoro, Chinonyerem; Stifelman, Michael D

    2014-08-01

    To compare renal functional outcomes in robotic partial nephrectomy (RPN) with selective arterial clamping guided by near-infrared fluorescence (NIRF) imaging to a matched cohort of patients who underwent RPN without selective arterial clamping and NIRF imaging. From April 2011 to December 2012, NIRF imaging-enhanced RPN with selective clamping was used in 42 cases. Functional outcomes of successful cases were compared with a cohort of patients, matched by tumor size, preoperative estimated glomerular filtration rate (eGFR), functional kidney status, age, sex, body mass index, and American Society of Anesthesiologists score, who underwent RPN without selective clamping and NIRF imaging. In matched-pair analysis, selective clamping with NIRF was associated with superior kidney function at discharge, as demonstrated by postoperative eGFR (78.2 vs 68.5 mL/min/1.73 m(2); P = .04), absolute reduction of eGFR (-2.5 vs -14.0 mL/min/1.73 m(2); P functional outcomes when compared with RPN without selective arterial clamping and NIRF imaging. With this effect attenuated at later follow-up, randomized prospective studies and long-term assessment of kidney-specific functional outcomes are needed to further assess the benefits of this technology. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. SafePatch for Windows Version 1.0 User Manual

    Energy Technology Data Exchange (ETDEWEB)

    Lim, D; Meier, T

    2003-05-01

    SafePatch for Windows provides automated analysis of network-based Microsoft Windows{trademark} computer systems to determine the status of security patches. SafePatch determines what patches need to be installed on a system or group of systems. SafePatch collects and packages the necessary patches and the script to install those patches for the selected remote systems. SafePatch for Windows also supports browsing the Microsoft{trademark} patch database and the viewing of the bulletins associated with the patches.

  3. The hedgehog receptor patched is involved in cholesterol transport.

    Directory of Open Access Journals (Sweden)

    Michel Bidet

    Full Text Available BACKGROUND: Sonic hedgehog (Shh signaling plays a crucial role in growth and patterning during embryonic development, and also in stem cell maintenance and tissue regeneration in adults. Aberrant Shh pathway activation is involved in the development of many tumors, and one of the most affected Shh signaling steps found in these tumors is the regulation of the signaling receptor Smoothened by the Shh receptor Patched. In the present work, we investigated Patched activity and the mechanism by which Patched inhibits Smoothened. METHODOLOGY/PRINCIPAL FINDINGS: Using the well-known Shh-responding cell line of mouse fibroblasts NIH 3T3, we first observed that enhancement of the intracellular cholesterol concentration induces Smoothened enrichment in the plasma membrane, which is a crucial step for the signaling activation. We found that binding of Shh protein to its receptor Patched, which involves Patched internalization, increases the intracellular concentration of cholesterol and decreases the efflux of a fluorescent cholesterol derivative (BODIPY-cholesterol from these cells. Treatment of fibroblasts with cyclopamine, an antagonist of Shh signaling, inhibits Patched expression and reduces BODIPY-cholesterol efflux, while treatment with the Shh pathway agonist SAG enhances Patched protein expression and BODIPY-cholesterol efflux. We also show that over-expression of human Patched in the yeast S. cerevisiae results in a significant boost of BODIPY-cholesterol efflux. Furthermore, we demonstrate that purified Patched binds to cholesterol, and that the interaction of Shh with Patched inhibits the binding of Patched to cholesterol. CONCLUSION/SIGNIFICANCE: Our results suggest that Patched may contribute to cholesterol efflux from cells, and to modulation of the intracellular cholesterol concentration. This activity is likely responsible for the inhibition of the enrichment of Smoothened in the plasma membrane, which is an important step in Shh pathway

  4. Dendritic Actin Filament Nucleation Causes Traveling Waves and Patches

    CERN Document Server

    Carlsson, Anders E

    2010-01-01

    The polymerization of actin via branching at a cell membrane containing nucleation-promoting factors is simulated using a stochastic-growth methodology. The polymerized-actin distribution displays three types of behavior: a) traveling waves, b) moving patches, and c) random fluctuations. Increasing actin concentration causes a transition from patches to waves. The waves and patches move by a treadmilling mechanism which does not require myosin II. The effects of downregulation of key proteins on actin wave behavior are evaluated.

  5. Physical Properties of Gum Karaya-Starch-Essential Oil Patches

    OpenAIRE

    2010-01-01

    Essential oils are used in foods, cosmetics, and pharmaceuticals. Despite the recent marketing of novel essential-oil-containing patches, there is no information on their production, constituents, or physical properties. The objectives of this study were to produce essential-oil patches and characterize their physical properties. The essential oil of Lavandula angustifolia (lavender) was included at concentrations of 2.5% to 10% in patches manufactured from the exudate gum karaya, propylene g...

  6. The Formation of the Surface during AN Abrasive Finishing at Constant and Variable Clamping Forces: Finishing at Constant and Variable Clamping Forces

    Science.gov (United States)

    Muratov, Karim Ravilevich; Muratov, Ravil Arifovich; Ablyaz, Timur Rizovich; Gashev, Evgeniy Anatolyevich

    2017-06-01

    In this work the flat abrasive finishing process is reported. The mechanical and chemical phenomena taking place during the finishing process are described. The most common forming process schemes observed during abrasive treatment are reviewed. The schemes of pulsed, geometrical and energetic models are discussed. On the basis of the energetic hypothesis and Preston hypothesis, the rational law of clamping force variation during the finishing is established. This law allowed for the stabilization of the contact pressure and an increase of the treatment efficiency. An exponential dependence of a boundary contact area variation during the finishing of planes with different initial profiles of the macro-topography is developed. An experimental confirmation of the Preston hypothesis during the abrasive finishing is carried out with the plane-finishing machine “Rastr 220”. The comparison experiments are carried out at constant and variable clamping forces of the treated surface towards the tool. It is found that by varying the forces according to the exponential law (i.e. similar to the changing of the boundary contact area during the abrasive finishing) the process efficiency is increasing by a factor of 2.5-3. It is shown that the changes of the root mean square deviation σ of the roughness Ra of a treated surface in the beginning of the process (at time t=1 min) during the finishing at a constant clamping force is two times higher compared to the treatment at a variable clamping force in the same time period.

  7. Cost benefit of patch testing with textile finish resins

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Hamann, K

    1982-01-01

    Eleven years experience of textile finish resin patch testing of suspected textile dermatitis patients revealed 15 cases of allergic textile dermatitis among 428 patients tested. Ten of the 15 patients had a relevant positive patch test to one or more of a limited series of textile finishes; 1...... was negative and 4 were not tested with textile finishes. All 15 patients were formaldehyde sensitive. No unexpected, relevant, positive textile finish resin patch test was found. In this study a negative patch test to formaldehyde virtually excluded allergic contact dermatitis from textile finishes....

  8. Histological distinction between early allergic and irritant patch test reactions

    DEFF Research Database (Denmark)

    Vestergaard, L; Clemmensen, Ole; Sørensen, Flemming Brandt

    1999-01-01

    differentiate between early allergic and irritant patch test reactions. 8 patients with known contact allergy to either colophony or quarternium-15 participated in the study. In each patient, allergic and irritant patch tests reactions were elicited, and 4-mm punch biopsies were taken after 6 8 h from...... clinically equipotent reactions. Paired sets of slides were assessed blindly by 2 pathologists. 1 patient showing a pityrosporum folliculitis was excluded from the study. All biopsies from allergic patch tests were characterized by follicular spongiosis, while biopsies from irritant patch tests showed...... the diagnostic significance of the histological classification of allergic and irritant cutaneous reactions in punch biopsies....

  9. Facile route to morphologically tailored silver patches on colloidal particles.

    Science.gov (United States)

    Klupp Taylor, Robin N; Bao, Huixin; Tian, Chenting; Vasylyev, Serhiy; Peukert, Wolfgang

    2010-08-17

    Here we demonstrate, for the first time, the heterogeneous nucleation and growth of silver patches on submicrometer silica spheres. While patches can be grown directly onto native silica particles, it is shown that a higher patch yield can be obtained by first treating the silica with a mixture of an alkanolamine and silver nitrate. Variation of the pretreatment and subsequent coating reactions allowed the patch yield, number, size, thickness, and shape to be adjusted. The patchy particles were shown to possess plasmon modes extending from the visible into the near-IR region, making these structures highly interesting for both their asymmetric morphological and functional properties.

  10. M. tuberculosis sliding β-clamp does not interact directly with the NAD+-dependent DNA ligase.

    Directory of Open Access Journals (Sweden)

    Vandna Kukshal

    Full Text Available The sliding β-clamp, an important component of the DNA replication and repair machinery, is drawing increasing attention as a therapeutic target. We report the crystal structure of the M. tuberculosis β-clamp (Mtbβ-clamp to 3.0 Å resolution. The protein crystallized in the space group C222(1 with cell-dimensions a = 72.7, b = 234.9 & c = 125.1 Å respectively. Mtbβ-clamp is a dimer, and exhibits head-to-tail association similar to other bacterial clamps. Each monomer folds into three domains with similar structures respectively and associates with its dimeric partner through 6 salt-bridges and about 21 polar interactions. Affinity experiments involving a blunt DNA duplex, primed-DNA and nicked DNA respectively show that Mtbβ-clamp binds specifically to primed DNA about 1.8 times stronger compared to the other two substrates and with an apparent K(d of 300 nM. In bacteria like E. coli, the β-clamp is known to interact with subunits of the clamp loader, NAD(+-dependent DNA ligase (LigA and other partners. We tested the interactions of the Mtbβ-clamp with MtbLigA and the γ-clamp loader subunit through radioactive gel shift assays, size exclusion chromatography, yeast-two hybrid experiments and also functionally. Intriguingly while Mtbβ-clamp interacts in vitro with the γ-clamp loader, it does not interact with MtbLigA unlike in bacteria like E. coli where it does. Modeling studies involving earlier peptide complexes reveal that the peptide-binding site is largely conserved despite lower sequence identity between bacterial clamps. Overall the results suggest that other as-yet-unidentified factors may mediate interactions between the clamp, LigA and DNA in mycobacteria.

  11. Design and Comparison of 24 GHz Patch Antennas on Glass Substrates for Compact Wireless Sensor Nodes

    Directory of Open Access Journals (Sweden)

    Florian Ohnimus

    2010-01-01

    Full Text Available Three patch antennas suitable for integration and operation in a compact 24 GHz wireless sensor node with radar and communication functions are designed, characterized, and compared. The antennas are manufactured on a low loss glass wafer using thin film (BCB/Cu wafer level processing (WLP technologies. This process is well suited for 3D stacking. The antennas are fed through a microstrip line underneath a ground plane coupling into the patch resonator through a slot aperture. Linear polarization (LP, dual mode (DM operation, and circular polarization (CP are achieved through the layout of the slot aperture and rectangular patch dimensions. Antenna gain values of ∼5.5 dBi are obtained in addition to the 10 dB impedance bandwidths of 900 MHz and 1.3 GHz as well as 500 MHz CP bandwidth with a 3 dB axial ratio for the LP, DM, and CP patch antennas, respectively.

  12. Evaluation of Changes in Morphology and Function of Human Induced Pluripotent Stem Cell Derived Cardiomyocytes (HiPSC-CMs Cultured on an Aligned-Nanofiber Cardiac Patch.

    Directory of Open Access Journals (Sweden)

    Mahmood Khan

    Full Text Available Dilated cardiomyopathy is a major cause of progressive heart failure. Utilization of stem cell therapy offers a potential means of regenerating viable cardiac tissue. However, a major obstacle to stem cell therapy is the delivery and survival of implanted stem cells in the ischemic heart. To address this issue, we have developed a biomimetic aligned nanofibrous cardiac patch and characterized the alignment and function of human inducible pluripotent stem cell derived cardiomyocytes (hiPSC-CMs cultured on this cardiac patch. This hiPSC-CMs seeded patch was compared with hiPSC-CMs cultured on standard flat cell culture plates.hiPSC-CMs were cultured on; 1 a highly aligned polylactide-co-glycolide (PLGA nanofiber scaffold (~50 microns thick and 2 on a standard flat culture plate. Scanning electron microscopy (SEM was used to determine alignment of PLGA nanofibers and orientation of the cells on the respective surfaces. Analysis of gap junctions (Connexin-43 was performed by confocal imaging in both the groups. Calcium cycling and patch-clamp technique were performed to measure calcium transients and electrical coupling properties of cardiomyocytes.SEM demonstrated >90% alignment of the nanofibers in the patch which is similar to the extracellular matrix of decellularized rat myocardium. Confocal imaging of the cardiomyocytes demonstrated symmetrical alignment in the same direction on the aligned nanofiber patch in sharp contrast to the random appearance of cardiomyocytes cultured on a tissue culture plate. The hiPSC-CMs cultured on aligned nanofiber cardiac patches showed more efficient calcium cycling compared with cells cultured on standard flat surface culture plates. Quantification of mRNA with qRT-PCR confirmed that these cardiomyocytes expressed α-actinin, troponin-T and connexin-43 in-vitro.Overall, our results demonstrated changes in morphology and function of human induced pluripotent derived cardiomyocytes cultured in an anisotropic

  13. Blending Parametric Patches with Subdivision Surfaces

    Institute of Scientific and Technical Information of China (English)

    李桂清; 李华

    2002-01-01

    In this paper the problem of blending parametric surfaces using subdivision patches is discussed. A new approach, named removing-boundary, is presented to generate piecewise-smooth subdivision surfaces through discarding the outmost quadrilaterals of the open meshes derived by each subdivision step. Then the approach is employed both to blend parametric bicubic B-spline surfaces and to fill n-sided holes. It is easy to produce piecewisesmooth subdivision surfaces with both convex and concave corners on the boundary, and limit surfaces are guaranteed to be C2 continuous on the boundaries except for a few singular points by the removing-boundary approach. Thus the blending method is very efficient and the blending surface generated is of good effect.

  14. E-SHAPED STACKED BROADBAND PATCH ANTENNA

    Directory of Open Access Journals (Sweden)

    Bharat Rochani

    2014-10-01

    Full Text Available A coaxial feed modified E-shaped patch antenna has been presented with parametric study of the antenna parameters. The proposed antenna is designed for WLAN and WiMAX applications from 5 – 6 GHz. The 5 – 6 GHz band has been chosen because it provides higher data rate (>50 Mbps for laptops, note-book computers and many new wireless digital applications devices without interference. Although current 5.0 GHz wireless computer network systems operated from 5.15 GHz – 5.35 GHz band. But in future, for faster data rate 5.725 – 5.85 GHz band becomes popular in addition to 5.15 – 5.35 GHz.

  15. A decision algorithm for patch spraying

    DEFF Research Database (Denmark)

    Christensen, Svend; Heisel, Torben; Walter, Mette

    2003-01-01

    It has been established that weeds are spatially aggregated with a spatially varying composition of weed species within agricultural fields. Site-specific spraying therefore requires a decision method that includes the spatial variation of the weed composition and density. A computerized decision...... method that estimates an economic optimal herbicide dose according to site-specific weed composition and density is presented in this paper. The method was termed a ‘decision algorithm for patch spraying’ (DAPS) and was evaluated in a 5-year experiment, in Denmark. DAPS consists of a competition model......, a herbicide dose–response model and an algorithm that estimates the economically optimal doses. The experiment was designed to compare herbicide treatments with DAPS recommendations and the Danish decision support system PC-Plant Protection. The results did not show any significant grain yield difference...

  16. New Local Duals in Eternal Inflation

    CERN Document Server

    Bousso, Raphael

    2012-01-01

    Global-local duality is the equivalence of seemingly different regulators in eternal inflation. For example, the light-cone time cutoff (a global measure, which regulates time) makes the same predictions as the causal patch (a local measure that cuts off space). We show that global-local duality is far more general. It rests on a redundancy inherent in any global cutoff: at late times, an attractor regime is reached, characterized by the unlimited exponential self-reproduction of a certain fundamental region of spacetime. An equivalent local cutoff can be obtained by restricting to this fundamental region. We derive local duals to several global cutoffs of interest. The New Scale Factor Cutoff is dual to the Short Fat Geodesic, a geodesic of fixed infinitesimal proper width. Vilenkin's CAH Cutoff is equivalent to the Hubbletube, whose width is proportional to the local Hubble volume. The famous youngness problem of the Proper Time Cutoff can be readily understood by considering its local dual, the Incredible ...

  17. A central swivel point in the RFC clamp loader controls PCNA opening and loading on DNA.

    Science.gov (United States)

    Sakato, Miho; O'Donnell, Mike; Hingorani, Manju M

    2012-02-17

    Replication factor C (RFC) is a five-subunit complex that loads proliferating cell nuclear antigen (PCNA) clamps onto primer-template DNA (ptDNA) during replication. RFC subunits belong to the AAA(+) superfamily, and their ATPase activity drives interactions between the clamp loader, the clamp, and the ptDNA, leading to topologically linked PCNA·ptDNA. We report the kinetics of transient events in Saccharomyces cerevisiae RFC-catalyzed PCNA loading, including ATP-induced RFC activation, PCNA opening, ptDNA binding, ATP hydrolysis, PCNA closing, and PCNA·ptDNA release. This detailed perspective enables assessment of individual RFC-A, RFC-B, RFC-C, RFC-D, and RFC-E subunit functions in the reaction mechanism. Functions have been ascribed to RFC subunits previously based on a steady-state analysis of 'arginine-finger' ATPase mutants; however, pre-steady-state analysis provides a different view. The central subunit RFC-C serves as a critical swivel point in the clamp loader. ATP binding to this subunit initiates RFC activation, and the clamp loader adopts a spiral conformation that stabilizes PCNA in a corresponding open spiral. The importance of RFC subunit response to ATP binding decreases as RFC-C>RFC-D>RFC-B, with RFC-A being unnecessary. RFC-C-dependent activation of RFC also enables ptDNA binding, leading to the formation of the RFC·ATP·PCNA(open)·ptDNA complex. Subsequent ATP hydrolysis leads to complex dissociation, with RFC-D activity contributing the most to rapid ptDNA release. The pivotal role of the RFC-B/C/D subunit ATPase core in clamp loading is consistent with the similar central location of all three ATPase active subunits of the Escherichia coli clamp loader.

  18. Timing of umbilical cord-clamping and infant anaemia: the role of maternal anaemia.

    Science.gov (United States)

    Blouin, Brittany; Penny, Mary E; Maheu-Giroux, Mathieu; Casapía, Martín; Aguilar, Eder; Silva, Hermánn; Creed-Kanashiro, Hilary M; Joseph, Serene A; Gagnon, Anita; Rahme, Elham; Gyorkos, Theresa W

    2013-05-01

    Evidence from randomized controlled trials has shown that delayed cord-clamping is beneficial to infant iron status. The role of maternal anaemia in this relationship, however, has not been established. To determine the effect of maternal anaemia at delivery on the association between timing of umbilical cord-clamping and infant anaemia at 4 and 8 months of age. A cohort of pregnant women admitted to the labour room of Hospital Iquitos (Iquitos, Peru) and their newborns were recruited into the study during two time periods (18 May to 3 June and 6-20 July 2009). Between the two recruitment periods, the hospital's policy changed from early to delayed umbilical cord-clamping. Maternal haemoglobin levels were measured before delivery, and the time between delivery and cord-clamping was recorded at delivery for the entire cohort. Mother-infant pairs were followed-up at 4 (n = 207) and 8 months (n = 184) post partum. Infant haemoglobin levels were measured at follow-up visits. Data were analysed using logistic regression models. The prevalence of maternal anaemia (Hb cord-clamping and infant anaemia was modified by the mother's anaemia status. Significant benefits of delayed cord-clamping in preventing anaemia were found in infants born to anaemic mothers at both 4 months (aOR = 0.59, 95% CI 0.36-0.99) and 8 months (aOR = 0.38, 95% CI 0.19-0.76) of age. The study contributes additional evidence in support of delayed cord-clamping. This intervention is likely to have most public health impact in areas with a high prevalence of anaemia during pregnancy.

  19. Timing of umbilical cord clamping after birth for optimizing placental transfusion.

    Science.gov (United States)

    Raju, Tonse N K

    2013-04-01

    A brief delay in clamping the umbilical cord after birth offers health benefits to the newborn, with no adverse effects to the mother or her infant. Yet, in most obstetric practice, the cord is clamped soon after birth. A summary of the current evidence on delayed cord clamping and some reasons for the disconnect between the evidence and practice are discussed here, along with the recommendations from professional organizations and societies about this practice. In term infants, umbilical cord clamping between 30 and 180 s after birth results in higher concentrations of hemoglobin and hematocrit during the neonatal period, and increased serum ferritin levels and a lower incidence of iron-deficiency anemia at 4-6 months of age. These are important benefits for children in low and middle income countries where iron-deficiency anemia is highly prevalent. In preterm infants, delayed cord clamping for at least 30 s increases the concentrations of hemoglobin and hematocrit, improves mean systemic blood pressure, urine output, and cardiac function, and decreases the need for vasopressors and blood transfusions during the neonatal period. It also decreases the prevalence of necrotizing enterocolitis, sepsis, and intraventricular hemorrhage (all grades). Milking of the unclamped umbilical cord toward the infant soon after birth also has similar beneficial effects. In some studies, more infants in the delayed cord clamping groups required phototherapy for jaundice. Many professional organizations, societies, and experts recommend at least a 30-s delay before clamping the umbilical cord, especially after preterm births. The value of this practice for term births in resource-rich settings has not been evaluated.

  20. Design of UWB monopole antenna with dual notched bands using one modified electromagnetic-bandgap structure.

    Science.gov (United States)

    Liu, Hao; Xu, Ziqiang

    2013-01-01

    A modified electromagnetic-bandgap (M-EBG) structure and its application to planar monopole ultra-wideband (UWB) antenna are presented. The proposed M-EBG which comprises two strip patch and an edge-located via can perform dual notched bands. By properly designing and placing strip patch near the feedline, the proposed M-EBG not only possesses a simple structure and compact size but also exhibits good band rejection. Moreover, it is easy to tune the dual notched bands by altering the dimensions of the M-EBG. A demonstration antenna with dual band-notched characteristics is designed and fabricated to validate the proposed method. The results show that the proposed antenna can satisfy the requirements of VSWR WiMAX) and the wireless local area network (WLAN) at 3.5 GHz and 5.5 GHz, respectively.

  1. Umbilical cord blood acid-base and gas analysis after early versus delayed cord clamping in neonates at term.

    Science.gov (United States)

    De Paco, Catalina; Florido, Jesús; Garrido, Mari Carmen; Prados, Sonia; Navarrete, Luis

    2011-05-01

    To compare umbilical cord acid-base status and blood gas analysis between umbilical cords clamped within 10 s and at 2 min of delivery. A total of 158 healthy full-term mothers were randomly assigned to an early clamping (clamping (2 min post-delivery, n = 79) group. After application of inclusion criteria, umbilical vein blood acid-base status and gases were analyzed in 65 early clamped and 51 delayed clamped cords. Fewer cases could be examined in the umbilical artery: 55 cords in the early clamping group and 44 in the delayed one. Acid-base and gas analysis results did not significantly differ between the groups in the umbilical vein or umbilical artery, with the exception of a higher (p umbilical artery pO(2) value in the delayed versus early clamping group. No significant differences in umbilical vein or artery pCO(2) or HCO(3) (-) values were observed between the early and delayed clamp groups. A delay of 2 min before umbilical cord clamping does not significantly change acid-base and gas analysis results, with the exception of a higher mean umbilical artery pO(2) value in the delayed clamping group.

  2. Texture synthesis via the matching compatibility between patches

    Institute of Scientific and Technical Information of China (English)

    WANG WenCheng; LIU FeiTong; HUANG PeiJie; WU EnHua

    2009-01-01

    A new patch-based texture synthesis method is presented in this paper.By the method,a set of patches that can be matched with a sampled patch for growing textures effectively,called the matching compatibility between patches,is generated first for each patch,and the set is further optimized by culling the patches that may cause synthesis conflicts.In this way,similarity measurement calculation for selecting suitable patches in texture synthesis can be greatly saved,and synthesis conflicts between neighbouring patches are substantially reduced.Furthermore,retrace computation is Integrated in the synthesis process to improve the texture quality.As a result,the new method can produce high quality textures as texture optimization,the best method to date for producing good textures,and run in a time complexity linear to the size of the output texture.Experimental results show that the new method can interactively generate a large texture in 1024 × 1024 pixels,which is very difficult to achieve by existing methods.

  3. Hydrophobic patches on the surfaces of protein structures

    NARCIS (Netherlands)

    Lijnzaad, P.; Berendsen, H.J.C.; Argos, P.

    1996-01-01

    A survey of hydrophobic patches on the surface of 112 soluble, monomeric proteins is presented, The largest patch on each individual protein averages around 400 Angstrom(2) but can range from 200 to 1,200 Angstrom(2). These areas are not correlated to the sizes of the proteins and only weakly to the

  4. Patch based predation in a southern Appalachian stream

    Science.gov (United States)

    C.A. Gibson; R.E. Ratajezak; G.D. Grossman

    2004-01-01

    Streams are characterized by high degrees of patchiness that could influence the role of predators in these systems. Here we assess the impact of predatory benthic fishes on benthic macroinvertebrate density, biomass, and community structure at the patch scale in a fourth order stream in the southern Appalachians. We tested the role of predation in two different patch...

  5. Trends and developments in two decades of patch testing

    NARCIS (Netherlands)

    Christoffers, W.A.; Schuttelaar, M.-L.A.; Coenraads, P.J.

    2013-01-01

    Introduction: Allergic contact dermatitis is a common condition with an estimated lifetime prevalence of 19.5%. The diagnosis is confirmed by patch tests. This study aims to visualise trends and developments in patch testing over 23 years and to evaluate the influence of legal restrictions with spec

  6. Phosphorus leaching from cow manure patches on soil columns

    NARCIS (Netherlands)

    Chardon, W.J.; Aalderink, G.H.; Salm, van der C.

    2007-01-01

    The loss of P in overland flow or leachate from manure patches can impair surface water quality. We studied leaching of P from 10-cmhigh lysimeters filled with intact grassland soil or with acid-washed sand. A manure patch was created on two grassland and two sandfilled lysimeters, and an additional

  7. Organic transdermal iontophoresis patch with built-in biofuel cell.

    Science.gov (United States)

    Ogawa, Yudai; Kato, Koichiro; Miyake, Takeo; Nagamine, Kuniaki; Ofuji, Takuya; Yoshino, Syuhei; Nishizawa, Matsuhiko

    2015-03-11

    A completely organic iontophoresis patch is reported. A built-in biofuel cell is mounted on the patch that generates transdermal iontophoretic administration of compounds into the skin. The amplitude of transdermal current is tuned by integrating a conducting polymer-based stretchable resistor of predetermined resistance.

  8. SIERPIENSKI & CROWN SQUARE FRACTAL SHAPES SLOTTED MICROSTRIP PATCH ANTENNA

    Directory of Open Access Journals (Sweden)

    Dr. Yogesh Bhomia

    2014-01-01

    Full Text Available A new Sierpienski & Crown Square Fractal Shapes Slotted Microstrip Patch Antenna is proposed. A patch antenna is a narrowband, wide-beam antenna. These antennas are low profile, conformal to planar and non-planar surface, simple and inexpensive to manufacture using modern printed circuit technology, mechanically robust when mounted on rigid surface, compatible with MMIC designs and when the particular shape and mode are selected they are very versatile in terms of resonant frequency, polarization, field pattern and impedance. Microstrip patch antenna consist of a very thin metallic strip (patch placed a small fraction of a wavelength above a ground plane. The patch is generally made of conducting material such as copper or gold and can take any possible shape. This paper presents a design of Sierpienski & Crown Square Fractal Shapes Slotted Microstrip Patch Antenna and experimentally studied on IE3D software. This design is achieved by cutting Sierpienski & Crown Square Fractal Shapes Slottes in a patch. With Sierpienski & Crown Square Fractal Shapes patch antenna is designed on a FR4 substrate of thickness 1.524 mm and relative permittivity of 4.4 and mounted above the ground plane at a height of 6 mm. Bandwidth as high as 36.6% are achieved with stable pattern characteristics, such as gain and cross polarization, within its bandwidth. Impedance bandwidth, antenna gain and return loss are observed for the proposed antenna. Details of the measured and simulated results are presented and discussed.

  9. Clampe de Ganz no tratamento de urgência em lesões do anel pélvico Ganz clamps to treat emergencies in pelvic ring lesions

    Directory of Open Access Journals (Sweden)

    Gilberto José Cação Pereira

    2008-07-01

    Full Text Available OBJETIVO: Avaliar a eficiência do clampe de Ganz na estabilização e redução dos deslocamentos da pelve, quando utilizado no tratamento de urgência, além de aquilatar eventuais dificuldades e facilidades do método. MÉTODOS: O clampe de Ganz foi utilizado no tratamento de urgência em 31 pacientes com graves lesões do anel pélvico (Tile C associadas a importante instabilidade hemodinâmica. RESULTADO: Entre os pacientes, 27 (87,1% apresentaram evolução favorável, com estabilização, redução dos deslocamentos e compressão da região posterior do anel, além de estabilização hemodinâmica, e quatro (12,9% evoluíram para óbito. CONCLUSÃO: O clampe de Ganz mostrou-se eficiente ferramenta no tratamento de urgência das lesões do anel pélvico, por ser de concepção simples, de rápida colocação, não impedir ou dificultar procedimentos no abdome e, principalmente, por permitir a estabilização da pelve, redução dos deslocamentos e compressão na região posterior do anel, local onde ocorrem os maiores sangramentos, reduzindo-os ou eliminando-os.OBJECTIVE: To evaluate the effectiveness of Ganz clamp to stabilize and reduce pelvic dislocations in emergency situations, and to assess possible difficult and easy aspects of the method. METHOD: Ganz clamp was used in the emergency treatment of 31 patients with severe lesions of the pelvic ring (Tile C associated to major hemodynamic instability. RESULTS: Among the patients, 27 (87.1% presented a favorable evolution, with stabilization, reduction of dislocations, and compression of the posterior portion of the ring, and also hemodynamic stabilization, and 4 (12.9% died. CONCLUSION: The Ganz clamp was found to be an effective tool in the emergency treatment of pelvic ring lesions because it has an uncomplicated conception, allowing for a fast placement, because it does not prevent nor make it difficult for abdominal procedures, and most of all because it allows for the

  10. Incision Below The Clamp sebagai Modifikasi Teknik Insisi pada Frenektomi untuk Minimalisasi Perdarahan

    Directory of Open Access Journals (Sweden)

    S. Suryono

    2016-10-01

    Full Text Available Latar Belakang. Perlekatan frenulum tinggi berdampak merugikan bagi jaringan periodontal maupun fungsi estetik. Perlekatan tinggi yang terjadi pada labialis superior, menimbulkan gingivitis dan sentral diastema yang menjadikan indikasi untuk dilakukan frenektomi. Frenektomi dengan teknik melakukan insisi di atas dan di bawah clamp berakibat lebarnya luka karena tarikan otot bibir, yang berdampak terjadi banyak perdarahan. Tujuan. Melakukan evaluasi terhadap modifikasi teknik insisi yang diharapkan dapat mengurangi perdarahan. Kasus dan Penanganan. Laporan kasus ini memaparkan penanganan kasus pada perlekatan frenulum tinggi yang diikuti adanya sentral diastema. Pasien dengan diagnosa frenulum tinggi dan indikasi frenektomi dilakukan tindakan preoperasi. Tindakan operasi dilakukan dengan menggunakan pisau bedah, modifikasi insisi (Insision below the Clamp dilakukan dengan cara menempatkan clamp frenulum pada posisi yang berdekatan dan sejajar dengan bibir, tindakan insisi dilakukan di bawah clamp, disusul dengan penjahitan pada area mucolabial fold. Selama operasi dilakukan terlihat luka tidak melebar, tidak banyak darah yang keluar, pasien dan dokter merasa nyaman. Kesimpulan. Insision below the Clamp merupakan modifikasi teknik insisi pada frenektomi yang bisa dilakukan oleh para praktisi untuk meminimalisir perdarahan yang terjadi selama proses pengambilan frenulum dengan menggunakan pisau bedah.   Background. Attachment of high frenulum has negative impact on periodontal tissues as well as an aesthetic function. High attachment of frenulum that occurs in labialis superior, causing gingivitis and central diastema that are indications to do Frenectomy. Conventional techniques of Frenectomy performed with insisions above and below the clamp resulted in wide injury due to muscle contraction, which affects a lot of bleeding. Objective. To evaluate modification insision technique which hopefully can minimize the bleeding. Case and Treatment. This

  11. Dual Income Taxes

    DEFF Research Database (Denmark)

    Sørensen, Peter Birch

    This paper discusses the principles and practices of dual income taxation in the Nordic countries. The first part of the paper explains the rationale and the historical background for the introduction of the dual income tax and describes the current Nordic tax practices. The second part...... of the paper focuses on the problems of taxing income from small businesses and the issue of corporate-personal tax integration under the dual income tax, considering alternative ways of dealing with these challenges. In the third and final part of the paper, I briefly discuss whether introducing a dual income...... tax could be relevant for New Zealand....

  12. Dual Income Taxes

    DEFF Research Database (Denmark)

    Sørensen, Peter Birch

    This paper discusses the principles and practices of dual income taxation in the Nordic countries. The first part of the paper explains the rationale and the historical background for the introduction of the dual income tax and describes the current Nordic tax practices. The second part...... of the paper focuses on the problems of taxing income from small businesses and the issue of corporate-personal tax integration under the dual income tax, considering alternative ways of dealing with these challenges. In the third and final part of the paper, I briefly discuss whether introducing a dual income...... tax could be relevant for New Zealand....

  13. Analysis of a multi patch dynamical model about cattle brucellosis

    Directory of Open Access Journals (Sweden)

    Juan Zhang

    2014-10-01

    Full Text Available The dissemination of cattle brucellosis in Zhejiang province of China can be attributed to the transport of cattle between cities within the province. In this paper,an n-patch dynamical model is proposed to study the effect of cattle dispersal on brucellosis spread. Theoretically,we analyze the dynamical behavior of the muti-patch model. For the 2-patch submodel,sensitivity analyses of the basic reproduction number R0 and the number of the infectious cattle in term of model parameters are carried out. By numerical analysis,it is obtained that the dispersal of susceptible cattle between patches and the centralization of infected cattle to the large scale patch can alleviate the epidemic and are in favor of the control of disease in the whole region.

  14. Nickel patch test reactivity and the menstrual cycle

    DEFF Research Database (Denmark)

    Rohold, A E; Halkier-Sørensen, L; Thestrup-Pedersen, K;

    1994-01-01

    Premenstrual exacerbation of allergic contact dermatitis and varying allergic patch test responses have been reported at different points of the period. Using a dilution series of nickel sulphate, we studied the variation in patch test reactivity in nickel allergic women in relation...... to the menstrual cycle. Twenty women with regular periods were tested on day 7-10 and on day 20-24. Ten nickel patch tests with different concentrations were applied using the TRUE test assay, and the threshold concentration of nickel sulphate eliciting an erythematous reaction was determined. Half of the women...... an increased nickel sensitivity at the second patch test (0.02 nickel sulphate patch tests premenstrually in 20 nickel allergic women, but we found that elicitation...

  15. Formulation and Characterization of Transdermal Patches of Losartan

    Directory of Open Access Journals (Sweden)

    Ujjawal Nautiyal*1, Devendra Singh2

    2013-03-01

    Full Text Available Administration of drugs through skin has received great attention through the last decade. Hence this study aims to formulate an anti-hypertensive drug losartan as transdermal patch using different bioadhesive polymers such as ethyl cellulose, cellulose acetate, and polyvinyl pyrrolidon,hydroxyl propylemethylcellulose with plasticizers propylene glycol (PG. Patches were prepared though solvent evaporation method, The backing membrane was a non permeable aluminium foil laminated with polyethylene and evaluated for thickness uniformity, Uniformity of weight, Scanning Electron Microscopy, Surface pH, Swelling studies, Drug content uniformity Effect on agingn, skin irritation potential, and In vitro release study.Patches exhibited controlled release over more than 2 hr.It was concluded that patches containing 30 mg of losartane with HPMC (formulation F2 ,showed moderate swelling, surface pH and controlled drug release, thus can be selected for the development of transdermal patches for effective uses.

  16. Low-Power Optically Controlled Patch Antenna of Reconfigurable Beams

    Directory of Open Access Journals (Sweden)

    Deshuang Zhao

    2014-01-01

    Full Text Available A novel compact beam-reconfigurable patch antenna based on light control of no more than 30 mW optical powers is successfully demonstrated. It consists of one T-shape driven patch and one slot-etched parasitic patch. A silicon dice is employed as the photoconductive switch that is bridged across the slot center for optical control of reconfigurable beams. The antenna greatly reduces the total optical powers required for reconfigurable beams. Such design is based on the fact that the current phase change of the parasitic patch is sensitive to the conductivity of the silicon dice. A few conductivity changes of the silicon dice induced by the optical light can lead to a big phase change of the parasitic patch currents, eventually resulting in reconfigurable beams with low optical power requirement.

  17. Reduction of the spatially mutual coupling between dual-polarized patch antennas using coupled metamaterial slabs

    OpenAIRE

    2016-01-01

    Mutual coupling inside antenna array is usually caused by two routes: signal leakage via conducting currents on the metallic background or surface wave along substrates; radio leakage received from space between antenna elements. The former one can be depressed by changing the distribution of surface currents, as reported in literatures. But when it comes to the latter one, the radiation-leakage-caused coupling, traditional approaches using circuit manipulation may be inefficient. In this art...

  18. Novel Low Loss Active Voltage Clamp Circuit for Series Connection of RCGCT thyristors

    Science.gov (United States)

    Ito, Hiroshi; Suzuki, Akihiro; Iwata, Akihiko

    This paper describes novel low loss active voltage clamp circuits for the series connection of RCGCT thyristors. For high voltage converters the series connection of power semiconductor devices is an essential technique for direct switching of high voltages. Several protection circuits have been applied to the series connection of RCGCT thyristors such as CRD snubber circuits which suppress over-voltages across RCGCT thyristors, and voltage balancing resistors to equalize voltage sharing in steady states. However, significant losses in these protection circuits lower the converter’s efficiency. We propose novel low-loss protection circuits, which have active voltage clamp snubber circuits and static voltage balancing circuits. The clamp capacitor voltage of the active voltage clamp snubber circuits are designed to be higher than the equally divided DC-Link voltage. This method can reduce the loss of the clamp circuit to no more than 1/10 of that of the conventional CRD snubber. Also the static voltage balancing circuits compensate for the voltage imbalance generated by the difference in the leakage current between the series connection RCGCT thyristors.

  19. Gain-clamping techniques in two-stage double-pass L-band EDFA

    Indian Academy of Sciences (India)

    S W harun; N Md Samsuri; H Ahmad

    2006-03-01

    Two designs of long-wavelength band erbium-doped fiber amplifier (L-band EDFA) for gain clamping in double-pass systems are demonstrated and compared. The first design is based on ring laser technique where a backward amplified spontaneous emission (ASE) from the second stage is routed into the feedback loop to create an oscillating laser for gain clamping. The gain is clamped at 18.6 dB from -40 to -8 dBm with a gain variation of less than ± 0.1 dB and a noise figure of less than 6 dB. Another scheme is based on partial reflection of ASE into the EDFA, which is demonstrated using a narrowband fiber Bragg grating. This scheme achieves a good gain clamping characteristic up to -12 dBm of input signal power with a gain variation of less than ± 0.3 dB from a clamped gain of 22 dB. The noise figure of a 1580 nm signal is maintained below 5 dB in this amplifier since this scheme is not based on lasing mechanism. The latter scheme is also expected to be free from the relaxation oscillation problem.

  20. Effect of timing of umbilical cord clamping of term infants on maternal and neonatal outcomes.

    Science.gov (United States)

    McDonald, Susan J; Middleton, Philippa; Dowswell, Therese; Morris, Peter S

    2013-07-11

    Policies for timing of cord clamping vary, with early cord clamping generally carried out in the first 60 seconds after birth, whereas later cord clamping usually involves clamping the umbilical cord more than one minute after the birth or when cord pulsation has ceased. The benefits and potential harms of each policy are debated. To determine the effects of early cord clamping compared with late cord clamping after birth on maternal and neonatal outcomes We searched the Cochrane Pregnancy and Childbirth Group's Trials Register (13 February 2013). Randomised controlled trials comparing early and late cord clamping. Two review authors independently assessed trial eligibility and quality and extracted data. We included 15 trials involving a total of 3911 women and infant pairs. We judged the trials to have an overall moderate risk of bias. Maternal outcomes: No studies in this review reported on maternal death or on severe maternal morbidity. There were no significant differences between early versus late cord clamping groups for the primary outcome of severe postpartum haemorrhage (risk ratio (RR) 1.04, 95% confidence interval (CI) 0.65 to 1.65; five trials with data for 2066 women with a late clamping event rate (LCER) of ~3.5%, I(2) 0%) or for postpartum haemorrhage of 500 mL or more (RR 1.17 95% CI 0.94 to 1.44; five trials, 2260 women with a LCER of ~12%, I(2) 0%). There were no significant differences between subgroups depending on the use of uterotonic drugs. Mean blood loss was reported in only two trials with data for 1345 women, with no significant differences seen between groups; or for maternal haemoglobin values (mean difference (MD) -0.12 g/dL; 95% CI -0.30 to 0.06, I(2) 0%) at 24 to 72 hours after the birth in three trials. Neonatal outcomes: There were no significant differences between early and late clamping for the primary outcome of neonatal mortality (RR 0.37, 95% CI 0.04 to 3.41, two trials, 381 infants with a LCER of ~1%), or for most other